Aromatic compound for liquid crystal aligning agent

Abstract

The present invention provides an aromatic compound for a liquid crystal aligning agent, the aromatic compound being used for obtaining a liquid crystal aligning agent having a high voltage holding ratio and good liquid crystal aligning properties in a harsh environment even in the case of an alignment treatment using a photo-alignment method in which a chemical change is caused by irradiation with radiation or the like. The liquid crystal display element is capable of suppressing burn-in that occurs in liquid crystal display elements of IPS and FFS methods. The aromatic compound for the liquid crystal aligning agent is any one selected from the group consisting of formulae (b-1) to (b-4). # imgabs0 #

Description

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

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

[0003] International filing date: September 30, 2020

[0004] International application number: PCT / JP2020 / 037265

[0005] National application number: 202080070176.8 Technical Field

[0006] The present invention relates to a liquid crystal aligning agent, a liquid crystal aligning film obtained from the liquid crystal aligning agent, a liquid crystal display element using the liquid crystal aligning film, and a novel compound for a liquid crystal aligning agent. Background Art

[0007] In the past, various driving methods have been developed as liquid crystal display elements, which differ in electrode structure, physical properties of liquid crystal molecules used, etc. For example, various display elements are known, such as TN (Twisted Nematic), STN (Super Twisted Nematic), VA (Vertical Alignment), IPS (In-Plane Switching), FFS (Finge Field Switching), etc. These liquid crystal display elements usually have a liquid crystal alignment film for aligning liquid crystal molecules.

[0008] As the material of the liquid crystal alignment film, for example, polymers such as polyamic acid, polyamic acid ester, polyimide, and polyamide are known. At present, the most popular liquid crystal alignment film in industry is made by performing a so-called rubbing treatment, which is to unidirectionally rub the surface of a film formed by a polymerizable composition containing the above polymer on an electrode substrate using cloth such as cotton, nylon, and polyester.

[0009] The rubbing treatment is a simple and industrially useful method with excellent productivity. However, with the high performance, high precision and large size of liquid crystal display elements, there are various problems such as damage to the surface of the alignment film caused by the rubbing treatment, dust, influence caused by mechanical force and static electricity, and non-uniformity in the alignment treatment surface.

[0010] As a method to replace the rubbing treatment, a photo-alignment method is known, which imparts the ability to orient the liquid crystal by irradiating polarized radiation. As for the liquid crystal alignment treatment using the photo-alignment method, a method using a photoisomerization reaction, a method using a photocrosslinking reaction, a method using a photodecomposition reaction, etc. have been proposed (see Non-Patent Document 1). In Patent Document 1, it is proposed to use a polyimide film having an alicyclic structure such as a cyclobutane ring in the main chain in the photo-alignment method.

[0011] The photo-orientation method as described above is a rubbingless orientation treatment method, which can not only be produced industrially through a simple manufacturing process, but also in IPS drive mode and FFS drive mode liquid crystal display elements, it can be expected to improve the contrast and viewing angle characteristics of the liquid crystal display elements compared to the liquid crystal orientation film obtained by the rubbing treatment method. Therefore, it has attracted attention as a desired liquid crystal orientation treatment method.

[0012] Prior art literature

[0013] Patent Literature

[0014] Patent Document 1: Japanese Patent Application Laid-Open No. 9-297313

[0015] Non-patent literature

[0016] Non-patent document 1: "Liquid crystal photo-alignment film" Kidowaki, Ichimura Functional Materials, November 1997, Vol. 17, No. 1113-22 Summary of the invention

[0017] Problems to be solved by the invention

[0018] In recent years, the use range of liquid crystal display elements has been further expanded, and liquid crystal display elements are sometimes used for a long time in an environment of high temperature and high humidity, or in an environment exposed to light. As a liquid crystal alignment film, it is required to withstand use in such a harsh environment, and in particular, a high voltage holding rate has become one of the important characteristics. However, based on the insights of the inventors of the present application, in the case of a photo-alignment method that causes chemical changes by irradiation with radiation, etc., there is a clear tendency for the voltage holding rate to be easily reduced. In addition, in the case of using a photo-alignment method to impart orientation ability, it is obvious that the liquid crystal orientation is insufficient, or, for example, burn-in becomes a problem in liquid crystal display elements of IPS drive mode and FFS drive mode.

[0019] Therefore, the object of the present invention is to provide a liquid crystal alignment agent, a liquid crystal alignment film obtained by the liquid crystal alignment agent, and a liquid crystal display element having the liquid crystal alignment film, and further to provide a new compound for a liquid crystal alignment agent, wherein the liquid crystal alignment agent is used to obtain a liquid crystal display element that has a high voltage retention rate and good liquid crystal orientation under harsh environments even when an orientation treatment is performed using a photo-orientation method that causes chemical changes by irradiation with radiation or the like, and can suppress screen burn-in that occurs in liquid crystal display elements of IPS drive mode and FFS drive mode.

[0020] Solutions for solving problems

[0021] The present inventors have conducted intensive studies and, as a result, have found that the above-mentioned objects can be achieved by a liquid crystal aligning agent containing an aromatic compound having a specific chemical structure shown below as an additive, thereby completing the present invention.

[0022] 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 in that it contains an aromatic compound having a structure represented by two or more of the following formula (1).

[0023]

[0024] Here, R is a hydrogen atom or a methyl group. Any hydrogen atom on the benzene ring may be substituted with a hydroxyl group, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a monovalent organic group having 1 to 6 carbon atoms and containing a fluorine atom.

[0025] Effects of the Invention

[0026] According to the present invention, a liquid crystal alignment agent, a liquid crystal alignment film obtained from the liquid crystal alignment agent, and a liquid crystal display element having the liquid crystal alignment film are provided, and further a new compound for a liquid crystal alignment agent is provided. The liquid crystal alignment agent is used to obtain a liquid crystal display element having a high voltage retention rate and good liquid crystal orientation even in a harsh environment when an alignment treatment is performed using a photoalignment method that causes chemical changes by irradiation with radiation or the like, and in particular, can suppress screen burn-in in an IPS drive mode or an FFS drive mode. DETAILED DESCRIPTION

[0027] <Aromatic compound of formula (1)>

[0028] The liquid crystal aligning agent of the present invention is characterized by containing an aromatic compound having a structure represented by two or more of the following formula (1) (hereinafter, sometimes referred to as an aromatic compound of the formula (1)).

[0029]

[0030] In the above formula (1), R represents a hydrogen atom or a methyl group. Any hydrogen atom on the benzene ring may be substituted by a hydroxyl group, a halogen atom, an alkyl group having 1 to 6 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, preferably an alkoxy group having 1 to 4 carbon atoms, or a monovalent organic group having 1 to 6 carbon atoms and having fluorine atoms, preferably a monovalent organic group having 1 to 4 carbon atoms and having fluorine atoms. Here, examples of the monovalent organic group having fluorine atoms include trifluoromethyl, trifluoroethyl, trifluoromethoxy, trifluoroethoxy, and the like.

[0031] In the liquid crystal alignment agent of the present invention, by containing the aromatic compound of the above formula (1) as an additive, as specifically exemplified in the embodiments described later, a liquid crystal alignment film in a liquid crystal display element having a high voltage holding ratio and good liquid crystal orientation can be obtained even in the case of an alignment treatment using a photo-alignment method that causes a chemical change by irradiation with radiation or the like. The mechanism may not be clear, but it can be roughly considered as follows.

[0032] In an orientation treatment using a photo-orientation method, for example, the surface of a film-like object formed by a liquid crystal orientation agent formed on a substrate surface is irradiated with high-energy UV light with approximately linear polarization. In this case, decomposition products of organic matter constituting the film-like object are generated by the irradiation with UV light. The decomposition products become impurities that cause a decrease in the voltage holding ratio of the liquid crystal orientation film. Therefore, it is believed that the voltage holding ratio of the liquid crystal orientation film is reduced.

[0033] However, in the liquid crystal alignment agent of the present invention, when the above impurities are generated by irradiation with UV light, since the aromatic compound of the above formula (1) has a functional group that can react with the impurities, the impurities contained in the obtained liquid crystal alignment film can be reduced by the reaction of the functional group with the impurities that cause the voltage holding ratio to decrease. Therefore, it can be considered that the liquid crystal alignment film obtained by the liquid crystal alignment agent of the present invention maintains a high voltage holding ratio.

[0034] In addition, the aromatic compound of the above formula (1) contained in the liquid crystal alignment agent of the present invention has a highly planar structure, so it is believed that the liquid crystal orientation of the obtained liquid crystal alignment film will not be hindered, and a liquid crystal alignment film with high liquid crystal orientation is obtained. Therefore, in the IPS driving method and the FFS driving method, even when the liquid crystal display element is driven for a long time, the liquid crystal returns to the same state as before the drive, so it is believed that a liquid crystal display element with less screen burn-in is obtained.

[0035] The aromatic compound of the above formula (1) is preferably a compound represented by the following formula (b1).

[0036]

[0037] In the above formula (b1), R has the same meaning as in the above formula (1). n is an integer of 2 to 6, and when n is 2, A represents a single bond or a divalent linking group, and when n is 3 to 6, A represents an n-valent organic group.

[0038] Examples of the n-valent organic group include an n-valent hydrocarbon group, an n-valent heteroatom-containing group containing a group having a heteroatom between carbon atoms of the hydrocarbon group or at the end of the hydrocarbon group, and an n-valent organic group in which a part or all of the hydrogen atoms in the above hydrocarbon group and the heteroatom-containing group are substituted with a substituent.

[0039] Examples of the divalent linking group in A include a divalent hydrocarbon group, a divalent heteroatom-containing group containing a group having a heteroatom between carbon atoms of the hydrocarbon group or at the end of the hydrocarbon group, a divalent linking group in which a part or all of the hydrogen atoms possessed by the above hydrocarbon group and the heteroatom-containing group are substituted by a substituent, -S(=O)2-, -CO-, -O-, -S-, -NR-CO- (R represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms), -NR-CO-NR- (R represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms), and the like.

[0040] Examples of the n-valent hydrocarbon group include chain hydrocarbons having 1 to 30 carbon atoms, such as alkanes such as methane, ethane, propane, and butane; alkenes such as ethylene, propylene, butene, and pentene; and alkynes such as acetylene, propyne, butyne, and pentyne; alicyclic hydrocarbons having 3 to 30 carbon atoms, such as cycloalkanes such as cyclopropane, cyclobutane, cyclopentane, cyclohexane, norbornane, and adamantane; and cycloalkenes such as cyclopropene, cyclobutene, cyclopentene, cyclohexene, and norbornene; aromatic hydrocarbons having 6 to 30 carbon atoms, such as benzene, toluene, xylene, mesitylene, naphthalene, methylnaphthalene, dimethylnaphthalene, and anthracene; and n-valent groups formed by removing n hydrogen atoms from hydrocarbons selected from the group consisting of hydrocarbons in which a part of the carbon-carbon bonds of the chain hydrocarbons is substituted by the alicyclic hydrocarbons or aromatic hydrocarbons. Examples of the divalent hydrocarbon group include divalent groups formed by removing two hydrogen atoms from the hydrocarbons exemplified in the n-valent hydrocarbon group.

[0041] As the above-mentioned group having a heteroatom, for example, there can be mentioned a group having at least one selected from the group consisting of an oxygen atom, a nitrogen atom, a silicon atom, a phosphorus atom and a sulfur atom. If specific examples are listed, there can be listed: -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 them. Among them, -O- is preferred.

[0042] Examples of the substituent include halogen atoms such as fluorine, chlorine, bromine and iodine atoms; alkoxy groups such as methoxy, ethoxy and propoxy; alkoxycarbonyl groups such as methoxycarbonyl and ethoxycarbonyl; alkoxycarbonyloxy groups such as methoxycarbonyloxy and ethoxycarbonyloxy; cyano and nitro groups.

[0043] In the above formula (b1), n ​​is preferably 2, and A is preferably a single bond or a divalent linking group.

[0044] The divalent linking group preferably has a structure represented by the following formula (a-1) or formula (a-2).

[0045]

[0046] In the above formulas (a-1) and (a-2), R1, R 1’ , R2, R 2’ Each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, preferably 1 or 2 carbon atoms. m1 and m2 each independently represent an integer of 1 to 18, preferably an integer of 1 to 6. n represents an integer of 1 to 6, preferably an integer of 1 to 4. In addition, "*" represents a bond.

[0047] The molecular weight of the aromatic compound of the formula (1) is preferably 2000 or less, more preferably 1500 or less, from the viewpoint of improving the reactivity with the decomposition product generated by the photo-alignment method. On the other hand, from the viewpoint of suppressing the sublimation of the aromatic compound caused by calcination, the molecular weight of the aromatic compound is preferably 150 or more, more preferably 200 or more.

[0048] Preferred examples of the aromatic compound of the formula (1) include compounds selected from the group consisting of the following formulae (b-1) to (b-7). The compounds of the following formulae (b-1) to (b-4) are novel compounds not disclosed in existing documents.

[0049]

[0050] <Polymer>

[0051] The liquid crystal aligning agent of the present invention containing the aromatic compound of the above formula (1) contains a polymer capable of aligning liquid crystals, similarly to known liquid crystal aligning agents, and the polymer is not particularly limited as long as it has the ability to align liquid crystals.

[0052] Examples of the polymer include polyimide precursors, polyimides that are imides of polyimide precursors, acrylic polymers, methacrylic polymers, acrylamide polymers, methacrylamide polymers, polystyrene, polysiloxane, polyamide, polyester, polyurethane, polycarbonate, polyurea, polyphenol (novolac resin), maleimide polymers, and polymers into which compounds having an isocyanuric acid skeleton or a triazine skeleton are introduced. The polymer may be used alone or in combination of two or more.

[0053] As raw materials for producing these polymers, the following raw materials can be mentioned respectively.

[0054] When the polymer is a polyimide precursor or polyimide such as polyamic acid or polyamic acid ester, at least one tetracarboxylic acid component and a diamine selected from tetracarboxylic acids or their derivatives; when the polymer is a (meth)acrylic acid polymer, (meth)acrylic acid or its derivatives, (meth)acrylate or its derivatives; when the polymer is a (meth)acrylamide polymer, (meth)acrylamide or its derivatives; when the polymer is polystyrene, styrene or its derivatives; when the polymer is polysiloxane, a silane compound having a methoxy group or an ethoxy group; when the polymer is polyamide, at least one dicarboxylic acid component and a diamine component selected from dicarboxylic acids and their derivatives. when the polymer is a polyester, at least one dicarboxylic acid component and a diol component selected from dicarboxylic acids and their derivatives; when the polymer is a polyurethane, isocyanate and a compound having a hydroxyl group; when the polymer is a polycarbonate, a bisphenol derivative and phosgene or a phosgene equivalent (for example, trichlorophosgene) or diphenyl carbonate; when the polymer is a polyurea, a diisocyanate derivative and a diamine component; when the polymer is a maleimide polymer, a maleimide derivative homopolymer or a copolymer with styrene; when the polymer is a polymer into which a compound having an isocyanuric acid skeleton or a triazine skeleton is introduced, a compound having an isocyanuric acid skeleton or a triazine skeleton.

[0055] <Polyimide polymer>

[0056] The polymer contained in the liquid crystal alignment agent of the present invention is preferably one or more polymers selected from the group consisting of a polyimide precursor and a polyimide which is an imide product of a polyimide precursor (hereinafter also referred to as a polyimide-based polymer), from the viewpoint of practicality as a liquid crystal alignment agent, and mechanical and electrical properties of a coating film.

[0057] The polyimide polymer can be produced by a known method. For example, polyamic acid as a polyimide precursor is obtained by polymerizing (polycondensing) a tetracarboxylic acid component composed of tetracarboxylic dianhydride or a derivative thereof with a diamine component, and the polyimide is obtained by imidizing the polyimide precursor.

[0058] <Tetracarboxylic acid component>

[0059] As a polyamic acid precursor of polyimide, for example, polyamic acid obtained by tetracarboxylic acid components including aromatic, aliphatic or alicyclic tetracarboxylic dianhydride can be cited. Here, aromatic tetracarboxylic dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxyl groups including at least one carboxyl group bonded to an aromatic ring. Aliphatic tetracarboxylic dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxyl groups bonded to a chain hydrocarbon structure. Among them, it is not necessary to be composed only of a chain hydrocarbon structure, and a part of it may also have an alicyclic structure or an aromatic ring structure.

[0060] Alicyclic tetracarboxylic dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxyl groups including at least one carboxyl group bonded to an alicyclic structure, wherein none of the four carboxyl groups is bonded to an aromatic ring.

[0061] Furthermore, it is not necessary to consist of only an alicyclic structure, and a part of it may have a chain hydrocarbon structure or an aromatic ring structure.

[0062] The polyamic acid of the present invention is preferably obtained from a tetracarboxylic acid component containing tetracarboxylic dianhydride represented by the following formula (2).

[0063]

[0064] In the above formula (2), X is preferably selected from the following structures (x-1) to (x-13).

[0065]

[0066] In the above formulas (x-1) to (x-13), R 1 ~R 4 Each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, a monovalent organic group having 1 to 6 carbon atoms and having a fluorine atom, or a phenyl group.

[0067] R 5 and R 6Each independently represents a hydrogen atom or a methyl group. j and k each independently represent an integer of 0 or 1. A1 and A2 each independently represent a single bond, -O-, -CO-, -COO-, phenylene, -SO2-, or -CONH-. The two A2s may be the same or different. *1 is a bond bonded to the acid anhydride group of one side, and *2 is a bond bonded to the acid anhydride group of the other side.)

[0068] The above formula (x-1) is particularly preferably a formula selected from the group consisting of the following formulas (x1-1) to (x1-6).

[0069]

[0070] In the above formulae (x1-1) to (x1-6), *1 represents a bond to one of the acid anhydride groups, and *2 represents a bond to the other of the acid anhydride groups.

[0071] Preferred specific examples of the above formula (x-12) and formula (x-13) include the following formula (x-14) to formula (x-29). In addition, "*" in the formula represents a bonding position.

[0072]

[0073]

[0074] The usage-amount of the tetracarboxylic dianhydride or its derivative represented by said formula (2) is preferably 60-100 mol%, more preferably 80-100 mol%, and further preferably 90-100 mol%, based on 1 mol of all tetracarboxylic acid components which react with a diamine component.

[0075] <Diamine component>

[0076] Although the diamine component used for manufacture of a polyimide precursor is not specifically limited, The diamine component containing the diamine represented by following formula (3) is preferable.

[0077]

[0078] In the above formula (3), A1 represents an alkylene group having 2 to 14 carbon atoms, or a group in which at least one of the -CH2- groups of the alkylene group is substituted with -O-, -CO-, -OCO-, or -COO- under conditions in which at least one of the -CH2- groups of the alkylene group is discontinuous. A1 is more preferably an alkylene group having 2 to 12 carbon atoms, or a group in which at least one of the -CH2- groups of the alkylene group is substituted with -O-, -CO-, -OCO-, or -COO- under conditions in which at least one of the -CH2- groups of the alkylene group is discontinuous, and is further preferably an alkylene group having 2 to 10 carbon atoms, or a group in which at least one of the -CH2- groups of the alkylene group is substituted with -O-, -CO-, -OCO-, or -COO- under conditions in which at least one of the -CH2- groups of the alkylene group is discontinuous.

[0079] A2 represents a halogen atom, a hydroxyl group, an amino group, a thiol group, a nitro group, a phosphoric acid group, or a monovalent organic group having 1 to 20 carbon atoms. When there are multiple A2s, A2s may be the same or different. a is an integer of 0 to 4, and when there are multiple as, as may be the same or different. b and c are each independently an integer of 1 or 2, and d is an integer of 0 or 1.

[0080] As the diamine represented by the above formula (3), diamines represented by the following formulas (3d-1) to (3d-9) are preferred.

[0081]

[0082] (In formula (3d-8) and formula (3d-9), the two m's may be the same or different.)

[0083] As the diamine represented by the above formula (3), diamines represented by the following formulas (3-1) to (3-12) are more preferred.

[0084]

[0085] The usage-amount of the diamine represented by said formula (3) is preferably 60-100 mol%, more preferably 80-100 mol%, and further preferably 90-100 mol%, based on 1 mol of all diamine components which react with a tetracarboxylic acid component.

[0086] From the viewpoint of improving the voltage holding rate of the obtained liquid crystal alignment film, the polyimide polymer used in the present invention may also have at least one nitrogen-containing structure (hereinafter also referred to as nitrogen-containing structure) selected from the group consisting of nitrogen-containing heterocycles (wherein, excluding the imide ring possessed by polyimide), secondary amino groups and tertiary amino groups. The polyimide polymer having a nitrogen-containing structure can be obtained by using a monomer having a nitrogen-containing structure in at least a part of the raw materials, for example, using a diamine having a nitrogen-containing structure.

[0087] Examples of the nitrogen-containing heterocyclic ring include pyrrole, imidazole, pyrazole, triazole, pyridine, pyrimidine, pyridazine, pyrazine, indole, benzimidazole, purine, quinoline, isoquinoline, naphthyridine, quinoxaline, phthalazine, triazine, carbazole, acridine, piperidine, piperazine, pyrrolidine, and hexamethyleneimine. Among them, pyridine, pyrimidine, pyrazine, piperidine, piperazine, quinoline, carbazole, or acridine is preferred.

[0088] The secondary amino group and the tertiary amino group which the diamine having a nitrogen-containing structure may have are represented by, for example, the following formula (n).

[0089]

[0090] In the above formula (n), R represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. "*" represents a bond to the hydrocarbon group.

[0091] Examples of the monovalent hydrocarbon group of R in the above formula (n) include alkyl groups such as methyl, ethyl, and propyl; cycloalkyl groups such as cyclohexyl; and aromatic-containing groups such as phenyl and methylphenyl. R is preferably a hydrogen atom or a methyl group.

[0092] Specific examples of the diamine having a 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, N,N'-bis(4-aminophenyl)-benzidine, N,N'-bis(4-aminophenyl)-N,N'-dimethylbenzidine, 4,4'-diaminodiphenylamine, N,N-bis(4-aminophenyl)-methylamine, and compounds represented by the following formulas (z-1) to (z-18).

[0093]

[0094] From the viewpoint of improving the voltage holding rate of the liquid crystal display element, the usage ratio of the diamine having a nitrogen-containing structure is preferably 1 mol% or more, more preferably 2 mol% or more relative to the total amount of the diamine used in the synthesis. In addition, the usage ratio is preferably 90 mol% or less, more preferably 80 mol% or less.

[0095] The polyimide polymer used in the present invention may contain other diamines other than the diamines described above. Examples of other diamines are given below, but the present invention is not limited thereto.

[0096] 4-(2-(methylamino)ethyl)aniline, 4-(2-aminoethyl)aniline, 4,4'-diaminodiphenylmethane, 4,4'-diaminobenzophenone, 4,4'-diaminodiphenyl ether, diamines represented by the following formula (g-1) to formula (g-9) such as diamines having a photo-aligning group, 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, carboxyl group-containing diamines such as 3,5-diaminobenzoic acid, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenyl) oxy)benzene, bis[4-(4-aminophenoxy)phenyl]ether, 4,4'-bis(4-aminophenoxy)biphenyl, 1,4-diaminonaphthalene, 1,5-diaminonaphthalene, 2,6-diaminonaphthalene, 2,7-diaminonaphthalene, 2,2'-bis[4-(4-aminophenoxy)phenyl]propane, 2,2'-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2'-bis(4-aminophenyl)propane, diamines having urea bonds such as diamines represented by the following formulas (u-1) to (u-3), diamines having amide bonds such as diamines represented by the following formulas (u-4) to (u-7), 2-(2,4-diaminomethacrylate diamines having a steroid skeleton such as 3,5-diaminobenzoic acid cholesteryl ester, 3,5-diaminobenzoic acid cholesteryl ester, 3,5-diaminobenzoic acid lanosteryl ester, 3,6-bis(4-aminobenzoyloxy)cholestane, diamines represented by the following formulas (V-1) to (V-6); diamines having a siloxane bond such as 1,3-bis(3-aminopropyl)-tetramethyldisiloxane diamines having a group "-N(D)-" (D represents a protecting group which is detached by heating and replaced by a hydrogen atom, preferably a tert-butoxycarbonyl group) such as the following formula (5-1) to (5-11), diamines having an oxazoline structure such as the following formula (Ox-1) to (Ox-2), diamines having a free radical polymerization initiator function such as 1-(4-(2,4-diaminophenoxy)ethoxy)phenyl)-2-hydroxy-2-methylacetone, 2-(4-(2-hydroxy-2-methylpropionyl)phenoxy)ethyl-3,5-diaminobenzoate, 4,4-diaminobenzophenone, and 3,4'-diaminobenzophenone.

[0097]

[0098] (In formula (u-7), the two m's may be the same or different.)

[0099]

[0100] (In formula (v-6), the two k may be the same or different.)

[0101] (In the above formulas (V-1) to (V-6), X v1 ~X v4 , X p1 ~X p2 Each independently represents -(CH2) a -(a is an integer of 1 to 15), -CONH-, -NHCO-, -CON(CH3)-, -NH-, -O-, -CH2O-, -CH2OCO-, -COO-, or -OCO-, X v5 represents -O-, -CH2O-, -CH2OCO-, -COO-, or -OCO-. Xa represents a single bond, -O-, -NH-, or -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-. m is an integer from 1 to 8. v1 ~R v4 , R 1a ~R 1b Each independently represents an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an alkoxyalkyl group having 2 to 20 carbon atoms.

[0102]

[0103] (Boc represents tert-butoxycarbonyl.)

[0104]

[0105] <Method for producing polyamic acid>

[0106] The polyamic acid used as a polyimide precursor in the present invention can be produced by the following method. Specifically, it can be synthesized by reacting the tetracarboxylic acid component and the diamine component in the presence of an organic solvent at -20 to 150°C, preferably 0 to 50°C, for 30 minutes to 24 hours, preferably 1 to 12 hours (polycondensation).

[0107] From the solubility of monomers and polymers, the organic solvent used in the above reaction is preferably N, N-dimethylformamide, N-methyl-2-pyrrolidone, or γ-butyrolactone, and two or more of them can also be used in combination. From the viewpoint of not easily causing the precipitation of the polymer and easily obtaining a high molecular weight body, the concentration of the polymer is preferably 1 to 30% by mass, more preferably 5 to 20% by mass.

[0108] The polyamic acid obtained by the above reaction can be injected into a poor solvent while the reaction solution is fully stirred, so that the polyamic acid is precipitated and recovered. In addition, precipitation is performed several times, after cleaning with a poor solvent, normal temperature or heating drying can be obtained, thereby the powder of the purified polyamic acid can be obtained. The poor solvent is not particularly limited, and examples thereof include: water, methanol, ethanol, hexane, butyl cellosolve, acetone, toluene, etc.

[0109] When the polyimide precursor is polyamic acid ester, it can be produced by a known method such as (1) a method of esterifying a polyamic acid obtained from tetracarboxylic dianhydride and diamine, (2) a method of utilizing a reaction between a tetracarboxylic acid diester dichloride and a diamine, or (3) a method of polycondensing a tetracarboxylic acid diester and a diamine.

[0110] The polyimide precursor may be a terminal-capped polymer obtained by using an appropriate terminal-capping agent together with the above-mentioned tetracarboxylic acid derivative and diamine when producing the polyimide precursor.

[0111] Examples of the end-capping agent include: monoanhydrides such as maleic anhydride, nadic anhydride, phthalic anhydride, itaconic anhydride, cyclohexanedicarboxylic anhydride, 3-hydroxyphthalic anhydride, and trimellitic anhydride; di-tert-butyl dicarbonate; monoamine compounds such as aniline, 2-aminophenol, 3-aminophenol, 4-aminosalicylic acid, 5-aminosalicylic acid, 6-aminosalicylic acid, 2-aminobenzoic acid, 3-aminobenzoic acid, and 4-aminobenzoic acid; and monoisocyanate compounds such as ethyl isocyanate, phenyl isocyanate, and naphthyl isocyanate.

[0112] The usage ratio of the terminal blocking agent is preferably 40 parts by mole or less, and more preferably 30 parts by mole or less, based on 100 parts by mole of the total of the diamine components used.

[0113] <Production method of polyimide>

[0114] The polyimide used in the present invention can be produced by imidizing a polyamic acid or a polyamic acid ester as a polyimide precursor by a known method.

[0115] For example, in the case of producing polyimide from polyamic acid, (chemical) imidization by adding a catalyst to a solution of polyamic acid obtained by reaction of a diamine component and a tetracarboxylic acid component is simple. Imidization can be performed by stirring a polymer to be imidized in an organic solvent in the presence of a basic catalyst and an acid anhydride.

[0116] As the organic solvent, the solvent used in the above-mentioned polymerization reaction can be used. As the basic catalyst, pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine, etc. can be listed. Among them, pyridine has a moderate alkalinity for making the reaction proceed, so it is preferred. In addition, as the acid anhydride, acetic anhydride, trimellitic anhydride, pyromellitic anhydride, etc. can be listed. Among them, if acetic anhydride is used, purification after the reaction is completed becomes easy, so it is preferred.

[0117] The temperature during the imidization reaction is -20 to 140°C, preferably 0 to 100°C, and the reaction time can be 1 to 100 hours. The amount of the basic catalyst is 0.5 to 30 times by mole of the amic acid group, preferably 2 to 20 times by mole, and the amount of the acid anhydride is 1 to 50 times by mole of the amic acid group, preferably 3 to 30 times by mole. The imidization rate of the obtained polymer can be controlled by adjusting the amount of catalyst, temperature, and reaction time.

[0118] It should be noted that in this specification, the imidization rate refers to the ratio of the imide group to the total amount of the imide group and the carboxyl group (or its derivative) derived from tetracarboxylic dianhydride or its derivative. In polyimide, the imidization rate does not necessarily need to be 100%, and can be adjusted arbitrarily according to the use and purpose. The imidization rate of the polyimide used in the present invention is preferably 20% to 100%, and more preferably 50% to 99%.

[0119] The polymer can be precipitated by injecting the polyimide solution obtained as described above into a poor solvent while stirring. The precipitation is performed several times, and after washing with a poor solvent, it is dried at room temperature or by heating, thereby obtaining a purified polyimide powder.

[0120] The poor solvent is not particularly limited, and examples thereof include methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, and benzene.

[0121] The molecular weight of the polyimide precursor and polyimide produced as described above is preferably 2,000 to 500,000, more preferably 5,000 to 300,000, and further preferably 10,000 to 100,000. The number average molecular weight is preferably 1,000 to 250,000, more preferably 2,500 to 150,000, and further preferably 5,000 to 50,000.

[0122] <Liquid crystal alignment agent>

[0123] The liquid crystal aligning agent of the present invention has a form in which the aromatic compound of the above formula (1) is added to a solution in which a polymer having an ability to align a liquid crystal is dissolved in a solvent.

[0124] The content (concentration) of the polymer contained in the liquid crystal aligning agent of the present invention can be appropriately changed according to the setting of the thickness of the coating film to be formed, but from the perspective of forming a uniform and defect-free coating film, the content (concentration) of the polymer is preferably 1% by mass or more, and from the perspective of the storage stability of the solution, the content (concentration) of the polymer is preferably 10% by mass or less.

[0125] Moreover, content (concentration) of the aromatic compound of the said formula (1) added to the liquid crystal aligning agent of this invention is preferably 0.1-5 mass %, more preferably 0.15-5 mass %, particularly preferably 0.2-5 mass %.

[0126] The total content of the aromatic compound of the formula (1) is preferably 1 to 15% by mass, more preferably 2 to 10% by mass, and particularly preferably 2 to 8% by mass.

[0127] The solvent used for the liquid crystal aligning agent of the present invention will not be particularly limited as long as it is a solvent that dissolves the aromatic compound of the above formula (1) and the above polymer. Specific examples are given below.

[0128] For example, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethyl sulfoxide, γ-butyrolactone, 1,3-dimethyl-2-imidazolidinone, methyl ethyl ketone, cyclohexanone, cyclopentanone, 3-methoxy-N,N-dimethylpropaneamide or 4-hydroxy-4-methyl-2-pentanone, and solvents represented by the following formulas [D-1] to [D-3] can be cited.

[0129]

[0130] (In formula [D-1], D 1 represents an alkyl group having 1 to 3 carbon atoms, wherein D2 represents an alkyl group having 1 to 3 carbon atoms, wherein D 3 represents an alkyl group having 1 to 4 carbon atoms).

[0131] The solvent in the present invention is particularly preferably N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, γ-butyrolactone, 3-methoxy-N,N-dimethylpropaneamide, or 1,3-dimethyl-2-imidazolidinone (hereinafter, these are also referred to as good solvents).

[0132] In the liquid crystal aligning agent of the present invention, a solvent (also referred to as a poor solvent) may be contained to improve the coating properties and surface smoothness of the liquid crystal aligning film when the liquid crystal aligning agent is applied. These poor solvents are preferably 1 to 80% by mass of the total solvent contained in the liquid crystal aligning agent. Among them, preferably 10 to 80% by mass. More preferably, 20 to 70% by mass.

[0133] Specific examples of the poor solvent are listed below. They include ethanol, isopropanol, 1-butanol, 2-butanol, isobutanol, tert-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, isoamyl alcohol, tert-amyl alcohol, 3-methyl-2-butanol, neopentyl alcohol, 1-hexanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-ethyl-1-butanol, 1-heptanol, 2-heptanol, 3-heptanol, 1-octanol, 2-octanol, 2-ethyl-1-hexanol, cyclohexanol, 1-methylcyclohexanol, 2-methylcyclohexanol, 3-methylcyclohexanol, 1,2-ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 1, 4-Butanediol, 2,3-Butanediol, 1,5-pentanediol, 2-methyl-2,4-pentanediol, 2-ethyl-1,3-hexanediol, dipropyl ether, dibutyl ether, dihexyl ether, dioxane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, 1,2-butoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol dibutyl ether, 2-pentanone, 3-pentanone, 2-hexanone, 2-heptanone, 4-heptanone, 3-ethoxybutyl acetate, 1-methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, ethylene glycol monoacetate, ethylene glycol diacetate, propylene carbonate, Ethylene carbonate, 2-(methoxymethoxy)ethanol, butyl cellosolve, ethylene glycol monoisoamyl ether, ethylene glycol monohexyl ether, 2-(hexyloxy)ethanol, furfuryl alcohol, diethylene glycol, propylene glycol, 1-butoxy-2-propanol, 1-(butoxyethoxy)propanol, propylene glycol monomethyl ether acetate, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, tripropylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, butyl cellosolve acetate, ethylene glycol monoacetate, ethylene glycol diacetate, diethylene glycol monoethyl ether acetate, diacetone alcohol, propylene glycol diacetate, diisoamyl ether, diethylene glycol monobutyl ether acetate, 2-(2-ethoxyethoxy)ethyl acetate, diethylene glycol acetate, triethylene glycol, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol acetate monoethyl ether, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, n-propyl lactate, n-butyl lactate, isoamyl lactate, diisobutyl ketone, ethyl carbitol, or the solvents represented by the above formulas [D-1] to [D-3].

[0134] Among them, butyl cellosolve, 1-butoxy-2-propanol, butyl cellosolve acetate, dipropylene glycol monomethyl ether, diacetone alcohol, diethylene glycol diethyl ether, diisoamyl ether, propylene glycol diacetate, diisobutyl ketone, ethyl carbitol or dipropylene glycol dimethyl ether is preferably used.

[0135] The liquid crystal alignment agent of the present invention may also include: a cross-linking compound having an epoxy group, an isocyanate group, an oxetane group or a cyclocarbonate group, a cross-linking compound having at least one substituent selected from the group consisting of a hydroxyl group, a hydroxyalkyl group and a lower alkoxyalkyl group, or a cross-linking compound having a polymerizable unsaturated bond (excluding aromatic compounds of formula (1)). These substituents and polymerizable unsaturated bonds preferably have two or more in the cross-linking compound. The cross-linking compound may also be a combination of two or more. As specific examples of preferred cross-linking compounds, compounds represented by the following formulas (CL-1) to (CL-11) can be listed.

[0136]

[0137] It is preferable that it is 0.1-150 mass parts, and, as for content of the crosslinking compound in the liquid crystal aligning agent of this invention, it is more preferable that it is 0.1-100 mass parts with respect to 100 mass parts of all polymers.

[0138] Moreover, the liquid crystal aligning agent of this invention may contain the compound which improves the uniformity of the thickness of the film-like material obtained by applying it, and surface smoothness.

[0139] Examples of the compound include fluorine-based surfactants, silicone-based surfactants, and nonionic surfactants. More specifically, examples include EFTOP EF301, EF303, and EF352 (all manufactured by Mitsubishi Materials Electronics Chemicals Co., Ltd.), MEGAFACE F171, F173, and R-30 (all manufactured by DIC), FLUORAD FC430 and FC431 (all manufactured by 3M), AsahiGuard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, and SC106 (all manufactured by AGC), and the like.

[0140] Furthermore, in the liquid crystal aligning agent, a nitrogen-containing heterocyclic amine shown in

[0194] to

[0200] of International Publication WO2011 / 132751 (published on October 27, 2011) and represented by formula [M1] to [M156] may be added as a compound that promotes charge transfer in the liquid crystal aligning film and promotes charge release of the element. The amine may also be added directly to the liquid crystal aligning agent, but is preferably added after making a solution having a concentration of 0.1 to 10% by mass, preferably 1 to 7% by mass. The solvent is not particularly limited as long as it dissolves the specific polymer.

[0141] <Liquid crystal alignment film / liquid crystal display element>

[0142] The liquid crystal alignment film of the present invention is a film obtained by applying the above-mentioned liquid crystal alignment agent to a substrate, drying and firing. As a substrate, there is no particular limitation as long as it is a substrate with high transparency, and plastic substrates such as glass substrates, silicon nitride substrates, acrylic (Acrylic) substrates, and polycarbonate substrates can be listed. From the perspective of process simplification, it is preferred to form a substrate with an ITO electrode for driving liquid crystals. In a reflective liquid crystal display element, if it is only a single-sided substrate, an opaque object such as a silicon wafer can be used, and the electrode in this case can also use a material that reflects light such as aluminum.

[0143] As a method of applying a liquid crystal aligning agent to a substrate to form a film, screen printing, offset printing, flexographic printing, an inkjet method, a spray method, etc. are mentioned. Among them, the coating and film-forming method using the inkjet method can be preferably used.

[0144] After the liquid crystal alignment agent is applied to the substrate, the solvent can be evaporated by a heating unit such as a heating plate, a heat circulation oven or an IR (infrared) oven to form a film (film). The drying and firing steps after the liquid crystal alignment agent is applied can select any temperature and time. Usually, in order to fully remove the contained solvent, it can be fired at 50 to 180°C for 1 to 10 minutes; or in order to further perform thermal imidization, it can be fired at 150 to 300°C for 5 to 120 minutes. If the film after firing is too thin, the reliability of the liquid crystal display element is sometimes reduced, so it is preferably 5 to 300nm, and more preferably 10 to 200nm.

[0145] As the orientation treatment method of the liquid crystal orientation film obtained by the liquid crystal orientation agent of the present invention, it can also be a friction treatment method, but a photo-orientation treatment method is preferred. As a photo-orientation treatment method, the following method can be listed: the surface of the above-mentioned film-like object is irradiated with radiation polarized in a fixed direction, and it is preferably calcined at a temperature of 150 to 250°C according to the circumstances to impart liquid crystal orientation (also referred to as liquid crystal orientation ability). As radiation, ultraviolet rays or visible light with a wavelength of 100 to 800 nm can be used. Among them, ultraviolet rays with a wavelength of 100 to 400 nm, more preferably 200 to 400 nm, are preferred.

[0146] Furthermore, when irradiating with radiation, the substrate having the film-like material may be irradiated while being heated at 50 to 250° C. in order to improve the liquid crystal orientation. The irradiation amount of the radiation is preferably 1 to 10,000 mJ / cm 2 100 to 5000 mJ / cm is particularly preferred. 2 The liquid crystal alignment film produced in this way can stably align the liquid crystal molecules in a fixed direction.

[0147] Furthermore, these treatments may be performed using water or a solvent on the liquid crystal alignment film irradiated with polarized radiation by the above-mentioned method, or the liquid crystal alignment film irradiated with radiation may be subjected to a heat treatment.

[0148] The solvent used in the above-mentioned contact treatment is not particularly limited as long as it is a solvent that dissolves the decomposition product generated by the film-like material through the irradiation of radiation. As specific examples, 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 them, water, 2-propanol, 1-methoxy-2-propanol or ethyl lactate is preferred in terms of versatility and safety of the solvent. Water, 1-methoxy-2-propanol or ethyl lactate is more preferred. The solvent may be one or a combination of two or more.

[0149] As the above-mentioned contact treatment, immersion treatment and spray treatment (also referred to as spray treatment) can be listed. From the perspective of efficiently dissolving the decomposition products generated by the film-like material through the irradiation of radiation, the treatment time in these treatments is preferably 10 seconds to 1 hour. It is particularly preferred to perform immersion treatment for 1 to 30 minutes. In addition, the solvent during the above-mentioned contact treatment can be at room temperature or heated, preferably 10 to 80°C. It is particularly preferred to perform 20 to 50°C. In addition, from the perspective of the solubility of the decomposition products, ultrasonic treatment or the like can also be performed as needed.

[0150] After the above-mentioned contact treatment, it is preferred to perform washing (also referred to as rinsing) and calcining using a low boiling point solvent such as water, methanol, ethanol, 2-propanol, acetone, methyl ethyl ketone. At this time, either rinsing or calcining may be performed, or both may be performed. The calcining temperature is preferably 150 to 300°C. It is particularly preferably 180 to 250°C. It is more preferably 200 to 230°C. In addition, the calcining time is preferably 10 seconds to 30 minutes. It is particularly preferably 1 to 10 minutes.

[0151] The heat treatment of the coating film irradiated with the above-mentioned radiation is more preferably performed at 50 to 300° C. for 1 to 30 minutes, and further preferably performed at 120 to 250° C. for 1 to 30 minutes.

[0152] From the viewpoint of obtaining high liquid crystal orientation, the liquid crystal alignment film of the present invention is preferably used as a liquid crystal alignment film for a liquid crystal display element of a transverse electric field mode such as an IPS mode and an FFS mode, and is particularly useful as a liquid crystal alignment film for a liquid crystal display element of an FFS mode. After obtaining a substrate with a liquid crystal alignment film obtained from the liquid crystal alignment agent of the present invention, a liquid crystal cell is prepared by a known method, and a liquid crystal display element is obtained using the liquid crystal cell.

[0153] As an example of a method for manufacturing a liquid crystal cell, a passive matrix liquid crystal display element is used as an example. It should be noted that an active matrix liquid crystal display element in which each pixel portion constituting an image display is provided with a conversion element such as a TFT (Thin Film Transistor) may also be used.

[0154] Specifically, a transparent glass substrate is prepared, a common electrode is set on one substrate, and a segment electrode is set on the other substrate. These electrodes can be set as ITO electrodes, for example, and patterned in a manner that enables the desired image display. Next, an insulating film is set on each substrate in a manner that covers the common electrode and the segment electrode. The insulating film can be, for example, a SiO2-TiO2 film formed by a sol-gel method.

[0155] Next, a liquid crystal alignment film is formed on each substrate, and the substrate of one side is superimposed with the substrate of the other side in a manner that the liquid crystal alignment film faces face each other, and the periphery is bonded by a sealant. In order to control the substrate gap, a spacer is usually pre-mixed in the sealant. In addition, it is preferred that the spacer for controlling the substrate gap is also pre-spread in the surface part where the sealant is not provided. In a part of the sealant, an opening that can be filled with liquid crystal from the outside is pre-set. Next, through the opening provided in the sealant, a liquid crystal material is injected into the space surrounded by the two substrates and the sealant, and then the opening is sealed with an adhesive. The injection can use a vacuum injection method or a method that utilizes capillary phenomena in the atmosphere. The liquid crystal material can use any one of a positive liquid crystal material and a negative liquid crystal material, preferably a negative liquid crystal material. Next, a polarizer is set. Specifically, a pair of polarizers are bonded to the surface of the two substrates on the opposite side of the liquid crystal layer.

[0156] Example

[0157] The present invention will be described in more detail below with reference to Examples, but the present invention is not limited thereto. The abbreviations of the following compounds and the methods for measuring their properties are as follows.

[0158] <Solvent>

[0159] DMF: N,N-dimethylformamide, NMP: N-methyl-2-pyrrolidone.

[0160] GBL: gamma-butyrolactone, BCS: butyl cellosolve.

[0161] <Diamine>

[0162] DA-1: 1,2-bis(4-aminophenoxy)ethane.

[0163] DA-2: N-tert-butoxycarbonyl-N-(2-(4-aminophenyl)ethyl)-N-(4-aminobenzyl)amine.

[0164] DA-3: p-phenylenediamine, DA-4: refer to the following formula (DA-4).

[0165] DA-5: 4,4'-diaminodiphenylamine.

[0166] DA-6: 4,4'-diaminodiphenylmethane.

[0167]

[0168] <Tetracarboxylic dianhydride>

[0169]

[0170] <Additives>

[0171]

[0172] T-1 to T-4 are novel compounds not disclosed in literature or the like, and their synthesis methods are described in detail in the following Synthesis Examples 1 to 4.

[0173] < 1 H-NMR measurement>

[0174] Equipment: Fourier transform superconducting nuclear magnetic resonance device (FT-NMR) "AVANCE III" (manufactured by BRUKER) 500 MHz.

[0175] Solvent: deuterated chloroform (CDCl3) or deuterated N,N-dimethyl sulfoxide ([D6]-DMSO). Standard substance: tetramethylsilane (TMS).

[0176] (Synthesis example 1)

[0177] Synthesis of [T-1]:

[0178]

[0179] Into a 1L four-necked flask, 4,4'-biphenyldiboric acid (22.5g, 93mmol), 3-chloro-2-methyl-1-propylene (95.1g, 1050mmol), Najera catalyst I (0.244g, 0.3mmol), tetrabutylammonium bromide (13.5g, 42mmol), potassium carbonate (116.1g, 840mmol), DMF (250g), and pure water (13g) were placed, and stirred at 130°C. After the reaction was completed, the reaction solution was injected into ethyl acetate (1000g), neutralized with 1N aqueous hydrochloric acid solution (1000g), and then washed with pure water (1000g). The obtained organic layer was concentrated, and the obtained crude product was separated by silica gel column chromatography (eluent: hexane only), thereby obtaining 4.7g of white solid. According to the following 1 As a result of H-NMR, the solid was confirmed to be [T-1].

[0180] 1 H-NMR (500MHz, [D6]-DMSO): δ7.57-7.60 (d, 4H), 7.25-7.27 (d, 4H), 4.80-4.81 (m, 2H), 4.76-4.77 (m, 2H), 3.34 (s, 4H), 1.65 (s, 6H).

[0181] (Synthesis example 2)

[0182] Synthesis of [T-2]:

[0183]

[0184] 2,6-dimethylphenol (50.0 g, 409 mmol), 3-chloro-2-methyl-1-propylene (37.0 g, 409 mmol), potassium carbonate (84.8 g, 613 mmol), potassium iodide (6.80 g, 41 mmol), and DMF (500 g) were placed in a 1L four-necked flask and stirred at 80°C. After the reaction was completed, the reaction system was poured into ethyl acetate (500 g), and the organic layer was washed with pure water (1500 g). The obtained organic layer was concentrated, and the obtained crude product was isolated by silica gel column chromatography (eluent: hexane only), thereby obtaining 66.6 g of [T-2-1].

[0185] [T-2-1] (66.6 g, 378 mmol) and N,N-dimethylaniline (300 g) were placed in a 1 L four-necked flask and stirred at 180° C. After the reaction was completed, the reaction system was poured into ethyl acetate (1000 g), and the organic layer was washed with 1 N aqueous hydrochloric acid solution (1000 g), and then washed with pure water (1000 g), and the organic layer was concentrated to obtain 66.6 g of [T-2-2].

[0186] [T-2-2] (17.3 g, 98 mmol), 1,2-bis(toluenesulfonyloxy)ethane (18.5 g, 50 mmol), potassium carbonate (20.7 g, 150 mmol), and DMF (170 g) were placed in a 500 mL four-necked flask and stirred at 80°C. After the reaction was completed, the reaction system was injected into ethyl acetate (500 g), and the organic layer was washed with pure water (1000 g). The obtained organic layer was concentrated, and the crude product was separated by silica gel column chromatography (eluent: ethyl acetate / hexane = 1 / 30 (volume ratio)), thereby obtaining 10.0 g of a transparent liquid. According to the following 1 As a result of H-NMR, the liquid was confirmed to be [T-2].

[0187] 1 H-NMR (500MHz, CDCl3): δ6.83 (s, 4H), 4.78-4.79 (m, 2H), 4.72-4.73 (m, 2H), 4.09 (s, 4H), 3.20 (s, 4H), 2.30 (s, 12H), 1.67 (s, 6H).

[0188] (Synthesis example 3)

[0189] Synthesis of [T-3]:

[0190]

[0191] 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolane-2-yl)phenol (18.9 g, 86 mmol), 1,2-bis(toluenesulfonyloxy)ethane (15.9 g, 43 mmol), potassium carbonate (17.8 g, 129 mmol), and DMF (190 g) were placed in a 500 mL four-necked flask and stirred at 80°C. After the reaction was completed, the reaction system was filtered to remove potassium carbonate, the filtrate was poured into ethyl acetate (1000 g), and the organic layer was washed with pure water (2000 g). The obtained organic layer was concentrated, ethanol (60 g) was added to the crude product, and repulp washing was performed at room temperature to obtain 14.0 g of [T-3-1].

[0192] Into a 500 mL four-necked flask were placed [T-3-1] (13.5 g, 29 mmol), 3-chloro-2-methyl-1-propene (39.4 g, 435 mmol), Najera catalyst I (0.071 g, 0.09 mmol), tetrabutylammonium bromide (3.73 g, 12 mmol), potassium carbonate (32.1 g, 232 mmol), DMF (100 g), and pure water (25 g), and the mixture was stirred at 130°C.

[0193] After the reaction was completed, the reaction solution was poured into ethyl acetate (600 g) and washed with pure water (1200 g). The obtained organic layer was concentrated and the crude product was separated by silica gel column chromatography (eluent: ethyl acetate / hexane = 1 / 30 (volume ratio)) to obtain 1.6 g of a white solid. 1 As a result of H-NMR, it was confirmed that the solid was the target [T-3].

[0194] 1 H-NMR (500MHz, CDCl3): δ7.09-7.11 (d, 4H), 6.87-6.89 (d, 4H), 4.78-4.79 (m, 2H), 4.70-4.71 (m, 2H), 4.30 (s, 4H), 3.26 (s, 4H), 1.67 (s, 6H).

[0195] (Synthesis Example 4)

[0196] Synthesis of [T-4]:

[0197]

[0198] 2,6-dimethylphenol (25.0 g, 205 mmol), allyl bromide (29.8 g, 246 mmol), potassium carbonate (42.5 g, 308 mmol), and DMF (250 g) were placed in a 500 mL four-necked flask and stirred at 80° C. After the reaction was completed, the reaction system was poured into ethyl acetate (300 g), and the organic layer was washed with pure water (600 g) and concentrated to obtain 30.8 g of [T-4-1].

[0199] [T-4-1] (30.8 g, 190 mmol) and N,N-dimethylaniline (200 g) were placed in a 500 mL four-necked flask and stirred at 180° C. After the reaction was completed, the reaction system was poured into ethyl acetate (500 g), and the organic layer was washed with 1 N aqueous hydrochloric acid solution (500 g) and pure water (500 g), and the organic layer was concentrated to obtain 30.3 g of [T-4-2].

[0200] [T-4-2] (30.3 g, 187 mmol), 1,2-bis(toluenesulfonyloxy)ethane (34.4 g, 93 mmol), potassium carbonate (38.6 g, 279 mmol), and DMF (360 g) were placed in a 500 mL four-necked flask and stirred at 80°C. After the reaction was completed, the reaction system was injected into ethyl acetate (1000 g), and the organic layer was washed with pure water (2000 g). The obtained organic layer was concentrated, and the crude product was separated by silica gel column chromatography (eluent: ethyl acetate / hexane = 1 / 80 (volume ratio)), thereby obtaining 18.7 g of a transparent liquid. According to the following 1 As a result of H-NMR, it was confirmed that the liquid was the target [T-4].

[0201] 1 H-NMR (500MHz, [D6]-DMSO): δ7.02 (s, 4H), 5.87-5.96 (m, 2H), 5.05-5.09 (m, 2H), 5.00-5.03 (m, 2H), 4.04 (s, 4H), 3.24-3.25 (d, 4H), 2.22 (s, 12H).

[0202] <Method for measuring viscosity>

[0203] The measurement was performed using an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.) with a sample amount of 1.1 mL, a conical rotor TE-1 (1°34', R24), and a temperature of 25°C.

[0204] <Method for determination of molecular weight>

[0205] The number average molecular weight (Mn) and the weight average molecular weight (Mw) were calculated as polyethylene glycol and polyethylene oxide equivalent values ​​by measurement using a GPC (normal temperature gel permeation chromatography) apparatus.

[0206] GPC apparatus: manufactured by Shodex (GPC-101), chromatographic column: manufactured by Shodex (KD803 and KD805 in series), chromatographic column temperature: 50°C, eluent: N,N-dimethylformamide (as additives, lithium bromide monohydrate (LiBr·H2O) is 30 mmol / L, phosphoric acid / anhydrous crystals (o-phosphoric acid) is 30 mmol / L, and tetrahydrofuran (THF) is 10 ml / L), flow rate: 1.0 ml / min.

[0207] Standard samples for preparing the calibration curve: TSK standard polyethylene oxide manufactured by Tosoh (weight average molecular weight (Mw) of about 900,000, 150,000, 100,000, 30,000) and polyethylene glycol manufactured by Polymer Laboratory (peak molecular weight (Mp) of about 12,000, 4,000, 1,000). In order to avoid peak overlap, the measurement was performed on a sample of a mixture of four types of 900,000, 100,000, 12,000, and 1,000, and a sample of a mixture of three types of 150,000, 30,000, and 4,000.

[0208] <Method for measuring imidization ratio>

[0209] Add polyimide powder (20 mg) to an NMR sample tube (NMR Sampling Tube Standard, φ5 (manufactured by Kusano Scientific Co., Ltd.)), add deuterated dimethyl sulfoxide (DMSO-d6, 0.05% TMS (tetramethylsilane) mixture) (0.53 ml), and apply ultrasonic waves to completely dissolve it. The solution was measured for 500 MHz proton NMR using a Fourier transform superconducting nuclear magnetic resonance device (FT-NMR) "AVANCE III" (manufactured by BRUKER). The imidization rate was calculated as follows: the proton derived from the structure that does not change before and after imidization is determined as the reference proton, and the peak integral value of the proton derived from the NH group of the amic acid appearing near 9.5 ppm to 10.0 ppm is used to calculate it using the following formula.

[0210] Imidization rate (%) = (1-α·x / y) × 100

[0211] In the above formula, x is the peak integral value of protons derived from NH groups of amic acid, y is the peak integral value of reference protons, and α is the ratio of the number of reference protons to protons of one NH group of amic acid in the case of polyamic acid (imidation ratio 0%).

[0212] (Synthesis Example 5)

[0213] DA-1 (3.91 g, 16.0 mmol), DA-2 (2.19 g, 6.41 mmol), DA-3 (0.519 g, 4.80 mmol), and DA-4 (1.54 g, 4.81 mmol) were weighed into a 100 mL four-necked flask equipped with a stirring device and a nitrogen inlet tube, and NMP (46.2 g) was added, and stirred to dissolve while nitrogen was supplied. CA-1 (5.70 g, 25.4 mmol) and CA-2 (1.20 g, 4.80 mmol) were added while stirring the diamine solution, and NMP (39.1 g) was further added so that the solid content concentration became 15% by mass, and stirred at 40°C for 24 hours to obtain a polyamic acid solution (A) (viscosity: 450 mPa·s). The molecular weight of the polyamic acid was Mn=11200 and Mw=26900.

[0214] (Synthesis Example 6)

[0215] DA-5 (5.10 g, 25.6 mmol) and DA-6 (1.27 g, 6.41 mmol) were taken into a 100 mL four-necked flask equipped with a stirring device and a nitrogen inlet tube, and NMP (36.1 g) was added, and stirred while nitrogen was supplied to dissolve. CA-2 (4.00 g, 16.0 mmol) and CA-3 (4.42 g, 15.0 mmol) were added while stirring the diamine solution, and NMP (47.7 g) was further added in such a way that the solid content concentration became 15% by mass, and stirred at 50°C for 24 hours to obtain a polyamic acid solution (B) (viscosity: 904 mPa·s). The molecular weight of the polyamic acid is Mn=14600, Mw=37500.

[0216] (Synthesis Example 7)

[0217] The obtained polyamic acid solution (A) (30g) was measured in a 100ml four-necked flask with a stirring device and a nitrogen inlet tube, NMP (15.0g) was added, and stirred for 30 minutes. Acetic anhydride (4.89g) and pyridine (1.51g) were added to the obtained polyamic acid solution, and heated at 50°C for 2 hours and 30 minutes to carry out chemical imidization. The obtained reaction solution was put into methanol (154mL) while stirring, and the precipitate was filtered out, and then washed three times with methanol (154mL). The obtained resin powder was dried at 60°C for 12 hours to obtain a polyimide resin powder (A). The imidization rate of the polyimide resin powder was 64%, Mn=9900, and Mw=20000.

[0218] (Synthesis Example 8)

[0219] The polyimide resin powder (A) (3.00 g) obtained in Synthesis Example 7 was weighed in a 100 mL Erlenmeyer flask, NMP (22.0 g) was added so as to give a solid content concentration of 12%, and the mixture was stirred at 70°C for 24 hours to dissolve the mixture, thereby obtaining a polyimide solution (A).

[0220] (Example 1)

[0221] The polyimide solution (A) (3.80 g) obtained in Synthesis Example 8 and the polyamic acid solution (B) (4.56 g) obtained in Synthesis Example 6 were weighed in a 100 mL conical flask, and T-1 (0.114 g), NMP (1.64 g), GBL (6.00 g), and BCS (4.00 g) were added and stirred at room temperature for 3 hours to obtain a liquid crystal aligning agent (1). No abnormalities such as turbidity and precipitation were observed in the liquid crystal aligning agent, and it was confirmed to be a uniform solution.

[0222] (Examples 2 to 5)

[0223] Except that T-2, T-3, T-4, or T-5 was used instead of T-1, liquid crystal aligning agents (2) to (5) of Examples 2 to 5 were obtained by the same method as in Example 1. In these liquid crystal aligning agents (2) to (5), abnormalities such as turbidity and precipitation were not observed, and they were confirmed to be uniform solutions.

[0224] (Comparative Example 1)

[0225] The polyimide solution (A) (3.80 g) obtained in Synthesis Example 8 and the polyamic acid solution (B) (4.56 g) obtained in Synthesis Example 6 were weighed into a 100-mL conical flask, and NMP (1.64 g), GBL (6.00 g), and BCS (4.00 g) were added and stirred at room temperature for 3 hours to obtain a liquid crystal aligning agent (6).

[0226] (Comparative Example 2)

[0227] A liquid crystal aligning agent (7) was obtained by the same method as in Example 1 except having used T-6 instead of T-1.

[0228] In addition, in the liquid crystal aligning agents (6) and (7) obtained in the said comparative examples 1 and 2, abnormality, such as turbidity and precipitation, was not observed at all, and it was confirmed that it was a uniform solution.

[0229] (Example 6)

[0230] The liquid crystal aligning agent (1) obtained in Example 1 was filtered through a filter with a pore size of 1.0 μm, and then applied to a glass substrate with a transparent electrode by spin coating. The coating surface was dried on a hot plate at 80°C for 2 minutes at 0.25 J / cm2 After irradiating with ultraviolet rays having a wavelength of 254 nm and linearly polarized at an extinction ratio of 26:1 by means of a polarizer, the substrate was baked in a hot air circulation oven at 230° C. for 20 minutes to obtain a substrate with a liquid crystal alignment film having a film thickness of 100 nm.

[0231] The two obtained substrates were taken as a group, and spacers with a diameter of 6 μm were scattered on the liquid crystal orientation film surface of one substrate. A sealant was printed on the substrate, and the other substrate was attached in a manner that the liquid crystal orientation film surfaces faced each other and the orientation direction was 0°, and then the sealant was cured to produce an empty box. Liquid crystal MLC-7026-100 (manufactured by MERCK) was injected into the empty box by the reduced pressure injection method, and the injection port was sealed to obtain a liquid crystal box. The initial orientation of the liquid crystal box was confirmed, and the result was that no flow orientation was confirmed, and the orientation was good. The box was heat treated at 120°C for 60 minutes to produce a liquid crystal box.

[0232] [Evaluation method of liquid crystal orientation]

[0233] The liquid crystal orientation state in the liquid crystal box prepared according to the above steps was observed using a polarizing microscope (manufactured by NIKON, ECLIPSE E600 POL). The case where the orientation of the liquid crystal could be confirmed and there was no flow orientation was judged as "good", and the case where the orientation could not be confirmed and there was flow orientation was judged as "bad".

[0234] [Determination of voltage holding ratio]

[0235] The liquid crystal cell was placed on a backlight for 5 days for aging, and then a voltage of 1 V was applied for 60 μs at 60°C. The voltage after 500 ms was measured, and the voltage that could be maintained was calculated as the voltage holding ratio. The voltage holding ratio was measured using VHR-1 manufactured by TOYO TECHNICA.

[0236] As a result, the voltage holding ratio at 60° C. of the alignment film formed from the liquid crystal aligning agent (1) was 61.7%.

[0237] (Examples 7 to 10, Comparative Examples 3 to 4)

[0238] Liquid crystal cells were prepared in the same manner as in Example 6, except that the liquid crystal aligning agents shown in Table 1 were used instead of the liquid crystal aligning agent (1), and the liquid crystal orientation and voltage holding ratio were evaluated. The liquid crystal orientation and voltage holding ratio of each obtained liquid crystal cell are shown in Table 1.

[0239] [Table 1]

[0240] Liquid crystal alignment agent additive Liquid crystal orientation Voltage holding rate (%) Example 6 (1) T-1 good 61.7 Example 7 (2) T-2 good 72.6 Example 8 (3) T-3 good 58.3 Example 9 (4) T-4 good 72.7 Example 10 (5) T-5 good 78.0 Comparative Example 3 (6) none good 49.8 Comparative Example 4 (7) T-6 good 50.4

[0241] As shown in Table 1, it was confirmed that in Examples 6 to 10 to which additives (T-1) to (T-5) were added, the liquid crystal orientation was not reduced and the voltage holding ratio was improved compared with Comparative Example 3 to which these additives were not added and Comparative Example 4 to which an additive (T-6) different from the aromatic compound of the present invention was added.

[0242] It should be noted that the entire contents of the specification, claims, and abstract of Japanese Patent Application No. 2019-184619 filed on October 7, 2019 are incorporated herein by reference and incorporated as a disclosure of the specification of the present invention.

Claims

1. An aromatic compound, which is any one selected from the group consisting of the following formula (b-1) to formula (b-4),

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