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

Abstract

The present invention provides a liquid crystal aligning agent, a liquid crystal alignment film obtained from the liquid crystal aligning agent, and a liquid crystal display element using the liquid crystal alignment film. The liquid crystal aligning agent can obtain a liquid crystal alignment film that has a high voltage holding ratio even after being exposed to high temperature and high humidity for a long time, and in addition, has a fast relaxation of accumulated charges and excellent afterimage characteristics. The present invention also provides a liquid crystal aligning agent, a liquid crystal alignment film obtained from the liquid crystal aligning agent, and a liquid crystal display element using the liquid crystal alignment film. The liquid crystal aligning agent can obtain a liquid crystal alignment film having a high light transmittance. The liquid crystal aligning agent of the present invention contains a polymer component having a first repeating unit (a1) and a second repeating unit (a2). The first repeating unit (a1) is selected from the group consisting of the repeating units represented by the following formula (1-a) and the repeating units represented by the following formula (1-i). The second repeating unit (a2) is selected from the group consisting of the repeating units represented by the following formula (2-a) and the repeating units represented by the following formula (2-i). (The meanings of the respective substituents are as described in the specification.)

Description

Technical Field

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

[0002] Conventionally, as liquid crystal display elements, various driving methods different in electrode structure, physical properties of liquid crystal molecules used, etc. are being developed. For example, various display elements such as TN (Twisted Nematic) type, STN (Super Twisted Nematic) type, VA (Vertical Alignment) type, IPS type (In Plane Switching), FFS (Fringe Field Switching) type are known. These liquid crystal display elements have a liquid crystal alignment film for aligning liquid crystal molecules. As materials for the liquid crystal alignment film, for example, polyamic acid, polyamic acid ester, polyimide, polyamide, etc. are known.

[0003] In a VA type liquid crystal display element, which is one of the driving methods of liquid crystal display elements, a technique is known in which a photopolymerizable compound is previously added to a liquid crystal composition, and a vertical alignment film such as a polyimide-based film is used, and ultraviolet rays are irradiated while applying a voltage to one side of a liquid crystal cell, thereby accelerating the response speed of the liquid crystal (PSA (Polymer Sustained Alignment) method element) (for example, refer to Patent Document 1 and Non-Patent Document 1).

[0004] On the other hand, in such a liquid crystal display element, when static electricity accumulates in the liquid crystal cell, or when charges accumulate in the liquid crystal cell due to the application of a positive-negative asymmetric voltage generated by driving, these accumulated charges affect the display as disorders and afterimages of liquid crystal alignment, and significantly reduce the display quality level of the liquid crystal element. As a liquid crystal alignment film for solving such problems, a polyimide-based liquid crystal alignment film having a pyrrole structure is proposed in Patent Document 2.

[0005] In addition, in recent years, large-screen and high-definition liquid crystal TVs have been widely put into practical use. In the case of liquid crystal display elements for such applications, compared with the conventional display uses mainly for displaying characters and still images, the requirement for afterimages has become more stringent, and characteristics that can withstand long-term use in a harsh usage environment are required. Therefore, the liquid crystal alignment film used here needs to have higher reliability than before. Regarding the electrical characteristics of the liquid crystal alignment film, it is required that not only the initial characteristics are good, for example, even after being exposed to high temperature and high humidity for a long time, good characteristics are maintained. As a liquid crystal alignment film for solving such problems, in Patent Document 3, a polyimide-based liquid crystal alignment film having a diphenylamine structure has been proposed.

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2003-307720

[0009] Patent Document 2: International Publication No. 2019 / 013339

[0010] Patent Document 3: International Publication No. 2009 / 093709

[0011] Non-Patent Documents

[0012] Non-Patent Document 1: K. Hanaoka, SID 04 DIGEST, P1200-1202 Summary of the Invention

[0013] Problems to be Solved by the Invention

[0014] Furthermore, in ultra-high-definition liquid crystal display elements such as 4K and 8K, the occupancy rates of black matrices (BM) and TFTs, etc. increase, and the aperture ratio of the panel decreases. Therefore, improvement of the transmittance of the display portion is emphasized.

[0015] In view of the above circumstances, an object of the present invention is to provide a liquid crystal aligning agent, a liquid crystal alignment film obtained from the liquid crystal aligning agent, and a liquid crystal display element using the liquid crystal alignment film, wherein the liquid crystal aligning agent can obtain a liquid crystal alignment film having a high voltage holding ratio even after being exposed to high temperature and high humidity for a long time, and in addition, the relaxation of accumulated charges is fast and the afterimage characteristics are excellent.

[0016] Another object thereof is to provide a liquid crystal aligning agent, a liquid crystal alignment film obtained from the liquid crystal aligning agent, and a liquid crystal display element using the liquid crystal alignment film, wherein the liquid crystal aligning agent can obtain a liquid crystal alignment film having a high light transmittance.

[0017] Means for Solving the Problems

[0018] The inventor of the present invention conducted in-depth research to solve the above problems and found that a liquid crystal aligning agent containing specific components is effective for achieving the above object, thus completing the present invention.

[0019] Based on this insight, the present invention has the following gist.

[0020] A liquid crystal aligning agent containing a polymer component having a first repeating unit (a1) and a second repeating unit (a2), wherein the first repeating unit (a1) is selected from the group consisting of repeating units represented by the following formula (1-a) and repeating units represented by the following formula (1-i), and the second repeating unit (a2) is selected from the group consisting of repeating units represented by the following formula (2-a) and repeating units represented by the following formula (2-i).

[0021]

[0022] (X1 and X2 represent a tetravalent organic group. Y1 represents a divalent organic group having any one of the structures represented by the following formulas (S1) to (S3). Y2 represents a divalent organic group represented by the following formula (2c). Two R1 and R2 each independently represent a hydrogen atom or a monovalent organic group. Two Z1 and Z2 each independently represent a hydrogen atom or a monovalent organic group.)

[0023]

[0024] (X 1 and X 2 each independently represent a single bond, -(CH2) a -(a is an integer of 1 to 15), -CONH-, -NHCO-, -CON(CH3)-, -NH-, -O-, -COO-, -OCO- or -((CH2) a1 -A1) m1 -. Wherein, a1 is an integer of 1 to 15, A1 represents -O- or -COO-, and m1 is an integer of 1 to 2. G 1 and G 2 each independently represent a divalent cyclic group selected from the group consisting of a divalent aromatic group having 6 to 12 carbon atoms and a divalent alicyclic group having 3 to 8 carbon atoms. Any hydrogen atom on the above cyclic group is optionally substituted. m and n are each independently an integer of 0 to 3, and m + n is 1 to 6, preferably 1 to 4. R 1 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, and any hydrogen atom forming R 1 is optionally substituted by a fluorine atom. In the presence of a plurality of X 1 , X 2 , G 1 , G2 In the case of a1, m1, and A1, there are multiple Xs 1 、X 2 、G 1 、G 2 、a1, m1, and A1 are each independently defined as above.)

[0025] -x 3 -R 2 (S2)

[0026] (X 3 represents a single bond, -CONH-, -NHCO-, -CO-N(CH3)-, -NH-, -O-, -CH2O-, -COO-, or -OCO-. R 2 represents an alkyl group having 1 to 20 carbon atoms or an alkoxyalkyl group having 2 to 20 carbon atoms, and any hydrogen atom forming R 2 is optionally substituted with a fluorine atom.)

[0027] -X 4 -R 3 (S3)

[0028] (X 4 represents -CONH-, -NHCO-, -O-, -CH2O-, -COO-, or -OCO-. R 3 represents a structure having a steroid skeleton.)

[0029]

[0030] (R represents a hydrogen atom or a monovalent organic group. * represents a bonding bond.)

[0031] It should be noted that in this specification, * represents a bonding bond in any case. Boc represents tert-butoxycarbonyl. As the halogen atom, examples include: fluorine atom, chlorine atom, bromine atom, iodine atom. As the carbamate-based protecting group, examples include tert-butoxycarbonyl and 9-fluorenylmethoxycarbonyl.

[0032] Advantages of the Invention

[0033] According to the liquid crystal aligning agent of the present invention, a liquid crystal alignment film can be obtained which has a high voltage holding ratio even after being exposed to high temperature and high humidity for a long time, and in addition, has a fast relaxation of accumulated charges and excellent afterimage characteristics.

[0034] Moreover, according to the liquid crystal aligning agent of the present invention, a liquid crystal alignment film having a high light transmittance can be obtained.

[0035] The mechanism by which the present invention achieves the above effects is not necessarily clear, and the following may be considered as one of the reasons. That is, it is considered that by using the liquid crystal aligning agent containing the above polymer, hydrolysis of the polymer is less likely to occur even under high temperature and high humidity, and thus a liquid crystal alignment film with a high voltage holding ratio can be obtained. In addition, it is considered that one of the main reasons for the reduction in light transmittance is to determine the absorbance in the visible region using an oxidant of the polymer as a model compound. As a result, the absorbance of the oxidant composed of the above polymer is extremely small, and thus a liquid crystal alignment film with high light transmittance can be obtained. Detailed Embodiments

[0036] The following describes each component contained in the liquid crystal aligning agent of the present disclosure and other components optionally blended as needed.

[0037] <Polymer Component>

[0038] The liquid crystal aligning agent of the present invention contains a polymer component having a first repeating unit (a1) and a second repeating unit (a2), wherein the first repeating unit (a1) is selected from the group consisting of the repeating unit represented by the above formula (1-a) and the repeating unit represented by the above formula (1-i), and the second repeating unit (a2) is selected from the group consisting of the repeating unit represented by the above formula (2-a) and the repeating unit represented by the above formula (2-i).

[0039] As specific embodiments of the above polymer component, the following can be cited: (i) at least one polymer (P-a1+a2) (hereinafter, also referred to as a copolymer) selected from the group consisting of a polyimide precursor having the above first repeating unit (a1) and a second repeating unit (a2) in the same molecule and an imidized polymer of the polyimide precursor; (ii) a mixture of a polymer (P-a1) and a polymer (P-a2) (hereinafter, also referred to as a blended polymer), wherein the (P-a1) is at least one polymer selected from the group consisting of a polyimide precursor having the above first repeating unit (a1) and an imidized polymer of the polyimide precursor, and the (P-a2) is at least one polymer selected from the group consisting of a polyimide precursor having the above second repeating unit (a2) and an imidized polymer of the polyimide precursor. The above copolymer or the above blended polymer can be used alone or in combination.

[0040] It should be noted that the above polymer component may further contain at least one polymer selected from the group consisting of a polyimide precursor that does not have the first repeating unit (a1) and the second repeating unit (a2) and an imidized polymer of the polyimide precursor.

[0041] When the polymer component is the above copolymer, the total of the above first repeating unit (a1) and the above second repeating unit (a2) is preferably 5 to 100 mol%, more preferably 10 to 100 mol%, of the total repeating units constituting the above copolymer.

[0042] In addition, the content ratio of the above repeating unit (a1) is preferably 1 to 90 mol%, more preferably 1 to 85 mol%, of the total repeating units constituting the above copolymer.

[0043] When the polymer component is the above blend polymer, in terms of improving the liquid crystal orientation, the content ratio of the above repeating unit (a1) is preferably 1 mol% or more and 99 mol% or less, more preferably 2 mol% or more and 95 mol% or less, further preferably 5 mol% or more and 90 mol% or less, of the total repeating units constituting the above polymer (P-a1).

[0044] In addition, from the viewpoint of efficiently obtaining the effects of the present invention, the content ratio of the above repeating unit (a2) is 5 mol% or more and 90 mol% or less, more preferably 10 mol% or more and 80 mol% or less, of the total repeating units constituting the above polymer (P-a2).

[0045] In addition, the mass ratio of the content of the above polymer (P-a2) to the content of the above polymer (P-a1) is preferably 5 / 95 to 95 / 5, more preferably 10 / 90 to 90 / 10.

[0046] (First repeating unit (a1))

[0047] In the above formula (1-a) and the above formula (1-i), Y1 represents a divalent organic group having the structure shown in the above formula (S1) to (S3). Y1 is preferably a divalent organic group derived from a diamine having the structure shown in the above formula (S1) to (S3).

[0048] Specific examples of the divalent organic group having the structure shown in the above formula (S1) to (S3) include a divalent organic group derived from an aromatic diamine (d) having the structure shown in the above formula (S1) to (S3) in the side chain. The divalent organic group having the structure shown in the above formula (S1) to (S3) is preferably a group obtained by removing two amino groups from the above aromatic diamine (d).

[0049] In G of the above formula (S1) 1 and G 2Among them, as substituents on the above-mentioned cyclic group, for example, substituents selected from the group consisting of a halogen atom, a halogen atom-containing alkyl group, a halogen atom-containing alkoxy group, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 1 to 10 carbon atoms, and a heteroatom-containing group in which any carbon-carbon bond of the above-mentioned halogen atom-containing alkyl group, halogen atom-containing alkoxy group, alkyl group, alkoxy group, and alkenyl group is interrupted by an oxygen atom can be cited.

[0050] As preferred specific examples of the structure represented by the above formula (S1), structures represented by the following formulas (S1-1) to (S1-7) can be cited. As a preferred specific example of the structure represented by the above formula (S3), the structure represented by (S3-a) can be cited. It should be noted that in the formula (S3-a), X represents the formula (X1), the formula (X2), or -CH2O-, Col represents the formula (Col-1), the formula (Col-2), or the formula (Col-3), and G represents the formula (G1), the formula (G2), the formula (G3), or the formula (G4).

[0051]

[0052] In the above formula, R 1 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. X p represents -(CH2) a -(where a is an integer from 1 to 15), -CONH-, -NHCO-, -CO-N(CH3)-, -NH-, -O-, -CH2O-, -CH2-OCO-, -COO-, or -OCO-. A1 represents an oxygen atom or -COO-* (where the bonded bond with "*" is bonded to (CH2) a2 bonded), A2 represents an oxygen atom or *-COO- (where the bonded bond with "*" is bonded to (CH2) a2 bonded), a1 and a3 are each independently an integer 0 or 1, a2 is an integer from 1 to 10, and Cy represents 1,4-cyclohexylene or 1,4-phenylene.

[0053]

[0054] In the above formula (S2), from the viewpoint of improving the liquid crystal alignment, X 3 is preferably -CONH-, -NHCO-, -O-, -CH2O-, -COO-, or -OCO-.

[0055] From the viewpoint of liquid crystal alignment, R 2 is preferably an alkyl group having 3 to 20 carbon atoms or an alkoxyalkyl group having 2 to 20 carbon atoms. Forming R 2Any hydrogen atom thereof is optionally substituted by a fluorine atom.

[0056] The above aromatic diamine (d) preferably has at least one benzene ring.

[0057] As specific examples of the aromatic diamine (d), diamines represented by the following formula (d1) or formula (d2) can be cited.

[0058]

[0059] (X represents a single bond, -O-, -C(CH3)2-, -NH-, -CO-, -(CH2) m -, -SO2-, -O-(CH2) m -O-, -O-C(CH3)2-, -CO-(CH2) m -, -NH-(CH2) m -, -SO2-(CH2) m -, -CONH-(CH2) m -, -CONH-(CH2) m -NHCO- or -COO-(CH2) m -OCO- divalent organic group. m is an integer from 1 to 8. Y represents any structure in the above formula (S1) to (S3). In the above formula (d2), the two Ys are optionally the same or different from each other.)

[0060] As preferred examples of the diamine represented by the above formula (d1), the following formula (d1-1) to (d1-7) can be cited. As preferred examples of the diamine represented by the above formula (d2), the following formula (d2-1) to (d2-6) can be cited.

[0061]

[0062] (X v1 ~X v4 、X p1 ~X p8 each independently represents -(CH2) a -(a is an integer from 1 to 15), -CONH-, -NHCO-, -CO-N(CH3)-, -NH-, -O-, -CH2O-, -CH2-OCO-, -COO-, or -OCO-, X V5 ~X V6 、X s1 ~X s4 each independently represents -O-, -CH2O-, -COO-, or -OCO-. X v7represents a single bond, -CONH-, -NHCO-, -CO-N(CH3)-, -NH-, -O-, -CH2O-, -COO- or -OCO-. X a ~X f represents a single bond, -O-, -NH-, or -O-(CH2) m -O-(where m represents an integer from 1 to 8), R v1 ~R v4 、R 1a ~R 1h each independently represents -C n H 2n+1 (where n represents an integer from 1 to 20), or -O-C n H 2n+1 (where n represents an integer from 2 to 20). )

[0063] In the above formula (1-a) and the above formula (1-i), X1 represents a tetravalent organic group. X1 preferably represents a tetravalent organic group derived from a tetracarboxylic dianhydride or its derivative. As such a tetravalent organic group, examples include: a tetravalent organic group derived from an acyclic aliphatic tetracarboxylic dianhydride or its derivative, a tetravalent organic group derived from a cycloaliphatic tetracarboxylic dianhydride or its derivative, or a tetravalent organic group derived from an aromatic tetracarboxylic dianhydride or its derivative, preferably a tetravalent organic group derived from the tetracarboxylic dianhydride or its derivative represented by the following formula (3).

[0064]

[0065] (X represents any structure selected from the following formulas (x-1) to (x-13).)

[0066]

[0067] (R 1 ~R 4 each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, a monovalent organic group having 1 to 6 carbon atoms containing a fluorine atom, or a phenyl group. R 5 and R 6 each independently represents a hydrogen atom or a methyl group. j and k are integers 0 or 1, and A1 and A2 each independently represent a single bond, -O-, -CO-, -COO-, a phenylene group, a sulfonyl group, or an amide group. *1 is a bonding bond bonded to one acid anhydride group, and *2 is a bonding bond bonded to the other acid anhydride group. In the above formula (x-13), the two A2s are optionally the same as or different from each other. )

[0068] As more preferred specific examples of the above formula (x-1), the following formulas (X1-1) to (X1-6) can be cited.

[0069]

[0070] As preferred specific examples of the above formulas (x - 12) and (x - 13), the following formulas (x - 14) to (x - 29) can be cited.

[0071]

[0072]

[0073] As preferred examples of the tetracarboxylic dianhydride or its derivative represented by the above formula (3), the tetracarboxylic dianhydride or its derivative represented by the formula (3) in which X is the above formulas (x - 1) to (x - 7), (x - 11) to (x - 13) can be cited.

[0074] In the above formula (1 - a), two R1s each independently represent a hydrogen atom or a monovalent organic group. Examples of the monovalent organic group include a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. Two R1s each independently preferably represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.

[0075] In the above formula (1 - a), two Z1s each independently represent a hydrogen atom or a monovalent organic group. Examples of the monovalent organic group include: a hydrogen atom, an optionally substituted alkyl group having 1 to 10 carbon atoms, an optionally substituted alkenyl group having 2 to 10 carbon atoms, an optionally substituted alkynyl group having 2 to 10 carbon atoms, a tert - butoxycarbonyl group or a 9 - fluorenylmethoxycarbonyl group. Examples of the above substituents include: a halogen atom, a hydroxyl group, a carboxyl group, an amino group, a nitrile group, etc. Two Z1s each independently preferably represent a hydrogen atom or a methyl group.

[0076] In the above formula (1 - a) and the above formula (1 - i), X1, Y1, R1, and Z1 can each be one kind or two or more kinds.

[0077] (Second repeating unit (a2))

[0078] In the above formula (2 - a) and the above formula (2 - i), Y2 represents a divalent organic group represented by the following formula (2c).

[0079]

[0080] (R represents a hydrogen atom or a monovalent organic group.)

[0081] Examples of the monovalent organic group of R in the above formula (2c) include: an alkyl group having 1 to 12 carbon atoms, an alkoxyalkyl group, a phenyl group, etc. Examples of the alkyl group having 1 to 12 carbon atoms include: a methyl group, an ethyl group, a propyl group, etc.

[0082] In the above formula (2c), from the viewpoint of preferably obtaining the effects of the present invention, R is preferably a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an alkoxyalkyl group, or a phenyl group.

[0083] As a more preferred specific example of the above Y2, a group formed by removing two amino groups from a carbazole selected from the group consisting of 3,6-diaminocarbazole, 9-methyl-3,6-diaminocarbazole, 9-ethyl-3,6-diaminocarbazole, and 9-phenyl-3,6-diaminocarbazole can be cited.

[0084] Examples of X2 in the above formula (2-a) and the above formula (2-i) include the same groups as X1 in the above formula (1-a) and the above formula (1-i).

[0085] Examples of R2 in the above formula (2-a) include the same groups as R1 in the above formula (1-a).

[0086] Examples of Z2 in the above formula (2-a) include the same groups as Z1 in the above formula (1-a).

[0087] In the above formula (2-a) and the above formula (2-i), X2, Y2, R2, and Z2 can each be one kind or two or more kinds.

[0088] (Third repeating unit)

[0089] The above polymer component may further have a third repeating unit (a3) selected from the group consisting of a repeating unit represented by the following formula (3-a) and a repeating unit represented by the following formula (3-i).

[0090]

[0091] (X3 represents a tetravalent organic group. Y3 represents a divalent organic group, which represents a divalent organic group other than the divalent organic groups having the structures shown in the above formulas (S1) to (S3) and the divalent organic group shown in the above formula (2c). Two R3s and two Z3s are synonymous with R1 and Z1 in formula (1-a), respectively.)

[0092] As a specific embodiment of the polymer component further having the above third repeating unit (a3), copolymer and blended polymer embodiments can be cited.

[0093] Examples of the above copolymer include at least one polymer selected from the group consisting of a polyimide precursor having the above first repeating unit (a1), the above second repeating unit (a2), and the above third repeating unit (a3) in the same molecule and an imidized polymer of the polyimide precursor.

[0094] Examples of the above-mentioned copolymerized polymer include a mixture of a polymer (P-a1+a2) and a polymer (P-a1+a3), where (P-a1+a2) is at least one polymer selected from the group consisting of a polyimide precursor having the above-mentioned first repeating unit (a1) and the above-mentioned second repeating unit (a2) in the same molecule and an imidized polymer of the polyimide precursor, and (P-a1+a3) is at least one polymer selected from the group consisting of a polyimide precursor having the above-mentioned first repeating unit (a1) and the above-mentioned third repeating unit (a3) in the same molecule and an imidized polymer of the polyimide precursor. The above-mentioned polymer (P-a1+a3) may not have the above-mentioned second repeating unit (a2). The above-mentioned copolymer or the above-mentioned copolymerized polymer may be used alone or in combination.

[0095] When the polymer component is the above-mentioned copolymer, the content ratio of the above-mentioned repeating unit (a3) is preferably 5 to 90 mol%, more preferably 10 to 80 mol%, based on the total repeating units constituting the above-mentioned copolymer.

[0096] In this case, the total of the above-mentioned first repeating unit (a1) and the above-mentioned second repeating unit (a2) is preferably 10 to 95 mol%, more preferably 20 to 90 mol%, based on the total repeating units constituting the above-mentioned copolymer.

[0097] When the polymer component is the above-mentioned copolymerized polymer, the mass ratio of the content of the above-mentioned polymer (P-a1+a3) to the content of the above-mentioned polymer (P-a1+a2) is preferably 5 / 95 to 95 / 5, more preferably 10 / 90 to 90 / 10.

[0098] Y3 preferably represents a divalent organic group derived from a diamine.Specific examples of the divalent organic group of Y3 include, but are not limited to, organic groups formed by removing two amino groups from the following diamines (hereinafter also referred to as other diamines): p-phenylenediamine, m-phenylenediamine, 4-(2-(methylamino)ethyl)aniline, 2,4-diaminobenzoic acid, 2,5-diaminobenzoic acid, 3,5-diaminobenzoic acid, and diamines having a carboxyl group such as diamine compounds represented by the following formulas (3b-1) to (3b-4), 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 1,2-bis(4-aminophenyl)ethane, 1,3-bis(4-aminophenyl)propane, 1,4-bis(4-aminophenyl)butane, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,2-bis(4-aminophenoxy)ethane, 1,2-bis(4-amino-2-methylphenoxy)ethane, 1,3-bis(4-aminophenoxy)propane, 1,4-bis(4-aminophenoxy)butane, 1,5-bis(4-aminophenoxy)pentane, 1,6-bis(4-aminophenoxy)hexane, 4-(2-(4-aminophenoxy)ethoxy)-3-fluoroaniline, bis(2-(4-aminophenoxy)ethyl) ether, 4-amino-4'-(2-(4-aminophenoxy)ethoxy)biphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl, 1,4-diaminonaphthalene, 1,5-diaminonaphthalene, 2,6-diaminonaphthalene, 2,7-diaminonaphthalene, 2,2'-bis[4-(4-aminophenoxy)phenyl]propane, 2,2'-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2'-bis(4-aminophenyl)propane, diamines having a urea bond such as 1,3-bis(4-aminophenethyl)urea, diamines having a photopolymerizable group at the terminal such as 2-(2,4-diaminophenoxy)ethyl methacrylate, 2,4-diamino-N,N-diallylaniline, diamines having a free radical initiating function such as the following formulas (R1) to (R5), diamines having a photosensitizing function that exhibit a sensitizing effect upon light irradiation such as 4,4'-diaminobenzophenone, 3,3'-diaminobenzophenone, 9,9-bis(4-aminophenyl)fluorene, diamines having a heterocycle such as 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, and the following formulas (z-1) to (z-18), diamines having a diphenylamine skeleton such as the following formulas (Dp-1) to (Dp-9), diamines having a group "-N(D)-" (D represents a protecting group that is removed by heating and replaced by a hydrogen atom, preferably a tert-butoxycarbonyl group) such as the following formulas (5-1) to (5-10), diamines having an oxazoline structure such as the following formulas (Ox-1) to (Ox-2), etc.

[0099]

[0100] (In formula (3b-1), A 1 represents a single bond, -CH2-, -C2H4-, -C(CH3)2-, -CF2-, -C(CF3)2-, -O-, -CO-, -NH-, -N(CH3)-, -CONH-, -NHCO-, -CH2O-, -OCH2-, -COO-, -OCO-, -CON(CH3)- or -N(CH3)CO-, m1 and m2 each independently represent an integer from 0 to 4, and m1 + m2 represents an integer from 1 to 4. In formula (3b-2), m3 and m4 each independently represent an integer from 1 to 5. In formula (3b-3), A 2 represents a linear or branched alkyl group having 1 to 5 carbon atoms, and m5 represents an integer from 1 to 5. In formula (3b-4), A 3 and A 4 each independently represent a single bond, -CH2-, -C2H4-, -C(CH3)2-, -CF2-, -C(CF3)2-, -O-, -CO-, -NH-, -N(CH3)-, -CONH-, -NHCO-, -CH2O-, -OCH2-, -COO-, -OCO-, -CO-N(CH3)- or -N(CH3)CO-, and m6 represents an integer from 1 to 4.)

[0101]

[0102]

[0103] (In formulas (R3) to (R5), n is an integer from 1 to 6.)

[0104]

[0105]

[0106] From the aspect of accelerating the response speed of liquid crystal display elements using the PSA method and the SC-PVA (Patterned Vertical Alignment) mode, one or more of the above-mentioned 4,4'-diaminobenzophenone, 3,3'-diaminobenzophenone, diamines having a photopolymerizable group at the terminal, diamines represented by the above formulas (R1) to (R5), and diamines represented by the above formulas (z-1) to (z-18) can be used in the production of the above polymer component.)

[0107] As other diamines, among those described above, from the viewpoint of preferably achieving the effects of the present invention, paraphenylenediamine, 3,5-diaminobenzoic acid, 4,4'-diaminodiphenylmethane, 4,4'-diaminobenzophenone, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2-(2,4-diaminophenoxy)ethyl methacrylate, 2,4-diamino-N,N-diallylaniline, the diamines represented by the above formulas (R1) to (R5), the diamines represented by the above formulas (z-1) to (z-18), the diamines represented by the above formulas (Dp-1) to (Dp-9), and the diamines represented by the above formulas (Ox-1) to (Ox-2) are preferred.

[0108] Examples of X3 in the above formula (3-a) and the above formula (3-i) include the same groups as X1 in the above formula (1-a) and the above formula (1-i).

[0109] Examples of R3 in the above formula (3-a) include the same groups as R1 in the above formula (1-a).

[0110] Examples of Z3 in the above formula (3-a) include the same groups as Z1 in the above formula (1-a).

[0111] In the above formula (3-a) and the above formula (3-i), X3, Y3, R3, and Z3 can each be one kind or two or more kinds.

[0112] <Manufacturing method of polymer>

[0113] Examples of the polyimide precursor used in the present invention include polyamic acid, polyamic acid ester, etc. The polyimide precursor used in the present invention can be synthesized, for example, by a known method as described in International Publication WO2013 / 157586.

[0114] Specifically, it is synthesized by subjecting a diamine component and a tetracarboxylic acid derivative component to a (polycondensation) reaction in a solvent. Examples of the above tetracarboxylic acid derivative component include a tetracarboxylic dianhydride or its derivative (tetracarboxylic dihalide, tetracarboxylic diester, or tetracarboxylic diester dihalide). When a part of the polymer contains an amic acid structure, for example, by reacting a tetracarboxylic dianhydride component with a diamine component, a polymer having an amic acid structure (polyamic acid) can be obtained. The solvent is not particularly limited as long as it can dissolve the resulting polymer.

[0115] For example, when obtaining a polymer having a repeating unit represented by the above formula (1-a) in which R1 is a hydrogen atom, as the diamine component, a diamine having a structure of -N(Z1)-Y1-N(Z1)- (the definitions of Y1 and Z1 are the same as those in the above formula (1-a)) is used, and in addition, as the tetracarboxylic acid derivative component, a tetracarboxylic acid derivative having a structure of the following formula is used.

[0116]

[0117] (The definition of X1 is the same as that in the above formula (1-a).)

[0118] In addition, polyimide can be obtained by subjecting the above polyimide precursor to a ring-closure (imidization) reaction. It should be noted that the imidization rate referred to in this specification means the proportion of imide groups in the total amount of imide groups and carboxyl groups (or their derivatives) derived from the tetracarboxylic dianhydride or its derivatives. In polyimide, the imidization rate does not necessarily need to be 100%, and can be arbitrarily adjusted according to the use and purpose.

[0119] From the viewpoint of ensuring solubility, the imidization rate of the polyimide contained in the liquid crystal aligning agent of the present invention is 10% to 95%, preferably 20% to 95%, and more preferably 30% to 90%.

[0120] As a method for imidizing the polyimide precursor, thermal imidization in which the solution of the polyimide precursor is directly heated or catalytic imidization in which a catalyst is added to the solution of the polyimide precursor can be cited.

[0121] When the polyimide precursor is thermally imidized in solution, the temperature is 100 to 400 °C, preferably 120 to 250 °C, and it is preferably carried out while removing the water generated by the imidization reaction outside the system.

[0122] The catalytic imidization of the polyimide precursor can be carried out as follows: A basic catalyst and an acid anhydride are added to the solution of the polyimide precursor, and stirring is carried out at -20 to 250 °C, preferably at 0 to 180 °C. The amount of the basic catalyst is 0.5 to 30 molar times that of the amic acid group, preferably 2 to 20 molar times, and the amount of the acid anhydride is 1 to 50 molar times that of the amic acid group, preferably 3 to 30 molar times. As the basic catalyst, pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine, etc. can be cited. Pyridine has an appropriate basicity to promote the reaction, so it is preferred. As the acid anhydride, acetic anhydride, trimellitic anhydride, pyromellitic anhydride, etc. can be cited. If acetic anhydride is used, the purification after the reaction is easy, so it is preferred. The imidization rate by catalytic imidization can be controlled by adjusting the amount of the catalyst, the reaction temperature, and the reaction time.

[0123] When recovering the resulting polyimide precursor or polyimide from the reaction solution of a polyimide precursor or polyimide, it is only necessary to pour the reaction solution into a solvent to precipitate it. Solvents for precipitation include: methanol, ethanol, isopropanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, toluene, benzene, water, etc. The polymer precipitated by pouring into the solvent can be recovered by filtration and then dried at normal pressure or reduced pressure at room temperature or by heating. In addition, if the operation of redissolving the polymer recovered by precipitation into an organic solvent and then reprecipitating and recovering is repeated 2 to 10 times, the impurities in the polymer can be reduced. As the solvent at this time, for example, alcohols, ketones, or hydrocarbons can be cited. If solvents selected from three or more of them are used, the purification efficiency is further improved, so it is preferred.

[0124] In the case of the polymer used in the present invention, considering the strength of the resulting liquid crystal alignment film, workability during film formation, and coatability, the weight-average molecular weight measured by the GPC (Gel Permeation Chromatography) method is preferably set to 5000 to 1,000,000, more preferably 10,000 to 150,000.

[0125] The mixing ratio of the polymer components used in the method for manufacturing the liquid crystal alignment film of the present invention is not particularly limited. For example, the total amount of the polymer components contained in the liquid crystal aligning agent is 0.1 to 30% by mass, preferably 3 to 10% by mass.

[0126] In addition, for example, the content of the above copolymer (polymer (P-a1+a2)) contained in the liquid crystal aligning agent is 1.5 to 9% by mass, preferably 2.5 to 9% by mass.

[0127] Moreover, for example, the total content of the above blend polymer (a mixture of polymer (P-a1) and polymer (P-a2)) contained in the liquid crystal aligning agent is 1.5 to 9% by mass, preferably 2.5 to 9% by mass.

[0128] In addition, in the liquid crystal aligning agent for manufacturing a liquid crystal alignment film, other polymers other than the above copolymer and the above blend polymer can also be mixed. At this time, the content of the other polymer is 0.5% by mass to 15% by mass of the total amount of the polymer components, preferably 1% by mass to 10% by mass. Examples of the other polymer include: polyimide precursors or their imidized polymers, acrylic polymers, methacrylic polymers, polystyrene, polyamides, or polysiloxanes other than the above copolymer and the above blend polymer.

[0129] The solvent contained in the liquid crystal aligning agent is not particularly limited as long as it can dissolve the polymer. For example, the following can be cited: lactone solvents such as γ-valerolactone and γ-butyrolactone; lactam solvents such as γ-butyrolactam, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-(n-propyl)-2-pyrrolidone, N-isopropyl-2-pyrrolidone, N-(n-butyl)-2-pyrrolidone, N-(tert-butyl)-2-pyrrolidone, N-(n-pentyl)-2-pyrrolidone, N-methoxypropyl-2-pyrrolidone, N-ethoxyethyl-2-pyrrolidone, N-methoxybutyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone; amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethyl lactamide, 3-methoxy-N,N-dimethylpropionamide, 3-butoxy-N,N-dimethylpropionamide; 4-hydroxy-4-methyl-2-pentanone, 2,6-dimethyl-4-heptanone (diisobutyl ketone), methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate, isoamyl lactate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monopropyl ether, ethylene glycol monoisopropyl ether, ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monobutyl ether, propylene glycol diacetate, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, tripropylene glycol monomethyl ether, isoamyl propionate, isoamyl isobutyrate, diisopropyl ether, diisopentyl ether; carbonate solvents such as ethylene carbonate and propylene carbonate; 1-hexanol, cyclohexanol, 1,2-ethylene glycol, 2,6-dimethyl-4-heptanol (diisobutyl carbinol), etc. They can be used alone or in combination of two or more.

[0130] As preferred solvent combinations, the following can be cited: N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether; N-methyl-2-pyrrolidone, γ-butyrolactone, and ethylene glycol monobutyl ether; N-methyl-2-pyrrolidone, γ-butyrolactone, and propylene glycol monobutyl ether; N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether; N-methyl-2-pyrrolidone, γ-butyrolactone, 4-hydroxy-4-methyl-2-pentanone, and diethylene glycol diethyl ether; N-ethyl-2-pyrrolidone, N-methyl-2-pyrrolidone, and 4-hydroxy-4-methyl-2-pentanone; N-methyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone, and 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 propylene glycol diacetate; γ-butyrolactone, 4-hydroxy-4-methyl-2-pentanone, and diisobutyl ketone; γ-butyrolactone, 4-hydroxy-4-methyl-2-pentanone, and propylene glycol diacetate; N-methyl-2-pyrrolidone, γ-butyrolactone, propylene glycol monobutyl ether, and diisobutyl ketone; N-methyl-2-pyrrolidone, γ-butyrolactone, propylene glycol monobutyl ether, and diisopropyl ether; N-methyl-2-pyrrolidone, γ-butyrolactone, propylene glycol monobutyl ether, and diisobutyl carbinol; N-methyl-2-pyrrolidone, γ-butyrolactone, and dipropylene glycol dimethyl ether; N-methyl-2-pyrrolidone, propylene glycol monobutyl ether, and dipropylene glycol dimethyl ether, etc. The types and contents of such solvents can be appropriately selected according to the coating device, coating conditions, coating environment, etc. of the liquid crystal aligning agent.

[0131] <Liquid Crystal Aligning Agent>

[0132] The liquid crystal aligning agent of the present invention may also contain other components other than those described above as needed, such as crosslinking compounds, functional silane compounds, surfactants, compounds having a photopolymerizable group, etc.

[0133] The crosslinking compound can be used for the purpose of improving the strength of the liquid crystal alignment film. As such a crosslinking compound, the following can be cited: the compounds having an isocyanate group or a cyclic carbonate group described in paragraphs

[0109] to

[0113] of International Publication Gazette WO2016 / 047771, or the compounds having at least one group selected from the group consisting of lower alkoxyalkyl groups, and further, compounds having a blocked isocyanate group, etc.

[0134] Block isocyanate compounds are commercially available. For example, CORONATE APSTABLE M, CORONATE 2503, 2515, 2507, 2513, 2555, MILLIONATE MS-50 (manufactured by Tosoh Corporation), TAKENATE B-830, B-815N, B-820NSU, B-842N, B-846N, B-870N, B-874N, B-882N (manufactured by Mitsui Chemicals, Inc.) etc. can be preferably used.

[0135] As specific examples of the preferred crosslinkable compounds, compounds represented by the following formulas (CL-1) to (CL-11) can be cited.

[0136]

[0137] The above is an example of the crosslinkable compound and is not limited thereto. In addition, the crosslinkable compound for the liquid crystal aligning agent of the present invention may be one kind, or two or more kinds may be combined.

[0138] The content of other crosslinkable compounds in the liquid crystal aligning agent of the present invention is 0.1 to 150 parts by mass, or 0.1 to 100 parts by mass, or 1 to 50 parts by mass with respect to 100 parts by mass of all polymer components.

[0139] The functional silane compound can be used for the purpose of improving the adhesion between the liquid crystal alignment film and the substrate. As specific examples, silane compounds described in paragraph

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

[0140] The surfactant can be used for the purpose of improving the thickness uniformity and surface smoothness of the liquid crystal alignment film. As the above compounds, fluorine-based surfactants, silicone-based surfactants, nonionic surfactants, etc. can be cited. Specific examples thereof can be cited as surfactants described in paragraph

[0117] of International Publication No. WO2016 / 047771. The amount of the surfactant used is preferably 0.01 to 2 parts by mass, more preferably 0.01 to 1 part by mass with respect to 100 parts by mass of all polymer components contained in the liquid crystal aligning agent.

[0141] Examples of the compound having a photopolymerizable group include compounds having one or more polymerizable unsaturated groups such as acrylate group and methacrylate group in the molecule, such as compounds represented by the following formulas (M-1) to (M-7).

[0142]

[0143] Moreover, in the liquid crystal aligning agent of the present invention, as a compound that promotes charge movement in the liquid crystal alignment film and promotes charge extraction of the device, a nitrogen atom-containing heterocyclic amine compound represented by Formula [M1] to Formula [M156] described in paragraphs

[0194] to

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

[0144] In the liquid crystal aligning agent of the present invention, an imidization accelerator or the like can also be added for the purpose of efficiently performing imidization by heating when firing the coating film.

[0145] The solid content concentration in the liquid crystal aligning agent (the ratio of the total mass of the components other than the solvent of the liquid crystal aligning agent to the total mass of the liquid crystal aligning agent) is appropriately selected in consideration of viscosity, volatility, etc., and is preferably in the range of 0.5 to 15% by mass, more preferably in the range of 1 to 10% by mass.

[0146] The particularly preferred range of the solid content concentration varies depending on the method used when coating the liquid crystal aligning agent on the substrate. For example, in the case of using the spin coating method, the solid content concentration is particularly preferably in the range of 1.5 to 4.5% by mass. In the case of using the printing method, it is particularly preferred that the solid content concentration is in the range of 3 to 9% by mass, thereby setting the solution viscosity in the range of 12 to 50 mPa·s. In the case of using the inkjet method, it is particularly preferred that the solid content concentration is in the range of 1 to 5% by mass, thereby setting the solution viscosity in the range of 3 to 15 mPa·s.

[0147] <Liquid Crystal Alignment Film / Liquid Crystal Display Element>

[0148] The liquid crystal alignment film of the present invention is obtained from the above-mentioned liquid crystal alignment agent. The liquid crystal alignment film of the present invention can be used for a horizontally oriented or vertically oriented liquid crystal alignment film, and is a liquid crystal alignment film suitable for a vertically oriented liquid crystal display element such as a VA mode or a PSA mode. The liquid crystal display element of the present invention has the above-mentioned liquid crystal alignment film. The liquid crystal display element of the present invention can be manufactured, for example, by a method comprising the following steps (1) to (3) or steps (1) to (4). In addition, the liquid crystal alignment film of the present invention can be preferably used for a liquid crystal display element obtained by the following method for manufacturing a liquid crystal display element, that is, coating on a pair of substrates having a conductive film to form a coating film, and the coating film is arranged in a relative manner with a layer of liquid crystal molecules sandwiched therebetween to form a liquid crystal box, and the liquid crystal box is irradiated with light in a state where a voltage is applied between the conductive films of the above-mentioned pair of substrates. More specifically, it is a PSA type liquid crystal display element and a liquid crystal display element for SC-PVA mode described later.

[0149] (1) Process of applying a liquid crystal alignment agent on a substrate

[0150] The liquid crystal alignment agent of the present invention is applied to one side of a substrate provided with a patterned transparent conductive film by a suitable coating method such as a roller coater method, a spin coating method, a printing method, an inkjet method, etc. Here, as a substrate, there is no particular limitation as long as it is a substrate with high transparency, and a plastic substrate such as an acrylic substrate, a polycarbonate substrate, etc. may also be used together with a glass substrate, a silicon nitride substrate, etc. In addition, in a reflective liquid crystal display element, if it is only a single-sided substrate, an opaque object such as a silicon wafer may also be used, and the electrode in this case may also use a light-reflecting material such as aluminum.

[0151] (2) Process of firing the coating film

[0152] After the liquid crystal orientation agent is applied, it is preferred to first perform preliminary heating (pre-baking) in order to prevent the liquid of the orientation agent after application from dripping. The pre-baking temperature is preferably 30 to 200°C, more preferably 40 to 150°C, and particularly preferably 40 to 100°C. The pre-baking time is preferably 0.25 to 10 minutes, more preferably 0.5 to 5 minutes. And it is preferred to further perform a heating (post-baking) process. The post-baking temperature is preferably 80 to 300°C, more preferably 120 to 250°C. The post-baking time is preferably 5 to 200 minutes, more preferably 10 to 100 minutes. The film thickness of the film formed in this way is preferably 5 to 300nm, more preferably 10 to 200nm.

[0153] The coating film formed in the above step (1) can be used as a liquid crystal alignment film as it is, or an alignment ability imparting treatment can be performed on the coating film. Examples of the alignment ability imparting treatment include, for example, a rubbing treatment in which a cloth made of fibers such as nylon, rayon, and cotton is wound into a roll and the coating film is rubbed in a certain direction; a photo-alignment treatment in which polarized or non-polarized radiation is irradiated onto the coating film, etc.

[0154] In the photo-alignment treatment, as the radiation irradiated onto the coating film, for example, ultraviolet rays and visible light containing light with a wavelength of 150 to 800 nm can be used. In the case where the radiation is polarized, it can be linearly polarized or partially polarized. Further, in the case where the radiation used is linearly polarized or partially polarized, the irradiation can be performed from a direction perpendicular to the substrate surface, from an inclined direction, or they can be combined. In the case of irradiating non-polarized radiation, the irradiation direction is set as an inclined direction.

[0155] (3) Step of forming a liquid crystal layer

[0156] (3-1) In the case of a VA type liquid crystal display element

[0157] As described above, two substrates formed with liquid crystal alignment films are prepared, and liquid crystal is disposed between the two substrates disposed opposite to each other. Specifically, the following two methods can be cited. The first method is a conventionally known method. First, the two substrates are disposed opposite to each other with a gap (cell gap) therebetween in such a manner that their respective liquid crystal alignment films face each other. Then, the peripheral portions of the two substrates are bonded using a sealant, and a liquid crystal composition is injected into the cell gap defined by the substrate surfaces and the sealant and brought into contact with the film surfaces, and then the injection holes are sealed.

[0158] In addition, the second method is a method called the ODF (One Drop Fill) method. At a prescribed location on one of the two substrates formed with liquid crystal alignment films, for example, an ultraviolet curable sealant is coated, and the liquid crystal composition is further dropped at several prescribed locations on the liquid crystal alignment film surface. Then, the other substrate is bonded in such a manner that the liquid crystal alignment films face each other, and the liquid crystal composition is spread over the entire surface of the substrate and brought into contact with the film surfaces. Then, ultraviolet light is irradiated onto the entire surface of the substrate to cure the sealant. In any case of using any method, it is desirable to further heat the liquid crystal composition used to a temperature at which it becomes isotropic and then slowly cool it to room temperature, thereby removing the flow alignment during liquid crystal filling.

[0159] (3-2) In the case of manufacturing a PSA type liquid crystal display element

[0160] Inject or drop a liquid crystal composition containing a polymerizable compound. Other than this aspect, it is the same as the above (3-1). As the polymerizable compound, for example, the polymerizable compounds represented by the above formulas (M-1) to (M-7) can be cited.

[0161] (3-3) In the case of using a liquid crystal aligning agent containing a compound having a polymerizable group to form a coating film on a substrate

[0162] After performing the same as the above (3-1), a method of manufacturing a liquid crystal display element by performing a process of irradiating ultraviolet rays described later can also be adopted. According to this method, similar to the case of manufacturing the above-mentioned PSA type liquid crystal display element, a liquid crystal display element excellent in response speed can be obtained with a small light irradiation amount. The compound having a polymerizable group can be a compound having one or more polymerizable unsaturated groups such as acrylate group and methacrylate group in the molecule represented by the above formulas (M-1) to (M-7). Its content is preferably 0.1 to 30 parts by mass, more preferably 1 to 20 parts by mass, based on 100 parts by mass of all polymer components. In addition, the above polymerizable group can also have a polymer for a liquid crystal aligning agent. As such a polymer, for example, a polymer obtained by using the following diamine component for reaction can be cited, and the diamine component contains a diamine having the above photopolymerizable group at the end.

[0163] (4) Process of irradiating ultraviolet rays

[0164] The liquid crystal cell is irradiated with light in a state where a voltage is applied between the conductive films of a pair of substrates obtained in the above (3-2) or (3-3). The voltage applied here can be set to, for example, a direct current or an alternating current of 5 to 50 V. In addition, as the light for irradiation, for example, ultraviolet rays and visible light containing light having a wavelength of 150 to 800 nm can be used, and ultraviolet rays containing light having a wavelength of 300 to 400 nm are preferred. As the light source for irradiation light, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, an excimer laser, etc. can be used. As the light irradiation amount, it is preferably 1000 to 200000 J / m 2 and more preferably 1000 to 100000 J / m 2 .

[0165] Moreover, a liquid crystal display element can be obtained by attaching a polarizing plate to the outer surface of the liquid crystal cell. As the polarizing plate attached to the outer surface of the liquid crystal cell, a polarizing plate made of a polarizing film called an "H film" can be cited; or a polarizing plate composed of the H film itself, and the H film is formed by sandwiching a polyvinyl alcohol stretched and oriented while absorbing iodine with a cellulose acetate protective film.

[0166] The liquid crystal display element of the present invention can be effectively used in various devices. For example, it can be used in various display devices such as clocks, portable game consoles, word processors, notebook computers, in-vehicle navigation systems, camcorders, PDAs (Personal Digital Assistants), digital cameras, mobile phones, smart phones, various monitors, liquid crystal TVs, and information displays.

[0167] Examples

[0168] Hereinafter, further detailed description will be made based on examples, but the present invention is not limited by any of the examples.

[0169] <Synthesis of Liquid Crystal Alignment Agent>

[0170] The abbreviations used in the preparation of the following liquid crystal alignment agent are as described below.

[0171] (Dianhydride)

[0172] BODA: Bicyclo[3,3,0]octane-2,4,6,8-tetracarboxylic dianhydride.

[0173] CBDA: 1,2,3,4-Cyclobutanetetracarboxylic dianhydride.

[0174] TCA: 2,3,5-Tricarboxycyclopentylacetic dianhydride.

[0175] (Diamine)

[0176] DA-1 to DA-11: Compounds represented by the following formulas (DA-1) to (DA-11), respectively.

[0177]

[0178]

[0179] (Additive)

[0180] AD-1: Compound represented by the following formula (AD-1).

[0181]

[0182] (Solvent)

[0183] NMP: N-Methyl-2-pyrrolidone, BCS: Butyl cellosolve.

[0184] <Molecular Weight Measurement>

[0185] Measuring device: Normal temperature gel permeation chromatography (GPC) (SSC-7200) manufactured by Senshu Science Co., Ltd.; Chromatographic column: Chromatographic column manufactured by Shodex Co., Ltd. (KD-803 and KD-805 in series); Column temperature: 50 °C; Eluent: N,N-dimethylformamide (as an additive, lithium bromide monohydrate (LiBr·H2O) is 30 mmol / L, phosphoric acid / anhydrous crystal (o-phosphoric acid) is 30 mmol / L, tetrahydrofuran (THF) is 10 mL / L); Flow rate: 1.0 mL / min; Standard sample for making calibration curve: TSK standard polyethylene oxide manufactured by Tosoh Corporation (molecular weight of about 900000, 150000, 100000, 30000), and polyethylene glycol manufactured by Polymer Laboratory Company (molecular weight of about 12000, 4000, 1000).

[0186] <Measurement of imidization rate>

[0187] Add 20 mg of polyimide powder to an NMR sample tube (NMR standard sampling tube φ5 manufactured by Kusano Science Co., Ltd.), add 1.0 mL of deuterated dimethyl sulfoxide (DMSO-d6, 0.05% TMS mixture), and apply ultrasonic waves to completely dissolve it. The proton NMR at 500 MHz of this solution was measured using an NMR measuring device (JNW-ECA500) manufactured by JEOL DATUM Co., Ltd.

[0188] The chemical imidization rate is obtained as follows: The proton derived from the structure that does not change before and after imidization is determined as the reference proton, and the peak integral value of this proton and the peak integral value of the proton of the NH group of amic acid that appears near 9.5 - 10.0 ppm are used to obtain it using the following formula. It should be noted that in the formula, x is the peak integral value of the proton of the NH group of amic acid, y is the peak integral value of the reference proton, and α is the ratio of the number of reference protons to one NH group proton of amic acid in the case of polyamic acid (imidization rate of 0%).

[0189] Imidization rate (%) = (1 - α·x / y) × 100

[0190] <Synthesis Example 1>

[0191] Dissolve BODA (2.50 g, 10.0 mmol), DA-1 (2.76 g, 14.0 mmol), and DA-8 (2.28 g, 6.0 mmol) in NMP (30.2 g), react at 60 °C for 3 hours, then add CBDA (1.92 g, 9.8 mmol) and NMP (7.7 g), and react at 40 °C for 4 hours to obtain a polyamic acid solution (1). The number average molecular weight Mn of this polyamic acid is 10360, and the weight average molecular weight Mw is 30350.

[0192] <Synthesis Example 2>

[0193] BODA (2.50 g, 10.0 mmol), DA-2 (2.96 g, 14.0 mmol), and DA-8 (2.28 g, 6.0 mmol) were dissolved in NMP (31.0 g). After reacting at 60 °C for 3 hours, CBDA (1.92 g, 9.8 mmol) and NMP (7.7 g) were added, and the reaction was carried out at 40 °C for 4 hours to obtain a polyamic acid solution (2). The Mn of this polyamic acid was 12,140 and the Mw was 37,600.

[0194] <Synthesis Example 3>

[0195] BODA (2.50 g, 10.0 mmol), DA-4 (2.79 g, 14.0 mmol), and DA-8 (2.28 g, 6.0 mmol) were dissolved in NMP (30.3 g). After reacting at 60 °C for 3 hours, CBDA (1.92 g, 9.8 mmol) and NMP (7.7 g) were added, and the reaction was carried out at 40 °C for 4 hours to obtain a polyamic acid solution (3). The Mn of this polyamic acid was 12,630 and the Mw was 36,540.

[0196] <Synthesis Example 4>

[0197] BODA (2.50 g, 10.0 mmol), DA-3 (5.90 g, 14.0 mmol), and DA-8 (2.28 g, 6.0 mmol) were mixed in NMP (38.3 g). After reacting at 60 °C for 3 hours, CBDA (1.81 g, 9.2 mmol) and NMP (7.8 g) were added, and the reaction was carried out at 40 °C for 3 hours to obtain a polyamic acid solution (4). The Mn of this polyamic acid was 12,340 and the Mw was 46,260.

[0198] <Synthesis Example 5>

[0199] BODA (2.50 g, 10.0 mmol), DA-1 (1.58 g, 8.0 mmol), DA-6 (1.94 g, 8.0 mmol), and DA-9 (1.58 g, 4.0 mmol) were mixed in NMP (30.4 g). After reacting at 60 °C for 3 hours, CBDA (1.94 g, 9.9 mmol) and NMP (7.7 g) were added, and the reaction was carried out at 40 °C for 3 hours to obtain a polyamic acid solution (5-a). The Mn of this polyamic acid was 11450 and the Mw was 37590. To the obtained polyamic acid solution (5-a) (6.0 g), NMP (6.0 g) and BCS (8.0 g) were added, and the mixture was stirred at room temperature for 2 hours to obtain a polyamic acid solution (5).

[0200] <Synthesis Example 6>

[0201] To the polyamic acid solution (5-a) (20.0 g) obtained in Synthesis Example 5, it was diluted with NMP to 6.5 mass%, and then acetic anhydride (4.27 g) and pyridine (1.33 g) as imidization catalysts were added, and the reaction was carried out at 50 °C for 3 hours. The reaction solution was poured into methanol (270 mL), and the obtained precipitate was filtered out. The precipitate was washed with methanol and dried under reduced pressure at 60 °C to obtain a polyimide powder. The imidization rate of this polyimide powder was 37%, the Mn was 10980, and the Mw was 34300. To the obtained polyimide powder (3.0 g), NMP (22.0 g) was added, and the mixture was stirred at 70 °C for 12 hours to dissolve it, obtaining a polyimide solution (1).

[0202] <Synthesis Example 7>

[0203] BODA (2.50 g, 10.0 mmol), DA-2 (1.69 g, 8.0 mmol), DA-6 (1.94 g, 8.0 mmol), and DA-9 (1.58 g, 4.0 mmol) were mixed in NMP (30.8 g). After reacting at 60 °C for 3 hours, CBDA (1.94 g, 9.9 mmol) and NMP (7.8 g) were added, and the reaction was carried out at 40 °C for 3 hours to obtain a polyamic acid solution (6-a). The Mn of this polyamic acid was 10860 and the Mw was 36010. To the obtained polyamic acid solution (6-a) (6.0 g), NMP (6.0 g) and BCS (8.0 g) were added, and the mixture was stirred at room temperature for 2 hours to obtain a polyamic acid solution (6).

[0204] <Synthesis Example 8>

[0205] To the polyamic acid solution (6-a) (20.0 g) obtained in Synthesis Example 7, NMP was added to dilute it to 6.5% by mass, and then acetic anhydride (4.23 g) and pyridine (1.31 g) as imidization catalysts were added, and the reaction was carried out at 50 °C for 3 hours. The reaction solution was poured into methanol (270 mL), and the resulting precipitate was filtered out. The precipitate was washed with methanol and dried under reduced pressure at 60 °C to obtain a polyimide powder. The imidization rate of this polyimide powder was 53%, Mn was 9920, and Mw was 32300. To the obtained polyimide powder (3.0 g), NMP (22.0 g) was added, and it was stirred at 70 °C for 12 hours to dissolve it, obtaining a polyimide solution (2).

[0206] <Synthesis Example 9>

[0207] BODA (2.50 g, 10.0 mmol), DA-4 (1.59 g, 8.0 mmol), DA-6 (1.94 g, 8.0 mmol), and DA-9 (1.58 g, 4.0 mmol) were mixed in NMP (30.4 g), and after reacting at 60 °C for 3 hours, CBDA (1.92 g, 9.8 mmol) and NMP (7.7 g) were added, and the reaction was carried out at 40 °C for 3 hours to obtain a polyamic acid solution (7-a). The Mn of this polyamic acid was 11030, and Mw was 33050. To the obtained polyamic acid solution (7-a) (6.0 g), NMP (6.0 g) and BCS (8.0 g) were added, and it was stirred at room temperature for 2 hours to obtain a polyamic acid solution (7).

[0208] <Synthesis Example 10>

[0209] To the polyamic acid solution (7-a) (20.0 g) obtained in Synthesis Example 9, NMP was added to dilute it to 6.5% by mass, and then acetic anhydride (4.27 g) and pyridine (1.32 g) as imidization catalysts were added, and the reaction was carried out at 50 °C for 3 hours. The reaction solution was poured into methanol (270 mL), and the resulting precipitate was filtered out. The precipitate was washed with methanol and dried under reduced pressure at 60 °C to obtain a polyimide powder. The imidization rate of this polyimide powder was 58%, Mn was 10490, and Mw was 31280. To the obtained polyimide powder (3.0 g), NMP (22.0 g) was added, and it was stirred at 70 °C for 12 hours to dissolve it, obtaining a polyimide solution (3).

[0210] <Synthesis Example 11>

[0211] BODA (2.50 g, 10.0 mmol), DA-3 (3.37 g, 8.0 mmol), DA-7 (1.42 g, 6.0 mmol), and DA-8 (2.28 g, 6.0 mmol) were mixed in NMP (38.3 g). After reacting at 60 °C for 3 hours, CBDA (1.95 g, 9.9 mmol) and NMP (7.8 g) were added, and the reaction was carried out at 40 °C for 3 hours to obtain a polyamic acid solution. The Mn of this polyamic acid was 9100 and the Mw was 24540. After diluting the obtained polyamic acid solution (20.0 g) with NMP to 6.5 mass%, acetic anhydride (3.54 g) and pyridine (1.10 g) as imidization catalysts were added, and the reaction was carried out at 80 °C for 3 hours. The reaction solution was poured into methanol (230 mL), and the obtained precipitate was filtered out. The precipitate was washed with methanol and dried under reduced pressure at 60 °C to obtain a polyimide powder. The imidization rate of this polyimide powder was 78%, the Mn was 9040, and the Mw was 21020. NMP (22.0 g) was added to the obtained polyimide powder (3.0 g), and it was stirred at 70 °C for 12 hours to dissolve, obtaining a polyimide solution (4).

[0212] <Synthesis Example 12>

[0213] TCA (4.37 g, 19.5 mmol), DA-1 (1.58 g, 8.0 mmol), DA-6 (1.94 g, 8.0 mmol), and DA-9 (1.58 g, 4.0 mmol) were mixed in NMP (37.9 g). After reacting at 60 °C for 6 hours, a polyamic acid solution was obtained. The Mn of this polyamic acid was 11860 and the Mw was 45870. After diluting the obtained polyamic acid solution (20.0 g) with NMP to 6.5 mass%, acetic anhydride (8.53 g) and pyridine (1.32 g) as imidization catalysts were added, and the reaction was carried out at 80 °C for 4 hours. The reaction solution was poured into methanol (285 mL), and the obtained precipitate was filtered out. The precipitate was washed with methanol and dried under reduced pressure at 60 °C to obtain a polyimide powder. The imidization rate of this polyimide powder was 66%, the Mn was 10500, and the Mw was 41300. NMP (22.0 g) was added to the obtained polyimide powder (3.0 g), and it was stirred at 70 °C for 12 hours to dissolve, obtaining a polyimide solution (5).

[0214] <Synthesis Example 13>

[0215] TCA (4.46 g, 19.9 mmol), DA-4 (1.59 g, 8.0 mmol), DA-6 (1.45 g, 6.0 mmol), and DA-8 (2.28 g, 6.0 mmol) were mixed in NMP (39.1 g) and reacted at 60 °C for 6 hours to obtain a polyamic acid solution. The Mn of this polyamic acid was 11,900 and the Mw was 44,800. After diluting the obtained polyamic acid solution (20.0 g) with NMP to 6.5 mass%, acetic anhydride (6.66 g) and pyridine (1.29 g) as imidization catalysts were added, and the mixture was reacted at 100 °C for 2 hours. The reaction solution was poured into methanol (243 mL), and the obtained precipitate was filtered out. The precipitate was washed with methanol and dried under reduced pressure at 60 °C to obtain a polyimide powder. The imidization rate of this polyimide powder was 73%, the Mn was 10,500, and the Mw was 40,300. NMP (22.0 g) was added to the obtained polyimide powder (3.0 g), and the mixture was stirred at 70 °C for 12 hours to dissolve it, obtaining a polyimide solution (6).

[0216] <Synthesis Example 14>

[0217] TCA (4.42 g, 19.7 mmol), DA-3 (3.37 g, 8.0 mmol), DA-8 (2.28 g, 6.0 mmol), and DA-7 (1.42 g, 6.0 mmol) were mixed in NMP (46.0 g) and reacted at 60 °C for 6 hours to obtain a polyamic acid solution. The Mn of this polyamic acid was 11,750 and the Mw was 54,510. After diluting the obtained polyamic acid solution (20.0 g) with NMP to 6.5 mass%, acetic anhydride (5.65 g) and pyridine (1.09 g) as imidization catalysts were added, and the mixture was reacted at 80 °C for 2 hours. The reaction solution was poured into methanol (239 mL), and the obtained precipitate was filtered out. The precipitate was washed with methanol and dried under reduced pressure at 60 °C to obtain a polyimide powder. The imidization rate of this polyimide powder was 71%, the Mn was 10,700, and the Mw was 48,300. NMP (22.0 g) was added to the obtained polyimide powder (3.0 g), and the mixture was stirred at 70 °C for 12 hours to dissolve it, obtaining a polyimide solution (7).

[0218] <Synthesis Example 15>

[0219] BODA (2.50 g, 10.0 mmol), DA-5 (0.99 g, 5.0 mmol), DA-10 (0.66 g, 2.0 mmol), DA-7 (1.43 g, 6.0 mmol) and DA-9 (2.76 g, 7.0 mmol) were mixed in NMP (33.4 g). After reacting at 60 °C for 3 hours, CBDA (1.93 g, 9.8 mmol) and NMP (7.7 g) were added, and the reaction was carried out at 40 °C for 3 hours to obtain a polyamic acid solution. The Mn of this polyamic acid was 11900 and the Mw was 44800. After diluting the obtained polyamic acid solution (20.0 g) with NMP to 6.5 mass%, acetic anhydride (3.96 g) and pyridine (1.23 g) as imidization catalysts were added, and the reaction was carried out at 50 °C for 3 hours. The reaction solution was poured into methanol (270 mL), and the obtained precipitate was filtered out. The precipitate was washed with methanol and dried under reduced pressure at 60 °C to obtain a polyimide powder. The imidization rate of this polyimide powder was 59%, the Mn was 9260, and the Mw was 23400. NMP (22.0 g) was added to the obtained polyimide powder (3.0 g), and after stirring and dissolving at 70 °C for 12 hours, NMP (5.0 g) and BCS (20.0 g) were added, and the mixture was stirred at room temperature for 2 hours to obtain a polyimide solution (8).

[0220] <Synthesis Example 16>

[0221] TCA (4.45 g, 19.8 mmol), DA-5 (1.39 g, 7.0 mmol), DA-10 (1.65 g, 5.0 mmol), DA-7 (0.94 g, 4.0 mmol) and DA-11 (3.03 g, 4.0 mmol) were mixed in NMP (45.9 g). After reacting at 60 °C for 6 hours, a polyamic acid solution was obtained. The Mn of this polyamic acid was 10360 and the Mw was 27730. After diluting the obtained polyamic acid solution (20.0 g) with NMP to 6.5 mass%, acetic anhydride (7.10 g) and pyridine (1.10 g) as imidization catalysts were added, and the reaction was carried out at 80 °C for 4 hours. The reaction solution was poured into methanol (240 mL), and the obtained precipitate was filtered out. The precipitate was washed with methanol and dried under reduced pressure at 60 °C to obtain a polyimide powder. The imidization rate of this polyimide was 68%, the Mn was 10210, and the Mw was 23320. NMP (22.0 g) was added to the obtained polyimide powder (3.0 g), and after stirring and dissolving at 70 °C for 12 hours, NMP (5.0 g) and BCS (20.0 g) were added, and the mixture was stirred at room temperature for 2 hours to obtain a polyimide solution (9).

[0222] The specifications of the polymers obtained in the above synthesis examples are shown in Table 1 below.

[0223] [Table 1]

[0224]

[0225] <Preparation of Liquid Crystal Alignment Agent>

[0226] [Example 1]

[0227] To the polyamic acid solution (1) (6.0 g) obtained in Synthesis Example 1, NMP (6.0 g) and BCS (8.0 g) were added, and the mixture was stirred at room temperature for 2 hours to obtain a liquid crystal alignment agent (A-1).

[0228] [Example 2, Comparative Examples 1 and 2]

[0229] The polyamic acid solutions (2), (3), and (4) were used respectively to replace the polyamic acid solution (1), and except for this, the liquid crystal alignment agents (A-2), (B-1), and (B-2) of Example 2, Comparative Examples 1 and 2 were obtained in the same manner as in Example 1.

[0230] [Example 3]

[0231] To the polyimide solution (1) (10.0 g) obtained in Synthesis Example 6, NMP (2.0 g) and BCS (8.0 g) were added, and the mixture was stirred at room temperature for 2 hours to obtain a liquid crystal alignment agent (A-3).

[0232] [Examples 4 and 5, Comparative Examples 3 to 6]

[0233] The polyimide solutions (2), (5), (3), (4), (6), and (7) were used respectively to replace the polyimide solution (1), and except for this, the liquid crystal alignment agents (A-4), (A-5), (B-3) to (B-6) of Examples 4 and 5, Comparative Examples 3 to 6 were obtained in the same manner as in Example 3.

[0234] [Example 6]

[0235] The polyamic acid solution (5) (7.0 g) obtained in Synthesis Example 5, the polyimide solution (8) (3.0 g) obtained in Synthesis Example 15, and AD-1 (0.06 g) were mixed to obtain a liquid crystal alignment agent (C-1).

[0236] [Examples 7, Comparative Example 7]

[0237] The polyamic acid solutions (6) and (7) were used respectively to replace the polyamic acid solution (5), and except for this, the liquid crystal alignment agents (C-2) and (C-3) of Examples 7 and Comparative Example 7 were obtained in the same manner as in Example 6.

[0238] [Comparative Example 8]

[0239] The liquid crystal aligning agent (B-4) (7.0 g) obtained in Comparative Example 4, the polyimide solution (9) (3.0 g) obtained in Synthesis Example 16, and AD-1 (0.06 g) were mixed to obtain a liquid crystal aligning agent (C-4).

[0240] [Table 2]

[0241]

[0242] No abnormalities such as turbidity or precipitation were observed in the liquid crystal aligning agents (A-1) to (A-5), (B-1) to (B-6), and (C-1) to (C-4) obtained as described above, and a uniform solution was confirmed. Using the obtained liquid crystal aligning agents, evaluation of transmittance, production of a liquid crystal cell, evaluation of voltage holding ratio, residual DC voltage, and evaluation of afterimage characteristics were performed.

[0243] [Evaluation of Transmittance]

[0244] The liquid crystal aligning agents (A-1) to (A-4), (B-1) to (B-3), and (C-1) to (C-4) obtained in the examples and comparative examples were spin-coated on a quartz substrate and dried on a hot plate at 70°C for 90 seconds. Then, firing was performed in an IR (infrared) oven at 230°C for 20 minutes to form a coating film with a film thickness of 100 nm, and a substrate with a liquid crystal alignment film was obtained. The substrate with this liquid crystal alignment film was set as the inner side, and another quartz substrate was used to sandwich a refractive liquid (contact liquid manufactured by Shimadzu Corporation) for the purpose of preventing light interference. In the evaluation of transmittance, a UV-3600 (manufactured by Shimadzu Corporation) was used as the measuring device, and measurement was performed at a temperature of 25°C and a scanning wavelength of 380 to 800 nm. At this time, two uncoated quartz substrates sandwiching the refractive liquid were used as a reference. The evaluation was based on the transmittance at a wavelength of 550 nm, and the values are shown in Table 3 below.

[0245] [Fabrication of Liquid Crystal Display Element for Evaluation of Voltage Holding Ratio and Residual DC Characteristics]

[0246] Using the liquid crystal aligning agents (A-1) to (A-5), (B-1) to (B-6), and (C-1) to (C-4) obtained in the use examples and comparative examples, a liquid crystal cell was fabricated in the order shown below. The liquid crystal aligning agent was spin-coated on a glass substrate with an ITO electrode, dried on a hot plate at 70 °C for 90 seconds, and then fired in an IR oven at 230 °C for 20 minutes to form a liquid crystal alignment film with a film thickness of 100 nm. Two substrates with this liquid crystal alignment film were prepared. On the liquid crystal alignment film of one of them, bead spacers with a diameter of 4 μm (manufactured by JGC Catalysts & Chemicals Ltd., Silk Ball, SW-D1) were coated, and a thermosetting sealant (XN-1500T manufactured by Mitsui Chemicals, Inc.) was printed. Then, the surface of the other substrate on which the liquid crystal alignment film was formed was set as the inner side, and after being bonded to the previous substrate, the sealant was cured to produce an empty cell. Liquid crystal MLC-3023 (manufactured by MERCK & Co., Inc.) was injected into this empty cell by the vacuum injection method to fabricate a liquid crystal cell. Then, while a DC voltage of 15 V was applied to this liquid crystal cell, UV that had passed through a cut-off filter of 325 nm or less was irradiated from the outside of the liquid crystal cell. 2 It should be noted that the illuminance of the UV was measured using a UV-MO3A manufactured by ORC Inc. Then, for the purpose of deactivating the unreacted polymerizable compounds remaining in the liquid crystal cell, a UV-FL irradiation device manufactured by Toshiba Lighting & Technology Corporation was used to irradiate UV for 30 minutes (UV lamp: FLR40SUV32 / A-1) in a state where no voltage was applied.

[0247] [Fabrication of Liquid Crystal Display Element for Residual Image Characteristic Evaluation]

[0248] Using the liquid crystal aligning agents (A-1) to (A-5), (B-1) to (B-5), and (C-1) to (C-4) obtained in the use examples and comparative examples, a liquid crystal cell was fabricated in the order shown below. The liquid crystal aligning agent was spin-coated on the ITO surfaces of an ITO electrode substrate (length: 35 mm, width: 30 mm, thickness: 0.7 mm) on which an ITO electrode pattern with a pixel size of 200 μm × 600 μm and a line width / line pitch (line / space) of 3 μm, respectively, was formed and a glass substrate with an ITO electrode (length: 35 mm, width: 30 mm, thickness: 0.7 mm) on which an optical spacer with a height of 3.2 μm was patterned. After drying on a hot plate at 70 °C for 90 seconds, it was fired in an IR oven at 230 °C for 20 minutes to form a liquid crystal alignment film with a film thickness of 100 nm. It should be noted that the ITO electrode substrate on which the ITO electrode pattern was formed was divided into four crosschecker (square grid) patterns and could be driven separately for each of the four regions.

[0249] Next, a sealant (XN-1500T manufactured by Mitsui Chemicals, Inc.) was printed. Next, the surface of the other substrate on which the liquid crystal alignment film was formed was set as the inner side, and after being bonded to the previous substrate, the sealant was cured to fabricate an empty cell. Liquid crystal MLC-3023 (manufactured by MERCK) was injected into the empty cell by a reduced-pressure injection method to fabricate a liquid crystal cell. While a DC voltage of 15V was applied to the liquid crystal cell, UV that had passed through a cut-off filter of 325 nm or less was irradiated from the outside of the liquid crystal cell at 10 J / cm 2 It should be noted that the illuminance of the UV was measured using a UV-MO3A manufactured by ORC Corporation. Then, for the purpose of deactivating unreacted polymerizable compounds remaining in the liquid crystal cell, UV (UV lamp: FLR40SUV32 / A-1) was irradiated for 30 minutes using a UV-FL irradiation device manufactured by Toshiba Lighting & Technology Corporation in a state where no voltage was applied.

[0250] [Evaluation of voltage holding ratio]

[0251] The voltage holding ratio was measured using the liquid crystal cell for evaluating the voltage holding ratio after UV irradiation. A voltage of 1V was applied for 60 μs in a hot air circulation oven at 60°C, and then the voltage after 16.67 msec was measured, and the percentage of voltage retention was calculated as the voltage holding ratio. A VHR-1 manufactured by TOYO Corporation was used for the measurement of the voltage holding ratio. The values are shown in Table 3 below. The higher the value, the better.

[0252] [Aging]

[0253] The liquid crystal cell after PSA treatment was placed in a high-temperature and high-humidity oven set at 85°C and a humidity of 85% for 3 to 7 days to be aged under high-temperature and high-humidity conditions. At this time, the voltage holding ratios at the initial stage, after PSA treatment, and after aging were measured. In addition, the reduction value of the voltage holding ratio due to aging (Δ (after PSA treatment - after aging)) was estimated. The respective results are shown in Table 3 below.

[0254] [Evaluation of residual DC voltage]

[0255] A rectangular wave of 30 Hz and 7.8 Vpp with a DC of 2V superimposed was applied to the liquid crystal cell for evaluating the voltage holding ratio fabricated above at 25°C for 100 hours, and the voltage remaining in the liquid crystal cell (residual DC voltage) after cutting off the DC voltage for 1 hour was obtained by the flicker elimination method. This value becomes an index of the afterimage caused by DC accumulation. When this value is 50 mV or less, it is considered that the afterimage characteristics are excellent, i.e., "good", and when it is greater than 50 mV, it is considered "bad". The results are shown in Table 3 below.

[0256] [Afterimage characteristics]

[0257] Using the liquid crystal cell for evaluating the afterimage characteristics produced as described above, an AC voltage of 60 Hz and 20 Vp-p is applied to two diagonal regions out of the four pixel regions, and it is driven for 168 hours at a temperature of 25°C. Then, all four pixel regions are driven with an AC voltage of 5 Vp-p, and the brightness difference of the pixels is visually observed. The state where almost no brightness difference is confirmed is set as "good", and the state where a brightness difference can be confirmed is set as "bad". The evaluation results are shown in Table 3.

[0258] [Table 3]

[0259]

[0260] *1) Aging for 3 days, *2) Aging for 7 days.

[0261] As shown in Table 3, compared with the liquid crystal alignment films obtained using the liquid crystal aligning agents (B-1) to (B-3), (C-3), (C-4) of Comparative Examples 1 to 3, 7, 8, the liquid crystal alignment films obtained using the liquid crystal aligning agents (A-1) to (A-4), (C-1), (C-2) of Examples 1 to 4, 6, 7 have a high transmittance. The liquid crystal aligning agents (A-1) to (A-4), (C-1), (C-2) of Examples 1 to 4, 6, 7 contain polyamic acid or polyimide obtained by using a diamine having the structure shown by formula (S1) and a diamine having the structure shown by formula (2c). It should be noted that a 1% difference in transmittance is a significant difference in this technical field.

[0262] In addition, when using the liquid crystal aligning agent in the examples, it is known that a liquid crystal alignment film having a high voltage holding ratio can also be obtained in the evaluation of voltage holding ratio and aging. In addition, it is known that a liquid crystal alignment film showing good characteristics can also be obtained in the evaluation of residual DC voltage and the evaluation of afterimage characteristics.

[0263] It should be noted that the entire contents of the specification, claims, drawings, and abstract of Japanese Patent Application No. 2020-060306 filed on March 30, 2020 are incorporated herein by reference as the disclosure of the specification of the present invention.

Claims

1. A liquid crystal aligning agent containing a polymer component having a first repeating unit (a1) and a second repeating unit (a2), wherein the first repeating unit (a1) is selected from the group consisting of a repeating unit represented by the following formula (1-a) and a repeating unit represented by the following formula (1-i), and the second repeating unit (a2) is selected from the group consisting of a repeating unit represented by the following formula (2-a) and a repeating unit represented by the following formula (2-i), wherein X1 and X2 represent a tetravalent organic group; Y1 represents a divalent organic group having any structure among the structures represented by the following formulas (S1-1) to (S1-7); Y2 represents a divalent organic group represented by the following formula (2c); two R1 and R2 each independently represent a hydrogen atom or a monovalent organic group; two Z1 and Z2 each independently represent a hydrogen atom or a monovalent organic group, In formulas (S1-1) to (S1-7), R 1 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; X p represents -(CH2) a -, -CONH-, -NHCO-, -CO-N(CH3)-, -NH-, -O-, -CH2O-, -CH2-OCO-, -COO- or -OCO-, in the -(CH2) a -, a is an integer of 1 to 15; A1 represents an oxygen atom or -COO-*, where, The bonding bond with "*" bonds to (CH2) a2 bonds; A2 represents an oxygen atom or *-COO-, wherein the bonding bond with "*" bonds to (CH2) a2 bonds; a1 and a3 are each independently an integer of 0 or 1, a2 is an integer from 1 to 10, Cy represents 1,4-cyclohexylene or 1,4-phenylene in formula (2c), R represents a hydrogen atom or a monovalent organic group; * represents a bonding bond.

2. The liquid crystal aligning agent according to claim 1, wherein the polymer component contains at least one polymer selected from the group consisting of a polyimide precursor having the repeating unit (a1) and the repeating unit (a2) in the same molecule and an imidized polymer of the polyimide precursor.

3. The liquid crystal aligning agent according to claim 1, wherein the polymer component contains a mixture of a polymer (P-a1) and a polymer (P-a2), the (P-a1) being at least one polymer selected from the group consisting of a polyimide precursor having the repeating unit (a1) and an imidized polymer of the polyimide precursor, and the (P-a2) being at least one polymer selected from the group consisting of a polyimide precursor having the repeating unit (a2) and an imidized polymer of the polyimide precursor.

4. The liquid crystal aligning agent according to any one of claims 1 to 3, wherein in the formula (1-a) and the formula (1-i), Y1 is a divalent organic group derived from a diamine represented by the following formula (d1) or formula (d2), In formula (d1) and formula (d2), X represents a divalent organic group of a single bond, -O-, -C(CH3)2-, -NH-, -CO-, -(CH2) m -, -SO2-, -O-(CH2) m -O-, -O-C(CH3)2-, -CO-(CH2) m -, -NH-(CH2) m -, -SO2-(CH2) m -, -CONH-(CH2) m -, -CONH-(CH2) m -NHCO-, or -COO-(CH2) m -OCO-; m is an integer from 1 to 8; Y represents any structure in the formula (S1-1) to (S1-7); in the formula (d2), two Ys are optionally the same or different from each other.

5. The liquid crystal aligning agent according to any one of claims 1 to 3, wherein in the formula (2c), R represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an alkoxyalkyl group, or a phenyl group.

6. The liquid crystal aligning agent according to any one of claims 1 to 3, wherein in the formula (2-a) and the formula (2-i), Y2 is a group obtained by removing two amino groups from a carbazole selected from the group consisting of 3,6-diaminocarbazole, 9-methyl-3,6-diaminocarbazole, 9-ethyl-3,6-diaminocarbazole, and 9-phenyl-3,6-diaminocarbazole.

7. The liquid crystal aligning agent according to any one of claims 1 to 3, wherein the polymer component further has a third repeating unit (a3), and the third repeating unit (a3) is selected from the group consisting of a repeating unit represented by the following formula (3-a) and a repeating unit represented by the following formula (3-i), In the formula, X3 represents a tetravalent organic group; Y3 represents a divalent organic group, which represents a divalent organic group other than the divalent organic groups having the structures shown in formulas (S1) to (S3) and the divalent organic group shown in formula (2c); two R3s and two Z3s are synonymous with R1 and Z1 in formula (1-a), respectively. In formula (S1), X 1 and X 2 each independently represents a single bond, -(CH2) a -, -CONH-, -NHCO-, -CON(CH3)-, -NH-, -O-, -COO-, -OCO- or -((CH2) a1 -A1) m1 -, where in the -(CH2) a -, a is an integer from 1 to 15; in the -((CH2) a1 -A1) m1 -, a1 is an integer from 1 to 15, A1 represents -O- or -COO-, and m1 is an integer from 1 to 2; G 1 and G 2 each independently represents a divalent cyclic group selected from the group consisting of a divalent aromatic group having 6 to 12 carbon atoms and a divalent alicyclic group having 3 to 8 carbon atoms; any hydrogen atom on the cyclic group is optionally substituted; m and n are each independently an integer from 0 to 3, and m + n is from 1 to 6; R 1 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, and any hydrogen atom forming R 1 is optionally substituted by a fluorine atom; when there are multiple X 1 , X 2 , G 1 , G 2 , a1, m1, and A1, the multiple X 1 , X 2 , G 1 , G 2 , a1, m1, and A1 each independently have the above definitions, --X 3 —R 2 (S2) In formula (S2), X 3 represents a single bond, -CONH-, -NHCO-, -CO-N(CH3)-, -NH-, -O-, -CH2O-, -COO- or -OCO-; R 2 represents an alkyl group having 1 to 20 carbon atoms or an alkoxyalkyl group having 2 to 20 carbon atoms, and any hydrogen atom forming R 2 is optionally substituted by a fluorine atom, —X 4 —R 3 (S3) In formula (S3), X 4 represents -CONH-, -NHCO-, -O-, -CH2O-, -COO- or -OCO-; R 3 represents a structure having a steroid skeleton.

8. The liquid crystal aligning agent according to claim 7, wherein the polymer component contains a mixture of polymer (P-a1+a2) and polymer (P-a1+a3), and the (P-a1+a2) is at least one polymer selected from the group consisting of a polyimide precursor having the first repeating unit (a1) and the second repeating unit (a2) in the same molecule and an imidized polymer of the polyimide precursor, and the (P-a1+a3) is at least one polymer selected from the group consisting of a polyimide precursor having the first repeating unit (a1) and the third repeating unit (a3) in the same molecule and an imidized polymer of the polyimide precursor.

9. The liquid crystal aligning agent according to any one of claims 1 to 3, wherein the polymer component is composed of at least one polymer selected from the group consisting of a polyimide precursor obtained by using a tetracarboxylic acid component containing the tetracarboxylic dianhydride or its derivative represented by the following formula (3) and an imidized polymer of the polyimide precursor. In formula (3), X represents a structure selected from the group consisting of the following (x-1) to (x-13). In (x-1) to (x-13), R 1 to R 4 each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, a monovalent organic group having 1 to 6 carbon atoms containing a fluorine atom, or a phenyl group; R 5 and R 6 each independently represents a hydrogen atom or a methyl group; j and k are integers 0 or 1, A1 and A2 each independently represents a single bond, -O-, -CO-, -COO-, a phenylene group, a sulfonyl group, or an amide group; *1 is a bonding bond bonded to one acid anhydride group, *2 is a bonding bond bonded to the other acid anhydride group; in the formula (x-13), the two A2s are optionally the same as or different from each other.

10. The liquid crystal aligning agent according to any one of claims 1 to 3, wherein the liquid crystal aligning agent further contains at least one crosslinkable compound selected from the group consisting of a compound having an isocyanate group or a cyclic carbonate group, a compound having a lower alkoxyalkyl group, and a compound having a blocked isocyanate group.

11. The liquid crystal aligning agent according to claim 3, wherein the mass ratio of the content of the polymer (P-a2) to the content of the polymer (P-a1) is 5 / 95 to 95 / 5.

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

13. A liquid crystal display element having the liquid crystal alignment film according to claim 12.

14. A method for manufacturing a liquid crystal display element, which is as follows: Coat the liquid crystal aligning agent according to any one of claims 1 to 11 on a pair of substrates having a conductive film to form a coating film, form a liquid crystal cell by opposingly disposing the coating films with a layer of liquid crystal molecules interposed therebetween, and irradiate the liquid crystal cell with light while a voltage is applied between the conductive films of the pair of substrates.

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