WO2022270287A1

WO2022270287A1 - Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element

Info

Publication number: WO2022270287A1
Application number: PCT/JP2022/022806
Authority: WO
Inventors: 圭太慈道
Original assignee: 日産化学株式会社
Priority date: 2021-06-24
Filing date: 2022-06-06
Publication date: 2022-12-29
Also published as: TW202317740A; KR20240023525A; JPWO2022270287A1; CN117546082A

Abstract

The present invention provides: a liquid crystal alignment agent which makes it possible to obtain a liquid crystal alignment film in which there is little variation of liquid crystal twist angles, in which an AC afterimage can be suppressed, and in which substrate separation is unlikely to occur; a liquid crystal alignment film; and a liquid crystal display element.　The liquid crystal alignment agent contains component (A) and component (B).　Component (A): A polyamic acid ester (A) which has two or more types of a structural unit (a-1Da) represented by formula (1Da) and a structural unit (a-1Ta) represented by formula (1Ta). Component (B): A polyamic acid (B) which has a structural unit (b-1Tb) represented by formula (1Tb) and a structural unit (b-1Db) represented by formula (1Db). (R11 to R14 represent a hydrogen atom, a C1-C6 alkyl group, or the like, and at least one of R11 to R14 represents a group other than a hydrogen atom. The two R1 represent a hydrogen atom or a t-alkyl group, where at least one of the two represents a t-alkyl group. Y1 is a divalent organic group represented by formula (H1). Z represents a hydrogen atom or the like.) (Ar1 and Ar1' represent a benzene ring or the like. A represents a C1-C10 divalent organic group having an alkylene structure. L1 and L1' represent a single bond or the like.) (Xb represents a tetravalent organic group, Yb represents a divalent organic group, and Z represents a hydrogen atom or the like.)

Description

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

The present invention relates to a liquid crystal aligning agent, a liquid crystal aligning film, and a liquid crystal display element that can provide a liquid crystal aligning film that has a small variation in the twist angle of liquid crystals, can suppress AC afterimages, and is less prone to substrate peeling.

Liquid crystal display devices are widely used, from small applications such as mobile phones and smartphones to relatively large applications such as televisions and monitors. A liquid crystal display device includes, for example, a liquid crystal layer sandwiched between an element substrate and a color filter substrate, a pixel electrode and a common electrode for applying an electric field to the liquid crystal layer, an alignment film for controlling the orientation of liquid crystal molecules in the liquid crystal layer, A thin film transistor (TFT) or the like is provided for switching an electric signal supplied to the pixel electrode. Known methods for driving liquid crystal molecules include vertical electric field methods such as the TN (Twisted Nematic) method and VA (Vertical Alignment) method, and horizontal electric field methods such as the IPS (In Plane Switching) method and the FFS (Fringe Field Switching) method. It is

Currently, the liquid crystal alignment film that is most widely used industrially is formed on an electrode substrate, and the surface of a film made of polyamic acid and/or polyimide imidized thereof is covered with a cloth such as cotton, nylon, or polyester. It is produced by rubbing in one direction, that is, by performing a so-called rubbing process. The rubbing treatment is a simple and useful method with excellent productivity. However, along with the high performance, high definition, and large size of liquid crystal display elements, scratches on the surface of the alignment film caused by rubbing, dust generation, mechanical force and static electricity, and furthermore, the alignment processing surface Various problems such as the non-uniformity of the As an alignment treatment method that replaces the rubbing treatment, a photo-alignment method is known in which polarized radiation is applied to impart liquid crystal alignment ability. As the photo-alignment method, a method using a photoisomerization reaction, a method using a photocrosslinking reaction, a method using a photodecomposition reaction, etc. have been proposed (for example, Non-Patent Document 1, Patent Document 1, Patent Document 2 reference).

Japanese Patent Laid-Open No. 9-297313 Japanese Patent Application Laid-Open No. 2004-206091

Liquid crystal alignment films used in liquid crystal display elements of the IPS driving method and the FFS driving method require a high alignment regulating force for suppressing afterimages (hereinafter also referred to as AC afterimages) generated by long-term AC driving. Moreover, when the alignment treatment is performed by a photo-alignment method, the amount of light irradiation is a factor that affects the energy cost and the production speed, so it is preferable that the alignment treatment can be performed with a small amount of light irradiation. On the other hand, as the size of the liquid crystal display element increases, a problem arises that the twist angle of the liquid crystal within the plane of the liquid crystal display element varies slightly due to variations in the manufacturing process. Such variations lead to non-uniform brightness in the plane of the liquid crystal display element when black is displayed, leading to deterioration of the quality of the liquid crystal display element.
Furthermore, in recent years, in touch panel type liquid crystal display devices, it has been found that the durability against external pressure such as pressure from a finger or a pointing device such as a pen is high. It is required that point defects hardly occur. In addition, tablet terminals and mobile terminals are becoming lighter and thinner, and stress is more likely to be applied to the inside of the panel due to the distortion of the panel during the panel assembly process during the manufacture of the liquid crystal display device. Such panel distortion and stress may cause the liquid crystal alignment film to peel off from the substrate, and may also cause defects such as bright spots and poor alignment. Therefore, the liquid crystal alignment film is required to have a high film strength to prevent substrate peeling.

Therefore, an object of the present invention is to obtain a liquid crystal alignment film that has a small variation (non-uniformity) in the twist angle of the liquid crystal in the plane of the liquid crystal alignment film and can suppress the AC afterimage, and at the time of manufacturing the liquid crystal display device. To provide a liquid crystal aligning agent that can obtain a liquid crystal aligning film that is difficult to peel off from a substrate in such as, a liquid crystal aligning film obtained from the liquid crystal aligning agent, and a liquid crystal display element using the liquid crystal aligning film.

As a result of intensive research, the present inventors have found that the above problems can be solved by using a liquid crystal aligning agent containing a specific component, and have completed the present invention.
The present invention specifically has the following aspects.

A liquid crystal aligning agent characterized by containing the following (A) component and (B) component.
Component (A): As a structural unit derived from a tetracarboxylic acid derivative, it has a structural unit (a-1Ta) represented by the following formula (1Ta), and as a structural unit derived from a diamine, represented by the following formula (1Da). Polyamic acid ester (A) having two or more types of structural units (a-1Da).
Component (B): As a structural unit derived from a tetracarboxylic acid derivative, it has a structural unit (b-1Tb) represented by the following formula (1Tb), and as a structural unit derived from a diamine, represented by the following formula (1Db). Polyamic acid (B) having a structural unit (b-1Db).

(In formula (1Ta), R ₁₁ to R ₁₄ each independently represent 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, group, a monovalent organic group having 1 to 6 carbon atoms containing a fluorine atom, or a phenyl group, and at least one of R ₁₁ to R ₁₄ represents a group other than a hydrogen atom as defined above. Each ₁ independently represents a hydrogen atom or a tert-alkyl group, at least one of which represents a tert-alkyl group.
In formula (1Da), Y ₁ is a divalent organic group represented by the following formula (H ₁ ). Each Z independently represents a hydrogen atom or a monovalent organic group. )

(In formula (H ₁ ), Ar ₁ and Ar ₁ _′ each independently represent a benzene ring, a biphenyl structure, or a naphthalene ring _. may be substituted with a valent group, A represents a divalent organic group having an alkylene structure and having 1 to 10 carbon atoms, L ₁ and L _1′ each independently represent a single bond, —O— , -S-, -C(=O)-, -OC(=O)-, -C(=O)-NR- (R represents a hydrogen atom or a monovalent organic group.), or - NR-C(=O)-(R represents a hydrogen atom or a monovalent organic group. * represents a bond.)

(In formula (1Tb), _Xb represents a tetravalent organic group, Yb in formula ( _1Db ) represents a divalent organic group, and Z each independently represents a hydrogen atom or a monovalent organic group. show.)

Throughout this specification, the meanings of the following terms and abbreviations are as follows. A halogen atom includes a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like. "Tert-" meaning tertiary is also referred to as "t-". A Boc group represents a tert-butoxycarbonyl group. * represents a bond.

ADVANTAGE OF THE INVENTION According to this invention, the liquid crystal aligning film which can suppress an AC afterimage with little dispersion|variation (non-uniformity) of the twist angle of the liquid crystal in a liquid crystal aligning film surface is obtained, even in the alignment process by the light irradiation amount with a small amount. At the same time, it is possible to obtain a liquid crystal aligning agent, the liquid crystal aligning film, and a liquid crystal display element using the liquid crystal aligning film that can obtain a liquid crystal aligning film that does not easily peel off from the substrate during manufacturing of the liquid crystal display device.
Although the mechanism by which the above effects are obtained by the present invention is not necessarily clear, the following is considered to be one of the reasons. The liquid crystal aligning agent of the present invention contains a specific polyamic acid ester (A) and polyamic acid (B) as polymer components. Since the polyamic acid ester (A) has a highly hydrophobic t-alkyl ester structure, the formation of hydrogen bonds with the polyamic acid (B) is suppressed, and the component to the air interface when used as a liquid crystal alignment film. The migration becomes high, and the uneven distribution of the polyamic acid ester at the liquid crystal interface becomes high. In addition, since the polyamic acid ester (A) having a bulky structure has a t-alkyl ester that is easily eliminated when the coating film is baked, thermal imidization proceeds more easily than with a normal methyl ester structure. It becomes difficult for the t-alkyl ester to remain in the resulting liquid crystal alignment film.

As a result, high liquid crystal orientation can be uniformly obtained in the plane, so even with a small amount of light irradiation, the variation (non-uniformity) in the twist angle of the liquid crystal in the plane of the liquid crystal alignment film is small, and AC afterimages are suppressed. It is considered that a liquid crystal alignment film that can be obtained is obtained. Further, in the above polyamic acid ester (A), for example, when R ₁ is a t-butyl group, isobutene is eliminated during firing, and imidization proceeds via polyamic acid, so the obtained liquid crystal The film strength of the alignment film is also improved. In addition, since the liquid crystal aligning agent of the present invention contains the polyamic acid (B) and has a highly polar structure, it is thought that a liquid crystal aligning film that is less prone to substrate peeling can be obtained.

1 is a schematic partial 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 partial cross-sectional view showing another example of the horizontal electric field liquid crystal display device of the present invention;

<Polyamic acid ester (A)>
The liquid crystal aligning agent of the present invention has a structural unit (a-1Ta) represented by the above formula (1Ta) as a structural unit derived from a tetracarboxylic acid derivative, and a structural unit derived from a diamine having the above formula (1Da). Contains a polyamic acid ester (A) having two or more structural units (a-1Da) represented by. In addition, the polymer (A) may be composed of one type or two or more types.
The polyamic acid ester (A) has two or more types of structural units (a-1Da) represented by the above formula (1Da), thereby achieving an appropriate balance with respect to multiple properties such as high alignment control force and high photosensitivity. Therefore, it is possible to obtain a liquid crystal alignment film capable of suppressing an AC afterimage and reduce the irradiation amount of light required for the alignment treatment.

All the repeating units of the polyamic acid ester (A) of the present invention may have an amic acid ester structure, or a part of the repeating units may have an amic acid ester structure. When some of the repeating units have an amic acid ester structure, the remaining repeating units may have an amic acid structure, or may have an imidized structure of the amic acid structure. Moreover, as the remaining repeating units, it may have a repeating unit with an amic acid structure and a repeating unit with an imidized structure.

Specific examples of the alkyl group having 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms in R ₁₁ to R ₁₄ in the formula (1Ta) representing the structural unit derived from the tetracarboxylic acid derivative of the polyamic acid ester (A) include: Examples include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-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 ₁₁ to R ₁₄ include a vinyl group, a propenyl group, a butynyl group and the like, and these may be linear or branched. . Specific examples of alkynyl groups having 2 to 6 carbon atoms, preferably 2 to 4 carbon atoms in R ₁₁ to R ₁₄ include ethynyl group, 1-propynyl group and 2-propynyl group. The fluorine atom-containing monovalent organic group having 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms for R ₁₁ to R ₁₄ is fluoromethyl group, trifluoromethyl group, pentafluoroethyl group, pentafluoropropyl and the like.

A more preferable combination of R ₁₁ to R ₁₄ is that, from the viewpoint of high photoreactivity, R ₁₁ to R ₁₄ are hydrogen atoms or methyl groups, and at least one of R ₁₁ to R ₁₄ is a methyl group. , R ₁₁ to R ₁₄ are more preferably methyl groups. More preferably, R ₁₁ and R ₁₄ are methyl groups and R ₁₂ and R ₁₃ are hydrogen atoms.
The t-alkyl group of R ₁ of the polyamic acid ester (A) is a t-alkyl group having 4 to 10 carbon atoms, preferably 4 to 7 carbon atoms. Specific examples include t-butyl group, t-pentyl group, t-hexyl group and t-heptyl group. Among them, a t-butyl group is preferred.

The structural unit (a-1Ta) of the polyamic acid ester (A) of the present invention is, from the viewpoint of suitably obtaining the effects of the present invention, 1 mol of all structural units derived from the tetracarboxylic acid derivative of the polyamic acid ester (A). is preferably 5 mol % or more, more preferably 25 mol % or more, and even more preferably 60 mol % or more.

The polyamic acid ester (A) of the present invention may have a structural unit (a-2Ta) represented by the following formula (2Ta) as a structural unit derived from a tetracarboxylic acid derivative.

(Two R ₂ each independently represent a hydrogen atom or a monovalent organic group. X _2a represents a tetravalent organic group, provided that X _2a is 4 represented by the following formula (g). In the case of a valent organic group, _R2 represents a hydrogen atom.)

(R _11′ to R _14′ , including their preferred embodiments, are synonymous with R ₁₁ to R ₁₄ in formula (1Ta) above.)

The monovalent organic group for R ₂ in the above formula (2Ta) is a monovalent hydrocarbon group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, and the methylene group of the hydrocarbon group is -O-, - S—, —CO—, —COO—, —COS—, —NR ³ — (where R ³ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms), —CO—NR ³ - (provided that R ³ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms), -Si(R ³ ) ₂ - (provided that R ³ is a hydrogen atom or a to 10 monovalent hydrocarbon groups), a monovalent group A substituted with —SO ₂ — or the like, the above monovalent hydrocarbon group or a hydrogen bonded to a carbon atom of the above monovalent group A at least one of the atoms is a halogen atom, a hydroxy group, an alkoxy group, a nitro group, an amino group, a mercapto group, a nitroso group, an alkylsilyl group, an alkoxysilyl group, a silanol group, a sulfino group, a phosphino group, a carboxy group, a cyano group, A monovalent group substituted with a sulfo group, an acyl group, or the like, or a monovalent group having a heterocyclic ring can be mentioned.
Examples of the monovalent organic group for R ₂ in the above formula (2Ta) include, among others, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, and t-butoxycarbonyl. or a 9-fluorenylmethoxycarbonyl group, more preferably an alkyl group having 1 to 3 carbon atoms, and even more preferably a methyl group.
From the viewpoint of suitably obtaining the effects of the present invention, the two R ₂ are each independently preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, more preferably a hydrogen atom or a methyl group.

Specific examples of the tetravalent organic group of X _2a in the above formula (2Ta) include, in addition to the tetravalent organic group represented by the above formula (g), the following tetracarboxylic dianhydrides (hereinafter collectively referred to as (also referred to as other tetracarboxylic dianhydrides.) with two acid anhydride groups removed.

Acyclic aliphatic tetracarboxylic dianhydrides such as 1,2,3,4-butanetetracarboxylic dianhydride; 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3 ,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3′,4,4′-dicyclohexyltetracarboxylic dianhydride, 2,3, 5-Tricarboxycyclopentylacetic acid dianhydride, 4-(2,5-dioxotetrahydrofuran-3-yl)tetrahydronaphthalene-1,2-dicarboxylic dianhydride, 5-(2,5-dioxotetrahydrofuran-3 -yl)-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 5-(2,5-dioxotetrahydrofuran-3-yl)-8-methyl-3a ,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic acid di anhydride, bicyclo[2.2.2]octane-2,3,5,6-tetracarboxylic dianhydride, 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2: Alicyclic tetracarboxylic dianhydrides such as 4,6:8-dianhydride; pyromellitic dianhydride, 3,3′,4,4′-benzophenonetetracarboxylic dianhydride, 3,3′ ,4,4′-diphenylsulfonetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3 ',4,4'-diphenyl ether tetracarboxylic dianhydride, 3,3',4,4'-perfluoroisopropylidenedi(phthalic anhydride), 3,3',4,4'-biphenyltetracarboxylic acid acid dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)-2,2-diphenylpropane dianhydride, ethylene Glycol bisanhydrotrimellitate, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 4,4'-carbonyldiphthalic anhydride, 4,4'-oxydi(1,4-phenylene)bis (Phthalic acid) dianhydride, or aromatic tetracarboxylic dianhydride such as 4,4′-methylenedi(1,4-phenylene)bis(phthalic acid) dianhydride; Tetraka described in the publication Rubonic acid dianhydride, etc.

More preferred examples of the other tetracarboxylic dianhydrides include 1,2,3,4-butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1, 2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3′,4,4′-dicyclohexyltetracarboxylic dianhydride, 2 , 3,5-tricarboxycyclopentyl acetic acid dianhydride, 5-(2,5-dioxotetrahydrofuran-3-yl)-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1, 3-dione, 5-(2,5-dioxotetrahydrofuran-3-yl)-8-methyl-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 2 ,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-dianhydride, pyromellitic dianhydride, 3,3′,4,4′-benzophenone tetra Carboxylic dianhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 3,3′,4,4′-diphenyl ether tetracarboxylic dianhydride, 3,3′,4,4′-biphenyltetracarboxylic dianhydride, 2,2′,3, 3'-biphenyltetracarboxylic dianhydride is mentioned.

The tetravalent organic group of X _2a in the above formula (2Ta) is more preferably a tetravalent organic group represented by the above formula (g) from the viewpoint of suitably obtaining the effects of the present invention.

The ratio of the structural units represented by the formula (2Ta) in the polyamic acid ester (A) is 95 mol% or less with respect to 1 mol of all structural units derived from the tetracarboxylic acid derivative in the polyamic acid ester (A). Preferably, 75 mol % or less is more preferable, and 40 mol % or less is even more preferable.

Y ₁ in the above formula (1Da) is a divalent organic group represented by the above formula (H ₁ ). In formula (H ₁ ), L ₁ and L _1' are as described above. The monovalent organic group for R in -C(=O)-NR- or -NR-C(=O)- representing L ₁ or L _1' is an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, an alkenyl group having 2 to 3 carbon atoms, an acyl group having 2 to 3 carbon atoms, an alkylsilyl group having 1 to 3 carbon atoms, an alkoxysilyl group having 1 to 3 carbon atoms, or any of these A monovalent organic group in which a part of the hydrogen atoms of the group is substituted with at least one of a halogen atom and a hydroxy group can be mentioned.

The monovalent group which is a substituent of any hydrogen atom on the ring of Ar ₁ and Ar _1′ in the above formula (H ₁ ) includes a halogen atom; an alkyl group having 1 to 3 carbon atoms; Alkyl group with 1 to 3 carbon atoms partially substituted with halogen atom or hydroxy group; an alkoxy group having 1 to 3 carbon atoms; an alkenyl group having 2 to 3 carbon atoms; an acyl group having 2 to 3 carbon atoms; an alkylsilyl group having 1 to 3 carbon atoms; an alkoxysilyl group having 1 to 3 carbon atoms; A monovalent group such as a nitrile group can be mentioned.

Specific examples of Ar ₁ and Ar _1′ in the above formula (H ₁ ) include 1,4-phenylene, 1,3-phenylene, 2-methyl-1,4-phenylene, 2-ethyl-1,4-phenylene , 2-propyl-1,4-phenylene, 2-butyl-1,4-phenylene, 2-isopropyl-1,4-phenylene, 2-t-butyl-1,4-phenylene, 2-methoxy-1,4 -phenylene, 2-ethoxy-1,4-phenylene, 2-propoxy-1,4-phenylene, 2-butoxy-1,4-phenylene, 2-fluoro-1,4-phenylene, 2,3-dimethyl-1 ,4-phenylene, 4-methyl-1,3-phenylene, 5-methyl-1,3-phenylene, 4-fluoro-1,3-phenylene, 2,3,5,6-tetramethyl-1,4- Benzene ring optionally having a substituent such as phenylene; 4,4'-biphenylylene, 2-methyl-4,4'-biphenylylene, 2-ethyl-4,4'-biphenylylene, 2-propyl-4,4 '-biphenylylene, 2-butyl-4,4'-biphenylylene, 2-t-butyl-4,4'-biphenylylene, 2-methoxy-4,4'-biphenylylene, 2-ethoxy-4,4'-biphenylylene, 2-fluoro-4,4'-biphenylylene, 3-methyl-4,4'-biphenylylene, 3-ethyl-4,4'-biphenylylene, 3-propyl-4,4'-biphenylylene, 3-butyl-4, 4'-biphenylylene, 3-t-butyl-4,4'-biphenylylene, 3-methoxy-4,4'-biphenylylene, 3-ethoxy-4,4'-biphenylylene, 3-fluoro-4,4'-biphenylylene , 2,2′-dimethyl-4,4′-biphenylylene, 3,3′-dimethyl-4,4′-biphenylylene, 3,3′-biphenylylene, 5-methyl-3,3′-biphenylylene, 5,5 biphenyl structure optionally having a substituent such as '-dimethyl-3,3'-biphenylylene; a naphthalene ring that may be used.

A in the above formula (H ₁ ) is a divalent organic group having an alkylene structure. When the alkylene structure has 3 or more carbon-carbon bonds, any carbon-carbon bonds making up the alkylene structure may be replaced with a carbon-carbon double bond. A is preferably an alkylene group having 1 to 10 carbon atoms (q0); =O)-, or a divalent organic group (q1) in which -C(=O)-O- is inserted; or between the carbon-carbon bonds of the alkylene group, -NR-C(=O)- A divalent organic group (q2) having at least one NR- (R represents a hydrogen atom or a monovalent organic group).
Here, the monovalent organic group for R in -NR-C(=O)-NR- is -C(=O)-NR- representing L ₁ and L _1' of formula (H ₁ ). Structures exemplified for R in are mentioned.

Preferable specific examples of (q0), (q1), and (q2) above are as follows.
*-( _CH2 ) _n- *,
*-(CH ₂ ) _n1 -O-(CH ₂ ) _n2 -*,
*-(CH ₂ ) _m1 -O-C(=O)-(CH ₂ ) _n' -C(=O)-O-(CH ₂ ) _m2 -*,
*-(CH ₂ ) _m1 -C(=O)-O-(CH ₂ ) _n' -O-C(=O)-(CH ₂ ) _m2 -*,
*-(CH ₂ ) _n1 -NR-C(=O)-NR-(CH ₂ ) _n2 -*

In the above chemical formula, R represents a hydrogen atom or a monovalent organic group. Examples of the monovalent organic group include the structures exemplified for R in -C(=O)-NR- representing L ₁ and L _1' of the above formula (H ₁ ). Two R's may be the same or different. n is an integer of 1-10, more preferably an integer of 2-10, more preferably an integer of 2-6. m1 and m2 are each independently an integer of 0 to 4, n' is an integer of 1 to 6, and the sum of m1, m2 and n' is 1 to 8. n1 and n2 in *-(CH ₂ ) _n1 -O-(CH ₂ ) _n2 -* are each independently an integer of 1-6, and the sum of n1 and n2 is 2-10. n1 and n2 in *-(CH ₂ ) _n1 -NR-C(=O)-NR-(CH ₂ ) _n2 -* are each independently an integer of 1 to 6, and the sum of n1 and n2 is 2 ~9.

*-L ₁ -AL _1′ -* preferably has the following aspects from the viewpoint of suitably obtaining the effects of the present invention. Definitions of m1, m2, n, n', n1 and n2 in the following formula are the same as those in the above formula. In the following formula, R in -C(=O)-NR- or -NR-C(=O)-NR- represents a hydrogen atom or a monovalent organic group. Examples of the monovalent organic group include the structures exemplified for R in -C(=O)-NR- representing L ₁ and L _1' of the formula (H ₁ ).
*-(CH ₂ ) _n -*, -O-(CH ₂ ) _n -O-*,
*—O—(CH ₂ ) _n1 —O—(CH ₂ ) _n2 —O—*,
*-C(=O)-( _CH2 ) _n -C(=O)-*,
*-C(=O)-NR-( _CH2 ) _n -O-*,
*-O-C(=O)-( _CH2 ) _n -O-*,
*-OC(=O)-( _CH2 ) _n -OC(=O)-*,
*-O-C(=O)-( _CH2 ) _n -C(=O)-O-*,
*-(CH ₂ ) _m1 -O-C(=O)-(CH ₂ ) _n' -C(=O)-O-(CH ₂ ) _m2 -*
*-S-(CH ₂ ) _n -S-*,
*-C(=O)-NR-( _CH2 ) _n -NR-C(=O)-*,
*-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 -*, *-S-(CH ₂ ) _n -*,
*-NR-C(=O)-( _CH2 ) _n -C(=O)-NR-*
*-(CH ₂ ) _n1 -NR-C(=O)-NR-(CH ₂ ) _n2 -*
Furthermore, *-(CH ₂ ) _n -*, *-O-(CH ₂ ) _n -O-*, and *-O-(CH ₂ ) _n -* are preferable from the viewpoint of suitably obtaining the effects of the present invention. .

From the viewpoint of suitably obtaining the effects of the present invention, the polyamic acid ester (A) is represented by the above formula (1Da), in which Y ₁ is a divalent organic group having three or more benzene rings as a diamine-derived structural unit. It preferably contains at least one structural unit represented.
Here, the benzene ring in the "divalent organic group having 3 or more benzene rings" includes a benzene ring constituting a condensed ring. When counting the number of benzene rings in the formula (H ₁ ), the naphthalene ring has two benzene rings, the anthracene ring has three benzene rings, and the biphenyl structure has two benzene rings. count as having one.

In the polyamic acid ester (A), from the viewpoint of suitably obtaining the effects of the present invention, at least one of Y ₁ is a divalent organic compound represented by the formula (H ₁ ) in which Ar ₁ and Ar _1' have the same structure. a structural unit represented by the formula (1Da), wherein at least one of the other Y ₁ is a divalent organic group represented by the formula (H ₁ ) in which Ar ₁ and Ar _1′ have different structures It is preferred to have
A preferable combination when Ar ₁ and Ar _1′ have the same structure is a combination of the biphenyl structure optionally having the above substituent and the biphenyl structure optionally having the above substituent, and A combination of a naphthalene ring which may be substituted with a naphthalene ring which may have one of the above substituents may be mentioned. Further, as a preferable combination when Ar ₁ and Ar _1′ have different structures, a combination of a benzene ring optionally having the above substituent and a biphenyl structure optionally having the above substituent, A combination of a benzene ring which may have a substituent and a naphthalene ring which may have a substituent, and a combination of a biphenyl structure which may have a substituent and a naphthalene ring which may have a substituent. mentioned.

Y ₁ in the above formula (1Da) is preferably a divalent organic group represented by any one of the following formulas (h1-1) to (h1-13) from the viewpoint of favorably obtaining the effects of the present invention. In formulas (h1-1) to (h1-13), the bonding positions of the benzene ring are preferably the 1- and 4-positions, and the bonding positions of the naphthalene ring are preferably the 2- and 6-positions. In formula (h1-4), the total number of —CH ₂ — is 10 or less. In formulas (h1-7) and (h1-8), the total number of —CH ₂ — is 8 or less, and two m may be the same or different.

The ratio of the structural unit (a-1Da) contained in the polyamic acid ester (A) is preferably 5 to 95 mol% with respect to 1 mol of all diamine-derived structural units possessed by the polyamic acid ester (A), 10 to 95 mol % is more preferred, and 20 to 80 mol % is even more preferred.

The monovalent organic group of Z in the above formula (1Da) includes a monovalent hydrocarbon group having 1 to 6 carbon atoms, and the methylene group of the hydrocarbon group is -O-, -S-, -CO-, - COO-, -COS-, -NR ³ -, -CO-NR ³ -, -Si(R ³ ) ₂ - (where R ³ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms) ), the monovalent group A substituted with —SO ₂ —, etc., the monovalent hydrocarbon group, or at least one of the hydrogen atoms bonded to the carbon atoms of the monovalent group A is a halogen atom, hydroxy group, alkoxy group, nitro group, amino group, mercapto group, nitroso group, alkylsilyl group, alkoxysilyl group, silanol group, sulfino group, phosphino group, carboxy group, cyano group, sulfo group, acyl group, etc. and monovalent groups having a heterocyclic ring.
The monovalent organic group for Z in the above formula (1Da) includes, among others, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, or tert-butoxycarbonyl. is preferred, an alkyl group having 1 to 3 carbon atoms is more preferred, and a methyl group is even more preferred.
Two Zs in the above formula (1Da) are each independently preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, more preferably a hydrogen atom or a methyl group, from the viewpoint of suitably obtaining the effects of the present invention.

The polyamic acid ester (A) used in the present invention may contain other diamine-derived structural units (a-1Da-2) other than the structural units (a-1Da) as diamine-derived structural units. good. The structural unit (a-1Da-2) may be of one type or two or more types.
Examples of other diamines in the structural unit (a-1Da-2) derived from other diamines include the following.
p-phenylenediamine, 2,3,5,6-tetramethyl-p-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, m-phenylenediamine, 2,4-dimethyl-m-phenylenediamine, 1, 4-diamino-2,5-methoxybenzene, 2,5-diaminotoluene, 2,6-diaminotoluene, 4-aminobenzylamine, 2-(4-aminophenyl)ethylamine, 4-(2-(methylamino) ethyl)aniline, 4-(2-aminoethyl)aniline, 2-(6-aminonaphthyl)ethylamine, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4' -diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-dihydroxy-4,4'-diaminobiphenyl, 3-trifluoromethyl-4,4'-diaminobiphenyl, 2- trifluoromethyl-4,4'-diaminobiphenyl, 3-fluoro-4,4'-diaminobiphenyl, 2-fluoro-4,4'-diaminobiphenyl, 2,2'-difluoro-4,4'-diaminobiphenyl , 3,3′-difluoro-4,4′-diaminobiphenyl, 2,2′-bis(trifluoromethyl)-4,4′-diaminobiphenyl, 3,3′-bis(trifluoromethyl)-4, 4'-diaminobiphenyl, 3,4'-diaminobiphenyl, 4,4'-diaminobiphenyl, 3,3'-diaminobiphenyl, 2,2'-diaminobiphenyl, 2,3'-diaminobiphenyl, 1,5- Specific diamines such as diaminonaphthalene, 1,6-diaminonaphthalene, 1,7-diaminonaphthalene, 2,5-diaminonaphthalene, 2,6-diaminonaphthalene, and 2,7-diaminonaphthalene (hereinafter referred to as specific diamines ( 1).);

1,4-phenylene bis(4-aminobenzoate), 1,4-phenylene bis(3-aminobenzoate), 1,3-phenylene bis(4-aminobenzoate), 1,3-phenylene bis(3-aminobenzoate ), bis(4-aminophenyl) terephthalate, bis(3-aminophenyl) terephthalate, bis(4-aminophenyl) isophthalate, bis(3-aminophenyl) isophthalate; 4,4′-diaminoazobenzene, diaminotran , 4,4-diaminochalcone, or [4-[(E)-3-[2-(2,4-diaminophenyl)ethoxy]-3-oxo-prop-1-enyl]phenyl]4-(4, 4,4-trifluorobutoxy)benzoate, or [4-[(E)-3-[[5-amino-2-[4-amino-2-[[(E)-3-[4-[4- (4,4,4-trifluorobutoxy)benzoyl]oxyphenyl]prop-2-enoyl]oxymethyl]phenyl]phenyl]methoxy]-3-oxo-prop-1-enyl]phenyl]4-(4,4 ,4-trifluorobutoxy) diamines having photoalignable groups such as aromatic diamines having a cinnamate structure typified by benzoate; 2-(2,4-diaminophenoxy)ethyl methacrylate or 2,4-diamino-N , N-diallylaniline and other photopolymerizable group-terminated diamines; 1-(4-(2-(2,4-diaminophenoxy)ethoxy)phenyl)-2-hydroxy-2-methylpropanone, 2- Diamines with a radical polymerization initiator function such as (4-(2-hydroxy-2-methylpropanoyl)phenoxy)ethyl-3,5-diaminobenzoate; Diamines with an amide bond such as 4,4′-diaminobenzanilide diamines having a urea bond such as 1,3-bis(4-aminophenyl)urea; H ₂ N-Y _D -NH ₂ (Y _D is intramolecular, Represents a protective group that is eliminated and replaced by a hydrogen atom.) Represents a divalent organic group having a diamine having a thermally releasable group such as);

3,3′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl ether, 3,3′-diaminodiphenylmethane, 3,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylmethane, 4, 4′-sulfonyldianiline, 3,3′-sulfonyldianiline, bis(4-aminophenyl)silane, bis(3-aminophenyl)silane, dimethyl-bis(4-aminophenyl)silane, dimethyl-bis(3 -aminophenyl)silane, 4,4'-thiodianiline, 3,3'-thiodianiline, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 2,2' -bis[4-(4-aminophenoxy)phenyl]propane, 2,2'-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2'-bis(4-aminophenyl)hexafluoro Propane, 2,2'-bis(3-aminophenyl)hexafluoropropane, 2,2'-bis(3-amino-4-methylphenyl)hexafluoropropane, 2,2'-bis(4-aminophenyl) Propane, 2,2'-bis(3-aminophenyl)propane, 2,2'-bis(3-amino-4-methylphenyl)propane, 4,4'-diaminobenzophenone, 1,4-bis(4- aminobenzyl)benzene; 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, 1,4-bis- (4-aminophenyl)-piperazine, 3,6-diaminoacridine, N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N-(3-(1H-imidazole-1- yl)propyl-3,5-diaminobenzamide, 4-[4-[(4-aminophenoxy)methyl]-4,5-dihydro-4-methyl-2-oxazolyl]-benzenamine, 4-[4-[ (4-aminophenoxy)methyl]-4,5-dihydro-2-oxazolyl]-benzenamine, 1,4-bis(p-aminobenzyl)piperazine, 4,4′-[4,4′-propane-1 ,3-diylbis(piperidine-1,4-diyl)]dianiline, 4-(4-aminophenoxycarbonyl)-1-(4-aminophenyl)piperidine, 2,5-bis(4-aminophenyl) phenyl)pyrrole, 4,4′-(1-methyl-1H-pyrrole-2,5-diyl)bis[benzenamine], 1,4-bis-(4-aminophenyl)-piperazine, 2-N-( 4-aminophenyl)pyridine-2,5-diamine, 2-N-(5-aminopyridin-2-yl)pyridine-2,5-diamine, 2-(4-aminophenyl)-5-aminobenzimidazole, 2-(4-aminophenyl)-6-aminobenzimidazole, 5-(1H-benzimidazol-2-yl)benzene-1,3-diamine, or the following formulas (z-1) to (z-5) Heterocycle-containing diamines such as diamines represented by or 4,4′-diaminodiphenylamine, 4,4′-diaminodiphenyl-N-methylamine, N,N′-bis(4-aminophenyl)-benzidine, N,N'-bis(4-aminophenyl)-N,N'-dimethylbenzidine, or N,N'-bis(4-aminophenyl)-N,N'-dimethyl-1,4-benzenediamine, etc. At least one nitrogen atom-containing structure selected from the group consisting of a nitrogen atom-containing heterocycle, a secondary or tertiary amino group, typified by a diamine having a diphenylamine structure of -N(D)- (D represents a protective group that is eliminated by heating and replaced with a hydrogen atom. ) except amino groups derived from Hereinafter, it is also referred to as a specific nitrogen atom-containing structure. );

2,4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4,6-diaminoresorcinol, 4,4'-diamino-3,3'-dihydroxy Biphenyl; 2,4-diaminobenzoic acid, 2,5-diaminobenzoic acid, 3,5-diaminobenzoic acid, 4,4'-diaminobiphenyl-3-carboxylic acid, 4,4'-diaminodiphenylmethane-3-carboxylic acid acid, 4,4'-diaminodiphenylethane-3-carboxylic acid, 4,4'-diaminobiphenyl-3,3'-dicarboxylic acid, 4,4'-diaminobiphenyl-2,2'-dicarboxylic acid, 3, 3'-diaminobiphenyl-4,4'-dicarboxylic acid, 3,3'-diaminobiphenyl-2,4'-dicarboxylic acid, 4,4'-diaminodiphenylmethane-3,3'-dicarboxylic acid, 4,4' -Diamines having a carboxy group such as diaminodiphenylethane-3,3'-dicarboxylic acid, 4,4'-diaminodiphenyl ether-3,3'-dicarboxylic acid; 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; cholestanyloxy-3,5- Diaminobenzene, cholestenyloxy-3,5-diaminobenzene, cholestanyloxy-2,4-diaminobenzene, cholestanyl 3,5-diaminobenzoate, cholestenyl 3,5-diaminobenzoate, 3,5-diaminobenzoic acid Diamines having a steroid skeleton such as lanostanil and 3,6-bis(4-aminobenzoyloxy)cholestane; diamines represented by the following formulas (V-1) to (V-2); 1,3-bis(3- aminopropyl)-tetramethyldisiloxane, diamines having siloxane bonds; Alicyclic diamines such as 3-bis(aminomethyl)cyclohexane, 1,4-diaminocyclohexane, 4,4′-methylenebis(cyclohexylamine), formulas (Y-1) to (Y- 167) in which two amino groups are bonded to a group represented by any one of the groups, and the like.

(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.)

D in -N(D)- of the other diamines described above is a carbamate-based organic compound represented by a benzyloxycarbonyl group, a 9-fluorenylmethyloxycarbonyl group, an allyloxycarbonyl group, a Boc group, and the like. groups are preferred. The Boc group is particularly preferred from the viewpoint that it is efficiently desorbed by heat, is desorbed at a relatively low temperature, and is discharged as a harmless gas when desorbed.

Preferred examples of diamines having a thermally leaving group exemplified as other diamines are diamines selected from the following formulas (d-1) to (d-7).

(In formulas (d-2), (d-6) and (d-7), R represents a hydrogen atom or a Boc group.)

When the polyamic acid ester (A) used in the present invention has a structural unit (a-1Da-2), it contains a structural unit derived from the specific diamine (1) from the viewpoint of suitably obtaining the effects of the present invention. is more preferable. The structural unit derived from the specific diamine (1) is preferably 5 to 95 mol%, more preferably 5 to 90, with respect to 1 mol of all structural units derived from the diamine contained in the polyamic acid ester (A). mol %, more preferably 20 to 80 mol %.
In addition, the polyamic acid ester (A) has a structure derived from the diamine having the thermally releasable group as the structural unit (a-1Da-2), from the viewpoint of enhancing the two-layer separability from the polyamic acid (B). May contain units. The structural unit derived from the diamine having the thermally leaving group is preferably 5 to 40 mol% with respect to 1 mol of all structural units derived from the diamine contained in the polyamic acid ester (A), more preferably It is 5 to 35 mol %, more preferably 5 to 30 mol %.

<Polyamic acid (B)>
The liquid crystal aligning agent of the present invention has a structural unit (b-1Tb) represented by the above formula (1Tb) as a structural unit derived from a tetracarboxylic acid derivative together with the polyamic acid ester (A), and has a diamine-derived structural unit (b-1Tb). As a structural unit, it contains a polyamic acid (B) having a structural unit (b-1Db) represented by the above formula (1Db). The polyamic acid (B) may be composed of one type or two or more types. Further, each of the structural units constituting the polyamic acid (B) may be composed of one type or two or more types. The polyamic acid (B) preferably does not have the structural unit (a-1Ta) and the structural unit (a-1Da) of the polyamic acid ester (A) in the same molecule.

The tetravalent organic group for X _b in the above formula (1Tb) includes a tetravalent organic group obtained by removing two acid dianhydride groups from an acyclic aliphatic tetracarboxylic dianhydride, an alicyclic tetracarboxylic acid A tetravalent organic group obtained by removing two dianhydride groups from an acid dianhydride or a tetravalent organic group obtained by removing two acid dianhydride groups from an aromatic tetracarboxylic dianhydride, specifically Examples include the tetravalent organic groups exemplified for X _2a above.
The aromatic tetracarboxylic dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxy groups including at least one carboxy group bonded to an aromatic ring.
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.
An 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.
From the viewpoint of suitably obtaining the effect of the present invention, the tetravalent organic group in _Xb has at least one partial structure selected from the group consisting of a benzene ring, a cyclobutane ring structure, a cyclopentane ring structure and a cyclohexane ring structure. Tetracarboxylic dianhydrides are preferred. More preferable X _b includes a tetravalent organic group represented by the above formula (g), a structure exemplified for X _2a in the above formula (2Ta), and other tetravalent organic groups exemplified for the polyamic acid ester (A) above. A tetravalent organic group obtained by removing two acid dianhydride groups from a carboxylic acid dianhydride is more preferable. In addition, the acyclic aliphatic or alicyclic tetracarboxylic dianhydride is at least one selected from the group consisting of a cyclobutane ring structure, a cyclopentane ring structure, and a cyclohexane ring structure, from the viewpoint of enhancing the liquid crystal orientation. A tetracarboxylic dianhydride having a partial structure of is preferred.

In the polyamic acid (B), from the viewpoint of suitably obtaining the effects of the present invention, X _b is a tetravalent organic group obtained by removing two acid anhydride groups from an acyclic aliphatic tetracarboxylic dianhydride, an alicyclic A structure that is a tetravalent organic group obtained by removing two acid anhydride groups from the formula tetracarboxylic dianhydride, or a tetravalent organic group obtained by removing two acid anhydride groups from an aromatic tetracarboxylic dianhydride The unit (b-1Tb) is preferably 5 mol% or more, more preferably 10 mol% or more, relative to 1 mol of all structural units derived from the tetracarboxylic acid derivative contained in the polyamic acid (B), More preferably, it is 20 mol % or more.

Examples of the divalent organic group in Yb of the formula ( _1Tb ) include divalent organic groups obtained by removing two amino groups from Y1 _and the other diamines exemplified in the polyamic acid ester (A). be done. In the polyamic acid (B), Y _b is a diamine having a urea bond (for example, A in the above formula (H ₁ ) represents a divalent organic group (q2), and the Diamines in which two amino groups are bonded to a divalent organic group represented by the formula (H ₁ ), diamines having a urea bond as exemplified in the other diamines above, etc.), diamines having the above-mentioned amide bond, the above-mentioned specific diamine having a nitrogen atom-containing structure, the diamine having a carboxy group, 4,4'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, p-phenylene Divalent organic groups obtained by removing two amino groups from diamine and m-phenylenediamine (these are also collectively referred to as specific divalent organic groups) are preferred.

In the polyamic acid (B), the structural unit (b-1Db) represented by the formula (1Db) in which Y _b is the specific divalent organic group is added to the polyamic acid ( It may be contained in an amount of 5 mol% or more, preferably 10 mol% or more preferably 20 mol% or more, relative to 1 mol of all diamine-derived structural units of B).

Examples of the monovalent organic group for Z in the above formula (1Db) include the structures exemplified for Z in the above formula (1Da).

In the liquid crystal aligning agent of the present invention, the effect of the present invention, especially from the viewpoint of less afterimage derived from residual DC, the content ratio of the polyamic acid ester (A) and the polyamic acid (B) is set to [polyamic acid ester (A) /polyamic acid (B)] may be 10/90 to 90/10, may be 20/80 to 90/10, or may be 20/80 to 80/20. .

<Production of polyamic acid and polyamic acid ester>
Polyamic acid esters such as polyamic acid ester (A) and polyamic acids such as polyamic acid (B) contained in the liquid crystal aligning agent of the present invention can be produced, for example, by the following methods. In this case, as the tetracarboxylic acid derivative, not only tetracarboxylic dianhydride but also its derivatives such as tetracarboxylic acid dihalide compounds, tetracarboxylic acid dialkyl esters, and tetracarboxylic acid dialkyl ester dihalides can be used. .

(Production of polyamic acid)
A polymer having an amic acid structure (polyamic acid) is obtained by reacting the tetracarboxylic dianhydride component and the diamine component. When the polyamic acid has a structure represented by the above formula (1Db), for example, the diamine component has a structure of -N(Z)-Y ₁ -N(Z)- (where Y ₁ and Z are defined as is the same as above), and as the tetracarboxylic acid derivative component, a tetracarboxylic dianhydride having X _b (the definition of X _b is the same as above) is used. be.

The polyamic acid ester (A) is, for example, a tetracarboxylic acid derivative component containing a tetracarboxylic dianhydride represented by the following formula (T ₁ ) and a diamine component containing a diamine represented by the formula (D ₁ ). After reacting to obtain a polyamic acid, it can be obtained as a polyamic acid ester by the method described later.

(R ₁₁ to R ₁₄ have the same definitions as R ₁₁ to R ₁₄ in formula (1Ta), and Y ₁ and Z have the same definitions as Y ₁ in formula (1Ta) and Z in formula (1Da), respectively. )

The ratio of the tetracarboxylic dianhydride and the diamine used in the production of the polyamic acid is 0.2 to 2 equivalents of the acid anhydride group of the tetracarboxylic dianhydride with respect to 1 equivalent of the amino group of the diamine. and more preferably 0.3 to 1.2 equivalents. As in ordinary polycondensation reactions, the closer the equivalent of the acid anhydride group of this tetracarboxylic dianhydride to one equivalent, the greater the molecular weight of the polyamic acid produced.
The reaction temperature in the production of polyamic acid is preferably -20 to 150°C, more preferably 0 to 100°C. Also, the reaction time is preferably 0.1 to 24 hours, more preferably 0.5 to 12 hours.
Polyamic acid can be produced at any concentration, preferably 1 to 50% by mass, more preferably 5 to 30% by mass. The initial stage of the reaction may be carried out at a high concentration, and then the solvent may be added.

Specific examples of the organic solvent used for producing the polyamic acid include cyclohexanone, cyclopentanone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide, 1,3-dimethyl-2-imidazolidinone. Further, when the polyamic acid to be produced has high solvent solubility, methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl Solvents such as ether, ethylene glycol monopropyl ether, diethylene glycol monomethyl ether, or diethylene glycol monoethyl ether can be used.

(Production of Polyamic Acid Ester)
The polyamic acid ester can be obtained, for example, by [I] a method of reacting the polyamic acid obtained by the above method with an esterifying agent, [II] a tetracarboxylic acid diester and a diamine, preferably in an organic solvent, with a dehydration catalyst ( For example, 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium halide, carbonylimidazole, phosphorus-based condensing agent, etc.), [III ] with a tetracarboxylic acid diester dihalide and a diamine, preferably in an organic solvent, with a base (e.g. tertiary amines such as pyridine, triethylamine, sodium hydride, potassium hydride, sodium hydroxide, potassium hydroxide, sodium, potassium Alkali metals such as), [IV] Polyamic acid and dehydration condensation agent (such as trifluoroacetic anhydride) are reacted to isoimidize, followed by alcohol (e.g., methanol, ethanol, n- (fatty alcohols such as propanol, isopropanol, butanol, t-butanol) can be obtained by known methods such as a method of reacting.

The tetracarboxylic diester used in [II] above can be obtained by ring-opening a tetracarboxylic dianhydride with an alcohol or the like. The tetracarboxylic acid diester dihalide used in the above [III] can be obtained by reacting the tetracarboxylic acid diester obtained as described above with a suitable chlorinating agent such as thionyl chloride. When the polyamic acid ester is obtained as a solution by the above reaction, the solution may be directly subjected to the preparation of the liquid crystal aligning agent, and the polyamic acid ester contained in the reaction solution is isolated and used for the preparation of the liquid crystal aligning agent. may be provided.

A more preferable method of [I] above is a method of adding an esterifying agent to a solution of polyamic acid and stirring to obtain a polyamic acid ester. As the solvent used in this reaction, the same organic solvents as exemplified as those used in the production of the polyamic acid can be mentioned. The reaction is carried out in an organic solvent at a reaction temperature of preferably 0-100° C., more preferably 0-50° C., for 0.5-48 hours. Moreover, an esterification agent may be added at the time of preparation of the liquid crystal aligning agent mentioned later, and may form polyamic acid ester.
In the above method [I], the esterification rate can be arbitrarily adjusted by changing the addition amount of the esterifying agent used. The "esterification rate" referred to here is, for example, in the case of the polyamic acid ester (A), based on all the amic acid structures of the polyamic acid before being esterified, esterified to an amic acid ester structure. It is the ratio expressed in %. The esterification rate can be estimated from the amount of change in the peak intensity of the carboxy group using ¹ H-NMR. The esterification rate of the polyamic acid ester (A) used in the present invention is preferably 5 to 100%, more preferably 25 to 100%, still more preferably 25 to 65%.

The amount of the esterifying agent added in the method [I] is 0.01 to 50 molar equivalents, more preferably 0.1 to 20 molar equivalents, relative to 1 molar equivalent of the structural unit of the amic acid contained in the polyamic acid. , more preferably 1 to 10 molar equivalents.
Examples of the esterifying agent include t-

butyl

2,2,2-trichloroacetimidate, Ot-butyl-N,N'-diisopropyl isopropyl, and t-butyl-N,N'-diisopropyl isopropyl. Urea, N,N-dimethylformamide di-t-butyl acetal can be mentioned.

<Solution Viscosity/Molecular Weight of Polyamic Acid and Polyamic Acid Ester>
From the viewpoint of workability, the polyamic acid and polyamic acid ester used in the present invention preferably have a solution viscosity of, for example, 10 to 1000 mPa·s when made into a solution having a concentration of 10 to 15% by mass. The solution viscosity (mPa s) of the polymer is a polymer having a concentration of 10 to 15 mass% prepared using a good solvent for the polymer (eg, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.). It is a value measured at 25° C. for a solution using an E-type rotational viscometer.
The polystyrene equivalent weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) of the polyamic acid and polyamic acid ester is preferably 1,000 to 500,000, more preferably 2,000 to 300,000. In addition, the molecular weight distribution (Mw/Mn) represented by the ratio of Mw to the polystyrene equivalent number average molecular weight (Mn) measured by GPC is preferably 15 or less, more preferably 10 or less. With such a molecular weight range, good orientation and stability of the liquid crystal display device can be ensured.

<Terminal blocking agent>
The polyamic acid ester and polyamic acid in the present invention may be converted into a terminal-blocked polymer by using an appropriate terminal-blocking agent together with the tetracarboxylic acid derivative component and the diamine component as described above. . The end-blocking polymer has effects of improving the film hardness of the liquid crystal alignment film obtained by the coating film and improving the adhesion properties between the sealant and the liquid crystal alignment film.
Examples of the terminal of the polyamic acid ester (A) and polyamic acid (B) in the present invention include an amino group, a carboxyl group, an acid anhydride group, or a group derived from a terminal blocking agent to be described later. An amino group, a carboxyl group, and an acid anhydride group can be obtained by a normal condensation reaction, or can be obtained by terminal blocking using the following terminal blocking agents.

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. di-t-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 , n-heptylamine, n-octylamine and other monoamine compounds; ethyl isocyanate, phenyl isocyanate, naphthyl isocyanate, 2-acryloyloxyethyl isocyanate, 2-methacryloyloxyethyl isocyanate and other unsaturated bonds monoisocyanate compounds such as isocyanate; and isothiocyanate compounds such as ethyl isothiocyanate and allyl isothiocyanate.
The proportion of the terminal blocking agent used is preferably 0.01 to 20 mol parts, more preferably 0.01 to 10 mol parts, with respect to the total 100 mol parts of the diamine component used in the production of the polymer. is more preferred.

<Liquid crystal aligning agent>
The liquid crystal aligning agent of the present invention contains polyamic acid ester (A) and polyamic acid (B). The liquid crystal aligning agent of the present invention may contain other polymers in addition to the polyamic acid ester (A) and the polyamic acid (B).
Specific examples of such other polymers include polyimide precursors other than polyamic acid ester (A) and polyamic acid (B), polyimides, polysiloxanes, polyesters, polyamides, polyureas, polyurethanes, polyorganosiloxanes, cellulose derivatives, and polyacetals. , polystyrene derivatives, poly(styrene-maleic anhydride) copolymer, poly(isobutylene-maleic anhydride) copolymer, poly(vinyl ether-maleic anhydride) copolymer, poly(styrene-phenylmaleimide) Examples include derivatives, polymers selected from the group consisting of poly(meth)acrylates, and the like.

Specific examples of the poly(styrene-maleic anhydride) copolymer include SMA1000, 2000 and 3000 (manufactured by Cray Valley) and GSM301 (manufactured by Gifu Shellac Mfg. Co.). A specific example of the poly(isobutylene-maleic anhydride) copolymer is Isovan-600 (manufactured by Kuraray Co., Ltd.). A specific example of the poly(vinyl ether-maleic anhydride) copolymer is Gantrez AN-139 (methyl vinyl ether maleic anhydride resin, manufactured by Ashland). Other polymers may be used 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 alignment agent is used to produce the liquid crystal alignment film, and takes the form of a coating liquid from the viewpoint of forming a uniform thin film. Also in the liquid crystal aligning agent of the present invention, it is preferable that the liquid crystal aligning agent is a coating liquid containing the above-described polymer component and an organic solvent. At that time, the concentration of the polymer in the liquid crystal aligning agent can be appropriately changed by setting the thickness of the coating film to be formed. The concentration of the polymer in the liquid crystal aligning agent is preferably 1% by mass or more from the viewpoint of forming a uniform and defect-free coating film, and is preferably 10% by mass or less from the viewpoint of the storage stability of the solution. A particularly preferred polymer concentration is 2 to 8% by weight.

The organic solvent contained in the liquid crystal aligning agent is not particularly limited as long as it dissolves the polymer component uniformly. Specific examples include N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethyllactamide, N,N-dimethylpropionamide, N,N-diethylpropionamide, tetramethylurea, N, N-diethylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethyl sulfoxide, γ-butyrolactone, γ-valerolactone, 1,3-dimethyl-2-imidazolidinone, methyl ethyl ketone, cyclohexanone, cyclo pentanone, 3-methoxy-N,N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropanamide, N-(n-propyl)-2-pyrrolidone, N-isopropyl-2-pyrrolidone, N-( n-butyl)-2-pyrrolidone, N-(t-butyl)-2-pyrrolidone, N-(n-pentyl)-2-pyrrolidone, N-methoxypropyl-2-pyrrolidone, N-ethoxyethyl-2-pyrrolidone , N-methoxybutyl-2-pyrrolidone, and N-cyclohexyl-2-pyrrolidone (these are collectively referred to as “good solvents”). 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. 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. Specific examples of the poor solvent used in combination are shown below, but are not limited thereto.
For example, diisopropyl ether, diisobutyl ether, diisobutylcarbinol (2,6-dimethyl-4-heptanol), ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, 1,2-butoxyethane, 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-butoxy ethoxy)-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 monoacetate ethyl ether, cyclohexyl acetate, 4-methyl-2-pentyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, butyl 3-methoxypropionate, Examples include n-butyl lactate, isoamyl lactate, diethylene glycol monoethyl ether, diisobutyl ketone (2,6-dimethyl-4-heptanone) and the like.

Poor solvents are, inter alia, 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 combinations of a good solvent and a poor solvent include N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone and ethylene glycol monobutyl ether, and N-methyl-2-pyrrolidone. γ-butyrolactone and propylene glycol monobutyl ether, N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether, N-ethyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone, N-ethyl-2-pyrrolidone and Propylene glycol diacetate, N,N-dimethyl lactamide and diisobutyl ketone, N-methyl-2-pyrrolidone and ethyl 3-ethoxypropionate, N-ethyl-2-pyrrolidone and ethyl 3-ethoxypropionate, N-methyl- 2-pyrrolidone and ethyl 3-ethoxypropionate and dipropylene glycol monomethyl ether, N-ethyl-2-pyrrolidone and 3-ethoxyethyl propionate and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone and 3-ethoxypropionic acid Ethyl and diethylene glycol monopropyl ether, N-ethyl-2-pyrrolidone and ethyl 3-ethoxypropionate and diethylene glycol monopropyl ether, N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether acetate, N-ethyl-2-pyrrolidone and Dipropylene glycol dimethyl ether, N,N-dimethyl lactamide and ethylene glycol monobutyl ether, N,N-dimethyl lactamide and propylene glycol diacetate, N-ethyl-2-pyrrolidone and diethylene glycol diethyl ether, N-ethyl-2-pyrrolidone and diethylene glycol monoethyl ether and butyl cellosolve acetate, N-methyl-2-pyrrolidone and diethylene glycol monomethyl ether and butyl cellosolve acetate, N,N-dimethyllactamide and diethylene glycol diethyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and 4- Hydroxy-4-methyl-2-pentanone and diethylene glycol diethyl ether, N-ethyl-2-pyrrolidone and N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone, N-ethyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and propylene glycol monobutyl Ether, N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and diisobutyl ketone, N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and dipropylene glycol monomethyl ether , N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and propylene glycol diacetate , N-ethyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and dipropylene glycol dimethyl ether, γ-butyrolactone and 4-hydroxy-4-methyl-2-pentanone and diisobutyl ketone, γ-butyrolactone and 4 -hydroxy-4-methyl-2-pentanone and propylene glycol diacetate, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether and diisobutyl ketone, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol Monobutyl ether and diisopropyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone, propylene glycol monobutyl ether and diisobutylcarbinol, N-methyl-2-pyrrolidone, γ-butyrolactone and dipropylene glycol dimethyl ether, N-methyl-2- pyrrolidone and propylene glycol monobutyl ether and dipropylene glycol dimethyl ether, N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether and dipropylene glycol monomethyl ether, N-ethyl-2-pyrrolidone and diethylene glycol diethyl ether and dipropylene glycol monomethyl ether, N -ethyl-2-pyrrolidone and propylene glycol monobutyl ether and propylene glycol diacetate, N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether and diisobutyl ketone, N-ethyl-2-pyrrolidone and γ-butyrolactone and diisobutyl ketone, N- Ethyl-2-pyrrolidone and N,N-dimethyllactamide and diisobutyl ketone, N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether and ethylene glycol monobutyl ether acetate, γ-butyrolactone and ethylene glycol monobutyl ether acetate and dipro pyrene 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, cyclohexyl acetate, diacetone alcohol, cyclohexanone, propylene glycol monomethyl ether, cyclopentanone, propylene glycol monomethyl ether, N-methyl-2-pyrrolidone, cyclohexanone, propylene glycol monomethyl ether, and the like.

The liquid crystal aligning agent of the present invention may contain components (hereinafter also referred to as additive components) other than the polymer component and the organic solvent. Additive components include adhesion aids for enhancing the adhesion between the liquid crystal alignment film and the substrate and the adhesion between the liquid crystal alignment film and the sealant, compounds for increasing the strength of the liquid crystal alignment film (hereinafter referred to as cross-linking compounds ), compounds for promoting imidization, and dielectrics and conductive substances for adjusting the dielectric constant and electrical resistance of the liquid crystal alignment film.
From the viewpoint of suitably obtaining the effects of the present invention, the crosslinkable compound includes an oxiranyl group, an oxetanyl group, a protected isocyanate group, a protected isothiocyanate group, a group containing an oxazoline ring structure, a group containing a Meldrum's acid structure, a cyclocarbonate group, and A compound having at least one group selected from the group consisting of a hydroxyalkylamide bond; a phenolic compound having at least one of an alkoxymethyl group and a methylol group; and at least a compound having a polymerizable unsaturated group. It may be one compound.

Specific examples of the compound having an oxiranyl group include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, Epicoat 828 (Mitsubishi Chemical bisphenol A type epoxy resins such as Epicoat 807 (manufactured by Mitsubishi Chemical Corporation), hydrogenated bisphenol A type epoxy resins such as YX-8000 (manufactured by Mitsubishi Chemical Corporation), YX6954BH30 (Mitsubishi Chemical (manufactured by Nippon Kayaku Co., Ltd.), phenolic novolac type epoxy resins such as EPPN-201 (manufactured by Nippon Kayaku Co., Ltd.), and (o, m, p-) cresols such as EOCN-102S (manufactured by Nippon Kayaku Co., Ltd.). Novolak epoxy resins, triglycidyl isocyanurates such as TEPIC (manufactured by Nissan Chemical Industries, Ltd.), alicyclic epoxy resins such as Celoxide 2021P (manufactured by Daicel Chemical Industries, Ltd.), N,N,N',N'-tetraglycidyl-m -xylylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, tetrakis(glycidyloxymethyl)methane is mentioned.

Specific examples of the compound having an oxetanyl group include compounds having two or more oxetanyl groups described in [0170] to [0175] of WO2011/132751.
Specific examples of the compound having a protected isocyanate group include compounds having two or more protected isocyanate groups described in [0046] to [0047] of JP-A-2014-224978, [0119] of WO2015/141598. ] to [0120], and compounds having three or more protected isocyanate groups. Commercially available products include, for example, 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.) and the like can be preferably used. Also included are compounds having two or more protected isothiocyanate groups described in Japanese Patent Application Laid-Open No. 2016-200798.

Specific examples of the compound having a group containing an oxazoline ring structure include compounds containing two or more oxazoline ring structures, preferably 2,2', described in [0115] of JP-A-2007-286597. -bis(2-oxazoline), 2,2'-bis(4-methyl-2-oxazoline), 2,2'-bis(5-methyl-2-oxazoline), 1,2,4-tris-(2 -oxazolinyl-2)-benzene and compounds having an oxazoline group such as Epocross (manufactured by Nippon Shokubai Co., Ltd.).
Specific examples of the compound having a group containing a Meldrum's acid structure include compounds having two or more Meldrum's acid structures described in WO2012/091088.
Specific examples of the compound having a cyclocarbonate group include compounds described in WO2011/155577. Specific examples of the compound having a hydroxyalkylamide bond include WO2015/072554, compounds described in [0058] of JP-A-2016-118753, compounds described in JP-A-2016-200798, N,N,N',N'-tetrakis(2-hydroxyethyl)adipamide is preferred.

Specific examples of the phenol compound having at least one of an alkoxyalkyl group and a methylol group include compounds described in WO2010/074269, preferably 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. Examples of the compound having a polymerizable unsaturated bond include 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 above compounds are examples of crosslinkable compounds, and are not limited to these. For example, components other than the above disclosed in [0105] to [0116] on pages 55 of WO2015/060357 may be used. Moreover, you may combine two or more types of crosslinkable compounds.

The crosslinkable compounds are, among others, N,N,N',N'-tetraglycidyl-m-xylylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N' , N'-tetraglycidyl-4, 4'-diaminodiphenylmethane, Takenate B-830, B-815N, B-820NSU, B-842N, B-846N, B-870N, B-874N, B-882N, 1, 3,5-tris(2-hydroxyethyl)isocyanurate, triglycidyl isocyanurate, 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 is preferred.

The content of the crosslinkable compound in the liquid crystal aligning agent of the present invention is preferably 0.5 to 20 parts by mass with respect to 100 parts by mass of the polymer component contained in the liquid crystal aligning agent, and the effect of the present invention is preferably obtained. From the viewpoint of obtaining , it is more preferably 1 to 15 parts by mass.

Examples of the adhesion aid include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyldiethoxymethylsilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3- glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyl trimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, tris-(trimethoxysilylpropyl)isocyanurate, 3-mercaptopropylmethyldimethoxysilane , 3-mercaptopropyltrimethoxysilane, and 3-isocyanatopropyltriethoxysilane. When using a silane coupling agent, from the viewpoint of expressing good resistance to AC afterimage, it is 0.1 to 30 parts by weight with respect to 100 parts by weight of the polymer component contained in the liquid crystal aligning agent. It is preferably from 0.1 to 20 parts by mass.

Compounds for promoting imidization include basic sites (e.g., primary amino groups, aliphatic heterocycles (e.g., pyrrolidine skeleton), aromatic heterocycles (e.g., imidazole ring, indole ring), guanidino groups, etc.) (excluding the above-mentioned cross-linking compounds and adhesion aids), or compounds in which the above-mentioned basic sites are generated during baking. More preferably, it is a compound in which the above-mentioned basic site is generated during baking. Specific examples include a protecting group (for example, a Boc group, or a 9-fluorene Amino acids protected with a carbamate-based protecting group such as a nylmethoxycarbonyl group) can be mentioned. Specific examples of the above amino acids include glycine, alanine, cysteine, methionine, asparagine, glutamine, valine, leucine, phenylalanine, tyrosine, tryptophan, proline, hydroxyproline, arginine, histidine, lysine, ornithine. A more preferred specific example of the compound for promoting imidization is N-α-(9-fluorenylmethoxycarbonyl)-N-τ-(t-butoxycarbonyl)-L-histidine.
The content of the compound for promoting imidization is preferably 2 mol parts or less, more preferably 1 mol part or less, with respect to 1 mol part of the amic acid site or amic acid ester site possessed by the polyamic acid ester or polyamic acid. , more preferably 0.5 mol parts or less.

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 range of the solid content concentration 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.

<Liquid crystal alignment film/liquid crystal display element>
The liquid crystal alignment film of the present invention is obtained from the above liquid crystal alignment agent. The liquid crystal alignment film of the present invention can be used for horizontal alignment type or vertical alignment type (VA type) liquid crystal display elements, and is particularly suitable for horizontal alignment type liquid crystal display elements such as IPS mode and FFS mode. The liquid crystal alignment film of the present invention is preferably used as a liquid crystal alignment film for photo-alignment treatment.

The liquid crystal display element of the present invention comprises the liquid crystal alignment film, for example, by the following steps (1) to (3) and (5), or by a method including steps (1) to (2) and (5) can be manufactured. More preferably, it is produced by a method comprising steps (1) to (5).
<Step (1): Step of applying a liquid crystal aligning agent onto a substrate>
A process (1) is a process of apply|coating a liquid crystal aligning agent on a board|substrate. A specific example of step (1) is as follows.
A liquid crystal aligning agent 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 material of the substrate is not particularly limited as long as it is highly transparent, and glass, silicon nitride, plastics such as acrylic and polycarbonate 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 or FFS 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 applying the liquid crystal aligning agent on the substrate in step (1), the solvent is evaporated or the polyamic acid or polyamic acid ester is heated by heating means such as a hot plate, a thermal circulation oven, or an IR (infrared) oven. Thermal imidization can be performed. 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 firing temperature can be, for example, 40 to 180°C. From the viewpoint of shortening the process, it may be carried out at 40 to 150°C. The firing time at that time is not particularly limited, but may be 1 to 10 minutes or 1 to 5 minutes. When the polyamic acid or polyamic acid ester is thermally imidized, a step of firing at 150 to 300°C or 150 to 250°C may be added. The firing time at that time is not particularly limited, but includes a firing time of 5 to 40 minutes or 5 to 30 minutes.
The 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 Orientation Treatment>
Step (3) is a step of subjecting the baked film (coating film) obtained in step (2) to an orientation treatment depending on the case. That is, in a horizontal alignment type 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 a VA system or a PSA system (Polymer Sustained Alignment), the formed coating film can be used as it is as a liquid crystal alignment film, but the coating film is subjected to an alignment ability imparting treatment. may be applied. The alignment treatment method for the liquid crystal alignment film includes a rubbing treatment method and a photo-alignment treatment method, and the photo-alignment treatment method is more preferable. 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 , more preferably 100 to 5,000 mJ/cm ² , still more preferably 100 to 1,500 mJ/cm ² , and 100 to 1,000 mJ/cm ² . is particularly preferred, and 100-400 mJ/cm ² is even more preferred. When a normal liquid crystal aligning agent is used, the light irradiation amount in the alignment treatment is 100 to 5,000 mJ/cm ² , but in the liquid crystal aligning agent of the present invention, the light irradiation amount in the alignment treatment is reduced. Even so, it is possible to obtain a liquid crystal alignment film in which the variation (non-uniformity) of the liquid crystal alignment in the plane of the liquid crystal alignment film is suppressed.
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.
Further, the liquid crystal alignment film irradiated with polarized radiation can be subjected to contact treatment using 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. Among them, water, 2-propanol, 1-methoxy-2-propanol and ethyl lactate are preferable from the viewpoint of versatility and solvent safety. More preferred are water, 1-methoxy-2-propanol or ethyl lactate. Solvents may be used singly or in combination of two or more.

<Step (4): Step of performing heat treatment>
Step (4) is a step of heat-treating the liquid crystal alignment film oriented in step (3). You may heat-process with respect to the irradiation film (coating film) which irradiated the said radiation. The temperature of the heat treatment for the coating film irradiated with radiation is preferably 50 to 300.degree. C., more preferably 120 to 250.degree. The heat treatment time is preferably 1 to 30 minutes.

<Step (5): 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 to face each other with a gap (cell gap) therebetween so that the respective liquid crystal alignment films face each other. Next, the peripheral portions 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 opened. Seal.

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 of the respective coating films are at a predetermined angle, for example, orthogonal or antiparallel.
As the sealing agent, for example, an epoxy resin containing aluminum oxide spheres as a curing agent and spacers can be used. Liquid crystals include nematic liquid crystals and smectic liquid crystals, among which nematic liquid crystals are preferred.
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 system, 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 method, includes a base material, a plane electrode formed on the base material, 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 partial cross-sectional view showing an example of the lateral electric field liquid crystal display device of the present invention, which is an example of an IPS mode liquid crystal display device.
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 base material 2a, a plurality of linear electrodes 2b formed on the base material 2a and arranged in a comb-like shape, and a plurality of linear electrodes 2b formed on the base material 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 electric lines of force L. FIG.

FIG. 2 is a schematic partial sectional view showing another example of the horizontal electric field liquid crystal display device of the present invention, which is an example of the FFS mode liquid crystal display device.
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 plane electrode 2e and the linear electrode 2g, an electric field is generated between the plane electrode 2e and the linear electrode 2g as indicated by electric lines of force L. FIG.

Although the present invention will be described in more detail with examples below, the present invention should not be construed as being limited to these examples. The abbreviations of the compounds used and methods for measuring physical properties are as follows.

(diamine)

(tetracarboxylic dianhydride)

(Esterification agent)

(Additive)

(solvent)
NMP: N-methyl-2-pyrrolidone, GBL: γ-butyrolactone BCS: ethylene glycol monobutyl ether

(Measurement of viscosity)
Using an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.), a sample amount of 1.1 mL, and a cone rotor TE-1 (1°34', R24), measurement was performed at a temperature of 25°C.
(Measurement of ¹ H-NMR)
Fourier transform superconducting nuclear magnetic resonance (FT-NMR) (AVANCE III, manufactured by BRUKER) 500 MHz.

(Measurement of esterification rate)
150 mg of a polyamic acid ester NMP solution with a solid content concentration of 12% by mass was placed in an NMR sample tube (NMR sampling tube standard φ5 manufactured by Kusano Kagaku Co., Ltd.), and deuterated dimethyl sulfoxide (DMSO-d ₆ , 0.05% TMS (tetramethyl 0.53 mL of silane (mixture) was added and completely dissolved by applying ultrasonic waves. ¹ H-NMR of this solution was measured. For the esterification rate, a proton derived from a structure that does not change before and after esterification is determined as a reference proton, and the peak integrated value of this proton and the proton peak integrated value derived from the COOH group of the carboxylic acid appearing around 11 to 13.5 ppm. and was obtained by the following formula.
Esterification rate (%) = (1-α x/y) x 100
In the above formula, x is the proton peak integrated value derived from the COOH group of the carboxylic acid, y is the peak integrated value of the reference protons, and α is the COOH of the carboxylic acid in the case of polyamic acid (the esterification rate is 0%). It is the ratio of the number of reference protons to one base proton.

<Measurement of imidization rate>
20 mg of polyimide powder is placed in an NMR sample tube (NMR sampling tube standard, φ5 (manufactured by Kusano Kagaku Co., Ltd.)), deuterated dimethyl sulfoxide (0.05% TMS mixture) (0.53 mL) is added, and ultrasonic waves are added. to dissolve completely. ¹ H-NMR of this solution was measured. For the imidization rate, a proton derived from a structure that does not change before and after imidization is determined as a reference proton. It was obtained by the following formula using the integrated value.
Imidation rate (%) = (1-α x/y) x 100
In the above formula, x is the proton peak integrated value derived from the NH group of the amic acid, y is the peak integrated value of the reference protons, and α is the NH of the amic acid in the case of polyamic acid (imidization rate is 0%). It is the ratio of the number of reference protons to one base proton.

<Synthesis of polyamic acid>
(Synthesis example 1)
A1 (0.541 g, 5.00 mmol), A2 (1.83 g, 7.50 mmol), A3 (2.40 g, 7.50 mmol), A4 are added to a 100 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube. (1.99 g, 5.00 mmol), B1 (5.31 g, 23.7 mmol) and NMP (88 g) were added and stirred at 40 ° C. for 20 hours to obtain a polyamic acid (PAA -1) solution (viscosity: 400 mPa·s) was obtained.

(Synthesis example 2)
A5 (2.99 g, 15.0 mmol), A6 (2.11 g, 5.00 mmol), A7 (1.49 g, 5.00 mmol), B2 (6.91 g, 23.5 mmol) and NMP (99 g) were added and stirred at 40 ° C. for 20 hours to give a solution of polyamic acid (PAA-2) with a solid content concentration of 12% by mass (viscosity: 380 mPa s ).

(Synthesis Example 3)
A1 (0.541 g, 5.00 mmol), A2 (1.83 g, 7.50 mmol), A3 (2.40 g, 7.50 mmol), A8 were added to a 100 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube. (1.71 g, 5.00 mmol), B1 (5.31 g, 23.7 mmol) and NMP (86 g) were added and stirred at 40 ° C. for 20 hours to obtain a polyamic acid (PAA A solution of -3) (viscosity: 400 mPa·s) was obtained.

<Synthesis of polyamic acid ester>
(Synthesis Example 4)
A solution (30.0 g) of polyamic acid (PAA-1) was dispensed into a 100 mL Erlenmeyer flask equipped with a nitrogen inlet tube, C1 (12.7 g) was added, and the mixture was stirred at room temperature for 12 hours to obtain a polyamic acid ester. A solution of (PAE-1) was obtained. The esterification rate of this polyamic acid ester was 60%.

(Synthesis Example 5)
A solution (42.7 g) of polyamic acid ester (PAE-1) was poured into isopropyl alcohol (214 g), and the precipitate formed was filtered off. The precipitate was washed with isopropyl alcohol and dried under reduced pressure at 80° C. to obtain polyamic acid ester powder. NMP (26.4 g) was added to the obtained polyamic acid ester powder (3.6 g) and dissolved by stirring at 70° C. for 20 hours to obtain a polyamic acid ester solution (PAE-1A).

(Synthesis Example 6)
A solution of polyamic acid ester (PAE-2) was obtained in the same manner as in Synthesis Example 4, except that the amount of C1 added was 6.35 g. The esterification rate of this polyamic acid ester was 28%.

<Synthesis of polyimide>
(Synthesis Example 7)
A solution (60.0 g) of polyamic acid (PAA-3) was dispensed into a 200 mL Erlenmeyer flask, NMP (20.0 g) was added, then acetic anhydride (4.65 g) and pyridine (0.60 g). was added and reacted at 55° C. for 2 hours. This reaction solution was poured into methanol (341 g) and the precipitate formed was filtered off. This precipitate was washed with methanol and dried under reduced pressure at 80° C. to obtain polyimide powder. The imidization rate of this polyimide was 66%. NMP (48.4 g) was added to the obtained polyimide powder (6.6 g) and dissolved by stirring at 60° C. for 24 hours to obtain a polyimide (SPI-1) solution.

Table 1 summarizes the types and amounts of the diamine component and the tetracarboxylic anhydride component used in Synthesis Examples 1-7. 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>
(Example 1)
Polyamic acid ester (PAE-1) solution (2.75 g) obtained in Synthesis Example 4, polyamic acid (PAA-2) solution (6.42 g) obtained in Synthesis Example 2, NMP (4.83 g) and BCS (6.00 g) were added and stirred at room temperature for 2 hours to obtain a liquid crystal aligning agent (V-1).

(Example 2) to (Example 3)
In the same manner as in Example 1, except that the polyamic acid ester solution used was changed from the (PAE-1) solution to the (PAE-1A) and (PAE-2) solutions, a liquid crystal aligning agent (V- 2) and (V-3) were obtained.

(Reference example 1)
Polyamic acid ester (PAE-1A) solution (9.17 g) obtained in Synthesis Example 5, NMP 10 mass% diluted solution of AD-1 (0.550 g), NMP (4.28 g) and BCS (6.00 g ) was added and stirred at room temperature for 2 hours to obtain a liquid crystal aligning agent (SV-1).

(Comparative example 1)
Except that the polymer solution used was changed from the polyamic acid ester (PAE-1) solution to the polyamic acid (PAA-1) solution, the liquid crystal aligning agent (RV-1) was prepared in the same manner as in Example 1. Obtained.

(Comparative example 2)
Polyimide (SPI-1) solution (5.83 g) obtained in Synthesis Example 7, polyamic acid (PAA-2) solution (2.50 g) obtained in Synthesis Example 2, NMP (2.77 g), GBL (4.90 g) and BCS (4.00 g) were added and stirred at room temperature for 2 hours to obtain a liquid crystal aligning agent (RV-2).

(Comparative Example 3)
Except that the polymer solution used was changed from the polyamic acid ester (PAE-1A) solution to the polyamic acid (PAA-1) solution, the liquid crystal aligning agent (RV-3) was prepared in the same manner as in Reference Example 1. Obtained.

(Comparative Example 4)
The polyimide (SPI-1) solution (8.33 g) obtained in Synthesis Example 7 was added with a 10 mass% diluted solution of AD-1 in NMP (0.50 g), NMP (4.93 g), GBL (2.33 g), and BCS (4.00 g) were added and stirred at room temperature for 2 hours to obtain a liquid crystal aligning agent (RV-4).

Table 2 shows the specifications of the liquid crystal aligning agents obtained in Examples 1 to 3, Reference Example 1 and Comparative Examples 1 to 4.

Using each liquid crystal aligning agent obtained above, an FFS-driven liquid crystal cell was produced in the following procedure, and various evaluations were performed.
<Configuration of FFS-driven liquid crystal cell>
A liquid crystal cell having the structure of an FFS mode liquid crystal display element was produced.
First, a substrate with electrodes was prepared. The substrate was a 30 mm x 50 mm rectangular glass plate with a thickness of 0.7 mm. An ITO electrode having a solid pattern is formed on the substrate as a first layer to form a counter electrode, and a CVD (chemical vapor deposition) electrode is formed as a second layer on the first layer counter electrode. A SiN (silicon nitride) film formed by the method was formed. The SiN film of the second layer has a film thickness of 300 nm and functions as an interlayer insulating film. On the SiN film of the second layer, a comb-shaped pixel electrode formed by patterning an ITO film is arranged as a third layer, and two pixels of a first pixel and a second pixel are formed. The size of each pixel was 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, the liquid crystal aligning agents (V-1) to (V-3) and (RV-1) to (RV-2) obtained in Examples 1 to 3 and Comparative Examples 1 and 2 were each sized to have a pore size of 1.5. After filtration with a 0 μm filter, the substrate with electrodes (first glass substrate) prepared above and a glass substrate (second glass substrate) having columnar spacers with a height of 4 μm and having an ITO film formed on the back surface (second It was applied to the surface of the glass substrate) by spin coating. Then, after drying on a hot plate at 80° C. for 2 minutes, baking was performed in a hot air circulating oven at 230° C. for 30 minutes to form a coating film with a thickness of 100 nm. The coated film surface was subjected to alignment treatment by irradiating linearly polarized ultraviolet light having a wavelength of 254 nm and an extinction ratio of 26:1 through a polarizing plate for each dose shown in Table 3 to obtain a substrate with a liquid crystal alignment film. . In addition, the liquid crystal alignment film formed on the substrate with the electrode is aligned so that the direction of equally dividing the interior angle of the bent portion of the pixel is orthogonal to the alignment direction of the liquid crystal, and the liquid crystal alignment film is formed on the second glass substrate. In No. 1, alignment treatment was performed so that the alignment direction of the liquid crystal on the first glass substrate and the alignment direction of the liquid crystal on the second glass substrate were the same when the liquid crystal cell was produced. The above two substrates are used as a set, a sealant (Mitsui Chemicals XN-1500T) is printed on the substrate, and another substrate is placed so that the alignment direction facing the liquid crystal alignment film surface is 0°. and glued together. After that, the sealant was heat-treated at 150° C. for 60 minutes and cured to prepare an empty cell. Liquid crystal MLC-3019 (manufactured by Merck & Co.) was injected into this empty cell by a vacuum injection method, and the injection port was sealed to obtain an FFS-driven liquid crystal cell. After that, the obtained liquid crystal cell was heated at 120° C. for 1 hour and left to stand overnight before being used for evaluation.

<Evaluation of in-plane uniformity of contrast>
Variation in the twist angle of the liquid crystal display element was evaluated using AxoStep manufactured by AXOMETRICS. The liquid crystal cell produced above was placed on a measurement stage, and the distribution of Circular Retardance in the pixel plane was measured with no voltage applied to calculate 3σ, which is three times the standard deviation σ. It can be said that the smaller the 3σ value, the better the in-plane uniformity. As evaluation criteria, the above 3σ value was "excellent" when it was 1.10 or less, "good" when it was greater than 1.10 and 1.20 or less, and "poor" when it was greater than 1.20. .
Table 3 shows the evaluation results of the liquid crystal display elements using the liquid crystal aligning agents of the above Examples and Comparative Examples.

<Evaluation of stability of liquid crystal alignment>
This evaluation evaluates afterimages (also referred to as AC afterimages) caused by deterioration of the alignment performance of the liquid crystal alignment film during long-term AC driving. It can be considered that the better the stability of the liquid crystal alignment, the higher the effect of suppressing the AC afterimage.
An AC voltage of ±4 V at a frequency of 60 Hz was applied to the FFS-driven liquid crystal cell produced above for 120 hours in a constant temperature environment of 60°C. After that, the pixel electrode and the counter electrode of the liquid crystal cell were short-circuited and left at room temperature for one day. For the liquid crystal cell subjected to the above treatment, the deviation between the alignment direction of the liquid crystal in the first region of the pixel and the alignment direction of the liquid crystal in the second region was calculated as an angle when no voltage was applied. Specifically, a liquid crystal cell is placed between two polarizing plates whose polarization axes are orthogonal to each other, a backlight is turned on, and the liquid crystal cell is arranged so that the transmitted light intensity in the first region of the pixel is minimized. was adjusted, and then the rotation angle required when the liquid crystal cell was rotated so that the intensity of transmitted light in the second region of the pixel was minimized was obtained. It can be said that the smaller the rotation angle, the better the stability of the liquid crystal alignment. As evaluation criteria, the value of the rotation angle is "excellent" if it is less than 0.10, "good" if it is 0.10° or more and 0.20° or less, and is greater than 0.20°. was defined as "defective".
Table 3 shows the evaluation results of the liquid crystal display devices using the liquid crystal aligning agents of Examples 1-3 and Comparative Examples 1-2.

As shown in Table 3, a liquid crystal alignment film obtained from a liquid crystal aligning agent that is a mixture of a specific polyamic acid ester and a specific polyamic acid is a mixture of two polyamic acids, or a mixture of polyimide and polyamic acid. Compared with the liquid crystal alignment film obtained from the liquid crystal alignment agent, it exhibited high in-plane uniformity or high stability of liquid crystal alignment under a small amount of ultraviolet irradiation.

<Rubbing resistance test>
Next, in order to confirm the strength of the liquid crystal alignment films formed using the respective liquid crystal alignment agents obtained in Reference Example 1 and Comparative Examples 3 and 4, a rubbing resistance test was performed. It can be considered that the better the evaluation of the rubbing resistance test, the more difficult it is for the liquid crystal alignment film to be peeled off from the substrate.
The liquid crystal aligning agents (SV-1) and (RV-3) to (RV-4) obtained in Reference Example 1 and Comparative Examples 3 and 4, respectively, were applied to the ITO surface of a glass substrate having an ITO electrode on the entire surface. was applied by spin coating. After drying on a hot plate at 80° C. for 2 minutes, baking was performed at 230° C. for 30 minutes using an IR oven to form a coating film with a thickness of 100 nm. The coated film surface was subjected to orientation treatment by irradiating polarized ultraviolet rays at 300 mJ/cm ² . Baking was performed again at 230° C. for 30 minutes using an IR oven to obtain a substrate with a liquid crystal alignment film.
After rubbing the substrate with the liquid crystal alignment film obtained as described above with a rayon cloth (roller diameter: 120 mm, roller rotation speed: 1000 rpm, moving speed: 20 mm / sec, pushing length: 0.6 mm), Microscopic observation was performed to evaluate the rubbing resistance of the liquid crystal alignment film.
A film in which no streaks due to the rubbing treatment were observed on the surface of the liquid crystal alignment film was evaluated as "◯", and a film in which streaks were observed was evaluated as "x".

Table 4 below shows the evaluation results of the rubbing resistance test of the liquid crystal alignment films formed using the liquid crystal alignment agents obtained in Reference Example 1 and Comparative Examples 3 and 4.

As shown in Table 4, the liquid crystal alignment film obtained from the polyamic acid ester (PAE-1A) liquid crystal alignment agent exhibits the same rubbing resistance as the liquid crystal alignment film obtained from the polyamic acid (PAA-1), and the polyimide ( It exhibits higher rubbing resistance than the liquid crystal alignment film obtained from SPI-1). Therefore, the liquid crystal alignment film of the present invention obtained from the liquid crystal alignment agent containing the polyamic acid ester (A) and the polyamic acid (B) is comparable to the liquid crystal alignment film obtained from the liquid crystal alignment agent containing the polyamic acid. It is suggested that it exhibits rubbing resistance and exhibits higher rubbing resistance than a liquid crystal aligning film obtained from a liquid crystal aligning agent containing polyimide and polyamic acid.

The liquid crystal alignment film obtained from the liquid crystal alignment agent of the present invention is used for various types of liquid crystal display elements for display purposes, light control windows and optical shutters for controlling the transmission and blocking of light, and other than these. It is also effectively used for various uses. For example, liquid crystal alignment films for retardation films, liquid crystal alignment films for scanning antennas and array antennas, liquid crystal alignment films for transmission scattering type liquid crystal light control elements, and other applications such as protective films (e.g. protective films for color filters), spacer films, interlayer insulating films, antireflection films, wiring coating films, antistatic films, electric motor insulating films (gate insulating films of flexible displays), etc.

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. 2021-105052 filed on June 24, 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.
Component (A): As a structural unit derived from a tetracarboxylic acid derivative, it has a structural unit (a-1Ta) represented by the following formula (1Ta), and as a structural unit derived from a diamine, represented by the following formula (1Da). Polyamic acid ester (A) having two or more types of structural units (a-1Da)
Component (B): As a structural unit derived from a tetracarboxylic acid derivative, it has a structural unit (b-1Tb) represented by the following formula (1Tb), and as a structural unit derived from a diamine, represented by the following formula (1Db). Polyamic acid (B) having a structural unit (b-1Db)

(In formula (1Ta), R 11 to R 14 each independently represent 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, group, a monovalent organic group having 1 to 6 carbon atoms containing a fluorine atom, or a phenyl group, and at least one of R 11 to R 14 represents a group other than a hydrogen atom as defined above. 1 each independently represents a hydrogen atom or a tert-alkyl group, at least one of which represents a tert-alkyl group, in formula (1Da), Y 1 is represented by the following formula (H 1 ) 2 is a valent organic group. Each Z independently represents a hydrogen atom or a monovalent organic group.)

(In formula (H 1 ), Ar 1 and Ar 1 ′ each independently represent a benzene ring, a biphenyl structure, or a naphthalene ring . may be substituted with a valent group, A represents a divalent organic group having an alkylene structure and having 1 to 10 carbon atoms, L 1 and L 1′ each independently represent a single bond, —O— , -S-, -C(=O)-, -OC(=O)-, -C(=O)-NR- (R represents a hydrogen atom or a monovalent organic group.), or - NR-C(=O)-(R represents a hydrogen atom or a monovalent organic group. * represents a bond.)

(In formula (1Tb), X b represents a tetravalent organic group, and in formula (1Db), Y b represents a divalent organic group, and two Z are each independently a hydrogen atom or a monovalent represents the organic group of
A in the formula (H 1 ) is any one of the following groups (provided that R represents a hydrogen atom or a monovalent organic group. Two R may be the same or different. n is 1 n1 and n2 in *-(CH 2 ) n1 -O-(CH 2 ) n2 -* are each independently an integer of 1 to 6, and the sum of n1 and n2 is 2 to 10. n1 and n2 in *-(CH 2 ) n1 -NR-C(=O)-NR-(CH 2 ) n2 -* are each independently an integer of 1 to 6, and n1 and n2 is 2 to 9. m1 and m2 are each independently an integer of 0 to 4, n' is an integer of 1 to 6, and the sum of m1, m2 and n' is 1 to 8. * represents a bond.), the liquid crystal aligning agent according to claim 1.
*-( CH2 ) n- *,
*-(CH 2 ) n1 -O-(CH 2 ) n2 -*,
*-(CH 2 ) m1 -O-C(=O)-(CH 2 ) n' -C(=O)-O-(CH 2 ) m2 -*,
*-(CH 2 ) m1 -C(=O)-O-(CH 2 ) n' -O-C(=O)-(CH 2 ) m2 -*,
*-(CH 2 ) n1 -NR-C(=O)-NR-(CH 2 ) n2 -*
In the polyamic acid ester (A), as a diamine-derived structural unit, at least one of Y 1 is a divalent organic group represented by the formula (H 1 ) in which Ar 1 and Ar 1' have the same structure. , and at least one of the other Y 1 is a divalent organic group represented by the formula (H 1 ) in which Ar 1 and Ar 1′ have different structures, having a structural unit represented by the formula (1Da), The liquid crystal aligning agent according to claim 1 or 2.
The polyamic acid ester (A) contains at least one structural unit represented by the formula (1Da), wherein Y 1 is a divalent organic group having three or more benzene rings, as a diamine-derived structural unit. The liquid crystal aligning agent according to any one of claims 1 to 3.
Y 1 in formula (1Da) is a divalent organic group represented by any one of the following formulas (h1-1) to (h1-13), according to any one of claims 1 to 4. Liquid crystal aligning agent.

(In formula (h1-4), the total number of —CH 2 — is 10 or less. In formulas (h1-7) and (h1-8), the total number of —CH 2 — is 8 or less, The two m's may be the same or different, and * represents a bond.)
X b in the above formula (1Tb) is a tetravalent organic group obtained by excluding two acid dianhydride groups from an acyclic aliphatic tetracarboxylic dianhydride, and two groups from an alicyclic tetracarboxylic dianhydride. A tetravalent organic group excluding an acid dianhydride group, or a tetravalent organic group excluding two acid dianhydride groups from an aromatic tetracarboxylic dianhydride, and a benzene ring or cyclobutane ring structure , a tetravalent organic group derived from a tetracarboxylic dianhydride or a derivative thereof having at least one partial structure selected from the group consisting of a cyclopentane ring structure and a cyclohexane ring structure, any one of claims 1 to 5 The liquid crystal aligning agent according to item 1.
The polyamic acid ester (A) contains 5 mol% or more of the structural unit (a-1Ta) relative to 1 mol of all structural units derived from a tetracarboxylic acid derivative, according to any one of claims 1 to 6. Liquid crystal aligning agent.
Any one of claims 1 to 7, wherein the polyamic acid ester (A) contains the structural unit (a-1Da) in an amount of 5 to 95 mol% with respect to 1 mol of all diamine-derived structural units of the polyamic acid ester (A). or the liquid crystal aligning agent according to item 1.
The liquid crystal aligning agent according to any one of claims 1 to 8, which is used for forming a liquid crystal alignment film for a photo-alignment method.
A liquid crystal alignment film obtained from 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 element, 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 Step (3): Step (2 ) Orientation treatment of the fired film obtained in
The method for manufacturing a liquid crystal display element according to claim 12, wherein the alignment treatment is a photo-alignment treatment.
14. The method for manufacturing a liquid crystal display element according to claim 13, wherein the irradiation amount of radiation in the photo-alignment treatment is 100 to 1,500 mJ/cm 2 .
15. The method for manufacturing a liquid crystal display element according to any one of claims 12 to 14, further comprising the following step (4).
Step (4): A step of further subjecting the fired film that has been oriented in step (3) to heat treatment at 50 to 300°C.