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

Abstract

The purpose of the present invention is to provide a liquid crystal alignment film in which alignment unevenness of liquid crystal does not occur. Furthermore, another purpose of the present invention is to provide: a liquid crystal alignment agent for producing the liquid crystal alignment film; and a liquid crystal display element including the liquid crystal alignment film.　Provided is a liquid crystal alignment agent containing a component (A) and a component (B) or the component (A) and a component (C).　Component (A): a polyimide polymer obtained by reacting a compound represented by formula [A-CA] with a diamine component and by reacting the reaction product with a dicarboxylic acid anhydride represented by formula [EA-1a] to formula [EA-2b] or a monoepoxy compound.　Component (B): a polyimide polymer obtained by reacting a diamine component with a compound represented by formula [B-CA].　Component (C): a polyimide polymer obtained by reacting a compound represented by formula [B-CA] with a diamine component and by reacting the reaction product with a dicarboxylic acid anhydride represented by formula [EB-1a] to formula [EB-3b] or a monoepoxy compound. (In the formulas, each symbol is as defined in the specification.)

Description

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

[0001] The present invention relates to a liquid crystal alignment agent used in the manufacture of liquid crystal display elements, a liquid crystal alignment film obtained from the liquid crystal alignment agent, and a liquid crystal display element using the liquid crystal alignment film.

[0002] Currently, polyimide-based organic films, which offer excellent durability, are widely used as resin coatings in industrial applications. In particular, these polyimide-based organic films are also used as liquid crystal alignment films for liquid crystal display elements. Polyimide-based organic films are formed from a resin composition containing polyimide precursors such as polyamic acid and polyimide. That is, a resin composition containing polyamic acid and polyimide is applied to a substrate and formed through a firing process. In lateral electric field driven liquid crystal display elements such as IPS (In-Plane Switching) and FFS (Fringe Field Switching) drive systems, orientation treatments such as rubbing or photo-alignment are performed on the liquid crystal alignment film after firing to align the liquid crystals horizontally. This involves rubbing the film in a specific direction with a roll wrapped in a cloth made of nylon, rayon, or cotton.

[0003] In recent years, with the increasing size and resolution of liquid crystal display elements, problems such as low in-plane uniformity of liquid crystal orientation have arisen. In response to this, photo-alignment processing, which regulates the orientation of liquid crystals by irradiating them with polarized radiation (light), has begun to be adopted. This photo-alignment processing utilizes photoisomerization reactions, photocrosslinking reactions, and photodecomposition reactions (see, for example, Patent Documents 1 to 3).

[0004] Japanese Patent Publication No. 9-297313, Japanese Patent Publication No. 2004-206091, International Patent Publication No. WO2017 / 047596

[0005] Currently, in IPS-driven and FFS-driven liquid crystal display elements, alignment is performed by optical alignment processing. However, optical alignment processing is prone to variations in the amount of light irradiated within the liquid crystal alignment film surface (uneven illumination). As a result, uneven alignment of the liquid crystal is likely to occur, leading to problems such as display unevenness defects in liquid crystal display elements. Therefore, the present invention aims to provide a liquid crystal alignment film that does not produce uneven alignment of the liquid crystal. Furthermore, the present invention aims to provide a liquid crystal alignment agent for producing the liquid crystal alignment film, and a liquid crystal display element having the liquid crystal alignment film.

[0006] The inventors have diligently conducted research to achieve the above objectives and have completed the present invention having the following gist. That is, a liquid crystal alignment agent containing the following components (A) and (B), or the following components (A) and (C). Component (A): A tetracarboxylic acid component containing a tetracarboxylic acid dianhydride of the following formula [A-CA] and its derivatives (hereinafter also referred to as "specific tetracarboxylic acid (A)") is reacted with a diamine component, and at least one polyimide precursor and at least one polymer selected from polyimides (hereinafter also referred to as "specific compound (A)") obtained by reacting the tetracarboxylic acid component, which includes a tetracarboxylic acid dianhydride of the following formula [EA-1a] to [EA-3a], or at least one monoepoxy compound selected from the following formulas [EA-1b] and [EA-2b] (hereinafter collectively referred to as "specific compound (A)"). Component (B): At least one polymer selected from polyimide precursors and polyimides obtained by reacting a tetracarboxylic acid component containing the tetracarboxylic acid dianhydride of the following formula [B-CA] and its derivatives (hereinafter also referred to as "specific tetracarboxylic acid (B)") with a diamine component (hereinafter also referred to as "specific polymer (B)"). However, this is different from component (C) below. Component (C): At least one polymer selected from polyimide precursors and polyimides obtained by reacting a tetracarboxylic acid component containing the tetracarboxylic acid dianhydride of the following formula [B-CA] and its derivatives with a diamine component, and then reacting it with at least one dicarboxylic acid anhydride selected from the following formulas [EB-1a] to [EB-11a] or at least one monoepoxy compound selected from the following formulas [EB-1b] to [EB-3b] (hereinafter collectively referred to as "specific compound (B)") (hereinafter also referred to as "specific polymer (C)"). (R １ ~R ４ Each independently represents a hydrogen atom, a halogen atom, a C1-C6 alkyl group, a C2-C6 alkenyl group, a C2-C6 alkynyl group, a C1-C6 monovalent organic group containing a fluorine atom, a C1-C6 alkoxy group, a C2-C6 alkoxyalkyl group, a C2-C6 alkyloxycarbonyl group, or a phenyl group, R １ ~R ４At least one of them represents a group other than a hydrogen atom in the above definition. B ｃａ represents an aromatic tetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, or a tetravalent organic group derived from an alicyclic structure having a 5-membered ring or more.

[0007] (Z １ａ and Z ２ａ each independently represents an alkyl group or an alkenyl group having 6 to 18 carbon atoms, and non-adjacent -CH ２ - groups may be substituted with -O-, -CO-, or -NH-. Z ３ａ and Z ４ａ each independently represents an alkyl group or an alkenyl group having 6 to 18 carbon atoms, or a monovalent organic group having 9 to 18 carbon atoms containing a benzene ring or a cyclohexane ring, and non-adjacent -CH ２ - groups of the alkyl group and the alkenyl group may be substituted with -O-, -CO-, or -NH-. Z １ｂ and Z ２ｂ each independently represents an alkyl group or an alkenyl group having 6 to 18 carbon atoms, and non-adjacent -CH ２ - groups may be substituted with -O-, -CO-, or -NH-.

[0008] (W １ａ to W ４ａ each independently represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, or an organic group having 6 to 8 carbon atoms having one benzene ring or cyclohexane ring, and non-adjacent -CH ２ - groups of the alkyl group and the alkenyl group may be substituted with -O-, -CO-, or -NH-. W ５ａ to W １１ａ and Ｗ１４ａ each independently represents a hydrogen atom, a hydroxyl group, a carboxyl group, an alkyl group having 1 to 5 carbon atoms, or an alkenyl group or alkynyl group having 2 to 5 carbon atoms, and non-adjacent -CH ２ - groups of the alkyl group, the alkenyl group, and the alkynyl group may be substituted with -O-, -CO-, or -NH-. W１２ａ and W １３ａ Each of these independently represents either a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. １５ａ and W １６ａ Each of these independently represents an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, or an organic group having 6 to 8 carbon atoms having one benzene ring, a cyclohexane ring, or a pyridine ring, and the alkyl group and alkenyl group are not adjacent to each other -CH ２ The - group may be substituted with -O-, -CO-, or -NH-. １ｂ and W ２ｂ Each of these independently represents an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, or an organic group having 6 to 8 carbon atoms having one benzene ring or cyclohexane ring, and the non-adjacent -CH groups of the alkyl group and alkenyl group. ２ The - group may be substituted with -O-, -CO-, or -NH-. ３ｂ -CH represents a hydrogen atom, a C1-C5 alkyl group, or a C2-C5 alkenyl group, and the alkyl group and alkenyl group are adjacent to each other. ２ (The - group may be substituted with -O-, -CO-, or -NH-.)

[0009] According to the present invention, a liquid crystal alignment film can be obtained that does not exhibit uneven liquid crystal alignment, thus providing a liquid crystal display element that is less prone to display irregularities. This is particularly useful in liquid crystal display elements obtained by photo-alignment treatment utilizing the photodecomposition reaction of polyimide. As a result, the liquid crystal display element of the present invention has excellent display quality and can be used in smartphones, tablet devices, and other devices as a transverse electric field driven element such as an IPS drive system or an FFS drive system. The mechanism by which the present invention yields a liquid crystal display element with the above-mentioned excellent characteristics is not entirely clear, but it is presumed to be approximately as follows.

[0010] The specific compound (A) of the present invention has a highly hydrophobic structure. Therefore, the specific polymer (A) obtained by reacting with specific compound (A) can be abundant near the interface of the liquid crystal alignment film. In particular, if the tetracarboxylic acid component and diamine component of specific polymer (A) have high interaction with liquid crystals, the above effect results in a liquid crystal alignment film that is less prone to uneven liquid crystal alignment. In liquid crystal alignment agents that use multiple polyimide polymers with large differences in hydrophilicity and hydrophobicity, for example, liquid crystal alignment agents that use a highly hydrophilic polyimide polymer and a highly hydrophobic polyimide polymer, layer separation occurs between these polymers, and the coating properties of the liquid crystal alignment film tend to deteriorate. In contrast, the specific polymer (C) of the present invention is less hydrophobic than specific polymer (A), but its hydrophilicity is reduced by reacting it with specific compound (B). Therefore, large layer separation does not occur between specific polymer (A) and specific polymer (C), and a liquid crystal alignment film with good coating properties can be obtained.

[0011] This is a schematic cross-sectional view showing an example of a transverse electric field type liquid crystal display element of the present invention. This is a schematic cross-sectional view showing another example of a transverse electric field type liquid crystal display element of the present invention.

[0012] <Specific Polymer (A)> Specific polymer (A) is as shown above. R in the formula [A-CA] is specific tetracarboxylic acid (A). １ ~R ４ This is defined above. In particular, R １ ~R ４ Preferably, each of these is an alkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, an alkynyl group having 2 to 4 carbon atoms, or a monovalent organic group having 1 to 4 carbon atoms containing a fluorine atom. Specifically, examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a t-butyl group, an n-pentyl group, a vinyl group, an ethyl group, a butyl group, an ethynyl group, a 1-propynyl group, a 2-propynyl group, a fluoromethyl group, a trifluoromethyl group, a trifluoromethoxy group, a 2,2,2-trifluoroethyl group, a 2,2,2-trifluoroethoxy group, a pentafluoroethyl group, or a pentafluoropropyl group.

[0013] Specific examples of the specified tetracarboxylic acid (A) include tetracarboxylic dianhydrides of the following formulas [A-CA-1] to [A-CA-5], and their tetracarboxylic acid derivatives, such as tetracarboxylic acid, tetracarboxylic acid dihalide, tetracarboxylic acid dialkyl ester, or tetracarboxylic acid dialkyl ester dihalide. In the present invention, it is preferable to use these. Among these, formula [A-CA-1] is preferred from the viewpoint of suitably obtaining the effects of the present invention.

[0014] From the viewpoint of suitably obtaining the effects of the present invention, the specific tetracarboxylic acid (A) is preferably 60 mol% or more, relative to 1 mole of total structural units derived from the tetracarboxylic acid derivative in the specific polymer (A). More preferably, it is 70 mol% or more. Particularly preferably, it is 100 mol%. Furthermore, one type or two or more types of specific tetracarboxylic acid (A) can be used in combination, depending on the characteristics. The specific polymer (A) may also contain tetracarboxylic acids other than the specific tetracarboxylic acid (A) (hereinafter also referred to as "other tetracarboxylic acids"). In this case, examples of other tetracarboxylic acids include those of the following formulas [CA-1a] to [CA-17a].

[0015] Furthermore, the following tetracarboxylic acid components can also be listed: 1,2,3,4-butanetetracarboxylic acid dianhydride, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, pyromellitic acid dianhydride, 3,3',4,4'-benzophenonetetracarboxylic acid dianhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic acid dianhydride, 1,4,5,8-naphthalenetetracarboxylic acid dianhydride, 2,3,6,7-naphthalenetetracarboxylic acid dianhydride, 3,3',4,4'-diphenylethertetracarboxylic acid dianhydride, 3,3',4,4'-perfluoroisopropylidene di(phthalic acid anhydride), 3,3',4,4'-biphenyltetracarboxylic acid Examples include dianhydrides of tetracarboxylic acids, 2,2',3,3'-biphenyltetracarboxylic acid dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)-2,2-diphenylpropane dianhydride, ethylene glycol bis-anhydrotrimellitate, 4,4'-(hexafluoroisopropylidene)diphthalic acid anhydride, 4,4'-carbonyl diphthalic acid anhydride, 4,4'-oxydi(1,4-phenylene)bis(phthalic acid) dianhydride, 4,4'-methylenedi(1,4-phenylene)bis(phthalic acid) dianhydride, or tetracarboxylic acid dianhydrides of the following formulas [CA-1] to [CA-32].

[0016]

[0017] In particular, the structures of formulas [CA-1a] to [CA-4a], 1,2,3,4-butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, pyromellitic acid dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3',4,4'-diphenylethertetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, or 2,2',3,3'-biphenyltetracarboxylic dianhydride are preferred. In addition, other tetracarboxylic acid components can be used individually or in mixtures of two or more types depending on their respective properties.

[0018] In the specified polymer (A), it is preferable to use a primary diamine represented by any of the following formulas [A-DA-1a] to [A-DA-8a], and a secondary diamine in which a hydrogen atom on the primary amino group of the primary diamine is substituted with a monovalent organic group (hereinafter also referred to as "specified diamine (A)").

[0019] (X １ａ and X ２ａ These are, independently, -O-, -COO-, -OCO-, and -NR ａ -, -NR ａ -CO- or -CO-NR ａ - indicates R ａ X represents a hydrogen atom, a linear or branched alkyl group having 1 to 3 carbon atoms, or a protecting group that is removed by heating and replaced by a hydrogen atom. ３ａ and X ４ａ Each of these independently represents an alkylene group having 1 to 12 carbon atoms, and the non-adjacent -CH ２ - The bases are -O-, -CO-, and -NR ｂ It may be replaced with -, R ｂ R represents a hydrogen atom, a linear or branched alkyl group having 1 to 3 carbon atoms, or a protecting group that is removed by heating and replaced by a hydrogen atom. Ｘａ R represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. Ｘａ If multiple instances exist, they may be the same or different. Ｘｂ and R ＸｃEach of these independently represents a hydrogen atom, a halogen atom, a C1-C6 alkyl group, a C2-C6 alkenyl group, a C2-C6 alkynyl group, a C1-C6 monovalent organic group containing a fluorine atom, a C1-C6 alkoxy group, a C2-C6 alkoxyalkyl group, a C2-C6 alkyloxycarbonyl group, or a phenyl group. m1 represents 2 or 3. m2 represents an integer from 1 to 12. m3 and m4 independently represent integers from 1 to 6. m5 and m6 independently represent 1 or 2. m7 and m8 independently represent 0 or 1. The benzene rings in formulas [A-DA-1a], [A-DA-2a], [A-DA-4a], [A-DA-6a], and [A-DA-8a] may be partially or entirely replaced by naphthalene rings.

[0020] More specifically, examples include primary diamines represented by any of the following formulas [DA-1a] to [DA-49a], and secondary diamines obtained by substituting a hydrogen atom on the primary amino group of the primary diamine with a monovalent organic group. (In formula [DA-1a], m represents an integer from 1 to 6, and n represents 1 or 2. In formula [DA-2a], m and n each independently represent an integer from 1 to 6. In formulas [DA-3a] to [DA-7a], m and l each independently represent an integer from 0 to 6, and n represents an integer from 1 to 6. In formulas [DA-6a] and [DA-7a], R ａ (This represents a hydrogen atom, a tert-butoxycarbonyl group, or a 9-fluorenylmethyloxycarbonyl group.)

[0021] (In formulas [DA-8a] to [DA-11a], m and l each independently represent an integer from 0 to 6, and n represents an integer from 1 to 6. In formulas [DA-10a] and [DA-11a], R ａ represents a hydrogen atom, a tert-butoxycarbonyl group, or a 9-fluorenylmethyloxycarbonyl group. In formulas [DA-12a] and [DA-13a], m represents an integer from 1 to 6.

[0022] (In formulas [DA-14a] and [DA-15a], m and l each independently represent an integer from 0 to 6, and n represents 1 or 2. In formula [DA-16a], m represents an integer from 1 to 6. In formula [DA-17a], m and n each independently represent an integer from 1 to 6. In formula [DA-19a], l represents 1 or 2. In formulas [DA-14a] to [DA-19a], Boc represents a tert-butoxycarbonyl group.)

[0023]

[0024]

[0025] From the viewpoint of suitably obtaining the effects of the present invention, the specific diamine (A) is preferably 40 mol% or more, relative to 1 mole of total structural units derived from the diamine in the specific polymer (A). More preferably, it is 50 mol% or more. Particularly preferably, it is 60 mol% or more. Furthermore, one type or two or more types of specific diamine (A) can be used, depending on the characteristics. Other diamines besides the specific diamine (A) (hereinafter also referred to as "other diamines") can be used in the specific polymer (A). Specific examples include the diamines of formulas [B-DA-1a] to [B-DA-16a] listed below, other diamine compounds described in paragraphs

[0044] to

[0051] of WO2013 / 125595, or the diamines of formulas (Y-1) to (Y-167) described in paragraphs

[0062] to

[0080] of WO2018 / 117239.

[0026] The specific polymer (A) is a polyimide precursor and polyimide obtained by reacting a specific tetracarboxylic acid (A) with a diamine component, and then reacting it with a specific compound (A). The specific compound (A) is as described above. Specific examples of the specific compound (A) of dicarboxylic acid anhydrides represented by any of the above formulas [EA-1a] to [EA-3a] include decenyl succinic anhydride, decyl succinic anhydride, 2-dodecene-1-yl succinic anhydride, dodecyl succinic anhydride, hexadecyl succinic anhydride, 2-hexene-1-yl succinic anhydride, isooctadecenyl succinic anhydride, isononenyl succinic anhydride, octadecenyl succinic anhydride, and octadecyl Examples include succinic anhydride, 2-octenyl succinic anhydride, n-octyl succinic anhydride, dodecenyl succinic anhydride, decanoic acid anhydride, heptanoic acid anhydride, nonanoic acid anhydride, nonenyl succinic acid anhydride, n-octanoic acid anhydride, diphenylacetic acid anhydride, oleic acid anhydride, lauric acid anhydride, linoleic acid anhydride, myristic acid anhydride, palmitic acid anhydride, stearic acid anhydride, or 3,4,5-trimethoxybenzoic acid anhydride. In particular, from the viewpoint of suitably obtaining the effects of the present invention, decenyl succinic anhydride, decyl succinic anhydride, 2-dodecene-1-yl succinic anhydride, dodecyl succinic anhydride, 2-hexen-1-yl succinic anhydride, isononenyl succinic anhydride, 2-octenyl succinic anhydride, n-octyl succinic anhydride, dodecenyl succinic anhydride, decanoic acid anhydride, heptanoic acid anhydride, nonanoic acid anhydride, or n-octanoic acid anhydride are preferred.

[0027] Specific examples of the specific compound (A) of the monoepoxy compound represented by either formula [EA-1b] or formula [EA-2b] include 2-ethylhexylglycidyl ether, 1,2-epoxydecane, glycidyl lauryl ether, 1,2-epoxyoctane, 1,2-epoxy-9-decene, 1,2-epoxydodecane, 1,2-epoxytetradecane, glycidyl stearate, 1,2-epoxyoctadecane, 1,2-epoxyeicosane, 1,2-epoxyhexadecane, or polyethylene glycol glycidyl lauryl ether. Among these, 2-ethylhexylglycidyl ether, 1,2-epoxydecane, glycidyl lauryl ether, 1,2-epoxy-9-decene, or 1,2-epoxydodecane are preferred from the viewpoint of suitably obtaining the effects of the present invention. Specific compound (A) can be used individually or in mixtures of two or more types, depending on the characteristics. The amount of specific compound (A) used is preferably 0.1 moles to 40 moles per 100 moles of the total diamine components. More preferably, from the viewpoint of suitably obtaining the effects of the present invention, it is 0.2 moles to 30 moles.

[0028] <Specific Polymer (B)> The specific polymer (B) is as shown above. The specific tetracarboxylic acid (B) in the formula [B-CA] is B ｃａAs defined above, pyromellitic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, or tetracarboxylic acid dianhydrides of the above formulas [CA-1a] to [CA-17a] are preferred. More preferred, from the viewpoint of suitably obtaining the effects of the present invention, are pyromellitic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, or 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride. Particularly preferred are 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride or 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride. From the viewpoint of suitably obtaining the effects of the present invention, it is preferable that the specific tetracarboxylic acid (B) is 60 mol% or more relative to 1 mole of total structural units derived from the tetracarboxylic acid derivative in the specific polymer (B). More preferably, the concentration is 70 mol% or more. Particularly preferred is 100 mol%. Furthermore, depending on the properties, one or more types of specific tetracarboxylic acid (B) can be used.

[0029] The specified polymer (B) may contain tetracarboxylic acids other than the specified tetracarboxylic acid (B). In this case, examples of other tetracarboxylic acids include the specified tetracarboxylic acid (A) or other tetracarboxylic acids. It is preferable to use a primary diamine represented by any of the following formulas [B-DA-1a] to [B-DA-16a], and a secondary diamine (hereinafter also referred to as "specified diamine (B)") obtained by substituting a hydrogen atom on the primary amino group of the primary diamine with a monovalent organic group.

[0030]

[0031] (X １ｂ and X ２ｂ Each of these independently represents a single bond or an alkylene group having 1 to 8 carbon atoms, and is not adjacent to a nitrogen atom -CH ２ The - group may be substituted with -O-. ３ｂ This is a single bond, -CH ２-, -O-, -COO-, -OCO-, -NR ａ -, -NR ａ -CO- or -CO-NR ａ - indicates R ａ X represents a hydrogen atom, a linear or branched alkyl group having 1 to 3 carbon atoms, or a protecting group that is removed by heating and replaced by a hydrogen atom. ４ｂ and X ５ｂ Each of these is independently a single bond or -CH ２ It indicates -. X ６ｂ and X ７ｂ Each is independent of the single bond, -CH ２ -, -O-, -COO-, -OCO-, -NR ｂ -, -NR ｂ CO- or -CONR ｂ - indicates R ｂ R represents a hydrogen atom, a linear or branched alkyl group having 1 to 3 carbon atoms, or a protecting group that is removed by heating and replaced by a hydrogen atom. Ｙａ R represents a hydrogen atom, a linear or branched alkyl group having 1 to 3 carbon atoms, or a protecting group that is removed by heating and replaced by a hydrogen atom. Ｙａ If multiple instances exist, they may be the same or different. Ｙｂ (where n1 represents a hydrogen atom or a methyl group; n2 represents 1 or 2; n3 represents an integer from 1 to 6.)

[0032] Specifically, the following equations [DA-1b] to [DA-32b] are examples.

[0033]

[0034] From the viewpoint of suitably obtaining the effects of the present invention, the specific diamine (B) is preferably 40 mol% or more, relative to 1 mole of total structural units derived from the diamine in the specific polymer (B). More preferably, it is 50 mol% or more. Particularly preferably, it is 60 mol% or more. Furthermore, one type or two or more types of specific diamine (B) can be used depending on the characteristics. The specific polymer (B) may contain diamines other than specific diamine (B). In that case, other diamines include the above-mentioned specific diamine (A) or other diamines.

[0035] <Specific Polymer (C)> Specific polymer (C) is as described above, and is a polyimide precursor and polyimide obtained by reacting specific tetracarboxylic acid (B) with a diamine component, and then reacting it with specific compound (B). In the present invention, it is preferable to use the above-mentioned specific polymer (B) for the polyimide precursor and polyimide obtained by reacting specific tetracarboxylic acid (B) with a diamine component. Specific compound (B) is as described above.

[0036] Specific examples of the specific compound (B) of the dicarboxylic acid anhydride represented by any of the formulas [EB-1a] to [EB-12a] include phthalic anhydride, maleic anhydride, succinic anhydride, allyl succinic anhydride, itaconic anhydride, trimellitic anhydride, 1,2,4-cyclohexanetricarboxylic acid-1,2-anhydride, 4-ethynylphthalic anhydride, cyclohexene-1,2-dicarboxylic acid anhydride, 3-acetamidophthalic anhydride, and 4-hexene-1,2-dicarboxylic acid anhydride. Bonic anhydride, 4-tert-butylphthalic anhydride, butylsuccinic anhydride, citraconic anhydride, 1,2-cyclohexanedicarboxylic acid anhydride, diacetyl-L-tartaric acid anhydride, 3,3-dimethylglutaric acid anhydride, 2,3-dimethylmaleic acid anhydride, 2,3-diphenylmaleic acid anhydride, pyridine-3,4-dicarboxylic acid anhydride, glutaric acid anhydride, homophthalic acid anhydride, 3-hydroxyphthalic acid anhydride, 4-methylcyclohexane-1,2-dical Phenyl anhydride, 3-methyl-4-cyclohexene-1,2-dicarboxylic acid anhydride, 3-methylglutaric acid anhydride, 3-methylphthalic acid anhydride, 4-methylphthalic acid anhydride, 4-methyl-4-pentene-1,2-dicarboxylic acid anhydride, 2,3-naphthalenedicarboxylic acid anhydride, 1,2-naphthalenedicarboxylic acid anhydride, phenylmaleic acid anhydride, phenylsuccinic acid anhydride, 4-(methylethynyl)phthalic acid anhydride, 2,3-pyridinedicarboxylic acid anhydride, anhydrous vinegar Examples include acids, acrylic anhydride, crotonic anhydride, isobutyric anhydride, methacrylic anhydride, 2-methoxyacetic anhydride, pivalic anhydride, propionic anhydride, 3-pyridinecarboxylic acid anhydride, angelic acid anhydride, benzoic acid anhydride, butyric acid anhydride, cyclohexanecarboxylic acid anhydride, di-tert-butyl dicarbonate, hexanoic acid anhydride, isovaleric acid anhydride, 4-methoxybenzoic acid anhydride, 2-methylbenzoic acid anhydride, phenoxyacetic acid anhydride, or valeric acid anhydride.In particular, from the viewpoint of suitably obtaining the effects of the present invention, phthalic anhydride, maleic anhydride, 2,3-dimethylmaleic anhydride, 2,3-diphenylmaleic anhydride, phenylmaleic anhydride, succinic anhydride, allylsuccinic anhydride, itaconic anhydride, 4-methyl-4-pentene-1,2-dicarboxylic acid anhydride, cyclohexene-1,2-dicarboxylic acid anhydride, acrylic anhydride, crotonic acid anhydride, isobutyric acid anhydride, methacrylic acid anhydride, propionic acid anhydride, or 3-pyridinecarboxylic acid anhydride are preferred.

[0037] Specific examples of the specific compound (B) of the monoepoxy compound represented by any of the formulas [EB-1b] to [EB-3b] include allyl glycidyl ether, 1,2-epoxybutane, 1,2-epoxypropane, ethyl glycidyl ether, 1,2-epoxypentane, 3,4-epoxy-1-butane, tert-butyl glycidyl ether, butyl glycidyl ether, 1,2-epoxy-5-hexene, glycidyl isopropyl ether, glycidyl acrylate, glycidyl methacrylate, glycidyl propargyl ether, glycidyl phenyl ether, 1,2-epoxyethylbenzene, glycidyl 2-methoxyphenyl ether, benzyl glycidyl ether, 1,2-epoxy-4-vinylcyclohexane, methyl 3,4-epoxycyclohexanecarboxylate, or methyl (3,4-epoxycyclohexyl) acrylate. In particular, from the viewpoint of suitably obtaining the effects of the present invention, allyl glycidyl ether, 1,2-epoxybutane, 1,2-epoxypropane, ethyl glycidyl ether, glycidyl acrylate, glycidyl methacrylate, 1,2-epoxy-4-vinylcyclohexane, or (3,4-epoxycyclohexyl)methyl acrylate are preferred. Specific compound (B) can be used individually or in mixtures of two or more types, depending on the characteristics.

[0038] The amount of specific compound (B) used is preferably 0.1 moles to 40 moles per 100 moles of the total diamine components. More preferably, from the viewpoint of suitably obtaining the effects of the present invention, it is 0.2 moles to 30 moles.

[0039] The polyimide precursor and polyimide of the present invention (hereinafter collectively referred to as "polyimide polymer") are preferably obtained by reacting a diamine component with a tetracarboxylic acid component. The polyimide precursor is preferably a polyamic acid (hereinafter also referred to as "polyamic acid") or a polyamic acid ester having the structure of the following formula [A]. (R ａ R indicates a tetravalent organic group. ｂ This indicates a divalent organic group. A １ and A ２ A represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and these may be the same or different. ３ and A ４ (where n represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an acetyl group, and these may be the same or different. n represents a positive integer.)

[0040] Polyimides have the structure shown in formula [A-4] below and can be obtained by cyclizing (hereinafter also referred to as "imidization") a polyamic acid precursor. In this case, if the cyclization rate of the amidic acid group (hereinafter also referred to as the "imidization rate") is less than 100%, the polyimide contains at least one of the structures shown in formulas [A-1] to [A-3] below in addition to the structure shown in formula [A-4]. (R ａ and R ｂ This has the same meaning as defined in formula [A] above.

[0041] The diamine component is a diamine having two primary or secondary amino groups in its molecule, and the tetracarboxylic acid component includes tetracarboxylic acid compounds, tetracarboxylic acid dianhydrides, tetracarboxylic acid dihalide compounds, tetracarboxylic acid dialkyl ester compounds, or tetracarboxylic acid dialkyl ester dihalide compounds. Polyimide polymers are preferred because they can be obtained relatively easily using a tetracarboxylic acid dianhydride of formula [B] and a diamine of formula [C] as raw materials, and are either polyamic acids consisting of repeating units of formula [D] or polyimides obtained by imidizing said polyamic acids. (R ａ and R ｂis synonymous with that defined by the above formula [A].)

[0042] (R ａ and R ｂ are synonymous with that defined by the above formula [A].) Also, by ordinary synthetic methods, A of formula [A] and A of formula [A] having an alkyl group with 1 to 8 carbon atoms, and A of formula [A] and A of formula [A] having an alkyl group with 1 to 5 carbon atoms or an acetyl group can be introduced into the polymer of formula [D]. １ and A ２ of formula [A], and A of formula [A] and A of formula [A] having an alkyl group with 1 to 5 carbon atoms or an acetyl group can be introduced into the polymer of formula [D]. ３ and A ４ of formula [A], and A of formula [A] and A of formula [A] having an alkyl group with 1 to 5 carbon atoms or an acetyl group can be introduced into the polymer of formula [D].

[0043] The method for synthesizing the polyimide-based polymer is not particularly limited. Specific examples include the methods described in paragraphs

[0059] and

[0059] of WO2015 / 012368. The synthesis of the polyamic acid ester includes, for example, a method of reacting a polyamic acid, which is a polyimide precursor obtained by reacting a diamine component and a tetracarboxylic acid component, with an esterifying agent, a method of reacting the above tetracarboxylic acid diester with a diamine, or a method of reacting the above tetracarboxylic acid diester dihalide, and other known methods.

[0044] The solvent used for the reaction between the diamine component and the tetracarboxylic acid component is not particularly limited as long as the resulting polyimide precursor is soluble. Specific examples include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, or 1,3-dimethyl-imidazolidinone. Also, when the solvent solubility of the polyimide precursor is high, methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, or solvents of the following formulas [D1] to [D3] can be used. (D １ and D ２ represent an alkyl group having 1 to 3 carbon atoms. D ３ represents an alkyl group having 1 to 4 carbon atoms.)

[0045] These may be used individually or in combination. Furthermore, even if the solvent does not dissolve the polyimide precursor, it may be mixed with the above solvent as long as precipitation does not occur. Also, since water in the solvent inhibits the polymerization reaction and can cause hydrolysis of the polyimide precursor, it is preferable to use a dehydrated and dried solvent. When obtaining specific polymer (A) and specific polymer (B), the method of reacting the polyimide precursor with specific compound (A) and specific compound (B) is not particularly limited. For example, methods include reacting these specific compounds together with the diamine component and the tetracarboxylic acid component when synthesizing the polyimide precursor, or reacting these specific compounds after synthesizing the polyimide precursor. In the polymerization reaction of the polyimide precursor, the total number of moles of the tetracarboxylic acid component when the total number of moles of the diamine component is 1.0 is preferably 0.8 to 1.2. However, in the case of specific polymer (A) and specific polymer (C), it is preferable that it be less than 1.0 because specific compounds are reacted.

[0046] Polyimides are obtained by ring-closing polyimide precursors, and the imidization rate does not necessarily have to be 100%, but can be arbitrarily prepared depending on the application and purpose. Among these, 30 to 90% is preferred from the viewpoint of solubility in solvents. More preferably, it is 40 to 90%. The molecular weight of the polyimide polymer is preferably 5,000 to 1,000,000 in terms of Mw (weight-average molecular weight) in terms of polyethylene glycol oxide, measured by the GPC (Gel Permeation Chromatography) method, from the viewpoint of the strength of the liquid crystal alignment film obtained therefrom, workability during film formation, and coating properties. More preferably, it is 10,000 to 150,000.

[0047] <Liquid Crystal Alignment Agent> The liquid crystal alignment agent is a solution for forming a liquid crystal alignment film, and is a solution containing a specific polymer (A) and a specific polymer (B), or a specific polymer (A) and a specific polymer (C), and a solvent. In the present invention, the specific polymer (B) is preferably 0.5 to 950 parts by mass per 100 parts by mass of specific polymer (A). More preferably, it is 10 to 900 parts by mass. Particularly preferably, it is 40 to 250 parts by mass. The specific polymer (C) is also preferably 0.5 to 950 parts by mass per 100 parts by mass of specific polymer (A). More preferably, it is 10 to 900 parts by mass. Particularly preferably, it is 40 to 250 parts by mass. The polymer components are not all these specific polymers; polyimide polymers that do not use specific tetracarboxylic acid (A) and specific tetracarboxylic acid (B), or polymers other than polyimide polymers may be mixed in. Specifically, examples include 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, or poly(meth)acrylates. Specific examples of poly(styrene-maleic anhydride) copolymers include SMA1000, SMA2000, SMA3000 (manufactured by Cray Valley Co., Ltd.), and GSM301 (manufactured by Gifu Cerates Manufacturing Co., Ltd.). Specific examples of poly(isobutylene-maleic anhydride) copolymers include Isoban-600 (manufactured by Kuraray Co., Ltd.). A specific example of a poly(vinyl ether-maleic anhydride) copolymer is Gantrez AN-139 (methyl vinyl ether maleic anhydride resin, manufactured by Ashland).

[0048] When using these specific polymers and other polymers as polymer components, the proportion of other polymers used is preferably 90 parts by mass or less per 100 parts by mass of the total polymers contained in the liquid crystal alignment agent. More preferably, it is 10 to 90 parts by mass. Most preferably, it is 20 to 80 parts by mass. The solvent content in the liquid crystal alignment agent can be appropriately selected from the viewpoint of the coating method of the liquid crystal alignment agent and obtaining the desired film thickness. In particular, from the viewpoint of forming a uniform liquid crystal alignment film by coating, the solvent content in the liquid crystal alignment agent is preferably 50 to 99.9% by mass. More preferably, it is 60 to 99% by mass. Particularly preferred is 65 to 99% by mass.

[0049] The solvent used in the liquid crystal alignment agent is not particularly limited as long as it is a solvent that dissolves these specific polymers. In particular, the following solvents (hereinafter also referred to as "solvent A") are preferred. For example, N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethyllactamide, N,N-dimethylpropionamide, tetramethylurea, N,N-diethylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethyl sulfoxide, γ-butyrolactone, γ-valerolactone, 1,3-dimethyl-2-imidazolidinone, methyl ethyl ketone, cyclohexanone, cyclopentanone, 3-methoxy-N,N-dimethylpropaneamide Examples include 3-butoxy-N,N-dimethylpropanamide, 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 (hereinafter collectively referred to as "good solvents"). Among these, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 3-methoxy-N,N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropanamide, or γ-butyrolactone are particularly favored. These may be used individually or in combination of two or more.

[0050] If these specific polymers have high solubility in a solvent, the following solvents (hereinafter also referred to as "solvents B") can be used.For example, diisopropyl ether, diisobutyl ether, diisobutylcarbinol (2,6-dimethyl-4-heptanol), ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, 1,2-dibutoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, 4-hydroxy-4-methyl-2-pentanone, diethylene glycol methyl ethyl ether, diethylene glycol dibutyl ether, 3-ethoxybutyl acetate, 1-methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, ethylene glycol monoacetate, ethylene glycol diacetate, propylene carbonate, ethylene carbonate, ethylene glycol monobutyl ether, ethylene glycol monoisoamyl ether, ethylene glycol monohexyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, 1-(2-butoxyethoxy)-2-propanol, 2-(2-butoxyethoxy) Examples include xy)-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, ethylene glycol monoethyl ether, n-butyl acetate, propylene glycol monoethyl ether acetate, cyclohexyl acetate, 4-methyl-2-pentyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, butyl 3-methoxypropionate, n-butyl lactate, isoamyl lactate, diethylene glycol monoethyl ether, or diisobutyl ketone (2,6-dimethyl-4-heptanone).In particular, it is preferable to use diisobutylcarbinol, 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. These may be used individually or in combination of two or more.

[0051] In the present invention, from the viewpoint of coating properties of the liquid crystal alignment film, it is preferable to use a solvent that combines solvent A and solvent B. Specific examples 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-di Methyl lactamide and diisobutyl ketone, N-methyl-2-pyrrolidone and ethyl 3-ethoxypropionate, N-ethyl-2-pyrrolidone and ethyl 3-ethoxypropionate, 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 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 N-methyl-2-pyrrolidone and diethylene glycol monoethyl ether and butyl cellosolve acetate, N-methyl-2-pyrrolidone and diethylene glycol monomethyl ether and butyl cellosolve acetate, N,N-dimethyllactamide 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 and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone and 4-hydroxy-4- Methyl-2-pentanone and propylene glycol diacetate, N-ethyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and dipropylene glycol dimethyl ether, γ-butyrolactone and 4-hydroxy-4-methyl-2-pentanone and diisobutyl ketone, γ-butyrolactone and 4-hydroxy-4-methyl-2-pentanone and propylene glycol diacetate, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether and diisobutyl ketone, N-methyl-2- Roridone and γ-butyrolactone and propylene glycol monobutyl ether and diisopropyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether and diisobutylcarbinol, 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 dipro Pyrene 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,Examples include 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, or N-methyl-2-pyrrolidone and cyclohexanone and propylene glycol monomethyl ether, and combinations of these are preferred.

[0052] When solvent A and solvent B are used in combination, solvent B is preferably 1 to 99% by mass of the total solvent contained in the liquid crystal alignment agent. More preferably, 10 to 99% by mass is preferred. Most preferably, 20 to 95% by mass is preferred.

[0053] The liquid crystal alignment agent can be a compound that promotes the imidation of these specific polymers. Specifically, compounds having basic moieties (e.g., primary amino groups, aliphatic heterocycles (e.g., pyrrolidine skeletons), aromatic heterocycles (e.g., imidazole rings, indole rings), or guanidino groups, etc.) (excluding the crosslinking compounds and adhesion aids described below), or compounds that generate the above basic moieties during firing are preferred. More specifically, formulas [B-1] to [B-17] below are examples, and it is preferable to use these. The usage ratio is preferably 0.1 to 20 parts by mass per 100 parts by mass of all polymer components. More preferably 1 to 20 parts by mass. Particularly preferred is 5 to 15 parts by mass. (D represents an organic group that is eliminated by heating, preferably a tert-butoxycarbonyl group or a 9-fluorenylmethyloxycarbonyl group. If there are multiple D groups, they may be the same or different from one another.)

[0054] In order to increase the film strength of the liquid crystal alignment film, it is preferable to introduce a compound having at least one structure selected from epoxy groups, isocyanate groups, oxetanyl groups, oxazoline groups, cyclocarbonate groups, hydroxyl groups, hydroxyalkyl groups, lower alkoxyalkyl groups, and polymerizable unsaturated groups (hereinafter collectively referred to as "crosslinkable compounds"). In this case, the compound must contain two or more of these groups.

[0055] Specific examples of crosslinkable compounds having epoxy groups or isocyanate groups include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, dibromo neopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, bisphenol A type epoxy resins such as Epicote 828 (manufactured by Mitsubishi Chemical Corporation), bisphenol F type epoxy resins such as Epicote 807 (manufactured by Mitsubishi Chemical Corporation), and YX-8000 (manufactured by Mitsubishi Chemical Corporation). Compounds in which a tertiary nitrogen atom is bonded to an aromatic carbon atom, such as hydrogenated bisphenol A epoxy resins like YX6954BH30 (manufactured by Mitsubishi Chemical Corporation), biphenyl skeleton-containing epoxy resins like EPPN-201 (manufactured by Nippon Kayaku Co., Ltd.), (o,m,p-) cresol novolac epoxy resins like EOCN-102S (manufactured by Nippon Kayaku Co., Ltd.), tetrakis(glycidyloxymethyl)methane, N,N,N',N'-tetraglycidyl-1,4-phenylenediamine, N,N,N',N'-tetraglycidyl-2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2-bis[4-(N,N-diglycidyl-4-aminophenoxy)phenyl]propane, and N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane;N,N,N',N'-tetraglycidyl-1,2-diaminocyclohexane, N,N,N',N'-tetraglycidyl-1,3-diaminocyclohexane, N,N,N',N'-tetraglycidyl-1,4-diaminocyclohexane, bis(N,N-diglycidyl-4-aminocyclohexyl)methane, bis(N,N-diglycidyl-2-methyl-4-aminocyclohexyl)methane, bis(N,N-diglycidyl-3-methyl-4-aminocyclohexyl)methane, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, 1,4-bis(N,N-diglycidylaminomethyl)cyclohexane, 1 Examples include compounds in which a tertiary nitrogen atom is bonded to an aliphatic carbon atom, such as 3-bis(N,N-diglycidylaminomethyl)benzene, 1,4-bis(N,N-diglycidylaminomethyl)benzene, 1,3,5-tris(N,N-diglycidylaminomethyl)cyclohexane, and 1,3,5-tris(N,N-diglycidylaminomethyl)benzene; isocyanurate compounds such as triglycidyl isocyanurate (manufactured by Nissan Chemical Corporation); and those described in paragraph

[0037] of Japanese Patent Publication No. 10-338880 and paragraphs

[0051] to

[0054] of WO2017 / 170483.

[0056] Specific examples of crosslinkable compounds having an oxetanyl group include 1,4-bis{[(3-ethyl-3-oxetanyl)methoxy]methyl}benzene (Aronoxetane OXT-121 (XDO)), bis[2-(3-oxetanyl)butyl]ether (Aronoxetane OXT-221 (DOX)), 1,4-bis[(3-ethyloxetan-3-yl)methoxy]benzene (HQOX), 1,3-bis[(3-ethyloxetan-3-yl)methoxy]benzene (RSOX), 1,2-bis[(3-ethyloxetan-3-yl)methoxy]benzene (CTOX), and those described in paragraphs

[0170] to

[0175] of WO2011 / 132751.

[0057] Specific examples of crosslinkable compounds having an oxazoline group include compounds such as 2,2'-bis(2-oxazoline) and 2,2'-bis(4-methyl-2-oxazoline), polymers and oligomers having an oxazoline group such as Epocross (manufactured by Nippon Shokubai Co., Ltd.), and those described in paragraph

[0115] of Japanese Patent Publication No. 2007-286597. Specific examples of crosslinkable compounds having a cyclocarbonate group include N,N,N',N'-tetra[(2-oxo-1,3-dioxolan-4-yl)methyl]-4,4'-diaminodiphenylmethane, N,N'-di[(2-oxo-1,3-dioxolan-4-yl)methyl]-1,3-phenylenediamine, and those described in paragraphs

[0025] to

[0030] and paragraph

[0032] of WO2011 / 155577.

[0058] Specific examples of crosslinkable compounds having a blocked isocyanate group include Coronate AP Stable M, Coronate 2503, 2515, 2507, 2513, 2555, Millionate MS-50 (all manufactured by Tosoh Corporation), Takenate B-830, B-815N, B-820NSU, B-842N, B-846N, B-870N, B-874N, B-882N (all manufactured by Mitsui Chemicals, Inc.), and those described in paragraphs

[0046] to

[0047] of Japanese Patent Publication No. 2014-224978 and paragraphs

[0119] to

[0120] of WO2015 / 141598.

[0059] Specific examples of crosslinkable compounds having a hydroxyl group, a hydroxyalkyl group, and a lower alkoxyalkyl group include N,N,N',N'-tetrakis(2-hydroxyethyl)adipoamide, 2,2-bis(4-hydroxy-3,5-dihydroxymethylphenyl)propane, 2,2-bis(4-hydroxy-3,5-dimethoxyphenyl)propane, 2,2-bis(4-hydroxy-3,5-dihydroxymethylphenyl)-1,1,1,3,3,3-hexafluoropropane, and those described in paragraph

[0058] of Japanese Patent Publication No. 2016-118753, paragraph

[0055] of Japanese Patent Publication No. 2016-200798, and paragraphs

[0017] to

[0029] of WO2010 / 074269.

[0060] Specific examples of crosslinkable compounds having polymerizable unsaturated groups include glycerin mono(meth)acrylate, glycerin di(meth)acrylate (1,2-,1,3-compound mixture), glycerin tris(meth)acrylate, glycerol 1,3-diglycerolate di(meth)acrylate, pentaerythritol tri(meth)acrylate, diethylene glycol mono(meth)acrylate, triethylene glycol mono(meth)acrylate, tetraethylene glycol mono(meth)acrylate, pentaethylene glycol mono(meth)acrylate, and hexaethylene glycol mono(meth)acrylate.

[0061] The amount of crosslinkable compound used in the liquid crystal alignment agent is preferably 0.1 to 100 parts by mass per 100 parts by mass of all polymer components. More preferably, from the viewpoint of allowing the crosslinking reaction to proceed and exhibiting the desired effect, it is 0.1 to 50 parts by mass. Particularly preferred is 1 to 30 parts by mass. The liquid crystal alignment agent may also be a compound that improves the uniformity of the film thickness and surface smoothness of the liquid crystal alignment film, or a compound that improves the adhesion between the liquid crystal alignment film and the substrate.

[0062] Compounds that improve the uniformity of the film thickness and surface smoothness of the liquid crystal alignment film include fluorine-based surfactants, silicone-based surfactants, and nonionic surfactants. Specific examples include the surfactant described in paragraph

[0122] of WO2014 / 171493. The preferred usage ratio is 0.01 to 2 parts by mass, more preferably 0.01 to 1 part by mass, per 100 parts by mass of all polymer components.

[0063] Specific examples of compounds that improve the adhesion between the liquid crystal alignment film and the substrate include the compounds described in paragraph

[0123] of WO2014 / 171493. The preferred proportion of these compounds is 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 to compounds other than those mentioned above, dielectric or conductive substances may be added to the liquid crystal alignment agent to change the electrical properties of the liquid crystal alignment film, such as dielectric constant and conductivity.

[0064] <Liquid crystal alignment film / Liquid crystal display element> A liquid crystal display element can be manufactured, for example, by a method including the following steps (1) to (3), a method including steps (1) to (4), a method including steps (1) to (3), (3b) and (4), a method including steps (1) to (2) and (4), a method including steps (1) to (3), (4) and (5), or a method including steps (1) to (3), (4) and (6).

[0065] <Step (1): Step of applying liquid crystal alignment agent to at least one of the first and second substrates> Step (1) is a step of applying a liquid crystal alignment agent to a substrate. A specific example is as follows: That is, a liquid crystal alignment agent is applied to one surface of a substrate on which a patterned transparent conductive film is provided, by an application method such as a roll coater, spin coat, printing, or inkjet. The substrate is not particularly limited as long as it is a highly transparent substrate, and plastic substrates such as acrylic substrates and polycarbonate substrates can be used along with glass substrates and silicon nitride substrates. In addition, in reflective liquid crystal display elements, an opaque substrate such as a silicon wafer can be used on only one side of the substrate, and in this case, light-reflecting materials such as aluminum can be used for the electrodes.

[0066] When manufacturing IPS-driven or FFS-driven liquid crystal display elements, a substrate is used that has electrodes made of a comb-shaped patterned transparent conductive film or metal film, and a counter substrate is used that does not have electrodes. The transparent conductive film is formed by known methods using indium tin oxide (ITO), indium zinc oxide (IZO), or mixtures thereof. Methods for applying the liquid crystal alignment agent to the substrate include screen printing, offset printing, flexographic printing, inkjet printing, or spray printing. Among these, the inkjet printing method is preferred in the present invention.

[0067] <Step (2): Step of firing the coated liquid crystal alignment agent> Step (2) is a step of firing the liquid crystal alignment agent coated on the substrate to form a liquid crystal alignment film. Specifically, it is as follows: That is, after coating the substrate with liquid crystal alignment agent in step (1), the solvent is evaporated or the polyamic acid or polyamic acid ester is thermally imidized by firing using a heating means such as a hot plate, a heat circulation oven or an IR (infrared) oven (hereinafter this process is also called the "firing step"). The temperature and time of the firing step can be arbitrarily selected, and the firing step may be repeated multiple times. The temperature of the firing step is preferably 30 to 230°C. More preferably 30 to 200°C. If the residual solvent in the liquid crystal alignment film is to be reduced, it may be 40 to 150°C or 40 to 120°C. The firing time is not particularly limited, but examples include 1 to 10 minutes or 1 to 5 minutes.

[0068] When performing thermal imidation of polyimide precursors such as polyamic acid or polyamic acid esters, an additional firing (hereinafter referred to as the "main firing process") may be performed after the firing process. The temperature at this time is preferably 150 to 230°C. More preferably 150 to 200°C. Particularly preferred is 160 to 200°C. Most preferably 160 to 190°C. The firing time for the main firing process is not particularly limited, but examples include 5 to 40 minutes or 5 to 30 minutes. Note that the main firing process may not be performed in step (2), and the main firing process or step (3b) may be performed after step (3) below. The film thickness of the liquid crystal alignment film after firing is preferably 5 to 300 nm, more preferably 10 to 200 nm, because if it is too thick, it will be disadvantageous in terms of the power consumption of the liquid crystal display element, and if it is too thin, the reliability of the element may decrease.

[0069] <Process (3): Process of performing alignment treatment on the liquid crystal alignment film obtained in Process (2)>Process (3) is a process of performing alignment treatment on the liquid crystal alignment film obtained in Process (2). In a horizontal electric field driving type liquid crystal display element such as an IPS driving method or an FFS driving method, as described above, in order to horizontally align the liquid crystal, an alignment treatment such as a rubbing treatment or an optical alignment treatment is performed on the liquid crystal alignment film. In the present invention, an optical alignment treatment is preferable. On the other hand, in a vertical electric field driving type liquid crystal display element such as a VA (Vertical Alignment) driving method or a PSA (Polymer Sustained Alignment) driving method, an alignment treatment may not be performed. The rubbing treatment is a treatment of rubbing the liquid crystal alignment film in a certain direction with a roll wrapped with a cloth made of fibers such as nylon, rayon or cotton. Examples of the optical alignment treatment include a method of irradiating the surface of the liquid crystal alignment film with radiation polarized in a certain direction to regulate the alignment of the liquid crystal (hereinafter, also referred to as "imparting liquid crystal alignment property or liquid crystal alignment ability").

[0070] The radiation can use ultraviolet rays or visible light rays having a wavelength of 100 to 800 nm. Among them, ultraviolet rays having a wavelength of 100 to 400 nm are preferable. More preferable is ultraviolet rays having a wavelength of 200 to 400 nm. The irradiation amount of the radiation is preferably 1 to 10,000 mJ / cm ２ is preferable. More preferable is 100 to 1,000 mJ / cm ２ is. Particularly preferable is 100 to 500 mJ / cm ２ is. Also, when the radiation is polarized light, it may be linearly polarized light or partially polarized light. Further, when the radiation is linearly polarized light or partially polarized light, the irradiation may be performed from a direction perpendicular to the liquid crystal alignment film surface, from an oblique direction, or in combination thereof. When irradiating non-polarized radiation, the irradiation direction is preferably an oblique direction with respect to the liquid crystal alignment film surface. When irradiating the radiation, in order to enhance the stability of the liquid crystal alignment, it is preferable to irradiate while heating the substrate with the liquid crystal alignment film at 50 to 250 °C. Thereby, the liquid crystal can be stably aligned in a certain direction.

[0071] <Step (3b): Heat treatment step> The liquid crystal alignment film irradiated with the radiation plug in step (3) can be subjected to heat treatment. The temperature at this time is preferably 50 to 250°C. More preferably 120 to 230°C. The time is preferably 1 to 30 minutes.

[0072] <Step (4): Step of manufacturing a liquid crystal cell (liquid crystal display element) by arranging a liquid crystal layer between the first substrate and the second substrate so as to be adjacent to the oriented liquid crystal alignment film> Step (4) is a step of manufacturing a liquid crystal cell by arranging a liquid crystal layer between the first substrate and the second substrate so as to be adjacent to the oriented liquid crystal alignment film. The following is an example of a case in which a liquid crystal alignment film is formed on each of the first and second substrates. In the first method, first, two substrates are placed facing each other with a gap (hereinafter also called a "cell gap") between them so that their respective liquid crystal alignment films face each other. Next, the peripheral parts of the two substrates are bonded together using a sealant, and a liquid crystal composition is injected and filled into the cell gap partitioned by the substrate surface and the sealant, and after contact with the liquid crystal alignment film surface, the injection hole is sealed.

[0073] The second method is called the ODF (One Drop Filling) method. In this method, a UV-curable resin composition (hereinafter also referred to as "sealant") is applied to a predetermined location on one of two substrates on which a liquid crystal alignment film has been formed, and then liquid crystal composition is dropped onto several predetermined locations on the surface of the liquid crystal alignment film. After that, the other substrate is bonded together so that the liquid crystal alignment films face each other, and the liquid crystal composition is spread over the entire surface of the substrate and brought into contact with the film surface. Next, the entire surface of the substrate is irradiated with ultraviolet light to cure the sealant. In both the first and second methods, it is desirable to heat the liquid crystal composition to a temperature at which it forms an isotropic phase, and then slowly cool it to room temperature to remove the flow orientation during the filling of the liquid crystal composition. When rubbing is performed, the two substrates are arranged facing each other so that the rubbing directions of each liquid crystal alignment film are at a predetermined angle to each other, for example, orthogonal or antiparallel. As the sealant, epoxy resin containing a curing agent and aluminum oxide spheres as spacers can be used.

[0074] There are no particular restrictions on the liquid crystal composition; any composition containing at least one liquid crystal compound (liquid crystal molecule) can be used, and various liquid crystal compositions with positive or negative dielectric anisotropy can be used. In the following, a liquid crystal composition with positive dielectric anisotropy will also be called a positive-type liquid crystal, and a liquid crystal composition with negative dielectric anisotropy will also be called a negative-type liquid crystal. The liquid crystal composition may contain a liquid crystal compound having a fluorine atom, a hydroxyl group, an amino group, a fluorine atom-containing group (e.g., a trifluoromethyl group), a cyano group, an alkyl group, an alkoxy group, an alkenyl group, an isothiocyanate group, a heterocycle, a cycloalkane, a cycloalkene, a steroid skeleton, a benzene ring, or a naphthalene ring, and may also contain a compound having two or more rigid parts (mesogenic skeletons) that exhibit liquid crystallinity within the molecule (e.g., a bimesogenic compound in which two rigid biphenyl or terphenyl structures are linked by an alkylene group). The liquid crystal composition may be a liquid crystal composition exhibiting a nematic phase, a liquid crystal composition exhibiting a smectic phase, or a liquid crystal composition exhibiting a cholesteric phase.

[0075] Furthermore, the liquid crystal composition may contain additives from the viewpoint of improving liquid crystal alignment. Examples of additives include photopolymerizable monomers such as compounds having polymerizable groups; optically active compounds (for example, S-811 from Merck KGaA); antioxidants; ultraviolet absorbers; dyes; defoamers; polymerization initiators; or polymerization inhibitors. Examples of positive-type liquid crystals include ZLI-2293, ZLI-4792, MLC-2003, MLC-2041, MLC-3019, or MLC-7081 from Merck KGaA; and PA-1492 from DIC Corporation. Examples of negative-type liquid crystals include MLC-6608, MLC-6609, MLC-6610, or MLC-7026-100 from Merck KGaA.

[0076] Liquid crystals containing polymerizable compounds include MLC-3023 manufactured by Merck. The liquid crystal alignment agent can also be used in liquid crystal display elements (PSA type liquid crystal display elements) manufactured by a process in which a liquid crystal composition containing a polymerizable compound that polymerizes by at least one of active energy rays and heat is placed between the pair of substrates, and the polymerizable compound is polymerized by irradiation with active energy rays and heating while a voltage is applied between the electrodes (hereinafter, this process is also referred to as "step (5)"). The liquid crystal alignment agent can also be used in liquid crystal display elements (SC-PVA type liquid crystal display elements) manufactured by a process in which a liquid crystal alignment film containing a polymerizable compound that polymerizes 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 (hereinafter, this process is also referred to as "step (6)").

[0077] The liquid crystal cell obtained as described above can have a polarizing plate bonded to its outer surface if necessary. Examples of polarizing plates bonded to the outer surface of the liquid crystal cell include a polarizing plate in which a polarizing film called an "H film," which is made by stretching and aligning polyvinyl alcohol while absorbing iodine, is sandwiched between cellulose acetate protective films, or a polarizing plate of an H film. An IPS substrate, which is a comb-tooth electrode substrate used in an IPS driving method, has a substrate, a plurality of linear electrodes formed on the substrate and arranged in a comb-tooth pattern, and a liquid crystal alignment film formed on the substrate to cover the linear electrodes. An FFS substrate, which is a comb-tooth electrode substrate used in an FFS method, has a substrate, a surface electrode formed on the substrate, an insulating film formed on the surface electrode, a plurality of linear electrodes formed on the insulating film and arranged in a comb-tooth pattern, and a liquid crystal alignment film formed on the insulating film to cover the linear electrodes.

[0078] Figure 1 is a schematic cross-sectional view showing an example of a transverse electric field type liquid crystal display element of the present invention, and is an example of an IPS-driven liquid crystal display element. In the transverse electric field type liquid crystal display element 1 illustrated in Figure 1, liquid crystal 3 is sandwiched between a comb-tooth electrode substrate 2 having a liquid crystal alignment film 2c and a counter substrate 4 having a liquid crystal alignment film 4a. The comb-tooth electrode substrate 2 has a substrate 2a, a plurality of linear electrodes 2b formed on the substrate 2a and arranged in a comb-tooth shape, and a liquid crystal alignment film 2c formed on the substrate 2a so as to cover the linear electrodes 2b. The counter substrate 4 has a substrate 4b and a liquid crystal alignment film 4a formed on the substrate 4b. The liquid crystal alignment film 2c is, for example, the liquid crystal alignment film of the present invention. Similarly, the liquid crystal alignment film 4a is also the liquid crystal alignment film of the present invention. In this transverse electric field type liquid crystal display element 1, when a voltage is applied to the linear electrodes 2b, an electric field is generated between the linear electrodes 2b as shown by the electric field lines L.

[0079] Figure 2 is a schematic cross-sectional view showing another example of a transverse electric field driven liquid crystal display element, and is an example of an FFS driven liquid crystal display element. In the transverse electric field driven liquid crystal display element 1 illustrated in Figure 2, liquid crystal 3 is sandwiched between a comb-tooth electrode substrate 2 having a liquid crystal alignment film 2h and a counter substrate 4 having a liquid crystal alignment film 4a. The comb-tooth electrode substrate 2 has a substrate 2d, a surface electrode 2e formed on the substrate 2d, an insulating film 2f formed on the surface electrode 2e, a plurality of linear electrodes 2g formed on the insulating film 2f and arranged in a comb-tooth pattern, and a liquid crystal alignment film 2h formed on the insulating film 2f so as to cover the linear electrodes 2g. The counter substrate 4 has a substrate 4b and a liquid crystal alignment film 4a formed on the substrate 4b. The liquid crystal alignment film 2h is, for example, the liquid crystal alignment film of the present invention. Similarly, the liquid crystal alignment film 4a is the liquid crystal alignment film of the present invention. In this transverse electric field driven liquid crystal display element 1, when a voltage is applied to the surface electrode 2e and the linear electrode 2g, an electric field is generated between the surface electrode 2e and the linear electrode 2g, as shown by the electric field lines L. The liquid crystal display element of the present invention can be effectively applied to various devices. For example, it can be used in display devices such as clocks, portable games, word processors, notebook computers, car navigation systems, camcorders, PDAs, digital cameras, mobile phones, smartphones, various monitors, liquid crystal televisions, or information displays. The liquid crystal alignment film of the present invention can be applied to applications other than those described above. For example, it can be used as a liquid crystal alignment film for phase difference films, a liquid crystal alignment film for scanning antennas and liquid crystal array antennas, or a liquid crystal alignment film for transmission-scattering type liquid crystal dimming elements. Furthermore, it can be used in applications other than liquid crystal alignment films, such as protective films (e.g., protective films for color filters), spacer films, interlayer insulating films, anti-reflective films, wiring coating films, anti-static films, and motor insulating films (e.g., gate insulating films for flexible displays).

[0080] The present invention will be further described in detail below with reference to examples, but is not limited to these. The abbreviations used in the examples and comparative examples, and the methods for measuring each physical property are as follows.

[0081] <Solvents> NMP: N-methyl-2-pyrrolidone GBL: γ-butyrolactone BCS: Ethylene glycol monobutyl ether

[0082] <Specific tetracarboxylic acids (A) and (B)> CA-1 to CA-2: Tetracarboxylic dianhydrides of the following formulas [CA-1] to [CA-2]

[0083] <Specific Diamines (A)> DA-1 to DA-2: Diamines of the following formulas [DA-1] to [DA-2]

[0084] <Specific Diamines (B)> DB-1 to DB-3: Diamines of the following formulas [DB-1] to [DB-3] (Boc represents the tert-butoxycarbonyl group.)

[0085] <Other Diamines> DC-1 to DC-2: Diamines of the following formulas [DC-1] to [DC-2]

[0086] <Specific Compounds (A)> EA-1: Compound of the following formula [EA-1] (Licacid (trademark registered) DDSA (manufactured by Shin-Nippon Rika Co., Ltd.)) EA-2: Compound of the following formula [EA-2] (Licacid (trademark registered) OSA (manufactured by Shin-Nippon Rika Co., Ltd.)) EA-3: Compound of the following formula [EA-3] EA-4: Compound of the following formula [EA-4] EA-5: Compound of the following formula [EA-5]

[0087] <Specific Compound (B)> EB-1: Compound of the following formula [EB-1]

[0088] <Compounds that improve adhesion> B-1: Compound of the following formula [B-1]

[0089] <Cross-linkable compounds> C-1: Compounds of the following formula [C-1]

[0090] "Viscosity Measurement" Viscosity was measured using an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.) at a temperature of 25°C, with a sample volume of 1.1 mL and a cone rotor TE-1 (1°34', R24).

[0091] "Molecular Weight Measurement" The number-average molecular weight (hereinafter also referred to as "Mn") and weight-average molecular weight (hereinafter also referred to as "Mw") of polyimide polymers were measured using the following apparatus and conditions. Room temperature gel permeation chromatography (GPC) apparatus: GPC-101 (manufactured by Resonaq Corporation) Column: GPC KD-803, KD-805 (manufactured by Resonaq Corporation) in series Column temperature: 50°C Eluent: N,N-dimethylformamide (with lithium bromide monohydrate (LiBr·H) as an additive) ２ (O) 30 mmol / L, anhydrous crystalline phosphoric acid (o-phosphate) 30 mmol / L, tetrahydrofuran (THF) 10 ml / L) Flow rate: 1.0 mL / min Standard sample for calibration curve preparation: EasiVial PEG / PEO polyethylene glycol oxide PL2080-0201 (molecular weight: approx. 1,500, approx. 4,000, approx. 13,000, approx. 30,000, approx. 70,000, approx. 130,000, approx. 500,000, approx. 1,000,000, approx. 1,500,000) (manufactured by GL Sciences)

[0092] "Synthesis of Polyimide Polymers" <Synthesis Example 1> DA-1 (3.91 g, 16.0 mmol), DC-1 (1.73 g, 16.0 mmol), and NMP (57.0 g) were added to a 200 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, and dissolved by stirring at 25°C while supplying nitrogen. Then, under ice cooling, CA-1 (6.67 g, 29.8 mmol) and NMP (33.3 g) were added, and the mixture was stirred at 40°C for 12 hours to obtain a polyamic acid solution (PAA-1) with a solid content of 12% by mass (viscosity: 235 mPa·s, Mn: 9700, Mw: 23500).

[0093] <Synthesis Example 2> In a 200 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, DA-1 (3.30 g, 13.5 mmol), DA-2 (2.45 g, 9.00 mmol), DB-3 (3.66 g, 9.00 mmol), DC-1 (0.73 g, 6.80 mmol), DC-2 (0.83 g, 6.80 mmol), and NMP (61.7 g) were added and dissolved by stirring at 25°C while supplying nitrogen. Then, under ice cooling, CA-1 (9.16 g, 40.9 mmol) and NMP (18.5 g) were added and stirred at 40°C for 12 hours to obtain a polyamic acid solution (PAA-2) with a solid content of 20% by mass (viscosity: 691 mPa·s, Mn: 6200, Mw: 16000).

[0094] <Synthesis Example 3> DB-1 (1.80 g, 6.00 mmol), DB-2 (4.78 g, 24.0 mmol), and NMP (59.2 g) were added to a 200 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, and dissolved by stirring at 25°C while supplying nitrogen. Then, under ice cooling, CA-2 (5.33 g, 27.0 mmol) and NMP (47.7 g) were added, and the mixture was stirred at 25°C for 12 hours to obtain a polyamic acid solution (PAA-3) with a solid content of 10% by mass (viscosity: 122 mPa·s, Mn: 8800, Mw: 23300).

[0095] <Synthesis Example 4> To the polyamic acid solution (PAA-1) (50.0 g) obtained by the method of Synthesis Example 1, EA-1 (0.64 g, 2.40 mmol) and NMP (4.70 g) were added and stirred at 25°C for 24 hours to obtain a polyimide polymer solution (PAA-1-EA1) in which the polymer ends were modified with EA-1.

[0096] <Synthesis Example 5> To the polyamic acid solution (PAA-1) (50.0 g) obtained by the method of Synthesis Example 1, EA-2 (0.51 g, 2.40 mmol) and NMP (3.70 g) were added and stirred at 25°C for 24 hours to obtain a polyimide polymer solution (PAA-1-EA2) in which the polymer ends were modified with EA-2.

[0097] <Synthesis Example 6> To the polyamic acid solution (PAA-1) (50.0 g) obtained by the method of Synthesis Example 1, EA-3 (0.85 g, 2.40 mmol) and NMP (6.21 g) were added and stirred at 25°C for 24 hours to obtain a polyimide polymer solution (PAA-1-EA3) in which the polymer ends were modified with EA-3.

[0098] <Synthesis Example 7> To the polyamic acid solution (PAA-1) (50.0 g) obtained by the method of Synthesis Example 1, EA-4 (0.78 g, 2.40 mmol) and NMP (5.75 g) were added and stirred at 25°C for 24 hours to obtain a polyimide polymer solution (PAA-1-EA4) in which the polymer ends were modified with EA-4.

[0099] <Synthesis Example 8> To the polyamic acid solution (PAA-1) (50.0 g) obtained by the method of Synthesis Example 1, EA-5 (0.45 g, 2.40 mmol) and NMP (3.28 g) were added and stirred at 60°C for 24 hours to obtain a polyimide polymer solution (PAA-1-EA5) in which the polymer ends were modified with EA-5.

[0100] <Synthesis Example 9> To the polyamic acid solution (PAA-2) (50.0 g) obtained by the method of Synthesis Example 2, EA-1 (1.21 g, 4.54 mmol) and NMP (4.84 g) were added and stirred at 40°C for 24 hours to obtain a polyimide polymer solution (PAA-2-EA1) in which the polymer ends were modified with EA-1.

[0101] <Synthesis Example 10> To the polyamic acid solution (PAA-2) (50.0 g) obtained by the method of Synthesis Example 2, EA-2 (0.96 g, 4.54 mmol) and NMP (3.82 g) were added and stirred at 25°C for 24 hours to obtain a polyimide polymer solution (PAA-2-EA2) in which the polymer ends were modified with EA-2.

[0102] <Synthesis Example 11> To the polyamic acid solution (PAA-2) (50.0 g) obtained by the method of Synthesis Example 2, EA-5 (0.85 g, 4.54 mmol) and NMP (3.39 g) were added and stirred at 60°C for 24 hours to obtain a polyimide polymer solution (PAA-2-EA5) in which the polymer ends were modified with EA-5.

[0103] <Synthesis Example 12> To the polyamic acid solution (PAA-3) (50.0 g) obtained by the method of Synthesis Example 3, EB-1 (0.28 g, 2.78 mmol) and NMP (2.50 g) were added and stirred at 25°C for 24 hours to obtain a polyimide polymer solution (PAA-3-EB1) in which the polymer ends were modified with EB-1.

[0104] <Synthesis Example 13> To the polyamic acid solution (PAA-1) (50.0 g) obtained by the method of Synthesis Example 1, EB-1 (0.24 g, 2.78 mmol) and NMP (2.14 g) were added and stirred at 25°C for 24 hours to obtain a polyimide polymer solution (PAA-1-EB1) in which the polymer ends were modified with EB-1.

[0105] The specifications of the polyimide polymers are shown in Tables 1 and 2.

[0106]

[0107] "Manufacturing of Liquid Crystal Alignment Agents" Examples 1 to 12, Comparative Example 1, and Comparative Example 2 below describe examples of liquid crystal alignment agents. These liquid crystal alignment agents are used for the evaluation of liquid crystal display elements. The specifications of the liquid crystal alignment agents are shown in Table 3.

[0108] "Fabrication of FFS-driven liquid crystal cells" FFS-driven liquid crystal cells were fabricated using liquid crystal alignment agents obtained by the methods described in the Examples and Comparative Examples. A rectangular glass substrate measuring 30 mm x 35 mm with a thickness of 0.7 mm was used as the substrate. An ITO electrode with a solid pattern, forming a common electrode, was formed on the substrate as the first layer. A SiN (silicon nitride) film deposited by CVD (chemical vapor deposition) was formed on the first layer common electrode as the second layer. The thickness of the second SiN film was 300 nm, which was sufficient to function as an interlayer insulating film. On the second SiN film, a comb-shaped pixel electrode formed by patterning the ITO film was arranged as the third layer, forming two pixels, the first and second pixels, with each pixel measuring 10 mm vertically and 5 mm horizontally. This electrode-equipped substrate had a structure in which the first layer common electrode and the third layer pixel electrode were insulated by the second layer SiN film. The third layer of pixel electrodes had a comb-like shape, with the central portion bent at an internal angle of 160°, and multiple electrode lines with a width of 3 μm arranged parallel to each other at intervals of 6 μm. Each pixel was formed by multiple electrode lines and had a first region and a second region separated by a line connecting the bends.

[0109] Next, the liquid crystal alignment agent was filtered through a 1.0 μm pore size filter, and then spin-coated onto the electrode-equipped substrate (hereinafter referred to as the "electrode substrate") and a glass substrate with a 3.3 μm high columnar spacer on its back surface, on which an ITO electrode film was deposited (hereinafter referred to as the "opposing substrate"). Afterward, the substrates were dried on an 80°C hot plate for 1 minute, and then fired in a 230°C infrared heating furnace for 30 minutes to obtain an electrode substrate and an opposing substrate with a 60 nm thick liquid crystal alignment film. Polarized ultraviolet light at 254 nm, mediated by a 240 nm low-cut filter and polarizer, was applied to the liquid crystal alignment film surface of both substrates at a rate of 400 mJ / cm². ２ (extinction ratio 40:1) or 300mJ / cm ２Each liquid crystal alignment agent was irradiated with the optimal irradiation dose (extinction ratio 5:1), and then fired in an infrared heating furnace at 230°C for 30 minutes to obtain an electrode substrate with an aligned liquid crystal alignment film and a counter substrate. As a result, the liquid crystal alignment film on the electrode substrate was aligned so that the direction dividing the inner angle of the pixel bending portion was perpendicular to the orientation direction of the liquid crystal, and the liquid crystal alignment film on the counter substrate was aligned so that the orientation direction of the liquid crystal on the electrode substrate and the orientation direction of the liquid crystal on the counter substrate coincided when creating the liquid crystal cell. Taking the electrode substrate with the above-described alignment-treated liquid crystal alignment film and the counter substrate as a pair, a thermosetting sealant (XN-1500T, manufactured by Mitsui Chemicals, Inc.) was printed around the liquid crystal alignment film surface of one substrate, leaving a liquid crystal injection port. Next, with the liquid crystal alignment film surface of the other substrate facing inward, the two substrates were bonded together so that the orientation direction of each liquid crystal alignment film was 0°. After bonding, the bonded substrates were pressed together and heated in a 150°C hot air circulating oven for 60 minutes to cure the sealant and create empty cells. Positive-type liquid crystal (PA-1492, manufactured by DIC Corporation) was injected into these empty cells using a reduced-pressure injection method, and the injection port was sealed to obtain FFS-driven liquid crystal cells (hereinafter referred to as "liquid crystal cells"). The obtained liquid crystal cells were heated at 120°C for 1 hour, and then left overnight at 23°C to evaluate the liquid crystal alignment. Specifically, the alignment state of the liquid crystal was observed using a polarizing microscope (ECLIPSE E600 POL, manufactured by Nikon Corporation). As a result, the liquid crystal was uniformly oriented in all liquid crystal cells.

[0110] "Evaluation of Liquid Crystal Alignment Unevenness" Using a liquid crystal cell with an FFS drive system fabricated using the method described above, the in-plane uniformity of the twist angle was evaluated. This evaluation is intended to assess the display unevenness of liquid crystal display elements caused by liquid crystal alignment unevenness. The variation in the liquid crystal twist angle was evaluated using AxoStep (manufactured by AXOMETRICS). Specifically, the liquid crystal cell was placed on a measurement stage, and the distribution of Circular Retardance within the pixel plane was measured without applying voltage, and 3σ, which is three times the standard deviation σ, was calculated. The in-plane uniformity of the twist angle is better the smaller the value of 3σ. That is, the smaller the value of 3σ, the less liquid crystal alignment unevenness occurs, and the less likely display unevenness is to occur in the liquid crystal display element. The results of the evaluation of liquid crystal alignment unevenness are shown in Table 3.

[0111] <Example 1> In a sample tube containing a stirring bar, the polyimide polymer solution (PAA-1-EA1) obtained by the method of Synthesis Example 4 and the polyimide polymer solution (PAA-3) obtained by the method of Synthesis Example 3 were mixed so that the mass ratio of PAA-1-EA1 to PAA-3 polymers was 40:60. Furthermore, NMP, GBL, BCS, B-1 (1 part by mass per 100 parts by mass of all polymers) and C-1 (5 parts by mass per 100 parts by mass of all polymers) were added, and the mixture was stirred at 25°C for 1 hour to obtain a liquid crystal alignment agent (1) (solid content: NMP:GBL:BCS = 4:46:30:20 mass ratio). No abnormalities such as turbidity or precipitate formation were observed in this liquid crystal alignment agent, and it was confirmed to be a homogeneous solution. In addition, the obtained liquid crystal alignment agent (1) was used to "fabricate a liquid crystal cell using an FFS drive method" and "evaluate the alignment unevenness of the liquid crystal".

[0112] <Example 2> In a sample tube containing a stirring bar, the polyimide polymer solution (PAA-1-EA1) obtained by the method of Synthesis Example 4 and the polyimide polymer solution (PAA-3-EB1) obtained by the method of Synthesis Example 12 were mixed so that the mass ratio of PAA-1-EA1 to PAA-3-EB1 polymers was 40:60. Furthermore, NMP, GBL, BCS, B-1 (1 part by mass per 100 parts by mass of all polymers) and C-1 (5 parts by mass per 100 parts by mass of all polymers) were added, and the mixture was stirred at 25°C for 1 hour to obtain liquid crystal alignment agent (2) (solid content: NMP:GBL:BCS = 4:46:30:20 mass ratio). No abnormalities such as turbidity or precipitate formation were observed in this liquid crystal alignment agent, and it was confirmed to be a homogeneous solution. In addition, the obtained liquid crystal alignment agent (2) was used to "fabricate a liquid crystal cell using an FFS drive method" and "evaluate the alignment unevenness of the liquid crystal".

[0113] <Example 3> In a sample tube containing a stirring bar, the polyimide polymer solution (PAA-1-EA2) obtained by the method of Synthesis Example 5 and the polyimide polymer solution (PAA-3-EB1) obtained by the method of Synthesis Example 12 were mixed so that the mass ratio of PAA-1-EA2 to PAA-3-EB1 polymers was 40:60. Furthermore, NMP, GBL, BCS, B-1 (1 part by mass per 100 parts by mass of all polymers) and C-1 (5 parts by mass per 100 parts by mass of all polymers) were added, and the mixture was stirred at 25°C for 1 hour to obtain a liquid crystal alignment agent (3) (solid content: NMP:GBL:BCS = 4:46:30:20 mass ratio). No abnormalities such as turbidity or precipitate formation were observed in this liquid crystal alignment agent, and it was confirmed to be a homogeneous solution. In addition, the obtained liquid crystal alignment agent (3) was used to "fabricate a liquid crystal cell using an FFS drive method" and "evaluate the alignment unevenness of the liquid crystal".

[0114] <Example 4> In a sample tube containing a stirring bar, the polyimide polymer solution (PAA-1-EA3) obtained by the method of Synthesis Example 6 and the polyimide polymer solution (PAA-3-EB1) obtained by the method of Synthesis Example 12 were mixed so that the mass ratio of PAA-1-EA3 to PAA-3-EB1 polymers was 40:60. Furthermore, NMP, GBL, BCS, B-1 (1 part by mass per 100 parts by mass of all polymers) and C-1 (5 parts by mass per 100 parts by mass of all polymers) were added, and the mixture was stirred at 25°C for 1 hour to obtain a liquid crystal alignment agent (4) (solid content: NMP:GBL:BCS = 4:46:30:20 mass ratio). No abnormalities such as turbidity or precipitate formation were observed in this liquid crystal alignment agent, and it was confirmed to be a homogeneous solution. In addition, the obtained liquid crystal alignment agent (4) was used to "fabricate a liquid crystal cell using an FFS drive method" and "evaluate the alignment unevenness of the liquid crystal".

[0115] <Example 5> In a sample tube containing a stirring bar, the polyimide polymer solution (PAA-1-EA4) obtained by the method of Synthesis Example 7 and the polyimide polymer solution (PAA-3-EB1) obtained by the method of Synthesis Example 12 were mixed so that the mass ratio of PAA-1-EA4 to PAA-3-EB1 polymers was 40:60. Furthermore, NMP, GBL, BCS, B-1 (1 part by mass per 100 parts by mass of all polymers) and C-1 (5 parts by mass per 100 parts by mass of all polymers) were added, and the mixture was stirred at 25°C for 1 hour to obtain a liquid crystal alignment agent (5) (solid content: NMP:GBL:BCS = 4:46:30:20 mass ratio). No abnormalities such as turbidity or precipitate formation were observed in this liquid crystal alignment agent, and it was confirmed to be a homogeneous solution. In addition, the obtained liquid crystal alignment agent (5) was used to "fabricate a liquid crystal cell using an FFS drive method" and "evaluate the alignment unevenness of the liquid crystal".

[0116] <Example 6> In a sample tube containing a stirring bar, the polyimide polymer solution (PAA-1-EA5) obtained by the method of Synthesis Example 8 and the polyimide polymer solution (PAA-3-EB1) obtained by the method of Synthesis Example 12 were mixed so that the mass ratio of PAA-1-EA5 to PAA-3-EB1 polymers was 40:60. Furthermore, NMP, GBL, BCS, B-1 (1 part by mass per 100 parts by mass of all polymers) and C-1 (5 parts by mass per 100 parts by mass of all polymers) were added, and the mixture was stirred at 25°C for 1 hour to obtain a liquid crystal alignment agent (6) (solid content: NMP:GBL:BCS = 4:46:30:20 mass ratio). No abnormalities such as turbidity or precipitate formation were observed in this liquid crystal alignment agent, and it was confirmed to be a homogeneous solution. In addition, the obtained liquid crystal alignment agent (6) was used to "fabricate a liquid crystal cell using an FFS drive method" and "evaluate the alignment unevenness of the liquid crystal".

[0117] <Example 7> In a sample tube containing a stirring bar, the polyimide polymer solution (PAA-2-EA1) obtained by the method of Synthesis Example 9 and the polyimide polymer solution (PAA-3-EB1) obtained by the method of Synthesis Example 12 were mixed so that the mass ratio of PAA-2-EA1 to PAA-3-EB1 polymers was 40:60. Furthermore, NMP, GBL, BCS, B-1 (1 part by mass per 100 parts by mass of all polymers) and C-1 (5 parts by mass per 100 parts by mass of all polymers) were added, and the mixture was stirred at 25°C for 1 hour to obtain a liquid crystal alignment agent (7) (solid content: NMP:GBL:BCS = 4:46:30:20 mass ratio). No abnormalities such as turbidity or precipitate formation were observed in this liquid crystal alignment agent, and it was confirmed to be a homogeneous solution. In addition, the obtained liquid crystal alignment agent (7) was used to "fabricate a liquid crystal cell using an FFS drive method" and "evaluate the alignment unevenness of the liquid crystal".

[0118] <Example 8> In a sample tube containing a stirring bar, the polyimide polymer solution (PAA-2-EA1) obtained by the method of Synthesis Example 9 and the polyimide polymer solution (PAA-3-EB1) obtained by the method of Synthesis Example 12 were mixed so that the mass ratio of PAA-2-EA1 to PAA-3-EB1 polymers was 30:70. Furthermore, NMP, GBL, BCS, B-1 (1 part by mass per 100 parts by mass of all polymers) and C-1 (5 parts by mass per 100 parts by mass of all polymers) were added, and the mixture was stirred at 25°C for 1 hour to obtain a liquid crystal alignment agent (8) (solid content: NMP:GBL:BCS = 4:46:30:20 mass ratio). No abnormalities such as turbidity or precipitate formation were observed in this liquid crystal alignment agent, and it was confirmed to be a homogeneous solution. In addition, the obtained liquid crystal alignment agent (8) was used to "fabricate a liquid crystal cell using an FFS drive method" and "evaluate the alignment unevenness of the liquid crystal".

[0119] <Example 9> In a sample tube containing a stirring bar, the polyimide polymer solution (PAA-2-EA2) obtained by the method of Synthesis Example 10 and the polyimide polymer solution (PAA-3-EB1) obtained by the method of Synthesis Example 12 were mixed so that the mass ratio of PAA-2-EA1 to PAA-3-EB1 polymers was 40:60. Furthermore, NMP, GBL, BCS, B-1 (1 part by mass per 100 parts by mass of all polymers) and C-1 (5 parts by mass per 100 parts by mass of all polymers) were added, and the mixture was stirred at 25°C for 1 hour to obtain a liquid crystal alignment agent (9) (solid content: NMP:GBL:BCS = 4:46:30:20 mass ratio). No abnormalities such as turbidity or precipitate formation were observed in this liquid crystal alignment agent, and it was confirmed to be a homogeneous solution. Furthermore, using the obtained liquid crystal alignment agent (9), we performed "fabrication of a liquid crystal cell using an FFS drive method" and "evaluation of liquid crystal alignment unevenness."

[0120] <Example 10> In a sample tube containing a stirring bar, the polyimide polymer solution (PAA-2-EA2) obtained by the method of Synthesis Example 10 and the polyimide polymer solution (PAA-3-EB1) obtained by the method of Synthesis Example 12 were mixed so that the mass ratio of the PAA-2-EA1 and PAA-3-EB1 polymers was 30:70. Furthermore, NMP, GBL, BCS, B-1 (1 part by mass per 100 parts by mass of all polymers) and C-1 (5 parts by mass per 100 parts by mass of all polymers) were added, and the mixture was stirred at 25°C for 1 hour to obtain a liquid crystal alignment agent (10) (solid content: NMP:GBL:BCS = 4:46:30:20 mass ratio). No abnormalities such as turbidity or precipitate formation were observed in this liquid crystal alignment agent, and it was confirmed to be a homogeneous solution. Furthermore, using the obtained liquid crystal alignment agent (10), we performed "fabrication of a liquid crystal cell using an FFS drive method" and "evaluation of liquid crystal alignment unevenness."

[0121] <Example 11> In a sample tube containing a stirring bar, the polyimide polymer solution (PAA-2-EA2) obtained by the method of Synthesis Example 10 and the polyimide polymer solution (PAA-3-EB1) obtained by the method of Synthesis Example 12 were mixed so that the mass ratio of PAA-2-EA1 to PAA-3-EB1 polymers was 20:80. Furthermore, NMP, GBL, BCS, B-1 (1 part by mass per 100 parts by mass of all polymers) and C-1 (5 parts by mass per 100 parts by mass of all polymers) were added, and the mixture was stirred at 25°C for 1 hour to obtain a liquid crystal alignment agent (11) (solid content: NMP:GBL:BCS = 4:46:30:20 mass ratio). No abnormalities such as turbidity or precipitate formation were observed in this liquid crystal alignment agent, and it was confirmed to be a homogeneous solution. Furthermore, using the obtained liquid crystal alignment agent (11), we performed "fabrication of a liquid crystal cell using an FFS drive method" and "evaluation of liquid crystal alignment unevenness."

[0122] <Example 12> In a sample tube containing a stirring bar, the polyimide polymer solution (PAA-2-EA5) obtained by the method of Synthesis Example 11 and the polyimide polymer solution (PAA-3-EB1) obtained by the method of Synthesis Example 12 were mixed so that the mass ratio of the PAA-2-EA5 and PAA-3-EB1 polymers was 40:60. Furthermore, NMP, GBL, BCS, B-1 (1 part by mass per 100 parts by mass of all polymers) and C-1 (5 parts by mass per 100 parts by mass of all polymers) were added, and the mixture was stirred at 25°C for 1 hour to obtain a liquid crystal alignment agent (12) (solid content: NMP:GBL:BCS = 4:46:30:20 mass ratio). No abnormalities such as turbidity or precipitate formation were observed in this liquid crystal alignment agent, and it was confirmed to be a homogeneous solution. Furthermore, using the obtained liquid crystal alignment agent (12), we performed "fabrication of a liquid crystal cell using an FFS drive method" and "evaluation of liquid crystal alignment unevenness."

[0123] <Comparative Example 1> In a sample tube containing a stirring bar, the polyimide polymer solution (PAA-1) obtained by the method of Synthesis Example 1 and the polyimide polymer solution (PAA-3) obtained by the method of Synthesis Example 3 were mixed so that the mass ratio of PAA-1 to PAA-3 polymers was 40:60. Furthermore, NMP, GBL, BCS, B-1 (1 part by mass per 100 parts by mass of all polymers) and C-1 (5 parts by mass per 100 parts by mass of all polymers) were added, and the mixture was stirred at 25°C for 1 hour to obtain a liquid crystal alignment agent (13) (solid content: NMP:GBL:BCS = 4:46:30:20 mass ratio). No abnormalities such as turbidity or precipitate formation were observed in this liquid crystal alignment agent, and it was confirmed to be a homogeneous solution. In addition, the obtained liquid crystal alignment agent (13) was used to "fabricate a liquid crystal cell using an FFS drive method" and "evaluate the alignment unevenness of the liquid crystal".

[0124] <Comparative Example 2> In a sample tube containing a stirring bar, the polyimide polymer solution (PAA-1-EB1) obtained by the method of Synthesis Example 13 and the polyimide polymer solution (PAA-3) obtained by the method of Synthesis Example 3 were mixed so that the mass ratio of PAA-1-EB1 to PAA-3 polymers was 40:60. Furthermore, NMP, GBL, BCS, B-1 (1 part by mass per 100 parts by mass of all polymers) and C-1 (5 parts by mass per 100 parts by mass of all polymers) were added, and the mixture was stirred at 25°C for 1 hour to obtain a liquid crystal alignment agent (14) (solid content: NMP:GBL:BCS = 4:46:30:20 mass ratio). No abnormalities such as turbidity or precipitate formation were observed in this liquid crystal alignment agent, and it was confirmed to be a homogeneous solution. In addition, the obtained liquid crystal alignment agent (14) was used to "fabricate a liquid crystal cell using an FFS drive method" and "evaluate the alignment unevenness of the liquid crystal".

[0125]

[0126] As can be seen from the results above, liquid crystal cells using liquid crystal alignment films obtained from the liquid crystal alignment agents of the embodiments of the present invention are less prone to uneven liquid crystal alignment. Specifically, this is demonstrated by comparing the embodiments using specific polymer (A) and specific polymer (B) with comparative examples that do not use them, i.e., comparing Embodiment 1 with Comparative Example 1 (comparing Embodiment 1, where the 3σ value indicating variation in the twist angle of the liquid crystal is 1.11, with Comparative Example 1, where the 3σ value is 1.46), and comparing the embodiments using specific polymer (A) and specific polymer (C) with comparative examples that do not use them, i.e., comparing Embodiments 2 to 6 with Comparative Example 1 (comparing Embodiments 2 to 6, where the 3σ value is 0.99 to 1.20, with Comparative Example 1, where the 3σ value is 1.46). Furthermore, when specific compound (B) was used instead of specific compound (A), the above 3σ increased, making uneven liquid crystal alignment more likely to occur. Specifically, this involves a comparison between Example 1 and Comparative Example 2 (a comparison between Example 1, where the 3σ value is 1.11, and Comparative Example 2, where the 3σ value is 1.41).

[0127] By using a liquid crystal alignment agent containing the specific polymer of the present invention, a liquid crystal alignment film without uneven liquid crystal alignment can be obtained, providing a liquid crystal display element that is less prone to display unevenness. This is particularly useful in liquid crystal display elements obtained by photo-alignment treatment utilizing the photodecomposition reaction of polyimide. Therefore, the liquid crystal display element of the present invention has excellent display quality and is useful as a transverse electric field driven element such as an IPS drive system or an FFS drive system for smartphones, tablet terminals, and the like.

[0128] 1: Transverse field liquid crystal display element, 2: Comb-tooth electrode substrate, 2a: Substrate, 2b: Linear electrode, 2c: Liquid crystal alignment film, 2d: Substrate, 2e: Surface electrode, 2f: Insulating film, 2g: Linear electrode, 2h: Liquid crystal alignment film, 3: Liquid crystal, 4: Opposing substrate, 4a: Liquid crystal alignment film, 4b: Substrate, L: Electric field lines

[0129] Furthermore, the entire contents of the specification, claims, abstract, and drawings of Japanese Patent Application No. 2024-189127, filed on October 28, 2024, are incorporated herein by reference as the disclosure of the specification of this invention.

Claims

1. A liquid crystal alignment agent containing the following components (A) and (B), or components (A) and (C). Component (A): At least one polymer selected from polyimide precursors and polyimides obtained by reacting a tetracarboxylic acid component, including tetracarboxylic dianhydride of the following formula [A-CA] and its derivatives, with a diamine component, and reacting it with at least one dicarboxylic anhydride selected from the following formulas [EA-1a] to [EA-3a] or at least one monoepoxy compound selected from the following formulas [EA-1b] and [EA-2b]. Component (B): At least one polymer selected from polyimide precursors and polyimides obtained by reacting a tetracarboxylic acid component, including tetracarboxylic dianhydride of the following formula [B-CA] and its derivatives, with a diamine component. However, this is different from component (C) below. (C) Component: A tetracarboxylic acid component, including a tetracarboxylic dianhydride of the following formula [B-CA] and its derivatives, reacts with a diamine component, and then reacts with at least one dicarboxylic anhydride selected from the following formulas [EB-1a] to [EB-11a] or at least one monoepoxy compound selected from the following formulas [EB-1b] to [EB-3b] to obtain a polyimide precursor and at least one polymer selected from polyimides. (R １ ~R ４ Each independently represents a hydrogen atom, a halogen atom, a C1-C6 alkyl group, a C2-C6 alkenyl group, a C2-C6 alkynyl group, a C1-C6 monovalent organic group containing a fluorine atom, a C1-C6 alkoxy group, a C2-C6 alkoxyalkyl group, a C2-C6 alkyloxycarbonyl group, or a phenyl group, R １ ~R ４ At least one of them represents a group other than a hydrogen atom in the above definition. B ｃａ This represents an aromatic tetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, or a tetravalent organic group derived from an alicyclic structure with five or more members. (Z １ａ and Z ２ａ Each independently represents an alkyl or alkenyl group having 6 to 18 carbon atoms, and non-adjacent -CH ２ - groups may be substituted with -O-, -CO- or -NH-. Z ３ａ and Z ４ａ Each independently represents an alkyl or alkenyl group having 6 to 18 carbon atoms, or a monovalent organic group having 9 to 18 carbon atoms containing a benzene ring or a cyclohexane ring, and non-adjacent -CH ２ - groups may be substituted with -O-, -CO- or -NH-. Z １ｂ and Z ２ｂ Each independently represents an alkyl or alkenyl group having 6 to 18 carbon atoms, and non-adjacent -CH ２ - groups may be substituted with -O-, -CO- or -NH-. ) (W １ａ to W ４ａ Each independently represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, or an organic group having 6 to 8 carbon atoms having one benzene ring or cyclohexane ring, and non-adjacent -CH ２ - groups may be substituted with -O-, -CO- or -NH-. W ５ａ to W １１ａ and Ｗ１４ａ Each independently represents a hydrogen atom, a hydroxyl group, a carboxyl group, an alkyl group having 1 to 5 carbon atoms, or an alkenyl or alkynyl group having 2 to 5 carbon atoms, and non-adjacent -CH ２ - groups may be substituted with -O-, -CO- or -NH-. W １２ａ and W １３ａ Each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. W １５ａ and W １６ａ Each independently represents an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, or an organic group having 6 to 8 carbon atoms having one benzene ring, cyclohexane ring or pyridine ring, and non-adjacent -CH ２ - groups may be substituted with -O-, -CO- or -NH-. W １ｂ and W ２ｂ Each of these independently represents an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, or an organic group having 6 to 8 carbon atoms having one benzene ring or cyclohexane ring, and the non-adjacent -CH groups of the alkyl group and alkenyl group. ２ The - group may be substituted with -O-, -CO-, or -NH-. ３ｂ -CH represents a hydrogen atom, a C1-C5 alkyl group, or a C2-C5 alkenyl group, and the alkyl group and alkenyl group are adjacent to each other. ２ (The - group may be substituted with -O-, -CO-, or -NH-.) 2. The liquid crystal alignment agent according to claim 1, wherein the liquid crystal alignment agent contains component (A) and component (C).

3. The liquid crystal alignment agent according to claim 1 or claim 2, wherein the tetracarboxylic dianhydride of formula [A-CA] and its derivatives in component (A) are at least one selected from the following formulas [A-CA-1] to [A-CA-5].

4. The liquid crystal alignment agent according to claim 1 or claim 2, wherein the tetracarboxylic dianhydride of formula [B-CA] and its derivative in component (B) and component (C) is at least one selected from pyromellitic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, and 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride.

5. The liquid crystal alignment agent according to claim 1 or claim 2, wherein the diamine component in component (A) comprises at least one diamine selected from the following formulas [A-DA-1a] to [A-DA-8a]. (X １ａ and X ２ａ These are, independently, -O-, -COO-, -OCO-, and -NR ａ -, -NR ａ -CO- or -CO-NR ａ - indicates R ａ X represents a hydrogen atom, a linear or branched alkyl group having 1 to 3 carbon atoms, or a protecting group that is removed by heating and replaced by a hydrogen atom. ３ａ and X ４ａ Each of these independently represents an alkylene group having 1 to 12 carbon atoms, and the non-adjacent -CH ２ - The bases are -O-, -CO-, and -NR ｂ It may be replaced with -, R ｂ R represents a hydrogen atom, a linear or branched alkyl group having 1 to 3 carbon atoms, or a protecting group that is removed by heating and replaced by a hydrogen atom. Ｘａ R represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. Ｘａ If multiple instances exist, they may be the same or different. Ｘｂ and R Ｘｃ Each of these independently represents a hydrogen atom, a halogen atom, a C1-C6 alkyl group, a C2-C6 alkenyl group, a C2-C6 alkynyl group, a C1-C6 monovalent organic group containing a fluorine atom, a C1-C6 alkoxy group, a C2-C6 alkoxyalkyl group, a C2-C6 alkyloxycarbonyl group, or a phenyl group. m1 represents 2 or 3. m2 represents an integer from 1 to 12. m3 and m4 independently represent integers from 1 to 6. m5 and m6 independently represent 1 or 2. m7 and m8 independently represent 0 or 1. The benzene rings in formulas [A-DA-1a], [A-DA-2a], [A-DA-4a], [A-DA-6a], and [A-DA-8a] may be partially or entirely replaced by naphthalene rings.

6. The liquid crystal alignment agent according to claim 1 or claim 2, wherein the diamine component in component (B) and component (C) comprises at least one diamine selected from the following formulas [B-DA-1a] to [B-DA-16a]. (X １ｂ and X ２ｂ Each of these independently represents a single bond or an alkylene group having 1 to 8 carbon atoms, and is not adjacent to a nitrogen atom -CH ２ The - group may be substituted with -O-. ３ｂ This is a single bond, -CH ２ -, -O-, -COO-, -OCO-, -NR ａ -, -NR ａ -CO- or -CO-NR ａ - indicates R ａ X represents a hydrogen atom, a linear or branched alkyl group having 1 to 3 carbon atoms, or a protecting group that is removed by heating and replaced by a hydrogen atom. ４ｂ and X ５ｂ Each of these is independently a single bond or -CH ２ It indicates -. X ６ｂ and X ７ｂ Each is independent of the single bond, -CH ２ -, -O-, -COO-, -OCO-, -NR ｂ -, -NR ｂ CO- or -CONR ｂ - indicates R ｂ R represents a hydrogen atom, a linear or branched alkyl group having 1 to 3 carbon atoms, or a protecting group that is removed by heating and replaced by a hydrogen atom. Ｙａ R represents a hydrogen atom, a linear or branched alkyl group having 1 to 3 carbon atoms, or a protecting group that is removed by heating and replaced by a hydrogen atom. Ｙａ If multiple instances exist, they may be the same or different. Ｙｂ (where n1 represents a hydrogen atom or a methyl group; n2 represents 1 or 2; n3 represents an integer from 1 to 6.) 7. The liquid crystal alignment agent according to claim 1 or claim 2, wherein the dicarboxylic acid anhydride or monoepoxy compound in component (A) is at least one selected from decenyl succinic anhydride, decyl succinic anhydride, 2-dodecene-1-yl succinic anhydride, dodecyl succinic anhydride, 2-hexen-1-yl succinic anhydride, isononenyl succinic anhydride, 2-octenyl succinic anhydride, n-octyl succinic anhydride, dodecenyl succinic anhydride, decanoic acid anhydride, heptanoic acid anhydride, nonanoic acid anhydride, n-octanoic acid anhydride, 2-ethylhexyl glycidyl ether, 1,2-epoxydecane, glycidyl lauryl ether, 1,2-epoxy-9-decene, or 1,2-epoxydodecane.

8. The liquid crystal aligning agent according to claim 1 or claim 2, wherein the dicarboxylic acid anhydride or monoepoxy compound in component (C) is at least one selected from phthalic acid anhydride, maleic acid anhydride, 2,3-dimethylmaleic acid anhydride, 2,3-diphenylmaleic acid anhydride, phenylmaleic acid anhydride, succinic acid anhydride, allyl succinic acid anhydride, itaconic acid anhydride, 4-methyl-4-pentene-1,2-dicarboxylic acid anhydride, cyclohexene-1,2-dicarboxylic acid anhydride, acrylic acid anhydride, crotonic acid anhydride, isobutyric acid anhydride, methacrylic acid anhydride, propionic acid anhydride, 3-pyridinecarboxylic acid anhydride, allyl glycidyl ether, 1,2-epoxybutane, 1,2-epoxypropane, ethyl glycidyl ether, glycidyl acrylate, glycidyl methacrylate, 1,2-epoxy-4-vinylcyclohexane, or methyl acrylic acid (3,4-epoxycyclohexyl)methyl.

9. The liquid crystal alignment agent according to claim 1 or claim 2, wherein the polymer of component (B) is 0.5 to 950 parts by mass with respect to 100 parts by mass of the polymer of component (A).

10. The liquid crystal alignment agent according to claim 1 or claim 2, wherein the polymer of component (C) is 0.5 to 950 parts by mass with respect to 100 parts by mass of the polymer of component (A).

11. A liquid crystal alignment film obtained from the liquid crystal alignment agent according to claim 1 or claim 2.

12. A liquid crystal display element comprising the liquid crystal alignment film according to claim 11.

13. A method for manufacturing a liquid crystal display element, comprising the following steps (1) to (4): Step (1): Applying the liquid crystal alignment agent described in claim 1 or claim 2 to at least one of a first substrate and a second substrate; Step (2): Firing the applied liquid crystal alignment agent to obtain a film; Step (3): Performing an alignment treatment on the film obtained in step (2); Step (4): Arranging a liquid crystal layer between the first substrate and the second substrate so as to be adjacent to the aligned film to produce a liquid crystal cell.

14. The method for manufacturing a liquid crystal display element according to claim 13, wherein the orientation treatment is a photo-alignment treatment.

15. A method for manufacturing a liquid crystal display element according to claim 14, further comprising step (3b) of performing a heat treatment between step (3) and step (4).

16. The method for manufacturing a liquid crystal display element according to claim 15, wherein the liquid crystal display element uses an IPS drive system or an FFS drive system.

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