Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element using the same

Abstract

The present invention provides a liquid crystal display element with high reliability, which has little generation of afterimages and can minimize bright spots even when physical friction such as scratches caused by spacers occurs, and a preferred liquid crystal alignment film and liquid crystal alignment agent in the liquid crystal display element. A liquid crystal alignment agent, characterized in that it contains the following components (A) and (B). Component (A): a polymer (A) having at least one repeating unit selected from the group consisting of a repeating unit represented by the following formula (1) and a repeating unit represented by the following formula (2). Component (B): a compound represented by the following formula (B). (The definitions of the symbols in the formula are as described in the specification.)#imgabs0#

Description

Technical Field

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

[0002] In liquid crystal display elements, various driving methods have been developed with different electrode structures, physical properties of liquid crystal molecules used, manufacturing processes, etc. For example, known liquid crystal display elements include TN (twisted nematic), STN (super-twisted nematic), VA (vertical alignment), MVA (multi-domain vertical alignment), IPS (in-plane switching), FFS (fringe field switching), and PSA (polymer-sustained alignment).

[0003] These liquid crystal display elements have a liquid crystal alignment film for aligning liquid crystal molecules. The material of the liquid crystal alignment film is generally a film made of a polymer such as polyamic acid, polyimide, or polysiloxane, because of its excellent properties such as heat resistance, mechanical strength, and affinity with liquid crystal.

[0004] In recent years, the demand for high-quality images of liquid crystal display elements has become increasingly high. In particular, in displays of medical equipment and liquid crystal televisions, residual images, so-called "afterimages", have become a major problem when they are driven for a long time, and there is a high demand for reducing afterimages. From the perspective of further improving the quality of liquid crystal display elements, it is ideal to obtain liquid crystal display elements that are less likely to produce afterimages than before.

[0005] In view of such a situation, it is known to provide a liquid crystal aligning film and a liquid crystal aligning agent for providing a liquid crystal display element excellent in reducing the afterimage (Patent Documents 1, 2, and 3).

[0006] In addition, the liquid crystal display elements used in the above-mentioned applications are also required to have the ability to withstand long-term use in harsh usage environments. Patent document 4 discloses that a liquid crystal alignment agent containing specific compounds can produce a liquid crystal alignment film with little reduction in voltage retention even after long-term exposure to backlight, thereby obtaining a liquid crystal display element with high reliability.

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: International Publication No. 2016 / 063834 Pamphlet

[0010] Patent Document 2: International Publication No. 2015 / 060366 Pamphlet

[0011] Patent Document 3: Japanese Patent Application Publication No. 2018-054761

[0012] Patent Document 4: International Publication No. 2010 / 074269 Pamphlet Summary of the invention

[0013] Problems to be solved by the invention

[0014] In addition, so-called touch panel type liquid crystal display elements are widely used, and users frequently apply strong pressure to the display element with their fingers. At this time, the spacer inside the liquid crystal display element moves inside the liquid crystal display element and scratches the liquid crystal alignment film. This becomes the following technical problem: the liquid crystal alignment film, which is pressured by the spacer, cannot restrict the orientation of the liquid crystal, and even if the liquid crystal display element is displayed black, for example, light leaks from the periphery of the spacer and is displayed as a bright spot.

[0015] The liquid crystal alignment agents proposed in the past cannot necessarily solve all the above-mentioned technical problems. The present invention is completed based on the above situation, and its purpose is to provide a liquid crystal display element with less generation of residual images, which can minimize bright spots even if physical friction such as scratches caused by spacers occurs, and has high reliability. In addition, its purpose is to provide a liquid crystal alignment film and a liquid crystal alignment agent suitable for such a liquid crystal display element.

[0016] Solutions for solving problems

[0017] The present inventors have conducted intensive studies and, as a result, have found that the above-mentioned technical problems can be solved by using a liquid crystal aligning agent containing specific components, thereby completing the present invention.

[0018] The present invention is based on the following contents.

[0019] A liquid crystal aligning agent characterized by containing the following (A) component and (B) component.

[0020] Component (A): a polymer (A) having at least one repeating unit selected from the group consisting of a repeating unit represented by the following formula (1) and a repeating unit represented by the following formula (2).

[0021] Component (B): a compound (B) represented by the following formula (B).

[0022]

[0023] (X1 is a tetravalent organic group, Y1 is a divalent organic group. R1 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. Z 11 , Z 12 Each independently represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may have a substituent, an alkenyl group having 2 to 10 carbon atoms which may have a substituent, an alkynyl group having 2 to 10 carbon atoms which may have a substituent, a tert-butoxycarbonyl group, or a 9-fluorenylmethoxycarbonyl group.)

[0024]

[0025] (R represents an alkanediyl group having 1 to 4 carbon atoms. m and n each independently represent an integer of 1 or 2. 1 represents a single bond, -O-, -CO-, -OCO-, -COO-, -CONR- (R represents a hydrogen atom or a methyl group), -NRCONR- (R represents a hydrogen atom or a methyl group), -N=N-, -CH2-, -(CH2) n -(n is an integer of 2 to 18) or a divalent organic group (L), wherein the divalent organic group (L) is -(CH2) n -, wherein any CH2 is substituted by -O-, -CO-, -OCO-, -COO-, -CONR- (R represents a hydrogen atom or a methyl group), -NRCONR- (R represents a hydrogen atom or a methyl group), phenylene or biphenylene. In the divalent organic group (L), two oxygen atoms are not adjacent to each other, and two groups selected from -OCO-, -COO-, -CONR- (R represents a hydrogen atom or a methyl group) and -NRCONR- (R represents a hydrogen atom or a methyl group) are not adjacent to each other. In addition, any hydrogen atom on the phenylene or biphenylene ring is optionally substituted by a monovalent organic group. )

[0026] Effects of the Invention

[0027] According to the liquid crystal aligning agent of the present invention, it is possible to obtain a liquid crystal display element with little generation of afterimages and with the smallest bright spots even when physical friction such as scratches caused by spacers occurs, and a liquid crystal aligning film providing the liquid crystal display element. DETAILED DESCRIPTION

[0028] Each component contained in the liquid crystal aligning agent of this invention, and other components mix|blended arbitrarily as needed are demonstrated.

[0029] <Polymer (A)>

[0030] The liquid crystal aligning agent of the present invention contains a polymer (A) having at least one repeating unit selected from the group consisting of a repeating unit represented by the above formula (1) and a repeating unit represented by the above formula (2).

[0031] Specific examples of the alkyl group having 1 to 5 carbon atoms in R1 in the above formula (2) include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, etc. From the viewpoint of ease of imidization by heating, R1 is preferably a hydrogen atom or a methyl group.

[0032] As Z in the above formula (2) 11 , Z 12 Specific examples of the alkyl group having 1 to 10 carbon atoms include, in addition to the specific examples of the alkyl group having 1 to 5 carbon atoms exemplified in R1 above, hexyl, heptyl, octyl, nonyl, decyl, etc. 11 , Z 12 Specific examples of alkenyl groups having 2 to 10 carbon atoms include vinyl, propenyl, butenyl, etc. These may be linear or branched. 11 , Z 12 Specific examples of the alkynyl group having 2 to 10 carbon atoms include ethynyl, 1-propynyl, and 2-propynyl.

[0033] The above Z 11 , Z 12 It may have a substituent, and examples of the substituent include a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), a hydroxyl group, a cyano group, and an alkoxy group.

[0034] From the perspective of less afterimage, the Z 11 , Z 12 A hydrogen atom or a methyl group is respectively preferred independently.

[0035] In the above formulas (1) and (2), X1 and Y1 are the same as those defined above. As X1 of formula (1), a tetravalent organic group derived from at least one of the group consisting of tetracarboxylic dianhydride, tetracarboxylic diester and tetracarboxylic diester dihalide (hereinafter, they are collectively referred to as tetracarboxylic acid derivatives) can be cited. If specific examples are cited, a tetravalent organic group derived from aromatic tetracarboxylic dianhydride, aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, or their tetracarboxylic diester or tetracarboxylic diester dihalide can be cited. Y1 of formula (1) is a divalent organic group derived from diamine.

[0036] Here, aromatic tetracarboxylic dianhydride refers to an acid dianhydride obtained by intramolecular dehydration of four carboxyl groups, which contain at least one carboxyl group bonded to an aromatic ring. Aliphatic tetracarboxylic dianhydride refers to an acid dianhydride obtained by intramolecular dehydration of four carboxyl groups bonded to a chain hydrocarbon structure. Among them, it is not necessary to be composed only of a chain hydrocarbon structure, and a part of it may also have an alicyclic structure or an aromatic ring structure. Alicyclic tetracarboxylic dianhydride refers to an acid dianhydride obtained by intramolecular dehydration of four carboxyl groups, which contain at least one carboxyl group bonded to an alicyclic structure. Among them, none of the four carboxyl groups are bonded to an aromatic ring. In addition, it is not necessary to be composed only of an alicyclic structure, and a part of it may also have a chain hydrocarbon structure or an aromatic ring structure.

[0037] From the viewpoint of reducing the amount of afterimages in the obtained liquid crystal aligning film and suppressing bright spots, X1 is preferably a tetravalent organic group selected from the group consisting of the following formulae (4a) to (4n), (5a), and (6a).

[0038]

[0039] (x and y each independently represent a single bond, -O-, -CO-, -COO-, an alkylene group having 1 to 5 carbon atoms, a 1,4-phenylene group, a sulfonyl group or an amide group. 1 ~Z 6 Each independently represents a hydrogen atom, a methyl group, an ethyl group, a propyl group, a chlorine atom or a benzene ring. j and k are integers 0 or 1. m is an integer from 1 to 5. * represents a bonding bond. )

[0040] As a preferred specific example of the formula (4a) from the viewpoint of less afterimage, a structure represented by any of the following formulas (4a-1) to (4a-4) can be cited.

[0041]

[0042] Examples of the alkylene group having 1 to 5 carbon atoms in the formulae (5a) and (6a) include a methylene group, an ethylene group, a 1,3-propylene group, a 1,4-butylene group, and a 1,5-pentylene group.

[0043] From the viewpoint of reducing afterimages and ensuring solubility, X1 in the formula (1) is preferably a tetravalent organic group selected from the group consisting of the formulae (4a) to (4h), (4j), (4l), (4m) to (4n).

[0044] From the viewpoint of reducing afterimages, X1 in the formula (1) is preferably a tetravalent organic group selected from the group consisting of the formulae (4a) to (4h), (4j), (4l), and (4m) to (4n).

[0045] From the viewpoint of less afterimage, it is preferred that the content of one or more repeating units (hereinafter also referred to as repeating units (t)) selected from the group consisting of the repeating units represented by the formula (1) and the repeating units represented by the formula (2) is preferably 5 mol% or more, more preferably 10 mol% or more, and more preferably 20 mol% or more, in total, relative to all the repeating units. In the formula (1), X1 is a tetravalent organic group selected from the group consisting of the formulae (4a) to (4n), (5a) and the formula (6a), and Y1 is a divalent organic group.

[0046] As Y1 in formula (1), a divalent organic group derived from a diamine can be cited, for example, a divalent organic group derived from an aliphatic diamine, an alicyclic diamine or an aromatic diamine can be cited. Specific examples include, for example, m-xylylenediamine, ethylenediamine, 1,3-propanediamine, tetramethylenediamine, hexamethylenediamine, etc. as alicyclic diamines, for example, p-cyclohexanediamine, 4,4'-methylenebis(cyclohexylamine), etc.

[0047] Examples of the aromatic diamine include p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminobenzophenone, 4,4'-diaminodiphenyl ether, 4,4'-diaminoazobenzene, 1-(4-aminophenyl)-1,3,3-trimethyl-1H-indan-5-amine, 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-indan-6-amine, 3,5-diaminobenzoic acid, bis(4-aminophenyl)amine, N,N-bis(4-aminophenyl)amine, 1,4-bis(4-aminophenyl)-piperazine, N,N'-bis(4-aminophenyl)-benzidine, N,N'-bis(4-aminophenyl)-N,N'-dimethylbenzidine, 2,2'-dimethyl-4,4'-diaminobiphenyl, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, bis[4-(4-aminophenoxy)phenyl]ether, 4,4'-bis(4-aminophenoxy)biphenyl, 4-(4-aminophenoxycarbonyl)- 1-(4-aminophenyl)piperidine, 4,4'-[4,4'-propane-1,3-diylbis(piperidin-1,4-diyl)]diphenylamine, 1,3-bis(3-aminopropyl)-tetramethyldisiloxane, a diamine represented by any of the following formulas (z-1) to (z-19), a diamine represented by the following formula (H), a diamine represented by any of the following formulas (H2) to (H3), a diamine represented by any of the following formulas (V1) to (V3), a diamine represented by any of the following formulas (R1) to (R5) diamines having a free radical initiating function, diamines having a photopolymerizable group at the end such as 2-(2,4-diaminophenoxy)ethyl methacrylate and 2,4-diamino-N,N-diallylaniline, diamines having a photo-alignment structure as described in paragraph

[0053] of International Publication No. (hereinafter also referred to as WO) 2014 / 080865, diamines having a carbon-carbon unsaturated bond as described in paragraph

[0057] , diamines having an azobenzene skeleton as described in paragraph

[0058] , etc.

[0048]

[0049]

[0050] (R 3 Indicates -NRCO-, -COO-, -NRCONR- or -(CH2) n - (where n is an integer from 2 to 20), any -CH2- is optionally substituted by -O-, -COO-, -ND-, -NRCO-, -NRCONR-, -NRCOO- or -OCOO-. D represents a thermally detachable group, and R represents a hydrogen atom or a monovalent organic group. 4 is a single bond or a benzene ring, and any hydrogen atom on the benzene ring is optionally substituted by a monovalent organic group.

[0051]

[0052] (X1 represents -CO-, -O-, -COO-, -L1-R-L2- (L1 and L2 are each independently a single bond, an oxygen atom or -COO-, and R is -(CH2) n -(n is an integer of 1 to 12)) or -NRCO-(R represents a hydrogen atom or a methyl group). X2 represents a single bond, -NRCO-(R represents a hydrogen atom or a methyl group) or -COO-. n represents an integer of 1 or 2. Any hydrogen atom on the benzene ring may be substituted with a monovalent organic group.

[0053]

[0054] (two Xs independently represent -O-, -COO-, -NHCO-, -C(=O)-, or -(CH2) n -(n is an integer of 1 to 12). L1 and L2 are each independently a single bond, -O- or -COO-. R represents -CH2-, -(CH2) n -(n is an integer of 2 to 12) or -(CH2) n - is a group formed by replacing any CH2 with an oxygen atom. Any hydrogen atom on the benzene ring is optionally replaced with a monovalent organic group.)

[0055]

[0056] (X represents a single bond, -O-, -C(CH3)2-, -NH-, -CO-, -NHCO-, -COO-, -(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-.

[0057] X 1 and X 2 Each independently represents 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 independently an integer of 1 to 15, A1 is independently an oxygen atom or -COO-, and m1 is an integer of 1 or 2. 3 Represents a single bond, -CONH-, -NHCO-, -CON(CH3)-, -NH-, -O-, -CH2O-, -COO-, or -OCO-. X 4 It represents -CONH-, -NHCO-, -O-, -COO- or -OCO-.

[0058] G1 and G2 each independently represent a divalent cyclic group selected from a divalent aromatic group having 6 to 12 carbon atoms such as phenylene, biphenylene, naphthylene, or a divalent alicyclic group having 3 to 8 carbon atoms such as cyclopropylene, cyclohexylene, etc. Any hydrogen atom on the cyclic group is optionally substituted by an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a fluorinated alkyl group having 1 to 3 carbon atoms, a fluorinated alkoxy group having 1 to 3 carbon atoms, or a fluorine atom. k represents an integer of 0 or 1, m and n each independently represent an integer of 0 to 3, and the total of m and n is 1 to 4.

[0059] 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. 1 Any hydrogen of is optionally replaced by fluorine.

[0060] R 2 represents an alkyl group having 1 to 20 carbon atoms or an alkoxyalkyl group having 2 to 20 carbon atoms, forming R 2 Any hydrogen of R is optionally substituted by fluorine. 3 Indicates a structure with a steroidal skeleton.)

[0061]

[0062] (n represents an integer from 2 to 10.)

[0063] In the formulas (H), (H2), and (H3), the hydrogen atoms on the benzene ring are optionally replaced by alkyl groups having 1 to 5 carbon atoms such as methyl and ethyl, alkoxy groups having 1 to 5 carbon atoms such as methoxy, halogen atoms such as fluorine atoms, haloalkyl groups having 1 to 5 carbon atoms such as trifluoromethyl, -NR1R2 (R1 and R2 each independently represent a hydrogen atom, a methyl group, or Boc), cyano groups, hydroxyl groups, and other monovalent organic groups. It should be noted that Boc represents a tert-butoxycarbonyl group, and the same applies to the following.

[0064] As a preferable specific example of the diamine represented by the above formula (H), from the viewpoint of less afterimage, a diamine represented by any of the following formulae (H-1) to (H-14) can be mentioned.

[0065]

[0066] (R represents a hydrogen atom, a methyl group or a Boc group.)

[0067] As a preferable specific example of the diamine represented by the said formula (H2), the diamine represented by any of the following formulae (H2-1) to (H2-17) is mentioned from a viewpoint of less afterimage.

[0068]

[0069] (R represents a hydrogen atom, a methyl group or a Boc group. * represents a bonding bond.)

[0070] As a preferable specific example of the diamine represented by the said formula (H3), the diamine represented by any of the following formulae (H3-1) to (H3-4) is mentioned from a viewpoint of less afterimage.

[0071]

[0072] As more preferable specific examples of the diamine represented by (V-1) to (V-3), diamine represented by any of the following formulas (V2-1) to (V2-13) can be mentioned.

[0073]

[0074]

[0075] (X v1 ~X v4 , X p1 ~X p8 Each independently represents -(CH2) a -(a is an integer of 1 to 15), -CONH-, -NHCO-, -CON(CH3)-, -NH-, -O-, -CH2O-, -CH2OCO-, -COO- or -OCO-. X v5 Represents -O-, -CH2O-, -CH2OCO-, -COO- or -OCO-. X V6 ~X V7 , X s1 ~X s4 Each independently represents -O-, -COO- or -OCO-. a ~X f Represents a single bond, -O-, -NH-, or -O-(CH2) m -O-. v1 ~R v4 , R 1a ~R 1hEach independently represents an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an alkoxyalkyl group having 2 to 20 carbon atoms. m represents an integer of 1 to 8.

[0076] In the case of a liquid crystal alignment agent for a TN type, STN type or vertical alignment type liquid crystal display element, the polymer (A) preferably comprises one or more repeating units selected from the group consisting of the repeating units represented by the formula (1) and the repeating units represented by the formula (2) (hereinafter also referred to as repeating units (a)), wherein X1 is a tetravalent organic group, and Y1 is a divalent organic group derived from a diamine represented by any one of the formulas (V1) to (V3). Preferably, the content of the repeating unit (a) is preferably 1 mol% or more, more preferably 3 mol% or more, and more preferably 5 mol% or more relative to the total repeating units of the polymer (A).

[0077] The content of the repeating unit (a) is preferably 99 mol% or less, more preferably 95 mol% or less, and even more preferably 90 mol% or less, based on all the repeating units of the polymer (A).

[0078] In the case of a liquid crystal aligning agent for a PSA-type liquid crystal display element, the polymer (A) preferably includes one or more repeating units selected from the group consisting of the repeating units represented by the formula (1) and the repeating units represented by the formula (2) (hereinafter, also referred to as repeating units (b)), wherein X1 is a tetravalent organic group, and Y1 is a divalent organic group derived from a diamine selected from the group consisting of the diamine having a free radical initiating function and the diamine having a photopolymerizable group at the end. Preferably, the content of the repeating unit (b) is preferably 1 mol% or more, more preferably 3 mol% or more, and more preferably 5 mol% or more relative to all the repeating units possessed by the polymer (A). In this case, the polymer (A) can use one or more repeating units (a) in combination.

[0079] The content of the repeating unit (a) and the repeating unit (b) is preferably 99 mol% or less, more preferably 97 mol% or less, and further preferably 95 mol% or less relative to all the repeating units possessed by the polymer (A) in total. It should be noted that, in this case, repeating units other than the repeating unit (a) and the repeating unit (b) may also be included according to the purpose.

[0080] In the case of a liquid crystal aligning agent for an IPS type or FFS type liquid crystal display element, the polymer (A) preferably contains one or more repeating units selected from the group consisting of the repeating units represented by the formula (1) and the repeating units represented by the formula (2) (hereinafter also referred to as repeating units (c)), wherein in the formula (1), X1 is a tetravalent organic group, and Y1 is derived from a group selected from p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 4,4'-diaminoazobenzene, 1,4-bis(4-aminophenyl)-piperazine, 2,2'-dimethyl-4,4'-diaminobiphenyl, 1,3-bis(4-aminophenoxy)benzene , 1,4-bis(4-aminophenoxy)benzene, bis[4-(4-aminophenoxy)phenyl]ether, 4,4'-bis(4-aminophenoxy)biphenyl, 4-(4-aminophenoxycarbonyl)-1-(4-aminophenyl)piperidine, 4,4'-[4,4'-propane-1,3-diylbis(piperidine-1,4-diyl)]diphenylamine, 1,3-bis(3-aminopropyl)-tetramethyldisiloxane, a diamine represented by any of the formulae (z-1) to (z-2), (z-3) and (z-5), a diamine represented by the formula (H) and a diamine represented by any of the formulae (H2) to (H3). Preferably, the content of the repeating unit (c) is preferably 5 mol% or more, more preferably 10 mol% or more, based on the total of all the repeating units in the polymer (A).

[0081] The content of the repeating unit (c) is preferably 99 mol% or less, more preferably 95 mol% or less, and even more preferably 90 mol% or less, based on all the repeating units of the polymer (A).

[0082] In the case where the coating formed by the liquid crystal aligning agent is endowed with liquid crystal alignment ability by a photo-alignment method, the polymer (A) preferably comprises one or more repeating units selected from the group consisting of the repeating units represented by the formula (1) and the repeating units represented by the formula (2) (hereinafter, also referred to as repeating units (d)), wherein X1 is a tetravalent organic group, and Y1 is a divalent organic group derived from a diamine selected from the group consisting of the diamine having a photo-alignment structure, the diamine having a carbon-carbon unsaturated bond, and the diamine having an azobenzene skeleton. Preferably, the content of the repeating unit (d) is preferably 20 mol% or more, more preferably 30 mol% or more, and further preferably 80 mol% or less, in total relative to all the repeating units possessed by the polymer (A).

[0083] The content of the repeating unit (d) is preferably 99 mol% or less, more preferably 95 mol% or less, and even more preferably 90 mol% or less, based on all the repeating units of the polymer (A).

[0084] In addition, from the viewpoint of less residual image when imparting liquid crystal orientation ability by photo-orientation method, the polymer (A) preferably contains one or more repeating units selected from the group consisting of the repeating units represented by the formula (1) and the repeating units represented by the formula (2) (hereinafter also referred to as repeating units (e)), wherein X1 is the formula (4a) to (4c), (4f) to (4g), and Y1 is a divalent organic group. Preferably, the content of the repeating unit (e) is preferably 5 mol% or more, more preferably 10 mol% or more, in total relative to all the repeating units possessed by the polymer (A).

[0085] The polymer (A) may be composed of one or more types. If a specific example of the case where the polymer (A) is composed of two or more types is listed, from the viewpoint of less generation of residual images and suppression of bright spots, a polymer containing at least one or more repeating units (t) and any one of (a) to (e) can be listed. It should be noted that when the polymer (A) is composed of two types, from the viewpoint of less generation of residual images and suppression of bright spots, the mixing ratio of the first polymer to the second polymer (first polymer / second polymer) is preferably 5 / 95 to 95 / 5 by weight, more preferably 10 / 90 to 90 / 10, and more preferably 20 / 80 to 80 / 20.

[0086] <Compound (B)>

[0087] The liquid crystal aligning agent of the present invention contains the compound (B) shown in the formula (B). Compound (B) is a structure with small steric hindrance, so the liquid crystal orientation of the liquid crystal aligning film containing polymer (A) will not be significantly hindered, and the obtained liquid crystal aligning film has high liquid crystal orientation. In addition, there is a hydroxymethyl group in the molecule, so a cross-linking reaction is generated between polymer (A) and compound (B) or in any one of compound (B), so the film strength of the obtained liquid crystal aligning film can be improved. Therefore, the generation of the liquid crystal display element afterimage of the liquid crystal aligning film of the present invention is small, even when physical friction such as scratching caused by a spacer is generated, the bright spot can be minimized. In addition, compound (B) can obtain the effect of improving the cross-linking density of the liquid crystal aligning film, so the ability to capture impurity components from the substrate is excellent, so the obtained liquid crystal aligning film shows a high voltage holding ratio, so a liquid crystal display element with high reliability can be obtained.

[0088] In the above formula (B), examples of the alkylene group having 1 to 4 carbon atoms as R include methylene, ethylene, propylene, and butylene. Among them, a methylene group is preferred from the viewpoint of high crosslinking effect.

[0089] Specific examples of the divalent organic group (L) that are preferred from the viewpoint of less afterimages include the following formulae (L-1) to (L-25) and (L2-1) to (L2-3).

[0090]

[0091]

[0092] (L1, L2 represent a single bond, -O-, -CO-, -OCO-, -COO-, -CONR- (R represents a hydrogen atom or a methyl group), -NRCONR- (R represents a hydrogen atom or a methyl group), -N=N-, -(CH2) n -(n is an integer of 1 to 18) or the above formulas (L-1) to (L-25), L3 represents -(CH2) n -(n is an integer of 1 to 18), the above formula (L-2), (L-4), (L-7), (L-8), (L-10) to (L-11), (L-13), (L-15), (L-17) to (L-18), (L-20) or (L-25). When L3 is (L-2), (L-15) or (L-17), -(CH2) in L3 n -bonded with -NHCO-. )

[0093] Preferred specific examples of the compound (B) include compounds represented by the following formulae (B-1) to (B-34) and (B2-1) to (B2-20).

[0094]

[0095]

[0096]

[0097]

[0098]

[0099]

[0100] The content of the compound (B) is preferably 0.1 to 30 parts by weight, more preferably 0.5 to 25 parts by weight, and even more preferably 0.5 to 20 parts by weight, based on 100 parts by weight of the component (A).

[0101] <Production method of polyamic acid>

[0102] The polymer (A) in the present invention can be obtained by reacting a tetracarboxylic acid derivative having the structure of X1 and a diamine having the structure of Y1 by a known method described in WO2013 / 157586, for example.

[0103] [Terminus modification agent]

[0104] The polymer (A) in the present invention may be a terminal-modified polymer by using a terminal-modifying agent together with the above-mentioned tetracarboxylic acid derivative and diamine.

[0105] Examples of the terminal modification agent include acid anhydrides, dicarbonic acid diester compounds, chlorocarbonyl compounds, monocarboxylic acid chlorides, monoamine compounds, and monoisocyanate compounds.

[0106] Examples of the acid anhydride include maleic anhydride, nadic anhydride, phthalic anhydride, itaconic anhydride, cyclohexanedicarboxylic anhydride, 3-hydroxyphthalic anhydride, trimellitic anhydride, a compound represented by any of the following formulas (m-1) to (m-6), n-decylsuccinic anhydride, n-dodecylsuccinic anhydride, n-tetradecylsuccinic anhydride, n-hexadecylsuccinic anhydride, 3-(3-trimethoxysilyl)propyl)-3,4-dihydrofuran-2,5-dione, and 4,5,6,7-tetrafluoroisobenzofuran-1,3-dione.

[0107]

[0108] As said dicarbonic acid diester compound, the compound etc. represented by following formula (D) are mentioned, for example.

[0109]

[0110] (R represents a monovalent organic group having 1 to 30 carbon atoms.)

[0111] Examples of the chlorocarbonyl compound include compounds represented by the following formula (Mc).

[0112]

[0113] (A represents a single bond, -O-, -S-, or -NR1-, R and R1 each independently represent a monovalent organic group having 1 to 30 carbon atoms, and R and R1 may be bonded to each other to form a ring structure.)

[0114] Examples of the monocarboxylic acid chloride include compounds described in paragraphs

[0069] to

[0082] of WO2011 / 115076.

[0115] Examples of the monoamine compound include aniline, 2-aminophenol, 3-aminophenol, 2-amino-m-cresol, 2-amino-p-cresol, 3-amino-o-cresol, 4-amino-o-cresol, 4-amino-m-cresol, 5-amino-o-cresol, 6-amino-m-cresol, 4-amino-2,3-xylenol, 4-amino-3,5-xylenol, 6-amino-2,4-xylenol, 2-amino-4-ethylphenol, 3-amino-4-ethylphenol, 2-amino-4-tert-butylphenol, 2-amino-4-phenylphenol, 4-amino-2,6-diphenylphenol, 4-aminosalicylic acid, 5-aminosalicylic acid, and 6-aminosalicylic acid. , 2-aminobenzoic acid, 3-aminobenzoic acid, 4-aminobenzoic acid, 2-amino-m-toluic acid, 3-amino-o-toluic acid, 3-amino-p-toluic acid, 4-amino-m-toluic acid, 6-amino-o-toluic acid, 6-amino-m-toluic acid, 3-aminobenzenesulfonic acid, 4-aminobenzenesulfonic acid, 4-aminotoluene-3-sulfonic acid, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, 3-(trifluoromethoxy)aniline, 4-(trifluoromethoxy)aniline, triethoxysilylamine, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropylmethoxydiethoxysilane, etc.

[0116] As said monoisocyanate compound, ethyl isocyanate, phenyl isocyanate, naphthyl isocyanate etc. are mentioned, for example.

[0117] It should be noted that specific examples of the monovalent organic group having 1 to 30 carbon atoms in R of the formula (D) and (Mc) include: alkyl groups such as methyl, ethyl, propyl, tert-butyl, cyclobutyl, 1-methylcyclobutyl or 1-adamantyl; alkenyl groups such as vinyl and allyl; alkynyl groups such as 1,1-dimethylpropynyl; halogenated alkyl groups such as 2,2,2-trichloroethyl or 1,1-dimethyl-2-chloroethyl; silylalkyl groups such as 2-trimethylsilylethyl; cyanated alkyl groups such as 1,1-dimethyl-2-cyanoethyl; aryl groups such as phenyl, naphthyl or anthracenyl; benzyl, 1-methyl- Arylalkyl such as 1-phenylethyl or 1-methyl-1-(4-biphenylyl)ethyl, 9-fluorenylmethyl, halogenated aryl such as 2, 4-dichlorobenzyl; nitrated aryl such as p-nitrobenzyl or 3, 4-dimethoxy-6-nitrobenzyl; alkoxyaryl such as methoxyphenyl; arylalkenyl such as cinnamyl; heteroaryl such as imidazolyl, pyridyl, pyrimidyl, pyridazinyl, pyrazinyl, quinolyl; aliphatic heterocyclic groups such as piperidinyl, N-hydroxypiperidinyl, piperazinyl, morpholinyl, pyrrolidinyl; imide such as phthalic acid imide or succinimide; cyclic urea such as imidazolinone or a combination thereof. It should be noted that any -CH2- of the alkyl group may be optionally substituted by a divalent group such as -O-, -COO-, -NHCO-, -N(CH3)CO-, -CO-, -NHCONH-, etc.

[0118] The amount of the terminal modifying agent used is preferably 20 parts by mole or less, more preferably 10 parts by mole or less, based on 100 parts by mole of the total amount of the diamine used.

[0119] <Liquid crystal alignment agent>

[0120] The liquid crystal aligning agent of the present invention may contain other polymers in addition to the polymer (A). As the types of other polymers, polyesters, polyamides, polyureas, polyorganosiloxanes, cellulose derivatives, polyacetates, polystyrene or its derivatives, poly(styrene-phenylmaleimide) derivatives, poly(meth)acrylates, etc. It should be noted that, as polyorganosiloxane, from the viewpoint of easy synthesis, it is preferred to have at least one of an oxetane group and an oxirane group.

[0121] The liquid crystal alignment agent is used to make a liquid crystal alignment film, and from the viewpoint of forming a uniform film, a coating liquid is used. In the liquid crystal alignment agent of the present invention, a coating liquid containing the polymer component and an organic solvent is also preferred. At this time, the concentration of the polymer in the liquid crystal alignment agent can be appropriately changed according to the setting of the thickness of the coating film to be formed. From the perspective of forming a uniform and defect-free coating film, the concentration of the polymer is preferably 1% by weight or more, and from the perspective of the storage stability of the solution, it is more preferably 10% by weight or less, and particularly preferably 2 to 8% by weight.

[0122] The organic solvent contained in the liquid crystal alignment agent is not particularly limited as long as it uniformly dissolves the polymer component. If specific examples are listed, they include: N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethyl sulfoxide, γ-butyrolactone, γ-valerolactone, 1, 3-dimethylimidazolidinone, methyl ethyl ketone, cyclohexanone, cyclopentanone, N, N-dimethyl lactamide, 3-methoxy-N, N-dimethyl propaneamide, 3-butoxy-N, N-dimethyl propaneamide (they are also collectively referred to as "good solvents"), etc. Among them, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 3-methoxy-N, N-dimethyl propaneamide, 3-butoxy-N, N-dimethyl propaneamide or γ-butyrolactone is preferably used. The good solvent in the liquid crystal aligning agent of the present invention is preferably 20 to 99% by weight of the whole solvent contained in the liquid crystal aligning agent, more preferably 20 to 90% by weight, particularly preferably 30 to 80% by weight.

[0123] In addition, the organic solvent contained in the liquid crystal aligning agent is preferably a mixed solvent using a solvent (also called a poor solvent) that improves the coating property and surface smoothness of the coating film when the liquid crystal aligning agent is applied in addition to the above-mentioned solvent. Specific examples of the organic solvent used in combination are listed below, but are not limited to these examples.

[0124] For example, diisopropyl ether, diisobutyl ether, diisobutyl carbinol (2,6-dimethyl-4-heptanol), ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, 1,2-butoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, 4-hydroxy-4-methyl-2-pentanone, diethylene glycol methyl ethyl ether, diethylene glycol dibutyl ether, 3-ethoxybutyl acetate, 1-methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, ethylene glycol monoacetate, ethylene glycol diacetate, propylene carbonate, ethylene carbonate, ethylene glycol monobutyl ether, ethylene glycol monoisopentyl ether, ethylene glycol monohexyl ether, propylene glycol monobutyl ether, 1-(2-butoxyethoxy)-2-propanol, 2 -(2-Butoxyethoxy)-1-propanol, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, ethylene glycol monobutyl ether acetate, ethylene glycol monoacetate, ethylene glycol diacetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, 2-(2-ethoxyethoxy)ethyl acetate, diethylene glycol acetate, propylene glycol diacetate, n-butyl acetate, propylene glycol monoethyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, butyl 3-methoxypropionate, n-butyl lactate, isopentyl lactate, diethylene glycol monoethyl ether, diisobutyl ketone (2,6-dimethyl-4-heptanone), etc.

[0125] Among them, diisobutylcarbinol, propylene glycol monobutyl ether, propylene glycol diacetate, diethylene glycol diethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monobutyl ether, ethylene glycol monobutyl ether acetate, and diisobutyl ketone are preferably used.

[0126] Preferred combinations of good solvents and poor solvents include: N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether; N-methyl-2-pyrrolidone, γ-butyrolactone and ethylene glycol monobutyl ether; N-methyl-2-pyrrolidone, γ-butyrolactone and propylene glycol monobutyl ether; N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether; N-methyl-2-pyrrolidone, γ-butyrolactone, 4-hydroxy-4-methyl-2-pentanone and diethylene glycol diethyl ether; N-methyl-2-pyrrolidone, γ-butyrolactone, propylene glycol monobutyl ether Diol monobutyl ether and 2,6-dimethyl-4-heptanone; N-methyl-2-pyrrolidone, γ-butyrolactone, propylene glycol monobutyl ether and diisopropyl ether; N-methyl-2-pyrrolidone, γ-butyrolactone, propylene glycol monobutyl ether and 2,6-dimethyl-4-heptanol; N-methyl-2-pyrrolidone, γ-butyrolactone and dipropylene glycol dimethyl ether; N-methyl-2-pyrrolidone, propylene glycol monobutyl ether and dipropylene glycol dimethyl ether; N-ethyl-2-pyrrolidone, propylene glycol monobutyl ether and dipropylene glycol dimethyl ether and the like. These poor solvents are preferably 1 to 80% by weight of the total solvent contained in the liquid crystal alignment agent, more preferably 10 to 80% by weight, and particularly preferably 20 to 70% by weight. The type and content of such solvents are appropriately selected according to the coating device, coating conditions, coating environment, etc. of the liquid crystal alignment agent.

[0127] The liquid crystal aligning agent of the present invention may also contain additional components other than the polymer component, the (B) component and the organic solvent. Such additional components include: a bonding aid for improving the adhesion between the liquid crystal aligning film and the substrate, and the adhesion between the liquid crystal aligning film and the sealing material; a compound for improving the strength of the liquid crystal aligning film (hereinafter, also referred to as a cross-linking compound); a dielectric for adjusting the dielectric constant and resistance of the liquid crystal aligning film, a conductive substance, etc.

[0128] As the cross-linking compound, from the viewpoint of less generation of afterimages and high improvement effect of film strength, it is preferred to have a compound having at least one group selected from the group consisting of an oxirane group, an oxetane group, a protected isocyanate group, a protected isothiocyanate group, a group containing an oxazoline ring structure, a group containing a Michaelis acid structure, a cyclocarbonate group as shown below, and a group represented by formula (d); or a compound selected from the compounds represented by any of the following formulas (e-1) to (e-8) (hereinafter collectively referred to as compound (C)).

[0129]

[0130] (R1, R2, and R3 are each independently a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or "*-CH2-OH". * represents a bonding bond.)

[0131]

[0132] Specific examples of compounds having an oxirane group include compounds described in paragraph

[0037] of Japanese Patent Application Laid-Open No. 10-338880, compounds having a triazine ring in the skeleton described in WO2017 / 170483, and compounds having two or more oxirane groups. Among them, compounds containing nitrogen atoms such as N,N,N',N'-tetraglycidyl-m-xylene diamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, N,N,N',N'-tetraglycidyl-p-phenylenediamine, and compounds represented by the following formulas (r-1) to (r-3) are particularly preferred.

[0133]

[0134] Specific examples of the compound having an oxetane group include compounds having two or more oxetane groups described in paragraphs

[0170] to

[0175] of WO2011 / 132751.

[0135] Specific examples of the compound having a protected isocyanate group include compounds having two or more protected isocyanate groups described in paragraphs

[0046] to

[0047] of JP-A-2014-224978, compounds having three or more protected isocyanate groups described in paragraphs

[0119] to

[0120] of WO2015 / 141598, etc. Among them, compounds represented by the following formulas (bi-1) to (bi-3) are preferred.

[0136]

[0137] Specific examples of the compound having a protected isothiocyanate group include compounds having two or more protected isothiocyanate groups described in JP-A-2016-200798.

[0138] Specific examples of the compound having a group containing an oxazoline ring structure include compounds containing two or more oxazoline structures described in paragraph

[0115] of JP-A-2007-286597.

[0139] Specific examples of the compound having a group containing a Michaelis acid structure include compounds having two or more Michaelis acid structures described in WO2012 / 091088.

[0140] Specific examples of the compound having a cyclic carbonate group include compounds described in WO2011 / 155577.

[0141] Examples of the alkyl group having 1 to 3 carbon atoms in R1, R2, and R3 of the group represented by the formula (d) include the groups exemplified in the above formulas (l) and (n).

[0142] Specific examples of the compound having a group represented by the formula (d) include: compounds having two or more groups represented by the formula (d) described in paragraph

[0058] of WO2015 / 072554 and JP-A-2016-118753, compounds described in JP-A-2016-200798, etc. Among them, compounds represented by any of the following formulas (hd-1) to (hd-8) are preferred.

[0143]

[0144] The above compound is an example of a crosslinking compound, but is not limited thereto. For example, components other than those disclosed in paragraphs 1 to 3 of WO2015 / 060357 can be cited. In addition, two or more crosslinking compounds contained in the liquid crystal aligning agent may be combined.

[0145] The content of the crosslinking compound in the liquid crystal aligning agent of the present invention is preferably 0.5 to 20 parts by weight relative to 100 parts by weight of the polymer component contained in the liquid crystal aligning agent, and is more preferably 1 to 15 parts by weight from the viewpoints of allowing the crosslinking reaction to proceed, achieving the target effect, and reducing AC afterimage characteristics.

[0146] Examples of the adhesion aid include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyldiethoxymethylsilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, and N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane. Ethoxycarbonyl-3-aminopropyl triethoxysilane, N-triethoxysilylpropyl triethylenetriamine, N-trimethoxysilylpropyl triethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl-3-aminopropyl trimethoxysilane, N-benzyl-3-aminopropyl triethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis(oxyethylene)-3-aminopropyltrimethoxysilane, N-bis(oxyethylene)-3-aminopropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyl Silane coupling agents such as oxypropyl triethoxysilane, p-phenylvinyl trimethoxysilane, 3-methacryloxypropyl methyl dimethoxysilane, 3-methacryloxypropyl trimethoxysilane, 3-methacryloxypropyl methyl diethoxysilane, 3-methacryloxypropyl triethoxysilane, 3-acryloxypropyl trimethoxysilane, tris-(trimethoxysilylpropyl) isocyanurate, 3-mercaptopropyl methyl dimethoxysilane, 3-mercaptopropyl trimethoxysilane, and 3-isocyanate propyl triethoxysilane. When using a silane coupling agent, from the viewpoint of less AC residual image, the amount is preferably 0.1 to 30 parts by weight, and more preferably 0.1 to 20 parts by weight, relative to 100 parts by weight of the polymer component contained in the liquid crystal aligning agent.

[0147] <Liquid crystal alignment film / liquid crystal display element>

[0148] A liquid crystal alignment film can be manufactured by using the above-mentioned liquid crystal alignment agent. In addition, the liquid crystal display element of the present invention has a liquid crystal alignment film formed by using the above-mentioned liquid crystal alignment agent. The operation mode of the liquid crystal display element of the present invention is not particularly limited, for example, it can be applied in various operation modes such as TN type, STN type, vertical alignment type (including VA-MVA type, VA-PVA (Patterned Vertical Alignment: image vertical curvature) type, etc.), in-plane switching type (IPS type), FFS type, optically compensated bending type (OCB: Optically Compensated Birefringence type).

[0149] The liquid crystal display element of the present invention can be produced, for example, by the following steps (1-1) to (1-3). Step (1-1) uses different substrates depending on the desired operation mode. Step (1-2) and step (1-3) are common to each operation mode.

[0150] [Step (1-1): Formation of coating film]

[0151] First, the liquid crystal aligning agent of the present invention is applied on a substrate, and then the applied surface is heated to form a coating film on the substrate.

[0152] (1-1A)

[0153] For example, in the case of manufacturing a TN type, STN type or VA type liquid crystal display element, first, two substrates provided with patterned transparent conductive films are used as a pair, and the liquid crystal alignment agent prepared in the above is applied to each transparent conductive film forming surface thereof by preferably offset printing, spin coating, roll coating or inkjet printing. As a substrate, for example, a transparent substrate composed of glass such as float glass and soda glass; plastics such as polyethylene terephthalate, polybutylene terephthalate, polyether sulfone, polycarbonate, and poly (alicyclic olefin) can be used. As a transparent conductive film provided on one side of the substrate, a NESA film (trade name of PPG Company, USA) composed of tin oxide (SnO2), an ITO film composed of indium oxide-tin oxide (In2O3-SnO2), etc. can be used. In order to obtain a patterned transparent conductive film, for example, the following methods can be used: a method of forming a transparent conductive film without a pattern and then forming a pattern by photolithography; a method of using a mask having a desired pattern when forming the transparent conductive film; etc. When applying the liquid crystal alignment agent, in order to further improve the adhesion between the substrate surface and the transparent conductive film and the coating film, a pretreatment of applying a functional silane compound, a functional titanium compound, etc. in advance on the surface of the substrate where the coating film is to be formed can also be implemented.

[0154] After the liquid crystal alignment agent is applied, it is preferred to perform preliminary heating (pre-baking) for the purpose of preventing the liquid of the applied liquid crystal alignment agent 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, and more preferably 0.5 to 5 minutes. Afterwards, the solvent is completely removed, and as needed, a calcination (post-baking) process is performed for the purpose of thermally imidizing the amide acid structure present in the polymer. The calcination temperature (post-baking temperature) at this time is preferably 80 to 300°C, and more preferably 120 to 250°C. The post-baking time is preferably 5 to 200 minutes, and more preferably 10 to 100 minutes. The film thickness of the liquid crystal alignment film formed in this way is preferably 0.001 to 1 μm, and more preferably 0.005 to 0.5 μm.

[0155] (1-1B)

[0156] In the case of manufacturing an IPS type or FFS type liquid crystal display element, a liquid crystal alignment agent is applied to the electrode forming surface of a substrate provided with an electrode composed of a transparent conductive film or metal film patterned into a comb shape and a side of an opposing substrate without an electrode, and then each coated surface is heated to form a coating film. The material of the substrate and transparent conductive film used at this time, the coating method, the heating conditions after coating, the patterning method of the transparent conductive film or metal film, the pretreatment of the substrate, and the preferred film thickness of the formed coating film are the same as those described above (1-1A). As a metal film, for example, a film composed of a metal such as chromium can be used.

[0157] In any of the above (1-1A) and (1-1B), a liquid crystal alignment film or a coating film of a liquid crystal alignment film is formed by applying a liquid crystal alignment agent to a substrate and then removing an organic solvent. In this case, the coating film may be further heated after formation to allow a dehydration ring-closure reaction of the polyamic acid, polyamic acid ester and polyimide contained in the liquid crystal alignment agent of the present invention to proceed, thereby forming a coating film that has been further imidized.

[0158] [Step (1-2): Orientation-imparting treatment]

[0159] In the case of manufacturing TN type, STN type, IPS type or FFS type liquid crystal display elements, the coating formed in the above step (1-1) is subjected to a treatment of imparting liquid crystal orientation ability. As a result, the coating is endowed with the orientation ability of the liquid crystal molecules, and becomes a liquid crystal orientation film. As an orientation ability imparting treatment, for example, there can be listed: a brushing treatment in which a roll made of a cloth composed of fibers such as nylon, rayon, and cotton is wound to rub the coating in a certain direction; a light orientation treatment in which the coating is irradiated with polarized or non-polarized radiation, etc. On the other hand, in the case of manufacturing a VA type liquid crystal display element, the coating formed in the above step (1-1) can be directly used as a liquid crystal orientation film, or the coating can be subjected to an orientation ability imparting treatment.

[0160] In the case where the coating film is given liquid crystal orientation ability by photo-orientation treatment, as the radiation irradiated to the coating film, for example, ultraviolet rays and visible light containing wavelengths of 150 to 800 nm can be used. In the case where the radiation is polarized, it can be linearly polarized or partially polarized. In addition, 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 oblique direction, or in combination thereof. In the case of irradiating non-polarized radiation, the irradiation direction is set to an oblique direction.

[0161] As the light source used, 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. Ultraviolet rays in a preferred wavelength range can be obtained by combining a light source with, for example, a filter, a diffraction grating, etc. The irradiation amount of the radiation is preferably 10 to 5000 mJ / cm 2 , more preferably 30 to 2000 mJ / cm 2 .

[0162] In order to improve the reactivity, the coating film may be irradiated with light while being heated. The temperature during heating is usually 30 to 250°C, preferably 40 to 200°C, and more preferably 50 to 150°C.

[0163] In addition, when ultraviolet rays containing light with a wavelength of 150 to 800 nm are used, the light irradiation film obtained in the above process can be used directly as a liquid crystal alignment film, or the light irradiation film can be calcined, cleaned with water, an organic solvent, or a combination thereof. The calcination temperature at this time is preferably 80 to 300 ° C, more preferably 80 to 250 ° C. The calcination time is preferably 5 to 200 minutes, more preferably 10 to 100 minutes. It should be noted that the calcination can also be performed more than twice. The photo-alignment treatment here is equivalent to the treatment of light irradiation in a state not in contact with the liquid crystal layer.

[0164] The organic solvent used for the above-mentioned cleaning is not particularly limited. Specific examples thereof include water, methanol, ethanol, 2-propanol, acetone, methyl ethyl ketone, 1-methoxy-2-propanol, 1-methoxy-2-propanol acetate, butyl cellosolve, ethyl lactate, methyl lactate, diacetone alcohol, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propyl acetate, butyl acetate, or cyclohexyl acetate.

[0165] It should be noted that the liquid crystal alignment film after the brushing treatment can also be further treated as follows so that each area of ​​the liquid crystal alignment film has different liquid crystal orientation capabilities, and the treatment is: by irradiating a portion of the liquid crystal alignment film with ultraviolet rays, the pretilt angle of a portion of the liquid crystal alignment film is changed; on the basis of forming a protective (rasist) film on a portion of the surface of the liquid crystal alignment film, the brushing treatment is performed in a direction different from the previous brushing treatment, and then the protective film is removed. In this case, the visual field characteristics of the obtained liquid crystal display element can be improved. The liquid crystal alignment film preferred in the VA type liquid crystal display element can also be preferably used in the PSA type liquid crystal display element.

[0166] [Step (1-3): Construction of liquid crystal cell]

[0167] (1-3A)

[0168] As described above, two substrates with liquid crystal alignment films are prepared, and liquid crystal is arranged between the two substrates arranged opposite to each other, thereby manufacturing a liquid crystal box. In order to manufacture a liquid crystal box, for example, the following two methods can be listed. The first method is a method known in the past. First, the gap (unit gap) is separated in a manner that each liquid crystal alignment film is opposite to each other, and the two substrates are arranged opposite to each other. The peripheral parts of the two substrates are bonded together using a sealant, and the liquid crystal is injected into the unit gap divided by the substrate surface and the sealant. After filling the liquid crystal, the injection hole is sealed, thereby manufacturing a liquid crystal box. The second method is a method called ODF (One Drop Fill: liquid crystal dripping) method. A sealant such as a UV-curable sealant is applied to a specified location on one of the two substrates with a liquid crystal alignment film, and after liquid crystal is further dripped into several specified locations on the surface of the liquid crystal alignment film, the other substrate is bonded in a manner that the liquid crystal alignment film is opposite to each other, and it is extended to the entire surface of the liquid crystal substrate, and then the entire surface of the substrate is irradiated with ultraviolet light to cure the sealant, thereby manufacturing a liquid crystal box. In the case of using any of the methods, it is desirable to further heat the liquid crystal used in the liquid crystal cell manufactured as described above to a temperature at which the liquid crystal becomes isotropic and then gradually cool it to room temperature to remove the flow alignment during liquid crystal filling.

[0169] As the sealant, for example, an epoxy resin containing a curing agent and alumina balls as spacers can be used.

[0170] Examples of liquid crystals include nematic phase liquid crystals, smectic phase liquid crystals, etc. Among them, nematic phase liquid crystals are preferred, such as Schiff base-based, azoxy-based, biphenyl-based, phenylcyclohexane-based, ester-based, terphenyl-based, biphenylcyclohexane-based, pyrimidine-based, dioxane-based, bicyclooctane-based, and cubane-based liquid crystals.

[0171] In addition, cholesteric liquid crystals such as cholesteryl chloride, cholesteryl nonanoate, and cholesteryl carbonate may be added to these liquid crystals; chiral agents sold as C-15 and CB-15 (trade names of MERCK); strong dielectric liquid crystals such as p-decyloxybenzylidene amino-2-methylbutylcinnamate, etc. The liquid crystal may additionally contain anisotropic dyes. "Dye" refers to a substance that can absorb light in at least a part or the entire range or deform it in the visible light region, such as the 400nm or 700nm wavelength range. "Anisotropic dye" refers to a substance that can anisotropically absorb light in at least a part or the entire range of the visible light region. The color sense of the liquid crystal box can be adjusted by using the dye. The type of anisotropic dye is not particularly limited, for example, black dye or color dye can be used. The ratio of the anisotropic dye to the liquid crystal can be appropriately selected, for example, the anisotropic dye can be preferably contained in 0.01 to 5 parts by weight relative to 100 parts by weight of the liquid crystal compound.

[0172] (1-3B)

[0173] When a PSA type liquid crystal display element is produced, a liquid crystal cell is constructed in the same manner as in (1-3A) above except that a photopolymerizable compound such as the following formula (w-1) to (w-5) is injected or dropped together with the liquid crystal.

[0174]

[0175] Then, the liquid crystal box is irradiated with light while a voltage is applied between the conductive films of a pair of substrates. The voltage applied here can be set to, for example, a direct current or alternating current of 5 to 50 V. In addition, as the irradiated light, for example, ultraviolet rays and visible rays containing wavelengths of 150 to 800 nm can be used, but ultraviolet rays containing wavelengths of 300 to 400 nm are preferred. As the light source of the irradiated 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. It should be noted that the ultraviolet rays in the above-mentioned preferred wavelength range can be obtained by a method of using a light source, for example, with a filter, a diffraction grating, etc. The irradiation amount of light is preferably 100 mJ / cm 2 Above and less than 30000mJ / cm 2, more preferably 100 to 20000 mJ / cm 2 .

[0176] (1-3C)

[0177] When a coating film is formed on a substrate using a liquid crystal alignment agent containing a compound (polymer or additive) having a photopolymerizable group, a liquid crystal box is constructed in the same manner as in (1-3A) above, and then a method for manufacturing a liquid crystal display element can be adopted by irradiating the liquid crystal box with light while applying a voltage between the conductive films of a pair of substrates. According to this method, the advantages of the PSA mode can be achieved with a small amount of light irradiation. The light irradiation of the liquid crystal box can be performed in a state where the liquid crystal is driven by applying a voltage, or it can be performed in a state where a low voltage is applied to the extent that the liquid crystal is not driven. The applied voltage can be set to, for example, a direct current or alternating current of 0.1 to 30 V. Regarding the conditions of the irradiated light, the description of (1-3B) above can be applied. The light irradiation treatment here is equivalent to the treatment of light irradiation in a state of contact with the liquid crystal layer.

[0178] Furthermore, by attaching a polarizing plate to the outer surface of the liquid crystal cell, the liquid crystal display element of the present invention can be obtained. Examples of the polarizing plate attached to the outer surface of the liquid crystal cell include: a polarizing plate formed by sandwiching a polarizing film called "H film" that stretches and orients polyvinyl alcohol and absorbs iodine with a cellulose acetate protective film; or a polarizing plate composed of the H film itself.

[0179] 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, car navigation systems, portable cameras, PDAs (Personal Digital Assistants), digital cameras, mobile phones, smart phones, various monitors, liquid crystal televisions, information displays, etc.

[0180] As described above, by using the liquid crystal alignment agent of the present invention, it is possible to obtain a liquid crystal alignment film with less afterimages and minimum bright spots even when physical friction such as scratches caused by spacers occurs, and a liquid crystal display element having a high reliability including the liquid crystal alignment film.

[0181] [Example]

[0182] The present invention will be described in more detail below with reference to Examples, but the present invention is not limited thereto. The abbreviations of the following compounds and the methods for measuring the properties are as follows.

[0183] (Diamine)

[0184] DA-1 to DA-22: compounds represented by the following formula (DA-1) to (DA-22), respectively.

[0185] (Tetracarboxylic dianhydride)

[0186] CA-1 to CA-8: compounds represented by the following formula (CA-1) to formula (CA-8), respectively.

[0187] (Tetracarboxylic acid diester dihalide)

[0188] CE-1: A compound represented by the following formula (CE-1).

[0189] (monocarboxylic acid chloride)

[0190] E-1: Acryloyl chloride.

[0191] (Compound B)

[0192] B-1 to B-10: compounds represented by the following formula (B-1) to (B-10), respectively.

[0193] (additive)

[0194] c-1 to c-3: compounds represented by the following formula (c-1) to (c-3), respectively.

[0195] F-1: N-α-(9-fluorenylmethyloxycarbonyl)-N-τ-tert-butoxycarbonyl-L-histidine (a compound represented by the following formula (F-1)).

[0196] s-1: 3-Glycidoxypropyltriethoxysilane (a compound represented by the following formula (s-1)).

[0197] s-2: 3-Glycidoxypropylmethyldiethoxysilane (a compound represented by the following formula (s-2)).

[0198] M-1:3-aminomethylpyridine.

[0199] (Organic Solvent)

[0200] NMP: N-methyl-2-pyrrolidone, GBL: γ-butyrolactone.

[0201] BCS: Butyl Cellosolve, DIBK: Diisobutyl Ketone.

[0202] NEP: N-ethyl-2-pyrrolidone, DAA: diacetone alcohol.

[0203] PC: ethylene carbonate, DME: dipropylene glycol dimethyl ether.

[0204] DPM: dipropylene glycol monomethyl ether.

[0205] PB: Propylene glycol monobutyl ether.

[0206] PGDAC: propylene glycol diacetate.

[0207] DEDE: Diethylene glycol diethyl ether.

[0208] GVL: γ-valerolactone, DML: N,N-dimethyllactamide.

[0209]

[0210]

[0211]

[0212] (Fmoc represents 9-fluorenylmethyloxycarbonyl.)

[0213] [Viscosity]

[0214] The measurement was performed at a temperature of 25° C. using an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.) with a sample amount of 1.1 mL and a conical rotor TE-1 (1°34′, R24).

[0215] [Molecular weight]

[0216] The number average molecular weight (Mn) and the weight average molecular weight (Mw) were calculated as polyethylene glycol and polyethylene oxide equivalent values ​​by measurement using a GPC (normal temperature gel permeation chromatography) apparatus.

[0217] GPC apparatus: manufactured by Shodex (GPC-101), chromatographic column: manufactured by Shodex (KD803, KD805 in series), chromatographic column temperature: 50°C, eluent: N,N-dimethylformamide (as additives, lithium bromide monohydrate (LiBr·H2O) is 30 mmol / L, phosphoric acid / anhydrous crystals (o-phosphoric acid) is 30 mmol / L, tetrahydrofuran (THF) is 10 ml / L), flow rate: 1.0 ml / min.

[0218] Standard samples for preparing the calibration curve: TSK standard polyethylene oxide manufactured by Tosoh Corporation (weight average molecular weight (Mw) of about 900,000, 150,000, 100,000, 30,000); and polyethylene glycol manufactured by Polymer Laboratory (peak top molecular weight (Mp) of about 12,000, 4,000, 1,000). In order to avoid peak overlap, two samples, a sample of a mixture of four kinds of 900,000, 100,000, 12,000, and 1,000 and a sample of a mixture of three kinds of 150,000, 30,000, and 4,000, were measured separately.

[0219] <Measurement of Imidization Ratio>

[0220] Add 20 mg of polyimide powder to an NMR sample tube (NMR standard sampling tube, φ5 (manufactured by Kusano Scientific Co., Ltd.)), add deuterated dimethyl sulfoxide (DMSO-d6, 0.05% TMS (tetramethylsilane) mixture) (0.53 ml), and apply ultrasound to completely dissolve it. Use an NMR measuring machine (JNW-ECA500) (manufactured by JEOL DATUM Co., Ltd.) to measure the 500 MHz proton NMR of the solution. The imidization rate is calculated 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 the proton derived from the NH group of the amide acid appearing near 9.5 ppm to 10.0 ppm is used to calculate it using the following formula.

[0221] Imidization rate (%) = (1-α·x / y) × 100

[0222] In the above formula, x is the peak integral value of protons derived from NH groups of amic acid, y is the peak integral value of reference protons, and α is the ratio of the number of reference protons to protons of one NH group of amic acid in the case of polyamic acid (imidation ratio 0%).

[0223] [Synthesis of polymer (A)]

[0224] <Synthesis example 1>

[0225] CA-2 (2.25 g, 8.99 mmol), DA-6 (2.97 g, 8.99 mmol), DA-7 (3.43 g, 9.01 mmol) and NMP (34.6 g) were added to a four-necked flask equipped with a stirrer and a nitrogen inlet tube, dissolved, and reacted at 60° C. for 4 hours. Then, CA-3 (1.75 g, 8.92 mmol) and NMP (6.99 g) were added, reacted at 40° C. for 4 hours, and a polyamic acid solution was obtained.

[0226] After adding NMP to the polyamic acid solution (40g) to dilute it to 6.5% by weight, acetic anhydride (7.06g) and pyridine (2.19g) were added as imidization catalysts, and the mixture was reacted at 80°C for 4 hours. The reaction solution was put into methanol (463g), and the resulting precipitate was filtered out. The precipitate was washed with methanol and dried under reduced pressure at 100°C to obtain a polyimide powder. The imidization rate of the polyimide was 74%, Mn was 12500, and Mw was 38500.

[0227] NMP (18.0 g) was added to the obtained polyimide powder (2.0 g), and M-1 was added to give 1 wt % based on the polyimide solid content, and stirred at 70° C. for 12 hours to dissolve the mixture, thereby obtaining a polyimide (PI-V-1) solution having a solid content concentration of 10%.

[0228] <Synthesis example 2>

[0229] CA-2 (1.20 g, 4.80 mmol), DA-8 (1.46 g, 9.59 mmol), DA-9 (1.74 g, 7.18 mmol), DA-7 (2.74 g, 7.20 mmol) and NMP (28.58 g) were added to a four-necked flask equipped with a stirrer and a nitrogen inlet tube, dissolved, and reacted at 60° C. for 2 hours. Then, CA-5 (1.05 g, 4.81 mmol) and NMP (4.19 g) were added, reacted at room temperature for 4 hours, and CA-3 (2.78 g, 14.18 mmol) and NMP (11.1 g) were further added, reacted at room temperature for 4 hours, and a polyamic acid solution was obtained.

[0230] After adding NMP to the polyamic acid solution (40g) to dilute it to 6.5% by weight, acetic anhydride (8.90g) and pyridine (2.76g) were added as imidization catalysts, and the mixture was reacted at 80°C for 4 hours. The reaction solution was put into methanol (472g), and the resulting precipitate was filtered out. The precipitate was washed with methanol and dried under reduced pressure at 100°C to obtain a polyimide powder. The imidization rate of the polyimide was 74%, Mn was 13000, and Mw was 39000.

[0231] NMP was added to the obtained polyimide powder so as to give a solid content concentration of 10 wt %, and M-1 was added so as to give 1 wt % relative to the polyimide solid content, and the mixture was stirred at 70° C. for 12 hours to dissolve the mixture, thereby obtaining a polyimide (PI-V-2) solution.

[0232] <Synthesis Example 3>

[0233] DA-2 (5.86 g, 24.0 mmol), DA-10 (5.46 g, 16.0 mmol), DA-4 (1.73 g, 16.0 mmol), DA-1 (7.69 g, 24.0 mmol) and NMP (194 g) were added to a four-necked flask equipped with a stirring device and a nitrogen inlet tube, and stirred to dissolve while nitrogen was supplied. CA-1 (17.1 g, 76.4 mmol) was added while stirring the diamine solution, and NMP was further added so that the solid content concentration became 12% by weight, and stirred at 40°C for 24 hours to obtain a polyamic acid solution (viscosity: 549 mPa·s). The Mn of the polyamic acid was 12400 and the Mw was 33000.

[0234] After adding NMP to the polyamic acid solution (225g) to dilute it to 9.0% by weight, acetic anhydride (17.1g) and pyridine (3.54g) were added as imidization catalysts, and the mixture was reacted at 55°C for 3 hours. The reaction solution was put into methanol (1111g), and the resulting precipitate was filtered out. The precipitate was washed with methanol and dried at 60°C for 12 hours to obtain a polyimide powder. The imidization rate of the polyimide powder was 66%, Mn was 11000, and Mw was 28000.

[0235] NMP was added to the obtained polyimide powder so as to have a solid content concentration of 15% by weight, and the mixture was dissolved by stirring at 70° C. for 24 hours to obtain a solution of a polyimide (PI-I-3).

[0236] <Synthesis example 4>

[0237] DA-5 (5.73 g, 20.0 mmol) was weighed into a 5 L four-necked flask equipped with a stirring device and a nitrogen inlet tube, and NMP was added so that the solid content concentration was 7%, and the mixture was stirred and dissolved while nitrogen was supplied. CA-3 (2.94 g, 15.0 mmol) was added while stirring the diamine solution under water cooling, and NMP was added so that the solid content concentration was 6%, and the mixture was stirred at 23°C for 1 hour under a nitrogen atmosphere. Then, DA-3 (11.9 g, 40.0 mmol) and DA-11 (6.01 g, 40.0 mmol) were weighed, and the mixture was stirred and dissolved while nitrogen was supplied. CA-3 (15.9 g, 81.0 mmol) was added while stirring the diamine solution under water cooling, NMP was added so that the solid content concentration became 15 wt%, s-1 was added so that the solid content became 1 wt% relative to the polyamic acid, and the mixture was stirred at 23° C. for 6 hours under a nitrogen atmosphere to obtain a solution of a polyamic acid (PAA-I-4). The polyamic acid had an Mn of 12,000 and an Mw of 30,000.

[0238] <Synthesis example 5>

[0239] A 500 mL four-necked flask with a stirring device was placed in a nitrogen atmosphere, and DA-4 (2.80 g, 25.9 mmol), DA-2 (1.58 g, 6.47 mmol), NMP (111 g) and pyridine (6.18 g, 78.1 mmol) as a base were added and stirred to dissolve. Then, CE-1 (9.89 g, 30.4 mmol) was added while stirring the diamine solution, and the mixture was reacted at 15°C overnight. After stirring overnight, E-1 (0.38 g, 4.21 mmol) was added and reacted at 15°C for 4 hours. The obtained polyamic acid ester solution was added into 1230 g of water while stirring, and the precipitated white precipitate was filtered out, and then washed 5 times with 1230 g of IPA and dried to obtain 10.2 g of white polyamic acid ester resin powder. The yield was 83.0%. Moreover, Mn of this polyamic acid ester was 20786, and Mw was 40973.

[0240] GBL was added to the obtained polyamic acid ester so that solid content concentration might become 10 weight%, and it was stirred at room temperature for 24 hours and it melt|dissolved, and the solution of polyamic acid ester (PAE-I-5) was obtained.

[0241] <Synthesis Example 6>

[0242] DA-8 (0.46 g, 3.00 mmol), DA-13 (3.00 g, 15.0 mmol), DA-14 (2.56 g, 12.0 mmol), NMP (11.0 g) and GBL (8.10 g) were added to a four-necked flask equipped with a stirring device and a nitrogen inlet tube, and stirred to dissolve while supplying nitrogen. CA-6 (4.76 g, 24.0 mmol) was added while stirring the diamine solution, and GBL (10.9 g) was added, and stirred at room temperature for 2 hours. Next, GBL (10.8 g) was added and stirred, and then CA-5 (1.31 g, 6.01 mmol) was added, and GBL (14.3 g) was added, and stirred at room temperature for 24 hours. The viscosity of the obtained polyamic acid solution at 25°C was 2041 mPa·s. In addition, the Mn of the polyamic acid was 14200 and the Mw was 30110. Then, s-2 was added to give 1 wt % of the polyamic acid solid content, and the mixing ratio of NMP and GBL was NMP:GBL=20:80 by weight. NMP and GBL were added to give a solid content concentration of 15 wt %, thereby obtaining a solution of polyamic acid (PAA-I-6).

[0243] <Synthesis Examples 7 to 11>

[0244] Using the diamines, tetracarboxylic acid derivatives and organic solvents shown in Table 1 below, the same procedures as in the above Synthesis Examples were followed to obtain solutions of polyimides (PAA-I-7, (PI-V-8), (PI-V-9), (PAA-I-10) and (PI-I-11) shown in Table 1 below. These are shown in Table 1 together with Synthesis Examples 1 to 6 above.

[0245] In Table 1, the values ​​in parentheses indicate the mixing ratio (mol parts) of each compound relative to 100 mol parts of the total amount of tetracarboxylic acid derivatives used for synthesis for the tetracarboxylic acid component, and the mixing ratio (mol parts) of each compound relative to 100 mol parts of the total amount of diamines used for synthesis for the diamine acid component. For the terminal modifier, the mixing ratio (mol parts) relative to 100 mol parts of the total amount of diamines used for synthesis is indicated. For the organic solvent, the mixing ratio (weight parts) of each organic solvent relative to 100 parts by weight of the total amount of organic solvents used for synthesis is indicated.

[0246] [Table 1]

[0247]

[0248] [Synthesis of other polymers]

[0249] <Synthesis Example 12>

[0250] According to the method described in paragraph

[0091] of Japanese Patent Application Laid-Open No. 2018-54761, a reactive polyorganosiloxane polymer was obtained using 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane (ECETS). Then, according to the method described in paragraph

[0093] of Japanese Patent Application Laid-Open No. 2018-54761, a polymer of a polyorganosiloxane represented by the following formula (P-S1) was obtained. It should be noted that the numerical value in formula (P-S1) represents the usage ratio of each compound relative to the total of each silane compound used for synthesis.

[0251]

[0252] <Synthesis Example 13>

[0253] According to the method described in paragraph

[0091] of Japanese Patent Application Laid-Open No. 2018-54761, a reactive polyorganosiloxane polymer was obtained using 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane (ECETS). Then, according to the method described in paragraph

[0093] of Japanese Patent Application Laid-Open No. 2018-54761, a polymer of a polyorganosiloxane represented by the following formula (P-S2) was obtained. It should be noted that the numerical value in formula (P-S2) represents the usage ratio of each compound relative to the total of each silane compound used for synthesis.

[0254]

[0255] <Example 1>

[0256] [Preparation of Liquid Crystal Alignment Agent]

[0257] The solution of the polyimide (PI-V-1) obtained in Synthesis Example 1 and the solution of the polyimide (PI-V-2) obtained in Synthesis Example 2 were diluted with NMP and BCS, and the compound (B-3) was further added in an amount of 5 parts by weight relative to 100 parts by weight of all polymers, and stirred at room temperature. Next, the obtained solution was filtered using a filter with a pore size of 0.5 μm, thereby obtaining a liquid crystal aligning agent (V1) having a polymer component ratio of (PI-V-1): (PI-V-2) = 30:70 (solid content conversion weight ratio), a solvent composition ratio of NMP: BCS = 60:40 (weight ratio), a polymer solid content concentration of 4.5%, and a compound (B-3) mixing ratio of 5 parts by weight (see Tables 2-1 to 2-3 below). It was confirmed that no abnormalities such as turbidity and precipitation were observed in the liquid crystal aligning agent, and it was a uniform solution.

[0258] <Examples 2 to 47, Comparative Examples 1 to 4>

[0259] Liquid crystal aligning agents (V2) to (V11), (I12-P) to (I29-P), (I30-U) to (I37-U), (V38) to (V43), (I44-P) to (I47-P), (R-V1) to (R-V2), and (R-I3-P) to (R-I4-P) were obtained in the same manner as in Example 1 except that the polymers and additives shown in Tables 2-1 to 2-3 below were used.

[0260] In Tables 2-1 to 2-3, the values ​​in parentheses indicate the mixing ratio (parts by weight) of each polymer component or additive to 100 parts by weight of the total polymer component used in the preparation of the liquid crystal aligning agent for polymers and additives, respectively. For organic solvents, the values ​​in parentheses indicate the mixing ratio (parts by weight) of each organic solvent to 100 parts by weight of the total organic solvent used in the preparation of the liquid crystal aligning agent.

[0261] [Table 2-1]

[0262]

[0263] [Table 2-2]

[0264]

[0265] [Table 2-3]

[0266]

[0267] [Production and evaluation of liquid crystal display elements]

[0268] 1-1. Fabrication of PSA-type liquid crystal display elements

[0269] 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 spacing (line / space) of 3 μm was formed and a glass substrate (length: 35 mm, width: 30 mm, thickness: 0.7 mm) with an ITO electrode patterned with a photo spacer with a height of 3.2 μm was prepared and cleaned with pure water and isopropyl alcohol. Next, liquid crystal alignment agents (V1) to (V11), (V38) to (V43) and (R-V1) to (R-V2) filtered with a filter with a pore size of 1.0 μm were spin-coated on each ITO surface, and heated at 70°C for 90 seconds on a hot plate and at 230°C for 30 minutes in a heat circulation type clean oven to obtain an ITO substrate with a liquid crystal alignment film with a film thickness of 100 nm.

[0270] The ITO electrode substrate on which the ITO electrode pattern is formed is divided into four cross checker (grid) patterns, and can be driven separately for each of the four regions.

[0271] Next, a sealant (XN-1500T manufactured by Mitsui Chemicals) was applied around the periphery. Next, the surface of the other substrate on which the liquid crystal alignment film was formed was placed inside, and after being bonded to the previous substrate, the sealant was cured to produce an empty box. Liquid crystal MLC-3023 (trade name manufactured by MERCK) was injected into the empty box by a reduced pressure injection method to produce a liquid crystal box.

[0272] Then, a DC voltage of 15 V was applied to the obtained liquid crystal cell, and in a state where all pixel regions were driven, an ultraviolet irradiation device using a high-pressure mercury lamp as a light source was used to irradiate the liquid crystal cell at 10 J / cm 2 Ultraviolet rays were passed through a bandpass filter with a wavelength of 365 nm to obtain a vertical alignment type liquid crystal display element. The ultraviolet irradiation amount was measured by connecting a UV-M03A manufactured by ORC Corporation to a UV-35 light receiver.

[0273] 1-2. Evaluation of Liquid Crystal Display Elements

[0274] (i) Image retention evaluation based on long-term AC drive

[0275] Using the liquid crystal display element prepared in 1-1 above, an AC voltage of 60 Hz and 20 Vp-p was applied to two diagonal areas of the four pixel areas, and the device was driven at a temperature of 23°C for 168 hours. Then, all four pixel areas were driven with an AC voltage of 5 Vp-p, and the brightness difference of the pixels was visually observed. The state in which almost no brightness difference was confirmed was regarded as good, and the state in which the brightness difference was confirmed was regarded as bad. The evaluation results are shown in Tables 3-1 to 3-3.

[0276] (ii) Voltage holding ratio evaluation

[0277] Two 40 mm × 30 mm glass substrates with ITO electrodes (length: 40 mm, width: 30 mm, thickness: 1.1 mm) were prepared, and a liquid crystal alignment film with a thickness of 100 nm was produced on the ITO surface in the same order as in 1-1 above. Bead-shaped spacers with a diameter of 4 μm (made by Nikko Catalysts & Chemicals Co., Ltd., silk balls, SW-D1) were applied on the liquid crystal alignment film surface of the other substrate.

[0278] Next, a sealant (Mitsui Chemicals XN-1500T) was applied around the periphery. Next, the surface of the other substrate with the liquid crystal alignment film formed on the inner side was bonded to the previous substrate, and the sealant was cured to produce an empty box. Liquid crystal MLC-3023 (Merck product name) was injected into the empty box by the reduced pressure injection method to produce a liquid crystal box.

[0279] Then, while applying a DC voltage of 15 V to the obtained liquid crystal cell, an ultraviolet irradiation device using a high-pressure mercury lamp as a light source was used to irradiate the liquid crystal cell at 15 J / cm 2 Ultraviolet rays passed through a bandpass filter with a wavelength of 365nm to obtain a vertically oriented liquid crystal display element. It should be noted that the measurement of ultraviolet irradiation used a UV-35 photoreceiver in UV-M03A manufactured by ORC. Next, the liquid crystal display element was left to stand in an 80°C oven under LED light for 200 hours, then left to stand at room temperature and naturally cooled to room temperature. Then, at 60°C, a voltage of 1V was applied with an application time of 60 microseconds and a time span of 1667 milliseconds, and the voltage retention rate was measured 1000 milliseconds after the application was released. As a measuring device, a device manufactured by TOYO Corporation was used.

[0280] (iii) Scratch resistance evaluation

[0281] A liquid crystal alignment film was produced on a pair of glass substrates (length: 40 mm, width: 30 mm, thickness: 1.1 mm) in the same procedure as in the above 1-1. A scratch test was performed on each liquid crystal alignment film surface using UMT-2 (manufactured by BRUKER AXS Corporation).

[0282] Select FVL in the UMT-2 sensor and install a 1.6mm sapphire ball on the top of the scratch part.

[0283] The scratch was made in a range of 0.5 mm horizontally and 2.0 mm vertically with the top of the scratched part in contact with the surface of the liquid crystal alignment film at a load of 40 mN. The moving direction of the top of the scratched part was set to be horizontal reciprocating, and the moving speed was 5.0 mm / second. The scratched area was moved in the vertical direction so that the substrate with the liquid crystal alignment film moved in the vertical direction at 20 μm / second.

[0284] After the scratch test, liquid crystal (MLC-3019) was dripped onto the surface of the liquid crystal alignment film that had completed the scratch test. The substrates formed by dispersing spacers with a diameter of 4 μm on another substrate with a liquid crystal alignment film were overlapped with the liquid crystal alignment film surfaces facing each other to sandwich the dripped liquid crystal.

[0285] The parts subjected to the scratch test were observed under a polarizing microscope (ECLIPSE E600WPOL) (manufactured by Nikon Corporation) with the polarization axes of the upper and lower polarizing plates at 90° (crossed nicols) to observe whether light was transmitted. For the parts subjected to the scratch test, the state in which no bright spot was observed and light leakage was considered good, and the state in which the scratched parts were completely light-shedding was considered bad, and the results are shown in Table 6.

[0286] 2-1. Fabrication of FFS-type liquid crystal display element using photo-alignment

[0287] First, a substrate with electrodes is prepared. The substrate is a glass substrate with a size of 30 mm long and 50 mm wide and a thickness of 0.7 mm. On the substrate, as the first layer, an ITO electrode with a dense pattern constituting a counter electrode is formed. On the counter electrode of the first layer, as the second layer, a SiN (silicon nitride) film formed by a CVD method is formed. The film thickness of the second layer of the SiN film is 500 nm, and it functions as an interlayer insulating film. On the second layer of the SiN film, as the third layer, a comb-shaped pixel electrode formed by patterning the ITO film is arranged, forming two types of pixels, the first pixel and the second pixel. The size of each pixel is 10 mm long and about 5 mm wide. At this time, the counter electrode of the first layer and the pixel electrode of the third layer are electrically insulated due to the action of the SiN film of the second layer.

[0288] The pixel electrode of the third layer has a comb-like shape formed by arranging a plurality of electrode elements in the shape of a "< symbol" whose central portion is bent at an internal angle of 160°. The width of each electrode element in the short dimension direction is 3μm, and the interval between the electrode elements is 6μm. The pixel electrode forming each pixel is composed of a plurality of electrode elements in the shape of a "< symbol" bent in the central portion, so the shape of each pixel is not a rectangle, but has a shape similar to a bold "< symbol" bent in the central portion like the electrode elements. In addition, each pixel is divided into upper and lower parts with the bent portion in the center as the boundary, and has a first area on the upper side of the bent portion and a second area on the lower side.

[0289] Next, the liquid crystal alignment agents (I12-P) to (I29-P), (I44-P) to (I47-P), (R-I3-P) to (R-I4-P) were filtered using a filter with a pore size of 1.0 μm, and then applied by spin coating to the above-mentioned substrate with electrodes and a glass substrate with a columnar spacer with a height of 4 μm and an ITO film formed on the back.

[0290] The coating films obtained from the liquid crystal aligning agents (I12-P) to (I29-P) and (R-I3-P) to (R-I4-P) were dried on a hot plate at 80°C for 5 minutes and then fired in a hot air circulation oven at 230°C for 20 minutes to obtain a polyimide film with a film thickness of 100 nm. The coating film surface was then irradiated with 500 mJ / cm 2 The substrate was irradiated with linearly polarized ultraviolet light of a wavelength of 254 nm having an extinction ratio of 26:1, and then baked in a hot air circulation oven at 230° C. for 30 minutes to obtain a substrate with a liquid crystal alignment film having a film thickness of 100 nm.

[0291] The coating films obtained from the liquid crystal aligning agents (I44-P) to (I47-P) were dried on a hot plate at 80°C for 5 minutes, and then the coating film surface was irradiated with 500 mJ / cm 2 The substrate was irradiated with linearly polarized ultraviolet light of a wavelength of 254 nm having an extinction ratio of 26:1, and then baked in a hot air circulation oven at 230° C. for 30 minutes to obtain a substrate with a liquid crystal alignment film having a film thickness of 100 nm.

[0292] Next, a sealant was printed on one side of the above-mentioned set of glass substrates with a liquid crystal alignment film, and the other substrate was bonded in such a way that the liquid crystal alignment film faces each other, and the sealant was cured to produce an empty box. Liquid crystal MLC-3019 (Merck) was injected into the empty box by a reduced pressure injection method, and the injection port was sealed to obtain an FFS-driven liquid crystal display element. Then, the obtained liquid crystal box was heated at 120°C for 1 hour, and after being left overnight, the afterimage characteristics were evaluated.

[0293] 2-2. Evaluation of Liquid Crystal Display Element

[0294] (i) Image retention evaluation based on long-term AC drive

[0295] Using the liquid crystal cell prepared in 2-1 above, an AC voltage of ±5 V with a frequency of 60 Hz was applied for 120 hours in a constant temperature environment of 60° C. Then, the pixel electrode and the counter electrode of the liquid crystal cell were short-circuited and left at room temperature for one day.

[0296] After placement, the liquid crystal box is placed between two polarizing plates arranged in a manner such that the polarization axes are orthogonal, the backlight is turned on without applying voltage, and the configuration angle of the liquid crystal box is adjusted so that the brightness of the transmitted light becomes minimum. In addition, the rotation angle when the liquid crystal box is rotated from the angle at which the second area of ​​the first pixel becomes darkest to the angle at which the first area becomes darkest is calculated as angle Δ. Similarly, in the second pixel, the second area is compared with the first area, and the same angle Δ is calculated.

[0297] When the angle Δ was less than 0.3°, it was considered good, and when Δ was 0.3° or more, it was considered bad. The evaluation results are shown in Tables 3-1 to 3-3.

[0298] (ii) Voltage holding ratio evaluation

[0299] Two 40 mm × 30 mm glass substrates with ITO electrodes (length: 40 mm, width: 30 mm, thickness: 1.1 mm) were prepared, and a liquid crystal alignment film with a thickness of 100 nm was produced on the ITO surface in the same order as in 2-1 above. Bead-shaped spacers with a diameter of 4 μm (made by Nikko Catalysts & Chemicals Co., Ltd., silk balls, SW-D1) were coated on the liquid crystal alignment film surface of the other substrate.

[0300] Next, a sealant (XN-1500T manufactured by Mitsui Chemicals) was applied around. Next, the surface of the other substrate on which the liquid crystal orientation film was formed was placed as the inner side, and after being bonded to the previous substrate, the sealant was cured to produce an empty box. Liquid crystal MLC-3019 (trade name manufactured by MERCK) was injected into the empty box by a reduced pressure injection method to produce a liquid crystal display element. Next, the liquid crystal display element was left standing in an oven at 80°C under LED light for 200 hours, then left standing at room temperature and naturally cooled to room temperature. Then, the evaluation was carried out in the same order as (ii) of 1-2.

[0301] (iii) Scratch resistance evaluation

[0302] The same procedure as (iii) of the above 1-2 was carried out except that the same liquid crystal alignment film as that of the above 2-1 was used and the liquid crystal was made into MLC-3019.

[0303] 3-1. Fabrication of FFS-type liquid crystal display element using brushing orientation

[0304] First, use an inkjet coating device (HIS-200, manufactured by Hitachi Plant Technologies) to apply the liquid crystal alignment agent (I30-U) to (I37-U) filtered by a filter with a pore size of 1.0 μm to each surface of a pair of glass substrates identical to the above 2-1. The coating was carried out under the following conditions: the coating area was 70×70 mm, the nozzle spacing was 0.423 mm, the scanning spacing was 0.5 mm, the coating speed was 40 mm / second, and it was left to stand for 60 seconds from coating to drying. Then, after drying on a hot plate at 80°C for 5 minutes, it was calcined in a hot air circulation oven at 230°C for 20 minutes to obtain a polyimide film with a film thickness of 100 nm. The polyimide film was brushed with rayon cloth (roller diameter: 120 mm, roller speed: 500 rpm, moving speed: 30 mm / sec, pressing length: 0.3 mm, brushing direction: 10° tilted relative to the 3-layer IZO comb electrode), and then cleaned by ultrasonic irradiation in pure water for 1 minute to remove water droplets. Then, it was dried at 80°C for 15 minutes to obtain a substrate with a liquid crystal orientation film. The two substrates with liquid crystal orientation films were set as a group, and the sealant was printed in the form of a liquid crystal injection port remaining on the substrate, and the other substrate was attached in a manner such that the liquid crystal orientation film surfaces faced each other and the brushing direction was reversely parallel. Then, the sealant was cured to produce an empty box with a unit gap of 4 μm. Liquid crystal MLC-7026-100 (manufactured by MERCK) was injected into the empty box by a reduced pressure injection method, and the injection port was sealed to obtain an FFS liquid crystal display element. Then, the obtained liquid crystal display element was heated at 120° C. for 1 hour, left to stand at 23° C. overnight, and then used for afterimage evaluation.

[0305] 3-2. Evaluation of Liquid Crystal Display Elements

[0306] (i) Image retention evaluation based on long-term AC drive

[0307] The same liquid crystal alignment film as in 3-1 was used, and the liquid crystal was MLC-7026-100, and the evaluation was performed in the same procedure as in 2-2 (i). In the evaluation, a value of less than 0.2° was considered good, and a value of 0.2° or more was considered bad.

[0308] (ii) Voltage holding ratio evaluation

[0309] Evaluation was performed in the same procedure as in (ii) of the above 2-2 except that the same liquid crystal aligning film as in the above 3-1 was used and the liquid crystal was made into MLC-7026-100.

[0310] (iii) Scratch resistance evaluation

[0311] Evaluation was performed in the same procedure as in (iii) of the above 2-2 except that the same liquid crystal alignment film as in the above 3-1 was used and the liquid crystal was made into MLC-7026-100.

[0312] [Table 3-1]

[0313]

[0314] [Table 3-2]

[0315]

[0316] [Table 3-3]

[0317]

[0318] In the table, asterisks indicate comparative examples.

[0319] Industrial Applicability

[0320] The liquid crystal aligning agent of the present invention is useful for forming a liquid crystal aligning film in various liquid crystal display elements such as a vertical alignment type and an FFS drive system.

[0321] It should be noted that all the contents of the specification, claims, drawings, and abstract of Japanese Patent Application No. 2019-018889 filed on February 5, 2019 are cited herein and incorporated as a disclosure of the specification of the present invention.

Claims

1. A liquid crystal alignment agent, It is characterized in that Containing the following components (A) and (B), Component (A): a polymer (A) having at least one repeating unit selected from the group consisting of a repeating unit represented by the following formula (1) and a repeating unit represented by the following formula (2), Component (B): a compound (B) represented by the following formula (B), Where, X 1 is a tetravalent organic group, Y 1 is a divalent organic group, R 1 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and Z 11 , Z 12 each independently represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may have a substituent, an alkenyl group having 2 to 10 carbon atoms which may have a substituent, an alkynyl group having 2 to 10 carbon atoms which may have a substituent, a tert-butoxycarbonyl group or a 9-fluorenylmethoxycarbonyl group, In the formula, R represents an alkylene group having 1 to 4 carbon atoms, m and n are each independently an integer of 1 or 2, and A 1 Represents a single bond, -O-, -CO-, -OCO-, -COO-, -CONR-, -NRCONR-, -N=N-, -CH 2 -, -(CH 2 ) n -, or a divalent organic group (L), wherein the divalent organic group (L) is -(CH 2 ) n Any CH 2 Substituted with -O-, -CO-, -OCO-, -COO-, -CONR-, -NRCONR-, phenylene or biphenylene, wherein in the -CONR-, R represents a hydrogen atom or a methyl group, in the -NRCONR-, R represents a hydrogen atom or a methyl group, and the -(CH 2 ) n -, n is an integer from 2 to 18, wherein, in the divalent organic group (L), two oxygen atoms are not adjacent to each other, two groups selected from -OCO-, -COO-, -CONR- and -NRCONR- are not adjacent to each other, in the -CONR-, R represents a hydrogen atom or a methyl group, in the -NRCONR-, R represents a hydrogen atom or a methyl group, and any hydrogen atom on the phenylene or biphenylene ring is optionally substituted with a monovalent organic group, The divalent organic group (L) is a group selected from the group consisting of the following formulae (L-1) to (L-25) and (L2-1) to (L2-3), Where, L 1 , L 2 represents a single bond, -O-, -CO-, -OCO-, -COO-, -CONR-, -NRCONR-, -(CH 2 ) n - or the above formula (L-1) to (L-25), in the above -CONR-, R represents a hydrogen atom or a methyl group, in the above -NRCONR-, R represents a hydrogen atom or a methyl group, and the above -(CH 2 ) n -, n is an integer from 1 to 14, L 3 Represents a single bond, -(CH 2 ) n -, the formula (L-2), (L-4), (L-7), (L-8), (L-10) to (L-11), (L-13), (L-15), (L-17) to (L-18), (L-20) or (L-25), the -(CH 2 ) n -, n is an integer from 1 to 15, wherein 3 In the case of (L-2), (L-15), (L-17), L 3 In - (CH 2 ) n -bonded with -NHCO-.

2. The liquid crystal alignment agent according to claim 1, in, The X 1 is a tetravalent organic group selected from the group consisting of the following formulae (4a) to (4n), (5a) and (6a), In the formula, x and y each independently represent a single bond, -O-, -CO-, -COO-, an alkylene group having 1 to 5 carbon atoms, 1,4-phenylene, a sulfonyl group or an amide group, and Z 1 ~Z 6 Each independently represents a hydrogen atom, a methyl group, an ethyl group, a propyl group, a chlorine atom or a benzene ring, j and k are integers of 0 or 1, m is an integer of 1 to 5, and * represents a bond.

3. The liquid crystal alignment agent according to claim 2, in, In the polymer (A), the content of one or more repeating units selected from the group consisting of the repeating units represented by the formula (1) and the repeating units represented by the formula (2) is 5 mol% or more in total relative to all the repeating units. In the formula (1), the X 1 is a tetravalent organic group selected from the group consisting of the formulae (4a) to (4n), (5a) and (6a), and Y 1 It is a divalent organic group.

4. The liquid crystal alignment agent according to claim 1 or 2, in, The polymer (A) comprises at least one repeating unit selected from the group consisting of the repeating unit represented by the formula (1) and the repeating unit represented by the formula (2), namely, a repeating unit (a), wherein the content of the repeating unit (a) is 1 mol% or more relative to all the repeating units. In the formula (1), X 1 is a tetravalent organic group, and Y 1 is a divalent organic group derived from a diamine represented by any of the following formulae (V1) to (V3), In the formula, X represents a single bond, -O-, -C(CH 3 ) 2 -, -NH-, -CO-, -NHCO-, -COO-, -(CH 2 ) m -、-SO 2 -、-O-(CH 2 ) m -O-, -O-C(CH 3 ) 2 -、-CO-(CH 2 ) m -、-NH-(CH 2 ) m -、-SO 2 -(CH 2 ) m -、-CONH-(CH 2 ) m -、-CONH-(CH 2 ) m -NHCO- or -COO-(CH 2 ) m -OCO-,X 1 and X 2 Each independently represents a single bond, -(CH 2 ) a -, -CONH-, -NHCO-, -CON(CH 3 )-, -NH-, -O-, -COO-, -OCO- or -((CH 2 ) a1 -A 1 ) m1 -, said - (CH 2 ) a -, a is an integer of 1 to 15, wherein each of a1 is independently an integer of 1 to 15, and a plurality of A 1 Each independently represents an oxygen atom or -COO-, m 1 is an integer of 1 or 2, X 3 Indicates a single bond, -CONH-, -NHCO-, -CON(CH 3 )-, -NH-, -O-, -CH 2 O-, -COO- or -OCO-, X 4 Indicates -CONH-, -NHCO-, -O-, -COO- or -OCO-, G 1 and G 2 Each independently represents a divalent cyclic group which is a divalent aromatic group having 6 to 12 carbon atoms or a divalent alicyclic group having 3 to 8 carbon atoms, wherein any hydrogen atom on the cyclic group is optionally substituted by an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a fluorinated alkyl group having 1 to 3 carbon atoms, a fluorinated alkoxy group having 1 to 3 carbon atoms, or a fluorine atom, k is an integer of 0 or 1, m and n are each independently an integer of 0 to 3, and the total of m and n is 1 to 4, and 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, forming R 1 Any hydrogen of R is optionally substituted by fluorine, 2 represents an alkyl group having 1 to 20 carbon atoms or an alkoxyalkyl group having 2 to 20 carbon atoms, forming R 2 Any hydrogen of R is optionally substituted by fluorine, 3 It indicates a structure having a steroidal skeleton.

5. The liquid crystal aligning agent according to claim 1 or 2, in, The polymer (A) comprises at least one repeating unit selected from the group consisting of the repeating unit represented by the formula (1) and the repeating unit represented by the formula (2), namely, a repeating unit (c), wherein the content of the repeating unit (c) is 5 mol% or more relative to all the repeating units. In the formula (1), X 1 is a tetravalent organic group, and Y 1 It is derived from a compound selected from the group consisting of p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 4,4'-diaminoazobenzene, 1,4-bis(4-aminophenyl)-piperazine, 2,2'-dimethyl-4,4'-diaminobiphenyl, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, bis[4-(4-aminophenoxy)phenyl]ether, 4,4'-bis(4-aminophenoxy)biphenyl, 4-(4-aminophenyl)- a divalent organic group of a diamine in the group consisting of: a diamine represented by any of the following formulas (z-1), (z-2), (z-3) and (z-5); a diamine represented by the following formula (H) and a diamine represented by any of the following formulas (H2) to (H3); In the formula, R 3 Indicates -NRCO-, -COO-, -NRCONR- or -(CH 2 ) n -, said - (CH 2 ) n -, n is an integer from 2 to 20, any -CH 2 - is optionally substituted with -O-, -COO-, -ND-, -NRCO-, -NRCONR-, -NRCOO- or -OCOO-, D represents a thermally detachable group, R represents a hydrogen atom or a monovalent organic group, R 4 represents a single bond or a benzene ring, and any hydrogen atom on the benzene ring is optionally substituted by a monovalent organic group, Where, X 1 Indicates -CO-, -O-, -COO-, or -L 1 -R-L 2 - or -NRCO-, the -L 1 -R-L 2 - Medium, L 1 , L 2 Each independently represents a single bond, an oxygen atom or -COO-, and R represents -(CH 2 ) n -, said - (CH 2 ) n -, n is an integer of 1 to 12, in the -NRCO-, R is a hydrogen atom or a methyl group, and X 2 represents a single bond, -NRCO- or -COO-, wherein -NRCO-, R is a hydrogen atom or a methyl group, wherein in the formula (H2), n is an integer of 1 or 2, and any hydrogen atom on the benzene ring is optionally substituted by a monovalent organic group, In the formula, two Xs independently represent -O-, -COO-, -NHCO-, -C(=O)-, -(CH 2 ) n -, said - (CH 2 ) n -, n is an integer from 1 to 12, L 1 , L 2 Each independently represents a single bond, -O-, or -COO-, and R represents -CH 2 -, -(CH 2 ) n - or the said - (CH 2 ) n Any CH 2 The group formed by substitution with an oxygen atom, the -(CH 2 ) n -, n is an integer of 2 to 12, and any hydrogen atom on the benzene ring may be substituted with a monovalent organic group.

6. The liquid crystal aligning agent according to claim 1 or 2, in, The polymer (A) comprises one or more repeating units selected from the group consisting of the repeating units represented by the formula (1) and the repeating units represented by the formula (2), namely, repeating units (b), wherein the content of the repeating units (b) is 1 mol% or more relative to all the repeating units. In the formula (1), X 1 is a tetravalent organic group, and Y 1 It is a divalent organic group derived from a diamine selected from the group consisting of a diamine having a radical initiating function and a diamine having a photopolymerizable group at a terminal.

7. The liquid crystal alignment agent according to claim 6, in, The polymer (A) comprises a repeating unit (a) and a repeating unit (b), and the total content of the repeating unit (a) and the repeating unit (b) is 99 mol% or less based on all the repeating units.

8. The liquid crystal aligning agent according to claim 1 or 2, in, The liquid crystal alignment agent further includes polyorganosiloxane having at least any one of an oxetane group and an oxirane group.

9. The liquid crystal alignment agent according to claim 1 or 2, in, The polymer (A) is composed of two or more types.

10. The liquid crystal alignment agent according to claim 1 or 2, in, The component (B) is contained in an amount of 0.1 to 30 parts by weight based on 100 parts by weight of the component (A). 11 . A liquid crystal alignment film obtained from the liquid crystal alignment agent according to claim 1 . 12 . A liquid crystal display element comprising the liquid crystal alignment film according to claim 11 .

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