Liquid crystal aligning agent, liquid crystal alignment film, liquid crystal display element, and method for producing same

Abstract

The invention provides a liquid crystal aligning agent, a liquid crystal alignment film, a liquid crystal display element and a manufacturing method of the liquid crystal aligning agent. The liquid crystal aligning agent can obtain a liquid crystal alignment film which can restrain ghosting just after switching under the condition that display brightness is greatly changed. A liquid crystal aligning agent which contains a polymer component (P) containing one or more polymers and a component (C), and wherein the polymer component (P) contains at least one polymer (P) selected from the group consisting of polyimide precursors and polyimides that are imides of the polyimide precursors. Component (C): at least one compound selected from the group consisting of acids and salts containing periodate ions.

Description

Technical Field

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

[0002] Liquid crystal display elements include, for example, a liquid crystal layer sandwiched between an element substrate and a color filter substrate; pixel electrodes and a common electrode for applying an electric field to the liquid crystal layer; a liquid crystal alignment film for controlling the orientation of liquid crystal molecules in the liquid crystal layer; and a thin film transistor (TFT) for switching the electrical signal supplied to the pixel electrode. As driving methods for liquid crystal molecules, known methods include longitudinal electric field methods such as TN (Twisted Nematic) method and VA (Vertical Alignment) method; and transverse electric field methods such as IPS (In-Plane Switching) method and FFS (Fringe Field Switching) method.

[0003] At present, the most popular liquid crystal alignment film in industry is made by performing so-called rubbing treatment, which is to use cloth such as cotton, nylon, polyester, etc. to rub the surface of the film formed on the electrode substrate, which is formed by a polymer represented by polyamic acid and / or polyimide imidized therefrom, in one direction (for example, refer to patent document 1). Rubbing treatment is a simple and industrially useful method with excellent productivity. On the other hand, with the high performance, high refinement and large-scale of liquid crystal display elements, as an orientation treatment method replacing rubbing treatment, it is known to have a photo-orientation method that imparts liquid crystal orientation ability by irradiating polarized radiation. As far as the photo-orientation method is concerned, it is proposed: a method using photoisomerization reaction, a method using photocrosslinking reaction, a method using photodecomposition reaction, etc. (for example, refer to patent document 2, non-patent document 1).

[0004] In addition, static electricity is easily accumulated in liquid crystal display elements represented by IPS and FFS methods. The accumulated charge affects the display in the form of disordered orientation of liquid crystal molecules, afterimages, and sintering, which significantly reduces the display quality of the liquid crystal display element. In particular, in the IPS and FFS methods, the distance between the pixel electrode and the common electrode is closer than that in the longitudinal electric field method, so there is the following problem: a strong electric field acts on the liquid crystal alignment film and the liquid crystal layer, and such adverse conditions are easy to become significant.

[0005] As a method for suppressing accumulated charges, use of a liquid crystal aligning agent containing a specific polymer component has been reported (for example, refer to Patent Document 3).

[0006] In recent years, large-screen, high-definition liquid crystal display elements have become the mainstream. In addition, the popularity of small display terminals such as smartphones, tablet PCs, and car navigation systems has continued to grow, and the demand for higher quality liquid crystal display elements has increased and further improved than ever before.

[0007] In particular, it is required to reduce afterimages (hereinafter also referred to as afterimages immediately after switching) which are caused when the display brightness of a liquid crystal display element is not displayed at the correct brightness immediately after returning to the original display brightness after a large change in the display brightness.

[0008] Prior art literature

[0009] Patent Literature

[0010] Patent Document 1: WO2016 / 063834

[0011] Patent Document 2: Japanese Patent Application Publication No. 2011-107266

[0012] Patent Document 3: WO2015 / 050135

[0013] Non-patent literature

[0014] Non-patent document 1: "Liquid crystal photo-alignment film" Kidowaki, Ichimura Functional Materials, November 1997, Vol. 17, No. 1113-22 Summary of the invention

[0015] Problems to be solved by the invention

[0016] From the above, an object of the present invention is to provide a liquid crystal aligning agent that can obtain a liquid crystal aligning film capable of suppressing image sticking immediately after switching when display brightness is greatly changed, and a liquid crystal aligning film and a liquid crystal display element obtained from the liquid crystal aligning agent.

[0017] Solutions for solving problems

[0018] The present inventors have conducted intensive studies to solve the above-mentioned technical problems and have found that the use of a liquid crystal aligning agent containing a polymer component (P) containing one or more polymers and a specific compound component is extremely effective in achieving the above-mentioned purpose, thereby completing the present invention.

[0019] The present invention includes the following aspects.

[0020] A liquid crystal aligning agent comprising: a polymer component (P) comprising one or more polymers and a component (C), wherein the polymer component (P) comprises at least one polymer (P) selected from the group consisting of a polyimide precursor and a polyimide which is an imide product of the polyimide precursor.

[0021] Component (C): at least one compound selected from the group consisting of acids and salts containing periodate ions.

[0022] It should be noted that, throughout the present specification, the following terms and abbreviations have the following meanings: Halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, and the like.

[0023] * In any case, it represents a bond. In addition, Boc represents tert-butyloxycarbonyl, and Fmoc represents 9-fluorenylmethoxycarbonyl.

[0024] Effects of the Invention

[0025] According to the present invention, a liquid crystal alignment agent for a liquid crystal alignment film capable of suppressing afterimages immediately after switching when display brightness is greatly changed, a liquid crystal alignment film obtained from the liquid crystal alignment agent, and a liquid crystal display element can be obtained. In addition, the liquid crystal display element has high display quality with few display defects.

[0026] The mechanism by which the above-mentioned effects of the present invention are obtained is not necessarily clear, but is roughly estimated as follows.

[0027] The liquid crystal alignment film obtained by the liquid crystal alignment agent containing the component (C) described in the present invention contains periodate ions. The periodate ions present in the liquid crystal alignment film suppress the change of the electrical properties of the liquid crystal and the liquid crystal alignment film driven for a long time, thereby suppressing the DC voltage accumulated in the liquid crystal display element, so it can be considered that the above-mentioned effect is obtained. DETAILED DESCRIPTION

[0028] <Polymer component (P)>

[0029] The polymer component (P) contained in the liquid crystal aligning agent of this invention contains at least 1 polymer (P) selected from the group consisting of a polyimide precursor and a polyimide which is an imide product of the polyimide precursor.

[0030] The polymer (P) may have one or more structural units, for example, and may have at least one structural unit selected from the group consisting of a structural unit (p0) represented by the following formula (P0) and an imidized structural unit of the structural unit (p0).

[0031]

[0032] (In formula (P0), X represents a tetravalent organic group, and Y represents a divalent organic group. R and Z each independently represent a hydrogen atom or a monovalent organic group. A plurality of R and Z each independently have the above definition.)

[0033] In the above formula (P0), X represents a tetravalent organic group, preferably a tetravalent tetracarboxylic acid residue. Here, the tetravalent tetracarboxylic acid residue can be, for example, a tetravalent organic group between four carbonyl groups of tetracarboxylic dianhydride or a derivative thereof (e.g., tetracarboxylic acid, tetracarboxylic acid dihalide, tetracarboxylic acid dialkyl ester, or tetracarboxylic acid dialkyl ester dihalide, etc.).

[0034] From the viewpoint of appropriately obtaining the effects of the present invention, X is preferably a tetravalent tetracarboxylic acid residue derived from acyclic aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, aromatic tetracarboxylic dianhydride, or a derivative thereof.

[0035] Among the tetracarboxylic dianhydride or its derivative which provides X, tetracarboxylic dianhydride or its derivative which has 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.

[0036] Here, the non-cyclic aliphatic tetracarboxylic dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxyl groups bonded to a chain hydrocarbon structure. However, it is not necessary to be composed of only a chain hydrocarbon structure, and a part of it may have an alicyclic structure or an aromatic ring structure.

[0037] Alicyclic tetracarboxylic dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxyl groups including at least one carboxyl group bonded to an alicyclic structure. Among them, none of these four carboxyl groups is bonded to an aromatic ring. In addition, it is not necessary to be composed only of an alicyclic structure, and a chain hydrocarbon structure or an aromatic ring structure may also be present in part.

[0038] Aromatic tetracarboxylic dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxyl groups including at least one carboxyl group bonded to an aromatic ring. It is not necessary to be composed of only an aromatic ring structure, and may have a chain hydrocarbon structure or an alicyclic structure in part.

[0039] From the viewpoint of appropriately obtaining the effects of the present invention, X in the above formula (P0) may be the following formulas (Xa1-1) to (Xa1-8), the following formulas (X-1) to (X-17), or the following formula (X b1 -a)~(X b1 -c) is a tetravalent organic group represented by any one of the above.

[0040]

[0041] (In formulas (Xa1-1) to (Xa1-3), R1 to R 15 Each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, a monovalent organic group having 1 to 6 carbon atoms containing a fluorine atom, or a phenyl group, and they may be the same or different.

[0042] * indicates a bonding key. )

[0043]

[0044]

[0045] (x and y are each independently a single bond, an ether group, a carbonyl group, an ester group, an alkanediyl group having 1 to 10 carbon atoms, a 1,4-phenylene group, a sulfonyl group or an amide bond. j and k are 0 or 1.)

[0046] As R1 to R 15 Specific examples of the alkyl group having 1 to 6 carbon atoms in the group include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, and n-pentyl. 15 Specific examples of the alkenyl group having 2 to 6 carbon atoms in the group include ethenyl, propenyl, butenyl, etc., and these may be linear or branched. 15 Specific examples of the alkynyl group having 2 to 6 carbon atoms in include ethynyl, 1-propynyl, 2-propynyl, 1-butynyl, 2-butynyl, and 3-butynyl. 15 Examples of the monovalent organic group having 1 to 6 carbon atoms and containing a fluorine atom include a fluoromethyl group, a trifluoromethyl group, a pentafluoroethyl group, and a pentafluoropropyl group.

[0047] From the viewpoint of improving the liquid crystal orientation and the reliability of the liquid crystal display element, the above X a1 It is preferably a tetravalent organic group represented by the above formula (Xa1-1). Furthermore, from the viewpoint of high photoreactivity, R1 to R4 are each independently a hydrogen atom or a methyl group, preferably at least one of R1 to R4 is a methyl group, and more preferably at least two of R1 to R4 are methyl groups. It is further preferred that R1 and R4 are methyl groups, and R2 and R3 are hydrogen atoms. The above formula (Xa1-1) is preferably a tetravalent organic group selected from the group consisting of the following formulas (Xa1-1-1) to (Xa1-1-5).

[0048]

[0049] From the viewpoint of appropriately obtaining the effects of the present invention, the above formula (X b1 -a)~(X b1 The tetravalent organic group represented by -c) is more preferably the following formula (X b1 -1)~(X b1 -21) is a tetravalent organic group represented by any one of the above.

[0050]

[0051] The divalent organic group of Y in the above formula (P0) is not particularly limited, and examples thereof include divalent organic groups represented by the following formulas (3) to (4).

[0052]

[0053] (In formula (3) and formula (4), R3, R4, and R 4’ Each independently represents a halogen atom, a hydroxyl group, an optionally protected amino group, a thiol group, a nitro group, a phosphoric acid group, or a monovalent organic group having 1 to 20 carbon atoms.

[0054] A4 represents an ester bond, an amide bond, a thioester bond, or a divalent organic group having 2 to 20 carbon atoms. 4’ The substituted divalent organic groups and divalent organic groups formed by linking these divalent organic groups are excluded.

[0055] a3, a4 and a4' are each independently an integer of 0 to 4.

[0056] a is an integer of 1 to 4. b and c are each independently an integer of 1 to 2. 4’ If there are multiple 4’ The structures of a3, a4 and a4' are optionally the same or different. When there are multiple a3, a4 and a4', they are optionally the same or different. * represents a bonding bond. )

[0057] As R3, R4 and R 4’ The monovalent organic group having 1 to 20 carbon atoms in the formula (a) includes a monovalent hydrocarbon group having 1 to 20 carbon atoms, -O-, -S-, -C(=O)-, -C(=O)-O-, -C(=O)-S-, -NR 3 - (where R 3 represents a hydrogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms, or a tert-butyloxycarbonyl group), -CO-NR 3 - (where R 3 represents a hydrogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms, or a tert-butyloxycarbonyl group), -Si(R 3 )2-(where R 3A monovalent group (A) in which any methylene group of the hydrocarbon group is substituted by a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms), -S(=O)2-, etc. (hereinafter, these groups are also referred to as heteroatom-containing groups (A)), a monovalent group (A2) in which at least one hydrogen atom bonded to a carbon atom of the monovalent hydrocarbon group or the monovalent group A is substituted by a halogen atom, a hydroxyl group, an alkoxy group, a nitro group, an amino group optionally protected by a protecting group, a mercapto group, a nitroso group, an alkylsilyl group, an alkoxysilyl group, a silanol group, a sulfinyl group, a phosphino group, a carboxyl group, a cyano group, a sulfo group, an acyl group, etc., and a monovalent group having a heterocyclic ring. It should be noted that the group (A), the group (A2), and the monovalent group having a heterocyclic ring have 1 to 20 carbon atoms.

[0058] As R3, R4 and R 4’ The monovalent organic group having 1 to 20 carbon atoms in the hydrocarbon group is more preferably an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, and a monovalent group in which any methylene group of the hydrocarbon group is substituted with the heteroatom-containing group (A).

[0059] Examples of the above-mentioned optionally protected amino group include -N(R)2, wherein R represents a hydrogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms, or a tert-butyloxycarbonyl group.

[0060] R3, R4 and R 4’ The monovalent organic group having 1 to 20 carbon atoms is preferably a methyl group, a methoxy group, a vinyl group, a halogen atom, a hydroxyl group, an amino group optionally protected by a protecting group, or a monovalent group in which at least one hydrogen atom possessed by an alkyl group having 1 to 3 carbon atoms is substituted with a halogen atom or an amino group optionally protected by a protecting group.

[0061] a in the above formula (3) is preferably an integer of 1 to 2. a3 in the above formula (3) is preferably an integer of 0 to 2, and when a plurality of a3s exist, they are optionally the same or different. a4 and a4' in the above formula (4) are each independently preferably an integer of 0 to 2, and when a plurality of a4 and a4' exist, they are optionally the same or different.

[0062] Examples of the divalent organic group having 2 to 20 carbon atoms in A4 of the above formula (4) include: a hydrocarbon group having 2 to 20 carbon atoms; a hydrocarbon group consisting of -C(=O)-, -NR-, -C(=O)-O-, -Si(R 0)2- and -O-C(=O)- substituted with any alkylene group possessed by the hydrocarbon group (wherein the number of carbon atoms of the divalent organic group (4a) is 2 to 20); a divalent organic group (4b) formed by inserting -O- at at least one place between the end of a hydrocarbon group having 2 to 20 carbon atoms and a carbon-carbon bond of any alkylene group possessed by the hydrocarbon group; a divalent organic group (4c) formed by inserting -O- at at least one place between the carbon-carbon bonds of any alkylene group possessed by the divalent organic group (4a); a divalent organic group (4d) having 2 to 20 carbon atoms and having a heterocyclic ring; etc.

[0063] R in the above-mentioned -NR- represents a hydrogen atom, a monovalent hydrocarbon group having 1 to 5 carbon atoms, or a tert-butyloxycarbonyl group. 0 )2-R 0 It represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms.

[0064] Examples of the hydrocarbon group include chain hydrocarbon groups, alicyclic hydrocarbon groups, and hydrocarbon groups having an aromatic group (the aromatic ring structure in the aromatic group includes, for example, a benzene ring, a naphthalene ring, a biphenyl structure, an anthracene ring, etc.).

[0065] Specific examples of the chain hydrocarbon group include a divalent straight-chain hydrocarbon group or a branched hydrocarbon group having 1 to 20 carbon atoms and having no ring structure, preferably an alkylene group having 1 to 20 carbon atoms, an alkenylene group having 2 to 20 carbon atoms, and an alkynylene group having 2 to 20 carbon atoms.

[0066] Specific examples of the alicyclic hydrocarbon group include an alicyclic structure (for example, a cyclohexylene group or a dicyclohexylene group) or a hydrocarbon group having an alicyclic structure and a chain hydrocarbon structure.

[0067] Specific examples of the hydrocarbon group having an aromatic group include an aromatic group, a hydrocarbon group having an aromatic group and a chain hydrocarbon structure, and a hydrocarbon group having an aromatic group and an alicyclic structure.

[0068] Examples of the heterocyclic ring in the divalent organic group (4d) include piperidine ring, piperazine ring, morpholine ring, pyrrolidine ring, pyrrole ring, furan ring, thiophene ring, imidazole ring, pyrazole ring, imide ring, oxazole ring, isoxazole ring, thiazole ring, isothiazole ring, pyridine ring, pyrimidine ring, pyridazine ring, or pyrazine ring, or a condensed ring containing these ring structures in a part of the structure, and the hydrogen atoms on the above rings may be substituted. Examples of the substituent include halogen atoms, methyl groups, or methoxy groups.

[0069] From the viewpoint of appropriately obtaining the effects of the present invention, A4 in the above formula (4) is preferably a group "-L1-A-L 1’-" or a divalent organic group having 2 to 20 carbon atoms and having a heterocyclic ring.

[0070] It should be noted that the group “-L1-A-L 1’ -" in L1, L 1’ And the total number of carbon atoms of A is 2-20.

[0071] L1 and L 1’ Each independently represents a single bond, -O-, -NR-, -C(=O)-NR-, -C(=O)-, or -O-C(=O)-, and R represents a hydrogen atom, a monovalent hydrocarbon group having 1 to 5 carbon atoms, or a tert-butyloxycarbonyl group.

[0072] From the viewpoint of appropriately obtaining the effects of the present invention, the group "-L1-A-L 1’ A in "-" represents an alkylene group having 1 to 12 carbon atoms, -CH=CH-, -C≡C-, -CR0=CR 0’ -C(=O)-O-(R0 and R 0’ each independently represents a hydrogen atom or a methyl group), or -O-, -NR-, -C(=O)-NR-, -C(=O)-NR-C(=O)-, -C(=O)-O-, -Si(R a )2- and -O-C(=O)-, -O-Ar-O-, -O-C(=O)-Ar-C(=O)-O-, -C(=O)-O-Ar-O-C(=O)-. 1’ When it represents a single bond, A represents a group other than a methylene group.

[0073] In the above-mentioned -C(=O)-NR- and -C(=O)-NR-C(=O)-, R represents a hydrogen atom, a monovalent hydrocarbon group having 1 to 5 carbon atoms, or a tert-butyloxycarbonyl group. -Si(R a )2-R a represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 3 carbon atoms. Any hydrogen atom possessed by A may be substituted with a halogen atom.

[0074] Ar in the above-mentioned -O-Ar-O-, -O-C(=O)-Ar-C(=O)-O- and -C(=O)-O-Ar-O-C(=O)- represents a phenylene structure or a biphenyl structure.

[0075] More preferable specific examples of the above formulae (3) and (4) include the following formula (d AL -1)~(d AL-12), (5-1) to (5-6), (z-1) to (z-7), (o2-1) to (o2-12), (h-1) to (h-13), and the structures shown in (Im-1) to (Im-6).

[0076] It should be noted that in the following formula (d AL -1)~(d AL In the structures represented by (d -8), (5-1) to (5-6), (z-1) to (z-7), (o2-1) to (o2-12), and (h-1) to (h-13), the bonding positions of the benzene ring bonded to * are set to 1,4-positions. AL -9), the bonding positions of all benzene rings are set to 1,4-position.

[0077]

[0078] (In formula (d AL -6), when m1 and m2 are 0, the total of m1, m2 and n is 1 to 12, and when at least one of m1 and m2 is an integer other than 0, the total of m1, m2 and n is 2 to 12. AL -8), the total of m1, m2 and n is 3 to 12. AL -11) and formula (d AL -12), the total of m1, m2 and n is 3 to 12.

[0079]

[0080]

[0081]

[0082] From the viewpoint of appropriately obtaining the effects of the present invention, the polymer (P) is preferably a polymer containing a structural unit having a divalent organic group (also collectively referred to as a specific divalent organic group (b)), wherein the divalent organic group is selected from a divalent organic group having a urea bond; a divalent organic group having an amide bond; a divalent organic group having a structure containing at least one nitrogen atom selected from the group consisting of a nitrogen-containing heterocyclic ring, a secondary amino group and a tertiary amino group; and a group consisting of a divalent organic group having a carboxyl group.

[0083] Examples of the divalent organic group having a urea bond include a divalent organic group represented by the formula (4) in which A4 in the formula (4) has a group “—NH—C(═O)—NR—”.

[0084] Examples of the divalent organic group having an amide bond include a divalent organic group represented by the above formula (4) in which A4 in the above formula (4) has an amide bond.

[0085] Examples of the divalent organic group having at least one nitrogen-containing structure selected from the group consisting of a nitrogen-containing heterocyclic ring, a secondary amino group, and a tertiary amino group include divalent organic groups obtained by removing two amino groups from a diamine selected from the group consisting of the following diamines: 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, 3,6-diaminoacridine, N-ethyl-3,6-diaminocarbazole, Heterocyclic diamines such as N-phenyl-3,6-diaminocarbazole and diamines having structures represented by the above formulas (z-1) to (z-7); diamines having a diphenylamine structure represented by 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-phenylenediamine.

[0086] Examples of the divalent organic group having a carboxyl group include divalent organic groups obtained by removing two amino groups from a diamine having a carboxyl group, such as 2,4-diaminobenzoic acid, 2,5-diaminobenzoic acid, 3,5-diaminobenzoic acid, 4,4'-diaminobiphenyl-3-carboxylic acid, 4,4'-diaminodiphenylmethane-3-carboxylic acid, 1,2-bis(4-aminophenyl)ethane-3-carboxylic acid, 4,4'-diaminobiphenyl-3,3'-dicarboxylic acid, 4,4'-diaminobiphenyl-2,2'-dicarboxylic acid, 3,3'-diaminobiphenyl-4,4'-dicarboxylic acid, 3,3'-diaminobiphenyl-2,4'-dicarboxylic acid, 4,4'-diaminodiphenylmethane-3,3'-dicarboxylic acid, 1,2-bis(4-aminophenyl)ethane-3,3'-dicarboxylic acid, and 4,4'-diaminodiphenyl ether-3,3'-dicarboxylic acid.

[0087] In addition, Y in the above formula (A1) a1 The divalent organic group may have a structure other than the divalent organic groups represented by the above formulae (3) to (4).

[0088] Other structures include: a divalent organic group (3L) in which the bonding position of the benzene ring bonded to * in the above formula (3) is changed from 1,4-position to 2,5-position; a divalent organic group (4L) in which at least one bonding position of the benzene ring bonded to * in the above formula (4) is changed from 1,4-position to 2,5-position; or a divalent organic group obtained by removing two amino groups from the following diamine (the diamine is also collectively referred to as diamine (W)). It should be noted that in the above divalent organic groups (3L) and (4L), R3, R4, R 4’ Preferred embodiments of A4, a3, a4, a4′, a, b and c have the same meanings as those in the above formulae (3) to (4).

[0089] Aromatic diamines having a naphthalene ring such as 1,2-bis(6-amino-2-naphthyloxy)ethane, 1,2-bis(6-amino-2-naphthyl)ethane, or 6-[2-(4-aminophenoxy)ethoxy]-2-naphthylamine, 4,4'-diaminoazobenzene, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 4,4'- diaminobenzophenone, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, 3,6-diaminoacridine, N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, 4,4'-diaminodiphenylamine, 4,4'-diaminodiphenyl-N-methylamine, 4-(2-(methylamino)ethyl)aniline, 4-(2-aminoethyl)aniline, 1-(4-aminophenyl)-1 , 3,3-trimethyl-1H-indane-5-amine, 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-indane-6-amine, cholesteryloxy-3,5-diaminobenzene, cholesteryloxy-3,5-diaminobenzene, cholesteryloxy-2,4-diaminobenzene, 3,5-diaminobenzoic acid cholesteryl ester, 3,5-diaminobenzoic acid cholesteryl ester, 3,5-diaminobenzoic acid lanosteryl ester and 3,6-bis(4-aminobenzoyloxy)cholestane, etc. Diamines having a steroid skeleton, diamines having a siloxane bond such as 1,3-bis(3-aminopropyl)-tetramethyldisiloxane; meta-xylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, 1,3-bis(aminomethyl)cyclohexane, 1,4-diaminocyclohexane, 4,4'-methylenebis(cyclohexylamine), and a diamine having two amino groups bonded to a group represented by any one of the formulas (Y-1) to (Y-167) described in WO2018 / 117239, etc.

[0090] From the viewpoint of appropriately obtaining the effects of the present invention, the polymer (P) preferably contains 10 to 100 mol % of all structural units possessed by the polymer (P), and more preferably contains 15 to 100 mol % of the total of the structural units (p0) and the imidized structural units of the structural units (p0).

[0091] It should be noted that the total herein includes the case where either the structural unit (p0) or the imidized structural unit of the structural unit (p0) is 0 mol %. When referred to as the total below, the case where 1 or 2 or more of the structural unit elements are 0 mol % is also included.

[0092] From the viewpoint of appropriately obtaining the effects of the present invention, the polymer (P) preferably contains 10 to 100 mol %, more preferably 15 to 100 mol % of structural units having divalent organic groups represented by the above formulae (3) to (4), based on all structural units contained in the polymer (P).

[0093] Examples of the monovalent organic group in R and Z of the formula (P0) include a monovalent hydrocarbon group having 1 to 20 carbon atoms, -O-, -S-, -CO-, -COO-, -COS-, -NR 3 -、-CO-NR 3 -、-Si(R 3 )2-, -SO2-, etc. to replace the methylene group of the hydrocarbon group to form a monovalent group A (wherein R 3 is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, in which R 3 When there are multiple R 3 The monovalent organic group in R and Z in the above formula (1) is preferably an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, a Boc group or a Fmoc group, and more preferably an alkyl group having 1 to 3 carbon atoms, and still more preferably a methyl group.

[0094] From the viewpoint of appropriately obtaining 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.

[0095] The polymer component (P) contained in the liquid crystal aligning agent of this invention may be a polymer component which contains two or more polymers and satisfies at least one of the following conditions (i) to (iii).

[0096] (i) A polymer component (P1) comprising at least one polymer selected from the group consisting of a polyimide precursor (A) and a polyimide which is an imide product of the polyimide precursor, wherein the polyimide precursor (A) has at least one structural unit and has a structural unit (a1) represented by the following formula (A1).

[0097] (ii) The polymer component (P2) comprises two or more polyimide precursors (B), wherein the polyimide precursor (B) is a polymer different from the polyimide precursor (A) and has one or more structural units and a structural unit (b1) represented by the following formula (B1).

[0098] (iii) A polymer component (P3) comprising at least one polymer selected from the group consisting of the polyimide precursor (A) and a polyimide which is an imide product of the polyimide precursor, and the polyimide precursor (B).

[0099]

[0100] (In formula (A1), X a1 represents a tetravalent organic group selected from the group consisting of the above formulae (Xa1-1) to (Xa1-8), and Y a1 In the above formula (A1), R and Z have the same meanings as in the above formula (P0).

[0101]

[0102] (In formula (B1), X b1 represents a tetravalent organic group having an aromatic group having 6 to 30 carbon atoms, and X b1 At least one of the carbonyl carbons is bonded to X b1 The aromatic group of Y b1 In the above formula (B1), R and Z have the same meanings as in the above formula (P0).

[0103] The polymer component (P) may also be composed of a polymer having no acid leaving group. Here, the acid leaving group refers to a group having a bond cleaved by an acid, and a part or all of the acid leaving group is removed from the main chain of the polymer by cleavage of the bond.

[0104] Preferred acid leaving groups include protecting groups for protecting amino groups, hydroxyl groups, etc. Such protecting groups include carbamate protecting groups (specifically, tert-butyloxycarbonyl and 9-fluorenylmethoxycarbonyl), or groups that form an acetal structure or a tertiary ether structure together with the protected oxygen atom.

[0105] The polymer having no acid leaving group can be obtained, for example, by using a raw material component having no acid leaving group (specific examples of the raw material having no acid leaving group include diamine having no acid leaving group, tetracarboxylic dianhydride or its derivative having no acid leaving group, and a terminal modifier that does not form an acid leaving group).

[0106] <Polyimide precursor (A)>

[0107] The polymer components (P1) and (P3) contained in the liquid crystal alignment agent of the present invention contain a polyimide precursor (A) having one or more structural units and having a structural unit (a1) shown in the above formula (A1). It should be noted that the polyimide precursor (A) can also use one or more polymers. In addition, the polyimide precursor (A) can have one structural unit, or can have two or more different structural units, or can have three or more different structural units, or can have four or more different structural units.

[0108] In the above formula (A1), Y a1 The divalent organic group is not particularly limited, and examples thereof include the divalent organic groups represented by the above formulae (3) to (4). It should be noted that the above divalent organic group is introduced into the structural unit of the polyimide precursor (A) by, for example, using a diamine having the above divalent organic group as a diamine component for obtaining the polyimide precursor (A).

[0109] From the viewpoint of appropriately obtaining the effects of the present invention, at least one of the structural units constituting the polyimide precursor (A) preferably has a structure selected from the group consisting of divalent organic groups represented by the above formulae (3) to (4), and more preferably has a structure selected from the group consisting of divalent organic groups represented by the above formulae (3) to (4) bonded to a nitrogen atom derived from a diamine.

[0110] Furthermore, from the viewpoint of appropriately obtaining the effects of the present invention, in the above formula (A1), Y a1 Preferred is a divalent organic group selected from the group consisting of the above formulae (3) to (4).

[0111] More preferred specific examples of the above formulae (3) and (4) are the same as the preferred embodiments of the above formulae (3) to (4) in the above polymer (P). AL -1)~(d AL -12), (5-1) to (5-6), (z-1) to (z-7), (o2-1) to (o2-12), (h-1) to (h-13), and (Im-1) to (Im-6). It should be noted that in the above formula (dAL -1)~(d AL In the structures represented by (d -8), (5-1) to (5-6), (z-1) to (z-7), (o2-1) to (o2-12), and (h-1) to (h-13), the bonding positions of the benzene ring bonded to * are set to 1,4-positions. AL -9), the bonding positions of all benzene rings are set to 1,4-position.

[0112] In addition, Y in the above formula (A1) a1 The divalent organic group may have a structure other than the divalent organic groups represented by the above formulae (3) to (4).

[0113] Other structures include: a divalent organic group (3L) in which the bonding position of the benzene ring bonded to * in the above formula (3) is changed from 1,4-position to 2,5-position; a divalent organic group (4L) in which at least one bonding position of the benzene ring bonded to * in the above formula (4) is changed from 1,4-position to 2,5-position; or a divalent organic group obtained by removing two amino groups from the above diamine (W). It should be noted that in the above divalent organic groups (3L) and (4L), R3, R4, R 4’ Preferred embodiments of A4, a3, a4, a4′, a, b and c have the same meanings as those in the above formulae (3) to (4).

[0114] From the viewpoint of appropriately obtaining the effects of the present invention, the polyimide precursor (A) may have the structural unit (a1) represented by the above formula (A1) and further have the structural unit (a2) represented by the following formula (A2).

[0115]

[0116] (In formula (A2), X a2 represents a tetravalent organic group represented by any one of the above formulae (X-1) to (X-17), or a tetravalent organic group derived from an aromatic tetracarboxylic dianhydride, and Y a2 In the above formula (A2), R and Z have the same meanings as in the above formula (P0).

[0117] As Y in the above formula (A2) a2 Specific examples of the divalent organic group, including preferred embodiments, include Y in the above formula (A1): a1 The structure exemplified by the divalent organic group.

[0118] The above-mentioned aromatic tetracarboxylic dianhydride is as defined above including preferred embodiments. Preferred specific examples of aromatic tetracarboxylic dianhydride include the above-mentioned formula (Xb1 -a)~(X b1 -c) and more preferably the tetravalent organic group represented by the above formula (X b1 -1)~(X b1 -21) is a tetravalent organic group.

[0119] From the viewpoint of appropriately obtaining the effects of the present invention, the polyimide precursor (A) preferably contains 10 to 100 mol % of all structural units of the polyimide precursor (A), and more preferably contains 15 to 100 mol % of the total of the structural units (a1) and the imidized structural units of the structural unit (p0).

[0120] From the viewpoint of appropriately obtaining the effects of the present invention, the polyimide precursor (A) preferably contains 10 to 100 mol %, more preferably 15 to 100 mol % of structural units having divalent organic groups represented by the above formulae (3) and (4), based on all structural units contained in the polyimide precursor (A).

[0121] When the polyimide precursor (A) contains structural units other than the imidized structural units of the structural units (a1) and / or repeating units (a1), the total of the structural units (a1) and the imidized structural units of the structural units (a1) preferably contains 95 mol% or less of all the structural units possessed by the polyimide precursor (A), and more preferably contains 90 mol% or less.

[0122] <Polyimide precursor (B)>

[0123] The polymer components (P2) and (P3) contained in the liquid crystal alignment agent of the present invention contain a polyimide precursor (B), which is a polymer different from the polyimide precursor (A), having one or more structural units, and having a structural unit (b1) shown in the following formula (B1). It should be noted that the polyimide precursor (B) can use one or more polymers. In addition, the polyimide precursor (B) can have one structural unit, or can have two or more different structural units, or can have three or more different structural units, or can have four or more different structural units.

[0124]

[0125] (In formula (B1), X b1 represents a tetravalent organic group having an aromatic group having 6 to 30 carbon atoms, and X b1 At least one of the carbonyl carbons is bonded to X b1 The aromatic group of Y b1In the above formula (B1), R and Z have the same meanings as in the above formula (P0).

[0126] X in the above formula (B1) b1 represents a tetravalent organic group having an aromatic group having 6 to 30 carbon atoms, and X b1 At least one of the carbonyl carbons is bonded to X b1 More preferably, it is a tetravalent organic group derived from an acid dianhydride obtained by intramolecular dehydration of four carboxyl groups including at least one carboxyl group bonded to an aromatic ring (benzene ring, naphthalene ring, etc.). It is not necessary to be composed of only an aromatic ring structure, and a part of it may have a chain hydrocarbon structure or an alicyclic structure.

[0127] As X b1 Preferred specific examples of include tetravalent organic groups derived from aromatic tetracarboxylic acid compounds. b1 Preferably, the above formula (X b1 -a)~(X b1 -c) is a tetravalent organic group, more preferably the above formula (X b1 -1)~(X b1 -21) is a tetravalent organic group represented by any one of the formula (X b1 -1)~(X b1 -13) is a tetravalent organic group. It is further preferably selected from the above formula (X b1 -1)~(X b1 -7) a tetravalent organic group in the group consisting of:

[0128] As the above Y b1 The divalent organic group in the formula (I) may be exemplified by the above Y a1 The divalent organic groups exemplified above. From the viewpoint of appropriately obtaining the effects of the present invention, the polyimide precursor (B) is preferably a polymer containing a structural unit having the above-mentioned specific divalent organic group (b).

[0129] Furthermore, from the viewpoint of appropriately obtaining the effects of the present invention, the polyimide precursor (B) preferably contains Y b1 A polymer having a structural unit of the above-mentioned specific divalent organic group (b).

[0130] From the viewpoint of appropriately obtaining the effects of the present invention, the polyimide precursor (B) preferably contains structural units having the above-mentioned specific divalent organic group (b) (more preferably structural units having the above-mentioned specific divalent organic group bonded to a nitrogen atom derived from a diamine) in an amount of 1 mol % or more, preferably 5 mol % or more, more preferably 10 mol % or more, and further preferably 20 mol % or more of all structural units contained in the polyimide precursor (B).

[0131] In addition, from the viewpoint of appropriately obtaining the effects of the present invention, the polyimide precursor (B) preferably contains 1 mol% or more, preferably 5 mol% or more, more preferably 10 mol% or more, and further preferably 20 mol% or more of Y based on all the structural units contained in the polyimide precursor (B). b1 It is a structural unit of the above-mentioned specific divalent organic group (b).

[0132] From the viewpoint of appropriately obtaining the effects of the present invention, the polyimide precursor (B) may have the structural unit (b1) represented by the above formula (B1) and further have the structural unit (b2) represented by the following formula (B2).

[0133]

[0134] (In formula (B2), X b2 represents a non-cyclic aliphatic tetracarboxylic dianhydride or a tetravalent organic group derived from alicyclic tetracarboxylic dianhydride, Y b2 In the above formula (B2), R and Z have the same meanings as in the above formula (P0).

[0135] The definitions of the non-cyclic aliphatic tetracarboxylic dianhydride and the alicyclic tetracarboxylic dianhydride in the above formula (B2) are as described above.

[0136] From the viewpoint of appropriately obtaining the effects of the present invention, X b2 It is preferably a tetravalent organic group represented by any one of the above formulae (X-1) to (X-17) or (Xa1-1) to (Xa1-8).

[0137] From the viewpoint of appropriately obtaining the effects of the present invention, the polyimide precursor (B) preferably contains 10 to 100 mol % of all structural units of the polyimide precursor (B), and more preferably contains 15 to 100 mol % of the total of the structural units (b1) and the imidized structural units of the structural unit (p0).

[0138] In addition, when the polyimide precursor (B) contains structural units other than the imidized structural units of the structural units (b1) and / or repeating units (b1), the structural unit (b1) preferably contains 95 mol% or less of all the structural units possessed by the polyimide precursor (B), and more preferably contains 90 mol% or less.

[0139] The polyimide precursor (B) preferably contains 5 mol% or more of all the structural units possessed by the polyimide precursor (B), and more preferably contains 10 mol% or more of the above-mentioned structural unit (b2). In addition, it is preferred that the above-mentioned structural unit (b2) contains 90 mol% or less of all the structural units possessed by the polyimide precursor (B), and more preferably contains 85 mol% or less of the above-mentioned structural unit (b2).

[0140] The mass ratio of the content of the first polyimide precursor to the content of the second polyimide precursor in the polymer component (P) (content of the first polyimide precursor / content of the second polyimide precursor) is preferably 10 / 90 to 90 / 10, more preferably 20 / 80 to 90 / 10, and further preferably 20 / 80 to 80 / 20.

[0141] From the viewpoint of less image sticking due to residual DC, the mass ratio of the content of the polyimide precursor (A) to the content of the polyimide precursor (B) (content of the polyimide precursor (A) / content of the polyimide precursor (B)) is preferably 10 / 90 to 90 / 10, more preferably 20 / 80 to 90 / 10, and further preferably 20 / 80 to 80 / 20.

[0142] <Polymer (P), polyimide precursor (A), and method for producing polyimide precursor (B)>

[0143] The polymer (P) and the polyimide precursors (A) and (B) in the present invention can be synthesized by a known method such as that described in WO2013 / 157586, for example.

[0144] Specifically, it is obtained by reacting a tetracarboxylic acid derivative component containing tetracarboxylic dianhydride with a diamine component in a solvent (polycondensation). The solvent is not particularly limited as long as it is a solvent that dissolves the generated polymer.

[0145] For example, when synthesizing a polyimide precursor (A) having a repeating unit represented by the above formula (A1), a diamine component having -NZ-Y a1 -NZ- structure (Y a1 , Z and Y of formula (A1) a1 As the tetracarboxylic acid derivative component, a diamine having the above formula (X a1 ) structure (X a1With X in formula (A1) a1 (the same definition as above) tetracarboxylic dianhydride.

[0146] The ratio of tetracarboxylic dianhydride to diamine used in the synthesis reaction of the polyimide precursor is preferably 0.5 to 2 equivalents of the anhydride group of the tetracarboxylic dianhydride relative to 1 equivalent of the amino group of the diamine, and more preferably 0.8 to 1.2 equivalents. As in a conventional polycondensation reaction, the closer the equivalent of the anhydride group of the tetracarboxylic dianhydride is to 1 equivalent, the greater the molecular weight of the generated polyimide precursor.

[0147] The reaction temperature of the synthesis reaction of the polyimide precursor is preferably -20 to 150° C., and more preferably 0 to 100° C. The reaction time is preferably 0.1 to 24 hours, and more preferably 0.5 to 12 hours.

[0148] The synthesis reaction of the polyimide precursor can be carried out at any concentration, and the concentration of the polyimide precursor in the reaction solution is preferably 1 to 50% by mass, more preferably 5 to 30% by mass. The reaction may be carried out at a high concentration in the initial stage and then a solvent may be added.

[0149] Specific examples of the above-mentioned solvent when reacting the diamine component with the tetracarboxylic acid derivative component include: N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, 1,3-dimethyl-2-imidazolidinone. In addition, when the solvent solubility of the polymer is high, methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, or H3C-CH(OH)-CH2-O-D 1 (D 1 represents an alkyl group having 1 to 3 carbon atoms), HO-CH2-CH2-O-D 2 (D 2 represents an alkyl group having 1 to 3 carbon atoms), HO-CH2-CH2-O-CH2-CH2-D 3 (D 3 represents an alkyl group having 1 to 4 carbon atoms). These solvents may be used alone or in combination.

[0150] As the above H3C-CH(OH)-CH2-O-D 1 , HO-CH2-CH2-O-D 2 ,HO-CH2-CH2-O-CH2-CH2-D 3 Specific examples of the solvent include 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.

[0151] <Polymer solution viscosity / molecular weight>

[0152] From the viewpoint of workability, it is preferred that the polymer (P), the polyimide precursor (A), and the polyimide precursor (B) in the present invention have a solution viscosity of, for example, 10 to 1000 mPa·s when they are made into a solution with a concentration of 10 to 15% by mass, but it is not particularly limited. It should be noted that the solution viscosity (mPa·s) of the above polymer is a value measured at 25° C. using an E-type rotational viscometer for a polymer solution with a concentration of 10 to 15% by mass prepared using a good solvent for the polymer (e.g., γ-butyrolactone, N-methyl-2-pyrrolidone, etc.).

[0153] The weight average molecular weight (Mw) of the polymer (P), the polyimide precursor (A) and the polyimide precursor (B) measured by gel permeation chromatography (GPC) in terms of polystyrene is preferably 1000 to 500000, more preferably 2000 to 300000. In addition, the molecular weight distribution (Mw / Mn) represented by the ratio of Mw to the number average molecular weight (Mn) in terms of polystyrene measured by GPC is preferably 15 or less, more preferably 10 or less. From the viewpoint of appropriately obtaining the effect of the present invention, it is preferably within this molecular weight range.

[0154] <Capping agent>

[0155] It is also possible to use a suitable end-capping agent together with the tetracarboxylic acid derivative component and the diamine component as described above to synthesize an end-capped polymer when synthesizing the polymer (P), polyimide precursor (A) and polyimide precursor (B) of the present invention. The end-capped polymer has the effect of improving the film hardness of the liquid crystal alignment film obtained from the coating film and improving the adhesion characteristics of the sealant and the liquid crystal alignment film.

[0156] Examples of the terminal of the polymer (P), polyimide precursor (A), and polyimide precursor (B) in the present invention include amino groups, carboxyl groups, acid anhydride groups, or derivatives thereof. Amino groups, carboxyl groups, and acid anhydride groups can be obtained by a conventional condensation reaction, or by blocking with the following blocking agents, for example, they can be obtained in the same manner using the following blocking agents.

[0157] Examples of the end-capping agent include: acid monoanhydrides such as acetic anhydride, maleic anhydride, nadic anhydride, phthalic anhydride, itaconic anhydride, cyclohexanedicarboxylic anhydride, 3-hydroxyphthalic anhydride, trimellitic anhydride, 3-(3-trimethoxysilyl)propyl)-3,4-dihydrofuran-2,5-dione, 4,5,6,7-tetrafluoroisobenzofuran-1,3-dione, 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 nicotinoyl chloride; and aniline. , 2-aminophenol, 3-aminophenol, 4-aminosalicylic acid, 5-aminosalicylic acid, 6-aminosalicylic acid, 2-aminobenzoic acid, 3-aminobenzoic acid, 4-aminobenzoic acid, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine and other monoamine compounds; isocyanate compounds having unsaturated bonds such as ethyl isocyanate, phenyl isocyanate, naphthyl isocyanate, 2-acryloyloxyethyl isocyanate and 2-methacryloyloxyethyl isocyanate; isothiocyanate compounds such as ethyl isothiocyanate and allyl isothiocyanate, etc.

[0158] The amount of the terminal blocking agent used is preferably 0.01 to 20 parts by mole, more preferably 0.01 to 10 parts by mole, based on 100 parts by mole of the total diamine component used.

[0159] <(C) Ingredients>

[0160] The liquid crystal aligning agent of this invention contains at least 1 compound selected from the group consisting of the acid and salt containing periodate ion (hereinafter, the compound which comprises (C) component is also called a compound (C)).

[0161] The periodate ion in compound (C) includes metaperiodate ion (IO4 － ), and / or orthoperiodate ion (IO6 5－ ).

[0162] Preferred specific examples of the compound (C) include periodic acid, metal salts of periodic acid (eg, sodium salt, potassium salt, etc.), and organic salts of periodic acid (eg, ammonium salt, etc.).

[0163] It should be noted that the periodic acid contains metaperiodic acid (HIO4) and / or orthoperiodic acid (H5IO6), and the periodate contains metaperiodate and / or orthoperiodate.

[0164] More preferred specific examples of the compound (C) include periodic acid, sodium periodate, potassium periodate, ammonium periodate, and the like.

[0165] When all the components in the liquid crystal aligning agent are 100 mass %, content of the (C) component is preferably 0.01 mass % or more, more preferably 0.02 mass % or more, further preferably 0.03 mass % or more.

[0166] In addition, when all the components in the liquid crystal aligning agent are set to 100 mass %, from the viewpoint of appropriately obtaining the effect of the present invention, the content of the component (C) is preferably 20 mass % or less, preferably 10 mass % or less, more preferably 5 mass % or less, and further preferably 3 mass % or less.

[0167] In addition, when all the components in the liquid crystal alignment agent are set to 100% by mass, the total mass of the components other than the (C) component of the liquid crystal alignment agent accounts for 99.99% by mass or less, more preferably 99.98% by mass or less, and further preferably 99.97% by mass or less. Furthermore, when all the components in the liquid crystal alignment agent are set to 100% by mass, the total mass of the components other than the (C) component of the liquid crystal alignment agent accounts for 80% by mass or more, and more preferably 90% by mass or more.

[0168] The liquid crystal alignment agent of the present invention contains an organic solvent. Specific 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-dimethylpropionamide , 3-butoxy-N, N-dimethylpropionamide, N-(n-propyl)-2-pyrrolidone, N-isopropyl-2-pyrrolidone, N-(n-butyl)-2-pyrrolidone, N-(tert-butyl)-2-pyrrolidone, N-(n-pentyl)-2-pyrrolidone, N-methoxypropyl-2-pyrrolidone, N-ethoxyethyl-2-pyrrolidone, N-methoxybutyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone (these are also collectively referred to as "good solvents"). Among them, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 3-methoxy-N, N-dimethylpropionamide, 3-butoxy-N, N-dimethylpropionamide or γ-butyrolactone is preferred. When the total components in the liquid crystal aligning agent are set to 100% by mass, the content of the good solvent is preferably 20% by mass or more, and preferably 30% by mass or more.

[0169] In addition, the organic solvent contained in the liquid crystal aligning agent preferably uses a mixed solvent of a solvent (also called a poor solvent) that improves the coating property and surface smoothness of the coating film when the liquid crystal aligning agent is applied in addition to the above-mentioned solvent. When the total component in the liquid crystal aligning agent is set to 100% by mass, the content of the poor solvent is preferably 1% by mass or more, more preferably 5% by mass or more, and further preferably 10% by mass or more.

[0170] Moreover, when all components in a liquid crystal aligning agent are set to 100 mass %, the sum total of content of the said good solvent and poor solvent is preferably 99.99 mass % or less, more preferably 99.98 mass % or less, further preferably 99.97 mass % or less.

[0171] The kind and content of the poor solvent are appropriately selected according to the coating device of the liquid crystal aligning agent, coating conditions, coating environment, etc. Specific examples of the poor solvent are as follows, but the present invention is not limited to these.

[0172] Examples thereof 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 diacetate, propylene carbonate, ethylene carbonate, ethylene glycol monobutyl ether, ethylene glycol monoisopentyl ether, ethylene glycol monohexyl ether, propylene glycol monobutyl ether, 1-(2-butoxyethoxy)-2-propanol, 2-(2-butoxyethoxy)-1-propanol, propylene glycol monomethyl ether, Ether acetate, propylene glycol diacetate, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, ethylene glycol monobutyl ether acetate, diethylene glycol monopropyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, 2-(2-ethoxyethoxy)ethyl acetate, diethylene glycol diacetate, propylene glycol diacetate, n-butyl acetate, propylene glycol monoethyl ether acetate, cyclohexyl acetate, 4-methyl-2-pentyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, butyl 3-methoxypropionate, n-butyl lactate, isopentyl lactate, diethylene glycol monoethyl ether, diisobutyl ketone (2,6-dimethyl-4-heptanone), etc.

[0173] Among them, the poor solvent is preferably diisobutylcarbinol, 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.

[0174] Preferred combinations of good solvents and poor solvents include: N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether, N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether, N-ethyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone, N-ethyl-2-pyrrolidone and propylene glycol diacetate, N,N-dimethyl lactamide and diisobutyl ketone, N-methyl-2-pyrrolidone and ethyl 3-ethoxypropionate, N-ethyl-2-pyrrolidone and ethyl 3-ethoxypropionate, N-ethyl-2-pyrrolidone and 3 -Ethoxy propionate and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone and ethyl 3-ethoxy propionate and diethylene glycol monopropyl ether, N-ethyl-2-pyrrolidone and ethyl 3-ethoxy propionate 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 and diethylene glycol monoethyl ether and butyl cellosolve acetate, N-methyl-2-pyrrolidone and diethylene glycol monomethyl ether and butyl cellosolve acetate, N,N-dimethyl lactamide and diethylene glycol diethyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and 4-hydroxy-4-methyl-2-pentanone and diethylene glycol diethyl ether, N-ethyl-2-pyrrolidone and N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone, N-ethyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and diisobutyl ketone, N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and dipropylene glycol monomethyl ether, N -Methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and propylene glycol diacetate, N-ethyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and dipropylene glycol dimethyl ether, γ-butyrolactone and 4-hydroxy-4-methyl-2-pentanone and diisobutyl ketone, γ-butyrolactone and 4-hydroxy-4-methyl-2-pentanone and propylene glycol diacetate, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether and diisobutyl ketone, N-methyl-2-pyrrolidone With γ-butyrolactone and propylene glycol monobutyl ether and diisopropyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether and diisobutyl carbinol, N-methyl-2-pyrrolidone and γ-butyrolactone and dipropylene glycol dimethyl ether, N-methyl-2-pyrrolidone and propylene glycol monobutyl ether and dipropylene glycol dimethyl ether, N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether and dipropylene glycol monomethyl ether, N-ethyl-2-pyrrolidone and diethylene glycol diethyl ether and dipropylene glycol monomethyl ether, N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether and propylene glycol diacetate, N-ethyl-2-pyrrolidone and propylene glycol diacetate Alcohol monobutyl ether and diisobutyl ketone, N-ethyl-2-pyrrolidone and γ-butyrolactone and diisobutyl ketone, N-ethyl-2-pyrrolidone and N, N-dimethyl lactamide and diisobutyl ketone, N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether and ethylene glycol monobutyl ether acetate, γ-butyrolactone and ethylene glycol monobutyl ether acetate and dipropylene glycol dimethyl ether, N-ethyl-2-pyrrolidone and ethylene glycol monobutyl ether acetate and propylene glycol dimethyl ether, N-methyl-2-pyrrolidone and 4-methyl-2-pentyl acetate and ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone and cyclohexanone and propylene glycol monomethyl ether, etc.

[0175] The solid content concentration in the liquid crystal aligning agent (the ratio of the total mass of the components other than the solvent of the liquid crystal aligning agent to the total mass of the liquid crystal aligning agent) can be appropriately selected in consideration of viscosity, volatility, etc., but is preferably in the range of 1 to 10 mass%. From the perspective of forming a uniform and defect-free coating film, it is preferably 1 mass% or more, and from the perspective of the storage stability of the solution, it is preferably 10 mass% or less. A particularly preferred solid content concentration is 2 to 8 mass%.

[0176] The range of solid content concentration can be appropriately selected according to the method used when the liquid crystal alignment agent is applied to the substrate. For example, in the case of spin coating, the solid content concentration is particularly preferably 1.5 to 4.5% by mass. In the case of a printing method, it is particularly preferred to set the solid content concentration to 3 to 9% by mass, thereby setting the solution viscosity to 12 to 50 mPa·s. In the case of an inkjet method, it is particularly preferred to set the solid content concentration to 1 to 5% by mass, thereby setting the solution viscosity to 3 to 15 mPa·s. The temperature when preparing the liquid crystal alignment agent is preferably 10 to 50°C, more preferably 20 to 30°C.

[0177] The concentration of the polymer component in the liquid crystal aligning agent can be appropriately changed according to the setting of the thickness of the coating film to be formed. From the perspective of forming a uniform and defect-free coating film, the concentration of the polymer component in the liquid crystal aligning agent (the total concentration of the polymer) is preferably 1% by mass or more, and from the perspective of the storage stability of the solution, it is preferably 10% by mass or less. The concentration of the polymer is particularly preferably 2 to 8% by mass.

[0178] From the viewpoint of appropriately obtaining the effects of the present disclosure, the content of the polymer component (P) in the liquid crystal aligning agent (the total amount of polymers constituting the polymer component (P)) is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, and further preferably 50 parts by mass or more, relative to 100 parts by mass of the total polymer components contained in the liquid crystal aligning agent.

[0179] When the liquid crystal aligning agent contains other polymers mentioned later, content of the polymer component (P) is preferably 99.9 parts by mass or less, more preferably 99 parts by mass or less, relative to 100 parts by mass of the total of the polymers contained in the liquid crystal aligning agent.

[0180] As for the liquid crystal alignment agent of the present invention, in addition, it can also contain components other than the above as needed. As the component, for example, other polymers other than polymer (P), polyimide precursor (A) and (B) can be listed; at least one compound selected from the group consisting of a cross-linking compound having at least one substituent selected from epoxy, isocyanate, oxetane, cyclocarbonate, blocked isocyanate, hydroxyl and alkoxy, and a cross-linking compound having a polymerizable unsaturated group; functional silane compound; metal chelate compound; curing accelerator; surfactant; antioxidant; sensitizer; preservative; compound for adjusting the dielectric constant and resistance of the liquid crystal alignment film; compound for promoting imidization, etc.

[0181] If specific examples of other polymers are listed, there may be mentioned polymers selected from the group consisting of polysiloxanes, polyesters, polyamides, polyureas, polyurethanes, polyorganosiloxanes, cellulose derivatives, polyacetals, polystyrene derivatives, poly(styrene-maleic anhydride) copolymers, poly(isobutylene-maleic anhydride) copolymers, poly(vinyl ether-maleic anhydride) copolymers, poly(styrene-phenylmaleimide) derivatives, and poly(meth)acrylates.

[0182] As specific examples of poly(styrene-maleic anhydride) copolymers, SMA1000, 2000, 3000 (manufactured by CrayValley), GSM301 (manufactured by Gifu Shellac Manufacturing Co., Ltd.), etc. can be cited. As specific examples of poly(isobutylene-maleic anhydride) copolymers, isobam-600 (manufactured by KURARAY) can be cited. As specific examples of poly(vinyl ether-maleic anhydride) copolymers, Gantrez AN-139 (methyl vinyl ether maleic anhydride resin, manufactured by Ashland) can be cited. Other polymers can be used alone or in combination of two or more. The content ratio of other polymers is preferably 90 parts by mass or less, and more preferably 80 parts by mass or less, relative to a total of 100 parts by mass of the polymers contained in the liquid crystal alignment agent. In addition, the content ratio of other polymers is preferably 0.1 parts by mass or more, and more preferably 1 part by mass or more, relative to a total of 100 parts by mass of the polymers contained in the liquid crystal alignment agent.

[0183] Preferred specific examples of the crosslinking 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, glycerol diglycidyl ether, dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, bisphenol A type epoxy resins such as EPIKOTE 828 (manufactured by Mitsubishi Chemical Co., Ltd.), bisphenol F type epoxy resins such as EPIKOTE 807 (manufactured by Mitsubishi Chemical Co., Ltd.), hydrogenated bisphenol A type epoxy resins such as YX-8000 (manufactured by Mitsubishi Chemical Co., Ltd.), YX6954BH30 (manufactured by Mitsubishi Chemical Co., Ltd.), and bisphenol A type epoxy resins such as EPICOTE 828 (manufactured by Mitsubishi Chemical Co., Ltd.). Epoxy resins containing biphenyl skeletons such as EPPN-201 (manufactured by Nippon Kayaku Co., Ltd.), phenol novolac type epoxy resins such as EOCN-102S (manufactured by Nippon Kayaku Co., Ltd.), triglycidyl isocyanurate such as TEPIC (manufactured by Nissan Chemical Co., Ltd.), Celloxide Alicyclic epoxy resins such as 2021P (manufactured by Daicel Co., Ltd.), compounds containing tertiary nitrogen atoms such as N,N,N',N'-tetraglycidyl-m-phenylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, or N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, and compounds having two or more oxirane groups such as tetrakis(glycidyloxymethyl)methane; compounds having two or more oxetane groups as described in paragraphs to of WO2011 / 132751; CORONATE AP stable M, CORONATE 2503, 2515, 2507, 2513, 2555, MILLIONATE MS-50 (all manufactured by Tosoh Co., Ltd.), TAKENATE Compounds having a blocked isocyanate group such as B-830, B-815N, B-820NSU, B-842N, B-846N, B-870N, B-874N, B-882N (all manufactured by Mitsui Chemicals, Inc.); compounds having an oxazoline group such as 2,2'-bis(2-oxazoline), 2,2'-bis(4-methyl-2-oxazoline), 2,2'-bis(5-methyl-2-oxazoline), 1,2,4-tris(2-oxazolinyl)-benzene, and epocros (manufactured by Nippon Catalyst Co., Ltd.); compounds having a cyclic carbonate group as described in paragraphs to in WO2011 / 155577;Compounds having a hydroxyl group or an alkoxy group such as N,N,N',N'-tetrakis(2-hydroxyethyl)adipamide, 2,2-bis(4-hydroxy-3,5-dihydroxymethylphenyl)propane, 2,2-bis(4-hydroxy-3,5-dimethoxyphenyl)propane, and 2,2-bis(4-hydroxy-3,5-dihydroxymethylphenyl)-1,1,1,3,3,3-hexafluoropropane; compounds represented by glyceryl mono(meth)acrylate, glyceryl di(meth)acrylate (1,2-,1,3-isomer mixture), glyceryl tri(meth)acrylate, 1,3-diglycerol alcohol 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 crosslinking compound is preferably 0.1 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, relative to 100 parts by mass of the polymer component contained in the liquid crystal aligning agent. ;

[0184] Examples of the compound for adjusting the dielectric constant and the resistance include monoamines having an aromatic heterocyclic ring containing a nitrogen atom, such as 3-picolylamine. The content of the monoamine having an aromatic heterocyclic ring containing a nitrogen atom is preferably 0.1 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, relative to 100 parts by mass of the polymer component contained in the liquid crystal aligning agent.

[0185] Preferred specific 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, 3-glycidoxypropylmethyldimethoxysilane, 3-(Trimethoxysilyl)propyl)isocyanurate, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-isocyanatepropyltriethoxysilane, 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, relative to 100 parts by mass of the polymer component contained in the liquid crystal aligning agent.

[0186] As the compound for promoting the above-mentioned imidization, a compound having a basic site (for example, a primary amino group, an aliphatic heterocycle (for example, a pyrrolidine skeleton), an aromatic heterocycle (for example, an imidazole ring, an indole ring), or a guanidine group, etc.) is preferred (except for the above-mentioned cross-linking compound and the adhesion aid), or a compound that generates the above-mentioned basic site when calcined. More preferred are compounds that generate the above-mentioned basic site when calcined. If preferred specific examples are listed, amino acids in which part or all of the basic sites of amino acids are protected can be listed. As the protecting group of the basic site of the above-mentioned amino acid, carbamate-based protecting groups such as Boc group can be listed. Specific examples of the above-mentioned amino acids include: glycine, alanine, cysteine, methionine, asparagine, glutamine, valine, leucine, phenylalanine, tyrosine, tryptophan, proline, hydroxyproline, arginine, histidine, lysine, and ornithine. If more preferred specific examples of compounds for promoting imidization are listed, N-α-(9-fluorenylmethoxycarbonyl)-N-τ-(tert-butyloxycarbonyl)-L-histidine can be listed. The content of the compound for promoting the above-mentioned imidization contained in the liquid crystal aligning agent of the present invention is preferably 0.1 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, and further preferably 5 to 20 parts by mass relative to 100 parts by mass of the polymer component contained in the liquid crystal aligning agent.

[0187] (Liquid crystal alignment film and liquid crystal display element)

[0188] The liquid crystal display element of this invention is equipped with the liquid crystal aligning film formed using the said liquid crystal aligning agent.

[0189] The liquid crystal aligning film of the present invention can be produced, for example, by a method including the following steps (1) to (2) or a method including the following steps (1) to (3).

[0190] The operating mode of the liquid crystal display element is not particularly limited. For example, it can be applied to various operating modes such as TN mode, STN mode, vertical alignment mode (including VA-MVA mode, VA-PVA mode, etc.), plane switching mode (IPS mode, FFS mode), optical compensation bend mode (OCB mode), etc.

[0191] The liquid crystal display element of the present invention can be manufactured, for example, by a method comprising the following steps (1) to (4), a method comprising steps (1) to (2) and (4), a method comprising steps (1) to (3), (4-2) and (4-4), or a method comprising steps (1) to (3), (4-3) and (4-4).

[0192] Moreover, one aspect of the liquid crystal display element of the present invention is a liquid crystal display element including a liquid crystal alignment film formed by a method for producing a liquid crystal alignment film including the following steps (1) to (2) or steps (1) to (3).

[0193] <Step (1): Step of applying a liquid crystal aligning agent onto a substrate>

[0194] The step (1) is a step of applying a liquid crystal aligning agent onto a substrate. A specific example of the step (1) is as follows.

[0195] The liquid crystal alignment agent is applied to one side of a substrate provided with a patterned transparent conductive film by a suitable coating method such as a roller coater method, a spin coating method, a printing method, an inkjet method, etc. Here, as the material of the substrate, there is no particular limitation as long as it is a substrate with high transparency, and plastics such as acrylic acid, polycarbonate, etc. can also be used together with glass and silicon nitride. In addition, in a reflective liquid crystal display element, if it is only a single-sided substrate, opaque objects such as silicon wafers can also be used, and the electrodes in this case can also use materials that reflect light such as aluminum. In addition, in the case of manufacturing a liquid crystal display element of an IPS method or an FFS method, a substrate provided with an electrode composed of a transparent conductive film or a metal film patterned into a comb-shaped shape and an opposing substrate without an electrode are used.

[0196] An IPS substrate as a comb-tooth electrode substrate used in an IPS liquid crystal display element includes, for example, a substrate, a plurality of linear electrodes formed on the substrate and arranged in a comb-tooth shape, and a liquid crystal alignment film formed on the substrate so as to cover the linear electrodes.

[0197] It should be noted that the FFS substrate used as a comb-tooth electrode substrate in the FFS-type liquid crystal display element has, for example, a substrate, a surface electrode formed on the substrate, an insulating film formed on the surface electrode, a plurality of linear electrodes formed on the insulating film and arranged in a comb-tooth shape, and a liquid crystal orientation film formed on the insulating film in a manner covering the linear electrodes.

[0198] As a method of applying a liquid crystal aligning agent to a substrate to form a film, screen printing, offset printing, flexographic printing, an inkjet method, a spray method, etc. are mentioned. Among them, the coating and film-forming method by the inkjet method can be preferably used.

[0199] <Step (2): Step of calcining the applied liquid crystal aligning agent>

[0200] The step (2) is a step of baking the liquid crystal aligning agent applied on the substrate to form a film. A specific example of the step (2) is as follows.

[0201] After the liquid crystal alignment agent is applied to the substrate in step (1), the solvent can be evaporated by a heating unit such as a heating plate, a hot air circulation oven or an IR (infrared) oven, or the thermal imidization of the polyimide precursor represented by polyamic acid can be performed. The drying and firing steps after the liquid crystal alignment agent is applied can be selected at any temperature and time, and can also be performed multiple times. As the temperature for firing the liquid crystal alignment agent, it can be carried out at 40 to 180°C, for example. From the perspective of shortening the process, it can be carried out at 40 to 150°C. As for the firing time, it is not particularly limited, and 1 to 10 minutes or 1 to 5 minutes can be listed. In the case of thermal imidization of the polyimide precursor represented by polyamic acid, after the above-mentioned process, for example, a firing step can be added at 150 to 300°C or 150 to 250°C. As for the firing time, it is not particularly limited, and a firing time of 5 to 40 minutes or 5 to 30 minutes can be listed.

[0202] If the film thickness of the film-like material after firing is too thin, the reliability of the liquid crystal display element may decrease. Therefore, the film thickness is preferably 5 to 300 nm, and more preferably 10 to 200 nm.

[0203] <Step (3): Step of orienting the film obtained in step (2)>

[0204] Step (3) is a step of orienting the film obtained in step (2) according to the circumstances. That is, in a liquid crystal display element of a horizontal orientation mode such as an IPS mode or an FFS mode, the coating is subjected to an orientation ability imparting treatment. On the other hand, in a liquid crystal display element of a vertical orientation mode such as a VA mode or a PSA mode, the formed coating can be used directly as a liquid crystal alignment film, but the coating can also be subjected to an orientation ability imparting treatment. As an orientation treatment method for a liquid crystal alignment film, a rubbing orientation treatment method and a photo-orientation treatment method can be listed. As a photo-orientation treatment method, for example, the following method can be listed: preferably, the surface of the above-mentioned film-like object is irradiated with radiation polarized in a certain direction, preferably subjected to a heat treatment, and imparted with liquid crystal orientation (also referred to as liquid crystal orientation ability). As radiation, ultraviolet rays or visible light having a wavelength of 100 to 800 nm can be used. Among them, ultraviolet rays having a wavelength of 100 to 400 nm are preferred, and ultraviolet rays having a wavelength of 200 to 400 nm are more preferred.

[0205] The radiation dose is preferably 1 to 10000 mJ / cm 2 , among which 100 to 5000 mJ / cm 2 In addition, when irradiating with radiation, the substrate having the film-like material may be heated at 50 to 250° C. to improve the liquid crystal orientation. The liquid crystal alignment film produced as described above can stably align liquid crystal molecules in a fixed direction.

[0206] As the light source of the irradiation light, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, a Deep UV lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, a mercury-xenon lamp, an excimer laser (for example, a KrF excimer laser), a fluorescent lamp, an LED lamp, a halogen lamp (for example, a sodium lamp), a microwave-excited electrodeless lamp, etc. can be used.

[0207] Furthermore, when polarized light is used as irradiation light, the higher the extinction ratio of polarized light is, the higher the anisotropy can be imparted. Therefore, for example, in the case of ultraviolet light, the extinction ratio of polarized ultraviolet light is more preferably greater than 10:1, and even more preferably greater than 20:1.

[0208] Moreover, in the above method, the coating film irradiated with polarized radiation or the coating film subjected to rubbing orientation treatment may be contact treated with water or solvent. In addition, the film subjected to the above orientation treatment may be heat treated without contact treatment. Furthermore, the film subjected to the above contact treatment may be further heat treated.

[0209] The solvent used in the above-mentioned contact treatment is not particularly limited as long as it is a solvent that dissolves the decomposition product generated by the film-like material due to the irradiation of radiation. Specific examples include: water, methanol, ethanol, 2-propanol, acetone, methyl ethyl ketone, 1-methoxy-2-propanol, 1-methoxy-2-propanol acetate, butyl cellosolve, ethyl lactate, methyl lactate, diacetone alcohol, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propyl acetate, butyl acetate, cyclohexyl acetate, etc. The solvent may be one kind or a combination of two or more kinds.

[0210] The temperature of the heat treatment of the coating film irradiated with radiation or the film subjected to the contact treatment is preferably 50 to 300° C., more preferably 120 to 300° C., further preferably 150 to 300° C., most preferably 150 to 250° C. The heat treatment time is preferably 1 to 30 minutes.

[0211] <Step (4): Step of manufacturing a liquid crystal cell>

[0212] Two substrates on which the liquid crystal alignment films are formed as described above are prepared, and liquid crystal is arranged between the two substrates arranged to face each other. Specifically, the following two methods can be cited.

[0213] The first method is to firstly place two substrates opposite to each other with a gap (cell gap) between them so that each liquid crystal alignment film is opposite to each other. Then, the peripheries of the two substrates are bonded together using a sealant, and a liquid crystal composition is injected and filled into the cell gap defined by the substrate surface and the sealant, and after the liquid crystal composition contacts the film surface, the injection hole is sealed.

[0214] In addition, the second method is a method called ODF (One Drop Fill: liquid crystal dripping) method. For example, a UV-curable sealant is applied at a predetermined location on one of the two substrates on which a liquid crystal alignment film is formed, and a liquid crystal composition is further dripped at a predetermined number of locations on the surface of the liquid crystal alignment film. Then, the liquid crystal alignment film is bonded to the other substrate in a manner that the liquid crystal alignment film is opposite, and the liquid crystal composition is pushed to the entire surface of the substrate and in contact with the film surface. Then, ultraviolet light is irradiated on the entire surface of the substrate to cure the sealant. Regardless of which method is used, it is ideal that the liquid crystal composition used is further heated to a temperature at which it becomes isotropic, and then slowly cooled to room temperature, thereby removing the flow orientation during liquid crystal filling.

[0215] In addition, when the coating film is subjected to a rubbing orientation treatment, the two substrates are disposed facing each other so that the rubbing directions of the coating films form a predetermined angle, for example, orthogonal or antiparallel.

[0216] As the sealant, for example, an epoxy resin containing a curing agent and alumina balls as spacers can be used.

[0217] As the above-mentioned liquid crystal composition, there is no particular limitation, and a composition comprising at least one liquid crystal compound (liquid crystal molecule) can be listed, that is, a liquid crystal composition in a nematic phase (hereinafter, also referred to as a nematic liquid crystal), a liquid crystal in a smectic phase, or a liquid crystal composition in a cholesteric phase, wherein a nematic liquid crystal is preferred. In addition, various liquid crystal compositions having a positive or negative dielectric anisotropy can be used. It should be noted that, hereinafter, a liquid crystal composition having a positive dielectric anisotropy is also referred to as a positive liquid crystal, and a liquid crystal composition having a negative dielectric anisotropy is also referred to as a negative liquid crystal.

[0218] The above-mentioned liquid crystal composition may contain liquid crystal compounds having fluorine atoms, hydroxyl groups, amino groups, fluorine-containing groups (such as trifluoromethyl groups), cyano groups, alkyl groups, alkoxy groups, alkenyl groups, isothiocyanate groups, heterocyclic rings, cycloalkanes, cycloolefins, steroid skeletons, benzene rings, or naphthalene rings, and may also contain compounds having two or more rigid sites (mesogenic skeletons) that embody liquid crystal properties in the molecule (for example, a bi-mesogenic compound in which two rigid biphenyl structures or terphenyl structures are linked by alkyl groups).

[0219] In addition, from the viewpoint of improving the orientation of the liquid crystal, the liquid crystal composition may further contain additives. Such additives include: photopolymerizable monomers such as compounds having polymerizable groups (such as (meth)acryloyl groups); optically active compounds (such as S-811 manufactured by Merck, Inc.); antioxidants; ultraviolet absorbers; pigments; defoamers; polymerization initiators; or polymerization inhibitors.

[0220] Examples of the positive liquid crystal include ZLI-2293, ZLI-4792, MLC-2003, MLC-2041, MLC-3019, and MLC-7081 manufactured by Merck.

[0221] As a negative liquid crystal, MLC-6608, MLC-6609, MLC-6610, MLC-7026, or MLC-7026-100 manufactured by Merck & Co., Ltd. can be cited, for example.

[0222] Moreover, as a liquid crystal containing a compound which has a polymerizable group, MLC-3023 manufactured by Merck can be mentioned.

[0223] The liquid crystal alignment agent of the present invention is also preferably used in a liquid crystal display element (PSA liquid crystal display element) manufactured by the following process: a liquid crystal layer is provided between a pair of substrates having electrodes, a liquid crystal composition containing a polymerizable compound that is polymerized by at least one of active energy rays and heat is arranged between the pair of substrates, and a voltage is applied between the electrodes while polymerizing the polymerizable compound by at least one of irradiation with active energy rays and heating.

[0224] In addition, the liquid crystal alignment agent of the present invention is also preferably used in a liquid crystal display element (SC-PVA liquid crystal display element) manufactured through the following process, wherein a liquid crystal layer is provided between a pair of substrates having electrodes, a liquid crystal alignment film containing polymerizable groups that are polymerized by at least one of active energy rays and heat is arranged between the above pair of substrates, and a voltage is applied between the electrodes.

[0225] <Step (4-2): In the case of a PSA-type liquid crystal display element>

[0226] The same method as in (4) is carried out 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 acrylate groups and methacrylate groups in the molecule.

[0227] <Step (4-3): In the case of SC-PVA liquid crystal display element>

[0228] After the same process as in (4) above, a method for manufacturing a liquid crystal display element by irradiating ultraviolet rays described later can also be adopted. According to this method, as in the case of manufacturing the liquid crystal display element of the PSA method, a liquid crystal display element with excellent response speed can be obtained with a small amount of light irradiation. The compound having a polymerizable group can be a compound having one or more of the above-mentioned polymerizable unsaturated groups in the molecule, and its content is preferably 0.1 to 30 parts by mass, more preferably 1 to 20 parts by mass relative to 100 parts by mass of the polymer component contained in the liquid crystal aligning agent. In addition, the above-mentioned polymerizable group may also have a polymer for a liquid crystal aligning agent, and as such a polymer, for example, a polymer obtained by reacting a diamine component containing a diamine having the above-mentioned photopolymerizable group at the end can be cited.

[0229] <Step (4-4): Ultraviolet irradiation step>

[0230] The liquid crystal box is irradiated with light while a voltage is applied between the conductive films of a pair of substrates obtained in (4-2) or (4-3) above. The voltage applied here can be set to, for example, a direct current or alternating current of 5 to 50 V. In addition, as the irradiation light, for example, ultraviolet rays and visible rays containing wavelengths of 150 to 800 nm can be used, preferably ultraviolet rays containing wavelengths of 300 to 400 nm. As the light source of the irradiation light, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, an excimer laser, etc. can be used. The irradiation amount of light is preferably 1000 to 200,000 J / m 2 , more preferably 1000 to 100000 J / m 2 .

[0231] Furthermore, a liquid crystal display element can be obtained by attaching a polarizing plate to the outer surface of the liquid crystal cell as needed. Examples of the polarizing plate attached to the outer surface of the liquid crystal cell include a polarizing plate formed by sandwiching a polarizing film called an "H film" between cellulose acetate protective films, or a polarizing plate composed of the H film itself, wherein the H film is formed by absorbing iodine while stretching and orienting polyvinyl alcohol.

[0232] [Example]

[0233] The present invention will be described in more detail below with reference to Examples, but the present invention is not limited to these Examples. It should be noted that the abbreviations of the compounds and solvents are as follows.

[0234] (Organic Solvent)

[0235] NMP: N-methyl-2-pyrrolidone.

[0236] BCS: ethylene glycol monobutyl ether.

[0237] Compound (C)

[0238] Periodic acid (manufactured by Macklin).

[0239] (Diamine)

[0240] DA-1 to DA-6: compounds represented by the following structural formulas (DA-1) to (DA-6), respectively.

[0241] (Tetracarboxylic acid derivatives)

[0242] CA-1 to CA-2: compounds represented by the following structural formulas (CA-1) to (CA-2), respectively.

[0243] (additive)

[0244] AD-1: A compound represented by the following structural formula (AD-1).

[0245] AD-2: 3-Glycidoxypropyltriethoxysilane.

[0246] AD-3: N-α-(9-fluorenylmethoxycarbonyl)-N-τ-(tert-butyloxycarbonyl)-L-histidine.

[0247]

[0248] <Viscosity>

[0249] In the synthesis example, the viscosity of the polymer solution was measured using an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.) with a sample amount of 1.1 mL, a conical rotor TE-1 (1°34′, R24), and a temperature of 25°C.

[0250] [Synthesis of polymer]

[0251] (Synthesis example 1)

[0252] In a 500 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, 2.16 g (20.0 mmol) of DA-1, 7.33 g (30.0 mmol) of DA-2, 9.61 g (30.0 mmol) of DA-4, and 7.97 g (20.0 mmol) of DA-5 were taken, 311.3 g of NMP was added, and the mixture was dissolved by stirring while nitrogen was supplied. While stirring the diamine solution, 20.85 g (91.0 mmol) of CA-1 was added, and 40.1 g of NMP was further added so that the solid content concentration became 12% by mass, and the mixture was heated and stirred at 40° C. for 24 hours to obtain a polymer solution (polymer-1) (viscosity: 201 mPa·s).

[0253] (Synthesis example 2)

[0254] In a 100 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, 4.14 g (20.8 mmol) of DA-5 and 0.89 g (5.20 mmol) of DA-6 were taken, and 44.4 g of NMP was added, and the mixture was dissolved by stirring while nitrogen was supplied. While stirring the diamine solution, 7.27 g (24.7 mmol) of CA-2 was added, and 45.1 g of NMP was further added so that the solid content concentration became 12% by mass, and the mixture was heated at 60° C. under a nitrogen atmosphere and stirred for 24 hours to obtain a polymer solution (polymer-2) (viscosity: 398 mPa·s).

[0255] The specifications of the polymers obtained in the above synthesis examples are shown in Table 1. In the table, the numerical values ​​in brackets of the tetracarboxylic acid component represent the amount (mol parts) of each tetracarboxylic dianhydride used relative to 100 mol parts of the total amount of the tetracarboxylic acid component used in the polymerization. The numerical values ​​in brackets of the diamine component represent the amount (mol parts) of each diamine used relative to 100 mol parts of the total amount of the diamine component used in the polymerization.

[0256] [Table 1]

[0257]

[0258] [Preparation of Liquid Crystal Alignment Agent]

[0259] (Example 1)

[0260] In a 30 mL conical flask containing a stirrer, a solution (4.58 g) of the polymer (polymer-1) obtained in Synthesis Example 1 and a solution (4.58 g) of the polymer (polymer-2) obtained in Synthesis Example 2 were measured, and NMP (3.03 g), BCS (6.00 g), periodic acid (0.01 g), a 10% by mass NMP solution of AD-1 (0.55 g), a 1% by mass NMP solution of AD-2 (1.10 g), and AD-3 (0.15 g) were added, and the mixture was stirred at room temperature for 2 hours, thereby obtaining a liquid crystal aligning agent (1).

[0261] (Comparative Example 1)

[0262] In a 30 mL conical flask containing a stirrer, a solution (4.58 g) of the polymer (polymer-1) obtained in Synthesis Example 1 and a solution (4.58 g) of the polymer (polymer-2) obtained in Synthesis Example 2 were measured, and NMP (3.03 g), BCS (6.00 g), a 10% by mass NMP solution of AD-1 (0.56 g), a 1% by mass NMP solution of AD-2 (1.10 g), and AD-3 (0.15 g) were added, and the mixture was stirred at room temperature for 2 hours to obtain a liquid crystal aligning agent (2).

[0263] The polymer of the liquid crystal aligning agent obtained in Example 1 and Comparative Example 1, and the kind and ratio of the (C) component described in the present invention are shown in Table 2 below.

[0264] In the table, the numerical value in the parenthesis of the (C) component described in the present invention represents content (mass %) of each compound relative to 100 mass % of the total amount of each liquid crystal aligning agent.

[0265] [Table 2]

[0266]

[0267] [Fabrication of FFS drive liquid crystal cell (photo-alignment treatment)]

[0268] (Example 2 and Comparative Example 2)

[0269] A liquid crystal cell having a configuration of a liquid crystal display element of the FFS driving method (hereinafter referred to as an FFS liquid crystal cell) was produced.

[0270] First, prepare a substrate with electrodes. A glass substrate with a size of 30 mm × 50 mm and a thickness of 0.7 mm is used as the substrate. On the substrate, as the first layer, an ITO electrode with a whole-surface pattern constituting a counter electrode is formed. On the counter electrode of the first layer, as the second layer, a SiN (silicon nitride) film formed by a CVD method is formed. The second layer of SiN film uses a film with a thickness of 500 nm that functions as an interlayer insulating film. On the second layer of SiN film, as the third layer, a comb-shaped pixel electrode formed by patterning the ITO film is arranged to form two pixels, the first pixel and the second pixel. The size of each pixel is 10 mm long and about 5 mm wide. At this time, the counter electrode of the first layer and the pixel electrode of the third layer are electrically insulated due to the action of the SiN film of the second layer.

[0271] The pixel electrode of the third layer has a comb-tooth shape in which a plurality of electrode elements with a width of 3 μm are arranged in parallel at intervals of 6 μm and the central portion is bent at an internal angle of 160°. One pixel has a first region and a second region with a line connecting the bent portions of the plurality of electrode elements as a boundary.

[0272] If the first area and the second area of ​​each pixel are compared, the electrode elements constituting the pixel electrodes thereof are formed in different directions. That is, with the direction of connecting the bent portions of the above-mentioned plurality of electrode elements as a reference, in the first area of ​​the pixel, the electrode elements of the pixel electrode are formed in a manner of forming an angle of 80° clockwise, and in the second area of ​​the pixel, the electrode elements of the pixel electrode are formed in a manner of forming an angle of 80° counterclockwise. That is, in the first area and the second area of ​​each pixel, the directions of the rotational movement (in-plane switching) of the liquid crystal molecules induced by the voltage application between the pixel electrode and the opposing electrode within the substrate surface are configured to be opposite to each other.

[0273] Next, the liquid crystal alignment agent (1) obtained in Example 1 of the above-mentioned liquid crystal alignment agent and the liquid crystal alignment agent (2) obtained in Comparative Example 1 were filtered with a 1.0 μm filter, and then applied to the above-mentioned substrate with electrodes and a glass substrate with a columnar spacer with a height of 4 μm and an ITO film formed on the back by spin coating. After drying it on a hot plate at 80°C for 5 minutes, it was sintered in a hot air circulation oven at 230°C for 30 minutes to form a coating with a film thickness of 100 nm. Next, a photo-alignment treatment was performed. Specifically, the coating surface was irradiated with ultraviolet rays of a wavelength of 254 nm with a linear polarization having an extinction ratio of 10:1 or more by means of a polarizing plate. It should be noted that the irradiation amount of the irradiated ultraviolet rays was carried out under the conditions described in Table 3 below. Next, the above-mentioned substrate with the coating was heated on a hot plate at 230°C for 30 minutes to obtain a substrate with a liquid crystal alignment film.

[0274] [Table 3]

[0275] Liquid crystal alignment agent Orientation treatment method Example 2 (1) <![CDATA[Optical orientation (400 mJ / cm 2 )]]> Comparative Example 2 (2) <![CDATA[Photo-orientation (400 mJ / cm 2 )]]>

[0276] Prepare two substrates with liquid crystal alignment films as described above, print a sealant (XN-1500T manufactured by Mitsui Chemicals Co., Ltd.) around the liquid crystal injection port, and adhere them in a manner that the liquid crystal alignment film surfaces are opposite and the orientation direction is 0°. Then, heat treatment is performed at 120°C for 90 minutes to cure the sealant and prepare an empty box. After vacuum injection of positive liquid crystal MLC-3019 (manufactured by Merck) into the empty box at room temperature, the injection port is sealed to prepare an FFS liquid crystal box with an anti-parallel orientation. The obtained FFS liquid crystal box is heated at 120°C for 1 hour, left overnight at 23°C, and used for the following evaluations.

[0277] [Evaluation of long-term image retention at room temperature]

[0278] The FFS liquid crystal cell prepared as above was set to a crossed Nicol state using two polarizing plates, with a brightness of 10000 cd / m 2The LED backlight was illuminated while applying an AC voltage of ±6.2V at a frequency of 30Hz to the first pixel for 48 hours. Then, an AC voltage of ±2.9V at a frequency of 30Hz was applied to the first pixel and the second pixel, respectively. The brightness (A) of the first pixel and the brightness (B) of the second pixel just after the driving voltage was switched were measured using a brightness and color uniformity meter (TOPCON model: UA-10H). The rate of change of the brightness (A) of the first pixel relative to the brightness (B) of the second pixel was calculated by the following formula.

[0279] Brightness change rate [%] = (A - B) / B × 100

[0280] It can be said that the smaller the value of the luminance change rate is, the better the image sticking characteristics are. As described above, the results of the normal temperature long-term image sticking evaluation (hereinafter, normal temperature long-term image sticking) are shown in Table 4 below.

[0281] [Table 4]

[0282]

[0283] If the results of the above-mentioned Example 1 and Comparative Example 2 are compared, it is confirmed that the test unit using the liquid crystal orientation film obtained by the liquid crystal orientation agent containing the (C) component described in the present invention has better long-term image retention at room temperature than the FFS liquid crystal box using the liquid crystal orientation film obtained by the liquid crystal orientation agent not containing the (C) component.

[0284] That is, it was confirmed that the liquid crystal display element using the liquid crystal aligning agent of the present invention has excellent image sticking characteristics.

[0285] Industrial Applicability

[0286] By using a liquid crystal display element having the structure of the present invention, a liquid crystal display element having good afterimage characteristics, especially afterimage characteristics when the light is turned on for a long time, can be obtained. Therefore, it can be expected to be used in liquid crystal display elements requiring high display quality. Moreover, these elements are also useful in liquid crystal displays for display purposes, and further, in dimming windows, optical shutters, etc. for controlling the transmission and interception of light.

Claims

1. A liquid crystal aligning agent comprising: a polymer component (P) containing one or more polymers and a component (C), in, The polymer component (P) contains at least one polymer (P) selected from the group consisting of a polyimide precursor and a polyimide which is an imide product of the polyimide precursor. Component (C): at least one compound selected from the group consisting of acids and salts containing periodate ions.

2. The liquid crystal alignment agent according to claim 1, wherein The component (C) is at least one compound selected from the group consisting of periodic acid, metal salts of periodic acid, and organic salts of periodic acid.

3. The liquid crystal alignment agent according to claim 1, wherein The component (C) is at least one compound selected from the group consisting of periodic acid, sodium periodate, potassium periodate, and ammonium periodate.

4. The liquid crystal alignment agent according to claim 1, wherein The polymer (P) has one or more structural units, and has at least one structural unit selected from the group consisting of a structural unit (p0) represented by the following formula (P0) and an imidized structural unit of the structural unit (p0), In formula (P0), X represents a tetravalent organic group, Y represents a divalent organic group, R and Z each independently represent a hydrogen atom or a monovalent organic group, and a plurality of R and Z each independently have the above definition.

5. The liquid crystal alignment agent according to claim 1, wherein The divalent organic group of Y in the formula (P0) is a divalent organic group represented by the following formulas (3) to (4), In formula (3) and formula (4), R3, R4, and R 4’ each independently represents a halogen atom, a hydroxyl group, an optionally protected amino group, a thiol group, a nitro group, a phosphoric acid group, or a monovalent organic group having 1 to 20 carbon atoms, A4 represents an ester bond, an amide bond, a thioester bond, or a divalent organic group having 2 to 20 carbon atoms, wherein 1,4-phenylene, 1 to 4 hydrogen atoms on the phenylene are replaced by R4, and R 4’ Except for substituted divalent organic groups, or divalent organic groups formed by connecting these divalent organic groups to each other, a3, a4 and a4' are each independently an integer from 0 to 4, a is an integer of 1 to 4, b and c are each independently an integer of 1 to 2, and R3, R4, R 4’ If there are multiple 4’ The structures of a3, a4 and a4' may be the same or different. When a plurality of a3, a4 and a4' exist, they may be the same or different. * represents a bonding bond.

6. The liquid crystal alignment agent according to claim 1, wherein The polymer (P) is a polymer containing a structural unit having a divalent organic group, wherein the divalent organic group is selected from the group consisting of a divalent organic group having a urea bond, a divalent organic group having an amide bond, a divalent organic group having a structure containing at least one nitrogen atom selected from the group consisting of a nitrogen-containing heterocycle, a secondary amino group and a tertiary amino group, and a divalent organic group having a carboxyl group.

7. The liquid crystal alignment agent according to claim 1, wherein: The polymer constituting the polymer component (P) has no acid leaving group.

8. A liquid crystal aligning agent comprising: a polymer component (P) containing two or more polymers and a component (C), in, The polymer component (P) satisfies at least one of the following conditions (i) to (iii): (i) the polymer component (P1) comprises at least two polymers selected from the group consisting of a polyimide precursor (A) and a polyimide which is an imide product of the polyimide precursor, wherein the polyimide precursor (A) has at least one structural unit and has a structural unit (a1) represented by the following formula (A1); (ii) a polymer component (P2) comprising two or more polyimide precursors (B), wherein the polyimide precursor (B) is a polymer different from the polyimide precursor (A) and has one or more structural units, and has a structural unit (b1) represented by the following formula (B1), (iii) a polymer component (P3) comprising at least one polymer selected from the group consisting of the polyimide precursor (A) and a polyimide which is an imide product of the polyimide precursor, and the polyimide precursor (B), In formula (A1), X a1 represents a tetravalent organic group selected from the group consisting of the following formulae (Xa1-1) to (Xa1-8), and Y a1 represents a divalent organic group, and multiple R and Z each independently represent a hydrogen atom or a monovalent organic group, In formulas (Xa1-1) to (Xa1-3), R1 to R 15 Each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, a monovalent organic group having 1 to 6 carbon atoms and containing a fluorine atom, or a phenyl group, and they may be the same or different, and * represents a bond, In formula (B1), X b1 represents a tetravalent organic group having an aromatic group having 6 to 30 carbon atoms, and X b1 At least one of the carbonyl carbons is bonded to X b1 Aromatic group bonding, Y b1 represents a divalent organic group, R and Z each independently represent a hydrogen atom or a monovalent organic group, and a plurality of R and Z each independently have the above definition. 9 . A liquid crystal alignment film obtained from the liquid crystal alignment agent according to claim 1 .

10. A method for producing a liquid crystal alignment film, comprising the following steps (1) to (3): Step (1): a step of applying the liquid crystal alignment agent according to any one of claims 1 to 9 onto a substrate; Step (2): a step of firing the applied liquid crystal alignment agent; Step (3): a step of subjecting the film obtained in step (2) to an orientation treatment.

11. The method for manufacturing a liquid crystal alignment film according to claim 10, wherein: The alignment treatment is a photo-alignment treatment.

12. The method for manufacturing a liquid crystal alignment film according to claim 11, wherein: After step (3), the following calcination step is further included: Firing process: a process of sintering at 150°C to 300°C. 13 . A liquid crystal alignment film formed by the method for producing a liquid crystal alignment film according to claim 10 . 14 . A liquid crystal display element comprising the liquid crystal alignment film according to claim 9 . 15 . A liquid crystal display element comprising the liquid crystal alignment film according to claim 13 .

16. A method for manufacturing a liquid crystal display element, comprising: A process for forming the liquid crystal alignment film according to claim 9 or 13.

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