Liquid crystal alignment agent, polymer manufacturing method, liquid crystal alignment film, and liquid crystal display element

Abstract

The present invention provides a liquid crystal aligning agent which has a reduced risk of moisture absorption whitening and excellent mass production stability, and which enables the achievement of a liquid crystal alignment film that has a high voltage holding ratio; and a liquid crystal display element which is provided with this liquid crystal alignment film.　A liquid crystal aligning agent which is characterized by comprising the component (A) described below. Component (A): At least one polymer (A) which is selected from the group consisting of copolymers that have a repeating unit represented by formula (a), a repeating unit represented by formula (1) and a repeating unit represented by formula (2), and polyimides that are imidized products of the copolymers, wherein at least one of the repeating unit represented by formula (a), the repeating unit represented by formula (1) and the repeating unit represented by formula (2) has a divalent organic group that is represented by formula (EG). (The substituents are as defined in the description.)

Description

[Technical Field]

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

[0002] Liquid crystal display elements used in LCD televisions, navigation systems, smartphones, and other devices typically incorporate a liquid crystal alignment film to control the alignment of liquid crystal molecules. Liquid crystal alignment films function to align liquid crystal molecules in a specific direction. For example, liquid crystal display elements have a structure in which liquid crystal molecules forming a liquid crystal layer are sandwiched between liquid crystal alignment films formed on the surfaces of a pair of substrates. The liquid crystal molecules are aligned in a specific direction by the liquid crystal alignment film and respond to the application of voltage to electrodes provided between the substrates and the liquid crystal alignment film. As a result, liquid crystal display elements display desired images by utilizing the alignment changes induced by the response of the liquid crystal molecules. To date, polyimide-based liquid crystal alignment films have primarily been used, which are formed by applying a liquid crystal alignment agent, primarily composed of a polyimide precursor such as polyamic acid (polyamic acid) or a solution of a soluble polyimide, to a glass substrate or the like and then baking the applied liquid crystal alignment agent. In recent years, liquid crystal alignment films have been required to have not only excellent liquid crystal alignment properties but also a high voltage holding ratio in order to reduce the power consumption of liquid crystal display elements. In order to meet the above demands, Patent Document 1 proposes a liquid crystal aligning agent containing a polyimide obtained by using a specific diamine component in a reaction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2019-082975 Summary of the Invention [Problem to be solved by the invention]

[0004] On the other hand, organic polar solvents such as N-methylpyrrolidone and γ-butyrolactone are commonly used for liquid crystal alignment agents containing polyimides. However, while these solvents have high solubility, they have the drawback of being highly hygroscopic. Therefore, when handling liquid crystal alignment agents containing polyimides with low solubility in a humid environment, there is a risk of moisture whitening, in which the polyimide precipitates during application, causing the film to turn white, posing a challenge in terms of mass production stability.

[0005] In view of the above, the present invention aims to provide a liquid crystal alignment agent that can produce a liquid crystal alignment film having a high voltage holding ratio, reduces the risk of whitening due to moisture absorption, and has excellent mass production stability, and a liquid crystal display element that includes the liquid crystal alignment film. [Means for solving the problem]

[0006] As a result of intensive research to achieve the above object, the present inventors have found that a liquid crystal aligning agent containing a specific component is effective in achieving the above object, and have completed the present invention.

[0007] The present invention is based on this finding and has the following gist. A liquid crystal aligning agent characterized by containing 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 which is an imidized 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). [ka] (X represents a tetravalent organic group. Y represents a divalent organic group derived from 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.) [ka] (A1 is a divalent organic group, A 1’ is a divalent organic group derived from diamine, and C1 and C 1’ are each independently a hydrogen atom or a monovalent organic group. [ka] (A2 is a divalent organic group, A 2’ is a divalent organic group formed by removing the hydrogen atoms contained in the two hydroxyl groups from an organic diol. [ka] (R represents a hydrogen atom or a methyl group, and n is an integer of 3 to 40.) [Effects of the Invention]

[0008] The liquid crystal aligning 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 aligning agent can provide a liquid crystal alignment film having excellent mass production stability with a reduced risk of whitening due to moisture absorption. Furthermore, the liquid crystal aligning agent of the present invention can provide a liquid crystal display element with fewer display defects. The mechanism by which the above-described effects of the present invention are obtained is not entirely clear, but is presumed to be as follows: The introduction of urea groups and urethane groups into the polymer generates hydrogen bonds of appropriate strength, improving voltage retention characteristics, and the introduction of hydrophilic polyethylene glycol chains into the polymer improves solubility in water, resulting in the above-described effects. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, each component contained in the liquid crystal aligning agent of the present disclosure and other components that are optionally blended as necessary will be described. In this specification, examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0010] <Polymer (A)> The liquid crystal aligning agent of the present invention is at least one polymer (A) selected from the group consisting of a copolymer (hereinafter also referred to as polyimide precursor (A)) 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 imidized 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). In the above formula (EG), the upper limit of n is preferably 40, more preferably 30, and particularly preferably 20, from the viewpoint of improving liquid crystal alignment. The lower limit of n is preferably 3, more preferably 4, from the viewpoint of improving liquid crystal alignment.

[0011] (Repeating unit represented by formula (a)) 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 singly or in combination of two or more.

[0012] Diamines represented by the following formula (O); diamines having a photoalignment group such as 4,4'-diaminoazobenzene or diaminotolane; 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, diamines represented by the following formula (d odiamines having at least one nitrogen atom-containing structure (hereinafter also referred to as specific nitrogen atom-containing structure) selected from the group consisting of a nitrogen atom-containing heterocycle, a secondary amino group, and a tertiary amino group; 2,4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4,6-diaminoresorcinol; diamines having a carboxy group such as 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); 4-(2-(methylamino)ethyl)aniline, 4-(2-aminoethyl)aniline, 1-(4-aminophenyl)-1,3,3-trimethyl-1H-indan-5-amine, 1-(4-aminophenyl)- 2,3-Dihydro-1,3,3-trimethyl-1H-inden-6-amine; diamines having a photopolymerizable group at the end, such as 2-(2,4-diaminophenoxy)ethyl methacrylate and 2,4-diamino-N,N-diallylaniline; cholestanyloxy-3,5-diaminobenzene, cholestanyloxy-3,5-diaminobenzene, cholestanyloxy-2,4-diaminobenzene, cholestanyloxy-3,5-diaminobenzoate diamines having a steroid skeleton such as cholestenyl 3,5-diaminobenzoate, cholestenyl 3,5-diaminobenzoate, lanostannyl 3,5-diaminobenzoate, and 3,6-bis(4-aminobenzoyloxy)cholestane; diamines represented by the following formulae (V-1) to (V-6); and the group "-N(D)-" (D represents a protecting group which is eliminated by heating and replaced with a hydrogen atom, preferably a tert-butoxycarbonyl group) represented by the following formulae (5-1) to (5-11).), diamines having a siloxane bond such as 1,3-bis(3-aminopropyl)-tetramethyldisiloxane and diamines represented by the following formula (Ds-1); diamines having an oxazoline structure such as those represented by the following formulas (Ox-1) to (Ox-2); metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, 1,3-bis(aminomethyl)cyclohexane, 1,4-diaminocyclohexane, 4,4'-methylenebis(cyclohexylamine), diamines in which two amino groups are bonded to a group represented by any of formulas (Y-1) to (Y-167) described in WO 2018 / 117239, and the like.

[0013] [ka] (Ar represents a divalent benzene ring, biphenyl structure, or naphthalene ring. Two Ar may be the same or different, and any hydrogen atom of the benzene ring, biphenyl structure, or naphthalene ring may be replaced with a monovalent group. p is an integer of 0 or 1. Q2 is -(CH2) n -(n is an integer of 2 to 18), or the -(CH2) n represents a group in which at least a portion of the -CH2- in - is replaced with either -O-, -C(=O)- or -OC(=O)-. However, when Q2 has an ether bond, the total number of ether bonds in Q2 is 3 or less.

[0014] [ka]

[0015] [ka] (Multiple m's may be the same or different.)

[0016] [ka] (In formula (3b-1), A 1represents a single bond, -CH2-, -C2H4-, -C(CH3)2-, -CF2-, -C(CF3)2-, -O-, -CO-, -NH-, -N(CH3)-, -CONH-, -NHCO-, -C2O-, -OCH2-, -COO-, -OCO-, -CON(CH3)- or -N(CH3)CO-, and m1 and m2 each independently represent an integer of 0 to 4, and m1 + m2 represents an integer of 1 to 4. In formula (3b-2), m3 and m4 each independently represent an integer of 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-, -C2O-, -OCH2-, -COO-, -OCO-, -CON(CH3)- or N-(CH3)CO-, and m6 is an integer of 1 to 4.

[0017] [ka] (X v1 ~X v4 , X p1 ~X p2 are each independently -(CH2) a - (a is an integer of 1 to 15), -CONH-, -NHCO-, -CON(CH3)-, -NH-, -O-, -CHO-, -CHOCO-, -COO-, or -OCO-; X v5 represents -O-, -CHO-, -CHOCO-, -COO-, or -OCO-. Xa represents a single bond, -O-, -NH-, or -O-(CH) m -O- (m represents an integer of 1 to 6), and 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's may be the same or different. [ka] (Boc represents a tert-butoxycarbonyl group.) [ka]

[0018] [ka]

[0019] The above formula (d o From the viewpoint of enhancing the liquid crystal alignment property, the diamine represented by the following formula (d o -1)~(d o Preferred are diamines represented by the formula (6), 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether and 4,4'-diaminodiphenyl ether. [ka]

[0020] In the diamine represented by the above formula (O), any hydrogen atom in the benzene ring, biphenyl structure, or naphthalene ring may be replaced 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.

[0021] As the diamine represented by the above formula (O), diamines represented by the following formulas (o-1) to (o-16) are preferred from the viewpoint of enhancing the liquid crystal alignment property.

[0022] [ka]

[0023] [ka]

[0024] [ka] (In formula (o-14), two m's may be the same or different.)

[0025] Examples of the nitrogen atom-containing heterocycle that may be contained in the diamine having the specific nitrogen atom-containing structure include pyrrole, imidazole, pyrazole, triazole, pyridine, pyrimidine, pyridazine, pyrazine, indole, benzimidazole, purine, quinoline, isoquinoline, naphthyridine, quinoxaline, phthalazine, triazine, carbazole, acridine, piperidine, piperazine, pyrrolidine, hexamethyleneimine, etc. Among these, pyridine, pyrimidine, pyrazine, piperidine, piperazine, quinoline, carbazole, or acridine is preferred.

[0026] The secondary amino group and tertiary amino group that the diamine having the specific nitrogen atom-containing structure may have are represented, for example, by the following formula (n). [ka] In the above formula (n), R represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. "*" represents a bond bonded to the hydrocarbon group, and at least one of the bonds is bonded to an aromatic hydrocarbon group.

[0027] Examples of the monovalent hydrocarbon group represented by R in the above 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.

[0028] Specific examples of diamines having the 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 formulae (Dp-1) to (Dp-8), and diamines represented by the following formulae (z-1) to (z-18).

[0029] [ka]

[0030] [ka]

[0031] [ka]

[0032] When the repeating unit (a) has a divalent organic group represented by the formula (EG), it is preferable that at least one of X and Y has a divalent organic group represented by the formula (EG). When Y has a divalent organic group represented by the formula (EG), for example, Y may be a divalent organic group derived from a diamine having amino groups at both ends of the divalent organic group represented by the formula (EG) via aromatic groups. Examples of the aromatic group include a benzene ring, a biphenyl structure, or a naphthalene ring. It is more preferable that Y has a group represented by the following formula (d EG ) is a divalent organic group derived from a diamine represented by the formula: [ka]

[0033] Each Ar independently represents a divalent aromatic group or fused ring group and may be the same or different. One or more hydrogen atoms on the aromatic group or fused ring group may be substituted with a monovalent group. Specific examples of the Ar include a benzene ring, a biphenyl structure, and a naphthalene ring. 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, a carboxy group, a hydroxy group, an alkyloxycarbonyl group having 1 to 10 carbon atoms, a cyano group, and a nitro group. n represents an integer of 3 to 40. The upper limit of n is preferably 30, and more preferably 20. Throughout this specification, an m-valent "aromatic group" refers to an m-valent group obtained by removing m hydrogen atoms from the ring portion of an aromatic ring. An m-valent "fused ring group" refers to an m-valent group obtained by removing m hydrogen atoms from the ring portion of a fused ring.

[0034] The above Y is a diamine represented by the above 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, or a diamine represented by the above formula (d o ), 4-(2-(methylamino)ethyl)aniline, 4-(2-aminoethyl)aniline, diamines having the group "-N(D)-" (D represents a protecting group which is eliminated by heating and replaced with a hydrogen atom, preferably a tert-butoxycarbonyl group), and EG When Y satisfies this structure, the pretilt angle of the liquid crystal and the afterimage that occurs during long-term AC driving are reduced, and the relaxation characteristic of accumulated charges is accelerated, which is advantageous.

[0035] 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. Here, the acyclic aliphatic tetracarboxylic acid dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxy groups bonded to a chain hydrocarbon structure. However, it does not need to be composed solely of a chain hydrocarbon structure, and it may have an alicyclic structure or an aromatic ring structure as part of it. The alicyclic tetracarboxylic acid dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxy groups, including at least one carboxy group bonded to the alicyclic structure. However, none of these four carboxy groups are bonded to an aromatic ring. Furthermore, it does not need to be composed solely of an alicyclic structure, and it may have a chain hydrocarbon structure or an aromatic ring structure as part of it. The aromatic tetracarboxylic acid dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxy groups, including at least one carboxy group bonded to an aromatic ring. Derivatives of the above tetracarboxylic acid dianhydrides include tetracarboxylic acid dihalides, tetracarboxylic acid dialkyl esters, and tetracarboxylic acid dialkyl ester dihalides. The tetracarboxylic dianhydrides or derivatives thereof may be used singly or in combination of two or more kinds.

[0036] The acyclic aliphatic or alicyclic tetracarboxylic acid dianhydride or a derivative thereof is preferably a tetracarboxylic acid dianhydride 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, from the viewpoint of enhancing the liquid crystal alignment property.

[0037] The above X is preferably a tetravalent organic group derived from a tetracarboxylic dianhydride represented by the following formula (t) or a derivative thereof.

[0038] [ka] In the formula, X1 is a structure selected from the following formulae (X1-1) to (X1-25), where * represents a bond.

[0039] [ka]

[0040] [ka]

[0041] [ka]

[0042] [ka]

[0043] In formulas (X1-1) to (X1-4), R1 to R 21 are each independently 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. From the viewpoint of improving the liquid crystal alignment property, R1 to R 21 is preferably a hydrogen atom, a halogen atom, a methyl group, or an ethyl group, and more preferably a hydrogen atom or a methyl group. 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-, phenylene, a sulfonyl group, or an amide group. Multiple A2s may be the same or different.

[0044] Specific examples of formula (X1-1) include the following formulae (1-1) to (1-6). From the viewpoint of improving the liquid crystal alignment property, formulae (1-1) and (1-2) are particularly preferred. * has the same meaning as above.

[0045] [ka]

[0046] Preferred specific examples of the above formulae (X1-24) and (X1-25) include the following formulae (X1-26) to (X1-41), where * has the same meaning as above. [ka] [ka]

[0047] From the viewpoint of improving liquid crystal alignment properties, X1 is preferably represented by the formulae (X1-1) to (X1-10), (X1-18) to (X1-23), (X1-24) to (X1-25), or (X1-26) to (X1-30), more preferably represented by the formulae (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 still more preferably represented by the formulae (1-1), (1-2), (X1-5), (X1-7), (X1-9), or (X1-26) to (X1-30).

[0048] As described above, when the repeating unit (a) has a divalent organic group represented by the formula (EG), it is preferable that at least one of X and Y has a divalent organic group represented by the formula (EG). When X has a divalent organic group represented by the formula (EG), examples of X include a tetravalent organic group derived from a tetracarboxylic dianhydride or a derivative thereof represented by the following formula: [ka]

[0049] The monovalent organic groups for R and Z in the above formula (a) include monovalent hydrocarbon groups having 1 to 20 carbon atoms, and methylene groups of the hydrocarbon groups may be -O-, -S-, -CO-, -COO-, -COS-, -NR 3 -(However, R 3 is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, -CO-NR 3 -(However, R 3 is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms.) 3 )2-(where R 3 is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms.), a monovalent group A obtained by replacing with -SO- or the like, a monovalent group in which at least one hydrogen atom bonded to a carbon atom of a monovalent hydrocarbon group or the monovalent group A is replaced with a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc.), a hydroxy group, an alkoxy group, a nitro group, an amino group, a mercapto group, a nitroso group, an alkylsilyl group, an alkoxysilyl group, a silanol group, a sulfino group, a phosphino group, a carboxy group, a cyano group, a sulfo group, an acyl group, or the like, and a monovalent group having a heterocycle. The monovalent organic groups for R and Z in the above formula (a) are preferably alkyl groups having 1 to 10 carbon atoms, alkenyl groups having 2 to 10 carbon atoms, alkynyl groups having 2 to 10 carbon atoms, tert-butoxycarbonyl groups, or 9-fluorenylmethoxycarbonyl groups, more preferably alkyl groups having 1 to 3 carbon atoms, and even more preferably methyl groups. From the viewpoint of obtaining the effects of the present invention, R and Z are each independently preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, more preferably a hydrogen atom or a methyl group.

[0050] In the above formula (a), each of X, Y, R, and Z may be one type or two or more types.

[0051] (Repeating unit represented by formula (1)) In the above formula (1), A1 is a divalent organic group. Examples of A1 include divalent organic groups derived from diisocyanates. The diisocyanates may be used singly or in combination of two or more. Examples of diisocyanates include aromatic diisocyanates and aliphatic diisocyanates. Here, "aromatic diisocyanate" means a diisocyanate having at least one aromatic group, and "aliphatic diisocyanate" means a diisocyanate having an aliphatic group and no aromatic group. Examples of A1 include (i) a divalent organic group derived from an aromatic diisocyanate in which R in the diisocyanate structure (O=C=NRN=C=O) is an organic group having 6 to 30 carbon atoms and at least one benzene ring, or (ii) a divalent organic group derived from an aliphatic diisocyanate in the diisocyanate structure (O=C=NRN=C=O) in which R is an organic group having 4 to 30 carbon atoms and having an aliphatic group but no aromatic group. The aliphatic group includes both acyclic aliphatic groups and alicyclic groups. Specific examples of A1 include o-phenylene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, toluene diisocyanates (e.g., 2,4-diisocyanate tolylene, 2,6-diisocyanate tolylene), 1,4-diisocyanate-2-methoxybenzene, 2,5-diisocyanate xylenes, 3,3'-dimethyl-4,4'-diisocyanate biphenyl, 4,4'-diisocyanate diphenyl ether, 2,2'-bis(4-diisocyanate phenyl)propane, 4,4'-diisocyanate diphenylmethane ( Examples of the divalent organic group include divalent organic groups derived from aromatic diisocyanates such as 4,4'-diphenylmethane diisocyanate, 4,4'-diisocyanic acid diphenyl ether, 4,4'-diisocyanic acid diphenyl sulfone, 3,3'-diisocyanic acid diphenyl sulfone, and 2,2'-diisocyanic acid benzophenone, and divalent organic groups derived from aliphatic diisocyanates such as isophorone diisocyanate, norbornene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, and tetramethylene diisocyanate.

[0052] In the above formula (1), A 1‘ is a divalent organic group derived from a diamine. Examples of the diamine include the diamines exemplified above for the repeating unit (a), and preferred embodiments are the same as those described above.

[0053] When the formula (1) has a divalent organic group represented by the formula (EG), the above A1 and A 1’ At least one of them preferably has a divalent organic group represented by the above formula (EG). Above A 1’ When A has a divalent organic group represented by the above formula (EG), 1’ Specific examples of the structure include a divalent organic group derived from a diamine having a divalent organic group represented by the formula (EG) given above as an example of the repeating unit (a), and preferred embodiments thereof.

[0054] When A1 has a divalent organic group represented by formula (EG), examples of A1 include divalent organic groups derived from diisocyanates, as represented below. [ka]

[0055] C1 and C in the above formula (1) 1’ Examples of the monovalent organic group include the structures exemplified for R and Z in the repeating unit (a) above. 1’ and are each independently preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, more preferably a hydrogen atom or a methyl group, from the viewpoint of obtaining the effects of the present invention.

[0056] In the above formula (1), A1, A 1’ , C1, C 1’ may be one type or two or more types.

[0057] (Repeating unit represented by formula (2)) In the above formula (2), A2 is a divalent organic group. Examples of A2 include divalent organic groups derived from diisocyanates, such as the structures exemplified for A1 in the above repeating unit (1), and preferred embodiments are also the same as those for A1.

[0058] In the above formula (2), A 2’is a divalent organic group obtained by removing hydrogen atoms contained in two hydroxy 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 diols containing a divalent organic group represented by the above formula (EG); alkylene diols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,3-propanediol, 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, and 1,4-cyclohexanedimethanol; dimethylolpropionic acid (2,2-bis(hydroxymethyl)propionic acid), dimethylolbutanoic acid (2,2-bis(hydroxymethyl)butanoic acid), 2,3-dihydroxybenzoic acid, and 2,4-dihydroxybenzoic acid. Examples of the diol include carboxyl group-containing diols such as benzoic acid, 2,5-dihydroxybenzoic acid, 2,6-dihydroxybenzoic acid, 3,4-dihydroxybenzoic acid, and 3,5-dihydroxybenzoic acid; polytetramethylene glycol, a random copolymer of tetramethylene glycol and neopentyl glycol; polyester diols obtained by reacting polyhydric alcohols with polybasic acids; polycarbonate diols having a carbonate skeleton; polycaprolactone diols obtained by ring-opening addition reactions of lactones such as γ-butyllactone, ε-caprolactone, and δ-valerolactone; bisphenol A, ethylene oxide adducts of bisphenol A; propylene oxide adducts of bisphenol A; hydrogenated bisphenol A, ethylene oxide adducts of hydrogenated bisphenol A; and propylene oxide adducts of hydrogenated bisphenol A.

[0059] The diol containing a divalent organic group represented by the formula (EG) is not particularly limited as long as it contains the formula (EG) in the molecule, but is preferably a diol having hydrogen atoms bonded to both ends of the formula (EG). In the diol having hydrogen atoms bonded to both ends of the formula (EG), the upper limit of n is preferably 40, more preferably 30, and particularly preferably 20, from the viewpoint of improving liquid crystal alignment. The lower limit of n is preferably 3, more preferably 4, from the viewpoint of improving liquid crystal alignment.More specifically, the diol containing a divalent organic group represented by the formula (EG) includes tetraethylene glycol, pentaethylene glycol, hexaethylene glycol, and products manufactured by Sanyo Chemical Industries, Ltd. under the trade names 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; and products manufactured by Merck under the trade names PEG300, PEG1000, PEG2000, PEG4000, PEG6000, PEG8000, PEG10000, and PEG1 2000, PEG20000, PEG35000; SIGMA-ALDRICH product numbers P2139, P3265, P3515, 81210, 81240, 81260, 81285, 81310, 181986, 181994, 182001, 182028, 189456, 202304, 202312 , 202320, 202339, 202398, 202421, 202436, 202444, 202452, 295906, 309028, 372773, 372781, 373001, 412325, 435406, 435422, 435457, 637726; trade name SINOPOL manufactured by Chunichi Synthetic Chemical Co., Ltd. Examples of suitable polyethylene glycols include polyethylene glycols such as PEG600, SINOPOL PEG1500, and SINOPOL PEG4000; those commercially available under the trade names PEG#300, PEG#400, PEG#600, PEG#1000, PEG#1500, PEG#1540, PEG#4000, and PEG#6000M from Lion Specialty Chemicals; and those commercially available under the trade names Polyethylene Glycol 400 and Polyethylene Glycol 600 from Tokyo Chemical Industry Co., Ltd.; tripropylene glycol, tetrapropylene glycol, and polypropylene glycol (with a more preferred average molecular weight of 300 to 10,000); and copolymers of ethylene oxide and propylene oxide having an average molecular weight of 200 to 5,000. The polyethylene glycols and polypropylene glycols may be those obtained by anionic ring-opening polymerization of ethylene oxide or propylene oxide.The polymerization reaction can be carried out using a polymerization initiator (e.g., water, ethylene glycol, propylene glycol, etc.) and a catalytic amount of base (e.g., potassium hydroxide). Specific examples of preferred diols having hydrogen atoms bonded to both ends of the formula (EG) include tetraethylene glycol, pentaethylene glycol, hexaethylene glycol, Sanyo Chemical Industries, Ltd. (trade names: PEG-300, PEG-400, PEG-600, PEG-1000), Merck & Co., Ltd. (product names: PEG300, PEG1000, Merck & Co., Ltd. (product name: PEG300), Chunichi Synthetic Chemical Industry Co., Ltd. (product name: PEG1000), SINOPOL PEG600, Lion Specialty Chemicals Co., Ltd. (trade names: PEG#300, PEG#400, PEG#600, PEG#1000), and Tokyo Chemical Industry Co., Ltd. (product names: Polyethylene Glycol 400, Polyethylene Glycol 600). The average molecular weight of the glycol exemplified in the diol containing a divalent organic group represented by (EG) above is the weight average molecular weight obtained by gel permeation chromatography (GPC) using polystyrene as a standard.

[0060] When the formula (2) has a divalent organic group represented by the formula (EG), the above A2 and A 2’ At least one of them preferably has a divalent organic group represented by the above formula (EG). When A2 has a divalent organic group represented by formula (EG), specific structures of A2 include divalent organic groups derived from diisocyanates having a divalent organic group represented by formula (EG), which are exemplified in the repeating unit (1). Above A 2’ When A has a divalent organic group represented by the above formula (EG), 2’ Specific examples of the structure include divalent organic groups obtained by removing hydrogen atoms contained in two hydroxy groups from a diol containing a divalent organic group represented by the formula (EG) described above in detail.

[0061] In the above formula (2), A2, A 2’may be one type or two or more types.

[0062] (Repeating units constituting polymer (A)) 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 imidized product of the copolymer (provided that 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.

[0063] Here, the term "terminal group" refers to a group bonded to the terminal of the repeating unit constituting the polymer (A). Examples of the terminal group include an amino group, a carboxy group, an acid anhydride group, an isocyanate group, or a derivative thereof. The amino group, the carboxy group, the acid anhydride group, and the isocyanate group can be obtained by a conventional condensation reaction, and the derivatives can be obtained by modifying the terminal group using, for example, a terminal blocking agent, as described below.

[0064] The content of the repeating unit represented by formula (a) is preferably from 2 to 98 mol %, more preferably from 10 to 96 mol %, of all the repeating units constituting the polymer (A). The content of the repeating unit represented by formula (1) is preferably from 1 to 49 mol %, more preferably from 2 to 45 mol %, of all repeating units constituting the polymer (A). The content of the repeating unit represented by formula (2) is preferably from 1 to 49 mol %, more preferably from 2 to 45 mol %, of all the repeating units constituting the polymer (A).

[0065] <Polymer (B)> From the viewpoint of improving electrical properties, the liquid crystal aligning agent of the present invention may further contain at least one polymer (B) selected from the group consisting of polyimide precursors and imidized polymers thereof, which is different from the polymer (A). The polymer (B) is preferably at least one polymer selected from the group consisting of polyimide precursors having a repeating unit represented by the following formula (b) and imidized polymers thereof.

[0066] [ka] (X b represents a tetravalent organic group. b represents a divalent organic group. Two R b each independently represents a hydrogen atom or a monovalent organic group. b each independently represents a hydrogen atom or a monovalent organic group.

[0067] The polymer (B) preferably does not have at least one repeating unit 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). X b Examples of the tetravalent organic group in include a tetravalent organic group derived from an acyclic aliphatic tetracarboxylic dianhydride, a tetravalent organic group derived from an alicyclic tetracarboxylic dianhydride, or a tetravalent organic group derived from an aromatic tetracarboxylic dianhydride, and specific examples include the tetravalent organic groups exemplified as X1 in the above formula (a). From the viewpoint of efficiently achieving the effects of the present invention, the tetravalent organic groups represented by the above formulas (X1-1) to (X1-25) (these are also collectively referred to as specific tetravalent organic groups) are preferred.

[0068] In order to efficiently obtain the effects of the present invention, the polymer (B) is b The repeating units in which R is the specific tetravalent organic group preferably account for 5 mol % or more, and more preferably 10 mol % or more of all repeating units contained in the polymer (B).

[0069] Y bSpecific examples of the divalent organic group include the diamine-derived diamines exemplified in the polymer (A). b is preferably a polymer containing a repeating unit which is a divalent organic group (these are also collectively referred to as specific divalent organic groups) selected from the group consisting of diamines having a carboxy group, such as diamines 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), from which two amino groups have been removed.

[0070] The polymer (B) is a polymer containing Y b The repeating units in which R is the specific divalent organic group may account for 1 mol % or more, or 5 mol % or more of all repeating units contained in the polymer (B).

[0071] From the viewpoint of improving electrical properties, the content ratio of the (A) component to the (B) component may be 10 / 90 to 90 / 10, 20 / 80 to 90 / 10, or 20 / 80 to 80 / 20, in terms of the mass ratio of [(A) component] / [(B) component].

[0072] <Production of Polymer (A) and Polymer (B)> The polyimide precursor (A) can be produced by a method including the steps of: (a) reacting a component (o) containing an organic diol having two hydroxy groups in the molecule with a component (a) containing a compound having two isocyanate groups in the molecule to synthesize a terminal isocyanate compound; (b) reacting the component (b) containing a compound having two primary or secondary amino groups in the molecule to synthesize a terminal amine urea oligomer; and (c) reacting the resulting oligomer with a 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. [ka] (R represents a hydrogen atom or a methyl group, and n is an integer of 3 to 40.)

[0073] On the other hand, the polyimide precursor (A) can also be produced by a process comprising the steps of reacting the (a) component with the (b) component to obtain a terminal isocyanate compound, and reacting the (o) component with the (c) component to obtain a terminal diol compound, and then reacting the obtained terminal isocyanate compound with the terminal diol compound.

[0074] Alternatively, the polyimide precursor (A) can be produced by a process comprising the steps of reacting the components (b) and (c) to obtain an amine-terminated amic acid oligomer or a derivative thereof, adding the component (o) to the resulting mixture to form a mixed solution, and then reacting the resulting mixture with the component (a).

[0075] Each of the component (o), the component (a), the component (b) and the component (c) may be one type or two or more types.

[0076] Examples of the component (o) include the organic diols exemplified as the repeating unit represented by the formula (2) above. 2’ -H" (A 2’ is A in Eq. (2) 2’The diol compounds represented by the formula (I) are also preferred.

[0077] Examples of the component (a) include diisocyanate compounds represented by O=C=N-A1-N=C=O (A1 is the same as A1 in formula (1)).

[0078] An example of the component (b) is a diamine represented by the following formula (mb): [ka] (In formula (mb), C1, C 1’ , A 1’ are C1 and C in equation (1). 1’ , A 1’ is the same as Specific examples of the compound represented by the formula (mb) include the diamines exemplified as the repeating unit represented by the formula (a) above.

[0079] Examples of the tetracarboxylic dianhydride or derivative thereof contained in component (c) include tetracarboxylic dianhydride or derivative thereof represented by the following formula (mc) (tetracarboxylic dihalide, tetracarboxylic acid dialkyl ester, or tetracarboxylic acid dialkyl ester dihalide). [ka] (In formula (mc), X is the same as X in formula (a) above.)

[0080] More specifically, X in the above formula (mc) may be a tetravalent organic group derived from an acyclic aliphatic tetracarboxylic dianhydride or a derivative thereof, a tetravalent organic group derived from an alicyclic tetracarboxylic dianhydride or a derivative thereof, or a tetravalent organic group derived from an aromatic tetracarboxylic dianhydride or a derivative thereof, as exemplified in the repeating unit represented by the above formula (a). The above acyclic aliphatic or alicyclic tetracarboxylic dianhydride or a derivative thereof is preferably a tetracarboxylic dianhydride or a derivative thereof 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, from the viewpoint of high liquid alignment. The tetracarboxylic dianhydride or a derivative thereof contained in component (c) is preferably a tetracarboxylic dianhydride or a derivative thereof represented by the above formula (t).

[0081] The tetracarboxylic dianhydride represented by formula (t) or a derivative thereof preferably accounts for 1 mol % or more of the entire component (c), more preferably 5 mol % or more, and particularly preferably 10 mol % or more.

[0082] When at least one of the compounds constituting the components (o), (a), (b) and (c) has a partial structure represented by the formula (EG) in the molecule, it is considered to be "HA 2’ A in the diol compound represented by "-H" 2’ A1 in the diisocyanate compound represented by O=C=N-A1-N=C=O, A 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.

[0083] The reaction of components (o), (a), (b), and (c) is usually carried out in an organic solvent, and the organic solvent used is not particularly limited as long as it dissolves the resulting polyimide precursor. Specific examples include N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methyl-ε-caprolactam, dimethyl sulfoxide, tetramethylurea, pyridine, dimethyl sulfone, hexamethylphosphoric triamide, γ-butyrolactone, isopropyl alcohol, methoxymethyl pentanol, dipentene, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, methyl cellosolve, ethyl 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 ... Pyrene 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 monoethyl 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,Examples of suitable solvents include 4-dioxane, n-hexane, n-pentane, n-octane, diethyl ether, cyclohexanone, ethylene carbonate, propylene carbonate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether acetate, 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, diglyme, and 4-hydroxy-4-methyl-2-pentanone. These may be used alone or in combination. Furthermore, even if a solvent does not dissolve the polyimide precursor, it may be mixed with the above solvent to the extent that the resulting polyimide precursor does not precipitate. Furthermore, since moisture in the organic solvent inhibits the polymerization reaction and may cause the generated polyimide precursor to hydrolyze, it is preferable to use an organic solvent that has been dehydrated and dried.

[0084] <Method for synthesizing terminal isocyanate compounds> The method for synthesizing the terminal isocyanate compound obtained by reacting component (o) containing the organic diol used in the present invention with component (a) containing a diisocyanate compound containing two isocyanate groups in the molecule is to react the components (o) and (a) in an organic solvent in such amounts that the ratio of the number of hydroxy groups to the number of isocyanate groups, i.e., isocyanate groups / hydroxy groups, is 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.

[0085] When two or more organic diols are used, the reaction with the diisocyanate compound may be carried out after mixing the two or more organic diols, or each organic diol may be reacted with the diisocyanate compound separately. After reacting the organic diol with the diisocyanate compound, the resulting terminal isocyanate compound may be further reacted with another organic diol compound, which may then be reacted with a diisocyanate compound. The same applies when two or more diisocyanate compounds are used. In this way, the desired terminal isocyanate compound can be produced.

[0086] The reaction temperature between component (o) and component (a) is preferably 0 to 160°C, more preferably 10 to 150°C. The reaction time can be appropriately selected depending on the reaction scale and reaction conditions used. If necessary, the reaction may be carried out in the presence of a catalyst such as a tertiary amine, or a metal or semimetal compound such as an alkali metal, alkaline earth metal, tin, zinc, titanium, or cobalt. The total concentration of component (o) and component (a) in the reaction liquid is preferably 1 to 50% by mass, more preferably 5 to 30% by mass. The reaction can be carried out at a high concentration initially, with subsequent addition of an organic solvent.

[0087] <Method for synthesizing terminal amine urea oligomer> The method for synthesizing a terminal amine urea oligomer by reacting the terminal isocyanate compound obtained by the above method with component (b) containing a compound having two primary or secondary amino groups in the molecule is carried out in an organic solvent. The reaction temperature is preferably 0 to 160°C, more preferably 10 to 150°C. The reaction time can be appropriately selected depending on the reaction scale and reaction conditions used. The reaction concentration in the reaction solution is preferably 1 to 50% by mass, more preferably 5 to 30% by mass. The reaction can also be carried out at a high concentration initially, with additional organic solvent added later.

[0088] <Synthesis method for obtaining polyimide precursor (a) from terminal amine urea oligomer> The polyimide precursor (a) can be obtained by reacting the amine-terminated urea oligomer obtained by the above method with component (c) containing a tetracarboxylic dianhydride or a derivative thereof, and optionally component (b) containing a compound containing two primary or secondary amino groups in the molecule. The reaction is preferably carried out in an organic solvent, and the reaction temperature is preferably 20 to 100°C, more preferably 20 to 80°C. The reaction time can be appropriately selected depending on the reaction scale and reaction conditions used. The reaction concentration in the reaction solution is preferably 1 to 50% by mass, more preferably 5 to 30% by mass. The reaction can also be carried out at a high concentration initially, with additional organic solvent added later.

[0089] The ratio of the reacted components (o), (a), (b), and (c) is preferably, for example, in molar ratio, (total amount of components (a) and (c):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%.

[0090] Examples of the polyimide precursor that is the polymer (B) include polyamic acid, polyamic acid ester, etc. The polyimide precursor that is the polymer (B) can be synthesized by a known method, for example, as described in International Publication WO2013 / 157586.

[0091] [Terminal Modifier] In synthesizing the polymers (A) and (B) of the present invention, a terminal-modified polymer may be synthesized using an appropriate terminal-modifying agent from the above-mentioned components (o), (a), (b), and (c), and optionally all of them.

[0092] Examples of the terminal modifier include acid monoanhydrides such as acetic anhydride, maleic anhydride, nadic anhydride, phthalic anhydride, itaconic anhydride, cyclohexanedicarboxylic anhydride, 3-hydroxyphthalic anhydride, trimellitic anhydride, compounds represented by the following formulae (m-1) to (m-6), 3-(3-trimethoxysilyl)propyl)-3,4-dihydrofuran-2,5-dione, 4,5,6,7-tetrafluoroisobenzofuran-1,3-dione, and 4-ethynylphthalic anhydride; [ka] Examples of the alkyl esters include dicarbonate diester compounds such as di-tert-butyl dicarbonate and diallyl dicarbonate; chlorocarbonyl compounds such as acryloyl chloride, methacryloyl chloride and nicotinic acid 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; and monoisocyanate compounds such as ethyl isocyanate, phenyl isocyanate and naphthyl isocyanate.

[0093] The proportion of the terminal modifier used is preferably 20 parts by mole or less, and more preferably 10 parts by mole or less, per 100 parts by mole of the total of the diamine component used and the organic diol component used as needed.

[0094] Polyimides can also be obtained by ring-closing (imidizing) the polyimide precursor (A) of polymer (A) or the polyimide precursor of polymer (B) (hereinafter collectively referred to simply as "polyimide precursors"). The "imidization rate" as used herein refers to the proportion of imide groups in the total amount of imide groups derived from tetracarboxylic dianhydride or its derivatives and carboxyl groups (or their derivatives). The imidization rate does not necessarily need to be 100% and can be adjusted as desired depending on the application and purpose.

[0095] Methods for imidizing the polyimide precursor include thermal imidization, in which a solution of the polyimide precursor is heated as is, and catalytic imidization, in which a catalyst is added to a solution of the polyimide precursor.

[0096] When the polyimide precursor is thermally imidized in a solution, the temperature is preferably 100 to 400° C., more preferably 120 to 250° C., and it is preferable to carry out the imidization while removing water produced by the imidization reaction from the system.

[0097] Catalytic imidization of polyimide precursors can be carried out by adding a basic catalyst and an acid anhydride to a solution of the polyimide precursor and stirring the mixture at preferably -20 to 250°C, more preferably 0 to 180°C. The amount of the basic catalyst is preferably 0.5 to 30 times, more preferably 2 to 20 times, the molar ratio of the amic acid groups, and the amount of the acid anhydride is preferably 1 to 50 times, more preferably 3 to 30 times, the molar ratio of the amic acid groups. Examples of basic catalysts include pyridine, triethylamine, trimethylamine, tributylamine, and trioctylamine. Of these, pyridine is preferred because it has adequate basicity for promoting the reaction. Examples of acid anhydrides include acetic anhydride, trimellitic anhydride, and pyromellitic anhydride. Of these, acetic anhydride is preferred because it facilitates purification after the reaction. The imidization rate by catalytic imidization can be controlled by adjusting the amount of catalyst, reaction temperature, and reaction time.

[0098] To recover the resulting polyimide precursor or polyimide from a reaction solution of the polyimide precursor or polyimide, the reaction solution may be precipitated by pouring the reaction solution into a solvent. Examples of solvents used for precipitation include methanol, ethanol, isopropyl alcohol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, toluene, benzene, and water. The polymer precipitated by pouring into the solvent can be recovered by filtration and then dried at room temperature or by heating under atmospheric or reduced pressure. Furthermore, the precipitated polymer can be redissolved in an organic solvent and reprecipitated and recovered, repeating this process, for example, 2 to 10 times, to reduce the amount of impurities in the polymer. Examples of solvents used in this process include alcohols, ketones, and hydrocarbons. Using three or more solvents selected from these solvents is preferred because it further increases the efficiency of purification.

[0099] 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, in terms of weight average molecular weight measured by GPC (Gel Permeation Chromatography), taking into consideration the strength of the liquid crystal alignment film obtained therefrom, workability during film formation, and coating properties.

[0100] The blending ratio of the polymer components used in the manufacturing method of the liquid crystal alignment film of the present invention is not particularly limited, but for example, the total amount of the polymer components contained in the liquid crystal alignment agent is preferably 0.1 to 30 mass %, more preferably 3 to 10 mass %. The content of polymer (A) in the liquid crystal aligning agent can be appropriately changed depending on the application method of the liquid crystal aligning agent and the intended film thickness of the liquid crystal alignment film, but is preferably 0.1 to 30 mass %, and particularly preferably 0.5 to 9.5 mass %.

[0101] The liquid crystal aligning agent used for producing the liquid crystal alignment film may contain, in addition to the polymer (A) and the polymer (B), other polymers. In this case, the content of the other polymers is 0.5 to 15 mass %, preferably 1 to 10 mass %, of the total amount of the polymer components. Examples of other polymers include acrylic polymers, methacrylic polymers, polystyrene, polyamides, and polysiloxanes.

[0102] 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 lactam solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethyllactamide, 3-methoxy-N,N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropanamide, etc.;4-Hydroxy-4-methyl-2-pentanone, 2,6-dimethyl-4-heptanone (diisobutyl ketone), methyl lactate, ethyl lactate, n-propyl lactate, 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 Examples of suitable solvents include ethyl 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, and diisopentyl ether; carbonate solvents such as ethylene carbonate and propylene carbonate, 1-hexanol, cyclohexanol, 1,2-ethanediol, 2,6-dimethyl-4-heptanol (diisobutylcarbinol), and 1,3-dimethyl-2-imidazolidinone. These may be used alone or in combination.

[0103] Preferred solvent combinations include N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone and ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone and propylene glycol monobutyl ether, N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone, 4-hydroxy-4-methyl-2-pentanone and diethylene glycol diethyl ether, N-Ethyl-2-pyrrolidone, N-methyl-2-pyrrolidone, and 4-hydroxy-4-methyl-2-pentanone, N-methyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone, and 2,6-dimethyl-4-heptanone, N-methyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone, and dipropylene glycol monomethyl ether, N-methyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone, and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone and 4-hydroxy -4-Methyl-2-pentanone and propylene glycol diacetate, γ-butyrolactone, 4-hydroxy-4-methyl-2-pentanone and 2,6-dimethyl-4-heptanone, γ-butyrolactone, 4-hydroxy-4-methyl-2-pentanone and propylene glycol diacetate, N-methyl-2-pyrrolidone, γ-butyrolactone, propylene glycol monobutyl ether and 2,6-dimethyl-4-heptanone, N-methyl-2-pyrrolidone, γ-butyrolactone, propylene glycol monobutyl ether and diisopropyl ether Examples of the solvent include isopropyl 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, and N-methyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone, and ethylene glycol monobutyl ether. The type and content of such a solvent are appropriately selected depending on the coating device, coating conditions, coating environment, etc. of the liquid crystal alignment agent.

[0104] <Liquid crystal alignment agent> The liquid crystal aligning agent of the present invention may contain other components other than those described above, such as a crosslinkable compound, a functional silane compound, a surfactant, a compound having a photopolymerizable group, etc., as needed.

[0105] The crosslinkable compound can be used for the purpose of increasing the strength of the liquid crystal alignment film. Examples of such crosslinkable compounds include compounds having an isocyanate group or a cyclocarbonate group, or compounds having at least one group selected from the group consisting of lower alkoxyalkyl groups, as described in paragraphs

[0109] to

[0113] of International Publication WO2016 / 047771, as well as compounds having a blocked isocyanate group.

[0106] Compounds having a blocked isocyanate group are commercially available, and for example, Coronate AP Stable M, Coronate 2503, 2515, 2507, 2513, 2555, Millionate MS-50 (all manufactured by Tosoh Corporation), Takenate B-830, B-815N, B-820NSU, B-842N, B-846N, B-870N, B-874N, B-882N (all manufactured by Mitsui Chemicals, Inc.), etc. can be preferably used.

[0107] Specific examples of preferred crosslinkable compounds include compounds represented by the following formulas (CL-1) to (CL-11). [ka]

[0108] The above are examples of the crosslinkable compound, and the present invention is not limited to these. The crosslinkable compound used in the liquid crystal aligning agent of the present invention may be one type or a combination of two or more types.

[0109] The content of the other crosslinkable compounds in the liquid crystal aligning agent of the present invention is 0.1 to 150 parts by mass, or 0.1 to 100 parts by mass, or 1 to 50 parts by mass, relative to 100 parts by mass of all polymer components.

[0110] The functional silane compound 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, per 100 parts by mass of all polymer components.

[0111] The surfactant can be used to improve the uniformity of the film thickness and the surface smoothness of the liquid crystal alignment film. Examples of the compound include fluorine-based surfactants, silicone-based surfactants, and nonionic surfactants. Specific examples of these surfactants include those described in paragraph

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

[0112] Examples of the compound having a photopolymerizable group include compounds having one or more polymerizable unsaturated groups, such as an acrylate group or a methacrylate group, in the molecule.

[0113] Furthermore, the liquid crystal aligning agent of the present invention can contain a compound that promotes charge transfer in the liquid crystal alignment film and promotes charge dissipation in the device. The nitrogen-containing heterocyclic amine compounds represented by formulas [M1] to [M156], more preferably 3-picolylamine and 4-picolylamine, are described in paragraphs

[0194] to

[0200] of International Publication WO 2011 / 132751 (published October 27, 2011). These amine compounds may be added directly to the liquid crystal aligning agent, or may be added after being prepared into a solution having a concentration of, for example, 0.1 to 10% by mass, preferably 1 to 7% by mass. The solvent used is not particularly limited, as long as it dissolves the polymer component.

[0114] An imidization accelerator or the like may be added to the liquid crystal aligning agent of the present invention for the purpose of efficiently promoting imidization by heating when the coating film is baked.

[0115] The solid content concentration in the liquid crystal aligning agent (the ratio of the total mass of the components other than the solvent of the liquid crystal aligning agent to the total mass of the liquid crystal aligning agent) is appropriately selected taking into consideration viscosity, volatility, etc., but is preferably in the range of 0.5 to 15 mass%, more preferably 1 to 10 mass%. The particularly preferred range of solid content varies depending on the method used to apply the liquid crystal alignment agent to the substrate. For example, when using a spinner method, a particularly preferred solid content range is 1.5 to 4.5 mass%. When using a printing method, a particularly preferred solid content range is 3 to 9 mass%, thereby resulting in a solution viscosity range of 12 to 50 mPa·s. When using an inkjet method, a particularly preferred solid content range is 1 to 5 mass%, thereby resulting in a solution viscosity range of 3 to 15 mPa·s.

[0116] <Liquid crystal alignment film / LCD element> A liquid crystal alignment film can be produced by using the liquid crystal aligning agent. A liquid crystal display element according to the present invention includes a liquid crystal alignment film formed using the liquid crystal aligning agent. The operation mode of the liquid crystal display element according to the present invention is not particularly limited, and it can be applied to various operation modes, such as TN (Twisted Nematic) type, STN type, vertical alignment type (including VA-MVA type, VA-PVA type, etc.), in-plane switching type (IPS type), FFS (Fringe Field Switching) type, and optically compensated bend type (OCB type).

[0117] The liquid crystal display element of the present invention can be produced, 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).

[0118] <Step (1): Step of applying a liquid crystal alignment agent onto a substrate> The liquid crystal aligning agent of the present invention is applied to one side of a substrate having a patterned transparent conductive film by an appropriate application method, such as a roll coater method, a spin coat method, a printing method, or an inkjet method. The substrate is not particularly limited as long as it is highly transparent; glass substrates, silicon nitride substrates, and plastic substrates such as acrylic substrates and polycarbonate substrates can also be used. In addition, in reflective liquid crystal display devices, an opaque material such as a silicon wafer can be used for only one substrate, and in this case, a light-reflecting material such as aluminum can also be used for the electrode. Furthermore, when manufacturing IPS or FFS liquid crystal devices, a substrate having an electrode made of a comb-shaped patterned transparent conductive film or metal film and an opposing substrate having no electrode are used.

[0119] Examples of a method for applying the liquid crystal alignment agent to a substrate and forming a film include screen printing, offset printing, flexographic printing, an inkjet method, and a spray method. Among these, the application and film formation method by the inkjet method is preferably used.

[0120] <Step (2): Step of baking the applied liquid crystal alignment agent> Step (2) is a step of baking the liquid crystal aligning agent applied to the substrate to form a film. After the liquid crystal aligning agent is applied to the substrate, the solvent can be evaporated or the polyamic acid or polyamic acid ester can be thermally imidized using a heating means such as a hot plate, a heat circulation oven, or an IR (infrared) oven. The drying and baking steps after application of the liquid crystal aligning agent of the present invention can be performed at any temperature and for any time, and may be performed multiple times. The temperature for reducing the solvent in the liquid crystal aligning agent can be, for example, 40 to 180°C. From the perspective of shortening the process, it may be performed at 40 to 150°C. The baking time is not particularly limited, but may be 1 to 10 minutes or 1 to 5 minutes. When thermally imidizing the polyamic acid or polyamic acid ester, a baking step at a temperature range of, for example, 150 to 300°C or 150 to 250°C may be added after the above step. The baking time is not particularly limited, but may be 5 to 40 minutes or 5 to 30 minutes. If the film-like material after firing is too thin, the reliability of the liquid crystal display element may decrease, so the thickness is preferably 5 to 300 nm, more preferably 10 to 200 nm.

[0121] <Step (3): Step of subjecting the film obtained in step (2) to alignment treatment> Step (3) is a step of optionally performing an alignment treatment on the film obtained in step (2). That is, in horizontal alignment type liquid crystal display devices such as IPS mode or FFS mode, the coating film is subjected to an alignment ability imparting treatment. On the other hand, in vertical alignment type liquid crystal display devices such as VA mode or PSA mode, the formed coating film can be used as a liquid crystal alignment film as is, or the coating film may be subjected to an alignment ability imparting treatment. Alignment treatment methods for liquid crystal alignment films include rubbing treatment and photo-alignment treatment. Photo-alignment treatment methods include a method in which the surface of the film-like material is irradiated with radiation polarized in a certain direction and, optionally, subjected to heat treatment at a temperature preferably of 150 to 250°C to impart liquid crystal alignment properties (also referred to as liquid crystal alignment ability). As the radiation, ultraviolet light or visible light having a wavelength of 100 to 800 nm can be used. Among these, ultraviolet light having a wavelength of 100 to 400 nm is preferred, and more preferably 200 to 400 nm is more preferred.

[0122] The radiation dose is 1 to 10,000 mJ / cm 2 Among these, 100 to 5,000 mJ / cm is preferable. 2 In addition, when irradiating with radiation, the substrate having the film-like material may be irradiated while being heated at 50 to 250° C. in order to improve the liquid crystal alignment. The liquid crystal alignment film prepared in this manner can stably align liquid crystal molecules in a certain direction. Furthermore, the liquid crystal alignment film irradiated with polarized radiation by the above method can be contacted with water or a solvent, or the liquid crystal alignment film irradiated with radiation can be heat-treated.

[0123] The solvent used in the contact treatment is not particularly limited as long as it dissolves the decomposition products generated from the film-like material by irradiation. Specific examples include water, methanol, ethanol, 2-propanol, acetone, methyl ethyl ketone, 1-methoxy-2-propanol, 1-methoxy-2-propanol acetate, butyl cellosolve, ethyl lactate, methyl lactate, diacetone alcohol, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propyl acetate, butyl acetate, and cyclohexyl acetate. Among these, water, 2-propanol, 1-methoxy-2-propanol, and ethyl lactate are preferred, with water, 1-methoxy-2-propanol, and ethyl lactate being more preferred, from the standpoint of versatility and solvent safety. The solvent may be used alone or in combination of two or more.

[0124] The temperature for the heat treatment of the coating film irradiated with the radiation is more preferably 50 to 300° C., and even more preferably 120 to 250° C. The heat treatment time is preferably 1 to 30 minutes.

[0125] <Step (4): Step of Producing a Liquid Crystal Cell> Two substrates on which liquid crystal alignment films are formed are prepared as described above, and liquid crystal is placed between the two substrates arranged opposite each other. Specifically, the following two methods can be used. In the first method, the two substrates are first arranged opposite each other with a gap (cell gap) between them so that the liquid crystal alignment films face each other. Next, the peripheries of the two substrates are bonded together using a sealant, and a liquid crystal composition is injected into the substrate surfaces and the cell gap defined by the sealant to contact the film surface, and then the injection hole is sealed.

[0126] The second method is called the ODF (One Drop Fill) method. A UV-curable sealant, for example, is applied to a predetermined location on one of two substrates on which a liquid crystal alignment film has been formed, and a liquid crystal composition is then dropped onto several predetermined locations on the liquid crystal alignment film. The other substrate is then attached so that the liquid crystal alignment film faces the other substrate, and the liquid crystal composition is spread over the entire surface of the substrate and brought into contact with the film surface. Next, the entire surface of the substrate is irradiated with UV light to cure the sealant. In either method, it is desirable to further heat the substrate to a temperature at which the liquid crystal composition is in an isotropic phase, and then slowly cool it to room temperature to remove flow alignment that occurs during liquid crystal filling. When the coating films are subjected to a rubbing treatment, the two substrates are placed opposite each other so that the rubbing directions of the coating films are at a predetermined angle, for example, perpendicular or antiparallel to each other. The sealing agent may be, for example, an epoxy resin containing a hardener and aluminum oxide spheres as spacers. The liquid crystal may be a nematic liquid crystal or a smectic liquid crystal, with a nematic liquid crystal being preferred.

[0127] The liquid crystal aligning agent of the present invention is also preferably used for a liquid crystal display element (PSA type liquid crystal display element) which has a liquid crystal layer between a pair of substrates provided with electrodes, and is produced through a process of disposing a liquid crystal composition containing a polymerizable compound which is polymerized by at least one of active energy rays and heat between the pair of substrates, and polymerizing the polymerizable compound by at least one of irradiation with active energy rays and heating while applying a voltage between the electrodes. The liquid crystal aligning agent of the present invention is also preferably used for a liquid crystal display element (SC-PVA mode liquid crystal display element) which has a liquid crystal layer between a pair of substrates equipped with electrodes, and is manufactured by disposing a liquid crystal alignment film containing a polymerizable group that is polymerized by at least one of active energy rays and heat between the pair of substrates, and applying a voltage between the electrodes.

[0128] (4-2) PSA type LCD element The procedure is the same as in (4) above, except that a liquid crystal composition containing a polymerizable compound is injected or dropped.

[0129] (4-3) SC-PVA mode LCD element A method for producing a liquid crystal display element may be employed in which, after the same procedure as in (4) above, a step of irradiating with ultraviolet light, as described below, is carried out. This method, similar to the production of the PSA-type liquid crystal display element, allows for the production of a liquid crystal display element with excellent response speed with a small amount of light irradiation. The compound having a polymerizable group may be a compound having one or more polymerizable unsaturated groups, such as an acrylate group or a methacrylate group, in the molecule, and its content is preferably 0.1 to 30 parts by mass, more preferably 1 to 20 parts by mass, per 100 parts by mass of all polymer components. The polymerizable group may also be contained in a polymer used in a liquid crystal aligning agent. Examples of such polymers include polymers obtained by reacting a diamine component containing a diamine having the photopolymerizable group at its terminal.

[0130] Step (4-4): Step of irradiating with ultraviolet light The liquid crystal cell is irradiated with light while a voltage is applied between the conductive films of the pair of substrates obtained in (4-2) or (4-3) above. The voltage applied here can be, for example, 5 to 50 V DC or AC. The light to be irradiated can be, for example, ultraviolet light and visible light containing light with a wavelength of 150 to 800 nm, but ultraviolet light containing light with a wavelength of 300 to 400 nm is preferred. The light source for the irradiation light can be, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, or an excimer laser. The light irradiation dose is preferably 1,000 to 200,000 J / m 2 and more preferably 1,000 to 100,000 J / m 2 is.

[0131] A liquid crystal display element can be obtained by attaching a polarizing plate to the outer surface of the liquid crystal cell as needed. Examples of the polarizing plate to be attached to the outer surface of the liquid crystal cell include a polarizing film called an "H film" made by stretching and aligning polyvinyl alcohol and absorbing iodine, sandwiched between cellulose acetate protective films, and a polarizing plate made of the H film itself.

[0132] The liquid crystal display element of the present invention can be effectively applied to various devices, and can be used in various display devices such as watches, portable games, word processors, notebook computers, car navigation systems, camcorders, PDAs, digital cameras, mobile phones, smartphones, various monitors, liquid crystal televisions, information displays, etc. In addition, the polymer composition contained in the liquid crystal aligning agent can be used as a liquid crystal alignment film for a retardation film, a liquid crystal alignment film for a scanning antenna or a liquid crystal array antenna, or a liquid crystal alignment film for a transmissive / scattering liquid crystal dimming element, or for other applications such as a protective film for a color filter, a gate insulating film for a flexible display, or a substrate material. [Example]

[0133] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. The abbreviations for compounds and solvents are as follows. (organic solvent) NMP: N-methyl-2-pyrrolidone GBL: gamma-butyrolactone BCS: Ethylene glycol monobutyl ether (diamine) DA-1 to DA-8: Compounds represented by the following structural formulas (DA-1) to (DA-8), respectively. (acid dianhydride) CA-1 to CA-5: Compounds represented by the following structural formulas (CA-1) to (CA-5), respectively (Diisocyanate) DI-1: 4,4'-diphenylmethane diisocyanate (diol) EG-1: Tetraethylene glycol EG-2: Polyethylene Glycol 400 (Tokyo Chemical Industry Co., Ltd.) EG-3: Polyethylene Glycol 600 (Tokyo Chemical Industry Co., Ltd.)

[0134] [ka]

[0135] [ka]

[0136] <Viscosity> 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 cone rotor TE-1 (1°34', R24), and a temperature of 25°C. <Measurement of imidization rate of polyimide> The imidization ratio of the polyimide in the synthesis examples was measured as follows. 30 mg of polyimide powder was placed in an NMR (nuclear magnetic resonance) sample tube (NMR sampling tube standard, φ5 (Kusano Scientific Co., Ltd.)), and deuterated dimethyl sulfoxide (DMSO-d6, 0.05 wt% TMS (tetramethylsilane) mixture) (0.53 mL) was added. Complete dissolution was achieved by ultrasonic irradiation. This solution was measured by proton NMR at 500 MHz using an NMR spectrometer (JNW-ECA500) (JEOL Datum Co., Ltd.). The proton derived from the structure that remained unchanged before and after imidization was determined as the reference proton. The imidization ratio was calculated using the integrated peak value of this proton and the integrated peak value of the proton derived from the NH group of the amic acid, which appeared around 9.5 to 10.0 ppm, according to the following equation: Imidization rate (%) = (1 - α x / y) x 100 In the above formula, x is the integrated value of the proton peak derived from the NH group of the amic acid, y is the integrated value of the peak of the reference proton, and α is the ratio of the number of reference protons to one NH group proton of the amic acid in the case of polyamic acid (imidization rate 0%).

[0137] [Polymer synthesis] (Synthesis Example 1) EG-1 (0.32 g, 1.65 mmol) was weighed into a 50 mL recovery flask equipped with a stirrer and a nitrogen inlet tube, and NMP (1.3 g) was added. The mixture was stirred and dissolved under nitrogen. DI-1 (0.83 g, 3.30 mmol) and NMP (3.30 g) were added to the resulting solution while cooling with water and stirring, and the mixture was stirred at 70°C under a nitrogen atmosphere for 3 hours. Subsequently, NMP (22.0 g) was added to dilute the mixture, and the mixture was stirred for an additional 30 minutes. Subsequently, a solution of DA-6 (1.85 g, 9.35 mmol) in NMP (5.00 g) was added, followed by NMP (2.50 g), and the mixture was stirred at 23°C under a nitrogen atmosphere for 2 hours. Subsequently, 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 polymer (polymer-1) (viscosity: 32 mPa·s).

[0138] (Synthesis Examples 2 to 5) Solutions of polyurethane amic acids (polymer-2) to (polymer-5) shown in Table 1 were obtained using the diamines, acid dianhydrides, diisocyanates, and diols shown in Table 1 below, respectively, in the same manner as in Synthesis Example 1. In Table 1, the numbers shown below under the compound names represent the mass of each compound used in the synthesis, and the numbers in parentheses represent the amount (parts by mole) of each compound used relative to 100 parts by mole of the total amount of the diamine component and diol component.

[0139] [Table 1]

[0140] (Synthesis Example 6) EG-2 (0.34 g, 0.84 mmol) and NMP (1.9 g) were weighed into a 100 mL recovery flask equipped with a stirrer and a nitrogen inlet tube and dissolved by stirring while supplying nitrogen. DI-1 (0.42 g, 1.68 mmol) and NMP (2.24 g) were added to this solution while stirring under water cooling, and the mixture was stirred at 70 °C under a nitrogen atmosphere for 3 hours. Subsequently, NMP (20.0 g) and GBL (20.0 g) were added to dilute the mixture and the mixture was stirred for an additional 30 minutes. A solution of DA-5 (5.77 g, 20.2 mmol) in NMP (10.9 g) and GBL (15.1 g) was then added and the mixture was stirred at 23 °C under a nitrogen atmosphere for 2 hours. Subsequently, 3.67 g (18.7 mmol) of CA-2, 2.25 g of NMP, and 2.25 g of GBL were added, and the mixture was stirred for 2 hours at 23°C under a nitrogen atmosphere. After the reaction was completed, 8.50 g of NMP and 8.50 g of GBL were added to adjust the solution concentration, and the mixture was stirred for 1 hour to obtain a solution of polymer (polymer-6) (viscosity: 112 mPa·s).

[0141] (Synthesis Examples 7 to 14) Solutions of polymers (polymer-7) to (polymer-14) shown in Table 2 were obtained using the diamines, acid dianhydrides, diisocyanates, and diols shown in Table 2 below, respectively, in the same manner as in Synthesis Example 6. In Table 2, the numbers shown below under the compound names represent the mass of each compound used in the synthesis, and the numbers in parentheses represent the amount (parts by mole) of each compound used relative to 100 parts by mole of the total amount of the diamine component and diol component.

[0142] [Table 2]

[0143] (Synthesis Example 15) DA-5 (3.16 g, 11.0 mmol) and NMP (28.5 g) were weighed into a 100 mL recovery flask equipped with a stirrer and nitrogen inlet tube and dissolved by stirring under nitrogen. CA-2 (1.67 g, 8.52 mmol) and NMP (6.98 g) were added to the solution while stirring under water cooling and stirring 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 stirred at 50 °C for 3 hours under a nitrogen atmosphere to obtain a solution of polymer (polymer-15) (viscosity: 178 mPa s).

[0144] (Synthesis Example 16) DA-5 (7.45 g, 26.0 mmol), NMP (33.5 g), and GBL (33.5 g) were weighed into a 100 mL recovery flask equipped with a stirrer and nitrogen inlet tube and dissolved by stirring under nitrogen. CA-2 (4.74 g, 24.2 mmol), NMP (11.2 g), and GBL (11.2 g) were added to this diamine solution while stirring under water cooling. The mixture was stirred under a nitrogen atmosphere for 2 hours to obtain a solution of polyamic acid (PAA-1) (viscosity: 182 mPa s).

[0145] (Synthesis Example 17) DA-5 (7.45 g, 26.0 mmol), NMP (33.5 g), and GBL (33.5 g) were weighed into a 100 mL recovery flask equipped with a stirrer and nitrogen inlet tube and dissolved by stirring under nitrogen. CA-3 (5.42 g, 24.2 mmol), NMP (13.8 g), and GBL (13.8 g) were added to this diamine solution while stirring under water cooling. The mixture was stirred under a nitrogen atmosphere for 2 hours to obtain a solution of polyamic acid (PAA-2) (viscosity: 167 mPa s).

[0146] (Synthesis Example 18) 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 recovery flask equipped with a stirrer and nitrogen inlet tube and dissolved under stirring with nitrogen. CA-1 (9.40 g, 47.5 mmol) and NMP (32.4 g) were added to the diamine solution while stirring under water cooling and stirred at 50 °C for 2 h under a nitrogen atmosphere. CA-2 (4.61 g, 23.5 mmol) and NMP (16.6 g) were then added and stirred at 23 °C for 2 h under a nitrogen atmosphere to obtain a solution of polyamic acid (PAA-3) (viscosity: 1230 mPa s). The solution (100 g) of polyamic acid (PAA-3) obtained above was weighed into a 200 mL Erlenmeyer flask containing a stirrer, and di-tert-butyl dicarbonate (hereinafter also referred to as BocO) (1.32 g, 6.05 mmol), which was a terminal modifier, was added. The mixture was stirred at 40°C for 15 hours to obtain a solution of terminal-modified polyamic acid (PAA-3-1). A 200 mL Erlenmeyer flask containing a stirrer was charged with 100 g of the above (PAA-3-1) solution, and NMP (66.7 g), acetic anhydride (12.9 g), and pyridine (4.27 g) were added. The mixture was stirred at room temperature for 30 minutes, and then reacted at 60°C for 4 hours. The reaction solution was poured into methanol (640 g), and the resulting precipitate was filtered off. The precipitate was washed with methanol and then dried under reduced pressure at 80°C to obtain a polyimide powder (imidization rate: 91%). Furthermore, this polyimide powder (9.60 g) was dispensed into a 100 mL Erlenmeyer flask containing a stirrer, and NMP (70.4 g) was added. The mixture was stirred at 70°C for 24 hours to dissolve the polyimide, thereby obtaining a solution of polyimide (SPI-1).

[0147] (Synthesis Example 19) 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 recovery flask equipped with a stirrer and nitrogen inlet tube and dissolved under stirring with nitrogen. CA-1 (9.40 g, 47.5 mmol) and NMP (37.6 g) were added to the diamine solution while stirring under water cooling and stirred at 50 °C for 2 h under a nitrogen atmosphere. CA-2 (4.65 g, 23.7 mmol) and NMP (18.6 g) were then added and stirred at 23 °C for 2 h under a nitrogen atmosphere to obtain a solution of polyamic acid (PAA-4) (viscosity: 1230 mPa s). The polyamic acid (PAA-4) solution (100 g) obtained above was placed in a 200 mL Erlenmeyer flask equipped with a stir bar, and BocO (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). A 200 mL Erlenmeyer flask containing a stirrer was charged with 100 g of the above (PAA-4-1) solution, and NMP (66.7 g), acetic anhydride (14.2 g), and pyridine (4.70 g) were added. The mixture was stirred at room temperature for 30 minutes, and then reacted at 60°C for 4 hours. The reaction solution was poured into methanol (650 g), and the resulting precipitate was filtered off. The precipitate was washed with methanol and then dried under reduced pressure at 80°C to obtain a polyimide powder (imidization rate: 90%). Furthermore, this polyimide powder (9.60 g) was dispensed into a 100 mL Erlenmeyer flask containing a stirrer, and NMP (70.4 g) was added. The mixture was stirred at 70°C for 24 hours to dissolve the polyimide, thereby obtaining a solution of polyimide (SPI-2).

[0148] (Synthesis Example 20) 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 recovery flask equipped with a stirrer and nitrogen inlet tube and dissolved by stirring under nitrogen. CA-4 (6.19 g, 24.8 mmol) was added to this diamine solution while stirring under water cooling, followed by NMP (10.7 g). The mixture was stirred at 50 °C for 3 h under a nitrogen atmosphere. CA-5 (2.04 g, 6.93 mmol) was then added, followed by NMP (11.6 g). The mixture was stirred at 70 °C for 6 h under a nitrogen atmosphere to obtain a solution of polymer (PAA-5) (viscosity: 495 mPa s).

[0149] [Preparation of liquid crystal alignment agent] Example 1 A solution (6.60 g) of the polymer (polymer-1) obtained in Synthesis Example 1 was weighed into a 50 mL Erlenmeyer flask containing a stirring bar, and NMP (0.06 g), GBL (9.34 g) and BCS (4.00 g) were added thereto, followed by stirring at room temperature for 2 hours to obtain a liquid crystal alignment agent (1). (Examples 2 to 16, Comparative Examples 1 to 4) 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 solutions and solvents used were changed as shown in Table 3.

[0150] [Table 3]

[0151] A method for producing a liquid crystal display element for evaluating the voltage holding ratio will be described below. [Fabrication of liquid crystal display elements] First, a substrate with electrodes was prepared. The substrate was a glass substrate measuring 30mm x 40mm and 1.1mm thick. ITO electrodes with a film thickness of 35nm were formed on the substrate, and the electrodes were in a stripe pattern measuring 40mm in length and 10mm in width. Next, the liquid crystal alignment agent obtained above was filtered through a filter with a pore size of 1.0 μm and then spin-coated onto the prepared substrate with electrodes. After drying on a hot plate at 80°C for 2 minutes, it was baked in an IR oven at 230°C for 20 minutes to form a coating film with a thickness of 100 nm, yielding a substrate with a liquid crystal alignment film. This liquid crystal alignment film was rubbed with a rayon cloth (roller diameter: 120 mm, roller rotation speed: 1000 rpm, movement speed: 20 mm / sec, indentation length: 0.4 mm), then ultrasonically washed in pure water for 1 minute, water droplets removed by air blowing, and then dried at 80°C for 10 minutes to obtain a substrate with a liquid crystal alignment film. Two substrates with this liquid crystal alignment film were prepared. 4 μm diameter spacers (JGC Catalysts and Chemicals, Shinshikyu, SW-D1) were sprayed onto the liquid crystal alignment film surface of one substrate, and then a thermosetting sealant (Mitsui Chemicals, XN-1500T) was printed on top of them. The other substrate was then attached with the rubbing direction reversed and the film surfaces facing each other. The sealant was then cured to create an empty cell. Negative-type liquid crystal MLC-7026 (Merck) was injected into this empty cell by vacuum injection, and the injection port was sealed to obtain a liquid crystal cell. The resulting liquid crystal cell was then heated at 120°C for 1 hour and left at 23°C overnight before being used for various evaluations.

[0152] <Voltage holding ratio> A voltage of 1V was applied to the above liquid crystal display element at 60°C for 60 μs, and the voltage was measured after 16.67 msec to evaluate how long the voltage was maintained as the voltage retention ratio. The results are shown in Table 4. The higher the voltage retention ratio, the better the performance. It is known that an increase in the voltage retention ratio, which is one of the electrical properties of liquid crystal display elements, makes line burn-in, a display defect of liquid crystal display elements, less likely to occur.

[0153] [Table 4]

[0154] <Evaluation of whitening properties> 0.1 mL of each of the liquid crystal alignment agents (1) to (20) was dropped onto a chromium-deposited substrate and allowed to stand in an environment at a temperature of 23°C and a humidity of 70%. After a predetermined time had passed since dropping, the edges and center of the droplets were observed under an optical microscope to confirm whether they had whitened. The results are shown in Table 5. In this evaluation, whitening is defined as the phenomenon in which the droplets become cloudy and white due to precipitation or aggregation of dissolved polyimide. A state in which the droplets were not whitened at all was evaluated as "Good", a state in which only the edges of the droplets were whitened was evaluated as "Good", and a state in which the entire surface of the droplets was whitened was evaluated as "Poor". The longer the time it took for the droplets to show "Good", the better the result.

[0155] [Table 5]

[0156] Normally, when a negative liquid crystal is used as a liquid crystal material, the voltage holding ratio decreases and display defects (line burn-in) tend to occur. However, by using the liquid crystal alignment agent 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)) was obtained even when a negative liquid crystal was used as the liquid crystal material. Furthermore, the liquid crystal alignment agent described in the examples of the present invention is less likely to undergo the moisture absorption whitening phenomenon, so that foreign matter and clogging are less likely to occur when obtaining a coating film, and the obtained film has less surface roughness, and furthermore, can exhibit the original properties of a liquid crystal alignment film even after drying or heating.

[0157] The entire contents of the specification, claims, drawings and abstract of Japanese Patent Application No. 2020-192467, filed on November 19, 2020, are hereby incorporated by reference as the disclosure of the specification of the present invention.

Claims

1. A liquid crystal aligning agent comprising 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 which is an imidized product of the copolymer, At least one of the repeating units represented by the following formula (a), the repeating units represented by the following formula (1), and the repeating units represented by the following formula (2) has a divalent organic group represented by the following formula (EG), and the content of the repeating units represented by the formula (a) is 2 to 98 mol % of all the repeating units constituting the polymer (A), the content of the repeating units represented by the formula (1) is 1 to 49 mol % of all the repeating units constituting the polymer (A), and the content of the repeating units represented by the formula (2) is 1 to 49 mol % of all the repeating units constituting the polymer (A). 【Chemical 1】 (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.) 【Chemistry 2】 (A １ is a divalent organic group, and A １’ is a divalent organic group derived from diamine, and C １ and C １’ are each independently a hydrogen atom or a monovalent organic group. 【Chemistry 3】 (A ２ is a divalent organic group, and A ２’ is a divalent organic group obtained by removing hydrogen atoms contained in two hydroxy groups from an organic diol. 【Chemistry 4】 (R represents a hydrogen atom or a methyl group, and n is an integer of 3 to 40.)

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

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

4. Y in the above formula (a) and A in the above formula (1) １’ each independently represents 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, ｏ ), 4-(2-(methylamino)ethyl)aniline, 4-(2-aminoethyl)aniline, diamines having a group "-N(D)-" (D represents a protecting group which is eliminated by heating and replaced with a hydrogen atom), and ＥＧ The liquid crystal aligning agent according to any one of claims 1 to 3, wherein the divalent organic group is derived from a diamine selected from the group consisting of diamines represented by the formula (I). 【Chemistry 5】 (Ar represents a divalent benzene ring, a biphenyl structure, or a naphthalene ring. Two Ars may be the same or different, and any hydrogen atom in the benzene ring, biphenyl structure, or naphthalene ring may be replaced with a monovalent group. p is an integer of 0 or 1. Q ２ Ha-(CH ２ ) ｎ -(n is an integer of 2 to 18), or the -(CH ２ ) ｎ -of-CH ２ represents a group in which at least a part of - has been replaced with -O-, -C(=O)- or -O-C(=O)-. ２ When has an ether bond, Q ２ The total number of ether bonds contained in 【Chemistry 6】 (Multiple m's may be the same or different.) 【Chemistry 7】 (Each Ar independently represents a divalent aromatic group or a fused ring group, and may be the same or different. One or more hydrogen atoms on the aromatic group or the fused ring group may be substituted with a monovalent group. n represents an integer of 3 to 40.)

5. A in the above formula (1) １ and A in the above formula (2) ２ are each independently (i) a divalent organic group derived from an aromatic diisocyanate, in which R is an organic group having 6 to 30 carbon atoms and having at least one benzene ring in the diisocyanate structure (O=C=N-R-N=C=O), or (ii) a divalent organic group derived from an aliphatic diisocyanate, in which R is an organic group having 4 to 30 carbon atoms and having an aliphatic group and not having an aromatic group in the diisocyanate structure (O=C=N-R-N=C=O), the liquid crystal aligning agent according to any one of claims 1 to 4.

6. A in the above formula (1) １ and A in the above formula (2) ２ The liquid crystal aligning agent according to any one of claims 1 to 5, wherein each independently represents a divalent organic group derived from a diisocyanate selected from the following: 【Chemistry 8】

7. The liquid crystal aligning agent according to any one of claims 1 to 6, 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 aligning agent according to claim 7, wherein the diol containing the divalent organic group represented by the formula (EG) is a diol in which hydrogen atoms are bonded to both ends of the divalent organic group represented by the formula (EG).

9. The liquid crystal aligning agent according to any one of claims 1 to 8, wherein X in the (a) is a tetravalent organic group derived from an acyclic aliphatic tetracarboxylic acid dianhydride or a derivative thereof, a tetravalent organic group derived from an alicyclic tetracarboxylic acid dianhydride or a derivative thereof, or a tetravalent organic group derived from an aromatic tetracarboxylic acid dianhydride or a derivative thereof.

10. The liquid crystal aligning agent according to any one of claims 1 to 9, wherein X in (a) is a tetravalent organic group derived from a tetracarboxylic dianhydride represented by formula (t) or a derivative thereof. 【Chemistry 9】 X in the formula １ is a structure selected from the following formulae (X1-1) to (X1-25), where * represents a bond. 【Chemistry 10】 【Chemistry 11】 【Chemistry 12】 【Chemistry 13】 (In formulas (X1-1) to (X1-4), R １ ~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 and containing a fluorine atom, or a phenyl group. * represents a bond. In formulae (X1-24) and (X1-25), j and k are integers of 0 or 1, and A １ and A ２ each independently represents a single bond, —O—, —CO—, —COO—, phenylene, a sulfonyl group, or an amide group. ２ may be the same or different.)

11. The liquid crystal aligning agent according to any one of claims 1 to 10, further comprising a component (B). Component (B): at least one polymer (B) selected from the group consisting of polyimide precursors and imidized polymers thereof, which is different from polymer (A).

12. A liquid crystal alignment film formed by using the liquid crystal aligning agent according to any one of claims 1 to 11.

13. A liquid crystal display device comprising the liquid crystal alignment film according to claim 12.

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