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

Abstract

The present invention provides a liquid crystal alignment agent, a liquid crystal alignment film and a liquid crystal element. The liquid crystal alignment agent comprises: a polymer [A] comprising a structural unit (U1) and excluding a structural unit (U2); and a polymer [B] comprising a structural unit (U2) and a structural unit (U3). Structural unit (U1): a structural unit derived from a diamine having a partial structure represented by formula (1). Structural unit (U2): a structural unit derived from a diamine having a partial structure represented by formula (2). Structural unit (U3): a structural unit derived from a diamine having a partial structure Y(-(CH 2 ) n ‑, etc.) of the diamine structural unit.

Description

Technical Field

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

[0002] As the liquid crystal material of the liquid crystal element, negative liquid crystal is used in liquid crystal elements of vertical alignment (VA) drive mode or multi-domain vertical alignment (MVA) drive mode, and positive liquid crystal is used in liquid crystal elements of twisted nematic (TN) type or in-plane switching (IPS) drive mode, fringe field switching (FFS) drive mode, etc. In addition, in recent years, in order to achieve further high-precision liquid crystal elements, it has been proposed to use negative liquid crystal in liquid crystal elements of IPS drive mode or FFS drive mode (for example, refer to patent document 1).

[0003] In recent years, liquid crystal elements are used in a wide range of applications, from relatively large display devices such as liquid crystal televisions or information displays to small display devices such as smart phones. With the versatility of such liquid crystal elements, further high quality of liquid crystal elements is required. Therefore, it has been previously proposed that a liquid crystal alignment agent contains a polymer having a nitrogen-containing meta-arylene structure, thereby obtaining a liquid crystal alignment film with low resistance and high transparency, and obtaining a liquid crystal element with less burn marks (direct current (DC) afterimage) caused by accumulated charge (for example, refer to patent document 2).

[0004] [Prior art literature]

[0005] [Patent Document]

[0006] [Patent Document 1] International Publication No. 2016 / 152928

[0007] [Patent Document 2] International Publication No. 2019 / 093037 Summary of the invention

[0008] [Problems to be solved by the invention]

[0009] In addition to the DC afterimage, the afterimage generated in the liquid crystal element also includes an alternating current (AC) afterimage caused by the deviation of the orientation direction of the liquid crystal from the initial orientation. In order to suppress the generation of afterimages and realize further high-precision of the liquid crystal element, it is required to suppress the AC afterimage in addition to the DC afterimage. In addition, in the case of introducing the meta-arylene structure into the polymer as in the technology of patent document 2, there is a concern that the solubility of the polymer will be reduced due to the introduction of the rigid structure into the main chain, and the coating property of the liquid crystal alignment agent will be reduced. Furthermore, when considering the situation of obtaining a liquid crystal alignment film by a friction method or suppressing the reduction of yield, etc., high mechanical strength is required for the film formed using the liquid crystal alignment agent. However, it is difficult to meet the multiple characteristics at the same time, and the liquid crystal alignment agent has room for further improvement.

[0010] The present invention has been made in view of the above-mentioned problems, and a main object of the present invention is to provide a liquid crystal aligning agent which can obtain a liquid crystal aligning film which is less likely to generate an afterimage, has good coating properties, and has high mechanical strength.

[0011] [Technical means to solve the problem]

[0012] The present inventors have conducted intensive studies to solve the above-mentioned problems and have found that the above-mentioned problems can be solved by using a plurality of polymers having different molecular structures, thereby completing the present invention. Specifically, the present invention provides the following means.

[0013] <1> A liquid crystal aligning agent comprising: a polymer [A] having the following structural unit (U1) and not having the following structural unit (U2); and a polymer [B] having the following structural unit (U2) and the following structural unit (U3).

[0014] Structural unit (U1): A structural unit derived from a diamine having a partial structure represented by the following formula (1)

[0015] Structural unit (U2): A structural unit derived from a diamine having a partial structure represented by the following formula (2)

[0016] Structural unit (U3): a structural unit derived from a diamine having the following partial structure Y

[0017] Partial structure Y: -(CH2) n -(wherein n is an integer from 1 to 20), in -(CH2) n+1 - In the structure represented by, any methylene group is replaced by -O-, -S-, -COO-, -NR 7 -、-NR 7 -CO-、-NR 7 -COO-, -NR 7 -CO-NR 8- or a structure substituted with a nitrogen-containing non-aromatic heterocyclic group (wherein R 7 and R 8 are independently a hydrogen atom or a monovalent organic group; when n is 2 or more, -O-, -S-, -COO-, -NR 7 -、-NR 7 -CO-、-NR 7 -COO-, -NR 7 -CO-NR 8 - and nitrogen-containing non-aromatic heterocyclic groups are not adjacent to each other), -O-, -S-, -COO-, -NR 7 -CO-、-NR 7 -COO- or -NR 7 -CO-NR 8 -

[0018] [Chemistry 1]

[0019]

[0020] (In formula (1), X 1 and X 2 are independently divalent aromatic ring groups; wherein, in X 1 Among the aromatic rings, 1 The bonding position of the base to which "*" is bonded is different from the bonding position of the base to which "*" is bonded. 2 Among the aromatic rings, 2 The bonding position of and the bonding position of the base to which "*" is bonded are different from the bonding position of the base to which "*" is bonded, and there is no substituent bonded; R 1 and R 2 are each independently a single bond, an alkanediyl group having 1 to 10 carbon atoms, or a substituted alkanediyl group having 1 to 10 carbon atoms; Y 1 and Y 2 Independently* 1 -NR 3 -CO- or * 1 -CO-NR 3 -; R 3 is a hydrogen atom or a monovalent organic group; "* 1 " indicates that the 1 The bonding bond of Z 1 is a single bond or a divalent organic group; m is 0 or 1; when m is 0, R 1 and R 2 At least one of them is an alkanediyl group having 1 to 10 carbon atoms or a substituted alkanediyl group; "*" indicates a bonding bond)

[0021] [Chemistry 2]

[0022]

[0023] (In formula (2), A 1 and A 2 are independently a divalent aromatic ring group; 1 For-NR 4 - or a divalent aromatic heterocyclic group; in B 1 When it is a divalent aromatic heterocyclic group, R 5 and R 6 are independently a hydrogen atom or a monovalent organic group; in B 1 For-NR 4 -In the case of R 4 , R 5 and R 6 is (i) or (ii) below;

[0024] (i)R 4 is a hydrogen atom or a monovalent organic group; R 5 and R 6 are independently a hydrogen atom or a monovalent organic group, or represent R 5 With R 6 Combined with A 1 、-NR 4 - and A 2 Together they form a ring structure;

[0025] (ii) R 4 and R 5 are independently a hydrogen atom or a monovalent organic group, or represent R 4 With R 5 Combined with A 1 and nitrogen atoms together to form a ring structure; R 6 is a hydrogen atom or a monovalent organic group;

[0026] "*" indicates a bond)

[0027] <2> A liquid crystal alignment film, formed from the liquid crystal alignment agent according to <1>.

[0028] <3> A liquid crystal element comprising the liquid crystal alignment film according to <2>.

[0029] [Effects of the Invention]

[0030] According to the liquid crystal aligning agent of the present invention, a liquid crystal aligning film which is less likely to produce afterimages, has excellent coating properties, and has high mechanical strength can be obtained. In particular, according to the liquid crystal aligning agent of the present invention, a liquid crystal aligning film which can achieve both AC afterimage characteristics and DC afterimage characteristics can be obtained. DETAILED DESCRIPTION

[0031] The liquid crystal aligning agent of the present disclosure contains a polymer [A] and a polymer [B] which is a polymer different from the polymer [A]. Hereinafter, each component contained in the liquid crystal aligning agent of the present disclosure and other components arbitrarily prepared as needed will be described.

[0032] In addition, in this specification, "hydrocarbon group" means a chain hydrocarbon group, an alicyclic hydrocarbon group and an aromatic hydrocarbon group. The so-called "chain hydrocarbon group" refers to a straight-chain hydrocarbon group and a branched hydrocarbon group that does not contain a cyclic structure in the main chain and is only composed of a chain structure. Among them, it can be saturated or unsaturated. The so-called "alicyclic hydrocarbon group" refers to a hydrocarbon group that only contains an alicyclic hydrocarbon structure as a ring structure and does not contain an aromatic ring structure. Among them, it is not necessary to be composed only of an alicyclic hydrocarbon structure, and a group having a chain structure in a part thereof is also included. The so-called "aromatic hydrocarbon group" refers to a hydrocarbon group containing an aromatic ring structure as a ring structure. Among them, it is not necessary to be composed only of an aromatic ring structure, and a chain structure or an alicyclic hydrocarbon structure may also be included in a part thereof. The so-called "structural unit" refers to a unit that mainly constitutes the main chain structure, and is a unit that contains at least two or more in the main chain structure. As for each component and each compound, as long as it is not specifically mentioned, one can be used alone, or two or more can be used in combination.

[0033] <Polymer [A]>

[0034] The polymer [A] is a polymer containing a structural unit (U1) derived from a diamine (hereinafter also referred to as “specific diamine (A)”) having a partial structure represented by the following formula (1).

[0035] [Chemistry 3]

[0036]

[0037] (In formula (1), X 1 and X 2 are independently divalent aromatic ring groups; wherein, in X 1 Among the aromatic rings, 1 The bonding position of the base to which "*" is bonded is different from the bonding position of the base to which "*" is bonded. 2 Among the aromatic rings, 2 The bonding position of and the bonding position of the base to which "*" is bonded are different from the bonding position of the base to which "*" is bonded, and there is no substituent bonded; R 1 and R 2 are each independently a single bond, an alkanediyl group having 1 to 10 carbon atoms, or a substituted alkanediyl group having 1 to 10 carbon atoms; Y 1 and Y 2 Independently* 1 -NR 3 -CO- or * 1 -CO-NR 3 -; R3 is a hydrogen atom or a monovalent organic group; "* 1 " indicates that the 1 The bonding bond of Z 1 is a single bond or a divalent organic group; m is 0 or 1; R 1 and R 2 At least one of them is an alkanediyl group having 1 to 10 carbon atoms or a substituted alkanediyl group; "*" indicates a bonding bond)

[0038] Structural unit (U1)

[0039] The structural unit (U1) is derived from a polycyclic aromatic ring having two aromatic rings and at least one amide bond (-NR 3 -CO-) diamine structural unit. In the formula (1), X 1 and X 2 The divalent aromatic ring group of X is preferably an aromatic hydrocarbon group. 1 , X 2 Specific examples of include groups obtained by removing any two hydrogen atoms bonded to carbon atoms constituting an aromatic hydrocarbon ring such as a benzene ring, a naphthalene ring, and anthracene ring.

[0040] In addition, X 1 and X 2 The aromatic ring has no substituent. 1 Among the aromatic rings, 1 The substituent is not bonded to the bonding position of X and the bonding position of the base bonded to the bonding bond represented by "*". 2 Among the aromatic rings, 2 No substituent is bonded to the bonding position of and to a position different from the bonding position of the group bonded to the bonding bond represented by "*".

[0041] From the perspective of achieving high density of liquid crystal alignment film, improving the effect of reducing residual image and the mechanical strength of the film, X 1 and X 2 The divalent aromatic ring group is preferably a phenylene group, and particularly preferably a 1,4-phenylene group.

[0042] In R 1 and R 2 In the case of an alkanediyl group having 1 to 10 carbon atoms, R 1 and R 2 , examples include: straight-chain alkanediyl such as methylene, ethylene, 1,3-propanediyl, 1,4-butanediyl, 1,5-pentanediyl, etc.; branched alkanediyl such as 1,2-propanediyl, 1,2-butanediyl, 2-methyl-1,3-propanediyl, etc. 1 and R 2In the case of a substituted alkanediyl group having 1 to 10 carbon atoms, examples of the substituent include a halogen atom, a hydroxyl group, an amino group, a cyano group, an alkoxy group, a protected hydroxyl group, and a protected amino group.

[0043] In terms of improving the voltage holding characteristics and reliability of the liquid crystal element, R 1 and R 2 At least one of them is preferably an alkanediyl group having 1 to 10 carbon atoms or a substituted alkanediyl group having 1 to 10 carbon atoms, and R 1 and R 2 Each of them is an alkanediyl group having 1 to 10 carbon atoms or a substituted alkanediyl group having 1 to 10 carbon atoms. In terms of exhibiting good voltage holding characteristics and liquid crystal orientation, R 1 and R 2 The carbon number of R is preferably 1 to 8, and more preferably 2 to 8. In terms of improving the liquid crystal orientation and having a high effect of reducing the afterimage, R 1 and R 2 A straight chain is preferred.

[0044] Y 1 and Y 2 Amide bond (* 1 -NR 3 -CO- or * 1 -CO-NR 3 -). 3 The monovalent organic group is preferably a monovalent hydrocarbon group having 1 to 10 carbon atoms, or a group that generates a hydrogen atom by detachment (protecting group). 3 In the case of a monovalent hydrocarbon group, the monovalent hydrocarbon group is preferably an alkyl group having 1 to 3 carbon atoms or a phenyl group, and more preferably an alkyl group having 1 to 3 carbon atoms.

[0045] In R 3 In the case of a protecting group, the protecting group is preferably a monovalent group that is detached by heat, for example, carbamate protecting groups, amide protecting groups, imide protecting groups, sulfonamide protecting groups, etc. Among these, carbamate protecting groups are preferred in terms of high heat-induced detachability, and specific examples thereof include tert-butoxycarbonyl, benzyloxycarbonyl, 1,1-dimethyl-2-haloethoxycarbonyl, allyloxycarbonyl, 2-(trimethylsilyl)ethoxycarbonyl, 9-fluorenylmethoxycarbonyl, allyloxycarbonyl, etc. Among these, tert-butoxycarbonyl (Boc group) is particularly preferred in terms of excellent heat-induced detachability and the ability to reduce the residual amount in the film of the deprotected portion.

[0046] R 3 A hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a protecting group is preferred, and a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a tert-butoxycarbonyl group is particularly preferred.

[0047] Z 1 Z is a single bond or a divalent organic group. In terms of improving the voltage holding characteristics of the liquid crystal element and the liquid crystal orientation, 1 A divalent organic group is preferred.

[0048] In Z 1 In the case of a divalent organic group, examples of the divalent organic group include a divalent hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbon group having -O-, -S- or -NR- 3 -(where R 3 With Y 1 and Y 2 R 3 has the same meaning). 1 Relative to Y 1 and Y 2 The amide bond is bonded using a hydrocarbon group.

[0049] Among these, Z 1 The divalent organic group is preferably a divalent chain hydrocarbon group having 1 to 20 carbon atoms, a divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, or a chain hydrocarbon group having -O-, -S- or -NR between carbon-carbon bonds. 3 - is a divalent group, and is particularly preferably an alkanediyl group having 1 to 20 carbon atoms or a cycloalkylene group having 4 to 12 carbon atoms.

[0050] Z 1 The carbon number of is preferably 1-12, more preferably 1-10.

[0051] m is 0 or 1, and is preferably 1 in that the effect of reducing the AC afterimage can be further enhanced.

[0052] The specific diamine (A) is preferably an aromatic diamine, and among them, an aromatic diamine having a structure capable of introducing the partial structure represented by the formula (1) into the main chain of the polymer [A] is preferred. Specifically, the specific diamine (A) is particularly preferably a compound represented by the following formula (DA). In addition, the so-called "main chain" refers to the part of the "trunk" containing the longest atomic chain in the polymer. The part of the "trunk" is allowed to contain a ring structure. For example, the so-called "having a specific structure in the main chain" means that the specific structure constitutes a part of the main chain. The so-called "side chain" refers to the part branching from the "trunk" of the polymer.

[0053] [Chemistry 4]

[0054]

[0055] (In formula (DA), R 1 , R 2 , Y1 , Y 2 , Z 1 and m has the same meaning as in the formula (1))

[0056] In the formula (DA), with respect to R 1 , R 2 , Y 1 , Y 2 , Z 1 With regard to the examples and preferred examples of m, the description of the above formula (1) can be applied.

[0057] As a specific example of the specific diamine (A), the compound etc. represented by each of following formula (DA-1) - formula (DA-23) are mentioned.

[0058] [Chemistry 5]

[0059]

[0060] [Chemistry 6]

[0061]

[0062] [Chemistry 7]

[0063]

[0064] (wherein "Boc" represents tert-butoxycarbonyl)

[0065] As long as the polymer [A] is a polymer having the structural unit (U1), it is preferably selected from at least one of the group consisting of polyamic acid, polyamic acid ester and polyimide in terms of being able to form a liquid crystal alignment film having high affinity with liquid crystals and high mechanical strength and reliability. In the case where the polymer [A] is at least one of the group consisting of polyamic acid, polyamic acid ester and polyimide, the partial structure represented by the formula (1) can be introduced into the main chain of the polymer [A]. In addition, by introducing the partial structure represented by the formula (1) into the main chain of the polymer, it is preferred that the effect of reducing the residual image and improving the film strength can be further improved.

[0066] (Polyamic acid)

[0067] When the polymer [A] is a polyamic acid, the polyamic acid (hereinafter also referred to as “polyamic acid [A]”) can be obtained by, for example, reacting tetracarboxylic dianhydride with a diamine compound containing a specific diamine (A).

[0068] Tetracarboxylic dianhydride

[0069] Examples of tetracarboxylic dianhydrides used in the synthesis of polyamic acid [A] include aliphatic tetracarboxylic dianhydrides, alicyclic tetracarboxylic dianhydrides, and aromatic tetracarboxylic dianhydrides. Specific examples of these include 1,2,3,4-butanetetracarboxylic dianhydrides and ethylenediaminetetraacetic dianhydrides; and alicyclic tetracarboxylic dianhydrides include 1,2,3,4-cyclobutanetetracarboxylic dianhydrides, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydrides, 2,3,5-tricarboxycyclopentylacetic dianhydride, 5-(2,5-dioxotetrahydrofuran-3-yl)-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 5-(2,5-dioxotetrahydrofuran-3-yl)-8-methyl-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione. 2-c] furan-1,3-dione, 2,4,6,8-tetracarboxy bicyclo [3.3.0] octane-2:4,6:8-dianhydride, cyclopentane tetracarboxylic dianhydride, cyclohexane tetracarboxylic dianhydride, etc.; aromatic tetracarboxylic dianhydride includes pyromellitic dianhydride, 3,3',4,4'-biphenyl tetracarboxylic dianhydride, 4,4'-(hexafluoroisopropylidene) diphthalic anhydride, ethylene glycol ditrimellitate anhydride, 4,4'-(hexafluoroisopropylidene) diphthalic anhydride, 4,4'-carbonyl diphthalic anhydride, etc., in addition to these, tetracarboxylic dianhydrides described in Japanese Patent Laid-Open No. 2010-97188 can also be used. As tetracarboxylic dianhydride, one kind can be used alone or two or more kinds can be used in combination.

[0070] In terms of obtaining a liquid crystal alignment film having high solubility in a solvent and exhibiting good electrical properties and low residual image properties, the tetracarboxylic dianhydride used in the synthesis of the polyamic acid [A] preferably contains at least one compound selected from the group consisting of aliphatic tetracarboxylic dianhydride and alicyclic tetracarboxylic dianhydride, and more preferably contains alicyclic tetracarboxylic dianhydride. The proportion of alicyclic tetracarboxylic dianhydride used relative to the total amount of tetracarboxylic dianhydride used in the synthesis of the polyamic acid [A] is preferably 20 mol% or more, more preferably 40 mol% or more, and further preferably 50 mol% or more.

[0071] ·Diamine compounds

[0072] The diamine compound used in the synthesis of the polyamic acid [A] may be the specific diamine (A) alone, or a diamine different from the specific diamine (A) (hereinafter also referred to as "other diamine (A)") may be used together with the specific diamine (A). Examples of the other diamine (A) include aliphatic diamines, alicyclic diamines, aromatic diamines, diaminoorganosiloxanes, and the like. Specific examples of other diamines (A) include p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylethane, 4,4'-diaminodiphenylpropane, 4-aminophenyl-4-aminobenzoate, 2,5-diaminobenzoic acid, 3,5-diaminobenzoic acid, 1,5-bis(4-aminophenoxy)pentane, 1,2-bis(4-aminophenoxy)ethane, 1,3-bis(4-aminophenoxy)propane, 1,6-bis(4-aminophenoxy)hexane, 4,4'-diaminodiphenyl ether, N,N'-bis(5-amino-2-pyridyl)-N,N'-bis(tert-butoxycarbonyl)ethylenediamine, 6,6'-(pentamethylenedioxy)bis(3-aminopyridine), and 2,2'-dimethyl-4,4'-diaminobiphenyl.

[0073] When synthesizing polyamic acid [A], from the perspective of fully achieving the reduction of residual images and obtaining a liquid crystal alignment film with high mechanical strength, the ratio of the specific diamine (A) is preferably 10 mol% or more, more preferably 15 mol% or more, further preferably 20 mol% or more, further preferably 30 mol% or more, particularly preferably 40 mol% or more, and particularly preferably 60 mol% or more relative to the total amount of diamine compounds used in the synthesis of polyamic acid [A]. In addition, the ratio of the specific diamine (A) can be set within a range of 100 mol% or less relative to the total amount of diamine compounds used in the synthesis of polyamic acid [A].

[0074] Synthesis of polyamic acid

[0075] Polyamic acid [A] can be obtained by reacting tetracarboxylic dianhydride with a diamine compound and a molecular weight modifier as needed. In the synthesis reaction of polyamic acid, the use ratio of tetracarboxylic dianhydride and diamine compound is preferably a ratio of 0.2 equivalents to 2 equivalents of the anhydride group of tetracarboxylic dianhydride relative to 1 equivalent of the amino group of the diamine compound. As molecular weight modifiers, for example, acid monoanhydrides such as maleic anhydride, phthalic anhydride, and itaconic anhydride; monoamine compounds such as aniline, cyclohexylamine, and n-butylamine; monoisocyanate compounds such as phenyl isocyanate and naphthyl isocyanate, etc. The use ratio of the molecular weight modifier is preferably set to 20 parts by mass or less relative to a total of 100 parts by mass of the tetracarboxylic dianhydride and diamine compound used.

[0076] The synthesis reaction of polyamic acid is preferably carried out in an organic solvent. The reaction temperature at this time is preferably -20°C to 150°C, and the reaction time is preferably 0.1 hour to 24 hours. As the organic solvent used in the reaction, for example, aprotic polar solvents, phenolic solvents, alcoholic solvents, ketone solvents, ester solvents, ether solvents, halogenated hydrocarbons, hydrocarbons, etc. can be cited. As specific examples of these, it is preferred to use one or more selected from the group consisting of N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphoric triamide, meta-cresol, dimethyl phenol and halogenated phenol as a reaction solvent, or use a mixture of one or more of these and other organic solvents (such as butyl cellosolve, diethylene glycol diethyl ether, etc.). The usage-amount (a) of an organic solvent is preferably an amount in which the total amount (b) of tetracarboxylic dianhydride and diamine becomes 0.1 mass % - 50 mass % with respect to the whole amount (a+b) of a reaction solution.

[0077] In this manner, a polymer solution in which the polyamic acid [A] is dissolved is obtained. The polymer solution may be used directly for the preparation of a liquid crystal aligning agent, or may be used for the preparation of a liquid crystal aligning agent after the polyamic acid [A] contained in the polymer solution is separated.

[0078] (Polyamic acid ester)

[0079] When the polymer [A] is a polyamic acid ester, the polyamic acid ester can be obtained, for example, by the following methods, etc.: [I] a method of reacting a polyamic acid [A] with an esterifying agent; [II] a method of reacting a tetracarboxylic acid diester with a diamine compound containing a specific diamine (A); [III] a method of reacting a tetracarboxylic acid diester dihalide with a diamine compound containing a specific diamine (A). The polyamic acid ester may have only an amic acid ester structure, or may be a partially esterified product in which an amic acid structure and an amic acid ester structure coexist. The reaction solution formed by dissolving the polyamic acid ester may be directly used for the preparation of a liquid crystal aligning agent, or may be used for the preparation of a liquid crystal aligning agent after separating the polyamic acid ester contained in the reaction solution.

[0080] (Polyimide)

[0081] When the polymer [A] is a polyimide, the polyimide can be obtained, for example, by dehydrating and ring-closing the polyamic acid [A] synthesized in the above manner and imidizing it. The polyimide can be a completely imidized product formed by dehydrating and ring-closing all the amic acid structures possessed by the polyamic acid as its precursor, or it can be a partially imidized product in which only a part of the amic acid structure is dehydrated and ring-closed so that the amic acid structure and the imide ring structure coexist. The imidization rate of the polyimide is preferably 20% to 99%, and more preferably 30% to 90%. In addition, the imidization rate is expressed as a percentage of the proportion of the number of imide ring structures relative to the total number of amic acid structures and the number of imide ring structures of the polyimide. Here, a part of the imide ring may be an isoimide ring.

[0082] The dehydration ring-closure of polyamic acid is preferably carried out by the following method: dissolving polyamic acid in an organic solvent, adding a dehydrating agent and a dehydration ring-closure catalyst to the solution, and heating as needed. In the method, as a dehydrating agent, for example, anhydrides such as acetic anhydride, propionic anhydride, and trifluoroacetic anhydride can be used. The amount of the dehydrating agent used is preferably set to 0.01 mol to 20 mol relative to 1 mol of the amic acid structure of the polyamic acid. As a dehydration ring-closure catalyst, for example, tertiary amines such as pyridine, trimethylpyridine, dimethylpyridine, and triethylamine can be used. Relative to 1 mol of the dehydrating agent used, the amount of the dehydration ring-closure catalyst used is preferably set to 0.01 mol to 10 mol. As an organic solvent used in the dehydration ring-closure reaction, an organic solvent exemplified as an organic solvent used in the synthesis of polyamic acid can be cited. The reaction temperature of the dehydration ring-closure reaction is preferably 0°C to 180°C. The reaction time is preferably 1.0 hour to 120 hours. Moreover, the reaction solution containing a polyimide may be used for preparation of a liquid crystal aligning agent as it is, and may be used for preparation of a liquid crystal aligning agent after isolating a polyimide.

[0083] <Polymer [B]>

[0084] The polymer [B] is a polymer having the structural unit (U2) and the structural unit (U3). Hereinafter, each structural unit of the polymer [B] will be described in detail.

[0085] Structural unit (U2)

[0086] The structural unit (U2) is a structural unit derived from a diamine having a partial structure represented by the following formula (2) (hereinafter also referred to as "specific diamine (B1)"). The structural unit (U2) imparts a function of relaxing the accumulated charge in the liquid crystal alignment film to the polymer [B]. In addition, the polymer [A] does not have the structural unit (U2), and in this respect, the polymer [B] is different from the polymer [A].

[0087] [Chemistry 8]

[0088]

[0089] (In formula (2), A 1 and A 2 are independently a divalent aromatic ring group; 1 For-NR 4 - or a divalent aromatic heterocyclic group; in B 1 When it is a divalent aromatic heterocyclic group, R 5 and R 6 are independently a hydrogen atom or a monovalent organic group; in B 1 For-NR 4 -In the case of R 4 , R 5 and R 6 is (i) or (ii) below;

[0090] (i)R 4 is a hydrogen atom or a monovalent organic group; R 5 and R 6 are independently a hydrogen atom or a monovalent organic group, or represent R 5 With R 6 Combined with A 1 、-NR 4 - and A 2 Together they form a ring structure;

[0091] (ii) R 4 and R 5 are independently a hydrogen atom or a monovalent organic group, or represent R 4 With R 5 Combined with A 1 and nitrogen atoms together to form a ring structure; R 6 is a hydrogen atom or a monovalent organic group;

[0092] "*" indicates a bond)

[0093] In addition, in this specification, the so-called other polymer "does not have" the structural unit possessed by at least one polymer among the multiple polymers contained in the liquid crystal alignment agent (hereinafter referred to as "specific unit") means that the other polymer is allowed to have the specific unit within the range that does not damage the effect of the present invention. In this specification, when it is recorded that other polymers "do not have" specific units, the content of the specific units in other polymers is preferably 1 mol% or less, more preferably 0.5 mol% or less, and further preferably 0.1 mol% or less relative to all structural units possessed by other polymers.

[0094] In the formula (2), A 1 and A2 The divalent aromatic ring group may be a divalent aromatic hydrocarbon group or a divalent aromatic heterocyclic group. Examples of the divalent aromatic heterocyclic group include a nitrogen-containing aromatic heterocyclic group, an oxygen-containing aromatic heterocyclic group, a sulfur-containing aromatic heterocyclic group, etc., preferably a nitrogen-containing aromatic heterocyclic group. 1 and A 2 The aromatic ring portion may have a substituent, and examples of the substituent include an alkyl group having 1 to 5 carbon atoms and a halogen atom.

[0095] As A 1 , A 2 Specific examples include divalent aromatic hydrocarbon groups which are obtained by removing any two hydrogen atoms bonded to carbon atoms constituting a benzene ring, naphthalene ring or anthracene ring; divalent nitrogen-containing aromatic heterocyclic groups which are obtained by removing any two hydrogen atoms bonded to carbon atoms constituting a pyridine ring, pyrimidine ring, pyridazine ring or pyrazine ring; divalent oxygen-containing aromatic heterocyclic groups which are obtained by removing any two hydrogen atoms bonded to carbon atoms constituting a furan ring; and divalent sulfur-containing aromatic heterocyclic groups which are obtained by removing any two hydrogen atoms bonded to carbon atoms constituting a thiophene ring. From the perspective of achieving high density and high transmittance of a liquid crystal alignment film, A 1 and A 2 The divalent aromatic ring group is preferably a divalent aromatic hydrocarbon group, more preferably a phenylene group.

[0096] B 1 For-NR 4 - or a divalent aromatic heterocyclic group. 1 In the case of a divalent aromatic heterocyclic group, examples of the aromatic heterocyclic group include A 1 , A 2 Among these, B 1 The divalent aromatic heterocyclic group is preferably a group obtained by removing any two hydrogen atoms bonded to carbon atoms constituting the pyrrole ring, furan ring, and thiophene ring.

[0097] In B 1 When it is a divalent aromatic heterocyclic group, R 5 and R 6 are independently a hydrogen atom or a monovalent organic group. 5 Specific examples and preferred examples of R 3 As R 6 Examples of the monovalent organic group include an alkyl group having 1 to 3 carbon atoms, a halogen atom, and a cyano group.

[0098] In B 1 For-NR 4 -In the case of R 4, R 5 and R 6 Satisfies the above (i) or (ii). 4 , R 5 and R 6 When (i) is satisfied, R 4 is a hydrogen atom or a monovalent organic group. 4 Specific examples and preferred examples of R 3 About R 5 and R 6 When it is a hydrogen atom or a monovalent organic group, the specific examples and preferred examples thereof can also be cited as those of R 3 About R 5 and R 6 , in R 5 With R 6 Combined with A 1 、-NR 4 - and A 2 When they constitute a ring structure together, examples of the ring structure include a carbazole structure, a 9-methylcarbazole structure, and a 9-ethylcarbazole structure.

[0099] In R 4 , R 5 and R 6 When the above (ii) is satisfied, 4 Specific examples and preferred examples of when R is a hydrogen atom or a monovalent organic group include the above 3 In R 5 and R 6 In the case of a hydrogen atom or a monovalent organic group, examples of the monovalent organic group include an alkyl group having 1 to 3 carbon atoms, a halogen atom, a cyano group, and the like.

[0100] About R 4 and R 5 , in R 4 With R 5 Combined with A 1 When forming a ring structure together with a nitrogen atom, examples of the ring structure include an indoline structure and an isoindoline structure.

[0101] As a preferred specific example of the partial structure represented by the formula (2), in B 1 For-NR 4 -, the partial structures represented by the following formulae (2-1) to (2-7) can be cited; in B 1 In the case of a divalent aromatic heterocyclic group, examples include partial structures represented by the following formulae (2-8) to (2-10).

[0102] [Chemistry 9]

[0103]

[0104] (In formula (2-1) to formula (2-10), R 4 and R 33 are independently a hydrogen atom or a monovalent organic group; "*" represents a bonding bond)

[0105] The specific diamine (B1) may have only one partial structure represented by the formula (2), or may have two or more. From the viewpoint of ensuring the solubility of the polymer [B], it is preferably one or two. The specific diamine (B1) is preferably an aromatic diamine, and among them, it is preferably an aromatic diamine having a structure capable of introducing the partial structure represented by the formula (2) into the main chain of the polymer [B]. Specific examples of the specific diamine (B1) include compounds represented by the following formulas (DB-1) to (DB-21), etc. In addition, the specific diamine (B1) does not have the partial structure Y possessed by the structural unit (U3).

[0106] [Chemistry 10]

[0107]

[0108] [Chemistry 11]

[0109]

[0110] [Chemistry 12]

[0111]

[0112] Structural unit (U3)

[0113] The structural unit (U3) is a structural unit derived from a diamine having the following partial structure Y (hereinafter also referred to as "specific diamine (B2)"). In addition, the specific diamine (B2) is a compound that does not have the partial structure represented by the formula (2) and is different from the specific diamine (B1). When the polymer [B2] has the structural unit (U2) and the structural unit (U3), the solubility of the polymer [B2] can be improved, and a liquid crystal alignment film showing low afterimage characteristics (particularly reduced AC afterimage) can be obtained.

[0114] Partial structure Y: -(CH2) n -(wherein n is an integer from 1 to 20), in -(CH2) n+1 - In the structure represented by, any methylene group is replaced by -O-, -S-, -COO-, -NR 7 -、-NR 7 -CO-、-NR 7 -COO-, -NR 7-CO-NR 8 - or a structure substituted with a nitrogen-containing non-aromatic heterocyclic group (wherein R 7 and R 8 are independently a hydrogen atom or a monovalent organic group; when n is 2 or more, -O-, -S-, -COO-, -NR 7 -、-NR 7 -CO-、-NR 7 -COO-, -NR 7 -CO-NR 8 - and nitrogen-containing non-aromatic heterocyclic groups are not adjacent to each other), -O-, -S-, -COO-, -NR 7 -CO-、-NR 7 -COO- or -NR 7 -CO-NR 8 -

[0115] In the partial structure Y, n is preferably 1 to 14, more preferably 1 to 12, from the viewpoint of improving the solubility of the polymer [B], improving the low afterimage characteristics (reduction of AC afterimage and DC afterimage), and the mechanical strength of the liquid crystal alignment film. In the partial structure Y is -(CH2) n+1 In the case of a structure in which any methylene group in the structure represented by - is substituted with -O- or the like (hereinafter also referred to as a "heteroatom-containing structure"), n is preferably 2 or more, and more preferably 2-14.

[0116] In the partial structure Y, examples of the nitrogen-containing non-aromatic heterocyclic group include piperidine-1,4-diyl, piperazine-1,4-diyl, and 2-oxo-4-imidazolidinone-1,3-diyl.

[0117] About R 7 and R 8 Examples and preferred embodiments of R 3 Description.

[0118] As the partial structure Y, among these, -(CH2) is preferred. n - represented by a structure, a structure containing a heteroatom or -O-, more preferably -(CH2) n -The structure represented or the structure containing heteroatoms.

[0119] The specific diamine (B2) is not particularly limited as long as it is a diamine having a partial structure Y, and examples thereof include aliphatic diamines, alicyclic diamines, aromatic diamines, diaminoorganosiloxanes, etc. The specific diamine (B2) preferably has a structure capable of introducing the partial structure Y into the main chain of the polymer [B], and specifically, is preferably a compound represented by the following formula (DB2).

[0120] [Chemistry 13]

[0121] H2N-A 3 -Y 3 -A 4 -NH2 (DB2)

[0122] (In formula (DB2), Y 3 -(CH2) n -The structure represented by -(CH2) n+1 - In the structure represented by, any methylene group is replaced by -O-, -S-, -COO-, -NR 7 -、-NR 7 -CO-、-NR 7 -COO-, -NR 7 -CO-NR 8 - or a structure substituted with a nitrogen-containing non-aromatic heterocyclic group (a structure containing a heteroatom), -O-, -S-, -COO-, -NR 7 -CO-、-NR 7 -COO- or -NR 7 -CO-NR 8 -;A 3 and A 4 are independently a single bond, a substituted or unsubstituted cyclohexylene group, or a substituted or unsubstituted phenylene group; n, R 7 and R 8 The definition is the same as that described above; when n is 2 or more, in the heteroatom-containing structure, -O-, -S-, -COO-, -NR 7 -、-NR 7 -CO-、-NR 7 -COO-, -NR 7 -CO-NR 8 - and nitrogen-containing non-aromatic heterocyclic groups are not adjacent to each other)

[0123] Specific examples of the specific diamine (B2) include m-xylylenediamine, pentamethylenediamine, hexamethylenediamine, etc. as aliphatic diamines; 4,4′-methylenebis(cyclohexylamine) as alicyclic diamines; 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylethane, 4,4′-diaminodiphenylpropane, 4-aminophenyl-4-aminobenzoate, 4,4′-diaminobenzanilide, 1,3-bis(4-aminophenyl)urea, 1,3-bis(4-aminophenethyl)urea, 1,3-bis(4-aminobenzyl)urea, 1,5-bis(4-aminophenoxy)pentane, 1,2-bis(4-aminophenoxy)ethane, 1,3-bis(4-aminophenoxy)propane Examples of the present invention include 1,6-bis(4-aminophenoxy)hexane, bis[2-(4-aminophenyl)ethyl]adipic acid, 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl sulfide, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 4,4′-[4,4′-propane-1,3-diylbis(piperidin-1,4-diyl)]diphenylamine, diethylene glycol bis(4-aminophenyl) ether, 1,4-bis(4-aminophenoxy)benzene, compounds represented by the above formulas (DA-1) to (DA-15) and (DA-17) to (DA-20), and compounds represented by the following formulas (DC-1) to (DC-7). Examples of the diaminoorganosiloxane include 1,3-bis(3-aminopropyl)-tetramethyldisiloxane, and the like.

[0124] [Chemistry 14]

[0125]

[0126] As the specific diamine (B2), among these, it is preferred to use at least one selected from the group consisting of 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylethane, 4,4'-diaminodiphenyl ether, 1,2-bis(4-aminophenoxy)ethane, 4,4'-[4,4'-propane-1,3-diylbis(piperidine-1,4-diyl)]diphenylamine, bis[2-(4-aminophenyl)ethyl]adipic acid, diethylene glycol bis(4-aminophenyl) ether, hexamethylenediamine, hexamethylenediamine and the compound represented by the formula (DC-5).

[0127] In terms of high affinity with polymer [A], polymer [B] is preferably at least one selected from the group consisting of polyamic acid, polyamic acid ester and polyimide. In particular, when polymer [B] has the partial structure represented by formula (2) and the partial structure Y in the main chain, the solubility of polymer [B] can be improved, the accumulated charge can be quickly relaxed, and the AC residual image can be sufficiently reduced, which is preferred in this regard.

[0128] When the polymer [B] is a polyamic acid, the polyamic acid (hereinafter also referred to as "polyamic acid [B]") can be obtained by reacting tetracarboxylic dianhydride with a diamine compound containing a specific diamine (B1) and a specific diamine (B2). Polyamic acid [B], polyamic acid ester and polyimide as the polymer [B] can also be produced in the same manner as the polymer [A].

[0129] As the tetracarboxylic dianhydride used in the synthesis of polymer [B], the examples and preferred examples of the tetracarboxylic dianhydride used in the synthesis of polymer [A] can be cited. That is, the tetracarboxylic dianhydride used in the synthesis of polyamic acid [B] preferably contains at least one compound selected from the group consisting of aliphatic tetracarboxylic dianhydride and alicyclic tetracarboxylic dianhydride, and more preferably contains alicyclic tetracarboxylic dianhydride. The proportion of alicyclic tetracarboxylic dianhydride used relative to the total amount of tetracarboxylic dianhydride used in the synthesis of polyamic acid [B] is preferably 20 mol% or more, more preferably 40 mol% or more, and further preferably 50 mol% or more.

[0130] In addition, when synthesizing polyamic acid [B], polyamic acid ester and polyimide as polymer [B], as diamine compounds, compounds different from specific diamine (B1) and specific diamine (B2) (hereinafter also referred to as "other diamine (B)") may be further used. Examples of other diamines (B) include p-phenylenediamine, 3,5-diaminobenzoic acid, 2,5-diaminobenzoic acid, 4,4-diamino-2,2'-dimethylbiphenyl, 3,5-diamino-N,N-bis(pyridin-3-ylmethyl)benzamide, etc. During synthesis, the amount of other diamines (B) used is preferably 20 mol% or less, more preferably 10 mol% or less, relative to the total amount of diamine compounds used in the synthesis of polymer [B].

[0131] When synthesizing the polymer [B], the amount of the specific diamine (B1) used is preferably 5 mol% or more, more preferably 10 mol% or more, and further preferably 15 mol% or more, relative to the total amount of the diamine compounds used in the synthesis of the polymer [B], from the viewpoint of rapidly relaxing the residual charge and sufficiently achieving the reduction of the DC residual image. In addition, from the viewpoint of suppressing the AC residual image and ensuring the solubility of the polymer [B], the amount of the specific diamine (B1) used is preferably 95 mol% or less, more preferably 80 mol% or less, and further preferably 70 mol% or less, relative to the total amount of the diamine compounds used in the synthesis of the polymer [B].

[0132] From the viewpoint of improving the solubility of the polymer [B], the amount of the specific diamine (B2) used is preferably 5 mol% or more, more preferably 10 mol% or more, and further preferably 15 mol% or more, relative to the total amount of the diamine compounds used in the synthesis of the polymer [B]. From the viewpoint of sufficiently achieving a reduction in DC residual image, the amount of the specific diamine (B2) used is preferably 90 mol% or less, more preferably 80 mol% or less, and further preferably 70 mol% or less, relative to the total amount of the diamine compounds used in the synthesis of the polymer [B].

[0133] In addition, regarding various conditions and the like in the synthesis method of each polymer such as the polyamic acid [B], the description of the polymer [A] can be cited.

[0134] Regarding the solution viscosity of polymer [A] and polymer [B] used in the preparation of the liquid crystal alignment agent, when a solution with a concentration of 10% by mass is prepared, it is preferably a solution viscosity of 10mPa·s to 800mPa·s, and more preferably a solution viscosity of 15mPa·s to 500mPa·s. In addition, the solution viscosity (mPa·s) is a value measured at 25°C using an E-type rotational viscometer for a polymer solution with a concentration of 10% by mass prepared using a good solvent for the polymer (e.g., γ-butyrolactone, N-methyl-2-pyrrolidone, etc.).

[0135] For each of polymer [A] and polymer [B], the weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) in terms of polystyrene is preferably 1,000 to 500,000, more preferably 2,000 to 300,000. In addition, the molecular weight distribution (Mw / Mn) represented by the ratio of Mw to the number average molecular weight (Mn) in terms of polystyrene measured by GPC is preferably 7 or less, more preferably 5 or less.

[0136] In the liquid crystal alignment agent, from the viewpoint of fully achieving the reduction of AC residual image, the content of polymer [A] is preferably 1% by mass or more, more preferably 2% by mass or more, further preferably 5% by mass or more, further preferably 10% by mass or more, relative to the total amount of polymer components contained in the liquid crystal alignment agent. In addition, from the viewpoint of reducing DC residual image by relaxing residual charge, the content of polymer [A] is preferably 90% by mass or less, more preferably 80% by mass or less, further preferably 70% by mass or less, relative to the total amount of polymer components contained in the liquid crystal alignment agent.

[0137] The content of polymer [B] is preferably 10% by mass or more, more preferably 20% by mass or more, and further preferably 30% by mass or more, relative to the total amount of the polymer components contained in the liquid crystal alignment agent. In addition, the content of polymer [B] is preferably 99% by mass or less, more preferably 98% by mass or less, further preferably 95% by mass or less, and further preferably 90% by mass or less, relative to the total amount of the polymer components contained in the liquid crystal alignment agent.

[0138] <Other ingredients>

[0139] The liquid crystal aligning agent may contain a component different from the polymer [A] and the polymer [B] (hereinafter also referred to as “other component”) as needed, in addition to the polymer [A] and the polymer [B].

[0140] (Other polymers)

[0141] The liquid crystal aligning agent of the present disclosure may also contain a polymer different from polymer [A] and polymer [B] (hereinafter also referred to as "other polymers") as a polymer component. The main skeleton of other polymers is not particularly limited. As other polymers, for example, polyamic acid, polyamic acid ester, polyimide, polysiloxane, polyester, polyenamine, polyurea, polyamide, polyamide-imide, polybenzoxazole precursor, polybenzoxazole, cellulose derivatives, polyacetal, (meth) acrylic polymer, styrene polymer, maleimide polymer or styrene-maleimide polymer. From the viewpoint of high affinity with liquid crystal when used in combination with polymer [A] and polymer [B], and improving the reliability of liquid crystal elements, other polymers are preferably selected from at least one of the group consisting of polyamic acid, polyamic acid ester and polyimide.

[0142] When the liquid crystal aligning agent contains other polymers, the content of other polymers in the liquid crystal aligning agent is preferably 30% by mass or less, more preferably 20% by mass or less, further preferably 10% by mass or less, and further more preferably 5% by mass or less, relative to the total amount of polymer [A], polymer [B] and other polymers.

[0143] (Solvent)

[0144] The liquid crystal aligning agent of the present disclosure is prepared in the form of a liquid composition in which the polymer [A], the polymer [B], and other components used as necessary are preferably dispersed or dissolved in an appropriate solvent.

[0145] As the solvent, an organic solvent can be preferably used. Specific examples thereof include: N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 1,2-dimethyl-2-imidazolidinone, 1,3-dimethyl-2-imidazolidinone, phenol, γ-butyrolactone, γ-butyrolactam, N,N-dimethylformamide, N,N-dimethylacetamide, 4-hydroxy-4-methyl-2-pentanone, diacetone alcohol, 1-hexanol, 2-hexanol, propane-1,2-diol, 3-methoxy-1-butanol, ethylene glycol monomethyl ether, methyl lactate, ethyl lactate, butyl lactate, methyl acetate, ethyl acetate, butyl acetate, acetoacetic acid Methyl ester, ethyl acetoacetate, ethyl propionate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-isopropyl ether, ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, diisoamyl ether, ethylene carbonate, propylene carbonate, propylene glycol monomethyl ether (Propylene Glycol Monomethyl Ether, PGME), diethylene glycol diethyl ether acetate, propylene glycol monomethyl ether acetate (Propylene Glycol Monomethyl Ether Acetate, PGMEA), propylene glycol diacetate, cyclopentanone, cyclohexanone, etc.

[0146] As other components contained in the liquid crystal alignment agent, in addition to the above, for example, antioxidants, metal chelate compounds, hardening accelerators, surfactants, fillers, dispersants, photosensitizers, etc. The proportion of other components can be appropriately selected according to each compound within the range that does not impair the effects of the present disclosure.

[0147] The solid content concentration in the liquid crystal aligning agent (the ratio of the total mass of the components other than the solvent of the liquid crystal aligning agent to the total mass of the liquid crystal aligning agent) is appropriately selected in consideration of viscosity, volatility, etc., preferably in the range of 1% to 10% by mass. If the solid content concentration is 1% by mass or more, the film thickness of the coating can be fully ensured, and it is easy to obtain a liquid crystal alignment film showing good liquid crystal orientation. On the other hand, if the solid content concentration is 10% by mass or less, the coating can be made of an appropriate thickness, and it is easy to obtain a liquid crystal alignment film showing good liquid crystal orientation. In addition, the viscosity of the liquid crystal aligning agent becomes moderate and has a tendency to make the coating property good.

[0148] 《Liquid crystal alignment film and liquid crystal element》

[0149] The liquid crystal alignment film of the present invention can be manufactured by a liquid crystal alignment agent prepared as described. In addition, the liquid crystal element of the present invention includes a liquid crystal alignment film formed using the liquid crystal alignment agent described above. The driving mode of the liquid crystal in the liquid crystal element is not particularly limited, for example, it can be applied to various modes such as TN type, Super Twisted Nematic (STN) type, VA type (including Vertical Alignment-Multi-domain Vertical Alignment (VA-MVA) type, Vertical Alignment-Patterned Vertical Alignment (VA-PVA) type, etc.), IPS type, FFS type, Optically Compensated Bend (OCB) type, Polymer Sustained Alignment (PSA) type. The liquid crystal element can be manufactured, for example, by a method including the following steps 1 to 3. Step 1 uses different substrates depending on the desired operating mode. Steps 2 and 3 are common to all operating modes.

[0150] <Step 1: Formation of coating film>

[0151] First, a coating film is formed on the substrate by coating a liquid crystal alignment agent on the substrate, preferably by heating the coated surface. As a substrate, for example, glass such as float glass and soda glass can be used; a transparent substrate containing plastics such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, and poly (alicyclic olefin). As a transparent conductive film disposed on one side of the substrate, a NESA film (registered trademark of PPG, USA) containing tin oxide (SnO2) and an indium tin oxide (Indium Tin Oxide, ITO) film containing indium oxide-tin oxide (In2O3-SnO2) can be cited. In the case of manufacturing a TN type, STN type or VA type liquid crystal element, two substrates provided with a patterned transparent conductive film are used. On the other hand, in the case of manufacturing an IPS type or FFS type liquid crystal element, a substrate provided with electrodes patterned into a comb-shaped shape and an opposing substrate without an electrode are used.

[0152] The coating method of the liquid crystal alignment agent on the substrate is not particularly limited, and can be carried out by, for example, spin coating, printing (for example, offset printing, flexographic printing, etc.), inkjet, slit coating, rod coater, extrusion die, direct gravure coater, chamber doctor coater, offset gravure coater, impregnation coater, MB coater, etc.

[0153] After applying the liquid crystal alignment agent, it is preferred to perform preheating (prebaking) for the purpose of preventing the applied liquid crystal alignment agent from sagging. The prebaking temperature is preferably 30°C to 200°C, and the prebaking time is preferably 0.25 minutes to 10 minutes. Thereafter, the solvent is completely removed, and a calcination (post-baking) process is performed as needed for the purpose of thermal imidization of the amide acid structure present in the polymer. The calcination temperature (post-baking temperature) at this time is preferably 80°C to 280°C, and more preferably 80°C to 250°C. The post-baking time is preferably 5 minutes to 200 minutes. The film thickness of the formed film is preferably 0.001μm to 1μm.

[0154] <Step 2: Orientation treatment>

[0155] In the case of manufacturing TN type, STN type, IPS type or FFS type liquid crystal elements, a process (orientation treatment) of imparting liquid crystal orientation ability to the coating formed in the process 1 is implemented. Thus, the orientation ability of the liquid crystal molecules is imparted to the coating to form a liquid crystal orientation film. As an orientation treatment, it is preferred to use a friction treatment in which the surface of the coating formed on the substrate is wiped with cotton or the like, or to irradiate the coating with light to impart a light orientation ability to the liquid crystal. In the case of manufacturing a vertically oriented liquid crystal element, the coating formed in the process 1 can be directly used as a liquid crystal orientation film, and in order to further improve the liquid crystal orientation ability, the coating can also be subjected to an orientation treatment.

[0156] Light irradiation for photo-orientation can be performed by the following methods, etc.: a method of irradiating the coating after the post-baking process; a method of irradiating the coating after the pre-baking process and before the post-baking process; a method of irradiating the coating during the heating of the coating in at least any one of the pre-baking process and the post-baking process. As radiation irradiated to the coating, for example, ultraviolet rays and visible light containing wavelengths of 150nm to 800nm ​​can be used. Preferably, ultraviolet rays containing wavelengths of 200nm to 400nm are used. When the radiation is polarized, it can be linearly polarized or partially polarized. When 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 these directions can be combined. The irradiation direction for non-polarized radiation is set to an oblique direction.

[0157] Examples of the light source include a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, and an excimer laser. The radiation dose is preferably 200 J / m 2 ~30,000J / m 2 , more preferably 500 J / m 2 ~10,000J / m 2 After the light irradiation for imparting the alignment ability, the following treatment may be performed: the substrate surface may be cleaned using water, an organic solvent (such as methanol, isopropanol, 1-methoxy-2-propanol acetate, butyl cellosolve, ethyl lactate, etc.) or a mixture thereof, or the substrate may be heated.

[0158] <Step 3: Construction of liquid crystal cell>

[0159] Prepare two substrates with liquid crystal alignment films formed in the manner described above, and configure liquid crystals between the two substrates arranged opposite to each other, thereby manufacturing a liquid crystal unit. When manufacturing a liquid crystal unit, for example, the following methods can be cited: two substrates are arranged opposite to each other with a gap in a manner that the liquid crystal alignment films face each other, and the peripheral portions of the two substrates are bonded using a sealant, and the method of injecting liquid crystals into the cell gap surrounded by the substrate surface and the sealant and closing the injection hole, and the method of using a liquid crystal drop (OneDrop Fill, ODF) method. As a sealant, for example, an epoxy resin containing a hardener and alumina balls as a spacer can be used. As a liquid crystal, any of positive and negative types can be used, preferably negative. As a negative liquid crystal, for example, "MLC-6608", "MLC-6609", "MLC-6610", "MLC-7026-100" manufactured by Merck (Merck) can be cited. In particular, when negative liquid crystals are used in IPS-type and FFS-type liquid crystal elements, the transmission loss of the upper part of the electrode can be reduced, and the contrast can be improved, which is preferred in this regard. Examples of the liquid crystal include nematic liquid crystal and smectic liquid crystal, and among these, nematic liquid crystal is preferred.

[0160] When manufacturing a liquid crystal display device, a polarizing plate is then attached to the outer surface of the liquid crystal cell to obtain a liquid crystal display element. Examples of the polarizing plate include a polarizing plate formed by sandwiching a polarizing film called "H film" between cellulose acetate protective films or a polarizing plate containing the H film itself. The "H film" is a film in which polyvinyl alcohol is stretched and oriented while absorbing iodine.

[0161] The liquid crystal element of the present invention can be effectively applied to various purposes. Specifically, for example, it can be used as various display devices or dimming devices such as clocks, portable game consoles, word processors, notebook personal computers, car navigation systems, camcorders, personal digital assistants (PDAs), digital cameras, mobile phones, smart phones, various monitors, liquid crystal televisions, information displays, etc., and phase difference films.

[0162] [Example]

[0163] Hereinafter, the embodiment will be described in more detail based on examples, but the present invention is not to be construed in a limitative manner by the following examples.

[0164] In the following examples, the imidization ratio of the polyimide in the polymer solution was measured by the following method. The necessary amounts of the raw material compounds and polymers used in the following examples were ensured by repeating the synthesis on the synthesis scale shown in the following synthesis examples as necessary.

[0165] [Imidization ratio of polyimide]

[0166] The polyimide solution was poured into pure water, the obtained precipitate was fully dried under reduced pressure at room temperature, and then dissolved in deuterated dimethyl sulfoxide. The reaction mixture was measured at room temperature using tetramethylsilane as the reference substance. 1 H-NMR ( 1 H-NuclearMagnetic Resonance, 1 H-NMR). According to the obtained 1 The imidization ratio [%] was determined from the H-NMR spectrum using the following formula (1).

[0167] Imidization rate [%] = (1-(β1 / (β2×α)))×100…(1)

[0168] (In formula (1), β1 is the peak area of ​​protons derived from NH groups appearing near the chemical shift of 10 ppm, β2 is the peak area derived from other protons, and α is the ratio of the number of other protons to one proton of NH groups in the polymer precursor (polyamic acid))

[0169] The abbreviations of the monomers used in the examples are as follows.

[0170] (Tetracarboxylic dianhydride)

[0171] Compounds (c-1) to (c-5): compounds represented by the following formulas (c-1) to (c-5)

[0172] [Chemistry 15]

[0173]

[0174] (Diamine compound)

[0175] Compound (DA-1) to Compound (DA-14): Compounds represented by Formula (DA-1) to Formula (DA-14)

[0176] Compound (DB-1) to Compound (DB-20): Compounds represented by Formula (DB-1) to Formula (DB-20)

[0177] Compounds (d-1) to (d-5): compounds represented by the following formulas (d-1) to (d-5)

[0178] Compounds (b-1) to (b-11): Compounds represented by the following formulas (b-1) to (b-11)

[0179] [Chemistry 16]

[0180]

[0181] [Chemistry 17]

[0182]

[0183] <Polymer Synthesis>

[0184] 1. Synthesis of polyamic acid

[0185] [Synthesis example 1]

[0186] 100 mol parts of the tetracarboxylic dianhydride compound (c-2) and 100 mol parts of the diamine compound (DA-1) were dissolved in N-methyl-2-pyrrolidone (NMP), and reacted at room temperature for 6 hours to obtain a solution containing 15% by mass of a polyamic acid (hereinafter referred to as "polymer (PAA-1)").

[0187] [Synthesis Example 2 to Synthesis Example 17, Synthesis Example 23 to Synthesis Example 46]

[0188] The same operation as in Synthesis Example 1 was performed except that the types and amounts of the tetracarboxylic dianhydride and diamine compound used were changed as described in Tables 1 and 2 below, thereby obtaining a solution containing polyamic acid (polymers (PAA-2) to (PAA-41)). In addition, in Tables 1 and 2, the amount of tetracarboxylic dianhydride added represents the ratio (mol%) to the total amount of tetracarboxylic dianhydride used in the synthesis of each polymer. The amount of the diamine compound added represents the ratio (mol%) to the total amount of the diamine compound used in the synthesis of each polymer.

[0189] 2. Synthesis of polyimide

[0190] [Synthesis Example 18]

[0191] 90 parts by mole of the compound (c-1) and 10 parts by mole of the compound (c-5) as tetracarboxylic dianhydride and 100 parts by mole of the compound (DA-2) as a diamine compound were dissolved in NMP, and reacted at room temperature for 6 hours to obtain a solution containing 15% by mass of polyamic acid. Then, NMP was added to the obtained polyamic acid solution to prepare a solution having a polyamic acid concentration of 10% by mass, and pyridine and acetic anhydride were added to perform a dehydration ring-closure reaction at 60°C for 4 hours. After the dehydration ring-closure reaction, the solvent in the system was replaced with a new NMP to obtain a solution containing 15% by mass of a polyimide (set to "polymer (PI-1)") having an imidization rate of about 80%.

[0192] [Synthesis Example 19 to Synthesis Example 22]

[0193] Except having changed the kind and amount of the tetracarboxylic dianhydride and the diamine compound used as described in the following Table 1, the same operation as in Synthesis Example 18 was carried out to obtain a solution containing polyimide (polymer (PI-2) to polymer (PI-5)).

[0194] [Table 1]

[0195]

[0196] [Table 2]

[0197]

[0198] [Example 1]

[0199] 1. Preparation of Liquid Crystal Alignment Agent

[0200] The solution of the polymer (PAA-1) obtained in Synthesis Example 1 and the solution of the polymer (PAA-36) obtained in Synthesis Example 41 were diluted with NMP and butyl cellosolve (BC) to obtain a solution having a solid content concentration of 4.0% by mass and a solvent composition ratio of NMP:BC=80:20 (mass ratio). The solution was filtered with a filter having a pore size of 0.2 μm to prepare a liquid crystal aligning agent (R-1).

[0201] 2. Fabrication of FFS-type liquid crystal cell using the rubbing method

[0202] Prepare a glass substrate (set as the first substrate) with a flat electrode (bottom electrode), an insulating layer and a comb-shaped electrode (top electrode) stacked on one side in sequence, and a glass substrate (set as the second substrate) without an electrode. Then, use a rotator to apply a liquid crystal alignment agent (R-1) to the electrode forming surface of the first substrate and the single side of the second substrate, respectively, and heat (pre-bake) on a hot plate at 110°C for 3 minutes. Thereafter, in a 230°C oven in which nitrogen is replaced in the warehouse, dry (post-bake) for 30 minutes to form a coating with an average film thickness of 0.08μm. Then, for the surface of the coating, a friction machine with a roller wound with a rayon cloth is used to perform friction treatment at a roller speed of 1000rpm, a platform moving speed of 3cm / second, and a hair pressing length of 0.3mm. Thereafter, ultrasonic cleaning is performed in ultrapure water for 1 minute, followed by drying in a 100°C clean oven for 10 minutes, thereby obtaining a pair of substrates with a liquid crystal alignment film.

[0203] Then, for a pair of substrates having a liquid crystal alignment film, a liquid crystal injection port is left at the edge of the surface where the liquid crystal alignment film is formed, and an epoxy resin adhesive with alumina balls of 3.5 μm in diameter is applied by screen printing. Thereafter, the substrates are overlapped and crimped, and the adhesive is thermally cured at 150°C for 1 hour. Then, a negative liquid crystal (Merck, MLC-6608) is filled into the gap between a pair of substrates from the liquid crystal injection port, and then the liquid crystal injection port is sealed with an epoxy adhesive. Furthermore, in order to remove the flow orientation during liquid crystal injection, it is heated at 120°C and then slowly cooled to room temperature to manufacture a liquid crystal unit. In addition, when a pair of substrates are overlapped, the friction method of each substrate is made anti-parallel.

[0204] 3. Evaluation of inkjet coating properties (evaluation of solubility)

[0205] As a substrate for coating a liquid crystal alignment agent, a glass substrate with a transparent electrode containing ITO is heated on a hot plate at 200°C for 1 minute, followed by ultraviolet / ozone cleaning, so that the contact angle of water on the transparent electrode surface is less than 10°. An inkjet coater (manufactured by Shibaura Mechatronics (stock)) is used to apply the liquid crystal alignment agent (R-1) prepared in 1. on the transparent electrode surface of the glass substrate with a transparent electrode. The coating conditions at this time are set to coat 2,500 times / (nozzle·minute) and 250 mg / 10 seconds of discharge for 2 round trips (4 times in total). After coating, let it stand for 1 minute, and then heat it at 80°C to form a coating film with an average film thickness of 0.1 μm. For the obtained coating film, the number of unevenness and depressions is observed with the naked eye under irradiation with an interference fringe measuring lamp (sodium lamp). The case where the total number of uneven and concave parts is 0 is set as "excellent (◎)", the case where the total number of uneven and concave parts is 1 or more and less than 3 is set as "good (○)", and the case where the total number of uneven and concave parts is 3 or more is set as "poor (×)" for evaluation. In addition, when the inkjet coating property is good, it can be said that the solubility of the polymer used in the preparation of the liquid crystal alignment agent is good. As a result, the inkjet coating property of the liquid crystal alignment agent of the embodiment is "excellent".

[0206] 4. Evaluation of AC afterimage characteristics

[0207] The FFS liquid crystal cell manufactured in 2. was driven at an AC voltage of 10 V for 72 hours, and then the minimum relative transmittance (%) expressed by the following formula (2) was measured using a device having a polarizer and an analyzer disposed between a light source and a light quantity detector.

[0208] Minimum relative transmittance (%) = (β-B0) / (B100-B0) × 100…(2)

[0209] (In formula (2), B0 is the light transmittance under blank and crossed nicols; B100 is the light transmittance under blank and parallel nicols; β is the light transmittance that is minimum under crossed nicols and when the liquid crystal cell is sandwiched between the polarizer and the analyzer)

[0210] The black level in the dark state is represented by the minimum relative transmittance of the liquid crystal unit. In the FFS type liquid crystal unit, the smaller the black level in the dark state, the better the contrast characteristics, and it can be said that the AC afterimage characteristics are excellent. The case where the minimum relative transmittance is less than 0.3% is set as "excellent (◎)", the case where it is more than 0.3% and less than 2.0% is set as "good (○)", and the case where it is more than 2.0% is set as "poor (×)". The result is "good" in the above embodiment.

[0211] 5. Evaluation of electrical properties

[0212] The FFS liquid crystal unit manufactured in 2. was placed in an oven at 60°C, and then the voltage holding ratio (VHR) was measured under the conditions of 1V and 1670msec using a VHR measuring device "VHR-1" manufactured by Toyo Technica. As an evaluation standard, when the VHR is 80% or more, it is set as "excellent (◎)", when it is less than 80% and more than 70%, it is set as "good (○)", when it is less than 70% and more than 60%, it is set as "acceptable (△)", and when it is less than 60%, it is set as "unacceptable (×)". As a result, the VHR of the embodiment was evaluated as "excellent".

[0213] 6. Evaluation of reliability after light irradiation

[0214] The reliability of the FFS type liquid crystal unit manufactured in 2. above was evaluated. The evaluation was performed as follows. First, after applying a voltage of 1V for 60 microseconds to the liquid crystal unit, the voltage holding rate (VHR1) was measured 1670 milliseconds after the application was released. Then, after irradiating the liquid crystal unit with a cold cathode fluorescent lamp (CCFL) (backlight) for one week at 60°C, it was left to stand at room temperature and naturally cooled to room temperature. After cooling, after applying a voltage of 1V for 60 microseconds to the liquid crystal unit, the voltage holding rate (VHR2) was measured 1670 milliseconds after the application was released. In addition, the measuring device used was a VHR measuring device "VHR-1" manufactured by Toyo Technica Corporation. The rate of change of VHR at this time (ΔVHR) was calculated based on the difference between VHR1 and VHR2 (ΔVHR=VHR1-VHR2), and the reliability was evaluated based on ΔVHR. The case where ΔVHR was less than 10% was judged as "excellent (◎)", the case where 10% or more and less than 15% was judged as "good (○)", the case where 15% or more and less than 20% was judged as "acceptable (△)", and the case where 20% or more was judged as "unacceptable (×)". As a result, the reliability in the above example was "excellent".

[0215] 7. Evaluation of DC afterimage characteristics

[0216] For the liquid crystal unit manufactured in 2., it is driven with AC 2.5V and the brightness difference between any two pixels is set to 0, and then it is driven with AC 2.5V and DC 1V is applied to only one of the pixels for 20 minutes to accumulate charge. When the application of DC 1V is terminated and the drive is returned to AC 2.5V only, a brightness difference is generated between the two pixels by the accumulated charge. By observing the change of the brightness difference over time, the relaxation time of the residual DC value attenuation process is calculated. The relaxation time is judged as "excellent (◎)" when it is less than 10 seconds, and "good (○)" when it is more than 10 seconds and less than 20 seconds, and "poor (×)" when the relaxation time is more than 20 seconds. As a result, it is evaluated as "excellent" in the embodiment.

[0217] 8. Evaluation of friction resistance

[0218] The liquid crystal alignment agent (R-1) prepared in 1. is applied to a glass substrate using a spinner and heated (pre-baked) on a hot plate at 110°C for 3 minutes. Thereafter, it is dried (post-baked) for 30 minutes in an oven at 230°C where nitrogen has been replaced in the storehouse to form a coating with an average film thickness of 0.08 μm, and the haze value of the coating is measured using a hazemeter. Subsequently, for the coating, a friction machine having a roller wound with cotton cloth is used to perform 5 friction treatments at a roller speed of 1000 rpm, a platform moving speed of 3 cm / second, and a hair pressing length of 0.3 mm. Thereafter, a haze meter is used to measure the haze value of the liquid crystal alignment film, and the difference (haze change value) from the haze value before the friction treatment is calculated using the following formula (3).

[0219] Haze change value (%) = [haze value of film after rubbing treatment (%)] - [haze value of film before rubbing treatment (%)]

[0220] …(3)

[0221] Regarding the friction resistance of the liquid crystal alignment film, the case where the haze change value is less than 0.8 is evaluated as "excellent (◎)", the case where the haze change value is greater than 0.8 and less than 1.5 is evaluated as "good (○)", and the case where the haze change value is greater than 1.5 is evaluated as "poor (×)". If the haze change value is less than 1.5 (more preferably less than 0.8), it can be said that the film strength is sufficiently high and the friction resistance is excellent. As a result, the friction resistance is "excellent" in the embodiment.

[0222] [Example 2 to Example 21 and Comparative Example 1 to Comparative Example 8]

[0223] The composition of the liquid crystal aligning agent was changed as shown in Table 3 below. Otherwise, the liquid crystal aligning agent was prepared in the same manner as in Example 1. In addition, the obtained liquid crystal aligning agent was used to manufacture an FFS type liquid crystal unit by a rubbing method in the same manner as in Example 1, and various evaluations were performed. The results are shown in Table 4 below. In Table 3, the blending amount represents the blending amount (parts by mass) of each polymer in terms of solid content relative to the total amount of the polymer component used in the preparation of the liquid crystal aligning agent.

[0224] [Example 22, Example 23]

[0225] Except that the composition of the liquid crystal alignment agent was changed as shown in Table 3 below and that the liquid crystal alignment film was subjected to the photo-alignment method instead of the rubbing method, the liquid crystal alignment agent was prepared in the same manner as in Example 1, and the FFS type liquid crystal cell was manufactured and various evaluations were performed. The results are shown in Table 4. The formation of the liquid crystal alignment film by the photo-alignment method was performed according to the following procedure.

[0226] (Formation of Liquid Crystal Alignment Film by Photo-Alignment Method)

[0227] On a single side of a glass substrate with a flat electrode (bottom electrode), an insulating layer and a comb-shaped electrode (top electrode) stacked in sequence, and on each side of an opposing glass substrate without an electrode, a liquid crystal alignment agent is applied using a spinner, and heated (pre-baked) on a hot plate at 80°C for 1 minute. Thereafter, in a 230°C oven substituted with nitrogen in the chamber, drying (post-baking) is performed for 30 minutes to form a coating with an average film thickness of 0.1 μm. The obtained coating is irradiated with 1,000 J / m ultraviolet rays containing a linearly polarized 254 nm bright line from the normal direction of the substrate using a Hg-Xe lamp. 2 The photo-alignment treatment was performed. The irradiation amount was a value measured using a light meter with a wavelength of 254 nm as a reference. Then, the coating film subjected to the photo-alignment treatment was heated in a clean oven at 230° C. for 30 minutes to perform a heat treatment, thereby forming a liquid crystal alignment film.

[0228] In addition, the UV irradiation after post-baking was set at 100 J / m 2 ~10,000J / m 2 The series of operations are performed by changing the exposure amount within the range of , and three or more liquid crystal units with different ultraviolet irradiation amounts are manufactured. The liquid crystal unit with the exposure amount (optimal exposure amount) showing the best orientation characteristics is used, and various evaluations are performed in the same way as in Example 1.

[0229] [Table 3]

[0230]

[0231] [Table 4]

[0232]

[0233] As shown in Table 4, compared with Comparative Examples 1 to 8, Examples 1 to 23 have achieved a balance of various characteristics including inkjet coating properties, AC afterimage characteristics, VHR, reliability, DC afterimage characteristics, and abrasion resistance. In particular, any of the characteristics of Examples 1 to 6, Example 8, Example 9, Example 11, and Examples 14 to 22 are evaluated as "◎" and are excellent. In contrast, at least any of the characteristics of Comparative Examples 1 to 8, including inkjet coating properties, AC afterimage characteristics, reliability, DC afterimage characteristics, and abrasion resistance, is evaluated as "×".

[0234] The above results show that a liquid crystal alignment agent containing polymer [A] and polymer [B] can produce a liquid crystal alignment film that can reduce residual images of liquid crystal display elements and has high mechanical strength. In addition, it is clear that a liquid crystal alignment agent having good solubility and excellent coating properties of polymer [A] and polymer [B] can be obtained.

Claims

1. A liquid crystal alignment agent, comprising: A polymer [A] having the following structural unit (U1) and not having the following structural unit (U2); and The polymer [B] has the following structural unit (U2) and the following structural unit (U3); The polymer [A] and the polymer [B] are at least one selected from the group consisting of polyamic acid, polyamic acid ester and polyimide, The tetracarboxylic dianhydride used in the synthesis of the polymer [A] comprises at least one compound selected from the group consisting of aliphatic tetracarboxylic dianhydride and alicyclic tetracarboxylic dianhydride. When synthesizing the polymer [A], the ratio of the diamine having a partial structure represented by the following formula (1) is 10 mol% or more relative to the total amount of the diamine compound used in the synthesis of the polymer [A], When synthesizing the polymer [B], the amount of the diamine having a partial structure represented by the following formula (2) used is 5 mol% or more and 95 mol% or less relative to the total amount of the diamine compound used in the synthesis of the polymer [B], When synthesizing the polymer [B], the amount of the diamine having the following partial structure Y used is 5 mol% or more and 90 mol% or less relative to the total amount of the diamine compound used in the synthesis of the polymer [B], The content of the polymer [A] is 1% by mass or more and 90% by mass or less relative to the total amount of the polymer components contained in the liquid crystal aligning agent, The content of the polymer [B] is 10% by mass or more and 99% by mass or less relative to the total amount of the polymer components contained in the liquid crystal aligning agent, Structural unit (U1): a structural unit derived from a diamine having a partial structure represented by the following formula (1); Structural unit (U2): a structural unit derived from a diamine having a partial structure represented by the following formula (2); Structural unit (U3): a structural unit derived from a diamine having the following partial structure Y; Partial structure Y: -(CH2) n -The structure represented by -(CH2) n+1 - In the structure represented by, any methylene group is replaced by -O-, -S-, -COO-, -NR 7 -、-NR 7 -CO-, -NR 7 -COO-, -NR 7 -CO-NR 8 - or a structure substituted by a nitrogen-containing non-aromatic heterocyclic group, -O-, -S-, -COO-, -NR 7 -CO-, -NR 7 -COO- or -NR 7 -CO-NR 8 -; -(CH2) n - In the structure represented by, n is an integer from 1 to 20; In-(CH2) n+1 - In the structure represented by, any methylene group is replaced by -O-, -S-, -COO-, -NR 7 -、-NR 7 -CO-, -NR 7 -COO-, -NR 7 -CO-NR 8 - or a structure substituted with a nitrogen-containing non-aromatic heterocyclic group, R 7 and R 8 are independently a hydrogen atom or a monovalent organic group; when n is 2 or more, -O-, -S-, -COO-, -NR 7 -、-NR 7 -CO-, -NR 7 -COO-, -NR 7 -CO-NR 8 - and the nitrogen-containing non-aromatic heterocyclic groups are not adjacent to each other; In formula (1), X 1 and X 2 are independently phenylene; wherein, in X 1 Among the benzene rings, 1 The bonding position of "*" and the bonding position of the base bonded to it are different from the position where no substituent is bonded. 2 Among the benzene rings, 2 The bonding position of and the bonding position of the base to which "*" is bonded are different from the bonding position of the base to which "*" is bonded, and there is no substituent bonded; R 1 and R 2 are each independently a single bond, an alkanediyl group having 1 to 10 carbon atoms, or a substituted alkanediyl group having 1 to 10 carbon atoms; Y 1 and Y 2 Independently* 1 -NR 3 -CO- or * 1 -CO-NR 3 -; R 3 is a hydrogen atom or a monovalent organic group; "* 1 " indicates that the 1 The bond of Z 1 A divalent chain hydrocarbon group having 1 to 20 carbon atoms, a divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, or a chain hydrocarbon group having -O-, -S-, or -NR between carbon-carbon bonds. 3 - a divalent group; m is 1; R 1 and R 2 At least one of them is an alkanediyl group or a substituted alkanediyl group having 1 to 10 carbon atoms; "*" represents a bonding bond; In formula (2), A 1 and A 2 are each independently a group formed by removing any two hydrogen atoms bonded to carbon atoms constituting a benzene ring, naphthalene ring or anthracene ring, a group formed by removing any two hydrogen atoms bonded to carbon atoms constituting a pyridine ring, pyrimidine ring, pyridazine ring or pyrazine ring, a group formed by removing any two hydrogen atoms bonded to carbon atoms constituting a furan ring, or a group formed by removing any two hydrogen atoms bonded to carbon atoms constituting a thiophene ring; B 1 For-NR 4 -, or a group formed by removing any two hydrogen atoms bonded to carbon atoms constituting a pyrrole ring, a furan ring or a thiophene ring; in B 1 In the case of a group formed by removing any two hydrogen atoms bonded to carbon atoms constituting a pyrrole ring, a furan ring or a thiophene ring, R 5 and R 6 are independently a hydrogen atom or a monovalent organic group; in B 1 For-NR 4 -In the case of R 4 , R 5 and R 6 is (i) or (ii) below; (i)R 4 is a hydrogen atom or a monovalent organic group; R 5 and R 6 are independently a hydrogen atom or a monovalent organic group, or represent R 5 With R 6 Combined with A 1 、-NR 4 - and A 2 Together they form a ring structure; (ii) R 4 and R 5 are independently a hydrogen atom or a monovalent organic group, or represent R 4 With R 5 Combined with A 1 and nitrogen atoms together to form a ring structure; R 6 is a hydrogen atom or a monovalent organic group; "*" indicates a bonding bond; In the A 1 , A 2 and B 1 The ring portion of may have a substituent. 2 . A liquid crystal alignment film, formed using the liquid crystal alignment agent according to claim 1 .

3. A liquid crystal element comprising the liquid crystal alignment film according to claim 2.

Images