Novel diamine compound, polymer obtained using diamine, liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element

Abstract

Provided is a novel diamine which, when used as a starting material for a polymer that constitutes a liquid crystal alignment film, is capable of suppressing the reduction in the molecular weight of the polymer during baking and is capable of forming a liquid crystal alignment film having a high voltage retention rate.　The diamine is represented by any of formulas (dA-1) through (dA-6).　

Description

Novel diamine compound, polymer obtained using the diamine, liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element

[0001] The present invention relates to a novel diamine compound, a polymer obtained by using the diamine, a liquid crystal aligning agent, a liquid crystal alignment film, and a liquid crystal display element.

[0002] Currently, polyimide films are often used as liquid crystal alignment films for liquid crystal display elements, and these polyimide films are produced by applying a polyimide precursor, such as a solution of polyamic acid or a solution of a solvent-soluble polyimide, to a substrate and baking it. Polyamic acid or solvent-soluble polyimide is generally synthesized by reacting a tetracarboxylic acid derivative, such as a tetracarboxylic acid dianhydride, with a diamine.

[0003] A liquid crystal display element includes, for example, a liquid crystal layer sandwiched between an element substrate and a color filter substrate, pixel electrodes and a common electrode that apply an electric field to the liquid crystal layer, a liquid crystal alignment film that controls the orientation of liquid crystal molecules in the liquid crystal layer, thin film transistors (TFTs) that switch electric signals supplied to the pixel electrodes, etc. Known methods for driving liquid crystal molecules include vertical electric field methods such as the TN (Twisted Nematic) method and the VA (Vertical Alignment) method, and horizontal electric field methods such as the IPS (In-Plane Switching) method and the FFS (Fringe Field Switching) method.

[0004] Currently, the most widely used industrial liquid crystal alignment films are produced by rubbing the surface of a film formed on an electrode substrate and made of a polymer, typically polyamic acid and / or imidized polyimide, in one direction with a cloth made of cotton, nylon, polyester, or the like. Rubbing is a simple, highly productive, and industrially useful method. Meanwhile, as liquid crystal display elements have become increasingly sophisticated, precise, and large, photoalignment methods, which impart liquid crystal alignment ability by irradiating polarized radiation, have been proposed as alternative alignment methods to rubbing. Proposed photoalignment methods include those utilizing photoisomerization reactions, photocrosslinking reactions, and photodecomposition reactions (see, for example, Non-Patent Document 1 and Patent Document 1).

[0005] In recent years, mobile applications such as smartphones and in-vehicle applications such as car navigation systems have required properties that can withstand long-term use in harsh environments. Liquid crystal alignment films used therein are now required to be more reliable than ever before. For example, the electrical properties of liquid crystal alignment films, known as voltage holding ratios, are required to not only have good initial characteristics but also maintain good characteristics even after prolonged exposure to high temperatures. As a means of solving the above problem, Patent Document 2 proposes a liquid crystal alignment agent using a diamine having a diaminodiphenylamine structure as a polyimide (precursor) raw material.

[0006] JP 9-297313 Publication WO2004 / 021076 Publication

[0007] "Liquid Crystal Photo-Alignment Film" Kidowaki, Ichimura, Functional Materials, November 1997, Vol. 17, No. 11, pp. 13-22

[0008] As the resolution of liquid crystal display elements increases, the level of the above requirements becomes even higher, and liquid crystal alignment films that can meet these requirements at a high level are required. Furthermore, in liquid crystal display elements used in mobile applications such as smartphones and car navigation systems, the thickness of the substrates (e.g., glass substrates) that make up the liquid crystal panel is often reduced to reduce weight. Therefore, liquid crystal alignment films with high film strength are sometimes required to prevent film abrasion of the liquid crystal alignment film that occurs as the substrate becomes thinner. Furthermore, in IPS and FFS driving modes, the stability of liquid crystal alignment is also important. If the alignment stability is low, the liquid crystal will not return to its initial state after long-term operation, causing a decrease in contrast and image retention (hereinafter referred to as AC image retention). Therefore, liquid crystal alignment films that suppress AC image retention are also required.

[0009] The polyimide (precursor) obtained using the diamine having a diphenylamine structure described in Patent Document 2 described above suffers from a significant decrease in the molecular weight of the polymer during the baking step in producing a liquid crystal alignment film, and therefore does not sufficiently solve the above-mentioned problems.

[0010] In light of the above, a first object of the present invention is to provide a novel diamine and a polymer obtained using the diamine. It is also an object of the present invention to provide a liquid crystal aligning agent that, when used with the polymer, can obtain a liquid crystal alignment film with a high voltage holding ratio even after prolonged exposure to high temperatures, a liquid crystal alignment film obtained from the liquid crystal aligning agent, and a liquid crystal display element using the same. It is also an object of the present invention to provide a liquid crystal aligning agent that can suppress a decrease in molecular weight of the polymer during baking when producing a liquid crystal alignment film, a liquid crystal alignment film obtained from the liquid crystal aligning agent, and a liquid crystal display element using the same. It is also an object of the present invention to provide a liquid crystal aligning agent that can obtain a liquid crystal alignment film with a high voltage holding ratio, high film strength, and reduced AC image retention even after prolonged exposure to high temperatures, a liquid crystal alignment film obtained from the liquid crystal aligning agent, and a liquid crystal display element using the same.

[0011] As a result of intensive research to achieve the above object, the present inventors have found that a liquid crystal aligning agent containing a polymer having a specific diamine as a constituent is extremely effective in achieving the above object, and have completed the present invention.

[0012] The present invention encompasses the following aspects: 1. A compound represented by the following formula (d Ａ -1) to (d Ａ -6). 2. At least one polymer selected from the group consisting of a polyimide precursor obtained using a diamine component containing the diamine described in 1 above, and a polyimide obtained by imidizing the polyimide precursor. 3. The polymer described in 2 above, wherein the diamine component further contains a diamine having at least one group selected from the group consisting of a urea bond, an amide bond, a carboxy group, and a hydroxy group in the molecule. 4. The polymer described in 2 or 3 above, wherein the amount of the diamine described in 1 above used is 5 mol % or more based on the diamine component. 5. The polymer described in any one of 2 to 4 above, wherein the polymer is obtained by a polymerization reaction between the diamine component and a tetracarboxylic acid component, and the tetracarboxylic acid component contains a tetracarboxylic acid dianhydride or a derivative thereof. 6. The polymer described in 5 above, wherein the tetracarboxylic acid dianhydride or a derivative thereof is an acyclic aliphatic tetracarboxylic acid dianhydride, an alicyclic tetracarboxylic acid dianhydride, an aromatic tetracarboxylic acid dianhydride, or a derivative thereof. 7. The tetracarboxylic acid dianhydride or a derivative thereof is an acyclic aliphatic tetracarboxylic acid dianhydride, which is 1,2,3,4-butanetetracarboxylic acid dianhydride;1,2,3,4-Cyclobutanetetracarboxylic acid dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-dichloro-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-difluoro-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-bis(trifluoromethyl)-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,3,4-cyclopentanetetracarboxylic acid dianhydride, 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride, 3,3',4,4'-dicyclohexyltetracarboxylic acid dianhydride, 2,3,5-trifluoromethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride Carboxycyclopentylacetic dianhydride, 4-(2,5-dioxotetrahydrofuran-3-yl)tetrahydronaphthalene-1,2-dicarboxylic acid anhydride, 5-(2,5-dioxotetrahydrofuran-3-yl)-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 5-(2,5-dioxotetrahydrofuran-3-yl)-8-methyl-3a,4,5,9 an alicyclic tetracarboxylic dianhydride selected from b-tetrahydronaphtho[1,2-c]furan-1,3-dione, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, bicyclo[2.2.2]octane-2,3,5,6-tetracarboxylic dianhydride, and 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-dianhydride;Pyromellitic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3',4,4'-diphenylethertetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride anhydride, 4,4'-bis(3,4-dicarboxyphenoxy)-2,2-diphenylpropane dianhydride, ethylene glycol bisanhydrotrimellitate, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 4,4'-carbonyldiphthalic anhydride, 4,4'-(1,4-phenylenedioxy)bis(phthalic anhydride), and 4,4'-(1,4-phenylenedimethylene)bis(phthalic anhydride);or a derivative thereof, the polymer according to any one of items 5 to 6 above. 8. A liquid crystal aligning agent characterized by containing the polymer according to any one of items 2 to 7 above. 9. The liquid crystal aligning agent according to item 8 above, further containing at least one polymer (B) selected from the group consisting of a polyimide precursor obtained using a diamine component not containing the diamine according to item 1 above, and a polyimide which is an imidized product of the polyimide precursor. 10. The liquid crystal aligning agent according to item 9 above, wherein the polymer (B) is obtained by a polymerization reaction between the diamine component and a tetracarboxylic acid component, and the tetracarboxylic acid component contains a tetracarboxylic dianhydride or a derivative thereof. 11. The liquid crystal aligning agent according to any one of claims 8 to 10, wherein the liquid crystal aligning agent further contains at least one crosslinking compound selected from the group consisting of a crosslinking compound (c-1) having at least one substituent selected from an oxiranyl group, an oxetanyl group, a blocked isocyanate group, an oxazoline group, a cyclocarbonate group, a hydroxy group, and an alkoxy group, and a crosslinking compound (c-2) having a polymerizable unsaturated group, a functional silane compound, a metal chelate compound, a curing accelerator, a surfactant, an antioxidant, a sensitizer, a preservative, a compound for adjusting the dielectric constant or electrical resistance of the resulting liquid crystal alignment film, and a compound for promoting imidization. 12. A liquid crystal alignment film obtained from the liquid crystal aligning agent according to any one of claims 8 to 11. 13. A liquid crystal display element comprising the liquid crystal alignment film according to claim 12. 14. A method for producing a liquid crystal display element, comprising the following steps (1) to (3): Step (1): A step of applying the liquid crystal alignment agent according to any one of the above items 8 to 11 onto a substrate; Step (2): A step of baking the applied liquid crystal alignment agent to obtain a film; Step (3): A step of performing an alignment treatment on the film obtained in step (2); 15. A method for producing a liquid crystal display element according to the above item 14, wherein the alignment treatment is a photo-alignment treatment.

[0013] The diamine of the present invention, when used as a raw material for a polymer constituting a liquid crystal alignment film, can suppress a decrease in the molecular weight of the polymer during baking and can form a liquid crystal alignment film having a high voltage holding ratio, and can provide a liquid crystal alignment agent, a liquid crystal alignment film obtained from the liquid crystal aligning agent, and a high-performance liquid crystal display element equipped with the liquid crystal alignment film.Furthermore, the diamine of the present invention can provide a liquid crystal aligning agent, a liquid crystal alignment film obtained from the liquid crystal aligning agent, and a liquid crystal display element using the same, which can provide a liquid crystal alignment film, when used as a raw material for a polymer constituting a liquid crystal alignment film, that has high film strength, suppresses AC afterimages, and has a high voltage holding ratio even after prolonged exposure to high temperatures.

[0014] The mechanism by which the above-mentioned effects of the present invention are obtained is not entirely clear, but is presumably as follows: The aromatic tetracarboxylic dianhydride skeleton, which is subject to a significant decrease in molecular weight upon baking, is pre-imidized to suppress the reverse reaction and the resulting decrease in molecular weight, thereby achieving the above-mentioned effects.

[0015] Hereinafter, a novel diamine, a polymer obtained using the diamine, a liquid crystal aligning agent containing the polymer, a liquid crystal alignment film formed using the liquid crystal aligning agent, and a liquid crystal display element having the liquid crystal alignment film will be described in detail, but the explanation of the constituent elements described below is an example of one embodiment of the present invention and is not intended to limit the present invention. In the following description, examples of "halogen atom" include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. "Boc" represents a tert-butoxycarbonyl group, and "*" represents a bonding position.

[0016] (Specific Diamine) The diamine of the present invention is a diamine represented by the following formula (d Ａ -1) to (d Ａ -6) (also referred to as specific diamine in the present invention).

[0017] The method for producing the specific diamine of the present invention is not particularly limited, but a preferred method includes a production method including the following steps (i) to (iv):

[0018] <Step (i)> A compound represented by the following formula (d ｉ A diamine represented by formula (d-1) is reacted with an amino-protecting reagent such as di-tert-butyl dicarbonate to obtain a compound (d) in which the amino group is protected with a Boc group. ｉ Here, Y in formula (i) represents a divalent organic group obtained by removing two amino groups from a diamine, and examples of the diamine include 4,4'-diaminodiphenylamine and 4,4'-diaminodiphenyl-N-methylamine.

[0019] <Step (ii)> Formula (d ｉ -2) is reacted with a tetracarboxylic dianhydride to obtain a compound represented by the following formula (d ｉ -3) to obtain a compound represented by the formula (ii). Here, X in formula (ii) represents a tetravalent organic group obtained by removing two acid anhydride groups from a tetracarboxylic dianhydride, and examples of the tetracarboxylic dianhydride include pyromellitic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, and 3,3',4,4'-biphenyltetracarboxylic dianhydride. Furthermore, Y in formula (ii) has the same meaning as in formula (i).

[0020] <Step (iii)> The compound of the formula (d ｉ The compound represented by formula (di-3) is imidized to obtain a diimide compound (di-4) in which the amino group is protected with a Boc group.

[0021] <Step (iv)> Compound (di-4) is reacted with an inorganic acid such as hydrochloric acid to carry out a deprotection reaction, thereby obtaining the diamine compound of the present invention. The reaction temperature is not particularly limited, but the reaction may be carried out at 0 to 100°C.

[0022] A solvent can be used in the synthesis reaction of the specific diamine, if necessary. The solvent is not particularly limited as long as it can dissolve the compound. Specific examples include water, alcohols such as methanol, ethanol, propanol, and butanol; ethers such as diethyl ether, tetrahydrofuran, and dioxane; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; esters such as ethyl acetate; and organic solvents such as N,N-dimethyl sulfoxide, dimethylformamide, dimethylacetamide, and N-methyl-2-pyrrolidone, which can be used appropriately depending on the type of reaction.

[0023] As a method for imidizing in the above step (iii), ｉ -3) in a solution thereof, or ｉ In the catalytic imidization, a catalyst is added to a solution of a compound represented by the formula (d-3), and the catalytic imidization method is preferred from the viewpoint of ease of synthesis. ｉ The reaction can be carried out by adding a basic catalyst and an acid anhydride to a solution of a compound represented by the formula (d-3), and reacting the compound at a temperature of preferably 0 to 120°C, more preferably 0 to 100°C. The amount of the basic catalyst is determined by the reaction temperature of the compound represented by the formula (d ｉ The amount of the acid anhydride is preferably 0.5 to 30 times by mole, more preferably 2 to 20 times by mole, the amount of the amic acid group contained in the compound represented by the formula (d-3). ｉ The molar amount of the base is preferably 1 to 50 times, more preferably 1 to 30 times, the molar amount of the amic acid group contained in the compound represented by formula (1-3). Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, and trioctylamine, and among these, pyridine is preferred because it has an appropriate basicity for promoting the reaction. Examples of the acid anhydride include acetic anhydride, trimellitic anhydride, and pyromellitic anhydride, and among these, acetic anhydride is preferred because it facilitates purification after completion of the reaction.

[0024] The diamine of the present invention can be used as a raw material for a polymer constituting a liquid crystal alignment film. Ａ -1) to (d Ａ and at least one polymer (P) selected from the group consisting of polyimide precursors obtained by using a diamine component containing a diamine (0) represented by any one of the following formulas:

[0025] (Polymer (P)) The polymer (P) of the present invention is a polyimide precursor obtained using a diamine component containing the diamine (0), or a polyimide which is an imidized product of the polyimide precursor. Here, the polyimide precursor is a polymer from which a polyimide can be obtained by imidizing a polyamic acid, a polyamic acid ester, or the like. The polyamic acid (P'), which is the polyimide precursor of the polymer (P), can be obtained by a polymerization reaction between a diamine component containing the diamine (0) and a tetracarboxylic acid component. The diamine (0) may be used alone or in combination of two or more. The amount of diamine (0) used is preferably 5 mol % or more, more preferably 10 mol % or more, and even more preferably 20 mol % or more, based on the total diamine components.

[0026] The diamine component used in the production of the polyamic acid (P') may contain a diamine other than the diamine (0) (hereinafter also referred to as "other diamine"). When the other diamine is used in addition to the diamine (0), the amount of the diamine (0) used relative to the diamine component is preferably 90 mol % or less, more preferably 80 mol % or less.

[0027] Examples of other diamines include, but are not limited to, the following. The above other diamines may be used singly or in combination of two or more: p-phenylenediamine, 2,3,5,6-tetramethyl-p-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, m-phenylenediamine, 2,4-dimethyl-m-phenylenediamine, 2,5-diaminotoluene, 2,6-diaminotoluene, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-dihydroxy-4,4' -diaminobiphenyl, 2,2'-difluoro-4,4'-diaminobiphenyl, 3,3'-difluoro-4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 3,3'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 3,4'-diaminobiphenyl, 4,4'-diaminobiphenyl, 3,3'-diaminobiphenyl, 2,2'-diaminobiphenyl, 2,3'-diaminobiphenyl, ＡＬ ) (preferably, a diamine represented by the following formula (d ＡＬ -1) to (d ＡＬ-10), 1,7-bis(4-aminophenoxy)heptane, 1,7-bis(3-aminophenoxy)heptane, 1,8-bis(4-aminophenoxy)octane, 1,8-bis(3-aminophenoxy)octane, 1,9-bis(4-aminophenoxy)nonane, 1,9-bis(3-aminophenoxy)nonane, 1,10-bis(4-aminophenoxy)decane, 1,10-bis(3-aminophenoxy) decane, 1,11-bis(4-aminophenoxy)undecane, 1,11-bis(3-aminophenoxy)undecane, 1,12-bis(4-aminophenoxy)dodecane, 1,12-bis(3-aminophenoxy)dodecane, 1,2-bis(6-amino-2-naphthyloxy)ethane, 1,2-bis(6-amino-2-naphthyl)ethane, or 6-[2-(4-aminophenoxy)ethoxy]-2-naphthylamine. ), 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, 4,4'-bis(4-aminophenoxy)diphenyl ether, 1,4-bis[4-(4-aminophenoxy)phenoxy]benzene, 1,4-phenylenebis(4-aminobenzoate), 1,4-phenylenebis(3-aminobenzoate), 1,3-phenylenebis(4-aminobenzoate), 1,3-phenylenebis(3-aminobenzoate), bis(4-aminophenyl) terephthalate, bis(3-aminophenyl)terephthalate, bis(4-aminophenyl)isophthalate, bis(3-aminophenyl)isophthalate; diamines having a tetracarboxylic acid diimide structure other than specific diamines, such as N,N'-bis(4-aminophenyl)-cyclobutane-(1,2,3,4)-tetracarboxylic acid diimide, N,N'-bis(4-aminophenyl)-1,3-dimethylcyclobutane-(1,2,3,4)-tetracarboxylic acid diimide, and N,N'-bis(2,2'-bis(trifluoromethyl)-4'-amino-1,1'-biphenyl-4-yl)-cyclobutane-(1,2,3,4)-tetracarboxylic acid diimide;Diamines having a photoalignable group such as 4,4'-diaminoazobenzene or diaminotolane; diamines having a photopolymerizable group at the end such as 2-(2,4-diaminophenoxy)ethyl methacrylate or 2,4-diamino-N,N-diallylaniline; 1-(4-(2-(2,4-diaminophenoxy)ethoxy)phenyl)-2-hydroxy-2-methylpropanone, 2-(4-(2-hydroxy-2-methylpropanoyl)phenoxy)ethyl Diamines having a radical polymerization initiator function such as 3,5-diaminobenzoate; diamines having an amide bond such as 4,4'-diaminobenzanilide; diamines having a urea bond such as 1,3-bis(4-aminophenyl)urea, 1,3-bis(4-aminobenzyl)urea, and 1,3-bis(4-aminophenethyl)urea; 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2, 2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2-bis(4-aminophenyl)hexafluoropropane, 2,2-bis(3-aminophenyl)hexafluoropropane, 2,2-bis(3-amino-4-methylphenyl)hexafluoropropane, 2,2-bis(4-aminophenyl)propane, 2,2-bis(3-aminophenyl)propane, 2,2-bis(3-amino-4-methylphenyl)propane, 4,4'-diaminobenzophenone, 1,4-bis(4-aminobenzyl)benzene;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-[3-(1H-imidazol-1-yl)propyl] Heterocycle-containing diamines such as 3,5-diaminobenzamide, 4-[4-[(4-aminophenoxy)methyl]-4,5-dihydro-4-methyl-2-oxazolyl]-benzeneamine, or diamines represented by the following formulas (z-1) to (z-13), or 4,4'-diaminodiphenylamine, 4,4'-diaminodiphenyl-N-methylamine, N,N'-bis(4-aminophenyl)-benzidine, N,N'-bis(4-aminophenyl)-N,N'-dimethylbenzidine, or N,N'-bis(4-aminophenyl)-N,N'-dimethyl-1,4-benzenediamine. diamines having at least one nitrogen atom-containing structure (hereinafter also referred to as specific nitrogen atom-containing structure) selected from the group consisting of a nitrogen atom-containing heterocycle, a secondary amino group, and a tertiary amino group, typified by diamines having any of the diphenylamine structures (provided that the molecule does not contain an amino group bonded to a protecting group that is eliminated by heating and replaced with a hydrogen atom); 2,4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4,6-diaminoresorcinol, 4,4'-diamino-3,3'-dihydroxybiphenyl;2,4-diaminobenzoic acid, 2,5-diaminobenzoic acid, 3,5-diaminobenzoic acid, 4,4'-diaminobiphenyl-3-carboxylic acid, 4,4'-diaminodiphenylmethane-3-carboxylic acid, 1,2-bis(4-aminophenyl)ethane-3-carboxylic acid, 4,4'-diaminobiphenyl-3,3'-dicarboxylic acid, 4,4'-diaminobiphenyl-2,2'-dicarboxylic acid, 3,3'-diaminobiphenyl-4,4'-dicarboxylic acid, 3,3'-diaminobiphenyl Diamines having a carboxy group such as phenyl-2,4'-dicarboxylic acid, 4,4'-diaminodiphenylmethane-3,3'-dicarboxylic acid, 1,2-bis(4-aminophenyl)ethane-3,3'-dicarboxylic acid, 4,4'-diaminodiphenylether-3,3'-dicarboxylic acid; 4-(2-(methylamino)ethyl)aniline, 4-(2-aminoethyl)aniline, 1-(4-aminophenyl)-1,3,3-trimethyl-1H-indan-5-amine, 1 -(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-inden-6-amine; diamines having the group "-N(D)-" (D represents a protecting group which is eliminated by heating and replaced with a hydrogen atom, preferably a carbamate protecting group, more preferably a tert-butoxycarbonyl group, except for the above-mentioned specific diamines) such as those of the following formulas (5-1) to (5-6), cholestanyloxy-3,5-diaminobenzene, cholestanyloxy-3, Diamines having a steroid skeleton such as 5-diaminobenzene, cholestanyloxy-2,4-diaminobenzene, cholestanyl 3,5-diaminobenzoate, cholestenyl 3,5-diaminobenzoate, lanostannyl 3,5-diaminobenzoate, and 3,6-bis(4-aminobenzoyloxy)cholestane, diamines represented by the following formulas (V-1) to (V-2), and diamines having a siloxane bond such as 1,3-bis(3-aminopropyl)-tetramethyldisiloxane.Metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, 1,3-bis(aminomethyl)cyclohexane, 1,4-diaminocyclohexane, 4,4'-methylenebis(cyclohexylamine), diamines in which two amino groups are bonded to a group represented by any one of formulas (Y-1) to (Y-167) described in WO2018 / 117239, and the like;

[0028] (Ar １ , and Ar １’ each independently represents a benzene ring, a biphenyl structure, or a naphthalene ring, and one or more hydrogen atoms on the benzene ring, the biphenyl structure, or the naphthalene ring may be substituted with a monovalent group. １ and L １’ each independently represents a single bond, —O—, —C(═O)—, —C(═O)—O—, or —O—C(═O)—. A is —CH ２ A represents an alkylene group having 2 to 12 carbon atoms, or a divalent organic group in which at least one of -O-, -C(=O)-O-, and -O-C(=O)- is inserted between the carbon-carbon bond of the alkylene group. Any hydrogen atom possessed by A may be substituted with a halogen atom. One or more hydrogen atoms on the benzene ring, biphenyl structure, or naphthalene ring may be substituted with a monovalent group, and examples of the monovalent group include a halogen atom, an alkyl group having 1 to 3 carbon atoms, an alkenyl group having 2 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a fluoroalkyl group having 1 to 3 carbon atoms, a fluoroalkenyl group having 2 to 3 carbon atoms, a fluoroalkoxy group having 1 to 3 carbon atoms, an alkyloxycarbonyl group having 2 to 3 carbon atoms, a cyano group, and a nitro group. (Formula (d ＡＬ In formula (d-6), the sum of m1, m2 and n is 3 to 12. ＡＬ -8) The sum of m1, m2 and n is 3 to 12.

[0029]

[0030]

[0031]

[0032] In the formula (V-1), m and n each independently represent an integer of 0 to 3, and satisfy the relationship 1≦m+n≦4. j represents an integer of 0 or 1. X １ is -(CH ２ ) ａ -(a is an integer of 1 to 15), -CONH-, -NHCO-, -CO-N(CH ３ )-, -NH-, -O-, -CH ２ O-, -CH ２ represents —OCO—, —COO—, or —OCO—. １ represents a monovalent group such as a fluorine atom, a fluorine atom-containing alkyl group having 1 to 10 carbon atoms, a fluorine atom-containing alkoxy group having 1 to 10 carbon atoms, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or an alkoxyalkyl group having 2 to 10 carbon atoms. ２ is -O-, -CH ２ O-, -CH ２ m, n, and X represent —OCO—, —COO—, or —OCO—. １ , R １ When two occur, each independently has the above definition.

[0033] When other diamines are used in addition to the diamine (0), the amount of the other diamines used is preferably 10 to 90 mol %, more preferably 20 to 80 mol %, based on the total diamine components used. Various other diamines can be used depending on the purpose. For example, from the viewpoint of improving voltage retention characteristics when used as a liquid crystal alignment film, at least one diamine selected from the group consisting of diamines having at least one group selected from the group consisting of a urea bond, an amide bond, a carboxy group, and a hydroxy group in the molecule, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, and the diamines having the specific nitrogen atom-containing structure is preferred. The amount of the other diamines used is preferably 10 to 90 mol %, more preferably 20 to 80 mol %, based on the total diamine components used in the production of the polymer (P).

[0034] (Tetracarboxylic Acid Component) When producing the polyamic acid (P′), the tetracarboxylic acid component to be reacted with the diamine component may be not only a tetracarboxylic acid dianhydride, but also a derivative of a tetracarboxylic acid dianhydride such as a tetracarboxylic acid, a tetracarboxylic acid dihalide, a tetracarboxylic acid dialkyl ester, or a tetracarboxylic acid dialkyl ester dihalide.

[0035] The tetracarboxylic acid dianhydride or derivative thereof may be an acyclic aliphatic tetracarboxylic acid dianhydride, an alicyclic tetracarboxylic acid dianhydride, an aromatic tetracarboxylic acid dianhydride, or a derivative thereof. Among these, a tetracarboxylic acid dianhydride having at least one partial structure selected from the group consisting of a benzene ring, a cyclobutane ring, a cyclopentane ring, and a cyclohexane ring, or a derivative thereof, is more preferred. A tetracarboxylic acid dianhydride having at least one structure selected from the group consisting of a cyclobutane ring, a cyclopentane ring, and a cyclohexane ring, or a derivative thereof, is particularly preferred.

[0036] Here, the acyclic aliphatic tetracarboxylic acid dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxy groups bonded to a chain hydrocarbon structure. However, it does not need to be composed solely of a chain hydrocarbon structure, and it may have an alicyclic structure or an aromatic ring structure as part of it. The alicyclic tetracarboxylic acid dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxy groups, including at least one carboxy group bonded to the alicyclic structure. However, none of these four carboxy groups are bonded to an aromatic ring. Furthermore, it does not need to be composed solely of an alicyclic structure, and it may have a chain hydrocarbon structure or an aromatic ring structure as part of it. The aromatic tetracarboxylic acid dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxy groups, including at least one carboxy group bonded to an aromatic ring. However, it does not need to be composed solely of an aromatic ring structure, and it may have a chain hydrocarbon structure or an alicyclic structure as part of it.

[0037] The tetracarboxylic acid component that can be used to produce the polyamic acid (P') preferably contains the following tetracarboxylic dianhydrides or derivatives thereof (in the present invention, these are also collectively referred to as specific tetracarboxylic acid derivatives): acyclic aliphatic tetracarboxylic acid dianhydrides such as 1,2,3,4-butanetetracarboxylic acid dianhydride; 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-dichloro-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-difluoro-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-bis(trifluoromethyl)-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,3,4-cyclopentanetetracarboxylic acid dianhydride, 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride, 3,3',4,4'-di ... 2,3,5-Tricarboxycyclopentylacetic dianhydride, 4-(2,5-dioxotetrahydrofuran-3-yl)tetrahydronaphthalene-1,2-dicarboxylic anhydride, 5-(2,5-dioxotetrahydrofuran-3-yl)-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 5-(2,5-dioxotetrahydrofuran-3-yl)- alicyclic tetracarboxylic acid dianhydrides such as 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-dianhydride, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic acid dianhydride, and 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-dianhydride;Pyromellitic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3',4,4'-diphenylethertetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 4,4'-bis(3,4- Aromatic tetracarboxylic acid dianhydrides such as 4,4'-(dicarboxyphenoxy)-2,2-diphenylpropane dianhydride, ethylene glycol bisanhydrotrimellitate, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 4,4'-carbonyldiphthalic anhydride, 4,4'-(1,4-phenylenedioxy)bis(phthalic anhydride), and 4,4'-(1,4-phenylenedimethylene)bis(phthalic anhydride); and also tetracarboxylic acid dianhydrides such as those described in JP 2010-97188 A.

[0038] Preferred examples of the specific tetracarboxylic acid derivatives include 1,2,3,4-butanetetracarboxylic acid dianhydride, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-difluoro ... 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-bis(trifluoromethyl)-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,3,4-cyclopentanetetracarboxylic acid dianhydride, 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride, 3,3',4,4'-dicyclohexyltetracarboxylic acid dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 5-(2,5-dioxo-1,2,3,4-cyclopentanetetracarboxylic acid dianhydride, 5-(2,5-dioxotetrahydrofuran-3-yl)-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 5-(2,5-dioxotetrahydrofuran-3-yl)-8-methyl-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-dianhydride, pyromellitic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3',4,4'-diphenylethertetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, or derivatives thereof.

[0039] The proportion of the specific tetracarboxylic acid derivative used is preferably 10 mol % or more, more preferably 20 mol % or more, and even more preferably 50 mol % or more, based on the total tetracarboxylic acid components used.

[0040] (Liquid Crystal Aligning Agent) The liquid crystal aligning agent of the present invention is a liquid composition obtained by dispersing or dissolving the polymer (P) and other components used as necessary, preferably in a suitable solvent. The total content of the polymers contained in the liquid crystal aligning agent of the present invention can be appropriately changed depending on the thickness of the coating film to be formed, but is preferably 1% by mass or more from the viewpoint of forming a uniform and defect-free coating film, and is preferably 10% by mass or less from the viewpoint of storage stability of the solution. A particularly preferred total polymer content is 2 to 8% by mass. The content of the polymer (P) used in the present invention is preferably 1 to 100% by mass, more preferably 10 to 100% by mass, and particularly preferably 20 to 100% by mass, based on the total polymers contained in the liquid crystal aligning agent.

[0041] The liquid crystal aligning agent of the present invention may contain other polymers other than the polymer (P). Specific examples of other polymers include, in addition to the polymer (P), at least one polymer selected from the group consisting of a polyimide precursor obtained using a diamine component not containing the specific diamine and a polyimide which is an imidized product of the polyimide precursor (also referred to as polymer (B) in the present invention), polysiloxane, polyester, polyamide, polyurea, polyorganosiloxane, cellulose derivative, polyacetal, polystyrene derivative, poly(styrene-maleic anhydride) copolymer, poly(isobutylene-maleic anhydride) copolymer, poly(vinyl ether-maleic anhydride) copolymer, poly(styrene-phenylmaleimide) derivative, and a polymer selected from the group consisting of poly(meth)acrylate.

[0042] Specific examples of poly(styrene-maleic anhydride) copolymers include SMA1000, SMA2000, and SMA3000 (manufactured by Cray Valley Corporation), and GSM301 (manufactured by Gifu Ceramics Manufacturing Co., Ltd.), and a specific example of poly(isobutylene-maleic anhydride) copolymers includes ISOBAM-600 (manufactured by Kuraray Co., Ltd.). A specific example of poly(vinyl ether-maleic anhydride) copolymers includes Gantrez AN-139 (methyl vinyl ether maleic anhydride resin, manufactured by Ashland Corporation). Of these, polymer (B) is more preferred from the viewpoints of maintaining the voltage holding ratio and reducing residual DC-induced image retention. The above other polymers may be used alone or in combination of two or more. The content of the other polymers is preferably 90 parts by mass or less, more preferably 10 to 90 parts by mass, and even more preferably 20 to 80 parts by mass, relative to 100 parts by mass of the total of the polymers contained in the liquid crystal aligning agent.

[0043] (Polymer (B)) Specific examples of the tetracarboxylic acid component used in the production of the polymer (B) include the same compounds as those exemplified for the polymer (P), including preferred specific examples. The tetracarboxylic acid component used in the production of the polymer (B) more preferably contains a tetracarboxylic acid dianhydride or a derivative thereof having at least one partial structure selected from the group consisting of a benzene ring, a cyclobutane ring, a cyclopentane ring, and a cyclohexane ring, and the specific tetracarboxylic acid derivatives described above are even more preferred. It is most preferred to use the more preferred specific examples of the specific tetracarboxylic acid derivatives described above. From the viewpoint of optimally achieving the effects of the present invention, the tetracarboxylic acid component used in the production of the polymer (B) is preferably an acyclic aliphatic tetracarboxylic acid dianhydride, an alicyclic tetracarboxylic acid dianhydride, or a derivative thereof. The amount of the specific tetracarboxylic acid derivative used is preferably 10 mol % or more, more preferably 20 mol % or more, and even more preferably 50 mol % or more, based on the total tetracarboxylic acid components used in the production of the polymer (B).

[0044] Examples of the diamine component for obtaining the polymer (B) include the diamines exemplified for the polymer (P) above. Among them, from the viewpoint of enhancing the liquid crystal alignment, the diamine component for obtaining the polymer (B) includes p-phenylenediamine, 2,3,5,6-tetramethyl-p-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, m-phenylenediamine, 2,4-dimethyl-m-phenylenediamine, 2,5-diaminotoluene, 2,6-diaminotoluene, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, and the like. nyl, 3,3'-dihydroxy-4,4'-diaminobiphenyl, 2,2'-difluoro-4,4'-diaminobiphenyl, 3,3'-difluoro-4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 3,3'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 3,4'-diaminobiphenyl, 4,4'-diaminobiphenyl, 3,3'-diaminobiphenyl, 2,2'-diaminobiphenyl, 2,3'-diaminobiphenyl, ＡＬ ) or a diamine having a tetracarboxylic acid diimide structure other than the specific diamines (hereinafter, these may be collectively referred to as diamine (c)). ＡＬ ) is a diamine represented by the above formula (d ＡＬ -1) to (d ＡＬ-10), 1,7-bis(4-aminophenoxy)heptane, 1,7-bis(3-aminophenoxy)heptane, 1,8-bis(4-aminophenoxy)octane, 1,8-bis(3-aminophenoxy)octane, 1,9-bis(4-aminophenoxy)nonane, 1,9-bis(3-aminophenoxy)nonane, 1,10-bis(4-aminophenoxy)decane, 1,10-bis(3-aminophenoxy) The diamine component may be decane, 1,11-bis(4-aminophenoxy)undecane, 1,11-bis(3-aminophenoxy)undecane, 1,12-bis(4-aminophenoxy)dodecane, 1,12-bis(3-aminophenoxy)dodecane, 1,2-bis(6-amino-2-naphthyloxy)ethane, 1,2-bis(6-amino-2-naphthyl)ethane, or 6-[2-(4-aminophenoxy)ethoxy]-2-naphthylamine. The diamine component may be a single diamine or a combination of two or more diamines. When the diamine (c) is used, the amount used is preferably 10 mol % or more, and more preferably 20 mol % or more, of the total diamine components used in the production of the polymer (B). When a diamine other than the diamine (c) is used, the amount used is preferably 90 mol % or less, more preferably 80 mol % or less, of the total diamine components used in the production of the polymer (B).

[0045] (Production of Polyamic Acid) Polyamic acid is produced by reacting a diamine component and a tetracarboxylic acid component in an organic solvent. The ratio of the tetracarboxylic acid component and the diamine component used in the polyamic acid production reaction is preferably such that 1 equivalent of the amino group of the diamine component corresponds to 0.5 to 2 equivalents of the acid anhydride group of the tetracarboxylic acid component, more preferably 0.8 to 1.2 equivalents. As with a typical polycondensation reaction, the closer the equivalent of the acid anhydride group of the tetracarboxylic acid component is to 1 equivalent, the higher the molecular weight of the resulting polyamic acid. The reaction temperature in the production of polyamic acid is preferably −20 to 150°C, more preferably 0 to 100°C. The reaction time is preferably 0.1 to 24 hours, more preferably 0.5 to 12 hours. Polyamic acid can be produced at any concentration, but the polyamic acid concentration is preferably 1 to 50% by mass, more preferably 5 to 30% by mass. The reaction can be carried out at a high concentration initially, with subsequent addition of solvent.

[0046] Specific examples of the organic solvent include cyclohexanone, cyclopentanone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, and 1,3-dimethyl-2-imidazolidinone. Furthermore, when the polymer has high solvent solubility, solvents such as methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, diethylene glycol monomethyl ether, and diethylene glycol monoethyl ether can be used.

[0047] (Production of Polyamic Acid Ester) The polyamic acid ester can be obtained by known methods such as [I] a method of reacting the polyamic acid obtained by the above method with an esterifying agent, [II] a method of reacting a tetracarboxylic acid diester with a diamine, or [III] a method of reacting a tetracarboxylic acid diester dihalide with a diamine.

[0048] (Production of Polyimide) Polyimide can be obtained by ring-closing (imidizing) a polyimide precursor such as the polyamic acid or polyamic acid ester. The imidization ratio in this specification refers to the ratio of imide groups to the total amount of imide groups derived from tetracarboxylic dianhydride or its derivatives and carboxyl groups (or their derivatives). The imidization ratio does not necessarily have to be 100% and can be adjusted as desired depending on the application and purpose.

[0049] Methods for imidizing the polyimide precursor include thermal imidization, in which a solution of the polyimide precursor is heated as is, and catalytic imidization, in which a catalyst is added to a solution of the polyimide precursor. When thermally imidizing the polyimide precursor in solution, the temperature is preferably 100 to 400°C, more preferably 120 to 250°C, and it is preferable to carry out the thermal imidization while removing water produced by the imidization reaction from the system.

[0050] Catalytic imidization of polyimide precursors can be carried out by adding a basic catalyst and an acid anhydride to a solution of the polyimide precursor and stirring the mixture at preferably -20 to 250°C, more preferably 0 to 180°C. The amount of the basic catalyst is preferably 0.5 to 30 times, more preferably 2 to 20 times, the molar ratio of the amic acid groups, and the amount of the acid anhydride is preferably 1 to 50 times, more preferably 3 to 30 times, the molar ratio of the amic acid groups. Examples of basic catalysts include pyridine, triethylamine, trimethylamine, tributylamine, and trioctylamine. Of these, pyridine is preferred because it has adequate basicity for promoting the reaction. Examples of acid anhydrides include acetic anhydride, trimellitic anhydride, and pyromellitic anhydride. Of these, acetic anhydride is preferred because it facilitates purification after the reaction. The imidization rate by catalytic imidization can be controlled by adjusting the catalyst amount, reaction temperature, and reaction time.

[0051] When recovering the produced polyimide precursor or polyimide from a reaction solution of a polyimide precursor or polyimide, the reaction solution may be precipitated by pouring the reaction solution into a solvent. Examples of solvents used for precipitation include methanol, ethanol, isopropyl alcohol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, toluene, benzene, and water. The polymer precipitated by pouring into the solvent can be recovered by filtration and then dried at room temperature or by heating under atmospheric or reduced pressure. Furthermore, the recovered polymer can be redissolved in an organic solvent and reprecipitated and recovered 2 to 10 times to reduce the amount of impurities in the polymer. Examples of solvents used in this process include alcohols, ketones, and hydrocarbons. Using three or more solvents selected from these solvents is preferred because it further increases the efficiency of purification.

[0052] When producing the polyimide precursor or polyimide of the present invention, a terminal-capped polymer may be produced using a tetracarboxylic acid component containing a tetracarboxylic dianhydride or a derivative thereof, a diamine component containing the above-mentioned diamine, and an appropriate terminal-capping agent. Terminal-capped polymers have the effect of improving the film hardness of the alignment film obtained by coating and improving the adhesion properties between the sealing agent and the alignment film. Examples of terminal groups of the polyimide precursor or polyimide of the present invention include amino groups, carboxy groups, acid anhydride groups, and groups derived from terminal-capping agents described below. The amino groups, carboxy groups, and acid anhydride groups can be obtained by a conventional condensation reaction or by terminal-capping with the following terminal-capping agents.

[0053] Examples of the end-capping agent include acid anhydrides such as acetic anhydride, maleic anhydride, nadic anhydride, phthalic anhydride, itaconic anhydride, 1,2-cyclohexanedicarboxylic anhydride, 3-hydroxyphthalic anhydride, trimellitic anhydride, 3-(3-trimethoxysilyl)propyl)-3,4-dihydrofuran-2,5-dione, 4,5,6,7-tetrafluoroisobenzofuran-1,3-dione, and 4-ethynylphthalic anhydride; dicarbonate diester compounds such as di-tert-butyl dicarbonate and diallyl dicarbonate; chlorocarbonyl compounds such as acryloyl chloride, methacryloyl chloride, and nicotinic acid chloride; Examples of suitable end-capping agents include monoamine compounds such as aniline, 2-aminophenol, 3-aminophenol, 4-aminosalicylic acid, 5-aminosalicylic acid, 6-aminosalicylic acid, 2-aminobenzoic acid, 3-aminobenzoic acid, 4-aminobenzoic acid, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, and n-octylamine; and isocyanates having unsaturated bonds such as ethyl isocyanate, phenyl isocyanate, naphthyl isocyanate, or 2-acryloyloxyethyl isocyanate and 2-methacryloyloxyethyl isocyanate. The proportion of the end-capping agent used is preferably 0.01 to 20 parts by mole, and more preferably 0.01 to 10 parts by mole, per 100 parts by mole of the total of the diamine components used.

[0054] The polystyrene-equivalent weight average molecular weight (Mw) of the polyimide precursor and polyimide measured by gel permeation chromatography (GPC) is preferably 1,000 to 500,000, more preferably 2,000 to 300,000. The molecular weight distribution (Mw / Mn), expressed as the ratio of Mw to the polystyrene-equivalent number average molecular weight (Mn) measured by GPC, is preferably 15 or less, more preferably 10 or less. Having the molecular weight within this range ensures good alignment in liquid crystal display elements.

[0055] The organic solvent contained in the liquid crystal aligning agent according to the present invention is not particularly limited as long as it can uniformly dissolve the polymer (P) and other polymers added as needed. Examples of the organic solvent include N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethyllactamide, N,N-dimethylpropionamide, tetramethylurea, N,N-diethylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethyl sulfoxide, γ-butyrolactone, γ-valerolactone, 1,3-dimethyl-2-imidazolidinone, methyl ethyl ketone, cyclohexanone, cyclopentanone, 3-methoxy-N,N-dimethylpropanamide, and the like. Examples of suitable solvents include 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, and N-cyclohexyl-2-pyrrolidone (collectively referred to as "good solvents"). Among these, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 3-methoxy-N,N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropanamide, and γ-butyrolactone are preferred. The content of the good solvent is preferably 20 to 99% by mass, more preferably 20 to 90% by mass, and particularly preferably 30 to 80% by mass of the total solvent contained in the liquid crystal aligning agent.

[0056] Furthermore, the organic solvent contained in the liquid crystal aligning agent is preferably a mixed solvent containing, in addition to the above solvent, a solvent (also referred to as a poor solvent) that improves the coatability and surface smoothness of the coating film when the liquid crystal aligning agent is applied. Specific examples of poor solvents are listed below, but are not limited to these. The content of the poor solvent is preferably 1 to 80 mass %, more preferably 10 to 80 mass %, and particularly preferably 20 to 70 mass %, of the total solvent contained in the liquid crystal aligning agent. The type and content of the poor solvent are appropriately selected depending on the coater, coating conditions, coating environment, etc. of the liquid crystal aligning agent.

[0057] Examples of poor solvents include diisopropyl ether, diisobutyl ether, diisobutyl carbinol (2,6-dimethyl-4-heptanol), ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, 1,2-dibutoxyethane, 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 monoisoamyl ether, ethylene glycol monohexyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, 1-(2-butoxyethoxy)-2-propanol ethanol, 2-(2-butoxyethoxy)-1-propanol, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, ethylene glycol monobutyl ether acetate, diethylene glycol monopropyl ether, 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, cyclohexyl acetate, 4-methyl-2-pentyl 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), and the like.

[0058] Of these, diisobutyl carbinol, 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 is preferred.

[0059] Preferred solvent combinations of a good solvent and a poor solvent include N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone and ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone and propylene glycol monobutyl ether, N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether, N-ethyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone, and N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether. Coal diacetate, N,N-dimethyl lactamide and diisobutyl ketone, N-methyl-2-pyrrolidone and ethyl 3-ethoxypropionate, N-ethyl-2-pyrrolidone and ethyl 3-ethoxypropionate, N-methyl-2-pyrrolidone, ethyl 3-ethoxypropionate and dipropylene glycol monomethyl ether, N-ethyl-2-pyrrolidone, ethyl 3-ethoxypropionate and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone, ethyl 3-ethoxypropionate and diethylene glycol mono propyl ether, N-ethyl-2-pyrrolidone, ethyl 3-ethoxypropionate, and diethylene glycol monopropyl ether, N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether acetate, N-ethyl-2-pyrrolidone and dipropylene glycol dimethyl ether, N,N-dimethyl lactamide and ethylene glycol monobutyl ether, N,N-dimethyl lactamide and propylene glycol diacetate, N-ethyl-2-pyrrolidone and diethylene glycol diethyl ether, N-ethyl-2 -pyrrolidone, diethylene glycol monoethyl ether, and butyl cellosolve acetate, N-methyl-2-pyrrolidone, diethylene glycol monomethyl ether, and butyl cellosolve acetate, N,N-dimethyl lactamide and diethylene glycol diethyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone, 4-hydroxy-4-methyl-2-pentanone, and diethylene glycol diethyl ether, N-ethyl-2-pyrrolidone, N-methyl-2-pyrrolidone, and 4-hydroxy-4-methyl-2-pentanone,N-ethyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone, and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone, and diisobutyl ketone, N-methyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone, and dipropylene glycol monomethyl ether, N-methyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone, and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone, and dipropylene glycol monomethyl ether Methyl-2-pentanone and propylene glycol diacetate, N-ethyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone and dipropylene glycol dimethyl ether, γ-butyrolactone, 4-hydroxy-4-methyl-2-pentanone and diisobutyl ketone, γ-butyrolactone, 4-hydroxy-4-methyl-2-pentanone and propylene glycol diacetate, N-methyl-2-pyrrolidone, γ-butyrolactone, propylene glycol monobutyl ether and diisobutyl ketone, N-methyl-2-pi rolidone, γ-butyrolactone, propylene glycol monobutyl ether, and diisopropyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone, propylene glycol monobutyl ether, and diisobutylcarbinol, N-methyl-2-pyrrolidone, γ-butyrolactone, and dipropylene glycol dimethyl ether, N-methyl-2-pyrrolidone, propylene glycol monobutyl ether, and dipropylene glycol dimethyl ether, N-ethyl-2-pyrrolidone, propylene glycol monobutyl ether, and dipropylene glycol pyrene glycol monomethyl ether, N-ethyl-2-pyrrolidone, diethylene glycol diethyl ether, and dipropylene glycol monomethyl ether, N-ethyl-2-pyrrolidone, propylene glycol monobutyl ether, and propylene glycol diacetate, N-ethyl-2-pyrrolidone, propylene glycol monobutyl ether, and diisobutyl ketone, N-ethyl-2-pyrrolidone, γ-butyrolactone, and diisobutyl ketone, N-ethyl-2-pyrrolidone, N,N-dimethyl lactamide, and diisobutyl ketone,Examples include N-methyl-2-pyrrolidone, ethylene glycol monobutyl ether, and ethylene glycol monobutyl ether acetate, γ-butyrolactone, ethylene glycol monobutyl ether acetate, and dipropylene glycol dimethyl ether, N-ethyl-2-pyrrolidone, ethylene glycol monobutyl ether acetate, and propylene glycol dimethyl ether, N-methyl-2-pyrrolidone, 4-methyl-2-pentyl acetate, and ethylene glycol monobutyl ether, N-ethyl-2-pyrrolidone, cyclohexyl acetate, and 4-hydroxy-4-methyl-2-pentanone, cyclohexanone, and propylene glycol monomethyl ether, cyclopentanone, and propylene glycol monomethyl ether, and N-methyl-2-pyrrolidone, cyclohexanone, and propylene glycol monomethyl ether.

[0060] (Additives) In addition to the polymer (P), the other polymers, and the organic solvent, the liquid crystal aligning agent of the present invention may contain other components (hereinafter also referred to as additive components). Examples of such additive components include at least one crosslinking compound selected from the group consisting of a crosslinking compound (c-1) having at least one substituent selected from an oxiranyl group, an oxetanyl group, a blocked isocyanate group, an oxazoline group, a cyclocarbonate group, a hydroxy group, and an alkoxy group, and a crosslinking compound (c-2) having a polymerizable unsaturated group, a functional silane compound, a metal chelate compound, a curing accelerator, a surfactant, an antioxidant, a sensitizer, a preservative, a compound for adjusting the dielectric constant or electrical resistance of the resulting liquid crystal alignment film, and a compound for promoting imidization.

[0061] Preferred specific examples of the crosslinkable compounds (c-1) and (c-2) include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, dibromoneopentyl glycol diglycidyl ether, 1,3,5, 6-tetraglycidyl-2,4-hexanediol, bisphenol A type epoxy resins such as Epicoat 828 (manufactured by Mitsubishi Chemical Corporation), bisphenol F type epoxy resins such as Epicoat 807 (manufactured by Mitsubishi Chemical Corporation), hydrogenated bisphenol A type epoxy resins such as YX-8000 (manufactured by Mitsubishi Chemical Corporation), biphenyl skeleton-containing epoxy resins such as YX6954BH30 (manufactured by Mitsubishi Chemical Corporation), phenol novolac type epoxy resins such as EPPN-201 (manufactured by Nippon Kayaku Co., Ltd.), (o,m) epoxy resins such as EOCN-102S (manufactured by Nippon Kayaku Co., Ltd.), ,p-)cresol novolac epoxy resins, triglycidyl isocyanurates such as TEPIC (manufactured by Nissan Chemical Industries, Ltd.), alicyclic epoxy resins such as Celloxide 2021P (manufactured by Daicel Corporation), compounds containing a tertiary nitrogen atom such as N,N,N',N'-tetraglycidyl-m-xylylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, or N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, and oxy groups such as tetrakis(glycidyloxymethyl)methane. compounds having two or more ranyl groups; compounds having two or more oxetanyl groups described in paragraphs

[0170] to

[0175] of WO 2011 / 132751; compounds having two or more blocked isocyanate groups such as Coronate AP Stable M, Coronate 2503, 2515, 2507, 2513, 2555, Millionate MS-50 (all manufactured by Tosoh Corporation), and Takenate B-830, B-815N, B-820NSU, B-842N, B-846N, B-870N, B-874N, and B-882N (all manufactured by Mitsui Chemicals, Inc.);Compounds having an oxazoline group such as 2,2'-bis(2-oxazoline), 2,2'-bis(4-methyl-2-oxazoline), 2,2'-bis(5-methyl-2-oxazoline), 1,2,4-tris(2-oxazolinyl)-benzene, and EPOCROS (manufactured by Nippon Shokubai Co., Ltd.); compounds having a cyclocarbonate group described in paragraphs

[0025] to

[0030] and

[0032] of WO2011 / 155577; N,N,N',N'-tetrakis(2-hydroxyethyl)adipamide, 2,2-bis(4-hydroxy-3,5-dihydroxymethylphenyl)propane, 2,2-bis(4-hydroxy-3,5-dimethoxyphenyl)propane, 2,2-bis(4-hydroxy-3,5-dihydro and compounds having a hydroxy group or an alkoxy group, such as (hydroxymethylphenyl)-1,1,1,3,3,3-hexafluoropropane; and compounds represented by the formula: glycerin mono(meth)acrylate, glycerin di(meth)acrylate (1,2-,1,3-diglycerolate di(meth)acrylate, pentaerythritol tri(meth)acrylate, diethylene glycol mono(meth)acrylate, triethylene glycol mono(meth)acrylate, tetraethylene glycol mono(meth)acrylate, pentaethylene glycol mono(meth)acrylate, and hexaethylene glycol mono(meth)acrylate. The content of the crosslinkable compounds (c-1) and (c-2) contained in the liquid crystal aligning agent of the present invention is preferably 0.1 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, and even more preferably 5 to 20 parts by mass, per 100 parts by mass of the polymer component contained in the liquid crystal aligning agent. ;

[0062] Examples of the compound for adjusting the dielectric constant or electrical resistance include monoamines having a nitrogen atom-containing aromatic heterocycle such as 3-picolylamine. The content of the monoamine having a nitrogen atom-containing aromatic heterocycle is preferably 0.1 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, per 100 parts by mass of the polymer component contained in the liquid crystal aligning agent.

[0063] Specific preferred examples of the functional silane compound include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyldiethoxymethylsilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and 3-glycidoxypropylmethyldimethoxysilane. Examples of the functional silane compound include 3-(2-methyl-2-methylpropyl)isocyanurate, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, tris(3-trimethoxysilylpropyl)isocyanurate, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-isocyanatopropyltriethoxysilane. The content of the functional silane compound is preferably 0.1 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, per 100 parts by mass of the polymer component contained in the liquid crystal alignment agent.

[0064] The compound for promoting the imidization is preferably a compound having a basic site (e.g., a primary amino group, an aliphatic heterocycle (e.g., a pyrrolidine skeleton), an aromatic heterocycle (e.g., an imidazole ring, an indole ring), or a guanidino group) (excluding the crosslinkable compound and the adhesion aid), or a compound that generates the basic site upon baking. A more preferred example is a compound that generates the basic site upon baking, and preferred specific examples include amino acids in which some or all of the basic sites of the amino acid are protected. Examples of protecting groups for the basic sites of the amino acids include carbamate protecting groups such as a Boc group. Specific examples of the amino acids include glycine, alanine, cysteine, methionine, asparagine, glutamine, valine, leucine, phenylalanine, tyrosine, tryptophan, proline, hydroxyproline, arginine, histidine, lysine, and ornithine. A more preferred specific example of the compound for promoting imidization is N-α-(9-fluorenylmethoxycarbonyl)-N-τ-(tert-butoxycarbonyl)-L-histidine. The content of the compound for promoting imidization contained in the liquid crystal aligning agent of the present invention is preferably 0.1 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, and even more preferably 5 to 20 parts by mass, relative to 100 parts by mass of the polymer component contained in the liquid crystal aligning agent.

[0065] The solids concentration in the liquid crystal aligning agent (the ratio of the total mass of the components other than the solvent of the liquid crystal aligning agent to the total mass of the liquid crystal aligning agent) is appropriately selected taking into consideration viscosity, volatility, etc., but is preferably 1 to 10% by mass. A particularly preferred range of solids concentration varies depending on the method used to apply the liquid crystal aligning agent to the substrate. For example, when using a spin coating method, a solids concentration of 1.5 to 4.5% by mass is particularly preferred. When using a printing method, a solids concentration of 3 to 9% by mass is particularly preferred, thereby resulting in a solution viscosity of 12 to 50 mPa·s. When using an inkjet method, a solids concentration of 1 to 5% by mass is particularly preferred, thereby resulting in a solution viscosity of 3 to 15 mPa·s. The temperature when preparing the polymer composition is preferably 10 to 50°C, more preferably 20 to 30°C.

[0066] (Liquid crystal alignment film and liquid crystal display element) The liquid crystal display element according to the present invention comprises a liquid crystal alignment film formed using the liquid crystal alignment agent. The operation mode of the liquid crystal display element is not particularly limited, and it can be applied to various operation modes, such as TN type, STN type, vertical alignment type (including VA-MVA type, VA-PVA type, etc.), in-plane switching type (IPS type, FFS type), optically compensated bend type (OCB type), etc.

[0067] The liquid crystal display element of the present invention can be produced, for example, by a method including the following steps (1) to (4), a method including steps (1) to (2) and (4), a method including steps (1) to (3), (4-2) and (4-4), or a method including steps (1) to (3), (4-3) and (4-4).

[0068] <Step (1): Applying a Liquid Crystal Alignment Agent to a Substrate> Step (1) is a step of applying a liquid crystal alignment agent to a substrate. A specific example of step (1) is as follows: The liquid crystal alignment agent is applied to one side of a substrate having a patterned transparent conductive film by an appropriate application method, such as a roll coater method, a spin coat method, a printing method, or an inkjet method. The substrate material is not particularly limited as long as it is highly transparent; glass, silicon nitride, and plastics such as acrylic and polycarbonate can also be used. In addition, in a reflective liquid crystal display element, an opaque material such as a silicon wafer can be used for only one substrate, and in this case, a light-reflecting material such as aluminum can also be used for the electrode. Furthermore, when manufacturing an IPS-type or FFS-type liquid crystal display element, a substrate having an electrode made of a comb-shaped patterned transparent conductive film or metal film and an opposing substrate having no electrode are used. An IPS substrate, which is a comb electrode substrate used in an IPS-type liquid crystal display element, has, for example, a base material, a plurality of linear electrodes formed on the base material and arranged in a comb-teeth pattern, and a liquid crystal alignment film formed on the base material so as to cover the linear electrodes. Meanwhile, an FFS substrate, which is a comb electrode substrate used in an FFS-type liquid crystal display element, has, for example, a base material, a surface electrode formed on the base material, an insulating film formed on the surface electrode, a plurality of linear electrodes formed on the insulating film and arranged in a comb-teeth pattern, and a liquid crystal alignment film formed on the insulating film so as to cover the linear electrodes.

[0069] Examples of a method for applying the liquid crystal alignment agent to a substrate and forming a film include screen printing, offset printing, flexographic printing, an inkjet method, and a spray method. Among these, the application and film formation method by the inkjet method is preferably used.

[0070] <Step (2): Step of Baking the Applied Liquid Crystal Alignment Agent> Step (2) is a step of baking the liquid crystal alignment agent applied to the substrate to form a film. Specific examples of step (2) are as follows. After applying the liquid crystal alignment agent to the substrate in step (1), the solvent can be evaporated or the polyamic acid can be thermally imidized using a heating means such as a hot plate, a hot air circulation oven, or an IR (infrared) oven. The drying and baking steps after applying the liquid crystal alignment agent can be performed at any temperature and for any time, and may be performed multiple times. The temperature for baking the liquid crystal alignment agent can be, for example, 40 to 180°C. From the perspective of shortening the process, it may also be performed at 40 to 150°C. The baking time is not particularly limited, but may be 1 to 10 minutes or 1 to 5 minutes. When thermally imidizing the polyamic acid, a baking step at, for example, 150 to 300°C or 150 to 250°C may be added after the above step. The baking time is not particularly limited, but may be 5 to 40 minutes or 5 to 30 minutes. If the thickness of the film-like substance after baking is too thin, the reliability of the liquid crystal display element may decrease, so the thickness is preferably 5 to 300 nm, more preferably 10 to 200 nm.

[0071] <Step (3): Alignment Treatment of the Film Obtained in Step (2)> Step (3) is a step of optionally aligning the film obtained in Step (2). That is, in horizontal alignment type liquid crystal display devices such as IPS mode or FFS mode, the coating film is subjected to an alignment ability imparting treatment. On the other hand, in vertical alignment type liquid crystal display devices such as VA mode or PSA mode, the formed coating film can be used as a liquid crystal alignment film as is, or the coating film may be subjected to an alignment ability imparting treatment. Alignment treatment methods for liquid crystal alignment films include rubbing alignment treatment and photo-alignment treatment. Photo-alignment treatment methods include irradiating the surface of the film-like material with polarized radiation in a certain direction and, optionally, performing a heat treatment at a temperature preferably between 150 and 250°C to impart liquid crystal alignment (also referred to as liquid crystal alignment ability). The radiation can be ultraviolet light or visible light having a wavelength of 100 to 800 nm. Among these, ultraviolet light having a wavelength of 100 to 400 nm is preferred, and more preferably between 200 and 400 nm.

[0072] The radiation dose is 1 to 10,000 mJ / cm ２ is preferable, and among these, 100 to 5,000 mJ / cm ２ In addition, 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 alignment. The liquid crystal alignment film prepared in this manner can stably align liquid crystal molecules in a certain direction.

[0073] Furthermore, the coating film irradiated with polarized radiation or the coating film subjected to rubbing alignment treatment by the above method may be subjected to a contact treatment using water or a solvent. Furthermore, the film subjected to the above alignment treatment may be subjected to a heat treatment without being subjected to a contact treatment. Furthermore, the film subjected to the above contact treatment may be further subjected to a heat treatment.

[0074] The solvent used in the contact treatment is not particularly limited as long as it dissolves the decomposition products generated from the film-like material by 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, and cyclohexyl acetate. The solvent may be used alone or in combination of two or more.

[0075] The temperature for the heat treatment of the coating film irradiated with the radiation is more preferably 50 to 300° C., and even more preferably 120 to 250° C. The heat treatment time is preferably 1 to 30 minutes.

[0076] <Step (4): Step of preparing a liquid crystal cell> Two substrates on which a liquid crystal alignment film has been formed are prepared as described above, and a liquid crystal is placed between the two substrates arranged opposite each other. Specifically, the following two methods can be mentioned. In the first method, the two substrates are first arranged opposite each other with a gap (cell gap) between them so that the liquid crystal alignment films face each other. Next, the peripheries of the two substrates are bonded together using a sealant, and a liquid crystal composition is injected into the substrate surfaces and the cell gap defined by the sealant to contact the film surface, and then the injection hole is sealed.

[0077] The second method is called the ODF (One Drop Fill) method. A UV-curable sealant, for example, is applied to a predetermined location on one of two substrates on which a liquid crystal alignment film has been formed, and a liquid crystal composition is then dropped onto several predetermined locations on the liquid crystal alignment film. The other substrate is then attached so that the liquid crystal alignment film faces the other substrate, and the liquid crystal composition is spread over the entire surface of the substrate and brought into contact with the film surface. The entire surface of the substrate is then irradiated with UV light to cure the sealant. In either method, it is desirable to further heat the substrate to a temperature at which the liquid crystal composition assumes an isotropic phase and then slowly cool it to room temperature to remove flow alignment that occurs during liquid crystal filling. If the coating film is subjected to a rubbing alignment treatment, the two substrates are positioned opposite each other so that the rubbing directions of the coating films are at a predetermined angle to each other, for example, perpendicular or antiparallel. For example, an epoxy resin containing a curing agent and aluminum oxide spheres as spacers can be used as the sealant. The liquid crystal composition is not particularly limited, and may be a composition containing at least one liquid crystal compound (liquid crystal molecule), such as a liquid crystal composition exhibiting a nematic phase (hereinafter also referred to as nematic liquid crystal), a liquid crystal exhibiting a smectic phase, or a liquid crystal composition exhibiting a cholesteric phase. Of these, nematic liquid crystal is preferred. Furthermore, various liquid crystal compositions having positive or negative dielectric anisotropy may be used. Hereinafter, a liquid crystal composition having positive dielectric anisotropy is also referred to as positive liquid crystal, and a liquid crystal composition having negative dielectric anisotropy is also referred to as negative liquid crystal. The liquid crystal composition may contain a liquid crystal compound having a fluorine atom, a hydroxy group, an amino group, a fluorine atom-containing group (e.g., a trifluoromethyl group), a cyano group, an alkyl group, an alkoxy group, an alkenyl group, an isothiocyanate group, a heterocycle, a cycloalkane, a cycloalkene, a steroid skeleton, a benzene ring, or a naphthalene ring, or may contain a compound having two or more rigid moieties (mesogenic skeletons) that exhibit liquid crystallinity in the molecule (e.g., a bimesogenic compound in which two rigid biphenyl structures or terphenyl structures are linked by an alkyl group). Furthermore, the liquid crystal composition may further contain an additive from the viewpoint of improving liquid crystal alignment properties.Such additives include photopolymerizable monomers such as compounds having a polymerizable group; optically active compounds (e.g., S-811 manufactured by Merck Co., Ltd.); antioxidants; ultraviolet absorbers; dyes; antifoaming agents; polymerization initiators; or polymerization inhibitors. Examples of positive-type liquid crystals include ZLI-2293, ZLI-4792, MLC-2003, MLC-2041, MLC-3019, and MLC-7081 manufactured by Merck Co., Ltd. Examples of negative-type liquid crystals include MLC-6608, MLC-6609, MLC-6610, MLC-7026, and MLC-7026-100 manufactured by Merck Co., Ltd. Examples of liquid crystals containing a compound having a polymerizable group include MLC-3023 manufactured by Merck Co., Ltd.

[0078] The liquid crystal aligning agent of the present invention is also preferably used in a liquid crystal display element (PSA-type liquid crystal display element) manufactured by a process of: having a liquid crystal layer between a pair of substrates equipped with electrodes, disposing a liquid crystal composition containing a polymerizable compound that polymerizes by at least one of active energy rays and heat between the pair of substrates, and polymerizing the polymerizable compound by at least one of irradiation with active energy rays and heating while applying a voltage between the electrodes. The liquid crystal aligning agent of the present invention is also preferably used in a liquid crystal display element (SC-PVA-mode liquid crystal display element) manufactured by a process of having a liquid crystal layer between a pair of substrates equipped with electrodes, disposing a liquid crystal alignment film containing a polymerizable group that polymerizes by at least one of active energy rays and heat between the pair of substrates, and applying a voltage between the electrodes.

[0079] <Step (4-2): In the case of a PSA-type liquid crystal display element> This step is carried out in the same manner as in the above step (4), except that a liquid crystal composition containing a polymerizable compound is injected or dropped. Examples of the polymerizable compound include polymerizable compounds having one or more polymerizable unsaturated groups, such as an acrylate group or a methacrylate group, in the molecule.

[0080] <Step (4-3): For SC-PVA Mode Liquid Crystal Display Elements> A method for producing a liquid crystal display element may be employed, following the procedure described above in (4), followed by a step of irradiating with ultraviolet light, as described below. This method, similar to the production of the PSA mode liquid crystal display element, allows for the production of a liquid crystal display element with excellent response speed with a low light exposure dose. The compound having a polymerizable group may be a compound having one or more of the above-described polymerizable unsaturated groups in the molecule, and the content thereof is preferably 0.1 to 30 parts by mass, more preferably 1 to 20 parts by mass, per 100 parts by mass of all polymer components. Furthermore, the polymerizable group may be contained in a polymer used in a liquid crystal aligning agent. Examples of such polymers include polymers obtained by reacting a diamine component containing a diamine having the above-described photopolymerizable group at its terminal.

[0081] <Step (4-4): Step of Irradiating Ultraviolet Light> The liquid crystal cell is irradiated with light while a voltage is applied between the conductive films of the pair of substrates obtained in step (4-2) or (4-3) above. The voltage applied here can be, for example, a direct current or alternating current of 5 to 50 V. The light to be irradiated can be, for example, ultraviolet light and visible light containing light with a wavelength of 150 to 800 nm, but ultraviolet light containing light with a wavelength of 300 to 400 nm is preferred. The light source for the irradiation light can be, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, or an excimer laser. The light irradiation dose is preferably 1,000 to 200,000 J / m ２ and more preferably 1,000 to 100,000 J / m ２ is.

[0082] A liquid crystal display element can be obtained by attaching a polarizing plate to the outer surface of the liquid crystal cell as needed. Examples of the polarizing plate to be attached to the outer surface of the liquid crystal cell include a polarizing film called an "H film" made by stretching and aligning polyvinyl alcohol and absorbing iodine, sandwiched between cellulose acetate protective films, and a polarizing plate made of the H film itself.

[0083] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. The abbreviations of the compounds used and the methods for measuring the physical properties are as follows:

[0084] (Tetracarboxylic acid dianhydrides) CA-1 to CA-6: Compounds represented by the following formulas (CA-1) to (CA-6), respectively

[0085] (Specific diamine) DA-W1 to DA-W6: Compounds represented by the following formulas (DA-W1) to (DA-W6), respectively (the compounds represented by the following formulas (DA-W1) to (DA-W6) are the compounds represented by the above formula (d Ａ -1) to (d Ａ -6) is the same as the diamine represented by

[0086] (Other diamines) DA-1 to DA-9: Compounds represented by the following formulas (DA-1) to (DA-9), respectively.

[0087] (Additives) AD-1 to AD-3: Compounds represented by the following formulas (AD-1) to (AD-3), respectively

[0088] (Solvent) NMP: N-methyl-2-pyrrolidone GBL: γ-butyrolactone BCS: ethylene glycol monobutyl ether AcOEt: ethyl acetate MeCN: acetonitrile THF: tetrahydrofuran CHCl ３ : Chloroform

[0089] [Measurement of Viscosity] Measurement was carried out at 25°C using an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.) with a sample volume of 1.1 mL and a cone rotor TE-1 (1°34', R24).

[0090] [Measurement of Molecular Weight] Measurement was carried out using the following room temperature GPC (gel permeation chromatography) device, and the molecular weight was calculated as a polyethylene glycol or polyethylene oxide equivalent value. GPC apparatus: SSC-7200 (manufactured by Senshu Scientific Co., Ltd.), column: GPC KD-803, GPC KD-805 (manufactured by Showa Denko K.K.) in series, column temperature: 50 ° C., eluent: N,N-dimethylformamide (additives: lithium bromide monohydrate (LiBr HO) 30 mmol / L, phosphoric acid anhydrous crystal (o-phosphoric acid) 30 mmol / L, tetrahydrofuran (THF) 10 mL / L), flow rate: 1.0 mL / min. Standard sample for preparing calibration curve: TSK standard polyethylene oxide (molecular weight: approximately 900,000, 150,000, 100,000 and 30,000) (manufactured by Tosoh Corporation) and polyethylene glycol (molecular weight: approximately 12,000, 4,000 and 1,000) (manufactured by Polymer Laboratory Co., Ltd.).

[0091] [Synthesis of Monomers] DA-W1 to DA-W6 are novel compounds not previously disclosed in literature, and their synthesis methods are described in detail below.

[0092] < １ H-NMR Measurement> Apparatus: Fourier transform superconducting nuclear magnetic resonance spectrometer (FT-NMR) "AVANCE III" (manufactured by BRUKER) 500 MHz Solvent: Deuterated N,N-dimethyl sulfoxide ([D ６ ]-DMSO) Standard substance: tetramethylsilane (TMS)

[0093] Example 1-1 Synthesis of [DA-W1]

[0094] 4-(4-tert-butoxycarbonylaminophenylamino)aniline (37.6 g, 126 mmol) and NMP (380 g) were added to a 1 L four-neck flask, followed by the addition of CA-3 (18.5 g, 63.0 mmol) in a water bath, followed by stirring at room temperature to allow the reaction to proceed. After confirming the disappearance of the amino groups by NMR, the reaction solution was poured into AcOEt (2000 g), and the organic layer was washed with purified water (1000 g) and concentrated. Pyridine (28.8 g, 364 mmol), acetic anhydride (18.6 g, 182 mmol), and NMP (500 g) were added to the obtained crude product, followed by stirring at 60°C to allow the reaction to proceed. After completion of the reaction, the reaction solution was poured into purified water (2500 g), and the precipitate was filtered off. MeCN (800 g) was added to the obtained crude product, and the mixture was repulped and washed at room temperature. Further, THF (700 g) was added to the crude product to completely dissolve it, and then the mixture was concentrated until precipitation occurred. AcOEt (300 g) was added, and the mixture was repulped and washed at room temperature to obtain [DA-W1-1] (42.7 g, 49.8 mmol, yield: 79%).

[0095] [DA-W1-1] (39.7 g, 46.3 mmol), 12 N hydrochloric acid (6.8 g), and AcOEt (1190 g) were added to a 2 L four-neck flask, and the mixture was stirred at 60°C to react. After completion of the reaction, the precipitate was filtered off, and MeCN (500 g) was added to the obtained crude product, and the mixture was neutralized with triethylamine until basic, and the precipitate was filtered off. DMF (90 g) was added to the obtained crude product and completely dissolved, and then MeCN (600 g) was added to precipitate a solid. The precipitate was filtered off, and MeCN (600 g) was added again to the crude product, and the mixture was repulped and washed at 80°C to obtain the target [DA-W1] (brown solid) (30.4 g, 46.3 mmol, yield: 100%). １ The results of H-NMR are shown below, and it was confirmed that the obtained solid was the target [DA-W1]. １ H-NMR (500MHz, [D ６ ]-DMSO): δ (ppm) = 8.33-8.36 (m, 4H), 8.04-8.06 (d, 2H), 7.76 (s, 2H), 7.13-7.15 (d, 4H), 6.85-6.90 (m, 8H), 6.58-6.59 (d, 4H), 4.90 (s, 4H).

[0096] Example 1-2: Synthesis of [DA-W2]

[0097] 4,4'-Diaminodiphenyl-N-methylamine (128 g, 600 mmol) and THF (1900 g) were added to a 3 L four-neck flask, and then di-tert-butyl dicarbonate (43.7 g, 200 mmol) was added dropwise in a water bath and the mixture was stirred at room temperature to allow the reaction to proceed. After completion of the reaction, the reaction solution was concentrated, and the resulting residue was isolated by silica gel column chromatography (ethyl acetate:hexane = 1:1 (volume ratio)) to obtain [DA-W2-1] (55.5 g, 177 mmol, yield: 89%).

[0098] [DA-W2-1] (55.5 g, 177 mmol) and NMP (550 g) were added to a 1 L four-neck flask, followed by the addition of CA-3 (26.0 g, 89 mmol) in a water bath and stirring at room temperature to allow the reaction to proceed. After confirming the disappearance of the amino group by NMR, pyridine (42.0 g, 531 mmol) and acetic anhydride (27.1 g, 266 mmol) were added to the reaction solution, followed by stirring at 60 ° C. The reaction was allowed to proceed. After completion of the reaction, the reaction solution was poured into pure water (2500 g), and the precipitate was filtered off. AcOEt (1000 g) was added to the obtained crude product, which was then repulped and washed at 70 ° C. to obtain [DA-W2-2] (36.3 g, 41.0 mmol, yield: 92%).

[0099] [DA-W2-2] (36.3 g, 41.0 mmol), 12 N hydrochloric acid (16.7 g), and AcOEt (720 g) were added to a 3 L four-neck flask, and the mixture was stirred at 70°C to react. After completion of the reaction, the precipitate was filtered off, and MeCN (600 g) was added to the obtained crude product, and the mixture was neutralized with triethylamine until basic, and the precipitate was filtered off. NMP (60 g) was added to the obtained crude product, and the mixture was completely dissolved, and then poured into MeCN (800 g). The precipitate was filtered off, and MeCN (300 g) was added again to the crude product, and the mixture was repulped and washed at 80°C to obtain the target [DA-W2] (brown solid) (25.8 g, 37.7 mmol, yield: 92%). １ The results of H-NMR are shown below, and it was confirmed that the obtained solid was the target [DA-W2]. １H-NMR (500MHz, [D ６ ]-DMSO): δ (ppm) = 8.33-8.36 (m, 4H), 8.04-8.05 (d, 2H), 7.15-7.17 (d, 4H), 6.9 0-6.92 (d, 4H), 6.68-6.70 (d, 4H), 6.62-6.64 (d, 4H), 5.08 (s, 4H), 3.19 (s, 6H).

[0100] Example 1-3: Synthesis of [DA-W3]

[0101] 4-(4-tert-butoxycarbonylaminophenylamino)aniline (29.9 g, 100 mmol) and NMP (300 g) were added to a 500 mL four-neck flask, followed by the addition of CA-6 (9.82 g, 45.0 mmol) in a water bath and stirring at room temperature to allow the reaction to proceed. After confirming the disappearance of the amino groups by NMR, the reaction solution was poured into AcOEt (1000 g), and the organic layer was washed with purified water (1000 g) and concentrated. Pyridine (21.4 g, 270 mmol), acetic anhydride (13.8 g, 135 mmol), and NMP (370 g) were added to the resulting crude product, followed by stirring at 60°C to allow the reaction to proceed. After completion of the reaction, the reaction solution was poured into MeCN (2000 g), and the precipitate was filtered off. MeCN (500 g) was added to the obtained precipitate, and the mixture was repulped and washed at 70° C. to obtain [DA-W3-1] (29.9 g, 38.3 mmol, yield: 85%).

[0102] [DA-W3-1] (29.9 g, 38.3 mmol), 12N hydrochloric acid (15.0 g), and AcOEt (600 g) were added to a 2 L four-neck flask, and the mixture was stirred at 60°C to react. After the reaction was completed, the precipitate was filtered off, and NMP (500 g) was added to the obtained crude product, and the mixture was neutralized with triethylamine until basic, and the precipitate was filtered off. MeCN (2500 g) was added to the obtained crude product, and the mixture was repulped and washed at room temperature to obtain the target [DA-W3] (dark brown solid) (17.3 g, 29.8 mmol, yield: 78%). １ The results of H-NMR are shown below, and it was confirmed that the obtained solid was the target [DA-W3]. １ H-NMR (500MHz, [D ６]-DMSO): δ (ppm) = 8.28 (s, 2H), 7.78 (s, 2H), 7.16-7.18 (d, 4H), 6.84-6.90 (m, 8H), 6.57-6.59 (d, 4H), 4.84 (s, 4H).

[0103] Example 1-4: Synthesis of [DA-W4]

[0104] [DA-W2-1] (22.1 g, 70.5 mmol) and NMP (220 g) were added to a 500 mL four-neck flask, followed by the addition of CA-6 (7.70 g, 35.3 mmol) in a water bath and stirring at room temperature to allow the reaction to proceed. After confirming the disappearance of the amino group by NMR, pyridine (16.7 g, 211 mmol) and acetic anhydride (10.7 g, 106 mmol) were added to the reaction solution, followed by stirring at 50 ° C. The reaction was allowed to proceed. After completion of the reaction, the reaction solution was poured into pure water (1500 g), and the precipitate was filtered off. MeCN (500 g) was added to the obtained crude product, and the mixture was repulped and washed at 70 ° C. to obtain [DA-W4-1] (24.5 g, 30.3 mmol, yield: 86%).

[0105] In a 500 mL four-neck flask, [DA-W4-1] (24.5 g, 30.3 mmol), trifluoroacetic acid (34.2 g, 300 mmol), and CHCl ３ (250 g) was added, and the mixture was stirred at 50°C to react. After completion of the reaction, the reaction solution was poured into hexane (250 g), and the precipitate was filtered off. THF (450 g) was added to the obtained crude product, and the mixture was neutralized with triethylamine until it became basic, and the precipitate was filtered off. THF (450 g) was added to the obtained crude product, and the mixture was repulped and washed at 60°C to obtain the target [DA-W4] (brown solid) (17.6 g, 28.9 mmol, yield: 95%). １ The results of H-NMR are shown below, and it was confirmed that the obtained solid was the target [DA-W4]. １ H-NMR (500MHz, [D ６ ]-DMSO): δ (ppm) = 8.27 (s, 2H), 7.18-7.19 (d, 4H), 6.90-6.92 (d, 4H), 6.68-6.70 (d, 4H), 6.62-6.64 (d, 4H), 5.09 (s, 4H), 3.31 (s, 6H).

[0106] Example 1-5: Synthesis of [DA-W5]

[0107] 4-(4-tert-butoxycarbonylaminophenylamino)aniline (12.0 g, 40.0 mmol) and NMP (120 g) were added to a 1 L four-neck flask, followed by the addition of CA-5 (6.44 g, 20.0 mmol) in a water bath, and the mixture was stirred and reacted at room temperature. After confirming the disappearance of the amino groups by NMR, the reaction solution was poured into AcOEt (600 g), and the organic layer was washed with purified water (400 g) and concentrated. Pyridine (9.5 g, 120 mmol), acetic anhydride (6.1 g, 60 mmol), and NMP (180 g) were added to the obtained crude product, and the mixture was stirred and reacted at 60°C. After completion of the reaction, the reaction solution was poured into MeCN (1000 g), and the precipitate was filtered off. MeCN (500 g) was added to the obtained precipitate, and the mixture was repulped and washed at room temperature to obtain [DA-W5-1] (15.8 g, 17.9 mmol, yield: 90%).

[0108] [DA-W5-1] (15.8 g, 17.9 mmol), 12 N hydrochloric acid (7.0 g), and AcOEt (320 g) were added to a 1 L four-neck flask, and the mixture was stirred at 70°C to react. After completion of the reaction, the precipitate was filtered off, and MeCN (400 g) was added to the obtained crude product, and the mixture was neutralized with triethylamine until basic, and the precipitate was filtered off. NMP (150 g) was added to the obtained crude product, and after complete dissolution, MeCN (400 g) was added. The precipitate was filtered off, and MeCN (250 g) was added again to the crude product, and the mixture was repulped and washed at 80°C to obtain the target [DA-W5] (reddish purple solid) (11.5 g, 16.8 mmol, yield: 94%). １ The results of H-NMR are shown below, and it was confirmed that the obtained solid was the target [DA-W5]. １ H-NMR (500MHz, [D ６ ]-DMSO): δ (ppm) = 8.23-8.25 (m, 2H), 8.13-8.14 (m, 4H), 7.76 (s, 2H), 7.13-7.15 (d, 4H), 6.84-6.89 (m, 8H), 6.57-6.59 (d, 4H), 4.89 (s, 4H).

[0109] Example 1-6: Synthesis of [DA-W6]

[0110] [DA-W2-1] (11.5 g, 36.7 mmol) and NMP (120 g) were added to a 300 mL four-neck flask, followed by the addition of CA-5 (5.9.0 g, 18.3 mmol) in a water bath, and the mixture was stirred and reacted at room temperature. After confirming the disappearance of the amino group by NMR, the reaction solution was poured into AcOEt (500 g), and the organic layer was washed with pure water (400 g) and concentrated. Pyridine (8.70 g, 110 mmol), acetic anhydride (5.60 g, 55.3 mmol), and NMP (180 g) were added to the obtained crude product, and the mixture was stirred and reacted at 60 °C. After completion of the reaction, the reaction solution was poured into pure water (600 g), and the precipitate was filtered off. MeCN (500 g) was added to the obtained crude product, and the mixture was repulped and washed at room temperature to obtain [DA-W6-1] (16.1 g, 17.6 mmol, yield: 96%).

[0111] [DA-W6-1] (16.1 g, 17.6 mmol), 12 N hydrochloric acid (29.7 g), and AcOEt (320 g) were added to a 3 L four-neck flask, and the mixture was stirred at 70°C to react. After completion of the reaction, the precipitate was filtered off, and MeCN (700 g) was added to the obtained crude product, and the mixture was neutralized with triethylamine until basic, and the precipitate was filtered off. NMP (60 g) was added to the obtained crude product, and the mixture was completely dissolved, and then poured into MeCN (360 g). The precipitate was filtered off, and MeCN (100 g) was added again to the crude product, and the mixture was repulped and washed at 80°C to obtain the target [DA-W6] (brown solid) (5.5 g, 7.72 mmol, yield: 44%). １ The results of H-NMR are shown below, and it was confirmed that the obtained solid was the target [DA-W6]. １ H-NMR (500MHz, [D ６ ]-DMSO): δ (ppm) = 8.22-8.24 (d, 2H), 8.12-8.14 (m, 4H), 7.15-7.17 (d, 4H), 6.9 0-6.91 (d, 4H), 6.68-6.70 (d, 4H), 6.61-6.63 (d, 4H), 5.09 (s, 4H), 3.19 (s, 6H).

[0112] [Synthesis of Polymer] Example 2-1 DA-W1 (2.56 g, 3.90 mmol), DA-4 (0.626 g, 2.10 mmol), and NMP (28.7 g) were added to a 50 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and the mixture was stirred at room temperature while supplying nitrogen to dissolve. Thereafter, CA-1 (0.977 g, 4.98 mmol) and NMP (1.85 g) were added, and the mixture was stirred at room temperature for 2 hours to obtain a solution of polyamic acid (PAA-A1) with a solids concentration of 12% by mass (viscosity: 563 mPa s).

[0113] Example 2-2 DA-W1 (2.15 g, 3.28 mmol), DA-4 (0.734 g, 2.46 mmol), DA-8 (1.04 g, 2.46 mmol), and NMP (35.3 g) were added to a 50 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and the mixture was stirred at room temperature while supplying nitrogen to dissolve the mixture. Thereafter, CA-1 (1.42 g, 7.23 mmol) and NMP (3.86 g) were added, and the mixture was stirred at room temperature for 2 hours to obtain a solution of polyamic acid (PAA-A2) with a solids concentration of 12% by mass (viscosity: 402 mPa s).

[0114] Example 2-3 DA-W1 (2.99 g, 4.55 mmol), DA-4 (0.731 g, 2.45 mmol), and NMP (27.3 g) were added to a 50 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and dissolved by stirring at room temperature while feeding nitrogen. Thereafter, CA-1 (0.153 g, 0.781 mmol) and NMP (1.13 g) were added, and the mixture was stirred at room temperature for 1 hour. Thereafter, CA-2 (1.31 g, 5.25 mmol) and NMP (9.63 g) were added, and the mixture was stirred at 50°C for 12 hours to obtain a solution of polyamic acid (PAA-A3) with a solids concentration of 12% by mass (viscosity: 396 mPa s).

[0115] Example 2-4 DA-W2 (2.67 g, 3.90 mmol), DA-4 (0.627 g, 2.10 mmol), and NMP (30.1 g) were added to a 50 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and the mixture was stirred at room temperature while supplying nitrogen to dissolve the mixture. Thereafter, CA-1 (1.06 g, 5.40 mmol) and NMP (2.26 g) were added, and the mixture was stirred at room temperature for 2 hours to obtain a solution of polyamic acid (PAA-A4) with a solids concentration of 12% by mass (viscosity: 411 mPa s).

[0116] Example 2-5 DA-W2 (2.25 g, 3.28 mmol), DA-4 (0.734 g, 2.46 mmol), DA-8 (1.04 g, 2.46 mmol), and NMP (36.2 g) were added to a 50 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and the mixture was stirred at room temperature while supplying nitrogen to dissolve the mixture. Thereafter, CA-1 (1.50 g, 7.67 mmol) and NMP (4.33 g) were added, and the mixture was stirred at room temperature for 2 hours to obtain a solution of polyamic acid (PAA-A5) with a solids concentration of 12% by mass (viscosity: 396 mPa s).

[0117] Example 2-6 DA-W3 (1.89 g, 3.25 mmol), DA-4 (0.522 g, 1.75 mmol), and NMP (25.9 g) were added to a 50 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and dissolved by stirring at room temperature while supplying nitrogen. Thereafter, CA-1 (0.804 g, 4.10 mmol) and NMP (2.99 g) were added, and the mixture was stirred at room temperature for 2 hours to obtain a solution of polyamic acid (PAA-A6) with a solids concentration of 10% by mass (viscosity: 237 mPa s).

[0118] Example 2-7 DA-W4 (2.37 g, 3.90 mmol), DA-4 (0.627 g, 2.10 mmol), and NMP (27.0 g) were added to a 50 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and the mixture was stirred at room temperature while supplying nitrogen to dissolve the mixture. Thereafter, CA-1 (1.02 g, 5.22 mmol) and NMP (2.49 g) were added, and the mixture was stirred at room temperature for 2 hours to obtain a solution of polyamic acid (PAA-A7) with a solids concentration of 12% by mass (viscosity: 413 mPa s).

[0119] <Comparative Example 2-1> DA-7 (3.79 g, 19.0 mmol), DA-4 (1.42 g, 4.76 mmol), and NMP (46.9 g) were added to a 50 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and the mixture was dissolved by stirring at room temperature while feeding nitrogen. Thereafter, CA-3 (2.80 g, 9.52 mmol) and NMP (11.9 g) were added, and the mixture was stirred at 70 ° C. for 4 hours. Thereafter, CA-1 (2.52 g, 12.8 mmol) and NMP (18.5 g) were added, and the mixture was stirred at room temperature for 2 hours to obtain a solution of polyamic acid (PAA-B1) having a solids concentration of 12% by mass (viscosity: 423 mPa s).

[0120] <Comparative Example 2-2> DA-7 (2.85 g, 14.3 mmol), DA-4 (1.42 g, 4.76 mmol), DA-8 (2.01 g, 4.76 mmol) and NMP (56.5 g) were added to a 50 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and the mixture was stirred at room temperature while feeding nitrogen to dissolve. Thereafter, CA-3 (2.80 g, 9.52 mmol) and NMP (10.1 g) were added, and the mixture was stirred at 70 ° C. for 4 hours. Thereafter, CA-1 (2.58 g, 13.2 mmol) and NMP (18.9 g) were added, and the mixture was stirred at room temperature for 2 hours to obtain a solution of polyamic acid (PAA-B2) with a solids concentration of 12% by mass (viscosity: 378 mPa s).

[0121] Comparative Example 2-3: DA-7 (3.79 g, 19.0 mmol), DA-4 (1.42 g, 4.76 mmol), and NMP (46.9 g) were added to a 50 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and the mixture was stirred at room temperature while supplying nitrogen to dissolve the mixture. Thereafter, CA-3 (2.80 g, 9.52 mmol) and NMP (11.9 g) were added, and the mixture was stirred at 70 ° C. for 4 hours. Thereafter, CA-1 (0.513 g, 2.62 mmol) and NMP (3.76 g) were added, and the mixture was stirred at room temperature for 1 hour. Thereafter, CA-2 (2.68 g, 10.7 mmol) and NMP (19.6 g) were added, and the mixture was stirred at 50 ° C. for 12 hours to obtain a solution of polyamic acid (PAA-B3) with a solids concentration of 12% by mass (viscosity: 410 mPa s).

[0122] Preparation Example 2-1: DA-1 (0.540 g, 4.99 mmol), DA-2 (1.83 g, 7.49 mmol), DA-3 (2.40 g, 7.49 mmol), DA-5 (1.99 g, 4.99 mmol), and NMP (68.4 g) were added to a 50 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and the mixture was stirred at room temperature while supplying nitrogen to dissolve. Thereafter, CA-4 (5.31 g, 23.7 mmol) and NMP (20.1 g) were added, and the mixture was stirred at 50° C. for 12 hours to obtain a solution of polyamic acid (PAA-U1) having a solids concentration of 12% by mass (viscosity: 402 mPa s).

[0123] Preparation Example 2-2: DA-1 (1.62 g, 15.0 mmol), DA-2 (2.20 g, 9.01 mmol), DA-6 (2.04 g, 5.97 mmol), and NMP (59.3 g) were added to a 100 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and the mixture was stirred at room temperature while supplying nitrogen to dissolve. Thereafter, CA-4 (6.32 g, 28.2 mmol) and NMP (30.0 g) were added, and the mixture was stirred at 40° C. for 3 hours to obtain a solution of polyamic acid (PAA-U2) with a solids concentration of 12% by mass (viscosity: 220 mPa s).

[0124] Preparation Example 2-3 DA-7 (4.78 g, 24.0 mmol), DA-4 (2.39 g, 8.01 mmol), DA-8 (3.37 g, 7.99 mmol), and NMP (77.3 g) were added to a 100 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and the mixture was stirred at room temperature while supplying nitrogen to dissolve. Thereafter, CA-3 (11.3 g, 38.4 mmol) and NMP (82.9 g) were added, and the mixture was stirred at 70°C for 24 hours to obtain a solution of polyamic acid (PAA-C1) with a solids concentration of 12% by mass.

[0125] Preparation Example 2-4 DA-7 (2.55 g, 12.8 mmol), DA-9 (0.487 g, 3.20 mmol), and NMP (22.3 g) were added to a 50 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and the mixture was stirred at room temperature while supplying nitrogen to dissolve. Thereafter, CA-3 (4.50 g, 15.3 mmol) and NMP (20.5 g) were added, and the mixture was stirred at 50° C. for 16 hours to obtain a solution of polyamic acid (PAA-C2) with a solids concentration of 15% by mass (viscosity: 350 mPa s).

[0126] The specifications of the polyamic acids obtained in the above synthesis examples are shown in Table 1. In the table, the numbers in parentheses for the tetracarboxylic acid component and diamine component represent the amount (parts by mole) of each tetracarboxylic acid component or each diamine used per 100 parts by mole of the total amount of diamine components used in the polymerization.

[0127]

[0128] Here, the specific diamine DA-W1 has a structure obtained by reacting one molecule of tetracarboxylic dianhydride CA-3 with two molecules of diamine DA-7, and the synthesis of polyamic acid PAA-A1 in Example 2-1 corresponds to a reaction using monomer components containing 4.98 mmol of CA-1, 3.90 mmol of CA-3, 7.80 mmol of DA-7, and 2.10 mmol of DA-4. In the above monomer components, if the total of DA-4 and DA-7 is 100 parts by mole, the molar ratio of each monomer component is 50 parts by mole of CA-1, 39 parts by mole of CA-3, 79 parts by mole of DA-7, and 21 parts by mole of DA-4, which is approximately the same monomer composition as polyamic acid PAA-B1 in Comparative Example 2-1. On the other hand, the polyamic acid PAA-A1 of Example 2-1 is a polymer having imide structures and in which the imide structures are located adjacent to each other, whereas the polyamic acid PAA-B1 of Comparative Example 2-1 is a polymer having only amic acid structures, and the resulting liquid crystal alignment films have different properties as described below. Similarly, the polyamic acids PAA-A2 to PAA-A3 have monomer compositions almost identical to those of the polyamic acids PAA-B2 to PAA-B3, respectively.

[0129] [Preparation of liquid crystal aligning agent] <Example 3-1> Using the solution of polyamic acid (PAA-A1) obtained in Example 2-1, dilute with NMP, GBL and BCS, and stir at room temperature for 2 hours, obtain liquid crystal aligning agent (AL-1) in which the mass ratio of polymer solid content to each solvent (polymer solid content:NMP:GBL:BCS) is 4.5:45.5:30:20.

[0130] <Examples 3-2 to 3-3, Comparative Examples 3-1 to 3-3> As shown in Table 2, the same procedure as in Example 3-1 was carried out except that the polyamic acid used was changed from PAA-A1 to PAA-A2 to PAA-A3, and PAA-B1 to PAA-B3, to obtain liquid crystal aligning agents (AL-2) to (AL-3), (AL-C1) to (AL-C3).

[0131] Example 3-4 The solution of polyamic acid (PAA-U1) obtained in Preparation Example 2-1 and the solution of polyamic acid (PAA-A1) obtained in Example 2-1 were diluted with NMP, GBL, and BCS, and the mixture was stirred at room temperature for 2 hours, thereby obtaining a liquid crystal aligning agent (AL-4) having a polymer solid content ratio (PAA-U1:PAA-A1) of 5:5 and a mass ratio of the total polymer solid content to each solvent (polymer solid content:NMP:GBL:BCS) of 5.5:44.5:30:20.

[0132] <Examples 3-5 to 3-6> As shown in Table 2, the same procedure as in Example 3-4 was carried out except that the polyamic acid used was changed from PAA-A1 to PAA-A2 to PAA-A3, to obtain liquid crystal aligning agents (AL-5) to (AL-6).

[0133] Example 3-7 The solution of polyamic acid (PAA-U1) obtained in Preparation Example 2-1 and the solution of polyamic acid (PAA-A1) obtained in Example 2-1 were diluted with NMP, GBL, and BCS, and AD-1 was further added and stirred at room temperature for 2 hours to obtain a liquid crystal aligning agent (AL-7) in which the polymer solid content ratio (PAA-U1:PAA-A1) was 5:5, the mass ratio of the total polymer solid content to each solvent (polymer solid content:NMP:GBL:BCS) was 5.5:44.5:30:20, and the blending ratio of AD-1 was 5 parts by mass per 100 parts by mass of the total amount of polymer.

[0134] <Examples 3-8 to 3-11, Comparative Example 3-4> As shown in Table 2, the same procedure as in Example 3-7 was carried out except that the polyamic acid used was changed from PAA-A1 to PAA-A2 to PAA-A5 and PAA-C1, to obtain liquid crystal aligning agents (AL-8) to (AL-11) and (AL-C4).

[0135] Comparative Example 3-5 The solution of polyamic acid (PAA-U2) obtained in Preparation Example 2-2 and the solution of polyamic acid (PAA-C2) obtained in Preparation Example 2-4 were diluted with NMP, GBL, and BCS, and AD-1 to AD-3 were further added and stirred at room temperature for 2 hours. A liquid crystal aligning agent (AL-C5) was obtained in which the polymer solid content ratio (PAA-U2:PAA-C2) was 3:7, the mass ratio of the total polymer solid content to each solvent (polymer solid content:NMP:GBL:BCS) was 5.5:44.5:30:20, and the blending ratios of AD-1, AD-2, and AD-3 were 5 parts by mass, 1 part by mass, and 14 parts by mass, respectively, relative to 100 parts by mass of the total amount of the polymer.

[0136]

[0137] In the table, the parenthesized values ​​for polyamic acid represent the content (parts by mass) of each polyamic acid relative to 100 parts by mass of the total amount of polymer contained in each liquid crystal alignment agent. The parenthesized values ​​for additives represent the content (parts by mass) of each additive relative to 100 parts by mass of the total amount of polymer contained in each liquid crystal alignment agent.

[0138] [Fabrication of Liquid Crystal Cell] A liquid crystal cell having the configuration of an FFS-mode liquid crystal display element was fabricated. First, a substrate with electrodes was prepared. The substrate was a rectangular glass substrate measuring 30 mm x 50 mm and 0.7 mm thick. A solid-patterned ITO electrode constituting the counter electrode was formed on the substrate as the first layer. A SiN (silicon nitride) film deposited by CVD (chemical vapor deposition) was formed on the first counter electrode as the second layer. The second SiN film had a thickness of 300 nm and functioned as an interlayer insulating film. A comb-shaped pixel electrode formed by patterning an ITO film was placed on the second SiN film as the third layer, forming two pixels, a first pixel and a second pixel. Each pixel measured 10 mm long and approximately 5 mm wide. The first counter electrode and the third pixel electrode were electrically insulated by the action of the second SiN film. The pixel electrode of the third layer had a comb-like shape in which multiple 3 μm-wide electrode elements, each bent at an interior angle of 160° at the center, were arranged parallel to each other at 6 μm intervals, and each pixel had a first region and a second region, each separated by a line connecting the bent portions of the multiple electrode elements. Next, the liquid crystal alignment agents AL-1 to AL11 and AL-C1 to AL-C5 obtained in Examples 3-1 to 3-11 and Comparative Examples 3-1 to 3-5 were each filtered through a 1.0 μm pore size filter, and then applied by spin coating to the surface of the electrode-attached substrate (first glass substrate) prepared above and the surface of a glass substrate (second glass substrate) having a 4 μm-high columnar spacer and an ITO film formed on its back side. Next, the resulting mixture was dried on a hot plate at 80 ° C for 2 minutes, and then baked in a hot air circulating oven at 230 ° C for 30 minutes to form a coating film with a thickness of 100 nm. On the surface of this coating film, linearly polarized ultraviolet light with a wavelength of 254 nm and an extinction ratio of 26:1 was irradiated at 300 mJ / cm through a polarizing plate. ２The substrate was irradiated with light and subjected to an alignment treatment to obtain a substrate with a liquid crystal alignment film. The liquid crystal alignment film formed on the electrode-attached substrate was aligned so that the direction dividing the interior angle of the pixel bends was perpendicular to the alignment direction of the liquid crystal. The liquid crystal alignment film formed on the second glass substrate was aligned so that the alignment direction of the liquid crystal on the first glass substrate would coincide with the alignment direction of the liquid crystal on the second glass substrate when the liquid crystal cell was fabricated. The two substrates were combined into a pair, and a sealant (Mitsui Chemicals, Inc., XN-1500T) was printed around the periphery, leaving only the liquid crystal injection port. The other substrate was then attached so that the alignment direction of the liquid crystal alignment film faces was 0°. The sealant was then cured to produce an empty cell. Positive liquid crystal MLC-3019 (Merck) was injected into this empty cell by a reduced-pressure injection method, and the injection port was sealed to obtain an FFS-driven liquid crystal cell. The resulting liquid crystal cell was then heated at 110°C for 1 hour and left overnight before being used for evaluation.

[0139] [Evaluation of Voltage Holding Ratio] A voltage of 1 V was applied to the FFS drive liquid crystal cell prepared by the above procedure for 60 μsec at a temperature of 60°C, and the voltage was measured after 1000 msec, and the voltage holding ratio was calculated to indicate how much voltage was held. To measure the voltage holding ratio, a VHR-1 manufactured by Toyo Corporation was used. The higher the voltage holding ratio, the better the result. The results are shown in Table 3.

[0140] [Evaluation of Liquid Crystal Alignment Stability] This evaluation evaluated image retention (also known as AC image retention) caused by a deterioration in the alignment performance of the liquid crystal alignment film during long-term AC driving. An AC voltage of ±4 V at a frequency of 60 Hz was applied to the FFS-driven liquid crystal cell prepared above for 120 hours at a constant temperature of 60°C. The pixel electrode and counter electrode of the liquid crystal cell were then shorted and left at room temperature for one day. For the liquid crystal cells subjected to the above treatment, the deviation in the alignment direction of the liquid crystal in the first region and the second region of the pixel in the no-voltage state was calculated as an angle. Specifically, the liquid crystal cell was placed between two polarizing plates arranged so that their polarization axes were perpendicular to each other. The backlight was turned on, and the liquid crystal cell was adjusted to minimize the transmitted light intensity in the first region of the first pixel. The required rotation angle Δ was then calculated as the angle required to rotate the liquid crystal cell to minimize the transmitted light intensity in the second region of the first pixel. The first and second regions of the second pixel were similarly compared, and the same angle Δ was calculated. The average value of the angles Δ of the first pixel and the second pixel was calculated as the rotation angle Δ of the liquid crystal cell. It can be said that the smaller the value of this rotation angle Δ, the better the stability of the liquid crystal alignment. As an evaluation criterion, when the rotation angle Δ of the liquid crystal cell obtained above was 0.10° or less, it was marked as "○", and when it was greater than 0.10°, it was marked as "×". The results are shown in Table 3.

[0141] [Evaluation of film hardness] The liquid crystal alignment agents AL-7 to AL-11 and AL-C4 to AL-C5 obtained in Examples 3-7 to 3-11 and Comparative Examples 3-4 to 3-5 were each applied to an ITO substrate by spin coating. After drying for 2 minutes on a hot plate at 80°C, the coating was baked for 30 minutes in an IR oven at 230°C to form a coating film with a thickness of 100 nm. Linearly polarized ultraviolet light with a wavelength of 254 nm and an extinction ratio of 26:1 was irradiated on the coating surface through a polarizer at 300 mJ / cm. ２The substrate was irradiated with light to perform an alignment treatment, and then baked in an IR oven at 230°C for 30 minutes to obtain a substrate with a liquid crystal alignment film. The liquid crystal alignment film was then rubbed with a rayon cloth (manufactured by Yoshikawa Chemical Industry Co., Ltd., YA-20R) (roller diameter: 120 mm, roller rotation speed: 1000 rpm, movement speed: 20 mm / sec, indentation length: 0.5 mm), and the haze value (turbidity) of the film was evaluated using a haze meter (manufactured by Suga Test Instruments Co., Ltd., HZ-V3). The smaller the haze value, the less the film was scraped, i.e., the higher the film hardness. As an evaluation criterion, a haze value of 0.20 or less was designated "○", and a value of more than 0.20 was designated "×". The results are shown in Table 3.

[0142] [Evaluation of Molecular Weight Change Before and After Baking] The liquid crystal alignment agents AL-1 to AL-3 and AL-C1 to AL-C3 obtained in Examples 3-1 to 3-3 and Comparative Examples 3-1 to 3-3 above were each applied to an ITO substrate by spin coating. After drying for 2 minutes on a hot plate at 80°C, the coating was baked for 30 minutes in an IR oven at 230°C to form a coating film with a thickness of 100 nm. The baked coating film was scraped off, and the molecular weight was measured. The change in molecular weight before and after baking (weight average molecular weight after baking ÷ weight average molecular weight before baking × 100 [%]) was evaluated. The results are shown in Table 3.

[0143]

[0144] As shown in Table 3, the liquid crystal alignment film obtained from the liquid crystal alignment agent using the diamine component containing the specific diamine exhibited less molecular weight reduction during baking than the liquid crystal alignment film obtained from the liquid crystal alignment agent using the diamine component not containing the specific diamine, and showed a high voltage holding ratio even after prolonged exposure to high temperatures. Furthermore, the liquid crystal alignment film obtained from the liquid crystal alignment agent using the diamine component containing the specific diamine exhibited high liquid crystal alignment stability and high film hardness. Furthermore, when the liquid crystal alignment agent used the polymer (B) obtained from the diamine component not containing the specific diamine in addition to the polymer (P) obtained from the diamine component containing the specific diamine, a further improvement in the voltage holding ratio was observed. (Comparison between Examples 3-1 to 3-3 and Examples 3-4 to 3-6.)

[0145] The entire contents of the specification, claims, drawings and abstract of Japanese Patent Application No. 2022-079186 filed on May 13, 2022 are hereby incorporated by reference as the disclosure of the present invention.

Claims

1. The following formula (d Ａ -1) to (d Ａ A diamine represented by any of the following (-6). 【Chemistry 1】 【Chemistry 2】

2. A polymer selected from the group consisting of a polyimide precursor obtained using a diamine component containing the diamine described in claim 1, and a polyimide which is an imidized product of the polyimide precursor.

3. The polymer according to claim 2, wherein the diamine component further comprises a diamine having at least one group selected from the group consisting of a urea bond, an amide bond, a carboxyl group, and a hydroxyl group in its molecule.

4. The polymer according to claim 2 or 3, wherein the amount of the diamine used according to claim 1 is 5 mol% or more relative to the diamine component.

5. The polymer according to claim 2, wherein the polymer is obtained by a polymerization reaction between the diamine component and the tetracarboxylic acid component, and the tetracarboxylic acid component comprises a tetracarboxylic dianhydride or a derivative thereof.

6. The polymer according to claim 5, wherein the tetracarboxylic dianhydride or its derivative is an acyclic aliphatic tetracarboxylic dianhydride, an alicyclic tetracarboxylic dianhydride, an aromatic tetracarboxylic dianhydride, or a derivative thereof.

7. The tetracarboxylic dianhydride or its derivative is Acyclic aliphatic tetracarboxylic dianhydride that is 1,2,3,4-butanetetracarboxylic dianhydride; 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-dichloro-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-difluoro-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-bis(trifluoromethyl)-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,3,4-cyclopentanetetracarboxylic acid dianhydride, 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride, 3,3',4,4'-dicyclohexyltetracarboxylic acid dianhydride, 2,3,5-tri Carboxycyclopentyl acetate dianhydride, 4-(2,5-dioxotetrahydrofuran-3-yl)tetrahydronaphthalene-1,2-dicarboxylic acid anhydride, 5-(2,5-dioxotetrahydrofuran-3-yl)-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 5-(2,5-dioxotetrahydrofuran-3-yl)-8-methyl-3a,4,5,9 Alicyclic tetracarboxylic dianhydrides selected from β-tetrahydronaphtho[1,2-c]furan-1,3-dione, bicyclo[2.2.2]octa-7-ene-2,3,5,6-tetracarboxylic dianhydride, bicyclo[2.2.2]octane-2,3,5,6-tetracarboxylic dianhydride, and 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-dianhydride; Pyromellitic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic acid dianhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic acid dianhydride, 1,4,5,8-naphthalenetetracarboxylic acid dianhydride, 2,3,6,7-naphthalenetetracarboxylic acid dianhydride, 3,3',4,4'-diphenylethertetracarboxylic acid dianhydride, 3,3',4,4'-biphenyltetracarboxylic acid dianhydride, 2,2',3,3'-biphenyltetracarboxylic acid dianhydride Aromatic tetracarboxylic dianhydrides selected from water, 4,4'-bis(3,4-dicarboxyphenoxy)-2,2-diphenylpropane dianhydride, ethylene glycol bisanhydrotrimellitate, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 4,4'-carbonyldiphthalic anhydride, 4,4'-(1,4-phenylenedioxy)bis(phthalic anhydride), and 4,4'-(1,4-phenylenedimethylene)bis(phthalic anhydride); or These derivatives are polymers according to any one of claims 5 to 6.

8. A liquid crystal alignment agent characterized by containing the polymer described in claim 2.

9. Furthermore, the liquid crystal alignment agent according to claim 8, further comprising at least one polymer (B) selected from the group consisting of a polyimide precursor obtained using a diamine component that does not contain the diamine described in claim 1 and a polyimide which is an imidized product of the polyimide precursor.

10. The liquid crystal aligning agent according to claim 9, wherein the polymer (B) is obtained by a polymerization reaction between the diamine component and the tetracarboxylic acid component, and the tetracarboxylic acid component comprises a tetracarboxylic dianhydride or a derivative thereof.

11. The liquid crystal alignment agent according to claim 8 or 9, further comprising: at least one crosslinkable compound selected from the group consisting of a crosslinkable compound (c-1) having at least one substituent selected from an oxiranyl group, an oxetanyl group, a blocked isocyanate group, an oxazoline group, a cyclocarbonate group, a hydroxyl group, and an alkoxy group, and a crosslinkable compound (c-2) having a polymerizable unsaturated group; a functional silane compound; a metal chelate compound; a curing accelerator; a surfactant; an antioxidant; a sensitizer; a preservative; a compound for adjusting the dielectric constant and electrical resistance of the resulting liquid crystal alignment film; and at least one additive selected from a compound for promoting imidization.

12. A liquid crystal alignment film obtained from the liquid crystal alignment agent according to claim 8 or 9.

13. A liquid crystal display element comprising the liquid crystal alignment film described in claim 12.

14. A method for manufacturing a liquid crystal display element, comprising the following steps (1) to (3). Step (1): A step of applying the liquid crystal alignment agent according to claim 8 or 9 onto a substrate. Step (2): A step of firing the coated liquid crystal alignment agent to obtain a film. Step (3): A step of orientation treatment on the film obtained in step (2).

15. The method for manufacturing a liquid crystal display element according to claim 14, wherein the orientation treatment is a photo-alignment treatment.

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