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

Abstract

Provided are: a liquid crystal alignment agent from which a liquid crystal alignment film that suppresses AC afterimages can be obtained; the liquid crystal alignment film; and a liquid crystal display element using the liquid crystal alignment film.　This liquid crystal alignment agent contains at least one polymer (P) selected from the group consisting of: polyimide precursors each obtained using a tetracarboxylic acid component including at least one selected from the group consisting of tetracarboxylic acid dianhydrides and derivatives thereof, and a diamine component including a diamine represented by formula (2); and polyimides that are imidization products of said polyimide precursors. (In the formula, the definition of each symbol is as defined in the description.)

Description

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

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

[0002] Liquid crystal display devices are widely used as display units for personal computers, smartphones, mobile phones, televisions, etc. Liquid crystal display devices typically include a liquid crystal layer sandwiched between a display element substrate and a color filter substrate, pixel electrodes and a common electrode that apply an electric field to the liquid crystal layer, an alignment film that controls the alignment of liquid crystal molecules in the liquid crystal layer, and thin film transistors (TFTs) that switch electric signals supplied to the pixel electrodes. Known driving methods for liquid crystal molecules include vertical electric field methods such as the TN method and the VA method, and horizontal electric field methods such as the IPS (In Plane Switching) driving method and the FFS (Fringe Field Switching) driving method.

[0003] The most widely used liquid crystal alignment films in industry are produced by rubbing the surface of a film made of polyamic acid and / or imidized polyimide formed on an electrode substrate in one direction with a cloth such as cotton, nylon, or polyester. Rubbing is a simple, highly productive, and industrially useful method. As an alternative to rubbing, a photoalignment method is known, in which polarized radiation is irradiated to impart liquid crystal alignment ability. Proposed photoalignment methods include those utilizing photoisomerization reactions, photocrosslinking reactions, and photodecomposition reactions (see, for example, Non-Patent Document 1, Patent Documents 1, 2, and 3).

[0004] Japanese Patent Laid-Open No. 9-297313 Japanese Patent Laid-Open No. 2004-206091 WO2017 / 047596

[0005] "Functional Materials," November 1997, Vol. 17, No. 11, pp. 13-22

[0006] In recent years, large-screen, high-resolution liquid crystal display elements have become mainstream, and compact display terminals such as smartphones, tablet PCs, and car navigation systems have become increasingly popular, resulting in ever-increasing demands for higher quality liquid crystal display elements. In particular, liquid crystal alignment films used in liquid crystal display elements, such as those of the IPS mode and FFS mode, require a high alignment control force to suppress image retention (hereinafter also referred to as AC image retention) that occurs due to long-term AC driving.

[0007] In view of the above circumstances, the present invention aims to provide a liquid crystal alignment agent capable of obtaining a liquid crystal alignment film that suppresses AC afterimages, the liquid crystal alignment film, and a liquid crystal display element using the liquid crystal alignment film.

[0008] The present inventors have conducted extensive research and have found that the above problems can be solved by using a liquid crystal aligning agent containing a specific component, thereby completing the present invention.

[0009] Specifically, the present invention has the following aspects.

[0010] A liquid crystal aligning agent comprising at least one polymer (P) selected from the group consisting of a polyimide precursor obtained by using a tetracarboxylic acid component containing at least one selected from the group consisting of tetracarboxylic acid dianhydrides and derivatives thereof, and a diamine component containing a diamine represented by the following formula (2), and a polyimide which is an imidized product of the polyimide precursor:

[0011]

[0012] (In formula (2), R ２１ ~R ２４ are each independently a hydrogen atom, *—CO ２ R or *-CONH-R, and R ２１ ~R ２４ At least two of the following are *-CO ２ R or *-CONH-R. R represents a monovalent organic group having 1 to 4 carbon atoms. One or more hydrogen atoms on the benzene ring bonded to the amino group are *-CO ２R or *may be substituted with a monovalent group other than -CONH-R.) Throughout this specification, examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms, and * represents a bond. Boc represents a tert-butoxycarbonyl group. Furthermore, "tert-" can also be referred to as "t-".

[0013] By using the liquid crystal aligning agent of the present invention, a liquid crystal alignment film that suppresses AC afterimages can be obtained.

[0014] 1 is a schematic cross-sectional view showing an example of a lateral electric field mode liquid crystal display element of the present invention, and FIG. 2 is a schematic cross-sectional view showing another example of a lateral electric field mode liquid crystal display element of the present invention.

[0015] <Polymer (P)> The liquid crystal aligning agent of the present invention contains at least one polymer (P) selected from the group consisting of a polyimide precursor obtained using a tetracarboxylic acid component containing at least one selected from the group consisting of tetracarboxylic acid dianhydrides and their derivatives, and a diamine component containing a diamine represented by the above formula (2) (also referred to as specific diamine (p) in the present invention), and a polyimide which is an imidized product of the polyimide precursor. The polymer (P) may be one type or two or more types. Here, the polyimide precursor is a polymer that can be obtained by imidizing polyamic acid, polyamic acid ester, etc.

[0016] (Tetracarboxylic Acid Component) The polyamic acid (P'), which is the polyimide precursor of the polymer (P), can be obtained, for example, by a polymerization reaction between the specific diamine component and a tetracarboxylic dianhydride component. When producing the polymer (P), the tetracarboxylic acid component to be reacted with the diamine component can be not only a tetracarboxylic dianhydride but also a derivative of a tetracarboxylic dianhydride, such as a tetracarboxylic acid, a tetracarboxylic dihalide, a tetracarboxylic acid dialkyl ester, or a tetracarboxylic acid dialkyl ester dihalide. Examples of tetracarboxylic acid dianhydrides or derivatives thereof that can be used to produce the polymer (P') include acyclic aliphatic tetracarboxylic acid dianhydrides, alicyclic tetracarboxylic acid dianhydrides, aromatic tetracarboxylic acid dianhydrides, or derivatives thereof (hereinafter, these are also referred to as specific tetracarboxylic acid components). Among these, it is more preferable to use a tetracarboxylic acid dianhydride or a derivative thereof 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. In particular, it is more preferable to contain a tetracarboxylic acid dianhydride having at least one structure selected from the group consisting of a cyclobutane ring, a cyclopentane ring, and a cyclohexane ring, or a derivative thereof.

[0017] The aromatic tetracarboxylic dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxy groups, including at least one carboxy group bonded to an aromatic ring.

[0018] The acyclic aliphatic tetracarboxylic acid dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxy groups bonded to a chain hydrocarbon structure. However, it does not need to be composed of only a chain hydrocarbon structure, and it may have an alicyclic structure or an aromatic ring structure as part of it. The alicyclic tetracarboxylic acid dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxy groups, including at least one carboxy group bonded to the alicyclic structure. However, none of these four carboxy groups is bonded to an aromatic ring. Furthermore, it does not need to be composed of only an alicyclic structure, and it may have a chain hydrocarbon structure or an aromatic ring structure as part of it. Specific examples of tetracarboxylic acid dianhydrides or derivatives thereof that can be used to produce the polymer (P') include the following: 1,2,3,4-butanetetracarboxylic acid dianhydride, or (Q) ２ -A (Q represents a monovalent succinic anhydride structure, and A represents -CH ２ -, an alkylene group having 2 to 18 carbon atoms, or -CH contained in the alkylene group ２represents a divalent organic group in which a portion of - is replaced by at least one group selected from the group consisting of a phenylene group, -O-, -NR- (R represents a hydrogen atom or a methyl group), -C(=O)-NR- (R represents a hydrogen atom or a methyl group), -C(=O)-O-, and -O-C(=O)-.acyclic aliphatic tetracarboxylic acid dianhydrides such as tetracarboxylic acid dianhydrides represented by the following formula (1), 1,2,3,4-cyclopentanetetracarboxylic acid dianhydride, 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride, 3,3',4,4'-dicyclohexyltetracarboxylic acid dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 4-(2,5-dioxotetrahydrofuran-3-yl)tetrahydronaphthalene-1,2-dicarboxylic acid anhydride, 5-(2,5-dioxotetrahydrofuran-3-yl)tetrahydronaphthalene-1,2-dicarboxylic acid anhydride, 5-(2,5-dioxotetrahydrofuran-3-yl)-8-methyl-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 5-(2,5-dioxotetrahydrofuran-3-yl)-8-methyl-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, bicyclo[2.2.2]octane-2,3,5,6-tetracarboxylic dianhydride, 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-dianhydride alicyclic tetracarboxylic dianhydrides such as pyromellitic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3',4,4'-diphenylethertetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 4,4 aromatic tetracarboxylic acid dianhydrides such as 4,4'-bis(3,4-dicarboxyphenoxy)-2,2-diphenylpropane dianhydride, ethylene glycol bisanhydrotrimellitate, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 4,4'-carbonyldiphthalic anhydride, 4,4'-(1,4-phenylenedioxy)bis(phthalic anhydride), or 4,4'-(1,4-phenylenedimethylene)bis(phthalic anhydride); and also tetracarboxylic acid dianhydrides described in JP 2010-97188 A.

[0019]

[0020] (In formula (1), R １ ~R ４ each 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 and containing a fluorine atom, or a phenyl group.) From the viewpoint of high photoreactivity, it is preferable to use a tetracarboxylic dianhydride or a derivative thereof represented by the above formula (1) as the tetracarboxylic dianhydride or a derivative thereof that can be used to produce the polymer (P'). R in the above formula (1) １ ~R ４ Specific examples of the alkyl group having 1 to 6 carbon atoms in the above R include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, and an n-pentyl group. １ ~R ４ Specific examples of the alkenyl group having 2 to 6 carbon atoms in the above R include a vinyl group, a propenyl group, and a butenyl group, which may be linear or branched. １ ~R ４ Specific examples of the alkynyl group having 2 to 6 carbon atoms in the above R include an ethynyl group, a 1-propynyl group, a 2-propynyl group, a 1-butynyl group, a 2-butynyl group, and a 3-butynyl group. １ ~R ４ In the above formula, examples of the monovalent organic group having 1 to 6 carbon atoms and containing a fluorine atom include a fluoromethyl group, a trifluoromethyl group, a pentafluoroethyl group, a pentafluoropropyl group, a trifluoromethoxy group, a 2,2,2-trifluoroethyl group, and a 2,2,2-trifluoroethoxy group. １ ~R ４ It is more preferable that at least two of R represent a group other than a hydrogen atom as defined above. １ and R ４ represents a group other than a hydrogen atom, and R ２ and R ３ It is more preferable that R represents a hydrogen atom. １ ~R ４are each independently a hydrogen atom or a methyl group, and R １ ~R ４ More preferably, at least one of R is a methyl group. １ ~R ４ It is more preferred that at least two of R are methyl groups. １ and R ４ is a methyl group, and R ２ and R ３ is a hydrogen atom.

[0021] Preferred specific examples of the tetracarboxylic acid dianhydride represented by the above formula (1) or a derivative thereof include 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-dichloro-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-difluoro-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-bis(trifluoromethyl)-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, etc. The proportion of the specific tetracarboxylic acid component used is more preferably 10 mol% or more, even more preferably 20 mol% or more, and most preferably 50 mol% or more, relative to 1 mol of all tetracarboxylic acid components used in the polymer (P). The tetracarboxylic acid component used in the production of polymer (P) may contain tetracarboxylic acid components other than the specific tetracarboxylic acid components described above. Specific examples include tetracarboxylic acid dianhydrides and derivatives thereof represented by the following formulae [CA-1] to [CA-26].

[0022]

[0023] When other tetracarboxylic acid components are used in addition to the specific tetracarboxylic acid component, the content of the specific tetracarboxylic acid component is more preferably 95 mol % or less, and even more preferably 90 mol % or less, based on 1 mol of all tetracarboxylic acid components used in polymer (P). The content of the other tetracarboxylic acid components is more preferably 5 mol % to 90 mol %, more preferably 10 to 80 mol %, and most preferably 10 to 50 mol %, based on 1 mol of all tetracarboxylic acid components used in polymer (P).

[0024] (Specific diamine (p)) The specific diamine (p) of the present invention is a diamine represented by the above formula (2). The specific diamine (p) may be used alone or in combination of two or more. R ２１ ~R ２４ are each independently a hydrogen atom, *—CO ２ R or *-CONH-R. *-CO ２Examples of the monovalent organic group having 1 to 4 carbon atoms for R and R in *-CONH-R include a monovalent hydrocarbon group having 1 to 4 carbon atoms, or a monovalent organic group (2n) having 1 to 4 carbon atoms obtained by substituting one or more hydrogen atoms of the hydrocarbon group having 1 to 4 carbon atoms with a halogen atom, a hydroxyl group, or the like. Specific examples of the hydrocarbon group having 1 to 4 carbon atoms include an alkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, and an alkynyl group having 2 to 4 carbon atoms. Specific examples of the alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, and the like. Specific examples of the alkenyl group having 2 to 4 carbon atoms include a vinyl group, a propenyl group, a butenyl group, and the like, which may be linear or branched. Specific examples of the alkynyl group having 2 to 4 carbon atoms include an ethynyl group, a 1-propynyl group, a 2-propynyl group, a 1-butynyl group, a 2-butynyl group, a 3-butynyl group, etc. Specific preferred examples of the monovalent organic group (2n) include a monovalent organic group containing a fluorine atom and having 1 to 4 carbon atoms, such as a monofluoromethyl group, a difluoromethyl group, a trifluoromethyl group, a pentafluoroethyl group, a pentafluoropropyl group, a trifluoromethoxy group, a 2,2,2-trifluoroethyl group, a 2,2,2-trifluoroethoxy group, etc.

[0025] In the above formula (2), one or more hydrogen atoms on the benzene ring bonded to the amino group are *-CO ２ It may be substituted with a monovalent group other than R or *-CONH-R. 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, a cyano group, and a nitro group. From the viewpoint of improving the liquid crystal alignment property, it is preferable that the two amino groups in the above formula (2) are bonded at the 4,4'-positions relative to the biphenyl structure. R ２１ ~R ２４ At least two of the following are *-CO ２ R or *-CONH-R, and R ２１ ~R ２４The two are *-CO ２ It is preferable that the specific diamine (p) represents R or *-CONH-R. The content of the specific diamine (p) relative to 1 mole of the diamine component used in the production of the polymer (P) is preferably 5 mol % or more, more preferably 10 mol % or more, and even more preferably 20 mol % or more.

[0026] More preferred specific examples of the diamine represented by the above formula (2) include the following formulas (2-1) to (2-4): (In the formulas, t-Bu represents a tert-butyl group.)

[0027]

[0028] The diamine component used in the production of the polymer (P) may contain a diamine other than the specific diamine (p) (hereinafter also referred to as "other diamines"). When other diamines are used in addition to the specific diamine (p), the content of the specific diamine (p) in the diamine component is preferably 95 mol% or less, more preferably 90 mol% or less, and even more preferably 85 mol% or less, per mole of the diamine component used in the production of the polymer (P).

[0029] Examples of other diamines are listed below, but are not limited to these. The other diamines may be used alone, in combination of two or more, or in combination of three or more. Phenylenediamines such as p-phenylenediamine, 2,3,5,6-tetramethyl-p-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, m-phenylenediamine, 2,4-dimethyl-m-phenylenediamine, 2,5-diaminotoluene, and 2,6-diaminotoluene; 2,2'-dimethyl-4,4'-diaminobiphenyl; 3,3'-dimethyl-4,4'-diaminobiphenyl; 3,3'-dimethoxy-4,4'-diaminobiphenyl; 3,3'-dihydroxy-4,4'- diaminobiphenyl compounds such as 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, and 2,3'-diaminobiphenyl; ＡＬ ) (preferably, a diamine represented by the following formula (d ＡＬ -1) to (d ＡＬ-8), 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, 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), a compound represented by the following formula (d ＢＺ -1) to (d ＢＺdiamines having a diphenyl ether structure such as 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, and 1,4-bis[4-(4-aminophenoxy)phenoxy]benzene (hereinafter, these are collectively referred to as first diamines having a tetracarboxylic acid diimide structure, such as N,N'-bis(4-aminophenyl)-cyclobutane-(1,2,3,4)-tetracarboxylic acid diimide, N,N'-bis(4-aminophenyl)-1,3-dimethylcyclobutane-(1,2,3,4)-tetracarboxylic acid diimide, and N,N'-bis(2,2'-bis(trifluoromethyl)-4'-amino-1,1'-biphenyl-4-yl)-cyclobutane-(1,2,3,4)-tetracarboxylic acid diimide;aromatic diamines having an azobenzene structure such as 4,4'-diaminoazobenzene, aromatic diamines having a stilbene structure such as 4,4'-diaminostilbene, aromatic diamines having a tolan structure such as diaminotlan, aromatic diamines having a chalcone structure such as 4,4'-diaminochalcone, aromatic diamines having a phenylbenzoate structure such as 1,4-phenylenebis(4-aminobenzoate), 1,4-phenylenebis(3-aminobenzoate), 1,3-phenylenebis(4-aminobenzoate), 1,3-phenylenebis(3-aminobenzoate), bis(4-aminophenyl)terephthalate, bis(3-aminophenyl)terephthalate, bis(4-aminophenyl)isophthalate, bis(3-aminophenyl)isophthalate, or (E)-4-aminophenyl 3-(4-aminophenyl)acrylate, (E)-4-amino-2-methylphenyl 3-(4-aminophenyl)acrylate, (E)-4-aminophenethyl Diamines having a photoalignment group, typified by aromatic diamines having a cinnamate structure, such as 3-(4-aminophenyl)acrylate, (E,E)-bis-(4'-aminophenyl) 1,3-benzenediacrylate, (E,E)-bis-(4'-aminophenyl) 1,4-benzenediacrylate, or 4-aminophenyl (2E)-3-(4-aminophenyl)-2-methyl-2-propenoate; diamines having a photopolymerizable group at the terminal, such as 2-(2,4-diaminophenoxy)ethyl methacrylate or 2,4-diamino-N,N-diallylaniline; 1-(4-(2-(2,4-diaminophenoxy)ethoxy)phenyl)-2-hydroxy-2-methylpropanone, 2-(4-(2-hydroxy-2-methylpropanoyl)phenoxy)ethyl Diamines having a radical polymerization initiator function, such as 3,5-diaminobenzoate; diamines having an amide bond, such as 4,4'-diaminobenzanilide; and diamines having a urea bond, such as 1,3-bis(4-aminophenyl)urea, 1,3-bis(4-aminobenzyl)urea, and 1,3-bis(4-aminophenethyl)urea;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] Heterocycle-containing diamines such as 3,5-diaminobenzamide, 4-[4-[(4-aminophenoxy)methyl]-4,5-dihydro-4-methyl-2-oxazolyl]-benzenamine, or diamines represented by the following formulas (z-1) to (z-13), or 4,4'-diaminodiphenylamine, 4,4'-diaminodiphenyl-N-methylamine, diamines represented by the following formula (z-14), N,N'-bis(4-aminophenyl)-benzidine, N,N'-bis(4-aminophenyl)-N,N'-dimethylbenzidine, or N diamines 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 (hereinafter also referred to as a specific nitrogen atom-containing structure, provided that the specific nitrogen atom-containing structure is a functional group other than the two amino groups involved in the polycondensation reaction), typified by diamines having a diphenylamine structure such as N,N'-bis(4-aminophenyl)-N,N'-dimethyl-1,4-benzenediamine (provided that the molecule does not have an amino group bonded with a protecting group that is cleaved by heating and replaced with a hydrogen atom);2,4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4,6-diaminoresorcinol, 4,4'-diamino-3,3'-dihydroxybiphenyl; 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, diamines having a carboxy group such as 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, 4,4'-diaminodiphenylether-3,3'-dicarboxylic acid; 4-(2-(methylamino)ethyl)aniline, 4-(2-aminoethyl)aniline, 1 -(4-aminophenyl)-1,3,3-trimethyl-1H-indan-5-amine, 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-inden-6-amine; diamines having the group "-N(D)-" (D represents a protecting group which is eliminated by heating and replaced with a hydrogen atom, preferably a carbamate protecting group, more preferably a tert-butoxycarbonyl group, except for the above-mentioned specific diamine (p)) such as those of the following formulas (5-1) to (5-9), cholestanyloxy-3,5-diaminobenzene, ... diamines having a steroid skeleton such as stenyloxy-3,5-diaminobenzene, cholestanyloxy-2,4-diaminobenzene, cholestanyl 3,5-diaminobenzoate, cholestenyl 3,5-diaminobenzoate, lanostannyl 3,5-diaminobenzoate, and 3,6-bis(4-aminobenzoyloxy)cholestane, diamines represented by the following formulae (V-1) and (V-2); aromatic diamines typified by diamines having a fluorene skeleton such as 2,7-diaminofluorene or 9,9-bis(4-aminophenyl)fluorene;Diamines having a siloxane bond, such as 1,3-bis(3-aminopropyl)-tetramethyldisiloxane; acyclic aliphatic diamines typified by metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, etc.; alicyclic diamines typified by 1,3-bis(aminomethyl)cyclohexane, 1,4-diaminocyclohexane, 4,4'-methylenebis(cyclohexylamine), etc., as well as diamines in which two amino groups are bonded to a group represented by any one of formulas (Y-1) to (Y-167) described in WO2018 / 117239, etc.;

[0030]

[0031] (Ar １ , and Ar １’ 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 may be substituted with a monovalent group. １ and L １’ respectively represent a single bond, —O—, —C(═O)—, or —O—C(═O)—. A is —CH ２ A represents an alkylene group having 2 to 12 carbon atoms, or a divalent organic group in which at least one of -O-, -C(=O)-O-, and -O-C(=O)- is inserted between the carbon-carbon bonds of the alkylene group. Any hydrogen atom possessed by A may be substituted with a halogen atom.

[0032] One or more hydrogen atoms on the benzene ring, biphenyl structure, or naphthalene ring may be 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, and a nitro group.

[0033]

[0034] (Formula (d ＡＬIn formula (d-1), k is an integer of 1 to 2. ＡＬ In formula (d-2), the sum of l, m, and n is 1 to 12. ＡＬ In formula (d-5), the sum of m1, m2 and n is 1 to 12. ＡＬ In formula (d-7), the sum of m1, m2 and n is 3 to 12. ＡＬ In the formula (d-8), the sum of l, m, and n is 3 to 12. ＡＬ -1) to (d ＡＬ In -8), one or more hydrogen atoms on the benzene ring may be substituted with a monovalent group, and specific examples of the monovalent group include the above-mentioned Ar １ and Ar １’ Examples of the monovalent groups include those exemplified in

[0035]

[0036]

[0037]

[0038]

[0039]

[0040] In the formula (V-1), m and n are integers of 0 to 3, and satisfy the relationship 1≦m+n≦4. j is an integer of 0 or 1. X １ is -(CH ２ ) ａ -(a is an integer of 1 to 15), -CONH-, -NHCO-, -CO-N(CH ３ )-, -NH-, -O-, -CH ２ O-, -CH ２ represents —OCO—, —COO—, or —OCO—. 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, or an alkoxyalkyl group having 2 to 10 carbon atoms. ２ is -O-, -CH ２ O-, -CH ２m, n, and X represent —OCO—, —COO—, or —OCO—. １ , R １ When two occur, each independently has the above definition.

[0041] Examples of the nitrogen atom-containing heterocycle that the diamine having the specific nitrogen atom-containing structure may have include pyrrole, imidazole, pyrazole, triazole, pyridine, pyrimidine, pyridazine, pyrazine, indole, benzimidazole, purine, quinoline, isoquinoline, naphthyridine, quinoxaline, phthalazine, triazine, carbazole, acridine, piperidine, piperazine, pyrrolidine, and hexamethyleneimine. Among these, pyridine, pyrimidine, pyrazine, piperidine, piperazine, quinoline, carbazole, and acridine are preferred.

[0042] From the viewpoint of enhancing liquid crystal alignment properties, the other diamine may be a diamine selected from the group consisting of the first diamine, a diamine having a tetracarboxylic diimide structure, a diamine having an amide bond, a diamine having a urea bond, and a diamine having a group "-N(D)-". In addition, diamines of the following formulas [DA-1] to [DA-103] can also be used as the other diamine.

[0043]

[0044] The content of the other diamines is more preferably 5 to 85 mol%, even more preferably 10 to 80 mol%, and still more preferably 15 to 80 mol%, relative to 1 mol of the diamine component used in the production of polymer (P). When two or more other diamines are contained, the content of each diamine constituting each of the other diamines may be 30 mol% or less.

[0045] (Liquid Crystal Aligning Agent) The liquid crystal aligning agent of the present invention is a liquid composition obtained by dispersing or dissolving the polymer (P) and other components used as needed, preferably in a suitable solvent.

[0046] The liquid crystal aligning agent of the present invention may contain other polymers other than the polymer (P). Specific examples of other polymers include at least one polymer selected from the group consisting of a polyimide precursor obtained using a diamine component not containing the specific diamine (p) and a polyimide which is an imidized product of the polyimide precursor (also referred to as polymer (B) in the present invention), polysiloxane, polyester, polyamide, polyurea, 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, and a polymer selected from the group consisting of poly(meth)acrylate.

[0047] Specific examples of poly(styrene-maleic anhydride) copolymers include SMA1000, SMA2000, SMA3000 (manufactured by Cray Valley Corporation) and GSM301 (manufactured by Gifu Ceramics Manufacturing Co., Ltd.), and a specific example of poly(isobutylene-maleic anhydride) copolymers includes ISOBAN-600 (manufactured by Kuraray Co., Ltd.). A specific example of poly(vinyl ether-maleic anhydride) copolymers includes Gantrez AN-139 (methyl vinyl ether maleic anhydride resin, manufactured by Ashland Corporation).

[0048] Among these, the polymer (B) is more preferred from the viewpoint of reducing afterimages resulting from residual DC.

[0049] The other polymers may be used singly or in combination of two or more. The content ratio of the other polymers is preferably 90 parts by mass or less, more preferably 10 to 90 parts by mass, and still more preferably 20 to 80 parts by mass, relative to 100 parts by mass of the total of the polymers contained in the liquid crystal aligning agent.

[0050] (Polymer (B)) Specific examples of the tetracarboxylic acid component used in the production of the polymer (B), including preferred specific examples, include the same compounds as those exemplified for the polymer (P), such as acyclic aliphatic tetracarboxylic acid dianhydrides, alicyclic tetracarboxylic acid dianhydrides, aromatic tetracarboxylic acid dianhydrides, or derivatives thereof. The tetracarboxylic acid component used in the production of the polymer (B) more preferably contains a tetracarboxylic acid dianhydride 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, or a derivative thereof (hereinafter, these may also be referred to as specific tetracarboxylic acid component (B)).

[0051] The content of the specific tetracarboxylic acid component (B) is preferably 10 mol% or more, more preferably 20 mol% or more, and even more preferably 50 mol% or more, based on 1 mol of all tetracarboxylic acid components used in the production of the polymer (B).

[0052] Examples of the diamine component for obtaining the polymer (B) include the diamines exemplified for the polymer (P) above. Among them, the first diamine, a diamine having a urea bond, a diamine having an amide bond, 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) ... It is preferable that the diamine component contains at least one diamine selected from the group consisting of 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, the diamines having the specific nitrogen atom-containing structure, the diamines having a carboxy group, 4-(2-(methylamino)ethyl)aniline, and 4-(2-aminoethyl)aniline (in the present invention, these are also referred to as specific diamine (b)). As the diamine component, one diamine may be used alone, or two or more diamines may be used in combination.

[0053] When the specific diamine (b) is used, its content is preferably 10 mol % or more, more preferably 20 mol % or more, of the total diamine components used in the production of the polymer (B).When a diamine other than the specific diamine (b) is used, the content of the specific diamine (b) is preferably 90 mol % or less, more preferably 80 mol % or less, based on 1 mol of the total diamine components used in the production of the polymer (B).

[0054] (Production of Polyamic Acid) Polyamic acid is produced by reacting a diamine component with a tetracarboxylic acid component in an organic solvent. The ratio of the tetracarboxylic acid component and the diamine component used in the reaction for producing polyamic acid is preferably such that 0.5 to 2 equivalents of acid anhydride groups in the tetracarboxylic acid component are present per equivalent of amino groups in the diamine component, and more preferably 0.8 to 1.2 equivalents. As in a typical polycondensation reaction, the closer the equivalent of acid anhydride groups in the tetracarboxylic acid component is to 1 equivalent, the higher the molecular weight of the resulting polyamic acid.

[0055] The reaction temperature in the production of polyamic acid is preferably −20 to 150° C., more preferably 0 to 100° C. The reaction time is preferably 0.1 to 24 hours, more preferably 0.5 to 12 hours. The production of polyamic acid can be carried out at any concentration, but the concentration of polyamic acid is preferably 1 to 50% by mass, more preferably 5 to 30% by mass. The reaction can be carried out at a high concentration in the early stages, and then a solvent can be added.

[0056] Specific examples of the organic solvent include cyclohexanone, cyclopentanone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, and 1,3-dimethyl-2-imidazolidinone. Furthermore, when the polymer has high solvent solubility, solvents such as methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, diethylene glycol monomethyl ether, and diethylene glycol monoethyl ether can be used.

[0057] (Production of Polyamic Acid Ester) The polyamic acid ester can be obtained by known methods such as [I] a method of reacting the polyamic acid obtained by the above method with an esterifying agent, [II] a method of reacting a tetracarboxylic acid diester with a diamine, or [III] a method of reacting a tetracarboxylic acid diester dihalide with a diamine.

[0058] (Production of Polyimide) Polyimide can be obtained by ring-closing (imidizing) a polyimide precursor such as the polyamic acid or polyamic acid ester. The imidization ratio in this specification refers to the ratio of imide groups to the total amount of imide groups derived from tetracarboxylic dianhydride or its derivatives and carboxyl groups (or their derivatives). The imidization ratio does not necessarily have to be 100% and can be adjusted as desired depending on the application and purpose.

[0059] Methods for imidizing the polyimide precursor include thermal imidization, in which a solution of the polyimide precursor is heated as is, and catalytic imidization, in which a catalyst is added to a solution of the polyimide precursor.

[0060] When the polyimide precursor is thermally imidized in a solution, the temperature is preferably 100 to 400°C, more preferably 120 to 250°C, and it is preferable to carry out the imidization while removing water produced by the imidization reaction from the system.

[0061] Catalytic imidization of polyimide precursors can be carried out by adding a basic catalyst and an acid anhydride to a solution of the polyimide precursor and stirring the mixture at preferably -20 to 250°C, more preferably 0 to 180°C. The amount of the basic catalyst is preferably 0.5 to 30 times, more preferably 2 to 20 times, the molar ratio of the amic acid groups, and the amount of the acid anhydride is preferably 1 to 50 times, more preferably 3 to 30 times, the molar ratio of the amic acid groups. Examples of basic catalysts include pyridine, triethylamine, trimethylamine, tributylamine, and trioctylamine. Of these, pyridine is preferred because it has adequate basicity for promoting the reaction. Examples of acid anhydrides include acetic anhydride, trimellitic anhydride, and pyromellitic anhydride. Of these, acetic anhydride is preferred because it facilitates purification after the reaction. The imidization rate by catalytic imidization can be controlled by adjusting the catalyst amount, reaction temperature, and reaction time.

[0062] When recovering the produced polyimide precursor or polyimide from a reaction solution of a polyimide precursor or polyimide, the reaction solution may be precipitated by pouring the reaction solution into a solvent. Examples of solvents used for precipitation include methanol, ethanol, isopropyl alcohol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, toluene, benzene, and water. The polymer precipitated by pouring into the solvent can be recovered by filtration and then dried at room temperature or by heating under atmospheric or reduced pressure. Furthermore, the recovered polymer can be redissolved in an organic solvent and reprecipitated and recovered 2 to 10 times to reduce the amount of impurities in the polymer. Examples of solvents used in this process include alcohols, ketones, and hydrocarbons. Using three or more solvents selected from these solvents is preferred because it further increases the efficiency of purification.

[0063] In producing the polyimide precursor or polyimide of the present invention, a terminal-capping polymer may be produced using a tetracarboxylic acid component containing a tetracarboxylic acid dianhydride or a derivative thereof, a diamine component containing a diamine, and an appropriate terminal-capping agent. The terminal-capping polymer has the effect of improving the film hardness of the liquid crystal alignment film obtained by coating and improving the adhesion properties between the sealant and the liquid crystal alignment film.

[0064] Examples of the terminals of the polyimide precursor or polyimide in the present invention include an amino group, a carboxy group, an acid anhydride group, or a group derived from an end-capping agent described below. The amino group, carboxy group, and acid anhydride group can be obtained by a conventional condensation reaction or by blocking the terminals with the following end-capping agents.

[0065] Examples of the end-capping agent include acid anhydrides such as acetic anhydride, maleic anhydride, nadic anhydride, phthalic anhydride, itaconic anhydride, 1,2-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, and 4-ethynylphthalic anhydride; dicarbonate diester compounds such as di-tert-butyl dicarbonate and diallyl dicarbonate; chlorocarbonyl compounds such as acryloyl chloride, methacryloyl chloride, and nicotinic acid chloride; Examples of the amino acid include 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, and n-octylamine; and isocyanates having an unsaturated bond such as ethyl isocyanate, phenyl isocyanate, naphthyl isocyanate, 2-acryloyloxyethyl isocyanate, and 2-methacryloyloxyethyl isocyanate.

[0066] The proportion of the end-capping agent used is preferably 0.01 to 20 parts by mole, and more preferably 0.01 to 10 parts by mole, per 100 parts by mole of the total of the diamine components used.

[0067] The polystyrene-equivalent weight average molecular weight (Mw) of the polyimide precursor and polyimide measured by gel permeation chromatography (GPC) is preferably 1,000 to 500,000, and more preferably 2,000 to 300,000. The molecular weight distribution (Mw / Mn), expressed as the ratio of Mw to the polystyrene-equivalent number average molecular weight (Mn) measured by GPC, is preferably 15 or less, more preferably 10 or less, and even more preferably 5 or less. By having the molecular weight within this range, good liquid crystal alignment properties can be ensured in liquid crystal display elements.

[0068] The organic solvent contained in the liquid crystal aligning agent according to the present invention is not particularly limited as long as it can uniformly dissolve the polymer (P) and other polymers added as needed. Examples of the organic solvent include N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethyllactamide, 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-dimethylpropanamide, and the like. Examples of suitable solvents include 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, and N-cyclohexyl-2-pyrrolidone (collectively referred to as "good solvents"). Among these, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 3-methoxy-N,N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropanamide, and γ-butyrolactone are 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 solvent contained in the liquid crystal aligning agent.

[0069] Furthermore, the organic solvent contained in the liquid crystal aligning agent is preferably a mixed solvent containing, in addition to the above solvent, a solvent (also referred to as a poor solvent) that improves the coatability and surface smoothness of the coating film when the liquid crystal aligning agent is applied. Specific examples of poor solvents are listed below, but are not limited to these. The content of the poor solvent is preferably 1 to 80 mass %, more preferably 10 to 80 mass %, and particularly preferably 20 to 70 mass %, of the total solvent contained in the liquid crystal aligning agent. The type and content of the poor solvent are appropriately selected depending on the coater, coating conditions, coating environment, etc. of the liquid crystal aligning agent.

[0070] Examples of poor solvents 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 ethanol, 2-(2-butoxyethoxy)-1-propanol, propylene glycol monomethyl ether acetate, 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 acetate, 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), and the like.

[0071] Of these, 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 is preferred.

[0072] Preferred solvent combinations of a good solvent and a poor solvent 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, and N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether. Coal 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 mono propyl 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 dipropylene glycol monomethyl ether 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-pi rolidone, γ-butyrolactone, propylene glycol monobutyl ether, and diisopropyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone, propylene glycol monobutyl ether, and diisobutylcarbinol, 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 pyrene 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,Examples include 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, and 4-hydroxy-4-methyl-2-pentanone, cyclohexanone, and propylene glycol monomethyl ether, cyclopentanone, and propylene glycol monomethyl ether, and N-methyl-2-pyrrolidone, cyclohexanone, and propylene glycol monomethyl ether.

[0073] (Liquid Crystal Aligning Agent) The liquid crystal aligning agent of the present invention contains the polymer (P) and, if necessary, the other polymers and the organic solvent. The total content of the polymers contained in the liquid crystal aligning agent of the present invention can be appropriately changed depending on the thickness of the coating film to be formed, but from the viewpoint of forming a uniform and defect-free coating film, it is preferably 1% by mass or more relative to 100% by mass of the liquid crystal aligning agent, and from the viewpoint of storage stability of the solution, it is preferably 10% by mass or less. A particularly preferred total polymer content is 2 to 8% by mass.

[0074] The content of the polymer (P) used in the present invention is preferably 1 to 100% by mass, more preferably 10 to 100% by mass, and particularly preferably 20 to 100% by mass, relative to the total amount of polymers contained in the liquid crystal aligning agent. In addition, the solid content concentration of the polymer (P) relative to 100% by mass of the liquid crystal aligning agent is preferably 0.1% by mass or more, more preferably 1% by mass or more, and is preferably 50% by mass or less, more preferably 35% by mass or less, from the viewpoint of the application method of the liquid crystal aligning agent and obtaining a desired film thickness.

[0075] The liquid crystal aligning agent of the present invention may contain, in addition to the polymer (P), the other polymer, and the organic solvent, other components (hereinafter also referred to as additive components). Examples of such additive components include at least one crosslinking compound selected from the group consisting of a crosslinking compound having at least one substituent selected from an oxiranyl group, an oxetanyl group, a blocked isocyanate group, an oxazoline group, a cyclocarbonate group, a hydroxyalkyl group, and an alkoxy group, and a crosslinking compound having a polymerizable unsaturated group, a functional silane compound, a metal chelate compound, a curing accelerator, a surfactant, an antioxidant, a sensitizer, a preservative, and a compound for adjusting the dielectric constant or electrical resistance of the resulting liquid crystal alignment film.

[0076] Specific preferred examples of the crosslinkable compound include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl ether, bisphenol A type epoxy resins such as Epicoat 828 (manufactured by Mitsubishi Chemical Corporation), bisphenol F type epoxy resins such as Epicoat 807 (manufactured by Mitsubishi Chemical Corporation), hydrogenated bisphenol A type epoxy resins such as YX-8000 (manufactured by Mitsubishi Chemical Corporation), biphenyl skeleton-containing epoxy resins such as YX6954BH30 (manufactured by Mitsubishi Chemical Corporation), phenol novolac type epoxy resins such as EPPN-201 (manufactured by Nippon Kayaku Co., Ltd.), (o, m, p-) epoxy resins such as EOCN-102S (manufactured by Nippon Kayaku Co., Ltd.), azole novolac type epoxy resins, triglycidyl isocyanurates such as TEPIC (manufactured by Nissan Chemical Industries, Ltd.), alicyclic epoxy resins such as Celloxide 2021P (manufactured by Daicel Corporation), compounds containing a tertiary nitrogen atom such as N,N,N',N'-tetraglycidyl-m-xylylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, or N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, and oxiranyl such as tetrakis(glycidyloxymethyl)methane. compounds having two or more oxetanyl groups described in paragraphs

[0170] to

[0175] of WO 2011 / 132751; compounds having two or more oxetanyl groups; Coronate AP Stable M, Coronate 2503, 2515, 2507, 2513, 2555, Millionate MS-50 (all manufactured by Tosoh Corporation), Takenate B-830, B-815N, B-820NSU, B-842N, B-846N, B-870N, B-874N, B-882N (all manufactured by Mitsui Chemicals, Inc.);Compounds having an oxazoline group such as 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, and EPOCROS (manufactured by Nippon Shokubai Co., Ltd.); compounds having a cyclocarbonate group described in paragraphs

[0025] to

[0030] and

[0032] of WO2011 / 155577; 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-dihydro compounds having a hydroxy group or an alkoxy group, such as (hydroxymethylphenyl)-1,1,1,3,3,3-hexafluoropropane; and compounds represented by glycerin mono(meth)acrylate, glycerin di(meth)acrylate (1,2-,1,3-dimer mixture), glycerin tris(meth)acrylate, glycerin 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, and hexaethylene glycol mono(meth)acrylate;

[0077] The content of the crosslinkable compound 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.

[0078] Examples of the compound for adjusting the dielectric constant or electrical resistance include monoamines having a nitrogen atom-containing aromatic heterocycle such as 3-picolylamine. The content of the monoamine having a nitrogen atom-containing aromatic heterocycle is preferably 0.1 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, per 100 parts by mass of the polymer component contained in the liquid crystal aligning agent.

[0079] Specific preferred examples of the functional silane compound include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyldiethoxymethylsilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and 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, etc. The content of the functional silane compound is preferably 0.1 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, per 100 parts by mass of the polymer component contained in the liquid crystal alignment agent.

[0080] The solid content concentration in the liquid crystal aligning agent (the ratio of the total mass of the components other than the solvent of the liquid crystal aligning agent to the total mass of the liquid crystal aligning agent) is appropriately selected in consideration of viscosity, volatility, etc., and is preferably 1 to 10 mass%.

[0081] The particularly preferred range of solid content varies depending on the method used to apply the liquid crystal aligning agent to the substrate. For example, when using a spin coating method, a solid content of 1.5 to 4.5 mass% is particularly preferred. When using a printing method, a solid content of 3 to 9 mass% is particularly preferred, thereby resulting in a solution viscosity of 12 to 50 mPa·s. When using an inkjet method, a solid content of 1 to 5 mass% is particularly preferred, thereby resulting in a solution viscosity of 3 to 15 mPa·s. The temperature when preparing the liquid crystal aligning agent is preferably 10 to 50°C, more preferably 20 to 30°C.

[0082] <Liquid Crystal Alignment Film / Liquid Crystal Display Element> A liquid crystal alignment film can be produced by using the liquid crystal aligning agent. The liquid crystal display element of the present invention comprises the liquid crystal alignment film. The operation mode of the liquid crystal display element of the present invention is not particularly limited, and it can be applied to various operation modes, such as TN mode, STN (Super Twisted Nematic) mode, vertical alignment mode (including VA-MVA mode, VA-PVA mode, etc.), IPS mode, FFS mode, and optically compensated bend mode (OCB mode). The liquid crystal alignment film of the present invention is particularly suitable for liquid crystal display elements of horizontal alignment mode, such as IPS mode or FFS mode.

[0083] The liquid crystal display element of the present invention can be produced, for example, by a method including the following steps (1) to (3), a method including steps (1) to (4), a method including steps (1) to (3), (3b) and (4), a method including steps (1) to (3), (3a), (3b) and (4), a method including steps (1) to (2) and (4), a method including steps (1) to (3), (4) and (5), or a method including steps (1) to (3), (4) and (6).

[0084] <Step (1): Applying a Liquid Crystal Alignment Agent to At Least One of the First and Second Substrates> Step (1) is a step of applying the liquid crystal aligning agent of the present invention to a substrate. Specific examples of step (1) are as follows: The liquid crystal aligning agent of the present invention is applied to one side of a substrate having a patterned transparent conductive film by an appropriate application method, such as a roll coater method, a spin coat method, a printing method, or an inkjet method. The substrate is not particularly limited as long as it is highly transparent. In addition to glass substrates and silicon nitride substrates, plastic substrates such as acrylic substrates and polycarbonate substrates can also be used. In addition, in reflective liquid crystal display elements, an opaque material such as a silicon wafer can be used for only one substrate. In this case, a light-reflecting material such as aluminum can also be used for the electrode. Furthermore, when manufacturing an IPS or FFS liquid crystal display element, a substrate having an electrode made of a comb-shaped patterned transparent conductive film or metal film and an opposing substrate having no electrode are used. The transparent conductive film can be formed by a known method using, for example, indium tin oxide (ITO), indium zinc oxide (IZO), or a mixture thereof.

[0085] Examples of a method for applying the liquid crystal alignment agent to a substrate and forming a film include screen printing, offset printing, flexographic printing, an inkjet method, and a spray method. Among these, the application and film formation method by the inkjet method is preferably used.

[0086] <Step (2): Step of Baking the Applied Liquid Crystal Alignment Agent> Step (2) is a step of baking the liquid crystal alignment agent applied to the substrate to form a film. Specific examples of step (2) are as follows. After applying the liquid crystal alignment agent to the substrate in step (1), the solvent can be evaporated or the polyamic acid or polyamic acid ester can be thermally imidized using a heating means such as a hot plate, a heat circulation oven, or an IR (infrared) oven. The drying and baking steps after applying the liquid crystal alignment agent of the present invention can be performed at any temperature and for any time, and may be performed multiple times. The temperature for reducing the solvent in the liquid crystal alignment agent can be, for example, 40 to 180°C. From the perspective of shortening the process, the baking can be performed at 40 to 150°C. The baking time is not particularly limited, but may be 1 to 10 minutes or 1 to 5 minutes. When thermal imidization of polyamic acid or polyamic acid ester is carried out, the above step may be followed by a step of baking at a temperature in the range of, for example, 150 to 300° C. or 150 to 250° C. The baking time is not particularly limited, but examples include baking times of 5 to 40 minutes or 5 to 30 minutes.

[0087] If the film-like material after baking is too thin, the reliability of the liquid crystal display device may decrease, so the film thickness is preferably 5 to 300 nm, more preferably 10 to 200 nm.

[0088] <Step (3): Alignment Treatment of the Film Obtained in Step (2)> Step (3) is a step of, in some cases, aligning the film obtained in Step (2). That is, in horizontal alignment type liquid crystal display devices such as IPS or FFS modes, the coating film is subjected to an alignment ability imparting treatment. On the other hand, in vertical alignment type liquid crystal display devices such as VA or PSA modes, the formed coating film can be used as a liquid crystal alignment film as is, but the coating film may also be subjected to an alignment ability imparting treatment. Alignment treatment methods for liquid crystal alignment films include rubbing treatment and photo-alignment treatment, and more preferably photo-alignment treatment. Photo-alignment treatment methods include irradiating the surface of the film with radiation (more preferably polarized radiation) to impart liquid crystal alignment (also referred to as liquid crystal alignment ability). The radiation can be ultraviolet light or visible light having a wavelength of 100 to 800 nm. Among these, ultraviolet light having a wavelength of 100 to 400 nm is preferred, more preferably 200 to 400 nm. The rubbing treatment may involve rubbing the coating film in a certain direction with a roll wrapped with a cloth made of fibers such as nylon, rayon, or cotton.

[0089] In the photo-alignment treatment method, when the radiation is polarized, it may be linearly polarized or partially polarized. When the radiation used is linearly polarized or partially polarized, the radiation may be irradiated from a direction perpendicular to the substrate surface, from an oblique direction, or a combination of these. When irradiating with unpolarized radiation, the irradiation direction is preferably oblique.

[0090] The radiation dose is 1 to 10,000 mJ / cm ２ is preferred, and 100 to 1,000 mJ / cm ２ More preferably, 100 to 700 mJ / cm ２ is more preferably 100 to 500 mJ / cm ２ is most preferred.

[0091] When radiation is irradiated in the photo-alignment treatment, in order to improve the liquid crystal alignment, the substrate having the film-like material may be irradiated while being heated at, for example, 50 to 250° C. The liquid crystal alignment film prepared in this manner can stably align liquid crystal molecules in a certain direction.

[0092] The liquid crystal alignment film obtained by the above method may further be subjected to a step of contact treatment using a solvent (hereinafter also referred to as step (3a)). The solvent used in the contact treatment in step (3a) is not particularly limited as long as it is a solvent that dissolves the decomposition products generated from the film-like material by irradiation with 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, and the like. Among these, water, 2-propanol, 1-methoxy-2-propanol, or ethyl lactate are preferred from the viewpoints of versatility and solvent safety. Water, 1-methoxy-2-propanol, or ethyl lactate are more preferred. The solvent may be one type or a combination of two or more types. The liquid crystal alignment film used in the liquid crystal display element of the present invention may be prepared by carrying out the following step (3b) after the step (3). The step (3b) may be carried out on a film that has been subjected to the treatment in the step (3a) above, in addition to the film that has been subjected to the alignment treatment in the step (3).

[0093] <Step (3b): Step of Heat Treatment> The coating film irradiated with the radiation may be subjected to a heat treatment. The temperature for such heat treatment is preferably 50 to 300° C., more preferably 120 to 250° C. The time for the heat treatment is preferably 1 to 30 minutes.

[0094] <Step (4): A step of disposing a liquid crystal layer between the first substrate and the second substrate so as to be adjacent to the alignment-treated film to prepare a liquid crystal cell> Step (4) is a step of disposing a liquid crystal layer between the first substrate and the second substrate so as to be adjacent to the alignment-treated film to prepare a liquid crystal cell. Note that the following describes an example in which a liquid crystal alignment film is formed on each of the first substrate and the second substrate. Specifically, the following two methods can be used.

[0095] In the first method, two substrates are placed opposite each other with a gap (cell gap) between them so that their liquid crystal alignment films face each other, and then the peripheries of the two substrates are bonded together using a sealant. A liquid crystal composition is injected into the substrate surfaces and the cell gap defined by the sealant so that it comes into contact with the film surface, and the injection hole is then sealed.

[0096] The second method is called the ODF (One Drop Fill) method. For example, a UV-curable resin composition (hereinafter also referred to as a sealant) is applied to a predetermined location on one of two substrates on which a liquid crystal alignment film has been formed, and a liquid crystal composition is then dropped onto several predetermined locations on the liquid crystal alignment film surface. The other substrate is then attached so that the liquid crystal alignment film faces the other substrate, and the liquid crystal composition is spread over the entire surface of the substrate and brought into contact with the film surface. Next, the entire surface of the substrate is irradiated with UV light to cure the sealant. In either method, it is desirable to further heat the substrate to a temperature at which the liquid crystal composition is in an isotropic phase, and then slowly cool it to room temperature to remove flow alignment that occurs during liquid crystal filling.

[0097] When the coating films are subjected to rubbing treatment, the two substrates are placed opposite each other so that the rubbing directions of the coating films are at a predetermined angle, for example, perpendicular or anti-parallel to each other.

[0098] The sealing agent may be, for example, an epoxy resin containing a curing agent and aluminum oxide spheres as spacers. The liquid crystal composition is not particularly limited, and any liquid crystal composition containing at least one liquid crystal compound (liquid crystal molecule) and having a positive or negative dielectric anisotropy may be used. Hereinafter, a liquid crystal composition having a positive dielectric anisotropy will be referred to as a positive liquid crystal, and a liquid crystal composition having a negative dielectric anisotropy will be referred to as a negative liquid crystal.

[0099] The liquid crystal composition may contain a liquid crystal compound having a fluorine atom, a hydroxy group, an amino group, a fluorine atom-containing group (e.g., a trifluoromethyl group), 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 contain a compound having two or more rigid moieties (mesogenic skeletons) that exhibit liquid crystallinity within the molecule (e.g., a bimesogenic compound in which two rigid biphenyl structures or terphenyl structures are linked by an alkylene group).

[0100] The liquid crystal composition may be a liquid crystal composition exhibiting a nematic phase, a liquid crystal composition exhibiting a smectic phase, or a liquid crystal composition exhibiting a cholesteric phase.

[0101] The liquid crystal composition may further contain an additive from the viewpoint of improving the liquid crystal alignment property, such as a photopolymerizable monomer having a polymerizable group, an optically active compound (e.g., S-811 manufactured by Merck Ltd.), an antioxidant, an ultraviolet absorber, a dye, an antifoaming agent, a polymerization initiator, or a polymerization inhibitor.

[0102] Examples of the positive liquid crystal include ZLI-2293, ZLI-4792, MLC-2003, MLC-2041, MLC-3019, and MLC-7081 manufactured by Merck.

[0103] Examples of negative liquid crystals include MLC-6608, MLC-6609, MLC-6610, and MLC-7026-100 manufactured by Merck.

[0104] Furthermore, an example of a liquid crystal containing a compound having a polymerizable group is MLC-3023 manufactured by Merck.

[0105] The liquid crystal aligning agent of the present invention is also preferably used for a liquid crystal display element (PSA type liquid crystal display element) manufactured through a step (hereinafter, this step may be referred to as step (5)) of having a liquid crystal layer between a pair of substrates provided with electrodes, and disposing a liquid crystal composition containing a polymerizable compound that is polymerized by at least one of active energy rays and heat between the pair of substrates, and polymerizing the polymerizable compound by at least one of irradiation with active energy rays and heating while applying a voltage between the electrodes.

[0106] The liquid crystal aligning agent of the present invention is also preferably used for a liquid crystal display element (SC-PVA type liquid crystal display element) which has a liquid crystal layer between a pair of substrates provided with electrodes, and is produced through a step of disposing a liquid crystal alignment film containing a polymerizable group that is polymerized by at least one of active energy rays and heat between the pair of substrates, and applying a voltage between the electrodes (hereinafter, this step is also referred to as step (6)).

[0107] 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 to be attached to the outer surface of the liquid crystal cell include a polarizing film called an "H film" made by stretching and aligning polyvinyl alcohol and absorbing iodine, sandwiched between cellulose acetate protective films, and a polarizing plate made of the H film itself.

[0108] An IPS substrate, which is a comb-tooth electrode substrate used in the IPS system, has a base material, a plurality of linear electrodes formed on the base material and arranged in a comb-tooth pattern, and a liquid crystal alignment film formed on the base material so as to cover the linear electrodes.

[0109] The FFS substrate, which is a comb-tooth electrode substrate used in the FFS method, has a base material, a surface electrode formed on the base material, an insulating film formed on the surface electrode, a plurality of linear electrodes formed on the insulating film and arranged in a comb-tooth shape, and a liquid crystal alignment film formed on the insulating film so as to cover the linear electrodes.

[0110] FIG. 1 is a schematic cross-sectional view showing an example of a lateral electric field type liquid crystal display element of the present invention, which is an example of an IPS type liquid crystal display element.

[0111] In the in-plane switching mode liquid crystal display element 1 illustrated in Fig. 1, liquid crystal 3 is sandwiched between a comb-tooth electrode substrate 2 having a liquid crystal alignment film 2c and a counter substrate 4 having a liquid crystal alignment film 4a. The comb-tooth electrode substrate 2 has a base material 2a, a plurality of linear electrodes 2b formed on the base material 2a and arranged in a comb-tooth pattern, and a liquid crystal alignment film 2c formed on the base material 2a so as to cover the linear electrodes 2b. The counter substrate 4 has a base material 4b and a liquid crystal alignment film 4a formed on the base material 4b. The liquid crystal alignment film 2c is, for example, the liquid crystal alignment film of the present invention. The liquid crystal alignment film 4c is also the liquid crystal alignment film of the present invention.

[0112] In this IPS mode liquid crystal display element 1, when a voltage is applied to the linear electrodes 2b, an electric field is generated between the linear electrodes 2b as indicated by electric force lines L.

[0113] FIG. 2 is a schematic cross-sectional view showing another example of the in-plane switching mode liquid crystal display element of the present invention, which is an example of an FFS mode liquid crystal display element.

[0114] In the in-plane switching mode liquid crystal display element 1 illustrated in Figure 2, 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 base material 2d, a surface electrode 2e formed on the base material 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-like pattern, 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 base material 4b and a liquid crystal alignment film 4a formed on the base material 4b. The liquid crystal alignment film 2h is, for example, a liquid crystal alignment film of the present invention. The liquid crystal alignment film 4a is also a liquid crystal alignment film of the present invention.

[0115] In this IPS mode liquid crystal display element 1, when a voltage is applied to the surface electrodes 2 e and the linear electrodes 2 g, an electric field is generated between the surface electrodes 2 e and the linear electrodes 2 g, as indicated by the electric field lines L. The liquid crystal alignment film of the present invention can be used for a variety of purposes in addition to the above-mentioned applications, such as a liquid crystal alignment film for a retardation film, a liquid crystal alignment film for a scanning antenna or a liquid crystal array antenna, or a liquid crystal alignment film for a transmissive / scattering liquid crystal dimming element. Furthermore, the film can also be used for applications other than liquid crystal alignment films, 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 covering film, an antistatic film, and a motor insulating film (a gate insulating film for a flexible display).

[0116] The liquid crystal display element of the present invention can be effectively applied to various devices, and can be used in various display devices such as watches, portable games, word processors, notebook computers, car navigation systems, camcorders, PDAs, digital cameras, mobile phones, smartphones, various monitors, liquid crystal televisions, and information displays.

[0117] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. The abbreviations of the compounds used and the methods for measuring the physical properties are as follows. (Organic solvents) THF: tetrahydrofuran IPA: 2-propanol NMP: N-methyl-2-pyrrolidone BCS: ethylene glycol monobutyl ether Me-THP: 4-methyltetrahydropyran DMF: N,N-dimethylformamide (Tetracarboxylic acid dianhydrides) CA-1 to CA-3: compounds represented by the following formulas (CA-1) to (CA-3), respectively

[0118]

[0119] (Diamine) DA-1 to DA-9: Compounds represented by the following formulas (DA-1) to (DA-9), respectively

[0120]

[0121] Among the above diamines, DA-3, DA-4, and DA-9 are included in the scope of the specific diamine (p). DA-4 was purchased from Beijing Pure Chem. Co., Ltd.

[0122] <Measurement of Viscosity> Measurement was carried out at 25°C using an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.) with a sample volume of 1.1 mL and a cone rotor TE-1 (1°34', R24).

[0123] <Measurement of Molecular Weight> Measurement was carried out using the following room temperature GPC (gel permeation chromatography) device, and Mn and Mw were calculated as values ​​converted into polyethylene glycol and polyethylene oxide.

[0124] GPC apparatus: GPC-101 (Showa Denko K.K.); column: GPC KD-803 and GPC KD-805 (Showa Denko K.K.) in series; column temperature: 50°C; eluent: N,N-dimethylformamide (with lithium bromide monohydrate (LiBr.H) as an additive). ２ o-Phosphoric acid (o-Phosphoric acid) 30 mmol / L, tetrahydrofuran (THF) 10 mL / L), flow rate: 1.0 mL / min. Standard samples for preparing a calibration curve: TSK standard polyethylene oxide (molecular weight: about 900,000, about 150,000, about 100,000, and about 30,000) (manufactured by Tosoh Corporation) and polyethylene glycol (molecular weight: about 12,000, about 4,000, and about 1,000) (manufactured by Polymer Laboratory Co., Ltd.).

[0125] [Synthesis of Monomers] DA-3 and DA-8 are novel compounds not previously disclosed in the literature, and their synthesis methods are described in detail below. The products described in Monomer Synthesis Examples 1 to 3 below were identified by 1H-NMR analysis (analysis conditions are as follows). Apparatus: Fourier transform superconducting nuclear magnetic resonance spectrometer (FT-NMR) "AVANCE III" (manufactured by BRUKER) 500 MHz. Solvent: deuterated dimethyl sulfoxide (DMSO-d ６ , standard substance: tetramethylsilane)

[0126] (Monomer Synthesis Example 1: Synthesis of DA-3) DA-3 was synthesized according to the route shown below.

[0127]

[0128] In a 500 mL four-neck flask, 4,4'-Dinitro-[1,1'-biphenyl]-2,2'-dicarboxylic acid (20.0 g, 60.2 mmol), 4-dimethylaminopyridine (DMAP, 1.47 g, 12.0 mmol), and THF (100 g) were added and dissolved, and the mixture was heated to 70°C. ２ A solution of DA-3-1 (46.0 g, 210.7 mmol) dissolved in THF (15.0 g) was slowly added dropwise using a dropping funnel. After the addition was completed, the mixture was stirred at 70°C for 2 hours. The reaction solution was concentrated to 50 g, and IPA (120 g) was added thereto. The mixture was stirred at 5°C for 30 minutes to precipitate crystals. The obtained crystals were separated by filtration, washed with IPA, and then dried under reduced pressure at 40°C to obtain DA-3-1 (yield: 21.0 g, 47.2 mmol, yield: 78%, white crystals).

[0129] To the DA-3-1 (20.0 g, 45.0 mmol) obtained above, THF (160 g) was added and the mixture was purged with nitrogen. Then, carbon-supported palladium (5 mass% Pd carbon powder (50% water content) K type, manufactured by N.E. Chemcat Corporation) (2.0 g) and activated carbon (Special Shirasagi, manufactured by Osaka Gas Chemicals Co., Ltd.) (2.0 g) were added, and the mixture was purged with nitrogen again. The mixture was stirred at 50°C under hydrogen pressure (0.3 MPa) for 12 hours. After completion of the reaction, the catalyst was filtered, and the mixture was concentrated to 50 g. IPA (240 g) was added, and the mixture was stirred at 5°C for 30 minutes. The precipitated crystals were filtered under reduced pressure, washed with IPA (40 g), and then dried under reduced pressure at 40°C to obtain powder crystals (DA-3) (yield: 14.4 g, 37.5 mmol, yield 83%, white crystals). １ H-NMR (500MHz) in DMSO-d ６ : δ (ppm) = 6.95 (2H, d), 6.74 (2H, d), 6.64-6.67 (2H, dd), 5.18 (4H, s), 1.14 (18H, s)

[0130] (Monomer Synthesis Example 2: Synthesis of DA-8) DA-8 was synthesized according to the route shown below.

[0131]

[0132] In a 1 L four-neck flask, 4,4'-Dinitro-[1,1'-biphenyl]-2,2'-dicarboxylic acid (23.9 g, 72.1 mmol), o-cresol (23.4 g, 216.3 mmol), 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC.HCl, 30.4 g, 158.6 mmol), 4-dimethylaminopyridine (DMAP, 0.88 g, 7.21 mmol), THF (190 g), and dichloromethane (CH ２ Cl ２ , 48 g) was added and dissolved, and the mixture was stirred at room temperature for 15 hours. 750 g of ethyl acetate was added to the reaction solution, and the mixture was separated and washed with 1 N hydrochloric acid (240 g), aqueous sodium sulfate solution (240 g), saturated saline (240 g), and water (240 g), in that order. The organic layer was concentrated to 75 g, and methanol (300 g) was added thereto. The mixture was stirred at room temperature for 30 minutes to precipitate crystals. The obtained crystals were filtered, washed with methanol (50 g), and then dried under reduced pressure at 40 ° C. to obtain DA-8-1 (yield: 17.3 g, 33.8 mmol, yield: 47%, white crystals).

[0133] To the DA-8-1 (17.2 g, 33.6 mmol) obtained above, THF (340 g) was added and the mixture was purged with nitrogen. Then, carbon-supported palladium (5 mass% Pd carbon powder (50% water content) K type, manufactured by N.E. Chemcat Corporation) (1.72 g) was added, the mixture was purged with nitrogen again, a Tedlar bag filled with hydrogen was attached, and the mixture was stirred at room temperature (23°C) for 24 hours. After completion of the reaction, the catalyst was filtered off, and the mixture was concentrated to 50 g. IPA (170 g) was added, and the mixture was stirred at room temperature for 30 minutes. The resulting crystals were filtered off, the cake was washed with IPA (40 g), and then dried under reduced pressure at 40°C to obtain DA-8 (yield: 14.4 g, 31.8 mmol, yield: 95%, yellow crystals). １ H-NMR (500MHz) in DMSO-d ６: δ (ppm) = 7.22-7.24 (4H, m), 7.10-7.19 (4H, m), 6.95 (2H, d), 6.77-6.80 (4H, dd), 5.38 (4H, s), 1.95 (6H, s).

[0134] (Monomer Synthesis Example 3: Synthesis of DA-9) DA-9 was synthesized according to the route shown below. 4,4'-Dinitro[1,1'-biphenyl]-2,2'-dicarboxylic acid (19.9 g, 60.0 mmol), Me-THP (200 g), and one drop of DMF were added to a 1 L four-neck flask and stirred in a water bath. Oxalyl chloride (19.0 g, 150.0 mmol) was slowly added dropwise, and the mixture was stirred at room temperature for 1 hour. The resulting acid chloride solution was then used for the next step. A 7% methylamine THF solution (225.0 g, 450.0 mmol) was cooled to 0°C and stirred, to which the acid chloride solution was slowly added dropwise using a dropping funnel. After the addition, the mixture was stirred at room temperature for 2 hours. Ethyl acetate (400 g) and purified water (200 g) were added to the reaction mixture for separation and washing. The organic layer was concentrated, and methanol (300 g) was added thereto. The mixture was stirred at room temperature for 30 minutes to precipitate crystals. The resulting crystals were separated by filtration, washed with methanol, and then dried under reduced pressure at 40°C to obtain DA-9-1 (yield: 18.2 g, 50.9 mmol, 84%, white crystals).

[0135] To the DA-9-1 (18.2 g, 50.9 mmol) obtained above, THF (275.0 g) was added and the mixture was purged with nitrogen. Then, carbon-supported palladium (5 mass% Pd carbon powder (50% water content) K type, manufactured by N.E. Chemcat Corporation) (1.82 g) was added, the mixture was purged with nitrogen again, a hydrogen Tedlar bag was attached, and the mixture was stirred at room temperature (23 ° C) for 22 hours. After completion of the reaction, DMF (180 g) was added and the mixture was dissolved by heating, and the catalyst was filtered off. The resulting reaction solution was concentrated to 50 g, and IPA (170 g) and heptane were added, followed by stirring at room temperature for 30 minutes. The resulting crystals were filtered off, the cake was washed with THF, and then dried under reduced pressure at 40 ° C to obtain DA-9 (yield: 11.0 g, 36.9 mmol, 74% yield, yellowish-white crystals). １ H-NMR (500MHz) in DMSO-d６ :8.24 (2H, q), 6.58-6.61 (4H, m), 6.49 (2H, dd), 5.60 (4H, s), 2.48 (6H, d)

[0136] [Polymer Synthesis] <Synthesis Example 1> DA-1 (1.47 g, 6.00 mmol), DA-2 (1.63 g, 6.00 mmol), and NMP (31.3 g) were added to a 50 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and dissolved by stirring at room temperature while introducing nitrogen. Thereafter, CA-1 (2.47 g, 11.0 mmol) and NMP (9.54 g) were added under ice cooling, and the mixture was stirred at 40°C for 12 hours to obtain a solution of polyamic acid (PAA-1) with a solids concentration of 12% by mass (viscosity: 69 mPa s). The Mn of this polyamic acid was 5,500 and the Mw was 10,900.

[0137] Synthesis Example 2 DA-1 (1.22 g, 5.00 mmol), DA-3 (1.92 g, 5.00 mmol), and NMP (23.0 g) were added to a 50 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and dissolved by stirring at room temperature while introducing nitrogen. Thereafter, CA-1 (2.06 g, 9.20 mmol) and NMP (15.1 g) were added under ice cooling, and the mixture was stirred at 40°C for 12 hours to obtain a solution of polyamic acid (PAA-2) with a solids concentration of 12% by mass (viscosity: 383 mPa s). The Mn of this polyamic acid was 16,100, and the Mw was 36,700.

[0138] Synthesis Example 3 DA-1 (1.34 g, 5.50 mmol), DA-4 (1.65 g, 5.50 mmol), and NMP (30.3 g) were added to a 50 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and dissolved by stirring at room temperature while introducing nitrogen. Subsequently, CA-1 (2.34 g, 10.5 mmol) and NMP (8.86 g) were added under ice cooling, and the mixture was stirred at 40°C for 12 hours to obtain a solution of polyamic acid (PAA-3) with a solids concentration of 12% by mass (viscosity: 553 mPa s). The Mn of this polyamic acid was 12,800, and the Mw was 32,700.

[0139] Synthesis Example 4 DA-5 (3.10 g, 10.4 mmol), DA-6 (8.28 g, 41.6 mmol), CA-2 (14.7 g, 49.9 mmol), and NMP (191 g) were added to a 200 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and the mixture was stirred at 70° C. for 15 hours to obtain a solution of polyamic acid (PAA-4) (viscosity: 461 mPa s) with a solids concentration of 12 mass %. The Mn of this polyamic acid was 11,400 and the Mw was 29,700.

[0140] Synthesis Example 5 DA-7 (3.46 g, 32.0 mmol), DA-5 (14.3 g, 48.0 mmol), and NMP (160 g) were added to a 200 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and dissolved by stirring at room temperature while feeding nitrogen. After that, after cooling to 15 ° C, CA-3 (5.48 g, 27.9 mmol) and NMP (10.6 g) were added and stirred at room temperature for 1 hour. Thereafter, CA-3 (9.08 g, 46.3 mmol) and NMP (66.8 g) were added and stirred at room temperature for 1 hour to obtain a solution of polyamic acid (PAA-5) with a solids concentration of 12% by mass (viscosity: 124 mPa s). The Mn of this polyamic acid was 8,057 and the Mw was 19,377.

[0141] Synthesis Example 6 DA-1 (1.34 g, 5.50 mmol), DA-8 (2.49 g, 5.50 mmol), and NMP (38.8 g) were added to a 50 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and the mixture was stirred at room temperature while introducing nitrogen to dissolve the mixture. Thereafter, CA-1 (2.29 g, 10.2 mmol) and NMP (6.17 g) were added under ice cooling, and the mixture was stirred at 40°C for 12 hours to obtain a solution of polyamic acid (PAA-6) with a solids concentration of 12% by mass (viscosity: 720 mPa s). The Mn of this polyamic acid was 17,000, and the Mw was 48,200.

[0142] Synthesis Example 7: DA-1 (1.34 g, 5.50 mmol), DA-9 (1.64 g, 5.50 mmol), and NMP (30.2 g) were added to a 50 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and dissolved by stirring at room temperature while feeding nitrogen. Thereafter, CA-1 (2.34 g, 10.5 mmol) and NMP (8.89 g) were added under ice cooling, and the mixture was stirred at 40°C for 12 hours to obtain a solution of polyamic acid (PAA-7) with a solids concentration of 12% by mass (viscosity: 807 mPa s). The Mn of this polyamic acid was 16,700, and the Mw was 38,700.

[0143] The specifications of the polyamic acids obtained in the above synthesis examples are shown in Table 1. In Table 1, the parenthesized numbers for the diamine components represent the amount (parts by mole) of each compound used relative to 100 parts by mole of the total amount of the diamine components used in each polymerization step. The parenthesized numbers for the tetracarboxylic acid components represent the amount (parts by mole) of each compound used relative to 100 parts by mole of the total amount of the tetracarboxylic acid components used in each polymerization step. The parenthesized numbers for the organic solvents represent the amount (parts by mass) of each compound used relative to 100 parts by mass of the total amount of the organic solvents used in each polymerization step.

[0144]

[0145] [Preparation of Liquid Crystal Alignment Agent] Comparative Example 1 The polyamic acid solution (PAA-1) obtained in Synthesis Example 1, NMP, and BCS were added to a sample tube containing a stirring bar, and the mixture was stirred at 23°C for 30 minutes to obtain a liquid crystal alignment agent (AL-R1) having a mass ratio of polymer solid content to each solvent (polymer solid content:NMP:BCS) of 6:74:20.

[0146] Comparative Example 2, Examples 1 to 5 Liquid crystal aligning agents (AL-R2) and (AL-1) to (AL-5) were obtained by carrying out the same procedure as in Comparative Example 1, except that the type of polyamic acid solution used was changed as shown in Table 2. In Table 2, the numbers in parentheses for the polymers represent the blending ratio (parts by mass) of each polymer component relative to 100 parts by mass of the total polymer components used in preparing the liquid crystal aligning agent. For the organic solvents, the numbers represent the blending ratio (parts by mass) of each organic solvent relative to 100 parts by mass of the liquid crystal aligning agent.

[0147]

[0148] [Fabrication of FFS Drive Liquid Crystal Cell] A liquid crystal cell having the structure of an FFS mode liquid crystal display element was fabricated.

[0149] First, a substrate with electrodes was prepared. The substrate was a rectangular glass substrate measuring 30 mm x 35 mm and 0.7 mm thick. A solid-patterned ITO electrode constituting a common electrode was formed on the substrate as the first layer. A SiN (silicon nitride) film formed by CVD (chemical vapor deposition) was formed on the first common electrode as the second layer. The second SiN film had a thickness of 300 nm, which served as an interlayer insulating film. A comb-shaped pixel electrode formed by patterning an ITO film as the third layer was placed on the second SiN film. Two pixels, a first pixel and a second pixel, were formed, each measuring 10 mm long and 5 mm wide. This electrode-equipped substrate had a structure in which the first common electrode and the third pixel electrode were insulated by the second SiN film.

[0150] The pixel electrode of the third layer had a comb-like shape with the central portion bent at an interior angle of 160° and multiple electrode lines, each 3 μm wide, arranged parallel to each other at intervals of 6 μm. One pixel was formed by multiple electrode lines and had a first region and a second region separated by a line connecting the bent portions.

[0151] Next, the liquid crystal alignment agent obtained above was filtered through a filter with a pore size of 1.0 μm, and then spin-coated onto the electrode-attached substrate (hereinafter referred to as the electrode substrate) and a glass substrate (hereinafter referred to as the counter substrate) having a 4 μm-high columnar spacer with an ITO film formed on the back side. After drying for 2 minutes on a hot plate at 80 ° C, the substrate was baked for 30 minutes in an IR oven at 230 ° C to form a coating film with a thickness of 100 nm. The coating surface was irradiated with 254 nm polarized ultraviolet light through a 240 nm low-cut filter and a polarizer at the irradiation dose listed in Table 3 (optimal irradiation dose for each liquid crystal alignment agent), and then baked for 30 minutes in an IR oven at 230 ° C to perform an alignment treatment, thereby obtaining a substrate with a liquid crystal alignment film. The liquid crystal alignment film formed on the electrode substrate was subjected to an alignment treatment so that the direction dividing the interior angle of the pixel bends was perpendicular to the alignment direction of the liquid crystal. The alignment film formed on the counter substrate was also subjected to an alignment treatment so that the alignment direction of the liquid crystal on the electrode substrate was aligned with the alignment direction of the liquid crystal on the counter substrate when the liquid crystal cell was fabricated. The two substrates were combined into a pair, and a sealant (Mitsui Chemicals, Inc., XN-1500T) was printed on one substrate using a dispenser. Another substrate was then attached to the other substrate, facing each other with the alignment directions of the liquid crystal alignment films aligned at 0°. The bonded substrates were then pressed together and heated in a hot air circulating oven at 150°C for 60 minutes to cure the sealant, producing an empty cell. Positive liquid crystal MLC-3019 (Merck) was injected into this empty cell by a vacuum injection method, and the injection port was sealed to obtain an FFS-driven liquid crystal cell. The resulting liquid crystal cell was then heated at 120°C for 1 hour and left overnight at 23°C before being used for evaluation.

[0152] [Evaluation of Liquid Crystal Alignment Stability] This evaluation is for evaluating image retention (also called AC image retention) that occurs due to deterioration of the alignment performance of the liquid crystal alignment film during long-term AC driving.

[0153] The FFS drive liquid crystal cell produced above was used in conjunction with a high-brightness backlight (light source: LED, brightness: 20,000 cd / m) with a surface temperature of 50°C. ２) and an AC voltage of ±4.3 V at a frequency of 30 Hz was applied for 168 hours. The pixel electrode and common electrode of the liquid crystal cell were then shorted and left at room temperature (23°C) for one day. For the liquid crystal cell subjected to the above treatment, the deviation between the alignment direction of the liquid crystal in the first region of the pixel and the alignment direction of the liquid crystal in the second region of the pixel when no voltage was applied was calculated as an angle. Specifically, the liquid crystal cell was placed between two polarizing plates arranged so that their polarization axes were perpendicular to each other, and the backlight was turned on. The liquid crystal cell was then adjusted to minimize the transmitted light intensity in the first region of the first pixel. The rotation angle Δ required to rotate the liquid crystal cell to minimize the transmitted light intensity in the second region of the first pixel was then calculated. The first and second regions of the second pixel were similarly compared, and the same angle Δ was calculated. The average of the angles Δ for the first and second pixels was then calculated as the rotation angle Δ of the liquid crystal cell. The smaller the rotation angle Δ, the better the stability of the liquid crystal alignment. As the evaluation criteria, when the rotation angle Δ of the liquid crystal cell obtained above was 0.50° or less, it was rated as "good", and when it was more than 0.50°, it was rated as "poor". The results are shown in Table 3.

[0154]

[0155] As shown in Table 3, the liquid crystal alignment film obtained from the liquid crystal alignment agent using the specific diamine (p) had better liquid crystal alignment stability than the liquid crystal alignment film obtained from the liquid crystal alignment agent not using the specific diamine (p).

[0156] By using the liquid crystal aligning agent of the present invention, a liquid crystal alignment film that suppresses AC image retention can be obtained. Therefore, it is expected to be used in liquid crystal display elements that require high display quality, particularly in liquid crystal display elements of the IPS driving system and FFS driving system. These elements are also useful in liquid crystal displays for display purposes, light control windows that control light transmission and blocking, optical shutters, etc.

[0157] 1: In-plane switching liquid crystal display element, 2: comb-tooth electrode substrate, 2a: substrate, 2b: linear electrode, 2c: liquid crystal alignment film, 2d: substrate, 2e: plane electrode, 2f: insulating film, 2g: linear electrode, 2h: liquid crystal alignment film, 3: liquid crystal, 4: opposing substrate, 4a: liquid crystal alignment film, 4b: substrate, L: electric field line

[0158] The entire contents of the specification, claims, drawings and abstract of Japanese Patent Application No. 2023-194650 filed on November 15, 2023 are hereby incorporated by reference as the disclosure of the present invention.

Claims

1. A liquid crystal aligning agent comprising at least one polymer (P) selected from the group consisting of a polyimide precursor obtained by using a tetracarboxylic acid component containing at least one selected from the group consisting of tetracarboxylic acid dianhydrides and derivatives thereof, and a diamine component containing a diamine represented by the following formula (2), and a polyimide which is an imidized product of the polyimide precursor: (In formula (2), R ２１ ~R ２４ are each independently a hydrogen atom, *-CO ２ R or *-CONH-R, R ２１ ~R ２４ At least two of the following are *-CO ２ R or *-CONH-R. Each of the R's independently represents a monovalent organic group having 1 to 4 carbon atoms. One or more hydrogen atoms on the benzene ring bonded to the amino group are *-CO ２ R or * may be substituted with a monovalent group other than -CONH-R. * represents a bond.) 2. The liquid crystal aligning agent according to claim 1, wherein the content of the diamine represented by formula (2) is 5 mol % or more relative to 1 mol of the diamine component used in the production of the polymer (P).

3. The liquid crystal aligning agent according to claim 1, wherein the diamine represented by formula (2) is a diamine represented by any one of the following formulas (2-1) to (2-4): (In the formula, t-Bu represents a tert-butyl group.) 4. The liquid crystal aligning agent according to claim 1, wherein the tetracarboxylic dianhydride and its derivative are selected from acyclic aliphatic tetracarboxylic dianhydrides, alicyclic tetracarboxylic dianhydrides, aromatic tetracarboxylic dianhydrides, and derivatives thereof.

5. The liquid crystal aligning agent according to claim 4, wherein the content of the acyclic aliphatic tetracarboxylic dianhydride, the alicyclic tetracarboxylic dianhydride, the aromatic tetracarboxylic dianhydride, or a derivative thereof is 10 mol% or more per 1 mol of the tetracarboxylic acid component used in the production of the polymer (P).

6. The diamine component further comprises a phenylenediamine, a diaminobiphenyl compound, or a compound represented by the following formula (d ＡＬ ), a diamine having a diphenyl ether structure, a diamine having a tetracarboxylic diimide structure, a diamine having an amide bond, a diamine having a urea bond, and a diamine having a group "-N(D)-" (D represents a protecting group that is eliminated by heating and replaced with a hydrogen atom). The liquid crystal aligning agent according to claim 1, containing at least one other diamine selected from the group consisting of diamines represented by the formula (I), diamines having a diphenyl ether structure, diamines having a tetracarboxylic diimide structure, diamines having an amide bond, diamines having a urea bond, and diamines having a group "-N(D)-" (D represents a protecting group that is eliminated by heating and replaced with a hydrogen atom). (Ar １ , 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 may be unsubstituted or substituted with a monovalent group. １ and L １’ each represents a single bond, -O-, -C(=O)-, or -O-C(=O)-. A is -CH ２ represents an alkylene group having 2 to 12 carbon atoms, or a divalent organic group in which at least one of -O-, -C(=O)-O-, and -O-C(=O)- is inserted between the carbon-carbon bonds of the alkylene group.

7. The liquid crystal aligning agent according to claim 1, further comprising another polymer other than the polymer (P).

8. A liquid crystal alignment film obtained from the liquid crystal aligning agent according to any one of claims 1 to 7.

9. A liquid crystal display device comprising the liquid crystal alignment film according to claim 8.

10. A method for manufacturing a liquid crystal display element, comprising the following steps (1) to (4): Step (1): A step of applying the liquid crystal alignment agent according to any one of claims 1 to 7 to at least one of a first substrate and a second substrate; Step (2): A step of baking the applied liquid crystal alignment agent to obtain a film; Step (3): A step of performing an alignment treatment on the film obtained in step (2); Step (4): A step of disposing a liquid crystal layer between the first substrate and the second substrate so as to be adjacent to the alignment-treated film to prepare a liquid crystal cell.

11. The method for producing a liquid crystal display element according to claim 10, wherein the alignment treatment is a photoalignment treatment.

12. The method for producing a liquid crystal display element according to claim 11, further comprising a step (3b) of carrying out a heat treatment between steps (3) and (4).

13. The method for producing a liquid crystal display element according to claim 12, wherein the liquid crystal display element is an IPS type or FFS type liquid crystal display element.

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