Hydroxyalkylamide compounds

Abstract

The present invention relates to a hydroxyalkylamide compound. The compound is represented by the following formula (Add-1) or (Add-2),

Description

[0001] This application is a divisional application of the following application:

[0002] Invention title: Liquid crystal alignment agent, liquid crystal alignment film and liquid crystal display element.

[0003] International application date: October 4, 2021.

[0004] International application number: PCT / JP2021 / 036656.

[0005] National application number: 202180076210.7. Technical Field

[0006] The present invention relates to a liquid crystal alignment agent, a liquid crystal alignment film obtained from the liquid crystal alignment agent, and a liquid crystal display element using the liquid crystal alignment film. Background Technology

[0007] Liquid crystal displays (LCDs) have historically been widely used as display units in personal computers, smartphones, mobile phones, television receivers, and the like. An LCD typically includes: a liquid crystal layer sandwiched between a component substrate and a color filter substrate; pixel electrodes and a common electrode that apply an electric field to the liquid crystal layer; an alignment film that controls the orientation of the liquid crystal molecules in the liquid crystal layer; and thin-film transistors (TFTs) that convert electrical signals supplied to the pixel electrodes. Known driving methods for liquid crystal molecules include: vertical electric field methods such as TN (Twisted Nematic) and VA (Vertical Alignment); and lateral electric field methods such as IPS (In-Plane Switching) and FFS (Fringe Field Switching).

[0008] Currently, the most widely used liquid crystal alignment films in industry are manufactured through a so-called rubbing process. This rubbing process involves unidirectionally rubbing the surface of a film formed on an electrode substrate using a cloth such as cotton, nylon, or polyester. This film is composed of polymers such as polyamic acid and / or polyimides formed by imidizing the polyamic acid. Rubbing is a simple and industrially useful method with excellent productivity. Furthermore, as an alternative to rubbing, photoalignment methods are known, which impart alignment capabilities to liquid crystals by irradiating them with polarized radiation. Regarding photoalignment methods, methods utilizing photoisomerization reactions, photocrosslinking reactions, and photodecomposition reactions have been proposed (see Non-Patent Literature 1, Patent Literature 1).

[0009] In recent years, large-screen, high-resolution LCD TVs have become the mainstream. Furthermore, the widespread adoption of smaller display terminals such as smartphones, tablet PCs, and car navigation systems has further increased the demands on the high quality of LCD display components. Reliability testing of LCD display components for mobile applications like smartphones and in-vehicle applications like car navigation systems sometimes involves panel vibration testing. This vibration test requires that no bright spots or other defects occur.

[0010] Furthermore, to ensure the largest possible display surface, the width of the sealant used between the substrates bonding the liquid crystal display elements is required to be as narrow as possible, a process known as narrow bezel application. With this narrow bezel application, the sealant used in manufacturing the liquid crystal display elements is overlapped onto the liquid crystal alignment film. Consequently, a liquid crystal alignment film with high adhesion (hereinafter also referred to as sealing tightness) between the sealant and the liquid crystal alignment film is required.

[0011] Furthermore, when alignment characteristics are achieved through friction processing, dust can easily accumulate due to the cutting of the liquid crystal alignment film. If dust accumulates on the surface of the liquid crystal alignment film, it can cause display defects. In addition, it can damage the circuitry of the TFT elements, leading to a decrease in yield.

[0012] Therefore, in order to obtain liquid crystal display elements that do not produce defects during vibration testing and friction treatment, and liquid crystal alignment films with high sealing and sealing performance, methods to improve the mechanical strength of the liquid crystal alignment film can be considered, for example. As a method to improve the mechanical strength, especially the film strength, of the liquid crystal alignment film, the addition of a crosslinking agent to the liquid crystal alignment agent can be cited. As a means to solve these problems, liquid crystal alignment agents containing specific polyimide components and specific hydroxyalkylamide compounds have been proposed (see Patent Document 2). Furthermore, regarding the electrical properties, which are a fundamental characteristic of liquid crystal alignment films, higher initial properties are also required.

[0013] Existing technical documents

[0014] Patent documents

[0015] Patent Document 1: Japanese Patent Application Publication No. 9-297313

[0016] Patent Document 2: WO2018 / 092811 Publication

[0017] Non-patent literature

[0018] Non-Patent Literature 1: "Liquid Crystal Optical Alignment Film" by Kido Waki ​​and Ichimura, Functional Materials, November 1997, Vol. 17, No. 11, pp. 13-22 Summary of the Invention

[0019] The problem that the invention aims to solve

[0020] According to the research of the inventors, when the specific hydroxyalkylamide compound described in Patent Document 2 is added, although the film strength of the obtained liquid crystal alignment film is improved, the anisotropy of the liquid crystal alignment film that contributes to the liquid crystal alignment is reduced.

[0021] Liquid crystal display elements with low anisotropy liquid crystal alignment films suffer from degraded contrast and may produce image retention (hereinafter also referred to as AC image retention) caused by long-term AC driving. Therefore, there is a need for a liquid crystal alignment agent that can improve the film strength of the liquid crystal alignment film while maintaining high anisotropy.

[0022] As described above, the object of the present invention is to provide a liquid crystal alignment agent, the liquid crystal alignment film, and a liquid crystal display element having the liquid crystal alignment film, wherein the liquid crystal alignment agent can produce a liquid crystal alignment film with high film strength and exhibiting high anisotropy.

[0023] Solution for solving the problem

[0024] In order to solve the above-mentioned problems, the inventors conducted in-depth research and found that the above-mentioned problems could be solved by using a specific hydroxyalkylamide compound, thereby completing the present invention.

[0025] The present invention relates to a liquid crystal alignment agent, a liquid crystal alignment film obtained from the liquid crystal alignment agent, a liquid crystal display element having the liquid crystal alignment film, and further to a novel compound for the liquid crystal alignment agent, wherein the liquid crystal alignment agent is characterized by containing the following components (A) and (B).

[0026] (A) Component: Polymer (A) with the ability to orient liquid crystals.

[0027] (B) Component: Hydroxyalkylamide compound (B) as shown in formula (1) below.

[0028] P—o—W—o—P (1)

[0029] (In formula (1), P independently represents a group having the group "*-C(=O)-N(R)2", W represents a partial structure exhibiting liquid crystal properties. R independently represents the group "*-(CR'2)2-OH", and R' independently represents a monovalent organic group with 1 to 6 hydrogen atoms or carbon atoms. * represents a bond).

[0030] It should be noted that in this specification, * in any case represents a bonded bond. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine. Preferred protecting groups for urethane esters include tert-butoxycarbonyl and 9-fluorenylmethoxycarbonyl.

[0031] Invention Effects

[0032] According to the present invention, a liquid crystal alignment agent capable of producing a liquid crystal alignment film with high film strength and exhibiting high anisotropy, the liquid crystal alignment film, and a liquid crystal display element having the liquid crystal alignment film can be obtained. Furthermore, a liquid crystal display element with fewer display defects is provided. In addition, a liquid crystal alignment film with excellent sealing performance, voltage retention rate, and image retention characteristics can be obtained.

[0033] The mechanism by which the above-mentioned effects of the present invention are obtained may not be clear, but the following may be considered as one of the reasons.

[0034] That is, the retention characteristics can be considered to be filled by utilizing the liquid crystal-like portion structure arranged in the center. In particular, it can be considered that the presence of chain hydrocarbons at both ends of the liquid crystal-like portion structure greatly helps to suppress stretching resistance and promote the liquid crystal performance. Detailed Implementation

[0035] <(A)Component>

[0036] The liquid crystal alignment agent of the present invention, like known liquid crystal alignment agents, contains a polymer capable of aligning liquid crystals; the polymer is not particularly limited as long as it possesses this ability. The liquid crystal alignment agent of the present invention may contain one or more of these polymers.

[0037] Examples of such polymers include: polyimide precursors, polyimides that are imide derivatives of polyimide precursors, acrylic polymers, methacrylic polymers, acrylamide polymers, methacrylamide polymers, polystyrene, polysiloxanes, polyamides, polyesters, polyurethanes, polycarbonates, polyureas, polyphenols (phenolic varnish resins), maleimide polymers, and polymers incorporating compounds having an isocyanuric acid backbone or a triazine backbone.

[0038] The following substances can be listed as raw materials used to manufacture these polymers.

[0039] In the case where the polymer is a polyimide precursor such as polyamic acid or polyamic acid ester, or a polyimide, at least one tetracarboxylic dianhydride and a diamine selected from tetracarboxylic acids or their derivatives may be included.

[0040] In the case of a polymer that is a (meth)acrylic acid polymer, examples include (meth)acrylic acid or its derivatives, or (meth)acrylates or their derivatives.

[0041] In the case of a polymer that is a (meth)acrylamide polymer, examples of (meth)acrylamide or its derivatives can be listed.

[0042] When the polymer is polystyrene, styrene or its derivatives can be listed.

[0043] In the case of a polymer that is a polysiloxane, examples of silane compounds having methoxy or ethoxy groups can be listed.

[0044] When the polymer is polyamide, at least one dicarboxylic acid component and a diamine component selected from dicarboxylic acids and their derivatives can be listed.

[0045] When the polymer is a polyester, at least one dicarboxylic acid component and a diol component selected from dicarboxylic acids and their derivatives can be listed.

[0046] In the case of a polymer that is polyurethane, compounds containing isocyanates and compounds containing hydroxyl groups can be listed.

[0047] In the case of a polymer that is polycarbonate, examples include bisphenol derivatives and phosgene or phosgene equivalents (e.g., trichlorophosgene) or diphenyl carbonate.

[0048] In the case of a polymer that is polyurea, diisocyanate derivatives and diamine components can be listed.

[0049] In the case where the polymer is a maleimide polymer, examples include maleimide derivative homopolymers or copolymers with styrene.

[0050] In the case where the polymer is a polymer incorporating compounds having an isocyanuric acid skeleton or a triazine skeleton, examples of compounds having an isocyanuric acid skeleton or a triazine skeleton can be listed.

[0051] <Polyimide polymers>

[0052] The polymer contained in the liquid crystal alignment agent of the present invention is preferably selected from one or more polymers (hereinafter also referred to as polyimide-based polymers) from the group consisting of polyimide precursors and polyimides that are imide derivatives of polyimide precursors, from the viewpoints of practicality as liquid crystal alignment agents, mechanical strength of coating films and liquid crystal alignment properties.

[0053] The aforementioned polyimide polymers can be manufactured using known methods. For example, polyamic acid, as a polyimide precursor, is obtained by polymerizing (condensing) a tetracarboxylic acid component composed of a tetracarboxylic dianhydride or its derivative with a diamine component, and then imidizing this polyimide precursor to obtain a polyimide. Examples of tetracarboxylic dianhydride derivatives include tetracarboxylic acid dihalides, tetracarboxylic acid dialkyl esters, or tetracarboxylic acid dialkyl ester dihalides.

[0054] <Tetracarboxylic acid component>

[0055] Polyamic acids, as precursors to polyimides, can be exemplified by substances derived from tetracarboxylic acid components comprising aromatic, acyclic, or alicyclic tetracarboxylic dianhydrides or their derivatives. The aforementioned tetracarboxylic dianhydrides or their derivatives can be used alone or in combination of two or more.

[0056] Here, aromatic tetracarboxylic dianhydrides are obtained by intramolecular dehydration of four carboxyl groups, including at least one carboxyl group bonded to an aromatic ring. Acyclic aliphatic tetracarboxylic dianhydrides are obtained by intramolecular dehydration of four carboxyl groups bonded to a chain hydrocarbon structure. It is not necessary for the structure to consist solely of a chain hydrocarbon; a portion of the structure may also have an alicyclic or aromatic ring structure.

[0057] Furthermore, alicyclic tetracarboxylic dianhydrides are obtained by intramolecular dehydration of four carboxyl groups, including at least one carboxyl group bonded to the alicyclic structure. None of these four carboxyl groups are bonded to an aromatic ring. Moreover, it is not necessary for the structure to consist solely of an alicyclic structure; it can also have a chain hydrocarbon structure or an aromatic ring structure in a portion thereof.

[0058] With regard to the polyamic acid of the present invention, it is preferable to obtain a substance containing a tetracarboxylic acid component comprising a tetracarboxylic acid dianhydride or a derivative thereof as shown in formula (2) below.

[0059]

[0060] (X represents a structure selected from the following formulas (x-1) to (x-13)).

[0061]

[0062] (R 1 ~R 4 Each of the following can be independently represented: a hydrogen atom, a halogen atom, an alkyl group with 1 to 6 carbon atoms, an alkenyl group with 2 to 6 carbon atoms, an alkynyl group with 2 to 6 carbon atoms, a monovalent organic group containing a fluorine atom with 1 to 6 carbon atoms, or a phenyl group. 5 and R 6 Each A1 and A2 independently represents a hydrogen atom or a methyl group. j and k are integers of 0 or 1. A1 and A2 independently represent a single bond, -O-, -CO-, -COO-, phenylene, sulfonyl, or amide group, respectively. The two A2 groups may be the same or different. *1 is a bond bonded to an anhydride group on one side, and *2 is a bond bonded to an anhydride group on the other side.

[0063] As a preferred specific example of the tetracarboxylic acid dianhydride or its derivatives shown in formula (2) above, X can be selected from substances in formulas (x-1) to (x-8) and (x-10) to (x-13) above.

[0064] Regarding the above formula (x-1), the structure is preferably selected from the group consisting of the following formulas (X1-1) to (X1-6).

[0065]

[0066] (*1 is a bond bonded to an anhydride group on one side, and *2 is a bond bonded to an anhydride group on the other side).

[0067] As preferred examples of the above formulas (x-12) and (x-13), the following formulas (x-14) to (x-29) can be listed. It should be noted that the "*" in the formulas indicates the bonding position.

[0068]

[0069]

[0070] The amount of tetracarboxylic acid dianhydride or its derivative shown in formula (2) above used relative to 1 mole of the total tetracarboxylic acid component reacting with the diamine component is preferably 60 to 100 mol%, more preferably 80 to 100 mol%, and even more preferably 90 to 100 mol%.

[0071] <Diamine component>

[0072] The diamine component used in the manufacture of the polyimide precursor is not particularly limited, but preferably contains at least one diamine selected from the diamines shown in formula (3) and formula (3A) below. The diamine contained in the above diamine component may be used alone or in combination of two or more.

[0073]

[0074] (Y3 represents the divalent organic group shown in formula (O) below. R independently represents either a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Y) 3a (This represents the divalent organic group shown in formula (a) below).

[0075]

[0076] (Ar represents a divalent benzene ring, biphenyl structure, or naphthalene ring. The two Ars may be the same or different, and any hydrogen atom of the aforementioned benzene ring, biphenyl structure, or naphthalene ring may be substituted with a monovalent substituent. p is an integer of 0 or 1. Q3 represents -(CH2).) n -(n is an integer from 2 to 18.), or the above -(CH2). n A group consisting of at least a portion of -CH2- replaced by any one of -O-, -C(=O)-, or -O-C(=O)-.

[0077]

[0078] (In formula (a), the hydrogen atoms on the benzene ring are optionally substituted with halogen atoms, alkyl groups having 1 to 10 carbon atoms, alkoxy groups having 1 to 10 carbon atoms, fluoroalkyl groups having 1 to 10 carbon atoms, or fluoroalkoxy groups having 1 to 10 carbon atoms. P is any aromatic ring selected from the benzene ring or biphenyl structure, and the hydrogen atoms on the benzene ring or biphenyl structure are optionally substituted with methyl or fluorine atoms. n is an integer from 0 to 5. When n is an integer greater than 2, n Ps independently have the above definition).

[0079] Substituents for the benzene ring, biphenyl structure, or naphthalene ring in the above formula (O) can include, for example, halogen atoms, alkyl groups with 1 to 10 carbon atoms, alkenyl groups with 2 to 10 carbon atoms, alkoxy groups with 1 to 10 carbon atoms, fluoroalkyl groups with 1 to 10 carbon atoms, fluoroalkenyl groups with 2 to 10 carbon atoms, fluoroalkoxy groups with 1 to 10 carbon atoms, carboxyl groups, hydroxyl groups, alkyloxycarbonyl groups with 1 to 10 carbon atoms, cyano groups, nitro groups, etc.

[0080] From the viewpoint of improving liquid crystal orientation, the divalent organic group shown in the above formula (O) is preferably the divalent organic group shown in the following formulas (o-1) to (o-16).

[0081]

[0082] (In equation (o-14), the two m's are independently defined as described above).

[0083]

[0084] From the viewpoint of improving liquid crystal orientation, the divalent organic group shown in the above formula (3a) is preferably the divalent organic group shown in the following formulas (A-1) to (A-7).

[0085]

[0086] The total proportion of at least one diamine selected from the diamines shown in formula (3) and formula (3A) is preferably 1 to 95 mol% of 1 mole of diamine component, more preferably 1 to 90 mol%, and even more preferably 5 to 90 mol%.

[0087] From the viewpoint of improving the voltage retention rate of the obtained liquid crystal alignment film, the polyimide polymer used in this invention may also have a structure containing at least one nitrogen atom selected from the group consisting of nitrogen-containing heterocycles (excluding the imide rings possessed by polyimides), secondary amino groups, and tertiary amino groups (hereinafter also referred to as a specific nitrogen-containing structure). A polyimide polymer having a specific nitrogen-containing structure can be obtained by using a monomer having a nitrogen-containing structure in at least a portion of the raw material, for example, using a diamine having a specific nitrogen-containing structure.

[0088] Examples of nitrogen-containing heterocycles that a diamine with a specific nitrogen-containing structure can possess include: pyrrole, imidazole, pyrazole, triazole, pyridine, pyrimidine, pyridazine, pyrazine, indole, benzimidazole, purine, quinoline, isoquinoline, naphthidine, quinoxaline, phthalazine, triazine, carbazole, acridine, piperidine, piperazine, pyrrolidine, hexamethyleneimine, etc. Pyridine, pyrimidine, pyrazine, piperidine, piperazine, quinoline, carbazole, or acridine are preferred.

[0089] The diamines with the above-mentioned structures containing specific nitrogen atoms may have secondary and tertiary amino groups, for example, represented by the following formula (n).

[0090]

[0091] In the above formula (n), R represents a hydrogen atom or a monovalent hydrocarbon group with 1 to 10 carbon atoms. "*1, *2" represent bonds bonded to the hydrocarbon group.

[0092] As a monovalent hydrocarbon group of R in the above formula (n), examples include: alkyl groups such as methyl, ethyl, and propyl; cycloalkyl groups such as cyclohexyl; and aryl groups such as phenyl and methylphenyl. R is preferably a hydrogen atom or a methyl group.

[0093] Specific examples of diamines having a specific nitrogen-containing structure include: 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, 1,4-bis-(4-aminophenyl)-piperazine, 3,6-diaminoacridine, N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, compounds represented by formulas (Dp-1) to (Dp-8), and compounds represented by formulas (z-1) to (z-18).

[0094]

[0095]

[0096] From the viewpoint of improving the voltage retention rate of liquid crystal display elements, the proportion of diamine having a specific nitrogen-containing structure used relative to the total amount of diamine used in synthesis is preferably 1 mol% or more, more preferably 2 mol% or more. Furthermore, this proportion is preferably 90 mol% or less, more preferably 80 mol% or less.

[0097] The polyimide polymers used in this invention may also contain diamines other than those described above. Examples of other diamines are listed below, but the invention is not limited thereto.

[0098] Examples include: diamines with 6 to 30 carbon atoms (excluding D) having the intramolecular group "-N(D)-" (D represents a carbamate protecting group); 4,4'-diaminoazobenzene; and the following formula (d T -1)~(d T-3) and other diamines having photo-oriented groups; 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminobenzophenone, 1,4-bis(4-aminobenzyl)benzene, diamines shown in formulas (3i-1) to (3i-5) below, 2,4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4,6-diaminoresorcinol; 2,4-diaminobenzoic acid, 2,5-diaminobenzoic acid, 3,5-diaminobenzoic acid and the following formula ( Diamines containing carboxyl groups, such as the diamine compounds shown in formulas (3b-1) to (3b-4); 4-(2-(methylamino)ethyl)aniline, 4-(2-aminoethyl)aniline, 4,4'-diaminodiphenylmethane, 4,4'-diaminobenzophenone, 4,4'-diaminodiphenyl ether, 4,4'-diaminobenzoylaniline, 4,4'-diaminoazobenzene, 1-(4-aminophenyl)-1,3,3-trimethyl-1H-indane-5-amine, 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-indane-6-amine Diamines containing urea bonds, such as those shown in formulas (h-1) to (h-3); diamines containing amide bonds, such as those shown in formulas (h-4) to (h-6); diamines with photopolymerizable groups at the ends, such as 2-(2,4-diaminophenoxy)ethyl methacrylate and 2,4-diamino-N,N-diallyl aniline; cholesteryloxy-3,5-diaminobenzene, cholesteryloxy-3,5-diaminobenzene, cholesteryloxy-2,4-diaminobenzene, cholesteryl 3,5-diaminobenzoate, and cholesteryl 3,5-diaminobenzoate. Diamines having a steroidal skeleton, such as lanosteryl 3,5-diaminobenzoate and 3,6-bis(4-aminobenzoyloxy)cholestane; diamines represented by formulas (V-1) to (V-6) below; diamines having a siloxane bond, such as 1,3-bis(3-aminopropyl)-tetramethyldisiloxane; diamines having an oxazoline structure, such as formulas (Ox-1) to (Ox-2) below; and diamines formed by bonding two amino groups to any one of the groups represented by formulas (Y-1) to (Y-167) as described in International Publication No. 2018 / 117239.

[0099]

[0100] (In equations (3i-1)~(3i-3), the two n can be chosen to be the same or different).

[0101]

[0102] (In equation (3b-1), A) 1The following symbols represent single bonds, -CH2-, -C2H4-, -C(CH3)2-, -CF2-, -C(CF3)2-, -O-, -CO-, -NH-, -N(CH3)-, -CONH-, -NHCO-, -CH2O-, -OCH2-, -COO-, -OCO-, -CON(CH3)-, or -N(CH3)CO-. m1 and m2 independently represent integers from 0 to 4, and m1+m2 represents integers from 1 to 4. In equation (3b-2), m3 and m4 independently represent integers from 1 to 5. In equation (3b-3), A... 2 m5 represents a straight-chain or branched alkyl group with 1 to 5 carbon atoms, where m5 represents an integer from 1 to 5. In formula (3b-4), A 3 and A 4 Each of these can independently represent a single bond, -CH2-, -C2H4-, -C(CH3)2-, -CF2-, -C(CF3)2-, -O-, -CO-, -NH-, -N(CH3)-, -CONH-, -NHCO-, -CH2O-, -OCH2-, -COO-, -OCO-, -CON(CH3)-, or -N(CH3)CO-, where m6 represents an integer from 1 to 4.

[0103]

[0104]

[0105] (In the above formulas (V-1)~(V-6), X v1 ~X v4 X p1 ~X p2 Each can be represented independently as -(CH2) a - (a is an integer from 1 to 15), -CONH-, -NHCO-, -CON(CH3)-, -NH-, -O-, -CH2O-, -CH2OCO-, -COO-, or -OCO-, X v5 This represents -O-, -CH2O-, -CH2OCO-, -COO-, or -OCO-. X a Represents single bonds, -O-, -NH-, -O-(CH2). m -O-, -C(CH3)2-, -CO-, -(CH2) m -, -SO2-, -O-C(CH3)2-, -CO-(CH2) m -、-NH-(CH2) m -, -SO2-(CH2) m -, -CONH-(CH2) m -, -CONH-(CH2) m-NHCO-, -COO-(CH2) m -OCO-, -CONH-, -NH-(CH2) m -NH- or -SO2-(CH2) m -SO2- (where m represents an integer from 1 to 6), R v1 ~R v4 R 1a ~R 1b Each of the following can be independently represented as an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an alkoxyalkyl group having 2 to 20 carbon atoms. (In formula (V-6), the two k may optionally be the same or different).

[0106]

[0107] As diamines with 6 to 30 carbon atoms other than D and having the intramolecular group "-N(D)- (D represents a carbamate protecting group)", the compounds shown in formulas (5-1) to (5-10) below can be listed.

[0108]

[0109] (Boc represents tert-butyloxycarbonyl.)

[0110] <(B) Component>

[0111] The liquid crystal alignment agent of the present invention is characterized in that it contains a hydroxyalkylamide compound (B) as shown in formula (1).

[0112] P—o—W—o—P (1)

[0113] (In formula (1), P independently represents a group having the group "*-C(=O)-N(R)2", and W represents a partial structure exhibiting liquid crystal properties. R independently represents the group "-(CR'2)2-OH", and R' independently represents a monovalent organic group with 1 to 6 hydrogen atoms or carbon atoms).

[0114] As a partial structure exhibiting liquid crystal properties in the aforementioned W, a mesocrystalline structure can be cited as an example. For instance, the structure shown in the following formula (w) can be cited as a mesocrystalline structure.

[0115]

[0116] (Ar1 and Ar2 are independently substituted or unsubstituted phenylene or cyclohexylene, respectively, and X1 is a single bond, -CO-, -COO-, -C=C-, -C≡C-, -N=N-, or -CONR1- (R1 is a hydrogen atom or a monovalent organic group). n is an integer from 1 to 3. When n is 2 or 3, Ar1 and X1 independently have the above definitions).

[0117] In the above formula (w), X1 is preferably a single bond or -COO-. Examples of monovalent organic groups as R1 include alkyl groups with 1 to 6 carbon atoms, protecting groups, etc. Specific examples of protecting groups include tert-butoxycarbonyl, benzyloxycarbonyl, 1,1-dimethyl-2-haloethyloxycarbonyl, allyloxycarbonyl, etc.

[0118] The substituents in the ring portions of Ar1 and Ar2 are preferably alkyl or halogen atoms with 1 to 5 carbon atoms, and more preferably methyl or fluorine atoms.

[0119] Specific examples of preferred partial structures shown in the above formula (w) include, for example, 4,4'-biphenyl, 4,4'-biscyclohexylene, p-terphenyl, and groups shown in each of the following formulas (1-1) to (1-4), as well as groups having methyl or fluorine atoms in the ring portion of these groups.

[0120]

[0121] In formula (1) above, P represents a group having the group "*-C(=O)-N(R)2". Specific examples of P include the group "*-C(=O)-N(R)2" or the group "*-A-C(=O)-N(R)2". A represents a divalent organic group with 1 to 30 carbon atoms. Examples of divalent organic groups in A include divalent hydrocarbon groups, divalent heteroatom-containing groups whose carbon-carbon bonds contain heteroatoms, and divalent organic groups formed by replacing some or all of the hydrogen atoms in the above-mentioned divalent hydrocarbon groups and divalent heteroatom-containing groups with substituents.

[0122] As divalent hydrocarbon groups in the above-mentioned group "*-A-C(=O)-N(R)2", examples include divalent hydrocarbon groups formed by removing two hydrogen atoms from the following hydrocarbons: alkanes such as methane, ethane, propane, and butane; alkenes such as ethylene, propylene, butene, and pentene; alkynes such as acetylene, propyne, butyne, and pentyne, which are chain hydrocarbons with 1 to 30 carbon atoms; cycloalkanes such as cyclopropane, cyclobutane, cyclopentane, cyclohexane, norbornane, and adamantane; alicyclic hydrocarbons such as cyclopropylene, cyclobutene, cyclopentene, cyclohexene, and norbornene, which are cycloalkenes with 3 to 30 carbon atoms; and aromatic hydrocarbons such as benzene, toluene, xylene, mesitylene, naphthalene, methylnaphthalene, dimethylnaphthalene, and anthracene, which are 6 to 30 carbon atoms.

[0123] As for the A in the above-mentioned group "*-A-C(=O)-N(R)2", it is preferably a divalent hydrocarbon group with 1 to 30 carbon atoms, and more preferably a divalent hydrocarbon group obtained by removing two hydrogen atoms from a divalent chain hydrocarbon with 1 to 30 carbon atoms or an aromatic hydrocarbon with 6 to 30 carbon atoms.

[0124] Preferably, the divalent chain hydrocarbons with 1 to 30 carbon atoms are divalent chain hydrocarbons with 2 to 30 carbon atoms, and more preferably divalent chain hydrocarbons with 2 to 16 carbon atoms.

[0125] Examples of monovalent organic groups with 1 to 6 carbon atoms in the group "-(CR'2)2-OH" include: alkyl groups with 1 to 6 carbon atoms, alkenyl groups with 2 to 6 carbon atoms, alkynyl groups with 2 to 6 carbon atoms, or heteroatom-containing groups whose carbon-carbon bonds contain heteroatoms, and groups formed by substituting some or all of the hydrogen atoms of the aforementioned alkyl, alkenyl, alkynyl, and heteroatom-containing groups with substituents.

[0126] In the above-mentioned group "*-A-C(=O)-N(R)2" and group "-(CR'2)2-OH", groups having heteroatoms include, for example, groups having at least one selected from the group consisting of oxygen, nitrogen, silicon, phosphorus, and sulfur atoms, such as: -O-, -NR- (R represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms), -CO-, -S-, -CO-, and groups formed by combining these. Among them, -O- is preferred.

[0127] In the above-mentioned group "*-A-C(=O)-N(R)2" and group "-(CR'2)2-OH", the substituents can include, for example: halogen atoms such as fluorine, chlorine, bromine, and iodine; alkoxy groups such as methoxy, ethoxy, and propoxy; alkoxycarbonyl groups such as methoxycarbonyl and ethoxycarbonyl; alkoxycarbonyloxy groups such as methoxycarbonyloxy and ethoxycarbonyloxy; cyano, nitro, and hydroxyl groups.

[0128] From the viewpoint of improving liquid crystal orientation, R' in the above-mentioned group "-(CR'2)2-OH" is preferably a hydrogen atom.

[0129] The hydroxyalkylamide compound (B) shown in formula (1) above is preferably a compound shown in formula (b-1) below. In formula (b-1) below, n is independent, more preferably 2 to 10, and even more preferably 2 to 8. More preferably, it is a compound shown in formulas (Add-1) to (Add-2) below. It should be noted that the compounds shown in formulas (Add-1) to (Add-2) below are novel compounds not disclosed in prior art literature.

[0130]

[0131] (In equation (b-1), the two n's are independently defined as described above).

[0132]

[0133] The preferred content of the hydroxyalkylamide compound (B) represented by the above formula (1) in the liquid crystal alignment agent of the present invention is 0.1 to 50 parts by mass relative to 100 parts by mass of component (A), more preferably 0.1 to 30 parts by mass.

[0134] <Manufacturing Method of Polyamic Acid>

[0135] Polyamic acid, the polyimide precursor used in this invention, can be manufactured by the following method. Specifically, it can be synthesized by reacting the above-mentioned tetracarboxylic acid component with the above-mentioned diamine component in the presence of an organic solvent at, for example, -20 to 150°C, preferably at, 0 to 50°C, for, for example, 30 minutes to 24 hours, preferably 1 to 12 hours (condensation reaction).

[0136] Specific examples of organic solvents used in the above reactions include: N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, and 1,3-dimethyl-2-imidazolinone. Furthermore, where the polymer has high solvent solubility, methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, or solvents shown in formulas [D-1] to [D-3] can be used. Two or more of these solvents can also be mixed.

[0137]

[0138] (In formula [D-1], D) 1 In formula [D-2], D represents an alkyl group with 1 to 3 carbon atoms. 2 In formula [D-3], D represents an alkyl group having 1 to 3 carbon atoms. 3 (Refers to alkyl groups with 1 to 4 carbon atoms).

[0139] The reaction can be carried out at any concentration, preferably 1-50% by mass, more preferably 5-30% by mass. The reaction is initially carried out at a high concentration, and solvent can be added subsequently. In the reaction, the ratio of the total molar number of the diamine component to the total molar number of the tetracarboxylic acid component is preferably 0.8-1.2. Similar to conventional polycondensation reactions, the closer this molar ratio is to 1.0, the larger the molecular weight of the resulting polyamic acid.

[0140] The polyamic acid obtained in the above reaction can be precipitated and recovered by injecting the reaction solution into a poor solvent while stirring it thoroughly. Alternatively, after several precipitation processes, washing with the poor solvent, and drying at room temperature or by heating, purified polyamic acid powder can be obtained. Poor solvents are not particularly limited, but examples include: water, methanol, ethanol, hexane, butyl cellosolve, acetone, and toluene.

[0141] When the polyimide precursor is a polyamic acid ester, it can be manufactured by the following known methods: (1) a method of esterifying a polyamic acid ester obtained from a tetracarboxylic acid dianhydride and a diamine; (2) a method based on the reaction of a tetracarboxylic acid diester dichloride with a diamine; (3) a method of polycondensing a tetracarboxylic acid diester with a diamine, etc.

[0142] The aforementioned polyimide precursor can also be an end-modified polymer obtained by using a suitable end-capping agent together with the tetracarboxylic acid derivative and diamine as described above during the manufacture of the polyimide precursor.

[0143] Examples of end-modifying agents include: acetic anhydride, maleic anhydride, nadic anhydride, phthalic anhydride, itaconic anhydride, cyclohexanedicarboxylic anhydride, 3-hydroxyphthalic anhydride, trimellitic anhydride, and other acid anhydrides; di-tert-butyl dicarbonate; aniline, 2-aminophenol, 3-aminophenol, 4-aminosalicylic acid, 5-aminosalicylic acid, 6-aminosalicylic acid, 2-aminobenzoic acid, 3-aminobenzoic acid, 4-aminobenzoic acid, and other monoamine compounds; ethyl isocyanate, phenyl isocyanate, naphthyl isocyanate, and other monoisocyanate compounds.

[0144] The proportion of the terminal modifier used relative to 100 moles of the total diamine component used is preferably 40 moles or less, more preferably 30 moles or less.

[0145] <Manufacturing Method of Polyimide>

[0146] The polyimide used in this invention can be manufactured by imidizing polyamic acid or polyamic acid ester as a polyimide precursor using known methods.

[0147] For example, in the case of manufacturing polyimides from polyamic acid, (chemical) imidization by adding a catalyst to a solution of polyamic acid obtained by reacting a diamine component with a tetracarboxylic acid component is straightforward. Imidization can be carried out, for example, by stirring the polymer to be imidized in an organic solvent in the presence of a basic catalyst and an acid anhydride.

[0148] In polyimides, the ring-closing rate (also known as the imidization rate) of the functional groups in polyamic acid or polyamic ester is not necessarily 100% and can be adjusted arbitrarily according to the application and purpose.

[0149] Methods for obtaining polyimide by imidizing the above-mentioned polyamic acid or polyamic acid ester include: thermal imidization by directly heating a solution of the above-mentioned polyamic acid or polyamic acid ester, or catalytic imidization by adding a catalyst to a solution of the above-mentioned polyamic acid or polyamic acid ester. The temperature during thermal imidization is 100–400°C, preferably 120–250°C, and preferably carried out while removing water generated by the imidization reaction from the system.

[0150] Catalytic imidization can be carried out by adding a basic catalyst and an acid anhydride to a polymer solution, preferably at -20 to 250°C, more preferably at 0 to 180°C with stirring. The amount of basic catalyst is preferably 0.5 to 30 molar times the amount of the ammonium acid group or ammonium ester group, more preferably 2 to 20 molar times, and the amount of acid anhydride is preferably 1 to 50 molar times the amount of the ammonium acid group or ammonium ester group, more preferably 3 to 30 molar times. Examples of basic catalysts include pyridine, triethylamine, trimethylamine, tributylamine, and trioctylamine, among which pyridine is preferred due to its moderate basicity for the reaction to proceed. Examples of acid anhydrides include acetic anhydride, trimellitic anhydride, and phenylmethyltetrahydroquinone, among which acetic anhydride is preferred because it facilitates purification after the reaction. The imidization rate obtained by catalytic imidization can be controlled by adjusting the amount of catalyst, reaction temperature, and reaction time.

[0151] In the case of recovering the generated polyimide from the reaction solution of catalytic imidization, the reaction solution is added to a solvent to precipitate the polymer. Examples of solvents for precipitation include methanol, ethanol, isopropanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, toluene, benzene, and water. The polymer precipitated by adding the polymer to the solvent can be filtered, recovered, and then dried at room temperature or under reduced pressure. Furthermore, repeating the reprecipitation recovery operation 2 to 10 times by dissolving the recovered polymer in a solvent again reduces impurities in the polymer. Examples of solvents used in this process include alcohols, ketones, and hydrocarbons. Using three or more solvents selected from these sources further improves the purification efficiency and is therefore preferred.

[0152] <Polymer solution viscosity / molecular weight>

[0153] Regarding the polyamic acid, polyamic acid ester, and polyimide used in this invention, from a workability point of view, it is preferable that when they are prepared into solutions with a concentration of 10-15% by weight, for example, a solution viscosity of 10-1000 mPa·s, but there is no particular limitation. It should be noted that the solution viscosity (mPa·s) of the above polymers is the value measured at 25°C using an E-type rotational viscometer for a polymer solution with a concentration of 10-15% by weight prepared using a good solvent (e.g., γ-butyrolactone, N-methyl-2-pyrrolidone, etc.).

[0154] The weight-average molecular weight (Mw) of the polyamic acid, polyamic acid ester, and polyimide, as determined by gel permeation chromatography (GPC), converted from polystyrene, is preferably 1,000 to 500,000, more preferably 2,000 to 500,000. Furthermore, the molecular weight distribution (Mw / Mn) shown by the ratio of Mw to the number-average molecular weight (Mn) of polystyrene determined by GPC is preferably 15 or less, more preferably 10 or less. This molecular weight range ensures good liquid crystal alignment of the liquid crystal display element.

[0155] <Liquid Crystal Alignment Agent>

[0156] The liquid crystal alignment agent of the present invention contains the polymer (A) having the ability to align liquid crystals and the hydroxyalkylamide compound (B) of formula (1) described above. Preferably, the liquid crystal alignment agent of the present invention comprises adding the hydroxyalkylamide compound (B) of formula (1) described above to a solution formed by dissolving the polymer (A) having the ability to align liquid crystals in a solvent.

[0157] The content (concentration) of polymer (A) contained in the liquid crystal alignment agent of the present invention can also be appropriately changed according to the setting of the thickness of the coating to be formed. From the viewpoint of forming a uniform and defect-free coating, it is preferably 1% by mass or more, and from the viewpoint of the storage stability of the solution, it is preferably 10% by mass or less.

[0158] The solvent used in liquid crystal alignment agents is not particularly limited as long as it uniformly dissolves the polymer components. Specific examples include: N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethyllactic acid, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethyl sulfoxide, γ-butyrolactone, γ-valerolactone, 1,3-dimethyl-2-imidazolinone, methyl ethyl ketone, cyclohexanone, cyclopentanone, 3-methoxy-N,N-dimethylpropionamide, and 3-butoxy-N,N-dimethylpropionamide. Amides, N-(n-propyl)-2-pyrrolidone, N-isopropyl-2-pyrrolidone, N-(n-butyl)-2-pyrrolidone, N-(tert-butyl)-2-pyrrolidone, N-(n-pentyl)-2-pyrrolidone, N-methoxypropyl-2-pyrrolidone, N-ethoxyethyl-2-pyrrolidone, N-methoxybutyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone (also collectively referred to as "good solvents"), etc. Among these, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 3-methoxy-N,N-dimethylpropionamide, 3-butoxy-N,N-dimethylpropionamide, or γ-butyrolactone are preferred. The content of the good solvent is preferably 20-99% by mass of the total solvent contained in the liquid crystal alignment agent, more preferably 20-90% by mass, and particularly preferably 30-80% by mass.

[0159] Furthermore, the solvent contained in the liquid crystal alignment agent is preferably a mixed solvent, in addition to the solvents mentioned above, which also includes a solvent (also known as a poor solvent) that improves the coatability and surface smoothness of the coating film when applying the liquid crystal alignment agent. Specific examples of the solvents used are given below, but are not limited thereto.

[0160] For example, the following can be listed: diisopropyl ether, diisobutyl ether, diisobutylmethanol (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-propanediol, etc. Alcohols, 2-(2-butoxyethoxy)-1-propanol, propylene glycol monomethyl ether acetate, propylene glycol diacetate, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, ethylene glycol monobutyl ether acetate, diethylene glycol 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 ether acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, butyl 3-methoxypropionate, n-butyl lactate, isoamyl lactate, diethylene glycol monoethyl ether, diisobutyl ketone (2,6-dimethyl-4-heptanone), etc.

[0161] The preferred solvents are diisobutylmethanol, propylene glycol monobutyl ether, propylene glycol diacetate, diethylene glycol diethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monobutyl ether, ethylene glycol monobutyl ether acetate, or diisobutyl ketone. The content of the undesirable solvent is preferably 1-80% by mass of the total solvent contained in the liquid crystal alignment agent, more preferably 10-80% by mass, and particularly preferably 20-70% by mass. The type and content of the undesirable solvent are appropriately selected based on the coating apparatus, coating conditions, and coating environment of the liquid crystal alignment agent.

[0162] Preferred combinations of solvents, representing a combination of good and poor solvents, include: N-methyl-2-pyrrolidone with ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone with γ-butyrolactone and ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone with γ-butyrolactone and propylene glycol monobutyl ether, N-ethyl-2-pyrrolidone with propylene glycol monobutyl ether, N-ethyl-2-pyrrolidone with 4-hydroxy-4-methyl-2-pentanone, N-ethyl-2-pyrrolidone with propylene glycol diacetate, N,N-dimethyllacticamide with diisobutyl ketone, N-methyl-2-pyrrolidone with ethyl 3-ethoxypropionate, N-ethyl-2-pyrrolidone with ethyl 3-ethoxypropionate, N- Methyl-2-pyrrolidone with ethylene glycol monobutyl ether acetate, N-ethyl-2-pyrrolidone with dipropylene glycol dimethyl ether, N,N-dimethyllacticamide with ethylene glycol monobutyl ether, N,N-dimethyllacticamide with propylene glycol diacetate, N-ethyl-2-pyrrolidone with diethylene glycol diethyl ether, N,N-dimethyllacticamide with diethylene glycol diethyl ether, N-methyl-2-pyrrolidone with γ-butyrolactone and 4-hydroxy-4-methyl-2-pentanone with diethylene glycol diethyl ether, N-ethyl-2-pyrrolidone with N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone, N-ethyl-2-pyrrolidone with 4-hydroxy-4-methyl-2-pentanone with propylene glycol monobutyl ether, N-methyl-2-pyrrolidone with 4 -Hydroxy-4-methyl-2-pentanone with 2,6-dimethyl-4-heptanone, N-methyl-2-pyrrolidone with 4-hydroxy-4-methyl-2-pentanone with dipropylene glycol monomethyl ether, N-methyl-2-pyrrolidone with 4-hydroxy-4-methyl-2-pentanone with propylene glycol monobutyl ether, N-methyl-2-pyrrolidone with 4-hydroxy-4-methyl-2-pentanone with propylene glycol diacetate, γ-butyrolactone with 4-hydroxy-4-methyl-2-pentanone with 2,6-dimethyl-4-heptanone, γ-butyrolactone with 4-hydroxy-4-methyl-2-pentanone with propylene glycol diacetate, N-methyl-2-pyrrolidone with γ-butyrolactone with propylene glycol monobutyl ether with 2,6-dimethyl-4-heptanone, N-methyl-2-pyrrolidone It can be used with γ-butyrolactone and propylene glycol monobutyl ether and diisopropyl ether; N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether and 2,6-dimethyl-4-heptanol; N-methyl-2-pyrrolidone and γ-butyrolactone and dipropylene glycol dimethyl ether; N-methyl-2-pyrrolidone and propylene glycol monobutyl ether and dipropylene glycol dimethyl ether; N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether and dipropylene glycol monomethyl ether; N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether and propylene glycol diacetate; N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether and diisobutyl ketone; N-ethyl-2-pyrrolidone and γ-butyrolactone and diisobutyl ketone; N-ethyl-2-pyrrolidone and N,N-dimethyllactic acid and diisobutyl ketone, etc.

[0163] In addition to the polymer (A) and the hydroxyalkylamide compound (B), the liquid crystal alignment agent of the present invention may also contain components other than solvents (hereinafter also referred to as additive components). Examples of such additive components include: adhesion promoters for improving the adhesion between the liquid crystal alignment film and the substrate, and the adhesion between the liquid crystal alignment film and the sealing material; compounds for improving the strength of the liquid crystal alignment film (hereinafter also referred to as crosslinking compounds); and dielectrics and conductive materials for adjusting the dielectric constant and resistance of the liquid crystal alignment film.

[0164] From the viewpoint of exhibiting good resistance to AC remnants and high improvement in film strength, the aforementioned crosslinking compound may be a compound selected from the following: a compound having at least one group selected from the group consisting of ethylene oxide, oxetane, protected isocyanate group, protected isothiocyanate group, a group containing an oxazoline ring structure, a group containing a Michaelis acid structure, and a cyclic carbonate group; a hydroxyalkylamide compound other than the compound shown in formula (1) above; or a compound shown in formula (e) below.

[0165]

[0166] (In formula (e), A represents an (m+n) valence organic group having an aromatic ring. m represents an integer from 1 to 6, and n represents an integer from 0 to 4. R represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Any hydrogen atom in the above aromatic ring may optionally be substituted with a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a fluoroalkyl group having 1 to 10 carbon atoms, a fluoroalkenyl group having 2 to 10 carbon atoms, or a fluoroalkoxy group having 1 to 10 carbon atoms. When m is 2 or more, R has the above definition independently.)

[0167] Specific examples of compounds containing ethylene oxide include compounds described in paragraph

[0037] of Japanese Patent Application Publication No. 10-338880 and compounds with a triazine ring skeleton as described in International Patent Publication No. 2017 / 170483, as well as compounds containing two or more ethylene oxide groups. These may also include nitrogen-containing compounds such as N,N,N',N'-tetraglycidyl-m-xylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, N,N,N',N'-tetraglycidyl-p-phenylenediamine, and compounds shown in formulas (r-1) to (r-3) below.

[0168]

[0169] Specific examples of compounds having oxetane groups include compounds having two or more oxetane groups as described in paragraphs

[0170] to

[0175] of International Publication No. 2011 / 132751.

[0170] Specific examples of compounds having protected isocyanate groups include: compounds having two or more protected isocyanate groups as described in paragraphs

[0046] to

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

[0119] to

[0120] of International Publication No. 2015 / 141598, and compounds with the following formulas (bi-1) to (bi-3).

[0171]

[0172] As a specific example of a compound having a protected isothiocyanate group, compounds having two or more protected isothiocyanate groups as described in Japanese Patent Application Publication No. 2016-200798 can be cited.

[0173] As a specific example of a compound having a group containing an oxazoline ring structure, the compound containing two or more oxazoline structures described in paragraph

[0115] of Japanese Patent Application Publication No. 2007-286597 can be cited.

[0174] As a specific example of a compound having a group containing a Michaelis acid structure, the compound having two or more Michaelis acid structures described in International Publication No. 2012 / 091088 can be cited.

[0175] As a specific example of a compound having a cyclic carbonate group, the compound described in International Publication No. 2011 / 155577 can be cited.

[0176] Specific examples of hydroxyalkylamide compounds other than those shown in formula (1) above include: compounds described in paragraph

[0058] of International Publication No. 2015 / 072554, Japanese Patent Application Publication No. 2016-118753, Japanese Patent Application Publication No. 2016-200798, and International Publication No. 2019 / 142927, as well as compounds shown in formulas (hd-1) to (hd-8) below and compounds shown in formulas (hd1-1) to (hd1-4) below.

[0177]

[0178]

[0179] Examples of (m+n) valence organic groups having aromatic rings in A of formula (e) above include: (m+n) valence aromatic hydrocarbon groups with 6 to 30 carbon atoms; (m+n) valence organic groups formed by direct or linked groups of aromatic hydrocarbon groups with 6 to 30 carbon atoms; and (m+n) valence groups having aromatic heterocycles. Examples of such aromatic hydrocarbons include benzene and naphthalene. Examples of such aromatic heterocycles include: pyrrole rings, imidazole rings, pyrazole rings, pyridine rings, pyrimidine rings, quinoline rings, isoquinoline rings, carbazole rings, pyridazine rings, pyrazine rings, benzimidazole rings, indole rings, quinoxaline rings, and acridine rings. Examples of such linked groups include: alkylene groups with 1 to 10 carbon atoms, groups formed by removing one hydrogen atom from the aforementioned alkylene groups, and divalent or trivalent cyclohexane rings. It should be noted that any hydrogen atom of the aforementioned alkylene group may optionally be replaced by an alkyl group having 1 to 6 carbon atoms, a fluorine atom, or an organic group such as a trifluoromethyl group. Specific examples include the compounds described in International Publication No. 2010 / 074269 and the compounds shown in formulas (e-1) to (e-10) below.

[0180]

[0181] The above-described compound is an example of a cross-linking compound, but is not limited thereto. For example, other components not described above may be listed in International Publication No. 2015 / 060357, pages 53

[0105] to 55

[0116] . Furthermore, two or more cross-linking compounds may be combined.

[0182] The content of the crosslinking compound in the liquid crystal alignment agent of the present invention is preferably 0.5 to 20 parts by mass relative to 100 parts by mass of the polymer component contained in the liquid crystal alignment agent, and more preferably 1 to 15 parts by mass from the viewpoint that the crosslinking reaction is carried out and good resistance to AC image retention is exhibited.

[0183] Examples of such sealing agents include: 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyldiethoxymethylsilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-ureopropyltrimethoxysilane, 3-ureopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxy 3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonylacetate, 9-triethoxysilyl-3,6-diazanonylacetate, N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane Alkane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis(oxyethylidene)-3-aminopropyltrimethoxysilane, N-bis(oxyethylidene)-3-aminopropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-epoxypropoxypropylmethyldimethoxysilane, 3-epoxypropoxypropyltrimethoxysilane, 3-epoxypropoxypropylmethyldiethoxysilane, 3-epoxypropoxypropylmethyldiethoxysilane, 3-epoxypropoxypropyl Silane coupling agents include oxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, tri-(trimethoxysilylpropyl)isocyanurate, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-isocyanatopropyltriethoxysilane. When using silane coupling agents, from the viewpoint of exhibiting good resistance to AC image retention, the amount of polymer component contained in the liquid crystal alignment agent is preferably 0.1 to 30 parts by weight, more preferably 0.1 to 20 parts by weight per 100 parts by weight.

[0184] <Liquid crystal alignment film / liquid crystal display element>

[0185] The liquid crystal alignment film of the present invention is obtained from the above-described liquid crystal alignment agent. The liquid crystal alignment film of the present invention can be used as a liquid crystal alignment film for horizontally aligned or vertically aligned (VA type) liquid crystal display elements, and is preferably suitable for liquid crystal alignment films of horizontally aligned liquid crystal display elements such as IPS or FFS types. The liquid crystal display element of the present invention includes the above-described liquid crystal alignment film. The liquid crystal display element of the present invention can be manufactured, for example, by a method including the following steps (1) to (4) or steps (1) to (2) and (4).

[0186] <Process (1): Process of applying liquid crystal alignment agent>

[0187] The liquid crystal alignment agent of the present invention is applied to one side of a substrate having a patterned transparent conductive film using a suitable coating method such as a roll coating method, spin coating method, printing method, or inkjet method. Here, the substrate is not particularly limited as long as it is a highly transparent substrate; acrylic substrates, polycarbonate substrates, or other plastic substrates can also be used with glass substrates or silicon nitride substrates. Furthermore, in reflective liquid crystal display elements, if only a single-sided substrate is used, an opaque material such as a silicon wafer can be used, and the electrodes can be made of light-reflecting materials such as aluminum. Moreover, in the manufacture of IPS-type or FFS-type liquid crystal elements, a substrate having electrodes composed of a patterned comb-shaped transparent conductive film or metal film and a counter substrate without electrodes are used.

[0188] Methods for coating a liquid crystal alignment agent onto a substrate and forming a film include screen printing, offset printing, flexographic printing, inkjet printing, and spraying. Among these, inkjet printing is a preferred method for coating and forming a film.

[0189] <Process (2): The process of firing the coated liquid crystal alignment agent>

[0190] Step (2) is a step of firing the liquid crystal alignment agent coated on the substrate to form a film. After the liquid crystal alignment agent is coated on the substrate, the solvent can be evaporated using a heating unit such as a heating plate, a thermally circulating oven, or an IR (infrared) oven, or the amyl acid or amyl ester in the polymer can be thermally imidized. The drying and firing steps after coating the liquid crystal alignment agent of the present invention can be performed at any temperature and time, and can be repeated multiple times. The temperature for removing the solvent from the liquid crystal alignment agent can be, for example, 40 to 180°C. From the viewpoint of shortening the process, it can be performed at 40 to 150°C. The firing time is not particularly limited, and examples include 1 to 10 minutes or 1 to 5 minutes. In the case of thermal imidization of the amyl acid or amyl ester in the polymer, after the step of removing the above-mentioned organic solvent, the firing step can be performed, for example, at a temperature range of 150 to 300°C or 150 to 250°C. The firing time is not particularly limited, and examples include 5 to 40 minutes or 5 to 30 minutes.

[0191] If the thickness of the film after firing is too thin, the reliability of the liquid crystal display element may sometimes be reduced. Therefore, the thickness is preferably 5 to 300 nm, and more preferably 10 to 200 nm.

[0192] <Step (3): The step of oriented treatment of the film obtained in step (2)>

[0193] Step (3) is a step of aligning the film obtained in step (2) as needed. That is, in horizontally aligned liquid crystal display elements such as IPS or FFS, the coating is subjected to an alignment capability treatment. On the other hand, in vertically aligned liquid crystal display elements such as VA or PSA, the formed coating can be used directly as a liquid crystal alignment film, or an alignment capability treatment can be performed on the coating. As an alignment treatment method for liquid crystal alignment film, the rubbing treatment method and the photo-alignment treatment method are preferred. As a photo-alignment treatment method, the following methods can be listed: irradiating the surface of the film with radiation deflected in a fixed direction, and, depending on the situation, preferably performing a heating treatment at a temperature of 150 to 250°C to impart liquid crystal alignment properties (also known as liquid crystal alignment capability). As radiation, ultraviolet light or visible light with a wavelength of 100 to 800 nm can be used. Among them, ultraviolet light with a wavelength of 100 to 400 nm is preferred, and ultraviolet light with a wavelength of 200 to 400 nm is more preferred.

[0194] The preferred radiation dose is 1–10,000 mJ / cm². 2 The preferred concentration is 100–5000 mJ / cm³. 2Furthermore, to improve liquid crystal alignment when irradiated with radiation, the substrate having the above-described film can be heated at 50–250°C while being irradiated with radiation. The liquid crystal alignment film fabricated as described above enables the liquid crystal molecules to be stably aligned in a fixed direction.

[0195] Furthermore, in the above methods, water or solvents can be used to contact the liquid crystal alignment film irradiated with polarized radiation, or the liquid crystal alignment film irradiated with radiation can be heated.

[0196] The solvent used in the above-described contact treatment is not particularly limited as long as it dissolves the decomposition products generated from the film due to radiation irradiation. Specific examples include: water, methanol, ethanol, 2-propanol, acetone, methyl ethyl ketone, 1-methoxy-2-propanol, 1-methoxy-2-propanol acetate, butyl cellosolve, ethyl lactate, methyl lactate, diacetone alcohol, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propyl acetate, butyl acetate, cyclohexyl acetate, etc. Among these, water, 2-propanol, 1-methoxy-2-propanol, or ethyl lactate are preferred from the perspective of versatility and solvent safety. Water, 1-methoxy-2-propanol, or ethyl lactate are more preferred. One solvent or a combination of two or more solvents can be used.

[0197] The heat treatment of the above-mentioned radiation-irradiated coating is preferably carried out at 50 to 300°C for 1 to 30 minutes, and more preferably at 120 to 250°C for 1 to 30 minutes.

[0198] <Process (4): Process of manufacturing LCD cell>

[0199] Prepare two substrates with liquid crystal alignment films formed thereon as described above, and place liquid crystal between the two substrates arranged opposite each other. Specifically, the following two methods can be listed. The first method is to first arrange the two substrates opposite each other with a gap (cell gap) between them, with each liquid crystal alignment film facing each other. Then, use a sealant to bond the peripheries of the two substrates together, inject a liquid crystal composition into the cell gap defined by the substrate surface and the sealant, and seal the injection hole after contact with the film surface.

[0200] Furthermore, the second method is known as the ODF (One Drop Fill) method. In this method, a UV-curable sealant is applied, for example, to a predetermined location on one of two substrates on which the liquid crystal alignment film has been formed. Then, the liquid crystal composition is dropped onto several predetermined locations on the surface of the alignment film. The alignment film is then bonded to the other substrate in an opposing manner, and the liquid crystal composition is pushed across the entire surface of the substrate to contact the film surface. Next, the entire surface of the substrate is irradiated with UV light to cure the sealant. Regardless of the method used, ideally, the liquid crystal composition is further heated to a temperature at which it becomes isotropic, and then slowly cooled to room temperature, thereby removing the flow alignment during liquid crystal filling.

[0201] It should be noted that when the coating has been rubbed, the two substrates are arranged opposite each other at a specified angle, such as orthogonal or antiparallel, with the rubbing directions of each coating being opposite each other.

[0202] As a sealant, for example, epoxy resin containing a curing agent and alumina spheres as spacers can be used. As for liquid crystals, nematic liquid crystals and smectic liquid crystals can be listed, with nematic liquid crystals being preferred.

[0203] Then, by attaching a polarizer to the outer surface of the liquid crystal cell as needed, a liquid crystal display element can be obtained. Examples of polarizers attached to the outer surface of the liquid crystal cell include polarizers made by clamping a polarizer called an "H-film" (which absorbs iodine while being stretched and oriented by polyvinyl alcohol) with a cellulose acetate protective film, or polarizers made of the H-film itself.

[0204] The liquid crystal display element of the present invention can be effectively applied to various devices, such as clocks, portable game consoles, word processors, notebook computers, in-vehicle navigation systems, portable camcorders, PDAs, digital cameras, mobile phones, smartphones, various monitors, LCD TVs, information displays, and other display devices. Furthermore, the polymer composition contained in the aforementioned liquid crystal alignment agent can also be used for liquid crystal alignment films for retardation films, liquid crystal alignment films for scanning antennas, liquid crystal array antennas, or liquid crystal alignment films for transmission-scattering type liquid crystal dimming elements, or for other applications, such as protective films for color filters, gate insulating films for flexible displays, and substrate materials.

[0205] Example

[0206] The following examples illustrate the invention in further detail, but the invention is not limited thereto. The abbreviations of the compounds and the methods for determining their properties are shown below. Furthermore, "TMS" represents trimethylsilyl.

[0207] (Tetracarboxylic acid dianhydride)

[0208] CA-1: The compound represented by the following formula (CA-1).

[0209] (Diamine)

[0210] DA-1: The compound represented by the following formula (DA-1).

[0211] (Hydroxyalkylamide compounds)

[0212] Add-1, Add-2: These are compounds represented by the following formulas (Add-1) and (Add-2), respectively.

[0213] (additive)

[0214] Add-C1 and Add-C2: These are compounds represented by the following formulas (Add-C1) and (Add-C2), respectively.

[0215] Add-S1: The compound represented by the following formula (Add-S1).

[0216] (Organic solvents)

[0217] NMP: N-methyl-2-pyrrolidone.

[0218] BCS: Ethylene glycol monobutyl ether.

[0219] DMF: N,N-dimethylformamide.

[0220]

[0221] < 1 H-NMR determination >

[0222] Apparatus: Fourier transform superconducting nuclear magnetic resonance (FT-NMR) device "AVANCE III" (BRUKER) 500MHz.

[0223] Solvent: Deuterated dimethyl sulfoxide ([D6]-DMSO). Standard substance: Tetramethylsilane.

[0224] <Viscosity Measurement>

[0225] The viscosity of the solution was measured using a TVE-22H type E viscometer (manufactured by Toki Sangyo Co., Ltd.), with a sample volume of 1.1 mL, using a conical rotor TE-1 (1°34', R24), at a temperature of 25°C.

[0226] <Determination of molecular weight>

[0227] Molecular weight was determined using a room-temperature GPC (gel permeation chromatography) apparatus, and the number-average molecular weight (Mn) and weight-average molecular weight (Mw) were calculated in the form of converted values ​​for polyethylene glycol and polyethylene oxide.

[0228] GPC apparatus: GPC-101 (manufactured by Showa Denko Corporation), chromatographic column: GPC KD-803 and GPC KD-805 (manufactured by Showa Denko Corporation) in series, column temperature: 50℃, eluent: N,N-dimethylformamide (as additives, lithium bromide monohydrate (LiBr·H2O) 30 mmol / L, phosphoric acid·anhydrous crystals (o-phosphoric acid) 30 mmol / L, tetrahydrofuran (THF) 10 mL / L), flow rate: 1.0 mL / min.

[0229] Standard samples used for calibration curve preparation: TSK standard polyethylene oxide (molecular weight; approximately 900,000, 150,000, 100,000 and 30,000) (manufactured by TOSOH) and polyethylene glycol (molecular weight; approximately 12,000, 4,000 and 1,000) (manufactured by Polymer Laboratories).

[0230] <<Synthesis of Hydroxyalkylamide Compounds>>

[0231] <Synthesis example 1 (Add-1)>

[0232] The compound (Add-1) was synthesized according to the following pathway.

[0233] (Synthesis of compound (1a) in the first step)

[0234]

[0235] Ethyl 4-chlorobutyrate (18.1 g, 120 mmol, 2.4 equivalents), potassium carbonate (20.7 g, 150 mmol), potassium iodide (0.830 g, 5 mmol), and DMF (93.0 g) were added to 4,4'-biphenol (9.30 g, 50.0 mmol), and the mixture was heated at 100 °C for 20 hours. After the reaction was complete, water (344 g) was added to the filtrate from the potassium carbonate to precipitate crystals, which were then filtered to obtain compound (1a). Compound (1a) was used directly in the next step.

[0236] (Synthesis of compound (2a) in the second step)

[0237]

[0238] Compound (1a) obtained above was added in its entirety to a mixture of a solution of potassium hydroxide (16.8 g, 300 mmol) dissolved in water (117 g) and ethanol (46.5 g), and the mixture was stirred at 80 °C for 20 hours to carry out a hydrolysis reaction. After the reaction was completed, 2N hydrochloric acid (200 mL, 400 mmol) was added for neutralization, resulting in the precipitation of crystals. After filtration and recovery, the filter cake was washed four times with water (195 g) and then washed with hexane (195 g) before being dried under reduced pressure to obtain compound (2a) (15.8 g, 44.1 mmol, two-stage yield: 88.2%).

[0239] (Synthesis of compound (3a) in the third step)

[0240]

[0241] Toluene (28.8 g), DMF (10.0 mg), and oxalyl chloride (3.39 g, 26.7 mmol) were added to compound (2a) (3.20 g, 8.92 mmol), and the mixture was stirred at 60 °C for 4 hours. After the reaction was complete, the reaction solution was concentrated to obtain compound (3a). Compound (3a) was used directly in the next step.

[0242] (Synthesis of compound (4a) in the fourth step)

[0243]

[0244] The entire amount of the obtained compound (3a) was dissolved in dichloromethane (93.3 g) and transferred to a 300 mL four-necked flask. Amidation was carried out by dropwise addition of a mixture of triethylamine (3.61 g, 35.7 mmol) and the trimethylsilyl protecting agent of diethanolamine (4.45 g, 17.8 mmol) over 15 minutes in an ice bath. It should be noted that the trimethylsilyl protecting agent of diethanolamine was synthesized with reference to the method described in WO2009 / 046536. After the addition was complete, the mixture was stirred for 1 hour, and then water (32.4 g) was added for separation and washing. The organic layer was again separated and washed with water (32.4 g), and the resulting organic layer was dehydrated with anhydrous magnesium sulfate (10 g) and dried under reduced pressure to obtain the oily compound (4a) (6.68 g, 8.13 mmol, two-stage yield: 91.1%).

[0245] (The synthesis of the fifth step, Add-1)

[0246]

[0247] Acetonitrile (66.8 g), acetic acid (3.34 g), and methanol (33.0 g) were added to the obtained compound (4a) (6.68 g, 8.13 mmol), and the mixture was heated at 40 °C for 48 hours. After the reaction was completed, the solvent was removed by distillation and the mixture was dried to give Add-1 (4.17 g, 7.83 mmol, yield: 96.2%).

[0248] According to the following... 1 The H-NMR results confirmed that the compound was Add-1.

[0249] 1 H-NMR (500MHz, [D6]-DMSO): δ = 7.52 (d, 4H, J = 8.5Hz), 6.99 (d, 4H, J = 8.5Hz), 4.70 (br, 4H), 4.00 (t, 4H, J=6.4Hz), 3.52-3.47(m, 8H), 3.40-3.35(m, 8H), 2.52(t, 4H, J=7.2Hz), 1.95(quin, 4H, J=6.6Hz)

[0250] <Synthesis example 2 (Add-2)>

[0251] The compound (Add-2) was synthesized according to the following pathway.

[0252] (Synthesis of compound (1b) in the first step)

[0253]

[0254] Compound (1b) was obtained by using 9.27 g (49.8 mmol) of 2,2'-biphenol instead of 4,4'-biphenol, except that the synthesis of compound (1a) was carried out in the same manner as that of the above-mentioned compound (1a).

[0255] (Synthesis of compound (2b) in the second step)

[0256]

[0257] Using compound (1b) instead of compound (1a), and otherwise carried out by the same method as the synthesis of compound (2a), 16.8 g (46.9 mmol, two-stage yield: 94.1%) of compound (2b) was obtained.

[0258] (Synthesis of compound (3b) in the third step)

[0259]

[0260] Compound (2b) was used in place of compound (2a) in 3.55 g (9.90 mmol), and compound (3b) was otherwise synthesized by the same method as compound (3a).

[0261] (Synthesis of compound (4b) in the fourth step)

[0262]

[0263] Compound (3b) was used in place of compound (3a), except that compound (4b) was synthesized by the same method as compound (4a), and compound (4b) was obtained in 7.60 g (9.25 mmol, two-stage yield: 93.4%).

[0264] (The synthesis of the fifth step, Add-2)

[0265]

[0266] Compound (4b) was used in place of compound (4a), and otherwise, Add-2 was obtained in 4.90 g (9.20 mmol, yield: 99.5%) by the same method as the synthesis of (Add-1).

[0267] According to the following... 1 The H-NMR results confirmed that the compound was Add-2.

[0268] 1 H-NMR (500MHz, [D6]-DMSO): δ=7.29 (t, 2H, J=8.2Hz), 7.16 (d, 2H, J=7.9Hz), 7.05 (d, 2H, J=8.2Hz), 6.97 (t, 2H, J=7.3Hz), 4 .70 (br, 4H), 3.94 (t, 4H, J=6.5Hz), 3.46-3.42 (m, 8H), 3.32-3.27 (m, 8H), 2.31 (t, 4H, J=8.0Hz), 1.77 (quin, 4H, J=7.1Hz).

[0269] <<Preparation of Liquid Crystal Alignment Agents>>

[0270] <Example 1>

[0271] DA-1 (14.3 g, 50.0 mmol) and NMP (145 g) were added to a 100 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, and stirred at room temperature under a nitrogen atmosphere until dissolved. Then, CA-1 (10.5 g, 48.0 mmol) and NMP (36.4 g) were added, and the mixture was stirred at 50 °C for 16 hours to obtain a 12% polyamic acid (PAA-1) solution (viscosity: 525 mPa·s). The Mn of this polyamic acid (PAA-1) was 14800, and the Mw was 32500.

[0272] NMP (4.61 g), BCS (3.75 g), Add-S1 (1% NMP solution, 0.680 g) and Add-1 (10% NMP solution, 0.340 g) were added to the above polyamic acid (PAA-1) solution (5.63 g), and the mixture was stirred at room temperature for 3 hours to obtain liquid crystal alignment agent (AL-1).

[0273] <Example 2>

[0274] NMP (4.28 g), BCS (3.75 g), Add-S1 (1% NMP solution, 0.680 g) and Add-1 (10% NMP solution, 0.680 g) were added to the above polyamic acid (PAA-1) solution (5.63 g), and the mixture was stirred at room temperature for 3 hours to obtain liquid crystal alignment agent (AL-2).

[0275] <Example 3>

[0276] NMP (4.61 g), BCS (3.75 g), Add-S1 (1% NMP solution, 0.680 g) and Add-2 (10% NMP solution, 0.340 g) were added to the above polyamic acid (PAA-1) solution (5.63 g), and the mixture was stirred at room temperature for 3 hours to obtain liquid crystal alignment agent (AL-3).

[0277] <Example 4>

[0278] NMP (4.28 g), BCS (3.75 g), Add-S1 (1% NMP solution, 0.680 g) and Add-2 (10% NMP solution, 0.680 g) were added to the above polyamic acid (PAA-1) solution (5.63 g), and the mixture was stirred at room temperature for 3 hours to obtain liquid crystal alignment agent (AL-4).

[0279] <Comparative Example 1>

[0280] NMP (4.61 g), BCS (3.75 g), Add-S1 (1% NMP solution, 0.680 g) and Add-C1 (10% NMP solution, 0.340 g) were added to the above polyamic acid (PAA-1) solution (5.63 g), and the mixture was stirred at room temperature for 3 hours to obtain liquid crystal alignment agent (AL-5).

[0281] <Comparative Example 2>

[0282] NMP (4.28 g), BCS (3.75 g), Add-S1 (1% NMP solution, 0.680 g) and Add-C1 (10% NMP solution, 0.680 g) were added to the above polyamic acid (PAA-1) solution (5.63 g), and the mixture was stirred at room temperature for 3 hours to obtain liquid crystal alignment agent (AL-6).

[0283] <Comparative Example 3>

[0284] NMP (4.95 g), BCS (3.75 g), Add-S1 (1% NMP solution, 0.680 g), and Add-C2 (0.0338 g) were added to the above polyamic acid (PAA-1) solution (5.63 g), and the mixture was stirred at room temperature for 3 hours to obtain liquid crystal alignment agent (AL-7).

[0285] <Comparative Example 4>

[0286] NMP (4.95 g), BCS (3.75 g), Add-S1 (1% NMP solution, 0.680 g) and Add-C2 (0.0675 g) were added to the above polyamic acid (PAA-1) solution (5.63 g), and the mixture was stirred at room temperature for 3 hours to obtain liquid crystal alignment agent (AL-8).

[0287] <Comparative Example 5>

[0288] NMP (4.95 g), BCS (3.75 g), and Add-S1 (1% NMP solution, 0.680 g) were added to the above polyamic acid (PAA-1) solution (5.63 g), and the mixture was stirred at room temperature for 3 hours to obtain liquid crystal alignment agent (AL-9).

[0289] <Evaluation of Friction Resistance>

[0290] First, a glass substrate with ITO electrodes on its entire surface was prepared. The substrate was 30mm × 40mm in size and 1.1mm thick, and ITO electrodes with a thickness of 35nm were formed on its entire surface. Next, the liquid crystal alignment agents AL-1 to AL-9 obtained in the above examples and comparative examples were filtered through a filter with a pore size of 1.0μm and then coated onto the ITO surface of the prepared electrode-bearing substrate by spin coating. After drying on a heating plate at 80°C for 2 minutes, it was fired in an infrared heating furnace at 230°C for 20 minutes to form a coating film with a thickness of 100nm, thus obtaining a polyimide film. The polyimide film was then subjected to friction treatment using rayon cloth (roller diameter: 120mm, roller speed: 1000rpm, moving speed: 20mm / sec, pressing length: 0.4mm). The substrate was observed under a microscope. The following conditions were evaluated: no streaks or chips caused by the friction process were observed on the film surface, which was defined as "◎", slightly observed as "〇", and severe streaks or chips were observed, which was defined as "×".

[0291] <Evaluation of Anisotropy>

[0292] For substrates subjected to the same rubbing treatment as the aforementioned rubbing resistance evaluation, anisotropy was evaluated using a liquid crystal alignment film evaluation system (LayScan LYS-LH30S-1A) (manufactured by Moritex). Anisotropy values ​​of 0.15 or higher were defined as "◎", values ​​of 0.1 or higher but less than 0.15 were defined as "〇", and values ​​less than 0.1 were defined as "×".

[0293] <Fabrication of a liquid crystal cell for evaluating sealing performance>

[0294] First, a glass substrate with ITO electrodes on its entire surface was prepared. The substrate was 30mm × 40mm in size and 1.1mm thick, and ITO electrodes with a thickness of 35nm were formed on its entire surface. Next, the liquid crystal alignment agents AL-1 to AL-9 obtained in the above examples and comparative examples were filtered through a filter with a pore size of 1.0μm and then coated onto the ITO surface of the prepared electrode-bearing substrate by spin coating. After drying on a hot plate at 80°C for 2 minutes, the film was fired in an infrared furnace at 230°C for 20 minutes to form a coating with a thickness of 100nm, thus obtaining a polyimide film. The polyimide film was subjected to friction treatment using rayon cloth (roller diameter: 120 mm, roller speed: 500 rpm, moving speed: 30 mm / sec, pressing length: 0.3 mm, friction direction: tilted at 10° relative to the third layer IZO comb electrode). After cleaning with ultrasonic irradiation in pure water for 1 minute, water droplets were removed using a blower, and the film was dried at 80°C for 10 minutes to obtain a substrate with a liquid crystal alignment film. Next, 4 μm spacers were dispersed on the liquid crystal alignment film surface of one substrate, and a sealant (723K1) (manufactured by Kyoritsu Chemical Industry Co., Ltd.) was applied to the liquid crystal alignment film surface of another substrate. The substrates were then bonded together with their liquid crystal alignment film surfaces facing each other and their friction directions opposite. The two substrates were overlapped by 1 cm at the ends, and the amount of sealant applied was adjusted so that the diameter of the sealant after bonding was 3 mm, reaching the center of the overlapping area. Then, an illuminance of 20 mW / cm² was used. 2 The metal halide lamp irradiates the laminated substrate at a wavelength of 365nm, which translates to 3J / cm². 2 The sample is exposed to ultraviolet light and then heated in a heat-circulating clean oven at 120°C for 60 minutes to produce a box for evaluating airtightness.

[0295] <Evaluation of Sealing and Tightness>

[0296] The sealing tightness was evaluated using a benchtop precision universal testing machine (AGS-X 500N) (manufactured by Shimadzu Corporation). Specifically, after fixing the ends of the upper and lower substrates of the obtained box, the overlapping portion of the two substrates was pressed in from above at a speed of 5 mm per second, and the pressure (N) during peeling was measured. Then, the area (cm²) estimated from the diameter of the sealant was calculated using the pressure (N). 2 The standardized values ​​were used to evaluate the sealing tightness. In terms of evaluation, a higher tensile strength value indicates better sealing tightness, i.e., a better evaluation. A pressure of 1.5 N / cm² was applied. 2 The above situation is defined as "0", meaning the pressure is less than 1.5 N / cm. 2 The situation is defined as "×" for evaluation.

[0297] <Fabrication of a liquid crystal cell for evaluating voltage retention>

[0298] First, a substrate with electrodes was prepared. The substrate was a glass substrate measuring 30mm × 40mm and 0.7mm thick. An ITO electrode with a film thickness of 35nm was formed on the substrate, and the electrode was a striped pattern with a length of 40mm and a width of 10mm.

[0299] Next, the liquid crystal alignment agents AL-1 to AL-9 obtained in the above examples and comparative examples were filtered through a filter with a pore size of 1.0 μm and then coated onto the prepared electrode-bearing substrate by spin coating. After drying on a heating plate at 80°C for 2 minutes, the substrate was fired in an infrared heating furnace at 230°C for 20 minutes to form a coating film with a thickness of 100 nm, thus obtaining a substrate with a polyimide film. The polyimide film was rubbed with rayon cloth (roller diameter: 120 mm, roller speed: 1000 rpm, moving speed: 20 mm / sec, pressing length: 0.4 mm), then cleaned by ultrasonic irradiation in pure water for 1 minute, water droplets were removed by blowing air, and the substrate was dried at 80°C for 10 minutes to obtain a substrate with a liquid crystal alignment film. Two substrates with liquid crystal alignment films were prepared. After spreading 4 μm spacers on the surface of one liquid crystal alignment film, a sealant was printed on it. The other substrate was then bonded together with the rubbing direction opposite and the film surfaces facing each other. The sealant was then cured to create an empty cell. Negative liquid crystal MLC-7026-100 (manufactured by Merck) was injected into this empty cell using a depressurized injection method, and the injection port was sealed to obtain the liquid crystal cell. The resulting liquid crystal cell was then heated at 120°C for 1 hour and left at 23°C overnight for evaluation.

[0300] <Evaluation of Voltage Holding Rate>

[0301] A voltage of 1V was applied to the liquid crystal cell at 60°C for 60μsec, and the voltage was measured after 166.7ms. The voltage retention rate was calculated as the percentage of voltage that could be maintained. A higher voltage retention rate is considered better. It should be noted that if the voltage retention rate, one of the electrical characteristics of a liquid crystal display element, increases, screen burn-in, a common display defect, is less likely to occur. A voltage retention rate of 75% or higher is defined as "◎", a voltage retention rate of 50% or higher but less than 75% is defined as "〇", and a voltage retention rate of less than 50% is defined as "×".

[0302] <Fabrication of FFS-driven LCD cell>

[0303] A liquid crystal cell is constructed using liquid crystal display elements that have fringe field switching (FFS) mode.

[0304] First, a substrate with electrodes is prepared. The substrate is a glass substrate measuring 30mm × 35mm and with a thickness of 0.7mm. On the substrate, as the first layer, an ITO electrode with a patterned surface constituting the counter electrode is formed. On the counter electrode of the first layer, as the second layer, a SiN (silicon nitride) film formed using CVD (chemical vapor deposition) is formed. The thickness of the second SiN film is 500nm. On the second SiN film, as the third layer, a comb-shaped pixel electrode formed by patterning the ITO film is disposed, thereby forming the first pixel and the second pixel. Each pixel is approximately 10mm long and 5mm wide. At this point, the counter electrode of the first layer and the pixel electrode of the third layer are electrically insulated by the SiN film of the second layer.

[0305] The third layer of pixel electrodes has multiple comb-shaped elements arranged in parallel at 6μm intervals, with a central portion of electrode elements that are bent at an interior angle of 160° and a width of 3μm. A pixel has a first region and a second region, with the line connecting the bent portions of the multiple electrode elements as the boundary.

[0306] Comparing the first and second regions of each pixel, the electrode elements constituting their pixel electrodes are formed in different directions. Specifically, based on the rubbing direction of the liquid crystal alignment film (described later), in the first region of the pixel, the electrode elements of the pixel electrode are formed at an angle of +10° (clockwise), while in the second region of the pixel, the electrode elements of the pixel electrode are formed at an angle of -10° (clockwise). In other words, in the first and second regions of each pixel, the direction of the in-plane rotation of the liquid crystal induced by the voltage applied between the pixel electrode and the counter electrode is configured to be opposite to each other.

[0307] Next, the liquid crystal alignment agents AL-1 to AL-9 obtained in the above examples and comparative examples were filtered through a filter with a pore size of 1.0 μm and then coated onto the prepared electrode substrate and a glass substrate with columnar spacers having an ITO film with a height of 4 μm on the back side by spin coating. After drying on a heating plate at 80°C for 2 minutes, the film was fired in an infrared heating furnace at 230°C for 20 minutes to obtain a polyimide film with a thickness of 60 nm. The polyimide film was rubbed with rayon cloth (roller diameter: 120 mm, roller speed: 500 rpm, moving speed: 30 mm / sec, pressing length: 0.3 mm, rubbing direction: tilted at 10° relative to the third layer IZO comb electrode) and then cleaned by ultrasonic irradiation in pure water for 1 minute. Water droplets were removed by blowing air, and the film was dried at 80°C for 10 minutes to obtain a substrate with a liquid crystal alignment film. Two substrates with liquid crystal alignment films were grouped together. A sealant was printed onto the substrates in a manner other than the liquid crystal injection port, and the substrates were then bonded together with the liquid crystal alignment film surfaces facing each other and the friction directions antiparallel. The sealant was then cured to create an empty cell with a cell gap of 4 μm. Negative liquid crystal MLC-7026-100 (manufactured by Merck) was injected into this empty cell using a depressurized injection method, and the injection port was sealed to obtain an FFS-type liquid crystal cell. The resulting liquid crystal cell was then heated at 120°C for 1 hour and placed at 23°C overnight before evaluation.

[0308] <Evaluation of image retention caused by long-term communication>

[0309] Using the liquid crystal cell fabricated above, an AC voltage of ±6V at a frequency of 60Hz was applied for 120 hours in a constant temperature environment of 60°C. Then, a state was formed in which the pixel electrode and the counter electrode of the liquid crystal cell were short-circuited, and the cell was placed directly at room temperature for one day.

[0310] After placement, a liquid crystal cell is positioned between two polarizers orthogonally aligned with their polarization axes. With no voltage applied, the backlight is illuminated, and the cell's angle is adjusted to minimize transmitted light brightness. Then, the rotation angle Δ is calculated as the angle by which the liquid crystal cell rotates from the darkest angle of the second region of the first pixel to the darkest angle of the first region of the first pixel. Similarly, in the second pixel, the second region is compared to the first region, and the same angle Δ is calculated.

[0311] When the average of the angle Δ of the first pixel and the angle Δ of the second pixel is less than 0.6°, it is defined as having particularly excellent afterimage characteristics, i.e., “◎”. When the average is greater than or equal to 0.6° but less than 1.0°, it is defined as “〇”. When the average is greater than or equal to 1.0°, it is defined as “×”.

[0312] The results of the evaluation of each characteristic are shown in Table 1.

[0313] [Table 1]

[0314]

[0315] As shown in Table 1, compared with the case of using a liquid crystal alignment agent containing hydroxyalkylamide compounds Add-1 to Add-2, which are components (B) of the present invention (Examples 1-4), the case of using a liquid crystal alignment agent without component (B) (Comparative Examples 1-5) exhibits excellent abrasion resistance and good anisotropy. Furthermore, the sealing performance, voltage retention rate, and image retention characteristics are also good.

[0316] Industrial availability

[0317] The liquid crystal alignment film obtained from the liquid crystal alignment agent of the present invention can be applied to various liquid crystal display elements, such as liquid crystal display elements driven by IPS and FFS. Moreover, these display elements are not limited to liquid crystal displays for display purposes. Furthermore, they can also be used as liquid crystal alignment films for phase retardation films, liquid crystal alignment films for scanning antennas, liquid crystal array antennas, or liquid crystal alignment films for transmission and scattering type liquid crystal dimming elements, or for other applications, such as protective films for color filters, gate insulating films for flexible displays, and substrate materials.

[0318] It should be noted that the entire contents of the specification, claims, drawings and abstract of Japanese Patent Application No. 2020-189724, filed on November 13, 2020, are incorporated herein by reference as a disclosure of the specification of this invention.

Claims

1. A compound represented by the following formula (Add-1) or (Add-2),

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