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

Abstract

Provided are: a liquid crystal aligning agent with which a resin coating film and a liquid crystal alignment film have high rework characteristics; and a liquid crystal aligning agent with which it is possible to obtain a liquid crystal alignment film that has high light transmittance.　Disclosed is a liquid crystal aligning agent which contains a polymer (P) that has a partial structure (A) represented by formula (1). (In formula (1), Ya represents a divalent organic group that has a partial structure obtained by removing two hydrogen atoms from a structure represented by formula (NY). Each Z independently represents a monovalent organic group having a chain hydrocarbon structure, and is bonded to a nitrogen atom via a carbon atom in the chain hydrocarbon structure. * represents a bonding hand that bonds to a carbonyl carbon.) (In the formula (NY), E1 and E2 each independently represent a monovalent group having an aromatic ring, and the aromatic ring is bonded to a nitrogen atom in the formula (NY), or E1 and E2 are combined with each other to form a nitrogen-containing fused heterocyclic structure (Cn) constituted together with the nitrogen atom to which E1 and E2 are bonded. E3 is a hydrogen atom or a monovalent organic group. However, in the cases where E1 and E2 form a nitrogen-containing fused heterocyclic structure (Cn), either of the following conditions (1) or (2) is satisfied.　(1) The nitrogen-containing fused heterocyclic structure (Cn) has two or more aromatic rings, and has a fused ring structure in which two aromatic rings of the nitrogen-containing fused heterocyclic structure (Cn) are bonded to each other while sharing a nitrogen atom in the formula (NY). (2) E3 has an aromatic ring, and the aromatic ring of E3 is bonded to a nitrogen atom in the formula (NY).)

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, 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] Liquid crystal display elements are widely used in applications ranging from small devices such as mobile phones and smartphones to relatively large applications such as televisions and monitors. Furthermore, various driving methods have been developed that differ in electrode structure and the physical properties of the liquid crystal molecules used. For example, liquid crystal display elements using various modes such as TN (Twisted Nematic), STN (Super Twisted Nematic), VA (Vertical Alignment), IPS (In-Plane Switching), and FFS (Fringe Field Switching) are known. These liquid crystal display elements generally have a liquid crystal alignment film, which is essential for controlling the arrangement of liquid crystal molecules. Polyamic acid and its derivatives (e.g., polyimide) are commonly used as materials for the liquid crystal alignment film (see Patent Document 1).

[0003] Currently, commercially available liquid crystal alignment films are manufactured by aligning the surface of a film made of a polymer, such as polyamic acid and / or polyimide (an imidized polyamic acid), formed on an electrode substrate. Known alignment treatments include rubbing, which involves rubbing in one direction with a cloth such as cotton, nylon, or polyester, as well as photo-alignment, which regulates the orientation of the liquid crystal by irradiating it with polarized radiation (light). (See, for example, Patent Documents 1 and 2.) Furthermore, liquid crystal display elements are prone to the accumulation of static electricity within the liquid crystal cell, and asymmetric voltages generated by voltage driving can cause charge accumulation within the liquid crystal display element. These accumulated charges disrupt the orientation of the liquid crystal or affect the display as afterimages, significantly degrading the display quality of the liquid crystal display element. Patent Documents 1 and 2 propose the use of polymers having specific substructures.

[0004] Japanese Patent Publication No. WO2018 / 110354, Japanese Patent Publication No. 2009-75140

[0005] On the other hand, in electronic devices, including liquid crystal display elements, economic efficiency during manufacturing is crucial, and in particular, the reuse of defective substrates generated during the manufacturing of electronic devices is required. Specifically, when defects such as foreign matter or uneven coating occur in the resin coating or liquid crystal alignment film, or when defects in liquid crystal alignment occur, it is necessary to remove the resin coating or liquid crystal alignment film from the substrate using organic solvents, recover the substrate, and reuse it (also known as rework). However, polyimide-based organic films have high resistance to organic solvents, which has made it difficult to rework their resin coatings and liquid crystal alignment films. Furthermore, in recent years, with ultra-high-definition liquid crystal display elements such as 4K and 8K, the occupancy rate of the black matrix (BM) and TFTs increases, reducing the aperture ratio of the panel, making it important to improve the light transmittance of the display area. As a result of the inventor's investigation, it was found that conventional technology could not produce a liquid crystal alignment film that could satisfy these characteristics at a high level.

[0006] The object of the present invention is to provide a liquid crystal alignment agent that uses a polymer having a specific structure to provide resin coatings and liquid crystal alignment films with high reworkability. Furthermore, the invention aims to provide a liquid crystal alignment agent that can produce a liquid crystal alignment film with high light transmittance, the liquid crystal alignment film, and a liquid crystal display element using the same.

[0007] The inventors conducted diligent research to achieve the above objectives and discovered that using a liquid crystal alignment agent containing a specific polymer is extremely effective in achieving the above objectives, thus completing the present invention.

[0008] The present invention encompasses the following embodiments.

[0009] A liquid crystal alignment agent containing a polymer (P) having a substructure (A) represented by the following formula (1). (In formula (1), Y ａ The formula is as follows (N Ｙ This represents a divalent organic group having a substructure consisting of the structure represented by ) with two hydrogen atoms removed. Each Z independently represents a monovalent organic group having a chain-like hydrocarbon structure, bonded to a nitrogen atom via a carbon atom in the chain-like hydrocarbon structure. * represents a bond that connects to a carbonyl carbon. (In formula (N Ｙ ), E １ and E ２ each independently represent a monovalent group having an aromatic ring, and the aromatic ring is bonded to the nitrogen atom in formula (N Ｙ ), or E １ and E ２ are combined with each other to form a nitrogen-containing condensed heterocyclic structure (Cn) composed of the nitrogen atom to which E １ and E ２ are bonded. E ３ is a hydrogen atom or a monovalent organic group. However, when E １ and E ２ form a nitrogen-containing condensed heterocyclic structure (Cn), they satisfy either of the following conditions (1) or (2). (1) The nitrogen-containing condensed heterocyclic structure (Cn) has two or more aromatic rings, and the two aromatic rings of the nitrogen-containing condensed heterocyclic structure (Cn) have a condensed ring structure in which the nitrogen atom in formula (N Ｙ ) is shared. (2) E ３ has an aromatic ring, and the aromatic ring of E ３ is bonded to the nitrogen atom in formula (N Ｙ ).)

[0010] According to the present invention, it is possible to provide a liquid crystal aligning agent having high rework characteristics for a resin film and a liquid crystal alignment film. Further, a liquid crystal aligning agent capable of obtaining a liquid crystal alignment film having a high light transmittance, a liquid crystal alignment film obtained from the liquid crystal aligning agent, and a liquid crystal display device can be provided.

[0011] It is a schematic cross-sectional view showing an example of an IPS-mode horizontal electric field liquid crystal display device including a liquid crystal alignment film obtained from the liquid crystal aligning agent of the present invention. It is a schematic cross-sectional view showing an example of an FFS-mode horizontal electric field liquid crystal display device including a liquid crystal alignment film obtained from the liquid crystal aligning agent of the present invention.

[0012] Hereinafter, a liquid crystal aligning agent containing a specific polymer component, a liquid crystal alignment film formed using the liquid crystal aligning agent, and a liquid crystal display device having the liquid crystal alignment film will be described in detail. However, the description of the constituent elements described below is an example as one embodiment of the present invention, and is not limited to these contents.

[0013] In the following description, "halogen atoms" include fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc. Also, "tert-" which means tertiary is also represented as "t-". "Boc" represents a tert-butoxycarbonyl group, and "Fmoc" represents a 9-fluorenylmethyloxycarbonyl group. "*" represents a bond. In this specification, carbon atoms in a chain hydrocarbon structure refer to carbon atoms other than those constituting an aromatic ring or an aliphatic ring, and the chain hydrocarbon may be saturated or unsaturated, and may contain heteroatoms such as oxygen atoms, nitrogen atoms, or sulfur atoms.

[0014] (Polymer (P)) The polymer (P) of the present invention includes a substructure (A) represented by the above formula (1), and it is more preferable that the substructure (A) represented by the above formula (1) is included in the main chain of the polymer. The polymer (P) of the present invention is preferably a polymer having structural units derived from a diamine compound, and examples include polyimide precursors (e.g., polyamic acid or polyamic acid esters), polyimides, polyamides, polyamideimides, or polyureas. From the viewpoint of suitably obtaining the effects of the present invention, the polymer (P) is preferably a polyimide precursor or a polyimide. In the above formula (1), Y ａ The formula is as follows (N Ｙ This represents a divalent organic group having a substructure consisting of the structure represented by ) with two hydrogen atoms removed. Each Z independently represents a monovalent organic group having a chain-like hydrocarbon structure, bonded to a nitrogen atom via a carbon atom in the chain-like hydrocarbon structure. * represents a bond that connects to a carbonyl carbon. (Formula (N Ｙ ) middle, E １ and E ２ Each of these independently represents a monovalent group having an aromatic ring, and the aromatic ring is represented by formula (N Ｙ ) is bonded to the nitrogen atom in, or E １ and E ２ and are combined with each other, E １ and E ２ It forms a nitrogen-containing condensed heterocyclic structure (Cn) with the nitrogen atom to which it is bonded. ３is a hydrogen atom or a monovalent organic group. However, E １ and E ２ However, when a nitrogen-containing condensed heterocyclic structure (Cn) is formed, either of the following conditions (1) or (2) is met. (1) The nitrogen-containing condensed heterocyclic structure (Cn) has two or more aromatic rings, and the two aromatic rings of the nitrogen-containing condensed heterocyclic structure (Cn) are of formula (N Ｙ (2) E ３ It has an aromatic ring, E ３ The aromatic ring possessed by is given by formula (N Ｙ It is bonded to the nitrogen atom inside.

[0015] In formula (1) above, the monovalent organic group having a chain-like hydrocarbon structure for Z is preferably an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, or an alkynyl group having 2 to 6 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms, and even more preferably a methyl group.

[0016] In formula (1) above, from the viewpoint of favorably obtaining the effects of the present invention, the two Zs are each preferably an alkyl group having 1 to 3 carbon atoms, and more preferably a methyl group.

[0017] E １ and E ２ The aromatic ring possessed by is given by formula (N Ｙ If it is bonded to the nitrogen atom in ) by a single bond, E １ and E ２ The aromatic ring inside can be monocyclic or polycyclic. E １ and E ２ Examples of aromatic rings within include benzene rings, naphthalene rings, and anthracene rings. Of these, E １ and E ２ The aromatic ring inside is preferably an aromatic hydrocarbon ring, more preferably a benzene ring or a naphthalene ring, and even more preferably a benzene ring. １ and E ２ The aromatic ring inside may have substituents. Examples of such substituents include methyl groups, ethyl groups, halogen atoms, and the like.

[0018] E １ and E ２When a nitrogen-containing condensed heterocyclic structure (Cn) is formed, examples of such nitrogen-containing condensed heterocyclic structures (Cn) include carbazole structures, phenoxazine structures, phenothiazine structures, indoline structures, indole structures, and benzimidazole structures. These heterocyclic structures may have substituents on the ring portion. Examples of such substituents include methyl groups, ethyl groups, and halogen atoms. Among these, carbazole structures, indoline structures, and indole structures are preferred as nitrogen-containing condensed heterocyclic structures (Cn).

[0019] E ３ When the group is a monovalent organic group, examples of such monovalent organic groups include monovalent hydrocarbon groups having 1 to 10 carbon atoms and thermally detachable groups. Examples of monovalent hydrocarbon groups include alkyl groups having 1 to 10 carbon atoms, cycloalkyl groups having 3 to 10 carbon atoms, and aryl groups having 6 to 10 carbon atoms.

[0020] A thermally leaving group is a substituent that is removed by heat and replaced by a hydrogen atom. Examples of thermally leaving groups include carbamate protecting groups, amide protecting groups, imide protecting groups, and sulfonamide protecting groups. Of these, carbamate protecting groups are preferred because they exhibit high thermal leaving properties. Specific examples include t-butoxycarbonyl group, benzyloxycarbonyl group, 1,1-dimethyl-2-haloethyloxycarbonyl group, allyloxycarbonyl group, 2-(trimethylsilyl)ethoxycarbonyl group, 9-fluorenylmethyloxycarbonyl group, and allyloxycarbonyl group. Among these, the t-butoxycarbonyl group (Boc group) is particularly preferred because it exhibits excellent thermal leaving properties and can reduce the amount of the deprotected portion remaining in the film.

[0021] E １ and E ２When the above nitrogen-containing condensed heterocyclic structure (Cn) is formed, the nitrogen-containing condensed heterocyclic structure (Cn) satisfies either of the following conditions (1-1) or (2-1). (1-1) In condition (1), the above nitrogen-containing condensed heterocyclic structure (Cn) may be a carbazole structure, a phenoxazine structure, a phenothiazine structure, etc., with the carbazole structure being preferred. (2-1) In condition (2), the above nitrogen-containing condensed heterocyclic structure (Cn) may be an indoline structure, an indole structure, a benzimidazole structure, etc., with the indoline structure and the indole structure being preferred.

[0022] Y in equation (1) above ａ The above formula (N Ｙ It is sufficient to have a substructure obtained by removing two hydrogen atoms from the substructure represented by the above formula (N Ｙ The hydrogen atoms removed from the substructure represented by ) are E １ ~E ３ It may be a hydrogen atom possessed by any of the following. Specifically, Y in formula (1) above ａ is, E １ and E ２ It may be a divalent group having a substructure in which one hydrogen atom is removed from each of the following, or E １ and E ３ It may also be a divalent group having a substructure obtained by removing one hydrogen atom at a time from the original group.

[0023] Y ａ From the viewpoint of favorably obtaining the effects of the present invention, the above formula (N Ｙ It is preferable that the polymer (P) has a substructure represented by ) in its main chain. ａ The above formula (N Ｙ The number of substructures represented by ) may be one or two or more.

[0024] Y ａ Preferred specific examples of the divalent organic group represented by the formulas (a1) to (a15) below include the divalent organic group represented by the formulas (a1) to (a15). (In the above formula, Ph ８ This represents a divalent organic group represented by formula (a2). ９ This represents a divalent organic group represented by formula (a7).１０ and Ph １０’ Each of these independently represents a divalent organic group represented by formula (a2). １１ This represents a divalent organic group represented by formula (a2). １２ (This represents a divalent organic group represented by formula (a5).)

[0025] <Polymer (A)> As a preferred example of the polyimide precursor or polyimide in polymer (P) of the present invention, polymer (A) is selected from the group consisting of a polyimide precursor containing the substructure (A) represented by formula (1) and an imidized polymer which is an imidized product of the polyimide precursor. From the viewpoint of suitably obtaining the effects of the present invention, polymer (A) is preferably configured to include the substructure (A) represented by formula (1) in the main chain of polymer (A), and more preferably to include the substructure (A) represented by formula (1) in the structural units constituting polymer (A). Furthermore, polymer (A) may also contain the substructure (A) represented by formula (1) in the structural units derived from the tetracarboxylic acid derivative and / or the structural units derived from the diamine that constitute polymer (A).

[0026] (Structural units derived from tetracarboxylic acid derivatives in polymer (A)) The polyimide precursor in polymer (A) of the present invention has structural units derived from tetracarboxylic acid derivatives, as shown in the following formula (1T ａ The polymer may have a structural unit (a-1Ta) represented by ). The polymer (A) may be composed of one or more types, and the structural unit (a-1Ta) may be one or more types. The above formula (1T) ａ In the above formula (1T), R independently represents either a hydrogen atom or a monovalent organic group. ａ In ), the monovalent organic group R is a monovalent hydrocarbon group having 1 to 6 carbon atoms; the methylene group of the hydrocarbon group is -O-, -S-, -CO-, -COO-, -COS-, -NR ３ -, -CO-NR ３ -, -Si(R ３ ) ２ - (However, R ３ R is a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms.３ If there are two of them, R ３ They may be the same or different from each other. ２ Examples include monovalent groups A obtained by substituting with -, etc.; monovalent groups obtained by substituting at least one hydrogen atom bonded to the carbon atom of the monovalent hydrocarbon group or the monovalent group A with a halogen atom, hydroxyl group, alkoxy group, nitro group, amino group, mercapto group, nitroso group, alkylsilyl group, alkoxysilyl group, silanol group, sulfino group, phosphino group, carboxyl group, cyano group, sulfo group, acyl group, etc.; and monovalent groups having a heterocycle.

[0027] The above formula (1T) ａ In the above formula (1T), the monovalent organic group of R is preferably an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, or an alkynyl group having 2 to 6 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms, and even more preferably a methyl group. ａ In the above formula (1T), the two Rs are, from the viewpoint of suitably obtaining the effects of the present invention, preferably each is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and more preferably a hydrogen atom or a methyl group. ａ ) of X ａExamples of tetravalent organic groups that give the compound include a tetravalent organic group obtained by removing two acid anhydride groups (-C(=O)-O-C(=O)-) from an aromatic tetracarboxylic dianhydride, a tetravalent organic group obtained by removing two acid anhydride groups from an acyclic aliphatic tetracarboxylic dianhydride, or a tetravalent organic group obtained by removing two acid anhydride groups from an alicyclic tetracarboxylic dianhydride. Here, an aromatic tetracarboxylic dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxyl groups, including at least one carboxyl group bonded to the aromatic ring. The aromatic tetracarboxylic dianhydride may have heteroatoms in its molecule. The acyclic aliphatic tetracarboxylic dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxyl groups bonded to a chain-like hydrocarbon structure. However, it is not necessary to consist only of a chain-like hydrocarbon structure; it may have an alicyclic structure, an aromatic ring structure, or a heteroatom in part. Alicyclic tetracarboxylic dianhydrides are acidic dianhydrides obtained by intramolecular dehydration of four carboxyl groups, including at least one carboxyl group bonded to the alicyclic structure. However, none of these four carboxyl groups are bonded to an aromatic ring. Furthermore, the structure does not need to consist solely of an alicyclic structure; it may also contain a chain-like hydrocarbon structure, an aromatic ring structure, or a heteroatom. Examples of heteroatoms in the above tetracarboxylic dianhydrides include nitrogen atoms, oxygen atoms, sulfur atoms, and silicon atoms. In the above tetracarboxylic dianhydrides, some of the hydrogen atoms in the alicyclic structure, chain-like hydrocarbon structure, and aromatic ring structure may be substituted with heteroatoms, and the chain-like structure or cyclic structure may be formed via the heteroatom. In terms of suitably obtaining the effects of the present invention, tetracarboxylic dianhydrides having a benzene ring are preferred. More preferred X ａThe tetravalent organic groups derived from aromatic tetracarboxylic dianhydrides in this context are the tetravalent organic groups obtained by removing two acid anhydride groups from the following aromatic tetracarboxylic dianhydrides: pyromellitic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 3,3',4,4'-diphenylsulfone tetracarboxylic dianhydride, 1,4,5,8-naphthalene tetracarboxylic dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride, 3,3',4,4'-perfluoroisopropylidene di(phthalic acid anhydride), 3,3',4,4'-biphenyl tetracarboxylic dianhydride, 2,2',3,3'-biphenyl tetracarboxylic dianhydride, 4,4'-bis(3,4-dicarboxyph Aromatic tetracarboxylic dianhydrides such as phenoxy)-2,2-diphenylpropanoic acid dianhydride, ethylene glycol bisanhydrotrimellitate, 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 dianhydrides represented by the following formulas [CA-2] to [CA-8], [CA-11] to [CA-13], [CA-16] to [CA-17], [CA-19] to [CA-20]. The above-mentioned acyclic aliphatic tetracarboxylic dianhydrides include, but are not limited to, 1,2,3,4-butanetetracarboxylic dianhydrides, or tetracarboxylic dianhydrides represented by the following formulas (AL-1) to (AL-7), or tetracarboxylic dianhydrides represented by the following formulas [CA-10], [CA-14], [CA-21], [CA-23] to [CA-25], and among these, 1,2,3,4-butanetetracarboxylic dianhydrides are preferred.

[0028]

[0029] The above alicyclic tetracarboxylic dianhydride is a tetracarboxylic dianhydride having a cyclobutane ring structure, or a tetravalent organic group having an alicyclic structure of 5 or more members (T ５ａA tetracarboxylic dianhydride having ) is preferred. Preferred specific examples of the tetracarboxylic dianhydride having a cyclobutane ring structure include tetracarboxylic dianhydrides having a tetravalent organic group represented by the following formula (x-1). (In the formula (x-1), R １ ~R ４ each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, a monovalent organic group having 1 to 6 carbon atoms containing a fluorine atom, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 6 carbon atoms, an alkyloxycarbonyl group having 2 to 6 carbon atoms, or a phenyl group. * represents a bond.) In the above formula (x-1), R １ ~R ４ Specific examples of the alkyl group having 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms, 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, and the like. Specific examples of the alkenyl group having 2 to 6 carbon atoms, preferably 2 to 4 carbon atoms, in the above R １ ~R ４ include a vinyl group, a propenyl group, a butenyl group, etc., and these may be linear or branched. Specific examples of the alkynyl group having 2 to 6 carbon atoms, preferably 2 to 4 carbon atoms, in the above R １ ~R ４ include, for example, an ethynyl group, a 1-propynyl group, a 2-propynyl group, and the like.

[0030] For the above R １ ~R ４ Examples of the monovalent organic group having 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms, containing a fluorine atom include a fluoromethyl group, a trifluoromethyl group, a trifluoromethoxy group, a 2,2,2-trifluoroethyl group, a 2,2,2-trifluoroethoxy group, a pentafluoroethyl group, a pentafluoropropyl group, and the like.

[0031] Among them, the above formula (x-1) is preferably selected from the group consisting of the following formulas (x1-1) to (x1-6).

[0032] The above tetravalent organic group (T５ａ Preferably, the alicyclic structure is a tetravalent organic group having a 5-8 membered ring alicyclic structure, and more preferably a tetravalent organic group having a 5-7 membered ring alicyclic structure. A alicyclic structure with 5 or more members refers to a polycyclic structure to which the acid anhydride group is bonded, where each ring in the polycyclic structure contains 5 or more atoms. Furthermore, the alicyclic structure only needs to be bonded to at least one of the two acid anhydride groups, and may also have a chain-like hydrocarbon structure or an aromatic ring structure.

[0033] The above tetravalent organic group (T ５ａ A preferred example of this is the following formula (X ５ａ -1) to (X ５ａ Examples of tetravalent organic groups are those represented by any of the following: (T) ５ａ ) is, from the viewpoint of suitably obtaining the effects of the present invention, (X ５ａ -1) to (X ５ａ -4) is more preferable.

[0034]

[0035] From the viewpoint of suitably obtaining the effects of the present invention, the structural unit (a-1Ta) of the polyimide precursor in polymer (A) of the present invention is preferably 60 mol% or more, and more preferably 70 mol% or more, relative to 1 mole of the total structural units derived from the tetracarboxylic acid derivative of the polyimide precursor. Furthermore, the structural unit (a-1Ta) of the polyimide precursor in polymer (A) of the present invention may be 100 mol% or less, 95 mol% or less, or 90 mol% or less, relative to 1 mole of the total structural units derived from the tetracarboxylic acid derivative of the polyimide precursor. ａ In ), the monovalent organic group of R is a monovalent hydrocarbon group having 1 to 6 carbon atoms, and the methylene group of the hydrocarbon group is -O-, -S-, -CO-, -COO-, -COS-, -NR ３ -, -CO-NR ３ -, -Si(R ３ ) ２ - (However, R ３ (This is a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms.) -SO２ Examples include a monovalent group A obtained by substituting with a hydroxyl group, a monovalent group obtained by substituting at least one hydrogen atom bonded to the carbon atom of the monovalent hydrocarbon group or the monovalent group A with a halogen atom, a hydroxyl group, an alkoxy group, a nitro group, an amino group, a mercapto group, a nitroso group, an alkylsilyl group, an alkoxysilyl group, a silanol group, a sulfino group, a phosphino group, a carboxyl group, a cyano group, a sulfo group, an acyl group, etc., or a monovalent group having a heterocycle.

[0036] The above formula (1T) ａ In the above, the monovalent organic group of R is preferably an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, or a t-butoxycarbonyl group, more preferably an alkyl group having 1 to 3 carbon atoms, and even more preferably a methyl group.

[0037] The above formula (1T) ａ In the above, the two Rs are preferably, independently, a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and more preferably a hydrogen atom or a methyl group, from the viewpoint of suitably obtaining the effects of the present invention.

[0038] (Diamine-derived structural units in polymer (A)) The polyimide precursor (A) in polymer (A) of the present invention has diamine-derived structural units as shown in the following formula (1D ａ The polymer may also contain a structural unit (a-1Da) represented by ). Furthermore, in the following, H-N(Z)-Y Ａ -N(Z)-H(Y) Ａ And Z is given by the above formula (1D ａ ) Y Ａ The diamine represented by the above formula (1D is synonymous with Z.) is also called a specific diamine. ａ Examples of monovalent alkyl groups with 1 to 4 carbon atoms in Z in the above formula (1D ａ ) during, Y ａ Y in equation (1) ａ This is synonymous. Z independently represents an alkyl group with 1 to 4 carbon atoms. Y ａA specific example of this is the divalent organic group represented by the following formulas (a1) to (a15).

[0039] In one embodiment, polymer (A) preferably contains 1 mol% or more of the above structural unit (a-1Da) relative to 1 mole of all diamine-derived structural units contained in polymer (A), and more preferably 5 mol% or more. Also in one embodiment, polymer (A) may contain 100 mol% or less, 90 mol% or less, or 80 mol% or less of the above structural unit (a-1Da) relative to 1 mole of all diamine-derived structural units contained in polymer (A).

[0040] The polymer (A) of the present invention has a structural unit derived from a diamine, as shown in the following formula (1D ａ２ The polyimide precursor (A) may have a structural unit (a-2Da) represented by ). The proportion of structural unit (a-2Da) is preferably 10 mol% or more, and more preferably 20 mol% or more, relative to 1 mole of total diamine-derived structural units contained in the polyimide precursor (A). Furthermore, the proportion of structural unit (a-2Da) contained in the polyimide precursor (A) is preferably 99 mol% or less, and more preferably 95 mol% or less, relative to 1 mole of total diamine-derived structural units contained in the polyimide precursor (A). (Formula (1D ａ２ ) during, Y ａ２ This represents a divalent organic group derived from diamines, excluding specific diamines. ２ (This represents a hydrogen atom or a monovalent organic group.)

[0041] The above formula (1D ａ２ ) of Z ２ As a specific example of a monovalent organic group in the above formula (1T), ａ The structure exemplified by the monovalent organic group of R in ) is an example, and preferred specific examples are similar. As a preferred specific example of a diamine that gives the above structural unit (a-2Da), the specific diamine (2) "H-N(Z)-Ar ２ -L ２ -A ２ -L ２’ -Ar ２’Examples include "-N(Z)-H", diamine (Ph) "H-N(Z)-Ar-N(Z)-H", or diamines other than the specified diamine (2) and diamine (Ph) mentioned above (hereinafter also referred to as other diamines). Here, Ar ２ Ar ２’ Each of these independently represents a benzene ring, a biphenyl structure, a naphthalene ring, or an aromatic heterocycle. ２ Ar ２’ Any hydrogen atom on the ring may be substituted with a monovalent group, and examples of such substituents include halogen atoms; C1-C3 alkyl groups; C1-C3 alkyl groups in which at least some of the hydrogen atoms are substituted with halogen atoms or hydroxyl groups; C1-C3 alkoxy groups, C1-C3 alkoxy groups in which at least some of the hydrogen atoms are substituted with at least one of the above halogen atoms and hydroxyl groups; C2-C3 alkenyl groups; C2-C3 acyl groups; C1-C3 alkylsilyl groups; C1-C3 alkoxysilyl groups; monovalent groups such as hydroxyl groups and nitrile groups.

[0042] The above Ar ２ and Ar ２’Preferred specific examples include 1,4-phenylene, 1,3-phenylene, 2-methyl-1,4-phenylene, 2-ethyl-1,4-phenylene, 2-propyl-1,4-phenylene, 2-butyl-1,4-phenylene, 2-isopropyl-1,4-phenylene, 2-t-butyl-1,4-phenylene, 2-methoxy-1,4-phenylene, 2-ethoxy-1,4-phenylene, 2-propoxy-1,4-phenylene, 2-butoxy-1,4-phenylene, and 2-fluoro-1,4-phenylene. A benzene ring which may have substituents such as phenylene, 2,3-dimethyl-1,4-phenylene, 4-methyl-1,3-phenylene, 5-methyl-1,3-phenylene, 4-fluoro-1,3-phenylene, 2,3,5,6-tetramethyl-1,4-phenylene; 4,4'-biphenylylene, 2-methyl-4,4'-biphenylylene, 2-ethyl-4,4'-biphenylylene, 2-propyl-4,4'-biphenylylene, 2-butyl-4,4'-biphenylylene, 2-t-butyl-4,4 '-biphenylylene, 2-methoxy-4,4'-biphenylylene, 2-ethoxy-4,4'-biphenylylene, 2-fluoro-4,4'-biphenylylene, 3-methyl-4,4'-biphenylylene, 3-ethyl-4,4'-biphenylylene, 3-propyl-4,4'-biphenylylene, 3-butyl-4,4'-biphenylylene, 3-t-butyl-4,4'-biphenylylene, 3-methoxy-4,4'-biphenylylene, 3-ethoxy-4,4'-biphenylylene, 3-fluoro-4, Biphenyl structures may have substituents such as 4'-biphenylylene, 2,2'-dimethyl-4,4'-biphenylylene, 3,3'-dimethyl-4,4'-biphenylylene, 3,3'-biphenylylene, 5-methyl-3,3'-biphenylylene, and 5,5'-dimethyl-3,3'-biphenylylene; naphthalene rings may have substituents such as 1,5-naphthylene, 2,6-naphthylene, and 1-methyl-2,6-naphthylene; and the following structures (Ht-1) to (Ht-3) are also examples.

[0043] L ２ , L ２’These independently represent a single bond, -O-, -S-, -C(=O)-, -O-C(=O)-, -C(=O)-O-, -NR- (where R represents a hydrogen atom or a monovalent organic group), -C(=O)-NR- (where R represents a hydrogen atom or a monovalent organic group), or -NR-C(=O)- (where R represents a hydrogen atom or a monovalent organic group). ２ , L ２’ Examples of monovalent organic groups for R in -NR-, -C(=O)-NR-, or -NR-C(=O)- include C1-C3 alkyl groups, C1-C3 alkoxy groups, C2-C3 alkenyl groups, C2-C3 acyl groups, C1-C3 alkylsilyl groups, C1-C3 alkoxysilyl groups, Boc groups, phenyl groups, or monovalent organic groups in which at least some of the hydrogen atoms of these groups are substituted with at least one of a halogen atom and a hydroxyl group.

[0044] A ２ This represents a divalent organic group having an alkylene structure with 1 to 20 carbon atoms, preferably a divalent organic group having 1 to 18 carbon atoms. ２ The group is preferably a divalent organic group having 1 to 12 carbon atoms, and more preferably a divalent organic group having 1 to 10 carbon atoms. When the alkylene structure has three or more carbon-carbon bonds, any carbon-carbon bond constituting the alkylene structure may be replaced with a carbon-carbon double bond or a heterocycle. Examples of the heterocycles include a pyrrole ring, imidazole ring, pyrazole ring, triazole ring, pyridine ring, pyrimidine ring, pyridazine ring, pyrazine ring, indole ring, benzimidazole ring, purine ring, quinoline ring, isoquinoline ring, naphthyridine ring, quinoxaline ring, phthalazine ring, triazine ring, carbazole ring, acridine ring, piperidine ring, piperazine ring, pyrrolidine ring, hexamethyleneimine ring, and the like. Among these, pyridine rings, pyrimidine rings, pyrazine rings, benzimidazole rings, piperidine rings, piperazine rings, quinoline rings, carbazole rings, or acridine rings are preferred.

[0045] A ２Preferred specific examples include an alkylene group having 1 to 20 carbon atoms (preferably an alkylene group having 1 to 18 carbon atoms) (q0); a divalent organic group having 1 to 18 carbon atoms (q1) formed by inserting -O-, -C(=O)-, -NR-, -O-C(=O)-, -C(=O)-O-, -NR-C(=O)-, -C(=O)-NR-, or -NR- (where R represents a monovalent organic group) between the carbon-carbon bonds of the alkylene group; or a divalent organic group having 1 to 18 carbon atoms (q2) formed by inserting -NR-C(=O)-NR- (where R represents a hydrogen atom or a monovalent organic group) between the carbon-carbon bonds of the alkylene group. The monovalent organic group of R in -NR-C(=O)-, -C(=O)-NR-, or -NR- is the above L ２ and L ２’ Examples of structures that represent -NR-, -C(=O)-NR-, or -NR-C(=O)- include structures that exemplify R. Preferred specific examples of (q0), (q1), and (q2) above are as follows.

[0046] *-(CH ２ ) ｎ -*, *-(CH ２ ) ｎ１ -O-(CH ２ ) ｎ２ -*, *-(-CH ２ -CH ２ -O) ２ -CH ２ -CH ２ - * * - (CH ２ ) ｎ１ -NR-(CH ２ ) ｎ２ -*, *-(CH ２ ) ｍ１ -OC(=O)-(CH ２ ) ｎ’ -C(=O)-O-(CH ２ ) ｍ２ -*, *-(CH ２ ) ｍ１ -C(=O)-O-(CH ２ ) ｎ’ -OC(=O)-(CH ２ ) ｍ２ -*, *-(CH ２ ) ｍ１ -C(=O)-NR-(CH２ ) ｎ’ -NR-C(=O)-(CH ２ ) ｍ２ -*, *-(CH ２ ) ｍ１ -NR-C(=O)- (CH ２ ) ｎ’ -C(=O)-NR-(CH ２ ) ｍ２ -*, *-(CH ２ ) ｎ１ -NR-C(=O)-NR-(CH ２ ) ｎ２ - * In the above chemical formula, R represents a hydrogen atom or a monovalent organic group. The monovalent organic group is L mentioned above. ２ , L ２’ Examples of structures are given for R in -NR-, -C(=O)-NR-, or -NR-C(=O)-. The two Rs may be the same or different.

[0047] n is an integer from 1 to 18, more preferably an integer from 1 to 10, and even more preferably an integer from 1 to 6. *-(CH ２ ) ｎ１ -O-(CH ２ ) ｎ２ - * and * - (CH ２ ) ｎ１ -NR-(CH ２ ) ｎ２ In -*, n1 and n2 are independent integers from 1 to 6. m1 and m2 are independent integers from 0 to 4, and n' is an integer from 1 to 6. *-(CH ２ ) ｎ１ -NR-C(=O)-NR-(CH ２ ) ｎ２ In -*, n1 and n2 are each independent integers between 1 and 6.

[0048] *-L ２ -A ２ -L ２’-* indicates that the following embodiments are preferred from the viewpoint of suitably obtaining the effects of the present invention. The definitions of m1, m2, n, n', n1, and n2 in the following formula are the same as in the above formula. n0 is an integer from 1 to 3. In addition, R in the following formula represents a hydrogen atom or a monovalent organic group, and a preferred specific example of a monovalent organic group in R is the above L ２ and L ２’ Examples of structures representing R include -NR-, -C(=O)-NR-, or -NR-C(=O)-. If there are two R's, each has the above definition independently. *-(CH ２ ) ｎ -*, *-O-(CH ２ ) ｎ -O-*, *-O-(CH ２ ) ｎ１ -O-(CH ２ ) ｎ２ -O-*, *-O(-CH ２ -CH ２ -O) ３ - * * - (CH ２ ) ｎ１ -NR-(CH ２ ) ｎ２ -*, *-O-(CH ２ ) ｎ１ -NR-(CH ２ ) ｎ２ -O-*, *-C(=O)-(CH ２ ) ｎ -C(=O)-*, *-C(=O)-NR-(CH ２ ) ｎ -O-*, *-OC(=O)-(CH ２ ) ｎ -O-*, *-OC(=O)-(CH ２ ) ｎ -OC(=O)-*, *-OC(=O)-(CH ２ ) ｎ -C(=O)-O-*, *-(CH ２ ) ｍ１ -OC(=O)-(CH ２ ) ｎ’ -C(=O)-O-(CH ２ ) ｍ２ - * * - O - (CH ２ )ｍ１ -OC(=O)-(CH ２ ) ｎ’ -C(=O)-O-(CH ２ ) ｍ２ -O-* *-S-(CH ２ ) ｎ -S-*, *-C(=O)-NR-(CH ２ ) ｎ -NR-C(=O)-*, *-C(=O)-O-(CH ２ ) ｎ -OC(=O)-*, *-(CH ２ ) ｍ１ -C(=O)-O-(CH ２ ) ｎ’ -OC(=O)-(CH ２ ) ｍ２ - * * - O - (CH ２ ) ｍ１ -C(=O)-O-(CH ２ ) ｎ’ -OC(=O)-(CH ２ ) ｍ２ -O-* *-O-(CH ２ ) ｎ -*, *-S-(CH ２ ) ｎ -*, *-NR-(CH ２ ) ｎ -*, *-NR-(CH ２ ) ｎ -NR-*, *-NR-C(=O)-(CH ２ ) ｎ -C(=O)-NR-* *-(CH ２ ) ｎ１ -NR-C(=O)-NR-(CH ２ ) ｎ２ - *

[0049] From the viewpoint of favorably obtaining the effects of the present invention, the following embodiments are preferred: *-(CH ２ ) ｎ -*, *-O-(CH ２ ) ｎ -O-*, *-O-(CH ２ ) ｎ -*.

[0050] The above-mentioned specific diamine (2) is, from the viewpoint of suitably obtaining the effects of the present invention, a diamine in which two hydrogen atoms are bonded to a divalent organic group represented by any of the following formulas (h1-1) to (h1-21), 2,2'-bis[4-(4-aminophenoxy)phenyl]propane, 2,2'-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2'-bis(4-aminophenyl)hexafluoropropane, 2,2'-bis(3-aminophenyl)hexafluoropropane, 2,2'-bis( 3-amino-4-methylphenyl)hexafluoropropane, 2,2'-bis(4-aminophenyl)propane, 2,2'-bis(3-aminophenyl)propane, 2,2'-bis(3-amino-4-methylphenyl)propane, or 4-[4-[(4-aminophenoxy)methyl]-4,5-dihydro-4-methyl-2-oxazolyl]-benzeneamine, 4-[4-[(4-aminophenoxy)methyl]-4,5-dihydro-2-oxazolyl]-benzeneamine, or the following (d Ｈｔ -1) to (d Ｈｔ A diamine represented by -9) is preferred. (d Ｈｔ -6), (d Ｈｔ -8) is preferably 1,4-bis(p-aminobenzyl)piperazine or 4,4'-[4,4'-propane-1,3-diylbis(piperidine-1,4-diyl)]dianiline.

[0051] In formulas (h1-1) to (h1-25), the bonding positions of the benzene ring are preferably at positions 1 and 4. In formula (h1-4), -CH ２ The total number of negative signs is preferably between 1 and 10. In formulas (h1-7) and (h1-8), the two m's may be the same or different. In addition, the hydrogen atoms on the benzene ring in the following formulas (h1-1) to (h1-25) may be substituted with methyl groups, methoxy groups, or fluorine atoms.

[0052] (Diamine (Ph)) In diamine (Ph) "H-N(Z)-Ar-N(Z)-H", Ar represents a benzene ring, a biphenyl structure, a naphthalene ring, or a divalent organic group represented by the following formula (Im). Any hydrogen atom on the benzene ring, biphenyl structure, or naphthalene ring of Ar may be substituted with a monovalent group, and examples of such monovalent groups include halogen atoms; C1-C3 alkyl groups; C1-C3 alkyl groups in which at least some of the hydrogen atoms are substituted with halogen atoms or hydroxyl groups; C1-C3 alkoxy groups, C1-C3 alkoxy groups in which at least some of the hydrogen atoms are substituted with at least one of the above halogen atoms and hydroxyl groups; C2-C3 alkenyl groups; C2-C3 acyl groups; C1-C3 alkylsilyl groups; C1-C3 alkoxysilyl groups; hydroxyl groups, nitrile groups, etc. (In formula (Im), X represents a tetravalent organic group obtained by removing two anhydride groups from an acyclic or alicyclic tetracarboxylic dianhydride.) In the above formula (Im), X is the above formula (x-1), or the above formula (X ５ａ -1) to (X ５ａ A tetravalent organic group represented by (-4) and a tetravalent organic group obtained by removing two anhydrides from 1,2,3,4-butanetetracarboxylic dianhydride are preferred. The divalent organic group represented by the above formula (Im) is preferably structured as shown in the following formulas (Im-1) to (Im-6).

[0053] Preferred specific examples of diamines (Ph) include p-phenylenediamine, 2,3,5,6-tetramethyl-p-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, m-phenylenediamine, 2,4-dimethyl-m-phenylenediamine, 1,4-diamino-2,5-methoxybenzene, 2,5-diaminotoluene, 2,6-diaminotoluene, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-dihydroxy-4,4'-diaminobiphenyl, 3-trifluoromethyl-4,4'-diaminobiphenyl, 2-trifluoromethyl-4,4'-diaminobiphenyl, 3-fluoro-4,4'-diaminobiphenyl, and 2-f Examples include ruolo-4,4'-diaminobiphenyl, 2,2'-difluoro-4,4'-diaminobiphenyl, 3,3'-difluoro-4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 3,3'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 3,4'-diaminobiphenyl, 4,4'-diaminobiphenyl, 3,3'-diaminobiphenyl, 2,2'-diaminobiphenyl, 2,3'-diaminobiphenyl, 1,5-diaminonaphthalene, 1,6-diaminonaphthalene, 1,7-diaminonaphthalene, 2,5-diaminonaphthalene, 2,6-diaminonaphthalene, 2,7-diaminonaphthalene, or diamines in which amino groups are bonded to both ends of a divalent organic group represented by the above formula (Im).

[0054] (Other Diamines) Examples of the above-mentioned other diamines include: 4-aminobenzylamine, 2-(4-aminophenyl)ethylamine, semi-aromatic diamines having a secondary amino group and a primary amino group (preferably 4-(2-(methylamino)ethyl)aniline) (where, a semi-aromatic diamine refers to a diamine in which one amino group is bonded to an aromatic ring and the other amino group is not bonded to an aromatic ring), 4-(2-aminoethyl)aniline, 2-(6-aminonaphthyl)ethylamine, etc. 1,4-phenylenebis(4-aminobenzoate), 1,4-phenylenebis(3-aminobenzoate), 1,3-phenylenebis(4-aminobenzoate), 1,3-phenylenebis(3-aminobenzoate), bis(4-aminophenyl)terephthalate, bis(3-aminophenyl)terephthalate, bis(4-aminophenyl)isophthalate, bis(3-aminophenyl)isophthalate; 4,4'-diaminoazobenzene, diaminotran, diamines represented by the following formulas (D-1) to (D-5), 4,4-diaminochalcone, or [4-[(E)-3-[2-(2,4-diaminophenyl)ethoxy]-3-oxopropa-1-enyl]phenyl]4-(4,4,4-trifluorobutoxy)benzoate, or [4-[(E)-3-[[5-amino-2-[4-amino-2-[ Diamines having photo-orienting groups, such as aromatic diamines having a cinnamate structure represented by [(E)-3-[4-[4-(4,4,4-trifluorobutoxy)benzoyl]oxyphenyl]propa-2-enoyl]oxymethyl]phenyl]phenyl]methoxy]-3-oxopropa-1-enyl]phenyl]4-(4,4,4-trifluorobutoxy)benzoate; diamines having photopolymerizable groups at the terminal, such as 2-(2,4-diaminophenoxy)ethyl methacrylate or 2,4-diamino-N,N-diallylaniline; diamines having radical polymerization initiator function, such as 1-(4-(2-(2,4-diaminophenoxy)ethoxy)phenyl)-2-hydroxy-2-methylpropanone and 2-(4-(2-hydroxy-2-methylpropanoyl)phenoxy)ethyl-3,5-diaminobenzoate;Diamines having an amide bond, such as 4,4'-diaminobenzanilide, diamines represented by the following formula (D-6), and diamines represented by the following formulas (Am-3) to (Am-6); diamines having a urea bond, such as 1,3-bis(4-aminophenyl)urea; 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, 4,4'-bis(4-aminophenoxy)diphenyl ether, 1,4-bis[4-(4-aminophenoxy)phenoxy]benzene, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-di Aminodiphenylmethane, 4,4'-sulfonyldianiline, 3,3'-sulfonyldianiline, bis(4-aminophenyl)silane, bis(3-aminophenyl)silane, dimethyl-bis(4-aminophenyl)silane, dimethyl-bis(3-aminophenyl)silane, 4,4'-thiodianiline, 3,3'-thiodianiline, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 4,4'-diaminobenzophenone, 1,4-bis(4-aminobenzyl)benzene;2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, 1,4-bis-(4-aminophenyl)-piperazine, 3,6-diaminoacridine, N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N-(3-(1H-imidazole-1-yl)propyl-3,5-diaminobenzyl Mido, 2,5-bis(4-aminophenyl)pyrrole, 4,4'-(1-methyl-1H-pyrrole-2,5-diyl)bis[benzeneamine], 1,4-bis-(4-aminophenyl)-piperazine, 2-N-(4-aminophenyl)pyridine-2,5-diamine, 2-N-(5-aminopyridine-2-yl)pyridine-2,5-diamine, 2-(4-aminophenyl)-5-aminobenzimidazole, 2-(4-aminophenyl)-6 Diamines having at least one nitrogen atom-containing structure selected from the group consisting of a heterocycle containing a nitrogen atom and a secondary or tertiary amino group (hereinafter also referred to as a specific nitrogen atom-containing structure; however, a specific nitrogen atom-containing structure is an atomic group other than the two amino groups involved in the polycondensation reaction), such as heterocyclic diamines represented by formulas (z-1) to (z-22) below, or diamines having a diphenylamine structure such as 4,4'-diaminodiphenylamine, 4,4'-diaminodiphenyl-N-methylamine, N,N'-bis(4-aminophenyl)-benzidine, N,N'-bis(4-aminophenyl)-N,N'-dimethylbenzidine, or N,N'-bis(4-aminophenyl)-N,N'-dimethyl-1,4-benzenediamine; 2,4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4,6-diaminoresorcinol, 4,4'-diamino-3,3'-dihydroxybiphenyl;Diamines having a carboxyl group, such as 2,4-diaminobenzoic acid, 2,5-diaminobenzoic acid, 3,5-diaminobenzoic acid, 4,4'-diaminobiphenyl-3-carboxylic acid, 4,4'-diaminodiphenylmethane-3-carboxylic acid, 4,4'-diaminodiphenylethane-3-carboxylic acid, 4,4'-diaminobiphenyl-3,3'-dicarboxylic acid, 4,4'-diaminobiphenyl-2,2'-dicarboxylic acid, 3,3'-diaminobiphenyl-4,4'-dicarboxylic acid, 3,3'-diaminobiphenyl-2,4'-dicarboxylic acid, 4,4'-diaminodiphenylmethane-3,3'-dicarboxylic acid, 4,4'-diaminodiphenylethane-3,3'-dicarboxylic acid, and 4,4'-diaminodiphenyl ether-3,3'-dicarboxylic acid; 1-(4-amino Diamines having siloxane bonds, such as phenyl)-1,3,3-trimethyl-1H-indane-5-amine, 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-indane-6-amine, 1,3-bis(3-aminopropyl)-tetramethyldisiloxane, acyclic aliphatic diamines such as metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, and hexamethylenediamine, alicyclic diamines such as 1,3-bis(aminomethyl)cyclohexane, 1,4-diaminocyclohexane, and 4,4'-methylenebis(cyclohexylamine), and diamines in which two amino groups are bonded to a group represented by any of the formulas (Y-1) to (Y-167) described in WO2018 / 117239. (X in (z-13) １３ (This represents a methyl group or a phenyl group.) (In formula (z-19), X １９ R represents a single bond, -C(=O)-, -O-, or -NH-. １９ , R １９’ Each of these independently represents either a hydrogen atom or a methyl group. In formula (z-22), X ２２ (This represents -NH-.)

[0055] (Production of polyimide precursors or polyimides) Polyamic acid or its derivatives, which are polyimide precursors, are usually produced by reacting a diamine component with a tetracarboxylic acid component. Specifically, the method described in WO2015 / 012368 is an example.

[0056] In producing the polyimide precursor or polyimide in the present invention, a tetracarboxylic acid component containing tetracarboxylic dianhydride or its derivative, and a diamine component containing diamine may be used together with a suitable end-sealing agent to produce a end-sealed polymer. The end-sealed polymer has the effect of improving the film hardness of the liquid crystal alignment film obtained by the coating film and improving the adhesion characteristics between the sealant and the liquid crystal alignment film.

[0057] Examples of polyimide precursors and polyimide ends in the present invention include amino groups, carboxyl groups, acid anhydride groups, or groups derived from end-capturing agents described later. Amino groups, carboxyl groups, and acid anhydride groups can be obtained by conventional condensation reactions or by encapsulating the ends using the following end-capturing agents.

[0058] Examples of end-capturing agents include acid anhydrides such as acetic anhydride, propionic anhydride, succinic anhydride, citraconic anhydride, maleic anhydride, nadic anhydride, phthalic anhydride, itaconic anhydride, 1,2-cyclohexanedicarboxylic acid anhydride, 3-hydroxyphthalic anhydride, trimellitic anhydride, 3-(3-trimethoxysilyl)propyl)-3,4-dihydrofuran-2,5-dione, 4,5,6,7-tetrafluoroisobenzofuran-1,3-dione, and 4-ethynylphthalic anhydride; dicarbonate diester compounds such as di-tert-butyl dicarbonate and diallyl dicarbonate; and acryloyl chloride, methacryloyl chloride, and nicotinic acid chloride. Examples include chlorocarbonyl compounds; monoamine compounds such as aniline, 2-aminophenol, 3-aminophenol, 4-aminosalicylic acid, 5-aminosalicylic acid, 6-aminosalicylic acid, 2-aminobenzoic acid, 3-aminobenzoic acid, 4-aminobenzoic acid, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, and n-octylamine; and isocyanates having unsaturated bonds such as ethyl isocyanate, phenyl isocyanate, naphthyl isocyanate, or 2-acryloyloxyethyl isocyanate and 2-methacryloyloxyethyl isocyanate.

[0059] The proportion of end-capturing agent used is preferably 0.01 to 20 moles, and more preferably 0.01 to 10 moles, per 100 moles of the total diamine components used.

[0060] The weight-average molecular weight (Mw) of the polyimide precursor and polyimide, measured by gel permeation chromatography (GPC), is preferably 1,000 to 500,000, and more preferably 2,000 to 300,000. Furthermore, the molecular weight distribution (Mw / Mn), expressed as the ratio of Mw to the number-average molecular weight (Mn) measured by GPC, is preferably 15 or less, and more preferably 10 or less. This molecular weight range ensures good liquid crystal alignment of the liquid crystal display element.

[0061] The polyimide precursor and polyimide used in the present invention are preferably those having a solution viscosity of, for example, 10 to 1000 mPa·s when prepared as a solution with a concentration of 10 to 15% by mass, from the viewpoint of workability. The solution viscosity (mPa·s) of the polymer is the value measured at 25°C using an E-type rotational viscometer for a polymer solution with a concentration of 10 to 15% by mass prepared using a good solvent for the polymer (e.g., γ-butyrolactone, N-methyl-2-pyrrolidone, etc.).

[0062] The weight-average molecular weight (Mw) of the polyimide precursor and polyimide, measured by gel permeation chromatography (GPC), is preferably 1,000 to 500,000, and more preferably 2,000 to 300,000. Furthermore, the molecular weight distribution (Mw / Mn), expressed as the ratio of Mw to the number-average molecular weight (Mn) measured by GPC, is preferably 15 or less, and more preferably 10 or less. This molecular weight range ensures good orientation and stability of the liquid crystal display element.

[0063] The liquid crystal alignment agent of the present invention may contain polymers other than polymer (A). Specific examples of other polymers include polymers selected from the group consisting of at least one polymer (Q) selected from the group consisting of polyimide precursors other than polymer (A) and polyimides which are imidized products of the polyimide precursors, 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) copolymers, and 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 Ceratek Manufacturing Co., Ltd.). Specific examples of poly(isobutylene-maleic anhydride) copolymers include Isoban-600 (manufactured by Kuraray Co., Ltd.). Specific examples of poly(vinyl ether-maleic anhydride) copolymers include Gantrez AN-139 (methyl vinyl ether maleic anhydride resin, manufactured by Ashland Co., Ltd.).

[0064] Other polymers may be used individually or in combination of two or more. The content ratio of the other polymers is preferably 10 to 90 parts by mass, and more preferably 20 to 80 parts by mass, per 100 parts by mass of polymer components contained in the liquid crystal alignment agent.

[0065] In this specification, the term "polymer component" refers to the collective term for polymer (A) and other polymers other than polymer (A) that are contained in the liquid crystal alignment agent and may be added as needed. If polymer (A) is the only polymer contained in the liquid crystal alignment agent, the term "polymer component" refers to polymer (A).

[0066] A preferred specific example of the polymer (Q) is the above formula (1D ａExamples include at least one polymer (hereinafter also referred to as polymer (B)) selected from the group consisting of a polyimide precursor and a polyimide which is an imidized product of the polyimide precursor, which does not contain the structural unit (a-1Da) represented by ).

[0067] <Polymer (B)> (Structural units derived from tetracarboxylic acid derivatives in polymer (B)) The liquid crystal alignment agent of the present invention is a polymer (B) having structural units derived from a tetracarboxylic acid derivative and structural units derived from a diamine, wherein the structural units derived from the tetracarboxylic acid derivative are of the following formula (1T ｂ The polymer may contain a structural unit (b-1Tb) represented by ). (Formula (1T ｂ ) Medium, X ｂ This represents a tetravalent organic group derived from tetracarboxylic dianhydride. Formula (1D) ｂ ) during, Y ｂ represents a divalent organic group derived from a diamine. R is the same as in the above formula (1T ａ This is equivalent to R in the above formula (1D). Z is the same as (1D) ａ２ ) of Z ２ (This is synonymous with...)

[0068] Polymer (B) may be composed of one or more types. Furthermore, each of the structural units constituting polymer (B) may be composed of one or more types. The above formula (1T) ｂ ) of X ｂ A specific example of a tetravalent organic group that gives is the above formula (1T). ａ ) of X ａ Examples include the tetravalent organic group shown above. ｂ ) of X ｂ The tetravalent organic group that gives is preferably a tetravalent organic group derived from an alicyclic tetracarboxylic dianhydride, which is a tetracarboxylic dianhydride having a cyclobutane ring structure, or a tetravalent organic group having an alicyclic structure of 5 or more members (T ５ａ A tetravalent organic group derived from a tetracarboxylic dianhydride having the following properties is preferred.

[0069] From the viewpoint of suitably obtaining the effects of the present invention, polymer (B) preferably contains more than 40 mol% of structural unit (b-1Tb) relative to 1 mole of total structural units derived from the tetracarboxylic acid derivative contained in polymer (B), and more preferably 50 mol% or more.

[0070] (Diamine-derived structural units of polymer (B)) Polymer (B) has diamine-derived structural units, as shown in the above formula (1D ｂ It has a structural unit (b-1Db) represented by the above formula (1D ｂ The monovalent organic group of Z in the above formula (1D ａ This is synonymous with Z.

[0071] A preferred specific example of the above structural unit (b-1Db) is a structural unit derived from a diamine, excluding the specific diamine exemplified in polymer (A). From the viewpoint of improving liquid crystal orientation, it is preferable that the structural unit (b-1Db) has a structural unit derived from a diamine selected from the group consisting of the specific diamine (2) and diamine (Ph). The proportion of structural unit (b-1Db) is preferably 10 mol% or more, and preferably 20 mol% or more, based on 1 mole of all diamine-derived structural units in polymer (B). Furthermore, the proportion of structural unit (b-1Db) in polymer (B) may be 100 mol%, 99 mol% or less, or 95 mol% or less, based on 1 mole of all diamine-derived structural units in polymer (B).

[0072] In the liquid crystal alignment agent of the present invention, from the viewpoint of enhancing the effects of the present invention, the content ratio of polymer (A) to polymer (B) may be 10 / 90 to 90 / 10, 20 / 80 to 90 / 10, or 20 / 80 to 80 / 20 in terms of the mass ratio of [polymer (A) / polymer (B)].

[0073] <Liquid Crystal Alignment Agent> The liquid crystal alignment agent of the present invention is used to produce a liquid crystal alignment film, and from the viewpoint of forming a uniform thin film, it takes the form of a coating solution. In the liquid crystal alignment agent of the present invention, it is preferable that it is a coating solution containing the polymer component described above and a solvent.

[0074] The content (concentration) of the polymer component contained in the liquid crystal alignment agent of the present invention can be appropriately changed depending on the desired thickness of the coating film to be formed. However, from the viewpoint of forming a uniform and defect-free coating film, it is preferable to have 1% by mass or more relative to the total amount of the liquid crystal alignment agent, and from the viewpoint of the storage stability of the solution, it is preferable to have 10% by mass or less.

[0075] From the viewpoint of suitably obtaining the effects of this disclosure, the total content ratio of polymer (A) and polymer (B) in the liquid crystal alignment agent is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, and even more preferably 50 parts by mass or more, based on 100 parts by mass of the total polymers contained in the liquid crystal alignment agent. When the liquid crystal alignment agent contains other polymers, the content ratio of polymer (A) and polymer (B) is preferably 10 to 90 parts by mass, and more preferably 20 to 80 parts by mass, based on 100 parts by mass of the polymer components contained in the liquid crystal alignment agent.

[0076] The solvent contained in the liquid crystal alignment agent is not particularly limited as long as it uniformly dissolves the polymer components. Specific examples include N,N-dimethylformamide, N,N-dimethylacetamide, N,N-diethylacetamide, N,N-dimethyllactamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethyl sulfoxide, γ-butyrolactone, γ-valerolactone, 1,3-dimethyl-2-imidazolidinone, methyl ethyl ketone, cyclohexanone, cyclopentanone, 3-methoxy-N,N-dimethylpropanamide, 3-butoxy-N,N-dimethyl Examples include lupropanamide, 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-(3-methoxypropyl)-2-pyrrolidone, N-(2-ethoxyethyl)-2-pyrrolidone, N-(4-methoxybutyl)-2-pyrrolidone, and N-cyclohexyl-2-pyrrolidone (collectively referred to as "good solvents"). Among these, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N,N-diethylacetamide, 3-methoxy-N,N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropanamide, or γ-butyrolactone are preferred. The content of good solvent is preferably 20 to 99% by mass of the total solvent contained in the liquid crystal alignment agent, more preferably 20 to 90% by mass, and particularly preferably 30 to 80% by mass.

[0077] Furthermore, it is preferable to use a mixed solvent in which the solvent contained in the liquid crystal alignment agent is combined with a solvent (also called a poor solvent) that improves the coatability and surface smoothness of the coating film when applying the liquid crystal alignment agent. Specific examples of poor solvents used in combination are listed below, but are not limited to these.

[0078] For example, diisopropyl ether, diisobutyl ether, diisobutylcarbinol (2,6-dimethyl-4-heptanol), ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, 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 monobutyl ether, 1-(2-butoxyethoxy)-2-propanol Examples include 2-(2-butoxyethoxy)-1-propanol, propylene glycol monomethyl ether acetate, propylene glycol diacetate, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, 2-(2-ethoxyethoxy)ethyl acetate, diethylene glycol diacetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, butyl 3-methoxypropionate, n-butyl lactate, isoamyl lactate, diethylene glycol monoethyl ether, and diisobutyl ketone (2,6-dimethyl-4-heptanone). The content of the poor solvent is preferably 1 to 80% by mass of the total solvent contained in the liquid crystal alignment agent, more preferably 10 to 80% by mass, and particularly preferably 20 to 70% by mass. The type and content of the poor solvent are appropriately selected depending on the coating apparatus, coating conditions, and coating environment of the liquid crystal alignment agent.

[0079] Among these, 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 are preferred.

[0080] Preferred solvent combinations of good and poor solvents include: N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether, N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and 4-hydroxy-4-methyl-2-pentanone and diethylene glycol diethyl ether, and N-methyl-2-pyrrolidone and γ- Examples include butyrolactone, propylene glycol monobutyl ether and diisobutyl ketone; N-methyl-2-pyrrolidone, γ-butyrolactone, propylene glycol monobutyl ether and diisopropyl ether; N-methyl-2-pyrrolidone, γ-butyrolactone, propylene glycol monobutyl ether and diisobutylcarbinol; N-methyl-2-pyrrolidone, γ-butyrolactone and dipropylene glycol dimethyl ether; and N-methyl-2-pyrrolidone, propylene glycol monobutyl ether and dipropylene glycol dimethyl ether.

[0081] The liquid crystal alignment agent of the present invention may additionally contain components other than polymer components and solvents (hereinafter also referred to as additive components). Examples of such additive components include compounds for increasing the strength of the liquid crystal alignment film (hereinafter also referred to as crosslinking compounds), adhesion aids for improving the adhesion between the liquid crystal alignment film and the substrate, and the adhesion between the liquid crystal alignment film and the sealant, dielectrics and conductive materials for adjusting the dielectric constant and electrical resistance of the liquid crystal alignment film, or imidization accelerators for promoting imidization.

[0082] Examples of the crosslinkable compounds include, for example, at least one crosslinkable compound selected from the group consisting of a crosslinkable compound (c-1) having at least one substituent selected from epoxy groups, oxetanyl groups, oxazoline structures, cyclocarbonate groups, blocked isocyanate groups, hydroxyl groups, and alkoxy groups, and a crosslinkable compound (c-2) having a polymerizable unsaturated group.

[0083] Preferred specific examples of the above crosslinkable compounds (c-1) and (c-2) include the following compounds: Compounds having an epoxy group 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 hydrogenated bisphenol F epoxy resins such as YX-8000 (manufactured by Mitsubishi Chemical Corporation). Compounds in which a tertiary nitrogen atom is bonded to an aromatic carbon atom, such as phenol A type epoxy resin, biphenyl skeleton-containing epoxy resins such as YX6954BH30 (manufactured by Mitsubishi Chemical Corporation), phenol novolac type epoxy resins such as EPPN-201 (manufactured by Nippon Kayaku Co., Ltd.), (o,m,p-) cresol novolac type epoxy resins such as 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 ) Compounds in which a tertiary nitrogen atom is bonded to an aliphatic carbon atom, such as cyclohexane, 1,3-bis(N,N-diglycidylaminomethyl)benzene, 1,4-bis(N,N-diglycidylaminomethyl)benzene, 1,3,5-tris(N,N-diglycidylaminomethyl)cyclohexane, 1,3,5-tris(N,N-diglycidylaminomethyl)benzene, isocyanurate compounds such as triglycidyl isocyanurate (manufactured by Nissan Chemical Corporation), compounds described in paragraph

[0037] of Japanese Patent Publication No. 10-338880, and compounds described in WO2017 / 170483, etc. 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 compounds having two or more oxetanyl groups as described in paragraphs

[0170] to

[0175] of WO2011 / 132751; Compounds having an oxazoline structure 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 (trade name, manufactured by Nippon Shokubai Co., Ltd.), and compounds described in paragraph

[0115] of Japanese Patent Publication No. 2007-286597;Examples of 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 the compounds described in paragraphs

[0025] to

[0030] and

[0032] of WO2011 / 155577; Compounds containing a blocked isocyanate group include Coronate AP Stable M, Coronate 2503, 2515, 2507, 2513, 2555, Millionate MS-50 (all manufactured by Tosoh Corporation), and Takenate B-830, B-815N, B-820NSU, B-842N, B-846N, B-870N, B-874N, B-882N (all manufactured by Mitsui Chemicals). Examples of commercially available compounds such as those listed below, compounds represented by formulas (bL-1) to (bL-3), compounds having two or more protected isocyanate groups as described in paragraphs

[0046] to

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

[0119] to

[0120] of WO2015 / 141598, etc.

[0084] Compounds having a hydroxyl group and / or alkoxy group include N,N,N',N'-tetrakis(2-hydroxyethyl)adipoamide, compounds represented by the following formulas (pL-1) to (pL-4), 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, compounds described in WO2015 / 072554 and paragraph

[0058] of Japanese Patent Publication No. 2016-118753, compounds described in Japanese Patent Publication No. 2016-200798, compounds described in WO2010 / 074269, etc.

[0085]

[0086] Examples of crosslinkable compounds having polymerizable unsaturated groups include glycerin mono(meth)acrylate, glycerin di(meth)acrylate (1,2-,1,3-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, hexaethylene glycol mono(meth)acrylate, etc.

[0087] The above compounds are examples of crosslinkable compounds and are not limited thereto. For example, other components disclosed on pages 53

[0105] to 55

[0116] of WO2015 / 060357 can be cited. Furthermore, two or more crosslinkable compounds may be combined.

[0088] When a crosslinkable compound is used, the content of the crosslinkable compound in the liquid crystal alignment agent is preferably 0.5 to 20 parts by mass, and more preferably 1 to 15 parts by mass, per 100 parts by mass of the polymer component contained in the liquid crystal alignment agent.

[0089] Examples of the adhesion aids mentioned above include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyldiethoxymethylsilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, and N-ethoxycarbonyl-3-aminopropyl Trimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-3-triethoxysilylpropyltriethylenetetramine, N-3-trimethoxysilylpropyltriethylenetetramine, 10-trimethoxysilyl-1,4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonylacetate, 9-triethoxysilyl-3,6-diazanonylacetate, N-benzyl-3-aminopropyltrimethoxysilane, N- Benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxy Examples of silane coupling agents include silane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, tris[3-(trimethoxysilyl)propyl]isocyanurate, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-isocyanatetopropyltriethoxysilane.

[0090] When an adhesion aid is used, the content of the adhesion aid in the liquid crystal alignment agent is preferably 0.1 to 30 parts by mass, and more preferably 0.1 to 20 parts by mass, per 100 parts by mass of the polymer component contained in the liquid crystal alignment agent.

[0091] Examples of dielectric or conductive materials include monoamines having nitrogen-containing aromatic heterocycles, such as 3-picolylamine.

[0092] When a dielectric or conductive material is used, the content of the dielectric or conductive material in the liquid crystal alignment agent is preferably 0.1 to 30 parts by mass, and more preferably 0.1 to 20 parts by mass, per 100 parts by mass of the polymer component contained in the liquid crystal alignment agent. As an imidation accelerator for promoting the above imidation, a compound having a basic site (e.g., a primary amino group, an aliphatic heterocycle (e.g., a pyrrolidine skeleton), an aromatic heterocycle (e.g., an imidazole ring, an indole ring), or a guanidino group, etc.) is preferred (however, the above crosslinking compound and compounds for adjusting the dielectric constant and electrical resistance of the liquid crystal alignment film are excluded), or a compound that generates the above basic site during firing. More preferably, a compound that generates the above basic site during firing is preferred, and a preferred specific example is an amino acid in which some or all of the basic site of the amino acid is protected. Examples of protecting groups for the basic site of the above amino acid include carbamate protecting groups such as a Boc group. Specific examples of the above amino acids include glycine, alanine, cysteine, methionine, asparagine, glutamine, valine, leucine, phenylalanine, tyrosine, tryptophan, proline, hydroxyproline, arginine, histidine, lysine, and ornithine. More preferred examples of compounds for promoting imidation include N-α-(9-fluorenylmethoxycarbonyl)-N-τ-(tert-butoxycarbonyl)-L-histidine, or N-α-(tert-butoxycarbonyl)-N-τ-(tert-butoxycarbonyl)-L-histidine. The content of the imidation promoter contained in the liquid crystal alignment agent of the present invention is preferably 0.1 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, and even more preferably 5 to 20 parts by mass, per 100 parts by mass of the polymer component contained in the liquid crystal alignment agent.

[0093] (Liquid crystal alignment film) The liquid crystal alignment film of the present invention is formed using the liquid crystal alignment agent of the present invention described above.

[0094] A preferred embodiment of the method for manufacturing a liquid crystal alignment film of the present invention includes, for example, a step of coating the above-mentioned liquid crystal alignment agent onto a substrate (step (1)), a step of firing the coated liquid crystal alignment agent (step (2)), and optionally, a step of performing an alignment treatment on the film obtained in step (2) (step (3)). <Step (1)> The substrate on which the liquid crystal alignment agent used in the present invention is coated is not particularly limited as long as it is a highly transparent substrate, and glass substrates, silicon nitride substrates, acrylic substrates, polycarbonate substrates and other plastic substrates can be used. In this case, it is preferable to use a substrate on which ITO (Indium Tin Oxide) electrodes for driving the liquid crystal are formed, from the viewpoint of simplifying the process. In addition, in the case of a reflective liquid crystal display element, an opaque material such as a silicon wafer can be used for only one side of the substrate, and in this case, a light-reflecting material such as aluminum can be used for the electrodes. Furthermore, 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.

[0095] Methods for applying liquid crystal alignment agents to a substrate and forming a film include screen printing, offset printing, flexographic printing, inkjet printing, and spray printing. Among these, the inkjet method for coating and forming the film is particularly suitable.

[0096] An IPS substrate, which is a comb-tooth electrode substrate used in the IPS method (mode), comprises a base material, a plurality of linear electrodes formed on the base material and arranged in a comb-tooth pattern, and a liquid crystal alignment film formed on the base material so as to cover the linear electrodes.

[0097] The FFS substrate, which is a comb-tooth electrode substrate used in the FFS method (mode), comprises a base material, surface electrodes formed on the base material, an insulating film formed on the surface electrodes, 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 so as to cover the linear electrodes.

[0098] Figure 1 is a schematic cross-sectional view showing an example of an IPS mode transverse electric field liquid crystal display element comprising a liquid crystal alignment film obtained from the liquid crystal alignment agent of the present invention.

[0099] In the transverse electric field 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 base material 2a, a plurality of linear electrodes 2b formed on the base material 2a and arranged in a comb-tooth pattern, and a liquid crystal alignment film 2c formed on the base material 2a so as to cover the linear electrodes 2b. The counter substrate 4 has a base material 4b and a liquid crystal alignment film 4a formed on the base material 4b. The liquid crystal alignment film 2c is the liquid crystal alignment film of the present invention. Similarly, the liquid crystal alignment film 4c is the liquid crystal alignment film of the present invention.

[0100] In the transverse electric field liquid crystal display element 1 shown in Figure 1, when a voltage is applied to the linear electrode 2b, an electric field is generated between the linear electrode 2b as shown by the electric field lines L.

[0101] Figure 2 is a schematic cross-sectional view showing an example of a transverse electric field liquid crystal display element in FFS mode that comprises a liquid crystal alignment film obtained from the liquid crystal alignment agent of the present invention.

[0102] In the transverse electric field 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 base material 2d, a surface electrode 2e formed on the base material 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 base material 4b and a liquid crystal alignment film 4a formed on the base material 4b. The liquid crystal alignment film 2h is 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.

[0103] In the transverse electric field liquid crystal display element 1 shown in Figure 2, 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. <Step (2)> Step (2) is a step of firing the liquid crystal alignment agent coated on the substrate to form a film. After coating the liquid crystal alignment agent on the substrate, the solvent can be evaporated or the amic acid or amic acid ester in the polymer can be thermally imidized using a heating means such as a hot plate, a hot air circulation type oven or an IR (infrared) type oven. The drying and firing steps after coating the liquid crystal alignment agent of the present invention can be performed at any temperature and time, and may be performed multiple times. The temperature at which the solvent of the liquid crystal alignment agent is evaporated can be, for example, 40 to 180°C as the temperature of the heating means, but from the viewpoint of shortening the process, it may be performed at 40 to 150°C. The firing time is not particularly limited, but for example it is 1 to 10 minutes, preferably 1 to 5 minutes. If, in addition to the step of evaporating the solvent, a step of thermal imidation of the amic acid in the polymer is performed, then after the step of evaporating the solvent, a further firing step can be performed at a temperature range of, for example, 150 to 300°C, preferably 150 to 250°C, using a heating means. The firing time in the thermal imidation step is not particularly limited, but is for example 5 to 40 minutes, preferably 5 to 30 minutes.

[0104] If the film-like material after firing is too thin, the reliability of the liquid crystal display element may decrease, so a thickness of 5 to 300 nm is preferred, and 10 to 200 nm is more preferred. <Step (3)> Step (3) is a step of orientation treatment on the film obtained in step (2). Methods for orientation treatment of the liquid crystal alignment film include a rubbing method and a photo-alignment method. The photo-alignment method involves irradiating the surface of the film-like material with radiation polarized in a certain direction, and optionally performing a heat treatment to impart liquid crystal alignment properties (also called liquid crystal alignment ability). As radiation, ultraviolet light or visible light having a wavelength of 100 to 800 nm can be used. In particular, ultraviolet light having a wavelength of 100 to 400 nm, and more preferably 200 to 400 nm.

[0105] The radiation doses mentioned above range from 1 to 10,000 mJ / cm². ２Preferably, 100 to 5,000 mJ / cm² ２ This is preferable.

[0106] As a light source for illumination, for example, low-pressure mercury lamps, high-pressure mercury lamps, deep UV lamps, deuterium lamps, metal halide lamps, argon resonance lamps, xenon lamps, mercury xenon lamps, excimer lasers (e.g., KrF excimer lasers), fluorescent lamps, LED lamps, halogen lamps (e.g., sodium lamps), microwave-excited electrodeless lamps, etc., can be used.

[0107] Furthermore, when polarized light is used as the irradiating light, a higher extinction ratio of the polarized light can impart greater anisotropy. For example, in the case of ultraviolet light, a extinction ratio of polarized ultraviolet light of 10:1 or higher is more preferable, and 20:1 or higher is even more preferable.

[0108] Furthermore, when irradiating with radiation, the substrate having the above-mentioned film-like material may be irradiated while being heated at 50 to 250°C in order to improve the liquid crystal alignment properties. The liquid crystal alignment film produced in this manner can stably align liquid crystal molecules in a certain direction.

[0109] Furthermore, using the method described above, the liquid crystal alignment film irradiated with polarized radiation can be brought into contact with these materials using a solvent, or the irradiated liquid crystal alignment film can be heat-treated.

[0110] The solvent used in the above contact treatment is not particularly limited, as long as it is a solvent that dissolves the decomposition products generated from the film-like material by irradiation with radiation. Specific examples include water, methanol, ethanol, 2-propanol, acetone, methyl ethyl ketone, 1-methoxy-2-propanol, 1-methoxy-2-propanol acetate, butyl cellosolve, ethyl lactate, methyl lactate, diacetone alcohol, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propyl acetate, butyl acetate, and cyclohexyl acetate. Among these, water, 2-propanol, 1-methoxy-2-propanol, or ethyl lactate are preferred in terms of versatility and solvent safety. More preferably, water, 1-methoxy-2-propanol, or ethyl lactate are preferred. The solvent may be one type or a combination of two or more types.

[0111] Examples of the above-mentioned contact treatments include immersion treatment and spray treatment (also called atomization treatment). The treatment time in these treatments is preferably 10 seconds to 1 hour, in order to efficiently dissolve the decomposition products generated from the film-like material by irradiation with radiation. In particular, immersion treatment for 1 minute to 30 minutes is more preferable. The solvent used in the above-mentioned contact treatment may be at room temperature or heated, but is preferably 10 to 80°C, and more preferably 20 to 50°C. In addition, ultrasonic treatment or the like may be performed as needed in terms of the solubility of the decomposition products.

[0112] After the above contact treatment, it is preferable to rinse (also called rinsing) or calcinate with a low-boiling point solvent such as water, methanol, ethanol, 2-propanol, acetone, or methyl ethyl ketone. At that time, either rinsing or calcination may be performed, or both may be performed. The calcination temperature is preferably 150 to 300°C, more preferably 180 to 250°C, and even more preferably 200 to 230°C. The calcination time is preferably 10 seconds to 30 minutes, and more preferably 1 minute to 10 minutes. The heat treatment of the irradiated coating film is preferably 50 to 300°C for 1 to 30 minutes, and more preferably 120 to 250°C for 1 to 30 minutes.

[0113] (Liquid Crystal Display Element) The liquid crystal display element of the present invention has the liquid crystal alignment film of the present invention. The operating mode of the liquid crystal display element is not particularly limited and can be applied to various operating modes such as TN method, STN method, vertical alignment method (including VA-MVA method, VA-PVA method, PSA method, SC-PVA method, etc.), in-plane switching method (IPS method, FFS method), optical compensation bend method (OCB method), etc. The liquid crystal alignment film of the present invention is suitable as a liquid crystal alignment film for transverse electric field type liquid crystal display elements such as the IPS method and FFS method from the viewpoint of obtaining high liquid crystal alignment, and is particularly useful as a liquid crystal alignment film for FFS method liquid crystal display elements.

[0114] A liquid crystal display element can be manufactured by first obtaining a substrate with a liquid crystal alignment film obtained from the liquid crystal alignment agent of the present invention, then fabricating a liquid crystal cell by a known method, and finally arranging liquid crystal within the liquid crystal cell. Specifically, the following two methods can be mentioned.

[0115] The first method involves first arranging two substrates opposite each other with a gap (cell gap) in between so that their respective liquid crystal alignment films face each other. Next, the periphery of the two substrates is bonded together using a sealant, and the liquid crystal composition is injected and filled into the cell gaps partitioned by the substrate surface and the sealant, making contact with the film surface, and then the injection holes are sealed.

[0116] The second method is called the ODF (One Drop Fill) method. In this method, a UV-curable 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 UV light to cure the sealant.

[0117] In either the first or second method, it is desirable to further remove the flow orientation during liquid crystal filling by heating the liquid crystal composition to a temperature at which it forms an isotropic phase, and then slowly cooling it to room temperature.

[0118] When a rubbing treatment is performed on the coating film, the two substrates are positioned opposite each other so that the rubbing directions in each coating film are at a predetermined angle to each other, for example, orthogonal or antiparallel. Similarly, when a photo-alignment treatment is performed, the substrates are positioned opposite each other so that their orientation directions are at a predetermined angle to each other, for example, orthogonal or antiparallel.

[0119] As a sealant, for example, an epoxy resin containing aluminum oxide spheres as a curing agent and spacer can be used. Examples of liquid crystals include nematic liquid crystals and smectic liquid crystals, with nematic liquid crystals being preferred.

[0120] The liquid crystal composition is not particularly limited and is a composition containing at least one liquid crystal compound (liquid crystal molecule). Either a liquid crystal composition with positive dielectric anisotropy (also called a positive-type liquid crystal composition or positive-type liquid crystal) or a liquid crystal composition with negative dielectric anisotropy (also called a negative-type liquid crystal composition or negative-type liquid crystal) may be used, but a negative-type liquid crystal material is preferred.

[0121] The above liquid crystal composition may contain liquid crystal compounds 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 compounds having two or more rigid sites (mesogenic skeletons) that exhibit liquid crystallinity within the molecule (for example, a bimesogenic compound in which two rigid biphenyl structures or terphenyl structures are linked by alkyl groups). 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.

[0122] Furthermore, the above liquid crystal composition may contain additional additives from the viewpoint of improving liquid crystal alignment. Examples of such additives include photopolymerizable monomers such as compounds having polymerizable groups as described below, optically active compounds (e.g., S-811 from Merck), antioxidants, ultraviolet absorbers, dyes, defoamers, polymerization initiators, or polymerization inhibitors.

[0123] Examples of positive-type LCDs include the ZLI-2293, ZLI-4792, MLC-2003, MLC-2041, MLC-3019, or MLC-7081, all manufactured by Merck.

[0124] Examples of negative-type liquid crystal displays include Merck's MLC-6608, MLC-6609, MLC-6610, MLC-6882, MLC-6886, MLC-7026, MLC-7026-000, MLC-7026-100, and MLC-7029.

[0125] In addition, in PSA mode, Merck's MLC-3023 is an example of a liquid crystal containing a polymerizable compound.

[0126] Next, the polarizing plates are installed. Specifically, a pair of polarizing plates are attached to the sides of the two substrates opposite to the liquid crystal layer. Examples of polarizing plates include polarizing plates made by sandwiching a polarizing film called an "H film," which is made by stretching and oriented polyvinyl alcohol while absorbing iodine, between cellulose acetate protective films, or polarizing plates made of the H film itself.

[0127] The present invention will be further described in detail below with reference to examples, but the present invention is not intended to be limited to these examples. The abbreviations of the compounds used and the methods for measuring each physical property are as follows: (Organic solvents) THF: Tetrahydrofuran MeOH: Methanol NMP: N-methyl-2-pyrrolidone BCS: Ethylene glycol monobutyl ether (Tetracarboxylic acid dianhydrides) CA-1 to CA-3: Compounds represented by the following formulas (CA-1) to (CA-3), respectively (Diamines) DA-1 to DA-19: Compounds represented by the following formulas (DA-1) to (DA-19), respectively.

[0128] <Molecular Weight Measurement> The molecular weight was measured using the following room-temperature GPC (gel permeation chromatography) apparatus, and Mn (number-average molecular weight) and Mw (weight-average molecular weight) were calculated as polyethylene glycol and polyethylene oxide equivalents. GPC apparatus: GPC-101 (Resonac Corporation), Column: GPC KD-803 and GPC KD-805 (Resonac Corporation) in series, Column temperature: 50°C, Eluent: N,N-dimethylformamide (with lithium bromide monohydrate (LiBr·H) as an additive) ２ 30 mmol / L of o-phosphate (O), 30 mmol / L of anhydrous crystalline o-phosphate, 10 mL / L of tetrahydrofuran (THF), 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).

[0129] [Monomer Synthesis] DA-6, DA-7, DA-8, and DA-9 are novel compounds not published in the literature, and their synthesis methods are described in detail below. The products described in the monomer synthesis examples 1 to 4 below are １ Identified by 1H-NMR analysis (analytical conditions are as follows): Instrument: Fourier transform superconducting nuclear magnetic resonance spectrometer (FT-NMR) "AVANCE III" (BRUKER) 500 MHz. Solvent: Deuterated dimethyl sulfoxide (DMSO-d ６ Standard substance: tetramethylsilane) or deuterated chloroform (CDCl) ３ Standard substance: tetramethylsilane) (Monomer synthesis example 1; synthesis of DA-6) DA-6 was synthesized according to the route shown below.

[0130] DA-3 (21.1 g, 50.0 mmol), triethylamine (TEA, 13.4 g, 132 mmol), and THF (420 g) were added to a 1 L four-necked flask and dissolved, and the mixture was stirred under ice. A solution of anhydrous trifluoroacetic acid (26.8 g, 128 mmol) dissolved in THF (15.0 g) was slowly added dropwise using a dropping funnel. After the addition was complete, the mixture was stirred at room temperature for 2 hours. The resulting reaction mixture was poured into pure water (800 g), and the precipitated crystals were filtered off. The obtained crystals were cake-washed with methanol and dried under reduced pressure at 40°C to obtain DA-6-1 (yield: 30.5 g, 49.5 mmol, yield: 99%).

[0131] To the DA-6-1 (15.3 g, 25.0 mmol) obtained above, NMP (77 g) was added and dissolved, then potassium carbonate (9.0 g, 65.0 mmol) was added and the mixture was heated and stirred at 60°C. Methyl iodide (MeI, 8.9 g, 62.5 mmol) was added dropwise, and the mixture was stirred at 60°C for 18 hours. After the resulting reaction solution was cooled to room temperature, it was poured into pure water (153 g), and the precipitated crystals were filtered off. The obtained crystals were cake-washed with water and methanol in that order, and dried under reduced pressure to obtain DA-6-2 (yield 13.6 g, 21.2 mmol, yield: 85%).

[0132] To the DA-6-2 (11.9 g, 18.6 mmol) obtained above, THF (60 g) was added and dissolved, then 4.2 g of 8 N potassium hydroxide aqueous solution was slowly added and the mixture was stirred at room temperature for 5 hours. Ethyl acetate (240 g) and pure water (60 g) were added to the resulting reaction solution and liquid-liquid extraction was performed. The organic layer was then washed twice with pure water (60 g), and the resulting organic layer was concentrated to 54 g. Heptane (60 g) was added, and the precipitated crystals were filtered off. DA-6 was obtained by washing the obtained crystals with heptane (yield 7.6 g, 16.9 mmol, yield: 91%). １ H-NMR (DMSO-d ６): 7.54 (2H, d), 7.33 (2H, d), 6.91-6.95 (2H, dd), 6.79-6.83 (4H, m), 6.48-6.52 (4H, m), 5.31 (2H, q), 3.75 (3H, s), 3.19 (6H, s), 2.50 (6H, d). (Monomer synthesis example 2; synthesis of DA-7) DA-7 was synthesized according to the route shown below.

[0133]

[0134] DA-4 (8.00 g, 20.3 mmol), triethylamine (TEA, 5.95 g, 58.8 mmol), and THF (120 g) were added to a 500 mL four-necked flask and dissolved, and the mixture was stirred under ice. A solution of anhydrous trifluoroacetic acid (11.5 g, 54.8 mmol) dissolved in THF (10.0 g) was slowly added dropwise using a dropping funnel. After the addition was complete, the mixture was stirred at room temperature for 2 hours. The resulting reaction mixture was poured into pure water (250 g), and the precipitated crystals were filtered off. The obtained crystals were cake-washed with methanol and dried under reduced pressure at 40°C to obtain DA-7-1 (yield: 11.5 g, 19.6 mmol, yield: 97%).

[0135] To the DA-7-1 (11.5 g, 19.6 mmol) obtained above, NMP (57 g) was added and dissolved, then potassium carbonate (7.1 g, 51.2 mmol) was added and the mixture was heated and stirred at 60°C. Methyl iodide (MeI, 7.0 g, 49.2 mmol) was added dropwise, and the mixture was stirred at 60°C for 21 hours. After the resulting reaction solution was cooled to room temperature, it was poured into pure water (120 g), and the precipitated crystals were filtered off. The obtained crystals were cake-washed with water and methanol in that order, and dried under reduced pressure to obtain DA-7-2 (yield 11.5 g, 18.7 mmol, yield: 95%).

[0136] To the DA-7-2 obtained above (10.5 g, 17.0 mmol), potassium carbonate (9.41 g, 68.1 mmol), THF (104 g), methanol (52 g), and pure water (105 g) were added and dissolved, and then the mixture was stirred at 60°C for 4 hours. After cooling to room temperature, the precipitated crystals were filtered off, and the resulting crystals were washed with water and methanol in that order, and dried under reduced pressure to obtain DA-7 (yield 6.8 g, 16.0 mmol, yield: 94%). １ H-NMR (DMSO-d ６ ): 7.32 (4H, d), 6.94 (4H, d), 6.65 (4H, d), 6.55 (4H, d), 5.60 (2H, q), 3.16 (6H, s), 2.58 (6H, d). (Monomer synthesis example 3; Synthesis of DA-8) DA-8 was synthesized according to the route shown below.

[0137]

[0138] DA-8-0 (15.0 g, 36.5 mmol), triethylamine (TEA, 10.0 g, 98.7 mmol), and THF (150.0 g) were added to a 1 L four-necked flask and dissolved, and the mixture was stirred under ice. Then, anhydrous trifluoroacetic acid (22.3 g, 106.0 mmol) was slowly added dropwise using a dropping funnel. After the addition was complete, the mixture was stirred at room temperature for 1 hour. Pure water (300 g) was added to the resulting reaction solution, and the precipitated crystals were filtered off. The obtained crystals were cake-washed with water, methanol, and heptane in that order, and dried under reduced pressure at 40°C to obtain DA-8-1 (yield: 21.5 g, 35.6 mmol, yield: 97%).

[0139] To the DA-8-1 (21.5 g, 35.6 mmol) obtained above, NMP (107 g) was added and dissolved, and potassium carbonate (12.8 g, 92.6 mmol) was added and the mixture was heated and stirred at 60°C. Methyl iodide (12.1 g, 85.5 mmol) was added dropwise, and the mixture was stirred at 60°C for 2 hours, and then at room temperature for 64 hours. Pure water (215 g) was added to the resulting reaction solution and extracted twice with ethyl acetate (430 g). The resulting organic layer was washed with pure water (430 g), concentrated under reduced pressure, and dried under reduced pressure at 40°C to obtain DA-8-2.

[0140] To the DA-8-2 obtained above, THF (215 g), methanol (107 g), pure water (215 g), and potassium carbonate (19.7 g, 142.5 mmol) were added, and the mixture was stirred at 60°C for 4 hours. After the resulting reaction mixture was cooled to room temperature, it was concentrated under reduced pressure, and ethyl acetate (430 g) was added and liquid-liquid extraction was performed. The resulting organic layer was washed with pure water (430 g), concentrated under reduced pressure, and purified by silica gel column chromatography to obtain DA-8 (yield 14.8 g, 22.8 mmol, yield: 95% in 2 steps). １ H-NMR (CDCl ３ ): 6.97 (4H,d), 8.84 (4H,d), 6.73 (4H,d), 6.60 (4H,d), 3.61 (2H,brs), 3.20 (6H,s), 2.83 (6H,s) (Monomer synthesis example 5; Synthesis of DA-9) DA-9 was synthesized according to the route shown below.

[0141]

[0142] 4,4'-[3,3'-Bi-9H-carbazole]-9,9'-diylbis[benzenamine] (15.4 g, 30.0 mmol), triethylamine (TEA, 8.2 g, 80.9 mmol), and THF (154.0 g) were added to a 1 L four-necked flask and dissolved, and the mixture was stirred under ice. Then, anhydrous trifluoroacetic acid (18.3 g, 86.9 mmol) was slowly added dropwise using a dropping funnel. After the addition was complete, the mixture was stirred at room temperature for 1 hour. Pure water (462 g) was added to the resulting reaction solution, and the precipitated crystals were filtered off. The obtained crystals were cake-washed with water, methanol, and heptane in that order, and dried under reduced pressure at 40°C to obtain DA-9-1.

[0143] To the DA-9-1 obtained above, NMP (106 g) was added and dissolved, and potassium carbonate (10.8 g, 77.9 mmol) was added and the mixture was heated and stirred at 60°C. Methyl iodide (10.2 g, 72.0 mmol) was added dropwise and the mixture was stirred at 60°C for 3 hours. After the resulting reaction solution was cooled to room temperature, pure water (318 g) was added and the precipitated crystals were filtered off. The obtained crystals were washed with water, diisopropyl ether and heptane in that order, and dried under reduced pressure at 40°C to obtain DA-9-2.

[0144] To the DA-9-2 obtained above, THF (212 g), methanol (106 g), pure water (212 g), and potassium carbonate (16.6 g, 119.9 mmol) were added, and the mixture was stirred at 60°C for 3 hours. After the resulting reaction mixture was cooled to room temperature, it was concentrated under reduced pressure, and ethyl acetate (414 g) was added and liquid-liquid extraction was performed. The resulting organic layer was washed with pure water (424 g), concentrated under reduced pressure, and diisopropyl ether (85 g) and THF (21 g) were added, and the precipitated crystals were filtered off. The obtained crystals were washed with diisopropyl ether and dried under reduced pressure at 40°C to obtain DA-9 (yield 15.5 g, 28.5 mmol, yield: 95% in 3 steps). １ H-NMR (CDCl ３ ): 8.44 (2H, s), 8.22 (2H, d), 7.76 (2H, d), 7.43-7.35 (10H, m), 7.28 (2H, t), 6.81 (4H, d), 3.95 (2H, brs), 2.95 (6H, s)

[0145] [Synthesis of Polymers] <Synthesis Example 1> DA-1 (0.75 g, 5.0 mmol) and NMP (16.2 g) were added to a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, and dissolved by stirring at room temperature while supplying nitrogen. Then, under ice cooling, CA-2 (1.46 g, 5.0 mmol) was added, and the mixture was stirred at 70°C for 12 hours to obtain a polyamic acid solution PAA-1 (Mn: 4,131, Mw: 7,869) with a solid content of 12% by mass. <Synthesis Example 2> DA-2 (1.07 g, 5.0 mmol) and NMP (18.1 g) were added to a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, and dissolved by stirring at room temperature while supplying nitrogen. Subsequently, under ice cooling, CA-2 (1.40 g, 4.8 mmol) was added and the mixture was stirred at 70°C for 12 hours to obtain a polyamic acid solution PAA-2 (Mn: 9,804, Mw: 22,908) with a solid content of 12% by mass. <Synthesis Example 3> DA-3 (2.11 g, 5.0 mmol) and NMP (25.6 g) were added to a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, and dissolved by stirring at room temperature while supplying nitrogen. Subsequently, CA-2 (1.38 g, 4.7 mmol) was added under ice cooling and the mixture was stirred at 70°C for 12 hours to obtain a polyamic acid solution PAA-3 (Mn: 10,613, Mw: 34,328) with a solid content of 12% by mass. <Synthesis Example 4> DA-4 (1.97 g, 5.0 mmol) and NMP (24.6 g) were added to a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, and dissolved by stirring at room temperature while supplying nitrogen. Then, under ice cooling, CA-2 (1.38 g, 4.7 mmol) was added, and the mixture was stirred at 70°C for 12 hours to obtain a polyamic acid solution PAA-4 (Mn: 12,753, Mw: 38,728) with a solid content of 12% by mass. <Synthesis Example 5> DA-5 (1.21 g, 5.0 mmol) and NMP (19.5 g) were added to a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, and dissolved by stirring at room temperature while supplying nitrogen. Subsequently, CA-2 (1.46 g, 5.0 mmol) was added under ice cooling, and the mixture was stirred at 70°C for 12 hours to obtain a polyamic acid solution PAA-5 (Mn: 2,128, Mw: 3,198) with a solid content of 12% by mass.<Synthesis Example 6> DA-6 (2.25 g, 5.0 mmol) and NMP (27.2 g) were added to a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, and dissolved by stirring at room temperature while supplying nitrogen. Then, under ice cooling, CA-2 (1.46 g, 5.0 mmol) was added, and the mixture was stirred at 70°C for 12 hours to obtain a polyamic acid solution PAA-6 (Mn: 3,001, Mw: 5,393) with a solid content of 12% by mass. <Synthesis Example 7> DA-7 (2.11 g, 5.0 mmol) and NMP (26.2 g) were added to a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, and dissolved by stirring at room temperature while supplying nitrogen. Subsequently, under ice cooling, CA-2 (1.46 g, 5.0 mmol) was added and the mixture was stirred at 70°C for 12 hours to obtain a polyamic acid solution PAA-7 (Mn: 2,773, Mw: 4,250) with a solid content of 12% by mass. <Synthesis Example 8> DA-8 (2.19 g, 5.0 mmol) and NMP (26.8 g) were added to a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, and dissolved by stirring at room temperature while supplying nitrogen. Subsequently, CA-2 (1.46 g, 5.0 mmol) was added under ice cooling and the mixture was stirred at 70°C for 12 hours to obtain a polyamic acid solution PAA-8 (Mn: 2,988, Mw: 4,836) with a solid content of 12% by mass. <Synthesis Example 9> DA-9 (2.71 g, 5.0 mmol) and NMP (30.8 g) were added to a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, and dissolved by stirring at room temperature while supplying nitrogen. Then, under ice cooling, CA-2 (1.46 g, 5.0 mmol) was added, and the mixture was stirred at 70°C for 12 hours to obtain a polyamic acid solution PAA-9 (Mn: 2,256, Mw: 3,129) with a solid content of 12% by mass. <Synthesis Example 10> DA-7 (2.11 g, 5.0 mmol) and NMP (22.8 g) were added to a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, and dissolved by stirring at room temperature while supplying nitrogen. Subsequently, CA-3 (0.97 g, 5.0 mmol) was added under ice cooling, and the mixture was stirred at 25°C for 24 hours to obtain a polyamic acid solution PAA-10 (Mn: 8,696, Mw: 19,280) with a solid content of 10% by mass.<Synthesis Example 11> In a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, DA-3 (0.42 g, 1.0 mmol), DA-10 (0.60 g, 2.0 mmol), DA-11 (0.40 g, 2.0 mmol), and NMP (20.9 g) were added and dissolved by stirring at room temperature while supplying nitrogen. Then, under ice cooling, CA-2 (1.43 g, 4.9 mmol) was added and stirred at 70°C for 12 hours to obtain a polyamic acid solution PAA-12 (Mn: 8,417, Mw: 21,185) with a solid content of 12% by mass. <Synthesis Example 12> DA-4 (0.39 g, 1.0 mmol), DA-10 (0.60 g, 2.0 mmol), DA-11 (0.40 g, 2.0 mmol), and NMP (20.6 g) were added to a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, and dissolved by stirring at room temperature while supplying nitrogen. Then, under ice cooling, CA-2 (1.43 g, 4.9 mmol) was added, and the mixture was stirred at 70°C for 12 hours to obtain a polyamic acid solution PAA-12 (Mn: 10,818, Mw: 26,873) with a solid content of 12% by mass. <Synthesis Example 13> In a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, DA-6 (0.45 g, 1.0 mmol), DA-10 (0.60 g, 2.0 mmol), DA-11 (0.40 g, 2.0 mmol), and NMP (21.20 g) were added and dissolved by stirring at room temperature while supplying nitrogen. Then, under ice cooling, CA-2 (1.43 g, 4.9 mmol) was added and stirred at 70°C for 12 hours to obtain a polyamic acid solution PAA-13 (Mn: 8,116, Mw: 20,099) with a solid content of 12% by mass. <Synthesis Example 14> In a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, DA-7 (0.42 g, 1.0 mmol), DA-10 (0.60 g, 2.0 mmol), DA-11 (0.40 g, 2.0 mmol), and NMP (21.12 g) were added and dissolved by stirring at room temperature while supplying nitrogen. Then, under ice cooling, CA-2 (1.46 g, 5.0 mmol) was added and stirred at 70°C for 12 hours to obtain a polyamic acid solution PAA-14 (Mn: 8,217, Mw: 18,996) with a solid content of 12% by mass.<Synthesis Example 15> In a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, DA-12 (0.16 g, 1.5 mmol), DA-13 (0.18 g, 1.5 mmol), DA-14 (0.73 g, 3.0 mmol), DA-15 (0.54 g, 2.0 mmol), DA-16 (0.80 g, 2.0 mmol) and NMP (33.29 g) were added and dissolved by stirring at room temperature while supplying nitrogen. Then, under ice cooling, CA-1 (2.13 g, 9.5 mmol) was added and stirred at 40°C for 12 hours to obtain a polyamic acid solution PAA-15 (Mn: 10,152, Mw: 23,910) with a solid content of 12% by mass. <Synthesis Example 16> DA-17 (0.32 g, 1.5 mmol), DA-18 (1.11 g, 2.5 mmol), DA-19 (0.58 g, 1.0 mmol) and NMP (22.90 g) were added to a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, and dissolved by stirring at room temperature while supplying nitrogen. Then, under ice cooling, CA-1 (1.11 g, 5.0 mmol) was added, and the mixture was stirred at 40°C for 12 hours to obtain a polyamic acid solution PAA-15 (Mn: 9,253, Mw: 18,270) with a solid content of 12% by mass.

[0146] Table 1 shows the specifications of the polyamic acid obtained in the above synthesis example.

[0147] [Preparation of Liquid Crystal Alignment Agents] <Comparative Example 1> To the above polyamic acid solution PAA-1 (5.00 g), NMP (2.00 g) and BCS (3.00 g) were added while stirring, and the mixture was further stirred at room temperature for 2 hours to obtain a liquid crystal alignment agent (AL-R1) in which the mass ratio of polymer solids to each solvent (polymer solids: NMP: BCS) was 6:64:30. <Comparative Examples 2-4, Examples 1-6> By performing the same procedure as in Comparative Example 1, liquid crystal alignment agents (AL-R2) to (AL-R4) and (AL-1) to (AL-6) were obtained, respectively, in which the mass ratio of polymer solids to each solvent (polymer solids: NMP: BCS) was 6:64:30. <Comparative Example 5> Using the polyamic acid solution PAA-15 and polyamic acid solution PAA-11 described above, polyamic acid solution PAA-16 (2.08 g) and polyamic acid solution PAA-11 (2.08 g) were mixed so that the mass ratio of the two types of polymer solids was 50:50. To this mixture, NMP (2.83 g) and BCS (3.00 g) were added while stirring, and the mixture was further stirred at room temperature for 2 hours to obtain a liquid crystal alignment agent (AL-R5) with a mass ratio of polymer solids to each solvent (polymer solids: NMP: BCS) of 5:65:30. <Comparative Example 6, Examples 7-10> By performing the same operation as in Comparative Example 5 using the mixing amounts shown in Table 2, liquid crystal alignment agents (AL-R6), (AL-7) to (AL-10) with a mass ratio of polymer solids to each solvent (polymer solids: NMP: BCS) of 5:65:30 were obtained, respectively.

[0148] [Fabrication of FFS-driven liquid crystal cell] A liquid crystal cell with an FFS mode liquid crystal display element configuration was fabricated. First, a substrate with electrodes was prepared. The substrate was a 30 mm x 35 mm rectangular glass substrate with a thickness of 0.7 mm. On the substrate, an ITO electrode with a solid pattern was formed as the first layer, constituting a common electrode. On the first layer common electrode, a SiN (silicon nitride) film deposited by CVD (chemical vapor deposition) was formed as the second layer. The thickness of the second SiN film was 300 nm, and it was a thickness that functioned 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 pixel and the second pixel, with the size of each pixel being 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 has a comb-like shape with a 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 is formed by multiple electrode lines and has a first region and a second region separated by a line connecting the bent portions. <Formation of liquid crystal alignment film by rubbing alignment method> The liquid crystal alignment agents (AL-R1) to (AL-R4) obtained in Comparative Examples 1 to 4 and (AL-1) to (AL-6) obtained in Examples 1 to 6 were filtered through a filter with a pore size of 1.0 μm, and then coated by spin coating onto the electrode-equipped substrate (hereinafter referred to as the electrode substrate) and a glass substrate having a columnar spacer with a height of 4 μm on which an ITO film was deposited on the back surface (hereinafter referred to as the opposing substrate). After drying on a hot plate at 80°C for 2 minutes, the film was baked in an IR oven at 230°C for 30 minutes to form a coating film with a thickness of 80 nm. The coated surface was subjected to a rubbing treatment with a rayon cloth under the following conditions: roll diameter 120 mm, roller rotation speed 1000 rpm, stage movement speed 20 mm / sec, and rubbing cloth pressing pressure 0.3 mm. Subsequently, ultrasonic cleaning was performed in pure water for 1 minute, and the surface was dried at 80°C for 10 minutes to obtain a substrate with a liquid crystal alignment film.The liquid crystal alignment film formed on the electrode substrate was oriented so that the direction dividing the inner angle of the pixel bending portion was perpendicular to the orientation direction of the liquid crystal. The liquid crystal alignment film formed on the opposing substrate was oriented so that the orientation direction of the liquid crystal on the electrode substrate matched the orientation direction of the liquid crystal on the opposing substrate when manufacturing the liquid crystal cell. The two substrates were treated as a pair, and a sealant (XN-1500T manufactured by Mitsui Chemicals, Inc.) was printed onto the substrate using a dispenser. The other substrate was then bonded to the pair so that the orientation directions of the respective liquid crystal alignment films were 0° and facing each other. The bonded substrates were then pressed together and heated in a 150°C hot air circulating oven for 60 minutes to cure the sealant and create an empty cell. Positive-type liquid crystal MLC-3019 (manufactured by Merck) was injected into this empty cell by a reduced-pressure injection method, and the injection port was sealed to obtain an FFS-driven liquid crystal cell. Subsequently, the obtained FFS-driven liquid crystal cell was heated at 120°C for 1 hour, left overnight at 23°C, and then used for evaluation. <Formation of liquid crystal alignment film by photo-alignment method> The liquid crystal alignment agents (AL-R5) to (AL-R6) obtained in Comparative Examples 5 to 6 and the liquid crystal alignment agents (AL-7) to (AL-10) obtained in Examples 7 to 10 were filtered through a filter with a pore size of 1.0 μm, and then coated by spin coating onto the electrode-equipped substrate (hereinafter referred to as the electrode substrate) and a glass substrate having a columnar spacer with a height of 4 μm on which an ITO film was deposited on the back surface (hereinafter referred to as the opposing substrate). After drying on a hot plate at 80°C for 2 minutes, the film was baked in an IR oven at 230°C for 30 minutes to form a coating film with a thickness of 80 nm. Polarized ultraviolet light with a wavelength of 254 nm was applied to this coating film surface at a rate of 400 mJ / cm via a 240 nm low-cut filter and polarizer. ２The substrates were irradiated and then baked in an IR oven at 230°C for 30 minutes to perform an alignment treatment, thereby obtaining a substrate with a liquid crystal alignment film. The liquid crystal alignment film formed on the electrode substrate was oriented so that the direction dividing the inner angle of the pixel bending portion was perpendicular to the orientation direction of the liquid crystal. The liquid crystal alignment film formed on the opposing substrate was oriented so that the orientation direction of the liquid crystal on the electrode substrate matched the orientation direction of the liquid crystal on the opposing substrate when fabricating the liquid crystal cell. The two substrates were treated as a pair, and a sealant (XN-1500T manufactured by Mitsui Chemicals, Inc.) was printed onto the substrate using a dispenser. The other substrate was then bonded to the pair so that the orientation directions of the respective liquid crystal alignment films were 0° and facing each other. The bonded substrates were then pressed together and heated in a hot air circulating oven at 150°C for 60 minutes to cure the sealant, thereby fabricating an empty cell. A positive-type liquid crystal MLC-3019 (manufactured by Merck) was injected into this empty cell using a reduced-pressure injection method, and the injection port was sealed to obtain an FFS-driven liquid crystal cell. Subsequently, the obtained FFS-driven liquid crystal cell was heated at 120°C for 1 hour, left overnight at 23°C, and then used for evaluation.

[0149] [Evaluation of Afterimage Erasing Time (DC Relaxation Characteristics)] When the FFS-driven liquid crystal cells obtained using the liquid crystal alignment agents (AL-R1) to (AL-R6) of the above comparative example and the liquid crystal alignment agents (AL-1) to (AL-10) of the above example were visually observed, it was confirmed that the liquid crystals were uniformly aligned within the plane. The fabricated FFS-driven liquid crystal cells were placed between two polarizing plates arranged so that their polarization axes were orthogonal, and with no voltage applied, the LED backlight was turned on, and the arrangement angle of the liquid crystal cells was adjusted so that the brightness of the transmitted light was minimized. Next, the V-T curve (voltage-transmittance curve) was measured while applying an AC voltage of 30 Hz to these liquid crystal cells, and the AC voltage at which the relative transmittance was 23% was calculated as the driving voltage. After driving for 5 minutes with an AC voltage of 30 Hz at which the relative transmittance was 23%, a DC voltage of 1 V was applied simultaneously with the AC voltage, and the cell was driven in that state for 12 hours. The transmittance difference ΔT was calculated from the transmittance before and after the application of a DC voltage, and the change in transmittance difference ΔT over time from the start of DC voltage application until 12 hours had elapsed was observed. The transmittance difference ΔT immediately after the application of the DC voltage was used as the initial value, and the time it took for ΔT to decrease to 36.8% of the initial value was quantified. Note that the shorter this time, the easier it is for the afterimage caused by the applied DC voltage to disappear, and the better the DC relaxation characteristics are considered to be. This afterimage evaluation was performed under conditions where the temperature of the liquid crystal cell was 23°C. The results are shown in Table 3.

[0150] [Evaluation of Transmittance of Liquid Crystal Alignment Film] The liquid crystal alignment agents (AL-R1) to (AL-R6) obtained in Comparative Examples 1 to 6 and the liquid crystal alignment agents (AL-1) to (AL-10) obtained in Examples 1 to 10 were filtered through a filter with a pore size of 1.0 μm and then coated onto a quartz substrate by spin coating. After drying on a hot plate at 80°C for 2 minutes, the coating was baked in an IR oven at 230°C for 30 minutes to form a coating film with a thickness of 80 nm on the quartz substrate. Two coated quartz substrates were made into a pair, and the two quartz substrates were bonded together using double-sided tape so that the film surfaces faced each other. Then, to prevent light interference, benzyl benzoate was filled into the gap between the two quartz substrates to complete a cell for transmittance measurement. The transmittance of this cell was measured using a Shimadzu UV-3600 under the conditions of temperature: 25°C and scan wavelength: 400 nm to 800 nm. For the reference, a cell consisting of benzyl benzoate sandwiched between two uncoated quartz substrates was used. For the comparison of transmittance, the average transmittance at wavelengths of 400 nm to 500 nm was used. The results are shown in Table 3.

[0151] [Evaluation of Reworkability of Liquid Crystal Alignment Films] The liquid crystal alignment agents (AL-R1) to (AL-R6) obtained in Comparative Examples 1 to 6 and the liquid crystal alignment agents (AL-1) to (AL-10) obtained in Examples 1 to 10 were filtered through a pore size filter of 1.0 μm and then applied to ITO substrates by spin coating. After drying on a hot plate at 80°C for 2 minutes, the substrates were baked in an IR oven at 230°C for 30 minutes to form a coating film with a thickness of 80 nm on the ITO substrate. The ITO substrates with this coating film were immersed in a 5% tetramethylammonium hydroxide (TMAH) aqueous solution heated to 55°C for 2 minutes, washed with pure water for 1 minute, and dried in an oven at 80°C. The ITO substrates were observed under a microscope, and those with no remaining coating film were marked "○" and those with remaining coating film were marked "×". The results are shown in Table 3.

[0152] As shown in Table 3, the liquid crystal alignment agent of Comparative Example 1 had excellent reworkability, but the afterimage erasure time was long. Furthermore, the liquid crystal alignment agents of Comparative Examples 2 to 4 had low transmittance of the alignment film and poor reworkability. In contrast, the liquid crystal alignment agents of Examples 1 to 6, which contained polymer (P), exhibited excellent transmittance and reworkability of the liquid crystal alignment film, as well as a short afterimage erasure time for the liquid crystal display element. Even when using the photo-alignment method, the liquid crystal alignment agents of Examples 7 to 10, which contained polymer (P), exhibited excellent transmittance and reworkability of the liquid crystal alignment film.

[0153] By using the liquid crystal alignment agent of the present invention, a liquid crystal display element with good afterimage characteristics and high transmittance can be obtained. The liquid crystal display element of the present invention is particularly useful for liquid crystal displays for smartphones and notebook computers, where high transmittance is required from the viewpoint of reducing power consumption.

[0154] The liquid crystal display element of the present invention can be effectively applied to devices with various functions, such as liquid crystal televisions, clocks, portable games, word processors, notebook computers, car navigation systems, camcorders, PDAs, digital cameras, mobile phones, smartphones, various monitors, and information displays.

[0155] 1: Transverse field liquid crystal display element, 2: Comb-tooth electrode substrate, 2a: Base material, 2b: Linear electrode, 2c: Liquid crystal alignment film, 2d: Base material, 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: Base material, L: Electric field lines

[0156] Furthermore, the entire contents of the specification, claims, abstract, and drawings of Japanese Patent Application No. 2024-231293, filed on December 26, 2024, are incorporated herein by reference as the disclosure of the specification of this invention.

Claims

1. A liquid crystal aligning agent containing a polymer (P) having a partial structure (A) represented by the following formula (1). (In formula (1), Y ａ represents a divalent organic group having a partial structure formed by removing two hydrogen atoms from the structure represented by the following formula (N Ｙ ). Z each independently represents a monovalent organic group having a chain hydrocarbon structure and is bonded to a nitrogen atom through a carbon atom in the chain hydrocarbon structure. * represents a bond bonded to a carbonyl carbon.) (In formula (N Ｙ ), E １ and E ２ each independently represent a monovalent group having an aromatic ring, and the aromatic ring is bonded to the nitrogen atom in formula (N Ｙ ), or E １ and E ２ are combined with each other to form a nitrogen-containing condensed heterocyclic structure (Cn) composed of the nitrogen atom to which E １ and E ２ are bonded. E ３ is a hydrogen atom or a monovalent organic group. However, when E １ and E ２ form a nitrogen-containing condensed heterocyclic structure (Cn), either of the following conditions (1) or (2) is satisfied. (1) The nitrogen-containing condensed heterocyclic structure (Cn) has two or more aromatic rings, and the two aromatic rings of the nitrogen-containing condensed heterocyclic structure (Cn) have a condensed ring structure in which the nitrogen atoms in formula (N Ｙ are shared and bonded. (2) E ３ has an aromatic ring, and the aromatic ring of E ３ is bonded to the nitrogen atom in formula (N Ｙ ).) 2. The liquid crystal alignment agent according to claim 1, wherein the polymer (P) is a polyamic acid, a polyamic acid ester, or a polyimide.

3. The liquid crystal alignment agent according to claim 1, wherein the polymer (P) is the polymer (A) described below. Polymer (A): A polymer selected from the group consisting of a polyimide precursor having structural units derived from a tetracarboxylic acid derivative and structural units derived from a diamine, and an imidized polymer which is an imidized product of the polyimide precursor, wherein the structural unit derived from the tetracarboxylic acid derivative is the following formula (1T ａ It contains the structural unit (a-1Ta) represented by the following formula (1D ａ The polymer comprising the structural unit (a-1Da) represented by ). (Formula (1T ａ ) Medium, X ａ R represents a tetravalent organic group. R independently represents either a hydrogen atom or a monovalent organic group. Formula (1D) ａ ) during, Y ａ This is equivalent to the definition described in claim 1.

4. The liquid crystal alignment agent according to claim 1, wherein when E1 and E2 form a nitrogen-containing condensed heterocyclic structure (Cn), the nitrogen-containing condensed heterocyclic structure (Cn) is a carbazole structure, an indoline structure, or an indole structure.

5. The above E １ and E ２ However, when a nitrogen-containing condensed heterocyclic structure (Cn) is formed, the liquid crystal alignment agent according to claim 1 satisfies either of the following conditions (1-1) or (2-1): (1-1) In condition (1), the nitrogen-containing condensed heterocyclic structure (Cn) is a carbazole structure. (2-1) In condition (2), the nitrogen-containing condensed heterocyclic structure (Cn) is an indoline structure or an indole structure.

6. The aforementioned Y ａ The liquid crystal alignment agent according to claim 1, wherein the divalent organic group is represented by any of the following formulas (a1) to (a15).

7. A method for manufacturing a liquid crystal alignment film, comprising the following steps (1) to (3): Step (1): Applying the liquid crystal alignment agent described in claim 1 to a substrate; Step (2): Firing the applied liquid crystal alignment agent; Step (3): Performing an alignment treatment on the film obtained in step (2).

8. The method for manufacturing a liquid crystal alignment film according to claim 7, wherein the alignment treatment is a rubbing treatment or a photo-alignment treatment.

9. The method for manufacturing a liquid crystal alignment film according to claim 7, wherein the firing temperature in the firing process is 150 to 250°C.

10. A liquid crystal alignment film formed from the liquid crystal alignment agent described in claim 1.

11. A liquid crystal display element comprising the liquid crystal alignment film described in claim 10.

12. The liquid crystal display element according to claim 11, which is an IPS drive system or an FFS drive system.

Images