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

Abstract

The present invention provides: a liquid crystal aligning agent which enlarges the range of light irradiance that enables the achievement of a liquid crystal alignment film having a small twist angle variation (unevenness) of liquid crystals within the liquid crystal alignment film surface, and which forms a liquid crystal alignment film having a high water contact angle for the purpose of achieving a liquid crystal alignment film that prevents the occurrence of display unevenness caused by a cleaning step; a liquid crystal alignment film which is formed by this liquid crystal aligning agent; and a high-performance liquid crystal display element which is provided with this liquid crystal alignment film.　The present invention provides: a liquid crystal aligning agent which is characterized by containing at least one polymer (P) that is selected from the group consisting of a polyimide precursor which is obtained using a diamine component that contains a novel diamine (0) represented by formula (DA), and a polyimide that is an imidized product of the polyimide precursor; a liquid crystal alignment film which is formed by this liquid crystal aligning agent; and a liquid crystal display element which is provided with this liquid crystal alignment film. (In the formula, the definition of each symbol is as described in the description.)

Description

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

[0001] The present invention relates to a liquid crystal aligning agent, a liquid crystal alignment film obtained from the liquid crystal aligning agent, a liquid crystal display device having the liquid crystal alignment film, and a novel diamine and polymer suitable for them.

[0002] Liquid crystal display elements are widely used in a wide range of applications, from small devices such as mobile phones and smartphones to relatively large devices such as televisions and monitors. Various driving methods have been developed, each differing in electrode structure and physical properties of the liquid crystal molecules used. Known liquid crystal display elements use various modes, such as twisted nematic (TN), super twisted nematic (STN), vertical alignment (VA), in-plane switching (IPS), and fringe field switching (FFS). These liquid crystal display elements generally have a liquid crystal alignment film, which is essential for controlling the alignment state of the liquid crystal molecules. Polyamic acid and polyimide are commonly used as materials for the liquid crystal alignment film because of their excellent properties, such as heat resistance, mechanical strength, and affinity with liquid crystals.

[0003] Currently, the most widely used industrial liquid crystal alignment films are produced by rubbing the surface of a resin film such as polyimide formed on an electrode substrate in one direction with a cloth made of cotton, nylon, polyester, or the like, in a process known as rubbing alignment. Rubbing alignment is a useful method that is simple and has excellent productivity. As an alternative to rubbing alignment, a photo-alignment method is known in which polarized radiation is irradiated to impart liquid crystal alignment ability. As photo-alignment methods, methods utilizing photoisomerization reactions, photo-crosslinking reactions, photodecomposition reactions, and the like have been proposed (see, for example, Non-Patent Document 1, Patent Document 1, and Patent Document 2).

[0004] Japanese Unexamined Patent Publication No. 9-297313 Japanese Unexamined Patent Publication No. 2004-206091

[0005] "Liquid Crystal Photo-Alignment Film," Functional Materials, November 1997, Vol. 17, No. 11, pp. 13-22

[0006] In recent years, with the advancement of performance of liquid crystal display elements, in addition to large-screen, high-definition liquid crystal televisions, applications are being considered for in-vehicle devices such as car navigation systems, meter panels, monitors for surveillance cameras and medical cameras, etc. Therefore, there is an increasing demand for higher performance, particularly higher definition, of liquid crystal display elements, and liquid crystal alignment films that can further improve the various properties of liquid crystal display elements are being sought.

[0007] Furthermore, as liquid crystal display elements have become larger, variations in the manufacturing process have led to the occurrence of problems such as slight variations in the twist angle of the liquid crystal within the surface of the liquid crystal display element. Such variations cause uneven brightness within the surface of the liquid crystal display element when it displays black, which leads to a decrease in the quality of the liquid crystal display element.

[0008] Furthermore, in the rubbing alignment treatment or photo-alignment treatment, a cleaning step using a solvent may be carried out after the alignment treatment to remove impurities. This cleaning step may cause the solvent to repel or droplets to form during air knife drying, resulting in locally uneven cleaning of the film surface, and may cause linear display irregularities along the air knife direction in the resulting liquid crystal display element.

[0009] The present invention has been made in consideration of the above circumstances, and aims to provide a liquid crystal alignment agent that expands the range of light exposure amounts that can produce a liquid crystal alignment film with small variations (non-uniformity) in the twist angle of the liquid crystal within the liquid crystal alignment film plane, and that can form a liquid crystal alignment film with a high water contact angle to produce a liquid crystal alignment film that does not cause display unevenness due to the cleaning process, and a liquid crystal display element that includes the liquid crystal alignment film.

[0010] As a result of intensive research to achieve the above object, the present inventors have found that a liquid crystal aligning agent containing a polymer using a novel diamine having a specific structure is effective in achieving the above object, and have completed the present invention.

[0011] The present invention relates to a compound represented by the following formula (D Ａand a polyimide obtained by imidizing the polyimide precursor; a liquid crystal alignment film obtained from the liquid crystal alignment agent; and a liquid crystal display device having the liquid crystal alignment film. (R １ are each independently a hydrogen atom, a methyl group, a fluorine atom, a fluoroalkyl group having 1 to 3 carbon atoms and two or more fluorine atoms, or a fluoroalkoxy group having 1 to 3 carbon atoms and two or more fluorine atoms; R １ At least one of Z represents a fluoroalkyl group having 1 to 3 carbon atoms and two or more fluorine atoms, or a fluoroalkoxy group having 1 to 3 carbon atoms and two or more fluorine atoms. １ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, or an alkynyl group having 2 to 6 carbon atoms, and the hydrogen atom of the alkyl group, alkenyl group, or alkynyl group may be substituted with a monovalent group. n is an integer of 1 to 6.) In the present invention, examples of halogen atoms include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Boc represents a tert-butoxycarbonyl group.

[0012] According to the present invention, a liquid crystal alignment agent that expands the range of light exposure doses that can produce a liquid crystal alignment film with small variations (non-uniformity) in the twist angle of the liquid crystal within the liquid crystal alignment film plane, and that forms a liquid crystal alignment film with a high water contact angle, in order to obtain a liquid crystal alignment film that does not cause display unevenness due to the cleaning process, a liquid crystal alignment film obtained from the liquid crystal alignment agent, a high-performance liquid crystal display element equipped with the liquid crystal alignment film, and a novel diamine and polymer used in the production of them are provided.

[0013] Although the mechanism by which the above-mentioned effects of the present invention are obtained is not entirely clear, it is presumed that the above-mentioned effects are obtained because the oxyaniline structure contained in the diamine (0) of the present invention allows for a liquid crystal alignment film with small variations in the twist angle of the liquid crystal, and the introduction of an organic group substituted with multiple highly hydrophobic fluorine atoms increases the water contact angle.

[0014] <Specific diamine> As described above, the liquid crystal aligning agent of the present invention is a diamine represented by the following formula (D Ａ The composition is characterized in that it contains at least one polymer (P) selected from the group consisting of polyimide precursors obtained using a diamine component containing diamine (0) (also referred to as specific diamine in the present invention) represented by the formula (I), and polyimides which are imidized products of the polyimide precursors. The above formula (D Ａ ) in which R １ , Z １ and n are as defined above.

[0015] The above formula (D Ａ In the formula (I), n is preferably an integer of 2 to 6, more preferably an integer of 2 to 4, from the viewpoint of obtaining high liquid crystal alignment properties.

[0016] The above formula (D Ａ ) in Z １ The hydrogen atoms of the alkyl group, alkenyl group, or alkynyl group in the above formula (D) may be substituted with a monovalent group, and examples of the monovalent group include a halogen atom, a carboxy group, a hydroxy group, a cyano group, and a nitro group. Among these, a halogen atom is preferred. Ａ ) in Z １ is more preferably a hydrogen atom or a methyl group.

[0017] The above formula (D Ａ ) R １ Examples of the fluoroalkyl group having 1 to 3 carbon atoms and two or more fluorine atoms in the above formula (D) include a difluoromethyl group, a trifluoromethyl group, a 2,2,2-trifluoroethyl group, a 1,1,2,2,2-pentafluoroethyl group, a 3,3,3-trifluoropropyl group, and a 1,1,2,2,3,3,3-heptafluoropropyl group. Ａ ) R １Examples of the fluoroalkoxy group having 1 to 3 carbon atoms and two or more fluorine atoms in the formula (I) include a difluoromethoxy group, a trifluoromethoxy group, a 2,2,2-trifluoroethoxy group, a 1,1,2,2,2-pentafluoroethoxy group, a 3,3,3-trifluoropropyloxy group, and a 1,1,2,2,3,3,3-heptafluoropropyloxy group.

[0018] The above formula (D Ａ ) in which R １ At least one of the above formula (D) represents a fluoroalkyl group having 1 to 3 carbon atoms and two or more fluorine atoms, or a fluoroalkoxy group having 1 to 3 carbon atoms and two or more fluorine atoms. Ａ ) in which R １ At least one of the above is preferably a fluoroalkyl group having 1 to 3 carbon atoms and 3 or more fluorine atoms, or a fluoroalkoxy group having 1 to 3 carbon atoms and 3 or more fluorine atoms. Ａ ) in which R １ At least one of the groups represented by the formula (D) is preferably a fluoroalkyl group having 1 to 3 carbon atoms and two or more fluorine atoms. Ａ ) in which two R １ are preferably both a fluoroalkyl group having 1 to 3 carbon atoms and having two or more fluorine atoms, or a fluoroalkoxy group having 1 to 3 carbon atoms. Ａ ) in which two R １ and both are more preferably fluoroalkyl groups having 1 to 3 carbon atoms and 3 or more fluorine atoms.

[0019] The above formula (D Ａ Preferred examples of the compound represented by the formula (d Ａ -1) to (d Ａ -6) can be mentioned. (In the formula, Z １ is the formula (D Ａ ) in Z １ is synonymous with

[0020] (Polymer (P)) The polymer (P) contained in the liquid crystal aligning agent of the present invention is a polyimide precursor obtained using a diamine component containing the above diamine (0), or a polyimide which is an imidized product of the polyimide precursor. Here, the polyimide precursor is a polymer from which a polyimide can be obtained by imidizing a polyamic acid, a polyamic acid ester, or the like. The polymer (P) may be used alone or in combination of two or more. The polymer (P) may be a polymer having at least one repeating unit selected from the group consisting of a repeating unit (p1) represented by the following formula (1) and an imidized structural unit of the repeating unit (p1): (In formula (1), X １ represents a tetravalent organic group. １ is a divalent organic group obtained by removing two amino groups from the specific diamine. R and Z each independently represent a hydrogen atom or a monovalent organic group.) The monovalent organic group for R and Z in the above formula (1) is a monovalent hydrocarbon group having 1 to 6 carbon atoms, and a methylene group of the hydrocarbon group can be replaced with -O-, -S-, -CO-, -COO-, -COS-, -NR ３ --CO-NR ３ -, -Si(R ３ ) ２ - (However, R ３ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms, —SO ２Examples of the monovalent organic group include a monovalent group A in which at least one hydrogen atom bonded to a carbon atom of the monovalent hydrocarbon group or the monovalent group A is substituted with a halogen atom, a hydroxy group, an alkoxy group, a nitro group, an amino group, a mercapto group, a nitroso group, an alkylsilyl group, an alkoxysilyl group, a silanol group, a sulfino group, a phosphino group, a carboxy group, a cyano group, a sulfo group, an acyl group, or the like, and a monovalent group having a heterocycle. The monovalent organic groups represented by R and Z in formula (1) are preferably alkyl groups having 1 to 6 carbon atoms, alkenyl groups having 2 to 6 carbon atoms, alkynyl groups having 2 to 6 carbon atoms, or tert-butoxycarbonyl groups, more preferably alkyl groups having 1 to 3 carbon atoms, and even more preferably methyl groups. From the viewpoint of optimally achieving the effects of the present invention, R and Z are each independently preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and more preferably a hydrogen atom or a methyl group. X in the above formula (1) １ Examples of the X include tetravalent organic groups derived from tetracarboxylic dianhydrides or derivatives thereof, which will be described later. １ A preferred embodiment of the tetracarboxylic dianhydride or a derivative thereof in the above can be a preferred embodiment of a tetracarboxylic dianhydride or a derivative thereof that can be used in the synthesis of the polymer (P) described below. The polyamic acid (P'), which is a polyimide precursor of the polymer (P), can be obtained by a polymerization reaction between a diamine component containing the diamine (0) and a tetracarboxylic acid component. The diamine (0) may be used alone or in combination of two or more. The amount of diamine (0) used is preferably 5 mol % or more, more preferably 10 mol % or more, and even more preferably 20 mol % or more, based on the total diamine components.

[0021] The diamine component used in the production of the polyamic acid (P') may contain a diamine other than the diamine (0) (hereinafter also referred to as "other diamine"). When the other diamine is used in addition to the diamine (0), the amount of the diamine (0) used relative to the diamine component is preferably 90 mol % or less, more preferably 80 mol % or less.

[0022] Examples of other diamines include, but are not limited to, the following. The above other diamines may be used singly or in combination of two or more: p-phenylenediamine, 2,3,5,6-tetramethyl-p-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, m-phenylenediamine, 2,4-dimethyl-m-phenylenediamine, 2,5-diaminotoluene, 2,6-diaminotoluene, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-dihydroxy-4,4' -diaminobiphenyl, 2,2'-difluoro-4,4'-diaminobiphenyl, 3,3'-difluoro-4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 3,3'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 3,4'-diaminobiphenyl, 4,4'-diaminobiphenyl, 3,3'-diaminobiphenyl, 2,2'-diaminobiphenyl, 2,3'-diaminobiphenyl, ＡＬ -1) to (d ＡＬ-10), 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, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, 4,4'-bis(4-aminophenoxy)diphenyl ether, 1,4-bis[4-(4-aminophenoxy)phenoxy]benzene, 1,2-bis(6-amino-2-naphthyloxy)ethane, 1,2-bis( 6-amino-2-naphthyl)ethane, 6-[2-(4-aminophenoxy)ethoxy]-2-naphthylamine, 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 diamines having a photo-alignable group such as 4,4'-diaminoazobenzene or diaminotolane; diamines having a photo-polymerizable group at the terminal such as 2-(2,4-diaminophenoxy)ethyl methacrylate or 2,4-diamino-N,N-diallylaniline; diamines having a radical polymerization initiator function such as 1-(4-(2-(2,4-diaminophenoxy)ethoxy)phenyl)-2-hydroxy-2-methylpropanone and 2-(4-(2-hydroxy-2-methylpropanoyl)phenoxy)ethyl 3,5-diaminobenzoate;Diamines having an amide bond such as 4,4'-diaminobenzanilide, 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; 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2- bis(4-aminophenyl)hexafluoropropane, 2,2-bis(3-aminophenyl)hexafluoropropane, 2,2-bis(3-amino-4-methylphenyl)hexafluoropropane, 2,2-bis(4-aminophenyl)propane, 2,2-bis(3-aminophenyl)propane, 2,2-bis(3-amino-4-methylphenyl)propane, 4,4'-diaminobenzophenone, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 1,4-bis(4-aminobenzyl)benzene;2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, 1,4-bis-(4-aminophenyl)-piperazine, 3,6-diaminoacridine, N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N-[3-(1H-imidazol-1-yl)propyl] Heterocycle-containing diamines such as 3,5-diaminobenzamide, 4-[4-[(4-aminophenoxy)methyl]-4,5-dihydro-4-methyl-2-oxazolyl]-benzeneamine, or diamines represented by the following formulas (z-1) to (z-13), or 4,4'-diaminodiphenylamine, 4,4'-diaminodiphenyl-N-methylamine, N,N'-bis(4-aminophenyl)-benzidine, N,N'-bis(4-aminophenyl)-N,N'-dimethylbenzidine, or N,N'-bis(4-aminophenyl)-N,N'-dimethyl-1,4-benzenediamine. diamines having at least one nitrogen atom-containing structure (hereinafter also referred to as specific nitrogen atom-containing structure) selected from the group consisting of a nitrogen atom-containing heterocycle, a secondary amino group, and a tertiary amino group, typified by diamines having any of the diphenylamine structures (provided that the molecule does not contain an amino group bonded to a protecting group that is eliminated 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'-di Diamines having a carboxy group such as aminobiphenyl-2,4'-dicarboxylic acid, 4,4'-diaminodiphenylmethane-3,3'-dicarboxylic acid, 1,2-bis(4-aminophenyl)ethane-3,3'-dicarboxylic acid, and 4,4'-diaminodiphenylether-3,3'-dicarboxylic acid; 4-(2-(methylamino)ethyl)aniline, 4-(2-aminoethyl)aniline, and 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 formulas (5-1) to (5-6), cholestanyloxy-3,5-diaminobenzene, ... Diamines having a steroid skeleton such as aminobenzene, cholestanyloxy-2,4-diaminobenzene, cholestanyl 3,5-diaminobenzoate, cholestenyl 3,5-diaminobenzoate, lanostannyl 3,5-diaminobenzoate, and 3,6-bis(4-aminobenzoyloxy)cholestane, diamines represented by the following formulae (V-1) and (V-2); diamines having a siloxane bond such as 1,3-bis(3-aminopropyl)-tetramethyldisiloxane;Metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, 1,3-bis(aminomethyl)cyclohexane, 1,4-diaminocyclohexane, 4,4'-methylenebis(cyclohexylamine), diamines in which two amino groups are bonded to a group represented by any one of formulas (Y-1) to (Y-167) described in WO 2018 / 117239, and the like;

[0023] (Formula (d ＡＬ -6) and (d ＡＬ In formula (8), m1 and m2 each independently have the above definition.

[0024]

[0025]

[0026]

[0027] In the formula (V-1), m and n each independently represent an integer of 0 to 3, and satisfy the condition 1≦m+n≦4. j represents an integer of 0 or 1. X １ is -(CH ２ ) ａ -(a is an integer of 1 to 15), -CONH-, -NHCO-, -CO-N(CH ３ )-, -NH-, -O-, -CH ２ O-, -CH ２ represents —OCO—, —COO—, or —OCO—. １ represents a monovalent group such as a fluorine atom, a fluorine atom-containing alkyl group having 1 to 10 carbon atoms, a fluorine atom-containing alkoxy group having 1 to 10 carbon atoms, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or an alkoxyalkyl group having 2 to 10 carbon atoms. ２ is -O-, -CH ２ O-, -CH ２ m, n, and X represent —OCO—, —COO—, or —OCO—. １ , R １ When two occur, each independently has the above definition.

[0028] From the viewpoint of suitably achieving the effects of the present invention, the diamine component used in the production of the polyamic acid (P') preferably contains at least one diamine selected from the group consisting of the other diamines (a) described above.

[0029] When other diamines are used in addition to the diamine (0), the amount of the other diamines used is preferably 10 to 90 mol %, more preferably 20 to 80 mol %, based on the total diamine components used in the production of the polymer (P).

[0030] (Tetracarboxylic Acid Component) When producing the polyamic acid (P′), the tetracarboxylic acid component to be reacted with the diamine component may be not only a tetracarboxylic acid dianhydride, but also a derivative of a tetracarboxylic acid dianhydride such as a tetracarboxylic acid, a tetracarboxylic acid dihalide, a tetracarboxylic acid dialkyl ester, or a tetracarboxylic acid dialkyl ester dihalide.

[0031] The tetracarboxylic acid dianhydride or its derivative may be an acyclic aliphatic tetracarboxylic acid dianhydride, an alicyclic tetracarboxylic acid dianhydride, an aromatic tetracarboxylic acid dianhydride, or a derivative thereof. Among these, a tetracarboxylic acid dianhydride or a derivative thereof having at least one partial structure selected from the group consisting of a benzene ring, a cyclobutane ring, a cyclopentane ring, and a cyclohexane ring is more preferable. A tetracarboxylic acid dianhydride or a derivative thereof having at least one structure selected from the group consisting of a cyclobutane ring, a cyclopentane ring, and a cyclohexane ring is even more preferable. The tetracarboxylic acid dianhydride or its derivative may be used alone or in combination of two or more. The acyclic aliphatic tetracarboxylic acid dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxy groups bonded to a chain hydrocarbon structure. However, it does not have to be composed solely of a chain hydrocarbon structure; it may also 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 an 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. 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. However, they do not need to be composed solely of an aromatic ring structure, and may partially contain a chain hydrocarbon structure or an alicyclic structure.

[0032] The tetracarboxylic acid component that can be used to produce the polyamic acid (P') preferably contains the following tetracarboxylic dianhydrides or derivatives thereof (in the present invention, these are also collectively referred to as specific tetracarboxylic acid derivatives): acyclic aliphatic tetracarboxylic acid dianhydrides such as 1,2,3,4-butanetetracarboxylic acid dianhydride; 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-dichloro-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-difluoro-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-bis(trifluoromethyl)-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,3,4-cyclopentanetetracarboxylic acid dianhydride, 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride, 3,3',4,4'-di ... 2,3,5-Tricarboxycyclopentylacetic dianhydride, 4-(2,5-dioxotetrahydrofuran-3-yl)tetrahydronaphthalene-1,2-dicarboxylic anhydride, 5-(2,5-dioxotetrahydrofuran-3-yl)-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 5-(2,5-dioxotetrahydrofuran-3-yl)- alicyclic tetracarboxylic acid dianhydrides such as 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-dianhydride, bicyclo[2.2.2]oct-7-ene-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-dicarboxyl) aromatic tetracarboxylic acid dianhydrides such as 4,4'-(1,4-phenylenedioxy)bis(phthalic anhydride), 4,4'-(1,4-phenylenedioxy)bis(phthalic anhydride), and 4,4'-methylenedi(1,4-phenylenedimethylene)bis(phthalic anhydride); and tetracarboxylic acid dianhydrides such as those described in JP 2010-97188 A.

[0033] Preferred examples of the specific tetracarboxylic acid derivatives include 1,2,3,4-butanetetracarboxylic acid dianhydride, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-difluoro ... 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-bis(trifluoromethyl)-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,3,4-cyclopentanetetracarboxylic acid dianhydride, 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride, 3,3',4,4'-dicyclohexyltetracarboxylic acid dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 5-(2,5-dioxo-1,2,3,4-cyclopentanetetracarboxylic acid dianhydride, 5-(2,5-dioxotetrahydrofuran-3-yl)-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 5-(2,5-dioxotetrahydrofuran-3-yl)-8-methyl-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-dianhydride, pyromellitic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic 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, or derivatives thereof.

[0034] The proportion of the specific tetracarboxylic acid derivative used is preferably 10 mol % or more, more preferably 20 mol % or more, and even more preferably 50 mol % or more, based on the total tetracarboxylic acid components used.

[0035] (Liquid Crystal Aligning Agent) The liquid crystal aligning agent of the present invention is a liquid composition obtained by dispersing or dissolving a polymer (P) and other components used as necessary, preferably in a suitable solvent. The total content of the polymer components contained in the liquid crystal aligning agent of the present invention can be appropriately changed depending on the thickness of the coating film to be formed. However, from the viewpoint of forming a uniform and defect-free coating film, it is preferably 1% by mass or more relative to the total mass of the liquid crystal aligning agent, and from the viewpoint of storage stability of the solution, it is preferably 10% by mass or less. The content of the polymer (P) used in the present invention is preferably 1 to 100 parts by mass, more preferably 10 to 100 parts by mass, and particularly preferably 20 to 100 parts by mass, relative to 100 parts by mass of the total polymers contained in the liquid crystal aligning agent.

[0036] The liquid crystal aligning agent of the present invention may contain other polymers besides the polymer (P). Specific examples of other polymers include at least one polymer selected from the group consisting of a polyimide precursor obtained using a diamine component that does not contain the specific diamine and a polyimide that is an imidized product of the polyimide precursor (also referred to as polymer (B) in the present invention), polysiloxane, polyester, polyamide, polyurea, polyorganosiloxane, cellulose derivative, polyacetal, polystyrene derivative, poly(styrene-maleic anhydride) copolymer, poly(isobutylene-maleic anhydride) copolymer, poly(vinyl ether-maleic anhydride) copolymer, poly(styrene-phenylmaleimide) derivative, and a polymer selected from the group consisting of poly(meth)acrylate.

[0037] 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.), while a specific example of poly(isobutylene-maleic anhydride) copolymers includes ISOBAM-600 (manufactured by Kuraray Co., Ltd.). A specific example of poly(vinyl ether-maleic anhydride) copolymers includes Gantrez AN-139 (methyl vinyl ether maleic anhydride resin, manufactured by Ashland). Among these, polymer (B) is more preferred from the viewpoint of reducing residual DC-derived afterimages. The above other polymers may be used alone or in combination of two or more. The content ratio of the other polymers is preferably 90 parts by mass or less, more preferably 10 to 90 parts by mass, and even more preferably 20 to 80 parts by mass, relative to 100 parts by mass of the total polymers contained in the liquid crystal aligning agent. The content of the polymer (P) may be 90 parts by mass or less, or 80 parts by mass or less, relative to 100 parts by mass of the total of the polymers contained in the liquid crystal aligning agent.

[0038] (Polymer (B)) Specific examples of the tetracarboxylic acid component used in the production of the polymer (B) include the same compounds as those exemplified for the polymer (P), including preferred specific examples. The tetracarboxylic acid component used in the production of the polymer (B) more preferably contains a tetracarboxylic acid dianhydride or a derivative thereof having at least one partial structure selected from the group consisting of a benzene ring, a cyclobutane ring, a cyclopentane ring, and a cyclohexane ring, even more preferably the specific tetracarboxylic acid derivatives described above, and most preferably the more preferred specific examples of the specific tetracarboxylic acid derivatives described above. The amount of the specific tetracarboxylic acid derivative used is preferably 10 mol % or more, more preferably 20 mol % or more, and even more preferably 50 mol % or more, based on the total tetracarboxylic acid components used in the production of the polymer (B).

[0039] Examples of the diamine component for obtaining the polymer (B) include the diamines exemplified for the polymer (P) above. Among them, diamines having at least one group selected from the group consisting of a urea bond, an amide bond, a carboxy group, and a hydroxy group in the molecule, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, and diamines represented by the formula (d ＡＬ -1) to (d ＡＬ Preferably, the polymer (B) contains at least one diamine selected from the group consisting of diamines represented by the formula (I-10) and diamines having the specific nitrogen atom-containing structure (these are also referred to as specific diamine (b) in the present invention). The diamine component may be a single diamine or a combination of two or more diamines. When the specific diamine (b) is used, the amount used is preferably 10 mol % or more, more preferably 20 mol % or more, of all diamine components used in the production of polymer (B). When a diamine other than the specific diamine (b) is used, the amount used is preferably 90 mol % or less, more preferably 80 mol % or less, of all diamine components used in the production of polymer (B).

[0040] (Production of Polyamic Acid) Polyamic acid is produced by reacting a diamine component and a tetracarboxylic acid component in an organic solvent. The ratio of the tetracarboxylic acid component and the diamine component used in the polyamic acid production reaction is preferably such that 0.5 to 2 equivalents of acid anhydride groups in the tetracarboxylic acid component are used per equivalent of amino groups in the diamine component, more preferably 0.8 to 1.2 equivalents. As with a typical polycondensation reaction, the closer the equivalent of the acid anhydride groups in the tetracarboxylic acid component is to 1 equivalent, the higher the molecular weight of the resulting polyamic acid. The reaction temperature in the production of polyamic acid is preferably −20 to 150°C, more preferably 0 to 100°C. The reaction time is preferably 0.1 to 24 hours, more preferably 0.5 to 12 hours. Polyamic acid can be produced at any concentration. The polyamic acid concentration is preferably 1 to 50% by mass, more preferably 5 to 30% by mass. The reaction can be carried out at a high concentration initially, with subsequent addition of solvent.

[0041] Specific examples of the organic solvent include cyclohexanone, cyclopentanone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, and 1,3-dimethyl-2-imidazolidinone. Furthermore, when the polymer has high solvent solubility, solvents such as methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, diethylene glycol monomethyl ether, and diethylene glycol monoethyl ether can be used.

[0042] (Production of Polyamic Acid Ester) The polyamic acid ester can be obtained by known methods such as [I] a method of reacting the polyamic acid obtained by the above method with an esterifying agent, [II] a method of reacting a tetracarboxylic acid diester with a diamine, or [III] a method of reacting a tetracarboxylic acid diester dihalide with a diamine.

[0043] (Production of Polyimide) Polyimide can be obtained by ring-closing (imidizing) a polyimide precursor such as the polyamic acid or polyamic acid ester. The imidization ratio in this specification refers to the ratio of imide groups to the total amount of imide groups derived from tetracarboxylic dianhydride or its derivatives and carboxyl groups (or their derivatives). The imidization ratio does not necessarily have to be 100% and can be adjusted as desired depending on the application and purpose.

[0044] Methods for imidizing the polyimide precursor include thermal imidization, in which a solution of the polyimide precursor is heated as is, and catalytic imidization, in which a catalyst is added to a solution of the polyimide precursor. When thermally imidizing the polyimide precursor in solution, the temperature is preferably 100 to 400°C, more preferably 120 to 250°C, and it is preferable to carry out the thermal imidization while removing water produced by the imidization reaction from the system.

[0045] Catalytic imidization of polyimide precursors can be carried out by adding a basic catalyst and an acid anhydride to a solution of the polyimide precursor and stirring the mixture at preferably -20 to 250°C, more preferably 0 to 180°C. The amount of the basic catalyst is preferably 0.5 to 30 times, more preferably 2 to 20 times, the molar ratio of the amic acid groups, and the amount of the acid anhydride is preferably 1 to 50 times, more preferably 3 to 30 times, the molar ratio of the amic acid groups. Examples of basic catalysts include pyridine, triethylamine, trimethylamine, tributylamine, and trioctylamine. Of these, pyridine is preferred because it has adequate basicity for promoting the reaction. Examples of acid anhydrides include acetic anhydride, trimellitic anhydride, and pyromellitic anhydride. Of these, acetic anhydride is preferred because it facilitates purification after the reaction. The imidization rate by catalytic imidization can be controlled by adjusting the catalyst amount, reaction temperature, and reaction time.

[0046] When recovering the produced polyimide precursor or polyimide from a reaction solution of a polyimide precursor or polyimide, the reaction solution may be precipitated by pouring the reaction solution into a solvent. Examples of solvents used for precipitation include methanol, ethanol, isopropyl alcohol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, toluene, benzene, and water. The polymer precipitated by pouring into the solvent can be recovered by filtration and then dried at room temperature or by heating under atmospheric or reduced pressure. Furthermore, the recovered polymer can be redissolved in an organic solvent and reprecipitated and recovered 2 to 10 times to reduce the amount of impurities in the polymer. Examples of solvents used in this process include alcohols, ketones, and hydrocarbons. Using three or more solvents selected from these solvents is preferred because it further increases the efficiency of purification.

[0047] When producing the polyimide precursor or polyimide of the present invention, a terminal-capped polymer may be produced using a tetracarboxylic acid component containing a tetracarboxylic dianhydride or a derivative thereof, a diamine component containing the above-mentioned diamine, and an appropriate terminal-capping agent. Terminal-capped polymers have the effect of improving the film hardness of the liquid crystal alignment film obtained by coating and improving the adhesion properties between the sealant and the liquid crystal alignment film. Examples of terminal groups of the polyimide precursor or polyimide of the present invention include amino groups, carboxy groups, acid anhydride groups, and groups derived from terminal-capping agents described below. The amino groups, carboxy groups, and acid anhydride groups can be obtained by a conventional condensation reaction or by terminal-capping with the following terminal-capping agents.

[0048] Examples of the end-capping agent include acid anhydrides such as acetic anhydride, maleic anhydride, nadic anhydride, phthalic anhydride, itaconic anhydride, 1,2-cyclohexanedicarboxylic anhydride, 3-hydroxyphthalic anhydride, trimellitic anhydride, 3-(3-trimethoxysilyl)propyl)-3,4-dihydrofuran-2,5-dione, 4,5,6,7-tetrafluoroisobenzofuran-1,3-dione, and 4-ethynylphthalic anhydride; dicarbonate diester compounds such as di-tert-butyl dicarbonate and diallyl dicarbonate; chlorocarbonyl compounds such as acryloyl chloride, methacryloyl chloride, and nicotinic acid chloride; Examples of suitable end-capping agents include monoamine compounds such as aniline, 2-aminophenol, 3-aminophenol, 4-aminosalicylic acid, 5-aminosalicylic acid, 6-aminosalicylic acid, 2-aminobenzoic acid, 3-aminobenzoic acid, 4-aminobenzoic acid, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, and n-octylamine; and isocyanates having unsaturated bonds such as ethyl isocyanate, phenyl isocyanate, naphthyl isocyanate, or 2-acryloyloxyethyl isocyanate and 2-methacryloyloxyethyl isocyanate. The proportion of the end-capping agent used is preferably 0.01 to 20 parts by mole, and more preferably 0.01 to 10 parts by mole, per 100 parts by mole of the total of the diamine components used.

[0049] The polystyrene-equivalent weight average molecular weight (Mw) of the polyimide precursor and polyimide measured by gel permeation chromatography (GPC) is preferably 1,000 to 500,000, more preferably 2,000 to 300,000. The molecular weight distribution (Mw / Mn), expressed as the ratio of Mw to the polystyrene-equivalent number average molecular weight (Mn) measured by GPC, is preferably 15 or less, more preferably 10 or less. By having the molecular weight within this range, good liquid crystal alignment properties can be ensured in liquid crystal display elements.

[0050] The organic solvent contained in the liquid crystal aligning agent according to the present invention is not particularly limited as long as it can uniformly dissolve the polymer (P) and other polymers added as needed. Examples of the organic solvent include N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethyllactamide, N,N-dimethylpropionamide, tetramethylurea, N,N-diethylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethyl sulfoxide, γ-butyrolactone, γ-valerolactone, 1,3-dimethyl-2-imidazolidinone, methyl ethyl ketone, cyclohexanone, cyclopentanone, 3-methoxy-N,N-dimethylpropanamide, 3-butanol, 2-methyl-2-pyrrolidone ... Examples of suitable solvents include N-(3-methoxypropyl)-2-pyrrolidone, N-isopropyl-2-pyrrolidone, N-(n-butyl)-2-pyrrolidone, N-tert-butyl)-2-pyrrolidone, N-(n-pentyl)-2-pyrrolidone, N-(3-methoxypropyl)-2-pyrrolidone, N-(2-ethoxyethyl)-2-pyrrolidone, N-(4-methoxybutyl)-2-pyrrolidone, and N-cyclohexyl-2-pyrrolidone (collectively referred to as "good solvents"). Among these, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 3-methoxy-N,N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropanamide, and γ-butyrolactone are preferred. The content of the good solvent is preferably 20 to 99% by mass, more preferably 20 to 90% by mass, and particularly preferably 30 to 80% by mass of the total solvent contained in the liquid crystal aligning agent.

[0051] Furthermore, the organic solvent contained in the liquid crystal aligning agent is preferably a mixed solvent containing, in addition to the above solvent, a solvent (also referred to as a poor solvent) that improves the coatability and surface smoothness of the coating film when the liquid crystal aligning agent is applied. Specific examples of poor solvents are listed below, but are not limited to these. The content of the poor solvent is preferably 1 to 80 mass %, more preferably 10 to 80 mass %, and particularly preferably 20 to 70 mass %, of the total solvent contained in the liquid crystal aligning agent. The type and content of the poor solvent are appropriately selected depending on the coater, coating conditions, coating environment, etc. of the liquid crystal aligning agent.

[0052] Examples of poor solvents include diisopropyl ether, diisobutyl ether, diisobutyl carbinol (2,6-dimethyl-4-heptanol), ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, 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 diacetate, propylene glycol diacetate, n-butyl acetate, propylene glycol monoethyl ether acetate, cyclohexyl acetate, 4-methyl-2-pentyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, butyl 3-methoxypropionate, n-butyl lactate, isoamyl lactate, diethylene glycol monoethyl ether, diisobutyl ketone (2,6-dimethyl-4-heptanone), and the like.

[0053] Of these, diisobutyl carbinol, propylene glycol monobutyl ether, propylene glycol diacetate, diethylene glycol diethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monobutyl ether, ethylene glycol monobutyl ether acetate, or diisobutyl ketone is preferred.

[0054] Preferred solvent combinations of a good solvent and a poor solvent include N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone and ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone and propylene glycol monobutyl ether, N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether, N-ethyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone, and N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether. Coal diacetate, N,N-dimethyl lactamide and diisobutyl ketone, N-methyl-2-pyrrolidone and ethyl 3-ethoxypropionate, N-ethyl-2-pyrrolidone and ethyl 3-ethoxypropionate, N-methyl-2-pyrrolidone, ethyl 3-ethoxypropionate and dipropylene glycol monomethyl ether, N-ethyl-2-pyrrolidone, ethyl 3-ethoxypropionate and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone, ethyl 3-ethoxypropionate and diethylene glycol mono propyl ether, N-ethyl-2-pyrrolidone, ethyl 3-ethoxypropionate, and diethylene glycol monopropyl ether, N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether acetate, N-ethyl-2-pyrrolidone and dipropylene glycol dimethyl ether, N,N-dimethyl lactamide and ethylene glycol monobutyl ether, N,N-dimethyl lactamide and propylene glycol diacetate, N-ethyl-2-pyrrolidone and diethylene glycol diethyl ether, N-ethyl-2 -pyrrolidone, diethylene glycol monoethyl ether, and butyl cellosolve acetate, N-methyl-2-pyrrolidone, diethylene glycol monomethyl ether, and butyl cellosolve acetate, N,N-dimethyl lactamide and diethylene glycol diethyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone, 4-hydroxy-4-methyl-2-pentanone, and diethylene glycol diethyl ether, N-ethyl-2-pyrrolidone, N-methyl-2-pyrrolidone, and 4-hydroxy-4-methyl-2-pentanone,N-ethyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone, and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone, and diisobutyl ketone, N-methyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone, and dipropylene glycol monomethyl ether, N-methyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone, and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone, and dipropylene glycol monomethyl ether Methyl-2-pentanone and propylene glycol diacetate, N-ethyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone and dipropylene glycol dimethyl ether, γ-butyrolactone, 4-hydroxy-4-methyl-2-pentanone and diisobutyl ketone, γ-butyrolactone, 4-hydroxy-4-methyl-2-pentanone and propylene glycol diacetate, N-methyl-2-pyrrolidone, γ-butyrolactone, propylene glycol monobutyl ether and diisobutyl ketone, N-methyl-2-pi rolidone, γ-butyrolactone, propylene glycol monobutyl ether, and diisopropyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone, propylene glycol monobutyl ether, and diisobutylcarbinol, N-methyl-2-pyrrolidone, γ-butyrolactone, and dipropylene glycol dimethyl ether, N-methyl-2-pyrrolidone, propylene glycol monobutyl ether, and dipropylene glycol dimethyl ether, N-ethyl-2-pyrrolidone, propylene glycol monobutyl ether, and dipropylene glycol pyrene glycol monomethyl ether, N-ethyl-2-pyrrolidone, diethylene glycol diethyl ether, and dipropylene glycol monomethyl ether, N-ethyl-2-pyrrolidone, propylene glycol monobutyl ether, and propylene glycol diacetate, N-ethyl-2-pyrrolidone, propylene glycol monobutyl ether, and diisobutyl ketone, N-ethyl-2-pyrrolidone, γ-butyrolactone, and diisobutyl ketone, N-ethyl-2-pyrrolidone, N,N-dimethyl lactamide, and diisobutyl ketone,Examples include N-methyl-2-pyrrolidone, ethylene glycol monobutyl ether, and ethylene glycol monobutyl ether acetate, γ-butyrolactone, ethylene glycol monobutyl ether acetate, and dipropylene glycol dimethyl ether, N-ethyl-2-pyrrolidone, ethylene glycol monobutyl ether acetate, and propylene glycol dimethyl ether, N-methyl-2-pyrrolidone, 4-methyl-2-pentyl acetate, and ethylene glycol monobutyl ether, N-ethyl-2-pyrrolidone, cyclohexyl acetate, and 4-hydroxy-4-methyl-2-pentanone, cyclohexanone, and propylene glycol monomethyl ether, cyclopentanone, and propylene glycol monomethyl ether, and N-methyl-2-pyrrolidone, cyclohexanone, and propylene glycol monomethyl ether.

[0055] (Liquid Crystal Alignment Agent) The liquid crystal aligning agent of the present invention may contain other components (hereinafter also referred to as additive components) in addition to the polymer (P), the other polymer, and the organic solvent. Examples of such additive components include at least one crosslinking compound selected from the group consisting of a crosslinking compound having at least one substituent selected from an oxiranyl group, an oxetanyl group, a blocked isocyanate group, an oxazoline group, a cyclocarbonate group, a hydroxy group, and an alkoxy group, and a crosslinking compound having a polymerizable unsaturated group, a functional silane compound, a metal chelate compound, a curing accelerator, a surfactant, an antioxidant, a sensitizer, a preservative, and a compound for adjusting the dielectric constant or electrical resistance of the resulting liquid crystal alignment film.

[0056] Specific preferred examples of the crosslinkable compound include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, dibromoneopentyl glycol diglycidyl ether, and 1,3,5,6-tetraglycidyl -2,4-hexanediol, bisphenol A type epoxy resins such as Epicoat 828 (manufactured by Mitsubishi Chemical Corporation), bisphenol F type epoxy resins such as Epicoat 807 (manufactured by Mitsubishi Chemical Corporation), hydrogenated bisphenol A type epoxy resins such as YX-8000 (manufactured by Mitsubishi Chemical Corporation), biphenyl skeleton-containing epoxy resins such as YX6954BH30 (manufactured by Mitsubishi Chemical Corporation), phenol novolac type epoxy resins such as EPPN-201 (manufactured by Nippon Kayaku Co., Ltd.), (o, m, p-)cresols such as EOCN-102S (manufactured by Nippon Kayaku Co., Ltd.), Novolac epoxy resins, triglycidyl isocyanurates such as TEPIC (manufactured by Nissan Chemical Industries, Ltd.), alicyclic epoxy resins such as Celloxide 2021P (manufactured by Daicel Chemical Industries, Ltd.), compounds containing a tertiary nitrogen atom typified by N,N,N',N'-tetraglycidyl-m-xylylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, or N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, oxyranilic acids such as tetrakis(glycidyloxymethyl)methane, etc. compounds having two or more oxetanyl groups described in paragraphs

[0170] to

[0175] of WO 2011 / 132751 having two or more oxetanyl groups; compounds having two or more blocked isocyanate groups such as Coronate AP Stable M, Coronate 2503, 2515, 2507, 2513, 2555, Millionate MS-50 (all manufactured by Tosoh Corporation), and Takenate B-830, B-815N, B-820NSU, B-842N, B-846N, B-870N, B-874N, and B-882N (all manufactured by Mitsui Chemicals, Inc.);Compounds having an oxazoline group such as 2,2'-bis(2-oxazoline), 2,2'-bis(4-methyl-2-oxazoline), 2,2'-bis(5-methyl-2-oxazoline), 1,2,4-tris-(2-oxazolinyl-2)-benzene, and EPOCROS (manufactured by Nippon Shokubai Co., Ltd.); compounds having a cyclocarbonate group described in paragraphs

[0025] to

[0030] and

[0032] of WO2011 / 155577; N,N,N',N'-tetrakis(2-hydroxyethyl)adipamide, 2,2-bis(4-hydroxy-3,5-dihydroxymethylphenyl)propane, 2,2-bis(4-hydroxy-3,5-dimethoxymethylphenyl)propane, 2,2-bis(4-hydroxy-3,5-di Examples of the crosslinkable compound include compounds having a hydroxy group or an alkoxy group, such as (hydroxymethylphenyl)-1,1,1,3,3,3-hexafluoropropane; and compounds represented by glycerin mono(meth)acrylate, glycerin di(meth)acrylate (1,2-,1,3-mixture), glycerin tris(meth)acrylate, glycerol 1,3-diglycerolate di(meth)acrylate, pentaerythritol tri(meth)acrylate, diethylene glycol mono(meth)acrylate, triethylene glycol mono(meth)acrylate, tetraethylene glycol mono(meth)acrylate, pentaethylene glycol mono(meth)acrylate, and hexaethylene glycol mono(meth)acrylate. The content of the crosslinkable compound is preferably 0.1 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, per 100 parts by mass of the polymer component contained in the liquid crystal aligning agent.

[0057] Examples of the compound for adjusting the dielectric constant or electrical resistance include monoamines having a nitrogen atom-containing aromatic heterocycle such as 3-picolylamine. The content of the monoamine having a nitrogen atom-containing aromatic heterocycle is preferably 0.1 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, per 100 parts by mass of the polymer component contained in the liquid crystal aligning agent.

[0058] Specific preferred examples of the functional silane compound include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyldiethoxymethylsilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and 3-glycidoxypropylmethyldimethoxysilane. , 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, tris[3-(trimethoxysilyl)propyl]isocyanurate, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, etc. The content of the functional silane compound is preferably 0.1 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, per 100 parts by mass of the polymer component contained in the liquid crystal alignment agent.

[0059] The solids concentration of the liquid crystal aligning agent (the ratio of the total mass of the components other than the solvent of the liquid crystal aligning agent to the total mass of the liquid crystal aligning agent) is appropriately selected taking into consideration viscosity, volatility, etc., but is preferably 1 to 10% by mass. The particularly preferred solids concentration range varies depending on the method used to apply the liquid crystal aligning agent to the substrate. For example, when using a spin coating method, a solids concentration of 1.5 to 4.5% by mass is particularly preferred. When using a printing method, a solids concentration of 3 to 9% by mass is particularly preferred, thereby resulting in a solution viscosity of 12 to 50 mPa·s. When using an inkjet method, a solids concentration of 1 to 5% by mass is particularly preferred, thereby resulting in a solution viscosity of 3 to 15 mPa·s. The temperature when preparing the liquid crystal aligning agent is preferably 10 to 50°C, more preferably 20 to 30°C.

[0060] (Liquid crystal alignment film and liquid crystal display element) The liquid crystal display element according to the present invention includes a liquid crystal alignment film formed using the liquid crystal aligning agent. The operation mode of the liquid crystal display element is not particularly limited, and it can be applied to various operation modes, such as TN mode, STN mode, vertical alignment mode (including VA-MVA mode, VA-PVA mode, etc.), in-plane switching mode (IPS mode, FFS mode), optically compensated bend mode (OCB mode), etc.

[0061] The liquid crystal display element of the present invention can be produced, for example, by a method including the following steps (1) to (4), a method including steps (1) to (2) and (4), a method including steps (1) to (3), (4-2) and (4-4), or a method including steps (1) to (3), (4-3) and (4-4).

[0062] <Step (1): Applying a Liquid Crystal Alignment Agent to a Substrate> Step (1) is a step of applying a liquid crystal alignment agent to a substrate. A specific example of step (1) is as follows: The liquid crystal alignment agent is applied to one side of a substrate having a patterned transparent conductive film by an appropriate application method, such as a roll coater method, a spin coat method, a printing method, an inkjet method, or a spray method. The material of the substrate is not particularly limited as long as it is highly transparent. In addition to glass and silicon nitride, plastics such as acrylic and polycarbonate can also be used. In addition, in a reflective liquid crystal display element, an opaque material such as a silicon wafer can be used for only one substrate. In this case, a light-reflecting material such as aluminum can also be used for the electrode. Furthermore, when manufacturing an IPS or FFS liquid crystal display element, a substrate having an electrode made of a comb-shaped patterned transparent conductive film or metal film and an opposing substrate having no electrode are used. An IPS substrate, which is a comb electrode substrate used in an IPS-mode liquid crystal display element, has, for example, a base material, a plurality of linear electrodes formed on the base material and arranged in a comb-teeth pattern, and a liquid crystal alignment film formed on the base material so as to cover the linear electrodes. Meanwhile, an FFS substrate, which is a comb electrode substrate used in an FFS-mode liquid crystal display element, has, for example, a base material, a surface electrode formed on the base material, an insulating film formed on the surface electrode, a plurality of linear electrodes formed on the insulating film and arranged in a comb-teeth pattern, and a liquid crystal alignment film formed on the insulating film so as to cover the linear electrodes.

[0063] More preferred examples of the method for applying the liquid crystal aligning agent to a substrate and forming a film include printing methods such as screen printing, offset printing, and flexographic printing, spin coating, inkjet printing, and spraying, etc. Among these, application and film formation methods by flexographic printing, spin coating, and inkjet printing are preferably used.

[0064] <Step (2): Step of Baking the Applied Liquid Crystal Alignment Agent> Step (2) is a step of baking the liquid crystal alignment agent applied to the substrate to form a film. Specific examples of step (2) are as follows. After applying the liquid crystal alignment agent to the substrate in step (1), the solvent can be evaporated or a polyimide precursor, such as polyamic acid, can be thermally imidized using a heating means such as a hot plate, a heat circulation oven, or an IR (infrared) oven. The drying and baking steps after applying the liquid crystal alignment agent can be performed at any temperature and for any time, and may be performed multiple times. The temperature at which the liquid crystal alignment agent is baked can be, for example, 40 to 180°C. From the perspective of shortening the process, it may be performed at 40 to 150°C. The baking time is not particularly limited, but may be 1 to 10 minutes or 1 to 5 minutes. When thermal imidization of a polyimide precursor, such as polyamic acid, is carried out, a baking step may be added after the above step, for example, at 150 to 300°C or 150 to 250°C. The baking time is not particularly limited, but is, for example, 5 to 40 minutes, and preferably 5 to 30 minutes. If the film-like material after baking is too thin, the reliability of the liquid crystal display element may decrease, so the film thickness is preferably 5 to 300 nm, and more preferably 10 to 200 nm.

[0065] <Step (3): Alignment Treatment of the Film Obtained in Step (2)> Step (3) is a step of optionally aligning the film obtained in Step (2). That is, in horizontal alignment mode liquid crystal display elements such as IPS mode or FFS mode, the coating film is subjected to an alignment ability imparting treatment. On the other hand, in vertical alignment mode liquid crystal display elements such as VA mode or PSA (Polymer Sustained Alignment) mode, the formed coating film can be used as a liquid crystal alignment film as is, or the coating film may be subjected to an alignment ability imparting treatment. Examples of alignment treatment methods for liquid crystal alignment films include rubbing alignment treatment and photoalignment treatment. Examples of photoalignment treatment methods include irradiating the surface of the film-like material with polarized radiation in a certain direction, and optionally performing a heat treatment to impart liquid crystal alignment (also referred to as liquid crystal alignment ability). The radiation can be ultraviolet light or visible light having a wavelength of 100 to 800 nm. Among these, ultraviolet light having a wavelength of 100 to 400 nm is preferred, and more preferably 200 to 400 nm.

[0066] The radiation dose is 1 to 10,000 mJ / cm ２ is preferable, and among these, 100 to 5,000 mJ / cm ２ In addition, when irradiating with radiation, the substrate having the film-like material may be irradiated while being heated at 50 to 250° C. in order to improve the liquid crystal alignment. The liquid crystal alignment film prepared in this manner can stably align liquid crystal molecules in a certain direction.

[0067] Furthermore, the coating film irradiated with polarized radiation or the coating film subjected to rubbing alignment treatment by the above method may be subjected to a contact treatment using water or a solvent. Furthermore, the film subjected to the above alignment treatment may be subjected to a heat treatment without being subjected to a contact treatment. Furthermore, the film subjected to the above contact treatment may be further subjected to a heat treatment.

[0068] The solvent used in the contact treatment is not particularly limited as long as it dissolves the decomposition products generated from the film-like material by irradiation. Specific examples include water, methanol, ethanol, 2-propanol, acetone, methyl ethyl ketone, 1-methoxy-2-propanol, 1-methoxy-2-propanol acetate, butyl cellosolve, ethyl lactate, methyl lactate, diacetone alcohol, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propyl acetate, butyl acetate, and cyclohexyl acetate. The solvent may be used alone or in combination of two or more.

[0069] The temperature for the heat treatment of the coating film irradiated with the radiation is more preferably 50 to 300° C., and even more preferably 120 to 250° C. The heat treatment time is preferably 1 to 30 minutes.

[0070] <Step (4): Step of Fabricating a Liquid Crystal Cell> Two substrates on which liquid crystal alignment films are formed are prepared as described above, and a liquid crystal is placed between the two substrates arranged opposite each other. Specifically, the following two methods can be used. In the first method, the two substrates are first arranged opposite each other with a gap (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. A liquid crystal composition is injected into the substrate surfaces and the cell gap defined by the sealant, contacting the film surface, and then the injection hole is sealed. 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. Note that, hereinafter, 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 include a liquid crystal compound having a fluorine atom, a hydroxy group, an amino group, a fluorine-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 include a compound having two or more rigid moieties (mesogenic skeletons) that exhibit liquid crystallinity within the molecule (e.g., a bimesogenic compound in which two rigid biphenyl structures or terphenyl structures are connected by an alkyl group). The liquid crystal composition may be a liquid crystal composition exhibiting a nematic phase, a smectic phase, or a cholesteric phase. Furthermore, the liquid crystal composition may further contain an additive to improve liquid crystal alignment properties. Such additives include photopolymerizable monomers such as compounds having a polymerizable group (e.g., meth(acryloyl group), etc.); optically active compounds (e.g., S-811 manufactured by Merck Ltd., etc.); antioxidants; ultraviolet absorbers; dyes; antifoaming agents; polymerization initiators; or polymerization inhibitors. Examples of positive liquid crystals include ZLI-2293, ZLI-4792, MLC-2003, MLC-2041, MLC-3019, and MLC-7081 manufactured by Merck Ltd.Examples of negative liquid crystals include MLC-6608, MLC-6609, MLC-6610, MLC-6882, MLC-6886, MLC-7026, MLC-7026-000, MLC-7026-100, and MLC-7029 manufactured by Merck & Co., Inc. In addition, in the PSA mode, an example of a liquid crystal containing a compound having a polymerizable group is MLC-3023 manufactured by Merck & Co., Inc.

[0071] The second method is called the ODF (One Drop Fill) method. A UV-curable sealant, for example, 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 either method, it is desirable to further 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 flow alignment that occurs during liquid crystal filling. If the coating film is subjected to a rubbing alignment treatment, the two substrates are positioned opposite each other so that the rubbing directions of the coating films are at a predetermined angle to each other, for example, perpendicular or antiparallel. For example, an epoxy resin containing a curing agent and aluminum oxide spheres as spacers can be used as the sealant. The liquid crystal may be a nematic liquid crystal or a smectic liquid crystal, with the nematic liquid crystal being preferred.

[0072] The liquid crystal aligning agent of the present invention is also preferably used in a liquid crystal display element (PSA-type liquid crystal display element) manufactured by a process of: having a liquid crystal layer between a pair of substrates equipped with electrodes, disposing a liquid crystal composition containing a polymerizable compound that polymerizes by at least one of active energy rays and heat between the pair of substrates, and polymerizing the polymerizable compound by at least one of irradiation with active energy rays and heating while applying a voltage between the electrodes. The liquid crystal aligning agent of the present invention is also preferably used in a liquid crystal display element (SC-PVA-type liquid crystal display element) manufactured by a process of having a liquid crystal layer between a pair of substrates equipped with electrodes, disposing a liquid crystal alignment film between the pair of substrates that contains a polymerizable group that polymerizes by at least one of active energy rays and heat, and applying a voltage between the electrodes.

[0073] <Step (4-2): In the case of a PSA-type liquid crystal display element> This step is carried out in the same manner as in the above step (4), except that a liquid crystal composition containing a polymerizable compound is injected or dropped. Examples of the polymerizable compound include polymerizable compounds having one or more polymerizable unsaturated groups, such as an acrylate group or a methacrylate group, in the molecule.

[0074] <Step (4-3): In the Case of an SC-PVA-Type Liquid Crystal Display Element> A method for producing a liquid crystal display element may be employed, following the procedure described above in (4), followed by a step of irradiating with ultraviolet light, as described below. This method, similar to the production of a PSA-type liquid crystal display element, allows for the production of a liquid crystal display element with excellent response speed with a low light exposure dose. The compound having a polymerizable group may be a compound having one or more of the above-described polymerizable unsaturated groups in the molecule, and the content thereof is preferably 0.1 to 30 parts by mass, more preferably 1 to 20 parts by mass, per 100 parts by mass of all polymer components. Furthermore, the polymerizable group may be contained in a polymer used in a liquid crystal aligning agent. Examples of such polymers include polymers obtained by reacting a diamine component containing a diamine having the above-described photopolymerizable group at its terminal.

[0075] <Step (4-4): Step of Irradiating Ultraviolet Light> The liquid crystal cell is irradiated with light while a voltage is applied between the conductive films of the pair of substrates obtained in step (4-2) or (4-3) above. The voltage applied here can be, for example, a direct current or alternating current of 5 to 50 V. The light to be irradiated can be, for example, ultraviolet light and visible light containing light with a wavelength of 150 to 800 nm, but ultraviolet light containing light with a wavelength of 300 to 400 nm is preferred. The light source for the irradiation light can be, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, or an excimer laser. The light irradiation dose is preferably 1,000 to 200,000 J / m ２ and more preferably 1,000 to 100,000 J / m ２ is.

[0076] A liquid crystal display element can be obtained by attaching a polarizing plate to the outer surface of the liquid crystal cell as needed. Examples of the polarizing plate to be attached to the outer surface of the liquid crystal cell include a polarizing film called an "H film" made by stretching and aligning polyvinyl alcohol and absorbing iodine, sandwiched between cellulose acetate protective films, and a polarizing plate made of the H film itself.

[0077] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. The abbreviations of the compounds used and the methods for measuring the physical properties are as follows:

[0078] (Organic solvent) NMP: N-methyl-2-pyrrolidone BCS: Butyl cellosolve (ethylene glycol monobutyl ether)

[0079] (Acid dianhydride) CA-1: A compound represented by the following formula (CA-1)

[0080] (Diamine) DA-1 to DA-5: Compounds represented by the following formulas (DA-1) to (DA-5), respectively. The diamine included in the scope of the specific diamine of the present invention is a compound represented by the following formula (DA-1).

[0081] <Measurement of Molecular Weight> Measurement was carried out using the following room temperature GPC (gel permeation chromatography) apparatus, and Mn and Mw were calculated as polyethylene glycol and polyethylene oxide equivalent values. GPC apparatus: GPC-101 (Showa Denko K.K.), column: GPC KD-803 and GPC KD-805 (Showa Denko K.K.) connected in series, column temperature: 50°C, eluent: N,N-dimethylformamide (containing lithium bromide monohydrate (LiBr.H) as an additive). ２ o) at 30 mmol / L, anhydrous crystalline phosphoric acid (o-phosphoric acid) at 30 mmol / L, tetrahydrofuran (THF) at 10 mL / L), flow rate: 1.0 mL / min. Standard samples for preparing a calibration curve: TSK standard polyethylene oxide (molecular weight: approximately 900,000, 150,000, 100,000, and 30,000) (manufactured by Tosoh Corporation) and polyethylene glycol (molecular weight: approximately 12,000, 4,000, and 1,000) (manufactured by Polymer Laboratory Co., Ltd.). [Synthesis of Monomers] DA-4 and DA-5 were synthesized by the method described in WO2017 / 047596. DA-1 and DA-3 are novel compounds not disclosed in the literature, and their synthesis methods are described in detail below. The products described in the following Monomer Synthesis Examples are １ The product was identified by H-NMR analysis (analysis conditions are as follows): Apparatus: Fourier transform superconducting nuclear magnetic resonance spectrometer (FT-NMR) "AVANCE III" (manufactured by BRUKER) 500 MHz; Solvent: Deuterated dimethyl sulfoxide (DMSO-d ６ , standard substance: tetramethylsilane)

[0082] (Monomer Synthesis Example 1: Synthesis of DA-1) DA-1 was synthesized according to the route shown below.

[0083] Under a nitrogen atmosphere, a 500 mL four-neck flask was charged with 1-fluoro-4-nitro-2 (trifluoromethyl) benzene (48.0 g, 230 mmol), ethylene glycol (6.83 g, 110 mmol), potassium carbonate (38.1 g, 276 mmol), and dimethylformamide (384 g), and the mixture was stirred at 80 ° C. for 15 hours to carry out the reaction. After the reaction, the potassium carbonate was removed by filtration, and the resulting filtrate was concentrated to 100 g, and then water (300 g) was added to precipitate crystals. The crystals were filtered off, and the cake was washed twice with water (100 g), and then the cake was washed twice with a mixed solution of acetone (100 g) and water (50 g). The resulting solid was dried to obtain DA-1-1 (41.7 g, 94.7 mmol, yield 86.1%, yellow solid).

[0084] Under a nitrogen atmosphere, DA-1-1 (40.9 g, 93.0 mmol) obtained above, tetrahydrofuran (283 g), and carbon-supported palladium (5% Pd carbon powder (50% water content) K type, manufactured by N.E. Chemcat Corporation, 8.00 g) were added to a 500 mL four-neck flask, and after replacing the atmosphere with hydrogen, the reaction was carried out at room temperature. After completion of the reaction, the carbon-supported palladium was removed by filtration, and the resulting filtrate was concentrated to obtain a wet product, which was then dried under vacuum at 50°C to obtain DA-1 (33.6 g, 88.5 mmol, yield 95.2%, brown solid). １ The results of H-NMR confirmed that this solid was DA-1. １ H-NMR (500MHz, DMSO-d ６ ): δ (ppm) = 6.75 (d, 2H, J = 9.2Hz), 6.80-6.73 (m, 4H), 5.04 (s, 4H), 4.17 (s, 4H).

[0085] (Monomer Synthesis Example 2: Synthesis of DA-3) DA-3 was synthesized according to the route shown below.

[0086] Under a nitrogen atmosphere, 2-fluoro-4-nitrophenol (24.2 g, 154 mmol), 1,2-dibromoethane (13.2 g, 70.3 mmol), potassium carbonate (18.7 g, 135 mmol), and dimethylformamide (120 g) were added to a 300 mL four-neck flask, and the mixture was stirred at 80 ° C. for 15 hours to carry out the reaction. After the reaction, the reaction solution was transferred to a 1 L beaker, and water (600 g) was added to precipitate crystals. The crystals were filtered off, and the cake was washed once with tetrahydrofuran (100 g), and the resulting solid was dried to obtain DA-3-1 (14.2 g, 41.7 mmol, yield 60.0%).

[0087] Under a nitrogen atmosphere, DA-3-1 (14.2 g, 41.7 mmol) obtained above, dimethylformamide (61.2 g), and carbon-supported platinum (3% Pt carbon powder (50% water content), manufactured by Evonik, 1.42 g) were added to a 200 mL four-neck flask, and after replacing the atmosphere with hydrogen, the reaction was carried out at room temperature for 48 hours. After completion of the reaction, the carbon-supported platinum was removed by filtration, and the obtained filtrate was transferred to a separatory funnel, and ethyl acetate (400 g) was added. Thereafter, separation washing was carried out twice with water (300 g), and the obtained organic layer was concentrated and further dried in vacuo at 50 ° C. to obtain DA-3 (8.00 g, 28.5 mmol, yield 68.3%). As shown below １ The results of H-NMR confirmed that this solid was DA-3. １ H-NMR (500MHz, DMSO-d ６ ): δ (ppm) = 6.86 (t, 2H, J = 9.0Hz), 6.39 (dd, 2H, J = 13.5Hz, 2.0Hz) 6.30-6.28 (m, 2H), 4.94 (s, 4H), 4.07 (s, 4H).

[0088] [Polymer Synthesis] <Synthesis Example 1> DA-2 (0.541 g, 5.00 mmol), DA-1 (1.90 g, 5.00 mmol), and NMP (17.9 g) were added to a 50 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and dissolved by stirring at room temperature while supplying nitrogen. Thereafter, CA-1 (2.15 g, 9.60 mmol) and NMP (15.8 g) were added, and the mixture was stirred at 40°C for 24 hours to obtain a solution of polyamic acid (PAA-1) with a solids concentration of 12% by mass. The Mn of this polyamic acid was 12,800 and the Mw was 31,600.

[0089] Synthesis Example 2 DA-2 (0.541 g, 5.00 mmol), DA-3 (1.40 g, 5.00 mmol), and NMP (14.2 g) were added to a 50 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and dissolved by stirring at room temperature while supplying nitrogen. CA-1 (2.15 g, 9.60 mmol) and NMP (15.8 g) were then added, and the mixture was stirred at 40° C. for 24 hours to obtain a solution of polyamic acid (PAA-2). The Mn of this polyamic acid was 13,000 and the Mw was 35,500.

[0090] Synthesis Example 3 DA-2 (0.541 g, 5.00 mmol), DA-4 (1.31 g, 5.00 mmol), and NMP (13.6 g) were added to a 50 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and dissolved by stirring at room temperature while supplying nitrogen. Thereafter, CA-1 (2.15 g, 9.60 mmol) and NMP (15.8 g) were added, and the mixture was stirred at 40° C. for 24 hours to obtain a solution of polyamic acid (PAA-3) with a solids concentration of 12% by mass. The Mn of this polyamic acid was 12,900 and the Mw was 34,600.

[0091] Synthesis Example 4 DA-2 (0.541 g, 5.00 mmol), DA-5 (1.36 g, 5.00 mmol), and NMP (14.0 g) were added to a 50 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and dissolved by stirring at room temperature while supplying nitrogen. Thereafter, CA-1 (2.15 g, 9.60 mmol) and NMP (15.7 g) were added, and the mixture was stirred at 40° C. for 24 hours to obtain a solution of polyamic acid (PAA-4) with a solids concentration of 12% by mass. The Mn of this polyamic acid was 13,000 and the Mw was 31,700.

[0092] The specifications of the polyamic acid solutions obtained in the above synthesis examples are shown in Table 1. In Table 1, the numbers in parentheses for the tetracarboxylic acid component and diamine component represent the amount (parts by mole) of each tetracarboxylic acid component and each diamine component used relative to 100 parts by mole of the total amount of the diamine components used in each polymerization step.

[0093]

[0094] [Preparation of Liquid Crystal Alignment Agent] <Example 1> NMP (14.0 g) and BCS (6.00 g) were added to the solution (10.0 g) of polyamic acid (PAA-1) obtained in Synthesis Example 1 above, and the mixture was stirred at room temperature for 30 minutes to obtain a liquid crystal alignment agent (AL-1).

[0095] Comparative Examples 1 to 3: Liquid crystal aligning agents (AL-2) to (AL-4) were obtained by carrying out the same procedure as in Example 1, except that the polyamic acid solution used was replaced from (PAA-1) to (PAA-2) to (PAA-4). The specifications of the liquid crystal aligning agents obtained in the above examples and comparative examples are shown in Table 2.

[0096]

[0097] The liquid crystal alignment agents (AL-1) to (AL-4) obtained as described above were confirmed to be homogeneous solutions without any abnormalities such as turbidity or precipitation. The obtained liquid crystal alignment agents were used to evaluate the in-plane uniformity of contrast and the water contact angle.

[0098] [Preparation of Liquid Crystal Cell] A liquid crystal cell was prepared using the liquid crystal alignment agent obtained above according to the procedure described below. Each liquid crystal alignment agent was filtered through a filter with a pore size of 1.0 μm, and then applied to a glass substrate (40 mm long x 30 mm wide x 0.7 mm thick) with an ITO electrode by spin coating. The substrate was dried on a hot plate at 80°C for 60 seconds, and then baked in an infrared heating furnace at 230°C for 20 minutes to form a liquid crystal alignment film with a film thickness of 100 nm. Linearly polarized ultraviolet light with a wavelength of 254 nm and an extinction ratio of 26:1 was irradiated on the coated film surface through a polarizer at 400 mJ / cm. ２ or 600 mJ / cm ２ or 800 mJ / cm ２ The substrate was then irradiated with either of the above-mentioned UV-IR or UV-IR IR sources, and baked in an infrared heating furnace at 230°C for 30 minutes to obtain a substrate with a liquid crystal alignment film (first glass substrate). A substrate with a liquid crystal alignment film (second glass substrate) was obtained in the same manner as above, except that the alignment treatment was performed so that the alignment direction was perpendicular to that of the first glass substrate. The two substrates were combined into a pair, and 4 μm diameter bead spacers (SW-D1, manufactured by JGC Catalysts and Chemicals) were applied to the liquid crystal alignment film of one of the substrates. A sealant (XN-1500T, manufactured by Mitsui Chemicals) was printed around the periphery, leaving a liquid crystal injection port, and the other substrate was attached so that the alignment direction of the liquid crystal alignment film surfaces facing each other was 0°. The sealant was then heat-treated at 150°C for 60 minutes to harden it, producing an empty cell. 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 a liquid crystal cell. The resulting liquid crystal cell was then heated at 120° C. for 1 hour before being used for evaluation.

[0099] [Evaluation of In-Plane Uniformity of Contrast] The variation in the twist angle of the liquid crystal cell was evaluated using an AxoStep manufactured by AXOMETRICS. The liquid crystal cell prepared as described above was placed on a measurement stage, and the distribution of circular retardance within the pixel plane was measured with no voltage applied, and 3σ, which is three times the standard deviation σ, was calculated. The smaller the 3σ value, the better the in-plane uniformity. As evaluation criteria, a 3σ value of 3.00 or less was evaluated as "○", a 3σ value of more than 3.00 and less than or equal to 5.00 was evaluated as "△", and a 3σ value of more than 5.00 was evaluated as "×". The results are shown in Table 3.

[0100] [Evaluation of Water Contact Angle] The liquid crystal alignment agents obtained above were each filtered through a filter with a pore size of 1.0 μm, and then applied by spin coating to a glass substrate (40 mm long x 30 mm wide x 1.1 mm thick) with an ITO electrode. The substrate was dried on a hot plate at 80° C. for 60 seconds, and then baked in an infrared heating furnace at 230° C. for 20 minutes to form a liquid crystal alignment film with a film thickness of 100 nm. Linearly polarized ultraviolet light with a wavelength of 254 nm and an extinction ratio of 26:1 was irradiated on the coated film surface through a polarizer at 500 mJ / cm. ２ The substrate was irradiated with light and further baked in an infrared heating furnace at 230°C for 30 minutes to obtain a substrate with a liquid crystal alignment film. The water contact angle of this substrate was measured using a fully automatic contact angle meter (DM-701, manufactured by Kyowa Interface Science Co., Ltd.). As the evaluation criteria, a water contact angle of more than 50° was rated as "○", and a water contact angle of 50° or less was rated as "×". The results are shown in Table 3.

[0101]

[0102] As shown in Table 3, the liquid crystal alignment film obtained using the liquid crystal alignment agent (AL-1) of Example 1 exhibited good in-plane uniformity over a wide range of exposure dose and a higher water contact angle than the liquid crystal alignment films obtained using the liquid crystal alignment agents (AL-2) to (AL-4) of Comparative Examples 1 to 3.

[0103] The liquid crystal alignment film obtained from the liquid crystal aligning agent of the present invention is widely used in liquid crystal display elements of various operation modes, and can also be used, for example, 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 type liquid crystal dimming element.

[0104] The liquid crystal display element of the present invention can be effectively applied to devices having various functions, and can be used, for example, in liquid crystal televisions, clocks, portable games, word processors, notebook computers, car navigation systems, camcorders, PDAs, digital cameras, mobile phones, smartphones, various monitors, information displays, etc.

[0105] In addition, the entire contents of the specification, claims, drawings and abstract of Japanese Patent Application No. 2021-177005 filed on October 28, 2021, and the entire contents of the specification, claims, drawings and abstract of Japanese Patent Application No. 2021-189680 filed on November 22, 2021 are hereby incorporated by reference as the disclosure of the specification of the present invention.

Claims

1. The following formula (D Ａ and a polyimide obtained by imidizing the polyimide precursor. 【Chemical 1】 (R １ are each independently a hydrogen atom, a methyl group, a fluorine atom, a fluoroalkyl group having 1 to 3 carbon atoms and two or more fluorine atoms, or a fluoroalkoxy group having 1 to 3 carbon atoms and two or more fluorine atoms; R １ At least one of the groups represents a fluoroalkyl group having 1 to 3 carbon atoms and two or more fluorine atoms, or a fluoroalkoxy group having 1 to 3 carbon atoms and two or more fluorine atoms. Z １ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, or an alkynyl group having 2 to 6 carbon atoms, and a hydrogen atom of the alkyl group, alkenyl group, or alkynyl group may be substituted with a monovalent group. n is an integer of 1 to 6.

2. The diamine (0) is represented by the following formula (d Ａ -1) to (d Ａ The liquid crystal aligning agent according to claim 1, wherein the diamine is any one selected from the group consisting of: 【Chemistry 2】 (Z １ is the formula (D Ａ ) in Z １ is synonymous with

3. The polymer (P) is a polymer having at least one repeating unit selected from the group consisting of a repeating unit (p1) represented by the following formula (1) and an imidized structural unit of the repeating unit (p1), any one of claims 1 to 2, the liquid crystal aligning agent. 【Chemistry 3】 (In formula (1), X １ represents a tetravalent organic group. １ is the formula (D Ａ R and Z each independently represent a hydrogen atom or a monovalent organic group.

4. The polymer (P) is obtained by a polycondensation reaction of the diamine component and a tetracarboxylic acid component containing an acyclic aliphatic tetracarboxylic acid dianhydride, an alicyclic tetracarboxylic acid dianhydride, an aromatic tetracarboxylic acid dianhydride, or a derivative thereof, the liquid crystal aligning agent according to any one of claims 1 to 3.

5. The liquid crystal aligning agent according to any one of claims 1 to 4, wherein the amount of the diamine (0) used is 5 mol% or more based on the diamine component.

6. Further, the liquid crystal aligning agent according to any one of claims 1 to 5, containing at least one polymer (B) selected from the group consisting of a polyimide precursor obtained using a diamine component not containing the diamine (0) and a polyimide which is an imidized product of the polyimide precursor.

7. A liquid crystal alignment film obtained from the liquid crystal aligning agent according to any one of claims 1 to 6.

8. A liquid crystal display device comprising the liquid crystal alignment film according to claim 7.

9. A method for manufacturing a liquid crystal display element, comprising the following steps (1) to (3): Step (1): A step of applying the liquid crystal aligning agent according to any one of claims 1 to 6 onto a substrate. Step (2): A step of baking the applied liquid crystal alignment agent to obtain a film. Step (3): A step of subjecting the film obtained in step (2) to an alignment treatment.

10. The method for manufacturing a liquid crystal display element according to claim 9 , wherein the alignment treatment is a photo-alignment treatment.

11. The following formula (d Ａ -1) to (d Ａ -6). 【Chemistry 4】 (Z １ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, or an alkynyl group having 2 to 6 carbon atoms, and a hydrogen atom of the alkyl group, alkenyl group, or alkynyl group may be substituted with a monovalent group. n is an integer of 1 to 6.

12. A polymer obtained from a diamine component comprising the diamine according to claim 11.

13. A polyimide precursor obtained by a polycondensation reaction between a diamine component containing the diamine according to claim 11 and a tetracarboxylic acid component, or an imidized product thereof.

14. The following formula (D Ａ and at least one polymer selected from the group consisting of polyimide precursors obtained by using a diamine component containing diamine (0) represented by the formula (I) and polyimides which are imidized products of the polyimide precursors. 【Chemistry 5】 (R １ are each independently a hydrogen atom, a methyl group, a fluorine atom, a fluoroalkyl group having 1 to 3 carbon atoms and two or more fluorine atoms, or a fluoroalkoxy group having 1 to 3 carbon atoms and two or more fluorine atoms; R １ At least one of the groups represents a fluoroalkyl group having 1 to 3 carbon atoms and two or more fluorine atoms, or a fluoroalkoxy group having 1 to 3 carbon atoms and two or more fluorine atoms. Z １ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, or an alkynyl group having 2 to 6 carbon atoms, and a hydrogen atom of the alkyl group, alkenyl group, or alkynyl group may be substituted with a monovalent group. n is an integer of 1 to 6.

15. The formula (d Ａ -1) to (d Ａ 12. The diamine according to claim 11, wherein -6) is the following formula DA-1: 【Chemistry 6】

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