Liquid crystal alignment agent, method for producing polymer, liquid crystal alignment film, liquid crystal display element

Abstract

The present invention provides a liquid crystal alignment film having a high voltage holding ratio and reducing the risk of whitening due to moisture absorption, and a liquid crystal alignment agent having excellent mass production stability, as well as a liquid crystal display element having the liquid crystal alignment film. A liquid crystal alignment agent, characterized in that it contains the following component (A). Component (A): at least one polymer (A) selected from the group consisting of a copolymer having a repeating unit represented by the following formula (a), a repeating unit represented by the following formula (1), and a repeating unit represented by the following formula (2), and a polyimide as an imide of the copolymer, wherein at least one of the repeating unit represented by the following formula (a), the repeating unit represented by the following formula (1), and the repeating unit represented by the following formula (2) has a divalent organic group represented by the following formula (EG). (Regarding each substituent, it is as defined in the specification.)#imgabs0#

Description

Technical Field

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

[0002] In terms of the liquid crystal display elements for liquid crystal televisions, navigation equipment, smart phones, etc., a liquid crystal alignment film that is generally used to control the arrangement state of liquid crystals is located in the element. The liquid crystal alignment film has the function of controlling the orientation of liquid crystal molecules in the liquid crystal display element to a certain direction. For example, the liquid crystal display element has a structure in which the liquid crystal molecules forming the liquid crystal layer are clamped by the liquid crystal alignment film formed on the surface of each of a pair of substrates. Therefore, the liquid crystal molecules are oriented in a certain direction by the liquid crystal alignment film, and are responded to by applying a voltage to the electrodes provided between the substrate and the liquid crystal alignment film. As a result, the liquid crystal display element utilizes the orientation change produced by the response of the liquid crystal molecules to display the desired image. As liquid crystal alignment film, in the past, mainly used was a liquid crystal alignment agent with a solution of a polyimide precursor such as polyamic acid (polyamic acid) and a soluble polyimide as the main component, applied to a glass substrate, etc. and fired to form a polyimide-based liquid crystal alignment film.

[0003] In recent years, in addition to excellent liquid-crystal orientation, a liquid crystal aligning film having a high voltage holding ratio is demanded for power saving of a liquid crystal display element.

[0004] In order to meet the above-mentioned demand, Patent Document 1 proposes a liquid crystal aligning agent containing a polyimide obtained by subjecting a specific diamine component to a reaction.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: International Publication No. 2019-082975 Summary of the Invention

[0008] Problems to be solved by the invention

[0009] Liquid crystal alignment agents containing polyimides, on the other hand, typically use organic polar solvents such as N-methylpyrrolidone and γ-butyrolactone. However, while these solvents have high solubility, they also have the disadvantage of being highly hygroscopic. Therefore, when liquid crystal alignment agents containing polyimides with low solubility are processed in high-humidity environments, there is a risk of hygroscopic whitening, where the polyimide precipitates during coating, causing the film to turn white due to hygroscopic whitening. This poses a problem in terms of mass production stability.

[0010] In view of the above, the technical problem of the present invention is to provide a liquid crystal alignment film having a high voltage holding ratio and reducing the risk of whitening due to moisture absorption, a liquid crystal alignment agent with excellent mass production stability, and a liquid crystal display element having the liquid crystal alignment film.

[0011] Solutions for solving problems

[0012] The present inventors have conducted intensive studies to solve the above-mentioned technical problems and, as a result, have found that a liquid crystal aligning agent containing specific components is effective for achieving the above-mentioned purpose, thereby completing the present invention.

[0013] The present invention is based on the above findings and has the following gist.

[0014] A liquid crystal aligning agent characterized by containing the following (A) component.

[0015] Component (A): at least one polymer (A) selected from the group consisting of a copolymer having a repeating unit represented by the following formula (a), a repeating unit represented by the following formula (1), and a repeating unit represented by the following formula (2), and a polyimide which is an imide product of the copolymer, wherein at least one of the repeating unit represented by the following formula (a), the repeating unit represented by the following formula (1), and the repeating unit represented by the following formula (2) has a divalent organic group represented by the following formula (EG).

[0016]

[0017] (X represents a tetravalent organic group. Y represents a divalent organic group derived from a diamine. The two Rs each independently represent a hydrogen atom or a monovalent organic group. The two Zs each independently represent a hydrogen atom or a monovalent organic group.)

[0018]

[0019] (A1 is a divalent organic group, A 1’ is a divalent organic group derived from diamine, C1 and C 1’ are each independently a hydrogen atom or a monovalent organic group.)

[0020]

[0021] (A2 is a divalent organic group, A 2’ A divalent organic group obtained by removing the hydrogen atoms contained in two hydroxyl groups from an organic diol.

[0022]

[0023] (R represents a hydrogen atom or a methyl group. n is an integer of 3 to 40.)

[0024] Effects of the Invention

[0025] The liquid crystal alignment agent of the present invention can provide a liquid crystal alignment film having a high voltage holding ratio, and a liquid crystal display element having the liquid crystal alignment film can be obtained. Furthermore, the liquid crystal alignment agent can reduce the risk of whitening due to moisture absorption and have excellent mass production stability. Furthermore, the liquid crystal alignment agent of the present invention can provide a liquid crystal display element with fewer display defects.

[0026] The mechanism by which the above-mentioned effects of the present invention are achieved is not necessarily clear, but is generally presumed as follows. Specifically, it is believed that the introduction of urea and urethane groups into the polymer generates hydrogen bonds of appropriate strength, thereby improving voltage holding characteristics. Furthermore, the introduction of hydrophilic polyethylene glycol chains into the polymer improves solubility in water, thereby achieving the above-mentioned effects. DETAILED DESCRIPTION

[0027] Hereinafter, each component contained in the liquid crystal aligning agent of the present disclosure and other components arbitrarily blended as needed will be described. In addition, in this specification, examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0028] <Polymer (A)>

[0029] The liquid crystal aligning agent of the present invention is at least one polymer (A) selected from the group consisting of a copolymer having a repeating unit represented by the above formula (a), a repeating unit represented by the above formula (1) and a repeating unit represented by the above formula (2) (hereinafter also referred to as a polyimide precursor (A)), and a polyimide which is an imide product of the copolymer, and at least one of the repeating unit represented by the above formula (a), the repeating unit represented by the above formula (1) and the repeating unit represented by the above formula (2) has a divalent organic group represented by the above formula (EG).

[0030] In the above formula (EG), from the viewpoint of improving liquid crystal orientation, the upper limit of n is preferably 40, more preferably 30, particularly preferably 20. From the viewpoint of improving liquid crystal orientation, the lower limit of n is preferably 3, more preferably 4.

[0031] (Repeating unit represented by formula (a))

[0032] In the above formula (a), Y represents a divalent organic group derived from a diamine. Examples of the diamine include the following diamines. The diamines may be used alone or in combination of two or more.

[0033] Diamines represented by the following formula (O); diamines having a photo-aligning group such as 4,4'-diaminoazobenzene or diaminodiphenylacetylene; diamines having an amide bond or a urea bond such as diamines represented by the following formulas (h-1) to (h-6); 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 4,4'-diaminobenzophenone, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 1,4-bis(4-aminobenzyl)benzene, the following formula (d o ); a diamine having at least one nitrogen-containing structure selected from the group consisting of a nitrogen-containing heterocycle, a secondary amino group, and a tertiary amino group (hereinafter also referred to as a specific nitrogen-containing structure); 2,4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4,6-diaminoresorcinol; 4,4'-diamino-3,3'-dihydroxybiphenyl, 2,4-diaminobenzoic acid, 2,5-diaminobenzoic acid, 3,5-diaminobenzoic acid, and diamines represented by the following formulas (3b-1) to (3b-4), etc. Diamines with carboxyl groups; 4-(2-(methylamino)ethyl)aniline, 4-(2-aminoethyl)aniline, 1-(4-aminophenyl)-1,3,3-trimethyl-1H-indan-5-amine, 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-indan-6-amine; diamines with photopolymerizable groups at the end, such as 2-(2,4-diaminophenoxy)ethyl methacrylate and 2,4-diamino-N,N-diallylaniline; cholesteryloxy-3,5-diaminobenzene, cholesteryloxy-3,5-diaminobenzene, cholesteryl Diamines having a steroid skeleton, such as alkyloxy-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; diamines represented by the following formulas (V-1) to (V-6); diamines having a group "-N(D)-" (D represents a protective group that is released by heating and substituted with a hydrogen atom, preferably a tert-butoxycarbonyl group), such as the following formulas (5-1) to (5-11); 1,3-bis(3-aminopropyl)- Diamines having a siloxane bond, such as tetramethyldisiloxane and a diamine represented by the following formula (Ds-1); diamines having an oxazoline structure, such as the following formulas (Ox-1) to (Ox-2); 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 International Publication No. 2018 / 117239.

[0034]

[0035] (Ar represents a divalent benzene ring, a biphenyl structure, or a naphthalene ring. Two Ars are optionally the same or different, and any hydrogen atom in the above benzene ring, biphenyl structure, or naphthalene ring is optionally substituted by a monovalent group. p is an integer of 0 or 1. Q2 represents -(CH2) n -(n is an integer from 2 to 18.), or the -(CH2) n A group in which at least a portion of -CH2- in - is substituted by any one of -O-, -C(=O)-, or -O-C(=O)-. However, when Q2 has an ether bond, the total number of all ether bonds possessed by Q2 is set to 3 or less.

[0036]

[0037] (A plurality of m's are optionally the same or different.)

[0038]

[0039] (In formula (3b-1), A 1 represents a single bond, -CH2-, -C2H4-, -C(CH3)2-, -CF2-, -C(CF3)2-, -O-, -CO-, -NH-, -N(CH3)-, -CONH-, -NHCO-, -CH2O-, -OCH2-, -COO-, -OCO-, -CON(CH3)- or -N(CH3)CO-, m1 and m2 are each independently an integer from 0 to 4, and m1+m2 is an integer from 1 to 4. In formula (3b-2), m3 and m4 are each independently an integer from 1 to 5. In formula (3b-3), A 2 represents a linear or branched alkyl group having 1 to 5 carbon atoms, and m5 is an integer of 1 to 5. In formula (3b-4), A 3 and A 4 Each independently represents a single bond, -CH2-, -C2H4-, -C(CH3)2-, -CF2-, -C(CF3)2-, -O-, -CO-, -NH-, -N(CH3)-, -CONH-, -NHCO-, -CH2O-, -OCH2-, -COO-, -OCO-, -CON(CH3)- or N-(CH3)CO-, and m6 is an integer from 1 to 4.)

[0040]

[0041] (X v1 ~X v4 、X p1 ~X p2 Each independently represents -(CH2) a-(a is an integer from 1 to 15), -CONH-, -NHCO-, -CON(CH3)-, -NH-, -O-, -CH2O-, -CH2OCO-, -COO-, or -OCO-, X v5 represents -O-, -CH2O-, -CH2OCO-, -COO-, or -OCO-. Xa represents a single bond, -O-, -NH-, or -O-(CH2) m -O- (m represents an integer from 1 to 6.), R v1 ~R v4 、R 1a ~R 1b Each independently represents an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an alkoxyalkyl group having 2 to 20 carbon atoms. In formula (V-6), two k are optionally the same or different.

[0042]

[0043] (Boc represents tert-butoxycarbonyl.)

[0044]

[0045] As the above formula (d o ) is preferably a diamine represented by the following formula (d o -1)~(d o -6) diamine, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether and 4,4'-diaminodiphenyl ether.

[0046]

[0047] In the diamine represented by the above formula (O), any hydrogen atom in the benzene ring, biphenyl structure, or naphthalene ring may be substituted with a monovalent group. Examples of the monovalent group include a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a fluoroalkyl group having 1 to 10 carbon atoms, a fluoroalkenyl group having 2 to 10 carbon atoms, a fluoroalkoxy group having 1 to 10 carbon atoms, an alkyloxycarbonyl group having 1 to 10 carbon atoms, a cyano group, and a nitro group.

[0048] As the diamine represented by the above formula (O), diamines represented by the following formulae (o-1) to (o-16) are preferred from the viewpoint of improving liquid crystal orientation.

[0049]

[0050]

[0051] (In formula (o-14), the two m's may be the same or different.)

[0052] Examples of the nitrogen-containing heterocyclic ring that the diamine having a specific nitrogen-containing structure may have include pyrrole, imidazole, pyrazole, triazole, pyridine, pyrimidine, pyridazine, pyrazine, indole, benzimidazole, purine, quinoline, isoquinoline, naphthyridine, quinoxaline, phthalazine, triazine, carbazole, acridine, piperidine, piperazine, pyrrolidine, and hexamethyleneimine. Among them, pyridine, pyrimidine, pyrazine, piperidine, piperazine, quinoline, carbazole, or acridine is preferred.

[0053] The secondary amino group and the tertiary amino group which the diamine having the specific nitrogen atom-containing structure may have are represented by, for example, the following formula (n).

[0054]

[0055] In the above formula (n), R represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. "*" represents a bond to a hydrocarbon group, and at least one of them is bonded to an aromatic hydrocarbon group.

[0056] Examples of the monovalent hydrocarbon group R in the formula (n) include alkyl groups such as methyl, ethyl, and propyl; cycloalkyl groups such as cyclohexyl; and aryl groups such as phenyl and methylphenyl. R is preferably a hydrogen atom or a methyl group.

[0057] Specific examples of the diamine having a specific nitrogen atom-containing structure include 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, 1,4-bis-(4-aminophenyl)-piperazine, 3,6-diaminoacridine, N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, diamines represented by the following formulas (Dp-1) to (Dp-8), and diamines represented by the following formulas (z-1) to (z-18).

[0058]

[0059]

[0060] When the repeating unit (a) has a divalent organic group represented by the above formula (EG), it is preferred that at least one of the above X and Y has a divalent organic group represented by the above formula (EG). When the above Y has a divalent organic group represented by the above formula (EG), examples of the above Y include divalent organic groups derived from diamines having amino groups at both ends of the divalent organic group represented by the above formula (EG) via aromatic groups. Examples of the aromatic group include a benzene ring, a biphenyl structure, or a naphthalene ring. The above Y is more preferably derived from the following formula (d EG) is a divalent organic group of a diamine shown.

[0061]

[0062] Ar each independently represents a divalent aromatic group or a condensed ring group, and is optionally the same or different. One or more hydrogen atoms on the aromatic group or the condensed ring group are optionally substituted by a monovalent group. Specific examples of the above-mentioned Ar include a benzene ring, a biphenyl structure or a naphthalene ring. Examples of the above-mentioned monovalent group include: a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a fluoroalkyl group having 1 to 10 carbon atoms, a fluoroalkenyl group having 2 to 10 carbon atoms, a fluoroalkoxy group having 1 to 10 carbon atoms, a carboxyl group, a hydroxyl group, an alkyloxycarbonyl group having 1 to 10 carbon atoms, a cyano group, a nitro group, and the like. n represents an integer from 3 to 40. The upper limit of n is preferably 30, and more preferably 20.

[0063] It should be noted that throughout this specification, an m-valent "aromatic group" refers to an m-valent group formed by removing m hydrogen atoms from an aromatic ring. An m-valent "condensed ring group" refers to an m-valent group formed by removing m hydrogen atoms from a condensed ring.

[0064] The above-mentioned Y is preferably a divalent organic group derived from a diamine selected from the group consisting of a diamine represented by the above-mentioned formula (O), a diamine having an amide bond or a urea bond, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 4,4'-diaminobenzophenone, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 1,4-bis(4-aminobenzyl)benzene, the above-mentioned formula (d o ), 4-(2-(methylamino)ethyl)aniline, 4-(2-aminoethyl)aniline, a diamine having a group "-N(D)-" (D represents a protective group that is released by heating and substituted with a hydrogen atom, preferably a tert-butoxycarbonyl group), and the above formula (d EG ) is represented by the group consisting of diamines. By making the above-mentioned Y satisfy this structure, it is possible to obtain the effect of reducing the pretilt angle of the liquid crystal, the afterimage caused by long-term AC driving, and the relaxation characteristics of the accumulated charge at a high speed, which is preferred.

[0065] In the above formula (a), X represents a tetravalent organic group. X preferably represents a tetravalent organic group derived from tetracarboxylic dianhydride or a derivative thereof. Examples of the tetravalent organic group include a tetravalent organic group derived from acyclic aliphatic tetracarboxylic dianhydride or a derivative thereof, a tetravalent organic group derived from alicyclic tetracarboxylic dianhydride or a derivative thereof, and a tetravalent organic group derived from aromatic tetracarboxylic dianhydride or a derivative thereof.

[0066] Here, non-cyclic aliphatic tetracarboxylic dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxyl groups bonded to a chain hydrocarbon structure. Wherein, it is not necessary to consist only of a chain hydrocarbon structure, and a part thereof may have an alicyclic structure or an aromatic ring structure. 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. Wherein, none of these four carboxyl groups are bonded to an aromatic ring. In addition, it is not necessary to consist only of an alicyclic structure, and a part thereof may have a chain hydrocarbon structure or an aromatic ring structure. 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. As derivatives of the above-mentioned tetracarboxylic dianhydride, there can be listed: tetracarboxylic acid dihalide, tetracarboxylic acid dialkyl ester, or tetracarboxylic acid dialkyl ester dihalide.

[0067] The tetracarboxylic dianhydride or its derivative may be used alone or in combination of two or more.

[0068] Among the above-mentioned non-cyclic aliphatic or alicyclic tetracarboxylic dianhydrides or their derivatives, from the viewpoint of improving liquid crystal orientation, tetracarboxylic dianhydrides or their derivatives having at least one partial structure selected from the group consisting of a cyclobutane ring structure, a cyclopentane ring structure and a cyclohexane ring structure are preferred.

[0069] It is preferable that the said X is a tetravalent organic group derived from tetracarboxylic dianhydride or its derivative represented by the following formula (t).

[0070]

[0071] In the formula, X1 is a structure selected from the following formulas (X1-1) to (X1-25). * represents a bonding bond.

[0072]

[0073] In formulas (X1-1) to (X1-4), R1 to R 21 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. * represents a bond. In order to improve the liquid crystal orientation, R1 to R 21 A hydrogen atom, a halogen atom, a methyl group, or an ethyl group is preferred, and a hydrogen atom or a methyl group is more preferred.

[0074] In formulae (X1-24) to (X1-25), j and k are integers of 0 or 1, and A1 and A2 each independently represent a single bond, -O-, -CO-, -COO-, a phenylene group, a sulfonyl group, or an amide group. Plural A2 groups may be the same or different.

[0075] Specific examples of formula (X1-1) include the following formulas (1-1) to (1-6). From the viewpoint of improving liquid crystal orientation, formulas (1-1) and (1-2) are particularly preferred. * has the same meaning as above.

[0076]

[0077] Preferred specific examples of the above formulae (X1-24) and (X1-25) include the following formulae (X1-26) to (X1-41). * has the same meaning as the above *.

[0078]

[0079]

[0080] From the viewpoint of improving the liquid crystal orientation, the above-mentioned X1 is preferably the above-mentioned formula (X1-1) to (X1-10), (X1-18) to (X1-23), (X1-24) to (X1-25), or (X1-26) to (X1-30), more preferably the above-mentioned formula (X1-1), (X1-5), (X1-7) to (X1-10), (X1-21), (X1-23), (X1-24) to (X1-25), or (X1-26) to (X1-30), and further preferably the above-mentioned formula (1-1), (1-2), (X1-5), (X1-7), (X1-9), or (X1-26) to (X1-30).

[0081] As described above, when the repeating unit (a) has a divalent organic group represented by the above formula (EG), it is preferred that at least one of X and Y has a divalent organic group represented by the above formula (EG). When X has a divalent organic group represented by the above formula (EG), for example, X can be a tetravalent organic group derived from tetracarboxylic dianhydride or a derivative thereof as shown below.

[0082]

[0083] Examples of the monovalent organic group in R and Z in the formula (a) include monovalent hydrocarbon groups having 1 to 20 carbon atoms, -O-, -S-, -CO-, -COO-, -COS-, -NR- 3 -(where R 3 is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms), -CO-NR 3 -(where R 3 is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms), -Si(R 3 )2-(where R 3(a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms), a monovalent group A in which the methylene group of the hydrocarbon group is substituted with a halogen atom (fluorine, chlorine, bromine, iodine, etc.), a hydroxyl group, an alkoxy group, a nitro group, an amino group, a mercapto group, a nitroso group, an alkylsilyl group, an alkoxysilyl group, a silanol group, a sulfinyl group, a phosphino group, a carboxyl group, a cyano group, a sulfo group, an acyl group, or a monovalent group having a heterocyclic ring. The monovalent organic group in R and Z in the above formula (a) 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 tert-butoxycarbonyl group, or a 9-fluorenylmethoxycarbonyl group, more preferably an alkyl group having 1 to 3 carbon atoms, and still more preferably a methyl group.

[0084] From the viewpoint of achieving the effects of the present invention, R and Z are each independently preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and more preferably a hydrogen atom or a methyl group.

[0085] In the above formula (a), X, Y, R, and Z may each be one or two or more.

[0086] (Repeating unit represented by formula (1))

[0087] In the above formula (1), A1 is a divalent organic group. Examples of A1 include divalent organic groups derived from diisocyanates. These diisocyanates may be used alone or in combination of two or more.

[0088] Here, examples of the diisocyanate include aromatic diisocyanate and aliphatic diisocyanate.

[0089] Here, "aromatic diisocyanate" refers to a diisocyanate having at least one aromatic group. Also, "aliphatic diisocyanate" refers to a diisocyanate having an aliphatic group and no aromatic group.

[0090] Examples of A1 include: (i) a divalent organic group derived from an aromatic diisocyanate, wherein in a diisocyanate structure (O=C=N-R-N=C=O), R is an organic group having 6 to 30 carbon atoms and having at least one benzene ring; or (ii) a divalent organic group derived from an aliphatic diisocyanate, wherein in a diisocyanate structure (O=C=N-R-N=C=O), R is an organic group having 4 to 30 carbon atoms and having an aliphatic group and no aromatic group.

[0091] In addition, the aliphatic group includes both a non-cyclic aliphatic group and an alicyclic group.

[0092] Specific examples of A1 include those derived from o-phenylenediisocyanate, m-phenylenediisocyanate, p-phenylenediisocyanate, toluene diisocyanates (e.g., 2,4-toluene diisocyanate, 2,6-toluene diisocyanate), 1,4-diisocyanate-2-methoxybenzene, 2,5-diisocyanate xylenes, 3,3'-dimethyl-4,4'-biphenyl diisocyanate, 4,4'-diisocyanate diphenyl ether, 2,2'-bis(4-diisocyanatephenyl)propane, 4,4'-diisocyanate divalent organic groups derived from aromatic diisocyanates such as ester diphenylmethane (4,4'-diphenylmethane diisocyanate), 4,4'-diisocyanate diphenyl ether, 4,4'-diisocyanate diphenyl sulfone, 3,3'-diisocyanate diphenyl sulfone, and 2,2'-diisocyanate dibenzophenone; and divalent organic groups derived from aliphatic diisocyanates such as isophorone diisocyanate, norbornene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, and tetramethylene diisocyanate.

[0093] In the above formula (1), A 1’ It is a divalent organic group derived from a diamine. Examples of the diamine include the diamines exemplified in the repeating unit (a), and preferred embodiments are the same as those of the diamines described above.

[0094] When the above formula (1) has a divalent organic group represented by the above formula (EG), it is preferred that the above A1 and A 1’ At least one of them has a divalent organic group represented by the above formula (EG).

[0095] In the above A 1’ In the case of having a divalent organic group represented by the above formula (EG), as A 1’ The specific structure of can be listed as follows: the divalent organic group derived from the diamine having the divalent organic group represented by the above formula (EG) as exemplified in the above repeating unit (a), or a preferred embodiment thereof.

[0096] When the above-mentioned A1 has a divalent organic group represented by the above-mentioned formula (EG), examples of the above-mentioned A1 include the following divalent organic groups derived from diisocyanate.

[0097]

[0098] As C1, C 1’ The monovalent organic group may be the structures exemplified by R and Z of the repeating unit (a). 1’ Each independently is preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and more preferably a hydrogen atom or a methyl group.

[0099] In the above formula (1), A1, A 1’ , C1, C 1’ Each of them may be one or two or more.

[0100] (Repeating unit represented by formula (2))

[0101] In the above formula (2), A2 is a divalent organic group. Examples of A2 include divalent organic groups derived from diisocyanates, and the structures exemplified by A1 in the above repeating unit (1) are also included. Preferred embodiments are the same as those for A1.

[0102] In the above formula (2), A 2’ It is a divalent organic group obtained by removing the hydrogen atoms contained in two hydroxyl groups from an organic diol. The organic diol may be used alone or in combination of two or more. Examples of the organic diol include: a diol containing a divalent organic group represented by the above formula (EG); ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,3-propylene glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 2-methyl-1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol and other alkylene glycols; dimethylolpropionic acid (2,2-bis(hydroxymethyl)propionic acid), dimethylolbutanoic acid (2,2-bis(hydroxymethyl)butanoic acid), 2,3-dihydroxybenzyl alcohol Carboxyl group-containing diols such as 2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, 2,6-dihydroxybenzoic acid, 3,4-dihydroxybenzoic acid and 3,5-dihydroxybenzoic acid; polytetramethylene glycol; random copolymers of tetramethylene glycol and neopentyl glycol; polyester diols obtained by reacting a polyol with a polybasic acid; polycarbonate diols having a carbonate skeleton; polycaprolactone diols obtained by subjecting lactones such as γ-butyrolactone, ε-caprolactone and δ-valerolactone to a ring-opening addition reaction; bisphenol A; ethylene oxide adducts of bisphenol A; propylene oxide adducts of bisphenol A; hydrogenated bisphenol A; ethylene oxide adducts of hydrogenated bisphenol A; propylene oxide adducts of hydrogenated bisphenol A, etc.

[0103] The diol containing the divalent organic group represented by the above formula (EG) is not particularly limited as long as it contains the above formula (EG) in the molecule, but is preferably a diol having hydrogen atoms bonded to both ends of the above formula (EG). In the diol having hydrogen atoms bonded to both ends of the above formula (EG), from the viewpoint of improving liquid crystal orientation, the upper limit of n is preferably 40, more preferably 30, and particularly preferably 20. From the viewpoint of improving liquid crystal orientation, the lower limit of n is preferably 3, more preferably 4. More specifically, examples of the diol containing a divalent organic group represented by the above formula (EG) include tetraethylene glycol, pentaethylene glycol, hexaethylene glycol, PEG-300, PEG-400, PEG-600, PEG-1000, PEG-1500, PEG-2000, PEG-4000N, PEG-4000S, PEG-6000E, PEG-6000P, PEG-10000, PEG-13000, and PEG-20000 manufactured by Sanyo Chemical Industries, Ltd.; PEG300, PEG1000, PEG2000, PEG4000, PEG6000, PEG8000, PEG10000, PEG12000, PEG20000, and PEG35000 manufactured by Merck; and SIGMA-ALDRI. Product numbers of CH company are P2139, P3265, P3515, 81210, 81240, 81260, 81285, 81310, 181986, 181994, 182001, 182028, 189456, 202304, 202312, 202320, 202339, 202398, 202421, 202436, 2 02444, 202452, 295906, 309028, 372773, 372781, 373001, 412325, 435406, 435422, 435457, 637726; manufactured by Sino-Japan Synthetic Chemical Co., Ltd. under the trade names SINOPOLPEG600, SINOPOLPEG1500, and SINOPOLPEG4000; LION Polyethylene glycol represented by products commercially available under the trade names PEG#300, PEG#400, PEG#600, PEG#1000, PEG#1500, PEG#1540, PEG#4000, and PEG#6000M manufactured by Specialty Chemicals, and product names Polyethylene Glycol 400 and Polyethylene Glycol 600 manufactured by Tokyo Chemical Industry Co., Ltd.; or tripropylene glycol, tetrapropylene glycol, polypropylene glycol (more preferably polypropylene glycol having an average molecular weight of 300 to 10,000), and copolymers composed of ethylene oxide and propylene oxide having an average molecular weight of 200 to 5,000.The polyethylene glycol and polypropylene glycol can be obtained by anionic ring-opening polymerization of ethylene oxide and propylene oxide. This polymerization reaction can be carried out using a polymerization initiator (e.g., water, ethylene glycol, propylene glycol, etc.) and a catalytic amount of a base (e.g., potassium hydroxide). Preferred specific examples of the diol having hydrogen atoms bonded to both ends of the above formula (EG) include tetraethylene glycol, pentaethylene glycol, hexaethylene glycol, PEG-300, PEG-400, PEG-600, and PEG-1000 manufactured by Sanyo Chemical Industries, Ltd., PEG 300 and PEG 1000 manufactured by Merck, PEG 1000 and SINOPOL PEG 600 manufactured by Chu-Nippon Gosei Chemical Co., Ltd., PEG #300, PEG #400, PEG #600, and PEG #100 manufactured by Lion Specialty Chemicals, and Polyethylene Glycol 400 and Polyethylene Glycol 600 manufactured by Tokyo Chemical Industry Co., Ltd.

[0104] In addition, the average molecular weight of the diol exemplified among the diols containing a divalent organic group represented by (EG) above refers to a weight average molecular weight obtained based on polystyrene according to gel permeation chromatography (GPC).

[0105] When the above formula (2) has a divalent organic group represented by the above formula (EG), it is preferred that the above A2 and A 2’ At least one of them has a divalent organic group represented by the above formula (EG).

[0106] When A2 has a divalent organic group represented by the above formula (EG), specific structures of A2 include divalent organic groups derived from diisocyanates having a divalent organic group represented by the above formula (EG) as exemplified in the above repeating unit (1).

[0107] In the above A 2’ In the case of having a divalent organic group represented by the above formula (EG), as A 2’ The specific structure of includes: a divalent organic group including the divalent organic group represented by the above formula (EG) described in detail above, which is obtained by removing hydrogen atoms contained in two hydroxyl groups from a diol.

[0108] In the above formula (2), A2, A 2’ Each of them may be one or two or more.

[0109] (Repeating units constituting polymer (A))

[0110] The polymer (A) in the present invention is at least one polymer selected from the group consisting of a copolymer having a repeating unit represented by the above formula (a), a repeating unit represented by the above formula (1), and a repeating unit represented by the above formula (2), and a polyimide which is an imide product of the copolymer (wherein at least one of the repeating unit represented by the above formula (a), the repeating unit represented by the above formula (1), and the repeating unit represented by the above formula (2) has a divalent organic group represented by the above formula (EG)). The polymer (A) may have a repeating unit represented by the above formula (a), a repeating unit represented by the above formula (1), a repeating unit represented by the above formula (2), and a terminal group.

[0111] Here, the term "terminal group" refers to a group bonded to the end of the repeating unit constituting the polymer (A). Examples of terminal groups include amino groups, carboxyl groups, acid anhydride groups, isocyanate groups, and derivatives thereof. Amino groups, carboxyl groups, acid anhydride groups, and isocyanate groups are obtained through conventional condensation reactions, while derivatives thereof can be obtained, for example, by modifying the terminal groups using a capping agent as described below.

[0112] The content of the repeating unit represented by formula (a) is preferably 2 to 98 mol%, more preferably 10 to 96 mol%, of the entire repeating units constituting the polymer (A).

[0113] The content of the repeating unit represented by formula (1) is preferably 1 to 49 mol%, more preferably 2 to 45 mol%, of the entire repeating units constituting the polymer (A).

[0114] The content of the repeating unit represented by formula (2) is preferably 1 to 49 mol%, more preferably 2 to 45 mol%, of the entire repeating units constituting the polymer (A).

[0115] <Polymer (B)>

[0116] From the viewpoint of improving electrical properties, the liquid crystal aligning agent of the present invention may further contain a polymer (B) different from the polymer (A), wherein the polymer (B) is at least one polymer selected from the group consisting of polyimide precursors and imidized polymers thereof.

[0117] The polymer (B) is preferably at least one polymer selected from the group consisting of a polyimide precursor having a repeating unit represented by the following formula (b) and an imidized polymer thereof.

[0118]

[0119] (X b Y represents a tetravalent organic group. b Represents a divalent organic group. Two R bEach independently represents a hydrogen atom or a monovalent organic group. b Each independently represents a hydrogen atom or a monovalent organic group.)

[0120] The polymer (B) preferably does not have at least one selected from the group consisting of the repeating unit represented by the above formula (1) and the repeating unit represented by the above formula (2).

[0121] As X b The tetravalent organic group in the formula (a) may be a tetravalent organic group derived from a non-cyclic aliphatic tetracarboxylic dianhydride, a tetravalent organic group derived from alicyclic tetracarboxylic dianhydride, or a tetravalent organic group derived from aromatic tetracarboxylic dianhydride. Specific examples include the tetravalent organic groups exemplified by X1 in the formula (a). From the perspective of efficiently achieving the effects of the present invention, the tetravalent organic groups represented by the formulas (X1-1) to (X1-25) are preferred (these are also collectively referred to as specific tetravalent organic groups).

[0122] From the viewpoint of efficiently obtaining the effects of the present invention, the polymer (B) preferably contains 5 mol% or more of X in all repeating units contained in the polymer (B). b The repeating unit is a specific tetravalent organic group, and more preferably contains 10 mol% or more of all the repeating units contained in the polymer (B). b is a repeating unit of the above-mentioned specific tetravalent organic group.

[0123] As Y b Specific examples include divalent organic groups derived from the diamines exemplified in the polymer (A). From the perspective of improving electrical properties, the polymer (B) is preferably a polymer comprising a repeating unit wherein the repeating unit is Y b The divalent organic group is a divalent organic group selected from the group consisting of divalent organic groups obtained by removing two amino groups from a diamine having a carboxyl group, such as a diamine having a specific nitrogen atom-containing structure, 2,4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4,6-diaminoresorcinol, 2,4-diaminobenzoic acid, 2,5-diaminobenzoic acid, 3,5-diaminobenzoic acid, and the diamine compounds represented by the above formulae (3b-1) to (3b-4) (these groups are also collectively referred to as specific divalent organic groups).

[0124] From the viewpoint of improving electrical properties, the polymer (B) may contain 1 mol% or more of Y based on all repeating units contained in the polymer (B). b The repeating unit is a specific divalent organic group, and may contain 5 mol% or more of all the repeating units contained in the polymer (B). b is a repeating unit of the above-mentioned specific divalent organic group.

[0125] From the viewpoint of improving electrical properties, the content ratio of component (A) to component (B) may be 10 / 90 to 90 / 10, 20 / 80 to 90 / 10, or 20 / 80 to 80 / 20 as the mass ratio of [component (A)] / [component (B)].

[0126] <Production of polymer (A) and polymer (B)>

[0127] The polyimide precursor (A) serving as the polymer (A) can be produced, for example, by a method comprising reacting a component (o) comprising an organic diol having two hydroxyl groups in its molecule with a component (a) comprising a compound having two isocyanate groups in its molecule to synthesize a terminal isocyanate compound, followed by reacting with a component (b) comprising a compound having two primary or secondary amino groups in its molecule to synthesize a terminal amine urea oligomer, and further reacting with a component (c) comprising tetracarboxylic dianhydride or a derivative thereof. At least one of the compounds constituting the components (o), (a), (b), and (c) has a partial structure represented by the following formula (EG) in its molecule.

[0128]

[0129] (R represents a hydrogen atom or a methyl group. n is an integer of 3 to 40.)

[0130] On the other hand, the polyimide precursor (A) can also be produced by the following method: having a step of reacting the components (a) and (b) to obtain a terminal isocyanate compound; and a step of reacting the components (o) and (c) to obtain a terminal diol compound, and then reacting the obtained terminal isocyanate compound with the terminal diol compound.

[0131] Alternatively, the polyimide precursor (A) may be produced by reacting the components (b) and (c) to obtain an amine-terminated amic acid oligomer or a derivative thereof, adding the component (o) thereto to prepare a mixed solution, and then reacting the component (a).

[0132] The component (o), the component (a), the component (b), and the component (c) may each be used in an amount of one or two or more.

[0133] As the component (o), for example, the organic diols exemplified in the repeating unit represented by the above formula (2) can be mentioned, and "H-A 2’ -H" (A 2’ and A in formula (2) 2’ The diol compound shown is the same).

[0134] Examples of the component (a) include diisocyanate compounds represented by O═C═N—A 1 —N═C═O (A 1 is the same as A 1 in formula (1)).

[0135] As (b)component, the diamine represented by following formula (mb) is mentioned, for example.

[0136]

[0137] (In formula (mb), C1, C 1’ 、A 1’ and C1, C in formula (1) 1’ 、A 1’ same.)

[0138] Specific examples of the compound represented by the above formula (mb) include the diamines exemplified as examples for the repeating unit represented by the above formula (a).

[0139] As tetracarboxylic dianhydride or its derivative contained in (c) component, tetracarboxylic dianhydride or its derivative (tetracarboxylic acid dihalide, tetracarboxylic acid dialkyl ester, or tetracarboxylic acid dialkyl ester dihalide) represented by the following formula (mc) is mentioned, for example.

[0140]

[0141] (In formula (mc), X is the same as X in the above formula (a).)

[0142] More specifically, X in the above formula (mc) can be exemplified by the following examples: tetravalent organic groups derived from acyclic aliphatic tetracarboxylic dianhydride or its derivatives, tetravalent organic groups derived from alicyclic tetracarboxylic dianhydride or its derivatives, or tetravalent organic groups derived from aromatic tetracarboxylic dianhydride or its derivatives, as exemplified by the repeating units represented by the above formula (a). With respect to the above-mentioned acyclic aliphatic or alicyclic tetracarboxylic dianhydride or its derivatives, from the viewpoint of high liquid crystal orientation, tetracarboxylic dianhydride or its derivatives having at least one partial structure selected from the group consisting of a cyclobutane ring structure, a cyclopentane ring structure, and a cyclohexane ring structure are preferred. As the tetracarboxylic dianhydride or its derivative contained in the (c) component, tetracarboxylic dianhydride or its derivative represented by the above formula (t) is preferred.

[0143] The tetracarboxylic dianhydride represented by formula (t) or its derivative is preferably 1 mol% or more of the entire component (c), more preferably 5 mol% or more, particularly preferably 10 mol% or more.

[0144] When at least one of the compounds constituting the above-mentioned components (o), (a), (b), and (c) has a partial structure represented by the above-mentioned formula (EG) in the molecule, "H-A 2’ A in the diol compound represented by -H" 2’ , A1 in the diisocyanate compound represented by O=C=N-A1-N=C=O, A1 in the diamine represented by the above formula (mb) 1’ At least one of X in the tetracarboxylic dianhydride represented by the above formula (mc) has a partial structure represented by the above formula (EG) in the molecule. Preferred specific examples thereof are as described above.

[0145] The reaction of component (o), component (a), component (b) and component (c) is usually carried out in an organic solvent. The organic solvent used at this time is not particularly limited as long as it is a solvent that dissolves the generated polyimide precursor. Specific examples include: N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methyl-ε-caprolactam, dimethyl sulfoxide, tetramethyl urea, pyridine, dimethyl sulfone, hexamethylphosphoric acid triamide, γ-butyrolactone, isopropyl alcohol, methoxymethylpentanol, dipentene, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, methyl cellosolve, ethyl cellosolve. Cellosolve, Methyl Cellosolve Acetate, Ethyl Cellosolve Acetate, Butyl Carbitol, Ethyl Carbitol, Ethylene Glycol, Ethylene Glycol Monoacetate, Ethylene Glycol Monoisopropyl Ether, Ethylene Glycol Monobutyl Ether, Propylene Glycol, Propylene Glycol Monoacetate, Propylene Glycol Monomethyl Ether, Propylene Glycol Tert-Butyl Ether, Dipropylene Glycol Monomethyl Ether, Diethylene Glycol, Diethylene Glycol Monoacetate, Diethylene Glycol Dimethyl Ether, Dipropylene Glycol Monoacetate Monomethyl Ether, Dipropylene Glycol Monomethyl Ether, Dipropylene Glycol Monoethyl Ether, Dipropylene Glycol Monoacetate Ethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, 1,4-dioxane, n-hexane, n-pentane, n-octane, diethyl ether, cyclohexanone, ethylene carbonate, ethylene carbonate Propyl ester, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, diethylene glycol dimethyl ether or 4-hydroxy-4-methyl-2-pentanone. These can be used alone or in combination. Moreover, the solvent can be a solvent that does not dissolve the polyimide precursor, or it can be mixed with the above solvents to the extent that the generated polyimide precursor does not precipitate. In addition, the water content in the organic solvent becomes a factor that hinders the polymerization reaction and causes the generated polyimide precursor to hydrolyze, so the organic solvent is preferably a dehydrated organic solvent.

[0146] <Method for synthesizing terminal isocyanate compounds>

[0147] The method for synthesizing a terminal isocyanate compound obtained by reacting a component (o) comprising an organic diol used in the present invention with a component (a) comprising a diisocyanate compound having two isocyanate groups in the molecule. The component (o) and the component (a) are mixed in an organic solvent so that the ratio of the number of hydroxyl groups to the number of isocyanate groups is isocyanate group / hydroxyl group = 1.01 or more, preferably 1.1 or more and 2.4 or less, and more preferably 1.1 or more and 2.1 or less.

[0148] In addition, when using two or more organic diols, the reaction with the diisocyanate compound can be carried out after mixing the two or more organic diols, or each organic diol and the diisocyanate compound can be reacted separately. In addition, after reacting the organic diol and the diisocyanate compound, the obtained terminal isocyanate compound can be further reacted with other organic diol compounds, and further reacted with the diisocyanate compound. In addition, the situation of using two or more diisocyanate compounds is also the same. In this way, the desired terminal isocyanate compound can be manufactured.

[0149] The reaction temperature of component (o) and component (a) is preferably set to 0-160°C, more preferably 10-150°C. The reaction time can be appropriately selected according to the reaction scale and the reaction conditions adopted. In addition, as needed, the reaction can also be carried out in the presence of a catalyst such as a metal or semi-metal compound such as a tertiary amine, an alkali metal, an alkaline earth metal, tin, zinc, titanium, or cobalt. The total concentration of component (o) and component (a) in the reaction solution is preferably 1-50% by mass, more preferably 5-30% by mass. The reaction is carried out at a high concentration in the initial stage, and then an organic solvent can be added.

[0150] <Method for Synthesizing Terminal Amine Urea Oligomers>

[0151] The synthesis method of the terminal amine urea oligomer obtained by reacting the component (b) of the compound containing two primary or secondary amino groups in the molecule with the terminal isocyanate compound obtained by the above method is obtained by reacting in an organic solvent. The reaction temperature is preferably set to 0 to 160°C, more preferably to 10 to 150°C. The reaction time can be appropriately selected according to the reaction scale and the reaction conditions adopted. The reaction concentration is preferably 1 to 50% by mass in the reaction solution, more preferably 5 to 30% by mass. The reaction is carried out at a high concentration in the initial stage, and then, an organic solvent can be added.

[0152] <Synthesis Method for Obtaining Polyimide Precursor (A) from Terminal Amine Urea Oligomer>

[0153] By reacting the component (c) comprising tetracarboxylic dianhydride or a derivative thereof, the component (b) comprising a compound containing two primary or secondary amino groups in the molecule as needed with a terminal amine urea oligomer that can be obtained by the above-mentioned method, a polyimide precursor (A) can be obtained. The reaction is preferably carried out in an organic solvent, and the reaction temperature is preferably set to 20 to 100 ° C, more preferably to 20 to 80 ° C. The reaction time can be appropriately selected according to the reaction scale and the reaction conditions adopted. The reaction concentration is preferably 1 to 50% by mass in the reaction solution, more preferably 5 to 30% by mass. The reaction is carried out at a high concentration in the initial stage, and then, an organic solvent can be added.

[0154] The ratio of the reacting components (o), (a), (b), and (c) to each other is preferably, for example, a molar ratio of the total amount of components (a) and (c): the total amount of components (o) and (b) = 0.8:1 to 1.2:1. The proportion of component (a) in the total amount of components (a) and (c) is preferably 2 to 98 mol%, more preferably 10 to 96 mol%. Furthermore, the proportion of component (o) in the total amount of components (o) and (b) is preferably 1 to 49 mol%, more preferably 2 to 45 mol%.

[0155] Examples of the polyimide precursor as the polymer (B) include polyamic acid and polyamic acid ester. The polyimide precursor as the polymer (B) can be synthesized by a known method such as that described in International Publication WO2013 / 157586.

[0156] [Terminus modification agent]

[0157] When synthesizing the polymers (A) and (B) in the present invention, terminally modified polymers may be synthesized by using the above-mentioned components (o), (a), (b), and (c) and, if necessary, an appropriate terminal modification agent.

[0158] Examples of the terminal modification agent include acetic anhydride, maleic anhydride, nadic anhydride, phthalic anhydride, itaconic anhydride, cyclohexanedicarboxylic anhydride, 3-hydroxyphthalic anhydride, trimellitic anhydride, compounds represented by the following formulas (m-1) to (m-6), acid monoanhydrides such as 3-(3-trimethoxysilyl)propyl)-3,4-dihydrofuran-2,5-dione, 4,5,6,7-tetrafluoroisobenzofuran-1,3-dione, and 4-ethynylphthalic anhydride;

[0159]

[0160] Dicarbonate diester compounds such as di-tert-butyl dicarbonate and diallyl dicarbonate; chlorocarbonyl compounds such as acryloyl chloride, methacryloyl chloride, and nicotinoyl chloride; monoamine compounds such as aniline, 2-aminophenol, 3-aminophenol, 4-aminosalicylic acid, 5-aminosalicylic acid, 6-aminosalicylic acid, 2-aminobenzoic acid, 3-aminobenzoic acid, 4-aminobenzoic acid, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, and n-octylamine; monoisocyanate compounds such as ethyl isocyanate, phenyl isocyanate, and naphthyl isocyanate, etc.

[0161] The proportion of the terminal modifying agent used is preferably 20 parts by mole or less, more preferably 10 parts by mole or less, based on 100 parts by mole of the total of the diamine component used and the organic diol component used as needed.

[0162] Alternatively, a polyimide can be obtained by ring-closing (imidizing) a polyimide precursor (A) of polymer (A) or a polyimide precursor (B) of polymer (B) (hereinafter, also collectively referred to as "polyimide precursor"). It should be noted that the imidization rate referred to in this specification refers to the ratio of imide groups to the total amount of imide groups derived from tetracarboxylic dianhydride or its derivatives and carboxyl groups (or its derivatives). The imidization rate does not necessarily have to be 100% and can be adjusted arbitrarily according to the application and purpose.

[0163] Examples of a method for imidating a polyimide precursor include thermal imidization in which a solution of a polyimide precursor is directly heated, and catalytic imidization in which a catalyst is added to a solution of a polyimide precursor.

[0164] When the polyimide precursor is thermally imidized in a solution, the temperature is preferably 100 to 400° C., more preferably 120 to 250° C., and the imidization reaction is preferably performed while removing water generated by the imidization reaction to the outside of the system.

[0165] The catalytic imidization of the polyimide precursor can be carried out by adding a basic catalyst and an acid anhydride to a solution of the polyimide precursor, preferably by stirring at -20 to 250°C, more preferably at 0 to 180°C. The amount of the basic catalyst is preferably 0.5 to 30 times the molar amount of the amic acid group, more preferably 2 to 20 times the molar amount of the amic acid group, and the amount of the acid anhydride is preferably 1 to 50 times the molar amount of the amic acid group, more preferably 3 to 30 times the molar amount of the amic acid group. Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, and trioctylamine. Among them, pyridine is preferred because it has a moderate alkalinity for the reaction to proceed. Examples of the acid anhydride include acetic anhydride, trimellitic anhydride, and pyromellitic anhydride. Among them, if acetic anhydride is used, purification after the reaction is easy, so it is preferred. The imidization rate based on the catalytic imidization can be controlled by adjusting the amount of catalyst, reaction temperature, and reaction time.

[0166] When the generated polyimide precursor or polyimide is recovered from the reaction solution of the polyimide precursor or polyimide, it is sufficient to put the reaction solution into a solvent and precipitate it. As solvents for precipitation, methanol, ethanol, isopropanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, toluene, benzene, water, etc. can be listed. After the polymer put into the solvent and precipitated is filtered and recovered, it can be dried under normal pressure or reduced pressure, at room temperature, or by heating. In addition, when the polymer after precipitation recovery is repeatedly subjected to an operation of redissolving with an organic solvent and reprecipitating and recovering for 2 to 10 times, the impurities in the polymer can be reduced. As solvents at this time, for example, alcohols, ketones or hydrocarbons can be listed. If three or more solvents selected from these are used, the efficiency of purification is further improved, so it is preferred.

[0167] The molecular weight of the polymers (A) and (B) used in the present invention is preferably 5,000 to 1,000,000, more preferably 10,000 to 150,000, as measured by a weight average molecular weight (GPC) method, taking into account the strength of the resulting liquid crystal alignment film, workability during film formation, and coating properties.

[0168] The mixing ratio of the polymer component used in the method for producing the liquid crystal aligning film of the present invention is not particularly limited. For example, the total amount of the polymer component contained in the liquid crystal aligning agent is preferably 0.1 to 30 mass %, more preferably 3 to 10 mass %.

[0169] Content of the polymer (A) in the liquid crystal aligning agent can be appropriately changed depending on the coating method of the liquid crystal aligning agent and the film thickness of the target liquid crystal aligning film, but is preferably 0.1 to 30 mass %, particularly preferably 0.5 to 9.5 mass %.

[0170] In addition, in the liquid crystal alignment agent for manufacturing the liquid crystal alignment film, in addition to the polymer (A) and the polymer (B), other polymers other than these may also be mixed. In this case, the content of the other polymer is 0.5 to 15% by mass of the total polymer component, preferably 1 to 10% by mass of the total polymer component. Examples of other polymers other than these include acrylic polymers, methacrylic polymers, polystyrene, polyamides, and polysiloxanes.

[0171] The solvent contained in the liquid crystal aligning agent is not particularly limited as long as it can dissolve the polymer (A), and examples thereof include lactone solvents such as γ-valerolactone and γ-butyrolactone; γ-butyrolactam, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 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 and other lactam solvents; N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethyllactamide, 3-methoxy-N,N-dimethylpropionamide, 3-butoxy-N,N-dimethylpropionamide and other amide solvents; 4-hydroxy-4-methyl-2-pentanone, 2,6-dimethyl-4-heptanone (diisobutyl ketone), methyl lactate, ethyl lactate, n-propyl lactate Ester, n-butyl lactate, isoamyl lactate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monopropyl ether, ethylene glycol monoisopropyl ether, ethylene glycol mono-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl Ether acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monobutyl ether, propylene glycol diacetate, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, tripropylene glycol monomethyl ether, isoamyl propionate, isoamyl isobutyrate, diisopropyl ether, diisoamyl ether; carbonate solvents such as ethylene carbonate and propylene carbonate; 1-hexanol, cyclohexanol, 1,2-ethylene glycol, 2,6-dimethyl-4-heptanol (diisobutylcarbinol), 1,3-dimethyl-2-imidazolidinone, etc. These can be used alone or in mixtures of two or more.

[0172] Preferred combinations of 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-methyl-2-pyrrolidone and γ-butyrolactone and 4-hydroxy-4-methyl-2-pentanone and diethylene glycol diethyl ... -ethyl-2-pyrrolidone and N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone, N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and 2,6-dimethyl-4-heptanone, 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, γ-butyrolactone and 4-hydroxy-4-methyl-2-pentanone and 2,6-dimethyl-4-heptanone, 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 2,6-dimethyl-4-heptanone, N-methyl-2-pyrrolidone Ketone, γ-butyrolactone, propylene glycol monobutyl ether, and diisopropyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone, propylene glycol monobutyl ether, and 2,6-dimethyl-4-heptanol, N-methyl-2-pyrrolidone, γ-butyrolactone, and dipropylene glycol dimethyl ether, N-methyl-2-pyrrolidone, propylene glycol monobutyl ether, and dipropylene glycol dimethyl ether, N-methyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone, and ethylene glycol monobutyl ether, etc. The type and content of such solvents are appropriately selected depending on the coating device, coating conditions, coating environment, etc. of the liquid crystal aligning agent.

[0173] Liquid crystal alignment agent

[0174] To the liquid crystal aligning agent of the present invention, other components other than those described above, for example, a crosslinking compound, a functional silane compound, a surfactant, a compound having a photopolymerizable group, etc. may be added as needed.

[0175] A cross-linking compound can be used to increase the strength of the liquid crystal alignment film. Examples of such cross-linking compounds include compounds having an isocyanate group or a cyclocarbonate group, compounds having at least one group selected from the group consisting of lower alkoxyalkyl groups, and compounds having a blocked isocyanate group, as described in paragraphs

[0109] to

[0113] of International Publication WO2016 / 047771.

[0176] Compounds having a blocked isocyanate group are commercially available, and for example, CORONATE APstable M, CORONATE 2503, 2515, 2507, 2513, 2555, and MILLIONATE MS-50 (all manufactured by TOSOH), and TAKENATE B-830, B-815N, B-820NSU, B-842N, B-846N, B-870N, B-874N, and B-882N (all manufactured by Mitsui Chemicals, Inc.) can be preferably used.

[0177] Specific examples of preferred cross-linking compounds include compounds represented by the following formulae (CL-1) to (CL-11).

[0178]

[0179] The above is an example of the crosslinking compound, but the invention is not limited thereto. Moreover, the crosslinking compound used for the liquid crystal aligning agent of the present invention may be one kind or a combination of two or more kinds.

[0180] Content of other crosslinking compounds in the liquid crystal aligning agent of this invention is 0.1-150 mass parts, or 0.1-100 mass parts, or 1-50 mass parts with respect to 100 mass parts of all polymer components.

[0181] Functional silane compounds can be used to improve the adhesion between the liquid crystal alignment film and the base substrate. Specific examples include the silane compounds described in paragraph

[0019] of International Publication No. 2014 / 119682. The content of the functional silane compound is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 20 parts by mass, relative to 100 parts by mass of all polymer components.

[0182] Surfactants can be used to improve the uniformity of the film thickness and surface smoothness of the liquid crystal alignment film. Examples of the above-mentioned compounds include fluorine-based surfactants, silicone-based surfactants, and nonionic surfactants. Specific examples thereof include the surfactants described in paragraph

[0117] of International Publication WO2016 / 047771. The amount of the surfactant used is preferably 0.01 to 2 parts by mass, more preferably 0.01 to 1 part by mass, relative to 100 parts by mass of all polymer components contained in the liquid crystal alignment agent.

[0183] Examples of the compound having a photopolymerizable group include compounds having one or more polymerizable unsaturated groups such as an acrylate group and a methacrylate group in the molecule.

[0184] Furthermore, in the liquid crystal aligning agent of the present invention, as a compound that promotes charge transfer in the liquid crystal aligning film and promotes charge release of the element, a nitrogen-containing heterocyclic amine compound represented by formula [M1] to formula [M156] described in paragraphs

[0194] to

[0200] of International Publication WO2011 / 132751 (published on October 27, 2011) can be added, and 3-aminomethylpyridine and 4-aminomethylpyridine are more preferably added. The amine compound can be added directly to the liquid crystal aligning agent, or it can be added after preparing a solution having a concentration of, for example, 0.1 to 10% by mass, preferably 1 to 7% by mass. The solvent is not particularly limited as long as it dissolves the polymer component.

[0185] In the liquid crystal aligning agent of this invention, you may add an imidation accelerator etc. for the purpose of carrying out imidation efficiently by heating when baking a coating film.

[0186] 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., and is preferably in the range of 0.5 to 15 mass %, more preferably 1 to 10 mass %.

[0187] The range of particularly preferred solid content concentration varies depending on the method used when applying the liquid crystal alignment agent to the substrate. For example, in the case of a spin coating method, the solid content concentration is particularly preferably in the range of 1.5 to 4.5% by mass. In the case of a printing method, it is particularly preferred to set the solid content concentration in the range of 3 to 9% by mass, thereby setting the solution viscosity in the range of 12 to 50 mPa·s. In the case of an inkjet method, it is particularly preferred to set the solid content concentration in the range of 1 to 5% by mass, thereby setting the solution viscosity in the range of 3 to 15 mPa·s.

[0188] <Liquid crystal alignment film / liquid crystal display element>

[0189] A liquid crystal alignment film can be manufactured by using the above-mentioned liquid crystal alignment agent. In addition, the liquid crystal display element of the present invention has a liquid crystal alignment film formed by using the above-mentioned liquid crystal alignment agent. The operation mode of the liquid crystal display element of the present invention is not particularly limited. For example, it can be applied to various operation modes such as TN (Twisted Nematic: twisted nematic) type, STN (Super Twisted Nematic: super twisted nematic) type, vertical alignment type (including VA (Vertical Alignment: vertical alignment)-MVA (Multi-domain Vertical Alignment: multi-quadrant vertical alignment) type, VA-PVA (Patterned Vertical Alignment: patterned vertical alignment) type, etc.), in-plane switching type (IPS type: In-Plane Switching type), FFS (Fringe Field Switching: fringe field switch) type, optically compensated bend type (OCB type: Optically Compensated Bend type), etc.

[0190] The liquid crystal display element of the present invention can be manufactured, for example, by the following steps (1) to (4), a method including steps (1) to (2) and (4), a method including steps (1) to (3), (4-2) and (4-4), or a method including steps (1) to (3), (4-3) and (4-4).

[0191] <Step (1): Step of applying a liquid crystal aligning agent onto a substrate>

[0192] The liquid crystal alignment agent of the present invention is applied to one side of a substrate having a patterned transparent conductive film by, for example, a roll coater method, a spin coating method, a printing method, an inkjet method, or an appropriate coating method. Here, as a substrate, there is no particular limitation as long as it is a substrate with high transparency. Plastic substrates such as acrylic substrates and polycarbonate substrates can also be used together with glass substrates and silicon nitride substrates. In addition, in a reflective liquid crystal display element, if it is only a single-sided substrate, an opaque object such as a silicon wafer can also be used, and the electrode in this case can also use a light-reflecting material such as aluminum. In addition, in the case of manufacturing an IPS type or FFS type liquid crystal element, a substrate having an electrode composed of a comb-shaped transparent conductive film or a metal film and an opposing substrate without an electrode are used.

[0193] Examples of a method for applying a liquid crystal aligning agent to a substrate to form a film include screen printing, offset printing, flexographic printing, an inkjet method, and a spray method. Among these, a method of applying and forming a film by an inkjet method can be preferably used.

[0194] <Step (2): Step of calcining the applied liquid crystal aligning agent>

[0195] Step (2) is a step of firing the liquid crystal aligning agent applied on the substrate to form a film. After the liquid crystal aligning agent is applied on the substrate, a heating unit such as a hot plate, a heat circulation oven or an IR (infrared) oven can be used to evaporate the solvent, or to perform thermal imidization of polyamic acid or polyamic acid ester. The drying and firing steps after applying the liquid crystal aligning agent of the present invention can be selected at any temperature and time, and can also be performed multiple times. As a temperature for reducing the solvent of the liquid crystal aligning agent, it can be performed at 40 to 180°C, for example. From the viewpoint of shortening the process, it can be performed at 40 to 150°C. As for the firing time, there is no particular limitation, and 1 to 10 minutes or 1 to 5 minutes can be listed. In the case of thermal imidization of polyamic acid or polyamic acid ester, after the above step, for example, a firing step can be added at a temperature range of 150 to 300°C or 150 to 250°C. As for the firing time, there is no particular limitation, and 5 to 40 minutes or 5 to 30 minutes can be listed.

[0196] If the film-like product after firing is too thin, the reliability of the liquid crystal display element may be reduced. Therefore, the thickness is preferably 5 to 300 nm, more preferably 10 to 200 nm.

[0197] <Step (3): Step of orienting the film obtained in step (2)>

[0198] Step (3) is a step of subjecting the film obtained in step (2) to an orientation treatment, as appropriate. That is, in a horizontally aligned liquid crystal display element such as an IPS mode or an FFS mode, the coating film is subjected to an orientation capability imparting treatment. On the other hand, in a vertically aligned liquid crystal display element such as a VA mode or a PSA mode, the formed coating film can be used directly as a liquid crystal alignment film, but the coating film can also be subjected to an orientation capability imparting treatment. As an orientation treatment method for a liquid crystal alignment film, a rubbing treatment method and a photo-alignment treatment method can be listed. As a photo-alignment treatment method, the following method can be listed: irradiating the surface of the above-mentioned film-like object with radiation polarized in a fixed direction, and preferably heating the surface at a temperature of 150 to 250° C. to impart liquid crystal orientation (also referred to as liquid crystal alignment capability). 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.

[0199] The radiation dose is preferably 1 to 10,000 mJ / cm 2 Among them, 100 to 5000 mJ / cm is preferred. 2Furthermore, 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.

[0200] Furthermore, in the above-mentioned method, the liquid crystal alignment film irradiated with polarized radiation may be subjected to a contact treatment using water or a solvent, or the liquid crystal alignment film irradiated with radiation may be subjected to a heat treatment.

[0201] The solvent used in the contact treatment is not particularly limited, as long as it dissolves decomposition products generated by the film-like material upon exposure to 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, and cyclohexyl acetate. Among these, water, 2-propanol, 1-methoxy-2-propanol, or ethyl lactate are preferred due to their versatility and safety, with water, 1-methoxy-2-propanol, or ethyl lactate being more preferred. The solvent may be used alone or in combination of two or more.

[0202] The temperature for heat-treating the coating film irradiated with radiation is more preferably 50 to 300° C., and even more preferably 120 to 250° C. The time for heat-treating is preferably 1 to 30 minutes.

[0203] <Step (4): Step of manufacturing a liquid crystal cell>

[0204] Prepare two substrates with liquid crystal alignment films formed as described above, and configure liquid crystal between the two opposing substrates. Specifically, the following two methods can be listed. The first method is to first arrange the two substrates opposite each other with a gap (cell gap) between the liquid crystal alignment films. Then, use a sealant to bond the peripheral portions of the two substrates together, inject a filling liquid crystal composition into the cell gap defined by the substrate surface and the sealant, and after contacting the cell gap with the film surface, seal the injection hole.

[0205] In addition, the second method is a method called ODF (One Drop Fill: liquid crystal dripping) method. A predetermined place on one of the two substrates with a liquid crystal alignment film is coated with a UV-curable sealant, for example, and a liquid crystal composition is further dripped at several predetermined places on the surface of the liquid crystal alignment film. Then, the liquid crystal alignment film is bonded to the substrate on the other side in a manner opposite to the substrate, 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 to remove the flow orientation during liquid crystal filling.

[0206] When the coating film is rubbed, 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.

[0207] As the sealant, for example, an epoxy resin containing a curing agent and alumina balls as spacers can be used. Examples of the liquid crystal include nematic liquid crystal and smectic liquid crystal, and among them, nematic liquid crystal is preferred.

[0208] The liquid crystal aligning agent of the present invention is also preferably used in the following liquid crystal display element (PSA type liquid crystal display element): 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, a voltage is applied between the electrodes and the polymerizable compound is polymerized by irradiation with at least one of active energy rays and heating to manufacture the liquid crystal display element.

[0209] Furthermore, the liquid crystal aligning agent of the present invention is also preferably used in the following liquid crystal display elements (SC-PVA mode Type liquid crystal display element): 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 the device is manufactured by applying a voltage between the electrodes.

[0210] (4-2) Case of PSA-type liquid crystal display element

[0211] The same procedure as in the above-mentioned (4) is carried out except that the liquid crystal composition containing the polymerizable compound is injected or dropped.

[0212] (4-3) Case of SC-PVA Mode Liquid Crystal Display Element

[0213] After proceeding in the same manner 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 above-mentioned PSA type liquid crystal display element, 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 polymerizable unsaturated groups such as acrylate groups and methacrylate groups in the molecule, and its content is preferably 0.1 to 30 parts by mass relative to 100 parts by mass of all polymer components, and more preferably 1 to 20 parts by mass. In addition, the above-mentioned polymerizable group can also be a polymer possessed by a polymer used for a liquid crystal aligning agent. As such a polymer, for example, a polymer obtained by reacting the following diamine component can be cited, wherein the diamine component contains a diamine having the above-mentioned photopolymerizable group at the end.

[0214] Step (4-4): Ultraviolet irradiation step

[0215] The liquid crystal box is irradiated with light while a voltage is applied between the conductive films of the pair of substrates obtained in (4-2) or (4-3) above. The voltage applied here can be, for example, a direct current or alternating current of 5 to 50 V. In addition, as the irradiation light, for example, ultraviolet rays and visible rays containing light with a wavelength of 150 to 800 nm can be used, preferably ultraviolet rays containing light with a wavelength 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. As the irradiation amount of light, 1000 to 200,000 J / m 2 , more preferably 1000 to 100000 J / m 2 .

[0216] Furthermore, a liquid crystal display element can be obtained by laminating a polarizing plate to the outer surface of the liquid crystal cell as needed. Examples of polarizing plates to be laminated to the outer surface of the liquid crystal cell include those made by sandwiching a polarizing film called "H film" between cellulose acetate protective films, or those made solely of H film, which is formed by stretching and aligning polyvinyl alcohol while absorbing iodine.

[0217] The liquid crystal display element of the present invention can be effectively applied to various devices, such as clocks, portable game consoles, word processors, notebook computers, car navigation systems, camcorders, PDAAs (Personal Digital Assistants), digital cameras, mobile phones, smartphones, various monitors, liquid crystal televisions, information displays, and other display devices. Furthermore, the polymer composition contained in the liquid crystal alignment agent can also be used in liquid crystal alignment films for phase difference films, scanning antennas, liquid crystal alignment films for liquid crystal array antennas, or liquid crystal alignment films for transmission scattering type liquid crystal dimming elements, as well as in applications other than these, such as protective films for color filters, gate insulating films for flexible displays, and substrate materials.

[0218] Example

[0219] The present invention will be described in detail below with reference to Examples, etc. However, the present invention is not limited to these Examples. The abbreviations of the compounds and solvents are as follows.

[0220] (Organic Solvent)

[0221] NMP: N-methyl-2-pyrrolidone.

[0222] GBL: gamma-butyrolactone.

[0223] BCS: ethylene glycol monobutyl ether.

[0224] (Diamine)

[0225] DA-1 to DA-8: compounds represented by the following structural formulas (DA-1) to (DA-8), respectively.

[0226] (Acid dianhydride)

[0227] CA-1 to CA-5: compounds represented by the following structural formulas (CA-1) to (CA-5), respectively.

[0228] (diisocyanate)

[0229] DI-1: 4,4'-diphenylmethane diisocyanate.

[0230] (diol)

[0231] EG-1: Tetraethylene glycol.

[0232] EG-2: Polyethylene Glycol 400 (manufactured by Tokyo Chemical Industry Co., Ltd.).

[0233] EG-3: Polyethylene Glycol 600 (manufactured by Tokyo Chemical Industry Co., Ltd.).

[0234]

[0235] Viscosity

[0236] In the synthesis examples, the viscosity of the polymer solution was measured using an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.) with a sample volume of 1.1 mL, a conical rotor TE-1 (1°34′, R24), and a temperature of 25°C.

[0237] <Measurement of Imidization Ratio of Polyimide>

[0238] The imidization rate of the polyimide in the synthesis example was measured as follows. 30 mg of polyimide powder was added to an NMR (nuclear magnetic resonance) sample tube (NMR standard sampling tube, φ5 (manufactured by Kusano Scientific Co., Ltd.)), deuterated dimethyl sulfoxide (DMSO-d6, 0.05% by mass TMS (tetramethylsilane) mixture) (0.53 mL) was added, and ultrasonic waves were applied to completely dissolve it. The solution was measured for 500 MHz proton NMR using an NMR measuring instrument (JNW-ECA500) (manufactured by JEOL DATUM Co., Ltd.). As for the imidization rate, the proton derived from the structure that did not change before and after imidization was determined as the reference proton, and the peak integral value of the proton derived from the NH group of the amide acid appearing near 9.5 to 10.0 ppm was used to calculate it by the following formula.

[0239] Imidization rate (%) = (1 - α·x / y) × 100

[0240] In the above formula, x is the peak integral value of protons derived from NH groups of amic acid, y is the peak integral value of reference protons, and α is the number ratio of reference protons to one NH proton of amic acid in the case of polyamic acid (imidization rate 0%).

[0241] [Synthesis of polymer]

[0242] (Synthesis example 1)

[0243] EG-1 (0.32 g, 1.65 mmol) was weighed into a 50 mL eggplant-shaped flask equipped with a stirrer and a nitrogen inlet tube. NMP (1.3 g) was added and dissolved with stirring while nitrogen was introduced. While stirring the solution under water cooling, DI-1 (0.83 g, 3.30 mmol) and NMP (3.30 g) were added and stirred at 70°C under a nitrogen atmosphere for 3 hours. NMP (22.0 g) was then added for dilution and stirred for an additional 30 minutes. A solution of DA-6 (1.85 g, 9.35 mmol) in NMP (5.00 g) was then added, followed by NMP (2.50 g) and stirring at 23°C under a nitrogen atmosphere for 2 hours. Next, CA-2 (1.49 g, 7.59 mmol) and NMP (6.30 g) were added, and the mixture was stirred at 23° C. for 2 hours under a nitrogen atmosphere to obtain a solution of a polymer (polymer-1) (viscosity: 32 mPa·s).

[0244] (Synthesis Examples 2 to 5)

[0245] Using the diamines, acid dianhydrides, diisocyanates, and diols shown in Table 1 below, the same procedures as in Synthesis Example 1 were followed to obtain solutions of polyurethane amic acids (Polymer-2) to (Polymer-5) shown in Table 1 below. In Table 1, the numerical values ​​listed below the compound names indicate the mass of each compound used in the synthesis, and the numerical values ​​in parentheses indicate the amount (parts by mole) of each compound used per 100 parts by mole of the combined amount of the diamine component and the diol component.

[0246] [Table 1]

[0247]

[0248] (Synthesis Example 6)

[0249] EG-2 (0.34 g, 0.84 mmol) and NMP (1.9 g) were weighed into a 100 mL eggplant-shaped flask equipped with a stirrer and a nitrogen inlet tube and dissolved with stirring while nitrogen was introduced. While stirring the solution under water cooling, DI-1 (0.42 g, 1.68 mmol) and NMP (2.24 g) were added, and the mixture was stirred at 70°C for 3 hours under a nitrogen atmosphere. NMP (20.0 g) and GBL (20.0 g) were then added for dilution, and the mixture was stirred for a further 30 minutes. A solution of DA-5 (5.77 g, 20.2 mmol) in NMP (10.9 g) and GBL (15.1 g) were then added, and the mixture was stirred at 23°C for 2 hours under a nitrogen atmosphere. CA-2 (3.67 g, 18.7 mmol), NMP (2.25 g), and GBL (2.25 g) were then added, and the mixture was stirred at 23°C for 2 hours under a nitrogen atmosphere. After the reaction, NMP (8.50 g) and GBL (8.50 g) were added to adjust the solution concentration, and the mixture was stirred for 1 hour to obtain a solution of a polymer (polymer-6) (viscosity: 112 mPa·s).

[0250] (Synthesis Examples 7 to 14)

[0251] Using the diamines, acid dianhydrides, diisocyanates, and diols shown in Table 2 below, the same procedures as in Synthesis Example 6 were followed to obtain solutions of polymers (Polymer-7) to (Polymer-14) shown in Table 2 below. In Table 2, the numerical values ​​listed below the compound names indicate the mass of each compound used in the synthesis, and the numerical values ​​in parentheses indicate the amount (parts by mole) of each compound used per 100 parts by mole of the combined amount of the diamine component and the diol component.

[0252] [Table 2]

[0253]

[0254] (Synthesis Example 15)

[0255] DA-5 (3.16 g, 11.0 mmol) and NMP (28.5 g) were weighed into a 100 mL eggplant-shaped flask equipped with a stirrer and a nitrogen inlet tube and dissolved with stirring while nitrogen was introduced. While stirring the solution under water cooling, CA-2 (1.67 g, 8.52 mmol) and NMP (6.98 g) were added, and the mixture was stirred at 23°C for 2 hours under a nitrogen atmosphere. EG-3 (0.58 g, 0.96 mmol) and NMP (4.22 g) were then added to the stirred solution. DI-1 (0.48 g, 1.92 mmol) and NMP (3.52 g) were then added, and the mixture was stirred at 50°C for 3 hours under a nitrogen atmosphere to obtain a polymer (Polymer-15) solution (viscosity: 178 mPa·s).

[0256] (Synthesis Example 16)

[0257] DA-5 (7.45 g, 26.0 mmol), NMP (33.5 g), and GBL (33.5 g) were weighed into a 100 mL eggplant-shaped flask equipped with a stirrer and a nitrogen inlet tube and dissolved with stirring while nitrogen was introduced. While stirring this diamine solution under water cooling, CA-2 (4.74 g, 24.2 mmol), NMP (11.2 g), and GBL (11.2 g) were added and stirred for 2 hours under a nitrogen atmosphere to obtain a polyamic acid (PAA-1) solution (viscosity: 182 mPa·s).

[0258] (Synthesis Example 17)

[0259] DA-5 (7.45 g, 26.0 mmol), NMP (33.5 g), and GBL (33.5 g) were weighed into a 100 mL eggplant-shaped flask equipped with a stirrer and a nitrogen inlet tube and dissolved with stirring while nitrogen was introduced. While stirring this diamine solution under water cooling, CA-3 (5.42 g, 24.2 mmol), NMP (13.8 g), and GBL (13.8 g) were added and stirred under a nitrogen atmosphere for 2 hours to obtain a polyamic acid (PAA-2) solution (viscosity: 167 mPa·s).

[0260] (Synthesis Example 18)

[0261] DA-4 (11.7 g, 40.2 mmol), DA-2 (8.73 g, 21.9 mmol), DA-3 (6.10 g, 11.0 mmol), and NMP (113.2 g) were weighed into a 200 mL eggplant-shaped flask equipped with a stirrer and a nitrogen inlet tube and dissolved with stirring while nitrogen was introduced. While stirring this diamine solution under water cooling, CA-1 (9.40 g, 47.5 mmol) and NMP (32.4 g) were added and stirred at 50°C for 2 hours under a nitrogen atmosphere. Furthermore, CA-2 (4.61 g, 23.5 mmol) and NMP (16.6 g) were added and stirred at 23°C for 2 hours under a nitrogen atmosphere to obtain a polyamic acid (PAA-3) solution (viscosity: 1230 mPa·s).

[0262] The polyamic acid (PAA-3) solution obtained above (100 g) was weighed into a 200 mL Erlenmeyer flask containing a stirrer, and di-tert-butyl dicarbonate (hereinafter also referred to as Boc2O) (1.32 g, 6.05 mmol) was added as a terminal modification agent. The mixture was stirred at 40°C for 15 hours to obtain a solution of terminal-modified polyamic acid (PAA-3-1).

[0263] The solution (100 g) of the above-mentioned (PAA-3-1) was aliquoted into a 200 mL Erlenmeyer flask equipped with a stirrer. NMP (66.7 g), acetic anhydride (12.9 g), and pyridine (4.27 g) were added, and the mixture was stirred at room temperature for 30 minutes, followed by reaction at 60°C for 4 hours. The reaction solution was added to methanol (640 g), and the resulting precipitate was filtered. The precipitate was washed with methanol and then dried under reduced pressure at 80°C to obtain a polyimide powder (imidation ratio: 91%).

[0264] Furthermore, the polyimide powder (9.60 g) was taken out to a 100 mL Erlenmeyer flask containing a stirrer, NMP (70.4 g) was added, and the mixture was stirred at 70° C. for 24 hours to dissolve the mixture, thereby obtaining a polyimide (SPI-1) solution.

[0265] (Synthesis Example 19)

[0266] DA-1 (8.04 g, 40.2 mmol), DA-2 (4.36 g, 10.9 mmol), DA-3 (12.2 g, 21.9 mmol), and NMP (98.4 g) were weighed into a 200 mL eggplant-shaped flask equipped with a stirrer and a nitrogen inlet tube and dissolved with stirring while nitrogen was introduced. While stirring the diamine solution under water cooling, CA-1 (9.40 g, 47.5 mmol) and NMP (37.6 g) were added, and the mixture was stirred at 50°C for 2 hours under a nitrogen atmosphere. Furthermore, CA-2 (4.65 g, 23.7 mmol) and NMP (18.6 g) were added, and the mixture was stirred at 23°C for 2 hours under a nitrogen atmosphere to obtain a polyamic acid (PAA-4) solution (viscosity: 1230 mPa·s).

[0267] The polyamic acid (PAA-4) solution (100 g) obtained above was placed in a 200 mL Erlenmeyer flask containing a stirrer, and Boc2O (1.24 g, 5.68 mmol) was added. The mixture was stirred at 40°C for 15 hours to obtain a solution of terminal-modified polyamic acid (PAA-4-1).

[0268] The solution (100 g) of the above-mentioned (PAA-4-1) was aliquoted into a 200 mL Erlenmeyer flask equipped with a stirrer. NMP (66.7 g), acetic anhydride (14.2 g), and pyridine (4.70 g) were added, and the mixture was stirred at room temperature for 30 minutes, followed by reaction at 60°C for 4 hours. The reaction solution was added to methanol (650 g), and the resulting precipitate was filtered. The precipitate was washed with methanol and then dried under reduced pressure at 80°C to obtain a polyimide powder (imidation ratio: 90%).

[0269] Furthermore, the polyimide powder (9.60 g) was taken out to a 100 mL Erlenmeyer flask containing a stirrer, NMP (70.4 g) was added, and the mixture was stirred at 70° C. for 24 hours to dissolve the mixture, thereby obtaining a polyimide (SPI-2) solution.

[0270] (Synthesis Example 20)

[0271] DA-7 (4.03 g, 16.5 mmol), DA-8 (3.29 g, 16.5 mmol), and NMP (65.9 g) were weighed into a 100 mL eggplant-shaped flask equipped with a stirrer and a nitrogen inlet tube and dissolved with stirring while nitrogen was introduced. While stirring the diamine solution under water cooling, CA-4 (6.19 g, 24.8 mmol) was added, followed by NMP (10.7 g), and the mixture was stirred at 50°C for 3 hours under a nitrogen atmosphere. Furthermore, CA-5 (2.04 g, 6.93 mmol) was added, followed by NMP (11.6 g), and the mixture was stirred at 70°C for 6 hours under a nitrogen atmosphere to obtain a polymer (PAA-5) solution (viscosity: 495 mPa·s).

[0272] [Preparation of Liquid Crystal Alignment Agent]

[0273] (Example 1)

[0274] The solution (6.60 g) of the polymer (polymer-1) obtained in Synthesis Example 1 was weighed into a 50 mL Erlenmeyer flask containing a stirrer, and NMP (0.06 g), GBL (9.34 g) and BCS (4.00 g) were added, followed by stirring at room temperature for 2 hours to obtain a liquid crystal aligning agent (1).

[0275] (Examples 2 to 16, Comparative Examples 1 to 4)

[0276] Liquid crystal aligning agents (2) to (20) were obtained by carrying out the same operation as in Example 1 except that the types and amounts of the polymer solution and the solvent used were changed as shown in Table 3.

[0277] [Table 3]

[0278]

[0279] A method for producing a liquid crystal display element for evaluating the voltage holding ratio is described below.

[0280] [Manufacturing of Liquid Crystal Display Elements]

[0281] First, a substrate with electrodes was prepared. The substrate was a 30 mm x 40 mm glass substrate with a thickness of 1.1 mm. On the substrate, ITO electrodes with a thickness of 35 nm were formed in a stripe pattern 40 mm long and 10 mm wide.

[0282] Next, the liquid crystal alignment agent obtained above was filtered through a filter with a pore size of 1.0 μm and then applied to the prepared substrate with electrodes by spin coating. After drying on a hot plate at 80°C for 2 minutes, it was calcined in an IR oven at 230°C for 20 minutes to form a coating with a thickness of 100 nm, thereby obtaining a substrate with a liquid crystal alignment film. The liquid crystal alignment film was rubbed with rayon cloth (roller diameter: 120 mm, roller speed: 1000 rpm, moving speed: 20 mm / sec, pressing length: 0.4 mm), and then cleaned by ultrasonic irradiation in pure water for 1 minute. After removing water droplets by blowing, it was dried at 80°C for 10 minutes to obtain a substrate with a liquid crystal alignment film. Two substrates with liquid crystal alignment films were prepared. 4μm-diameter spacers (JGC Catalysts & Chemicals, silk balls, SW-D1) were spread on one of the liquid crystal alignment films. A thermosetting sealant (Mitsui Chemicals, XN-1500T) was then printed on top. The other substrate was then bonded together with the film surfaces facing each other, in the opposite direction of rubbing. The sealant was then cured to create an empty cell. Negative-type liquid crystal MLC-7026 (Merck) was injected into the empty cell using a vacuum injection method, and the injection port was sealed to produce a liquid crystal cell. The resulting cell was then heated at 120°C for 1 hour and left at 23°C overnight before being used for various evaluations.

[0283] Voltage holding ratio

[0284] A voltage of 1V was applied to the liquid crystal display element at 60°C for 60 μsec. The voltage was measured 16.67 msec later, and the voltage retention was evaluated as the voltage holding ratio. The results are shown in Table 4. A higher voltage holding ratio indicates better performance. It is known that an increase in the voltage holding ratio, one of the electrical characteristics of a liquid crystal display element, reduces the likelihood of line burn-in, a common display defect in liquid crystal displays.

[0285] [Table 4]

[0286]

[0287] <Evaluation of whitening characteristics>

[0288] 0.1 mL of liquid crystal aligning agent (1) to (20) was dripped onto a chromium vapor-deposited substrate and allowed to stand in an environment with a temperature of 23°C and a humidity of 70%. After a predetermined time had passed after the dripping, the edge and central portion of the droplet were observed using an optical microscope to confirm whether or not it had whitened. The results are shown in Table 5. It should be noted that, in this evaluation, the phenomenon in which the dissolved polyimide precipitated or condensed and the droplet became turbid was defined as a whitening phenomenon. The state in which the droplet was not completely whitened was evaluated as "0", the state in which only the edge of the droplet was whitened was evaluated as "△", and the state in which the entire surface of the droplet was whitened was evaluated as "×". The longer the time to 0, the better.

[0289] [Table 5]

[0290]

[0291] Typically, when negative-type liquid crystals are used as liquid crystal materials, the voltage holding ratio decreases, making display defects (line burn-in) more likely to occur. However, by using the liquid crystal alignment agents of the embodiments of the present invention, a liquid crystal display element with a high voltage holding ratio (i.e., a liquid crystal display element with a low incidence of display defects (line burn-in)) can be obtained even when negative-type liquid crystals are used as liquid crystal materials.

[0292] In addition, the liquid crystal alignment agent described in the embodiments of the present invention is not prone to hygroscopic whitening, so it is not easy to produce foreign matter, blockage, etc. when obtaining the coating film, and the surface roughness of the obtained film is less. Moreover, even if it is dried and heated, it can still exert the original characteristics of the liquid crystal alignment film.

[0293] It should be noted that the entire contents of the specification, claims, drawings, and abstract of Japanese Patent Application No. 2020-192467 filed on November 19, 2020 are incorporated herein by reference and incorporated as a disclosure of the specification of the present invention.

Claims

1. A liquid crystal alignment agent, characterized in that: Contains the following ingredient A, Component A: at least one polymer A selected from the group consisting of a copolymer having a repeating unit represented by the following formula (a), a repeating unit represented by the following formula (1), and a repeating unit represented by the following formula (2), and a polyimide which is an imide product of the copolymer. At least one of the repeating unit represented by the following formula (a), the repeating unit represented by the following formula (1), and the repeating unit represented by the following formula (2) has a divalent organic group represented by the following formula (EG), X represents a tetravalent organic group, Y represents a divalent organic group derived from a diamine, two Rs each independently represent a hydrogen atom or a monovalent organic group, two Zs each independently represent a hydrogen atom or a monovalent organic group, A1 is a divalent organic group, A 1’ is a divalent organic group derived from diamine, C1 and C 1’ are each independently a hydrogen atom or a monovalent organic group, A2 is a divalent organic group, A 2’ A divalent organic group obtained by removing the hydrogen atoms contained in two hydroxyl groups from an organic diol. R represents a hydrogen atom or a methyl group, n is an integer from 3 to 40, Among them, the content ratio of the repeating unit represented by formula (a) is 2 to 98 mol% of the total repeating units constituting polymer A, the content ratio of the repeating unit represented by formula (1) is 1 to 49 mol% of the total repeating units constituting polymer A, and the content ratio of the repeating unit represented by formula (2) is 1 to 49 mol% of the total repeating units constituting polymer A.

2. The liquid crystal aligning agent according to claim 1, wherein X in the formula (a) is a tetravalent organic group derived from tetracarboxylic dianhydride or a derivative thereof, A1 in the formula (1) is a divalent organic group derived from diisocyanate, and A2 in the formula (2) is a divalent organic group derived from diisocyanate.

3. The liquid crystal aligning agent according to claim 1 or 2, wherein In the above formula (EG), n is an integer of 4 to 40.

4. The liquid crystal aligning agent according to claim 1 or 2, wherein Y in the formula (a) and A in the formula (1) 1’ Each independently represents a divalent organic group derived from the following diamine, the diamine being selected from the group consisting of a diamine represented by the following formula (O), a diamine having an amide bond or a urea bond, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 4,4'-diaminobenzophenone, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 1,4-bis(4-aminobenzyl)benzene, the diamine represented by the following formula (d o ), 4-(2-(methylamino)ethyl)aniline, 4-(2-aminoethyl)aniline, a diamine having a group "-N(D)-", and the following formula (d EG ), D represents a protective group that is released by heating and replaced by a hydrogen atom, Ar represents a divalent benzene ring, a biphenyl structure, or a naphthalene ring, two Ars are optionally the same or different, any hydrogen atom in the benzene ring, biphenyl structure, or naphthalene ring is optionally substituted by a monovalent group, p is an integer of 0 or 1, and Q2 represents -(CH2) n -, or the -(CH2) n -a group in which at least a portion of -CH2- in - is substituted by any one of -O-, -C(=O)-, or -O-C(=O)-, wherein n is an integer from 2 to 18, and when Q2 has an ether bond, the total number of ether bonds possessed by Q2 is 3 or less, Multiple m's are optionally the same or different. Ar each independently represents a divalent aromatic group or a condensed ring group, which may be the same or different, one or more hydrogen atoms on the aromatic group or condensed ring group may be substituted with a monovalent group, and n represents an integer of 3 to 40.

5. The liquid crystal aligning agent according to claim 1 or 2, wherein A1 in the formula (1) and A2 in the formula (2) are each independently: i. a divalent organic group derived from an aromatic diisocyanate, wherein, in the diisocyanate structure O=C=N-R-N=C=O, R is an organic group having 6 to 30 carbon atoms and having at least one benzene ring; or ii. a divalent organic group derived from an aliphatic diisocyanate, wherein, in the diisocyanate structure O=C=N-R-N=C=O, R is an organic group having 4 to 30 carbon atoms and having an aliphatic group and no aromatic group. The liquid crystal aligning agent according to claim 1 or 2, wherein A1 in the formula (1) and A2 in the formula (2) are each independently a divalent organic group derived from a diisocyanate selected from the following:

7. The liquid crystal aligning agent according to claim 1 or 2, wherein The organic diol in the formula (2) is a diol containing a divalent organic group represented by the formula (EG).

8. The liquid crystal alignment agent according to claim 7, wherein The diol containing a divalent organic group represented by the above formula (EG) is a diol in which hydrogen atoms are bonded to both ends of the divalent organic group represented by the above formula (EG).

9. The liquid crystal aligning agent according to claim 1 or 2, wherein X in (a) is a tetravalent organic group derived from acyclic aliphatic tetracarboxylic dianhydride or a derivative thereof, a tetravalent organic group derived from alicyclic tetracarboxylic dianhydride or a derivative thereof, or a tetravalent organic group derived from aromatic tetracarboxylic dianhydride or a derivative thereof.

10. The liquid crystal aligning agent according to claim 1 or 2, wherein X in (a) is a tetravalent organic group derived from tetracarboxylic dianhydride or a derivative thereof represented by formula (t), Wherein X1 is a structure selected from the following formulas (X1-1) to (X1-25), * represents a bonding bond, In formulas (X1-1) to (X1-4), R1 to R 21 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 * represents a bond. In formulae (X1-24) to (X1-25), j and k are integers of 0 or 1, A1 and A2 each independently represent a single bond, -O-, -CO-, -COO-, a phenylene group, a sulfonyl group, or an amide group, and a plurality of A2s may be the same or different.

11. The liquid crystal aligning agent according to claim 1 or 2, wherein The content ratio of the repeating unit represented by formula (a) is 10 to 96 mol% of the total repeating units constituting polymer A, the content ratio of the repeating unit represented by formula (1) is 2 to 45 mol% of the total repeating units constituting polymer A, and the content ratio of the repeating unit represented by formula (2) is 2 to 45 mol% of the total repeating units constituting polymer A.

12. The liquid crystal alignment agent according to claim 1 or 2, characterized in that: The liquid crystal aligning agent further contains a component B, Component B: a polymer B different from polymer A, wherein the polymer B is at least one polymer selected from the group consisting of a polyimide precursor and an imidized polymer thereof.

13. A method for producing a polymer, which is a method for producing the polymer A according to any one of claims 1 to 11, comprising the following steps: The component O containing an organic diol having two hydroxyl groups in the molecule is reacted with the component A containing a compound containing two isocyanate groups in the molecule to synthesize a terminal isocyanate compound, which is then reacted with the component B containing a compound containing two primary or secondary amino groups in the molecule to synthesize a terminal amine urea oligomer, which is further reacted with the component C containing tetracarboxylic dianhydride or a derivative thereof, wherein: At least one of the compounds constituting the o component, a component, b component, and c component has a partial structure represented by the following formula (EG) in the molecule, R represents a hydrogen atom or a methyl group, and n is an integer of 3 to 40.

14. The method for producing a polymer according to claim 13, wherein The process includes the following steps: Make it contain "H-A 2’ The o component of the diol compound represented by -H" reacts with the a component of the diisocyanate compound represented by O=C=N-A1-N=C=O to synthesize a terminal isocyanate compound, which is then reacted with the b component comprising the diamine represented by the following formula (mb) to synthesize a terminal amine urea oligomer, and further reacted with the c component comprising the tetracarboxylic dianhydride or its derivative represented by the following formula (mc), wherein A 2’ A in formula (2) defined in claim 1 2’ The same, A1 is the same as A1 in formula (1) defined in claim 1, said A1, A 1’ 、A 2’ and at least one of X has a partial structure represented by the formula (EG) in the molecule, In formula (mb), C1, C 1’ 、A 1’ Each of C1, C2 in the formula (1) defined in claim 1 1’ 、A 1’ same, In formula (mc), X is the same as X in formula (a) defined in claim 1. 15 . A liquid crystal alignment film formed using the liquid crystal alignment agent according to claim 1 . A liquid crystal display element comprising the liquid crystal alignment film according to claim 15 .

Images