Novel diamine compounds, polymers obtained using the diamine, liquid crystal alignment agents, liquid crystal alignment films, and liquid crystal display elements.

Abstract

This invention provides a novel diamine that, when used as a raw material for a polymer constituting a liquid crystal alignment film, can form a liquid crystal alignment film capable of suppressing the decrease in polymer molecular weight during calcination and possessing a high voltage retention rate. The diamine of this invention is a diamine represented by any one of the following formulas (d A-1) to (d A-6).

Description

Novel diamine compound, polymer obtained using the diamine, liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element The present invention relates to a novel diamine compound, a polymer obtained by using the diamine, a liquid crystal alignment agent, a liquid crystal alignment film and a liquid crystal display device. Liquid crystal alignment films currently used in liquid crystal displays (LCDs) are mostly polyimide films. These films are formed by coating a polyimide precursor, such as a solution of polyamic acid or a solvent-soluble polyimide, onto a substrate and then calcining the solution. These polyamic acid or solvent-soluble polyimides are typically synthesized by reacting tetracarboxylic acid derivatives, such as tetracarboxylic dianhydride, with diamines. Liquid crystal display devices, for example, include a liquid crystal layer sandwiched between a device substrate and a color filter substrate, pixel electrodes and a common electrode for applying an electric field to the liquid crystal layer, a liquid crystal alignment film for controlling the alignment of the liquid crystal molecules in the liquid crystal layer, and thin-film transistors (TFTs) for switching the electrical signals supplied to the pixel electrodes. Known methods for driving liquid crystal molecules include vertical electric field methods such as twisted nematic (TN) and vertical alignment (VA), and transverse electric field methods such as in-plane switching (IPS) and fringe field switching (FFS). The most popular liquid crystal alignment film in the industry today is produced by a so-called friction treatment, which involves rubbing a surface of a thin film formed on an electrode substrate and composed of a polymer represented by polyamide and / or polyimide obtained by imidizing the same, with a cloth such as cotton, nylon, or polyester in one direction. The friction treatment is a simple method with excellent productivity and is therefore useful in industry. On the other hand, as liquid crystal display elements become more high-performance, more refined, and larger in size, a photoalignment method that imparts alignment capabilities to liquid crystals by irradiating polarized radiation is known as an alignment treatment method that replaces the friction treatment. As far as the photoalignment method is concerned, methods utilizing photoisomerization reactions, methods utilizing photocrosslinking reactions, methods utilizing photodecomposition reactions, and the like have been proposed (for example, see Non-Patent Document 1 and Patent Document 1). In recent years, in mobile applications such as smartphones and in-vehicle applications such as vehicle navigation, characteristics that can withstand long-term use in harsh use environments have been required. The liquid crystal alignment films used therein are required to be higher than the previous reliability, such as the electrical characteristics of the liquid crystal alignment films regarding the so-called voltage holding rate, which require not only good initial characteristics but also their maintenance of good characteristics even after prolonged exposure to high temperature. As a means to address the above topics, patent literature 2 proposes a liquid crystal alignment agent that uses a diamine with a diamine-diphenylamine structure as a polyamide (precursor) feedstock. [Previous Technical Literature] [Patent Literature] [Patent Literature 1] Japan Special Bulletin No. 1997-297313 [Patent Literature 2] Bulletin WO2004 / 021076 [Non-Patent Literature] [Non-patent literature 1] “Liquid crystal light alignment film” Kitowaki, Ichimura Functional Materials November 1997 Vol.17, No. 11 pp. 13~22 [Invent the topic to be solved] With the high precision of liquid crystal display components, the standard for the above requirements becomes higher, and the requirement can meet higher standards of liquid crystal alignment films. Also, in liquid crystal display components used in mobile applications such as smartphones and car navigation, etc., from a lightweight point of view, the thickness of the substrates (e.g., glass substrates, etc.) that make up the liquid crystal panel are sometimes thinned. Therefore, from the viewpoint of inhibiting the loss of thin films of the liquid crystal aligned films that accompany the thinning of the substrate, a liquid crystal aligned film with high thin film strength is required. Furthermore, the stability of liquid crystal alignment also becomes important in IPS mode and FFS driven mode. If the stability of the alignment is low, the liquid crystal will not return to the initial state when driving the liquid crystal for a long time, but become the cause of reduced contrast, burn marks (hereinafter referred to as AC afterimage), and therefore also requires the AC afterimage to pass through the suppressed liquid crystal alignment film. Polyimide (precursor) obtained using diamines with diphenylamine structure as described in the above patent literature 2 significantly reduced the molecular weight of the polymer during the calcination step during preparation of liquid crystal alignment films, which could not adequately address the above topic. In view of the above, the first object of the present invention is to provide a novel diamine, a polymer obtained by using the diamine, and further to provide a liquid crystal alignment agent that can obtain a liquid crystal alignment film having a high voltage retention rate even after long-term exposure to high temperature when using the polymer, a liquid crystal alignment film obtained from the liquid crystal alignment agent, and a liquid crystal display element using the liquid crystal alignment film. In addition, a liquid crystal alignment agent that can suppress the decrease in molecular weight of the polymer during calcination when making the liquid crystal alignment film, a liquid crystal alignment film obtained from the liquid crystal alignment agent, and a liquid crystal display element using the liquid crystal alignment film are provided. Further, a liquid crystal alignment agent that can obtain a liquid crystal alignment film having a high voltage retention rate even after long-term exposure to high temperature, high film strength, and suppressed AC ghosting, a liquid crystal alignment film obtained from the liquid crystal alignment agent, and a liquid crystal display element using the liquid crystal alignment film are provided. [Means for Solving the Problem] The inventors of this case conducted detailed research to achieve the above-mentioned problems and found that a liquid crystal alignment agent containing a polymer having a specific diamine as a constituent component is extremely effective in achieving the above-mentioned purpose, thereby completing the present invention. The present invention includes the following aspects. 1. A diamine having the following formula (d A -1)~(d A -6) any diamine represented by. [Chemical 1] [Chemistry 2] 2. A polymer comprising at least one polymer selected from the group consisting of a polyimide precursor obtained using a diamine component comprising the diamine described in 1 above, and a polyimide which is an imide product of the polyimide precursor. 3. The polymer described in 2 above, 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 the molecule. 4. The polymer described in 2 or 3 above, wherein the amount of the diamine described in 1 above is 5 mol% or greater relative to the diamine component. 5. The polymer described in any one of 2 to 4 above, wherein the polymer is obtained by a polymerization reaction of the diamine component with a tetracarboxylic acid component, the tetracarboxylic acid component comprising tetracarboxylic dianhydride or a derivative thereof. 6. The polymer described in 5 above, wherein the tetracarboxylic dianhydride or a derivative thereof is a non-cyclic aliphatic tetracarboxylic dianhydride, an alicyclic tetracarboxylic dianhydride, an aromatic tetracarboxylic dianhydride, or a derivative thereof.7. The polymer according to 5 or 6 above, wherein the tetracarboxylic dianhydride or its derivative is the following: a non-cyclic aliphatic tetracarboxylic dianhydride of 1,2,3,4-butanetetracarboxylic dianhydride; 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dichloro-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-difluoro-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-bis(trifluoromethyl)-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3',4,4'-dicyclohexyltetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentyl acetic acid dihydride alicyclic tetracarboxylic acid dianhydrides selected from the group consisting of tetrahydronaphthalene-1,2-dicarboxylic anhydride, 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)-8-methyl-3a,4,5,9b-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; selected from pyromellitic dianhydride, 3,3',4,4'-diphenyl ketone tetracarboxylic dianhydride, 3,3',4,4'-diphenyl sulfonate tetracarboxylic dianhydride, 1,4,5,8-naphthalene tetracarboxylic dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride, 3,3',4,4'-biphenyl tetracarboxylic dianhydride, 2,2',3,3'-biphenyl tetracarboxylic dianhydride, 4,4'-bis(3, Aromatic tetracarboxylic dianhydrides selected from the group consisting of 4-dicarboxyphenoxy)-2,2-diphenylpropane dianhydride, ethylene glycol trimellitic anhydride, 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 derivatives thereof. 8. A liquid crystal alignment agent characterized by containing the polymer described in any one of 2 to 7 above. 9. The liquid crystal alignment agent described in 8 above, further containing 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 1 above, and a polyimide that is an imide product of the polyimide precursor.10. The liquid crystal alignment agent according to claim 9, wherein the polymer (B) is obtained by a polymerization reaction of the diamine component and a tetracarboxylic acid component, the tetracarboxylic acid component comprising tetracarboxylic dianhydride or a derivative thereof. 11. The liquid crystal alignment agent according to any one of claims 8 to 10, wherein the liquid crystal alignment agent further comprises at least one additive selected from the group consisting of a crosslinking compound, 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 resistance of the resulting liquid crystal alignment film, and a compound for promoting imidization, wherein the crosslinking compound is 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 oxetane group, a blocked isocyanate group, an oxazoline group, a cyclocarbonate group, a hydroxyl group, and an alkoxy group, and a crosslinking compound (c-2) having a polymerizable unsaturated group. 12. A liquid crystal alignment film obtained from the liquid crystal alignment agent as described in any one of 8 to 11 above. 13. A liquid crystal display element comprising the liquid crystal alignment film as described in 12 above. 14. A method for manufacturing a liquid crystal display element, comprising the following steps (1) to (3). Step (1): applying the liquid crystal alignment agent as described in any one of 8 to 11 above to a substrate. Step (2): calcining the applied liquid crystal alignment agent to obtain a thin film. Step (3): performing an alignment treatment on the thin film obtained in step (2). 15. The method for manufacturing a liquid crystal display element as described in 14 above, wherein the alignment treatment is a photoalignment treatment. [Effects of the Invention]. The diamine of the present invention, when used as a raw material for a polymer constituting a liquid crystal alignment film, can provide a liquid crystal alignment agent capable of forming a liquid crystal alignment film that suppresses molecular weight reduction of the polymer during calcination and exhibits a high voltage holding ratio; a liquid crystal alignment film obtained from the liquid crystal alignment agent; and a high-performance liquid crystal display device incorporating the liquid crystal alignment film. Furthermore, the diamine of the present invention, when used as a raw material for a polymer constituting a liquid crystal alignment film, can provide a liquid crystal alignment agent capable of forming a liquid crystal alignment film that exhibits high film strength, suppressed AC image sticking, and a high voltage holding ratio even after long-term exposure to high temperatures; a liquid crystal alignment film obtained from the liquid crystal alignment agent; and a liquid crystal display device incorporating the liquid crystal alignment film. The mechanism by which the present invention achieves the aforementioned effects is not necessarily clear, but is generally presumed as follows: It is believed that by pre-imidizing the aromatic tetracarboxylic dianhydride skeleton, which significantly reduces molecular weight during calcination, the reverse reaction and the resulting reduction in molecular weight are suppressed, thereby achieving the aforementioned effects. The following details a novel diamine, a polymer obtained from the diamine, a liquid crystal alignment agent containing the polymer, a liquid crystal alignment film formed using the liquid crystal alignment agent, and a liquid crystal display device having the liquid crystal alignment film. However, the description of the constituent elements described below is merely an example of one embodiment of the present invention and is not intended to be limiting. In the following description, "halogen atoms" include fluorine, chlorine, bromine, and iodine. "Boc" represents a tert-butyloxycarbonyl group, and "*" indicates the bonding position. (Specific diamine) The diamine of the present invention is the following formula (d A -1)~(d A -6) any one of the diamines (0) (also referred to as specific diamine in the present invention). [Chemical 3] [Chemistry 4] The method for producing the specific diamine of the present invention is not particularly limited, but a preferred method includes a production method comprising the following steps (i) to (iv). <Step (i)> Make the following formula (d i -1) reacts with an amine protecting agent such as di-tert-butyl dicarbonate to obtain a compound (d i -2). Here, Y in formula (i) represents a divalent organic group obtained by removing two amino groups from a diamine. Examples of the diamine include 4,4'-diaminodiphenylamine and 4,4'-diaminodiphenyl-N-methylamine. [Chemistry 5] <Step (ii)> Formula (d i -2) is reacted with tetracarboxylic dianhydride to obtain the following formula (d i -3). Here, X in formula (ii) represents a tetravalent organic group obtained by removing two anhydride groups from tetracarboxylic dianhydride. Examples of tetracarboxylic dianhydride include pyromellitic dianhydride, 3,3',4,4'-diphenylketone tetracarboxylic dianhydride, and 3,3',4,4'-biphenyltetracarboxylic dianhydride. In addition, Y in formula (ii) has the same meaning as in formula (i). [Chemistry 6] <Step (iii)> The above formula (d i -3) is imidized to obtain a diimide compound (di-4) in which the amino group is protected by a Boc group. [Chemistry 7] <Step (iv)> The compound (di-4) is reacted with an inorganic acid such as hydrochloric acid to perform a deprotection reaction to obtain the diamine compound of the present invention. The reaction temperature is not particularly limited and can be 0-100°C. In the synthesis reaction of the specific diamine, a solvent may be used as needed. 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; and esters such as ethyl acetate. Other examples include organic solvents such as N,N-dimethylsulfoxide, dimethylformamide, dimethylacetamide, and N-methyl-2-pyrrolidone, which can be used appropriately depending on the type of reaction. As the imidization method of the above step (iii), the following can be mentioned: i -3) a method of thermal imidization by directly heating a solution of a compound represented by formula (d i The catalytic imidization method of adding a catalyst to a solution of the compound represented by formula (d-3) is preferably a catalytic imidization method from the viewpoint of ease of synthesis. The above catalytic imidization can be carried out in the following manner: i -3) is added to the solution of the compound represented by formula (d) and the reaction is preferably carried out at 0-120°C, more preferably at 0-100°C. The amount of the alkaline catalyst is preferably i -3) of the amide group of the compound represented by the formula (d) 0.5 to 30 mole times, more preferably 2 to 20 mole times. The amount of acid anhydride is preferably i -3) is 1 to 50 molar times, more preferably 1 to 30 molar times, of the amino groups contained in the compound represented by hydroxy-4-nitropropane-2-ol (NH4-2-nitropropane-3). Examples of alkaline catalysts include pyridine, triethylamine, trimethylamine, tributylamine, and trioctylamine. Pyridine is preferred because of its suitable basicity for the reaction. Examples of acid anhydrides include acetic anhydride, trimellitic anhydride, and pyromellitic anhydride. Acetic anhydride is preferred because it facilitates purification after the reaction. The diamine of the present invention can be used as a raw material for a polymer constituting a liquid crystal alignment film. Examples of the polymer include: A -1)~(d A -6) At least one polymer (P) selected from the group consisting of a polyimide precursor obtained from a diamine component of the diamine (0) shown in any one of the above and a polyimide which is an imide product of the polyimide precursor. (Polymer (P)) The polymer (P) of the present invention is a polyimide precursor obtained by using a diamine component containing the above-mentioned diamine (0), or a polyimide that is an imide compound of the polyimide precursor. Among them, the polyimide precursor is a polymer that can obtain polyimide by imidization of polyamic acid, polyamic acid ester, etc. The polyamic acid (P') that is the polyimide precursor of the above-mentioned polymer (P) can be obtained by a polymerization reaction of a diamine component containing the above-mentioned diamine (0) and a tetracarboxylic acid component. The above-mentioned diamine (0) can 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 relative to all diamine components. The diamine component used in the production of the polyamine (P') may also contain a diamine other than diamine (0) (hereinafter also referred to as other diamines). When other diamines are used in addition to diamine (0), the amount of diamine (0) used is preferably 90 mol% or less, more preferably 80 mol% or less, relative to the diamine component. Examples of other diamines are given below, but are not limited thereto. The above other diamines may be used alone 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, Biphenyl, 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, the following formula (d AL ) represented by the diamine (preferably the following formula (d AL -1)~(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-aminobenzoate), 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; 4,4'-diaminoazobenzene or diaminodiphenylacetylene (diam diamines having photoaligning groups, such as inotolan; diamines having photopolymerizable groups at the end, such as 2-(2,4-diaminophenoxy)ethyl methacrylate or 2,4-diamino-N,N-diallylaniline; diamines having free radical polymerization initiator functions, such as 1-(4-(2-(2,4-diaminophenoxy)ethoxy)phenyl)-2-hydroxy-2-methylacetone and 2-(4-(2-hydroxy-2-methylpropionyl)phenoxy)ethyl-3,5-diaminobenzoate; diamines having amide bonds, such as 4,4'-diaminophenylaniline; diamines having urea bonds, 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-aminophenyl)hexafluoropropane, 2,2-bis(4-aminophenyl)propane, 2,2-bis(3-aminophenyl)propane, 2,2-bis(3-amino-4-methylphenyl)propane, 4,4'-Diaminodiphenyl ketone, 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)-piperidinium, 3,6-diaminoacridine, N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N-[3-(1H-imidazol-1-yl)propyl]-3,5-diaminobenzamide, 4-[4-[(4-aminophenoxy)methyl]-4,5-dihydro-4-methyl-2-oxazolyl]-aniline, or a diamine represented by the following formula (z-1) to formula (z-13), or a diamine containing a heterocyclic ring, such as 4,4'-diaminodiphenylamine, 4,4'-diaminodiphenyl-N-methylamine, N,N'-bis(4-aminophenyl)-biphenylamine Diamines having a diphenylamine structure, such as 1,4-diaminobenzylamine, N,N'-bis(4-aminophenyl)-N,N'-dimethylbenzidine, or N,N'-bis(4-aminophenyl)-N,N'-dimethyl-1,4-phenylenediamine, and having at least one nitrogen-containing structure selected from the group consisting of a nitrogen-containing heterocycle, a secondary amino group, and a tertiary amino group (hereinafter also referred to as a specific nitrogen-containing structure) (provided that the molecule does not contain an amino group bonded to a protecting group that is detached and substituted with a hydrogen atom by heating); 2,4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4,6-diaminoresorcinol, 4,4'-diamino-3,3'-dihydroxybiphenyl; 2, Diamines having a carboxyl group, such as 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-2,4'-dicarboxylic acid, 4,4'-diaminodiphenylmethane-3,3'-dicarboxylic acid, 1,2-bis(4-aminophenyl)ethane-3,3'-dicarboxylic acid, and 4,4'-diaminodiphenyl ether-3,3'-dicarboxylic acid;4-(2-(methylamino)ethyl)aniline, 4-(2-aminoethyl)aniline, 1-(4-aminophenyl)-1,3,3-trimethyl-1H-dihydroindene-5-amine, 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-indene-6-amine; diamines having the group "-N(D)-" (D represents a protecting group that is released upon heating and replaced by a hydrogen atom, preferably a carbamate-based protecting group, more preferably a tert-butyloxycarbonyl group; excluding the above-mentioned specific diamines), cholesteryloxy-3,5-diaminobenzene, cholesteryloxy-3,5-diaminobenzene, cholesteryloxy-2,4-diaminobenzene, cholesteryl-3,5-diaminobenzoate, 3,5 -Diamines having a steroid skeleton, such as cholesteryl diaminobenzoate, lanostane 3,5-diaminobenzoate, and 3,6-bis(4-aminobenzyloxy)cholestane; diamines represented by the following formulas (V-1) and (V-2); diamines having a siloxane bond, such as 1,3-bis(3-aminopropyl)-tetramethyldisiloxane; m-xylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, 1,3-bis(aminomethyl)cyclohexane, 1,4-diaminocyclohexane, 4,4'-methylenebis(cyclohexylamine); and diamines in which two amino groups are bonded to a group represented by any of formulas (Y-1) to (Y-167) described in International Publication No. WO2018 / 117239. [Chemistry 8] (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 by a monovalent group; L 1 and L 1’ Each independently represents a single bond, -O-, -C(=O)-, -C(=O)-O- or -OC(=O)-; A represents -CH 2-, an alkylene group having 2 to 12 carbon atoms, or a divalent organic group formed by inserting at least one of -O-, -C(=O)-O-, and -OC(=O)- between the carbon-carbon bonds of the alkylene group; any hydrogen atom possessed by A may be substituted by a halogen atom; one or more hydrogen atoms on the above-mentioned benzene ring, biphenyl structure, or naphthalene ring may be substituted by a monovalent group, such as a halogen atom, an alkylene 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 alkoxycarbonyl group having 2 to 3 carbon atoms, a cyano group, a nitro group, etc.). [Chemistry 9] (Formula (d AL -6), the sum of m1, m2 and n is 3 to 12; AL -8), the sum of m1, m2 and n is 3~12). [Chemistry 10] [Chemistry 11] [Chemistry 12] [Chemistry 13] In the above formula (V-1), m and n are each independently an integer of 0 to 3, satisfying 1≤m+n≤4; j is an integer of 0 or 1; X 1 Indicates -(CH 2) a -(a is an integer of 1 to 15), -CONH-, -NHCO-, -CO-N(CH 3) -、-NH-、-O-、-CH 2O-、-CH 2-OCO-, -COO- or -OCO-; R 1 represents a monovalent group such as a fluorine atom, an alkyl group containing 1 to 10 carbon atoms, an alkoxy group containing 1 to 10 carbon atoms, an alkyl group containing 1 to 10 carbon atoms, an alkoxy group containing 1 to 10 carbon atoms, and an alkoxyalkyl group containing 2 to 10 carbon atoms; in the above formula (V-2), X 2 Indicates -O-, -CH 2O-、-CH 2-OCO-, -COO- or -OCO-. M, n, X 1 、R 1 When there are two, they each independently have the above definition. When other diamines are used in addition to the diamine (0), the amount of the other diamine used is preferably 10 to 90 mol%, more preferably 20 to 80 mol%, based on the total diamine components used. A variety of other diamines can be used depending on the intended purpose. For example, when used as a liquid crystal alignment film, from the perspective of improving voltage holding characteristics, it is preferred to select at least one diamine from the group consisting of diamines 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 the molecule, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, and the above-mentioned diamines having a specific nitrogen-containing structure. The amount of the other diamine 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). (Tetracarboxylic acid component) When producing the polyamide (P'), the tetracarboxylic acid component to be reacted with the diamine component may be not only tetracarboxylic dianhydride but also derivatives of tetracarboxylic dianhydride such as tetracarboxylic acid, tetracarboxylic acid dihalide, tetracarboxylic acid dialkyl ester or tetracarboxylic acid dialkyl ester dihalide. Examples of the tetracarboxylic dianhydride or its derivative include acyclic aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, aromatic tetracarboxylic dianhydride, and derivatives thereof. More preferred are tetracarboxylic dianhydrides or derivatives thereof containing at least one substructure selected from the group consisting of a benzene ring, a cyclobutane ring, a cyclopentane ring, and a cyclohexane ring. Even more preferred are tetracarboxylic dianhydrides or derivatives thereof containing at least one structure selected from the group consisting of a cyclobutane ring, a cyclopentane ring, and a cyclohexane ring. Here, non-cyclic aliphatic tetracarboxylic dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxyl groups bonded to a chain hydrocarbon structure. However, it does not need to be composed solely of a chain hydrocarbon structure; a portion thereof may have an alicyclic structure or an aromatic ring structure. Alicyclic tetracarboxylic dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxyl groups, including at least one carboxyl group bonded to an alicyclic structure. However, none of these four carboxyl groups are bonded to an aromatic ring. Furthermore, it does not need to be composed solely of an alicyclic structure; a portion thereof may have a chain hydrocarbon structure or an aromatic ring structure. Aromatic tetracarboxylic dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxyl groups, including at least one carboxyl group bonded to an aromatic ring. However, it does not need to be composed solely of an aromatic ring structure; a portion thereof may have a chain hydrocarbon structure or an alicyclic structure. The tetracarboxylic acid component that can be used to produce the polyamide (P') preferably includes the following tetracarboxylic dianhydrides or their derivatives (hereinafter collectively referred to as specific tetracarboxylic acid derivatives): 1,2,3,4-butanetetracarboxylic dianhydride and other non-cyclic aliphatic tetracarboxylic dianhydrides; 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dichloro-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-difluoro-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-bis(trifluoromethyl)-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4 ...dichloro-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1, 2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3',4,4'-dicyclohexyltetracarboxylic dianhydride, 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)-8-methyl-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan- Alicyclic tetracarboxylic dianhydrides such as 1,3-diketone, 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'-diphenyl ketone tetracarboxylic dianhydride, 3,3',4,4'-diphenylsulfonium tetracarboxylic dianhydride, 1,4,5,8-naphthalene tetracarboxylic dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride, 3,3' , 4,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)-2,2-diphenylpropane dianhydride, ethylene glycol trimellitic anhydride, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 4,4'-carbonyldiphthalic anhydride, 4,4'-(1,4-phenylenedioxy)bis(phthalic anhydride), or 4,4'-(1,4-phenylenedimethylene)bis(phthalic anhydride) and other aromatic tetracarboxylic dianhydrides; in addition, tetracarboxylic dianhydrides described in Japanese Patent Application Publication No. 2010-97188, etc. Preferred examples of the above-mentioned specific tetracarboxylic acid derivatives include 1,2,3,4-butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-difluoro-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-bis(trifluoromethyl)-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3',4,4'-dicyclohexyltetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, 5-(2,5-dioxo-tetrahydro-)-tetrahydro- Furan-3-yl)-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 5-(2,5-dioxo-tetrahydrofuran-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 acid Dianhydride, 3,3',4,4'-diphenyl ketone tetracarboxylic dianhydride, 3,3',4,4'-diphenylsulfonate tetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride or derivatives thereof. The usage ratio of the above-mentioned specific tetracarboxylic acid derivative 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. (Liquid crystal alignment agent) The liquid crystal alignment agent of the present invention is a liquid composition in which a polymer (P) and other components used as needed are ideally dispersed or dissolved in an appropriate solvent. The total content of the polymer contained in the liquid crystal alignment agent of the present invention can be appropriately changed depending on the thickness setting of the coating to be formed, but from the perspective of forming a uniform and defect-free coating, it is preferably 1% by mass or more, and from the perspective of the storage stability of the solution, it is preferably 10% by mass or less. The total content of the polymer is preferably 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, relative to the total amount of the polymer contained in the liquid crystal alignment agent. The liquid crystal alignment agent of the present invention may also contain other polymers in addition to the polymer (P). Specific examples of other polymers include, in addition to the above-mentioned polymer (P), at least one polymer selected from the group consisting of a polyimide precursor obtained using a diamine component not containing the above-mentioned specific diamine and a polyimide which is an imide product of the polyimide precursor (also referred to as polymer (B) in the present invention), polysiloxanes, polyesters, polyamides, polyureas, polyorganosiloxanes, cellulose derivatives, polyacetals, polystyrene derivatives, poly(styrene-maleic anhydride) copolymers, poly(isobutylene-maleic anhydride) copolymers, poly(vinyl ether-maleic anhydride) copolymers, poly(styrene-phenylmaleimide) derivatives, and poly(meth)acrylates. Specific examples of poly(styrene-maleic anhydride) copolymers include SMA1000, SMA2000, SMA3000 (manufactured by Cray Valley), GSM301 (manufactured by GIFUSHELLAC Manufacturing Co., Ltd.), and the like. Specific examples of poly(isobutylene-maleic anhydride) copolymers include ISOBAM-600 (manufactured by Kuraray Co., Ltd.). Specific examples of poly(vinyl ether-maleic anhydride) copolymers include Gantrez AN-139 (methyl vinyl ether maleic anhydride resin, manufactured by Ashland Co., Ltd.). Among these, polymer (B) is more preferred from the perspective of maintaining voltage holding ratio and reducing image sticking from residual DC. The above-mentioned 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 polymers contained in the liquid crystal alignment agent. (Polymer (B)) Specific examples of the tetracarboxylic acid component used in the production of the above-mentioned polymer (B) include preferred specific examples, and the same compounds as those exemplified in the polymer (P) can be cited. The tetracarboxylic acid component used in the production of the polymer (B) is more preferably a tetracarboxylic dianhydride or a derivative thereof having at least one substructure selected from the group consisting of a benzene ring, a cyclobutane ring, a cyclopentane ring, and a cyclohexane ring. It is further preferred to use the above-mentioned specific tetracarboxylic acid derivative, and it is most preferred to use a more preferred specific example of the above-mentioned specific tetracarboxylic acid derivative. From the perspective of appropriately obtaining the effects of the present invention, the tetracarboxylic acid component used in the production of the polymer (B) is preferably a non-cyclic aliphatic tetracarboxylic dianhydride, an alicyclic tetracarboxylic dianhydride, or a derivative thereof. In addition, the usage amount of the above-mentioned specific tetracarboxylic acid derivative is preferably 10 mol% or more, more preferably 20 mol% or more, and even more preferably 50 mol% or more relative to all the tetracarboxylic acid components used in the production of the polymer (B). Examples of the diamine component for obtaining the polymer (B) include the diamines exemplified above for the polymer (P). From the perspective of improving the liquid crystal alignment, the diamine component for obtaining the polymer (B) preferably 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, and 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, the above formula (d AL ) or a diamine having a tetracarboxylic acid diimide structure other than the above-mentioned specific diamine (hereinafter collectively referred to as diamine (c)). AL A preferred specific example of the diamine represented by ) is the above formula (d AL -1)~(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-naphthyl)ethane, 1,2-bis(6-amino-2-naphthyl)ethane, or 6-[2-(4-aminophenoxy)ethoxy]-2-naphthylamine. The above-mentioned diamine components may be used alone or in combination. When the above-mentioned diamine (c) is used, its usage amount is preferably 10 mol% or more, more preferably 20 mol% or more, of all diamine components used in the production of polymer (B). When a diamine other than diamine (c) is used, its usage amount is preferably 90 mol% or less, more preferably 80 mol% or less, of all diamine components used in the production of polymer (B). (Production of Polyamide) The production of polyamide is carried out by reacting a diamine component and a tetracarboxylic acid component in an organic solvent. The ratio of the tetracarboxylic acid component to the diamine component used in the production reaction of polyamide is preferably 0.5 to 2 equivalents of the anhydride group of the tetracarboxylic acid component per 1 equivalent of the amino group of the diamine component, and more preferably 0.8 to 1.2 equivalents. As in general polycondensation reactions, the closer the equivalent of the anhydride group of the tetracarboxylic acid component is to 1 equivalent, the greater the molecular weight of the polyamide produced. The reaction temperature in the production of polyamide is preferably -20 to 150°C, more preferably 0 to 100°C. In addition, the reaction time is preferably 0.1 to 24 hours, more preferably 0.5 to 12 hours. The production of polyamide can be carried out at any concentration, but the concentration of polyamide is preferably 1 to 50% by mass, more preferably 5 to 30% by mass. The reaction is carried out at a high concentration in the initial stage, and solvent may be added later. 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, dimethylsulfoxide, and 1,3-dimethyl-2-imidazolidinone. Furthermore, when the polymer has high solubility in a solvent, 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. (Production of Polyamic Acid Ester) Polyamic acid ester can be obtained by, for example, the following known methods: [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, [III] a method of reacting a tetracarboxylic acid diester dihalide with a diamine, etc. (Production of Polyimide) Polyimide can be obtained by ring-closing (imidizing) a polyimide precursor such as the aforementioned polyamic acid or polyamic acid ester. The imidization rate described herein refers to the ratio of imide groups to the total amount of imide groups and carboxyl groups (or their derivatives) derived from tetracarboxylic dianhydride or its derivatives. The imidization rate does not need to be 100% and can be adjusted to suit the application and purpose. Methods for imidizing a polyimide precursor include thermal imidization, in which a solution of the polyimide precursor is directly heated, and catalytic imidization, in which a catalyst is added to the solution of the polyimide precursor. The temperature for thermal imidization of the polyimide precursor in the solution is preferably 100-400°C, more preferably 120-250°C. The reaction is preferably performed while discharging water generated by the imidization reaction to the outside of the system. Catalytic imidization of a polyimide precursor can be carried out by the following method: add an alkaline catalyst and an acid anhydride to a solution of the polyimide precursor, preferably stirring at -20 to 250°C, more preferably 0 to 180°C. The amount of alkaline catalyst is preferably 0.5 to 30 molar times, more preferably 2 to 20 molar times, based on the amount of amide groups, and the amount of acid anhydride is preferably 1 to 50 molar times, more preferably 3 to 30 molar times, based on the amount of amide groups. Examples of alkaline catalysts include pyridine, triethylamine, trimethylamine, tributylamine, or trioctylamine. Pyridine is preferred due to its alkalinity suitable for the reaction. Examples of acid anhydrides include acetic anhydride, trimellitic anhydride, or pyromellitic anhydride. Acetic anhydride is preferred because it facilitates purification after the reaction. The imidization rate of catalytic imidization can be controlled by adjusting the amount of catalyst, reaction temperature, and reaction time. To recover the resulting polyimide precursor or polyimide from a reaction solution of a polyimide precursor or polyimide, the reaction solution can be injected into a solvent to precipitate the resulting product. Examples of suitable solvents for precipitation include methanol, ethanol, isopropanol, acetone, hexane, butyl celulose, heptane, methyl ethyl ketone, methyl isobutyl ketone, toluene, benzene, and water. After filtering and recovering the precipitated polymer, it can be dried at room temperature under normal or reduced pressure or by heating. Alternatively, the recovered polymer can be redissolved in an organic solvent and reprecipitated. Repeating this process 2 to 10 times can reduce impurities in the polymer. Examples of suitable solvents include alcohols, ketones, and hydrocarbons. Using three or more solvents selected from these groups is preferred, as it improves purification efficiency. When manufacturing the polyimide precursor and polyimide in the present invention, an appropriate end-capping agent can also be used together with the tetracarboxylic acid component containing tetracarboxylic dianhydride or its derivatives and the diamine component containing the above-mentioned diamine to manufacture an end-sealed polymer. The end-sealed polymer has the effect of improving the film hardness of the alignment film obtained by the coating and improving the adhesion between the sealant and the alignment film. Examples of the ends of the polyimide precursor and polyimide in the present invention include amino groups, carboxyl groups, acid anhydride groups, or groups derived from the end-capping agents described below. The amino groups, carboxyl groups, and acid anhydride groups can be obtained by a general condensation reaction, or by using the following end-capping agents to cap the ends. 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; dicarbonic acid diester compounds such as di-t-butyl dicarbonate and diallyl dicarbonate; and acrylic acid. Chlorocarbonyl compounds such as chlorine, methacrylic acid chloride, and nicotinyl chloride; 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 with unsaturated bonds such as ethyl isocyanate, phenyl isocyanate, naphthyl isocyanate, 2-acryloyloxyethyl isocyanate, and 2-methacryloyloxyethyl isocyanate. The capping agent is preferably used in an amount of 0.01 to 20 mol parts, more preferably 0.01 to 10 mol parts, based on 100 mol parts of the total diamine component used. The polyimide precursor and polyimide preferably have a polystyrene-equivalent weight average molecular weight (Mw) of 1,000 to 500,000, more preferably 2,000 to 300,000, as measured by gel permeation chromatography (GPC). Furthermore, the molecular weight distribution (Mw / Mn), represented by 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. Maintaining the molecular weight within this range ensures good alignment properties in liquid crystal display devices. The organic solvent contained in the liquid crystal alignment agent of the present invention is not particularly limited as long as it can uniformly dissolve the polymer (P) and other polymers added as needed. Examples thereof 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, dimethylsulfoxide, γ-butyrolactone, γ-valerolactone, 1,3-dimethyl-2-imidazolidinone, methyl ethyl ketone, cyclohexanone, cyclopentanone, 3-methoxy-N,N-dimethylpropaneamide, 3-butoxy The good solvents include 3-methoxy-N,N-dimethylpropaneamide, 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 them, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 3-methoxy-N,N-dimethylpropaneamide, 3-butoxy-N,N-dimethylpropaneamide, and γ-butyrolactone are preferred. The content of the good solvent is preferably 20-99% by mass of the total solvent contained in the liquid crystal alignment agent, more preferably 20-90% by mass, and particularly preferably 30-80% by mass. Furthermore, the organic solvent contained in the liquid crystal alignment agent, in addition to the above-mentioned solvents, is preferably a mixed solvent containing a solvent (also known as a poor solvent) that improves the coating properties and surface smoothness of the coating film when the liquid crystal alignment agent is applied. Specific examples of the poor solvent are described below, but are not limited thereto. The content of the poor solvent is preferably 1-80% by mass of the total solvent contained in the liquid crystal alignment agent, more preferably 10-80% by mass, and particularly preferably 20-70% by mass. The type and content of the poor solvent are appropriately selected based on the coating equipment, coating conditions, and coating environment of the liquid crystal alignment agent. Examples of the poor solvent 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 glycol monobutyl ether, ethylene glycol monoisopentyl ether, ethylene glycol monohexyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, 1-(2-butoxyethoxy)-2-propanol, 2-( 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, 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. Among them, 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. Examples of ideal combinations of good solvents and poor solvents include N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone and 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, N-ethyl-2-pyrrolidone and propylene glycol diacetate, N,N-dimethyllactamide and diisobutyl ketone, N-methyl-2-pyrrolidone and ethyl 3-ethoxypropionate, N-ethyl-2-pyrrolidone and ethyl 3-ethoxypropionate, and N-methyl-2-pyrrolidone and ethyl 3-ethoxypropionate and dipropylene glycol monomethyl ether. , N-ethyl-2-pyrrolidone and ethyl 3-ethoxypropionate and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone and ethyl 3-ethoxypropionate and diethylene glycol monopropyl ether, N-ethyl-2-pyrrolidone and 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-dimethyllactamide and ethylene glycol monobutyl ether, N,N-dimethyllactamide and propylene glycol diacetate, N-ethyl-2-pyrrolidone and diethylene glycol diethyl ether, N-ethyl-2-pyrrolidone and diethylene glycol monoethyl ether and butyl cyloracetate, N-methyl-2-pyrrolidone and diethylene glycol monomethyl ether and butyl cyloracetate, N,N-dimethyl lactamide and diethylene glycol diethyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and 4-hydroxy-4-methyl-2-pentanone and diethylene glycol diethyl ether, N-ethyl-2-pyrrolidone and N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone, N-ethyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and diisobutyl ketone, N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and dipropylene glycol monomethyl ether, N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone with propylene glycol monobutyl ether, N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone with propylene glycol diacetate, N-ethyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone with dipropylene glycol dimethyl ether, γ-butyrolactone and 4-hydroxy-4-methyl-2-pentanone with diisobutyl ketone, γ-butyrolactone and 4-hydroxy-4-methyl-2-pentanone with propylene glycol diacetate, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether and diisobutyl ketone, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether and diisopropyl ether, N-methyl-2-pyrrolidone Pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether and diisobutyl carbinol, N-methyl-2-pyrrolidone and γ-butyrolactone and dipropylene glycol dimethyl ether, N-methyl-2-pyrrolidone and propylene glycol monobutyl ether and dipropylene glycol dimethyl ether, N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether and dipropylene glycol monomethyl ether, N-ethyl-2-pyrrolidone and diethylene glycol diethyl ether and dipropylene glycol monomethyl ether, N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether and propylene glycol diacetate, N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether and diisobutyl ketone, N-ethyl-2-pyrrolidone and γ-butyrolactone and diisobutyl ketone, N-ethyl-2 -pyrrolidone and N,N-dimethyllactamide and diisobutyl ketone, N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether and ethylene glycol monobutyl ether acetate, γ-butyrolactone and ethylene glycol monobutyl ether acetate and dipropylene glycol dimethyl ether, N-ethyl-2-pyrrolidone and ethylene glycol monobutyl ether acetate and propylene glycol dimethyl ether, N-methyl-2-pyrrolidone and 4-methyl-2-pentyl acetate and ethylene glycol monobutyl ether, N-ethyl-2-pyrrolidone and cyclohexyl acetate and 4-hydroxy-4-methyl-2-pentanone, cyclohexanone and propylene glycol monomethyl ether, cyclopentanone and propylene glycol monomethyl ether, N-methyl-2-pyrrolidone and cyclohexanone and propylene glycol monomethyl ether, etc. (Additives) The liquid crystal alignment agent of the present invention may contain, in addition to the polymer (P), the other polymer, and the organic solvent, 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 oxirane group, an oxetane group, a blocked isocyanate group, an oxazoline group, a cyclocarbonate group, a hydroxyl 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 resistance of the resulting liquid crystal alignment film; and a compound for promoting imidization. Preferred specific examples of the crosslinking 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, glycerol diglycidyl ether, dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraepoxypropyl-2,4-hexanediol 、Bisphenol A type epoxy resins such as EPIKOTE828 (Mitsubishi Chemical Corporation), bisphenol F type epoxy resins such as EPIKOTE807 (Mitsubishi Chemical Corporation), hydrogenated bisphenol A type epoxy resins such as YX-8000 (Mitsubishi Chemical Corporation), biphenyl skeleton-containing epoxy resins such as YX6954BH30 (Mitsubishi Chemical Corporation), phenol novolac type epoxy resins such as EPPN-201 (Nippon Kayaku Co., Ltd.), resin, (ortho-, meta-, para-) cresol novolac-type epoxy resins such as EOCN-102S (manufactured by Nippon Kayaku Co., Ltd.), triglycidyl isocyanurate such as TEPIC (manufactured by Nissan Chemical Co., Ltd.), alicyclic epoxy resins such as CELLOXIDE 2021P (manufactured by Daicel Co., Ltd.), compounds containing a tertiary nitrogen atom such as N,N,N',N'-tetraepoxypropyl-m-xylylenediamine, 1,3-bis(N,N-diepoxypropylaminomethyl)cyclohexane or N,N,N',N'-tetraepoxypropyl-4,4'-diaminodiphenylmethane, compounds having two or more oxiranyl groups such as tetrakis(glycidoxymethyl)methane; compounds having two or more oxetane groups as described in paragraphs

[0170] to

[0175] of WO2011 / 132751; CORONATEAP Stable M, CORONATE 2503, 2515, 2507, 2513, 2555, MILLIONATE MS-50 (all manufactured by Tosoh Corporation), TAKENATE Compounds having a blocked isocyanate group, such as 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 cyclic carbonate group, as described in paragraphs

[0025] to

[0030] and

[0032] of WO2011 / 155577;Compounds containing hydroxyl groups or alkoxy groups, such as N,N,N',N'-tetrakis(2-hydroxyethyl)hexanediamide, 2,2-bis(4-hydroxy-3,5-dihydroxymethylphenyl)propane, 2,2-bis(4-hydroxy-3,5-dimethoxyphenyl)propane, and 2,2-bis(4-hydroxy-3,5-dihydroxymethylphenyl)-1,1,1,3,3,3-hexafluoropropane; and compounds such as glycerol mono(meth)acrylate, glycerol di(meth)acrylate (1,2-, 1,3-isomeric mixture), glycerol tris(meth)acrylate, glycerol 1,3-diglycerol 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 crosslinking compounds (c-1) and (c-2) in the liquid crystal alignment 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 alignment agent. Examples of compounds used to adjust the dielectric constant and resistance include monoamines having a nitrogen-containing aromatic heterocycle, such as 3-picolylamine. The content of the monoamine having a nitrogen-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 of the liquid crystal alignment agent. Preferred specific 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, 3-glycidoxypropylmethyldimethoxysilane, Silane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-phenylenediaminetrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, tris(3-trimethoxysilylpropyl)isocyanurate, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-isocyanatepropyltriethoxysilane, etc. 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, based on 100 parts by mass of the polymer component of the liquid crystal alignment agent. Compounds used to promote the above-mentioned imidization are preferably compounds (excluding the above-mentioned cross-linking compounds and adhesion promoters) having a basic site (e.g., a primary amine group, an aliphatic heterocycle (e.g., a pyrrolidine skeleton), an aromatic heterocycle (e.g., an imidazole ring, an indole ring), or a guanidine group), or compounds that generate such a basic site during calcination. Compounds that generate such a basic site during calcination are more preferred. Preferred specific examples include amino acids in which the basic site is partially or completely protected. Examples of protecting groups for the basic sites of the amino acids include carbamate-based protecting groups such as the 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. More preferred examples of compounds promoting imidization include N-α-(9-fluorenylmethoxycarbonyl)-N-τ-(tert-butoxycarbonyl)-L-histidine. The amount of the compound promoting imidization in the liquid crystal alignment 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 alignment agent. The solid content concentration (the ratio of the total mass of the liquid crystal alignment agent components other than the solvent to the total mass of the liquid crystal alignment agent) in the liquid crystal alignment agent is appropriately selected based on viscosity, volatility, and other factors, but is preferably 1-10% by mass. The preferred solid content concentration range varies depending on the method used to apply the liquid crystal alignment agent to the substrate. For example, when using spin coating, the preferred solid content concentration is 1.5-4.5% by mass. When using printing, the preferred solid content concentration is 3-9% by mass, resulting in a solution viscosity of 12-50 mPa·s. When using inkjet printing, the preferred solid content concentration is 1-5% by mass, resulting in a solution viscosity of 3-15 mPa·s. The temperature for preparing the polymer composition is preferably 10-50°C, more preferably 20-30°C. (Liquid Crystal Alignment Film and Liquid Crystal Display Element) The liquid crystal display element of the present invention includes a liquid crystal alignment film formed using the above-described liquid crystal alignment agent. The operating mode of the liquid crystal display element is not particularly limited; for example, it can be applied to various operating modes, including TN, STN, vertical alignment (including VA-MVA, VA-PVA, etc.), in-plane switching (IPS, FFS), and optically compensatory bend (OCB) modes. The liquid crystal display element of the present invention can be manufactured, for example, by a method comprising steps (1) to (4), a method comprising steps (1) to (2) and (4), a method comprising steps (1) to (3), (4-2) and (4-4), or a method comprising steps (1) to (3), (4-3) and (4-4). <Step (1): Step of applying a liquid crystal alignment agent on a substrate> Step (1) is a step of applying a liquid crystal alignment agent on 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 coating method such as a roller coating method, a spin coating method, a printing method, an inkjet method, etc. Here, the material of the substrate is not particularly limited as long as it is a highly transparent substrate. Plastics such as acrylic and polycarbonate can be used together with glass and silicon nitride. In addition, in a reflective liquid crystal display element, if only a single-sided substrate is used, an opaque material such as a silicon wafer can also be used. In this case, the electrode can also use a material that reflects light such as aluminum. In addition, when manufacturing an IPS type or FFS type liquid crystal display element, a substrate having an electrode composed of a transparent conductive film or a metal film patterned into a comb-shaped shape and an opposing substrate having no electrode are used. An IPS substrate, which is a comb-tooth electrode substrate used in IPS-type liquid crystal display elements, comprises, for example, a substrate, a plurality of linear electrodes formed on the substrate and arranged in a comb-tooth shape, and a liquid crystal alignment film formed on the substrate so as to cover the linear electrodes. Furthermore, an FFS substrate, which is a comb-tooth electrode substrate used in FFS-type liquid crystal display elements, comprises, for example, a substrate, a planar electrode formed on the substrate, an insulating film formed on the planar electrode, a plurality of linear electrodes formed on the insulating film and arranged in a comb-tooth shape, and a liquid crystal alignment film formed on the insulating film so as to cover the linear electrodes. Examples of methods for coating a liquid crystal alignment agent on a substrate to form a film include screen printing, offset printing, flexographic printing, inkjet printing, and spraying. Among them, coating and film formation using an inkjet method is preferably used. <Step (2): calcining the applied liquid crystal alignment agent> Step (2) is a step of calcining the liquid crystal alignment agent applied on the substrate to form a film. A specific example of step (2) is described below. After the liquid crystal alignment agent is applied on the substrate in step (1), the solvent can be evaporated by heating means such as a heating plate, a hot air circulation oven or an IR (infrared) oven, or thermal imidization of polyamide can be performed. The drying and calcining steps after applying the liquid crystal alignment agent can be selected at any temperature and time, and can also be performed multiple times. As the temperature for calcining the liquid crystal alignment agent, it can be carried out at 40~180°C, for example. From the perspective of shortening the process, it can also be carried out at 40~150°C. The calcination time is not particularly limited, and can be 1~10 minutes or 1~5 minutes. When thermal imidization of polyamide is performed, a calcination step at, for example, 150-300°C or 150-250°C may be added after the above step. The calcination time is not particularly limited, but may be 5-40 minutes or 5-30 minutes. Too thin a film after calcination may reduce the reliability of the liquid crystal display device. Therefore, the film thickness is preferably 5-300 nm, more preferably 10-200 nm. <Step (3): Step of performing an alignment treatment on the film obtained in step (2)> Step (3) is a step of performing an alignment treatment on the film obtained in step (2) as appropriate. That is, in a horizontal alignment type liquid crystal display element such as the IPS mode or the FFS mode, the coating film is treated to impart alignment ability. On the other hand, in a vertical alignment type liquid crystal display element such as the VA mode or the PSA mode, the formed coating film can be used directly as a liquid crystal alignment film, or the coating film can be treated to impart alignment ability. As alignment treatment methods for liquid crystal alignment films, there are: rubbing alignment treatment method, photo alignment treatment method. As photo alignment treatment method, there is a method of irradiating the surface of the above-mentioned film-like object with radiation polarized in a certain direction and, as appropriate, heating it at a temperature of 150~250°C to impart liquid crystal alignment properties (also called liquid crystal alignment ability). As radiation, ultraviolet rays or visible light with a wavelength of 100~800nm ​​can be used. Among them, ultraviolet rays having a wavelength of 100 to 400 nm are preferred, and ultraviolet rays having a wavelength of 200 to 400 nm are more preferred. The radiation dose should be between 1 and 10,000 mJ / cm 2 , more preferably 100~5,000mJ / cm 2 Furthermore, in order to improve the liquid crystal alignment, the substrate with the film-like material may be heated at 50-250°C during the irradiation. The liquid crystal alignment film thus produced can stably align the liquid crystal molecules in a fixed direction. Furthermore, in the above method, a coating film irradiated with polarized radiation or a coating film subjected to a rubbing alignment treatment may be subjected to a contact treatment using water or a solvent. Furthermore, a film subjected to the above alignment treatment may be subjected to a heat treatment without undergoing a contact treatment. Furthermore, a film subjected to the above contact treatment may be further subjected to a heat treatment. The solvent used in the contact treatment is not particularly limited as long as it can dissolve the decomposition products generated in a film-like state by irradiation with radiation. Specific examples include water, methanol, ethanol, 2-propanol, acetone, methyl ethyl ketone, 1-methoxy-2-propanol, 1-methoxy-2-propanol acetate, butyl celecoxib, ethyl lactate, methyl lactate, diacetone alcohol, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propyl acetate, butyl acetate, and cyclohexyl acetate. The solvent may be a single species or a combination of two or more species. The temperature for heat treatment of the coating film irradiated with radiation is preferably 50 to 300° C., more preferably 120 to 250° C. The time for heat treatment is preferably 1 to 30 minutes. <Step (4): Step of making a liquid crystal cell> Prepare two substrates with liquid crystal alignment films formed in the above manner, and arrange liquid crystal between the two opposing substrates. Specifically, the following two methods can be cited. 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 are opposite each other. Then, the peripheral portions of the two substrates are bonded together using a sealant, and the cell gap separated by the substrate surface and the sealant is filled with a liquid crystal composition so that it contacts the film surface, and then the injection hole is sealed. Furthermore, the second method is a technique called ODF (One Drop Fill) method. A sealant such as a UV-curable sealant is applied to a predetermined location on one of the two substrates on which a liquid crystal alignment film is formed, and then a liquid crystal composition is dropped onto a predetermined number of locations on the surface of the liquid crystal alignment film. Afterwards, the other substrate is attached in a manner opposite to the liquid crystal alignment film, and the liquid crystal composition is pushed onto the entire surface of the substrate so that it contacts the film surface. Then, ultraviolet light is irradiated on the entire surface of the substrate to cure the sealant. In the case of any method, it is expected that after further heating to a temperature at which the liquid crystal composition used takes an isotropic phase, it is slowly cooled to room temperature to remove the flow alignment during liquid crystal filling. In addition, when the coating film is subjected to a friction alignment treatment, the two substrates are arranged opposite each other in such a manner that the friction directions in each coating film are at a predetermined angle to each other, such as orthogonal or antiparallel. As a sealant, for example, an epoxy resin containing a hardener and aluminum oxide balls as spacers can be used. The liquid crystal composition is not particularly limited. Examples include compositions comprising at least one liquid crystal compound (liquid crystal molecule), which may be a liquid crystal composition exhibiting a nematic phase (hereinafter also referred to as a nematic liquid crystal), a liquid crystal exhibiting a smectic phase, or a liquid crystal composition exhibiting a cholesteric phase. Nematic liquid crystals are preferred. Furthermore, various liquid crystal compositions having positive or negative dielectric anisotropy may be used. Liquid crystal compositions having positive dielectric anisotropy are hereinafter referred to as positive-type liquid crystals, and liquid crystal compositions having negative dielectric anisotropy are hereinafter referred to as negative-type liquid crystals. The liquid crystal composition may also contain liquid crystal compounds having fluorine atoms, hydroxyl groups, amino groups, fluorine-containing groups (e.g., trifluoromethyl groups), cyano groups, alkyl groups, alkoxy groups, alkenyl groups, isothiocyanate groups, heterocyclic rings, cycloalkanes, cycloolefins, steroid skeletons, benzene rings, or naphthalene rings. It may also contain compounds having two or more rigid sites (mesogen skeletons) exhibiting liquid crystal properties within the molecule (e.g., bimesogen compounds formed by two rigid biphenyl structures or terphenyl structures linked via an alkyl group). Furthermore, the liquid crystal composition may further contain additives from the perspective of improving the liquid crystal alignment. Examples of such additives include photopolymerizable monomers such as compounds having polymerizable groups; optically active compounds (e.g., S-811 manufactured by Merck & Co., Ltd.); antioxidants; ultraviolet absorbers; pigments; defoaming 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. Negative-type liquid crystals include MLC-6608, MLC-6609, MLC-6610, MLC-7026, and MLC-7026-100 manufactured by Merck & Co. Furthermore, examples of liquid crystals containing a compound having a polymerizable group include MLC-3023 manufactured by Merck & Co. The liquid crystal alignment agent of the present invention is also applicable to a liquid crystal display device having a liquid crystal layer between a pair of substrates having electrodes. Such a liquid crystal display device is manufactured by placing a liquid crystal composition containing a polymerizable compound polymerized by at least one of active energy rays and heat between the pair of substrates, and polymerizing the polymerizable compound by applying a voltage between the electrodes and at least one of irradiation with active energy rays and heating (a PSA-type liquid crystal display device). Furthermore, the liquid crystal alignment agent of the present invention is also applicable to a liquid crystal display device having a liquid crystal layer between a pair of substrates having electrodes. Such a liquid crystal alignment film containing polymerizable groups polymerized by at least one of active energy rays and heat is placed between the pair of substrates, and a voltage is applied between the electrodes (a SC-PVA mode liquid crystal display device). <Step (4-2): In the case of a PSA-type liquid crystal display element> The same method as (4) above is employed except that a liquid crystal composition containing a polymerizable compound is injected or dripped. Examples of the polymerizable compound include those having one or more polymerizable unsaturated groups such as acrylate groups or methacrylate groups in the molecule. <Step (4-3): Case of SC-PVA mode liquid crystal display element> A method for manufacturing a liquid crystal display element by performing the same operation as in the above (4) and then irradiating it with ultraviolet rays as described later can also be adopted. According to this method, as in the case of manufacturing the above-mentioned PSA type liquid crystal display element, a liquid crystal display element with excellent response speed can be obtained with a smaller amount of light. The compound having a polymerizable group may also be a compound having one or more of the above-mentioned polymerizable unsaturated groups in the molecule, and its content is preferably 0.1 to 30 parts by mass, more preferably 1 to 20 parts by mass relative to 100 parts by mass of all polymer components. In addition, the polymer used in the liquid crystal alignment agent may also have the above-mentioned polymerizable group. As such a polymer, for example, a polymer obtained by using a diamine component containing a diamine having the above-mentioned photopolymerizable group at the end in the reaction can be cited. <Step (4-4): Step of irradiating with ultraviolet rays> Irradiate the liquid crystal cell with a voltage applied between the conductive films of one pair of substrates obtained in the above (4-2) or (4-3). The voltage applied here may be, for example, a direct current or alternating current of 5 to 50 V. Furthermore, as the irradiating light, for example, ultraviolet rays and visible light containing light with a wavelength of 150 to 800 nm may be used, but ultraviolet rays containing light with a wavelength of 300 to 400 nm are preferably used. As the light source of the irradiating light, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, an excimer laser, etc. may be used. The irradiation amount of light is preferably 1,000 to 200,000 J / m 2 , preferably 1,000~100,000J / m 2 . Then, as needed, a polarizing plate is attached to the outer surface of the liquid crystal cell to produce a liquid crystal display device. Examples of polarizing plates attached to the outer surface of the liquid crystal cell include a polarizing plate formed by sandwiching a so-called "H-film," a polarizing film made by stretching and aligning polyvinyl alcohol while adsorbing iodine, with a cellulose acetate protective film, or a polarizing plate consisting solely of the H-film. [Example] The following examples are given to illustrate the present invention in more detail, but the present invention should not be construed as being limited to these examples. The abbreviations of the compounds used and the methods for measuring the physical properties are as follows. (Tetracarboxylic dianhydride) CA-1 to CA-6: compounds represented by the following formulas (CA-1) to (CA-6) respectively [Chemical 14] (Specific diamine) DA-W1 to DA-W6: compounds represented by the following formulas (DA-W1) to (DA-W6) respectively (In addition, the compounds represented by the following formulas (DA-W1) to (DA-W6) and the above formula (d A -1)~(d A -6) (the same as the diamine shown). [Chemical 15] (Other diamines) DA-1 to DA-9: compounds represented by the following formulas (DA-1) to (DA-9) [Chemical 16] (Additives) AD-1 to AD-3: Compounds represented by the following formulas (AD-1) to (AD-3) [Chemical 17] (Solvent) NMP: N-methyl-2-pyrrolidone GBL: γ-butyrolactone BCS: ethylene glycol monobutyl ether AcOEt: ethyl acetate MeCN: acetonitrile THF: tetrahydrofuran CHCl 3: Chloroform [Viscosity Measurement] Viscosity was measured 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 conical rotor TE-1 (1°34', R24). [Molecular weight determination] Molecular weights were determined using the following normal temperature gel permeation chromatography (GPC) apparatus and calculated as polyethylene glycol / polyethylene oxide equivalents. GPC apparatus: SSC-7200 (manufactured by Senshu Scientific Co., Ltd.), columns: GPC KD-803 and GPC KD-805 (manufactured by Showa Denko Co., Ltd.) in series, column temperature: 50°C, eluent: N,N-dimethylformamide (with lithium bromide monohydrate (LiBr･H) as the additive). 2O) at 30 mmol / L, anhydrous phosphoric acid (orthophosphoric acid) at 30 mmol / L, tetrahydrofuran (THF) at 10 mL / L, flow rate: 1.0 mL / min. Standard samples used for calibration curve preparation: TSK standard polyethylene oxide (molecular weight: approximately 900,000, 150,000, 100,000, and 30,000) (manufactured by Tosoh Corporation) and polyethylene glycol (molecular weight: approximately 12,000, 4,000, and 1,000) (manufactured by Polymer Laboratories). [Synthesis of Monomers] DA-W1 to DA-W6 are novel compounds not disclosed in literature or the like. Their synthesis methods are described in detail below. < 1 H-NMR measurement > Apparatus: Fourier transform superconducting nuclear magnetic resonance (FT-NMR) instrument "AVANCE III" (made by BRUKER) 500 MHz Solvent: deuterated N,N-dimethylsulfoxide ([D 6]-DMSO) Standard substance: tetramethylsilane (TMS) <Example 1-1 Synthesis of [DA-W1]> [Chemical 18] 4-(4-tert-Butoxycarbonylaminoanilino)aniline (37.6 g, 126 mmol) and NMP (380 g) were added to a 1 L four-necked flask. CA-3 (18.5 g, 63.0 mmol) was then added in a water bath and stirred at room temperature for reaction. After confirming the disappearance of the amino group by NMR, the reaction solution was poured into AcOEt (2000 g), and the organic layer was washed with pure 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 resulting crude product, and the product was stirred at 60°C for reaction. After the reaction was completed, the reaction solution was poured into pure water (2500 g), and the precipitate was filtered off. MeCN (800 g) was added to the resulting crude product, and the product was reslurried and washed at room temperature. THF (700 g) was further added to the crude product to completely dissolve it, and then the product was concentrated until precipitation occurred. AcOEt (300 g) was then added, and the product was reslurried and washed at room temperature to obtain [DA-W1-1] (42.7 g, 49.8 mmol, yield: 79%). After adding [DA-W1-1] (39.7 g, 46.3 mmol), 12N hydrochloric acid (6.8 g), and AcOEt (1190 g) to a 2L four-necked flask, the mixture was stirred at 60°C to react. After the reaction was completed, the precipitate was filtered out, MeCN (500 g) was added to the obtained crude product, and the mixture was neutralized with triethylamine until it became alkaline, and the precipitate was filtered out. DMF (90 g) was added to the obtained crude product, and after it was completely dissolved, MeCN (600 g) was added to precipitate the solid. The precipitate was filtered out, and MeCN (600 g) was added to the crude product again, and the mixture was re-slurried 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. From these results, it was confirmed that the obtained solid was the target [DA-W1]. 1 H-NMR (500 MHz, [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) <Example 1-2 Synthesis of [DA-W2]> [Chemical 19] To a 3 L four-necked flask, 4,4'-diaminodiphenyl-N-methylamine (128 g, 600 mmol) and THF (1900 g) were added dropwise in a water bath. Di-tert-butyl dicarbonate (43.7 g, 200 mmol) was added and the mixture was stirred at room temperature to allow reaction. 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, 89% yield). [DA-W2-1] (55.5 g, 177 mmol) and NMP (550 g) were added to a 1 L four-necked flask, followed by CA-3 (26.0 g, 89 mmol) in a water bath. The mixture was stirred 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 mixture, and the mixture was stirred at 60°C to allow the reaction to proceed. After the reaction was completed, the reaction mixture was poured into pure water (2500 g), and the precipitate was filtered off. AcOEt (1000 g) was added to the resulting crude product, and the mixture was reslurried and washed at 70°C to obtain [DA-W2-2] (36.3 g, 41.0 mmol, yield: 92%). After adding [DA-W2-2] (36.3 g, 41.0 mmol), 12N hydrochloric acid (16.7 g), and AcOEt (720 g) to a 3L four-necked flask, the mixture was stirred at 70°C to react. After the reaction was completed, the precipitate was filtered out, MeCN (600 g) was added to the crude product obtained, and the mixture was neutralized with triethylamine until it became alkaline, and the precipitate was filtered out. NMP (60 g) was added to the crude product obtained, and after it was completely dissolved, MeCN (800 g) was injected into it. The precipitate was filtered out, and MeCN (300 g) was added to the crude product again, and the product was re-slurried 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. From these results, it was confirmed that the obtained solid was the target [DA-W2]. 1 H-NMR (500 MHz, [D 6]-DMSO): δ(ppm)=8.33-8.36(m,4H), 8.04-8.05(d,2H), 7.15-7.17(d,4H), 6. 90-6.92(d,4H), 6.68-6.70(d,4H), 6.62-6.64(d,4H), 5.08(s,4H), 3.19(s,6H) <Example 1-3 Synthesis of [DA-W3]> [Chemical 20] 4-(4-tert-Butoxycarbonylaminoanilino)aniline (29.9 g, 100 mmol) and NMP (300 g) were added to a 500 mL four-necked flask, and CA-6 (9.82 g, 45.0 mmol) was added thereto in a water bath, and the mixture was stirred at room temperature to react. After confirming the disappearance of the amino group by NMR, the reaction solution was poured into AcOEt (1000 g), and the organic layer was washed with pure water (1000 g) and concentrated. The obtained crude product was Pyridine (21.4 g, 270 mmol), acetic anhydride (13.8 g, 135 mmol), and NMP (370 g) were added to the mixture and stirred at 60°C for reaction. After completion of the reaction, the reaction solution was poured into MeCN (2000 g), and the precipitate was filtered. MeCN (500 g) was added to the resulting precipitate, and the mixture was reslurried and washed at 70°C to obtain [DA-W3-1] (29.9 g, 38.3 mmol, yield: 85%). [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-necked flask and stirred at 60°C to allow the reaction to proceed. After the reaction was completed, the precipitate was filtered out, NMP (500 g) was added to the obtained crude product, and triethylamine was used to neutralize it until it became alkaline, and the precipitate was filtered out. MeCN (2500 g) was added to the obtained crude product, and the product was re-slurried 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. From these results, it was confirmed that the obtained solid was the target [DA-W3]. 1 H-NMR (500 MHz, [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) <Example 1-4 Synthesis of [DA-W4]> [Chemical 21] [DA-W2-1] (22.1 g, 70.5 mmol) and NMP (220 g) were added to a 500 mL four-necked flask, followed by the addition of CA-6 (7.70 g, 35.3 mmol) in a water bath. The mixture was stirred 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, and the mixture was stirred at 50°C to allow the reaction to proceed. After the reaction was completed, the reaction solution was poured into pure water (1500 g), and the precipitate was filtered off. MeCN (500 g) was added to the resulting crude product, and the mixture was reslurried and washed at 70°C to obtain [DA-W4-1] (24.5 g, 30.3 mmol, yield: 86%). [DA-W4-1] (24.5 g, 30.3 mmol), trifluoroacetic acid (34.2 g, 300 mmol), and CHCl were added to a 500 mL four-necked flask. 3 (250 g), stirred at 50 ° C to react. After the reaction is completed, the reaction solution is injected into hexane (250 g), and the precipitate is filtered out. THF (450 g) is added to the obtained crude product, and triethylamine is used to neutralize it until it becomes alkaline, and the precipitate is filtered out. THF (450 g) is added to the obtained crude product, and re-slurry washing is carried out at 60 ° C to obtain the target [DA-W4] (brown solid) (17.6 g, 28.9 mmol, yield: 95%). The target 1 The results of H-NMR are shown below. From these results, it was confirmed that the obtained solid was the target [DA-W4]. 1 H-NMR (500 MHz, [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) <Example 1-5 Synthesis of [DA-W5]> [Chemical 22] 4-(4-tert-Butoxycarbonylaminoanilino)aniline (12.0 g, 40.0 mmol) and NMP (120 g) were added to a 1 L four-necked flask, followed by the addition of CA-5 (6.44 g, 20.0 mmol) in a water bath. The mixture was stirred at room temperature for reaction. After confirming the disappearance of the amine group by NMR, the reaction solution was poured into AcOEt (600 g), and the organic layer was washed with pure 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 resulting crude product, and the mixture was stirred at 60°C for reaction. After completion of the reaction, the reaction solution was poured into MeCN (1000 g), and the precipitate was filtered. MeCN (500 g) was added to the obtained precipitate, and reslurry washing was performed at room temperature to obtain [DA-W5-1] (15.8 g, 17.9 mmol, yield: 90%). After adding [DA-W5-1] (15.8 g, 17.9 mmol), 12N hydrochloric acid (7.0 g), and AcOEt (320 g) to a 1L four-necked flask, the mixture was stirred at 70°C to react. After the reaction was completed, the precipitate was filtered out, MeCN (400 g) was added to the crude product obtained, and triethylamine was used to neutralize it until it became alkaline, and the precipitate was filtered out. NMP (150 g) was added to the crude product obtained, and after it was completely dissolved, MeCN (400 g) was added. The precipitate was filtered out, and MeCN (250 g) was added to the crude product again, and the product was re-slurried and washed at 80°C to obtain the target [DA-W5] (red-purple solid) (11.5 g, 16.8 mmol, yield: 94%). 1 The results of H-NMR are shown below. From these results, it was confirmed that the obtained solid was the target [DA-W5]. 1 H-NMR (500 MHz, [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) <Example 1-6 Synthesis of [DA-W6]> [Chemical 23] [DA-W2-1] (11.5 g, 36.7 mmol) and NMP (120 g) were added to a 300 mL four-necked flask, and CA-5 (5.9.0 g, 18.3 mmol) was added thereto in a water bath, and the mixture was stirred at room temperature to allow the reaction to proceed. 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 resulting crude product, and the mixture was stirred at 60°C to allow the reaction to proceed. After the reaction was completed, the reaction solution was poured into pure water (600 g) and the precipitate was filtered out. MeCN (500 g) was added to the obtained crude product, and reslurry washing was performed at room temperature to obtain [DA-W6-1] (16.1 g, 17.6 mmol, yield: 96%). After adding [DA-W6-1] (16.1 g, 17.6 mmol), 12N hydrochloric acid (29.7 g), and AcOEt (320 g) to a 3L four-necked flask, the mixture was stirred at 70°C to react. After the reaction was completed, the precipitate was filtered out, MeCN (700 g) was added to the crude product obtained, and the mixture was neutralized with triethylamine until it became alkaline, and the precipitate was filtered out. NMP (60 g) was added to the crude product obtained, and after it was completely dissolved, MeCN (360 g) was injected into it. The precipitate was filtered out, and MeCN (100 g) was added to the crude product again, and the product was re-slurried 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. From these results, it was confirmed that the obtained solid was the target [DA-W6]. 1 H-NMR (500 MHz, [D 6]-DMSO): δ(ppm)=8.22-8.24(d,2H), 8.12-8.14(m,4H), 7.15-7.17(d,4H), 6. 90-6.91(d,4H), 6.68-6.70(d,4H), 6.61-6.63(d,4H), 5.09(s,4H), 3.19(s,6H) [Polymer Synthesis] <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-necked flask equipped with a stirrer and a nitrogen inlet tube. The mixture was stirred at room temperature while nitrogen was introduced to dissolve the mixture. CA-1 (0.977 g, 4.98 mmol) and NMP (1.85 g) were then added and stirred at room temperature for 2 hours. This yielded a polyamide (PAA-A1) solution with a solids concentration of 12% by mass (viscosity: 563 mPa·s). <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-necked flask equipped with a stirrer and a nitrogen inlet tube. The mixture was stirred at room temperature while nitrogen was introduced until dissolved. CA-1 (1.42 g, 7.23 mmol) and NMP (3.86 g) were then added and stirred at room temperature for 2 hours. This yielded a polyamide (PAA-A2) solution with a solids concentration of 12% by mass (viscosity: 402 mPa·s). <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-necked flask equipped with a stirrer and a nitrogen inlet tube. Dissolution was achieved by stirring at room temperature while nitrogen was introduced. CA-1 (0.153 g, 0.781 mmol) and NMP (1.13 g) were then added, followed by stirring at room temperature for 1 hour. CA-2 (1.31 g, 5.25 mmol) and NMP (9.63 g) were then added, and the mixture was stirred at 50°C for 12 hours. This yielded a polyamide (PAA-A3) solution with a solids concentration of 12% by mass (viscosity: 396 mPa·s). <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-necked flask equipped with a stirrer and a nitrogen inlet tube. The mixture was stirred at room temperature while nitrogen was introduced to dissolve the mixture. CA-1 (1.06 g, 5.40 mmol) and NMP (2.26 g) were then added and stirred at room temperature for 2 hours. This yielded a polyamine (PAA-A4) solution with a solids concentration of 12% by mass (viscosity: 411 mPa·s). <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-necked flask equipped with a stirrer and a nitrogen inlet tube. The mixture was stirred at room temperature while nitrogen was introduced to dissolve the mixture. CA-1 (1.50 g, 7.67 mmol) and NMP (4.33 g) were then added and stirred at room temperature for 2 hours. This yielded a polyamide (PAA-A5) solution with a solids concentration of 12% by mass (viscosity: 396 mPa·s). <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-necked flask equipped with a stirrer and a nitrogen inlet tube. The mixture was stirred at room temperature while nitrogen was introduced to dissolve the mixture. CA-1 (0.804 g, 4.10 mmol) and NMP (2.99 g) were then added and stirred at room temperature for 2 hours. This yielded a polyamide (PAA-A6) solution with a solids concentration of 10% by mass (viscosity: 237 mPa·s). <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-necked flask equipped with a stirrer and a nitrogen inlet tube. The mixture was stirred at room temperature while nitrogen was introduced to dissolve the mixture. CA-1 (1.02 g, 5.22 mmol) and NMP (2.49 g) were then added and stirred at room temperature for 2 hours. This yielded a polyamide (PAA-A7) solution with a solids concentration of 12% by mass (viscosity: 413 mPa·s). <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-necked flask equipped with a stirrer and a nitrogen inlet tube. Dissolution was achieved by stirring at room temperature while nitrogen was introduced. CA-3 (2.80 g, 9.52 mmol) and NMP (11.9 g) were then added, followed by stirring at 70°C for 4 hours. CA-1 (2.52 g, 12.8 mmol) and NMP (18.5 g) were then added, and the mixture was stirred at room temperature for 2 hours. This yielded a polyamide (PAA-B1) solution having a solids concentration of 12% by mass (viscosity: 423 mPa·s). 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-necked flask equipped with a stirrer and a nitrogen inlet tube. Dissolution was achieved by stirring at room temperature while nitrogen was introduced. CA-3 (2.80 g, 9.52 mmol) and NMP (10.1 g) were then added, followed by stirring at 70°C for 4 hours. CA-1 (2.58 g, 13.2 mmol) and NMP (18.9 g) were then added, and the mixture was stirred at room temperature for 2 hours. This yielded a polyamide (PAA-B2) solution having a solids concentration of 12% by mass (viscosity: 378 mPa·s). <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-necked flask equipped with a stirrer and a nitrogen inlet tube. Dissolution was achieved by stirring at room temperature while nitrogen was introduced. CA-3 (2.80 g, 9.52 mmol) and NMP (11.9 g) were then added, and the mixture was stirred at 70°C for 4 hours. CA-1 (0.513 g, 2.62 mmol) and NMP (3.76 g) were then added, and the mixture was stirred at room temperature for 1 hour. CA-2 (2.68 g, 10.7 mmol) and NMP (19.6 g) were then added, and the mixture was stirred at 50°C for 12 hours. This yielded a polyamide (PAA-B3) solution with a solids concentration of 12% by mass (viscosity: 410 mPa·s). <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-necked flask equipped with a stirrer and a nitrogen inlet tube. The mixture was stirred at room temperature while nitrogen was introduced to dissolve the mixture. CA-4 (5.31 g, 23.7 mmol) and NMP (20.1 g) were then added and stirred at 50°C for 12 hours to obtain a polyamide (PAA-U1) solution having a solids concentration of 12% by mass (viscosity: 402 mPa·s). <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-necked flask equipped with a stirrer and a nitrogen inlet tube. The mixture was stirred at room temperature while nitrogen was introduced to dissolve the mixture. CA-4 (6.32 g, 28.2 mmol) and NMP (30.0 g) were then added and stirred at 40°C for 3 hours to obtain a polyamide (PAA-U2) solution with a solids concentration of 12% by mass (viscosity: 220 mPa·s). <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-necked flask equipped with a stirrer and a nitrogen inlet tube. The mixture was stirred at room temperature while nitrogen was introduced to dissolve the mixture. CA-3 (11.3 g, 38.4 mmol) and NMP (82.9 g) were then added, and the mixture was stirred at 70°C for 24 hours to obtain a polyamine (PAA-C1) solution having a solids concentration of 12% by mass. <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-necked flask equipped with a stirrer and a nitrogen inlet tube. The mixture was stirred at room temperature while nitrogen was introduced to dissolve the mixture. CA-3 (4.50 g, 15.3 mmol) and NMP (20.5 g) were then added and stirred at 50°C for 16 hours to obtain a polyamide (PAA-C2) solution with a solids concentration of 15% by mass (viscosity: 350 mPa·s). The specifications of the polyamide obtained in the above synthesis example are shown in Table 1. In the table, the values ​​in parentheses for the tetracarboxylic acid component and the diamine component represent the amount (in moles) of each tetracarboxylic acid component or each diamine component used per 100 moles of the total amount of the diamine component used in the polymerization. [Table 1] Here, the specific diamine DA-W1 is a structure obtained by reacting one molecule of tetracarboxylic dianhydride CA-3 with two molecules of diamine DA-7. The synthesis of the polyamide PAA-A1 of Example 2-1 is equivalent to reacting monomer components comprising 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. Of these monomer components, if the total of DA-4 and DA-7 is 100 mol parts, the molar ratio of each monomer component is 50 mol parts of CA-1, 39 mol parts of CA-3, 79 mol parts of DA-7, and 21 mol parts of DA-4, resulting in a monomer composition substantially the same as that of the polyamide PAA-B1 of Comparative Example 2-1. On the other hand, the polyamide PAA-A1 of Example 2-1 is a polymer having an imide structure with the imide structures located adjacent to each other. In contrast, the polyamide PAA-B1 of Comparative Example 2-1 is a polymer having only an imide structure. The resulting liquid crystal alignment film exhibits different properties as described below. Similarly, the polyamides PAA-A2 to PAA-A3 have substantially the same monomer composition as the polyamides PAA-B2 to PAA-B3, respectively. [Preparation of liquid crystal alignment agent] <Example 3-1> Use the solution of polyamine (PAA-A1) obtained in Example 2-1, dilute it with NMP, GBL and BCS, and stir it at room temperature for 2 hours to obtain a liquid crystal alignment agent (AL-1) with a mass ratio of polymer solid component to each solvent (polymer solid component: NMP: GBL: BCS) of 4.5:45.5:30:20. <Examples 3-2 to 3-3, Comparative Examples 3-1 to 3-3> As shown in Table 2, the same procedures as in Example 3-1 were followed except that the polyamine used was replaced with PAA-A2 to PAA-A3 and PAA-B1 to PAA-B3 from PAA-A1 to obtain liquid crystal alignment agents (AL-2) to (AL-3) and (AL-C1) to (AL-C3). <Example 3-4> A solution of polyamine (PAA-U1) obtained in Preparation Example 2-1 and a solution of polyamine (PAA-A1) obtained in Example 2-1 were diluted with NMP, GBL, and BCS, and stirred at room temperature for 2 hours to obtain a liquid crystal alignment 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. <Examples 3-5 to 3-6> As shown in Table 2, the same procedures as in Example 3-4 were followed except that the polyamine used was replaced with PAA-A2 to PAA-A3 from PAA-A1 to obtain liquid crystal alignment agents (AL-5) to (AL-6). <Example 3-7> The solution of polyamine (PAA-U1) obtained in Preparation Example 2-1 and the solution of polyamine (PAA-A1) obtained in Example 2-1 were diluted with NMP, GBL, and BCS, and AD-1 was added. The mixture was stirred at room temperature for 2 hours to obtain a liquid crystal alignment agent (AL-7) having a polymer solid content ratio (PAA-U1:PAA-A1) of 5:5, 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, and a blending ratio of AD-1 of 5 parts by mass relative to 100 parts by mass of the total polymer content. <Examples 3-8 to 3-11, Comparative Example 3-4> As shown in Table 2, the same procedures as in Example 3-7 were followed, except that the polyamine used was replaced with PAA-A2 to PAA-A5 and PAA-C1 instead of PAA-A1, to obtain liquid crystal alignment agents (AL-8) to (AL-11) and (AL-C4). Comparative Example 3-5: The polyamine solution (PAA-U2) obtained in Preparation Example 2-2 and the polyamine solution (PAA-C2) obtained in Preparation Example 2-4 were diluted with NMP, GBL, and BCS, and AD-1 to AD-3 were added. The mixture was stirred at room temperature for 2 hours to obtain a liquid crystal alignment agent (AL-C5) having a polymer solids ratio (PAA-U2:PAA-C2) of 3:7, a mass ratio of the total polymer solids to the solvents (polymer solids: NMP:GBL:BCS) of 5.5:44.5:30:20, and a blending ratio of AD-1, AD-2, and AD-3 of 5 parts by mass, 1 part by mass, and 14 parts by mass, respectively, relative to 100 parts by mass of the total polymer amount. [Table 2] In the table, the values ​​in parentheses for polyamines represent the content (parts by mass) of each polyamine relative to 100 parts by mass of the total polymer content of each liquid crystal alignment agent. The values ​​in parentheses for additives represent the content (parts by mass) of each additive relative to 100 parts by mass of the total polymer content of each liquid crystal alignment agent. [Fabrication of liquid crystal cells] A liquid crystal cell having the structure of an FFS mode liquid crystal display element is fabricated. First, a substrate with electrodes is prepared. A glass substrate with a rectangular shape of 30mm×50mm and a thickness of 0.7mm is used as the substrate. An ITO electrode with a full-plate pattern constituting a counter electrode is formed on the substrate as the first layer, and a SiN (silicon nitride) film formed by CVD (chemical vapor deposition) is formed on the counter electrode of the first layer as the second layer. The SiN film of the second layer uses a film with a thickness of 300nm, which functions as an interlayer insulating film. A comb-shaped pixel electrode formed by patterning the ITO film is arranged on the SiN film of the second layer as the third layer, in which two types of pixels, the first pixel and the second pixel, are formed, and the size of each pixel is 10mm in the vertical direction and about 5mm in the horizontal direction. At this time, the counter electrode of the first layer and the pixel electrode of the third layer are electrically insulated due to the action of the SiN film of the second layer. The pixel electrode in the third layer has a comb-like shape, with multiple electrode elements, each 3 μm wide and bent at an internal angle of 160°, arranged in parallel at intervals of 6 μm. Within each pixel, the lines connecting the bent portions of the multiple electrode elements form a boundary, each comprising a first region and a second region. 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 filtered through a 1.0 μm pore size filter and then spin-coated onto the surface of the electrode-attached substrate (first glass substrate) prepared above and onto the surface of a glass substrate (second glass substrate) with a 4 μm-high columnar spacer and an ITO film formed on the back surface. The coating was then dried on an 80°C hot plate for 2 minutes and then calcined in a 230°C hot air circulating oven for 30 minutes to form a 100 nm thick coating film. Through the polarizing plate at 300mJ / cm 2The coated surface was irradiated with linearly polarized ultraviolet light at a wavelength of 254 nm with an extinction ratio of 26:1 to perform an alignment treatment, yielding a substrate with a liquid crystal alignment film. Furthermore, the liquid crystal alignment film formed on the electrode-attached substrate was aligned so that the direction bisecting the inner angle of the pixel bend was perpendicular to the liquid crystal alignment direction. 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 and the second glass substrate would align during the formation of the liquid crystal cell. The two substrates were set together, and a sealant (XN-1500T manufactured by Mitsui Chemicals, Inc.) was printed around the liquid crystal injection port, leaving the liquid crystal injection port intact. The other substrate was then bonded together so that the alignment direction of the liquid crystal alignment film facing each other was 0°. The sealant was then cured to produce a cell. Positive-type liquid crystal MLC-3019 (Merck) was injected into the cell using a reduced-pressure injection method, and the injection port was sealed to produce an FFS-driven liquid crystal cell. Thereafter, the obtained liquid crystal cell was heated at 110° C. for 1 hour and allowed to stand overnight before evaluation. [Evaluation of Voltage Holding Ratio] A voltage of 1V was applied to the FFS-driven liquid crystal cell fabricated according to the above procedure at 60°C for 60 μsec. The voltage was measured 1000 msec later, and the degree to which the voltage could be maintained was calculated as the voltage holding ratio. The voltage holding ratio was measured using a VHR-1 manufactured by Dongyang Technology Co., Ltd. A higher voltage holding ratio value is preferred. The results are shown in Table 3. [Evaluation of Liquid Crystal Alignment Stability] This evaluation assesses image sticking (also known as AC image sticking) caused by degradation of the alignment performance of the liquid crystal alignment film during long-term AC drive. The FFS-driven liquid crystal cell fabricated above was subjected to an AC voltage of ±4V at a frequency of 60Hz for 120 hours at a constant temperature of 60°C. The pixel electrode and counter electrode of the liquid crystal cell were then short-circuited and left at room temperature for one day. For the treated liquid crystal cell, the deviation angle between the alignment direction of the liquid crystal in the first region of the pixel and the alignment direction of the liquid crystal in the second region in the absence of applied voltage was calculated. Specifically, the liquid crystal cell was placed between two polarizing plates with their polarization axes orthogonal to each other. The backlight was turned on, and the configuration angle of the liquid crystal cell was adjusted to minimize the intensity of light transmitted through the first region of the first pixel. The angle Δ was calculated as the angle required to rotate the liquid crystal cell to minimize the intensity of light transmitted through the second region of the first pixel. Similarly, the first and second regions of the second pixel were compared, and the angle Δ was calculated in the same manner. Next, the average of the angles Δ between the first and second pixels was calculated as the liquid crystal cell's rotation angle Δ. In terms of liquid crystal alignment stability, the smaller the rotation angle Δ, the better. As an evaluation standard, liquid crystal cell rotation angles Δ values ​​below 0.10° were rated "○," while those greater than 0.10° were rated "×." The results are shown in Table 3. [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 applied to an ITO substrate by spin coating. After drying on a hot plate at 80°C for 2 minutes, they were calcined in an IR oven at 230°C for 30 minutes to form a coating film with a thickness of 100 nm. The coating surface was subjected to a 300 mJ / cm2 irradiation through a polarizing plate. 2 Alignment treatment was performed by irradiating the substrate with linearly polarized ultraviolet light at a wavelength of 254 nm and an extinction ratio of 26:1, followed by calcination in a 230°C IR oven for 30 minutes to obtain a substrate with a liquid crystal alignment film. The liquid crystal alignment film was then rubbed with rayon cloth (YA-20R, manufactured by Yoshikawa Chemical Industry) (roller diameter: 120 mm, roller rotation speed: 1000 rpm, travel speed: 20 mm / sec, push length: 0.5 mm). The haze value (turbidity) of the film was evaluated using a haze meter (HZ-V3, manufactured by Suga Test Instruments). The lower the haze value, the less likely the film was scraped, indicating a higher film hardness. As an evaluation standard, haze values ​​of 0.20 or less were rated "○" and those greater than 0.20 were rated "×." The results are shown in Table 3. [Evaluation of Molecular Weight Change Before and After Calcination] 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 were spin-coated onto an ITO substrate. After drying on an 80°C hot plate for 2 minutes, the films were calcined in an IR oven at 230°C for 30 minutes to form a 100 nm thick film. The calcined films were scraped off, and their molecular weights were measured to evaluate the molecular weight change before and after calcination (weight average molecular weight after calcination ÷ weight average molecular weight before calcination × 100 [%]). The results are shown in Table 3. [Table 3] As shown in Table 3, liquid crystal alignment films obtained from liquid crystal alignment agents using a diamine component containing a specific diamine suppress molecular weight degradation during calcination compared to liquid crystal alignment films obtained from liquid crystal alignment agents using a diamine component not containing the specific diamine. They exhibit high voltage holding ratios even after prolonged exposure to high temperatures. Furthermore, liquid crystal alignment films obtained from liquid crystal alignment agents using a diamine component containing the specific diamine exhibit high liquid crystal alignment stability and film hardness. Furthermore, when a polymer (B) obtained from a diamine component not containing the specific diamine is used in addition to a polymer (P) obtained from a diamine component containing the specific diamine in the liquid crystal alignment agent, a further improvement in voltage holding ratio is observed. (Comparison of Examples 3-1 to 3-3 with Examples 3-4 to 3-6). In addition, all the contents of the specification, claims, drawings and abstract of Japanese Patent Application No. 2022-079186 filed on May 13, 2022 are hereby cited and incorporated into the disclosure of the specification of the present invention.

Claims

1. A diamine, which is a diamine represented by any one of the following formulas (dA-1) to (dA-6): .

2. A polymer comprising at least one polymer selected from the group consisting of a polyimide precursor obtained using a diamine component comprising a diamine as claimed in claim 1 and a polyimide of a polyimide derivative thereof.

3. The polymer as claimed in claim 2, wherein, The diamine component further includes diamines having at least one group selected from the group consisting of urea bonds, amide bonds, carboxyl groups, and hydroxyl groups within the molecule.

4. The polymer as claimed in claim 2 or 3, wherein, For example, the amount of diamine used in Request 1 is 5 moles or more relative to the diamine component.

5. The polymer as claimed in claim 2 or 3, wherein, The polymer is obtained by the polymerization reaction of the diamine component and the tetracarboxylic acid component, the tetracarboxylic acid component including tetracarboxylic dianhydride or its derivatives.

6. The polymer as claimed in claim 5, wherein, The tetracarboxylic dianhydride or its derivatives are acyclic aliphatic tetracarboxylic dianhydrides, alicyclic tetracarboxylic dianhydrides, aromatic tetracarboxylic dianhydrides, or derivatives thereof.

7. The polymer as claimed in claim 5, wherein, The tetracarboxylic dianhydride or its derivatives are as follows: noncyclic aliphatic tetracarboxylic dianhydrides of 1,2,3,4-butanetetracarboxylic dianhydride; Selected from 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dichloro-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-difluoro-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-bis(trifluoromethyl)-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3',4,4'-dicyclohexyltetracarboxylic dianhydride, 2,3,5-tricarboxylated cyclopentylacetic acid dicarboxylic acid dicarboxylic dianhydride, and 2,3,5-tricarboxylated cyclopentylacetic acid dicarboxylic dianhydride. Anhydrides, 4-(2,5-dioxytetrahydrofuran-3-yl)tetrahydronaphthyl-1,2-dicarboxylic anhydride, 5-(2,5-dioxytetrahydrofuran-3-yl)-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 5-(2,5-dioxytetrahydrofuran-3-yl)-8-methyl-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic anhydride, bicyclo[2.2.2]octane-2,3,5,6-tetracarboxylic anhydride and 2,4,6,8-tetracarboxylic bicyclo[3.3.0]octane-2:4,6:8-dianhydride, and alicyclic tetracarboxylic anhydrides; Selected from benzopyrene dianhydride, 3,3',4,4'-diphenyl ketone tetracarboxylic dianhydride, 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride, 1,4,5,8-naphthalene tetracarboxylic dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride, 3,3',4,4'-biphenyl tetracarboxylic dianhydride, 2,2',3,3'-biphenyl tetracarboxylic dianhydride, 4,4'-bis(3, Aromatic tetracarboxylic acid dianhydrides selected from 4-dicarboxyphenoxy)-2,2-diphenylpropane dianhydride, ethylene glycol bis(phenyltricarboxylic anhydride), 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 4,4'-carbonyldiphthalic anhydride, 4,4'-(1,4-epylphenyldioxy)bis(phthalic anhydride), and 4,4'-(1,4-epylphenyldimethyl)bis(phthalic anhydride); or derivatives thereof.

8. A liquid crystal alignment agent comprising a polymer as claimed in any one of claims 2 to 7.

9. The liquid crystal alignment agent of claim 8 further comprises at least one polymer (B) selected from the group consisting of a polyimide precursor obtained by using a diamine component that does not contain the diamine of claim 1 and a polyimide that is a polyimide derivative of the polyimide precursor.

10. The liquid crystal alignment agent as claimed in claim 9, wherein, The polymer (B) is obtained by the polymerization reaction of the diamine component and the tetracarboxylic acid component, the tetracarboxylic acid component including tetracarboxylic dianhydride or its derivatives.

11. The liquid crystal alignment agent as described in any of claims 8 to 10, wherein, The liquid crystal alignment agent further contains at least one additive selected from crosslinking compounds, functional silane compounds, metal chelate compounds, curing accelerators, surfactants, antioxidants, sensitizers, preservatives, compounds for adjusting the dielectric constant and resistance of the obtained liquid crystal alignment film, and compounds for promoting aceimination. The crosslinking compound is selected from at least one crosslinking compound (c-1) having at least one substituent selected from ethylene oxide, oxetane, terminal isocyanate, oxazolinyl, cyclocarbonate, hydroxyl, and alkoxy groups, and crosslinking compounds (c-2) having polymerizable unsaturated groups.

12. A liquid crystal alignment film obtained from a liquid crystal alignment agent as claimed in any one of claims 8 to 11.

13. A liquid crystal display element comprising a liquid crystal alignment film as claimed in claim 12.

14. A method for manufacturing a liquid crystal display element, comprising the following steps (1) to (3): Step (1): applying a liquid crystal alignment agent as claimed in any one of claims 8 to 11 onto a substrate; Step (2): calcining the applied liquid crystal alignment agent to obtain a thin film; Step (3): performing an alignment treatment on the thin film obtained in step (2).

15. A method for manufacturing a liquid crystal display element as claimed in claim 14, wherein, This alignment process is an optical alignment process.