WO2023286735A1

WO2023286735A1 - Liquid crystal alignment agent, liquid crystal alignment film, liquid crystal display element production method, and liquid crystal display element

Info

Publication number: WO2023286735A1
Application number: PCT/JP2022/027256
Authority: WO
Inventors: 崇仲井; 幸司巴; 功一朗別府
Original assignee: 日産化学株式会社
Priority date: 2021-07-12
Filing date: 2022-07-11
Publication date: 2023-01-19
Also published as: JPWO2023286735A1; KR20240032874A; TW202321427A

Abstract

Provided is a liquid crystal alignment agent that is used to obtain a liquid crystal alignment film having excellent resistance to AC image persistence, low pre-tilt angle characteristics, and a high voltage holding rate.　This liquid crystal alignment agent is characterized by containing component (A) and component (B). Component (A): At least one polymer (A) selected from the group consisting of polyimide precursors having at least 60 mol% of a repeating unit represented by formula (1) with respect to 1 mol of all repeating units in the polymer, and polyimides that are imidized products of the polyimide precursors. Component (B): At least one polymer (B) selected from the group consisting of: polyimide precursors that are each a reaction product between a tetracarbonic acid derivative component containing at least 5 mol% of a tetracarboxylic dianhydride represented by formula (T_f) with respect to the all tetracarbonic acid derivative components, and a diamine component containing a diamine represented by formula (d_n); and polyimides that are imidized products of the polyimide precursors. (In the formulae, the definition of each symbol is as described in the description.)

Description

Liquid crystal alignment agent, liquid crystal alignment film, method for manufacturing liquid crystal display element, and liquid crystal display element

The present invention relates to a liquid crystal aligning agent, a liquid crystal aligning film, a method for manufacturing a liquid crystal display element, and a liquid crystal display element.

Liquid crystal display elements used in liquid crystal televisions, navigators, smartphones, etc. usually have a liquid crystal alignment film inside the element to control the alignment state of liquid crystals. A liquid crystal alignment film has a function of controlling the alignment of liquid crystal molecules in a certain direction in a liquid crystal display element. For example, a liquid crystal display element has a structure in which liquid crystal molecules forming a liquid crystal layer are sandwiched between liquid crystal alignment films formed on respective surfaces of a pair of substrates. There, the liquid crystal molecules are aligned in a certain direction by the liquid crystal alignment film and respond by applying a voltage to the electrodes provided between the substrate and the liquid crystal alignment film. As a result, the liquid crystal display element displays a desired image by utilizing the alignment change due to the response of the liquid crystal molecules. Until now, liquid crystal alignment films have mainly been polyimide-based liquid crystal alignment films, which are obtained by applying a liquid crystal alignment agent whose main component is a polyimide precursor such as polyamic acid (polyamic acid) or a solution of soluble polyimide to a glass substrate or the like and baking it. used.

In recent years, as the performance of liquid crystal display elements has improved, in addition to applications such as large-screen, high-definition liquid crystal televisions, in-vehicle applications (e.g., car navigation systems and meter panels), monitoring cameras and medical camera monitors, etc. In view of the demand for viewing angle characteristics, lateral electric field systems such as IPS (In Plane Switching) and FFS (Fringe Field Switching) are being studied (Patent Documents 1 and 2). ).

WO2017-061575 WO2020-116585

The liquid crystal alignment film used in the IPS drive system and FFS drive system liquid crystal display elements requires an alignment regulating force for suppressing afterimages (hereinafter also referred to as AC afterimages) generated by long-term AC driving. In the liquid crystal display elements, which are rapidly becoming higher in definition, backlights with higher brightness than before are being applied, and the specifications for display defects such as "afterimages" are becoming more and more severe. It's becoming

Patent Document 1 describes a liquid crystal alignment film for photo-alignment suitable for liquid crystal display elements of the IPS drive system and the FFS drive system.

Further, Patent Document 2 describes that a liquid crystal alignment film obtained from a liquid crystal alignment agent containing two kinds of polyamic acids has high resistance to AC afterimages.
On the other hand, liquid crystal display elements used for the above applications are required to have a lower pretilt angle than conventional ones due to the demand for viewing angle characteristics. was found to be insufficient.
Furthermore, it is one of the required characteristics for the liquid crystal display element to exhibit a voltage holding ratio higher than that of the conventional one by applying the above-mentioned high-brightness backlight. If the voltage holding ratio is low, display defects such as image burn-in (image burn-in of divisions and lines), unevenness, and staining that occur over time due to external stimuli such as light and temperature will occur.

In view of the above, the present invention provides a liquid crystal aligning agent, the liquid crystal alignment film, and the liquid crystal alignment film that provide a liquid crystal alignment film having excellent resistance to AC afterimages, low pretilt angle characteristics, and high voltage holding ratio. An object of the present invention is to provide a liquid crystal display element having

As a result of intensive research to achieve the above objects, the present inventors, by forming a liquid crystal aligning film using a liquid crystal aligning agent containing a specific polymer component, to achieve the above objects It was found to be effective, and the present invention was completed.

The present invention is based on such findings, and has the following gist.

A liquid crystal aligning agent characterized by containing the following (A) component and (B) component.
(A) component: a polyimide precursor having 60 mol% or more of repeating units represented by the following formula (1) with respect to 1 mol of all repeating units in the polymer and a polyimide that is an imidized product of the polyimide precursor At least one polymer (A) selected from the group consisting of;
(B) component: a tetracarboxylic acid derivative component containing 5 mol% or more of the total tetracarboxylic acid derivative component of a tetracarboxylic dianhydride represented by the following formula (T _f ), and a tetracarboxylic acid derivative component represented by the following formula (d _n ) At least one polymer (B) selected from the group consisting of a polyimide precursor that is a reactant with a diamine component containing a diamine, and a polyimide that is an imidized product of the polyimide precursor.

(R ₁₁ to R ₁₄ each independently contain a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, a fluorine atom represents a monovalent organic group having 1 to 6 carbon atoms or a phenyl group, at least one of R ₁₁ to R ₁₄ represents a group other than a hydrogen atom as defined above, and Ar ₁ and Ar _1' each represent: represents a benzene ring, and one or more hydrogen atoms on the benzene ring may be substituted with a monovalent group.L ₁ and L _1′ are each a single bond, —O—, —C (=O )-, -O-C(=O)-, where A is an alkylene group having 5 to 12 carbon atoms, or between the carbon-carbon bonds of the alkylene group, -O- or -C(=O) Represents a divalent organic group (Qa) in which any group of —O— is inserted, provided that when L ₁ and L _1′ represent a single bond, A is a divalent organic group (Qa) and each of R ₁ and Z ₁ independently represents a hydrogen atom or a monovalent organic group having 1 to 5 carbon atoms, and the two R ₁ and Z ₁ may be the same or different.)

(X _f is a tetravalent organic group having a 5-membered or more alicyclic structure.)

(Y represents a nitrogen atom-containing heterocyclic ring and a group "*21-NR-*22" (*21 and *22 represent a bond that binds to a carbon atom constituting an aromatic ring, provided that the carbon atom does not form a ring with the nitrogen atom to which R is bonded.R represents a hydrogen atom or a monovalent organic group, and the above monovalent organic group is bonded to the nitrogen atom at a carbon atom other than the carbonyl carbon. represents a divalent organic group having a nitrogen atom-containing structure selected from the group consisting of amino groups.)
Throughout this specification, the following terms and abbreviations have the following meanings. A halogen atom is a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc., preferably a fluorine atom. * represents a bond. Boc represents a tert-butoxycarbonyl group.

According to the liquid crystal aligning agent of the present invention, it is possible to obtain a liquid crystal aligning agent having excellent resistance to AC afterimages, low pretilt angle characteristics, and a high voltage holding ratio. Further, a liquid crystal display element having the liquid crystal alignment film has excellent viewing angle characteristics and high display quality.

Although the mechanism by which the above effects of the present invention are obtained is not necessarily clear, it is estimated as follows. That is, two types of polymers (polymer (A) and polymer (B)) are used as the polymer component used in the liquid crystal aligning agent, and a repeating unit constituting one polymer (polymer (A)) However, by having a diamine-derived structure having a specific alkylene chain length, the uneven distribution on the surface of the polymer (A) can be enhanced. Further, in the diamine having the alkylene chain length, the benzene rings are present at a certain distance from each other, so that the glass transition temperature of the polymer (A) can be lowered. Then, when the polyimide film is subjected to a rubbing alignment treatment, the stretchability of the polyimide increases, and the uniformity of the pretilt angle of the liquid crystal in the film increases, so it is thought that the pretilt angle of the liquid crystal decreases.

1 is a schematic cross-sectional view showing an example of a lateral electric field liquid crystal display device of the present invention; FIG. FIG. 4 is a schematic cross-sectional view showing another example of the horizontal electric field liquid crystal display device of the present invention;

Below, each component contained in the liquid crystal aligning agent of this indication, and the other component arbitrarily mix|blended as needed are demonstrated.
Polymers (A) and (B) contained in the liquid crystal aligning agent of the present invention are polyimide precursors obtained using a tetracarboxylic acid derivative component and a diamine component, or polyimides that are imidized products of the polyimide precursors. be. Here, the polyimide precursor is a polymer from which a polyimide can be obtained by imidating polyamic acid, polyamic acid ester, or the like.

Polymers (A) and (B) are more preferably polyimide precursors, and still more preferably polyamic acids, from the viewpoint of suitably obtaining the effects of the present invention. When the polymer (A) is a polyamic acid, the polymer (A) has a repeating unit represented by formula (1) in which _R1 is a hydrogen atom. Moreover, when the polymer (A) is a polyamic acid ester, the polymer (A) has a repeating unit represented by formula (1) in which at least one of R ₁ is a group other than a hydrogen atom.
<Polymer (A)>
The liquid crystal aligning agent of the present invention is a polyimide precursor having 60 mol% or more of repeating units represented by the above formula (1) with respect to 1 mol of all repeating units in the polymer (A), and the polyimide precursor It contains at least one polymer (A) selected from the group consisting of polyimides which are imidized products. The polymer (A) contains the substituted cyclobutane skeleton, thereby defining the conformation upon imidization. Therefore, since the obtained polymer (A) has high stereoregularity, a liquid crystal alignment film having excellent resistance to AC afterimages can be obtained. In addition, since the above-mentioned substituted cyclobutane skeleton has a substituted structure, the probability that the polymer (A) component having high liquid crystal orientation is unevenly distributed in the surface layer is increased, and the effects of the present invention can be preferably obtained. Conceivable. The repeating unit represented by formula (1) may be of one type or two or more types.
Examples of monovalent organic groups for R ₁ and Z ₁ in the above formula (1) include alkyl groups such as methyl group, ethyl group and propyl group; alkenyl groups such as vinyl group; , ethoxy group) and the like. R ₁ and Z ₁ are preferably hydrogen atoms or methyl groups.
Specific examples of alkyl groups having 1 to 6 carbon atoms, preferably 1 to 3 carbon atoms for R ₁₁ to R ₁₄ in formula (1) include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group and isobutyl group. , sec-butyl group, tert-butyl group, n-pentyl group and the like. Specific examples of the alkenyl group having 2 to 6 carbon atoms, preferably 2 to 4 carbon atoms in R ₁ to R ₄ include vinyl group, propenyl group, butynyl group and the like, and these may be linear or branched. . Specific examples of alkynyl groups having 2 to 6, preferably 2 to 3 carbon atoms in R ₁₁ to R ₁₄ include ethynyl, 1-propynyl and 2-propynyl groups. The fluorine atom-containing monovalent organic group having 1 to 6 carbon atoms, preferably 1 to 3 carbon atoms for R ₁₁ to R ₁₄ is fluoromethyl group, trifluoromethyl group, pentafluoroethyl group, pentafluoropropyl and the like.
A more preferred combination of R ₁₁ to R ₁₄ is that R ₁₁ and R ₁₄ have the same structure, and R ₁₂ and R ₁₃ have the same structure, from the viewpoint of developing low pretilt angle characteristics. .
Further, R ₁₁ to R ₁₄ are hydrogen atoms or methyl groups, at least one of R ₁₁ to R ₁₄ is preferably a methyl group, more preferably at least two of R ₁₁ to R ₁₄ are methyl groups. preferable. More preferably, R ₁₁ and R ₁₄ are methyl groups and R ₁₂ and R ₁₃ are hydrogen atoms.

The alkylene group of A in the above formula (1) may be linear or branched, but is preferably a linear alkylene group.

Preferred specific examples of the group —L ₁ —AL _1′ — in the above formula (1) include the following structures.
—O—(CH ₂ ) _n —O—,
—O—(CH ₂ ) _n1 —O—(CH ₂ ) _n2 —O—,
-C(=O)-(CH ₂ ) _n -C(=O)-,
-O-C(=O)-( _CH2 ) _n -O-,
-O-C(=O)-( _CH2 ) _n -O-C(=O)-,
-O-C(=O)-( _CH2 ) _n -C(=O)-O-,
-(CH ₂ ) _m1 -O-C(=O)-(CH ₂ ) _n' -C(=O)-O-(CH ₂ ) _m2 -,
—(CH ₂ ) _m1 —O—(CH ₂ ) _n′ —O—(CH ₂ ) _m2 —,
-C(=O)-O-( _CH2 ) _n -O-C(=O)-,
-(CH ₂ ) _m1 -C(=O)-O-(CH ₂ ) _n' -O-C(=O)-(CH ₂ ) _m2 -,
—O—(CH ₂ ) _n —, and the like.
In the above chemical formula, n is an integer of 5-12, more preferably an integer of 5-10, more preferably an integer of 5-7.
The sum of n1 and n2 is an integer of 5-12, more preferably an integer of 5-10. n1 and n2 are preferably integers of 2-8, more preferably integers of 2-4.
The sum of m1, m2 and n' is an integer of 5-12, more preferably an integer of 5-10. Each of m1 and m2 is more preferably an integer of 1 to 4, and still more preferably an integer of 2 to 4. n′ is more preferably an integer of 2-6, and even more preferably an integer of 2-4.

The bonding positions of Ar ₁ and Ar _1′ in the above formula (1) are preferably 1,4-positions or 1,3-positions, respectively, from the viewpoint of obtaining high liquid crystal orientation. position is even more preferred.

In each of Ar ₁ and Ar _1′ , one or more hydrogen atoms on the benzene ring may be substituted with a monovalent group, and the monovalent group includes a halogen atom and 1 to 10 carbon atoms. (preferably 1 to 5 carbon atoms, more preferably 1 to 3 carbon atoms) alkyl group, 2 to 10 carbon atoms (preferably 2 to 5 carbon atoms, more preferably 2 to 3 carbon atoms) alkenyl group, carbon Alkoxy group having 1 to 10 carbon atoms (preferably 1 to 5 carbon atoms, more preferably 1 to 3 carbon atoms), 1 to 10 carbon atoms (preferably 1 to 5 carbon atoms, more preferably 1 to 3 carbon atoms) fluoroalkyl group, fluoroalkenyl group having 2 to 10 carbon atoms (preferably 2 to 5 carbon atoms, more preferably 2 to 3 carbon atoms), 1 to 10 carbon atoms (preferably 1 to 5 carbon atoms, more preferably carbon fluoroalkoxy groups having numbers 1 to 3), alkyloxycarbonyl groups having 1 to 10 carbon atoms (preferably 2 to 5 carbon atoms, more preferably 2 to 3 carbon atoms), cyano groups, nitro groups, and the like.

In the polymer (A), the ratio of the repeating unit represented by the above formula (1) is preferably 60 mol % to 100 mol % with respect to 1 mol of all repeating units in the polymer (A). The ratio of the repeating unit represented by the above formula (1) is more preferably 80 mol % to 100 mol %, still more preferably 90 mol % to 100 mol %, from the viewpoint of suitably obtaining the effects of the present invention.
When the polymer (A) is a polyamic acid, the polyamic acid is, for example, a tetracarboxylic acid derivative component containing a tetracarboxylic dianhydride represented by the following formula (T ₁ ) and a diamine (1) (H- NZ ₁ -Ar ₁ -L ₁ -AL _1′ -Ar _1′ -NZ ₁ -H (A, L ₁ , L _1′ , Ar ₁ , Ar _1′ , Z ₁ , Y ₁ are represented by formula (1 ) is synonymous with )) can be obtained by reacting a diamine component containing ). Further, when the polymer (A) is a polyamic acid containing a repeating unit represented by the formula (2) described later, a tetracarboxylic acid containing a tetracarboxylic dianhydride represented by the above formula (T ₁ ) It can be obtained by reacting an acid derivative component with a diamine component containing a diamine (H—NZ ₂ —Y ₂ —NZ ₂ —H (Y ₂ and Z ₂ are as defined in formula (2))).

(R ₁₁ to R ₁₄ have the same definitions as R ₁₁ to R ₁₄ in formula (1).)
The liquid crystal aligning agent of the present invention may be a polyimide precursor containing a repeating unit represented by the following formula (2) in addition to the repeating unit represented by the above formula (1), and the polyimide precursor. The repeating unit may be of one type or two or more types.

(X ₂ represents a tetravalent organic group represented by the following formula (g), and Y ₂ represents the group —Ar ₁ —L ₁ —AL _1′ —Ar _1′ —(Ar ₁ , Ar _{1 '} , L ₁ , and L _{1 '} have the same definitions as in formula (1).) R ₂ and Z ₂ are R ₁ and Z ₁ in formula (1), respectively. is synonymous with

(In formula (g), R ₁₁ to R ₁₄ have the same definitions as R ₁₁ to R ₁₄ in formula (1).)
In the above formula (2), Y ₂ is a divalent organic group and a diamine (H-NZ ₂ -Y ₂ -NZ ₂ -H (Y ₂ and Z ₂ have the same meaning as in formula (2).) ) from which two amino groups (—NZ ₂ —H) have been removed. Various diamines (hereinafter also referred to as other diamines (a)) can be used as the diamine depending on the desired properties of the liquid crystal aligning agent. As the other diamine (a), the following can be used. Among other diamines, from the viewpoint of suitably obtaining the effects of the present invention, diamines having no side chain groups having 4 or more carbon atoms (excluding protective groups that are detached by heating and replaced with hydrogen atoms, which will be described later). preferable.

Diamines represented by the above formula (d _n ), p-phenylenediamine, 2,3,5,6-tetramethyl-p-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, m-phenylenediamine, 2 ,4-dimethyl-m-phenylenediamine, 2,5-diaminotoluene, phenylenediamine such as 2,6-diaminotoluene; 2,2′-dimethyl-4,4′-diaminobiphenyl, 3,3′-dimethyl- 4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-dihydroxy-4,4'-diaminobiphenyl, 2,2'-difluoro-4,4'- Diaminobiphenyl, 3,3'-difluoro-4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 3,3'-bis(trifluoromethyl)- Biphenyls such as 4,4'-diaminobiphenyl, 3,4'-diaminobiphenyl, 4,4'-diaminobiphenyl, 3,3'-diaminobiphenyl, 2,2'-diaminobiphenyl, 2,3'-diaminobiphenyl structure containing diamine; 1,2-bis(6-amino-2-naphthyloxy)ethane, 1,2-bis(6-amino-2-naphthyl)ethane, 6-[2-(4-aminophenoxy)ethoxy] -Naphthalene structures such as 2-naphthylamine, 1,5-diaminonaphthalene, 1,6-diaminonaphthalene, 1,7-diaminonaphthalene, 2,5-diaminonaphthalene, 2,6-diaminonaphthalene and 2,7-diaminonaphthalene diamine having a photoalignment group such as 4,4′-diaminoazobenzene or diaminotran; amide bond or urea bond such as diamine represented by the following formulas (h-1) to (h-5) 3,3′-diaminodiphenylmethane, 3,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylmethane, 1,2-bis(4-aminophenyl)ethane, 1,2-bis(3-aminophenyl ) ethane, 1,3-bis(4-aminophenyl)propane, 1,3-bis(3-aminophenyl)propane, 1,4-bis(4-aminophenyl)butane, 1,4-bis(3- aminophenyl)butane, 1,5-bis(4-aminophenyl)pentane, 1,5-bis(3-aminophenyl)pentane, 1,6-bis(4-aminophenyl)hexane, 1,6-bis( 3-aminophen nyl)hexane, 4,4'-diaminobenzophenone, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 1,4-bis(4-aminobenzyl)benzene , bis(4-aminophenoxy)methane, 1,2-bis(4-aminophenoxy)ethane, 1,2-bis(4-amino-2-methylphenoxy)ethane, 1,3-bis(4-aminophenoxy) ) propane, 1,4-bis(4-aminophenoxy)butane, 4-(2-(4-aminophenoxy)ethoxy)-3-fluoroaniline, 4-amino-4′-(2-(4-aminophenoxy )ethoxy)biphenyl, a diamine represented by the following formula (d _o ); 2,4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4,6 -diaminoresorcinol; 4,4'-diamino-3,3'-dihydroxybiphenyl; 2,4-diaminobenzoic acid, 2,5-diaminobenzoic acid, 3,5-diaminobenzoic acid and 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-amino phenyl)ethane-3,3′-dicarboxylic acid, 4,4′-diaminodiphenyl ether-3,3′-dicarboxylic acid and other diamines having a carboxyl group; 4-(2-(methylamino)ethyl)aniline, 4- (2-aminoethyl)aniline, 1-(4-aminophenyl)-1,3,3-trimethyl-1H-indan-5-amine, 1-(4-aminophenyl)-2,3-dihydro-1, 3,3-trimethyl-1H-indene-6-amine; 2-(2,4-diaminophenoxy)ethyl methacrylate and 2,4-diamino-N,N-diallylaniline having a photopolymerizable group at its end Diamine; cholestanyloxy-3,5-diaminobenzene, cholestenyl oxy-3,5-diaminobenzene, cholestanyloxy-2,4-diaminobenzene, cholestanyl 3,5-diaminobenzoate, cholestenyl 3,5-diaminobenzoate, lanostanyl 3,5-diaminobenzoate and 3,6 -diamines having a steroid skeleton such as bis(4-aminobenzoyloxy)cholestane; diamines represented by the following formulas (V-1) to (V-2); the following formulas (5-1) to (5-9) A group such as “—N(D)—” (D represents a protective group that is eliminated by heating and replaced by a hydrogen atom, preferably a tert-butoxycarbonyl group. ) (excluding diamines represented by the formula (d _n )); diamines having a siloxane bond such as 1,3-bis(3-aminopropyl)-tetramethyldisiloxane; meta-xylylenediamine , 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, 1,3-bis(aminomethyl)cyclohexane, 1,4-diaminocyclohexane, 4,4′-methylenebis(cyclohexylamine), WO2018 and diamines in which two amino groups are bonded to a group represented by any one of formulas (Y-1) to (Y-167) described in JP, 117239/117239.

(When there are two or more m, the two or more m may be the same or different. One or more hydrogen atoms on the benzene ring may be substituted with a monovalent group.)
An example of formula (d ₀ ) will be described later.

(In the formula (V-1), m and n are integers of 0 to 3 (provided that 1 ≤ m + n ≤ 4), j is an integer of 0 or 1, X ¹ is -(CH ₂ ) _a- (a is an integer of 1 to 15), -CONH-, -NHCO-, -CO-N(CH ₃ )-, -NH-, -O-, -CH ₂ O-, - represents CH ₂ —OCO—, —COO—, or —OCO—, where R ¹ is a fluorine atom, a fluorine atom-containing alkyl group having 1 to 10 carbon atoms, a fluorine atom-containing alkoxy group having 1 to 10 carbon atoms, or represents an alkyl group having 3 to 10 carbon atoms, an alkoxy group having 3 to 10 carbon atoms, or an alkoxyalkyl group having 3 to 10 carbon atoms, wherein X ² is —O—, —CH ₂ O—, —CH ₂ —OCO—, —COO—, or —OCO—, and when there are two m, n, X ¹ and R ¹ , each independently has the above definition.)

Specific examples of the monovalent group in the above formula (d _o ) include the structures exemplified for the monovalent group in the above formula (d _AL ).

As the diamine represented by the above formula (d _o ), from the viewpoint of lowering the pretilt angle, diamines represented by the following formulas (d _o -1) to (d _o -6), 3,3′-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether and 4,4'-diaminodiphenyl ether are preferred.

In the polymer (A), the ratio of the repeating unit represented by the above formula (2) is 0 per 1 mol of all repeating units in the polymer (A) from the viewpoint of suitably obtaining the effects of the present invention. ~40 mol% is preferred, 0 to 20 mol% is preferred, and 0 to 10 mol% is more preferred.
<Polymer (B)>
The diamine component used for producing the polymer (B) contained in the liquid crystal aligning agent of the present invention contains the diamine represented by the above formula (d _n ). By containing the diamine component, it becomes possible to trap impurities that cause a decrease in voltage holding ratio, and the obtained liquid crystal alignment film has a high voltage holding ratio. The diamines represented by the above formula (d _n ) may be used singly or in combination of two or more.
The diamine component used for producing the polymer (B) may be composed of a diamine component that does not contain a diamine represented by the following formula (d _AL ).

(A is a group “*11-(CH ₂ ) _n —O—*12” (*11 represents a bond that bonds to an oxygen atom or a bond that bonds to a carbon atom that constitutes a benzene ring, and *12 is represents a bond, n is an integer of 1 to 5. Any hydrogen atom of the benzene ring bonded to the NH ₂ group is replaced with a monovalent group, and is also good.)

Examples of the nitrogen atom-containing heterocyclic ring in the above formula ( _dn ) include pyrrole ring, imidazole ring, pyrazole ring, triazole ring, pyridine ring, pyrimidine ring, pyridazine ring, pyrazine ring, indole ring, benzimidazole ring and purine ring. , quinoline ring, isoquinoline ring, naphthyridine ring, quinoxaline ring, phthalazine ring, triazine ring, carbazole ring, acridine ring, piperidine ring, piperazine ring, pyrrolidine ring, hexamethyleneimine ring and the like. Among these, a pyridine ring, a pyrimidine ring, a pyrazine ring, a piperidine ring, a piperazine ring, a quinoline ring, a carbazole ring and an acridine ring are preferred.

The monovalent organic group represented by R in the above formula (d _n ) includes, for example, alkyl groups such as methyl group, ethyl group and propyl group; alkenyl groups such as vinyl group; cycloalkyl groups such as cyclohexyl group; , an aryl group such as a methylphenyl group, an alkoxy group (eg, a methoxy group, an ethoxy group), and the like. R is preferably a hydrogen atom or a methyl group.

Specific examples of the diamine represented by the formula (d _n ) include 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminocarbazole, N-methyl -3,6-diaminocarbazole, 1,4-bis-(4-aminophenyl)-piperazine, 3,6-diaminoacridine, N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diamino Examples include carbazole and diamines represented by the following formulas (d _n -1) to (d _n -3).

In formula (d _n −1), m1 and m1′ are each independently an integer of 1 to 2. n1 is an integer of 1-3. R ₁ has the same definition as R in the amino group represented by "*21-NR-*22" above.

When a plurality of R ₁ and m1' are present, the plurality of R1 and m1' may be the same or different.

In formula (d _n -2), X ₂ represents a monovalent nitrogen atom-containing heterocyclic group, and specific examples of the nitrogen atom-containing heterocyclic ring in the monovalent nitrogen atom-containing heterocyclic group are the above formulas (d _n ) and the structures exemplified for the nitrogen atom-containing heterocycle in ).

n1 is an integer of 1 to 2, and n2 is an integer satisfying n1+n2=2. L ₁ and L ₂ are each independently a single bond, —CO—, an alkylene group having 1 to 6 carbon atoms, or —O— or —CO— between the carbon-carbon bonds of the alkylene group or at the terminal is a divalent organic group in which is inserted, and a nitrogen atom represents a divalent organic group bonded to a carbon atom. R represents a hydrogen atom or a methyl group.

When multiple X _{2 ,} L ₂ and R are present, multiple X _{2 ,} L ₂ and R may be the same or different.

In formula ( _d _n -3), X ₃ represents a divalent group having a nitrogen atom-containing heterocyclic ring. Examples include the structures illustrated.

Ar ₃ represents a divalent aromatic ring group or a divalent saturated nitrogen atom-containing heterocyclic group. Specific examples of the aromatic ring in the divalent aromatic ring group include benzene ring, naphthalene ring, anthracene ring, pyridine ring, pyrimidine ring, pyrazine ring, pyridazine ring, triazine ring, pyrrole ring, imidazole ring, pyrazole ring, quinoline ring, isoquinoline ring, carbazole ring, benzimidazole ring, indole ring, quinoxaline ring and acridine ring. Specific examples of the saturated nitrogen atom-containing heterocyclic ring in the divalent saturated nitrogen atom-containing heterocyclic group include a piperidine ring and a piperazine ring. A hydrogen atom of an aromatic ring and a saturated nitrogen atom-containing heterocyclic ring may be substituted with a monovalent group. Specific examples of the monovalent group include the structures exemplified for the monovalent group in the above formula (d _AL ).

L ₃ is a single bond, -(CH ₂ ) _n - (n is an integer of 1 to 6), -NR'-, -(CH ₂ ) _n -NR'- (n is an integer of 1 to 6 ), -O-, -NR'-CO-, -CO-NR'-, -O-CO-, or -CO-O-, and R' is a hydrogen atom, a methyl group, or tert- represents a butoxycarbonyl group.

m3 and m3' are each independently an integer of 0 to 2, and either m3 or m3' is an integer of 1 or more.

When a plurality of Ar ₃ and L ₃ are present, the plurality of Ar ₃ and L ₃ may be the same or different.

Both NH ₂ groups at both ends of formula (d _n -3) are bonded to carbon atoms constituting the aromatic ring.

Preferred specific examples of the diamines represented by the above formulas (d _n -1) to (d _n -3) include the diamines represented by the following formulas (Dp-1) to (Dp-6), the following formulas (z- 1) to diamines represented by formulas (z-14).

The content of the diamine represented by the formula (d _n ) in the constituent components of the polymer (B) is preferably 20 to 95 mol% of the total diamine components used in the production of the polymer (B). , more preferably 30 to 90 mol %, more preferably 40 to 90 mol %, and even more preferably 50 to 80 mol %.

The diamine component used in the production of the polymer (B) contained in the liquid crystal aligning agent of the present invention is, in addition to the above diamines, various diamines (hereinafter referred to as other diamines ( Also referred to as b).) can be used.

Other diamines (b) include, for example, the compounds exemplified for the diamines used in the production of the polymer (A) (diamine (1), other diamines (a)). Among other diamines (b), from the viewpoint of suitably obtaining the effects of the present invention, a side chain group having 4 or more carbon atoms (excluding the above-described protecting group that is eliminated by heating and replaced with a hydrogen atom). Diamines that do not are preferred. Among other diamines (b), from the viewpoint of suitably obtaining the effects of the present invention, the above phenylenediamine, the above biphenyl structure-containing diamine, 3,3′-diaminodiphenylmethane, 3,4′-diaminodiphenylmethane, 4,4 '-Diaminodiphenylmethane, 1,2-bis(4-aminophenyl)ethane, 1,2-bis(3-aminophenyl)ethane, 1,3-bis(4-aminophenyl)propane, 1,3-bis( 3-aminophenyl)propane, 1,4-bis(4-aminophenyl)butane, 1,4-bis(3-aminophenyl)butane, 1,5-bis(4-aminophenyl)pentane, 1,5- bis(3-aminophenyl)pentane, 1,6-bis(4-aminophenyl)hexane, 1,6-bis(3-aminophenyl)hexane, 4,4′-diaminobenzophenone, 1,4-bis(4 -aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 1,4-bis(4-aminobenzyl)benzene, bis(4-aminophenoxy)methane, 1,2-bis(4-amino phenoxy)ethane, 1,2-bis(4-amino-2-methylphenoxy)ethane, 1,3-bis(4-aminophenoxy)propane, 1,4-bis(4-aminophenoxy)butane, 4-( 2-(4-aminophenoxy)ethoxy)-3-fluoroaniline, 4-amino-4'-(2-(4-aminophenoxy)ethoxy)biphenyl, 3,3'-diaminodiphenyl ether, 3,4'-diamino At least one diamine selected from the group consisting of diphenyl ether, 4,4'-diaminodiphenyl ether, diamines having an amide bond or urea bond, and 4-(2-(methylamino)ethyl)aniline is preferred. Each of the other diamines (b) may be used alone or in combination of two or more.

The content of the other diamine (b) in the constituent components of the polymer (B) is preferably 5 to 80 mol%, preferably 10 to 70 mol%, of the total diamine component used in the production of the polymer (B). mol % is more preferred, 10 to 60 mol % is even more preferred, and 20 to 50 mol % is even more preferred.

The tetracarboxylic acid derivative component used in the production of the polymer (B) contained in the liquid crystal aligning agent of the present invention is the tetracarboxylic dianhydride represented by the above formula (T _f ). contains 5 mol % or more of

By containing the tetracarboxylic dianhydride represented by the above formula (T _f ), the decrease in the molecular weight of the polymer (B) is suppressed, resulting in high liquid crystal orientation and excellent resistance to AC afterimages. A liquid crystal alignment film is obtained. In addition, since the polymer (B) has a specific tetracarboxylic dianhydride that is difficult to imidize, a polymer having many hydrophilic groups such as carboxyl groups can be obtained. A liquid crystal alignment film having excellent two-layer separability from the union (B) is obtained. Therefore, as described above, a liquid crystal alignment film having high liquid crystal alignment properties and excellent resistance to AC afterimages can be obtained.

The tetravalent organic group having a 5- or more-membered alicyclic structure for X _f in the formula (T _f ) is preferably a tetravalent organic group having a 5- to 8-membered alicyclic structure. A tetravalent organic group having a membered alicyclic structure is more preferred. In addition, when the alicyclic structure to which the acid anhydride group is bonded is a polycyclic structure, the 5-membered or more alicyclic structure means that in each ring contained in the polycyclic structure, the atoms constituting the ring All numbers are 5 or more. Moreover, the alicyclic structure may be bonded to at least one of the two acid anhydride groups, and may have a chain hydrocarbon structure or an aromatic ring structure together with the alicyclic structure.

Preferred specific examples of X _f include tetravalent organic groups represented by any one of the following formulas (X _f -1) to (X _f -17). X _f is more preferably (X _f −1) to (X _f −4) from the viewpoint of suitably obtaining the effects of the present invention.

From the viewpoint of obtaining the effect of the present invention, the total amount of the tetracarboxylic dianhydride represented by the above formula (T _f ) is 10 mol% of the total tetracarboxylic acid derivative component used in the production of the polymer (B). The above is more preferable, and 20 mol % or more is even more preferable.
The tetracarboxylic acid derivative component used in the production of the polymer (B) contained in the liquid crystal aligning agent of the present invention is, in addition to the tetracarboxylic dianhydride represented by the above formula (T _f ), the desired liquid crystal alignment. Depending on the properties of the agent, a tetracarboxylic dianhydride other than the tetracarboxylic dianhydride represented by the above formula (T _f ) (these are collectively referred to as other tetracarboxylic dianhydrides (b) ) may be used. The other tetracarboxylic dianhydrides (b) may be used singly or in combination of two or more.

Specific examples of other tetracarboxylic dianhydrides (b) include alicyclic tetracarboxylic dianhydrides other than the tetracarboxylic dianhydrides represented by the above formula (T _f ), acyclic aliphatic A tetracarboxylic dianhydride or an aromatic tetracarboxylic dianhydride may be mentioned.

Here, the alicyclic tetracarboxylic dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxy groups including at least one carboxy group bonded to an alicyclic structure. However, none of these four carboxy groups are bonded to the aromatic ring. Moreover, it is not necessary to consist only of an alicyclic structure, and a part thereof may have a chain hydrocarbon structure or an aromatic ring structure.
An acyclic aliphatic tetracarboxylic dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxy groups bonded to a chain hydrocarbon structure. However, it does not need to be composed only of a chain hydrocarbon structure, and may have an alicyclic structure or an aromatic ring structure in part thereof.
The aromatic tetracarboxylic dianhydride is not particularly limited as long as it is an acid dianhydride obtained by intramolecular dehydration of four carboxy groups including at least one carboxy group bonded to an aromatic ring.

The acyclic aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, or aromatic tetracarboxylic dianhydride in the other tetracarboxylic dianhydride (b) is preferably It is a tetracarboxylic dianhydride represented by the above formula (T _c ) or a tetracarboxylic dianhydride represented by the following formula (t).

In the formula, X ₁ is a structure selected from formula (g) above and formulas (X1-1) to (X1-10) below.

(In formulas (X1-9) to (X1-10), j and k are integers of 0 or 1, A ₁ and A ₂ are each independently a single bond, -O-, -CO- , —COO—, a phenylene group, a sulfonyl group, or an amide bond.A plurality of A ₂ may be the same or different, and * represents a bond.)
Preferred specific examples of the above formulas (X1-9) to (X1-10) include the following formulas (X _R -1) to (X _R -14). From the viewpoint of enhancing liquid crystal orientation, the above formulas (X1-9) to (X1-10) are preferably the above (X _R -1) to (X _R -8), and (X _R -1), (X _R -4) to (X _R -6) and (X _R -8) are more preferred.

When the tetracarboxylic acid derivative component used for producing the polymer (B) contained in the liquid crystal aligning agent of the present invention contains other tetracarboxylic dianhydride (b), other tetracarboxylic dianhydride The content of (b) is preferably 5 to 95 mol%, more preferably 10 to 90 mol%, and more preferably 20 to 95 mol% of the total tetracarboxylic acid derivative component used in the production of the polymer (B). More preferably 80 mol %. In this case, the total amount of the tetracarboxylic dianhydride represented by the above formula (T _f ) is preferably 5 to 95 mol%, more preferably 10 to 90 mol% of the total tetracarboxylic acid derivative component. and more preferably 20 to 80 mol %.

From the viewpoint of obtaining the effect of the present invention, the content ratio of the above components (A) and (B) is such that the content ratio of the components (A) and (B) is [(A) component] / [(B) component ] may be from 10/90 to 90/10, from 20/80 to 90/10, or from 20/80 to 80/20.
<Production of polymer (A) and polymer (B)>
(Synthesis of polyamic acid)
Polyamic acid, which is a polyimide precursor contained in the liquid crystal aligning agent of the present invention, can be produced, for example, by the following method. The tetracarboxylic acid derivative used in the production of the polymer (A) or polymer (B) includes not only tetracarboxylic dianhydride, but also derivatives thereof such as tetracarboxylic acid dihalide compound and tetracarboxylic acid dialkyl. Esters, tetracarboxylic acid dialkyl ester dihalides, and the like can also be used. Specifically, the tetracarboxylic acid derivative component containing the tetracarboxylic dianhydride and the diamine component containing the diamine are mixed in the presence of an organic solvent at preferably −20 to 150° C., more preferably 0 to 50° C. , preferably 0.5 to 24 hours, more preferably 1 to 12 hours (polycondensation).

Specific examples of the organic solvent used in the above reaction include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide, 1,3-dimethyl-2-imidazolidinone and the like. 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, ethylene glycol monoethyl ether, ethylene Glycol monopropyl ether, diethylene glycol monomethyl ether, or diethylene glycol monoethyl ether can be used. These may be used in combination of two or more.

The reaction of polyamic acid can be carried out at any concentration, preferably 1 to 50% by mass, more preferably 5 to 30% by mass. The initial stage of the reaction can be carried out at a high concentration, and then the solvent can be added. In the reaction, the ratio of the total number of moles of the diamine component to the total number of moles of the tetracarboxylic acid component is preferably 0.8 to 1.2. Similar to a normal polycondensation reaction, the closer this molar ratio is to 1.0, the greater the molecular weight of the polyamic acid produced.

The polyamic acid obtained by the above reaction can be recovered by precipitating the polyamic acid by injecting the reaction solution into a poor solvent while stirring well. Further, a purified polyamic acid powder can be obtained by performing precipitation several times, washing with a poor solvent, and drying at room temperature or by heating. Poor solvents include, but are not limited to, water, methanol, ethanol, hexane, butyl cellosolve, acetone, and toluene.
(Synthesis of Polyamic Acid Ester)
Polyamic acid esters are produced by, for example, [I] a method of reacting the polyamic acid obtained by the above method with an esterifying agent, [II] a method of reacting a tetracarboxylic acid diester with a diamine, [III] a tetracarboxylic acid It can be obtained by a known method such as a method of reacting a diester dihalide and a diamine.
(Synthesis of polyimide)
Moreover, a polyimide can be obtained by ring-closing (imidating) a polyimide precursor such as the above polyamic acid or polyamic acid ester. The imidization ratio as used herein means the ratio of imide groups to the total amount of imide groups derived from tetracarboxylic dianhydride or derivatives thereof and carboxy groups (or derivatives thereof). The imidization rate does not necessarily have to be 100%, and can be arbitrarily adjusted according to the application and purpose.
[Terminal blocking agent]
When synthesizing the polymers (A) and (B) in the present invention, a tetracarboxylic acid derivative component containing a tetracarboxylic dianhydride, a diamine component, and an appropriate end-blocking agent are used to form a terminal-blocking polymer. It is good also as synthesize|combining union.

Terminal blockers include, for example, acetic anhydride, maleic anhydride, nadic anhydride, phthalic anhydride, itaconic anhydride, cyclohexanedicarboxylic anhydride, 3-hydroxyphthalic anhydride, trimellitic anhydride, 3-( 3-trimethoxysilyl)propyl)-3,4-dihydrofuran-2,5-dione, 4,5,6,7-tetrafluoroisobenzofuran-1,3-dione, 4-ethynylphthalic anhydride, etc. acid monoanhydride; di-tert-butyl dicarbonate, dicarbonic acid diester compounds such as diallyl dicarbonate; acryloyl chloride, methacryloyl chloride, chlorocarbonyl compounds such as nicotinic acid chloride; 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, monoamine compounds such as n-heptylamine and n-octylamine; isocyanates having unsaturated bonds such as ethyl isocyanate, phenyl isocyanate, naphthyl isocyanate, 2-acryloyloxyethyl isocyanate and 2-methacryloyloxyethyl isocyanate and isothiocyanate compounds such as ethyl isothiocyanate and allyl isothiocyanate.

The proportion of the terminal blocking agent used is preferably 0.1 to 30 mol parts, more preferably 0.1 to 20 mol parts, per 100 mol parts in total of the diamine components used.

When recovering the generated polyamic acid from the polyamic acid reaction solution, the reaction solution may be added to the solvent to precipitate. Solvents used for precipitation include methanol, ethanol, isopropyl alcohol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, toluene, benzene, and water. The polyamic acid precipitated by putting it into a solvent can be filtered and recovered, and then dried at room temperature or under heat under normal pressure or reduced pressure. In addition, the impurities in the polymer can be reduced by redissolving the precipitated and recovered polymer in an organic solvent and repeating the operation of reprecipitating and recovering 2 to 10 times. Solvents in this case include, for example, alcohols, ketones, hydrocarbons, and the like, and it is preferable to use three or more kinds of solvents selected from these, because the purification efficiency is further improved.

The molecular weights of the polymer (A) and polymer (B) used in the present invention are determined by GPC (Gel Permeation Chromatography) when considering the strength of the liquid crystal alignment film obtained therefrom, workability during film formation, and coating film properties. ), the weight average molecular weight is preferably 5,000 to 1,000,000, more preferably 10,000 to 150,000.

The total content of the polymer contained in the liquid crystal aligning agent of the present invention can be appropriately changed depending on the setting of the thickness of the coating film to be formed. % or more is preferable, and 10% by mass or less is preferable from the viewpoint of storage stability of the solution. A particularly preferred total polymer content is 2 to 8% by weight.

The liquid crystal aligning agent of the present invention may contain polymers other than the polymer (A) and the polymer (B). Specific examples of other polymers include polyimide precursors other than the polymer (A) and the polymer (B), polyimides, polysiloxanes, polyesters, polyamides, polyurea, polyurethanes, polyorganosiloxanes, cellulose derivatives, polyacetals, Polystyrene derivatives, poly(styrene-maleic anhydride) copolymers, poly(isobutylene-maleic anhydride) copolymers, poly(vinyl ether-maleic anhydride) copolymers, poly(styrene-phenylmaleimide) derivatives , and polymers selected from the group consisting of poly(meth)acrylates. Specific examples of poly(styrene-maleic anhydride) copolymers include SMA1000, 2000, 3000 (manufactured by Cray Valley), GSM301 (manufactured by Gifu Shellac), etc. Poly(isobutylene-maleic anhydride) ) copolymers include Isoban-600 (manufactured by Kuraray), and specific examples of poly(vinyl ether-maleic anhydride) copolymers include GANTREZ AN-139 (methyl vinyl ether maleic anhydride resin , manufactured by ISP Japan).

Other polymers may be used singly or in combination of two or more. The content of the other polymer is preferably 90 parts by mass or less, more preferably 10 to 90 parts by mass, and further 20 to 80 parts by mass with respect to the total 100 parts by mass of the polymer contained in the liquid crystal aligning agent. preferable.

The liquid crystal aligning agent according to the present invention is preferably a liquid composition in which the polymer (A) and polymer (B) are dissolved or dispersed in an organic solvent. Specifically, the organic solvent contained in the liquid crystal aligning agent is not particularly limited as long as it uniformly dissolves the polyamic acid, but N,N-dimethylformamide, N,N-diethylformamide, 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-dimethylpropanamide, 3-butoxy-N,N-dimethyl Propanamide, N-(n-propyl)-2-pyrrolidone, N-isopropyl-2-pyrrolidone, N-(n-butyl)-2-pyrrolidone, N-(t-butyl)-2-pyrrolidone, N-( n-pentyl)-2-pyrrolidone, N-methoxypropyl-2-pyrrolidone, N-ethoxyethyl-2-pyrrolidone, N-methoxybutyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone (these are collectively referred to as " (also referred to as "good solvent"). Among them, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 3-methoxy-N,N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropanamide and γ-butyrolactone are preferred. The content of the good solvent is preferably 20 to 99% by mass, more preferably 20 to 90% by mass, and particularly preferably 30 to 80% by mass of the total solvent contained in the liquid crystal aligning agent.

Further, the organic solvent contained in the liquid crystal aligning agent is a mixture of the above solvents and a solvent (also referred to as a poor solvent) that improves the coatability and the surface smoothness of the coating film when applying the liquid crystal aligning agent. The use of solvents is preferred. Specific examples of the poor solvent used in combination are shown below, but are not limited thereto. The content of the poor solvent is preferably 1 to 80% by mass, more preferably 10 to 80% by mass, particularly preferably 20 to 70% by mass, of the total solvent contained in the liquid crystal aligning agent. The type and content of the poor solvent are appropriately selected according to the liquid crystal aligning agent coating device, coating conditions, coating environment, and the like.

Examples of poor solvents include diisopropyl ether, diisobutyl ether, diisobutyl carbinol (2,6-dimethyl-4-heptanol), ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, 1,2-butoxyethane, and diethylene glycol. dimethyl ether, diethylene glycol diethyl ether, 4-hydroxy-4-methyl-2-pentanone, diethylene glycol methyl ethyl ether, diethylene glycol dibutyl ether, 3-ethoxybutyl acetate, 1-methylpentyl acetate, 2-ethylbutyl acetate, 2- ethylhexyl acetate, ethylene glycol monoacetate, ethylene glycol diacetate, propylene carbonate, ethylene carbonate, ethylene glycol monobutyl ether, ethylene glycol monoisoamyl ether, ethylene glycol monohexyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, 1 -(2-butoxyethoxy)-2-propanol, 2-(2-butoxyethoxy)-1-propanol, propylene glycol monomethyl ether acetate, propylene glycol diacetate, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, Dipropylene glycol dimethyl ether, ethylene glycol monobutyl ether acetate, diethylene glycol monopropyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, 2-(2-ethoxyethoxy) ethyl acetate, diethylene glycol acetate, n-butyl acetate , propylene glycol monoethyl ether acetate, cyclohexyl acetate, 4-methyl-2-pentyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, 3- butyl methoxypropionate, n-butyl lactate, isoamyl lactate, diethylene glycol monoethyl ether, diisobutyl ketone (2,6-dimethyl-4-heptanone) and the like.

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

Preferred solvent combinations of a good solvent and a poor solvent include N-methyl-2-pyrrolidone, γ-butyrolactone and ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone and propylene glycol monobutyl ether, N, N-dimethyl lactamide and diisobutyl ketone, N-methyl-2-pyrrolidone and ethyl 3-ethoxypropionate and dipropylene glycol monomethyl ether, N-ethyl-2-pyrrolidone and ethyl 3-ethoxypropionate and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone and ethyl 3-ethoxypropionate and diethylene glycol monopropyl ether, N-ethyl-2-pyrrolidone and ethyl 3-ethoxypropionate and diethylene glycol monopropyl ether, N,N-dimethyllactamide and ethylene glycol Monobutyl ether, N,N-dimethyllactamide and propylene glycol diacetate, N-ethyl-2-pyrrolidone and diethylene glycol diethyl ether, N-ethyl-2-pyrrolidone and diethylene glycol monoethyl ether and butyl cellosolve acetate, N-methyl-2- pyrrolidone and diethylene glycol monomethyl ether and butyl cellosolve acetate, N,N-dimethyllactamide and diethylene glycol diethyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and 4-hydroxy-4-methyl-2-pentanone and diethylene glycol diethyl ether, N -ethyl-2-pyrrolidone and N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone, N-ethyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and propylene glycol mono Butyl ether, N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and diisobutyl ketone, N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and dipropylene glycol monomethyl ether , N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and propylene glycol diacetate , N-ethyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and dipropylene glycol dimethyl ether, γ-butyrolactone and 4-hydroxy-4-methyl-2-pentanone and diisobutyl ketone, γ-butyrolactone and 4-hydroxy-4-methyl-2-pentanone and propylene glycol diacetate, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether and diisobutyl ketone, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether and diisopropyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether and Diisobutylcarbinol, N-methyl-2-pyrrolidone and γ-butyrolactone and dipropylene glycol dimethyl ether, N-methyl-2-pyrrolidone and propylene glycol monobutyl ether and dipropylene glycol dimethyl ether, N-ethyl-2-pyrrolidone and propylene glycol mono Butyl ether and dipropylene glycol monomethyl ether, N-ethyl-2-pyrrolidone and diethylene glycol diethyl ether and dipropylene glycol monomethyl ether, N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether and propylene glycol diacetate, N-ethyl-2- Pyrrolidone and propylene glycol monobutyl ether and diisobutyl ketone, N-ethyl-2-pyrrolidone and γ-butyrolactone and diisobutyl ketone, N-ethyl-2-pyrrolidone and N,N-dimethyllactamide and diisobutyl ketone, N-methyl-2- pyrrolidone and ethylene glycol monobutyl ether and ethylene glycol monobutyl ether acetate, γ-butyrolactone and ethylene glycol monobutyl ether acetate and dipropylene glycol dimethyl ether, N-ethyl-2-pyrrolidone and ethylene glycol monobutyl ether acetate and propylene glycol dimethyl ether, N -methyl-2-pyrrolidone and 4-methyl-2-pentyl acetate and ethylene glycol monobutyl ether, N-ethyl-2-pyrrolidone and cyclohexyl acetate and diacetone alcohol, cyclohexanone and propylene glycol monomethyl ether, cyclopentanone and propylene glycol monomethyl ether ether, N-methyl-2-pyrrolidone and cyclohexanone and propylene glycol monomethyl ether, tetramethyl luurea and 4-hydroxy-4-methyl-2-pentanone, tetramethylurea and propylene glycol diacetate, N,N-dimethylpropionamide and propylene glycol monobutyl ether, tetramethylurea and propylene glycol monobutyl ether, tetramethylurea and Cyclohexanone and propylene glycol monomethyl ether, N,N-dimethylpropionamide and propylene glycol monomethyl ether, N,N-dimethylpropionamide and ethylene glycol monobutyl ether acetate, N,N-dimethylpropionamide and ethylene glycol monobutyl ether, tetramethylurea and propylene glycol monomethyl ether, N,N-dimethylpropionamide, cyclohexanone and diethylene glycol diethyl ether, N,N-diethylformamide and propylene glycol monomethyl ether, N,N-diethylformamide and 4-hydroxy-4-methyl-2-pentanone , N,N-diethylformamide and propylene glycol monomethyl ether.

(Additive component)
The liquid crystal aligning agent of the present invention may additionally contain components other than the components (A), (B), and organic solvent (hereinafter also referred to as additive components). Such additive components include, for example, a crosslinkable compound (c-1) having at least one substituent selected from an epoxy group, an oxetane group, an oxazoline structure, a cyclocarbonate group, a blocked isocyanate group, a hydroxy group and an alkoxy group. , and at least one crosslinkable compound selected from the group consisting of a crosslinkable compound (c-2) having a polymerizable unsaturated group, a functional silane compound, a metal chelate compound, a curing accelerator, a surfactant, an antioxidant agents, sensitizers, preservatives, and compounds for adjusting the dielectric constant and electrical resistance of the resin film.

Preferred specific examples of the crosslinkable compounds (c-1) and (c-2) include the following compounds. Examples of epoxy group-containing compounds include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, and 1,6-hexane. Diol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, Epicoat 828 (manufactured by Mitsubishi Chemical Corporation), etc. Bisphenol A type epoxy resin, bisphenol F type epoxy resin such as Epicoat 807 (manufactured by Mitsubishi Chemical Corporation), hydrogenated bisphenol A type epoxy resin such as YX-8000 (manufactured by Mitsubishi Chemical Corporation), YX6954BH30 (manufactured by Mitsubishi Chemical Corporation) and the like biphenyl skeleton-containing epoxy resins, phenol novolac type epoxy resins such as EPPN-201 (manufactured by Nippon Kayaku Co., Ltd.), (o, m, p-) cresol novolac type epoxy resins such as EOCN-102S (manufactured by Nippon Kayaku Co., Ltd.), tetrakis(glycidyloxymethyl)methane, N,N,N',N'-tetraglycidyl-1,4-phenylenediamine, N,N,N',N'-tetraglycidyl-2,2'-dimethyl-4. 4'-diaminobiphenyl, 2,2-bis[4-(N,N-diglycidyl-4-aminophenoxy)phenyl]propane, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane compounds in which a tertiary nitrogen atom is bound to an aromatic carbon atom such as; 1,3-diaminocyclohexane, N,N,N',N'-tetraglycidyl-1,4-diaminocyclohexane, bis(N,N-diglycidyl-4-aminocyclohexyl)methane, bis(N,N-diglycidyl- 2-methyl-4-aminocyclohexyl)methane, bis(N,N-diglycidyl-3-methyl-4-aminocyclohexyl)methane, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, 1,4 -bis(N,N-diglycidylaminomethyl)cyclohexane, 1,3-bis(N,N-diglycidylaminomethyl)benzene, 1,4-bis(N,N-diglycidylaminomethyl) Tertiary nitrogen such as lysidylaminomethyl)benzene, 1,3,5-tris(N,N-diglycidylaminomethyl)cyclohexane, 1,3,5-tris(N,N-diglycidylaminomethyl)benzene Compounds whose atoms are bonded to aliphatic carbon atoms, isocyanurate compounds such as triglycidyl isocyanurate such as TEPIC (manufactured by Nissan Chemical Industries, Ltd.), compounds described in paragraph [0037] of JP-A-10-338880, and WO2017 / compounds described in No. 170483;
As compounds having an oxetanyl group, 1,4-bis{[(3-ethyl-3-oxetanyl)methoxy]methyl}benzene (aron oxetane OXT-121 (XDO)), di[2-(3-oxetanyl)butyl] Ether (aron oxetane OXT-221 (DOX)), 1,4-bis[(3-ethyloxetan-3-yl)methoxy]benzene (HQOX), 1,3-bis[(3-ethyloxetan-3-yl ) methoxy]benzene (RSOX), 1,2-bis[(3-ethyloxetan-3-yl)methoxy]benzene (CTOX), two described in paragraphs [0170] to [0175] of WO2011/132751 Compounds having the above oxetanyl group, etc.;
Compounds having an oxazoline group include compounds such as 2,2'-bis(2-oxazoline) and 2,2'-bis(4-methyl-2-oxazoline), and Epocross (trade name, manufactured by Nippon Shokubai Co., Ltd.). Polymers and oligomers having an oxazoline group, such as compounds described in paragraph [0115] of Japanese Patent Application Laid-Open No. 2007-286597;
As compounds having a cyclocarbonate group, N,N,N',N'-tetra[(2-oxo-1,3-dioxolan-4-yl)methyl]-4,4'-diaminodiphenylmethane, N,N' ,-Di[(2-oxo-1,3-dioxolan-4-yl)methyl]-1,3-phenylenediamine and paragraphs [0025] to [0030] and [0032] of WO2011/155577 compounds of;
Examples of compounds having a blocked isocyanate group include Coronate AP Stable M, Coronate 2503, 2515, 2507, 2513, 2555, Millionate MS-50 (manufactured by Tosoh Corporation), Takenate B-830, B-815N, B-820NSU, B-842N, B-846N, B-870N, B-874N, B-882N (manufactured by Mitsui Chemicals, Inc.), two pieces described in paragraphs [0046] to [0047] of Japanese Patent Application Laid-Open No. 2014-224978 compounds having the above protected isocyanate groups, compounds having three or more protected isocyanate groups described in paragraphs [0119] to [0120] of WO2015/141598;
As compounds having a hydroxy group and an alkoxy group, N,N,N',N'-tetrakis(2-hydroxyethyl)adipamide, 2,2-bis(4-hydroxy-3,5-dihydroxymethylphenyl)propane, 2 , 2-bis(4-hydroxy-3,5-dimethoxymethylphenyl)propane, 2,2-bis(4-hydroxy-3,5-dihydroxymethylphenyl)-1,1,1,3,3,3- Hexafluoropropane, WO2015/072554, the compound described in paragraph [0058] of JP 2016-118753, the compound described in JP 2016-200798, the compound described in WO2010/074269, etc. ;
As crosslinkable compounds having a polymerizable unsaturated group, glycerin mono(meth)acrylate, glycerin di(meth)acrylate (1,2-,1,3-body mixture), glycerin tris(meth)acrylate, glycerol 1,3 - diglycerolate di(meth)acrylate, pentaerythritol tri(meth)acrylate, diethylene glycol mono(meth)acrylate, triethylene glycol mono(meth)acrylate, tetraethylene glycol mono(meth)acrylate, pentaethylene glycol mono(meth)acrylate ) acrylate, hexaethylene glycol mono(meth)acrylate and the like.
The content of the crosslinkable compounds (c-1) and (c-2) contained in the liquid crystal aligning agent of the present invention is 0.5 parts per 100 parts by mass in total of the polymer components contained in the liquid crystal aligning agent. It is preferably 1 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, still more preferably 1 to 10 parts by mass.

Examples of compounds for adjusting the dielectric constant and electrical resistance of the resin film include monoamines having a nitrogen atom-containing aromatic heterocycle such as 3-picolylamine. When using a monoamine having a nitrogen atom-containing aromatic heterocycle, the content is preferably 0.1 to 30 parts by mass with respect to 100 parts by mass of the polymer component contained in the liquid crystal aligning agent, more preferably is 0.1 to 20 parts by mass.

Preferred specific examples of functional silane compounds include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyldiethoxymethylsilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane. Silane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxy silane, vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxysilane sidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, ethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, tris(3-trimethoxysilylpropyl)isocyanurate, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3 -isocyanatopropyltriethoxysilane and the like. When a functional silane compound is used, its content is preferably 0.1 to 30 parts by mass, more preferably 0.1 to 20 parts by mass with respect to 100 parts by mass of the polymer component contained in the liquid crystal aligning agent. part by mass.

The solid content concentration in the liquid crystal aligning agent (ratio of the total mass of components other than the solvent of the liquid crystal aligning agent to the total mass of the liquid crystal aligning agent) is appropriately selected in consideration of viscosity, volatility, etc., but preferably It is in the range of 1 to 10% by mass.

A particularly preferable solid content concentration range varies depending on the method used when applying the liquid crystal aligning agent to the substrate. For example, when a spin coating method is used, the solid content concentration is particularly preferably in the range of 1.5 to 4.5% by mass. When the printing method is used, it is particularly preferable to set the solid content concentration in the range of 3 to 9% by mass, thereby setting the solution viscosity in the range of 12 to 50 mPa·s. In the case of the ink jet method, it is particularly preferable to set the solid content concentration in the range of 1 to 5% by mass, thereby setting the solution viscosity in the range of 3 to 15 mPa·s. The temperature in preparing the polymer composition is preferably 10-50°C, more preferably 20-30°C.

The liquid crystal aligning agent described above can be effectively applied to various technical applications. type liquid crystal alignment film for liquid crystal light control element), protective film (e.g. protective film for color filter), spacer film, interlayer insulation film, antireflection film, wiring coating film, antistatic film, motor insulation film ( It can also be applied to gate insulating films of flexible displays, etc.
[Liquid crystal alignment film and liquid crystal display element]
A liquid crystal aligning film can be manufactured by using the said liquid crystal aligning agent. Moreover, the liquid crystal display element which concerns on this invention comprises the liquid crystal aligning film formed using the said liquid crystal aligning agent. The operation mode of the liquid crystal display device according to the present invention is not particularly limited. It can be applied to various operation modes such as type (IPS type, FFS type) and optically compensated bend type (OCB type).

The liquid crystal display element of the present invention can be produced, for example, by a method including the following steps (1) to (4), a method including steps (1) to (2) and (4), steps (1) to (3), and (4). -2) and (4-4), or by a method including steps (1) to (3), (4-3) and (4-4).
<Step (1): Step of applying a liquid crystal aligning agent onto a substrate>
A process (1) is a process of apply|coating the liquid crystal aligning agent of this invention on a board|substrate. A specific example of step (1) is as follows.

The liquid crystal aligning agent of the present invention is applied to one surface of the substrate provided with the patterned transparent conductive film by an appropriate coating method such as a roll coater method, a spin coat method, a printing method, an inkjet method, or the like. Here, the substrate is not particularly limited as long as it is highly transparent, and in addition to a glass substrate and a silicon nitride substrate, a plastic substrate such as an acrylic substrate or a polycarbonate substrate can also be used. In addition, in a reflective liquid crystal display element, if only one substrate is used, an opaque material such as a silicon wafer can be used, and in this case, a light-reflecting material such as aluminum can be used for the electrodes. In the case of manufacturing an IPS type or FFS type liquid crystal display element, a substrate provided with electrodes made of a transparent conductive film or a metal film patterned in a comb shape and a counter substrate provided with no electrodes are used. and

Screen printing, offset printing, flexographic printing, an inkjet method, a spray method, etc. are mentioned as a method of apply|coating a liquid crystal aligning agent to a board|substrate and forming into a film. Among them, the coating method and the film-forming method by the inkjet method can be preferably used.
<Step (2): Step of firing the applied liquid crystal aligning agent>
A process (2) is a process of baking the liquid crystal aligning agent apply|coated on the board|substrate, and forming a film|membrane. A specific example of step (2) is as follows.

After the liquid crystal aligning agent is applied onto the substrate in step (1), the solvent is evaporated or the polyamic acid is thermally imidized by heating means such as a hot plate, a thermal circulation oven, or an IR (infrared) oven. you can go The drying and baking steps after applying the liquid crystal aligning agent of the present invention can be performed at any desired temperature and time, and may be performed multiple times. The temperature for baking the liquid crystal aligning agent can be, for example, 40 to 180.degree. From the viewpoint of shortening the process, it may be carried out at 40 to 150°C. The firing time is not particularly limited, but may be 1 to 10 minutes or 1 to 5 minutes. When the polyamic acid is thermally imidized, a step of firing at a temperature range of 150 to 300° C. or 150 to 250° C. may be added after the above step. The firing time is not particularly limited, but may be 5 to 40 minutes or 5 to 30 minutes.

The film thickness of the film after baking is preferably 5 to 300 nm, more preferably 10 to 200 nm, because if it is too thin, the reliability of the liquid crystal display element may be lowered.

<Step (3): Step of subjecting the film obtained in Step (2) to orientation treatment>
Step (3) is a step of subjecting the film obtained in step (2) to orientation treatment. That is, in a horizontally aligned liquid crystal display element such as an IPS system or an FFS system, the coating film is subjected to an alignment ability imparting treatment. On the other hand, in a vertical alignment type liquid crystal display element such as VA mode or PSA mode, the formed coating film can be used as a liquid crystal alignment film as it is, but the coating film may be subjected to an alignment ability imparting treatment. Examples of the alignment treatment method for the liquid crystal alignment film include a rubbing treatment method and a photo-alignment treatment method. As a photo-alignment treatment method, the surface of the film is irradiated with radiation polarized in a certain direction, and optionally, preferably, heat treatment is performed at a temperature of 150 to 250 ° C. to improve liquid crystal alignment (liquid crystal alignment (also referred to as ability). As radiation, ultraviolet light or visible light having a wavelength of 100 to 800 nm can be used. Among them, ultraviolet rays having a wavelength of 100 to 400 nm, more preferably 200 to 400 nm are preferred.

The irradiation dose of the radiation is preferably 1 to 10,000 mJ/cm ² . Among them, 100 to 5,000 mJ/cm ² is preferable. In addition, when irradiating with radiation, the substrate having the film-like material may be irradiated with heating at 50 to 250° C. in order to improve liquid crystal orientation. The liquid crystal alignment film thus produced can stably orient liquid crystal molecules in a fixed direction.

Furthermore, the liquid crystal alignment film irradiated with polarized radiation can be subjected to contact treatment using water or a solvent, or the liquid crystal alignment film irradiated with radiation can be heat-treated.

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

The temperature of the heat treatment for the coating film irradiated with radiation is more preferably 50 to 300.degree. C., further preferably 120 to 250.degree. The heat treatment time is preferably 1 to 30 minutes.
<Step (4): Step of producing a liquid crystal cell>
Two substrates on which liquid crystal alignment films are formed as described above are prepared, and liquid crystal is arranged between the two substrates facing each other. Specifically, the following two methods are mentioned.

In the first method, first, two substrates are arranged facing each other with a gap (cell gap) between them so that the respective liquid crystal alignment films face each other. Next, the peripheries of the two substrates are bonded together using a sealing agent, and a liquid crystal composition is injected and filled into the cell gap defined by the substrate surface and the sealing agent to contact the film surface, and then the injection hole is sealed. stop.

The liquid crystal composition is not particularly limited, and various liquid crystal compositions containing at least one liquid crystal compound (liquid crystal molecule) and having positive or negative dielectric anisotropy can be used. In the following description, a liquid crystal composition with a positive dielectric anisotropy is also referred to as a positive liquid crystal, and a liquid crystal composition with a negative dielectric anisotropy is also referred to as a negative liquid crystal.
The above liquid crystal composition contains a fluorine atom, a hydroxy group, an amino group, a fluorine atom-containing group (e.g., trifluoromethyl group), a cyano group, an alkyl group, an alkoxy group, an alkenyl group, an isothiocyanate group, a heterocyclic ring, a cycloalkane, A liquid crystal compound having a cycloalkene, a steroid skeleton, a benzene ring, or a naphthalene ring may be included, and a compound having two or more rigid sites (mesogenic skeleton) exhibiting liquid crystallinity in the molecule (for example, two rigid biphenyl structure, or a bimesogenic compound in which a terphenyl structure is linked by an alkyl group). The liquid crystal composition may be a liquid crystal composition exhibiting a nematic phase, a liquid crystal composition exhibiting a smectic phase, or a liquid crystal composition exhibiting a cholesteric phase.
In addition, the liquid crystal composition may further contain an additive from the viewpoint of improving liquid crystal orientation. Such additives include photopolymerizable monomers such as compounds having a polymerizable group described below; optically active compounds (eg, S-811 manufactured by Merck Co., Ltd.); antioxidants; UV absorbers; dyes; antifoaming agents; polymerization initiators; or polymerization inhibitors.
Positive liquid crystals include ZLI-2293, ZLI-4792, MLC-2003, MLC-2041, MLC-3019 and MLC-7081 manufactured by Merck.
As the negative liquid crystal, for example, MLC-6608, MLC-6609, MLC-6610, MLC-6882, MLC-6886, MLC-7026, MLC-7026-000, MLC-7026-100, or MLC- 7029 and the like.
In addition, in the PSA mode, MLC-3023 manufactured by Merck Co., Ltd. can be used as a liquid crystal containing a compound having a polymerizable group.

The second method is a method called the ODF (One Drop Fill) method. A predetermined place on one of the two substrates on which the liquid crystal alignment film is formed is coated with, for example, an ultraviolet light-curing sealant, and a liquid crystal composition is applied to several predetermined places on the surface of the liquid crystal alignment film. drip. Thereafter, the other substrate is attached so that the liquid crystal alignment films face each other, and the liquid crystal composition is spread over the entire surface of the substrate and brought into contact with the film surface. Next, the entire surface of the substrate is irradiated with ultraviolet light to cure the sealant. In any method, it is desirable to remove the flow orientation at the time of liquid crystal filling by heating the liquid crystal composition to a temperature at which the used liquid crystal composition assumes an isotropic phase and then slowly cooling to room temperature.

When the coating film is subjected to the rubbing treatment, the two substrates are arranged opposite to each other so that the rubbing directions in each coating film are at a predetermined angle, for example, perpendicular or antiparallel.

As the sealant, for example, an epoxy resin or the like containing a curing agent and aluminum oxide spheres as spacers can be used. Examples of liquid crystals include nematic liquid crystals and smectic liquid crystals. Among them, nematic liquid crystals are preferable. Liquid crystals, terphenyl-based liquid crystals, biphenylcyclohexane-based liquid crystals, pyrimidine-based liquid crystals, dioxane-based liquid crystals, bicyclooctane-based liquid crystals, cubane-based liquid crystals, and the like can be used. These liquid crystals may also contain cholesteric liquid crystals such as cholestyl chloride, cholesteryl nonaate and cholesteryl carbonate; a ferroelectric liquid crystal such as p-decyloxybenzylidene-p-amino-2-methylbutyl cinnamate may be added and used. In addition, various types such as those disclosed in Japanese Patent Application Laid-Open No. 2019-132952 can be used.

The liquid crystal described above is prepared by mixing several liquid crystals so as to satisfy desired physical properties according to the intended use (hereinafter, a liquid crystal component obtained by mixing a plurality of liquid crystals is also referred to as a mixed liquid crystal). is common.

Among these, it is preferable to use fluorine-based mixed liquid crystals, which are currently generally used in liquid crystal display devices. In this specification, the fluorine-based mixed liquid crystal means a mixed liquid crystal containing one or more fluorine-based liquid crystals, and the cyano-based mixed liquid crystal means a mixed liquid crystal containing one or more cyano-based liquid crystals. .

The mixed liquid crystals described above are generally known and commercially available. -4792, and is sold by Merck Co., Ltd. under the trade name of MLC-6608 as a liquid crystal having a negative dielectric anisotropy Δε (also referred to as a negative type liquid crystal). Furthermore, the cyano-based mixed liquid crystal is sold by Chisso Petrochemical Co., Ltd. under the trade name of JC-5066XX as a positive type liquid crystal. Among others, the present invention provides a liquid crystal alignment film suitable for a liquid crystal display element using a negative liquid crystal, and a liquid crystal alignment agent that provides the liquid crystal alignment film.

The liquid crystal aligning agent of the present invention has a liquid crystal layer between a pair of substrates provided with electrodes, and a liquid crystal composition containing a polymerizable compound polymerized by at least one of active energy rays and heat between the pair of substrates. A liquid crystal display element (PSA type liquid crystal display element) manufactured through a process of polymerizing a polymerizable compound by at least one of irradiating an active energy ray and heating while placing an object and applying a voltage between electrodes. It is preferably used.

Further, the liquid crystal aligning agent of the present invention has a liquid crystal layer between a pair of substrates provided with electrodes, and a polymerizable group polymerized by at least one of active energy rays and heat is placed between the pair of substrates. It is also preferably used in a liquid crystal display element (SC-PVA mode type liquid crystal display element) manufactured through a process of arranging a liquid crystal alignment film containing a liquid crystal and applying a voltage between electrodes.
<Step (4-2): For PSA type liquid crystal display element>
The procedure is the same as in (4) above except that a liquid crystal composition containing a polymerizable compound is injected or dropped. Examples of the polymerizable compound include polymerizable compounds having one or more polymerizable unsaturated groups such as acrylate groups and methacrylate groups in the molecule.
<Step (4-3): For SC-PVA mode liquid crystal display element>
A method of manufacturing a liquid crystal display element may be employed in which a step of irradiating ultraviolet rays, which will be described later, is performed after performing the same as in the above (4). According to this method, a liquid crystal display device excellent in response speed can be obtained with a small amount of light irradiation, as in the case of manufacturing the PSA type liquid crystal display device. The compound having a polymerizable group may be a compound having one or more polymerizable unsaturated groups in the molecule, and its content is 0.1 to 30 per 100 parts by mass of all polymer components. It is preferably parts by mass, more preferably 1 to 20 parts by mass. Further, the polymerizable group may be present in the polymer used for the liquid crystal alignment agent, and such a polymer includes, for example, a diamine component containing a diamine having a photopolymerizable group at the end thereof, which is used in the reaction. The polymer obtained is mentioned.
<Step (4-4): Step of irradiating with ultraviolet rays>
The liquid crystal cell is irradiated with light while a voltage is applied between the conductive films of the pair of substrates obtained in (4-2) or (4-3) above. The voltage applied here can be, for example, 5 to 50 V direct current or alternating current. As the light for irradiation, for example, ultraviolet light containing light with a wavelength of 150 to 800 nm and visible light can be used, but ultraviolet light containing light with a wavelength of 300 to 400 nm is preferable. 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, or the like can be used as the light source for the irradiation light. The irradiation amount of light is preferably 1,000 to 200,000 J/m ² , more preferably 1,000 to 100,000 J/m ² .

Then, a liquid crystal display element can be obtained by bonding a polarizing plate to the outer surface of the liquid crystal cell as necessary. As the polarizing plate to be attached to the outer surface of the liquid crystal cell, a polarizing film called "H film" in which polyvinyl alcohol is stretched and oriented while absorbing iodine is sandwiched between cellulose acetate protective films, or the H film itself. A polarizing plate consisting of

The IPS substrate, which is a comb-teeth electrode substrate used in the IPS mode, includes a base material, a plurality of linear electrodes formed on the base material and arranged in a comb-like shape, and the base material covering the linear electrodes. and a liquid crystal alignment film formed as follows.

The FFS substrate, which is a comb-teeth electrode substrate used in the FFS mode, includes a substrate, a plane electrode formed on the substrate, an insulating film formed on the plane electrode, and an insulating film formed on the insulating film. , a plurality of linear electrodes arranged in a comb shape, and a liquid crystal alignment film formed on an insulating film so as to cover the linear electrodes.

FIG. 1 is a schematic cross-sectional view showing an example of the lateral electric field liquid crystal display element of the present invention, which is an example of an IPS mode liquid crystal display element.

In the lateral electric field liquid crystal display element 1 illustrated in FIG. 1, the liquid crystal 3 is sandwiched between the comb-teeth electrode substrate 2 having the liquid crystal alignment film 2c and the opposing substrate 4 having the liquid crystal alignment film 4a. The comb-shaped electrode substrate 2 includes a substrate 2a, a plurality of linear electrodes 2b formed on the substrate 2a and arranged in a comb-like shape, and formed on the substrate 2a so as to cover the linear electrodes 2b. and a liquid crystal alignment film 2c. The counter substrate 4 has a base material 4b and a liquid crystal alignment film 4a formed on the base material 4b. The liquid crystal alignment film 2c is, for example, the liquid crystal alignment film of the present invention. The liquid crystal alignment film 4c is also the liquid crystal alignment film of the present invention.

In the horizontal electric field liquid crystal display element 1, when a voltage is applied to the linear electrodes 2b, an electric field is generated between the linear electrodes 2b as indicated by the electric line of force L.

FIG. 2 is a schematic cross-sectional view showing another example of the lateral electric field liquid crystal display element of the present invention, which is an example of an FFS mode liquid crystal display element.

In the lateral electric field liquid crystal display element 1 illustrated in FIG. 2, the liquid crystal 3 is sandwiched between the comb-teeth electrode substrate 2 having the liquid crystal alignment film 2h and the opposing substrate 4 having the liquid crystal alignment film 4a. The comb-teeth electrode substrate 2 includes a base material 2d, a plane electrode 2e formed on the base material 2d, an insulating film 2f formed on the plane electrode 2e, and formed on the insulating film 2f to form a comb-like shape. It has a plurality of arranged linear electrodes 2g and a liquid crystal alignment film 2h formed on the insulating film 2f so as to cover the linear electrodes 2g. The counter substrate 4 has a base material 4b and a liquid crystal alignment film 4a formed on the base material 4b. The liquid crystal alignment film 2h is, for example, the liquid crystal alignment film of the present invention. The liquid crystal alignment film 4a is also the liquid crystal alignment film of the present invention.

In the horizontal electric field liquid crystal display element 1, when a voltage is applied to the planar electrode 2e and the linear electrode 2g, an electric field is generated between the planar electrode 2e and the linear electrode 2g as indicated by the electric line of force L.

The liquid crystal alignment film of the present invention can be applied to various uses other than the liquid crystal alignment film for the above uses. It can also be used for a liquid crystal alignment film for a transmission scattering type liquid crystal light control device. Furthermore, applications other than liquid crystal alignment films, such as protective films (e.g. protective films for color filters), spacer films, interlayer insulating films, antireflection films, wiring coating films, antistatic films, motor insulating films (flexible It can also be used for a gate insulating film of a display).

The liquid crystal display device of the present invention can be effectively applied to various devices such as watches, portable games, word processors, notebook computers, car navigation systems, camcorders, PDAs, digital cameras, mobile phones, smart phones, It can be used for various display devices such as various monitors, liquid crystal televisions, and information displays.

EXAMPLES The present invention will be specifically described below with reference to examples, etc., but the present invention is not limited to these examples. Abbreviations of compounds and solvents are as follows.
(organic solvent)
NMP: N-methyl-2-pyrrolidone GBL: γ-butyrolactone BCS: butyl cellosolve

(diamine)

(The diamine of formula (DA-2) is included in the range of diamines represented by formula (d _n ).)

(tetracarboxylic dianhydride)

(The tetracarboxylic dianhydrides of formulas (CA-3) and (CA-6) are included in the range of tetracarboxylic dianhydrides represented by formula (T _f ).)

(Additive)
AD-1: 3-glycidoxypropyltriethoxysilane

(Measurement of viscosity)
In the synthesis examples, the viscosity of the polymer solution was measured using an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.), a sample amount of 1.1 mL, a cone rotor TE-1 (1 ° 34', R24), and a temperature of 25. Measured in °C.
<Synthesis of polyamic acid>
(Synthesis example 1)
3.15 g (11.0 mmol) of DA-1 was weighed into a 100 mL eggplant flask equipped with a stirrer and a nitrogen inlet tube, 28.4 g of NMP was added, and dissolved by stirring while sending nitrogen. While stirring this diamine solution under water cooling, 2.37 g (10.6 mmol) of CA-1 was added, further 11.6 g of NMP was added, and the solution of polyamic acid ( Viscosity: 550 mPa·s) PAA-A1 was obtained.
(Synthesis example 2)
4.78 g (24.0 mmol) of DA-2 and 1.19 g (6.00 mmol) of DA-3 are weighed into a 100 mL eggplant flask equipped with a stirrer and a nitrogen inlet tube, and 56.9 g of NMP is added and nitrogen is added. was stirred while feeding to dissolve. While stirring this diamine solution under water cooling, 1.35 g (6.90 mmol) of CA-2 was added, 9.0 g of NMP was further added, and the mixture was stirred for 1 hour under a nitrogen atmosphere. Furthermore, 5.63 g (22.5 mmol) of CA-3 was added, and 7.5 g of NMP was added, and the mixture was stirred at 50°C for 15 hours under a nitrogen atmosphere to form a polyamic acid solution (viscosity: 530 mPa s) PAA-B1. got
(Synthesis Example 3)
2.99 g (15.0 mmol) of DA-2 and 2.97 g (15.0 mmol) of DA-3 are weighed into a 100 mL eggplant flask equipped with a stirrer and a nitrogen inlet tube, and 56.8 g of NMP is added, and nitrogen is added. was stirred while feeding to dissolve. While stirring this diamine solution under water cooling, 1.24 g (6.32 mmol) of CA-2 was added, 8.0 g of NMP was further added, and the mixture was stirred for 1 hour under a nitrogen atmosphere. Furthermore, 5.63 g (22.5 mmol) of CA-3 was added, and 7.9 g of NMP was added, and the mixture was stirred at 50°C for 15 hours under a nitrogen atmosphere to form a polyamic acid solution (viscosity: 310 mPa s) PAA-B2. got
(Synthesis Example 4)
6.97 g (35.0 mmol) of DA-2 and 6.94 g (35.0 mmol) of DA-3 are weighed into a 200 mL eggplant flask equipped with a stirring device and a nitrogen inlet tube, 102 g of NMP is added, and nitrogen is sent. Dissolved by stirring while stirring. While stirring this diamine solution under water cooling, 8.76 g (35.0 mmol) of CA-3 was added, 26.4 g of NMP was further added, and the mixture was stirred at 50° C. for 2 hours under a nitrogen atmosphere. Further, 9.54 g (32.4 mmol) of CA-4 was added, and 53.7 g of NMP was added, and the mixture was stirred at 50°C for 15 hours under a nitrogen atmosphere to form a solution of polyamic acid (viscosity: 400 mPa s) PAA-B3. got
(Synthesis Example 5)
2.99 g (15.0 mmol) of DA-2 and 2.97 g (15.0 mmol) of DA-3 are weighed into a 100 mL eggplant flask equipped with a stirrer and a nitrogen inlet tube, and 53.7 g of NMP is added and nitrogen is added. was stirred while feeding to dissolve. While stirring this diamine solution under water cooling, 5.63 g (22.5 mmol) of CA-3 was added, 12.0 g of NMP was further added, and the mixture was stirred at 50° C. for 2 hours under a nitrogen atmosphere. Furthermore, 1.90 g (6.46 mmol) of CA-4 was added, and 10.8 g of NMP was added, and the mixture was stirred at 50°C for 15 hours under a nitrogen atmosphere to form a polyamic acid solution (viscosity: 340 mPa s) PAA-B4. got
(Synthesis Example 6)
2.99 g (15.0 mmol) of DA-2 and 2.97 g (15.0 mmol) of DA-3 are weighed into a 100 mL eggplant flask equipped with a stirrer and a nitrogen inlet tube, and 53.7 g of NMP is added and nitrogen is added. was stirred while feeding to dissolve. While stirring this diamine solution under water cooling, 5.63 g (22.5 mmol) of CA-3 was added, 12.0 g of NMP was further added, and the mixture was stirred at 50° C. for 2 hours under a nitrogen atmosphere. Furthermore, 1.41 g (6.45 mmol) of CA-5 was added, and 8.4 g of NMP was added, and the mixture was stirred at 50°C for 15 hours under a nitrogen atmosphere to form a polyamic acid solution (viscosity: 340 mPa s) PAA-B5. got
(Synthesis Example 7)
1.83 g (7.50 mmol) of DA-4, 0.540 g (5.00 mmol) of DA-5, 2.40 g (7.00 mmol) of DA-6, and 2.40 g (7. 50 mmol), 1.99 g (5.00 mmol) of DA-7 was weighed out, 77.8 g of NMP was added, and dissolved by stirring while sending nitrogen. While stirring this diamine solution under water cooling, 5.38 g (24.0 mmol) of CA-1 was added, 11.3 g of NMP was further added, and the solution of polyamic acid ( Viscosity: 410 mPa·s) PAA-A2 was obtained.
(Synthesis Example 8)
6.87 g (24.0 mmol) of DA-1 was weighed into a 100 mL eggplant flask equipped with a stirrer and a nitrogen inlet tube, 61.9 g of NMP was added, and the mixture was dissolved by stirring while supplying nitrogen. While stirring this diamine solution under water cooling, 5.05 g (23.2 mmol) of CA-5 was added, 25.6 g of NMP was added, and the mixture was stirred at 50° C. for 15 hours under a nitrogen atmosphere to obtain a polyamic acid solution ( Viscosity: 530 mPa·s) PAA-A3 was obtained.
(Synthesis Example 9)
DA-4 3.66 g (15.0 mmol) and DA-2 2.99 g (15.0 mmol) are weighed into a 100 mL eggplant flask equipped with a stirring device and a nitrogen inlet tube, 59.9 g of NMP is added, and nitrogen is added. was stirred while feeding to dissolve. While stirring this diamine solution under water cooling, 5.63 g (22.5 mmol) of CA-3 was added, 9.7 g of NMP was further added, and the mixture was stirred at 50° C. for 2 hours under a nitrogen atmosphere. Further, 1.90 g (6.45 mmol) of CA-4 was added, and 10.8 g of NMP was added, and the mixture was stirred at 50°C for 15 hours under a nitrogen atmosphere to form a polyamic acid solution (viscosity: 515 mPa s) PAA-B6. got
(Synthesis Example 10)
4.74 g (23.8 mmol) of DA-2 and 2.02 g (10.2 mmol) of DA-3 are weighed into a 100 mL eggplant flask equipped with a stirrer and a nitrogen inlet tube, and 54.7 g of NMP is added and nitrogen is added. was stirred while feeding to dissolve. While stirring this diamine solution under water cooling, 3.81 g (17.0 mmol) of CA-6 was added, 5.20 g of NMP was further added, and the mixture was stirred at 50° C. for 2 hours under a nitrogen atmosphere. Further, 4.40 g (15.0 mmol) of CA-4 was added, and 24.7 g of NMP was added, and the mixture was stirred at 50°C for 15 hours under a nitrogen atmosphere to form a polyamic acid solution (viscosity: 299 mPa s) PAA-B7. got
(Synthesis Example 11)
4.74 g (23.8 mmol) of DA-2 and 3.04 g (10.2 mmol) of DA-8 are weighed into a 100 mL eggplant flask equipped with a stirrer and a nitrogen inlet tube, and 63.0 g of NMP is added, and nitrogen is added. was stirred while feeding to dissolve. While stirring this diamine solution under water cooling, 3.81 g (17.0 mmol) of CA-6 was added, 2.72 g of NMP was further added, and the mixture was stirred at 50° C. for 2 hours under a nitrogen atmosphere. Further, 4.40 g (15.0 mmol) of CA-4 was added, 24.7 g of NMP was added, and the mixture was stirred at 50°C for 15 hours under a nitrogen atmosphere to form a solution of polyamic acid (viscosity: 330 mPa s) PAA-B8. got
(Synthesis Example 12)
4.74 g (23.8 mmol) of DA-2 and 1.53 g (10.2 mmol) of DA-9 are weighed into a 100 mL eggplant flask equipped with a stirrer and a nitrogen inlet tube, and 50.8 g of NMP is added, and nitrogen is added. was stirred while feeding to dissolve. While stirring this diamine solution under water cooling, 3.81 g (17.0 mmol) of CA-6 was added, 6.38 g of NMP was further added, and the mixture was stirred at 50° C. for 2 hours under a nitrogen atmosphere. Further, 4.40 g (15.0 mmol) of CA-4 was added, 24.7 g of NMP was added, and the mixture was stirred at 50°C for 15 hours under a nitrogen atmosphere to form a solution of polyamic acid (viscosity: 298 mPa s) PAA-B9. got
Table 1 summarizes the types and amounts of the diamine component and the tetracarboxylic acid derivative component used in Synthesis Examples 1 to 12. In Table 1, the numbers in parentheses represent the amounts (mol parts) of the monomers used per 100 mol parts in total in each component.

<Preparation of liquid crystal aligning agent>
(Examples 1-9) and (Comparative Examples 1-2)
The polyamic acid solutions obtained in Synthesis Examples 1 to 12 were weighed and mixed so as to obtain a composition combination of Polymer 1 and Polymer 2 shown in the table below. Next, a GBL solution containing 1% by weight of NMP, GBL, BCS, and AD-1, and an NMP solution containing 10% by weight of AD-2 were added with stirring so as to have the composition shown in Table 2 below. By stirring at room temperature for 2 hours, liquid crystal aligning agents (1) to (9) of Examples 1 to 9 and liquid crystal aligning agents (R1) to (R2) of Comparative Examples 1 and 2 were obtained. Table 2 shows the specifications of the liquid crystal aligning agents obtained in Examples 1 to 9 and Comparative Examples 1 and 2.

Using each of the liquid crystal aligning agents obtained above, an FFS mode liquid crystal cell was produced according to the procedure described below, and the pretilt angle and the afterimage properties by long-term AC drive were evaluated. Moreover, using the same liquid crystal aligning agent, a longitudinal electric field liquid crystal cell was produced according to the procedure shown below, and the evaluation of the backlight resistance of the voltage holding ratio was evaluated.
[Fabrication of FFS mode liquid crystal cell]
First, a glass substrate with electrodes having a size of 30 mm×35 mm and a thickness of 0.7 mm was prepared. An IZO electrode having a solid pattern is formed as the first layer on the substrate to constitute the counter electrode. A SiN (silicon nitride) film formed by the method was formed. As for the film thickness of the SiN film of the second layer, a film having a film thickness of 500 nm functioning as an interlayer insulating film was used. A comb-like pixel electrode formed by patterning an IZO film as a third layer is arranged on the SiN film of the second layer, and two pixels, a first pixel and a second pixel, are formed. The size of each pixel is 10 mm long and 5 mm wide. At this time, the counter electrode of the first layer and the pixel electrode of the third layer were electrically insulated by the action of the SiN film of the second layer.
The pixel electrode of the third layer has a comb shape in which a plurality of electrode elements each having a width of 3 μm and having a central portion bent at an internal angle of 160° are arranged in parallel with an interval of 6 μm. Each pixel had a first region and a second region bounded by a line connecting bent portions of a plurality of electrode elements.

Next, after filtering the liquid crystal aligning agents (1) to (9) and (R1) to (R2) obtained in Examples 1 to 9 and Comparative Examples 1 to 2 with a filter having a pore size of 1.0 μm, the above An ITO film is formed on the surface and the back surface of the substrate with electrodes (first glass substrate) prepared in , and a glass substrate (second glass substrate) having a columnar spacer with a height of 4 μm. It was applied by spin coating. Then, after drying on a hot plate at 80° C. for 2 minutes, baking was performed at 230° C. for 20 minutes to obtain a polyimide film having a thickness of 60 nm on each substrate. After rubbing this liquid crystal alignment film with a rayon cloth (roller diameter: 140 mm, roller rotation speed: 1000 rpm, moving speed: 30 mm/sec, indentation length: 0.3 mm), ultrasonic irradiation was performed in pure water for 1 minute. After the substrate was washed with an air blower to remove water droplets, it was dried at 80° C. for 10 minutes to obtain a substrate with a liquid crystal alignment film.
Using the above two types of substrates with liquid crystal alignment films, they were combined so that their rubbing directions were antiparallel, and the surroundings were sealed except for a liquid crystal injection port to prepare an empty cell with a cell gap of 4 μm. Liquid crystal MLC-7026-100 (manufactured by Merck Co., Ltd., negative type liquid crystal) was vacuum-injected into this empty cell at normal temperature, and then the injection port was sealed to obtain an anti-parallel aligned liquid crystal cell. The obtained liquid crystal cell constituted an FFS mode liquid crystal display device. After that, the liquid crystal cell was heated at 120° C. for 1 hour, left overnight at 23° C., and then used for each evaluation described below.
[Fabrication of vertical electric field liquid crystal cell]
First, a glass substrate having a size of 30 mm×40 mm and a thickness of 1.1 mm was prepared. An ITO electrode having a film thickness of 35 nm was formed on the substrate, and the electrode had a stripe pattern of 40 mm long and 10 mm wide.
Next, after filtering the liquid crystal aligning agents (1) to (9) and (R1) to (R2) obtained in Examples 1 to 9 and Comparative Examples 1 to 2 with a filter having a pore size of 1.0 μm, preparation It was applied by spin coating to the above substrate with electrodes. After drying on a hot plate at 80° C. for 2 minutes, baking was performed in an IR oven at 230° C. for 20 minutes to form a coating film having a thickness of 100 nm to obtain a substrate with a liquid crystal alignment film. After rubbing this liquid crystal alignment film with a rayon cloth (roller diameter: 140 mm, roller rotation speed: 1000 rpm, moving speed: 30 mm/sec, indentation length: 0.3 mm), ultrasonic irradiation was performed in pure water for 1 minute. After the substrate was washed with an air blower to remove water droplets, it was dried at 80° C. for 10 minutes to obtain a substrate with a liquid crystal alignment film. Two substrates with this liquid crystal alignment film were prepared, and after scattering a 4 μm spacer on the surface of one of the liquid crystal alignment films, a sealant was printed thereon, and another substrate was rubbed in the opposite direction. , and after lamination with the film surfaces facing each other, the sealant was cured to prepare an empty cell. Liquid crystal MLC-7026-100 (manufactured by Merck Ltd., negative type liquid crystal) was injected into this empty cell by a vacuum injection method, and the injection port was sealed to obtain a liquid crystal cell. After that, the obtained liquid crystal cell was heated at 120° C. for 1 hour and allowed to stand at 23° C. overnight before being used for each evaluation.
<Evaluation of pretilt angle>
The pretilt angle of the FFS mode liquid crystal cell was evaluated using an AxoScan Muller matrix polarimeter manufactured by Optometrics. Viewing angle characteristics are better as the pretilt angle is lower. Specifically, a pretilt angle of less than 2.0° was defined as "good", and a pretilt angle of 2.0° or more was defined as "bad".
<Evaluation of afterimage characteristics by long-term AC drive>
Using the above FFS mode liquid crystal cell, an AC voltage of ±5.5 V was applied at a frequency of 30 Hz for 72 hours under illumination from a high luminance backlight (30,000 cd/m ² ). After that, the pixel electrode and the counter electrode of the liquid crystal cell were short-circuited.

After standing overnight at 23° C., the liquid crystal cell was placed between two polarizing plates arranged so that their polarization axes were orthogonal to each other, and the backlight was turned on with no voltage applied to measure the brightness of the transmitted light. The arrangement angle of the liquid crystal cell was adjusted so that . Then, the rotation angle when the liquid crystal cell is rotated from the angle at which the second region of the first pixel is the darkest to the angle at which the first region is the darkest is calculated as the angle Δθ1. The angle Δθ2 was calculated by comparing with the first region. The average value of these Δθ1 and Δθ2 was defined as the angle Δθ of the liquid crystal cell, and the smaller the value, the better the liquid crystal orientation.
Specifically, when the angle Δθ was less than 0.4°, the afterimage characteristics were excellent, that is, evaluated as “good”, and when the angle Δθ was 0.4° or more, the evaluation was performed by defining as “poor”.
<Backlight resistance evaluation of voltage holding rate>
Using a liquid crystal comprehensive evaluation device manufactured by Toyo Technica Co., Ltd., a voltage of 1 V was applied to the vertical electric field liquid crystal cell at a temperature of 60 ° C. for 60 μsec, and the voltage after 16.67 msec was measured to determine how long the voltage was maintained. It was evaluated as a voltage holding rate. This value was defined as VHR _ini .
Next, the vertical electric field liquid crystal cell was left for 72 hours under irradiation of a high luminance backlight (30,000 cd/m ² ), and the voltage holding ratio was measured in the same manner as the VHR _ini . This value was defined as VHR _BLU .
When this VHR _BLU is 90% or more, the aging resistance of the backlight is excellent, ie, "good", and when it is less than 90%, it is defined as "poor" and evaluated.

Table 3 below shows the evaluation results of the liquid crystal display elements using the liquid crystal aligning agents of Examples 1 to 9 and Comparative Examples 1 and 2.

As shown in the above table, the liquid crystal display elements using the liquid crystal aligning agents of Comparative Examples 1 and 2 were poor in at least one of the viewing angle characteristics, the afterimage characteristics, and the backlight resistance of the voltage holding ratio, The liquid crystal display elements using the liquid crystal aligning agent of the present invention of Examples 1 to 9 had good viewing angle characteristics, afterimage characteristics, and backlight resistance such as voltage holding ratio. From the above, it can be said that the liquid crystal display element using the liquid crystal aligning agent of the present invention has a small pretilt angle, good afterimage properties, and a good voltage holding ratio resistance to backlight aging.

1: Horizontal electric field liquid crystal display element 2: Comb

tooth electrode substrates

2a, 4b, 2d:

Base material

2b, 2g:

Linear electrodes

2c, 2h, 4a: Liquid crystal alignment film 2e: Planar electrodes 2f: Insulating film 3: Liquid crystal 4: Opposite substrate L: Line of electric force

In addition, the entire contents of the specification, claims, drawings and abstract of Japanese Patent Application No. 2021-115168 filed on July 12, 2021 are cited here, and as a disclosure of the specification of the present invention, It is taken in.

Claims

A liquid crystal aligning agent characterized by containing the following (A) component and (B) component.
(A) component: a polyimide precursor having 60 mol% or more of repeating units represented by the following formula (1) with respect to 1 mol of all repeating units in the polymer and a polyimide that is an imidized product of the polyimide precursor At least one polymer (A) selected from the group consisting of;
(B) component: a tetracarboxylic acid derivative component containing 5 mol% or more of the total tetracarboxylic acid derivative component of a tetracarboxylic dianhydride represented by the following formula (T f ), and a tetracarboxylic acid derivative component represented by the following formula (d n ) At least one polymer (B) selected from the group consisting of a polyimide precursor that is a reactant with a diamine component containing a diamine, and a polyimide that is an imidized product of the polyimide precursor.

(R 11 to R 14 each independently contain a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, a fluorine atom represents a monovalent organic group having 1 to 6 carbon atoms or a phenyl group, at least one of R 11 to R 14 represents a group other than a hydrogen atom as defined above, and Ar 1 and Ar 1' each represent: represents a benzene ring, and one or more hydrogen atoms on the benzene ring may be substituted with a monovalent group.L 1 and L 1′ are each a single bond, —O—, —C (=O )-, -O-C(=O)-, where A is an alkylene group having 5 to 12 carbon atoms, or between the carbon-carbon bonds of the alkylene group, -O- or -C(=O) Represents a divalent organic group (Qa) in which any group of —O— is inserted, provided that when L 1 and L 1′ represent a single bond, A is a divalent organic group (Qa) and each of R 1 and Z 1 independently represents a hydrogen atom or a monovalent organic group having 1 to 5 carbon atoms, and the two R 1 and Z 1 may be the same or different.)

(X f is a tetravalent organic group having a 5-membered or more alicyclic structure.)

(Y represents a nitrogen atom-containing heterocyclic ring and a group "*21-NR-*22" (*21 and *22 represent a bond that binds to a carbon atom constituting an aromatic ring, provided that the carbon atom does not form a ring with the nitrogen atom to which R is bonded.R represents a hydrogen atom or a monovalent organic group, and the above monovalent organic group is bonded to the nitrogen atom at a carbon atom other than the carbonyl carbon. represents a divalent organic group having a nitrogen atom-containing structure selected from the group consisting of amino groups.)
The group -L 1 -AL 1' - in the formula (1) is any of the following (n is an integer of 5 to 12; n1 and n2 are integers of 5 to 12 in total; The sum of m1, m2 and n' is an integer of 5 to 12.), the liquid crystal aligning agent according to claim 1.
—O—(CH 2 ) n —O—,
—O—(CH 2 ) n1 —O—(CH 2 ) n2 —O—,
-C(=O)-(CH 2 ) n -C(=O)-,
-O-C(=O)-( CH2 ) n -O-,
-O-C(=O)-( CH2 ) n -O-C(=O)-,
-O-C(=O)-( CH2 ) n -C(=O)-O-,
-(CH 2 ) m1 -O-C(=O)-(CH 2 ) n' -C(=O)-O-(CH 2 ) m2 -,
—(CH 2 ) m1 —O—(CH 2 ) n′ —O—(CH 2 ) m2 —,
-C(=O)-O-( CH2 ) n -O-C(=O)-,
-(CH 2 ) m1 -C(=O)-O-(CH 2 ) n' -O-C(=O)-(CH 2 ) m2 -,
—O—(CH 2 ) n —
The content of the diamine represented by the formula (d n ) in the constituent components of the polymer (B) is 20 to 95 mol% of the total diamine component used in the production of the polymer (B). Item 3. The liquid crystal aligning agent according to any one of Items 1 and 2.
The diamine represented by the above formula (d n ) is 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminocarbazole, N-methyl-3,6-diamino Carbazole, 1,4-bis-(4-aminophenyl)-piperazine, 3,6-diaminoacridine, N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, and the following formula ( 4. The liquid crystal aligning agent according to any one of claims 1 to 3, which is at least one diamine selected from the group consisting of diamines represented by d n -1) to (d n -3).

(In the formula (d n −1), m1 and m1′ are each independently an integer of 1 to 2. n1 is an integer of 1 to 3. R 1 is the above formula (d n ) is synonymous with R in the amino group represented by "*21-NR-*22" in the above.
When a plurality of R 1 and m1' are present, the plurality of R 1 and m1' may be the same or different.
In formula (d n -2), X 2 represents a monovalent nitrogen atom-containing heterocyclic group. n1 is an integer of 1 to 2, and n2 is an integer satisfying n1+n2=2. L 1 and L 2 are each independently a single bond, —CO—, an alkylene group having 1 to 6 carbon atoms, or between the carbon-carbon bonds of the alkylene group having 1 to 6 carbon atoms or at the terminal, — A divalent organic group into which O- or -CO- is inserted, and represents a divalent organic group bonded to a nitrogen atom via a carbon atom. R represents a hydrogen atom or a methyl group.
When multiple X 2 , L 2 and R are present, multiple X 2 , L 2 and R may be the same or different.
In formula (d n -3), X 3 represents a divalent group having a nitrogen atom-containing heterocyclic ring. Ar 3 represents a divalent aromatic ring group or a divalent saturated nitrogen atom-containing heterocyclic group. Arbitrary hydrogen atoms of aromatic ring groups and saturated nitrogen atom-containing heterocyclic groups may be replaced with monovalent groups.
L 3 is a single bond, -(CH 2 ) n - (n is an integer of 1 to 6), -NR'-, -(CH 2 ) n -NR'- (n is an integer of 1 to 6 ), -O-, -NR'-CO-, -CO-NR'-, -O-CO-, or -CO-O-, and R' is a hydrogen atom, a methyl group, or tert- represents a butoxycarbonyl group.
m3 and m3' are each independently an integer of 0 to 2, and either m3 or m3' is an integer of 1 or more.
When a plurality of Ar 3 and L 3 are present, the plurality of Ar 3 and L 3 may be the same or different.
However, both NH 2 groups at both ends of formula (d n -3) are bonded to carbon atoms constituting the aromatic ring. )
The diamines represented by the formulas (d n -1) to (d n -3) are the diamines represented by the following formulas (Dp-1) to (Dp-6), and the following formulas (z-1) to The liquid crystal aligning agent according to claim 4, which is a diamine selected from diamines represented by formula (z-14).
As a diamine component for obtaining the polymer (B), p-phenylenediamine, 2,3,5,6-tetramethyl-p-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, m- phenylenediamine, 2,4-dimethyl-m-phenylenediamine, 2,5-diaminotoluene, 2,6-diaminotoluene, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethyl- 4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-dihydroxy-4,4'-diaminobiphenyl, 2,2'-difluoro-4,4'- Diaminobiphenyl, 3,3'-difluoro-4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 3,3'-bis(trifluoromethyl)- 4,4'-diaminobiphenyl, 3,4'-diaminobiphenyl, 4,4'-diaminobiphenyl, 3,3'-diaminobiphenyl, 2,2'-diaminobiphenyl, 2,3'-diaminobiphenyl, 3, 3′-diaminodiphenylmethane, 3,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylmethane, 1,2-bis(4-aminophenyl)ethane, 1,2-bis(3-aminophenyl)ethane, 1, 3-bis(4-aminophenyl)propane, 1,3-bis(3-aminophenyl)propane, 1,4-bis(4-aminophenyl)butane, 1,4-bis(3-aminophenyl)butane, 1,5-bis(4-aminophenyl)pentane, 1,5-bis(3-aminophenyl)pentane, 1,6-bis(4-aminophenyl)hexane, 1,6-bis(3-aminophenyl) Hexane, 4,4'-diaminobenzophenone, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 1,4-bis(4-aminobenzyl)benzene, bis (4-aminophenoxy)methane, 1,2-bis(4-aminophenoxy)ethane, 1,2-bis(4-amino-2-methylphenoxy)ethane, 1,3-bis(4-aminophenoxy)propane , 1,4-bis(4-aminophenoxy)butane, 4-(2-(4-aminophenoxy)ethoxy)-3-fluoroaniline, 4-amino-4′-(2-(4-aminophenoxy)ethoxy ) biphenyl, 3,3′-diaminodiphenyl ether, 3 , 4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, a diamine having an amide bond or a urea bond, and at least one diamine selected from the group consisting of 4-(2-(methylamino)ethyl)aniline, The liquid crystal aligning agent according to any one of claims 1 to 5.
Any one of claims 1 to 6, wherein X f in the formula (T f ) is a tetravalent organic group represented by any one of the following formulas (X f -1) to (X f -17). The liquid crystal aligning agent according to the item.

(* represents a bond.)
Any one of claims 1 to 7, wherein the content ratio of the components (A) and (B) is 10/90 to 90/10 in terms of the mass ratio of [component (A)]/[component (B)]. The liquid crystal aligning agent according to item 1.
a crosslinkable compound (c-1) in which the liquid crystal aligning agent has at least one substituent selected from an epoxy group, an oxetane group, an oxazoline structure, a cyclocarbonate group, a blocked isocyanate group, a hydroxy group and an alkoxy group; at least one crosslinkable compound selected from the group consisting of a crosslinkable compound (c-2) having a polyunsaturated group, a functional silane compound, a metal chelate compound, a curing accelerator, a surfactant, an antioxidant, an 9. The composition according to any one of claims 1 to 8, further comprising at least one additive component selected from the group consisting of sensitizers, preservatives, and compounds for adjusting the dielectric constant and electrical resistance of the resin film. liquid crystal aligning agent.
A liquid crystal alignment film formed using the liquid crystal alignment agent according to any one of claims 1 to 9.
A liquid crystal display element comprising the liquid crystal alignment film according to claim 10.
A method for manufacturing a liquid crystal display device, comprising the following steps (1) to (3).
Step (1): A step of applying the liquid crystal aligning agent according to any one of claims 1 to 9 onto a substrate Step (2): A step of baking the applied liquid crystal aligning agent to obtain a film Step (3) ): a step of subjecting the film obtained in step (2) to orientation treatment