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

Abstract

The purpose of the present invention is to provide a liquid crystal display element in which AC image retention is not likely to occur even if firing is carried out at a low temperature when the liquid crystal alignment film is manufactured. The purpose of the present invention is further to provide: a liquid crystal alignment film used in the liquid crystal display element; and a liquid crystal aligning agent for manufacturing the liquid crystal alignment film.　The liquid crystal aligning agent contains at least one polymer (P) selected from among polyimide precursors and polyimides obtained using a tetracarboxylic acid component that contains at least one selected from among tetracarboxylic acid dianhydrides represented by formula (1) and derivatives thereof, and a diamine component that contains a diamine represented by formula (2). (In the formula, the meaning of each symbol is as defined in the description.) (In the formula, the meaning of each symbol is as defined in the description.)

Description

Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element using the same

[0001] The present invention relates to a liquid crystal aligning agent used in the production of a liquid crystal display element, a liquid crystal alignment film obtained from the liquid crystal aligning agent, and a liquid crystal display element using the liquid crystal alignment film.

[0002] Currently, highly durable polyimide-based organic films are used in industrially utilized resin coatings. In particular, these polyimide-based organic films are also used as liquid crystal alignment films in liquid crystal display elements. Polyimide-based liquid crystal alignment films are formed from liquid crystal alignment agents containing polyimide precursors such as polyamic acid and polyimide. Specifically, they are formed by applying a liquid crystal alignment agent containing polyamic acid or polyimide to a substrate and then baking the substrate at 200°C to 300°C (see, for example, Patent Document 1). Typically, in horizontal electric field drive liquid crystal display elements, such as those using the in-plane switching (IPS) drive system or the fringe field switching (FFS) drive system, a rubbing treatment is performed on the baked liquid crystal alignment film in a specific direction with a roll wrapped with a cloth made of fibers such as nylon, rayon, or cotton to horizontally align the liquid crystal.

[0003] In recent years, with the increase in size and resolution of liquid crystal display elements, problems have arisen, such as scratches and dust generation on liquid crystal alignment films caused by rubbing treatment, and low in-plane uniformity of liquid crystal alignment. In response to these problems, a new alignment treatment method has begun to be adopted, in which the alignment of liquid crystals is controlled by irradiating polarized radiation (light) (also known as photoalignment treatment). As this photoalignment treatment, methods utilizing photoisomerization reactions, photocrosslinking reactions, and photodecomposition reactions have been proposed (see, for example, Non-Patent Document 1 and Patent Documents 2 to 4).

[0004] Japanese Patent Application Publication No. 9-297313 Publication No. 9-297313 Publication No. 2004-206091 Publication WO2017 / 047596

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

[0006] When preparing a liquid crystal alignment film using a liquid crystal aligning agent containing polyamic acid or polyimide, the baking process requires a particularly high temperature among the processes for manufacturing liquid crystal display elements. However, due to the recent trend toward reducing CO2 emissions and to prevent deterioration of the color characteristics of color filters used in liquid crystal display elements, lower baking temperatures are required. Furthermore, as liquid crystal display elements become larger and higher resolution, demands for the quality of liquid crystal display elements are becoming stricter. In particular, liquid crystal alignment films used in liquid crystal display elements using IPS driving methods or FFS driving methods require high liquid crystal alignment control properties (also known as liquid crystal alignment stability or liquid crystal alignment properties) to suppress image retention (also known as AC image retention) caused by long-term AC driving. Therefore, an object of the present invention is to provide a liquid crystal alignment film that exhibits high liquid crystal alignment stability even when baked at a low temperature during preparation. Another object is to provide a liquid crystal alignment treatment agent for preparing such a liquid crystal alignment film and a liquid crystal display element having such a liquid crystal alignment film.

[0007] As a result of intensive research into achieving the above-mentioned object, the present inventors have completed the present invention having the following gist: That is, a liquid crystal aligning agent containing at least one polymer (P) (also referred to as a specific polymer) selected from a polyimide precursor and a polyimide obtained by using a tetracarboxylic acid component containing at least one selected from tetracarboxylic acid dianhydrides of the following formula (1) and derivatives thereof (also referred to as a specific acid dianhydride), and a diamine component containing a diamine of the following formula (2) (also referred to as a specific diamine): (R １ ~R ４ each independently represents a hydrogen 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, or a phenyl group; R １ ~R ４ At least one of represents a group other than a hydrogen atom as defined above.) (R ２１ ~R ２４ each independently represents a hydrogen 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, or a phenyl group; R ２１ ~R ２４At least one of Ar represents a group other than a hydrogen atom as defined above. ２ and Ar ２’ each independently represents a divalent organic group of the following formula (2a): (n is an integer of 2, 4, or 6. * represents a bond, and the benzene ring bonded to * is unsubstituted, or one or more hydrogen atoms on the benzene ring are substituted with monovalent groups.) Throughout this specification, halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc. * represents a bond. Boc represents a tert-butoxycarbonyl group. "Tert-" can also be called "t-".

[0008] According to the present invention, it is possible to provide a liquid crystal display element that is less susceptible to AC image retention even when the baking process for preparing a liquid crystal alignment film is performed at a low temperature. Therefore, the liquid crystal display element of the present invention is suitable for use in in-plane switching drive devices such as IPS drive systems and FFS drive systems, and is used in smartphones, tablet terminals, etc. The mechanism by which the present invention provides a liquid crystal display element with the above-mentioned excellent properties is not necessarily clear, but is generally presumed to be as follows.

[0009] Typically, the amidocarboxylic acid groups or amidocarboxylic acid ester groups of polyimide precursors are converted to imide groups, which have strong interactions with liquid crystals, by baking at high temperatures. Therefore, when a liquid crystal alignment agent containing a polyimide precursor is baked at low temperatures, the proportion of imide groups in the liquid crystal alignment film decreases. In contrast, specific diamines have imide groups in their structure. Therefore, when a liquid crystal alignment agent containing a specific polymer is baked at low temperatures, the proportion of imide groups in the liquid crystal alignment film increases, increasing the interaction between the liquid crystal and the liquid crystal alignment film and making AC afterimages less likely to occur. When liquid crystal alignment treatment is performed by photoalignment, the use of specific acid dianhydrides can reduce the amount of radiation (light) exposure. This prevents excessive decomposition of the liquid crystal alignment film, maintains the interaction between the liquid crystal and the liquid crystal alignment film, and further prevents the generation of impurities that reduce the reliability of liquid crystal display elements.

[0010] 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.

[0011] <Specific Acid Dianhydride / Tetracarboxylic Acid Component> The specific acid dianhydride is an acid dianhydride represented by the formula [1]. １ ~R ４ are as defined above, and specific examples thereof include the following: １ ~R ４ In the formula (I), examples of the alkyl group having 1 to 6 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 an n-pentyl group. Examples of the alkenyl group having 2 to 6 carbon atoms include a vinyl group, a propenyl group, and a butenyl group, which may be linear or branched. Examples of the alkynyl group having 2 to 6 carbon atoms 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.

[0012] From the viewpoint of increasing the photoreactivity in the photo-alignment treatment of the liquid crystal alignment film, R １ and R ４ is a group other than a hydrogen atom, and R ２ and R ３ is preferably a hydrogen atom. １ ~R ４ are each independently a hydrogen atom or a methyl group, and R １ ~R ４ It is preferred that at least one of R is a methyl group. １ ~R ４ At least two of R are methyl groups. １ and R ４ is a methyl group, and R ２ and R ３is a hydrogen atom. Specific examples of the specific acid dianhydride include 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, and 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, and these are preferably used.

[0013] The proportion of the specific acid dianhydride used is preferably 10 mol% or more relative to 1 mol of the total tetracarboxylic acid components used in the specific polymer. More preferably, it is 20 mol% or more. Most preferably, it is 50 mol% or more. Furthermore, the specific acid dianhydride can be used alone or in combination of two or more depending on the properties. The polyimide polymer can use tetracarboxylic acid dianhydrides other than the specific acid dianhydride and their derivatives (collectively referred to as "other tetracarboxylic acid components") as the tetracarboxylic acid component, as long as the effects of the present invention are not impaired. Examples of other tetracarboxylic acid components include alicyclic tetracarboxylic acid dianhydrides, acyclic aliphatic tetracarboxylic acid dianhydrides, or aromatic tetracarboxylic acid dianhydrides other than the specific acid dianhydrides, and derivatives thereof.

[0014] Acyclic aliphatic tetracarboxylic acid dianhydrides are acid dianhydrides obtained by intramolecular dehydration of four carboxy groups bonded to a chain hydrocarbon structure. However, they do not need to be composed solely of a chain hydrocarbon structure and may partially contain an alicyclic structure or an aromatic ring structure. Alicyclic tetracarboxylic acid dianhydrides are acid dianhydrides 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 are bonded to an aromatic ring. Furthermore, they do not need to be composed solely of an alicyclic structure and may partially contain a chain hydrocarbon structure or an aromatic ring structure. Among these, from the viewpoint of liquid crystal alignment properties, tetracarboxylic acid dianhydrides having a cyclobutane ring structure, a cyclopentane ring structure, or a cyclohexane ring structure, or derivatives thereof, are preferred. Aromatic tetracarboxylic acid dianhydrides are acid dianhydrides obtained by intramolecular dehydration of four carboxy groups, including at least one carboxy group bonded to an aromatic ring. Among these, from the viewpoint of liquid crystal alignment, tetracarboxylic dianhydrides having a benzene ring structure or derivatives thereof are preferred.

[0015] Other tetracarboxylic acid components include the following tetracarboxylic acid dianhydrides and derivatives thereof. Specifically, 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 1,2,3,4-cyclobutane tetracarboxylic acid dianhydride, 1,3-difluoro-1,2,3,4-cyclobutane tetracarboxylic acid dianhydride, 1,3-bis(trifluoromethyl)-1,2,3,4-cyclobutane tetracarboxylic acid dianhydride, 1,2,3,4-cyclopentane tetracarboxylic acid dianhydride, 1,2,4,5-cyclohexane tetracarboxylic acid dianhydride, 3,3',4,4'-dicyclohexyl tetracarboxylic acid dianhydride, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 4-(2,5-dioxotetrahydrofuran-3-yl)tetrahydronaphthalene-1,2 -dicarboxylic acid anhydrides, alicyclic tetracarboxylic acid dianhydrides such as 5-(2,5-dioxotetrahydrofuran-3-yl)-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 5-(2,5-dioxotetrahydrofuran-3-yl)-8-methyl-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic acid dianhydride, bicyclo[2.2.2]octane-2,3,5,6-tetracarboxylic acid dianhydride, and 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-dianhydride;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'-bis(3,4-diphenyl)tetracarboxylic dianhydride aromatic tetracarboxylic acid dianhydrides such as 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 4,4'-(1,4-phenylenedioxy)bis(phthalic anhydride), and 4,4'-(1,4-phenylenedimethylene)bis(phthalic anhydride); and other tetracarboxylic acid dianhydrides such as those described in JP 2010-97188 A.

[0016] In the present invention, tetracarboxylic dianhydrides and derivatives thereof represented by the following formulae [CA1] to [CA26] can also be used.

[0017] The specific acid dianhydride and other tetracarboxylic acid components can be used alone or in combination of two or more depending on the respective properties. When other tetracarboxylic acid components are used in combination with the specific acid dianhydride, the proportion of the specific acid dianhydride used is preferably 95 mol% or less, more preferably 90 mol% or less, based on 1 mol of all tetracarboxylic acid components used in the specific polymer. The proportion of the other tetracarboxylic acid components used is preferably 5 to 90 mol%, more preferably 10 to 80 mol%, and particularly preferably 10 to 50 mol%, based on 1 mol of all tetracarboxylic acid components used in the specific polymer.

[0018] <Specific diamine / diamine component> The specific diamine is a diamine of the formula [2]. ２１ ~R ２４ , Ar ２and Ar ２’ are as defined above, and specific examples thereof include the following: ２１ ~R ２４ In the formula, examples of the alkyl group having 1 to 6 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 an n-pentyl group. Examples of the alkenyl group having 2 to 6 carbon atoms include a vinyl group, a propenyl group, and a butenyl group, which may be linear or branched. Examples of the alkynyl group having 2 to 6 carbon atoms 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. From the viewpoint of increasing the photoreactivity of the liquid crystal alignment film in the photo-alignment treatment, R ２１ and R ２４ is a group other than a hydrogen atom, and R ２２ and R ２３ is preferably a hydrogen atom. ２１ ~R ２４ are each independently a hydrogen atom or a methyl group, and R ２１ ~R ２４ It is preferred that at least one of R is a methyl group. ２１ ~R ２４ At least two of R are methyl groups. ２１ and R ２４ is a methyl group, and R ２２ and R ２３ is a hydrogen atom. ２ and Ar ２’ are each independently a divalent organic group of the formula (2a). In the formula (2a), one or more hydrogen atoms on the benzene ring bonded to * may be substituted with a monovalent group. Specific monovalent groups 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, or a nitro group. n is preferably an integer of 2 or 4. Of these, 2 is preferred.

[0019] From the viewpoint of suitably obtaining the effects of the present invention, the formula (2a) preferably has the structures of the following formulae (2a-1) to (2a-9).

[0020] (** indicates a bond.) Specific specific diamines include those of the following formulae (2-1) to (2-9), and it is preferable to use these.

[0021] The proportion of the specific diamine used is preferably 5 mol% or more relative to 1 mol of all diamine components used in the specific polymer. More preferably, it is 10 mol% or more. Most preferably, it is 15 mol% or more. It may also be 95 mol% or less relative to 1 mol of all diamine components used in the specific polymer. It may also be 90 mol% or 85 mol% or less. In addition, the specific diamine may be used alone or in a mixture of two or more types depending on the properties. Diamines other than the specific diamine (also referred to as other diamines) may be used as diamine components in the polyimide polymer as long as the effects of the present invention are not impaired. Specific examples of other diamines include 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; diaminobiphenyl compounds such as 4,4'-diaminobiphenyl, 2,2'-difluoro-4,4'-diaminobiphenyl, 3,3'-difluoro-4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 3,3'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 3,4'-diaminobiphenyl, 4,4'-diaminobiphenyl, 3,3'-diaminobiphenyl, 2,2'-diaminobiphenyl, and 2,3'-diaminobiphenyl; ＡＬ ) diamine (preferably represented by the following formula (dＡＬ -1) to (d ＡＬ -8) diamines, 1,7-bis(4-aminophenoxy)heptane, 1,7-bis(3-aminophenoxy)heptane, 1,8-bis(4-aminophenoxy)octane, 1,8-bis(3-aminophenoxy)octane, 1,9-bis(4-aminophenoxy)nonane, 1,9-bis(3-aminophenoxy)nonane, 1,10-bis(4-aminophenoxy)decane, 1,10-bis(3-aminophenoxy)decane 1,11-bis(4-aminophenoxy)undecane, 1,11-bis(3-aminophenoxy)undecane, 1,12-bis(4-aminophenoxy)dodecane, 1,12-bis(3-aminophenoxy)dodecane, 1,2-bis(6-amino-2-naphthyloxy)ethane, 1,2-bis(6-amino-2-naphthyl)ethane, or 6-[2-(4-aminophenoxy)ethoxy]-2-naphthylamine), 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 also collectively referred to as first diamines) .); 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 (however, specific diamines are excluded);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, such as aromatic diamines having a cinnamate structure, for example, 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 initiating 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-aminophenyl)propane N-(4-methylphenyl)propane, 4,4'-diaminobenzophenone; 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]-benzeneamine, or diamines of the following formulae (z-1) to (z-13), or 4,4'-diaminodiphenylamine, 4,4'-diaminodiphenyl-N-methylamine, diamines of 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 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; however, 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'-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-3,3'-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 diamines having a carboxy group such as 4-aminophenylethane-3,3'-dicarboxylic acid and 4,4'-diaminodiphenylether-3,3'-dicarboxylic acid; semi-aromatic diamines having a primary amino group and a secondary amino group (preferably 4-(2-(methylamino)ethyl)aniline) (here, semi-aromatic diamine refers to a diamine in which one amino group is bonded to an aromatic ring and the other amino group is not bonded to an aromatic ring); semi-aromatic diamines having two primary amino groups (preferably 4-(2-aminoethyl)aniline or 2-(6-amino-2-naphthyl)ethylamine); 1-(4-aminophenyl)-1,3,3-trimethyl-1H-indan-5-amine, 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-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) such as those of the following formulae (5-1) to (5-9); diamines having a steroid skeleton such as cholestanyloxy-3,5-diaminobenzene, cholestenyloxy-3,5-diaminobenzene, cholestanyloxy-2,4-diaminobenzene, cholestanyl 3,5-diaminobenzoate, cholestanyl 3,5-diaminobenzoate, lanostannyl 3,5-diaminobenzoate, and 3,6-bis(4-aminobenzoyloxy)cholestane; diamines of the following formulae (V-1) to (V-2); 2,7-diaminofluorene; or 9,9-bis(4-aminobenzoyloxy)cholestane. Examples of the diamine include aromatic diamines typified by diamines having a fluorene skeleton such as 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 any of the groups of formulas (Y-1) to (Y-167) described in WO2018 / 117239.

[0022] (Ar １ and Ar １’ each represents a cyclic group selected from a benzene ring, a biphenyl structure, or a naphthalene ring, and one or more hydrogen atoms on these cyclic groups 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, or a nitro 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 formed by inserting at least one of -O-, -C(=O)-O-, and -O-C(=O)- between the carbon-carbon bonds of the alkylene group, and any hydrogen atom possessed by A may be substituted with a halogen atom.

[0023]

[0024] (Formula (d ＡＬ In formula (d-1), k is an integer of 1 to 2. ＡＬ In formula (d-2), the sum of l, m, and n is an integer of 1 to 12. ＡＬ In formula (d-5), the sum of m1, m2 and n is an integer of 1 to 12. ＡＬ In formula (d-7), the sum of m1, m2 and n is an integer of 3 to 12. ＡＬ In formula (d-8), the sum of l, m, and n is an integer of 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 are those listed above in A ｒ１ and A ｒ１’ Examples of the monovalent groups include those exemplified in

[0025]

[0026]

[0027] (In formula (V-1), m and n are integers of 0 to 3, and satisfy the condition 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—. １represents 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 ２ m, n, and X represent —OCO—, —COO—, or —OCO—. １ and R １ When two are present, each independently has the above definition.) Examples of the nitrogen atom-containing heterocycle in the diamine having a specific nitrogen atom-containing structure 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.

[0028] From the viewpoint of making AC afterimages less likely to occur, it is preferable to use a diamine selected from 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 the group "-N(D)-". It is more preferable to use a diamine selected from the first diamine and a diamine having a tetracarboxylic diimide structure. In the present invention, diamines of the following formulas [DA-1] to [DA-103] can also be used.

[0029]

[0030]

[0031]

[0032]

[0033] The proportion of the other diamine used is preferably 5 mol% or more relative to 1 mol of all diamine components used in the specific polymer. More preferably, it is 10 mol% or more. Most preferably, it is 15 mol% or more. Furthermore, the proportion is preferably 95 mol% or less relative to 1 mol of all diamine components used in the specific polymer. More preferably, it is 90 mol% or less. Most preferably, it is 85 mol% or less. In addition, the other diamines can be used alone or in combination of two or more types depending on the properties.

[0034] <Specific Polymer> The specific polymer is at least one polymer (P) selected from polyimide precursors and polyimides (collectively referred to as polyimide polymers) obtained using a tetracarboxylic acid component containing a specific acid dianhydride and a diamine component containing a specific diamine. The polyimide precursor is preferably a polyamic acid or polyamic acid ester having a structure of the following formula [A]: (R ａ represents a tetravalent organic group. ｂ represents a divalent organic group. １ and A ２ represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and may be the same or different. ３ and A ４ represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an acetyl group, and may be the same or different. n represents a positive integer.

[0035] Polyimide has a structure of the following formula [A-4] and can be obtained by ring-closing (also called imidization) a polyamic acid of a polyimide precursor. In this case, if the ring-closure rate (also called imidization rate) of the amic acid group is less than 100%, the polyimide contains at least one of the structures of the following formulas [A-1] to [A-3] in addition to the structure of formula [A-4].

[0036] (R ａ , R ｂ , A １ ~A ４is defined as in formula [A].) The diamine component is a diamine having two primary or secondary amino groups in the molecule, and examples of the tetracarboxylic acid component include a tetracarboxylic acid compound, a tetracarboxylic acid dianhydride, a tetracarboxylic acid dihalide compound, a tetracarboxylic acid dialkyl ester compound, and a tetracarboxylic acid dialkyl ester dihalide compound. The polyimide polymer is preferably a polyamic acid having a structural formula of a repeating unit of formula [D] below, or a polyimide obtained by imidizing the polyamic acid, because it can be obtained relatively easily by using a tetracarboxylic acid dianhydride of formula [B] below and a diamine of formula [C] below as raw materials.

[0037] (R ａ and R ｂ has the same meaning as defined in the above formula [A]. (R ａ and R ｂ is the same as defined in the formula [A].) In addition, by a conventional synthesis method, A of the formula [A] can be added to the polymer of the formula [D]. １ and A ２ and A in formula [A] ３ and A ４ It is also possible to introduce an alkyl group having 1 to 5 carbon atoms or an acetyl group.

[0038] The method for synthesizing a polyimide polymer is not particularly limited. It is typically obtained by reacting a diamine component with a tetracarboxylic acid component. Specifically, the method described on pages 35-36 of International Publication WO 2015 / 012368 (published January 29, 2015) is exemplified. Polyamic acid esters can be synthesized by known methods, such as reacting a polyamic acid of a polyimide precursor obtained by reacting a diamine component with a tetracarboxylic acid component with an esterifying agent, reacting the tetracarboxylic acid diester with a diamine, or reacting the tetracarboxylic acid diester with a dihalide. The reaction between the diamine component and the tetracarboxylic acid component is typically carried out in a solvent containing the diamine component and the tetracarboxylic acid component. The solvent used is not particularly limited as long as it dissolves the resulting polyimide precursor. Specific examples of the solvent include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, and 1,3-dimethyl-imidazolidinone. When the polyimide precursor has high solvent solubility, methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, or the solvents represented by the following formulas [D1] to [D3] can be used.

[0039] (D １ and D ２ represents an alkyl group having 1 to 3 carbon atoms. ３ represents an alkyl group having 1 to 4 carbon atoms.) These may be used alone or in combination. Furthermore, even if the solvent does not dissolve the polyimide precursor, it may be mixed with the solvent to the extent that it does not precipitate. Furthermore, since moisture in the solvent inhibits the polymerization reaction and may even cause hydrolysis of the polyimide precursor, it is preferable to use a solvent that has been dehydrated and dried.

[0040] In the polymerization reaction of the polyimide precursor, the total number of moles of the tetracarboxylic acid components is preferably 0.8 to 1.2 when the total number of moles of the diamine components is 1.0. When the total number of moles of the tetracarboxylic acid components is less than 1.0, i.e., when the total number of moles of the tetracarboxylic acid components is smaller than the number of moles of the diamine components, the polymer will have an amino group structure at its terminal. When the total number of moles of the tetracarboxylic acid components is greater than 1.0, i.e., when the total number of moles of the tetracarboxylic acid components is greater than the number of moles of the diamine components, the polymer will have a carboxylic anhydride or dicarboxylic acid structure at its terminal. Polyimides are obtained by ring-closing a polyimide precursor, and the imidization rate does not necessarily need to be 100% and can be adjusted as desired depending on the application and purpose. From the viewpoint of solubility in solvents, a ratio of 40 to 90% is preferred. A ratio of 50 to 80% is even more preferred.

[0041] The polyimide polymer may be converted into a terminal-capped polymer using a terminal-capping agent. Terminal-capping polymers have the effect of increasing the film hardness of resin coatings and liquid crystal alignment films, and improving the adhesion between the liquid crystal alignment film and the sealant in liquid crystal display elements. The method for obtaining the terminal-capped polymer is not particularly limited. Specific examples include the method described on pages 24 and 25 of International Publication WO2023 / 074568 (published May 4, 2023). In this case, the proportion of the terminal-capping agent used is preferably 0.01 to 20 mol parts per 100 mol parts of all diamine components. A ratio of 0.01 to 10 mol parts is more preferred. From the viewpoints of the strength of the resin coating film or liquid crystal alignment film obtained therefrom, workability during film formation, and coating properties, the molecular weight of the polyimide polymer is preferably 5,000 to 1,000,000, more preferably 10,000 to 150,000, in terms of Mw (weight average molecular weight) measured by GPC (Gel Permeation Chromatography).

[0042] <Liquid Crystal Alignment Agent> The liquid crystal alignment agent is a solution for forming a liquid crystal alignment film, and is a solution containing a specific polymer and a solvent. In this case, two or more types of specific polymers can be used. The polymer components do not all have to be specific polymers, and polyimide-based polymers that do not use specific acid dianhydrides or specific diamines, or polymers other than polyimide-based polymers, may be mixed. Specific examples include polysiloxane, polyester, polyamide, polyurea, polyorganosiloxane, cellulose derivatives, polyacetal, polystyrene derivatives, poly(styrene-maleic anhydride) copolymers, poly(isobutylene-maleic anhydride) copolymers, poly(vinyl ether-maleic anhydride) copolymers, poly(styrene-phenylmaleimide) derivatives, and poly(meth)acrylates. Specific examples of poly(styrene-maleic anhydride) copolymers include SMA1000, SMA2000, and SMA3000 (manufactured by Cray Valley Corporation), and GSM301 (manufactured by Gifu Ceramics Manufacturing Co., Ltd.). Specific examples of poly(isobutylene-maleic anhydride) copolymers include ISOBAM-600 (manufactured by Kuraray Co., Ltd.). Specific examples of poly(vinyl ether-maleic anhydride) copolymers include Gantrez AN-139 (methyl vinyl ether maleic anhydride resin, manufactured by Ashland Corporation).

[0043] In the present invention, when a specific polymer and other polymers are used as polymer components, the other polymer is preferably a polyimide-based polymer (also referred to as other polyimide-based polymer) that does not use a specific acid dianhydride or a specific diamine, from the viewpoint of the electrical characteristics of the liquid crystal display element (suppressing DC-induced image retention). The tetracarboxylic acid component used in this case can be the tetracarboxylic acid component described above. Specific examples include acyclic aliphatic tetracarboxylic acid dianhydrides, alicyclic tetracarboxylic acid dianhydrides, aromatic tetracarboxylic acid dianhydrides, or derivatives thereof. More specific examples include tetracarboxylic acid dianhydrides or derivatives thereof having at least one partial structure selected from a benzene ring, a cyclobutane ring, a cyclopentane ring, and a cyclohexane ring, and these are preferred. The proportion of these tetracarboxylic acid components used is preferably 10 mol% or more, more preferably 20 mol% or more, and most preferably 50 mol% or more, based on 1 mol of the total tetracarboxylic acid components used in the other polyimide-based polymer. Furthermore, these tetracarboxylic acid components can be used alone or in combination depending on the respective properties.

[0044] The diamine component may be any of the diamine components described above, including 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)propane, 2,2-bis(3-amino-4-methylphenyl)propane, 4,4′-diaminobenzophenone, the diamine having the specific nitrogen atom-containing structure, the diamine having a carboxy group, a semi-aromatic diamine having a primary amino group and a secondary amino group, and 4-(2-aminoethyl)aniline. The proportion of these diamine components used is preferably 10 mol% or more relative to 1 mol of all diamine components used in other polyimide-based polymers. More preferably, it is 20 mol% or more. Furthermore, the proportion is preferably 90 mol% or less relative to 1 mol of all diamine components used in other polyimide-based polymers. More preferably, it is 80 mol% or less. In addition, these diamine components can be used alone or in combination of two or more depending on the properties. When a specific polymer and other polymers are used as polymer components, the proportion of the other polymers used is preferably 90 parts by mass or less relative to 100 parts by mass of all polymers contained in the liquid crystal aligning agent. More preferably, it is 10 to 90 parts by mass. Most preferably, it is 20 to 80 parts by mass.

[0045] The content of the solvent in the liquid crystal aligning agent can be appropriately selected from the viewpoint of the application method and obtaining the desired film thickness of the liquid crystal alignment film. In particular, from the viewpoint of forming a uniform liquid crystal alignment film by application, the content of the solvent in the liquid crystal aligning agent is preferably 50 to 99.9 mass %, more preferably 60 to 99 mass %, and particularly preferably 65 to 99 mass %. The solvent used in the liquid crystal aligning agent is not particularly limited as long as it is a solvent that can dissolve the specific polymer. In particular, it is preferable to use the following solvents (also referred to as solvent type A): For example, 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, Examples of suitable solvents include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 3-butoxy-N,N-dimethylpropanamide, 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. These may be used alone or in combination of two or more.

[0046] When the specific polymer has high solubility in the solvent, the following solvent (also referred to as solvent type B) can be used. For example, diisopropyl ether, diisobutyl ether, diisobutyl carbinol (2,6-dimethyl-4-heptanol), ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, 1,2-dibutoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, 4-hydroxy-4-methyl-2-pentanone, diethylene glycol methyl ethyl ether, diethylene glycol dibutyl ether, 3-ethoxybutyl acetate, 1-methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, ethylene glycol monoacetate, ethylene glycol diacetate, propylene carbonate, ethylene carbonate, ethylene glycol monobutyl ether, ethylene glycol monoisoamyl ether, ethylene glycol monohexyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, 1-(2-butoxyethoxy)-2-propanol, 2- (2-butoxyethoxy)-1-propanol, propylene glycol monomethyl ether acetate, 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 Examples of suitable lactones include glycerin 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, and diisobutyl ketone (2,6-dimethyl-4-heptanone).Among 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 are preferably used. These may be used alone or in combination of two or more.

[0047] In the present invention, from the viewpoint of the coating properties of the liquid crystal alignment film, it is preferable to use a solvent that is a combination of Solvent A and Solvent B. Specifically, N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone and ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone and propylene glycol monobutyl ether, N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether, N-ethyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone, N-ethyl-2-pyrrolidone and propylene glycol diacetate, N,N-diphenyl ether, N-methyl-2-pyrrolidone and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone and γ-butyrolact ...methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone and γ-butyrolact Methyl lactamide and diisobutyl ketone, N-methyl-2-pyrrolidone and ethyl 3-ethoxypropionate, N-ethyl-2-pyrrolidone and ethyl 3-ethoxypropionate, N-methyl-2-pyrrolidone, ethyl 3-ethoxypropionate and dipropylene glycol monomethyl ether, N-ethyl-2-pyrrolidone, ethyl 3-ethoxypropionate and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone, ethyl 3-ethoxypropionate and diethylene glycol monopropyl ether, N -Ethyl-2-pyrrolidone, ethyl 3-ethoxypropionate, and diethylene glycol monopropyl ether, N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether acetate, N-ethyl-2-pyrrolidone and dipropylene glycol dimethyl ether, N,N-dimethyl lactamide and ethylene glycol monobutyl ether, N,N-dimethyl lactamide and propylene glycol diacetate, N-ethyl-2-pyrrolidone and diethylene glycol diethyl ether, N-ethyl-2-pyrrolidone N-methyl-2-pyrrolidone, diethylene glycol monomethyl 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 of the combination 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, and combinations of these are preferred.

[0048] When solvents A and B are used in combination, solvent B preferably accounts for 1 to 80% by mass of the total solvent contained in the liquid crystal aligning agent. More preferably, it is 10 to 80% by mass. Most preferably, it is 20 to 70% by mass. In order to increase the film strength of the liquid crystal alignment film, the liquid crystal aligning agent preferably incorporates a compound having at least one selected from an epoxy group, an oxetanyl group, an oxazoline group, a cyclocarbonate group, a blocked isocyanate group, a hydroxy group, and an alkoxy group, and further a compound having a polymerizable unsaturated group (collectively referred to as a crosslinkable compound). In this case, the compound must contain two or more of these groups.

[0049] Specific examples of crosslinkable compounds having an epoxy group include those described in paragraph

[0079] of International Publication WO2023 / 068085, paragraph

[0037] of Japanese Patent Publication JP-A-10-338880, and paragraphs

[0051] to

[0054] of International Publication WO2017 / 170483. Specific examples of crosslinkable compounds having an oxetanyl group include those described in paragraph

[0079] of International Publication WO2023 / 068085 and paragraphs

[0170] to

[0175] of International Publication WO2011 / 132751. Specific examples of crosslinkable compounds having an oxazoline group include those described in paragraph

[0079] of International Publication WO2023 / 068085 and paragraph

[0115] of Japanese Patent Publication JP-A-2007-286597. Specific examples of the crosslinkable compound having a cyclocarbonate group include those described in paragraph

[0079] of International Publication WO2023 / 068085 and paragraphs

[0025] to

[0030] and paragraph

[0032] of International Publication WO2011 / 155577. Specific examples of the crosslinkable compound having a blocked isocyanate group include those described in paragraph

[0079] of International Publication WO2023 / 068085 and paragraphs

[0119] to

[0120] of International Publication WO2015 / 141598. Specific examples of crosslinkable compounds having a hydroxy group and an alkoxy group include those described in paragraph

[0079] of International Publication WO2023 / 068085, paragraph

[0058] of Japanese Patent Publication No. 2016-118753, paragraph

[0055] of Japanese Patent Publication No. 2016-200798, and paragraphs

[0017] to

[0029] of International Publication WO2010 / 074269. Specific examples of crosslinkable compounds having a polymerizable unsaturated group include those described in paragraph

[0079] of International Publication WO2023 / 068085.

[0050] The proportion of the crosslinkable compound used in the liquid crystal aligning agent is preferably 0.1 to 100 parts by mass relative to 100 parts by mass of all polymer components. From the viewpoint of promoting the crosslinking reaction and achieving the desired effect, a proportion of 0.1 to 50 parts by mass is more preferred. A proportion of 1 to 30 parts by mass is particularly preferred. A compound that promotes the imidization of a specific polymer can be used as the liquid crystal aligning agent. Specific examples include compounds for promoting imidization represented by formulas [B-1] to [B-17] described on pages 48 to 49 of International Publication WO 2022 / 176680 (published August 25, 2022), and these are preferred. The proportion of the crosslinkable compound used is preferably 0.1 to 20 parts by mass relative to 100 parts by mass of all polymer components. A proportion of 1 to 20 parts by mass is more preferred. A proportion of 5 to 15 parts by mass is particularly preferred.

[0051] As long as the effects of the present invention are not impaired, the liquid crystal aligning agent can be a compound that improves the uniformity of the film thickness and surface smoothness of the liquid crystal alignment film, or a compound that improves the adhesion between the liquid crystal alignment film and the substrate. Examples of compounds that improve the uniformity of the film thickness and surface smoothness of the liquid crystal alignment film include fluorine-based surfactants, silicone-based surfactants, and nonionic surfactants. Specific examples include the surfactants described on page 67 of International Publication WO2014 / 171493 (published October 23, 2014). The amount used is preferably 0.01 to 2 parts by mass, more preferably 0.01 to 1 part by mass, based on 100 parts by mass of all polymer components. Specific examples of compounds that improve the adhesion between the liquid crystal alignment film and the substrate include the compounds described on pages 67 to 69 of International Publication WO2014 / 171493 (published October 23, 2014). The amount used is preferably 0.1 to 30 parts by mass, based on 100 parts by mass of all polymer components. The amount is more preferably 1 to 20 parts by mass. In addition to the compounds other than those mentioned above, the liquid crystal aligning agent may contain a dielectric or conductive substance for the purpose of changing the electrical properties such as the dielectric constant and conductivity of the liquid crystal alignment film.

[0052] <Liquid Crystal Alignment Film / Liquid Crystal Display Element> A liquid crystal display element can be manufactured by, for example, the following method: a method including 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 (2) and (4), a method including steps (1) to (3), (4) and (5), or a method including steps (1) to (3), (4) and (6). <Step (1): Applying a Liquid Crystal Alignment Agent to At Least One of the First Substrate and the Second Substrate> Step (1) is a step of applying a liquid crystal alignment agent to a substrate. Specific examples are as follows. That is, the liquid crystal alignment agent is applied to one surface of a substrate having a patterned transparent conductive film by a coating 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 a reflective liquid crystal display element, an opaque substrate such as a silicon wafer can be used for only one of the substrates, and in this case, a light-reflecting material such as aluminum can be used for the electrode.

[0053] When manufacturing a liquid crystal display element of an IPS drive system or an FFS drive system, a substrate provided with an electrode made of a transparent conductive film or a metal film patterned into a comb-tooth shape and an opposing substrate without an electrode are used. The transparent conductive film is formed by a known method using indium tin oxide (ITO), indium zinc oxide (IZO), or a mixture thereof. Methods for applying the liquid crystal alignment agent to the substrate include screen printing, offset printing, flexographic printing, an inkjet method, and a spray method. Among these, the inkjet method is preferred in the present invention.

[0054] <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 liquid crystal alignment film. Specifically, the process is as follows. That is, after the liquid crystal alignment agent is applied to the substrate in step (1), the substrate is baked using a heating means such as a hot plate, a heat circulation oven, or an IR (infrared) oven (this process is also referred to as the baking step) to evaporate the solvent and thermally imidize the polyamic acid or polyamic acid ester. The temperature and time of the baking step can be selected as desired, and the baking step may be repeated multiple times. The baking step temperature is preferably 30 to 230°C, more preferably 30 to 200°C. To reduce the residual solvent in the liquid crystal alignment film, a temperature of 40 to 150°C or 40 to 120°C may also be used. The baking time is not particularly limited, but may be 1 to 10 minutes or 1 to 5 minutes. When thermally imidizing a polyimide precursor such as polyamic acid or polyamic acid ester, an additional baking step (also referred to as a "main baking step") may be performed after the baking step. The temperature is preferably 150 to 230°C, more preferably 150 to 200°C, particularly preferably 160 to 200°C, and most preferably 160 to 190°C. The baking time for the main baking step is not particularly limited, but may be 5 to 40 minutes or 5 to 30 minutes. Alternatively, the main baking step may be omitted in step (2), and the main baking step or step (3b) may be performed after step (3) below. The thickness of the liquid crystal alignment film after baking is preferably 5 to 300 nm, because if it is too thick, it will be disadvantageous in terms of power consumption of the liquid crystal display element, and if it is too thin, it may reduce the reliability of the element. Therefore, a thickness of 10 to 200 nm is more preferable.

[0055] <Step (3): Step of Aligning the Liquid Crystal Alignment Film Obtained in Step (2)> Step (3) is a step of aligning the liquid crystal alignment film obtained in Step (2). In horizontal electric field drive type liquid crystal display elements such as IPS drive type and FFS drive type, as described above, alignment treatments such as rubbing treatment and photo-alignment treatment are performed on the liquid crystal alignment film to horizontally align the liquid crystal. In the present invention, photo-alignment treatment is preferred. In contrast, vertical electric field drive type liquid crystal display elements such as VA (Vertical Alignment) drive type and PSA (Polymer Sustained Alignment) drive type do not require alignment treatment. Rubbing treatment is a process in which the liquid crystal alignment film is rubbed in a certain direction with a roll wrapped with a cloth made of fibers such as nylon, rayon, or cotton. Examples of photo-alignment treatment include a method in which the surface of the liquid crystal alignment film is irradiated with polarized radiation in a certain direction to regulate the alignment of the liquid crystal (also referred to as imparting liquid crystal alignment property or liquid crystal alignment ability). The radiation may be ultraviolet light or visible light having a wavelength of 100 to 800 nm. Of these, ultraviolet light having a wavelength of 100 to 400 nm is preferred. Ultraviolet light having a wavelength of 200 to 400 nm is more preferred. The radiation dose is 1 to 10,000 mJ / cm. ２ More preferably, it is 100 to 1,000 mJ / cm ２ Particularly preferred is 100 to 500 mJ / cm ２ Furthermore, when the radiation is polarized, it may be linearly polarized or partially polarized. When the radiation is linearly polarized or partially polarized, the radiation may be applied from a direction perpendicular to the liquid crystal alignment film surface, from an oblique direction, or a combination of these. When applying unpolarized radiation, the radiation direction is preferably oblique to the liquid crystal alignment film surface. When applying radiation, it is preferable to apply radiation while heating the liquid crystal alignment film-coated substrate at 50 to 250°C in order to increase the stability of the liquid crystal alignment. This allows the liquid crystals to be stably aligned in a fixed direction.

[0056] <Step (3b): Step of performing heat treatment> The liquid crystal alignment film irradiated with the radiation plug in step (3) can be subjected to heat treatment. The temperature at this time is preferably 50 to 250°C, more preferably 120 to 230°C. The time for the heat treatment is preferably 1 to 30 minutes.

[0057] <Step (4): A step of preparing a liquid crystal cell (liquid crystal display element) by disposing a liquid crystal layer between the first substrate and the second substrate so as to be adjacent to the alignment-treated liquid crystal alignment film> Step (4) is a step of preparing a liquid crystal cell by disposing a liquid crystal layer between the first substrate and the second substrate so as to be adjacent to the alignment-treated liquid crystal alignment film. An example in which a liquid crystal alignment film is formed on each of the first substrate and the second substrate is shown below. In the first method, first, two substrates are arranged opposite each other with a gap (also called a cell gap) between them so that the liquid crystal alignment films face each other. Next, the peripheries of the two substrates are bonded together using a sealant, and a liquid crystal composition is injected into the substrate surfaces and the cell gap defined by the sealant. After contacting the liquid crystal alignment film surface, the injection hole is sealed.

[0058] The second method is called the ODF (One Drop Fill) method. 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. 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. The entire surface of the substrate is then irradiated with UV light to cure the sealant. In both the first and second methods, it is desirable to heat the substrate to a temperature at which the liquid crystal composition assumes an isotropic phase and then slowly cool it to room temperature to remove the flow alignment that occurred during filling with the liquid crystal composition. When a rubbing treatment is performed, the two substrates are positioned opposite each other so that the rubbing directions of the liquid crystal alignment films are at a predetermined angle to each other, e.g., perpendicular or antiparallel. The sealant can be an epoxy resin containing a curing agent and aluminum oxide spheres as spacers.

[0059] The liquid crystal composition is not particularly limited, and various liquid crystal compositions containing at least one liquid crystal compound (liquid crystal molecule) and having positive or negative dielectric anisotropy can be used. In the following, a liquid crystal composition with positive dielectric anisotropy is also referred to as a positive liquid crystal, and a liquid crystal composition with negative dielectric anisotropy is also referred to as a negative liquid crystal. 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) exhibiting liquid crystallinity within the molecule (e.g., a bimesogenic compound in which two rigid biphenyl or terphenyl structures are connected by an alkylene group). 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. The liquid crystal composition may contain additives from the viewpoint of improving the liquid crystal alignment property, such as photopolymerizable monomers having a polymerizable group, optically active compounds (e.g., S-811 manufactured by Merck Ltd.), antioxidants, ultraviolet absorbers, dyes, antifoaming agents, polymerization initiators, or polymerization inhibitors.

[0060] Examples of positive liquid crystals include ZLI-2293, ZLI-4792, MLC-2003, MLC-2041, MLC-3019, and MLC-7081 manufactured by Merck & Co.; and PA-1492 manufactured by DIC Corporation. Examples of negative liquid crystals include MLC-6608, MLC-6609, MLC-6610, and MLC-7026-100 manufactured by Merck & Co., Ltd. Examples of liquid crystals containing a compound having a polymerizable group include MLC-3023 manufactured by Merck & Co., Ltd. The liquid crystal aligning agent can also be used in a liquid crystal display element (PSA-type liquid crystal display element) manufactured through a process comprising: a liquid crystal layer between a pair of substrates equipped with electrodes; disposing a liquid crystal composition between the pair of substrates and including a polymerizable compound that polymerizes by at least one of active energy rays and heat; and polymerizing the polymerizable compound by at least one of irradiation with active energy rays and heating while applying a voltage between the electrodes (hereinafter, this process is also referred to as process (5)). The liquid crystal aligning agent can also be used in a liquid crystal display element (SC-PVA type liquid crystal display element) manufactured through a step of: having a liquid crystal layer between a pair of substrates each having an electrode; disposing a liquid crystal alignment film between the pair of substrates, the liquid crystal alignment film containing a polymerizable group that is polymerized by at least one of active energy rays and heat; and applying a voltage between the electrodes (hereinafter, this step may also be referred to as step (6)).

[0061] If necessary, a polarizing plate can be attached to the outer surface of the liquid crystal cell obtained as described above. Examples of polarizing plates to be attached to the outer surface of the liquid crystal cell include a polarizing plate in which a polarizing film called an "H film" made by absorbing iodine while stretching and aligning polyvinyl alcohol is sandwiched between cellulose acetate protective films, or an H film polarizing plate. An IPS substrate, which is a comb-shaped electrode substrate used in an IPS driving system, has a substrate, a plurality of linear electrodes formed on the substrate and arranged in a comb-like pattern, and a liquid crystal alignment film formed on the substrate so as to cover the linear electrodes. An FFS substrate, which is a comb-shaped electrode substrate used in an FFS system, has a substrate, a surface electrode formed on the substrate, an insulating film formed on the surface electrode, a plurality of linear electrodes formed on the insulating film and arranged in a comb-like pattern, and a liquid crystal alignment film formed on the insulating film so as to cover the linear electrodes.

[0062] FIG. 1 is a schematic cross-sectional view showing an example of an in-plane switching mode liquid crystal display element of the present invention, which is an example of an IPS-driven liquid crystal display element. The in-plane switching mode liquid crystal display element 1 shown in FIG. 1 has liquid crystal 3 sandwiched between a comb-shaped electrode substrate 2 having a liquid crystal alignment film 2c and a counter substrate 4 having a liquid crystal alignment film 4a. The comb-shaped electrode substrate 2 has a substrate 2a, a plurality of linear electrodes 2b formed on the substrate 2a and arranged in a comb-like pattern, and a liquid crystal alignment film 2c formed on the substrate 2a so as to cover the linear electrodes 2b. The counter substrate 4 has a substrate 4b and a liquid crystal alignment film 4a formed on the substrate 4b. The liquid crystal alignment film 2c is, 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. In this in-plane switching 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 field lines L. FIG. 2 is a schematic cross-sectional view showing another example of a liquid crystal display element of the in-plane switching driving type, which is an example of a liquid crystal display element of the FFS driving system.

[0063] The in-plane switching liquid crystal display element 1 illustrated in FIG. 2 has a liquid crystal 3 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 includes a substrate 2d, a surface electrode 2e formed on the substrate 2d, an insulating film 2f formed on the surface electrode 2e, a plurality of linear electrodes 2g formed on the insulating film 2f and arranged in a comb-like pattern, and a liquid crystal alignment film 2h formed on the insulating film 2f to cover the linear electrodes 2g. The counter substrate 4 includes a substrate 4b and a liquid crystal alignment film 4a formed on the substrate 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. When a voltage is applied to the surface electrodes 2e and the linear electrodes 2g in this in-plane switching liquid crystal display element 1, an electric field is generated between the surface electrodes 2e and the linear electrodes 2g, as indicated by electric field lines L. The liquid crystal display element of the present invention can be effectively applied to a variety of devices. For example, it can be used in 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.

[0064] The liquid crystal alignment film of the present invention can be used for applications other than those mentioned above. For example, it can be used 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, it can 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 an insulating film for an electric motor (e.g., a gate insulating film for a flexible display).

[0065] The present invention will be described in more detail below with reference to examples, but is not limited to these. The abbreviations used in the synthesis examples, examples, and comparative examples, and the methods for measuring each physical property are as follows. <Solvent> NMP: N-methyl-2-pyrrolidone BCS: Ethylene glycol monobutyl ether

[0066] <Specific diamine> A1: specific diamine of the following formula [A1]

[0067] <Other diamines> B1 to B6: Diamines of the following formulas [B1] to [B11]

[0068]

[0069] <Specific Acid Dianhydride> C1: Tetracarboxylic acid dianhydride represented by the following formula [C1]

[0070] <Other tetracarboxylic acid components> D1 and D2: tetracarboxylic acid dianhydrides of the following formulas [D1] and [D2]

[0071] <Compounds that improve adhesion between a liquid crystal alignment film and a substrate> F1: a compound of the following formula [F1] F2: a compound of the following formula [F2]

[0072] "Viscosity Measurement" Measurement was carried out using an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.) at a temperature of 25°C, a sample volume of 1.1 mL, and a cone rotor TE-1 (1°34', R24). "Synthesis of specific diamine" The specific diamine [A1] is a novel compound not previously disclosed in literature, and its synthesis method is shown in Example 1. Boc represents a tert-butoxycarbonyl group. The compound and the specific diamine [A1] are １ The compound was identified by H-NMR analysis. 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)

[0073] Example 1: Synthesis of specific diamine [A1] Under a nitrogen atmosphere, 2-(4-nitrophenoxy)ethyl methanesulfonate (22.9 g, 87.6 mmol), tert-butyl(4-hydroxy-2-methylphenyl)carbamate (21.5 g, 96.3 mmol), potassium carbonate (30.2 g, 219 mmol), and DMF (170 g) were placed in a 500 mL four-neck flask and stirred at 100° C. After completion of the reaction, methanol (350 g) and purified water (350 g) were added and stirred, and the resulting crystals were filtered off and dried under reduced pressure to obtain compound (1-1) (25.9 g, 66.7 mmol, yield: 76%, brown solid). １ H-NMR (500MHz, DMSO-d ６ ): δ (ppm) = 8.35 (s, 1H), 8.21 (d, 2H), 7.20 (d, 2H), 7.13 (d, 1H), 6.81 (s , 1H), 6.75 (d, 1H), 4.46 (d, 2H), 4.31 (d, 2H), 2.15 (s, 3H), 1.44 (s, 9H).

[0074] Under a nitrogen atmosphere, compound (1-1) (25.9 g, 66.7 mmol), tetrahydrofuran (520 g), and carbon-supported palladium (5% Pd carbon powder (50% water content) K type, manufactured by N.E. Chemcat Corporation) (2.59 g) were placed in a 1000 mL four-neck flask, and after replacing the atmosphere with hydrogen, the reaction was carried out at normal pressure and temperature. After completion of the reaction, the carbon-supported palladium was removed by filtration, and the obtained filtrate was concentrated. Isopropyl alcohol (100 g) was added to the obtained crude product, and the crystals were filtered off and dried to obtain compound (1-2) (20.2 g, 56.3 mmol, yield: 84%, pink-white solid). １ H-NMR (500MHz, DMSO-d ６ ): δ (ppm) = 8.33 (s, 1H), 7.11 (d, 1H), 6.79 (d, 1H), 6.74-6.68 (m, 3H), 6.51 (d, 2H), 4.60 (s, 2H), 4.18 (t, 2H), 4.12 (t, 2H), 2.15 (s, 3H), 1.44 (s, 9H).

[0075] Under a nitrogen atmosphere, compound (1-2) (18.5 g, 51.6 mmol), C1 (5.65 g, 25.2 mmol), and NMP (130 g) were added to a 500 mL four-neck flask and stirred at room temperature for 4 hours. Then, pyridine (11.9 g, 150 mmol) and acetic anhydride (7.70 g, 75.4 mmol) were added, and the mixture was heated to 60°C and stirred. After completion of the reaction, the precipitated crystals were filtered off and washed with methanol (500 g). The resulting solid was dried to obtain compound (1-3) (22.4 g, 24.8 mmol, yield: 98%, white solid). １ H-NMR (500MHz, DMSO-d ６ ): δ (ppm) = 8.36 (s, 2H), 7.34 (d, 4H), 7.15-7.13 (m, 6H), 6.83-6.76 (m, 4H) , 4.36 (d, 4H), 4.30 (d, 4H), 3.53 (s, 2H), 2.16 (s, 6H), 1.44-1.31 (m, 24H).

[0076] Under a nitrogen atmosphere, compound (1-3) (20.6 g, 22.8 mmol), ethyl acetate (400 g), and 12 N hydrochloric acid (11.4 mL, 137 mmol) were added to a 1000 mL four-neck flask and stirred at 60°C. The resulting solid was filtered off and transferred to another 1000 mL four-neck flask, followed by the addition of purified water (200 g) and triethylamine (11.5 g, 114 mmol) and stirring at room temperature. The resulting crystals were filtered off, and the cake was washed with purified water (200 g). The resulting solid was dried to obtain specific diamine [A1] (12.0 g, 17.0 mmol, yield: 75%, pink-white solid). １ H-NMR (500MHz, DMSO-d ６ ): δ (ppm) = 7.33 (d, 4H), 7.12 (d, 4H), 6.65-6.56 (m, 6H), 4.67 (s, 4H), 4.30 (d, 4H), 4.19 (d, 4H), 3.53 (s, 2H), 2.05 (s, 6H), 1.39 (s, 6H).

[0077] "Synthesis of Polyimide-Based Polymer" Example 2 A1 (3.52 g, 5.00 mmol) and NMP (31.7 g) were placed in a 50 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and dissolved by stirring at 23° C. while supplying nitrogen. Thereafter, C1 (0.998 g, 4.45 mmol) and NMP (1.44 g) were added under ice cooling, and the mixture was stirred at 40° C. for 12 hours, yielding a polyamic acid solution (PAA-1) (viscosity: 712 mPa s) with a solids concentration of 12% by mass.

[0078] Example 3 A 50 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube was charged with A1 (1.90 g, 2.70 mmol), B2 (0.195 g, 1.80 mmol), B3 (0.660 g, 2.70 mmol), B4 (0.717 g, 1.80 mmol), and NMP (31.3 g), and dissolved by stirring at 23° C. while supplying nitrogen. Thereafter, C1 (1.86 g, 8.28 mmol) and NMP (7.82 g) were added under ice cooling, and the mixture was stirred at 40° C. for 12 hours, thereby obtaining a polyamic acid solution (PAA-2) (viscosity: 251 mPa s) having a solids concentration of 12% by mass.

[0079] Example 4 A 50 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube was charged with A1 (0.951 g, 1.35 mmol), B2 (0.195 g, 1.80 mmol), B3 (0.989 g, 4.05 mmol), B4 (0.717 g, 1.80 mmol), and NMP (25.7 g), and dissolved by stirring at 23° C. while supplying nitrogen. Thereafter, C1 (1.86 g, 8.28 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 polyamic acid solution (PAA-3) (viscosity: 236 mPa s) having a solids concentration of 12% by mass.

[0080] Example 5 A1 (2.96 g, 4.20 mmol), B2 (0.151 g, 1.40 mmol), B4 (0.558 g, 1.40 mmol), and NMP (33.0 g) were added to a 50 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and the mixture was dissolved by stirring at 23° C. while supplying nitrogen. Thereafter, C1 (1.43 g, 6.37 mmol) and NMP (4.36 g) were added under ice cooling, and the mixture was stirred at 40° C. for 12 hours, thereby obtaining a polyamic acid solution (PAA-4) (viscosity: 426 mPa s) having a solids concentration of 12% by mass.

[0081] Comparative Example 1 B1 (8.09 g, 20.0 mmol) and NMP (81.8 g) were placed in a 50 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and dissolved by stirring at 23° C. while supplying nitrogen. Thereafter, C1 (4.12 g, 18.4 mmol) and NMP (7.78 g) were added under ice cooling, and the mixture was stirred at 40° C. for 12 hours, yielding a polyamic acid solution (PAA-5) (viscosity: 2,395 mPa s) with a solids concentration of 12% by mass.

[0082] Comparative Example 2 A1 (2.47 g, 3.50 mmol) and NMP (20.0 g) were placed in a 50 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and dissolved by stirring at 23° C. while supplying nitrogen. Thereafter, D1 (0.549 g, 2.80 mmol) and NMP (2.16 g) were added under ice cooling, and the mixture was stirred at 23° C. for 12 hours, yielding a polyamic acid solution (PAA-6) (viscosity: 455 mPa s) with a solids concentration of 12% by mass.

[0083] Synthesis Example 1 B5 (11.1 g, 55.9 mmol), B6 ​​(2.13 g, 14.0 mmol), and NMP (97.3 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 23°C while supplying nitrogen to dissolve. Thereafter, D2 (19.2 g, 65.2 mmol) and NMP (140 g) were added, and the mixture was stirred at 70°C for 12 hours to obtain a polyamic acid solution (PAA-7) (viscosity: 120 mPa s) with a solids concentration of 12% by mass. The specifications of the polyimide polymer are shown in Table 1.

[0084] Comparative Example 5: B7 (2.76 g, 5.99 mmol) and NMP (20.3 g) were added to a 100 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and the mixture was stirred at room temperature while supplying nitrogen to dissolve the mixture. Subsequently, C1 (1.20 g, 5.34 mmol) and NMP (8.78 g) were added under ice cooling, and the mixture was stirred at room temperature for 12 hours to obtain a solution of polyamic acid (PAA-8) with a solids concentration of 12% by mass (viscosity: 350 mPa s).

[0085] Comparative Example 6: B8 (3.24 g, 4.99 mmol) and NMP (23.8 g) were added to a 100 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and the mixture was stirred at room temperature while supplying nitrogen to dissolve the mixture. Subsequently, C1 (0.998 g, 4.44 mmol) and NMP (7.32 g) were added under ice cooling, and the mixture was stirred at room temperature for 12 hours to obtain a solution of polyamic acid (PAA-9) with a solids concentration of 12% by mass (viscosity: 257 mPa s).

[0086] Comparative Example 7: B9 (4.23 g, 6.00 mmol) and NMP (31.0 g) were added to a 100 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and the mixture was stirred at room temperature while supplying nitrogen to dissolve the mixture. Subsequently, C1 (1.20 g, 5.34 mmol) and NMP (8.78 g) were added under ice cooling, and the mixture was stirred at room temperature for 12 hours to obtain a solution of polyamic acid (PAA-10) with a solids concentration of 12% by mass (viscosity: 7,600 mPa s).

[0087] Comparative Example 8: B10 (3.36 g, 4.99 mmol) and NMP (30.3 g) were added to a 100 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and the mixture was stirred at room temperature while supplying nitrogen to dissolve. Thereafter, C1 (0.897 g, 3.99 mmol) and NMP (0.970 g) were added under ice cooling, and the mixture was stirred at room temperature for 12 hours to obtain a solution of polyamic acid (PAA-11) with a solids concentration of 12 mass% (viscosity: 327 mPa s).

[0088] Comparative Example 9: B11 (4.04 g, 6.00 mmol) and NMP (36.3 g) were added to a 100 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and the mixture was stirred at room temperature while supplying nitrogen to dissolve. Thereafter, C1 (1.20 g, 5.34 mmol) and NMP (2.05 g) were added under ice cooling, and the mixture was stirred at room temperature for 12 hours to obtain a solution of polyamic acid (PAA-12) with a solids concentration of 12 mass% (viscosity: 372 mPa s).

[0089]

[0090] "Production of Liquid Crystal Alignment Agent" Example 6 The polyamic acid solution (PAA-1) obtained by the method of Example 2, F1 (blending ratio of F1: 1 part by mass per 100 parts by mass of polyimide polymer), NMP, and BCS were added to a sample tube containing a stirring bar, and stirred at 25°C for 30 minutes to obtain a liquid crystal alignment agent (1) (solid content: NMP:BCS = 6:74:20 mass ratio). No abnormalities such as turbidity or the occurrence of precipitates were observed in this liquid crystal alignment agent, and it was confirmed that it was a homogeneous solution. In addition, using the obtained liquid crystal alignment agent (1), an "evaluation of the stability of liquid crystal alignment" was performed.

[0091] Examples 7 to 13 Liquid crystal aligning agents (2) to (8) were obtained in the same manner as in Example 6, except that the type of polyamic acid solution used was changed as shown in Table 2, and F1 (blending ratio of F1: 1 part by mass per 100 parts by mass of polyimide polymer) and F2 (blending ratio of F2: 5 parts by mass per 100 parts by mass of polyimide polymer) were added. These liquid crystal aligning agents did not show any abnormalities such as turbidity or the occurrence of precipitates, and were confirmed to be homogeneous solutions. In addition, the obtained liquid crystal aligning agents were used to perform an "evaluation of the stability of liquid crystal alignment."

[0092] Comparative Examples 3, 4, and 10 to 14 Liquid crystal aligning agents (9) to (15) were obtained in the same manner as in Example 6, except that the type of polyamic acid solution used was changed as shown in Table 2. These liquid crystal aligning agents were confirmed to be homogeneous solutions, with no abnormalities such as turbidity or precipitates observed. Furthermore, an "evaluation of liquid crystal alignment stability" was performed using the obtained liquid crystal aligning agents. The specifications of the liquid crystal aligning agents are shown in Table 2. In Table 2, the numbers in parentheses indicate the blending ratio (parts by mass) of each polymer component relative to a total of 100 parts by mass of the polymer components used in the liquid crystal aligning agent.

[0093]

[0094] "Evaluation of Liquid Crystal Alignment Stability" The liquid crystal alignment stability was evaluated using the liquid crystal alignment agents obtained by the methods of the Examples and Comparative Examples. This evaluation was intended to evaluate the AC afterimage of a liquid crystal display element, which occurs when the stability of the liquid crystal alignment decreases due to long-term AC driving. First, a liquid crystal cell using the FFS driving method was fabricated. A rectangular glass substrate measuring 30 mm x 35 mm and 0.7 mm thick was used as the substrate. A solid-patterned ITO electrode constituting a common electrode was formed on the substrate as the first layer. A SiN (silicon nitride) film deposited 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 was thick enough to function as an interlayer insulating film. A comb-shaped pixel electrode formed by patterning an ITO film was placed on the second SiN film as the third layer, forming two pixels, a first pixel and a second pixel, each measuring 10 mm long and 5 mm wide. This electrode-equipped substrate had a structure in which a first-layer common electrode and a third-layer pixel electrode were insulated by a second-layer SiN film. The third-layer pixel electrode had a comb-like shape, with a central portion bent at an interior angle of 160° and multiple 3-μm-wide electrode wires arranged in parallel at 6-μm intervals. Each pixel was formed by multiple electrode wires, and had a first region and a second region separated by a line connecting the bent portions.

[0095] Next, the liquid crystal alignment agent 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) with a 4 μm-high columnar spacer and an ITO electrode formed on the backside. The substrates were then dried on a hot plate at 80°C for 2 minutes and baked in an infrared heating furnace at 180°C or 230°C for 30 minutes to obtain an electrode substrate and a counter substrate with a liquid crystal alignment film having a thickness of 100 nm. The liquid crystal alignment film surfaces of both substrates were 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 (the optimal irradiation dose for each liquid crystal alignment agent), and then baked in an infrared heating furnace at 180°C or 230°C for 30 minutes to obtain an alignment-treated electrode substrate and a counter substrate with a liquid crystal alignment film. As a result, the liquid crystal alignment film on the electrode substrate was oriented so that the direction equally dividing the interior angle of the pixel bend was perpendicular to the alignment direction of the liquid crystal, and the liquid crystal alignment film on the counter substrate was oriented so that the alignment direction of the liquid crystal on the electrode substrate coincided with the alignment direction of the liquid crystal on the counter substrate when creating the liquid crystal cell.

[0096] The alignment-treated electrode substrate with a liquid crystal alignment film and the counter substrate were combined into a pair. A thermosetting sealant (XN-1500T, manufactured by Mitsui Chemicals, Inc.) was printed on the liquid crystal alignment film surface of one substrate, leaving a liquid crystal injection port. The other substrate was then bonded to the other substrate, with the liquid crystal alignment film facing inward, so that the alignment directions of the liquid crystal alignment films were at 0°. After bonding, the bonded substrates were pressed together and heated at 150°C in a hot air circulating oven for 60 minutes to cure the sealant and produce an empty cell. A positive liquid crystal (MLC-3019, manufactured by Merck) was injected into this empty cell by a reduced-pressure injection method, and the injection port was sealed to obtain an FFS-driven liquid crystal cell (hereinafter referred to as the "liquid crystal cell"). The resulting liquid crystal cell was heated at 120°C for 1 hour and then left overnight at 23°C to evaluate the stability of the liquid crystal alignment. A high-brightness backlight (light source: LED, brightness: 20,000 cd / m) with a surface temperature of 50°C was used for this liquid crystal cell. ２ ) and an AC voltage of ±4.3 V was applied at a frequency of 30 Hz for 168 hours. Thereafter, the pixel electrode and the common electrode of the liquid crystal cell were short-circuited, and the sample was left at 23° C. for one day.

[0097] For the liquid crystal cell subjected to the above treatment, the difference 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 inverted to adjust the alignment angle of the liquid crystal cell so that the transmitted light intensity in the first region of the first pixel was minimized. Next, the rotation angle Δ required to rotate the liquid crystal cell so that the transmitted light intensity in the second region of the first pixel was minimized was calculated. Similarly, the first and second regions of the second pixel were compared, and a similar 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 liquid crystal alignment stability, and the less likely AC image retention will occur in the liquid crystal display element. Specifically, a rotation angle Δ of 0.20° or less was rated "good," and a rotation angle Δ of 0.20° or more was rated "poor." The results of the evaluation of liquid crystal alignment stability are shown in Table 3.

[0098]

[0099] As can be seen from the above results, the liquid crystal display element using the liquid crystal alignment film obtained from the liquid crystal aligning agent of the example of the present invention exhibited higher liquid crystal alignment stability than the liquid crystal display element of the comparative example. In particular, this effect was obtained even when the baking temperature during preparation of the liquid crystal alignment film was as low as 180°C. Specifically, under the same conditions, a comparison was made between an example using a specific diamine and a comparative example not using it, i.e., Example 6 (rotation angle Δ value of 0.08°) and Comparative Example 3 (rotation angle Δ value of 1.13°). Furthermore, a comparison was made between an example using a specific acid dianhydride and a comparative example not using it, i.e., Example 6 (rotation angle Δ value of 0.08°) and Comparative Example 4 (rotation angle Δ value of 0.41°). Furthermore, when a diamine not using an ether group in the bonding group of the phenyl ring bonded to the imide group and the phenyl ring bonded to the amino group was used in comparison with the specific diamine of the present invention (Comparative Example 10), when the chain length of the alkylene group was different (Comparative Examples 11 and 12), and when the chain length of the bonding group was the same but there was only one ether group (Comparative Examples 13 and 14), the stability of the liquid crystal alignment was low. Specifically, this is a comparison between Example 6 (rotation angle Δ value of 0.08°) and the above Comparative Example (rotation angle Δ value greater than 1.13°).

[0100] By using a liquid crystal aligning agent containing a polyimide polymer obtained from a specific acid dianhydride and a specific diamine according to the present invention, a liquid crystal display element is obtained in which AC image retention is unlikely to occur, even if the baking is performed at a low temperature when preparing a liquid crystal alignment film. Therefore, the liquid crystal display element of the present invention is suitably used in in-plane switching drive elements such as IPS drive systems and FFS drive systems, and is useful for smartphones, tablet terminals, etc.

[0101] 1: In-plane switching liquid crystal display element, 2: Comb electrode substrate, 2a: Substrate, 2b: Linear electrode, 2c: Liquid crystal alignment film, 2d: Substrate, 2e: Planar electrode, 2f: Insulating film, 2g: Linear electrode, 2h: Liquid crystal alignment film, 3: Liquid crystal, 4: Counter substrate, 4a: Liquid crystal alignment film, 4b: Substrate, L: Electric force

[0102] The entire contents of the specification, claims, abstract and drawings of Japanese Patent Application No. 2024-17419 filed on February 7, 2024 are hereby incorporated by reference as the disclosure of the specification of the present invention.

Claims

1. A liquid crystal aligning agent containing at least one polymer (P) selected from a polyimide precursor and a polyimide obtained using a tetracarboxylic acid component containing at least one selected from tetracarboxylic acid dianhydrides of the following formula (1) and derivatives thereof, and a diamine component containing a diamine of the following formula (2): (R １ ~R ４ each independently represents a hydrogen 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, or a phenyl group; R １ ~R ４ At least one of represents a group other than a hydrogen atom as defined above.) (R ２１ ~R ２４ each independently represents a hydrogen 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, or a phenyl group; R ２１ ~R ２４ At least one of Ar represents a group other than a hydrogen atom as defined above. ２ and Ar ２’ each independently represents a divalent organic group of the following formula (2a): (n is an integer of 2, 4, or 6. * represents a bond, and the benzene ring bonded to * is unsubstituted, or one or more hydrogen atoms on the benzene ring are substituted with a monovalent group.) 2. The liquid crystal aligning agent according to claim 1, wherein the content of the diamine of 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 divalent organic group of the formula (2a) is at least one selected from the structures of the following formulae (2a-1) to (2a-9): (** indicates a bond.) 4. The liquid crystal aligning agent according to claim 1, wherein the diamine of formula (2) is at least one selected from the following formulas (2-1) to (2-9):

5. The liquid crystal aligning agent according to claim 1, wherein the content of at least one selected from the group consisting of tetracarboxylic dianhydrides represented by the formula (1) and derivatives thereof is 10 mol% or more relative to 1 mol of the tetracarboxylic acid component used in the production of the polymer (P).

6. The diamine component is a phenylenediamine, a diaminobiphenyl compound, or a compound represented by the following formula (d ＡＬ ) diamine, diamine having a tetracarboxylic acid diimide structure, diamine having an amide bond, diamine having a urea bond, and diamine having a group "-N(D)-" (D represents a protecting group which is eliminated by heating and replaced with a hydrogen atom), further containing at least one diamine selected from the group. (Ar １ and Ar １’ Each of L represents a cyclic group selected from a benzene ring, a biphenyl structure, or a naphthalene ring, and one or more hydrogen atoms on these cyclic groups may be 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 formed by inserting at least one of -O-, -C(=O)-O-, and -O-C(=O)- between the carbon-carbon bonds of the alkylene group, and any hydrogen atom possessed by A may be substituted with a halogen atom.

7. The liquid crystal aligning agent according to claim 1, further comprising a 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 of 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 arranging 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 photo-alignment 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 manufacturing a liquid crystal display element according to claim 12, wherein the liquid crystal display element is of an IPS drive system or an FFS drive system.

14. A diamine represented by any one of the following formulas (2-1) to (2-9):

15. A polymer selected from polyimide precursors and polyimides obtained using a tetracarboxylic acid component containing at least one selected from tetracarboxylic dianhydrides of the following formula (1) and derivatives thereof, and a diamine component containing at least one diamine selected from formulas (2-1) to (2-9) according to claim 14: (R １ ~R ４ each independently represents a hydrogen 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, or a phenyl group; R １ ~R ４ At least one of represents a group other than a hydrogen atom as defined above.

Images