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

Abstract

Provided is a liquid crystal alignment agent characterized by containing at least one polymer (A), which is selected from the group consisting of: polyimide precursors having a repeating unit (a1) represented by formula (1); and polyimides that are imidized products of the polyimide precursors. (1) In formula (1), X1represents a tetravalent organic base. Y1 is represented by formula (H) and is a divalent organic base having three or more benzene rings. (H) In formula (H), A represents a C4-C10 alkylene group.　Ar1 and Ar1' each independently represent a benzene ring, a biphenyl structure or a naphthalene ring. An arbitrary hydrogen atom on the Ar1 ring and Ar1' ring may be substituted with a monovalent group.

Description

[Technical Field]

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

[0002] Liquid crystal display devices have been widely used as display units for personal computers, smartphones, mobile phones, television receivers, etc. Liquid crystal display devices include, for example, a liquid crystal layer sandwiched between an element substrate and a color filter substrate, pixel electrodes and a common electrode that apply an electric field to the liquid crystal layer, an alignment film that controls the alignment of liquid crystal molecules in the liquid crystal layer, and thin film transistors (TFTs) that switch electric signals supplied to the pixel electrodes. Known methods for driving liquid crystal molecules include vertical electric field methods such as the TN method and the VA method, and horizontal electric field methods such as the IPS (In Plane Switching) method and the FFS (Fringe Field Switching) method.

[0003] Currently, the most widely used liquid crystal alignment films in industry are prepared by rubbing the surface of a film made of polyamic acid and / or imidized polyimide formed on an electrode substrate in one direction with a cloth made of cotton, nylon, polyester, or the like. Rubbing is a simple, productive, and industrially useful method. However, as liquid crystal display devices become increasingly sophisticated, precise, and large, various problems have emerged, including scratches on the alignment film surface, dust generation, mechanical force and static electricity, and unevenness within the alignment-treated surface. As an alternative to rubbing, a photoalignment method has been proposed, in which liquid crystal alignment ability is imparted by irradiating the film with polarized radiation. Photoalignment methods utilizing photoisomerization, photocrosslinking, and photodecomposition have been proposed (see, for example, Non-Patent Document 1, Patent Document 1, and Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 9-297313 [Patent Document 2] Japanese Patent Application Laid-Open No. 2004-206091 [Non-patent literature]

[0005] [Non-Patent Document 1] "Liquid Crystal Photo-Alignment Film" Kidowaki, Ichimura, Functional Materials, November 1997, Vol. 17, No. 11, pp. 13-22 Summary of the Invention [Problem to be solved by the invention]

[0006] Liquid crystal alignment films used in IPS and FFS drive liquid crystal display elements require a high alignment control force to suppress image retention (hereinafter referred to as AC image retention) that occurs during long-term AC drive. Furthermore, when alignment processing is performed using a photo-alignment method, the amount of light irradiation is a factor that affects energy costs and production speed, so it is preferable to be able to perform alignment processing with a small amount of light irradiation. However, the inventors' investigations revealed that the range of light exposure required for achieving liquid crystal alignment with a small amount of light exposure is narrow, resulting in a liquid crystal alignment film with small variations (non-uniformity) in the twist angle of the liquid crystal within the liquid crystal alignment film plane. Therefore, when attempting to increase the screen size of a liquid crystal display element, the liquid crystal alignment may become incomplete in part of the resulting liquid crystal alignment film, which may cause variations in brightness within the screen when an image is displayed for a long period of time, resulting in a deterioration in display quality.

[0007] Therefore, an object of the present invention is to provide a liquid crystal aligning agent that can efficiently obtain a high-quality liquid crystal alignment film by expanding the range of light irradiation dose that can obtain a liquid crystal alignment film with small variation (non-uniformity) in the twist angle of the liquid crystal within the liquid crystal alignment film plane, a liquid crystal alignment film obtained from the liquid crystal aligning agent, and a liquid crystal display element using the liquid crystal alignment film.Another object of the present invention is to provide a liquid crystal aligning agent that can efficiently obtain a high-quality liquid crystal alignment film by expanding the range of light irradiation dose that can obtain a liquid crystal alignment film that can suppress AC afterimage, a liquid crystal alignment film obtained from the liquid crystal aligning agent, and a liquid crystal display element using the liquid crystal alignment film. [Means for solving the problem]

[0008] The present inventors have conducted extensive research and found that the above-mentioned problems can be solved by using a liquid crystal aligning agent containing a specific component, and have thus completed the present invention. Specifically, the present invention is summarized as follows.

[0009] A liquid crystal aligning agent characterized by containing at least one polymer (A) selected from the group consisting of polyimide precursors having a repeating unit (a1) represented by the following formula (1) and polyimides which are imidized products of the polyimide precursors:

[0010] [ka] (In formula (1), X1 represents a tetravalent organic group. Y1 is represented by the following formula (H) and is a divalent organic group having three or more benzene rings. R and Z each independently represent a hydrogen atom or a monovalent organic group.) [ka] (In formula (H), L1 and L 1’ each independently represents a single bond, -O-, -S-, -C(=O)-, -OC(=O)-, or -C(=O)-NR- (wherein R represents a hydrogen atom or a monovalent organic group). A represents an alkylene group having 4 to 10 carbon atoms. Ar1, and Ar 1’each independently represents a benzene ring, a biphenyl structure, or a naphthalene ring. 1’ Any hydrogen atom on the ring may be substituted with a monovalent group. Throughout this specification, examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms, and * represents a bond. [Effects of the Invention]

[0011] According to the present invention, a liquid crystal aligning agent capable of efficiently obtaining a high-quality liquid crystal alignment film by expanding the range of light irradiation dose that can obtain a liquid crystal alignment film with small variation (non-uniformity) in the twist angle of the liquid crystal within the liquid crystal alignment film plane, a liquid crystal alignment film obtained from the liquid crystal aligning agent, and a liquid crystal display element using the liquid crystal alignment film are obtained.Furthermore, a liquid crystal aligning agent capable of efficiently obtaining a high-quality liquid crystal alignment film by expanding the range of light irradiation dose that can obtain a liquid crystal alignment film that can suppress AC afterimage, a liquid crystal alignment film obtained from the liquid crystal aligning agent, and a liquid crystal display element using the liquid crystal alignment film are obtained. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic cross-sectional view showing an example of a horizontal electric field liquid crystal display element of the present invention. [Figure 2] FIG. 10 is a schematic cross-sectional view showing another example of the in-plane switching liquid crystal display element of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] <Polymer (A)> The liquid crystal aligning agent of the present invention contains at least one polymer (A) selected from the group consisting of polyimide precursors having a repeating unit (a1) represented by the following formula (1) and polyimides which are imidized products of the polyimide precursors. The polymer (A) may be composed of one type or two or more types:

[0014] [ka] (In formula (1), X1 represents a tetravalent organic group. Y1 is represented by the following formula (H) and is a divalent organic group having three or more benzene rings. R and Z each independently represent a hydrogen atom or a monovalent organic group.)

[0015] The polymer (A) more preferably has a divalent organic group represented by the above formula (H) in the main chain direction of the polymer (A), and the polymer (A) more preferably has a benzene ring contained in Y1 in the main chain direction of the polymer (A). The main chain of a polymer refers to the part of the polymer that consists of the longest chain of atoms. The phrase "polymer (A) has a divalent organic group represented by formula (H) in the main chain direction of polymer (A)" means that the longest chain of atoms in the divalent organic group represented by formula (H) constitutes the main chain of polymer (A). In other words, the phrase "polymer (A) has a divalent organic group represented by formula (H) in the main chain direction of polymer (A)" means that both ends of the longest chain of atoms in the divalent organic group represented by formula (H) are bonded to the two nitrogen atoms bonded to Y1 in formula (1), respectively. It also means that at least two carbon atoms of each of all the benzene rings contained in Y1 constitute the main chain of the polymer (A).

[0016] Here, the benzene ring in the "divalent organic group having three or more benzene rings" includes a benzene ring constituting a fused ring. The number of benzene rings in formula (H) is counted as follows: The naphthalene ring has two benzene rings. The biphenyl structure has two benzene rings. The number of benzene rings in Y1 is not particularly limited as long as it is 3 or more, but may be, for example, 3 to 8 or 3 to 6. From the viewpoint of suitably obtaining the effects of the present invention, it may also be 4 to 6.

[0017] [ka] (In formula (H), L1 and L 1’ each independently represents a single bond, -O-, -S-, -C(=O)-, -OC(=O)-, or -C(=O)-NR- (R represents a hydrogen atom or a monovalent organic group). A represents an alkylene group having 4 to 10 carbon atoms, more preferably an alkylene group having 4, 6, 8, or 10 carbon atoms, and even more preferably an alkylene group having 4 or 6 carbon atoms. Ar1, and Ar 1’ each independently represents a benzene ring, a biphenyl structure, or a naphthalene ring. 1’ Any hydrogen atom on the ring may be substituted with a monovalent group.

[0018] The above L1 and L 1’ Examples of the monovalent organic group for R in the group "-C(=O)-NR-" in the formula include an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, an alkenyl group having 2 to 3 carbon atoms, an acyl group having 2 to 3 carbon atoms, an alkylsilyl group having 1 to 3 carbon atoms, an alkoxysilyl group having 1 to 3 carbon atoms, a tert-butoxycarbonyl group, and monovalent organic groups in which some of the hydrogen atoms in these groups have been substituted with at least one of a halogen atom and a hydroxy group.

[0019] Ar1 and Ar 1’ Examples of the monovalent group that is a substituent for any hydrogen atom on the ring include monovalent groups such as a halogen atom, an alkyl group having 1 to 3 carbon atoms, an alkyl group having 1 to 3 carbon atoms in which at least a portion of the hydrogen atoms is substituted with at least one of the above-mentioned halogen atoms and hydroxy groups; an alkoxy group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms in which at least a portion of the hydrogen atoms is substituted with at least one of the above-mentioned halogen atoms and hydroxy groups; an alkenyl group having 2 to 3 carbon atoms; an acyl group having 2 to 3 carbon atoms; an alkylsilyl group having 1 to 3 carbon atoms, an alkoxysilyl group having 1 to 3 carbon atoms, a hydroxy group, and a nitrile group.

[0020] The group "-L1-AL" in the above formula (H) 1’A preferred example of -* is the group *-(CH2) n -*”, group “*-O-(CH2) n -O-*”, group “*-C(=O)-(CH2) n -C(=O)-*”, group “*-C(=O)-NR-(CH2) n -O-*”, group “*-OC(=O)-(CH2) n -O-*”, group “*-OC(=O)-(CH2) n -OC(=O)-*”, group “*-OC(=O)-(CH2) n -C(=O)-O-*”, group “*-S-(CH2) n -S-*”, group “*-C(=O)-NR-(CH2) n -NR-C(=O)-*”, group “*-C(=O)-O-(CH2) n -OC(=O)-*”, group “*-O-(CH2) n -*”, group “*-S-(CH2) n -*" or the group "*-NR-C(=O)-(CH2) n -C(=O)-NR-*" (R represents a hydrogen atom or a monovalent organic group, and the monovalent organic group is the same as L1 and L2. 1’ Among these, the above-mentioned group "*-L1-AL 1’ -*" is a group "*-(CH2)" from the viewpoint of suitably obtaining the effects of the present invention. n -*”, group “*-O-(CH2) n -O-*”, group “*-O-(CH2) n -*" is preferred. n is an integer of 4 to 10, preferably an integer of 4, 6, 8, or 10, and more preferably an integer of 4 or 6.

[0021] In order to preferably obtain the effects of the present invention, Y1 in the above formula (1) is preferably a divalent organic group represented by any one of the following formulae (h-1) to (h-4). [ka] (In formulas (h-1) to (h-4), R a1 ~Ra4 represents a monovalent organic group. Specific examples thereof include Ar1 and Ar 1’ Examples of the substituents for the hydrogen atoms on the ring include the structures exemplified above. L is the group "*-L1-AL" in the above formula (H). 1’ -*" (* represents a bond). Each m is independently an integer of 0 to 6, and each n is independently an integer of 0 to 4. a1 ~R a4 When there are multiple, they may be the same or different.)

[0022] The monovalent organic group for R and Z in the above formula (1) is a monovalent hydrocarbon group having 1 to 20 carbon atoms, and the methylene group of the hydrocarbon group is -O-, -S-, -CO-, -COO-, -COS-, -NR 3 -, -CO-NR 3 -, -Si(R 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 the above monovalent hydrocarbon group or the above monovalent group A is replaced with a halogen atom, a hydroxy group, an alkoxy group, a nitro group, an amino group, a mercapto group, a nitroso group, an alkylsilyl group, an alkoxysilyl group, a silanol group, a sulfino group, a phosphino group, a carboxy group, a cyano group, a sulfo group, an acyl group or the like, and a monovalent group having a heterocycle. The monovalent organic groups for R and Z in the above formula (1) 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 suitably achieving the effects of the present invention, R and Z are each independently preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, more preferably a hydrogen atom or a methyl group.

[0023] From the viewpoint of suitably achieving the effects of the present invention, the polymer (A) may further comprise at least one polymer selected from the group consisting of a polyimide precursor having a repeating unit (a2) represented by the following formula (2) and a polyimide which is an imidized product of the polyimide precursor. In other words, the polymer (A) may further comprise at least one of a repeating unit (a2) represented by the following formula (2) and an imidized structure of the repeating unit (a2) represented by the following formula (2). The repeating unit (a2) may be composed of one type or two or more types.

[0024] [ka] (In formula (2), X2 represents a tetravalent organic group. Y2 represents a divalent organic group represented by the following formulas (o-1) to (o-14). R and Z are defined as R and Z in formula (1), respectively.)

[0025] [ka] [ka] (In formulas (o-13) to (o-14), two m's are independent of each other. Any hydrogen atom on the benzene ring, biphenyl structure, or naphthalene ring in formulas (o-1) to (o-14) may be replaced with a monovalent group.)

[0026] Examples of the monovalent group that is a substituent for any hydrogen atom on the benzene ring, biphenyl structure, or naphthalene ring in formulae (o-1) to (o-14) include monovalent groups such as a halogen atom, an alkyl group having 1 to 3 carbon atoms, an alkyl group in which at least a portion of the hydrogen atoms is substituted with at least one of the above-mentioned halogen atoms and hydroxy groups; an alkoxy group having 1 to 3 carbon atoms, an alkoxy group in which at least a portion of the hydrogen atoms is substituted with at least one of the above-mentioned halogen atoms and hydroxy groups; an alkenyl group having 2 to 3 carbon atoms; an acyl group having 2 to 3 carbon atoms; an alkylsilyl group having 1 to 3 carbon atoms, an alkoxysilyl group having 1 to 3 carbon atoms, a hydroxy group, and a nitrile group.

[0027] From the viewpoint of suitably achieving the effects of the present invention, the polymer (A) may further comprise at least one polymer selected from the group consisting of polyimide precursors having at least one selected from the group consisting of repeating units (a2') represented by the following formula (2') and repeating units (a3) ​​represented by the following formula (3), and polyimides which are imidized products of the polyimide precursors. In other words, the polymer (A) may further comprise at least one of repeating units (a2') represented by the following formula (2'), the imidized structure of repeating units (a2) represented by the following formula (2), repeating units (a3) ​​represented by the following formula (3), and the imidized structure of repeating units (a3) ​​represented by the following formula (3). [ka] (In formula (2') and formula (3), X 2’ and X3 represents a tetravalent organic group; Y 2’ represents a divalent organic group represented by the following formula (O2), and Y3 represents a divalent organic group having 6 to 30 carbon atoms and containing the group "-N(D)-" (D represents a carbamate protecting group) in the molecule. R and Z have the same meanings as R and Z in the above formula (1), respectively. [ka] (In formula (O2), m represents an integer of 0 to 2. When m is 0, Ar 2’represents a benzene ring or a naphthalene ring, and when m is 1 or 2, Ar 2’ each independently represents a benzene ring. 2’ Any hydrogen atom on the ring may be replaced with a monovalent group, and examples of the substituent include the structures exemplified as the monovalent group that is a substituent for any hydrogen atom on the benzene ring, biphenyl structure, or naphthalene ring in the above formulas (o-1) to (o-14). 2’ represents a single bond or -O-. 2’ , and Q 2’ If there are multiple Ar 2’ , and Q 2’ may be the same or different.)

[0028] As the divalent organic group represented by the above formula (O2), from the viewpoint of reducing the occurrence of AC afterimages, p-phenylenediamine, m-phenylenediamine, 2,5-diaminotoluene, 2,5-diamino-p-xylene, 1,4-diaminotrimethylbenzene, 1,4-diaminotetramethylbenzene, 1,4-diamino-2,5-methoxybenzene, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 2,2'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-dihydroxy- Preferred is a divalent organic group obtained by removing two amino groups from a diamine selected from the group consisting of 4,4'-diaminobiphenyl, 2,2'-dihydroxy-4,4'-diaminobiphenyl, 3,3'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 3-trifluoromethyl-4,4'-diaminobiphenyl, 2-trifluoromethyl-4,4'-diaminobiphenyl, 3-fluoro-4,4'-diaminobiphenyl, 2-fluoro-4,4'-diaminobiphenyl, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 2,6-diaminonaphthalene, and 1,5-diaminonaphthalene.

[0029] D in the above Y3 represents a carbamate-based protecting group, and examples of the carbamate-based protecting group include a tert-butoxycarbonyl group and a 9-fluorenylmethoxycarbonyl group. Specific examples of Y3 include divalent organic groups represented by the following formula (Dx).

[0030] [ka]

[0031] In formula (Dx), Q5 is a single bond, -(CH2) n -(n is an integer of 1 to 20), or the -(CH2) n Any -CH2- in - can be -O-, -Si(CH3)2-, -COO-, -OCO-, -NQ9-, -NQ9CO-, -CONQ9-, or -NQ9CONQ 10 -, -NQ9COO- or -OCOO-, and Q9 and Q 10 each independently represents a hydrogen atom or a monovalent organic group; Q6 and Q7 each independently represent -H, -NHD, -N(D)2, a group having -NHD, or a group having -N(D)2 (D represents a carbamate protecting group). However, when m=0, Q6 has a carbamate protecting group, and when m=1, at least one of Q5, Q6, and Q7 has a carbamate protecting group in the group. Furthermore, when Q6 and Q7 represent a group other than a hydrogen atom, the number of carbon atoms is preferably 1 to 8. Above Q9 and Q 10 Examples of the monovalent organic group include an alkyl group having 1 to 3 carbon atoms, an alkenyl group having 2 to 3 carbon atoms, an alkynyl group having 2 to 3 carbon atoms, and a monovalent organic group having 1 to 3 carbon atoms and containing a fluorine atom.

[0032] From the viewpoint of reducing AC afterimages, preferred specific examples of Y3 include divalent organic groups represented by any of the following formulae (Y3-1) to (Y3-9): "Boc" represents a tert-butoxycarbonyl group.

[0033] [ka]

[0034] The above X1, X2, and X 2’ and X3 may be a tetravalent organic group derived from an acyclic aliphatic tetracarboxylic acid dianhydride or a derivative thereof, an alicyclic tetracarboxylic acid dianhydride or a derivative thereof, or an aromatic tetracarboxylic acid dianhydride or a derivative thereof. Here, examples of the derivatives of tetracarboxylic dianhydrides include tetracarboxylic dihalides, tetracarboxylic acid dialkyl esters, and tetracarboxylic acid dialkyl ester dihalides. Among these, a tetravalent organic group derived from 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 is more preferred. 2’ Preferred specific examples of X1, X2, and X3 include a tetravalent organic group represented by the following formula (g), a tetravalent organic group represented by any one of the following formulae (X-1) to (X-25), and a tetravalent organic group derived from an aromatic tetracarboxylic dianhydride. 2’ and X3 are more preferably tetravalent organic groups represented by the following formulas (g), (X-1) to (X-5), (X-11), and (X-21) to (X-23), and even more preferably tetravalent organic groups represented by the following formula (g).

[0035] [ka] (In formula (g), R1 to R4 each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, a monovalent organic group having 1 to 6 carbon atoms and containing a fluorine atom, or a phenyl group, and at least one of R1 to R4 represents a group other than a hydrogen atom as defined above.)

[0036] [ka] [ka]

[0037] Specific examples of the alkyl group having 1 to 6 carbon atoms in R1 to R4 in formula (g) include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, and an n-pentyl group. Specific examples of the alkenyl group having 2 to 6 carbon atoms in R1 to R4 include a vinyl group, a propenyl group, and a butynyl group, which may be linear or branched. Specific examples of the alkynyl group having 2 to 6 carbon atoms in R1 to R4 include an ethynyl group, a 1-propynyl group, and a 2-propynyl group. Specific examples of the monovalent organic group having 1 to 6 carbon atoms and containing a fluorine atom in R1 to R4 include a fluoromethyl group, a trifluoromethyl group, a pentafluoroethyl group, and a pentafluoropropyl group. From the viewpoint of high photoreactivity, a more preferred combination of R1 to R4 is that R1 to R4 are hydrogen atoms or methyl groups, and it is preferable that at least one of R1 to R4 is a methyl group, and it is even more preferable that at least two of R1 to R4 are methyl groups. and when R4 is a methyl group, and R2 and R3 are hydrogen atoms.

[0038] Here, the aromatic tetracarboxylic acid dianhydride refers to an acid dianhydride obtained by intramolecular dehydration of a carboxy group bonded to an aromatic ring such as a benzene ring or a naphthalene ring. Specific examples include a tetravalent organic group represented by any one of the following formulae (Xa-1) to (Xa-2) and a tetravalent organic group represented by any one of the following formulae (Xr-1) to (Xr-7).

[0039] [ka] (In formulas (Xa-1) and (Xa-2), x and y each independently represent a single bond, an ether, a carbonyl, an ester, an alkanediyl group having 1 to 10 carbon atoms, 1,4-phenylene, a sulfonyl, or an amide bond. j and k each represent an integer of 0 or 1.)

[0040] [ka]

[0041] The tetravalent organic group represented by the above formula (Xa-1) or (Xa-2) may have a structure represented by any one of the following formulae (Xa-3) to (Xa-19).

[0042] [ka]

[0043] [ka]

[0044] The polymer (A) may be at least one polymer selected from the group consisting of polyimide precursors having a repeating unit (a4) represented by the following formula (4) in addition to the repeating units (a1), (a2), (a2'), and (a3) ​​and polyimides which are imidized products of the polyimide precursors:

[0045] [ka]

[0046] In formula (4), X4 represents a tetravalent organic group, and Y4 represents a divalent organic group other than the divalent organic group represented by formula (H) above, the divalent organic groups represented by formulas (o-1) to (o-14) above, the divalent organic group having 6 to 30 carbon atoms and containing the group "-N(D)- (D represents a carbamate protecting group)" in the molecule, and the divalent organic group represented by formula (O2) above. R and Z are defined as R and Z in formula (1) above, respectively.

[0047] Specific examples of X4 include the above X1, X2, and X 2’ and the tetravalent organic groups exemplified in the description of X3. From the viewpoint of suitably achieving the effects of the present invention, X4 is preferably a tetravalent organic group represented by the above formula (g) or a tetravalent organic group represented by any of the above formulas (X-1) to (X-25), more preferably a tetravalent organic group represented by the above formulas (g), (X-1) to (X-5), (X-11), and (X-21) to (X-23), and even more preferably a tetravalent organic group represented by the above formula (g).

[0048] Y4 represents a divalent organic group represented by the above formula (H), a divalent organic group represented by the above formulas (o-1) to (o-14), a divalent organic group having 6 to 30 carbon atoms and having the above group "-N(D)- (D represents a carbamate protecting group)" in the molecule, and a divalent organic group other than the divalent organic group represented by the above formula (O2) (hereinafter also referred to as other divalent organic group), and examples of such other divalent organic groups include divalent organic groups obtained by removing two amino groups from the following diamines: 4,4'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 3,3'-dimethyl-4,4'-diaminodiphenylmethane; diamines having a photoalignment group such as diamines represented by the following formulas (g-1) to (g-10); diamines having a urea bond such as diamines represented by the following formulas (u-1) to (u-3) (provided that the diamine does not have a carbamate-based protecting group in the molecule); diamines having an amide bond such as diamines represented by the following formulas (u-4) to (u-8) (provided that the diamine does not have a carbamate-based protecting group in the molecule); nitrogen atom-containing heterocycles and groups "* 21 -NR-* 22” (* 21 , and * 22represents a bond bonding to a carbon atom constituting an aromatic ring, provided that the carbon atom does not form a ring with the nitrogen atom to which R is bonded. R represents a hydrogen atom or a monovalent organic group, and the monovalent organic group is bonded to the nitrogen atom at a carbon atom other than the carbonyl carbon. Diamines having at least one nitrogen atom-containing structure (hereinafter also referred to as nitrogen atom-containing structure) selected from the group consisting of amino groups represented by the following formulas: 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol; 2,4-diaminobenzoic acid, 2,5-diaminobenzoic acid, 3,5-diaminobenzoic acid, 4,4'-diaminobiphenyl-3-carboxylic acid, 4,4'-diaminodiphenylmethane-3-carboxylic acid, 4,4'-diaminodiphenylethane-3-carboxylic acid, 4,4'-diamino diamines having a carboxy group such as 4,4'-diaminobiphenyl-3,3'-dicarboxylic acid, 4,4'-diaminobiphenyl-2,2'-dicarboxylic acid, 3,3'-diaminobiphenyl-4,4'-dicarboxylic acid, 3,3'-diaminobiphenyl-2,4'-dicarboxylic acid, 4,4'-diaminodiphenylmethane-3,3'-dicarboxylic acid, 4,4'-diaminodiphenylethane-3,3'-dicarboxylic acid, and 4,4'-diaminodiphenylether-3,3'-dicarboxylic acid; 4-(2-(methylamino) )ethyl)aniline, 4-(2-aminoethyl)aniline, 4,4'-diaminobenzophenone, 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-diaminobenzophenone diamines having a steroid skeleton such as cholestanyloxy-3,5-diaminobenzene, cholestanyloxy-2,4-diaminobenzene, cholestanyl 3,5-diaminobenzoate, cholestanyl 3,5-diaminobenzoate, lanostannyl 3,5-diaminobenzoate, and 3,6-bis(4-aminobenzoyloxy)cholestane; diamines represented by the following formulae (V-1) to (V-6); diamines having a siloxane bond such as 1,3-bis(3-aminopropyl)-tetramethyldisiloxane;Examples of such diamines include those having an oxazoline ring structure represented by the following formulae (Ox-1) to (Ox-2); divalent organic groups obtained by removing two amino groups from diamines such as diamines having radical polymerization initiator functions, such as 1-(4-(2,4-diaminophenoxy)ethoxy)phenyl)-2-hydroxy-2-methylpropanone, 2-(4-(2-hydroxy-2-methylpropanoyl)phenoxy)ethyl-3,5-diaminobenzoate, 4,4'-diaminobenzophenone, and 3,3'-diaminobenzophenone; and groups represented by any of formulae (Y-1) to (Y-167) described in WO2018 / 117239.

[0049] [ka] [ka] [ka]

[0050] (In the above formulas (V-1) to (V-6), X v1 ~X v4 , and X p1 ~X p2 are each independently -(CH2) a - (a is an integer of 1 to 15), -CONH-, -NHCO-, -CO-N(CH3)-, -NH-, -O-, -CHO-, -CH2-OCO-, -COO-, or -OCO-; X v5 represents -O-, -CH2O-, -CH2-OCO-, -COO-, or -OCO-. X a represents a single bond, -O-, -NH-, -O-(CH2) m -O- (m represents an integer of 1 to 6), -C(CH3)2-, -CO-, -(CH2) m - (m represents an integer of 1 to 6), -SO2-, -OC(CH3)2-, -CO-(CH2) m - (m represents an integer of 1 to 6), -NH-(CH2) m - (m represents an integer of 1 to 6), -SO2-(CH2) m-(m represents an integer of 1 to 6), -CONH-(CH2) m -(m represents an integer of 1 to 6), -CONH-(CH2) m -NHCO- (m represents an integer of 1 to 6), -COO-(CH2) m -OCO- (m represents an integer of 1 to 6), -CONH-, -NH-(CH2) m -NH- (wherein m represents an integer of 1 to 6), or -SO2-(CH2) m -SO2- (m represents an integer of 1 to 6), and R v1 ~R v4 , and 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.

[0051] [ka]

[0052] Examples of the nitrogen atom-containing heterocycle 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, and acridine are preferred.

[0053] The above group "* 21 -NR-* 22 " The monovalent organic group for R represents a monovalent hydrocarbon group having 1 to 10 carbon atoms, a monovalent group formed by inserting -O- or -C(=O)- into a portion of the carbon-carbon bond of the hydrocarbon group, or a monovalent organic group in which some of the hydrogen atoms in the hydrocarbon group or monovalent group have been substituted with halogen atoms or hydroxy groups. R is preferably a hydrogen atom or a methyl group.

[0054] Specific examples of diamines having a nitrogen atom-containing structure include 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, 1,4-bis-(4-aminophenyl)-piperazine, 3,6-diaminoacridine, compounds represented by the following formulae (Dp-1) to (Dp-8), and compounds represented by the following formulae (z-1) to (z-13). [ka] [ka] [ka]

[0055] From the viewpoint of suitably achieving the effects of the present invention, the other divalent organic group is preferably a divalent organic group that does not have a side chain structure having 4 or more carbon atoms. Examples of the divalent organic group that does not have a side chain structure having 4 or more carbon atoms include, from the other diamines mentioned above, 2-(2,4-diaminophenoxy)ethyl methacrylate, 2,4-diamino-N,N-diallylaniline, the diamines having a steroid skeleton mentioned above, diamines represented by the formulas (V-1) to (V-6) mentioned above, 1-(4- Examples of the diamine include a diamine selected from the group consisting of diamines excluding (2-(2,4-diaminophenoxy)ethoxy)phenyl)-2-hydroxy-2-methylpropanone, 2-(4-(2-hydroxy-2-methylpropanoyl)phenoxy)ethyl-3,5-diaminobenzoate, N-phenyl-3,6-diaminocarbazole, and diamines represented by (z-4) and (z-6), and a divalent organic group obtained by removing two amino groups from the diamine.

[0056] From the viewpoint of optimally achieving the effects of the present invention, the polymer (A) preferably contains the repeating unit (a1) and the imidized structure of the repeating unit (a1) in total of 5 to 100 mol %, and more preferably 10 to 100 mol %, of all repeating units. Note that this total includes cases where either the repeating unit (a1) or the imidized structure of the repeating unit (a1) is 0 mol %. Hereinafter, the term "total" also includes cases where one or more of the constituent elements are 0 mol %. When the polymer (A) contains a repeating unit other than the repeating unit (a1) and the imidized structure of the repeating unit (a1), the polymer (A) preferably contains the repeating unit (a1) and the imidized structure of the repeating unit (a1) in total at 95 mol % or less, more preferably at 90 mol % or less, and even more preferably at 80 mol % or less of all repeating units.

[0057] To obtain the effects of the present invention, the polymer (A) preferably contains the repeating unit (a2) and the imidized structure of the repeating unit (a2) in an amount of 5 mol % or more, more preferably 10 mol % or more, and even more preferably 20 mol % or more of the total repeating units, with the upper limit being preferably 90 mol %, more preferably 85 mol %.

[0058] From the viewpoint of optimally achieving the effects of the present invention, the polymer (A) preferably contains repeating units (a1) and (a2) and their imidized structures in a total amount of 10 mol % or more, more preferably 20 mol % or more, of all repeating units. When the polymer (A) contains repeating units other than repeating units (a1) and (a2) and their imidized structures, the upper limit of the total amount of repeating units (a1) and (a2) and their imidized structures is preferably 95 mol %, more preferably 90 mol %.

[0059] When the polymer (A) contains at least one of the repeating unit (a2') and the imidized structure of the repeating unit (a2'), from the viewpoint of optimally achieving the effects of the present invention, the polymer (A) preferably contains the repeating unit (a2') and the imidized structure of the repeating unit (a2') in total at 1 to 50 mol %, more preferably 1 to 40 mol %, and even more preferably 1 to 30 mol % of all repeating units. When the polymer (A) contains at least one of the repeating unit (a1) and the imidized structure thereof and at least one of the repeating unit (a2') and the imidized structure thereof, the lower limit of the total of the repeating unit (a1) and the repeating unit (a2') and their imidized structures is preferably 5 mol %, more preferably 10 mol %. To achieve the effects of the present invention, the polymer (A) preferably contains at least one of the repeating unit (a1) and its imidized structure, the repeating unit (a2) and its imidized structure, and the repeating unit (a2') and its imidized structure, and the total of the repeating units (a1), (a2), (a2'), and (a2') and their imidized structures is preferably 30 mol % or more, more preferably 40 mol % or more, of the total repeating units. When the polymer (A) contains a repeating unit other than the repeating unit (a1), (a2), (a2'), and (a2') and their imidized structures, the upper limit of the total of the repeating units (a1), (a2), (a2'), and (a2') and their imidized structures is preferably 95 mol %, more preferably 90 mol %.

[0060] When the polymer (A) contains at least one of the repeating unit (a3) ​​and the imidized structure of the repeating unit (a3), from the viewpoint of suitably achieving the effects of the present invention, the polymer (A) preferably contains the repeating unit (a3) ​​and the imidized structure of the repeating unit (a3) ​​in total in an amount of 1 to 40 mol %, more preferably 1 to 30 mol %, and even more preferably 1 to 25 mol % of all repeating units.

[0061] The polymer (A) may contain at least one of the repeating unit (a2') and the repeating unit (a3) ​​and imidized structures thereof.

[0062] <Polymer (B)> The liquid crystal aligning agent of the present invention may contain, in addition to the polymer (A), the repeating unit (a1) and a polymer (B) that does not have the imidized structure thereof in the molecule. The polymer (B) may be composed of one type or two or more types. From the viewpoint of suitably achieving the effects of the present invention, examples of the polymer (B) include a polymer having a repeating unit represented by the following formula (5) or an imidized structure thereof. The repeating unit or the imidized structure thereof that constitutes the polymer (B) may be one type, or two or more types. [ka] (In formula (5), X5 is a tetravalent organic group, and Y5 is a divalent organic group. R and Z have the same meanings as R and Z in formula (1), respectively.)

[0063] Examples of the tetravalent organic group for X5 include 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, and specific examples include the tetravalent organic groups exemplified for X1. From the viewpoint of optimally achieving the effects of the present invention, the 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, in particular from the viewpoint of highly enhancing liquid crystal alignment properties. More preferably, X5 is a tetravalent organic group represented by the above formula (g), a tetravalent organic group represented by any one of the above formulae (X-1) to (X-25), a tetravalent organic group represented by the above formulae (Xa-1) to (Xa-2), or a tetravalent organic group represented by the above formulae (Xr-1) to (Xr-7) (these are also collectively referred to as specific tetravalent organic groups).

[0064] In order to obtain the effects of the present invention, the polymer (B) preferably contains repeating units represented by formula (5), in which X5 is the specific tetravalent organic group, or imidized structures thereof, in an amount of 5 mol % or more, and more preferably 10 mol % or more, of all repeating units contained in the polymer (B).

[0065] Examples of the divalent organic group for Y5 include the divalent organic groups exemplified for Y4. From the viewpoint of reducing afterimages due to residual DC, it is preferable that the polymer (B) is a polymer containing a repeating unit represented by formula (5) in which Y5 is a divalent organic group (collectively referred to as a specific divalent organic group) obtained by removing two amino groups from the diamine having a urea bond, the diamine having an amide bond, the diamine having a nitrogen atom-containing structure, 2,4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4,6-diaminoresorcinol, the diamine having a carboxy group, 4,4'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, p-phenylenediamine, and m-phenylenediamine, or an imidized structure thereof.

[0066] From the viewpoint of increasing transmittance, the polymer (B) preferably has two or more repeating units represented by the above formula (5) or imidized structures thereof, and includes at least one of a repeating unit represented by formula (5) having Y5, which is a divalent organic group obtained by removing two amino groups from the diamine having a urea bond, the diamine having an amide bond, or the diamine having a nitrogen atom-containing structure, and an imidized structure thereof, and at least one of a repeating unit represented by formula (5) having Y5, which is a divalent organic group obtained by removing two amino groups from any other diamine, and an imidized structure thereof.

[0067] From the viewpoint of reducing afterimages due to residual DC, polymer (B) may contain repeating units represented by formula (5) in which Y5 is the specific divalent organic group and their imidized structures in an amount of 1 mol % or more, more preferably 10 mol % or more, and even more preferably 20 mol % or more, of all repeating units contained in polymer (B).

[0068] From the viewpoint of reducing afterimages caused by residual DC, the content ratio of polymer (A) to polymer (B) in the liquid crystal alignment agent 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 [polymer (A)] / [polymer (B)].

[0069] <Methods of producing polyamic acid, polyamic acid ester, and polyimide> The polyimide precursors used in the present invention, i.e., polyamic acid esters and polyamic acids, and imidized products thereof, i.e., polyimides, can be synthesized by known methods such as those described in WO2013 / 157586.

[0070] More specifically, this is carried out by reacting a diamine component with a tetracarboxylic acid derivative component in a solvent (condensation polymerization). Examples of the tetracarboxylic acid derivative component include tetracarboxylic acid dianhydrides and their derivatives (tetracarboxylic acid dihalides, tetracarboxylic acid diesters, or tetracarboxylic acid diester dihalides). When the polymer (A) or (B) contains an amic acid structure in part, for example, a polymer having an amic acid structure (polyamic acid) can be obtained by reacting the tetracarboxylic acid dianhydride component with the diamine component. The solvent is not particularly limited as long as it dissolves the resulting polymer. Specific examples of the solvent include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, and 1,3-dimethyl-2-imidazolidinone. When the polymer has high solubility in the solvent, methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, or solvents represented by the following formulas [D-1] to [D-3] can be used. [ka] (In formula [D-1], D 1 represents an alkyl group having 1 to 3 carbon atoms, and in formula [D-2], D 2 represents an alkyl group having 1 to 3 carbon atoms, and in formula [D-3], D 3 represents an alkyl group having 1 to 4 carbon atoms.

[0071] These solvents may be used alone or in combination. Furthermore, even if a solvent does not dissolve the polymer, it may be mixed with the above-mentioned solvent to the extent that the produced polymer does not precipitate. When the diamine component and the tetracarboxylic acid derivative component are reacted in a solvent, the reaction can be carried out at any concentration, preferably 1 to 50 mass %, more preferably 5 to 30 mass %. The reaction can be carried out at a high concentration in the early stage, and then additional solvent can be added. In the reaction, the ratio of the total number of moles of the diamine components to the total number of moles of the tetracarboxylic acid derivative components is preferably 0.8 to 1.2. As in a typical condensation polymerization reaction, the closer this molar ratio is to 1.0, the higher the molecular weights of the produced polymers (A) and (B).

[0072] The polyamic acid ester can be obtained by known methods such as [I] a method of reacting the polyamic acid obtained by the above method with an esterifying agent, [II] a method of reacting a tetracarboxylic acid diester with a diamine, or [III] a method of reacting a tetracarboxylic acid diester dihalide with a diamine.

[0073] Polyimide can be obtained by known methods such as thermal imidization, in which the solution of the polymer obtained by the above reaction is heated as is, or catalytic imidization, in which a catalyst is added to the solution of the polymer.

[0074] In the polyimide of the polymer (A) or polymer (B) of the present invention, the repeating units of the polyimide precursor are partially or entirely ring-closed, and the imidization rate of the polyimide is preferably 20 to 95%, more preferably 30 to 95%, and even more preferably 50 to 95%.

[0075] <Polymer solution viscosity and molecular weight> The polyamic acid, polyamic acid ester, and polyimide used in the present invention preferably have a solution viscosity of, for example, 10 to 1,000 mPa·s when made into a 10 to 15% by mass solution from the viewpoint of workability, but are not particularly limited thereto. The solution viscosity (mPa·s) of the polymer is a value measured at 25°C using an E-type rotational viscometer for a 10 to 15% by mass polymer solution prepared using a good solvent for the polymer (e.g., γ-butyrolactone, N-methyl-2-pyrrolidone, etc.). The polystyrene-equivalent weight-average molecular weight (Mw) of the polyamic acid, polyamic acid ester, and polyimide, measured by gel permeation chromatography (GPC), is preferably 1,000 to 500,000, and more preferably 2,000 to 300,000. The molecular weight distribution (Mw / Mn), expressed as the ratio of Mw to the polystyrene-equivalent number-average molecular weight (Mn) measured by GPC, is preferably 15 or less, and more preferably 10 or less. With the molecular weight in this range, good alignment and stability of the liquid crystal display device can be ensured.

[0076] <End-capping agent> In synthesizing the polymer (A) and polymer (B) of the present invention, a suitable end-capping agent may be used in addition to the tetracarboxylic acid derivative component and diamine component to synthesize an end-capping polymer. The end-capping polymer has the effect of improving the film hardness of the liquid crystal alignment film obtained by coating and improving the adhesion properties between the sealant and the liquid crystal alignment film. Examples of the terminals of the polymer (A) and polymer (B) in the present invention include an amino group, a carboxy group, an acid anhydride group, or a group derived from a terminal-capping agent described below. The amino group, carboxy group, and acid anhydride group can be obtained by a conventional condensation reaction or by blocking the terminals with the following terminal-capping agents.

[0077] Examples of the end-capping agent include acid monoanhydrides such as acetic anhydride, maleic anhydride, nadic anhydride, phthalic anhydride, itaconic anhydride, cyclohexanedicarboxylic anhydride, 3-hydroxyphthalic anhydride, trimellitic anhydride, 3-(3-trimethoxysilyl)propyl)-3,4-dihydrofuran-2,5-dione, 4,5,6,7-tetrafluoroisobenzofuran-1,3-dione, and 4-ethynylphthalic anhydride; dicarbonic acid diester compounds such as di-tert-butyl dicarbonate and diallyl dicarbonate; chlorocarbonyl compounds such as acryloyl chloride, methacryloyl chloride, and nicotinic acid chloride; aniline, 2-aminophenol, 3-aminophenol, 4- Examples of the isocyanate include monoamine compounds such as aminosalicylic acid, 5-aminosalicylic acid, 6-aminosalicylic acid, 2-aminobenzoic acid, 3-aminobenzoic acid, 4-aminobenzoic acid, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, and n-octylamine; monoisocyanate compounds such as isocyanates having an unsaturated bond, such as ethyl isocyanate, phenyl isocyanate, naphthyl isocyanate, 2-acryloyloxyethyl isocyanate, and 2-methacryloyloxyethyl isocyanate; and isothiocyanate compounds such as ethyl isothiocyanate and allyl isothiocyanate.

[0078] The proportion of the end-capping agent used is preferably 0.01 to 20 parts by mole, and more preferably 0.01 to 10 parts by mole, per 100 parts by mole of the total of the diamine components used.

[0079] <Liquid crystal alignment agent> The liquid crystal aligning agent of the present invention contains a polymer (A) and, if necessary, a polymer (B). The liquid crystal aligning agent of the present invention may contain other polymers in addition to the polymer (A) and the polymer (B). Specific examples of other polymers include polymers selected from the group consisting of polysiloxane, polyester, polyamide, polyurea, polyurethane, polyorganosiloxane, cellulose derivatives, polyacetal, polystyrene derivatives, poly(styrene-maleic anhydride) copolymers, poly(isobutylene-maleic anhydride) copolymers, poly(vinyl ether-maleic anhydride) copolymers, poly(styrene-phenylmaleimide) derivatives, and poly(meth)acrylates. Specific examples of poly(styrene-maleic anhydride) copolymers include SMA1000, 2000, and 3000 (manufactured by Cray Valley) and GSM301 (manufactured by Gifu Ceramics Manufacturing Co., Ltd.), a specific example of poly(isobutylene-maleic anhydride) copolymers includes ISOBAN-600 (manufactured by Kuraray Co., Ltd.), and a specific example of poly(vinyl ether-maleic anhydride) copolymers includes Gantrez AN-139 (methyl vinyl ether maleic anhydride resin, manufactured by Ashland). The other polymers may be used alone or in combination of two or more. The content of the other polymers is preferably 90 parts by mass or less, more preferably 10 to 90 parts by mass, and even more preferably 20 to 80 parts by mass, relative to 100 parts by mass of the total of the polymers contained in the liquid crystal aligning agent.

[0080] The liquid crystal aligning agent is used to prepare a liquid crystal alignment film, and takes the form of a coating liquid from the viewpoint of forming a uniform thin film. The liquid crystal aligning agent of the present invention is also preferably a coating liquid containing the above-mentioned polymer component and an organic solvent. In this case, the concentration of the polymer in the liquid crystal aligning agent can be appropriately changed depending on the thickness of the coating film to be formed. From the viewpoint of forming a uniform and defect-free coating film, the concentration of the polymer in the liquid crystal aligning agent is preferably 1% by mass or more, and from the viewpoint of the storage stability of the solution, it is preferably 10% by mass or less. A particularly preferred polymer concentration is 2 to 8% by mass.

[0081] The organic solvent contained in the liquid crystal alignment agent is not particularly limited as long as it can uniformly dissolve the polymer component. Specific examples thereof include N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethyllactamide, N,N-dimethylpropionamide, tetramethylurea, N,N-diethylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethyl sulfoxide, γ-butyrolactone, γ-valerolactone, 1,3-dimethyl-2-imidazolidinone, methyl ethyl ketone, cyclohexanone, cyclopentanone, 3-methoxy-N,N-dimethylpropionamide, tetramethylurea, N,N-diethylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethyl sulfoxide, γ-butyrolactone, γ-valerolactone, 1,3-dimethyl-2-imidazolidinone, methyl ethyl ketone, cyclohexanone, cyclopentanone, 3-methoxy-N,N-dimethylpropionamide, methyl ethyl ketone ... Examples of good solvents include N-pyrrolidone, 3-butoxy-N,N-dimethylpropanamide, N-(n-propyl)-2-pyrrolidone, N-isopropyl-2-pyrrolidone, N-(n-butyl)-2-pyrrolidone, N-(tert-butyl)-2-pyrrolidone, N-(n-pentyl)-2-pyrrolidone, N-methoxypropyl-2-pyrrolidone, N-ethoxyethyl-2-pyrrolidone, N-methoxybutyl-2-pyrrolidone, and N-cyclohexyl-2-pyrrolidone (collectively referred to as "good solvents"). Among these, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 3-methoxy-N,N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropanamide, and γ-butyrolactone are preferred. The content of the good solvent is preferably 20 to 99 mass %, more preferably 20 to 90 mass %, and particularly preferably 30 to 80 mass %, of the total solvent contained in the liquid crystal aligning agent.

[0082] The organic solvent contained in the liquid crystal aligning agent is preferably a mixed solvent containing, in addition to the above solvent, a solvent (also called a poor solvent) that improves the coatability and surface smoothness of the coating film when the liquid crystal aligning agent is applied. The content of the poor solvent is preferably 1 to 80 mass %, more preferably 10 to 80 mass %, and particularly preferably 20 to 70 mass % of the total solvent contained in the liquid crystal aligning agent. The type and content of the poor solvent are appropriately selected depending on the coater, coating conditions, coating environment, etc. of the liquid crystal aligning agent. Specific examples of the poor solvent to be used in combination are listed below, but are not limited to these. For example, diisopropyl ether, diisobutyl ether, diisobutyl carbinol (2,6-dimethyl-4-heptanol), ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, 1,2-dibutoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, 4-hydroxy-4-methyl-2-pentanone, diethylene glycol methyl ethyl ether, diethylene glycol dibutyl ether, 3-ethoxybutyl acetate, 1-methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, ethylene glycol monoacetate, ethylene glycol diacetate, propylene carbonate, ethylene carbonate, ethylene glycol monobutyl ether, ethylene glycol monoisoamyl ether, ethylene glycol monohexyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, 1-(2-butoxyethoxy)-2-propanol, 2-(2-butoxyethoxy)-2-propanol, )-1-Propanol, Propylene Glycol Monomethyl Ether Acetate, Propylene Glycol Diacetate, Dipropylene Glycol Monomethyl Ether, Dipropylene Glycol Monoethyl Ether, Dipropylene Glycol Dimethyl Ether, Ethylene Glycol Monobutyl Ether Acetate, Diethylene Glycol Monopropyl Ether, Diethylene Glycol Monoethyl Ether Acetate, Diethylene Glycol Monobutyl Ether Acetate, 2-(2-Ethoxyethoxy)ethyl Acetate, Diethylene Glycol Examples of suitable lactic acid bacteria include glycerin, propylene glycol diacetate, n-butyl acetate, propylene glycol monoethyl ether acetate, cyclohexyl acetate, 4-methyl-2-pentyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, butyl 3-methoxypropionate, n-butyl lactate, isoamyl lactate, diethylene glycol monoethyl ether, and diisobutyl ketone (2,6-dimethyl-4-heptanone).

[0083] Of these, diisobutyl carbinol, propylene glycol monobutyl ether, propylene glycol diacetate, diethylene glycol diethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monobutyl ether, ethylene glycol monobutyl ether acetate, or diisobutyl ketone is preferred.

[0084] Preferred solvent combinations of a good solvent and a poor solvent include N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone and ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone and propylene glycol monobutyl ether, N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether, N-ethyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone, and N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether. Coal diacetate, N,N-dimethyl lactamide and diisobutyl ketone, N-methyl-2-pyrrolidone and ethyl 3-ethoxypropionate, N-ethyl-2-pyrrolidone and ethyl 3-ethoxypropionate, N-methyl-2-pyrrolidone and ethyl 3-ethoxypropionate, N-methyl-2-pyrrolidone and ethyl 3-ethoxypropionate and dipropylene glycol monomethyl ether, N-ethyl-2-pyrrolidone and ethyl 3-ethoxypropionate and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone and ethyl 3-ethoxypropionate and diethylene glycol mono propyl ether, N-ethyl-2-pyrrolidone and ethyl 3-ethoxypropionate and diethylene glycol monopropyl ether, N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether acetate, N-ethyl-2-pyrrolidone and dipropylene glycol dimethyl ether, N,N-dimethyl lactamide and ethylene glycol monobutyl ether, N,N-dimethyl lactamide and propylene glycol diacetate, N-ethyl-2-pyrrolidone and diethylene glycol diethyl ether, N-ethyl-2 -pyrrolidone, diethylene glycol monoethyl ether, and butyl cellosolve acetate, N-methyl-2-pyrrolidone, diethylene glycol monomethyl ether, and butyl cellosolve acetate, N,N-dimethyl lactamide and diethylene glycol diethyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone, 4-hydroxy-4-methyl-2-pentanone, and diethylene glycol diethyl ether, N-ethyl-2-pyrrolidone, N-methyl-2-pyrrolidone, and 4-hydroxy-4-methyl-2-pentanone,N-Ethyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone, and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone, and diisobutyl ketone, N-methyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone, and dipropylene glycol monomethyl ether, N-methyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone, and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone, and dipropylene glycol monomethyl ether Methyl-2-pentanone and propylene glycol diacetate, N-ethyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and dipropylene glycol dimethyl ether, γ-butyrolactone and 4-hydroxy-4-methyl-2-pentanone and diisobutyl ketone, γ-butyrolactone and 4-hydroxy-4-methyl-2-pentanone and propylene glycol diacetate, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether and diisobutyl ketone, N-methyl-2-pyrrolidone rolidone, γ-butyrolactone, propylene glycol monobutyl ether, and diisopropyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone, propylene glycol monobutyl ether, and diisobutylcarbinol, N-methyl-2-pyrrolidone, γ-butyrolactone, and dipropylene glycol dimethyl ether, N-methyl-2-pyrrolidone, propylene glycol monobutyl ether, and dipropylene glycol dimethyl ether, N-ethyl-2-pyrrolidone, propylene glycol monobutyl ether, and dipropylene glycol pyrene glycol monomethyl ether, N-ethyl-2-pyrrolidone, diethylene glycol diethyl ether, and dipropylene glycol monomethyl ether, N-ethyl-2-pyrrolidone, propylene glycol monobutyl ether, and propylene glycol diacetate, N-ethyl-2-pyrrolidone, propylene glycol monobutyl ether, and diisobutyl ketone, N-ethyl-2-pyrrolidone, γ-butyrolactone, and diisobutyl ketone, N-ethyl-2-pyrrolidone, N,N-dimethyl lactamide, and diisobutyl ketone,Examples of such a mixture include N-methyl-2-pyrrolidone, ethylene glycol monobutyl ether, and ethylene glycol monobutyl ether acetate, γ-butyrolactone, ethylene glycol monobutyl ether acetate, and dipropylene glycol dimethyl ether, N-ethyl-2-pyrrolidone, ethylene glycol monobutyl ether acetate, and propylene glycol dimethyl ether, N-methyl-2-pyrrolidone, 4-methyl-2-pentyl acetate, and ethylene glycol monobutyl ether, N-ethyl-2-pyrrolidone, cyclohexyl acetate, and diacetone alcohol, cyclohexanone, and propylene glycol monomethyl ether, cyclopentanone, and propylene glycol monomethyl ether, and N-methyl-2-pyrrolidone, cyclohexanone, and propylene glycol monomethyl ether.

[0085] The liquid crystal aligning agent of the present invention may additionally contain components other than the polymer component and the organic solvent (hereinafter also referred to as additive components). Examples of such additive components include adhesion aids for improving the adhesion between the liquid crystal alignment film and the substrate or between the liquid crystal alignment film and the sealant, compounds for increasing the strength of the liquid crystal alignment film (hereinafter also referred to as crosslinking compounds), compounds for promoting imidization, and dielectrics or conductive substances for adjusting the dielectric constant or electrical resistance of the liquid crystal alignment film.

[0086] From the viewpoint of exhibiting good resistance to AC afterimages and significantly improving film strength, the crosslinkable compound may be at least one compound selected from the group consisting of a compound having at least one group selected from the group consisting of an oxiranyl group, an oxetanyl group, a protected isocyanate group, a protected isothiocyanate group, a group containing an oxazoline ring structure, a group containing a Meldrum's acid structure, a cyclocarbonate group, and a hydroxyalkylamide bond, and at least one compound selected from the group consisting of phenol compounds having at least one of an alkoxymethyl group and a methylol group.

[0087] Specific examples of compounds having an oxiranyl group include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, bisphenol A type epoxy resins such as Epikote 828 (manufactured by Mitsubishi Chemical Corporation), bisphenol F type epoxy resins such as Epikote 807 (manufactured by Mitsubishi Chemical Corporation), and YX-8000 (manufactured by Mitsubishi Chemical Corporation). hydrogenated bisphenol A epoxy resins such as EPPN-201 (manufactured by Nippon Kayaku Co., Ltd.), biphenyl skeleton-containing epoxy resins such as YX6954BH30 (manufactured by Mitsubishi Chemical Corporation), phenol novolac epoxy resins such as EPPN-201 (manufactured by Nippon Kayaku Co., Ltd.), (o, m, p-) cresol novolac epoxy resins such as EOCN-102S (manufactured by Nippon Kayaku Co., Ltd.), triglycidyl isocyanurates such as TEPIC (manufactured by Nissan Chemical Industries, Ltd.), alicyclic epoxy resins such as CELLOXIDE 2021P (manufactured by Daicel Chemical Industries, Ltd.), N,N,N',N'-tetraglycidyl-m-xylylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, and tetrakis(glycidyloxymethyl)methane.

[0088] Specific examples of the compound having an oxetanyl group include compounds having two or more oxetanyl groups described in paragraphs

[0170] to

[0175] of WO2011 / 132751.

[0089] Specific examples of compounds having a protected isocyanate group include compounds having two or more protected isocyanate groups described in paragraphs

[0046] to

[0047] of Japanese Patent Publication No. 2014-224978, and compounds having three or more protected isocyanate groups described in paragraphs

[0119] to

[0120] of WO2015 / 141598. Commercially available products that can be preferably used include, 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, and B-882N (all manufactured by Mitsui Chemicals, Inc.).

[0090] Specific examples of compounds having a protected isothiocyanate group include compounds having two or more protected isothiocyanate groups described in JP 2016-200798 A. Specific examples of compounds having a group containing an oxazoline ring structure include compounds having two or more oxazoline ring structures described in paragraph

[0115] of Japanese Patent Application Laid-Open No. 2007-286597. ring Examples of compounds include compounds containing the structure. Specific examples of compounds having a group containing a Meldrum's acid structure include compounds having two or more Meldrum's acid structures described in WO2012 / 091088. Specific examples of compounds having a cyclocarbonate group include compounds described in WO2011 / 155577.

[0091] Specific examples of the compound having the hydroxyalkylamide bond include compounds having two or more groups represented by the following formula (d), which are described in WO2015 / 072554 and paragraph

[0058] of JP 2016-118753 A, and compounds described in JP 2016-200798 A. [ka] (R2 and R3 each independently represent a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or "*-CH2-OH.")

[0092] Specific examples of the phenol compound having at least one of the alkoxyalkyl group and the methylol group include the compounds described in WO2010 / 074269.

[0093] The above compounds are examples of crosslinkable compounds, and are not limited thereto. For example, components other than those described above are disclosed on pages 53

[0105] to 55

[0116] of WO2015 / 060357. Two or more crosslinkable compounds may be used in combination.

[0094] The crosslinking compounds include, among others, N,N,N',N'-tetraglycidyl-m-xylylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, Takenate B-830, B-815N, B-820NSU, B-842N, B-846N, B-870N, B-874N, B-882N, 1,3,5-tris(2-hydroxyethyl) ) isocyanurate, triglycidyl isocyanurate, n,n,n',n'-tetrakis(2-hydroxyethyl)adipamide, 2,2-bis(4-hydroxy-3,5-dihydroxymethylphenyl)propane, 2,2-bis(4-hydroxy-3,5-dimethoxymethylphenyl)propane, and 2,2-bis(4-hydroxy-3,5-dihydroxymethylphenyl)-1,1,1,3,3,3-hexafluoropropane are preferred.

[0095] The content of the crosslinkable compound in the liquid crystal aligning agent of the present invention is preferably 0.5 to 20 parts by mass relative to 100 parts by mass of the polymer component contained in the liquid crystal aligning agent, and more preferably 1 to 15 parts by mass from the viewpoint of promoting the crosslinking reaction and exhibiting good resistance to AC afterimages.

[0096] Examples of the adhesion aid include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyldiethoxymethylsilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and the like. Examples of silane coupling agents include methoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, tris-(trimethoxysilylpropyl)isocyanurate, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-isocyanatopropyltriethoxysilane. When using a silane coupling agent, from the viewpoint of exhibiting good resistance to AC afterimages, the amount of the silane coupling agent is preferably 0.1 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, per 100 parts by mass of the polymer component contained in the liquid crystal alignment agent.

[0097] The compound for promoting imidization is preferably a compound having a basic moiety (e.g., a primary amino group, an aliphatic heterocycle (e.g., a pyrrolidine skeleton), an aromatic heterocycle (e.g., an imidazole ring, an indole ring), or a guanidino group) (excluding the crosslinkable compounds and adhesion aids), or a compound that generates the basic moiety upon baking. More preferred are compounds that generate the basic moiety upon baking, and specific examples include the compounds represented by the following formulas (B-1) to (B-17). The content of the compound for promoting imidization is preferably 2 molar parts or less, more preferably 1 molar part or less, and even more preferably 0.5 molar parts or less, per 1 molar part of the amic acid or amic acid ester moiety in the polymer (A). [ka] (D represents an organic group that is eliminated by heating, and is preferably a tert-butoxycarbonyl group or a 9-fluorenylmethoxycarbonyl group.)

[0098] The solid content concentration in the liquid crystal aligning agent (the proportion 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 1 to 10 mass%.

[0099] The particularly preferred range of solid content varies depending on the method used to apply the liquid crystal aligning agent to the substrate. For example, when using a spin coating method, a solid content of 1.5 to 4.5 mass% is particularly preferred. When using a printing method, a solid content of 3 to 9 mass% is particularly preferred, thereby resulting in a solution viscosity of 12 to 50 mPa·s. When using an inkjet method, a solid content of 1 to 5 mass% is particularly preferred, thereby resulting in a solution viscosity of 3 to 15 mPa·s. The temperature when preparing the polymer composition is preferably 10 to 50°C, more preferably 20 to 30°C.

[0100] <Liquid crystal alignment film / LCD element> The liquid crystal alignment film of the present invention is obtained from the liquid crystal aligning agent described above. The liquid crystal alignment film of the present invention can be used for horizontal alignment or vertical alignment (VA) liquid crystal alignment films, and is particularly suitable for horizontal alignment liquid crystal display elements such as IPS or FFS modes. The liquid crystal alignment film of the present invention is more preferably used as a liquid crystal alignment film for a photo-alignment treatment method. The liquid crystal alignment film of the present invention can also be effectively applied to various technical applications, such as liquid crystal alignment films for retardation films, scanning antennas, liquid crystal array antennas, and transmissive / scattering liquid crystal dimming elements, as well as other applications such as protective films (e.g., protective films for color filters), spacer films, interlayer insulating films, antireflection films, wiring covering films, antistatic films, and motor insulating films (gate insulating films for flexible displays). The liquid crystal display element of the present invention comprises the liquid crystal alignment film described above. The liquid crystal display element of the present invention can be produced, for example, by a method including the following steps (1) to (3): The liquid crystal display element of the present invention can be produced, for example, by a method including the following steps (1) to (3) and (5) or steps (1) to (2) and (5), more preferably by a method including steps (1) to (5).

[0101] <Step (1): Step of applying a liquid crystal alignment agent onto a substrate> Step (1) is a step of applying the liquid crystal aligning agent of the present invention onto a substrate. Specific examples of step (1) are as follows. 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 display 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.

[0102] 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.

[0103] <Step (2): Step of baking the applied liquid crystal alignment agent> In step (2), the liquid crystal alignment agent applied to the substrate is baked to form a film. Specific examples of step (2) are as follows. After applying the liquid crystal aligning agent to the substrate in step (1), 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 applying 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 baking temperature can be, for example, 40 to 180°C. To shorten the process, the baking can 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 step of removing the organic solvent. 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.

[0104] <Step (3): Step of Orientation Treatment> Step (3) is a step of optionally performing an alignment treatment on the baked film (coating 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, with photo-alignment treatment being more preferred. An example of the photo-alignment treatment method is a method in which the surface of the film-like material is irradiated with radiation polarized in a certain direction, and optionally, heat treatment is performed at a temperature preferably of 150 to 250°C to impart liquid crystal alignment (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.

[0105] The radiation dose is 1 to 10,000 mJ / cm 2 is preferred, and 100 to 5,000 mJ / cm 2 More preferably, 100 to 1,500 mJ / cm 2 is more preferably 100 to 1,000 mJ / cm 2 is particularly preferred, and 100 to 400 mJ / cm 2 When a normal liquid crystal alignment agent is used, the amount of light irradiation in the alignment treatment is 100 to 5,000 mJ / cm. 2 However, with the liquid crystal aligning agent of the present invention, even if the amount of light irradiation in the alignment treatment is reduced, it is possible to obtain a liquid crystal alignment film in which the variation (non-uniformity) of the liquid crystal alignment property within the liquid crystal alignment film plane is suppressed.

[0106] In addition, when irradiating with radiation, in order to improve the liquid crystal alignment, the substrate having the film-like material may be irradiated while being heated at 50 to 250° C. The liquid crystal alignment film thus produced 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 contact-treated with water or a solvent, or the liquid crystal alignment film irradiated with radiation can be heat-treated.

[0107] 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 in terms of versatility and solvent safety. Water, 1-methoxy-2-propanol, and ethyl lactate are more preferred. The solvent may be used alone or in combination of two or more.

[0108] <Step (4): Step of performing heat treatment> Step (4) is a step of subjecting the liquid crystal alignment film that has been subjected to the alignment treatment in step (3) to a heat treatment. The irradiated film (coating film) may be subjected to a heat treatment. The temperature for the heat treatment of the coating film irradiated with the radiation is preferably 50 to 300° C., more preferably 120 to 250° C. The heat treatment time is preferably 1 to 30 minutes.

[0109] <Step (5): Step of Producing a Liquid Crystal Cell> Two substrates on which liquid crystal alignment films have been formed as described above are prepared, and liquid crystal is placed between the two substrates arranged opposite each other. Specifically, there are two methods as follows: In the first method, two substrates are placed opposite each other with a gap (cell gap) between them so that their liquid crystal alignment films face each other. Next, the two substrates are bonded together around their peripheries using a sealant. A liquid crystal composition is injected into the substrate surfaces and the cell gap defined by the sealant so that it comes into contact with the film surface, and then the injection hole is sealed.

[0110] 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 curing agent and aluminum oxide spheres as spacers. The liquid crystal composition is not particularly limited, and various liquid crystal compositions containing at least one liquid crystal compound (liquid crystal molecule) and having positive or negative dielectric anisotropy may be used. Hereinafter, a liquid crystal composition having positive dielectric anisotropy will be referred to as a positive liquid crystal, and a liquid crystal composition having negative dielectric anisotropy will be referred to as a negative liquid crystal. Examples of liquid crystal compositions include liquid crystal compositions exhibiting a nematic phase and liquid crystal compositions exhibiting a smectic phase, with liquid crystal compositions exhibiting a nematic phase being preferred. The liquid crystal composition may contain a liquid crystal compound having a fluoro group, a hydroxy group, an amino group, a fluorine atom-containing group (e.g., a trifluoromethyl group), a cyano group, an alkyl group, an alkoxy group, an alkenyl group, an isothiocyanate group, a heterocycle, a cycloalkane, a cycloalkene, a steroid skeleton, a benzene ring, or a naphthalene ring, or may contain a compound having two or more rigid moieties (mesogenic skeletons) that exhibit liquid crystallinity within the molecule (e.g., a bimesogenic compound in which two rigid biphenyl structures or terphenyl structures are linked by an alkyl group). The liquid crystal composition may further contain additives to improve the liquid crystal alignment property, such as photopolymerizable monomers having a polymerizable group, optically active compounds (e.g., S-811 manufactured by Merck Ltd.), antioxidants, ultraviolet absorbers, dyes, antifoaming agents, polymerization initiators, or polymerization inhibitors. Examples of positive liquid crystals include ZLI-2293, ZLI-4792, MLC-2003, MLC-2041, MLC-3019, and MLC-7081 manufactured by Merck. Examples of negative liquid crystals include MLC-6608, MLC-6609, MLC-6610, and MLC-7026-100 manufactured by Merck. Furthermore, an example of a liquid crystal containing a compound having a polymerizable group is MLC-3023 manufactured by Merck.

[0111] 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.

[0112] An IPS substrate, which is a comb electrode substrate used in IPS (In-Plane Switching) mode, has a base material, a plurality of linear electrodes formed on the base material and arranged in a comb-like pattern, and a liquid crystal alignment film formed on the base material so as to cover the linear electrodes. The FFS substrate, which is a comb electrode substrate used in the FFS (Field Switching) mode, has a base material, a surface electrode formed on the base material, an insulating film formed on the surface electrode, a plurality of linear electrodes formed on the insulating film and arranged in a comb-like pattern, and a liquid crystal alignment film formed on the insulating film so as to cover the linear electrodes.

[0113] FIG. 1 is a schematic cross-sectional view showing an example of an in-plane switching liquid crystal display element of the present invention, which is an example of an IPS mode liquid crystal display element. In the IPS LCD element 1 illustrated in FIG. 1, liquid crystal 3 is sandwiched between a comb-shaped electrode substrate 2 having a liquid crystal alignment film 2c and a counter substrate 4 having a liquid crystal alignment film 4a. The comb-shaped electrode substrate 2 has a base material 2a, a plurality of linear electrodes 2b formed on the base material 2a and arranged in a comb-like pattern, and a liquid crystal alignment film 2c formed on the base material 2a so as to cover the linear electrodes 2b. The counter substrate 4 has a base material 4b and a liquid crystal alignment film 4a formed on the base material 4b. The liquid crystal alignment film 2c is, for example, a liquid crystal alignment film of the present invention. The liquid crystal alignment film 4c is also a liquid crystal alignment film of the present invention. In this IPS LCD element 1, when a voltage is applied to the linear electrodes 2b, an electric field is generated between the linear electrodes 2b as indicated by electric force lines L.

[0114] FIG. 2 is a schematic cross-sectional view showing another example of the in-plane switching liquid crystal display element of the present invention, which is an example of an FFS mode liquid crystal display element. In the IPS LCD element 1 shown in FIG. 2, liquid crystal 3 is sandwiched between a comb-shaped electrode substrate 2 having a liquid crystal alignment film 2h and a counter substrate 4 having a liquid crystal alignment film 4a. The comb-shaped electrode substrate 2 has a base 2d, a surface electrode 2e formed on the base 2d, an insulating film 2f formed on the surface electrode 2e, a plurality of linear electrodes 2g formed on the insulating film 2f and arranged in a comb-like pattern, and a liquid crystal alignment film 2h formed on the insulating film 2f so as to cover the linear electrodes 2g. The counter substrate 4 has a base 4b and a liquid crystal alignment film 4a formed on the base 4b. The liquid crystal alignment film 2h is, for example, a liquid crystal alignment film of the present invention. The liquid crystal alignment film 4a is also a liquid crystal alignment film of the present invention. In this IPS LCD element 1, when a voltage is applied to the surface electrodes 2e and the linear electrodes 2g, an electric field is generated between the surface electrodes 2e and the linear electrodes 2g as indicated by electric force lines L. [Example]

[0115] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. The abbreviations of the compounds used and the methods for measuring the various physical properties are as follows. "Boc" represents a tert-butoxycarbonyl group.

[0116] (specific diamine) WA-1 to WA-2: Compounds represented by the following formulas (WA-1) to (WA-2), respectively [ka]

[0117] (Other diamines) A1 to A8: Compounds represented by the following formulas (A1) to (A8), respectively [ka] The compounds represented by formulae A4 and A5 were synthesized by the synthesis method described in WO2020 / 080477.

[0118] (Tetracarboxylic acid dianhydride) B1 to B2: Compounds represented by the following formulas (B1) to (B2), respectively [ka]

[0119] (additives) AD-1 to AD-2: Compounds represented by the following formulae (AD-1) to (AD-2), respectively [ka]

[0120] (solvent) NMP: N-methyl-2-pyrrolidone BCS: Ethylene glycol monobutyl ether DMF: dimethylformamide DMAc: dimethylacetamide THF: tetrahydrofuran

[0121] (Viscosity measurement) The viscosity of the solution was measured at 25°C using an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.) with a sample volume of 1.1 mL and a cone rotor TE-1 (1°34', R24).

[0122] (Measurement of molecular weight) The molecular weight of the polyamic acid was measured using a room temperature gel permeation chromatography (GPC) apparatus (GPC-101) (Showa Denko K.K.) and columns (KD-803 and KD-805 in series) (Showa Denko K.K.) as follows. Column temperature: 50℃ Eluent: N,N-dimethylformamide (additives: lithium bromide monohydrate (LiBr·HO) 30 mmol / L, phosphoric acid anhydrous crystal (o-phosphoric acid) 30 mmol / L, tetrahydrofuran (THF) 10 mL / L) Flow rate: 1.0ml / min Standard samples for preparing a calibration curve: TSK standard polyethylene oxide (molecular weight: approximately 900,000, 150,000, 100,000, and 30,000) (manufactured by Tosoh Corporation) and polyethylene glycol (molecular weight: approximately 12,000, 4,000, and 1,000) (manufactured by Polymer Laboratory Co., Ltd.).

[0123] <Synthesis of specific diamines (WA-1) to (WA-2)> The synthesis methods of the specific diamines (WA-1) to (WA-2) are described in detail below. Note that the diamine (WA-2) is a novel compound that has not been published in any literature.

[0124] ( 1 H-NMR measurement) Equipment: Fourier transform superconducting nuclear magnetic resonance spectrometer (FT-NMR) "AVANCE III" (BRUKER) 500MHz. Solvent: deuterated dimethyl sulfoxide (DMSO-d6, standard: tetramethylsilane),

[0125] (Monomer Synthesis Example 1: Synthesis of (WA-1)) Diamine (WA-1) was synthesized according to the route shown below. [ka] In a 1 L four-neck flask, 6-bromo-2-naphthol (31.1 g, 140 mmol), potassium carbonate (38.7 g, 280 mmol), and potassium iodide (1.16 g, 7 mmol) were dissolved in DMF (249 g) and heated to 100 °C with stirring. 1,4-Dichlorobutane (8.8 g, 70 mmol) dissolved in DMF (63 g) was slowly added and stirred for 15 hours. After confirming the completion of the reaction by HPLC, the mixture was cooled to room temperature, purified water (620 g) was added, and the mixture was stirred for 1 hour. The precipitated crystals were filtered off, and the resulting solid was washed with methanol and dried under reduced pressure to obtain WA-1-1 (yield 28.7 g, 57.4 mmol, 82% yield, white solid). 1H-NMR(500MHz,DMSO-d6);δ(ppm)=8.10(2H,s), 7.83-7.75(4H,m), 7.56-7 .54(2H,m), 7.38(2H,s), 7.23-7.22(2H,m), 4.19(4H,t), 1.99-1.95(4H,m)

[0126] A 1-L four-neck flask was charged with WA-1-1 (20.0 g, 40 mmol), benzophenone imine (15.9 g, 88 mmol), tris(dibenzylideneacetone)dipalladium (Pd2(dba)3) (0.7 g, 0.8 mmol), 2-dicyclohexylphosphino-2',4',6'-triisopropyl-1,1'-biphenyl (XPhos) (1.52 g, 3.2 mmol), sodium tert-butoxide (10.8 g, 112 mmol), and THF (400 g). The mixture was heated to 70 °C and stirred for 1 hour. The reaction mixture was concentrated to 200 g, and then purified water (200 g) was added and stirred for 1 hour. The precipitated crystals were collected by vacuum filtration, transferred to a four-neck flask, and dissolved in DMAc (256 g). Trifluoroacetic acid (12.5 g, 110 mmol) was slowly added, and the mixture was heated to 50 °C. After stirring for 30 minutes, the solution was returned to room temperature, and N,N,N',N'-tetramethylethylenediamine (TMEDA) (16.9 g, 146 mmol) was added and neutralized. The reaction solution was concentrated to 128 g, and then methanol (256 g) was added and stirred for 1 hour. The precipitated crystals were filtered off, and the resulting solid was washed with methanol and dried under reduced pressure to obtain WA-1 (yield 13.0 g, 34.9 mmol, 88% yield, light brown solid). As shown below 1 The results of H-NMR confirmed that this solid was diamine (WA-1). 1 H-NMR(500MHz,DMSO-d6);δ(ppm)=7.49-7.47(2H,m), 7.44-7.42(2H,m), 7.10(2H,d), 6.99-6 .97(2H,m), 6.90-6.88(2H,m), 6.79(2H,d), 5.08-5.06(4H,m), 4.08(4H,t), 1,96-1.92(4H,m)

[0127] (Monomer Synthesis Example 2: Synthesis of (WA-2)) Diamine (WA-2) was synthesized according to the route shown below. [ka]

[0128] In a 300 mL four-neck flask, 1,4-dichlorobutane (63.5 g, 500 mmol) was dissolved in DMF (86 g), potassium carbonate (13.8 g, 100 mmol) was added, and the mixture was heated to 100 °C and stirred. 4-Bromo-4'-hydroxybiphenyl (12.4 g, 50 mmol) dissolved in DMF (38 g) was added and stirred for 2 hours. After confirming the completion of the reaction by HPLC, the mixture was cooled to room temperature and the precipitated salt was removed. The solution was concentrated to 64 g, and methanol (180 g) and purified water (180 g) were added and stirred for 1 hour. The precipitated crystals were filtered off, and the resulting solid was washed with methanol and dried under reduced pressure to obtain WA-2-1 (yield 14.6 g, 43.0 mmol, 86% yield, white solid). 1 H-NMR(500MHz,DMSO-d6);δ(ppm)=7.61-7.58(6H,m), 7.02(2H,d), 4.05(2H,t), 3.72(2H,t), 1.88-1.87(4H,m)

[0129] WA-2-1 (13.6 g, 40 mmol), 6-bromo-2-naphthol (8.9 g, 40 mmol), potassium carbonate (13.8 g, 100 mmol), and DMF (135 g) were added to a 500 mL four-neck flask, heated to 100 °C, and stirred for 18 hours. After confirming the completion of the reaction by HPLC, the solution was returned to room temperature, and purified water (202 g) was added and stirred for 1 hour. The precipitated crystals were filtered off, and the resulting solid was washed with acetonitrile and dried under reduced pressure to obtain WA-2-2 (yield 19.5 g, 37.1 mmol, 93% yield, white solid). 1H-NMR(500MHz,DMSO-d6);δ(ppm)=8.11(1H,m), 7.83-7.75(2H,m), 7.61-7.55(7H,m ), 7.37(1H,m), 7.23(1H,m), 7.04-7.03(2H,m), 4.17-4.11(4H,m), 1.04-1.03(4H,m)

[0130] A 1-L four-neck flask was charged with WA-2-2 (19.4 g, 37 mmol), benzophenone imine (14.7 g, 81 mmol), tris(dibenzylideneacetone)dipalladium (Pd2(dba)3) (0.6 g, 0.7 mmol), 2-dicyclohexylphosphino-2',4',6'-triisopropyl-1,1'-biphenyl (XPhos) (1.41 g, 2.9 mmol), sodium tert-butoxide (9.9 g, 103 mmol), and THF (389 g). The mixture was heated to 70 °C and stirred for 1 hour. The reaction mixture was concentrated to 190 g, and then purified water (200 g) was added and stirred for 1 hour. The precipitated crystals were collected by vacuum filtration, transferred to a four-neck flask, and dissolved in THF (537 g). Trifluoroacetic acid (12.6 g, 111 mmol) was slowly added, and the mixture was heated to 50 °C. After stirring for 30 minutes, the solution was returned to room temperature, and N,N,N',N'-tetramethylethylenediamine (TMEDA) (17.2 g, 148 mmol) was added and neutralized. The reaction solution was concentrated to 260 g, and then methanol (260 g) was added and stirred for 1 hour. The precipitated crystals were filtered off, and the resulting solid was washed with methanol and dried under reduced pressure to obtain WA-2 (yield 13.3 g, 33.4 mmol, 90% yield, light brown solid). As shown below 1 The results of H-NMR confirmed that this solid was diamine (WA-2). 1 H-NMR(500MHz,DMSO-d6);δ(ppm)=7.49-7.42(4H,m), 7.28-7.27(2H,m), 7.09(1H,d), 6.99-6.88 (4H,m), 6.79(1H,d), 6.622-6.60(2H,m), 5.11-5.10(4H,m), 4.07-4.05(4H,m), 1.98-1.90(4H,m)

[0131] <Polymer synthesis> (Synthesis Example 1) A1 (0.973 g, 9.00 mmol), A2 (2.20 g, 9.00 mmol), WA-1 (2.23 g, 6.00 mmol), A7 (2.39 g, 6.00 mmol), B1 (6.39 g, 28.5 mmol), and NMP (104 g) were added to a 100 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and the mixture was stirred at 40 °C for 20 hours to obtain a solution of polyamic acid (A-1) with a solids concentration of 12% by mass (viscosity: 379 mPa s). The number-average molecular weight (Mn) of this polyamic acid was 13,242, and the weight-average molecular weight (Mw) was 34,231.

[0132] (Synthesis Example 2) A1 (0.973 g, 9.00 mmol), A2 (2.20 g, 9.00 mmol), WA-2 (2.39 g, 6.00 mmol), A7 (2.39 g, 6.00 mmol), B1 (6.42 g, 28.7 mmol), and NMP (105 g) were added to a 100 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and the mixture was stirred at 40 °C for 20 hours to obtain a solution of polyamic acid (A-2) with a solids concentration of 12% by mass (viscosity: 398 mPa s). The Mn of this polyamic acid was 12,019 and the Mw was 33,291.

[0133] (Synthesis Example 3) A1 (0.649 g, 6.00 mmol), A8 (4.78 g, 24.0 mmol), B2 (5.59 g, 28.5 mmol), and NMP (99.2 g) were added to a 100 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and the mixture was stirred at room temperature for 5 hours to obtain a solution of polyamic acid (B-1) with a solids concentration of 10% by mass (viscosity: 338 mPa s). The Mn of this polyamic acid was 15,932 and the Mw was 39,013.

[0134] (Synthesis Example 4 (Comparative)) A1 (0.973 g, 9.00 mmol), A2 (2.20 g, 9.00 mmol), A3 (1.92 g, 6.00 mmol), A7 (2.39 g, 6.00 mmol), B1 (6.42 g, 28.7 mmol), and NMP (101 g) were added to a 100 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and the mixture was stirred at 40 °C for 20 hours to obtain a solution of polyamic acid (RA-1) with a solids concentration of 12% by mass (viscosity: 382 mPa s). The Mn of this polyamic acid was 11,912 and the Mw was 33,413.

[0135] (Synthesis Example 5 (Comparative)) A1 (0.973 g, 9.00 mmol), A2 (2.20 g, 9.00 mmol), A4 (2.07 g, 6.00 mmol), A7 (2.39 g, 6.00 mmol), B1 (6.38 g, 28.4 mmol), and NMP (102 g) were added to a 100 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and the mixture was stirred at 40 °C for 20 hours to obtain a solution of polyamic acid (RA-2) with a solids concentration of 12% by mass (viscosity: 411 mPa s). The Mn of this polyamic acid was 12,018 and the Mw was 37,021.

[0136] (Synthesis Example 6 (Comparative)) A1 (0.973 g, 9.00 mmol), A2 (2.20 g, 9.00 mmol), A5 (2.22 g, 6.00 mmol), A7 (2.39 g, 6.00 mmol), B1 (6.38 g, 28.4 mmol), and NMP (103 g) were added to a 100 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and the mixture was stirred at 40 °C for 20 hours to obtain a solution of polyamic acid (RA-3) with a solids concentration of 12% by mass (viscosity: 404 mPa s). The Mn of this polyamic acid was 10,383 and the Mw was 36,113.

[0137] (Synthesis Example 7 (Comparative)) A1 (0.973 g, 9.00 mmol), A2 (2.20 g, 9.00 mmol), A6 (2.15 g, 6.00 mmol), A7 (2.39 g, 6.00 mmol), B1 (6.46 g, 28.8 mmol), and NMP (103 g) were added to a 100 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and the mixture was stirred at 40 °C for 20 hours to obtain a solution of polyamic acid (RA-4) with a solids concentration of 12% by mass (viscosity: 401 mPa s). The Mn of this polyamic acid was 10,099 and the Mw was 36,030.

[0138] The types and amounts of diamine components and tetracarboxylic acid components used in Synthesis Examples 1 to 7 are summarized in Table 1. In the table, the numbers in parentheses indicate the amount (parts by mole) of the monomer used per 100 parts by mole of the total of each component.

[0139] [Table 1]

[0140] <Preparation of Liquid Crystal Alignment Agent> Example 1 To the polyamic acid (A-1) solution (6.67 g) obtained in Synthesis Example 1, NMP (9.33 g) and BCS (4.00 g) were added, and the mixture was stirred at room temperature for 2 hours to obtain a liquid crystal aligning agent (V-1).

[0141] Example 2 To the polyamic acid (A-1) solution (5.30 g) obtained in Synthesis Example 1, the polyamic acid (B-1) solution (9.54 g) obtained in Synthesis Example 3, NMP (3.78 g), BCS (9.00 g), a 10 mass % diluted solution of AD-1 in NMP (0.800 g), and a 1 mass % diluted solution of AD-2 in NMP (1.59 g) were added, and the mixture was stirred at room temperature for 2 hours to obtain a liquid crystal alignment agent (V-2).

[0142] Example 3 A liquid crystal aligning agent (V-3) was obtained by the same operation as in Example 2, except that the polyamic acid solution used was changed from the (A-1) solution to the (A-2) solution.

[0143] (Comparative Example 1) to (Comparative Example 4) Liquid crystal aligning agents (RV-1) to (RV-4) were obtained by operating in the same manner as in Example 1, except that the solution of the polyamic acid to be used was changed from the (A-1) solution to the (RA-1) to (RA-4) solutions.

[0144] (Comparative Example 5) to (Comparative Example 6) Liquid crystal aligning agents (RV-5) to (RV-6) were obtained by operating in the same manner as in Example 2, except that the solution of the polyamic acid to be used was changed from the (A-1) solution to the (RA-2) to (RA-3) solutions.

[0145] The specifications of the liquid crystal aligning agents obtained in the above Examples 1 to 3 and Comparative Examples 1 to 6 are shown in Table 2. The numerical values in parentheses of the polymer components represent the ratios (parts by mass) of the respective polymer components to 100 parts by mass in total of the polymer components.

[0146]

Table 2

[0147] Using the liquid crystal aligning agent obtained above, an FFS-driven liquid crystal cell was fabricated by the procedure shown below, and various evaluations were performed.

[0148] <Configuration of FFS-driven liquid crystal cell> A liquid crystal cell having the configuration of an FFS-mode liquid crystal display element was fabricated. First, a substrate with electrodes was prepared. The substrate was a rectangular 30 mm x 50 mm, 0.7 mm thick glass plate. A solid-patterned ITO electrode, which constituted the counter electrode, was formed on the substrate. A second layer, a silicon nitride (SiN) film, was deposited on top of the first counter electrode by chemical vapor deposition (CVD). The second SiN film was 500 nm thick and functioned as an interlayer insulating film. A comb-shaped pixel electrode, formed by patterning an ITO film, was placed on top of the second SiN film. Two pixels, the first and second, were formed, each measuring 10 mm long and 5 mm wide. The first counter electrode and the third pixel electrode were electrically insulated by the second SiN film. The pixel electrode on the third layer had a comb-like shape with multiple 3 μm-wide electrode elements bent at an internal angle of 160° in the center and arranged parallel to each other with 6 μm gaps between them. Each pixel had a first region and a second region, separated by a line connecting the bent portions of the multiple electrode elements. Next, the liquid crystal alignment agents (V-1) to (V-3) and (RV-1) to (RV-6) obtained in Examples 1 to 3 and Comparative Examples 1 to 6 were filtered through a 1.0 μm pore size filter and then spin-coated onto the prepared electrode-attached substrate (first glass substrate) and a glass substrate (second glass substrate) with a 4 μm-high columnar spacer and an ITO film formed on the backside. The resulting coating was dried on a hot plate at 80°C for 2 minutes and then baked in a hot air circulating oven at 230°C for 30 minutes to form a 100 nm-thick coating film. The coating surface was then irradiated with linearly polarized ultraviolet light at a wavelength of 254 nm with an extinction ratio of 26:1 through a polarizer at the respective doses shown in Table 3, thereby obtaining a substrate with a liquid crystal alignment film. The liquid crystal alignment film formed on the electrode-attached substrate was aligned so that the direction dividing the pixel bends was perpendicular to the liquid crystal alignment direction. The liquid crystal alignment film formed on the second glass substrate was aligned so that the alignment direction of the liquid crystal on the first glass substrate would be the same as that on the second glass substrate when the liquid crystal cell was fabricated. The two substrates were combined into a pair, and a sealant (Mitsui Chemicals XN-1500T) was printed on one substrate. The other substrate was then attached so that the alignment direction of the liquid crystal alignment film faces was 0°. The sealant was then cured by heating at 150°C for 60 minutes to produce an empty cell. Liquid crystal MLC-3019 (Merck) was injected into the empty cell by a vacuum injection method, and the injection port was sealed to obtain an FFS-driven liquid crystal cell. The resulting liquid crystal cell was then heated at 120°C for 1 hour and left overnight before being used for evaluation.

[0149] <Evaluation of in-plane contrast uniformity> The twist angle variation of the liquid crystal cell was evaluated using AxoStep manufactured by AXOMETRICS. The liquid crystal cell prepared above was placed on a measurement stage, and the distribution of circular retardance within the pixel plane was measured with no voltage applied, and 3σ, which is three times the standard deviation σ, was calculated. The smaller the 3σ value, the better the in-plane uniformity. The evaluation criteria were as follows: less than 1.00 was "excellent," 1.00 to 1.10 was "good," and greater than 1.10 was "poor." Table 3 shows the results of evaluations carried out on the liquid crystal display elements using the liquid crystal alignment agents of the above Examples and Comparative Examples.

[0150] <Evaluation of the stability of liquid crystal alignment> This evaluation is to evaluate the afterimage (also called AC afterimage) that occurs when the alignment performance of the liquid crystal alignment film deteriorates during long-term AC driving. The FFS-driven liquid crystal cell prepared as described above was subjected to an AC voltage of ±4V at a frequency of 60Hz for 120 hours at a constant temperature of 60°C. The pixel electrode and counter electrode of the liquid crystal cell were then shorted and left at room temperature for one day. For the liquid crystal cell subjected to the above treatment, the deviation in angle between the liquid crystal alignment direction in the first and second regions of the pixel was calculated when no voltage was applied. Specifically, the liquid crystal cell was placed between two polarizers arranged so that their polarization axes were perpendicular to each other. The backlight was turned on, and the liquid crystal cell was adjusted to minimize the transmitted light intensity in the first region of the pixel. The rotation angle required to minimize the transmitted light intensity in the second region of the pixel was then calculated. The smaller the rotation angle, the better the liquid crystal alignment stability. The evaluation criteria were as follows: a deviation of less than 0.05° was considered "excellent," a deviation of 0.05° to 0.10° was considered "good," and a deviation of more than 0.10° was considered "poor."

[0151] Table 3 shows the results of evaluations carried out on the liquid crystal display elements using the liquid crystal alignment agents of the above Examples and Comparative Examples.

[0152] [Table 3]

[0153] As shown in Table 3, the liquid crystal alignment films obtained from the liquid crystal alignment agents using the specific diamines WA-1 to WA-2 achieved high in-plane uniformity with a smaller amount of light irradiation than the liquid crystal alignment films obtained from the liquid crystal alignment agents composed of diamine components that do not contain the specific diamines. Furthermore, they showed high liquid crystal alignment stability equivalent to or even higher than that of conventional liquid crystal alignment films.

[0154] The liquid crystal alignment film obtained from the liquid crystal aligning agent of the present invention can be suitably used in liquid crystal display elements, and these elements are also useful in liquid crystal displays for display purposes, as well as in light control windows and optical shutters that control the transmission and blocking of light. [Industrial Applicability]

[0155] By using the liquid crystal aligning agent of the present invention, the variation (non-uniformity) in the twist angle of the liquid crystal within the liquid crystal alignment film plane is small, the range of light irradiation dose required to obtain a liquid crystal alignment film is expanded, and a high-quality liquid crystal alignment film can be efficiently obtained. Therefore, it is expected to be used in liquid crystal display elements that require high display quality. These elements are also useful in liquid crystal displays for display purposes, as well as in light control windows and optical shutters that control the transmission and blocking of light. [Explanation of symbols]

[0156] 1. In-plane switching liquid crystal display element 2. Interdigital electrode substrate 2a Base material 2b Linear electrode 2c Liquid crystal alignment film 2d base material 2e surface electrode 2f insulating film 2g linear electrode 2h Liquid crystal alignment film 3 LCD 4 Opposing substrate 4a Liquid crystal alignment film 4b Base material L electric field lines

Claims

1. A liquid crystal aligning agent comprising at least one polymer (A) selected from the group consisting of a polyimide precursor having a repeating unit (a1) represented by the following formula (1) and a polyimide which is an imidized product of the polyimide precursor: 【Chemistry 1】 (In formula (1), X １ represents a tetravalent organic group. １ is a divalent organic group represented by any one of the following formulas (h-1), (h-2), and (h-4). R and Z each independently represent a hydrogen atom or a monovalent organic group. 【Chemistry 2】 (In formulas (h-1), (h-2), and (h-4), R a1 , R a2 , and R a4 represent a monovalent organic group. L represents a group represented by the following formula (H1). Each m is independently an integer of 0 to 6, and each n is independently an integer of 0 to 4. When a plurality of R a1 , R a2 , and R a4 are present, they may be the same or different. * represents a bond.) 【Transformation 3】 In formula (H1), L 1 and L 1′ each independently represent a single bond, —O—, —S—, —C(═O)—, —O—C(═O)—, or —C(═O)—NR— (R represents a hydrogen atom or a monovalent organic group). A represents an alkylene group having 4 to 10 carbon atoms. * represents a bond.)

2. The formula (H1) is a group "*-(CH ２ ) ｎ -*", group "*-O-(CH ２ ) ｎ -O-*" and the group "*-C(=O)-(CH ２ ) ｎ -C(=O)-*", group "*-C(=O)-NR-(CH ２ ) ｎ -O-*" and the group "*-O-C(=O)-(CH ２ ) ｎ -O-*" and the group "*-O-C(=O)-(CH ２ ) ｎ -O-C(=O)-*" and the group "*-O-C(=O)-(CH ２ ) ｎ -C(=O)-O-*" and the group "*-S-(CH ２ ) ｎ -S-*", group "*-C(=O)-NR-(CH ２ ) ｎ -NR-C(=O)-*", group "*-C(=O)-O-(CH ２ ) ｎ -O-C(=O)-*" and the group "*-O-(CH ２ ) ｎ -*", group "*-S-(CH ２ ) ｎ -*" or the group "*-NR-C(=O)-(CH ２ ) ｎ -C(=O)-NR-*" (wherein R represents a hydrogen atom or a monovalent organic group, and n is an integer of 4 to 10. * represents a bond). The liquid crystal aligning agent according to claim 1,

3. The polymer (A) is at least one polymer selected from the group consisting of a polyimide precursor further having a repeating unit (a2) represented by the following formula (2) and a polyimide which is an imidized product of the polyimide precursor. The liquid crystal aligning agent according to claim 1 or 2. 【Chemistry 4】 (In formula (2), X ２ represents a tetravalent organic group. ２ represents a divalent organic group represented by the following formulas (o-1) to (o-14). R and Z have the same meanings as R and Z in the above formula (1), respectively. 【Transformation 5】 【Transformation 6】 (In formulas (o-1) to (o-14), * represents a bond. In formulas (o-13) to (o-14), two m's are independent of each other. Any hydrogen atom on the benzene ring, biphenyl structure, or naphthalene ring in formulas (o-1) to (o-14) may be replaced with a monovalent group.)

4. The polymer (A) further comprises at least one selected from the group consisting of a polyimide precursor having at least one selected from the group consisting of a repeating unit (a2') represented by the following formula (2') and a repeating unit (a3) ​​represented by the following formula (3), and at least one polymer selected from the group consisting of a polyimide precursor which is an imidized product of the polyimide precursor. 【Transformation 7】 (In formula (2') and formula (3), X ２’ , and X ３ represents a tetravalent organic group, Y ２’ represents a divalent organic group represented by the following formula (O2), and Y ３ represents a divalent organic group having 6 to 30 carbon atoms and containing the group "-N(D)- (D represents a carbamate protecting group)" in the molecule. R and Z have the same meanings as R and Z in the above formula (1), respectively. 【Transformation 8】 (In formula (O2), m represents an integer of 0 to 2. When m is 0, Ar ２’ represents a benzene ring or a naphthalene ring, and when m is 1 or 2, Ar ２’ each independently represents a benzene ring. ２’ Any hydrogen atom on the ring of Q may be replaced with a monovalent group. ２’ represents a single bond or -O-. * represents a bond. Ar ２’ , and Q ２’ When there are multiple, they may be the same or different.)

5. Above X １ is a tetravalent organic group derived from an acyclic aliphatic tetracarboxylic acid dianhydride or a derivative thereof, an alicyclic tetracarboxylic acid dianhydride or a derivative thereof, or an aromatic tetracarboxylic acid dianhydride or a derivative thereof, and is a tetravalent organic group derived from a tetracarboxylic acid 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, the liquid crystal aligning agent according to any one of claims 1 to 4.

6. The polymer (A) contains the repeating unit (a1) and the imidized structure of the repeating unit (a1) in a total amount of 5 to 100 mol% of all repeating units. The liquid crystal aligning agent according to any one of claims 1 to 5.

7. The polymer (A) contains the repeating unit (a1) and the imidized structure of the repeating unit (a1) in a total amount of 5 mol% or more and 95 mol% or less of all repeating units. The liquid crystal aligning agent according to any one of claims 1 to 6.

8. The polymer (A) contains the repeating unit (a1), the repeating unit (a2), and the imidized structure thereof in a total amount of 10 mol% or more of all repeating units. The liquid crystal aligning agent according to any one of claims 3 and 5 to 7.

9. The liquid crystal aligning agent according to any one of claims 1 to 8, which is used for forming a liquid crystal alignment film for a photo-alignment treatment method.

10. A liquid crystal alignment film obtained from the liquid crystal aligning agent according to any one of claims 1 to 9.

11. A liquid crystal display device comprising the liquid crystal alignment film according to claim 10.

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

13. The method for manufacturing a liquid crystal display element according to claim 12 , wherein the alignment treatment is a photo-alignment treatment.

14. The radiation dose in the photo-alignment treatment is 100 to 1,500 mJ / cm ２ The method for producing a liquid crystal display element according to claim 13,

15. The method for producing a liquid crystal display element according to any one of claims 12 to 14, further comprising the following step (4): Step (4): A step of further subjecting the fired film that has been subjected to the orientation treatment in step (3) to a heat treatment at 50 to 300°C.

16. A liquid crystal display element obtained by the method for producing a liquid crystal display element according to any one of claims 12 to 15.

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