TWI830451B - Liquid crystal alignment agent, liquid crystal alignment film and liquid crystal display element - Google Patents

Abstract

The present invention provides a liquid crystal alignment agent, which can expand the range of light irradiation amount, obtain a liquid crystal alignment film with small variation (non-uniformity) of the twist angle of the liquid crystal in the liquid crystal alignment film surface, and is used to obtain a liquid crystal alignment film that does not cause washing due to The uneven display of the liquid crystal alignment film caused by the cleaning step will form a liquid crystal alignment film with a high water contact angle. It also provides a liquid crystal alignment film obtained from the liquid crystal alignment agent and a liquid crystal display element having the high performance of the liquid crystal alignment film. A liquid crystal alignment agent characterized by containing a polymer (P) selected from a polyimide precursor obtained by using a diamine component containing a diamine (0) represented by the following formula ( _DA ) and at least one of the group consisting of polyimide and an imide compound of the polyimide precursor, and provide a liquid crystal alignment film obtained from the liquid crystal alignment agent, and a liquid crystal alignment film having the liquid crystal alignment film LCD components. The definitions of each symbol are as stated in the manual.

Description

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

The present invention relates to a liquid crystal alignment agent, a liquid crystal alignment film obtained from the liquid crystal alignment agent, and a liquid crystal display element provided with the liquid crystal alignment film.

Liquid crystal display elements are widely used in everything from small applications such as mobile phones and smartphones to relatively large applications such as televisions and screens. In addition, various driving methods have been developed that differ in electrode structure and physical properties of the liquid crystal molecules used. For example, it is known that the TN (Twisted Nematic) method and the STN (Super Twisted Nematic) method are used. , VA (Vertical Alignment) method, IPS (In-Plane Switching) method, FFS (Fringe Field Switching) method and other various modes of liquid crystal display elements. These liquid crystal display elements generally have a liquid crystal alignment film that is indispensable for controlling the alignment state of liquid crystal molecules. As for the material of the liquid crystal alignment film, polyamide and polyimide are generally used from the viewpoint of good properties such as heat resistance, mechanical strength, and affinity with liquid crystals.

The most popular liquid crystal alignment film in the industry today is produced by rubbing the surface of a polyimide or other resin film formed on an electrode substrate in one direction with a cotton, nylon, polyester or other cloth, a so-called rubbing treatment. Friction alignment treatment is a simple and useful method with excellent productivity. As an alignment treatment method that replaces the rubbing alignment treatment, there is known a photo alignment treatment method that imparts alignment ability to liquid crystal by irradiating polarized radiation. Regarding the photoalignment treatment method, a method using a photoisomerization reaction, a method using a photocrosslinking reaction, a method using a photodecomposition reaction, etc. have been proposed (see, for example, Non-Non-Patent Document 1, Patent Document 1, Patent Document 2). [Prior technical literature] [Patent Document]

[Patent Document 1] Japanese Patent Application Laid-Open No. 9-297313 [Patent Document 2] Japanese Patent Application Publication No. 2004-206091 [Non-patent literature]

[Non-Patent Document 1] "Liquid Crystal Optical Alignment Film", Functional Materials, November 1997, Vol. 17, No. 11, pages 13~22

(Problem to be solved by the invention)

In recent years, with the improvement of the performance of liquid crystal display elements, in addition to being used in large-screen and high-definition LCD TVs, applications are also being explored for automotive applications, such as car navigation systems, dashboards, surveillance cameras, and medical camera screens. Therefore, there are higher requirements for liquid crystal display elements, especially higher performance such as high definition, and liquid crystal alignment films are required to have better various characteristics of liquid crystal display elements.

In addition, as liquid crystal display elements become larger, the undesirable phenomenon of slight variations in the twist angle of the liquid crystal within the plane of the liquid crystal display element gradually begins to occur due to variations in the manufacturing process. Such variation causes the brightness of the liquid crystal display element to become uneven within the surface when the display is black, causing the quality of the liquid crystal display element to deteriorate.

Furthermore, in the above-mentioned rubbing alignment treatment and photo-alignment treatment, in order to remove impurities, sometimes a cleaning step using a solvent is performed after the above-mentioned alignment treatment. In this cleaning step, the shrinkage of the solvent and the generation of liquid droplets during air knife drying may occur. The surface of the film may be washed locally and unevenly, and the liquid crystal display element obtained may sometimes have cracks along the direction of the air knife. Linear display is uneven.

In view of the above situation, the purpose of the present invention is to provide a liquid crystal alignment agent that can expand the range of light irradiation amount, obtain a liquid crystal alignment film with small variation (non-uniformity) of the twist angle of the liquid crystal in the liquid crystal alignment film surface, and use In order to obtain a liquid crystal alignment film that does not produce uneven display due to the cleaning step, a liquid crystal alignment film with a high water contact angle will be formed. And provide a liquid crystal alignment film obtained from the liquid crystal alignment agent, and a liquid crystal display element equipped with the liquid crystal alignment film. (Ways to solve problems)

The inventor of the present case worked hard to achieve the above-mentioned subject, and found that the use of a liquid crystal alignment agent containing a polymer of a diamine with a specific structure is effective in achieving the above-mentioned purpose, and thus completed the present invention.

The present invention is a liquid crystal alignment agent, which is characterized by containing a polymer (P). The polymer (P) is selected from a polyamide obtained by using a diamine component containing a diamine (0) represented by the following formula ( _DA ). At least one kind from the group consisting of an amine precursor and a polyimide which is an imide compound of the polyimide precursor. The present invention also provides a liquid crystal alignment film obtained from the liquid crystal alignment agent and a liquid crystal display element having the liquid crystal alignment film. [Chemical 1] Ar represents a divalent aromatic group in any one of a divalent benzene ring, a biphenyl structure, or a naphthalene ring. Any hydrogen atom on the benzene ring, a biphenyl structure, or a naphthalene ring may also be substituted by a monovalent group. . m and n are each independently an integer between 1 and 3. Any hydrogen atom on the benzene ring to which the amine groups at both ends are bonded can also be substituted by a 1-valent group. In the present invention, the halogen atom includes a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like. Boc represents tertiary butoxycarbonyl. (The effect of the invention)

According to the present invention, a liquid crystal alignment agent can be obtained, which can expand the range of light irradiation amount, obtain a liquid crystal alignment film with small variation (non-uniformity) of the twist angle of the liquid crystal in the liquid crystal alignment film surface, and can be used to obtain a liquid crystal alignment film that does not produce The uneven display of the liquid crystal alignment film caused by the cleaning step will form a liquid crystal alignment film with a high water contact angle. A liquid crystal alignment film obtained from the liquid crystal alignment agent and a liquid crystal display element having the high performance of the liquid crystal alignment film can be obtained.

The mechanism by which the above-mentioned effects of the present invention are obtained is not necessarily clear, but it is roughly estimated as follows. It is thought that the oxyaniline structure contained in the diamine (0) of the present invention can produce a liquid crystal alignment film with a small variation in the twist angle of the liquid crystal, and the introduction of hydrophobic hydrocarbons such as aromatic rings and phenylene groups can increase the water contact angle. , so the above effects can be obtained.

<Specific diamine> The liquid crystal alignment agent of the present invention, as described above, is characterized in that it contains a polymer (P), and the polymer (P) is selected from a group consisting of a diamine (0) represented by the following formula ( _DA ) (this polymer) The invention is at least one of the group consisting of a polyimide precursor obtained from a diamine component (also called a specific diamine) and a polyimide that is an imide of the polyimide precursor. [Chemicalization 2] In the above formula ( _DA ), Ar, m and n are each as defined above.

In the above formula (D _A ), from the viewpoint of obtaining high liquid crystal alignment, m and n are preferably 1 to 2.

The monovalent group that replaces the hydrogen atom on the benzene ring, biphenyl structure, or naphthalene ring of Ar in the above formula (D _A ) can include halogen atoms, alkyl groups with 1 to 3 carbon atoms, and alkyl groups with 2 to 3 carbon atoms. Alkenyl group, alkoxy group having 1 to 3 carbon atoms, fluoroalkyl group having 1 to 3 carbon atoms, fluoroalkenyl group having 2 to 3 carbon atoms, fluoroalkoxy group having 1 to 3 carbon atoms, carboxyl group, hydroxyl group, carbon number 1~3 alkoxycarbonyl, cyano, nitro, etc. Among them, a halogen atom, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a fluoroalkyl group having 1 to 3 carbon atoms, or a fluoroalkoxy group having 1 to 3 carbon atoms is preferred. In addition, any hydrogen atom on the benzene ring to which the amine groups at both ends are bonded may also be substituted by a univalent group. Specific examples of the univalent group include the univalent group exemplified by Ar in the above formula ( _DA ). , the same example can be cited for the ideal state.

Ideal examples of the divalent aromatic group represented by Ar include 1,4-phenylene group, 1,3-phenylene group, 2-methyl-1,4-phenylene group, and 2-ethyl-1,4 -Phenylene, 2-propyl-1,4-phenylene, 2-isopropyl-1,4-phenylene, 2-methoxy-1,4-phenylene, 2-ethoxy Base-1,4-phenylene, 2-propoxy-1,4-phenylene, 2-fluoro-1,4-phenylene, 2,3-dimethyl-1,4-phenylene base, 4-methyl-1,3-phenylene, 5-methyl-1,3-phenylene, 4-fluoro-1,3-phenylene, 2,3,5,6-tetramethyl Biphenyl-1,4-phenyl, biphenyl-4,4'-diyl, 2-methylbiphenyl-4,4'-diyl, 2-ethylbiphenyl-4,4'-diyl , 2-propylbiphenyl-4,4'-diyl, 2-methoxybiphenyl-4,4'-diyl, 2-ethoxybiphenyl-4,4'-diyl, 2- Fluorobiphenyl-4,4'-diyl, 3-methylbiphenyl-4,4'-diyl, 3-ethylbiphenyl-4,4'-diyl, 3-propylbiphenyl-4 ,4'-diyl, 3-methoxybiphenyl-4,4'-diyl, 3-ethoxybiphenyl-4,4'-diyl, 3-fluorobiphenyl-4,4'- Diyl, 2,2'-dimethylbiphenyl-4,4'-diyl, 3,3'-dimethylbiphenyl-4,4'-diyl, biphenyl-3,3'-diyl base, 5-methylbiphenyl-3,3'-diyl, 5,5'-dimethylbiphenyl-3,3'-diyl, 1,5-naphthylene, 2,6-naphthylene base, or 1-methyl-2,6-naphthyl, etc.

Ideal examples of the above formula (D _A ) include the following formulas (d _A -1) to (d _A -3). In the following formulas (d _A -1) ~ (d _A -3), the benzene ring bonded by the amine groups at both ends, the benzene ring bonded by the alkylene group, the biphenyl structure, or any hydrogen on the naphthalene ring The atom may be substituted by a monovalent group. Specific examples of the monovalent group include the monovalent group exemplified for Ar in the above formula ( _DA ). In an ideal embodiment, the same examples can be cited. In the above formulas (d _A -1) to (d _A -3), a more preferred monovalent group as a substituent for the hydrogen atom on the benzene ring to which the amine groups at both ends are bonded is a methyl group. In addition, when the hydrogen atoms on the benzene rings bonded to the amine groups at both ends are substituted, it is better for 1 to 2 hydrogen atoms to be substituted in each benzene ring, and it is even better for 1 hydrogen atom to be substituted. At least one hydrogen atom on the benzene ring to which the amine groups at both ends are bonded can also be replaced by a halogen atom, an alkyl group with 1 to 3 carbon atoms, an alkoxy group with 1 to 3 carbon atoms, or an alkoxy group with 1 to 3 carbon atoms. Substituted with fluoroalkyl group or fluoroalkoxy group with 1 to 3 carbon atoms. [Chemical 3] m and n are each independently defined as above.

(Polymer (P)) The polymer (P) contained in the liquid crystal alignment agent of the present invention is a polyimide precursor obtained by using a diamine component containing the above-mentioned diamine (0), or the polyimide Polyimide is a precursor of an imide compound. Among them, the polyimide precursor is a polymer that can be obtained by imidizing polyamide acid, polyamide ester, or the like. The polymer (P) may be used alone or in combination of two or more types. The polymer (P) may have at least one repeating unit selected from the group consisting of a repeating unit (p1) represented by the following formula (1) and an imidized structural unit of the repeating unit (p1). of polymers. [Chemical 4] In formula (1), X ₁ represents a tetravalent organic group. Y ₁ removes a divalent organic group of two amine groups from the above-mentioned specific diamine. R and Z each independently represent a hydrogen atom or a monovalent organic group. In the above formula (1), the monovalent organic group of R and Z can be a monovalent hydrocarbon group having 1 to 6 carbon atoms. The methylene group of the hydrocarbon group is -O-, -S-, -CO-, -COO-. , -COS-, -NR ³ -, -CO-NR ³ -, -Si(R ³ ) ₂ - (but R ³ is a hydrogen atom or a monovalent hydrocarbon group with 1 to 6 carbon atoms), -SO ₂ -, etc. At least one of the hydrogen atoms bonded to the carbon atom of the monovalent group A, the above-mentioned monovalent hydrocarbon group or the above-mentioned monovalent group A is replaced by a halogen atom, a hydroxyl group, an alkoxy group, a nitro group, an amine group, a mercapto group, or a nitrosal group. A univalent group substituted by alkylsilyl group, alkoxysilyl group, silyl alcohol group, sulfinic acid group, phosphine group, carboxyl group, cyano group, sulfo group, hydroxyl group, etc., a univalent group with a heterocyclic ring base. In the above formula (1), the monovalent organic group of R and Z is preferably an alkyl group with 1 to 6 carbon atoms, an alkenyl group with 2 to 6 carbon atoms, an alkynyl group with 2 to 6 carbon atoms, or a third butyl group. An oxycarbonyl group is preferred, an alkyl group having 1 to 3 carbon atoms is more preferred, and a methyl group is more preferred. From the viewpoint of ideally obtaining the effects of the present invention, R and Z are preferably each independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and more preferably a hydrogen atom or a methyl group. X ₁ in the above formula (1) is, for example, a tetravalent organic group derived from tetracarboxylic dianhydride or a derivative thereof described below. Ideal aspects of the carboxylic dianhydride or derivatives thereof in the above X ₁ include ideal aspects of tetracarboxylic dianhydride or derivatives thereof that can be used in the synthesis of the polymer (P) described later. The polyamide acid (P') which is the polyimide precursor of the above-mentioned polymer (P) can be obtained by the polymerization reaction of a diamine component and a tetracarboxylic acid component containing the above-mentioned diamine (0). The above-mentioned diamine (0) may be used alone or in combination of two or more types. The usage amount of diamine (0) is preferably 5 mol% or more based on the total diamine components, more preferably 10 mol% or more, and still more preferably 20 mol% or more.

The diamine component used in the production of the above-mentioned polyamide (P') may contain diamines other than diamine (0) (hereinafter also referred to as other diamines.). When other diamines are used in combination with the above-mentioned diamine (0), the usage amount of the diamine (0) relative to the diamine component is preferably 90 mol% or less, and more preferably 80 mol% or less.

Examples of other diamines are listed below but are not limited thereto. The other diamines mentioned above may be used alone or in combination of two or more. Examples include p-phenylenediamine, 2,3,5,6-tetramethyl-p-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, m-phenylenediamine, and 2,4-dimethyl-m-phenylenediamine. 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 Benzene, 2,2'-difluoro-4,4'-diaminobiphenyl, 3,3'-difluoro-4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl methyl)-4,4'-diaminobiphenyl, 3,3'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 3,4'-diaminobiphenyl, 4 , 4'-diaminobiphenyl, 3,3'-diaminobiphenyl, 2,2'-diaminobiphenyl, 2,3'-diaminobiphenyl, the following formula (d _AL -1 )~(d _AL -10) represents diamine, 1,7-bis(4-aminophenoxy)heptane, 1,7-bis(3-aminophenoxy)heptane, 1,8 -Bis(4-aminophenoxy)octane, 1,8-bis(3-aminophenoxy)octane, 1,9-bis(4-aminophenoxy)nonane, 1, 9-bis(3-aminophenoxy)nonane, 1,10-bis(4-aminophenoxy)decane, 1,10-bis(3-aminophenoxy)decane, 1 ,11-bis(4-aminophenoxy)undecane, 1,11-bis(3-aminophenoxy)undecane, 1,12-bis(4-aminophenoxy)decane Dioxane, 1,12-bis(3-aminophenoxy)dodecane, 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, 1,2-bis(6-amino-2-naphthyloxy)ethane, 1,2-bis(6-amino-2-naphthyl)ethane Alkane, 6-[2-(4-aminophenoxy)ethoxy]-2-naphthylamine, 1,4-phenylenebis(4-aminobenzoate), 1,4-phenylenebis(4-aminobenzoate) Phenylbis(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 (hereinafter these diamines are also referred to as other diamines (a).); 4,4'-diaminoazobenzene or diaminobis Diamines with photoalignment groups such as phenylacetylene (diaminotolan); 2-(2,4-diaminophenoxy)ethyl methacrylate or 2,4-diamino-N,N-diene Diamines with photopolymerizable groups at the end such as propylaniline; 1-(4-(2-(2,4-diaminophenoxy)ethoxy)phenyl)-2-hydroxy-2-methyl Acetone, 2-(4-(2-hydroxy-2-methylpropyl)phenoxy)ethyl 3,5-diaminobenzoate and other diamines that function as free radical polymerization initiators; 4, 4'-Diaminobenzoaniline and other diamines with amide bonds, 1,3-bis(4-aminophenyl)urea, 1,3-bis(4-aminobenzyl)urea, 1 , 3-bis(4-aminophenylethyl)urea and other diamines with urea bonds; 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4' -Diaminodiphenyl ether, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl] Hexafluoropropane, 2,2-bis(4-aminophenyl)hexafluoropropane, 2,2-bis(3-aminophenyl)hexafluoropropane, 2,2-bis(3-amino-4) -Methylphenyl)hexafluoropropane, 2,2-bis(4-aminophenyl)propane, 2,2-bis(3-aminophenyl)propane, 2,2-bis(3-amino) -4-Methylphenyl)propane, 4,4'-diaminodiphenylketone, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenyl) )benzene, 1,4-bis(4-aminobenzyl)benzene; 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-bis Aminocarbazole, N-methyl-3,6-diaminocarbazole, 1,4-bis-(4-aminophenyl)-piperidine, 3,6-diaminoacridine, N- Ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N-[3-(1H-imidazol-1-yl)propyl]3,5-di Aminobenzamide, 4-[4-[(4-aminophenoxy)methyl]-4,5-dihydro-4-methyl-2-ethazolyl]-aniline, or the following formula (z-1) ~ diamines represented by formula (z-13) and other heterocyclic-containing diamines, or 4,4'-diaminodiphenylamine, 4,4'-diaminodiphenyl-N- Methylamine, N,N'-bis(4-aminophenyl)-benzidine, N,N'-bis(4-aminophenyl)-N,N'-dimethylbenzidine, or N, N'-bis(4-aminophenyl)-N,N'-dimethyl-1,4-phenylenediamine and other diamines with a diphenylamine structure are represented by heterocyclic rings selected from nitrogen-containing atoms, A diamine with at least one nitrogen atom-containing structure (hereinafter also referred to as a specific nitrogen atom-containing structure) in the group consisting of a secondary amine group and a tertiary amine group (but does not have a bond in the molecule and is detached due to heating And substituted by the amine group of the protecting group of hydrogen atom. ); 2,4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4,6-diaminoisophenylene Phenol, 4,4'-diamino-3,3'-dihydroxybiphenyl; 2,4-diaminobenzoic acid, 2,5-diaminobenzoic acid, 3,5-diaminobenzoic acid , 4,4'-diaminobiphenyl-3-carboxylic acid, 4,4'-diaminodiphenylmethane-3-carboxylic acid, 1,2-bis(4-aminophenyl)ethane -3-carboxylic acid, 4,4'-diaminobiphenyl-3,3'-dicarboxylic acid, 4,4'-diaminobiphenyl-2,2'-dicarboxylic acid, 3,3'-Diaminobiphenyl-4,4'-dicarboxylic acid, 3,3'-diaminobiphenyl-2,4'-dicarboxylic acid, 4,4'-diaminodiphenylmethane-3 ,3'-dicarboxylic acid, 1,2-bis(4-aminophenyl)ethane-3,3'-dicarboxylic acid, 4,4'-diaminodiphenyl ether-3,3'- Diamines with carboxyl groups such as dicarboxylic acids; 4-(2-(methylamino)ethyl)aniline, 4-(2-aminoethyl)aniline, 1-(4-aminophenyl)-1, 3,3-Trimethyl-1H-indene-5-amine, 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-indene- 6-amine; the following formulas (5-1)~(5-6) and the like have the group "-N(D)-" (D represents a protective group that is removed by heating and replaced with a hydrogen atom, preferably a urethane is a protecting group, more preferably tert-butoxycarbonyl.) diamine, cholestyloxy-3,5-diaminobenzene, cholestyloxy-3,5-diaminobenzene , Cholestanyloxy-2,4-diaminobenzene, cholestyl 3,5-diaminobenzoate, cholestyl 3,5-diaminobenzoate, 3,5-diaminobenzoate Diamines with steroid skeletons such as lanosteryl aminobenzoate and 3,6-bis(4-aminobenzoyloxy)cholestane are represented by the following formulas (V-1) to (V-2) diamines; 1,3-bis(3-aminopropyl)-tetramethyldisiloxane and other diamines with siloxane bonds; m-xylylenediamine, 1,3-propanediamine, Tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, 1,3-bis(aminomethyl)cyclohexane, 1,4-diaminocyclohexane, 4,4 '-Methylenebis(cyclohexylamine), the group represented by any one of the formulas (Y-1) to (Y-167) described in International Publication No. 2018/117239, two of the two amine groups are bonded Amines etc.

[Chemistry 5] In formulas (d _AL -6) and (d _AL -8), m1 and m2 each independently have the above definition.

[Chemical 6]

[Chemical 7]

[Chemical 8]

[Chemical 9] In the above formula (V-1), m and n are each independently an integer from 0 to 3, and conform to 1≦m+n≦4. j is an integer of 0 or 1. X ¹ represents -(CH ₂ ) _a -(a is an integer from 1 to 15.), -CONH-, -NHCO-, -CO-N(CH ₃ )-, -NH-, -O-, -CH ₂ O-, -CH ₂ -OCO-, -COO-, or -OCO-. R ¹ represents a fluorine atom, an alkyl group containing fluorine atoms with 1 to 10 carbon atoms, an alkoxy group containing fluorine atoms with 1 to 10 carbon atoms, an alkyl group with 1 to 10 carbon atoms, and an alkoxy group with 1 to 10 carbon atoms. groups, and univalent groups such as alkoxyalkyl groups with 2 to 10 carbon atoms. In the above formula (V-2), X ² represents -O-, -CH ₂ O-, -CH ₂ -OCO-, -COO-, or -OCO-. When two of m, n, X ¹ and R ¹ exist, each has the above definition independently.

From the viewpoint of optimally obtaining the effects of the present invention, the diamine component used in the production of the above-mentioned polyamide (P') preferably contains at least one diamine selected from the group consisting of the above-mentioned other diamines (a). Amines are preferred.

When other diamines are used in addition to the above-mentioned diamine (0), the usage amount of the above-mentioned other diamines is preferably 10 to 90 mol%, more preferably 20%, based on the total diamine components used in the production of the polymer (P). ~80 mol%.

(tetracarboxylic acid component) When producing the above-mentioned polyamic acid (P'), as the tetracarboxylic acid component that reacts with the diamine component, not only tetracarboxylic dianhydride, but also tetracarboxylic acid, tetracarboxylic acid dihalide, and tetracarboxylic acid dianhydride can be used. Derivatives of tetracarboxylic dianhydrides such as alkyl esters or tetracarboxylic acid dialkyl ester dihalides.

Examples of the tetracarboxylic dianhydride or derivatives thereof include acyclic aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, aromatic tetracarboxylic dianhydride, or derivatives thereof. Among them, it is more preferable to contain tetracarboxylic dianhydride or derivatives thereof having at least one substructure selected from the group consisting of benzene ring, cyclobutane ring, cyclopentane ring and cyclohexane ring. In particular, it is more preferable to contain tetracarboxylic dianhydride or a derivative thereof having at least one structure selected from the group consisting of a cyclobutane ring, a cyclopentane ring and a cyclohexane ring. The above-mentioned tetracarboxylic dianhydride or its derivatives may be used alone or in combination of two or more. In addition, non-cyclic aliphatic tetracarboxylic dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxyl groups bonded with a chain hydrocarbon structure. However, it does not need to be composed only of a chain hydrocarbon structure, and part of it may also have an alicyclic structure or an aromatic ring structure. Alicyclic tetracarboxylic dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxyl groups including at least one carboxyl group bonded to an alicyclic structure. However, these four carboxyl groups are not bonded to the aromatic ring. Moreover, it does not need to be composed only of an alicyclic structure, and a part thereof may have a chain hydrocarbon structure or an aromatic ring structure. Aromatic tetracarboxylic dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxyl groups including at least one carboxyl group bonded to an aromatic ring. However, it does not need to be composed only of an aromatic ring structure, and a part of it may have a chain hydrocarbon structure or an alicyclic structure.

The tetracarboxylic acid component that can be used in the production of the above-mentioned polyamide (P') preferably includes the following tetracarboxylic dianhydride or its derivatives (these are also collectively referred to as specific tetracarboxylic acid derivatives in the present invention. ). 1,2,3,4-butanetetracarboxylic dianhydride and other non-cyclic aliphatic tetracarboxylic dianhydride; 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl Methyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dichloro -1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3 -Difluoro-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-bis(trifluoromethyl)-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-Cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3',4,4'-dicyclohexyltetracarboxylic acid Dianhydride, 2,3,5-tricarboxycyclopentyl acetic dianhydride, 4-(2,5-bisoxytetrahydrofuran-3-yl)tetralin-1,2-dicarboxylic anhydride, 5-( 2,5-Dilateral oxytetrahydrofuran-3-yl)-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 5-(2,5- Bilateral oxytetrahydrofuran-3-yl)-8-methyl-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, bicyclo[2.2.2] Oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, bicyclo[2.2.2]octane-2,3,5,6-tetracarboxylic dianhydride, 2,4,6,8 - Tetracarboxybicyclo[3.3.0]octane-2:4,6:8-dianhydride and other alicyclic tetracarboxylic dianhydrides; pyromellitic dianhydride, 3,3',4,4'-dianhydride Phenyl ketone tetracarboxylic dianhydride, 3,3',4,4'-diphenyltetracarboxylic dianhydride, 1,4,5,8-naphthalene tetracarboxylic dianhydride, 2,3,6, 7-naphthalene tetracarboxylic dianhydride, 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride, 3,3',4,4'-biphenyl tetracarboxylic dianhydride, 2,2' ,3,3'-biphenyltetracarboxylic dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)-2,2-diphenylpropane dianhydride, ethylene glycol bistriphenylene trimethylene Anhydride, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 4,4'-carbonyldiphthalic anhydride, 4,4'-(1,4-phenylenedioxy Aromatic tetracarboxylic dianhydrides such as methyl)bis(phthalic anhydride) or 4,4'-methylenebis(1,4-phenylenedimethylene)bis(phthalic anhydride) ; In addition, tetracarboxylic dianhydride and the like described in Japanese Patent Application Laid-Open No. 2010-97188 can be cited.

Ideal examples of the specific tetracarboxylic acid derivatives include 1,2,3,4-butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2- Dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2, 3,4-Tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-difluoro-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1 ,3-Bis(trifluoromethyl)-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4 ,5-cyclohexanetetracarboxylic dianhydride, 3,3',4,4'-dicyclohexyltetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentyl acetic dianhydride, 5-(2 ,5-Dilateral oxytetrahydrofuran-3-yl)-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 5-(2,5-di Side oxytetrahydrofuran-3-yl)-8-methyl-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 2,4,6,8 -Tetracarboxybicyclo[3.3.0]octane-2:4,6:8-dianhydride, pyromellitic dianhydride, 3,3',4,4'-diphenylketone tetracarboxylic dianhydride, 3,3',4,4'-diphenyltetracarboxylic dianhydride, 1,4,5,8-naphthalene tetracarboxylic dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride, 3,3',4,4'-biphenyl tetracarboxylic dianhydride, 2,2',3,3'-biphenyl tetracarboxylic dianhydride Carboxylic dianhydrides, or their derivatives.

The usage ratio of the above-mentioned specific tetracarboxylic acid derivative is preferably 10 mol% or more, more preferably 20 mol% or more, and still more preferably 50 mol% or more, based on all the tetracarboxylic acid components used.

(Liquid crystal alignment agent) The liquid crystal alignment agent of the present invention is a liquid composition obtained by dispersing or dissolving the polymer (P) and other components as necessary in an appropriate solvent. The total content of the polymer components contained in the liquid crystal alignment agent of the present invention can be appropriately changed depending on the thickness of the coating film to be formed. Considering the viewpoint of forming a uniform and defect-free coating film, relative to the entire liquid crystal alignment agent The mass is preferably 1 mass% or more, and from the viewpoint of the storage stability of the solution, the mass is preferably 10 mass% or less. The content of the polymer (P) used in the present invention is preferably 1 to 100 parts by mass, more preferably 10 to 100 parts by mass, and 20 to 100 parts by mass relative to the total 100 parts by mass of the polymers contained in the liquid crystal alignment agent. Excellent.

The liquid crystal alignment agent of the present invention may also contain polymers other than polymer (P). Specific examples of other polymers include polymers selected from the group consisting of a polyimide precursor obtained by using a diamine component that does not contain the above-mentioned specific diamine, and the polyimide precursor. At least one polymer (also referred to as polymer (B) in the present invention) from the group consisting of polyimide and polyamide imide of an amine precursor, polysiloxane, polyester, and polyamide , polyurea, polyorganosiloxane, cellulose derivatives, polyacetal, polystyrene derivatives, poly(styrene-maleic anhydride) copolymer, poly(isobutylene-maleic anhydride) copolymer, poly( Vinyl ether-maleic anhydride) copolymer, poly(styrene-phenylmaleimide) derivatives, poly(meth)acrylate.

Specific examples of the poly(styrene-maleic anhydride) copolymer include SMA1000, SMA2000, SMA3000 (manufactured by Cray Valley Co., Ltd.), GSM301 (manufactured by GIFUSHELLAC MFG. Co., Ltd.), etc., and among the poly(isobutylene-maleic anhydride) copolymers Specific examples include ISOBAM-600 (manufactured by Kuraray Co., Ltd.). Specific examples of the poly(vinyl ether-maleic anhydride) copolymer include Gantrez AN-139 (methyl vinyl ether maleic anhydride resin, manufactured by Ashland Corporation). Among them, polymer (B) is more preferable from the viewpoint of reducing residual images due to residual DC. The above-mentioned other polymers may be used individually by one type, or in combination of two or more types. The content ratio of other polymers relative to the total 100 parts by mass of the polymers contained in the liquid crystal alignment agent is preferably 90 parts by mass or less, more preferably 10 to 90 parts by mass, and more preferably 20 to 80 parts by mass. The content of the above-mentioned polymer (P) may be 90 parts by mass or less or less than 80 parts by mass relative to the total 100 parts by mass of the polymers contained in the liquid crystal alignment agent.

(Polymer (B)) Specific examples of the tetracarboxylic acid component used in the production of the polymer (B) include the same compounds as those exemplified for the polymer (P), including ideal specific examples. The tetracarboxylic acid component used in the production of the polymer (B) is a tetracarboxylic acid component containing at least one substructure selected from the group consisting of a benzene ring, a cyclobutane ring, a cyclopentane ring, and a cyclohexane ring. Acid dianhydrides or derivatives thereof are more preferred, the above-mentioned specific tetracarboxylic acid derivatives are still more preferred, and more preferred specific examples of the above-mentioned specific tetracarboxylic acid derivatives are most preferred. In addition, the usage amount of the above-mentioned specific tetracarboxylic acid derivative is preferably 10 mol% or more, more preferably 20 mol% or more, and 50 mol% based on all the tetracarboxylic acid components used in the production of polymer (B). The above is even better.

The diamine component used to obtain the polymer (B) is, for example, the diamine exemplified for the above-mentioned polymer (P). Among them, it is preferable to contain at least one diamine selected from the group consisting of the following (these are also referred to as specific diamines (b) in the present invention): having a urea bond, an amide bond, and a carboxyl group in the molecule and at least one type of diamine, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, and 4,4'-diaminodiphenyl in the group consisting of hydroxyl group Ethers, diamines represented by the above formulas (d _AL -1) ~ (d _AL -10) and diamines having the above-mentioned specific structure containing nitrogen atoms. As the diamine component, one type of diamine may be used alone, or two or more types may be used in combination. When the above-mentioned specific diamine (b) is used, the usage amount is preferably 10 mol% or more, and more preferably 20 mol% or more of the total diamine components used in the production of the polymer (B). When a diamine other than the specific diamine (b) is used, the usage amount is preferably 90 mol% or less of the total diamine components used in the production of the polymer (B), and more preferably 80 mol% or less.

(Manufacturing of polyamide) Polyamide 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 polyamide production reaction is preferably 0.5 to 2 equivalents of the acid anhydride group of the tetracarboxylic acid component relative to 1 equivalent of the amine group of the diamine component. More preferably, it is 0.8~1.2 equivalents. Similar to a normal polycondensation reaction, the closer the equivalent of the acid anhydride group of the tetracarboxylic acid component is to 1 equivalent, the greater the molecular weight of the polyamic acid produced. The reaction temperature for producing polyamide is ideally -20~150℃, and 0~100℃ is more ideal. In addition, the reaction time is preferably 0.1 to 24 hours, and more preferably 0.5 to 12 hours. The production of polyamide can be carried out at any concentration. The concentration of polyamide is preferably 1 to 50 mass%, more preferably 5 to 30 mass%. The reaction is initially carried out at a high concentration, and the solvent can be added later.

Specific examples of the organic solvent include cyclohexanone, cyclopentanone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, γ-butyrolactone, and N,N-dimethylformamide. Amine, N,N-dimethylacetamide, dimethylstyrene, 1,3-dimethyl-2-imidazolidinone. In addition, when the solvent solubility of the polymer is high, methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, and ethylene glycol monomethyl ether can be used. Solvents such as glycol monoethyl ether, ethylene glycol monopropyl ether, diethylene glycol monomethyl ether, or diethylene glycol monoethyl ether.

(Manufacturing of polyamide ester) Polyamic acid ester can be obtained, for example, by the following known methods: [I] A method of reacting the polyamic acid obtained by the above method with an esterifying agent, [II] A method of reacting a tetracarboxylic acid diester with a diamine , [III] Method for reacting tetracarboxylic acid diester dihalide and diamine, etc.

(Manufacturing of polyimide) Polyimide can be obtained by ring-closing (imidizing) a polyimide precursor such as the above-mentioned polyamide acid or polyamide ester. In addition, the acyl imidization rate referred to in this description is the ratio of acyl imine groups to the total amount of acyl imine groups and carboxyl groups (or derivatives thereof) derived from tetracarboxylic dianhydride or its derivatives. . The imidization rate does not necessarily need to be 100% and can be adjusted arbitrarily according to the application and purpose.

Methods for imidizing the polyimide precursor include thermal imidization by directly heating the solution of the polyimide precursor, or adding a catalyst to the solution of the polyimide precursor. Imination of media. The temperature when the polyimide precursor is thermally imidized in the solution is preferably 100~400°C, and more preferably 120~250°C. It is advisable to drain the water generated by the imidization reaction into the system. Better to do it outside.

The catalytic imidization of the polyimide precursor can be achieved by adding an alkaline catalyst and an acid anhydride to the solution of the polyimide precursor, preferably at -20~250°C, and more preferably at 0~180°C. °C with stirring. The amount of alkaline catalyst is preferably 0.5 to 30 mol times of the amide acid group, more preferably 2 to 20 mol times, and the amount of the acid anhydride is preferably 1 to 50 mol times of the amide acid group, more preferably The best value is 3~30 molar times. Examples of the alkaline catalyst include pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine, and the like. Among them, pyridine is ideal because it has a moderate alkalinity that allows the reaction to proceed. Examples of the acid anhydride include acetic anhydride, trimellitic anhydride, pyromellitic anhydride, and the like. Among them, acetic anhydride is preferred because it facilitates purification after completion of the reaction. The imidization rate obtained by using a catalyst to imidize can be controlled by adjusting the catalyst amount, reaction temperature, and reaction time.

When recovering the generated polyimide precursor or polyimide from the reaction solution of the polyimide precursor or polyimide, the reaction solution may be put into a solvent and allowed to precipitate. Solvents used for precipitation include methanol, ethanol, isopropyl alcohol, acetone, hexane, butyl cellulose, heptane, methyl ethyl ketone, methyl isobutyl ketone, toluene, benzene, water, etc. The polymer precipitated by adding it to the solvent is filtered and recovered, and then dried under normal pressure or reduced pressure, at normal temperature or by heating. In addition, if the recovered polymer is redissolved in an organic solvent and reprecipitated for recovery, and this operation is repeated 2 to 10 times, the impurities in the polymer can be reduced. The solvent at this time is, for example, alcohol, ketone or hydrocarbon. If three or more solvents selected from these are used, the purification efficiency will be better, so it is preferable.

When producing the polyimide precursor and polyimide of the present invention, a tetracarboxylic acid component containing tetracarboxylic dianhydride or its derivatives and a diamine component containing the above-mentioned diamine can also be used together with an appropriate sealant. The terminal agent is made into an end-sealed polymer. The end-sealed polymer has the effect of increasing the film hardness of the liquid crystal alignment film obtained from the coating film and improving the adhesion properties between the sealant and the liquid crystal alignment film. In the present invention, examples of the terminals of the polyimide precursor and the polyimide include groups derived from an amine group, a carboxyl group, an acid anhydride group, or a terminal blocking agent described later. The amine group, carboxyl group, and acid anhydride group can be obtained by a normal condensation reaction, or by sealing the end using the following end-capping agent.

End-capping agents, such as: acetic anhydride, maleic anhydride, nedic anhydride, phthalic anhydride, itaconic anhydride, 1,2-cyclohexanedicarboxylic anhydride, 3-hydroxyphthalic anhydride, trimellitamine Anhydride, 3-(3-trimethoxysilyl)propyl)-3,4-dihydrofuran-2,5-dione, 4,5,6,7-tetrafluoroisobenzofuran-1,3 - Anhydrides such as diketone and 4-ethynyl phthalic anhydride; dicarbonate diester compounds such as ditert-butyl dicarbonate and diallyl dicarbonate; acrylic acid chloride, methacrylic acid chloride, and nicotine acid Chlorine and other chlorocarbonyl compounds; aniline, 2-aminophenol, 3-aminophenol, 4-aminosalicylic acid, 5-aminosalicylic acid, 6-aminosalicylic acid, 2-aminobenzoic acid , 3-aminobenzoic acid, 4-aminobenzoic acid, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine and other monoamine compounds; ethyl isocyanate, isocyanate Isocyanates with unsaturated bonds such as phenyl ester, naphthyl isocyanate, or 2-acrylyloxyethyl isocyanate, 2-methacryloyloxyethyl isocyanate, etc. The usage ratio of the end-capping agent is preferably 0.01 to 20 mole parts, and more preferably 0.01 to 10 mole parts per 100 mole parts of the total diamine components used.

The polystyrene-reduced weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) of the polyimide precursor and the polyimide is preferably 1,000 to 500,000, more preferably 2,000 to 300,000. Moreover, the molecular weight distribution (Mw/Mn) expressed as the ratio of Mw to the polystyrene-converted number average molecular weight (Mn) measured by GPC is preferably 15 or less, more preferably 10 or less. By staying within this molecular weight range, good liquid crystal alignment of the liquid crystal display element can be ensured.

The organic solvent contained in the liquid crystal alignment agent of the present invention is not particularly limited as long as it can uniformly dissolve the polymer (P) and other polymers added if necessary. For example: N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethyllactamide, N,N-dimethylpropionamide, tetramethylurea , N,N-diethylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethylsulfoxide, γ-butyrolactone, γ-valerolactone, 1, 3-Dimethyl-2-imidazolidinone, methyl ethyl ketone, cyclohexanone, cyclopentanone, 3-methoxy-N,N-dimethylpropionamide, 3-butoxy-N,N-di Methylpropylamide, N-(n-propyl)-2-pyrrolidone, N-isopropyl-2-pyrrolidone, N-(n-butyl)-2-pyrrolidone, N-(tert-butyl)-2 -Pyrrolidone, N-(n-pentyl)-2-pyrrolidone, N-(3-methoxypropyl)-2-pyrrolidone, N-(2-ethoxyethyl)-2-pyrrolidone, N-( 4-methoxybutyl)-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone (they are also collectively referred to as good solvents), etc. Among them, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 3-methoxy-N,N-dimethylpropylamine, 3-butoxy-N,N-dimethyl Propamide or γ-butyrolactone is preferred. The content of the good solvent is preferably 20 to 99 mass % of the total solvent contained in the liquid crystal alignment agent, more preferably 20 to 90 mass %, and particularly ideally 30 to 80 mass %.

In addition, the organic solvent contained in the liquid crystal alignment agent is preferably a mixed solvent (also called a poor solvent) that improves the coating properties and surface smoothness of the coating film when applying the liquid crystal alignment agent. good. Specific examples of the poor solvent used together are as follows, but are not limited thereto. The content of the poor solvent is preferably 1 to 80 mass % of the total solvents contained in the liquid crystal alignment agent, more preferably 10 to 80 mass %, and particularly preferably 20 to 70 mass %. The type and content of the poor solvent can be appropriately selected according to the coating device, coating conditions, coating environment, etc. of the liquid crystal alignment agent.

Poor solvents, such as: diisopropyl ether, diisobutyl ether, diisobutylmethanol (2,6-dimethyl-4-heptanol), ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol Alcohol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, 4-hydroxy-4-methyl-2-pentanone, diethylene glycol methyl ether, diethylene glycol dibutyl ether, 3-Ethoxybutyl acetate, 1-methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, ethylene glycol monoacetate, ethylene glycol Alcohol diacetate, propyl carbonate, ethyl 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, dipropylene glycol monomethyl ether, dipropylene glycol Monoethyl ether, dipropylene glycol dimethyl ether, ethylene glycol monobutyl ether acetate, diethylene glycol monopropyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, 2- (2-ethoxyethoxy)ethyl acetate, diethylene glycol diacetate, propylene glycol diacetate, n-butyl acetate, propylene glycol monoethyl acetate, cyclohexyl acetate, 4-methyl acetate -2-pentyl ester, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, 3-methyl Butyl oxypropionate, n-butyl lactate, isopentyl lactate, diethylene glycol monoethyl ether, diisobutyl ketone (2,6-dimethyl-4-heptanone), etc.

Among them, diisobutylmethanol, propylene glycol monobutyl ether, propylene glycol diacetate, diethylene glycol diethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether, 4-hydroxy-4-methyl-2-pentane Ketone, ethylene glycol monobutyl ether, ethylene glycol monobutyl ether acetate, or diisobutyl ketone are preferred.

Ideal solvent combinations of good solvents and poor solvents include N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and ethylene glycol. Monobutyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether, N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether, N-ethyl-2-pyrrolidone and 4-hydroxy -4-Methyl-2-pentanone, N-ethyl-2-pyrrolidone and propylene glycol diacetate, N,N-dimethyllactamide and diisobutyl ketone, N-methyl-2- Pyrrolidone and ethyl 3-ethoxypropionate, N-ethyl-2-pyrrolidone and ethyl 3-ethoxypropionate, N-methyl-2-pyrrolidone and ethyl 3-ethoxypropionate and Dipropylene glycol monomethyl ether, N-ethyl-2-pyrrolidone and ethyl 3-ethoxypropionate and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone and ethyl 3-ethoxypropionate and dipropylene glycol monobutyl ether. Ethylene glycol monopropyl ether, N-ethyl-2-pyrrolidone and ethyl 3-ethoxypropionate and diethylene glycol monopropyl ether, N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether acid ester, N-ethyl-2-pyrrolidone and dipropylene glycol dimethyl ether, N,N-dimethyllactamide and ethylene glycol monobutyl ether, N,N-dimethyllactamide and propylene glycol diethyl ether Acid ester, N-ethyl-2-pyrrolidone and diethylene glycol diethyl ether, N-ethyl-2-pyrrolidone and diethylene glycol monoethyl ether and butyl cellulose threonate, N-methyl-2 -Pyrrolidone and diethylene glycol monomethyl ether and butylcellulose threonate, N,N-dimethyllactamide and diethylene glycol diethyl ether, N-methyl-2-pyrrolidone and γ-butyrate Lactone and 4-hydroxy-4-methyl-2-pentanone and diethylene glycol diethyl ether, N-ethyl-2-pyrrolidone and N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl -2-Pentanone, N-ethyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl Hydroxy-2-pentanone and diisobutyl ketone, N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and dipropylene glycol monomethyl ether, N-methyl-2-pyrrolidone With 4-hydroxy-4-methyl-2-pentanone and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and propylene glycol diacetate, N -Ethyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and dipropylene glycol dimethyl ether, γ-butyrolactone and 4-hydroxy-4-methyl-2-pentanone and diiso Butyl ketone, γ-butyrolactone and 4-hydroxy-4-methyl-2-pentanone and propylene glycol diacetate, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether and Diisobutyl ketone, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether and diisopropyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether With diisobutylcarbinol, N-methyl-2-pyrrolidone with γ-butyrolactone and dipropylene glycol dimethyl ether, N-methyl-2-pyrrolidone with propylene glycol monobutyl ether and dipropylene glycol dimethyl ether, N- Ethyl-2-pyrrolidone and propylene glycol monobutyl ether and dipropylene glycol monomethyl ether, N-ethyl-2-pyrrolidone and diethylene glycol diethyl ether and dipropylene glycol monomethyl ether, N-ethyl-2-pyrrolidone and propylene glycol Monobutyl ether and propylene glycol diacetate, N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether and diisobutyl ketone, N-ethyl-2-pyrrolidone and γ-butyrolactone and diisobutyl ketone , N-ethyl-2-pyrrolidone and N,N-dimethyllactamide and diisobutyl ketone, N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether and ethylene glycol monobutyl ether B Acid ester, γ-butyrolactone and ethylene glycol monobutyl ether acetate and dipropylene glycol dimethyl ether, N-ethyl-2-pyrrolidone and ethylene glycol monobutyl ether acetate and propylene glycol dimethyl ether, N -Methyl-2-pyrrolidone and 4-methyl-2-pentyl acetate and ethylene glycol monobutyl ether, N-ethyl-2-pyrrolidone and cyclohexyl acetate and 4-hydroxy-4-methyl-2 -Pentanone, cyclohexanone and propylene glycol monomethyl ether, cyclopentanone and propylene glycol monomethyl ether, N-methyl-2-pyrrolidone, cyclohexanone and propylene glycol monomethyl ether, etc.

(Liquid crystal alignment agent) The liquid crystal alignment agent of the present invention may also contain other components (hereinafter also referred to as additive components) in addition to the above-mentioned polymer (P), the above-mentioned other polymers, and the above-mentioned organic solvent. This additive component is, for example, selected from the group consisting of at least one substituent selected from an ethylene oxide group, a propylene oxide group, a blocked isocyanate group, an oxazoline group, a cyclic carbonate group, a hydroxyl group, and an alkoxy group. At least one crosslinking compound, a functional silane compound, a metal chelate compound, a hardening accelerator, and a surfactant from the group consisting of a crosslinking compound and a crosslinking compound having a polymerizable unsaturated group, Antioxidants, sensitizers, preservatives, compounds used to adjust the dielectric constant and resistance of the obtained liquid crystal alignment film, etc.

Preferable specific examples of the crosslinking compound include ethylene glycol diepoxypropyl ether, polyethylene glycol diepoxypropyl ether, propylene glycol diepoxypropyl ether, tripropylene glycol diepoxypropyl ether, and polypropylene glycol diepoxypropyl ether. Oxypropyl ether, neopentyl glycol diepoxypropyl ether, 1,6-hexanediol diepoxypropyl ether, glycerol diepoxypropyl ether, dibromoneopentyl glycol diepoxypropyl ether, 1,3 , 5,6-tetraepoxypropyl-2,4-hexanediol, bisphenol A-type epoxy resins such as EPIKOTE828 (manufactured by Mitsubishi Chemical Corporation), and bisphenol F-type epoxy resins such as EPIKOTE807 (manufactured by Mitsubishi Chemical Corporation) Resins, hydrogenated bisphenol A-type epoxy resins such as YX-8000 (manufactured by Mitsubishi Chemical Corporation), epoxy resins containing biphenyl skeletons such as YX6954BH30 (manufactured by Mitsubishi Chemical Corporation), and phenols such as EPPN-201 (manufactured by Nippon Kayaku Co., Ltd.) Novolak-type epoxy resin, EOCN-102S (manufactured by Nippon Chemical Co., Ltd.), etc. (ortho, meta, para) cresol novolak-type epoxy resin, TEPIC (manufactured by Nissan Chemical Co., Ltd.), etc. Isocyanuric acid tricyclic Oxypropyl ester, CELLOXIDE2021P (manufactured by Daicel Chemical Industry Co., Ltd.) and other alicyclic epoxy resins, N,N,N',N'-tetraepoxypropyl-m-xylylenediamine, 1,3-bis( N,N-diepoxypropylaminomethyl)cyclohexane or N,N,N',N'-tetraepoxypropyl-4,4'-diaminodiphenylmethane containing 3 Compounds with 2 or more ethylene oxide groups such as compounds with nitrogen atoms, 4(glycidoxymethyl)methane, etc.; Paragraphs [0170]~[0175] of WO2011/132751 describe compounds with 2 The above propylene oxide based compounds; CORONATEAP Stable M, CORONATE2503, 2515, 2507, 2513, 2555, MILLIONATEMS-50 (the above are manufactured by Tosoh Corporation), TAKENATEB-830, B-815N, B-820NSU, B-842N , B-846N, B-870N, B-874N, B-882N (the above are manufactured by Mitsui Chemicals Co., Ltd.) and other compounds with blocked isocyanate groups; such as 2,2'-bis(2-tetrazoline), 2, 2'-bis(4-methyl-2-tetrazoline), 2,2'-bis(5-methyl-2-tetrazoline), 1,2,4-bis(2-tetrazolinyl) -2) Compounds having a tetrazoline group of benzene and EPOCROS (manufactured by Nippon Shokubai Co., Ltd.); compounds having a cyclic carbonate group described in paragraphs [0025] to [0030] and [0032] of WO2011/155577 ;N,N,N',N'-4(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 with hydroxyl and alkoxy groups; glycerol mono(meth)acrylate, glyceryl di(meth)acrylate (1,2-, 1,3-body mixture), Glyceryl ginseng (meth)acrylate, glyceryl 1,3-diglyceryl di(meth)acrylate, pentaerythritol tri(meth)acrylate, diethylene glycol mono(meth)acrylate, triethylene glycol Compounds represented by mono(meth)acrylate, tetraethylene glycol mono(meth)acrylate, pentaethylene glycol mono(meth)acrylate, and hexaethylene glycol mono(meth)acrylate. The content of the above-mentioned cross-linking compound is preferably 0.1 to 30 parts by mass, and more preferably 0.1 to 20 parts by mass relative to 100 parts by mass of the polymer component contained in the liquid crystal alignment agent.

Examples of the above-mentioned compounds for adjusting the dielectric constant and resistance include monoamines having an aromatic heterocyclic ring containing a nitrogen atom, such as 3-pyridylmethylamine. The content of the monoamine having an aromatic heterocyclic ring containing nitrogen atoms is preferably 0.1 to 30 parts by mass, and more preferably 0.1 to 20 parts by mass relative to 100 parts by mass of the polymer component contained in the liquid crystal alignment agent.

Preferable specific examples of the functional silane compound include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyldiethoxymethylsilane, 2 -Aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-amine Ethyl)-3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, vinyltrimethoxysilane, ethylene Triethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyloxysilane Propyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3- Methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3 -Methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, gins[3-(trimethoxysilyl)propyl]isocyanurate, 3- Mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-isocyanatepropyltriethoxysilane, etc. The content of the functional silane compound is preferably 0.1 to 30 parts by mass relative to 100 parts by mass of the polymer component contained in the liquid crystal alignment agent, and more preferably is 0.1 to 20 parts by mass.

The solid component concentration in the liquid crystal alignment agent (the ratio of the total mass of components other than the solvent of the liquid crystal alignment agent to the total mass of the liquid crystal alignment agent) can be appropriately selected considering viscosity, volatility, etc., preferably 1 to 10 mass %. The particularly ideal range of solid content concentration varies depending on the method used when coating the liquid crystal alignment agent on the substrate. For example, when using the spin coating method, the solid content concentration is particularly preferably 1.5 to 4.5% by mass. When using the printing method, the solid content concentration is 3~9% by mass, so that the solution viscosity is 12~50mPa·s. When using the inkjet method, the solid content concentration is 1~5% by mass, so that the solution viscosity is 3~15mPa·s. The temperature when preparing the liquid crystal alignment agent is preferably 10~50°C, and more preferably 20~30°C.

(Liquid crystal alignment film and liquid crystal display components) The liquid crystal display element of the present invention includes a liquid crystal alignment film formed using the above-mentioned liquid crystal alignment agent. There are no special restrictions on the operation mode of the liquid crystal display element. It can adopt, for example: TN mode, STN mode, vertical alignment mode (including VA-MVA mode, VA-PVA mode, etc.), in-plane switching mode (IPS mode, FFS mode), Various operation modes such as optical compensation bending method (OCB method).

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

<Step (1): Coating the liquid crystal alignment agent on the substrate> Step (1) is the step of coating the liquid crystal alignment agent on the substrate. Specific examples of step (1) are as follows. On one side of the substrate provided with the patterned transparent conductive film, the liquid crystal alignment agent is coated using an appropriate coating method such as roller coating, spin coating, printing, inkjet, or spray coating. Here, the material of the substrate is not particularly limited as long as it is a highly transparent substrate, and glass, silicon nitride, plastics such as acrylic and polycarbonate can be used together. In addition, in a reflective liquid crystal display element, if it is only a single-sided substrate, an opaque object such as a silicon wafer can also be used. In this case, the electrode can also use a material that reflects light, such as aluminum. In addition, when manufacturing an IPS-type or FFS-type liquid crystal display element, a substrate provided with electrodes composed of a transparent conductive film or a metal film patterned in a comb-tooth shape and a counter substrate without electrodes are used. The IPS substrate, which is a comb-tooth electrode substrate used in an IPS-type liquid crystal display element, has, for example: a base material; a plurality of linear electrodes formed on the base material and arranged in a comb-tooth shape; and a coated linear electrode on the base material. Liquid crystal alignment film formed by electrodes. Furthermore, the FFS substrate, which is a comb electrode substrate used in an FFS liquid crystal display element, has, for example: a base material; a surface electrode formed on the base material; an insulating film formed on the surface electrode; and A plurality of linear electrodes arranged in a comb-tooth shape; and a liquid crystal alignment film formed on the insulating film to cover the linear electrodes.

More preferred examples of methods for coating the liquid crystal alignment agent on a substrate and forming a film include printing methods such as screen printing, offset printing, or flexographic printing, spin coating methods, inkjet methods, or spray coating methods. Among them, coating and film-forming methods using flexographic printing, spin coating, or inkjet are ideally used.

<Step (2): Calcining the coated liquid crystal alignment agent> Step (2) is a step of calcining the liquid crystal alignment agent coated on the substrate to form a film. Specific examples of step (2) are as follows. After the liquid crystal alignment agent is coated on the substrate in step (1), the solvent can be evaporated by heating means such as a hot plate, a thermal cycle oven or an IR (infrared) oven, or polyamide represented by polyamide can be processed. Thermal imidization of imine precursors. The drying and calcining steps after coating the liquid crystal alignment agent can be carried out at any temperature and time, or multiple times. The temperature for calcining the liquid crystal alignment agent can be, for example, 40 to 180°C. Considering the shortening of the treatment, it can also be carried out at 40~150℃. The calcination time is not particularly limited and can be 1 to 10 minutes or 1 to 5 minutes. When performing thermal imidization of a polyimide precursor represented by polyamide acid, a step of calcining at 150 to 300°C or 150 to 250°C may be added after the above step. The calcination time is not particularly limited, for example, 5 to 40 minutes, preferably 5 to 30 minutes. If the film thickness of the calcined film is too thin, the reliability of the liquid crystal display element may be reduced. Therefore, 5 to 300 nm is ideal, and 10 to 200 nm is more ideal.

＜Step (3): The step of aligning the film obtained in step (2)＞ Step (3) is to perform an alignment treatment step on the film obtained in step (2) depending on the situation. That is, in a horizontally aligned liquid crystal display element such as an IPS method or an FFS method, the coating film is subjected to an alignment capability imparting process. On the other hand, in vertical alignment liquid crystal display elements such as the VA method or the PSA (Polymer Sustained Alignment) method, the formed coating film can be directly used as a liquid crystal alignment film, or the coating film can be subjected to an alignment capability imparting process. Alignment treatment methods for liquid crystal alignment films include rubbing alignment treatment and photo alignment treatment. The photo-alignment treatment method includes a method of irradiating the surface of the film-like object with radiation polarized in a certain direction, and optionally performing a heat treatment to impart liquid crystal alignment properties (also called liquid crystal alignment ability). As for radiation, ultraviolet or visible light with a wavelength of 100 to 800 nm can also be used. Among them, ultraviolet rays having a wavelength of 100 to 400 nm are preferred, and ultraviolet rays having a wavelength of 200 to 400 nm are more preferred.

The ideal exposure dose of the above-mentioned radiation is 1~10,000mJ/ ^cm2 , and 100~5,000mJ/ ^cm2 is more ideal. In addition, when irradiating radiation, in order to improve the alignment of the liquid crystal, the substrate with the film-like object may be heated at 50 to 250°C while irradiating. The above-mentioned liquid crystal alignment film produced in this way can stabilize the alignment of liquid crystal molecules in a certain direction.

Furthermore, the coating film irradiated with polarized radiation in the above method or the coating film subjected to rubbing alignment treatment may be subjected to contact treatment using water or a solvent. In addition, the film that has been subjected to the above-mentioned alignment treatment may be heat treated without being subjected to contact treatment. Furthermore, the film subjected to the contact treatment may be further subjected to heat treatment.

The solvent used in the above-mentioned contact treatment is not particularly limited as long as it can dissolve decomposition products generated from the film-like substance due to radiation irradiation. Specific examples include water, methanol, ethanol, 2-propanol, acetone, methyl ethyl ketone, 1-methoxy-2-propanol, 1-methoxy-2-propanol acetate, butyl cellulose, Ethyl lactate, methyl lactate, diacetone alcohol, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propyl acetate, butyl acetate, cyclohexyl acetate, etc. The solvent may be one type or a combination of two or more types.

The temperature for heat treatment of the above-mentioned coating film irradiated by radiation is preferably 50 to 300°C, and even more preferably 120 to 250°C. It is better to set the heating treatment time to 1 to 30 minutes.

＜Step (4): Steps to make liquid crystal cells＞ Prepare two substrates on which the liquid crystal alignment film is formed as described above, and arrange the liquid crystal between the two substrates facing each other. Specifically, the following two methods can be cited. The first method is to first arrange two substrates facing each other with a gap (cell gap) in such a way that the liquid crystal alignment films face each other. Next, a sealant is used to bond the peripheral parts of the two substrates, and the liquid crystal composition is injected and filled into the unit cell gap separated by the substrate surface and the sealant and contacts the film surface, and then the injection hole is sealed. The above-mentioned liquid crystal composition is not particularly limited, and various liquid crystal compositions containing at least one liquid crystal compound (liquid crystal molecule) and having a positive or negative dielectric anisotropy can be used. In the following, a liquid crystal composition having a positive dielectric anisotropy is also called a positive-type liquid crystal, and a liquid crystal composition having a negative dielectric anisotropy is called a negative-type liquid crystal. The above-mentioned liquid crystal composition may also contain fluorine atoms, hydroxyl groups, amine groups, groups containing fluorine atoms (for example: trifluoromethyl), cyano groups, alkyl groups, alkoxy groups, alkenyl groups, and isothiocyanate groups. , liquid crystal compounds of heterocyclic rings, cycloalkanes, cycloalkenes, steroid skeletons, benzene rings, or naphthalene rings, and may also contain compounds with more than two rigid parts (mesogen skeleton) exhibiting liquid crystallinity in the molecule (for example, rigid Two biphenyl structures, or a double mesogen compound formed by connecting a terphenyl structure with an alkyl group, etc.). The liquid crystal composition may be a liquid crystal composition in a nematic phase, a liquid crystal composition in a smectic phase, or a liquid crystal composition in a cholesteric phase. In addition, in the above-mentioned liquid crystal composition, additives may be further added from the viewpoint of improving liquid crystal alignment. Such additives include photopolymerizable monomers such as compounds having a polymerizable group (methacrylyl group, etc.); optically active compounds (for example: S-811 manufactured by Merck & Co., Ltd., etc.); antioxidants; UV absorbers; pigments; defoaming agents; polymerization initiators; or polymerization inhibitors, etc. Examples of positive type liquid crystals include ZLI-2293, ZLI-4792, MLC-2003, MLC-2041, MLC-3019 or MLC-7081 manufactured by Merck. Negative liquid crystal, such as MLC-6608, MLC-6609, MLC-6610, MLC-6882, MLC-6886, MLC-7026, MLC-7026-000, MLC-7026-100, or MLC-7029 manufactured by Merck wait. In addition, in the PSA mode, an example of the liquid crystal containing a compound having a polymerizable group is MLC-3023 manufactured by Merck.

Furthermore, the second method is a method called ODF (One Drop Fill) method. Apply a UV-curable sealant, for example, to a predetermined location on one of the two substrates on which the liquid crystal alignment film has been formed, and then drop the liquid crystal composition onto a predetermined number of locations on the surface of the liquid crystal alignment film. After that, another substrate is bonded with the liquid crystal alignment film facing each other, and then the liquid crystal composition is pressed on the entire surface of the substrate so that it contacts the film surface. Then, the entire surface of the substrate is irradiated with ultraviolet light to harden the sealant. When proceeding according to any method, it is preferable to heat the liquid crystal composition to a temperature at which it becomes an isotropic phase and then slowly cool it to room temperature to remove the flow alignment during filling of the liquid crystal. In addition, when the coating film is subjected to rubbing treatment, the two substrates are arranged facing each other so that the rubbing directions in each coating film are at a predetermined angle to each other, for example, at right angles or anti-parallel. As the sealant, for example, epoxy resin containing a hardener and alumina balls as spacers can be used. Examples of the liquid crystal include nematic liquid crystal and smectic liquid crystal. Among them, nematic liquid crystal is preferred.

The liquid crystal alignment agent of the present invention is preferably formed by having a liquid crystal layer between a pair of substrates equipped with electrodes, and a polymerizable compound containing a polymerizable compound polymerized by at least one of active energy rays and heat is disposed between the pair of substrates. The liquid crystal composition is a liquid crystal display element (PSA type liquid crystal display element) manufactured by a step of polymerizing a polymerizable compound using at least one of active energy ray irradiation and heating while applying a voltage between electrodes. In addition, the liquid crystal alignment agent of the present invention is preferably formed by having a liquid crystal layer between a pair of substrates provided with electrodes. The liquid crystal alignment agent is disposed between the pair of substrates and contains a polymerizable polymer that is polymerized by at least one of active energy rays and heat. Based on the liquid crystal alignment film, a liquid crystal display element (SC-PVA liquid crystal display element) is manufactured by applying a voltage between electrodes.

＜Step (4-2): PSA method liquid crystal display element＞ The procedure is carried out in the same manner as (4) above except for injecting or dropping the liquid crystal composition containing the polymerizable compound. The polymerizable compound is, for example, a polymerizable compound having at least one polymerizable unsaturated group such as an acrylate group or a methacrylate group in the molecule.

＜Step (4-3): SC-PVA liquid crystal display element＞ After performing the same procedure as in (4) above, a method of manufacturing a liquid crystal display element through ultraviolet irradiation steps described later may be used. According to this method, similarly to the production of the above-described PSA liquid crystal display element, a liquid crystal display element with excellent response speed can be obtained with a small amount of light irradiation. The compound having a polymerizable group can be a compound having at least one polymerizable unsaturated group in the molecule, and its content is preferably 0.1 to 30 parts by mass based on 100 parts by mass of all polymer components, more preferably 1 to 100 parts by mass. 20 parts by mass. In addition, the polymer used in the liquid crystal alignment agent may also have the above-mentioned polymerizable group. Such a polymer may be a polymer obtained by reacting a diamine component containing a diamine having the above-mentioned photopolymerizable group at its terminal.

<Step (4-4): Step of irradiating ultraviolet rays> The liquid crystal cell is illuminated with a voltage applied between the conductive films of the pair of substrates obtained in the above (4-2) or (4-3). The voltage applied here is, for example, 5~50V DC or AC. In addition, as the irradiation light, for example, ultraviolet rays and visible rays containing light with a wavelength of 150 to 800 nm can be used, but ultraviolet rays containing light with a wavelength of 300 to 400 nm are more preferred. As a light source for irradiating light, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, an excimer laser, etc. can be used. The amount of light irradiation is preferably 1,000~200,000J/m ² , more preferably 1,000~100,000J/m ² .

And if necessary, a liquid crystal display element can be obtained by bonding a polarizing plate to the outer surface of the liquid crystal cell. Examples of the polarizing plate attached to the outer surface of the liquid crystal cell include those in which a polarizing film called "H film" that absorbs iodine while stretching and aligning polyvinyl alcohol is sandwiched between a cellulose acetate protective film, or A polarizing plate composed of H film itself. [Example]

The following examples are given to illustrate the present invention in more detail, but the present invention is not limited to these examples. The abbreviations of the compounds used and the measurement methods of each physical property are as follows.

(solvent) NMP: N-methyl-2-pyrrolidone BCS: Ethylene glycol monobutyl ether DMF: N,N-dimethylformamide DMAc: N,N-dimethylacetamide THF: Tetrahydrofuran IPA: 2-propanol

(Tetracarboxylic dianhydride) CA-1: A compound represented by the following formula (CA-1) [Chemical 10]

(Diamine) DA-1 to DA-7: Each is a compound represented by the following formulas (DA-1) to (DA-7). The diamines contained in the specific diamine range of the present invention are compounds represented by the following formulas (DA-1), (DA-2) and (DA-7). [Chemical 11]

<Measurement of Molecular Weight> Measure using the following normal temperature GPC (gel permeation chromatography) device, and calculate Mn and Mw based on polyethylene glycol and polyethylene oxide conversion values. GPC device: GPC-101 (manufactured by Showa Denko Co., Ltd.), column: GPC KD-803, GPC KD-805 (manufactured by Showa Denko Co., Ltd.) in series, column temperature: 50°C, eluent: N, N-dimethyl Methamide (the additives are lithium bromide monohydrate (LiBr・H ₂ O) 30mmol/L, phosphoric acid・anhydrous crystal (orthophosphoric acid) 30mmol/L, tetrahydrofuran (THF) 10mL/L), flow rate: 1.0mL/sample Standard samples for measuring line production: TSK standard polyethylene oxide (molecular weight; approximately 900,000, 150,000, 100,000, and 30,000) (manufactured by Tosoh Corporation) and polyethylene glycol (molecular weight; approximately 12,000, 4,000, and 1,000) (Polymer Laboratory) Corporation).

[Synthesis of Monomers] DA-1 was purchased and used as a commercial product (manufactured by Chemieliva Pharmaceutical Co., Ltd.). DA-2 was synthesized according to the synthesis method described in Journal of Molecular Structure (2018), 1169, 46-58. DA-6 and DA-7 are new compounds that have not been disclosed in the literature. The synthesis method is described in detail below.

(Monomer synthesis example 1; synthesis of DA-6) DA-6 was synthesized according to the route shown below. [Chemical 12]

Dichloromethane (320 g) was added to 3-(4-nitrophenoxy)propan-1-ol (manufactured by Chemieliva Pharmaceutical Co., Ltd., 16.0 g, 81.1 mmol), and the mixture was dissolved and then cooled under ice-cooling. Triethylamine (12.3g, 122mmol), methanesulfonyl chloride (9.76g, 85.2mmol), and 4-dimethylaminopyridine (1.0g, 8.1mmol) were added, and the mixture was stirred at room temperature for 15 hours. reaction. Add pure water (160g) to the reaction solution, separate and recover the organic layer, separate and wash with 1N hydrochloric acid (80g) and pure water (80g) in sequence, and concentrate the organic layer to obtain DA-6-1 ( Yield 20.8g, 75.4mmol, yield 93%). [Chemical 13]

Add NMP (50g), DA-6-1 (18.9g, 68.7mmol) and potassium carbonate (10.8g, 78mmol) to 2,6-dihydroxynaphthalene (5.00g, 31.2mmol), and stir at 100°C for 18 hours. Make it react. Pure water (100g) was added to the reaction solution to precipitate crystals. The crystals obtained by separate filtration were repulped and washed with pure water, then DMF (500g) was added, completely dissolved at 100°C, and crystallized with methanol/water (1:1, volume ratio) to obtain DA. -6-2 (output 15.2g, 29.3mmol, yield 94%). [Chemical 14]

Add DMF (50g) and carbon-supported palladium (5% Pd carbon powder (50% water-containing product) K type, manufactured by NEChemcat Co., Ltd., 0.50g) to DA-6-2 (5.00g, 9.64mmol), and heat at 80°C Under a hydrogen atmosphere, stir under pressurized conditions (0.3 MPa) for 12 hours. Since crystals had precipitated, DMF (100 g) was added and the carbon-supported palladium was removed by filtration. IPA (150 g) was added to the obtained filtrate to crystallize it, thereby obtaining DA-6 (3.76 g, 8.20 mmol, yield 85%).

(Monomer synthesis example 2; synthesis of DA-7) DA-7 was synthesized according to the route shown below. [Chemical 15] In a 500mL four-necked flask, dissolve paraxylene dichloride (7.0g, 40mmol) in DMAc (140g), add 4-nitro-m-cresol (12.8g, 84mmol) and potassium carbonate (16.5g, 120mmol) , stirred at 90°C for 3 hours to react. After the reaction solution was cooled to room temperature, pure water (280 g) was added while stirring to precipitate crystals. The crystals obtained were separated and filtered, and the filter cake was washed with pure water, THF, and acetonitrile (35 g each) in order. Then, it was dried under reduced pressure at 40° C. to obtain DA-7-1 (yield: 15.5 g, 38 mmol, white solid, yield: 95%). From the ¹ H-NMR results shown below, it was confirmed that this solid was DA-7-1. ¹ H-NMR (500MHz), in DMSO-d ₆ : δ (ppm) = 8.06 (d, 2H), 7.50 (s, 4H), 7.15 (d, 2H), 7.06 (s, 2H), 5.25 (s , 4H), 2.55(s, 6H) [Chemical 16] In a nitrogen environment, add the above-obtained DA-7-1 (15.5g, 38mmol), DMF (466g), and carbon-supported platinum (3% Pt carbon powder (50% water-containing product)) into a 1L four-necked flask. Evonik Co., Ltd., 1.5 g), replaced with a hydrogen atmosphere, and stirred at 50° C. for 18 hours to react. After the reaction, the carbon-supported platinum was removed using a membrane filter, and the filtrate was concentrated. Add IPA (150g) to precipitate crystals, stir at room temperature, and then filter the crystals. The obtained crystallized filter cake was washed with IPA (75g) and dried under reduced pressure at 40°C to obtain DA-7 (yield: 10.8g, 31mmol, gray solid, yield: 81%). From the ¹ H-NMR results shown below, it was confirmed that this solid was DA-7. ¹ H-NMR (500MHz), in DMSO-d ₆ : δ (ppm) = 7.39 (4H, s), 6.66-6.51 (6H, m), 4.93 (4H, s), 4.38 (4H, s), 2.02 (6H,s)

[Synthesis of polymers] ＜Synthesis example 1＞ Add DA-3 (0.541g, 5.00mmol), DA-1 (1.60g, 5.00mmol) and NMP (15.7g) to a 50mL four-necked flask with a stirring device and a nitrogen gas inlet tube, while feeding nitrogen into the chamber. Stir warm to dissolve. Then, CA-1 (2.15g, 9.60mmol) and NMP (15.8g) were added, and the mixture was stirred at 40°C for 24 hours to obtain a polyamide (PAA-1) solution with a solid content concentration of 12% by mass. The Mn of this polyamide is 13,500 and the Mw is 39,800.

＜Synthesis example 2＞ Add DA-3 (0.541g, 5.00mmol), DA-2 (1.98g, 5.00mmol) and NMP (18.5g) to a 50mL four-necked flask with a stirring device and a nitrogen gas introduction tube, while feeding nitrogen into the chamber. Stir warm to dissolve. Then, CA-1 (2.15g, 9.60mmol) and NMP (15.8g) were added, and the mixture was stirred at 40°C for 24 hours to obtain a polyamide (PAA-2) solution with a solid content concentration of 12% by mass. The Mn of this polyamide is 14,600 and the Mw is 45,600.

＜Synthesis Example 3＞ Add DA-3 (0.541g, 5.00mmol), DA-4 (1.46g, 5.00mmol) and NMP (14.7g) to a 50mL four-necked flask with a stirring device and a nitrogen inlet tube, while feeding nitrogen into the chamber. Stir warm to dissolve. Then, CA-1 (2.15g, 9.60mmol) and NMP (15.8g) were added, and the mixture was stirred at 40°C for 24 hours to obtain a polyamide (PAA-3) solution with a solid content concentration of 12% by mass. The Mn of this polyamide is 10,900 and the Mw is 29,700.

＜Synthesis Example 4＞ Add DA-3 (0.541g, 5.00mmol), DA-5 (1.22g, 5.00mmol) and NMP (12.9g) to a 50mL four-necked flask with a stirring device and a nitrogen gas inlet tube, while feeding nitrogen into the chamber. Stir warm to dissolve. Then, CA-1 (2.12g, 9.45mmol) and NMP (15.5g) were added, and the mixture was stirred at 40°C for 24 hours to obtain a polyamide (PAA-4) solution with a solid content concentration of 12% by mass. The Mn of this polyamide is 11,200 and the Mw is 28,500.

＜Synthesis Example 5＞ Add DA-3 (0.541g, 5.00mmol), DA-6 (2.29g, 5.00mmol) and NMP (20.8g) to a 50mL four-necked flask with a stirring device and a nitrogen inlet tube, while feeding nitrogen into the chamber. Stir warm to dissolve. Then, CA-1 (2.15g, 9.60mmol) and NMP (15.8g) were added, and the mixture was stirred at 40°C for 24 hours to obtain a polyamide (PAA-5) solution with a solid content concentration of 12% by mass. The Mn of this polyamide is 18,400 and the Mw is 139,800.

＜Synthesis example 6＞ Add DA-3 (0.541g, 5.00mmol), DA-7 (1.74g, 5.00mmol) and NMP (16.7g) to a 50mL four-necked flask with a stirring device and a nitrogen gas introduction tube, while feeding nitrogen into the chamber. Stir warm to dissolve. Then, CA-1 (2.13g, 9.49mmol) and NMP (15.6g) were added, and the mixture was stirred at 40°C for 24 hours to obtain a polyamide (PAA-6) solution with a solid content concentration of 12% by mass. The Mn of this polyamide is 11,900 and the Mw is 30,400.

The specifications of the polyamic acid solution obtained in the above synthesis example are shown in Table 1. In Table 1, the numerical values in parentheses for the tetracarboxylic acid component and the diamine component represent the usage amounts of each tetracarboxylic acid component and each diamine component based on 100 mole parts of the total amount of the diamine components used in each polymerization step. (Moerfen).

[Table 1]

[Preparation of liquid crystal alignment agent] <Example 1> Add NMP (14.0g) and BCS (6.00g) to the polyamide (PAA-1) solution (10.0g) obtained in Synthesis Example 1 above, and stir at room temperature for 30 minutes to obtain a liquid crystal alignment agent (AL -1). <Examples 2 to 3, Comparative Examples 1 to 3> The polyamide solution used was changed from (PAA-1) to (PAA-2)~(PAA-6). Otherwise, the same procedure as in Example 1 was performed to obtain the liquid crystal alignment agent (AL-2)~( AL-6).

The specifications of the liquid crystal alignment agents obtained in the above examples and comparative examples are shown in Table 2.

[Table 2]

The liquid crystal alignment agents (AL-1) ~ (AL-6) obtained as above had no abnormalities such as turbidity or precipitation, and were confirmed to be homogeneous solutions. Using the obtained liquid crystal alignment agent, the in-plane uniformity of the contrast and the evaluation of the water contact angle were evaluated.

[Preparation of liquid crystal cell] Use the liquid crystal alignment agent obtained above to produce a liquid crystal cell according to the procedures shown below. The liquid crystal alignment agent was filtered through a filter with a pore size of 1.0 μm, and then coated on a glass substrate with an ITO electrode (length 40 mm × width 30 mm × thickness 0.7 mm) by spin coating, and dried on a hot plate at 80°C for 60 seconds. , calcined in an infrared heating furnace at 230°C for 20 minutes to form a liquid crystal alignment film with a film thickness of 100nm. The coating surface is irradiated with linearly polarized ultraviolet rays of 254nm wavelength 400mJ/ ^cm2 or 600mJ/ ^cm2 or 800mJ/ ^cm2 with an extinction ratio of 26:1 through a polarizing plate, and is subjected to alignment treatment. Then, it is calcined in an infrared heating furnace at 230° C. for 30 minutes to obtain a substrate with a liquid crystal alignment film (first glass substrate). Except that the alignment process is performed so that the alignment direction is perpendicular to the first glass substrate, the substrate with the liquid crystal alignment film (the second glass substrate) is obtained in the same manner as above. The above two substrates were used as a set, and a bead spacer with a diameter of 4 μm (manufactured by Nichiwa Catalyst Chemical Co., Ltd., silk ball, SW-D1) was coated on one liquid crystal alignment film, leaving the liquid crystal injection port and printing around it. Sealing agent (XN-1500T manufactured by Mitsui Chemicals Co., Ltd.) and bonded to another substrate so that the alignment direction facing the liquid crystal alignment film surface becomes 0°. Then, heat treatment is performed at 150°C for 60 minutes to harden the sealant and form a hollow cell. In this empty cell, liquid crystal MLC-3019 (manufactured by Merck & Co.) was injected using 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 then used for evaluation.

[Evaluation of in-plane uniformity of contrast] The variation of the twist angle of the liquid crystal cell was evaluated using AxoStep manufactured by AXOMETRICS. The liquid crystal cell prepared above was placed on a measurement stand, and the distribution of circular retardance (Circular Retardance) in the pixel plane was measured in a state where no voltage was applied, and three times 3σ of the standard deviation σ were calculated. Regarding in-plane uniformity, the smaller the value of 3σ, the better it is. Regarding the evaluation criteria, if each of the above 3σ values is 3.00 or less, it will be rated as "○", if it is greater than 3.00 and 5.00 or less, it will be rated as "△", and if it is greater than 5.00, it will be rated as "×". The results are shown in Table 3.

[Evaluation of Water Contact Angle] Each of the liquid crystal alignment agents obtained above was filtered through a filter with a pore size of 1.0 μm, and then coated on a glass substrate with an ITO electrode (length 40 mm × width 30 mm × thickness 1.1 mm) by spin coating, and dried at 80 After drying for 60 seconds on a hot plate at 230°C, it was calcined in an infrared heating furnace at 230°C for 20 minutes to form a liquid crystal alignment film with a film thickness of 100nm. The coating surface was irradiated with 500mJ/cm ² of linearly polarized ultraviolet light with an extinction ratio of 26:1 and a wavelength of 254nm through a polarizing plate, and then calcined in an infrared heating furnace at 230°C for 30 minutes to obtain a substrate with a liquid crystal alignment film. For this substrate, the water contact angle was measured using a fully automatic contact angle meter (DM-701, manufactured by Kyowa Interface Science Co., Ltd.). In terms of evaluation criteria, when the water contact angle is larger than 50°, it is rated as "○", and when it is less than 50°, it is rated as "×". The results are shown in Table 3.

[table 3]

As shown in Table 3, the liquid crystal alignment films obtained by using the liquid crystal alignment agents (AL-1), (AL-2) and (AL-6) of Examples 1 to 3 are better than those obtained using the liquid crystal alignment agents of Comparative Examples 1 to 3. The liquid crystal alignment film obtained by using agents (AL-3) ~ (AL-5) shows good in-plane uniformity and high water contact angle in a wide exposure range. [Industrial Applicability]

The liquid crystal alignment film obtained from the liquid crystal alignment agent of the present invention is widely used in liquid crystal display elements in various operation modes. It can also be used as, for example, a liquid crystal alignment film for phase difference films, a liquid crystal alignment film for scanning antennas, liquid crystal array antennas, or transmission films. Liquid crystal alignment film is used for scattering type liquid crystal dimming components.

The liquid crystal display element of the present invention can be effectively applied to devices with various functions, such as LCD televisions, watches, portable game consoles, word processors, notebook personal computers, navigation systems, video cameras, PDAs, digital cameras, etc. Cameras, mobile phones, smart phones, various screens, information displays, etc.

In addition, the entire contents of the specification, patent scope, drawings and abstract of Japanese Patent Application No. 2021-177004 filed on October 28, 2021, and Japanese Patent Application No. 2021 filed on November 22, 2021 are hereby quoted. The entire contents of the specification, patent application scope, drawings and abstract of No. 189679 shall be cited as the disclosure content of the specification of the present invention.

Claims (11)

A liquid crystal alignment agent characterized by containing a polymer (P) selected from a polyimide precursor obtained by using a diamine component containing a diamine (0) represented by the following formula ( _DA ) At least one of the group consisting of a polyimide and an imide of the polyimide precursor, bonded to the amine group and the linking group (-O) of the benzene ring of the formula (D _A ) -) The bonding positions are 1 and 4,

Ar is selected from 1,4-phenylene, 1,3-phenylene, 2-methyl-1,4-phenylene, 2-ethyl-1,4-phenylene, and 2-propyl -1,4-phenylene, 2-isopropyl-1,4-phenylene, 2-methoxy-1,4-phenylene, 2-ethoxy-1,4-phenylene , 2-propoxy-1,4-phenylene, 2-fluoro-1,4-phenylene, 2,3-dimethyl-1,4-phenylene, 4-methyl-1, 3-phenylene, 5-methyl-1,3-phenylene, 4-fluoro-1,3-phenylene, 2,3,5,6-tetramethyl-1,4-phenylene , biphenyl-4,4'-diyl, 2-methylbiphenyl-4,4'-diyl, 2-ethylbiphenyl-4,4'-diyl, 2-propylbiphenyl-4 ,4'-diyl, 2-methoxybiphenyl-4,4'-diyl, 2-ethoxybiphenyl-4,4'-diyl, 2-fluorobiphenyl-4,4'- Diyl, 3-methylbiphenyl-4,4'-diyl, 3-ethylbiphenyl-4,4'-diyl, 3-propylbiphenyl-4,4'-diyl, 3- Methoxybiphenyl-4,4'-diyl, 3-ethoxybiphenyl-4,4'-diyl, 3-fluorobiphenyl-4,4'-diyl, 2,2'-diyl Methylbiphenyl-4,4'-diyl, 3,3'-dimethylbiphenyl-4,4'-diyl, biphenyl-3,3'-diyl, 5-methylbiphenyl- 3,3'-diyl, 5,5'-dimethylbiphenyl-3,3'-diyl, 1,5-naphthylene, 2,6-naphthyl, or 1-methyl-2 , 6-naphthylene, m and n are each independently an integer from 1 to 3, and any hydrogen atom on the benzene ring bonded to the amine groups at both ends can also be substituted by a 1-valent group. Such as the liquid crystal alignment agent of claim 1, wherein the diamine (0) is any diamine selected from the group consisting of the following formulas (d _A -1) ~ (d _A -3),

In the formulas (d _A -1) to (d _A -3), the benzene ring bonded by the amine groups at both ends, the benzene ring bonded by the alkylene group, the biphenyl structure, or any hydrogen atom on the naphthalene ring It may also be substituted by a monovalent group, and m and n are each independently as defined above. Such as the liquid crystal alignment agent of claim 1 or 2, wherein at least one hydrogen atom on the benzene ring to which the amine groups at both ends are bonded is replaced by a halogen atom, an alkyl group with 1 to 3 carbon atoms, or an alkyl group with 1 to 3 carbon atoms. Substituted with an alkoxy group, a fluoroalkyl group with 1 to 3 carbon atoms, or a fluoroalkoxy group with 1 to 3 carbon atoms. For example, the liquid crystal alignment agent of claim 1 or 2, the polymer (P) has a group selected from the group consisting of a repeating unit (p1) represented by the following formula (1) and an imidized structural unit of the repeating unit (p1). A polymer of at least 1 repeating unit of the group,

In the formula (1), X ₁ represents a 4-valent organic group, Y ₁ is a divalent organic group obtained by removing two amine groups from the diamine (0) represented by the formula (D _A ), and R and Z are each independently Represents a hydrogen atom or a monovalent organic group. The liquid crystal alignment agent of claim 1 or 2, wherein the polymer (P) utilizes the diamine component and contains non-cyclic aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, aromatic It is obtained by the polycondensation reaction of the tetracarboxylic acid component of tetracarboxylic dianhydride or its derivatives. For the liquid crystal alignment agent of claim 1 or 2, the usage amount of the diamine (0) is more than 5 mol% relative to the diamine component. A liquid crystal alignment film is obtained from the liquid crystal alignment agent according to any one of claims 1 to 6. A liquid crystal display element provided with the liquid crystal alignment film of claim 7. A method for manufacturing a liquid crystal display element, including the following steps (1) to (3). Step (1): Coating the liquid crystal alignment agent according to any one of claims 1 to 6 on the substrate, step (2): The coated liquid crystal alignment agent is calcined to obtain a film. Step (3): Perform alignment treatment on the film obtained in step (2). As claimed in claim 9, the method for manufacturing a liquid crystal display element, wherein the alignment treatment is a photo-alignment treatment. A diamine represented by the following formula DA-7,