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

Abstract

Provided are: a liquid crystal aligning agent which enables the achievement of a liquid crystal alignment film that is capable of reducing accumulated electric charges in a short time, and which has excellent printability; a liquid crystal alignment film which is obtained from the liquid crystal aligning agent; and a liquid crystal display element which uses the liquid crystal alignment film.　Specifically provided is a liquid crystal aligning agent which contains a polymer (A) and polymers other than the polymer (A), wherein the content of the polymer (A) is 0.1 part by mass or more and 10 parts by mass or less with respect to a total of 100 parts by mass of the contents of the polymers other than the polymer (A). Polymer (A): a polymer (PA) which is selected from the group consisting of a polyimide precursor that is obtained using a tetracarboxylic acid derivative component that contains an aromatic tetracarboxylic acid dianhydride and a diamine component that contains 40% by mole or more of a diamine (A) represented by formula (DA) with respect to all diamine components, and a polyimide which is an imidized product of the polyimide precursor.　Formula (DA): Z-NH-Ar1-X1-(R1-L)n-R2-X2-Ar2-NH-Z

Description

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

[0001] The present invention relates to a liquid crystal aligning agent, a liquid crystal alignment film obtained from the liquid crystal aligning agent, and a liquid crystal display device having the liquid crystal alignment film.

[0002] Liquid crystal display elements are widely used in a wide range of applications, from small devices such as mobile phones and smartphones to relatively large devices such as televisions and monitors. Various driving methods have been developed, each differing in electrode structure and physical properties of the liquid crystal molecules used. Known liquid crystal display elements use various modes, such as twisted nematic (TN), super twisted nematic (STN), vertical alignment (VA), in-plane switching (IPS), and fringe field switching (FFS). These liquid crystal display elements generally have a liquid crystal alignment film, which is essential for controlling the alignment state of the liquid crystal molecules. Polyamic acid and its derivatives (e.g., polyimide) are commonly used as materials for the liquid crystal alignment film.

[0003] Liquid crystal display elements require high display quality. Patent Document 1 discloses a composition for a liquid crystal alignment film containing an aromatic diamine such as 1,5-bis(4-aminophenoxy)pentane. Patent Document 2 also discloses a diamine in which two aromatic groups are linked to an alkylene ester chain via an ether bond, and a liquid crystal alignment agent containing a polyamic acid or its derivative obtained using the diamine as a raw material. Furthermore, liquid crystal display elements such as IPS and FFS modes are prone to static electricity accumulation within the liquid crystal cell, and electric charge can also accumulate within the liquid crystal cell due to the application of asymmetric voltages generated by driving. These accumulated electric charges disrupt the alignment of the liquid crystal or affect the display as afterimages, significantly reducing the display quality of the liquid crystal display element. Patent Document 3 discloses a liquid crystal alignment agent containing a polyamic acid or its derivative obtained using a specific diamine component as a means to solve this problem.

[0004] Japanese Patent Application Publication No. 06-194670, WO2022 / 220199, WO2004 / 021076

[0005] A liquid crystal display element generally includes a liquid crystal layer sandwiched between an element substrate and a color filter substrate, pixel electrodes and common electrodes that apply an electric field to the liquid crystal layer, a liquid crystal alignment film that controls the orientation of liquid crystal molecules in the liquid crystal layer, and thin film transistors (TFTs) that switch electrical signals supplied to the pixel electrodes. In recent years, large-screen, high-resolution liquid crystal display elements have become mainstream, and display element standards with increased pixel counts, such as 4K and 8K, have been developed. Liquid crystal alignment films are required to not only reduce accumulated charge in a short time, as described above, but also to ensure a uniform film thickness even over uneven surfaces on the substrate equipped with TFTs. Therefore, there is a demand for liquid crystal alignment agents that can produce liquid crystal alignment films that can reduce accumulated charge in a shorter time than conventional liquid crystal alignment agents and that have better printability.

[0006] In view of the above, the object of the present invention is to provide a liquid crystal alignment agent that can obtain a liquid crystal alignment film that can reduce accumulated charge in a short period of time and has excellent printability, a liquid crystal alignment film obtained from the liquid crystal alignment agent, and a liquid crystal display element using the liquid crystal alignment film.

[0007] As a result of intensive research into achieving the above object, the present inventors have found that a liquid crystal aligning agent containing a specific polymer is effective in achieving the above object, and have thus completed the present invention.

[0008] The present invention provides the following: A liquid crystal aligning agent containing the following polymer (A) and a polymer other than the polymer (A), wherein the content of the polymer (A) is 0.1 parts by mass or more and 10 parts by mass or less relative to 100 parts by mass of the total content of the polymers other than the polymer (A). Polymer (A): A liquid crystal aligning agent containing a tetracarboxylic acid derivative component containing an aromatic tetracarboxylic acid dianhydride and a compound represented by the following formula (D Ａand a polymer (P) selected from the group consisting of a polyimide precursor obtained by using a diamine component containing 40 mol % or more of a diamine (A) (hereinafter also referred to as specific diamine (A)) represented by the formula (I) above, based on the total diamine components, and a polyimide obtained by imidizing the polyimide precursor. Ａ ). Z-NH-Ar １ -X １ - (R １ -L) ｎ -R ２ -X ２ -Ar ２ -NH-Z (D Ａ ) (Formula (D Ａ ) in Ar １ , Ar ２ Each of X independently represents a divalent aromatic group of a divalent benzene ring, a biphenyl structure, or a naphthalene ring, and any hydrogen atom of the aromatic group may be replaced with a monovalent group. １ , X ２ each independently represents a single bond, —O—, or *1-O—CO—. (*1 represents Ar １ or Ar ２ Represents a bond with .) R １ , R ２ are each independently a divalent hydrocarbon group, and some of the hydrogen atoms in the divalent hydrocarbon group may be substituted with a halogen atom, a methyl group, a trifluoromethyl group, or a hydroxy group. １ may be the same as or different from each other. L represents -O-, -C(=O)-, -O-C(=O)-, or -C(=O)-O-. When a plurality of Ls are present, the plurality of Ls may be the same as or different from each other. However, at least one L represents -O-C(=O)- or -C(=O)-O-. n is an integer of 1 to 6. Z represents a hydrogen atom or a monovalent organic group. A plurality of Zs may be the same as or different from each other.) In the present invention, examples of halogen atoms include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0009] According to the present invention, a liquid crystal alignment film can be obtained that can reduce accumulated charges in a short period of time, and a liquid crystal alignment agent that has excellent printability, a liquid crystal alignment film obtained from the liquid crystal alignment agent, a liquid crystal display element using the liquid crystal alignment film, and compounds and polymers that can be used therefor can be obtained.

[0010] The mechanism by which the above-described effects of the present invention are obtained is not entirely clear, but is presumed to be as follows. First, it is believed that the combined structure of the polymer (A) contained in the liquid crystal aligning agent of the present invention, which includes a tetracarboxylic acid derivative component containing an aromatic tetracarboxylic acid dianhydride and the specific diamine (A), promotes charge migration, thereby reducing accumulated charge. Furthermore, it is believed that the presence of a small amount of polymer (A), which has a highly flexible molecular structure, and the presence of polymers other than polymer (A) and polymer (A), suppresses aggregation between polymers, resulting in excellent printability.

[0011] 1 is a schematic partial cross-sectional view showing an example of a horizontal electric field liquid crystal display element of the present invention, and FIG. 2 is a schematic partial cross-sectional view showing another example of a horizontal electric field liquid crystal display element of the present invention.

[0012] The liquid crystal aligning agent of the present invention is a liquid crystal aligning agent containing the polymer (A) and a polymer other than the polymer (A), wherein the content of the polymer (A) is 0.1 parts by mass or more and 10 parts by mass or less relative to 100 parts by mass of the total content of the polymers other than the polymer (A), provided that the polymer other than the polymer (A) does not include those included in the definition of the polymer (A).

[0013] <Polymer (A)> The polymer (A) contained in the liquid crystal aligning agent of the present invention is a polymer containing a tetracarboxylic acid derivative component containing an aromatic tetracarboxylic acid dianhydride and a compound represented by the following formula (D Ａ and a polymer (P) selected from the group consisting of a polyimide precursor obtained by using a diamine component containing 40 mol % or more of a diamine (A) (hereinafter also referred to as specific diamine (A)) represented by the formula (I) above, based on the total diamine components, and a polyimide obtained by imidizing the polyimide precursor. Ａ The polymer (A) is one or more kinds of polymers (P Ａ ) may also be used. １ -X １- (R １ -L) ｎ -R ２ -X ２ -Ar ２ -NH-Z (D Ａ ) (Formula (D Ａ ) in Ar １ , Ar ２ Each of X independently represents a divalent aromatic group of a divalent benzene ring, a biphenyl structure, or a naphthalene ring, and any hydrogen atom of the aromatic group may be replaced with a monovalent group. １ , X ２ each independently represents a single bond, —O—, or *1-O—CO—. (*1 represents Ar １ or Ar ２ Represents a bond with .) R １ , R ２ are each independently a divalent hydrocarbon group, and some of the hydrogen atoms in the divalent hydrocarbon group may be substituted with a halogen atom, a methyl group, a trifluoromethyl group, or a hydroxy group. １ may be the same as or different from each other. L represents -O-, -C(=O)-, -O-C(=O)-, or -C(=O)-O-. When there are multiple Ls, the multiple Ls may be the same as or different from each other, provided that at least one L represents -O-C(=O)- or -C(=O)-O-. n is an integer of 1 to 6. Z represents a hydrogen atom or a monovalent organic group. The multiple Zs may be the same as or different from each other.

[0014] The above formula (D Ａ ) in which R １ , R ２ are each independently a divalent hydrocarbon group, examples of which include, but are not limited to, a linear or branched alkylene group, -CH=CH-, a phenylene group, or a cyclohexylene group. １ , R ２From the viewpoint of obtaining high liquid crystal alignment properties, R is preferably a hydrocarbon group having 2 to 6 carbon atoms, more preferably an alkylene group having 2 to 4 carbon atoms, and even more preferably an alkylene group having 2 or 4 carbon atoms. Some of the hydrogen atoms in the divalent hydrocarbon group may be substituted with halogen atoms, methyl groups, trifluoromethyl groups, or hydroxy groups, and fluorine atoms are preferred as halogen atoms substituting hydrogen atoms in the divalent hydrocarbon group. １ may be the same as or different from each other. L represents -O-, -C(=O)-, -O-C(=O)-, or -C(=O)-O-. When multiple Ls are present, the multiple Ls may be the same as or different from each other. However, it is preferable that at least one L represents -O-C(=O)- or -C(=O)-O-, and at least two Ls represent -O-C(=O)- or -C(=O)-O-. n represents an integer of 1 to 6, preferably an integer of 1 to 4, more preferably an integer of 2 to 4, and even more preferably an integer of 2 or 4.

[0015] The above formula (D Ａ ) in the group "*-(R １ -L) ｎ -R ２ More preferred examples of "-*" include the following structures: *-(CH ２ ) ｐ -OC(=O)-(CH ２ ) ｑ -C(=O)-O-(CH ２ ) ｒ - *, * - (CH ２ ) ｐ -C(=O)-O-(CH ２ ) ｑ -OC(=O)-(CH ２ ) ｒ - *, * - (CH ２ ) ｎ１ -OC(=O)-(CH ２ ) ｎ２ -C(=O)-O-(CH ２ ) ｎ３ -OC(=O)-(CH ２ ) ｎ４ -C(=O)-O-(CH ２ )ｎ５ - *; * - (CH ２ ) ｎ１ -C(=O)-O-(CH ２ ) ｎ２ -OC(=O)-(CH ２ ) ｎ３ -C(=O)-O-(CH ２ ) ｎ４ -OC(=O)-(CH ２ ) ｎ５ -*; In the above, p, q, and r each independently represent an integer of 1 to 6. n1 to n5 each independently represent an integer of 1 to 6, provided that the total number of carbon atoms in n1 to n5 is 20 or less. * represents a bond.

[0016] The above formula (D Ａ ) in Ar １ , Ar ２ Examples of the monovalent group that substitutes the hydrogen atom of the divalent aromatic group include a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a fluoroalkyl group having 1 to 10 carbon atoms, a fluoroalkenyl group having 2 to 10 carbon atoms, a fluoroalkoxy group having 1 to 10 carbon atoms, a carboxy group, a hydroxy group, an alkyloxycarbonyl group having 1 to 10 carbon atoms, a cyano group, and a nitro group. Among these, a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a fluoroalkyl group having 1 to 5 carbon atoms, or a fluoroalkoxy group having 1 to 5 carbon atoms is preferred. １ and Ar ２ In the above formula, the bonding positions of the benzene ring in which any hydrogen atom on the ring may be substituted are preferably the 1st and 4th positions, the bonding positions of the biphenyl structure in which any hydrogen atom on the ring may be substituted are preferably the 4th and 4'-positions, and the bonding positions of the naphthalene ring in which any hydrogen atom on the ring may be substituted are preferably the 2nd and 6th positions.

[0017] Ar １ and Ar ２Suitable examples of the divalent aromatic group represented by the formula (I) 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-tert-butyl-1,4-phenylene, 2-methoxy-1,4-phenylene, 2-ethoxy-1,4-phenylene, and 2-propoxy-1,4-phenylene. 2-butoxy-1,4-phenylene, 2-fluoro-1,4-phenylene, 2,3-dimethyl-1,4-phenylene, 2,6-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-tert-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 biphenylylene, 3-tert-butyl-4,4'-biphenylylene, 3-methoxy-4,4'-biphenylylene, 3-ethoxy-4,4'-biphenylylene, 3-fluoro-4,4'-biphenylylene, 2,2'-dimethyl-4,4'-biphenylylene, 3,3'-dimethyl-4,4'-biphenylylene, 3,3'-biphenylylene, 5-methyl-3,3'-biphenylylene, 5,5'-dimethyl-3,3'-biphenylylene, and the like.

[0018] The above formula (D Ａ In the above formula, the monovalent organic group of Z is a monovalent hydrocarbon group having 1 to 6 carbon atoms, and a methylene group of the hydrocarbon group may be substituted with -O-, -S-, -CO-, -COO-, -COS-, -NR ３ --CO-NR ３ -, -Si(R ３ ) ２ - (However, R ３is a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms, —SO ２ - or the like, a monovalent group A in which at least one hydrogen atom bonded to a carbon atom of the monovalent hydrocarbon group or the monovalent group A is substituted with a halogen atom, a hydroxy 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 carboxy group, a cyano group, a sulfo group, an acyl group, or the like, and a monovalent group having a heterocycle. Ａ In the above formula, the monovalent organic group represented by Z 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 tert-butoxycarbonyl group, more preferably an alkyl group having 1 to 3 carbon atoms, and even more preferably a methyl group. From the viewpoint of suitably achieving the effects of the present invention, each Z is independently preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and more preferably a hydrogen atom or a methyl group.

[0019] The above formula (D Ａ Preferred examples of the compound represented by the formula (d Ａ -1) to (d Ａ -10). Ａ -1) to (d Ａ The hydrogen atoms on the benzene ring in the formula (D-10) may be substituted with a monovalent substituent, and preferred examples of the substituent include those represented by the formula (D Ａ ) in Ar １ , Ar ２ Examples of the structures include those exemplified as the monovalent group substituting a hydrogen atom of a divalent aromatic group. p, q, r, and n1 to n5 are the same as those defined above for p, q, r, and n1 to n5.

[0020] Polymer (P ＡThe polyimide precursor may be a polyimide precursor obtained by using a tetracarboxylic acid derivative component containing an aromatic tetracarboxylic acid dianhydride and a diamine component containing the specific diamine (A), or a polyimide obtained by imidizing the polyimide precursor. Examples of the polyimide precursor include, but are not limited to, polymers that can be imidized to obtain polyimide, such as polyamic acid and polyamic acid ester.

[0021] The polymer (P Ａ ) is a polyimide precursor of polyamic acid (P Ａ The copolymer (A) can be obtained by a polymerization reaction between a diamine component containing the specific diamine (A) and a tetracarboxylic acid component. The specific diamine (A) may be used singly or in combination of two or more. The amount of the specific diamine (A) used is preferably 45 mol % or more, more preferably 50 mol % or more, and even more preferably 60 mol % or more, based on the total diamine components.

[0022] The polyamic acid (P Ａ The diamine component used in the production of the specific diamine (A′) may contain a diamine other than the specific diamine (A) (hereinafter also referred to as other diamine 1). When other diamine 1 is used in combination with the specific diamine (A), the amount of the specific diamine (A) used relative to the diamine component is preferably 90 mol % or less, more preferably 80 mol % or less.

[0023] Examples of other diamines 1 are listed below, but are not limited to these. The other diamines may be used alone or in combination of two or more. p-phenylenediamine, 2,3,5,6-tetramethyl-p-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, m-phenylenediamine, 2,4-dimethyl-m-phenylenediamine, 2,5-diaminotoluene, 2,6-diaminotoluene, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-dihydroxy-4,4'- Diaminobiphenyl, 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, specific diaminobiphenyls described below amine (B), 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 or diaminoazobenzene diamines having a photoalignable group such as oran; diamines having a photopolymerizable group at the terminal such as 2-(2,4-diaminophenoxy)ethyl methacrylate or 2,4-diamino-N,N-diallylaniline; diamines having a 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 having a urea bond such as 1,3-bis(4-aminophenyl)urea, 1,3-bis(4-aminobenzyl)urea, and 1,3-bis(4-aminophenethyl)urea; 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 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, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, and the like. bis(4-aminophenyl)hexafluoropropane, 2,2-bis(3-aminophenyl)hexafluoropropane, 2,2-bis(3-amino-4-methylphenyl)hexafluoropropane, 2,2-bis(4-aminophenyl)propane, 2,2-bis(3-aminophenyl)propane, 2,2-bis(3-amino-4-methylphenyl)propane, 4,4'-diaminobenzophenone, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 1,4-bis(4-aminobenzyl)benzene; 2,6-diaminopyridine, specific diamine (C) described below, 2,4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4,6-diaminoresorcinol, 4,4'-diamino-3,3'-dihydroxybiphenyl;2,4-Diaminobenzoic acid, 2,5-diaminobenzoic acid, 3,5-diaminobenzoic acid, 4,4'-diaminobiphenyl-3-carboxylic acid, 4,4'-diaminodiphenylmethane-3-carboxylic acid, 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'-dicarbo diamines having a carboxy group such as 4-(2-(methylamino)ethyl)aniline, 4-(2-aminoethyl)aniline, 1-(4-aminophenyl)-1,3,3-trimethyl-1H-indan-5-amine, 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-inden-6-amine; groups such as "-N(D)-" (D is eliminated by heating and forms a hydrogen atom) of the following formulae (5-1) to (5-8) and represents a protecting group substituting an atom, preferably a carbamate protecting group, more preferably a tert-butoxycarbonyl group; diamines having a steroid skeleton such as cholestanyloxy-3,5-diaminobenzene, cholestanyloxy-3,5-diaminobenzene, cholestanyloxy-2,4-diaminobenzene, cholestanyl 3,5-diaminobenzoate, cholestanyl 3,5-diaminobenzoate, lanostannyl 3,5-diaminobenzoate, and 3,6-bis(4-aminobenzoyloxy)cholestane; diamines represented by formulas (Y-1) to (Y-167) described in WO 2018 / 117239; diamines having a siloxane bond such as 1,3-bis(3-aminopropyl)-tetramethyldisiloxane; metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, 1,3-bis(aminomethyl)cyclohexane, 1,4-diaminocyclohexane, 4,4'-methylenebis(cyclohexylamine), diamines in which two amino groups are bonded to a group represented by any one of formulas (Y-1) to (Y-167) described in WO 2018 / 117239; (Boc represents a tert-butoxycarbonyl group. * represents a bond.) In the formula (V-1), m and n are integers of 1 to 3, and satisfy the condition 1≦m+n≦4. j is an integer of 0 or 1. X １ is -(CH ２ ) ａ -(a is an integer of 1 to 15), -CONH-, -NHCO-, -CO-N(CH ３ )-, -NH-, -O-, -CH ２ O-, -CH ２ represents —OCO—, —COO—, or —OCO—. １ represents a monovalent group such as a fluorine atom, a fluorine atom-containing alkyl group having 1 to 10 carbon atoms, a fluorine atom-containing alkoxy group having 1 to 10 carbon atoms, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or an alkoxyalkyl group having 2 to 10 carbon atoms. ２ is -O-, -CH ２ O-, -CH ２ m, n, and X represent —OCO—, —COO—, or —OCO—. １ , R １ When two occur, each independently has the above definition.

[0024] When the other diamine 1 is used in addition to the specific diamine (A), the amount of the other diamine 1 used is Ａ The amount of the diamine component is preferably 10 to 60 mol %, more preferably 20 to 55 mol %, based on the total amount of diamine components used in the production of the copolymer (A).

[0025] (Polymer (P Ａ ) the tetracarboxylic acid component of the polyamic acid (P Ａ In producing the above-mentioned tetracarboxylic acid component (a), the tetracarboxylic acid component to be reacted with the diamine component may be not only an aromatic tetracarboxylic acid dianhydride but also a derivative of an aromatic tetracarboxylic acid dianhydride such as an aromatic tetracarboxylic acid, an aromatic tetracarboxylic acid dihalide, an aromatic tetracarboxylic acid dialkyl ester, or an aromatic tetracarboxylic acid dialkyl ester dihalide.

[0026] The aromatic tetracarboxylic acid dianhydride or a derivative thereof more preferably contains a tetracarboxylic acid dianhydride having a benzene ring or a derivative thereof. The aromatic tetracarboxylic acid dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxy groups, including at least one carboxy group bonded to an aromatic ring. The polyamic acid (P Ａ The tetracarboxylic acid component that can be used in the production of (A) preferably includes the following aromatic tetracarboxylic acid dianhydrides or derivatives thereof (these are also collectively referred to as specific aromatic tetracarboxylic acid derivatives (A) in the present invention): pyromellitic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic acid dianhydride, 3,3',4,4'-biphenylsulfonetetracarboxylic acid dianhydride, 1,4,5,8-naphthalenetetracarboxylic acid dianhydride, 2,3,6,7-naphthalenetetracarboxylic acid dianhydride, 3,3',4,4'-biphenylethertetracarboxylic acid dianhydride, 3,3',4,4'-perfluoroisopropylidenediphthalic dianhydride, 3,3',4,4'-biphenyltetracarboxylic acid dianhydride, 2, Aromatic tetracarboxylic acid dianhydrides such as 2',3,3'-biphenyltetracarboxylic acid dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenylpropane dianhydride, ethylene glycol bisanhydrotrimate, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 4,4'-carbonyldiphthalic anhydride, 4,4'-oxydi(1,4-phenylene)bis(phthalic) dianhydride, and 4,4'-methylenedi(1,4-phenylene)bis(phthalic) dianhydride.

[0027] The proportion of the specific aromatic tetracarboxylic acid derivative (A) used is preferably 10 mol % or more, more preferably 20 mol % or more, and even more preferably 50 mol % or more, based on the total tetracarboxylic acid components used.

[0028] The polyamic acid (P ＡThe tetracarboxylic acid component used in the production of (A′) may contain a tetracarboxylic acid derivative other than the aromatic tetracarboxylic acid derivative (A) (hereinafter also referred to as other tetracarboxylic acid derivative). When other tetracarboxylic acid derivatives are used in combination with the aromatic tetracarboxylic acid derivative (A), the amount of the aromatic tetracarboxylic acid derivative (A) used relative to the tetracarboxylic acid component is preferably 90 mol % or less, more preferably 80 mol % or less.

[0029] Examples of the other tetracarboxylic acid derivatives include acyclic aliphatic tetracarboxylic acid dianhydrides, alicyclic tetracarboxylic acid dianhydrides, and derivatives thereof. The acyclic aliphatic tetracarboxylic acid dianhydrides are acid dianhydrides obtained by intramolecular dehydration of four carboxy groups bonded to a chain hydrocarbon structure. However, the chain hydrocarbon structure need not be composed solely of a chain hydrocarbon structure, and may partially contain an alicyclic structure or an aromatic ring structure. The alicyclic tetracarboxylic acid dianhydrides are acid dianhydrides obtained by intramolecular dehydration of four carboxy groups, including at least one carboxy group bonded to the alicyclic structure. However, none of these four carboxy groups are bonded to an aromatic ring. Furthermore, the chain hydrocarbon structure need not be composed solely of a chain hydrocarbon structure, and may partially contain a chain hydrocarbon structure or an aromatic ring structure. The other tetracarboxylic acid derivatives preferably include tetracarboxylic acid dianhydrides having at least one partial structure selected from the group consisting of a benzene ring, a cyclobutane ring, a cyclopentane ring, and a cyclohexane ring, or derivatives thereof. In particular, it is more preferable to contain a tetracarboxylic acid dianhydride having at least one structure selected from the group consisting of a cyclobutane ring, a cyclopentane ring, and a cyclohexane ring, or a derivative thereof.

[0030] The polyamic acid (P ＡOther tetracarboxylic acid derivatives that can be used in the production of (C)-(C)-(C), preferably include the following tetracarboxylic acid dianhydrides or derivatives thereof: acyclic aliphatic tetracarboxylic acid dianhydrides such as 1,2,3,4-butanetetracarboxylic acid dianhydride; 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-dichloro-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,3,4-tetramethyl-1, 2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-difluoro-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-bis(trifluoromethyl)-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,3,4-cyclopentanetetracarboxylic acid dianhydride, 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride, 3,3',4,4'-dicyclohexyltetracarboxylic acid dianhydride, 2, 3,5-Tricarboxycyclopentylacetic dianhydride, 4-(2,5-dioxotetrahydrofuran-3-yl)tetrahydronaphthalene-1,2-dicarboxylic dianhydride, 5-(2,5-dioxotetrahydrofuran-3-yl)-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 5-(2,5-dioxotetrahydrofuran-3-yl)-8-methyl-3a,4,5,9b-tetrahydronaphtho[ Alicyclic tetracarboxylic acid dianhydrides such as [1,2-c]furan-1,3-dione, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic acid dianhydride, bicyclo[2.2.2]octane-2,3,5,6-tetracarboxylic acid dianhydride, and 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-dianhydride; and tetracarboxylic acid dianhydrides described in JP-A-2010-97188.

[0031] More preferred examples of the other tetracarboxylic acid derivatives include 1,2,3,4-butanetetracarboxylic acid dianhydride, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-difluoro-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-bis(trifluoromethyl)-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,3,4-cyclopentanetetracarboxylic acid dianhydride, and 1,2,3,4-cyclopentanetetracarboxylic acid dianhydride. Tetracarboxylic acid dianhydride, 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride, 3,3',4,4'-dicyclohexyltetracarboxylic acid dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 5-(2,5-dioxotetrahydrofuran-3-yl)-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 5-(2,5-dioxotetrahydrofuran-3-yl)-8-methyl-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-dianhydride, or derivatives thereof.

[0032] <Polymers other than polymer (A)> The polymer other than polymer (A) contained in the liquid crystal aligning agent of the present invention is preferably at least one selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, polyorganosiloxane, and addition polymer. From the viewpoint of suitably obtaining the effects of the present invention, it is preferable to contain the following polymer (B) and / or the following polymer (C) as the polymer other than the polymer (A), and it is more preferable to contain polymer (B) and polymer (C).

[0033] <Polymer (B)> The polymer (B) is a polymer represented by the following formula (d ＡLand a polymer (P) selected from the group consisting of a polyimide precursor obtained by using a diamine component containing a diamine (B) represented by the formula (I) (hereinafter also referred to as specific diamine (B), excluding those included in specific diamine (A)), and a polyimide which is an imidized product of the polyimide precursor. Ｂ The polymer (B) is one or more kinds of polymers (P Ｂ ) may be used. However, when the diamine component contains a diamine other than the specific diamine (B) and also contains the specific diamine (A), the amount of the specific diamine (A) used is less than 40 mol % of the total diamine components. Also, when the diamine component contains a diamine other than the specific diamine (B), does not contain the specific diamine (A), and contains the specific diamine (C) described below, the amount of the specific diamine (C) used is less than 30 mol % of the total diamine components. (Ar １ , and Ar １’ represents a benzene ring, a biphenyl structure, or a naphthalene ring, and one or more hydrogen atoms on the benzene ring, the biphenyl structure, or the naphthalene ring may be substituted with a monovalent group. １ and L １’ respectively represent a single bond, —O—, —C(═O)—, or —O—C(═O)—. A is —CH ２ A represents an alkylene group having 2 to 12 carbon atoms, or a divalent organic group in which at least one of -O-, -C(=O)-O-, and -O-C(=O)- is inserted between the carbon-carbon bonds of the alkylene group. Any hydrogen atom possessed by A may be substituted with a halogen atom. However, the formula (d ＡL ) in L １ and L １’ is —O—, A is —CH ２Ar represents -, an alkylene group having 2 to 12 carbon atoms, or a divalent organic group formed by inserting -O- between the carbon-carbon bonds of the alkylene group. One or more hydrogen atoms on the benzene ring, biphenyl structure, or naphthalene ring may be substituted with a monovalent group, and examples of the monovalent group include a halogen atom, an alkyl group having 1 to 3 carbon atoms, an alkenyl group having 2 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a fluoroalkyl group having 1 to 3 carbon atoms, a fluoroalkenyl group having 2 to 3 carbon atoms, a fluoroalkoxy group having 1 to 3 carbon atoms, an alkyloxycarbonyl group having 2 to 3 carbon atoms, a cyano group, and a nitro group. １ , and Ar １’ In Ar, the bonding positions of the benzene ring in which any hydrogen atom on the ring may be substituted are preferably the 1st and 4th positions, and the bonding positions of the biphenyl structure in which any hydrogen atom on the ring may be substituted are preferably the 4th and 4' positions. １ , and Ar １’ In the formula (I), the bonding positions of the naphthalene ring, in which any hydrogen atom on the ring may be substituted, are preferably the 2nd and 6th positions. Z represents a hydrogen atom or a monovalent organic group. Multiple Zs may be the same or different.

[0034] The specific diamine (B) is preferably a diamine represented by the following formula (d ＡＬ -1) to (d ＡＬ-10), 1,7-bis(4-aminophenoxy)heptane, 1,7-bis(3-aminophenoxy)heptane, 1,8-bis(4-aminophenoxy)octane, 1,8-bis(3-aminophenoxy)octane, 1,9-bis(4-aminophenoxy)nonane, 1,9-bis(3-aminophenoxy)nonane, 1,10-bis(4-aminophenoxy)decane, 1,10-bis(3-aminophenoxy)decane, 1,11-bis(4 1,11-bis(3-aminophenoxy)undecane, 1,12-bis(4-aminophenoxy)dodecane, 1,12-bis(3-aminophenoxy)dodecane, 1,2-bis(6-amino-2-naphthyloxy)ethane, 1,4-bis(6-amino-2-naphthyloxy)butane, 1,2-bis(6-amino-2-naphthyl)ethane, or 6-[2-(4-aminophenoxy)ethoxy]-2-naphthylamine.

[0035] Polymer (P Ｂ The polyimide precursor may be a polyimide precursor obtained by using a diamine component containing the specific diamine (B), or a polyimide obtained by imidizing the polyimide precursor. Examples of the polyimide precursor include, but are not limited to, polymers that can be imidized to obtain polyimide, such as polyamic acid and polyamic acid ester.

[0036] The polymer (P Ｂ ) is a polyimide precursor of polyamic acid (P Ｂ The diamine (B) can be obtained by a polymerization reaction between a diamine component containing the specific diamine (B) and a tetracarboxylic acid component. The specific diamine (B) may be used singly or in combination of two or more. The amount of the specific diamine (B) used is preferably 5 mol % or more, more preferably 10 mol % or more, and even more preferably 20 mol % or more, based on the total diamine components.

[0037] The polyamic acid (P ＢThe diamine component used in the production of (A') may contain a diamine other than the specific diamine (B) (hereinafter also referred to as "other diamine 2"). When the other diamine 2 is used in combination with the specific diamine (B), the amount of the specific diamine (B) used relative to the diamine component is preferably 90 mol% or less, more preferably 80 mol% or less. When the other diamine 2 is included as a diamine component and the specific diamine (A) is also included, the amount of the specific diamine (A) used is less than 40 mol%, preferably less than 35 mol%, and more preferably less than 30 mol%. When the other diamine 2 is included as a diamine component but does not contain the specific diamine (A) and contains the specific diamine (C) described below, the amount of the specific diamine (C) used is less than 30 mol%, preferably less than 20 mol%. A preferred specific example of the other diamine 2 is the diamine obtained by excluding the specific diamine (B) from the above-mentioned other diamine 1. The other diamine 2 may be a diamine obtained by excluding the specific diamine (C) described below.

[0038] <Polymer (C)> The polymer (C) is a polymer represented by the following formula (d ｎ and a polymer (P) selected from the group consisting of a polyimide precursor obtained by using a diamine component containing 30 mol % or more of a diamine represented by the formula (hereinafter also referred to as specific diamine (C)) based on the total diamine components, and a polyimide which is an imidized product of the polyimide precursor. Ｃ ) is the polymer (P Ｃ However, when a diamine other than the specific diamine (C) is contained as the diamine component, the specific diamine (A) is not contained. (Y represents a divalent organic group having a nitrogen-atom-containing structure selected from the group consisting of nitrogen-atom-containing heterocycles and amino groups represented by the group "*21-NR-*22" (*21 and *22 represent bonds bonded to carbon atoms constituting the aromatic ring, provided that the carbon atoms do not form a ring with the nitrogen atom to which R is bonded; R represents a hydrogen atom or a monovalent organic group, and the monovalent organic group is bonded to the nitrogen atom at a carbon atom other than the carbonyl carbon); Z represents a hydrogen atom or a monovalent organic group. Multiple Zs may be the same or different.)

[0039] The above formula (d ｎ Examples of the nitrogen atom-containing heterocycle in (I) include a pyrrole ring, an imidazole ring, a pyrazole ring, a triazole ring, a pyridine ring, a pyrimidine ring, a pyridazine ring, a pyrazine ring, an indole ring, a benzimidazole ring, a purine ring, a quinoline ring, an isoquinoline ring, a naphthyridine ring, a quinoxaline ring, a phthalazine ring, a triazine ring, a carbazole ring, an acridine ring, a piperidine ring, a piperazine ring, a pyrrolidine ring, a hexamethyleneimine ring, etc. Among these, a pyridine ring, a pyrimidine ring, a pyrazine ring, a piperidine ring, a piperazine ring, a quinoline ring, a carbazole ring, or an acridine ring is preferred.

[0040] The above formula (d ｎ Examples of the monovalent organic group represented by R in the formula (I) include alkyl groups such as methyl, ethyl, and propyl; alkenyl groups such as vinyl; cycloalkyl groups such as cyclohexyl; aryl groups such as phenyl and methylphenyl; and alkoxy groups (e.g., methoxy and ethoxy). R is preferably a hydrogen atom or a methyl group.

[0041] The above formula (d ｎ Specific examples of the diamine represented by the formula (d) include 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, 1,4-bis-(4-aminophenyl)-piperazine, 3,6-diaminoacridine, N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, and diamines represented by the formula (d ｎ -1), or diamines represented by formula (z-1) to formula (z-14).

[0042] Formula (d ｎ In formula (1), m1 and m1' are each independently an integer of 1 to 2. n1 is an integer of 1 to 3. １ has the same meaning as R in the amino group represented by "*21-NR-*22" above. １When a plurality of R1's and m1's are present, the plurality of R1's and m1's may be the same or different.

[0043] The above formula (d ｎ Preferred specific examples of the diamine represented by formula (Dp-1) include diamines represented by the following formulae (Dp-1) to (Dp-6).

[0044] Polymer (P Ｃ The polyimide precursor is, for example, a polyimide precursor obtained by using a diamine component containing the specific diamine (C), or a polyimide obtained by imidizing the polyimide precursor. Here, the polyimide precursor is a polymer that can be obtained by imidizing a polyamic acid, a polyamic acid ester, or the like to obtain a polyimide.

[0045] The polymer (P Ｃ ) is a polyimide precursor of polyamic acid (P Ｃ The diamine (C) (a) and the diamine (B) (b) (c) (d) can be obtained by a polymerization reaction between a diamine component containing the specific diamine (C) and a tetracarboxylic acid component. The specific diamine (C) may be used singly or in combination of two or more. The amount of the specific diamine (C) used is preferably 35 mol % or more, more preferably 40 mol % or more, and even more preferably 45 mol % or more, based on the total diamine components.

[0046] The polyamic acid (P ＣThe diamine component used in the production of (A)′) may contain a diamine other than the specific diamine (C) (hereinafter also referred to as “other diamine 3”). When the other diamine 3 is used in combination with the specific diamine (C), the amount of the specific diamine (C) relative to the diamine component is preferably 90 mol % or less, more preferably 80 mol % or less. When the other diamine 3 is included as the diamine component, the specific diamine (A) is not included. A preferred example of the other diamine 3 is the diamine obtained by excluding the specific diamine (C) from the other diamine 1. The other diamine 3 preferably contains, among others, a diamine having at least one group selected from the group consisting of a urea bond, an amide bond, a carboxy group, and a hydroxy group in the molecule, and at least one diamine selected from the group consisting of the specific diamine (B) (in the present invention, these are also referred to as “specific diamine (c2)”). The diamine component may use one diamine alone or two or more diamines in combination.

[0047] When the polymer (B) and the following polymer (C) are contained as polymers other than the above polymer (A), a liquid crystal alignment film that can reduce accumulated charge in a short period of time and has excellent printability can be obtained. A liquid crystal alignment agent that forms a liquid crystal alignment film that suppresses the generation of image retention and exhibits low liquid crystal pretilt angle characteristics, a liquid crystal alignment film obtained from the liquid crystal alignment agent, and a high-performance liquid crystal display device that includes the liquid crystal alignment film can also be obtained.

[0048] The mechanism by which the above-mentioned effect is obtained is not entirely clear, but is presumed to be as follows: The specific diamine (A) has a repeating unit structure containing an alkylene chain and an oxygen atom, which increases the stretchability of the polymer (A), the polymer (B), and the polymer (C) when they are subjected to an orientation treatment, thereby achieving high liquid crystal alignment, and thus the above-mentioned effect is believed to be obtained.

[0049] (Polymer (P Ｂ ), polymer (P Ｃ ) the tetracarboxylic acid component of the polyamic acid (P Ｂ ') and polyamic acid (PＣ When producing polyamic acid (P'), the tetracarboxylic acid component to be reacted with the diamine component may be not only a tetracarboxylic acid dianhydride but also a derivative of a tetracarboxylic acid dianhydride such as a tetracarboxylic acid, a tetracarboxylic acid dihalide, a tetracarboxylic acid dialkyl ester, or a tetracarboxylic acid dialkyl ester dihalide. Ｂ ') and polyamic acid (P Ｃ Specific examples of the tetracarboxylic acid component used in the production of the polymer (P′), including preferred examples, are Ａ Examples of the polyamic acid include acyclic aliphatic tetracarboxylic acid dianhydrides, alicyclic tetracarboxylic acid dianhydrides, aromatic tetracarboxylic acid dianhydrides, and derivatives thereof, which are exemplified in the above (P'). Ｂ ') and polyamic acid (P Ｃ The tetracarboxylic acid component used in the production of the polyamic acid (P') more preferably contains a tetracarboxylic acid dianhydride having at least one partial structure selected from the group consisting of a benzene ring, a cyclobutane ring, a cyclopentane ring, and a cyclohexane ring, or a derivative thereof. Ｂ ') and polyamic acid (P Ｃ It is preferably 10 mol % or more, more preferably 20 mol % or more, and even more preferably 50 mol % or more, based on the total tetracarboxylic acid components used in the production of (a)).

[0050] (Liquid Crystal Alignment Agent) The liquid crystal aligning agent of the present invention is, for example, a liquid composition obtained by dispersing or dissolving polymer (A), a polymer other than polymer (A), and other components used as needed, preferably in a suitable solvent. The total content of the polymers contained in the liquid crystal aligning agent of the present invention can be appropriately changed depending on the thickness of the coating film to be formed. However, from the viewpoint of forming a uniform and defect-free coating film, it is preferably 1% by mass or more, and from the viewpoint of storage stability of the solution, it is preferably 10% by mass or less. A particularly preferred total polymer content is 2 to 8% by mass. When the liquid crystal aligning agent of the present invention contains polymer (A), polymer (B), and polymer (C), the total content of polymer (A), polymer (B), and polymer (C) is preferably 1 to 100% by mass, more preferably 10 to 100% by mass, and particularly preferably 20 to 100% by mass, based on the total polymers contained in the liquid crystal aligning agent.

[0051] The content of polymer (A) contained in the liquid crystal aligning agent of the present invention is 0.1 parts by mass or more and 10 parts by mass or less, relative to 100 parts by mass of the total content of polymers other than polymer (A). The content of polymer (A) is preferably 0.5 parts by mass or more and 1.0 part by mass or more, relative to 100 parts by mass of the total content of polymers other than polymer (A). When polymer (B) and polymer (C) are contained in the liquid crystal aligning agent of the present invention, the mass ratio of polymer (C) to the content of polymer (B) (content of polyimide precursor of polymer (C) / content of polyimide precursor of polymer (B)) is preferably 10 / 90 to 90 / 10, more preferably 20 / 80 to 90 / 10, and even more preferably 20 / 80 to 80 / 20.

[0052] When the liquid crystal aligning agent of the present invention contains the polymer (A), the polymer (B), and the polymer (C), Ａ ) ~ (P Ｃ ) may contain other polymers. Specific examples of other polymers include polymer (P Ａ ) ~ (P Ｃand at least one polymer selected from the group consisting of polyimide precursors other than those mentioned above, 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) derivatives, and polymers selected from the group consisting of poly(meth)acrylates.

[0053] Specific examples of poly(styrene-maleic anhydride) copolymers include SMA1000, SMA2000, and SMA3000 (manufactured by Cray Valley Corporation), and GSM301 (manufactured by Gifu Ceramics Manufacturing Co., Ltd.), and a specific example of poly(isobutylene-maleic anhydride) copolymer is ISOBAN-600 (manufactured by Kuraray Co., Ltd.). A specific example of poly(vinyl ether-maleic anhydride) copolymer is Gantrez AN-139 (methyl vinyl ether maleic anhydride resin, manufactured by Ashland). The above other polymers may be used alone or in combination of two or more. The content ratio of the other polymer is preferably 90 parts by mass or less, more preferably 10 to 90 parts by mass, and even more preferably 20 to 80 parts by mass, relative to 100 parts by mass of the total polymers contained in the liquid crystal aligning agent.

[0054] (Production of Polyamic Acid) Polyamic acid is produced by reacting a diamine component and a tetracarboxylic acid component in an organic solvent. The ratio of the tetracarboxylic acid component and the diamine component used in the polyamic acid production reaction is preferably such that 1 equivalent of the amino group of the diamine component corresponds to 0.5 to 2 equivalents of the acid anhydride group of the tetracarboxylic acid component, more preferably 0.8 to 1.2 equivalents. As with a typical polycondensation reaction, the closer the equivalent of the acid anhydride group of the tetracarboxylic acid component is to 1 equivalent, the higher the molecular weight of the resulting polyamic acid. The reaction temperature in the production of polyamic acid is preferably −20 to 150°C, more preferably 0 to 100°C. The reaction time is preferably 0.1 to 24 hours, more preferably 0.5 to 12 hours. Polyamic acid can be produced at any concentration, but the polyamic acid concentration is preferably 1 to 50% by mass, more preferably 5 to 30% by mass. The reaction can be carried out at a high concentration initially, with subsequent addition of solvent.

[0055] Specific examples of the organic solvent include cyclohexanone, cyclopentanone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, and 1,3-dimethyl-2-imidazolidinone. Furthermore, when the polymer has high solvent solubility, solvents such as methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, diethylene glycol monomethyl ether, and diethylene glycol monoethyl ether can be used.

[0056] (Production of Polyamic Acid Ester) The polyamic acid ester can be obtained by known methods such as [I] a method of reacting the polyamic acid obtained by the above method with an esterifying agent, [II] a method of reacting a tetracarboxylic acid diester with a diamine, or [III] a method of reacting a tetracarboxylic acid diester dihalide with a diamine.

[0057] (Production of Polyimide) Polyimide can be obtained by ring-closing (imidizing) a polyimide precursor such as the polyamic acid or polyamic acid ester. The imidization ratio in this specification refers to the ratio of imide groups to the total amount of imide groups derived from tetracarboxylic dianhydride or its derivatives and carboxyl groups (or their derivatives). The imidization ratio does not necessarily have to be 100% and can be adjusted as desired depending on the application and purpose.

[0058] Methods for imidizing the polyimide precursor include thermal imidization, in which a solution of the polyimide precursor is heated as is, and catalytic imidization, in which a catalyst is added to a solution of the polyimide precursor. When thermally imidizing the polyimide precursor in solution, the temperature is preferably 100 to 400°C, more preferably 120 to 250°C, and it is preferable to carry out the thermal imidization while removing water produced by the imidization reaction from the system.

[0059] Catalytic imidization of polyimide precursors can be carried out by adding a basic catalyst and an acid anhydride to a solution of the polyimide precursor and stirring at -20 to 250°C, preferably 0 to 180°C. The amount of the basic catalyst is 0.5 to 30 times, preferably 2 to 20 times, the molar ratio of the amic acid groups, and the amount of the acid anhydride is 1 to 50 times, preferably 3 to 30 times, the molar ratio of the amic acid groups. Examples of basic catalysts include pyridine, triethylamine, trimethylamine, tributylamine, and trioctylamine. Of these, pyridine is preferred because it has adequate basicity for promoting the reaction. Examples of acid anhydrides include acetic anhydride, trimellitic anhydride, and pyromellitic anhydride. Of these, acetic anhydride is preferred because it facilitates purification after the reaction. The imidization rate by catalytic imidization can be controlled by adjusting the catalyst amount, reaction temperature, and reaction time.

[0060] To recover the produced polyimide precursor or polyimide from a reaction solution of a polyimide precursor or polyimide, the reaction solution may be precipitated by pouring the reaction solution into a solvent. Examples of solvents used for precipitation include methanol, ethanol, isopropyl alcohol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, toluene, benzene, and water. The polymer precipitated by pouring into the solvent can be recovered by filtration and then dried at room temperature or by heating under atmospheric or reduced pressure. Furthermore, the recovered polymer can be redissolved in an organic solvent and reprecipitated and recovered 2 to 10 times to reduce the amount of impurities in the polymer. Examples of solvents used in this process include alcohols, ketones, and hydrocarbons. Using three or more solvents selected from these solvents is preferred because it further increases the efficiency of purification.

[0061] When producing the polyimide precursor or polyimide of the present invention, a terminal-capped polymer may be produced using a tetracarboxylic acid component containing a tetracarboxylic dianhydride or a derivative thereof, a diamine component containing the above-mentioned diamine, and an appropriate terminal-capping agent. Terminal-capped polymers have the effect of improving the film hardness of the alignment film obtained by coating and improving the adhesion properties between the sealing agent and the alignment film. Examples of terminal groups of the polyimide precursor or polyimide of the present invention include amino groups, carboxy groups, acid anhydride groups, and groups derived from terminal-capping agents described below. The amino groups, carboxy groups, and acid anhydride groups can be obtained by a conventional condensation reaction or by terminal-capping with the following terminal-capping agents.

[0062] Examples of the end-capping agent include acid anhydrides such as acetic anhydride, maleic anhydride, nadic anhydride, phthalic anhydride, itaconic anhydride, cyclohexanedicarboxylic anhydride, 3-hydroxyphthalic anhydride, trimellitic anhydride, 3-(3-trimethoxysilyl)propyl)-3,4-dihydrofuran-2,5-dione, 4,5,6,7-tetrafluoroisobenzofuran-1,3-dione, and 4-ethynylphthalic anhydride; dicarbonic acid diester compounds such as di-tert-butyl dicarbonate and diallyl dicarbonate; chlorocarbonyl compounds such as acryloyl chloride, methacryloyl chloride, and nicotinic acid chloride; and aniline compounds. Examples of suitable terminal blocking agents include monoamine compounds such as phosphorus, 2-aminophenol, 3-aminophenol, 4-aminosalicylic acid, 5-aminosalicylic acid, 6-aminosalicylic acid, 2-aminobenzoic acid, 3-aminobenzoic acid, 4-aminobenzoic acid, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, and n-octylamine; and isocyanates having unsaturated bonds such as ethyl isocyanate, phenyl isocyanate, naphthyl isocyanate, or 2-acryloyloxyethyl isocyanate and 2-methacryloyloxyethyl isocyanate. The proportion of the terminal blocking agent used is preferably 0.01 to 20 parts by mole, and more preferably 0.01 to 10 parts by mole, per 100 parts by mole of the total of the diamine components used.

[0063] The polystyrene-equivalent weight average molecular weight (Mw) of the polyimide precursor and polyimide measured by gel permeation chromatography (GPC) is preferably 1,000 to 500,000, more preferably 2,000 to 300,000, and even more preferably 10,000 to 50,000. The molecular weight distribution (Mw / Mn), expressed as the ratio of Mw to the polystyrene-equivalent number average molecular weight (Mn) measured by GPC, is preferably 15 or less, more preferably 10 or less. By having the molecular weight within this range, good liquid crystal alignment properties can be ensured in liquid crystal display elements.

[0064] The organic solvent contained in the liquid crystal aligning agent according to the present invention is not particularly limited as long as it can uniformly dissolve the polymer (A) and polymers other than the polymer (A). Examples of the organic solvent include N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethyllactamide, N,N-dimethylpropionamide, tetramethylurea, N,N-diethylformamide, N,N-diethylacetamide, 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-diisopropyl ether, methyl ethyl ketone, methyl methyl ether, methyl ethyl ketone, methyl ethyl ether, methyl methyl ether ... Examples of suitable solvents include methylpropanamide, 3-butoxy-N,N-dimethylpropanamide, N-(n-propyl)-2-pyrrolidone, N-isopropyl-2-pyrrolidone, N-(n-butyl)-2-pyrrolidone, N-(t-butyl)-2-pyrrolidone, N-(n-pentyl)-2-pyrrolidone, N-methoxypropyl-2-pyrrolidone, N-ethoxyethyl-2-pyrrolidone, N-methoxybutyl-2-pyrrolidone, and N-cyclohexyl-2-pyrrolidone (collectively referred to as "good solvents"). Among these, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 3-methoxy-N,N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropanamide, and γ-butyrolactone are preferred. The content of the good solvent is preferably 20 to 99% by mass, more preferably 20 to 90% by mass, and particularly preferably 30 to 80% by mass of the total solvent contained in the liquid crystal aligning agent.

[0065] Furthermore, the organic solvent contained in the liquid crystal aligning agent is preferably a mixed solvent containing, in addition to the above solvent, a solvent (also referred to as a poor solvent) that improves the coatability and surface smoothness of the coating film when the liquid crystal aligning agent is applied. Specific examples of poor solvents are listed below, but are not limited to these. The content of the poor solvent is preferably 1 to 80 mass %, more preferably 10 to 80 mass %, and particularly preferably 20 to 70 mass %, of the total solvent contained in the liquid crystal aligning agent. The type and content of the poor solvent are appropriately selected depending on the coater, coating conditions, coating environment, etc. of the liquid crystal aligning agent.

[0066] Examples of poor solvents include diisopropyl ether, diisobutyl ether, diisobutyl carbinol (2,6-dimethyl-4-heptanol), ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, 1,2-dibutoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, 4-hydroxy-4-methyl-2-pentanone, diethylene glycol methyl ethyl ether, diethylene glycol dibutyl ether, and 3-ethoxybutyl ether. Acetate, 1-methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, ethylene glycol monoacetate, ethylene glycol diacetate, propylene carbonate, ethylene carbonate, ethylene glycol monobutyl ether, ethylene glycol monoisoamyl ether, ethylene glycol monohexyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, 1-(2-butoxyethoxy)-2-propanol, 2-(2-butoxyethoxy)-1 -propanol, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, ethylene glycol monobutyl ether acetate, diethylene glycol monopropyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, 2-(2-ethoxyethoxy)ethyl acetate, diethylene glycol acetate, propylene glycol diacetate, Examples of suitable esters include n-butyl acetate, propylene glycol monoethyl ether acetate, cyclohexyl acetate, 4-methyl-2-pentyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, butyl 3-methoxypropionate, n-butyl lactate, isoamyl lactate, diethylene glycol monoethyl ether, diisobutyl ketone (2,6-dimethyl-4-heptanone), and (1S,5R)-6,8-dioxabicyclo[3.2.1]octan-4-one.

[0067] Of these, diisobutyl carbinol, propylene glycol monobutyl ether, propylene glycol diacetate, diethylene glycol diethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monobutyl ether, ethylene glycol monobutyl ether acetate, or diisobutyl ketone is preferred.

[0068] Preferred solvent combinations of a good solvent and a poor solvent include N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone and ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone and propylene glycol monobutyl ether, N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether, N-ethyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone, and N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether. Coal diacetate, N,N-dimethyl lactamide and diisobutyl ketone, N-methyl-2-pyrrolidone and ethyl 3-ethoxypropionate, N-ethyl-2-pyrrolidone and ethyl 3-ethoxypropionate, N-methyl-2-pyrrolidone, ethyl 3-ethoxypropionate and dipropylene glycol monomethyl ether, N-ethyl-2-pyrrolidone, ethyl 3-ethoxypropionate and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone, ethyl 3-ethoxypropionate and diethylene glycol mono propyl ether, N-ethyl-2-pyrrolidone, ethyl 3-ethoxypropionate, and diethylene glycol monopropyl ether, N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether acetate, N-ethyl-2-pyrrolidone and dipropylene glycol dimethyl ether, N,N-dimethyl lactamide and ethylene glycol monobutyl ether, N,N-dimethyl lactamide and propylene glycol diacetate, N-ethyl-2-pyrrolidone and diethylene glycol diethyl ether, N-ethyl-2 -pyrrolidone, diethylene glycol monoethyl ether, and butyl cellosolve acetate, N-methyl-2-pyrrolidone, diethylene glycol monomethyl ether, and butyl cellosolve acetate, N,N-dimethyl lactamide and diethylene glycol diethyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone, 4-hydroxy-4-methyl-2-pentanone, and diethylene glycol diethyl ether, N-ethyl-2-pyrrolidone, N-methyl-2-pyrrolidone, and 4-hydroxy-4-methyl-2-pentanone,N-ethyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone, and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone, and diisobutyl ketone, N-methyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone, and dipropylene glycol monomethyl ether, N-methyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone, and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone, and dipropylene glycol monomethyl ether Methyl-2-pentanone and propylene glycol diacetate, N-ethyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone and dipropylene glycol dimethyl ether, γ-butyrolactone, 4-hydroxy-4-methyl-2-pentanone and diisobutyl ketone, γ-butyrolactone, 4-hydroxy-4-methyl-2-pentanone and propylene glycol diacetate, N-methyl-2-pyrrolidone, γ-butyrolactone, propylene glycol monobutyl ether and diisobutyl ketone, N-methyl-2-pi rolidone, γ-butyrolactone, propylene glycol monobutyl ether, and diisopropyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone, propylene glycol monobutyl ether, and diisobutylcarbinol, N-methyl-2-pyrrolidone, γ-butyrolactone, and dipropylene glycol dimethyl ether, N-methyl-2-pyrrolidone, propylene glycol monobutyl ether, and dipropylene glycol dimethyl ether, N-ethyl-2-pyrrolidone, propylene glycol monobutyl ether, and dipropylene glycol pyrene glycol monomethyl ether, N-ethyl-2-pyrrolidone, diethylene glycol diethyl ether, and dipropylene glycol monomethyl ether, N-ethyl-2-pyrrolidone, propylene glycol monobutyl ether, and propylene glycol diacetate, N-ethyl-2-pyrrolidone, propylene glycol monobutyl ether, and diisobutyl ketone, N-ethyl-2-pyrrolidone, γ-butyrolactone, and diisobutyl ketone, N-ethyl-2-pyrrolidone, N,N-dimethyl lactamide, and diisobutyl ketone,Examples include N-methyl-2-pyrrolidone, ethylene glycol monobutyl ether, and ethylene glycol monobutyl ether acetate, γ-butyrolactone, ethylene glycol monobutyl ether acetate, and dipropylene glycol dimethyl ether, N-ethyl-2-pyrrolidone, ethylene glycol monobutyl ether acetate, and propylene glycol dimethyl ether, N-methyl-2-pyrrolidone, 4-methyl-2-pentyl acetate, and ethylene glycol monobutyl ether, N-ethyl-2-pyrrolidone, cyclohexyl acetate, and 4-hydroxy-4-methyl-2-pentanone, cyclohexanone, and propylene glycol monomethyl ether, cyclopentanone, and propylene glycol monomethyl ether, and N-methyl-2-pyrrolidone, cyclohexanone, and propylene glycol monomethyl ether.

[0069] (Liquid Crystal Alignment Agent) The liquid crystal aligning agent of the present invention may contain other components (hereinafter also referred to as additive components) in addition to the polymer (A), the polymer other than the polymer (A), and the organic solvent. Examples of such additive components include at least one crosslinking compound selected from the group consisting of a crosslinking compound having at least one substituent selected from an oxiranyl group, an oxetanyl group, a blocked isocyanate group, an oxazoline group, a cyclocarbonate group, a hydroxy group, and an alkoxy group, and a crosslinking compound having a polymerizable unsaturated group, a functional silane compound, a metal chelate compound, a curing accelerator, a surfactant, an antioxidant, a sensitizer, a preservative, and a compound for adjusting the dielectric constant or electrical resistance of the resulting liquid crystal alignment film.

[0070] Specific preferred examples of the crosslinkable compound 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, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexylglycerin diglycidyl ether, and 1,3,5,6-tetraglycidyl-2,4-hexylglycerin diglycidyl ether. bisphenol A type epoxy resins such as xanediol, Epicoat (registered trademark) 828 (manufactured by Mitsubishi Chemical Corporation), bisphenol F type epoxy resins such as Epicoat 807 (manufactured by Mitsubishi Chemical Corporation), hydrogenated bisphenol A type epoxy resins such as YX-8000 (manufactured by Mitsubishi Chemical Corporation), biphenyl skeleton-containing epoxy resins such as YX6954BH30 (manufactured by Mitsubishi Chemical Corporation), phenol novolac type epoxy resins such as EPPN-201 (manufactured by Nippon Kayaku Co., Ltd.), (o, m, p-) cresol novolac type epoxy resins such as EOCN-102S (manufactured by Nippon Kayaku Co., Ltd.), alicyclic epoxy resins such as TEPIC (registered trademark) (manufactured by Nissan Chemical Industries, Ltd.), triglycidyl isocyanurates such as CELLOXIDE (registered trademark) 2021P (manufactured by Daicel Chemical Industries, Ltd.), compounds containing a tertiary nitrogen atom such as N,N,N',N'-tetraglycidyl-m-xylylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, or N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, and compounds having two or more oxiranyl groups such as tetrakis(glycidyloxymethyl)methane. compounds having two or more oxetanyl groups described in paragraphs

[0170] to

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

[0025] to

[0030] and

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

[0071] Examples of the compound for adjusting the dielectric constant or electrical resistance include monoamines having a nitrogen atom-containing aromatic heterocycle such as 3-picolylamine. The content of the monoamine having a nitrogen atom-containing aromatic heterocycle is preferably 0.1 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, per 100 parts by mass of the polymer component contained in the liquid crystal aligning agent.

[0072] Specific preferred examples of the functional silane compound include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyldiethoxymethylsilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and 3-glycidoxypropylmethyldimethoxysilane. Examples of the functional silane compound include 3-(2-methyl-2-methylpropyl)isocyanurate, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, tris(3-trimethoxysilylpropyl)isocyanurate, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-isocyanatopropyltriethoxysilane. The content of the functional silane compound is preferably 0.1 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, per 100 parts by mass of the polymer component contained in the liquid crystal alignment agent.

[0073] The solids concentration in the liquid crystal aligning agent (the ratio of the total mass of the components other than the solvent of the liquid crystal aligning agent to the total mass of the liquid crystal aligning agent) is appropriately selected taking into consideration viscosity, volatility, etc., but is preferably 1 to 10% by mass. A particularly preferred range of solids concentration varies depending on the method used to apply the liquid crystal aligning agent to the substrate. For example, when using a spin coating method, a solids concentration of 1.5 to 4.5% by mass is particularly preferred. When using a printing method, a solids concentration of 3 to 9% by mass is particularly preferred, thereby resulting in a solution viscosity of 12 to 50 mPa·s. When using an inkjet method, a solids concentration of 1 to 5% by mass is particularly preferred, thereby resulting in a solution viscosity of 3 to 15 mPa·s. The temperature when preparing the polymer composition is preferably 10 to 50°C, more preferably 20 to 30°C.

[0074] (Liquid Crystal Alignment Film and Liquid Crystal Display Element) The liquid crystal display element according to the present invention comprises a liquid crystal alignment film formed using the liquid crystal aligning agent described above. The operation mode of the liquid crystal display element is not particularly limited, and it can be applied to various operation modes, such as TN type, STN type, vertical alignment type (including VA-MVA type, VA-PVA type, etc.), in-plane switching type (IPS type, FFS type), optically compensated bend type (OCB type), etc. The liquid crystal display element of the present invention can be manufactured, for example, by a method including the following steps (1) to (4), a method including steps (1) to (2) and (4), a method including steps (1) to (3), (4-2) and (4-4), or a method including steps (1) to (3), (4-3) and (4-4).

[0075] <Step (1): Applying a Liquid Crystal Alignment Agent to a Substrate> Step (1) is a step of applying a liquid crystal alignment agent to a substrate. A specific example of step (1) is as follows: The liquid crystal alignment agent is applied to one side of a substrate having a patterned transparent conductive film by an appropriate application method, such as a roll coater method, a spin coat method, a printing method, or an inkjet method. The substrate material is not particularly limited as long as it is highly transparent; glass, silicon nitride, and plastics such as acrylic and polycarbonate can also be used. In addition, in a reflective liquid crystal display element, an opaque material such as a silicon wafer can be used for only one substrate, and in this case, a light-reflecting material such as aluminum can also be used for the electrode. Furthermore, when manufacturing an IPS-type or FFS-type liquid crystal display element, a substrate having an electrode made of a comb-shaped patterned transparent conductive film or metal film and an opposing substrate having no electrode are used.

[0076] Examples of a method for applying the liquid crystal alignment agent to a substrate and forming a film include screen printing, offset printing, flexographic printing, an inkjet method, and a spray method. Among these, the application and film formation method by the inkjet method is preferably used.

[0077] <Step (2): Step of Baking the Applied Liquid Crystal Alignment Agent> Step (2) is a step of baking the liquid crystal alignment agent applied to the substrate to form a film. Specific examples of step (2) are as follows. After applying the liquid crystal alignment agent to the substrate in step (1), the solvent can be evaporated or the polyamic acid can be thermally imidized using a heating means such as a hot plate, a hot air circulation oven, or an IR (infrared) oven. The drying and baking steps after applying the liquid crystal alignment agent can be performed at any temperature and for any time, and may be performed multiple times. The temperature for baking the liquid crystal alignment agent can be, for example, 40 to 180°C. From the perspective of shortening the process, it may also be performed at 40 to 150°C. The baking time is not particularly limited, but may be 1 to 10 minutes or 1 to 5 minutes. When thermally imidizing the polyamic acid, a baking step at, for example, 150 to 300°C or 150 to 250°C may be added after the above step. The baking time is not particularly limited, but may be 5 to 40 minutes or 5 to 30 minutes. If the thickness of the film-like substance after baking is too thin, the reliability of the liquid crystal display element may decrease, so the thickness is preferably 5 to 300 nm, more preferably 10 to 200 nm.

[0078] <Step (3): Alignment Treatment of the Film Obtained in Step (2)> Step (3) is a step of optionally aligning the film obtained in Step (2). That is, in horizontal alignment type liquid crystal display devices such as IPS mode or FFS mode, the coating film is subjected to an alignment ability imparting treatment. On the other hand, in vertical alignment type liquid crystal display devices such as VA mode or PSA mode, the formed coating film can be used as a liquid crystal alignment film as is, or the coating film may be subjected to an alignment ability imparting treatment. Examples of alignment treatment methods for liquid crystal alignment films include rubbing treatment and photo-alignment treatment. Examples of photo-alignment treatment methods include irradiating the surface of the film with polarized radiation in a certain direction and, optionally, performing a heat treatment at a temperature preferably of 150 to 250°C to impart liquid crystal alignment (also referred to as liquid crystal alignment ability). The radiation can be ultraviolet light or visible light having a wavelength of 100 to 800 nm. Among these, ultraviolet light having a wavelength of 100 to 400 nm is preferred, and more preferably, ultraviolet light having a wavelength of 200 to 400 nm is more preferred.

[0079] The radiation dose is 1 to 10,000 mJ / cm ２ is preferable, and among these, 100 to 5,000 mJ / cm ２ is more preferable. When irradiating with radiation, the substrate having the film-like material may be irradiated while being heated at 50 to 250°C in order to improve the liquid crystal alignment. The liquid crystal alignment film produced in this manner can stably align the liquid crystal molecules in a fixed direction. Furthermore, the liquid crystal alignment film irradiated with polarized radiation by the above method can be contact-treated with water or a solvent, or the liquid crystal alignment film irradiated with radiation can be heat-treated.

[0080] The solvent used in the contact treatment is not particularly limited as long as it dissolves the decomposition products generated from the film-like material by irradiation. Specific examples include water, methanol, ethanol, 2-propanol, acetone, methyl ethyl ketone, 1-methoxy-2-propanol, 1-methoxy-2-propanol acetate, butyl cellosolve, ethyl lactate, methyl lactate, diacetone alcohol, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propyl acetate, butyl acetate, and cyclohexyl acetate. The solvent may be used alone or in combination of two or more.

[0081] The temperature for the heat treatment of the coating film irradiated with the radiation is more preferably 50 to 300° C., and even more preferably 120 to 250° C. The heat treatment time is preferably 1 to 30 minutes.

[0082] <Step (4): Step of preparing a liquid crystal cell> Two substrates on which liquid crystal alignment films have been formed are prepared as described above, and a liquid crystal composition is placed between the two substrates arranged opposite each other. Specifically, the following two methods can be mentioned. In the first method, the two substrates are first arranged opposite each other with a gap (cell gap) between them so that the liquid crystal alignment films face each other. Next, the peripheries of the two substrates are bonded together using a sealant, and the liquid crystal composition is injected and filled into the substrate surfaces and the cell gap defined by the sealant so that it comes into contact with the film surface, and then the injection hole is sealed.

[0083] The second method is called the ODF (One Drop Fill) method. A UV-curable sealant, for example, is applied to a predetermined location on one of two substrates on which a liquid crystal alignment film has been formed, and a liquid crystal composition is then dropped onto several predetermined locations on the liquid crystal alignment film. The other substrate is then attached so that the liquid crystal alignment film faces the other substrate, and the liquid crystal composition is spread over the entire surface of the substrate and brought into contact with the film surface. The entire surface of the substrate is then irradiated with UV light to cure the sealant. In either method, it is desirable to further heat the substrate to a temperature at which the liquid crystal composition assumes an isotropic phase and then slowly cool it to room temperature to remove flow alignment that occurs during liquid crystal filling. If the coating film is subjected to a rubbing treatment, the two substrates are positioned opposite each other so that the rubbing directions on each coating film are at a predetermined angle, for example, perpendicular or antiparallel. For example, an epoxy resin containing a curing agent and aluminum oxide spheres as spacers can be used as the sealant. The liquid crystal composition is not particularly limited, and may be a composition containing at least one liquid crystal compound (liquid crystal molecule), and may be a liquid crystal composition exhibiting a nematic phase (hereinafter also referred to as nematic liquid crystal), a liquid crystal exhibiting a smectic phase, or a liquid crystal composition exhibiting a cholesteric phase. Among these, nematic liquid crystal is preferred. Furthermore, various liquid crystal compositions having positive or negative dielectric anisotropy may be used. Hereinafter, a liquid crystal composition having a positive dielectric anisotropy is also referred to as a positive liquid crystal, and a liquid crystal composition having a negative dielectric anisotropy is also referred to as a negative liquid crystal. The liquid crystal composition may contain a liquid crystal compound having a fluorine atom, a hydroxy group, an amino group, a fluorine atom-containing group (e.g., a trifluoromethyl group), a cyano group, an alkyl group, an alkoxy group, an alkenyl group, an isothiocyanate group, a heterocycle, a cycloalkane, a cycloalkene, a steroid skeleton, a benzene ring, or a naphthalene ring, or may contain a compound having two or more rigid moieties (mesogenic skeletons) that exhibit liquid crystallinity in the molecule (e.g., a bimesogenic compound in which two rigid biphenyl structures or terphenyl structures are linked by an alkyl group). Furthermore, the liquid crystal composition may further contain an additive from the viewpoint of improving liquid crystal alignment properties.Such additives include photopolymerizable monomers such as compounds having a polymerizable group; optically active compounds (e.g., S-811 manufactured by Merck Co., Ltd.); antioxidants; ultraviolet absorbers; dyes; antifoaming agents; polymerization initiators; or polymerization inhibitors. Positive liquid crystals include ZLI-2293, ZLI-4792, MLC-2003, MLC-2041, MLC-3019, and MLC-7081 manufactured by Merck Co., Ltd. Negative liquid crystals include MLC-6608, MLC-6609, MLC-6610, MLC-7026, and MLC-7026-100 manufactured by Merck Co., Ltd., as well as NA-1559 manufactured by DIC Corporation. Furthermore, an example of a liquid crystal containing a compound having a polymerizable group is MLC-3023 manufactured by Merck Co., Ltd.

[0084] The liquid crystal aligning agent of the present invention is also preferably used in a liquid crystal display element (PSA-type liquid crystal display element) manufactured by a process of: having a liquid crystal layer between a pair of substrates equipped with electrodes, disposing a liquid crystal composition containing a polymerizable compound that polymerizes by at least one of active energy rays and heat between the pair of substrates, and polymerizing the polymerizable compound by at least one of irradiation with active energy rays and heating while applying a voltage between the electrodes. The liquid crystal aligning agent of the present invention is also preferably used in a liquid crystal display element (SC-PVA-mode liquid crystal display element) manufactured by a process of having a liquid crystal layer between a pair of substrates equipped with electrodes, disposing a liquid crystal alignment film containing a polymerizable group that polymerizes by at least one of active energy rays and heat between the pair of substrates, and applying a voltage between the electrodes.

[0085] <Step (4-2): In the case of a PSA-type liquid crystal display element> This step is carried out in the same manner as in the above step (4), except that a liquid crystal composition containing a polymerizable compound is injected or dropped. Examples of the polymerizable compound include polymerizable compounds having one or more polymerizable unsaturated groups, such as an acrylate group or a methacrylate group, in the molecule.

[0086] <Step (4-3): For SC-PVA Mode Liquid Crystal Display Elements> A method for producing a liquid crystal display element may be employed, following the procedure described above in (4), followed by a step of irradiating with ultraviolet light, as described below. This method, similar to the production of the PSA mode liquid crystal display element, allows for the production of a liquid crystal display element with excellent response speed with a low light exposure dose. The compound having a polymerizable group may be a compound having one or more of the above-described polymerizable unsaturated groups in the molecule, and the content thereof is preferably 0.1 to 30 parts by mass, more preferably 1 to 20 parts by mass, per 100 parts by mass of all polymer components. Furthermore, the polymerizable group may be contained in a polymer used in a liquid crystal aligning agent. Examples of such polymers include polymers obtained by reacting a diamine component containing a diamine having the above-described photopolymerizable group at its terminal.

[0087] <Step (4-4): Step of Irradiating Ultraviolet Light> The liquid crystal cell is irradiated with light while a voltage is applied between the conductive films of the pair of substrates obtained in step (4-2) or (4-3) above. The voltage applied here can be, for example, a direct current or alternating current of 5 to 50 V. The light to be irradiated can be, for example, ultraviolet light and visible light containing light with a wavelength of 150 to 800 nm, but ultraviolet light containing light with a wavelength of 300 to 400 nm is preferred. The light source for the irradiation light can be, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, or an excimer laser. The light irradiation dose is preferably 1,000 to 200,000 J / m ２ and more preferably 1,000 to 100,000 J / m ２ is.

[0088] A liquid crystal display element can be obtained by attaching a polarizing plate to the outer surface of the liquid crystal cell as needed. Examples of the polarizing plate to be attached to the outer surface of the liquid crystal cell include a polarizing film called an "H film" made by stretching and aligning polyvinyl alcohol and absorbing iodine, sandwiched between cellulose acetate protective films, and a polarizing plate made of the H film itself.

[0089] An IPS substrate, which is a comb electrode substrate used in IPS mode, has a base material, a plurality of linear electrodes formed on the base material and arranged in a comb-teeth pattern, and a liquid crystal alignment film formed on the base material so as to cover the linear electrodes. Meanwhile, an FFS substrate, which is a comb electrode substrate used in FFS mode, has a base material, a surface electrode formed on the base material, an insulating film formed on the surface electrode, a plurality of linear electrodes formed on the insulating film and arranged in a comb-teeth pattern, and a liquid crystal alignment film formed on the insulating film so as to cover the linear electrodes.

[0090] FIG. 1 is a schematic partial cross-sectional view showing an example of an IPS-mode liquid crystal display element of the present invention. In the IPS-mode liquid crystal display element 1 shown in FIG. 1 , liquid crystal 3 is sandwiched between a comb-shaped electrode substrate 2 having a liquid crystal alignment film 2c and a counter substrate 4 having a liquid crystal alignment film 4a. The comb-shaped electrode substrate 2 includes a base 2a, a plurality of linear electrodes 2b formed on the base 2a and arranged in a comb-like pattern, and a liquid crystal alignment film 2c formed on the base 2a to cover the linear electrodes 2b. The counter substrate 4 includes a base 4b and a liquid crystal alignment film 4a formed on the base 4b. The liquid crystal alignment film 2c is, for example, a liquid crystal alignment film of the present invention. The liquid crystal alignment film 4c is also a liquid crystal alignment film of the present invention. In this IPS-mode liquid crystal display element 1, when a voltage is applied to the linear electrodes 2b, an electric field is generated between the linear electrodes 2b, as indicated by electric field lines L.

[0091] FIG. 2 is a schematic partial cross-sectional view showing another example of an in-plane switching liquid crystal display element of the present invention, which is an example of an FFS-mode liquid crystal display element. In the in-plane switching liquid crystal display element 1 shown in FIG. 2, liquid crystal 3 is sandwiched between a comb-shaped electrode substrate 2 having a liquid crystal alignment film 2h and a counter substrate 4 having a liquid crystal alignment film 4a. The comb-shaped electrode substrate 2 includes 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-like 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 includes a base material 4b and a liquid crystal alignment film 4a formed on the base material 4b. The liquid crystal alignment film 2h is, for example, a liquid crystal alignment film of the present invention. The liquid crystal alignment film 4a is also a liquid crystal alignment film of the present invention. In this IPS LCD element 1, when a voltage is applied to the surface electrodes 2e and the linear electrodes 2g, an electric field is generated between the surface electrodes 2e and the linear electrodes 2g as indicated by electric force lines L.

[0092] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. The abbreviations of the compounds used and the methods for measuring the properties are as follows. (Organic solvents) NMP: N-methyl-2-pyrrolidone GBL: γ-butyrolactone BCS: butyl cellosolve (Tetracarboxylic acid dianhydride) CA-1 to CA-4: Compounds represented by the following formulas (CA-1) to (CA-4), respectively (Diamine) DA-1 to DA-5: Compounds represented by the following formulas (DA-1) to (DA-5), respectively (Additives) AD-1 to AD-2: Compounds represented by the following formulas (AD-1) to (AD-2), respectively

[0093] <Measurement of Viscosity> Measurement was carried out at 25°C using an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.) with a sample volume of 1.1 mL and a cone rotor TE-1 (1°34', R24).

[0094] <Measurement of Molecular Weight> Measurement was carried out using the following room temperature GPC (gel permeation chromatography) apparatus under the following conditions, and Mn and Mw were calculated as polyethylene glycol and polyethylene oxide equivalent values. GPC apparatus: GPC-101 (Showa Denko K.K.), Column: GPC KD-803 and GPC KD-805 (Showa Denko K.K.) connected in series, Column temperature: 50°C, Eluent: N,N-dimethylformamide (containing lithium bromide monohydrate (LiBr.H) as an additive), ２ o-Phosphoric acid (o-Phosphoric acid) 30 mmol / L, tetrahydrofuran (THF) 10 mL / L), Flow rate: 1.0 mL / min. Standard samples for preparing a calibration curve: TSK standard polyethylene oxide (molecular weight: about 900,000, about 150,000, about 100,000, and about 30,000) (manufactured by Tosoh Corporation) and polyethylene glycol (molecular weight: about 12,000, about 4,000, and about 1,000) (manufactured by Polymer Laboratory Co., Ltd.).

[0095] [Synthesis of Monomer] DA-2 is a novel compound not disclosed in any literature, and the product in Monomer Synthesis Example 1 below is １ The product was identified by H-NMR analysis. The analysis conditions were as follows: Apparatus: BRUKER ADVANCE III-500 MHz Measurement solvent: deuterated dimethyl sulfoxide (DMSO-d ６ ) Reference substance: tetramethylsilane (TMS) (δ 0.0 ppm for １ H)

[0096] <Monomer Synthesis Example 1: Synthesis of DA-2> 2-(4-nitrophenoxy)ethanol (50.0 g, 273 mmol) was charged with THF (600 g), 4-dimethylaminopyridine (DMAP, 16.6 g, 13.6 mmol), and succinic anhydride (34.1 g, 341 mmol), and the mixture was stirred at 50°C. 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC·HCl, 59.8 g, 312 mmol) and 1,4-butanediol (11.7 g, 130 mmol) were charged to the resulting solution, and the mixture was stirred at room temperature (25°C) for 3 hours. After completion of the reaction, water (1.5 kg) was added to precipitate crystals. The solid obtained by filtration was dried to obtain crude crystals. THF (300 g) was added to the crude crystals, and the mixture was heated and stirred at 65°C. After cooling to room temperature, methanol (1.5 kg) was added to recrystallize them. The crystals were filtered off and the resulting crystals were dried to obtain DA-2-1 (yield: 60.4 g, 97.2 mmol, 75%). １ H-NMR (500MHz) in DMSO-d ６ :8.21 (d, J=9.2Hz, 4H), 7.17 (d, J=9.2Hz, 4H), 4.37 (q, 8H), 3.99 (s, 4H), 2.58 (m, 8H), 1.57 (m, 4H).

[0097] To the DA-2-1 (60.3 g, 97.2 mmol) obtained above, THF (1.2 kg) was added and the mixture was purged with nitrogen. Then, carbon-supported palladium (5% Pd carbon powder (hydrated product) K type, manufactured by N.E. Chemcat Corporation) (6.0 g) was added, the mixture was purged with nitrogen again, a Tedlar bag containing sealed hydrogen was attached, and the mixture was stirred at room temperature for 4 days. After completion of the reaction, the carbon-supported palladium was removed by passing through a membrane filter, and the filtrate was completely concentrated to precipitate crude crystals. Isopropyl alcohol (240 g) was added to the crude crystals, and the mixture was washed by stirring at room temperature. The crystals obtained after filtration were dried to obtain DA-2 (yield: 44.8 g, 79.9 mmol, 82% yield). １ H-NMR (500MHz) in DMSO-d ６ :6.65 (d, J=8.9Hz, 4H), 6.50 (d, J=8.9Hz, 4H), 4.62 (s, 4H) 4.27 (m, 4H), 4.00 (m, 8H), 2.57 (m, 8H), 1.59 (m, 4H).

[0098] [Polymer Synthesis] <Synthesis Example 1> DA-3 (2.29 g, 8.00 mmol) and NMP (16.8 g) were added to a 50 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and dissolved by stirring at room temperature while supplying nitrogen. Thereafter, CA-1 (1.69 g, 7.54 mmol) and NMP (12.4 g) were added, and the mixture was stirred at 40°C for 18 hours to obtain a solution of polyamic acid (A-1) with a solids concentration of 12% by mass (viscosity: 225 mPa s). The Mn of this polyamic acid was 10,382 and the Mw was 32,874. Synthesis Example 2 DA-4 (0.977 g, 4.00 mmol), DA-5 (0.797 g, 4.00 mmol), and NMP (10.1 g) were added to a 50 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and dissolved by stirring at room temperature while supplying nitrogen. After cooling to room temperature, CA-2 (1.50 g, 6.00 mmol) and NMP (8.30 g) were added, and the mixture was stirred at 50°C for 5 hours. After cooling to room temperature, CA-3 (0.494 g, 1.68 mmol) and NMP (2.80 g) were added, and the mixture was stirred at 70°C for 18 hours, yielding a solution of polyamic acid (A-2) with a solids concentration of 15% by mass (viscosity: 304 mPa s). The Mn of this polyamic acid was 9,284, and the Mw was 26,834. Synthesis Example 3: DA-1 (2.50 g, 6.00 mmol) and NMP (18.3 g) were added to a 50 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and dissolved by stirring at 25°C while supplying nitrogen. Thereafter, CA-4 (1.05 g, 4.81 mmol) and NMP (7.70 g) were added, and the mixture was stirred at 40°C for 18 hours to obtain a solution of polyamic acid (A-3) with a solids concentration of 12% by mass (viscosity: 24 mPa s). The polyamic acid had an Mn of 3,871 and an Mw of 8,232. Synthesis Example 4: DA-1 (2.29 g, 5.50 mmol) and NMP (16.8 g) were added to a 50 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and dissolved by stirring at room temperature while supplying nitrogen. Thereafter, CA-4 (1.15 g, 5.27 mmol) and NMP (8.10 g) were added, and the mixture was stirred at 50° C. for 18 hours to obtain a solution of polyamic acid (A-4) with a solid content of 12 mass % (viscosity: 239 mPa·s).The polyamic acid had an Mn of 10,094 and an Mw of 33,198. Synthesis Example 5: DA-2 (1.74 g, 3.10 mmol) and NMP (12.7 g) were added to a 50 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and dissolved by stirring at room temperature while supplying nitrogen. Thereafter, CA-4 (0.541 g, 2.48 mmol) and NMP (4.00 g) were added, and the mixture was stirred at 50°C for 18 hours to obtain a solution of polyamic acid (A-5) with a solids concentration of 12% by mass (viscosity: 31 mPa s). The polyamic acid had an Mn of 4,765 and an Mw of 12,289. Synthesis Example 6: DA-1 (1.67 g, 4.01 mmol), DA-4 (0.980 g, 4.01 mmol), and NMP (23.8 g) were added to a 50 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and dissolved by stirring at room temperature while supplying nitrogen. Thereafter, CA-4 (1.63 g, 7.47 mmol) and NMP (7.60 g) were added, and the mixture was stirred at 50°C for 18 hours to obtain a solution of polyamic acid (A-6) with a solids concentration of 12% by mass (viscosity: 300 mPa s). The Mn of this polyamic acid was 9,351, and the Mw was 31,020. Synthesis Example 7: DA-1 (3.12 g, 7.49 mmol) and NMP (22.9 g) were added to a 50 mL four-neck flask equipped with a stirrer and a nitrogen inlet tube, and dissolved by stirring at room temperature while supplying nitrogen. Thereafter, CA-1 (1.60 g, 7.14 mmol) and NMP (10.8 g) were added and stirred at 40° C. for 18 hours to obtain a solution of polyamic acid (A-7) (viscosity: 282 mPa s) with a solids concentration of 12% by mass. The polyamic acid had an Mn of 10,704 and an Mw of 39,144.

[0099] The types and amounts of the tetracarboxylic acid components and diamine components used in Synthesis Examples 1 to 7 are shown in Table 1. In Table 1, the numbers in parentheses for the tetracarboxylic acid components and diamine components represent the proportion (parts by mole) of each compound used relative to 100 parts by mole of the total amount of the diamine components used in the synthesis of each polyamic acid. Polyamic acid A-1 corresponds to polymer (B) of the present invention, polyamic acid A-2 corresponds to polymer (C) of the present invention, and polyamic acids A-3 to A-6 correspond to polymer (A) of the present invention.

[0100]

[0101] [Preparation of Liquid Crystal Alignment Agent] <Example 1> To the solution (1.22 g) of the polyamic acid (A-1) obtained in Synthesis Example 1, the solution (2.93 g) of the polyamic acid (A-2) obtained in Synthesis Example 2, the solution (0.24 g) of the polyamic acid (A-3) obtained in Synthesis Example 3, NMP (0.46 g), GBL (4.77 g), BCS (4.50 g), AD-1 (1 mass% GBL solution, 0.59 g), and AD-2 (10 mass% NMP solution, 0.29 g) were added, and the mixture was stirred at room temperature for 2 hours, thereby obtaining a liquid crystal aligning agent (AL-1) of the present invention.

[0102] <Examples 2 to 8 and Comparative Examples 1 to 4> By performing the same operation as in Example 1 above, except that the type and amount of the polyamic acid solution and solvent used were changed as shown in Table 2, liquid crystal aligning agents AL-2 to AL-8, which are Examples 2 to 8 of the present invention, and liquid crystal aligning agents AL-C1 to AL-C4, which are Comparative Examples 1 to 4, were obtained.

[0103]

[0104] [Preparation of Liquid Crystal Cell] <Preparation of Liquid Crystal Cell for Pretilt Angle Evaluation> First, a substrate with electrodes was prepared. The substrate was a glass substrate measuring 30 mm x 40 mm and 0.7 mm thick. ITO electrodes with a thickness of 35 nm were formed on the substrate, and the electrodes were in a stripe pattern with a spacing of 40 mm vertically and 10 mm horizontally. Next, the liquid crystal alignment agent obtained above was filtered through a filter with a pore size of 1.0 μm and then applied to the substrate with electrodes prepared above by spin coating. Next, the resulting solution was dried on a hot plate at 80°C for 2 minutes and then baked in an infrared heating furnace at 230°C for 20 minutes to form a coating film with a thickness of 60 nm, thereby obtaining a substrate with a liquid crystal alignment film. This liquid crystal alignment film was subjected to a rubbing alignment treatment (roller diameter: 120 mm, roller rotation speed: 1000 rpm, movement speed: 20 mm / sec, indentation length: 0.4 mm) using a rayon cloth (HY-5318 manufactured by Hyperflex Corporation). Subsequently, the film was washed by ultrasonic irradiation in pure water for 1 minute, water droplets were removed by air blowing, and then the film was dried at 80 ° C for 10 minutes to obtain a substrate with a liquid crystal alignment film. Two substrates with this liquid crystal alignment film were prepared, and spherical spacers with a particle size of 4 μm were sprayed onto the liquid crystal alignment film surface of one of the substrates. After that, a sealant (XN-1500T manufactured by Mitsui Chemicals, Inc.) was printed around the periphery, leaving the liquid crystal injection port, and the other substrate was bonded to the other substrate with the rubbing direction in the opposite direction and the film surfaces facing each other. Subsequently, the substrate was heated at 150 ° C for 60 minutes to harden the sealant and produce an empty cell. Negative liquid crystal NA-1559 (DIC Corporation) was injected into this empty cell by a reduced pressure injection method, and the injection port was sealed to obtain a liquid crystal cell. The obtained liquid crystal cell was then heated at 120°C for 1 hour and allowed to stand at 23°C overnight before being used for evaluation of the pretilt angle.

[0105] <Fabrication of FFS-Driven Liquid Crystal Cell> A liquid crystal cell with the configuration of an FFS-mode liquid crystal display element was fabricated. First, a substrate with electrodes was prepared. The substrate was a rectangular glass substrate measuring 30 mm x 50 mm and 0.7 mm thick. A solid-patterned ITO electrode constituting a common electrode was formed on the substrate as a first layer. A SiN (silicon nitride) film deposited by CVD (chemical vapor deposition) was formed on the first common electrode as a second layer. The second SiN film had a thickness of 300 nm, which served as an interlayer insulating film. A comb-shaped pixel electrode formed by patterning an ITO film as a third layer was disposed on the second SiN film. Two pixels, a first pixel and a second pixel, were formed, each measuring 10 mm long and 5 mm wide. This electrode-equipped substrate had a structure in which the first common electrode and the third pixel electrode were insulated by the second SiN film. The third-layer pixel electrode had a comb-like shape with a central bend at an interior angle of 160° and multiple 3 μm-wide electrode lines arranged parallel to each other at 6 μm intervals. Each pixel was formed by multiple electrode lines, with a first and second region separated by a line connecting the bends. The liquid crystal alignment agent obtained above was then filtered through a 1.0 μm pore size filter and then spin-coated onto the electrode-attached substrate (hereinafter referred to as the electrode substrate) and a glass substrate (hereinafter referred to as the counter substrate) with a 4 μm-tall columnar spacer and an ITO film formed on its backside. The resulting solution was dried on a hot plate at 80°C for 2 minutes and then baked in a hot air circulating oven at 230°C for 20 minutes to form a 60 nm-thick coating film. This coating film was subjected to a rubbing alignment treatment (roller diameter: 120 mm, roller rotation speed: 1000 rpm, moving speed: 20 mm / sec, indentation length: 0.4 mm) using a rayon cloth (HY-5318 manufactured by Hyperflex Corp.). Thereafter, the substrate was washed by irradiating it with ultrasonic waves in pure water for 1 minute, water droplets were removed by air blowing, and then the substrate was dried on a hot plate 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 subjected to an alignment treatment so that the direction dividing the interior angle of the pixel bend was parallel to the alignment direction of the liquid crystal. The alignment film formed on the counter substrate was also subjected to an alignment treatment so that the alignment direction of the liquid crystal on the electrode substrate was aligned with the alignment direction of the liquid crystal on the counter substrate when the liquid crystal cell was fabricated. The two substrates were combined into a pair, and a sealant (Mitsui Chemicals XN-1500T) was printed on one substrate using a dispenser. Another substrate was then attached to the other substrate, facing each other with the alignment directions of the liquid crystal alignment films aligned at 0°. 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, producing an empty cell. Negative liquid crystal NA-1559 (DIC) was injected into this empty cell using a vacuum injection method, and the injection port was sealed to obtain an FFS-driven liquid crystal cell. The resulting liquid crystal cell was then heated at 120°C for 1 hour and left overnight at 23°C before being used for evaluation.

[0106] [Evaluation of Liquid Crystal Cell Characteristics] The characteristics of the liquid crystal cell for evaluating the pretilt angle and the FFS drive liquid crystal cell prepared above were evaluated as follows.

[0107] <Measurement of Pretilt Angle> The pretilt angle in the liquid crystal cell was measured by the Mueller matrix method using an Axometrics AxoScan. The lower the pretilt angle, the better the viewing angle characteristics. As the evaluation criteria, a pretilt angle of 2.10° or less was marked as "○", and a pretilt angle of more than 2.10° was marked as "×".

[0108] <Evaluation of Alignment Stability by Long-Term AC Drive> This evaluation is to evaluate the afterimage (also called AC afterimage) that occurs due to the deterioration of the alignment performance of the liquid crystal alignment film during long-term AC drive. Using the FFS drive liquid crystal cell prepared above, a high-brightness backlight (light source: LED, brightness: 30,000 cd / m) with a surface temperature of 50°C was used. ２) and an AC voltage of ±6.5 V at a frequency of 30 Hz was applied for 120 hours. The pixel electrode and common electrode of the liquid crystal cell were then shorted and left at room temperature (23°C) for one day. After leaving the liquid crystal cell, it was placed between two polarizing plates arranged so that their polarization axes were perpendicular to each other. The backlight was turned on with no voltage applied. The liquid crystal cell was then adjusted to minimize the transmitted light intensity of the first region of the first pixel. The rotation angle Δ required to rotate the liquid crystal cell to minimize the transmitted light intensity of the second region of the first pixel was calculated. The first and second regions of the second pixel were similarly compared, and the same angle Δ was calculated. The average of the angles Δ for the first and second pixels was then calculated as the rotation angle Δ of the liquid crystal cell. The smaller the rotation angle Δ, the better the liquid crystal alignment stability. As an evaluation criterion, an angle Δ of 0.25° or less was marked "Good," and an angle Δ of more than 0.25° was marked "Poor."

[0109] <Measurement of the Relaxation Rate of Accumulated Charge> The FFS-driven liquid crystal cell prepared above was placed between two polarizing plates arranged with their polarization axes perpendicular to each other. With the pixel electrode and the common electrode shorted and at the same potential, an LED backlight was irradiated from below the two polarizing plates. The angle of the FFS-driven liquid crystal was adjusted so that the brightness of the LED backlight transmitted through the two polarizing plates was minimized. Next, the temperature of the FFS-driven liquid crystal cell was set to 45°C, and a 30 Hz AC voltage was applied to the liquid crystal cell while measuring the VT curve (voltage-transmittance curve). The AC voltage at which the relative transmittance was 23% was calculated as the driving voltage. Furthermore, while applying a 30 Hz AC voltage at which the relative transmittance was 23%, a 1 V DC voltage was simultaneously applied and the cell was driven for 30 minutes. Then, the DC voltage application was stopped, and the cell was driven for another 15 minutes with only the AC voltage. As an evaluation criterion, the smaller the transmittance 15 minutes after the application of the DC voltage was stopped, the better the relaxation speed of the accumulated charges.

[0110] [Evaluation of Coatability] The liquid crystal alignment agent obtained above was applied by spin coating to an ITO substrate measuring 100 mm x 100 mm and having a thickness of 1.1 mm. After drying on a hot plate at 80°C for 2 minutes, the substrate was baked in a hot air circulating oven at 230°C for 20 minutes to obtain a substrate with a liquid crystal alignment film having a thickness of 60 nm. When the substrate with the liquid crystal alignment film was observed with the naked eye, if the coating surface was uniform and free of unevenness, it was rated as "○", and if unevenness was visible on the coating surface, it was rated as "×".

[0111] The evaluation results of the pretilt angle, afterimage characteristics, relaxation rate of accumulated charges, and coatability of the liquid crystal cells using the liquid crystal alignment agents of Examples 1 to 8 and Comparative Examples 1 to 4 are shown in Table 3. In Table 3, the numerical values ​​in parentheses for the polymers represent the blending ratio (parts by mass) of each polymer (solid content) when the total content of the polymers (solid content) other than polymer (A) is taken as 100 parts by mass.

[0112]

[0113] As shown in Table 3, the liquid crystal display element using the liquid crystal aligning agent of the present invention was excellent not only in viewing angle characteristics and afterimage characteristics, but also in the relaxation rate of accumulated charges and coatability. As shown in Table 3, the liquid crystal display element using the liquid crystal aligning agent of the present invention had a better relaxation rate of accumulated charges than the liquid crystal display element using the liquid crystal aligning agent not containing polymer (A). This is clear, for example, from a comparison between Example 1 and Comparative Example 1, or a comparison between Example 8 and Comparative Example 4.

[0114] The liquid crystal alignment film obtained from the liquid crystal aligning agent of the present invention is widely used in liquid crystal display elements of various operation modes, and can also be used, for example, as a liquid crystal alignment film for a retardation film, a liquid crystal alignment film for a scanning antenna or a liquid crystal array antenna, or a liquid crystal alignment film for a transmissive-scattering type liquid crystal dimming element.

[0115] The liquid crystal display element of the present invention can be effectively applied to devices having various functions, and can be used, for example, in liquid crystal televisions, clocks, portable games, word processors, notebook computers, car navigation systems, camcorders, PDAs, digital cameras, mobile phones, smartphones, various monitors, information displays, etc.

[0116] 1: In-plane switching liquid crystal display element, 2: Comb-tooth electrode substrate, 2a, 4b, 2d: Base material, 2b, 2g: Linear electrode, 2c, 2h, 4a: Liquid crystal alignment film, 2e: Planar electrode, 2f: Insulating film, 3: Liquid crystal, 4: Counter substrate, L: Electric line of force

[0117] The entire contents of the specification, claims, drawings and abstract of Japanese Patent Application No. 2023-175163 filed on October 10, 2023 are hereby incorporated by reference as the disclosure of the present invention.

Claims

1. A liquid crystal aligning agent containing the following polymer (A) and a polymer other than the polymer (A), wherein the content of the polymer (A) is 0.1 parts by mass or more and 10 parts by mass or less per 100 parts by mass of the total content of the polymer other than the polymer (A). Polymer (A): A tetracarboxylic acid derivative component containing an aromatic tetracarboxylic dianhydride and a compound represented by the following formula (D Ａ and a polyimide which is an imidized product of the polyimide precursor, the polyimide precursor being obtained by using a diamine component containing 40 mol % or more of a diamine (A) represented by the formula (A) based on the total diamine components. Ａ ). Z-NH-Ar １ -X １ - (R １ -L) ｎ -R ２ -X ２ -Ar ２ -NH-Z (D Ａ ) (Formula (D Ａ ) in Ar １ , Ar ２ Each of X independently represents a divalent aromatic group of a divalent benzene ring, a biphenyl structure, or a naphthalene ring, and any hydrogen atom of the aromatic group may be replaced with a monovalent group. １ , X ２ Each independently represents a single bond, -O-, or *1-O-CO-. (*1 is Ar １ Or Ar ２ Represents a bond with . １ , R ２ are each independently a divalent hydrocarbon group, and some of the hydrogen atoms in the divalent hydrocarbon group may be substituted with a halogen atom, a methyl group, a trifluoromethyl group, or a hydroxy group. １ may be the same as or different from each other. L represents -O-, -C(=O)-, -O-C(=O)-, or -C(=O)-O-. When a plurality of Ls are present, the plurality of Ls may be the same as or different from each other. However, at least one L represents -O-C(=O)- or -C(=O)-O-. n is an integer of 1 to 6. Z represents a hydrogen atom or a monovalent organic group. The plurality of Zs may be the same as or different from each other.

2. The liquid crystal aligning agent according to claim 1, wherein the polymer other than the polymer (A) contains the following polymer (B) and / or the following polymer (C). Polymer (B): a polymer represented by the following formula (d ＡＬ ) (however, those included in the diamine (A) are excluded. and a polyimide which is an imidized product of the polyimide precursor. Ｂ However, when the diamine component contains a diamine other than the diamine (B) and also contains the diamine (A), the amount of the diamine (A) used is less than 40 mol% based on the total diamine components. When the diamine component contains a diamine other than the diamine (B), does not contain the diamine (A), and contains the following diamine (C), the amount of the diamine (C) used is less than 30 mol% based on the total diamine components. (Ar １ , and Ar １’ each represents a benzene ring, a biphenyl structure, or a naphthalene ring, and one or more hydrogen atoms on the benzene ring, the biphenyl structure, or the naphthalene ring may be substituted with a monovalent group. １ and L １’ each represents a single bond, -O-, -C(=O)-, or -O-C(=O)-. A is -CH ２ A represents an alkylene group having 2 to 12 carbon atoms, or a divalent organic group in which at least one of -O-, -C(=O)-O-, and -O-C(=O)- is inserted between the carbon-carbon bonds of the alkylene group. Any hydrogen atom possessed by A may be substituted with a halogen atom. However, in the formula (d ＡＬ ) in L １ and L １’ When is -O-, A is -CH ２ -, an alkylene group having 2 to 12 carbon atoms, or a divalent organic group formed by inserting -O- between the carbon-carbon bonds of the alkylene group. One or more hydrogen atoms on the benzene ring, biphenyl structure, or naphthalene ring may be substituted with a monovalent group, and examples of the monovalent group include a halogen atom, an alkyl group having 1 to 3 carbon atoms, an alkenyl group having 2 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a fluoroalkyl group having 1 to 3 carbon atoms, a fluoroalkenyl group having 2 to 3 carbon atoms, a fluoroalkoxy group having 1 to 3 carbon atoms, an alkyloxycarbonyl group having 2 to 3 carbon atoms, a cyano group, and a nitro group. Z represents a hydrogen atom or a monovalent organic group. A plurality of Zs may be the same or different from each other. ) Polymer (C): The following formula (d ｎ and a polyimide which is an imidized product of the polyimide precursor, the polyimide precursor being obtained by using a diamine component containing 30 mol % or more of the diamine component represented by the formula (C), based on the total diamine components. Ｃ However, when a diamine other than the diamine (C) is contained as the diamine component, the diamine (A) is not contained. (Y represents a divalent organic group having a nitrogen-containing structure selected from the group consisting of nitrogen-containing heterocycles and amino groups represented by the group "*21-NR-*22" (*21 and *22 represent bonds bonded to carbon atoms constituting an aromatic ring, with the proviso that the carbon atom does not form a ring with the nitrogen atom to which R is bonded. R represents a hydrogen atom or a monovalent organic group, and the monovalent organic group is bonded to the nitrogen atom at a carbon atom other than the carbonyl carbon). Z represents a hydrogen atom or a monovalent organic group. Multiple Zs may be the same or different.) 3. The liquid crystal aligning agent according to claim 2, wherein the polymer other than the polymer (A) includes the polymer (B) and the polymer (C).

4. The above formula (D Ａ The group "-(R １ -L) ｎ -R ２ The liquid crystal aligning agent according to claim 1, wherein "-" is selected from the following structures: *-(CH ２ ) ｐ -OC(=O)-(CH ２ ) ｑ -C(=O)-O-(CH ２ ) ｒ - *, * - (CH ２ ) ｐ -C(=O)-O-(CH ２ ) ｑ -OC(=O)-(CH ２ ) ｒ - *, * - (CH ２ ) ｎ１ -OC(=O)-(CH ２ ) ｎ２ -C(=O)-O-(CH ２ ) ｎ３ -OC(=O)-(CH ２ ) ｎ４ -C(=O)-O-(CH ２ ) ｎ５ - *; * - (CH ２ ) ｎ１ -C(=O)-O-(CH ２ ) ｎ２ -OC(=O)-(CH ２ ) ｎ３ -C(=O)-O-(CH ２ ) ｎ４ -OC(=O)-(CH ２ ) ｎ５ -*; In the above, p, q, and r each independently represent an integer from 1 to 6. n1 to n5 each independently represent an integer from 1 to 6, provided that the total number of carbon atoms in n1 to n5 is 20 or less. * represents a bond.

5. The diamine (A) is represented by the following formula (d Ａ -1) to (d Ａ The liquid crystal aligning agent according to claim 1, wherein the diamine is any one selected from the group consisting of: (The above formula (d Ａ -1) to (d Ａ In -10), the hydrogen atom on the benzene ring may be substituted with a monovalent substituent. p, q, r, and n1 to n5 are the same as defined above for p, q, r, and n1 to n5.

6. The liquid crystal aligning agent according to claim 2, wherein the polymer (B) is obtained by a polycondensation reaction between the diamine component and a tetracarboxylic acid component containing an acyclic aliphatic tetracarboxylic acid dianhydride, an alicyclic tetracarboxylic acid dianhydride, an aromatic tetracarboxylic acid dianhydride, or a derivative thereof.

7. The liquid crystal aligning agent according to claim 2, wherein the polymer (C) is obtained by a polycondensation reaction between the diamine component and a tetracarboxylic acid component containing an acyclic aliphatic tetracarboxylic acid dianhydride, an alicyclic tetracarboxylic acid dianhydride, an aromatic tetracarboxylic acid dianhydride, or a derivative thereof.

8. The liquid crystal aligning agent according to claim 1, further comprising an additive component selected from the group consisting of a crosslinking compound having at least one substituent selected from an oxiranyl group, an oxetanyl group, a blocked isocyanate group, an oxazoline group, a cyclocarbonate group, a hydroxyl group, and an alkoxy group, and a crosslinking compound having a polymerizable unsaturated group, a functional silane compound, a metal chelate compound, a curing accelerator, a surfactant, an antioxidant, a sensitizer, a preservative, and a compound for adjusting the dielectric constant and electrical resistance of the resulting liquid crystal alignment film.

9. A liquid crystal alignment film obtained from the liquid crystal aligning agent according to any one of claims 1 to 8.

10. A liquid crystal display device comprising the liquid crystal alignment film according to claim 9.

11. The liquid crystal display element according to claim 10, which is a lateral electric field liquid crystal display element.

12. A method for manufacturing a liquid crystal display element, comprising the following steps (1) to (3): step (1): applying the liquid crystal alignment agent according to any one of claims 1 to 8 onto a substrate; step (2): baking the applied liquid crystal alignment agent to obtain a film; and step (3): performing an alignment treatment on the film obtained in step (2).