JP7428138B2 - Liquid crystal alignment agent, liquid crystal alignment film and liquid crystal display element - Google Patents

Description

The present invention relates to a liquid crystal alignment agent, a liquid crystal alignment film, and a liquid crystal display element using the same.

Liquid crystal devices have been widely used as display units for personal computers, smartphones, mobile phones, televisions, and the like. A liquid crystal 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 that apply an electric field to the liquid crystal layer, an alignment film that controls the orientation of liquid crystal molecules in the liquid crystal layer, and pixels. It is equipped with a thin film transistor (TFT), etc. that switches electrical signals supplied to the electrodes. As methods for driving liquid crystal molecules, vertical electric field methods such as TN method and VA method, and transverse electric field methods such as IPS method and fringe field switching (hereinafter referred to as FFS) method are known.

Currently, the liquid crystal alignment film that is most widely used industrially is a film made of polyamic acid and/or polyimide that is imidized with polyamic acid formed on an electrode substrate. It is manufactured by rubbing in one direction, a so-called rubbing process. Rubbing treatment is a simple, highly productive and industrially useful method. However, as liquid crystal display elements become more sophisticated, have higher definition, and become larger in size, scratches on the surface of the alignment film that occur during the rubbing process, dust generation, the effects of mechanical force and static electricity, and furthermore, Various problems such as non-uniformity have become clear. As a liquid crystal alignment treatment method that replaces rubbing treatment, a photo alignment method is known in which a liquid crystal alignment ability is imparted by irradiating polarized radiation. Liquid crystal alignment treatments using photoalignment methods have been proposed using photoisomerization reactions, photocrosslinking reactions, photodecomposition reactions, etc. (see Non-Patent Document 1, Patent Document 1). .

A liquid crystal alignment film, which is a component of a liquid crystal display element, is a film for uniformly arranging liquid crystals, and is required to have various characteristics in addition to alignment uniformity of liquid crystals. For example, the voltage that drives the liquid crystal causes charge to accumulate in the liquid crystal alignment film, which affects the display as an afterimage or burn-in (hereinafter referred to as an afterimage derived from residual DC), and can significantly degrade the display quality of the liquid crystal display element. Because of these problems, a liquid crystal aligning agent has been proposed to overcome these problems (see Patent Document 2).

Furthermore, in the IPS system and FFS driving system, stability of liquid crystal alignment is also important. If the alignment stability is low, the liquid crystal will not return to its initial state when it is driven for a long time, causing a decrease in contrast and image sticking (hereinafter referred to as AC afterimage). As a method for solving the above problems, Patent Document 3 discloses a specific liquid crystal aligning agent.

Furthermore, with the spread of tablets and smartphones, development of narrow frame liquid crystal display elements that secure as wide a display area as possible is underway. Due to this narrowing of the frame, it has become necessary to apply a sealant on the liquid crystal alignment film, so a liquid crystal alignment agent that maintains liquid crystal alignment and has good adhesion with the sealant is disclosed in Patent Document 4. There is.

Japanese Patent Publication No. 9-297313 International Publication No. 2005/083504 pamphlet International Publication No. 2015/050135 pamphlet International Publication No. 2015/060360 pamphlet

"Liquid Crystal Photoalignment Film" Kidowaki, Ichimura, Functional Materials, November 1997 issue, Vol. 17, No. 11, pp. 13-22

However, in actual liquid crystal display elements, the twist angle slightly varies within the plane of the liquid crystal display element due to manufacturing variations and the like. Then, due to such in-plane variations, the brightness during black display in the liquid crystal display element varies within the plane. Further, the demand for higher definition for liquid crystal display elements is increasing, and it is becoming more important than ever to exhibit good display quality.
The present invention has been made in view of the above circumstances, and provides a liquid crystal alignment film that exhibits good resistance to AC afterimages or afterimages derived from residual DC, and has good adhesion to sealants, as well as a liquid crystal alignment film that exhibits good adhesion to a sealing agent. One object of the present invention is to provide a liquid crystal aligning agent that can suppress in-plane brightness variations and obtain a liquid crystal display element with excellent contrast characteristics.

The inventor of the present invention conducted extensive research and found that the above-mentioned problem can be solved by using a liquid crystal aligning agent containing a specific component, and has completed the present invention. Specifically, the gist is as follows.

（Ｒ_１～Ｒ_４は、それぞれ独立して、水素原子、ハロゲン原子、炭素数１～６のアルキル基、炭素数２～６のアルケニル基、炭素数２～６のアルキニル基、フッ素原子を含有する炭素数１～６の１価の有機基、又はフェニル基であり、Ｒ_１～Ｒ_４の少なくとも一つは上記定義中の水素原子以外の基を表す。Ｙ_１は下記式（Ｈ）で表される部分構造を有する２価の有機基を表す。）

（Ｑ^３は－（ＣＨ_２）_ｎ－で表される構造であり（但し、ｎは２～２０の整数であり、任意の－ＣＨ_２－は－Ｏ－に置き換えられてもよい。但し、酸素原子同士が直接結合することはない。）、２つのベンゼン環上の任意の水素原子は１価の有機基で置き換えられてもよい。＊は結合手を表す。）

（Ｘ_３は芳香族酸二無水物に由来する４価の有機基を表す、Ｙ_３は下記式（ｍ）で表される部分構造を有する２価の有機基であり、＊は結合手である。Ｒ_３０は水素原子、又は炭素数１～４のアルキル基であり；Ｚ_３１、Ｚ_３２はそれぞれ独立して水素原子、置換基を有してもよい炭素数１～１０のアルキル基、置換基を有してもよい炭素数２～１０のアルケニル基、置換基を有してもよい炭素数２～１０のアルキニル基、ｔｅｒｔ－ブトキシカルボニル基、又は９－フルオレニルメトキシカルボニル基を表す。）

A liquid crystal aligning agent characterized by containing the following components (A) and (B).
Component (A): A polymer (A) having a repeating unit represented by the following formula (1).
Component (B): A polymer (B) containing a repeating unit represented by the following formula (3).

(R ₁ to R ₄ each independently contain a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, and a fluorine atom. is a monovalent organic group having 1 to 6 carbon atoms, or a phenyl group, and at least one of R ₁ to R ₄ represents a group other than a hydrogen atom in the above definition. Y ₁ is represented by the following formula (H): Represents a divalent organic group having the indicated partial structure.)

(Q ³ is a structure represented by -(CH ₂ ) _n - (however, n is an integer from 2 to 20, and any -CH ₂ - may be replaced with -O-. However, (Oxygen atoms do not bond directly to each other.) Any hydrogen atoms on the two benzene rings may be replaced with a monovalent organic group. * represents a bond.)

(X ₃ represents a tetravalent organic group derived from an aromatic acid dianhydride, Y ₃ is a divalent organic group having a partial structure represented by the following formula (m), and * is a bond. R ₃₀ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; Z ₃₁ and Z ₃₂ are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may have a substituent, An alkenyl group having 2 to 10 carbon atoms which may have a substituent, an alkynyl group having 2 to 10 carbon atoms which may have a substituent, a tert-butoxycarbonyl group, or a 9-fluorenylmethoxycarbonyl group. represent.)

According to the liquid crystal aligning agent of the present invention, a liquid crystal aligning film having good adhesion to the sealant can be obtained. Furthermore, a liquid crystal display element that is less likely to generate afterimages derived from residual DC or AC afterimages, and has excellent contrast with suppressed in-plane brightness variations during black display can be obtained.

<Polymer (A)>
The liquid crystal aligning agent of the present invention contains a polymer (A) having a repeating unit represented by the above formula (1). With such a configuration, it is possible to obtain a liquid crystal alignment film with less generation of AC afterimages, and also to obtain a liquid crystal display element with excellent contrast. In the above formula (1), X ₂ , Y ₁ , Y ₂ , R ₁ , R ₂ , R ₃ and R ₄ are as defined above.

The tetravalent organic group represented by X ₂ in formula (1) is preferably a tetravalent organic group having a 5- to 8-membered alicyclic structure; More preferably, it is a valent organic group. In addition, when the alicyclic structure to which an imide group is bonded is a polycyclic structure, an alicyclic structure with 5 or more members refers to the number of atoms constituting the ring in each ring included in the polycyclic structure. is 5 or more. Further, the alicyclic structure only needs to be bonded to at least one of the two imide groups, and may have a chain hydrocarbon structure or an aromatic ring structure together with the alicyclic structure.

Specific examples of the alkyl group having 1 to 6 carbon atoms in R ₁ to R ₄ above include methyl group, ethyl group, propyl group, i-propyl group, n-butyl group, i-butyl group, s-butyl group, Examples include t-butyl group and n-pentyl group. Specific examples of the alkenyl group having 2 to 6 carbon atoms in R ₁ to R ₄ include vinyl group, propenyl group, butynyl group, and these may be linear or branched. Specific examples of the alkynyl group having 2 to 6 carbon atoms in R ₁ to R ₄ include ethynyl group, 1-propynyl group, 2-propynyl group, and the like. Examples of the halogen atoms in R ₁ to R ₄ include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms. Examples of the monovalent organic group having 1 to 6 carbon atoms and containing a fluorine atom include a fluoromethyl group and a trifluoromethyl group. From the viewpoint of high photoreactivity, R ₁ to R ₄ are hydrogen atoms or methyl groups, preferably at least one of R ₁ to R ₄ is a methyl group, and more preferably at least one of R ₁ to R ₄ is a methyl group. Preferably, two are methyl groups. More preferably, R ₁ and R ₃ are methyl groups, and R ₂ and R ₄ are hydrogen atoms.

Specific examples of the monovalent organic group in the formula (H) include 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, and a fluorine atom. Examples include monovalent organic groups containing 1 to 6 carbon atoms, including the structures exemplified for R ₁ to R ₄ above. Examples of the partial structure represented by the formula (H) include partial structures represented by any of the following formulas (H-1) to (H-6) from the viewpoint of less generation of AC afterimages.

Preferred specific examples of Y ₁ in the above formula (1) include divalent organic groups represented by any of the following formulas (h-1) to (h-7) from the viewpoint of less generation of AC afterimages. Can be mentioned.

（式中、Ｘ_２は、５員環以上の脂環構造を有する４価の有機基である。Ｙ_２は上記式（Ｈ）で表される部分構造を有する２価の有機基を表す。） It is preferable that the polymer (A) further has a repeating unit represented by the following formula (2) from the viewpoint of improving heat resistance.

(In the formula, X ₂ is a tetravalent organic group having a 5-membered ring or more alicyclic structure. Y ₂ represents a divalent organic group having a partial structure represented by the above formula (H). )

The tetravalent organic group represented by X ₂ in formula (2) is preferably a tetravalent organic group having a 5- to 8-membered alicyclic structure; More preferably, it is a valent organic group. In addition, when the alicyclic structure to which an imide group is bonded is a polycyclic structure, an alicyclic structure with 5 or more members refers to the number of atoms constituting the ring in each ring included in the polycyclic structure. is 5 or more. Further, the alicyclic structure only needs to be bonded to at least one of the two imide groups, and may have a chain hydrocarbon structure or an aromatic ring structure together with the alicyclic structure.

ＡＣ残像の発生が少なく、液晶表示素子のコントラストを高める観点から、（Ｘ２－１）～（Ｘ２－４）がより好ましい。 Preferred specific examples of X ₂ include tetravalent organic groups represented by any of the following formulas (X2-1) to (X2-12).

(X2-1) to (X2-4) are more preferable from the viewpoint of reducing the occurrence of AC afterimages and increasing the contrast of the liquid crystal display element.

Preferred specific examples of Y ₂ in the formula (2) are the same as the preferred specific examples of Y ₁ in the formula (1).

The polymer (A) is at least one type selected from the group consisting of a repeating unit represented by the following formula (4) and a repeating unit represented by the following formula (5), from the viewpoint of increasing the contrast of the liquid crystal display element. It may further have a repeating unit.

R ₄₁ to R ₄₄ in the formulas (4) and (5) have the same meaning as R ₁ to R ₄ in the formula (1), including preferred specific examples. X ₅ in formula (5) has the same meaning as X ₂ in formula (2). Y ₄ and Y ₅ represent a divalent organic group represented by the following formula (I).

In the formula (I), Q represents a single bond or an oxygen atom, and n represents 0 to 2. Any hydrogen atom on the benzene ring may be replaced with a monovalent organic group, and examples of such monovalent organic groups include the structures exemplified in the specific examples of the monovalent organic group in formula (H) above. can be mentioned.

Y ₄ in the above formula (4) and Y ₅ in the above formula (5) are 2 represented by any of the following formulas (I-1) to (I-3) from the viewpoint of increasing the contrast of the liquid crystal display element. Preferably, it is a valent organic group. In the following formula, * represents a bond.

（式中、Ｒ_６１からＲ_６４はそれぞれ前記式（１）のＲ_１からＲ_４と好ましい具体例も含めて同義であり、Ｙ_６、Ｙ_７はそれぞれ独立して下記式（Ｊ－１）で表される部分構造を有する２価の有機基、又は下記式（Ｊ－２）で表される２価の有機基を表す。式（７）におけるＸ_７は前記式（２）のＸ_２と同義である。）

The polymer (A) contains at least one repeating unit selected from the group consisting of a repeating unit represented by the following formula (6) and a repeating unit represented by the following formula (7), from the viewpoint of improving adhesion with the sealant. It may further have different types of repeating units.

(In the formula, R ₆₁ to R ₆₄ have the same meanings as R ₁ to R ₄ of the above formula (1), including preferred specific examples, and Y ₆ and Y ₇ each independently correspond to the following formula (J-1) It represents a divalent organic group having a partial structure represented by, or a divalent organic group represented by the following formula (J-2).X ₇ in formula (7) is X ₂ in formula (2) above. (synonymous with).

In the formulas (J-1) and (J-2), Q ₅ is a single bond, -(CH ₂ ) _n - (n is an integer from 1 to 20), or any of -(CH ₂ ) _n - -O-, -COO-, -OCO-, -NQ ₉ -, -NQ ₉ CO-, -CONQ ₉ -, -NQ ₉ CONQ ₁₀ -, -NQ ₉ under the condition that -CH 2 - of -CH ₂ - are not adjacent to each other. A group that can be replaced with COO-, -OCOO-, and Q ₉ and Q ₁₀ each independently represent a hydrogen atom or a monovalent organic group;
Q ₆ and Q ₇ each independently represent a group having -H, -NHD, -N(D) ₂ or -NHD, or a group having -N(D) ₂ . Q ₈ represents -NHD, -N(D) ₂ , a group having -NHD, or a group having -N(D) ₂ . D represents a carbamate-based protecting group, and examples of the carbamate-based protecting group include a tert-butoxycarbonyl group and a 9-fluorenylmethoxycarbonyl group. However, at least one of Q ₅ , Q ₆ and Q ₇ has a carbamate protecting group in the group. *1 represents a bond. Preferred specific examples of Y ₆ and Y ₇ are represented by any of the following formulas (J-1-a) to (J-1-d) and (J-2-1) from the viewpoint of reducing AC afterimages. Examples include divalent organic groups. "Boc" represents a tert-butoxycarbonyl group.

The polymer (A) comprises a repeating unit represented by the above formula (1), a repeating unit represented by the above formula (2), a repeating unit represented by the above formula (4), and a repeating unit represented by the above formula (5). In addition to the repeating unit represented by the formula (6) and the repeating unit represented by the formula (7), the repeating unit represented by the following formula (PI-A-1) and the repeating unit represented by the formula (PI-A-1) and (PA It may have at least one repeating unit selected from the group consisting of repeating units represented by -1).

（Ｒ_１、Ｒ_２、Ｒ_３、Ｒ_４は、上記式（１）のＲ_１、Ｒ_２、Ｒ_３、Ｒ_４と同義である。） In formula (PI-A-1), X _I1 represents a tetravalent organic group, and Y _I1 represents a divalent organic group. However, if X _I1 has the same meaning as the tetravalent organic group represented by the following formula (g) or X ₂ in the above formula (2), Y _I1 has the partial structure represented by the above formula (H). a divalent organic group having the above formula (I), a divalent organic group having the partial structure represented by the above formula (J-1), the above formula (J-2) Represents a structure other than the divalent organic group represented by As X _I1 , in addition to the tetravalent organic group represented by the following formula (g) and the tetravalent organic group exemplified by X ₂ in the above formula (2), the following formulas (X _I1 -1) to (X _I1-13 ), a tetravalent organic group derived from an aromatic tetracarboxylic dianhydride, and the like.

(R ₁ , R ₂ , R ₃ , and R ₄ have the same meanings as R ₁ , R ₂ , R ₃ , and R ₄ in the above formula (1).)

（ｘ及びｙは、それぞれ独立に、単結合、エーテル（－Ｏ－）、カルボニル（－ＣＯ－）、エステル（－ＣＯＯ－）、炭素数１～５のアルカンジイル基、１，４－フェニレン、スルホニル又はアミド基である。ｊ及びｋは、それぞれ独立に、０又は１の整数である。＊は結合手を表す。）

Here, the aromatic tetracarboxylic dianhydride is an acid dianhydride obtained by intramolecular dehydration of a carboxyl group bonded to an aromatic ring such as a benzene ring or a naphthalene ring. To give specific examples, a tetravalent organic group represented by any of the following formulas (X3-1) to (X3-2), a tetravalent organic group represented by any of the following formulas (Xr-1) to (Xr-7), Examples include tetravalent organic groups.

(x and y are each independently a single bond, ether (-O-), carbonyl (-CO-), ester (-COO-), alkanediyl group having 1 to 5 carbon atoms, 1,4-phenylene, It is a sulfonyl or amide group. j and k are each independently an integer of 0 or 1. * represents a bond.)

In formula (PI-A-1), specific examples of the divalent organic group represented by Y _I1 include a divalent organic group having a partial structure represented by formula (H) above, and a divalent organic group represented by formula (I) above. In addition to the divalent organic group represented by the above formula (J-1), the divalent organic group having the partial structure represented by the above formula (J-1), the divalent organic group represented by the above formula (J-2), the following formula Divalent organic groups represented by (o-1) to (o-23), groups represented by any of formulas (Y-1) to (Y-167) described in International Publication No. 2018/117239 etc.

In formula (PA-1), X _A1 represents a tetravalent organic group, and Y _A1 represents a divalent organic group. Specific examples of X _A1 include the structure exemplified by X _I1 in the above formula (PI-A-1), and specific examples of Y _A1 include the structure exemplified by Y _I1 in the above formula (PI-A-1). An example of this is the structure

In formula (PA-1), R _A1 is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; Z _A11 and Z _A12 are each independently a hydrogen atom, or an alkyl group having 1 to 5 carbon atoms which may have a substituent. 10 alkyl group, an optionally substituted alkenyl group having 2 to 10 carbon atoms, an optionally substituted alkynyl group having 2 to 10 carbon atoms, a tert-butoxycarbonyl group, or a 9-fluorene group. It is a nylmethoxycarbonyl group.

Specific examples of the alkyl group having 1 to 5 carbon atoms for R _A1 above include methyl group, ethyl group, propyl group, i-propyl group, n-butyl group, i-butyl group, s-butyl group, t-butyl group. group, n-pentyl group, etc. From the viewpoint of ease of imidization by heating, R ₁ is preferably a hydrogen atom or a methyl group.

Specific examples of the alkyl group having 1 to 10 carbon atoms for Z _A11 and Z _A12 include hexyl group, heptyl group, octyl group, in addition to the specific examples of the alkyl group having 1 to 5 carbon atoms exemplified for R ₁ above. , nonyl group, decyl group, etc. Specific examples of the alkenyl group having 2 to 10 carbon atoms as Z _A11 and Z _A12 include vinyl group, propenyl group, butynyl group, and these may be linear or branched. Specific examples of the alkynyl group having 2 to 10 carbon atoms for Z _A11 and Z _A12 include ethynyl group, 1-propynyl group, 2-propynyl group, and the like.

Z _A11 and Z _A12 may have a substituent, and examples of the substituent include a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom, etc.), a hydroxyl group, a cyano group, an alkoxy group, etc. It will be done.

From the viewpoint of reducing AC afterimages, the total amount of the repeating unit represented by the formula (1) and the repeating unit represented by the formula (2) in the polymer (A) is 1 to 95 mol% of the total repeating units. It is preferable to include.

<Polymer (B)>
The liquid crystal aligning agent of the present invention contains a polymer (B) having a repeating unit represented by the above formula (3). With such a configuration, the heat resistance of the obtained liquid crystal alignment film can be increased, so that a liquid crystal alignment film with less AC afterimage can be obtained, and variations in the twist angle within the plane that occur during manufacturing can be suppressed. A liquid crystal display element with excellent contrast can be obtained. In the above formula (3), X ₃ , Y ₃ , R ₃₀ , Z ₃₁ and Z ₃₂ are as defined above.

Specific examples of the alkyl group having 1 to 5 carbon atoms for R ₃₀ include the structure exemplified by R _A1 in formula (PA-1) above. From the viewpoint of ease of imidization by heating, each R ₃₀ is preferably independently a hydrogen atom or a methyl group.

Specific examples of the alkyl group having 1 to 10 carbon atoms, alkenyl group having 2 to 10 carbon atoms, and alkynyl group having 2 to 10 carbon atoms of Z ₃₁ and Z ₃₂ include Z _A1 of the above formula (PA-1), Examples include the structure exemplified in Z _A2 .

Z ₃₁ and Z ₃₂ may have a substituent, and examples of the substituent include the structures exemplified for Z _A1 and Z _A2 in the above formula (PA-1).

From the viewpoint of reducing AC afterimages, Z ₃₁ and Z ₃₂ are preferably each independently a hydrogen atom or a methyl group.

As Y ₃ in the formula (3), a divalent organic group selected from the following formulas (Y3-1) to (Y3-2) may be used from the viewpoint of reducing AC afterimages.

Specific examples of the aromatic acid dianhydride represented by X ₃ in the formula (3) include the structures exemplified by X _I1 above. From the viewpoint of reducing AC afterimages, X ₃ is preferably a tetravalent organic group represented by the formula (X3-1) or (X3-2). More preferred specific examples of the tetravalent organic group represented by formula (X3-1) or (X3-2) are structures represented by any of the following formulas (X3-3) to (X3-19). can be mentioned.

The polymer (B) is composed of a repeating unit represented by the following formula (8) and a repeating unit represented by the following formula (9), from the viewpoint of increasing the seal adhesion of the liquid crystal alignment film and reducing the afterimage derived from residual DC. It may have at least one type of repeating unit selected from the group consisting of repeating units.

(In the formula, X ₈ is a tetravalent organic group having an alicyclic structure with a 5-membered ring or more, and has the same meaning as X ₂ in formula (2) above, including preferred embodiments. _{X 9} is a 5-membered ring or more It is a tetravalent organic group having an alicyclic structure or a tetravalent organic group derived from an aromatic acid dianhydride, and has a preferred embodiment with X ₂ of the above formula (2) or X ₃ of the above formula (3). _Y8 has the same meaning as _Y3 in formula (3) above, and _Y9 is a divalent organic compound having a partial structure represented by the following formula (n-1) or (n-2). A group. Z ₈₁ , Z ₈₂ , Z ₉₁ , and Z ₉₂ have the same meanings as Z ₃₁ and Z ₃₂ in formula (3), respectively. R ₈ and R ₉ are each independently a hydrogen atom or a carbon number of 1 -4 alkyl group, and Q ₁ and Q ₂ each independently represent a hydrogen atom or a methyl group.)

（Ｒ^２１及びＲ^２２はそれぞれ独立して水素原子又はメチル基を表し、Ｑ^２２は独立して単結合、又は＊１－Ｒ^２３－Ｐｈ－＊２を表し、Ｒ^２３は単結合、－Ｏ－、－ＣＯＯ－、－ＯＣＯ－、－（ＣＨ_２）_ｌ－、－Ｏ（ＣＨ_２）_ｍＯ－、－ＣＯＮＨ－、及び－ＮＨＣＯ－から選ばれる２価の有機基を表し（ｌ、ｍは１～５の整数を表す）、＊１は式（ＮＤ－１－２）中のベンゼン環と結合する部位を表し、＊２は式（ＮＤ－１－２）中のアミノ基と結合する部位を表す。Ｐｈはフェニレン基を表す。ｎは１～３の整数を表す。）

Specific examples of the divalent organic group having a partial structure represented by the above formula (n-1) or (n-2) include the following formulas (ND-1-2) and (ND-2-1). - (ND-2-3) or (ND-5).

(R ²¹ and R ²² each independently represent a hydrogen atom or a methyl group, Q ²² independently represents a single bond or *1-R ²³ -Ph-*2, R ²³ is a single bond, -O -, -COO-, -OCO-, -(CH ₂ ) _l -, -O(CH ₂ ) _m represents a divalent organic group selected from O-, -CONH-, and -NHCO- (l, m represents an integer from 1 to 5), *1 represents the site that binds to the benzene ring in formula (ND-1-2), and *2 represents the site that binds to the amino group in formula (ND-1-2). Ph represents a phenylene group. n represents an integer from 1 to 3.)

式中、Ｒ^２５は、単結合、－Ｏ－、－ＣＯＯ－、－ＯＣＯ－、－（ＣＨ_２）_ｌ－、－Ｏ（ＣＨ_２）_ｍＯ－、－ＣＯＮＲ－、及び－ＮＲＣＯ－から選ばれる２価の有機基を表し、ｋは１～５の整数を表す。なお、Ｒは水素もしくは炭素数１～３のアルキル基などの一価の有機基を表し、ｌ、ｍは１～５の整数を表す。＊１、＊２は結合手を表し、＊１は式（ＮＤ－２－１）～式（ＮＤ－２－３）中のベンゼン環と結合する。

（Ｒ^５１、Ｒ^５２は、それぞれ独立して水素原子又はメチル基を表す。Ａ_５は単結合又は－Ｏ－、－（ＣＨ_２）_ｎ－（ｎは１～４の整数）などの２価の有機基を表す。） In the formula, R ²¹ and R ²² are each a hydrogen atom or a methyl group. R ²⁴ each independently represents a single bond or the structure of the following formula (Ar), and n represents an integer from 1 to 3. * represents a bond. Further, any hydrogen atom of the benzene ring may be substituted with a monovalent organic group such as a methyl group or a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom, etc.).

In the formula, R ²⁵ is selected from a single bond, -O-, -COO-, -OCO-, -(CH ₂ ) _l -, -O(CH ₂ ) _m O-, -CONR-, and -NRCO- represents a divalent organic group, and k represents an integer of 1 to 5. Note that R represents hydrogen or a monovalent organic group such as an alkyl group having 1 to 3 carbon atoms, and l and m represent integers of 1 to 5. *1 and *2 represent bonds, and *1 is bonded to the benzene ring in formulas (ND-2-1) to (ND-2-3).

(R ⁵¹ and R ⁵² each independently represent a hydrogen atom or a methyl group. A ₅ is a single bond or a divalent bond such as -O-, -(CH ₂ ) _n - (n is an integer of 1 to 4) (represents an organic group)

Preferred specific examples of the formula (ND-1-2) include structures represented by any of the following formulas (n1-9) to (n1-14).

Preferred specific examples of the formulas (ND-2-1) to (ND-2-3) include structures represented by any of the following formulas (n2-1) to (n2-6).

Preferred specific examples of the formula (ND-5) include structures represented by any of the following formulas (n5-1) to (n5-8).

Polymer (B) contains the following formula (PA- It may have a repeating unit represented by 2).

In formula (PA-2), X _A2 represents a tetravalent organic group, and Y _A2 represents a divalent organic group. However, if X _A2 has the same meaning as X ₉ in the above formula (9), Y _A2 is a divalent organic group having a partial structure represented by the above formula (m) or the above formula (n-1) or Represents a structure other than a divalent organic group having a partial structure represented by (n-2). R _A2 has the same meaning as R ₃ in formula (3) above, including preferred embodiments, and Z _A21 and Z _A22 have the same meaning as Z ₃₁ and Z ₃₂ in formula (3), including preferred embodiments.

Specific examples of X _A2 include, in addition to aromatic tetracarboxylic dianhydrides exemplified by X ₃ in formula (3) above, those derived from aliphatic tetracarboxylic dianhydrides and alicyclic tetracarboxylic dianhydrides. Examples include tetravalent organic groups.
Specific examples of Y _A2 include a divalent organic group having a partial structure represented by the above formula (m) or a divalent organic group having a partial structure represented by the above formula (n-1) or (n-2). In addition to the organic group, the pyrrole structure described in International Publication No. WO2017/126627 can be added to a divalent organic group, preferably a divalent organic group represented by the following formula (pr), to International Publication No. WO2018/092759. Divalent organic group having a thiophene or furan structure as described, 2,4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4,6-diaminoresorcinol , 2,4-diaminobenzoic acid, 2,5-diaminobenzoic acid or 3,5-diaminobenzoic acid, and carboxyl groups such as diamine compounds represented by the following formulas [3b-1] to [3b-4]. A divalent organic group obtained by removing two amino groups from a diamine, a divalent organic group having -NH-CO-NH- in the molecule such as the following formulas (U-1) to (U-9), an international Examples include divalent organic groups described in paragraphs [0013] to [0030] of Publication Publication No. WO2018-181566.

式（ｐｒ）中、Ｒ^８１は水素原子、又はメチル基を表し、Ｒ^８２はそれぞれ独立して単結合又は基「＊１－Ｒ^８３－Ｐｈ－＊２」を表し、Ｒ^８３は単結合、－Ｏ－、－ＣＯＯ－、－ＯＣＯ－、－（ＣＨ_２）_ｌ－、－Ｏ（ＣＨ_２）_ｍＯ－、－ＣＯＮＨ－、及び－ＮＨＣＯ－から選ばれる２価の有機基を表し（ｌ、ｍは１～５の整数を表す）、＊１は式（ｐｒ）中のベンゼン環と結合する部位を表し、＊２は上記式（ＰＡ－２）中の窒素原子と結合する部位を表す。Ｐｈはフェニレン基を表す。ｎは１～３を表す。

In formula (pr), R ⁸¹ represents a hydrogen atom or a methyl group, R ⁸² each independently represents a single bond or a group "*1-R ⁸³ -Ph-*2", R ⁸³ represents a single bond, -O-, -COO-, -OCO-, -(CH ₂ ) _l -, -O(CH ₂ ) _m represents a divalent organic group selected from O-, -CONH-, and -NHCO- (l , m represents an integer from 1 to 5), *1 represents the site that is bonded to the benzene ring in formula (pr), and *2 represents the site that is bonded to the nitrogen atom in the above formula (PA-2). . Ph represents a phenylene group. n represents 1 to 3.

式［３ｂ－１］中、Ａ^１は単結合、－ＣＨ_２－、－Ｃ_２Ｈ_４－、－Ｃ（ＣＨ_３）_２－、－ＣＦ_２－、－Ｃ（ＣＦ_３）_２－、－Ｏ－、－ＣＯ－、－ＮＨ－、－Ｎ（ＣＨ_３）－、－ＣＯＮＨ－、－ＮＨＣＯ－、－ＣＨ_２Ｏ－、－ＯＣＨ_２－、－ＣＯＯ－、－ＯＣＯ－、－ＣＯＮ（ＣＨ_３）－又はＮ（ＣＨ_３）ＣＯ－を示し、ｍ^１及びｍ^２はそれぞれ独立して、０～４の整数を示し、かつｍ^１＋ｍ^２は１～４の整数を示し、式［３ｂ－２］中、ｍ^３及びｍ^４はそれぞれ独立して、１～５の整数を示し、式［３ｂ－３］中、Ａ^２は炭素数１～５の直鎖又は分岐アルキレン基を示し、ｍ^５は１～５の整数を示し、式［３ｂ－４］中、Ａ^３及びＡ^４はそれぞれ独立して、単結合、－ＣＨ_２－、－Ｃ_２Ｈ_４－、－Ｃ（ＣＨ_３）_２－、－ＣＦ_２－、－Ｃ（ＣＦ_３）_２－、－Ｏ－、－ＣＯ－、－ＮＨ－、－Ｎ（ＣＨ_３）－、－ＣＯＮＨ－、－ＮＨＣＯ－、－ＣＨ_２Ｏ－、－ＯＣＨ_２－、－ＣＯＯ－、－ＯＣＯ－、－ＣＯＮ（ＣＨ_３）－又はＮ（ＣＨ_３）ＣＯ－を示し、ｍ^６は１～４の整数を示す。

In formula [3b-1], A ¹ is a single bond, -CH ₂ -, -C ₂ H ₄ -, -C(CH ₃ ) ₂ -, -CF ₂ -, -C(CF ₃ ) ₂ -, - O-, -CO-, -NH-, -N(CH ₃ )-, -CONH-, -NHCO-, -CH ₂ O-, -OCH ₂ -, -COO-, -OCO-, -CON(CH ₃ )- or N(CH ₃ )CO-, m ¹ and m ² each independently represent an integer of 0 to 4, and m ¹ +m ² represents an integer of 1 to 4, and the formula [3b -2], m ³ and m ⁴ each independently represent an integer of 1 to 5, and in formula [3b-3], A ² represents a linear or branched alkylene group having 1 to 5 carbon atoms, m ⁵ represents an integer of 1 to 5, and in formula [3b-4], A ³ and A ⁴ each independently represent a single bond, -CH ₂ -, -C ₂ H ₄ -, -C(CH ₃ ) ₂ -, -CF ₂ -, -C(CF ₃ ) ₂ -, -O-, -CO-, -NH-, -N(CH ₃ )-, -CONH-, -NHCO-, -CH ₂ O -, -OCH ₂ -, -COO-, -OCO-, -CON(CH ₃ )- or N(CH ₃ )CO-, and m ⁶ represents an integer of 1 to 4.

From the viewpoint of increasing contrast, the polymer (B) of the present invention preferably contains 30 to 100 mol% of the repeating unit represented by the above formula (3) based on the total repeating units of the polymer (B), Alternatively, it is preferably contained in an amount of 40 to 100 mol%, or preferably contained in an amount of 50 to 100 mol%.

From the viewpoint of reducing AC afterimages and residual DC-derived afterimages, the orientation ratio of the polymer (A) and the polymer (B) is 5/95 in terms of mass ratio of polymer (A)/polymer (B). It is preferable that the ratio is between 95/5 and 95/5. From the viewpoint of obtaining a liquid crystal alignment film with high reproducibility, the alignment ratio of the polymer (A) and the polymer (B) is 10/ The ratio is more preferably 90 to 90/10, and even more preferably 20/80 to 80/20.

<Production method of polyamic acid, polyamic acid ester and polyimide>
The polyamic acid ester, polyamic acid, and polyimide that are the polyimide precursors used in the present invention can be synthesized, for example, by a known method as described in International Publication WO2013/157586.

<Liquid crystal alignment agent>
The liquid crystal aligning agent of the present invention contains a polymer (A) and a polymer (B). The liquid crystal aligning agent of the present invention may contain other polymers in addition to the polymer (A) and the polymer (B). Other types of polymers include polyamic acids, polyimides, polyamic acid esters, polyesters, polyamides, polyureas, polyorganosiloxanes, cellulose derivatives, polyacetals, polystyrene or its derivatives, poly(styrene-phenylmaleimide) derivatives, poly(meth) ) acrylate, etc.

The liquid crystal alignment agent is used for producing a 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 coating liquid contains 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 changed as appropriate depending on the thickness of the coating film to be formed. From the viewpoint of forming a uniform and defect-free coating film, the content is preferably 1% by mass or more, and from the viewpoint of storage stability of the solution, the content is preferably 10% by mass or less. Particularly preferred polymer concentrations are 2 to 8% by weight.

The organic solvent contained in the liquid crystal aligning agent is not particularly limited as long as the polymer component is uniformly dissolved therein. Specific examples include N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethylsulfoxide, γ-butyrolactone, 1,3-dimethyl -Imidazolidinone, methyl ethyl ketone, cyclohexanone, cyclopentanone, 3-methoxy-N,N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropanamide (these are also collectively referred to as "good solvents"), etc. can be mentioned. Among them, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 3-methoxy-N,N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropanamide or γ-butyrolactone can be used. preferable. The good solvent in the liquid crystal aligning agent of the present invention 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. It is.

In addition to the above-mentioned solvents, the organic solvent contained in the liquid crystal aligning agent may be used in combination with a solvent (also called a poor solvent) that improves the coating properties and surface smoothness of the coating film when applying the liquid crystal aligning agent. It is preferable to use a mixed solvent of Specific examples of organic solvents used in combination are listed below, but the invention is not limited to these examples.
For example, diisopropyl ether, diisobutyl ether, diisobutyl carbinol (2,6-dimethyl-4-heptanol), ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, 1,2-butoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether , 4-hydroxy-4-methyl-2-pentanone, diethylene glycol methyl ethyl ether, diethylene glycol dibutyl ether, 3-ethoxybutyl acetate, 1-methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, ethylene Glycol monoacetate, ethylene glycol diacetate, propylene carbonate, ethylene carbonate, ethylene glycol monobutyl ether, ethylene glycol monoisoamyl ether, ethylene glycol monohexyl ether, propylene glycol monobutyl ether, 1-(2-butoxyethoxy)-2- Propanol, 2-(2-butoxyethoxy)-1-propanol, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, ethylene glycol monobutyl ether acetate, ethylene glycol mono Acetate, ethylene glycol diacetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, 2-(2-ethoxyethoxy)ethyl acetate, diethylene glycol acetate, propylene glycol diacetate, n-butyl acetate, propylene acetate Glycol monoethyl ether, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, butyl 3-methoxypropionate, n-butyl lactic acid ester, isoamyl lactic acid ester, Examples include diethylene glycol monoethyl ether and diisobutyl ketone (2,6-dimethyl-4-heptanone).

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

Preferred solvent combinations of good and poor solvents 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 and γ-butyrolactone and ethylene glycol monobutyl ether. Pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether, N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone, 4-hydroxy-4-methyl-2-pentanone and diethylene glycol diethyl Ether, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether and 2,6-dimethyl-4-heptanone, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether and diisopropyl ether, N -Methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether and 2,6-dimethyl-4-heptanol, N-methyl-2-pyrrolidone and γ-butyrolactone and dipropylene glycol dimethyl ether, N-methyl-2-pyrrolidone and propylene glycol monobutyl ether and dipropylene glycol dimethyl ether. These poor solvents preferably account for 1 to 80% by mass, more preferably 10 to 80% by mass, and particularly preferably 20 to 70% by mass of the total solvent contained in the liquid crystal aligning agent. The type and content of such a solvent are appropriately selected depending on the liquid crystal aligning agent coating device, coating conditions, coating environment, and the like.

The liquid crystal aligning agent of the present invention may additionally contain components other than the polymer component and the organic solvent. Such additional components include adhesion aids to improve the adhesion between the liquid crystal alignment film and the substrate and the adhesion between the liquid crystal alignment film and the sealing material, and compounds (crosslinking compounds) to increase the strength of the liquid crystal alignment film. ), dielectric materials and conductive materials for adjusting the dielectric constant and electrical resistance of the liquid crystal alignment film.

式（ｄ）、（ｅ）中、Ｒ_７１、Ｒ_７２及びＲ_７３は、それぞれ独立に水素原子、炭素数１～３のアルキル基、又は＊－ＣＨ_２－ＯＨである。＊は結合手を示す。Ａは芳香環を有する（ｍ＋ｎ）価の有機基を表す。ｍは１～６の整数を表し、ｎは０～４の整数を表す。 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, and a Meldrum acid structure, from the viewpoint of less generation of AC afterimages and a high effect of improving film strength. group, a cyclocarbonate group, a compound having a group represented by the following formula (d), or a compound represented by the following formula (e) (these are also collectively referred to as compound (C)).

In formulas (d) and (e), R ₇₁ , R ₇₂ and R ₇₃ are each independently a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or *-CH ₂ -OH. * indicates a bond. A represents an (m+n)-valent organic group having an aromatic ring. m represents an integer of 1 to 6, and n represents an integer of 0 to 4.

Specific examples of compounds having an oxiranyl group include compounds described in paragraph [0037] of Japanese Patent Application Publication No. 10-338880, compounds having a triazine ring as a skeleton described in International Publication No. WO2017/170483, etc. Examples include compounds having two or more oxiranyl groups. Among these, N,N,N',N',-tetraglycidyl-m-xylene diamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N', -tetraglycidyl-4,4'-diaminodiphenylmethane, N,N,N',N'-tetraglycidyl-p-phenylenediamine, represented by any of the following formulas (r-1) to (r-3) Particularly preferred are compounds containing nitrogen atoms, such as compounds.

Specific examples of compounds having oxetanyl groups include, for example, compounds having two or more oxetanyl groups described in paragraphs [0170] to [0175] of International Publication No. 2011/132751.

Specific examples of compounds having a protected isocyanate group include, for example, compounds having two or more protected isocyanate groups described in paragraphs [0046] to [0047] of Japanese Patent Application Publication No. 2014-224978, International Publication No. 2015/ Examples include compounds having three or more protected isocyanate groups described in paragraphs [0119] to [0120] of No. 141598. Among these, compounds represented by any of the following formulas (bi-1) to (bi-3) are preferred.

Specific examples of compounds having a protected isothiocyanate group include, for example, compounds having two or more protected isothiocyanate groups described in Japanese Patent Application Publication No. 2016-200798.

Specific examples of compounds having a group containing an oxazoline ring structure include, for example, compounds containing two or more oxazoline structures described in paragraph [0115] of Japanese Patent Application Publication No. 2007-286597.

Specific examples of compounds having a group containing a Meldrum's acid structure include compounds having two or more Meldrum's acid structures described in International Publication No. WO2012/091088.
Specific examples of compounds having a cyclocarbonate group include, for example, the compounds described in International Publication No. WO2011/155577.

Examples of the alkyl group having 1 to 3 carbon atoms as R ₇₁ , R ₇₂ , and R ₇₃ in the formula (d) include a methyl group, an ethyl group, and a propyl group.

Specific examples of the compound having the group represented by the formula (d) include the compound having the formula ( Compounds having two or more groups represented by d), compounds described in Japanese Patent Application Publication No. 2016-200798, and the like can be mentioned. Among these, compounds represented by any of the following formulas (hd-1) to (hd-8) are preferred.

The (m+n)-valent organic group having an aromatic ring in A of the formula (e) includes an (m+n)-valent aromatic hydrocarbon group having 5 to 30 carbon atoms, and an aromatic hydrocarbon group having 5 to 30 carbon atoms. Examples include (m+n)-valent organic groups to which are bonded directly or via a linking group, and (m+n)-valent groups having an aromatic heterocycle. Examples of the aromatic hydrocarbon group include benzene and naphthalene. Examples of aromatic heterocycles include pyrrole ring, imidazole ring, pyrazole ring, pyridine ring, pyrimidine ring, quinoline ring, isoquinoline ring, carbazole ring, pyridazine ring, pyrazine ring, benzimidazole ring, benzimidazole ring, indole ring, and quinoxaline. ring, acridine ring, etc. Examples of the linking group include an alkylene group having 1 to 10 carbon atoms, a group obtained by removing one hydrogen atom from the alkylene group, and a divalent or trivalent cyclohexane ring. Note that any hydrogen atom of the alkylene group may be substituted with a fluorine atom or an organic group such as a trifluoromethyl group. Specific examples include compounds described in International Publication No. WO2010/074269. Preferred specific examples include any of the following formulas (e-1) to (e-9).

Examples of the above-mentioned crosslinkable compounds are not limited to these. For example, components other than the above disclosed in [0105] to [0116] of International Publication No. 2015/060357 can be mentioned. Further, two or more types of crosslinkable compounds may be used in combination.
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 based on 100 parts by mass of the polymer component contained in the liquid crystal aligning agent, and the desired effect is achieved. However, from the viewpoint of less generation of AC afterimages, the amount 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, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl -1,4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diaza Nonyl acetate, N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane , N-bis(oxyethylene)-3-aminopropyltrimethoxysilane, N-bis(oxyethylene)-3-aminopropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4- Epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p - Styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxy Examples include silane coupling agents such as silane, tris-(trimethoxysilylpropyl)isocyanurate, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-isocyanatepropyltriethoxysilane. When using these silane coupling agents, the amount used is preferably 0.1 to 30 parts by mass based on 100 parts by mass of the polymer component contained in the liquid crystal aligning agent, from the viewpoint of reducing generation of AC afterimages. It is preferably 0.1 to 20 parts by mass, and more preferably 0.1 to 20 parts by mass.

<Method for manufacturing liquid crystal alignment film>
The method for producing a liquid crystal aligning film using the liquid crystal aligning agent of the present invention includes the step of applying the liquid crystal aligning agent described above (step (A)), and heating the coating film of the liquid crystal aligning agent obtained in step (A). (step (B)), irradiating the film obtained in step (B) with polarized ultraviolet rays (step (C)), and preferably the film obtained in step (C). It is characterized by having a step (step (D)) of firing at a temperature of 100° C. or higher and higher than the step (B).

<Process (A)>
The substrate on which the liquid crystal aligning agent used in the present invention is applied is not particularly limited as long as it is a highly transparent substrate, and in addition to glass substrates and silicon nitride substrates, plastic substrates such as acrylic substrates and polycarbonate substrates can also be used. . In this case, it is preferable to use a substrate on which ITO electrodes and the like for driving the liquid crystal are formed, from the viewpoint of process simplification. Further, in a reflective liquid crystal display element, an opaque material such as a silicon wafer can be used for only one substrate, and in this case, a material that reflects light such as aluminum can also be used for the electrodes.
The method for applying the liquid crystal aligning agent is not particularly limited, but in industry, methods such as screen printing, offset printing, flexographic printing, or inkjet methods are common. Other coating methods include a dip method, a roll coater method, a slit coater method, a spinner method, and a spray method, and these may be used depending on the purpose.

<Process (B)>
Step (B) is a step of baking the liquid crystal aligning agent applied onto the substrate to form a film. After applying the liquid crystal aligning agent onto the substrate, the solvent is evaporated by heating means such as a hot plate, thermal circulation oven, or IR (infrared rays) oven, or the amic acid or amic acid ester in the polymer is heated. It is possible to perform imidization. The drying and baking steps after applying the liquid crystal aligning agent of the present invention can be performed at any temperature and time, and may be performed multiple times. The temperature at which the organic solvent of the liquid crystal aligning agent is removed can be, for example, within a temperature range of 40 to 150°C. From the viewpoint of shortening the process, it may be carried out at a temperature of 40 to 120°C. The firing time is not particularly limited, but includes a firing time of 1 to 10 minutes or 1 to 5 minutes. When performing thermal imidization of the amic acid or amic acid ester in the polymer, after the step of removing the organic solvent, a step of firing at a temperature range of, for example, 190 to 250°C or 200 to 240°C can be performed. . The firing time is not particularly limited, but examples include a firing time of 5 to 40 minutes or 5 to 30 minutes.

<Step (C)>
Step (C) is a step of irradiating the film obtained in step (B) with polarized ultraviolet light. As the ultraviolet rays, it is preferable to use ultraviolet rays having a wavelength of 200 to 400 nm, particularly preferably ultraviolet rays having a wavelength of 200 to 300 nm. In order to improve the liquid crystal alignment, the substrate coated with the liquid crystal alignment film may be heated at 50 to 250° C. and irradiated with ultraviolet rays. Further, the irradiation amount of the radiation is preferably 1 to 10,000 mJ/cm ² . Among these, 100 to 5,000 mJ/cm ² is preferable. The liquid crystal alignment film produced in this way can stably align liquid crystal molecules in a fixed direction.
The higher the extinction ratio of polarized ultraviolet rays is, the higher the anisotropy can be imparted, which is preferable. Specifically, the extinction ratio of linearly polarized ultraviolet light is preferably 10:1 or more, more preferably 20:1 or more.

<Step (D)>
Step (D) is a step of firing the film obtained in step (C) at a temperature of 100° C. or higher and higher than that of step (B). The firing temperature is not particularly limited as long as it is 100°C or higher and higher than the firing temperature in step (B), but it is preferably 150 to 300°C, more preferably 150 to 250°C, and even more preferably 200 to 250°C. . The firing time is preferably 5 to 120 minutes, more preferably 5 to 60 minutes, even more preferably 5 to 30 minutes.
The thickness of the liquid crystal alignment film after firing is preferably 5 to 300 nm, more preferably 10 to 200 nm, since the reliability of the liquid crystal display element may decrease if it is too thin.

Furthermore, after performing either step (C) or (D), the obtained liquid crystal alignment film can also be subjected to a contact treatment using water or a solvent.
The solvent used in the above-mentioned contact treatment is not particularly limited as long as it dissolves the decomposition product generated from the liquid crystal alignment film by irradiation with ultraviolet rays. 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- Examples include methyl methoxypropionate, ethyl 3-ethoxypropionate, propyl acetate, butyl acetate, and cyclohexyl acetate. Among these, water, 2-propanol, 1-methoxy-2-propanol or ethyl lactate are preferred from the viewpoint of versatility and solvent safety. More preferred are water, 1-methoxy-2-propanol or ethyl lactate. Two or more types of solvents may be used in combination.

Examples of the above-mentioned contact treatment, that is, treatment of the liquid crystal alignment film irradiated with polarized ultraviolet rays with water or a solvent, include immersion treatment and spray treatment (also referred to as spray treatment). The treatment time in these treatments is preferably 10 seconds to 1 hour from the viewpoint of efficiently dissolving decomposed products generated from the liquid crystal alignment film by ultraviolet rays. Among these, it is preferable to perform the immersion treatment for 1 minute to 30 minutes. Further, the solvent used in the contact treatment may be heated at room temperature or at a temperature of 10 to 80° C., preferably. Among these, 20 to 50°C is preferable. In addition, from the viewpoint of solubility of the decomposed product, ultrasonic treatment or the like may be performed as necessary.

After the contact treatment, rinsing (also referred to as rinsing) with a low boiling point solvent such as water, methanol, ethanol, 2-propanol, acetone or methyl ethyl ketone or baking of the liquid crystal alignment film is preferably performed. At that time, either rinsing or baking may be performed, or both may be performed. The firing temperature is preferably 150 to 300°C. Among these, 180 to 250°C is preferred. More preferred is 200 to 230°C. Further, the firing time is preferably 10 seconds to 30 minutes. Among these, 1 to 10 minutes is preferable.

The liquid crystal alignment film of the present invention is suitable as a liquid crystal alignment film for a horizontal electric field type liquid crystal display element such as an IPS type or an FFS type, and is particularly useful as a liquid crystal alignment film for an FFS type liquid crystal display element. A liquid crystal display element is obtained by obtaining a substrate with a liquid crystal alignment film obtained from the liquid crystal aligning agent of the present invention, producing a liquid crystal cell by a known method, and using the liquid crystal cell.
As an example of a method for manufacturing a liquid crystal cell, a liquid crystal display element having a passive matrix structure will be described as an example. Note that a liquid crystal display element having an active matrix structure in which a switching element such as a TFT (Thin Film Transistor) is provided in each pixel portion constituting an image display may be used.

Specifically, transparent glass substrates are prepared, and a common electrode is provided on one substrate and a segment electrode is provided on the other substrate. These electrodes can be, for example, ITO electrodes, and are patterned to display a desired image. Next, an insulating film is provided on each substrate so as to cover the common electrode and the segment electrode. The insulating film can be, for example, a SiO ₂ -TiO ₂ film formed by a sol-gel method.
Next, a liquid crystal alignment film is formed on each substrate, one substrate is stacked on the other substrate so that the surfaces of the liquid crystal alignment films face each other, and the periphery is bonded with a sealant. In order to control the gap between the substrates, a spacer is usually mixed into the sealant, and it is preferable that spacers for controlling the gap between the substrates are also sprinkled on the in-plane portion where the sealant is not provided. A portion of the sealant is provided with an opening that can be filled with liquid crystal from the outside. Next, a liquid crystal material is injected into a space surrounded by the two substrates and the sealant through an opening provided in the sealant, and then this opening is sealed with an adhesive. For injection, a vacuum injection method may be used, or a method utilizing capillary action in the atmosphere may be used. The liquid crystal material may be either a positive type liquid crystal material or a negative type liquid crystal material. Next, a polarizing plate is installed. Specifically, a pair of polarizing plates is attached to the surfaces of the two substrates opposite to the liquid crystal layer.

As described above, by using the manufacturing method of the present invention, it is possible to suppress afterimages caused by long-term AC driving that occur in liquid crystal display elements of the IPS drive method or the FFS drive method. Further, in step (B), by removing the organic solvent at a temperature range of 40 to 150° C. and then performing step (C), a liquid crystal aligning film can be obtained with fewer steps than conventional methods. The liquid crystal alignment agent of the present invention is particularly preferably used in a method for producing a liquid crystal alignment film, which includes a step of removing the organic solvent at a temperature range of 40 to 150° C. in step (B), and then carrying out step (C). Can be done.

As described above, by using the liquid crystal aligning agent of the present invention, it is possible to obtain a liquid crystal aligning film with less generation of residual DC-derived afterimages and AC afterimages and high seal adhesion. Further, it is possible to obtain a liquid crystal display element with excellent contrast in which variations in brightness within a plane are suppressed during black display, and a liquid crystal display element with good display quality can be obtained.

The present invention will be described in more detail with reference to Examples below, but the present invention is not limited thereto. The abbreviations of the compounds and the measurement methods for each property below are as follows.
(solvent)
NMP: N-methyl-2-pyrrolidone, GBL: γ-butyrolactone,
BCS: butyl cellosolve,
(diamine)
DA-1 to DA-8: compounds represented by the following formulas (DA-1) to (DA-8),
(Tetracarboxylic dianhydride)
CA-1 to CA-4: Compounds (additives) represented by the following formulas (CA-1) to (CA-4)
C-1: Compound represented by the following formula (C-1) C-2: 2,2'-bis(4-hydroxy-3,5-dihydroxymethylphenyl)propane S-1: Compound represented by the following formula (S-1) ),

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

<Measurement of imidization rate>
Put 20 mg of polyimide powder into an NMR sample tube (NMR sampling tube standard, φ5 (manufactured by Kusano Kagaku Co., Ltd.)), and add deuterated dimethyl sulfoxide (DMSO-d6, 0.05% TMS (tetramethylsilane) mixture) (0. 53 ml) was added and completely dissolved by applying ultrasound. This solution was subjected to proton NMR measurement at 500 MHz using an NMR measuring device (JNW-ECA500, manufactured by JEOL Datum). The imidization rate is determined using a proton derived from a structure that does not change before and after imidization as a reference proton, and the peak integrated value of this proton and the proton peak derived from the NH group of the amic acid that appears around 9.5 ppm to 10.0 ppm. It was calculated using the following formula using the integrated value.
Imidization rate (%) = (1-α・x/y)×100
In the above formula, x is the integrated value of the proton peak derived from the NH group of amic acid, y is the integrated peak value of the standard proton, and α is one NH group proton of the amic acid in the case of polyamic acid (imidization rate is 0%). This is the ratio of the number of standard protons to the standard proton.

[Example of polymer synthesis]
Examples of synthesis of polyamic acid and polyimide are shown below. In these nomenclatures, A represents component (A), B represents component (B), and PI represents polyimide.

<Synthesis example 1>
In a 300 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, add 4.89 g (20.0 mmol) of DA-1, 2.59 g (24.0 mmol) of DA-2, and 4.61 g (24.0 mmol) of DA-3. 20.0 mmol) and 5.46 g (16.0 mmol) of DA-5 were weighed out, 197 g of NMP was added thereto, and the mixture was stirred and dissolved while supplying nitrogen. While stirring this diamine solution, 14.2 g (63.2 mmol) of CA-1 and 3.00 g (12.0 mmol) of CA-2 were added, and the mixture was stirred at 40°C for 24 hours, and the polyamic acid solution (A-1 ) (viscosity: 425 mPa·s) was obtained.

<Synthesis example 2>
Weighed 52.6 g (0.264 mol) of DA-7 and 13.1 g (0.066 mol) of DA-8 into a 1 L separable flask equipped with a stirrer and a nitrogen inlet tube, and added 481.7 g of NMP. The mixture was stirred and dissolved while supplying nitrogen gas. While stirring this diamine solution, 41.3 g (0.165 mol) of CA-2 and 124.5 g of NMP were added, and the mixture was reacted at 50° C. for 4 hours. Then, 45.1 g (0.153 mol) of CA-4 and 255.8 g of NMP were added, and the mixture was stirred at 70°C for 24 hours to form a 15 wt% polyamic acid solution (B-1) (viscosity: 895 mPa・s). Obtained.

<Synthesis example 3>
3.42 g (0.014 mol) of DA-1 was weighed into a 100 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, and 30.8 g of NMP was added thereto, followed by stirring and dissolving while supplying nitrogen. While stirring this diamine solution, 3.62 g (0.012 mol) of CA-4 and 20.0 g of NMP were added, and the mixture was stirred at 50°C for 12 hours. :129 mPa·s) was obtained.

<Synthesis example 4>
Weighed 16.4 g (0.035 mol) of DA-6 and 22.2 g (0.091 mol) of DA-1 into a 500 mL separable flask equipped with a stirrer and a nitrogen introduction tube, and added 283.6 g of NMP. The mixture was stirred and dissolved while supplying nitrogen gas. While stirring this diamine solution, 6.51 g (0.026 mol) of CA-2 and 47.7 g of NMP were added, and the mixture was reacted at 50° C. for 2 hours. Thereafter, 28.8 g (0.098 mol) of CA-4 and 87.9 g of NMP were added, followed by stirring for 12 hours to obtain a 15 wt% polyamic acid solution (B-3) (viscosity: 791 mPa・s). .

<Synthesis example 5>
100 g of the obtained polyamic acid solution (A-1) was weighed into a 300 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, 50 g of NMP was added, and the mixture was stirred for 30 minutes. To the obtained polyamic acid solution, 16.78 g of acetic anhydride and 5.20 g of pyridine were added, and the mixture was heated at 50° C. for 3 hours to perform chemical imidization. The resulting reaction solution was poured into 600 ml of methanol with stirring, the precipitate was collected by filtration, the same operation was performed twice to wash the resin powder, and then dried at 60°C for 12 hours. Thus, polyimide resin powder was obtained. The imidization rate of this polyimide resin powder was 71%. 3.60 g of the obtained polyimide resin powder was placed in a 100 ml Erlenmeyer flask, 26.4 g of NMP was added so that the solid content concentration was 12%, and the mixture was stirred at 70°C for 24 hours to dissolve and form a polyimide solution (A-1- PI) was obtained.

The main points of the polyamic acid solutions and polyimide solutions obtained in Synthesis Examples 1 to 5 are shown in Table 1 below.

The numbers in parentheses in Table 1 represent the blending ratio (molar parts) of each compound relative to 100 molar parts of the total amount of tetracarboxylic acid derivatives used for the synthesis for the tetracarboxylic acid component, and for the diamic acid component, It represents the blending ratio (mol parts) of each compound relative to the total amount of 100 mol parts of diamines used in the synthesis. Regarding organic solvents, the blending ratio (parts by mass) of each organic solvent is expressed with respect to 100 parts by mass of the total amount of organic solvents used in the synthesis.

[Preparation of liquid crystal alignment agent]
<Comparative example 1>
Weigh out 3.00 g of polyimide solution (A-1-PI) and 3.60 g of polyamic acid solution (B-1) into a 20 ml sample tube containing a stirring bar, and then add 0.63 g of NMP and 3.0 g of GBL. 60 g, 3.0 g of BCS, 0.90 g of GBL solution containing 1% by weight of S-1, and 0.27 g of NMP solution containing 10% by weight of C-1 were added and stirred for 30 minutes with a magnetic stirrer to align the liquid crystal. Agent (R1) was obtained.

<Example 1>
Weigh out 3.67 g of polyimide solution (A-1-PI) and 5.50 g of polyamic acid solution (B-2) into a 20 ml sample tube containing a stirrer, and then add 0.50 g of NMP and 4.0 g of GBL. 90g of BCS, 4.00g of BCS, 1.10g of GBL solution containing 1% by weight of S-1, and 0.33g of NMP solution containing 10% by weight of C-1 were added and stirred with a magnetic stirrer for 30 minutes to align the liquid crystal. Agent (1) was obtained.

<Example 2>
Weigh out 3.00 g of polyimide solution (A-1-PI) and 3.60 g of polyamic acid solution (B-3) into a 20 ml sample tube containing a stirrer, and then add 0.63 g of NMP and 3.0 g of GBL. 60 g, 3.0 g of BCS, 0.90 g of GBL solution containing 1% by weight of S-1, and 0.27 g of NMP solution containing 10% by weight of C-1 were added and stirred for 30 minutes with a magnetic stirrer to align the liquid crystal. Agent (2) was obtained.

<Example 3>
Weigh out 3.00 g of polyimide solution (A-1-PI) and 3.60 g of polyamic acid solution (B-3) into a 20 ml sample tube containing a stirrer, and then add 0.63 g of NMP and 3.0 g of GBL. Magnetic The mixture was stirred with a stirrer for 30 minutes to obtain a liquid crystal aligning agent (3).

<Example 4>
Weigh out 3.00 g of polyimide solution (A-1-PI) and 3.60 g of polyamic acid solution (B-3) into a 20 ml sample tube containing a stirring bar, and then add 0.45 g of NMP and 3.0 g of GBL. Magnetic The mixture was stirred with a stirrer for 30 minutes to obtain a liquid crystal aligning agent (4).

The main points of the liquid crystal aligning agents obtained in Examples 1 to 4 and Comparative Example 1 are shown in Table 2 below.

The numbers in parentheses in Table 2 indicate the blending ratio (parts by mass) of each polymer component or additive relative to the total 100 parts by mass of the polymer components used to prepare the liquid crystal aligning agent. represent. Regarding organic solvents, the blending ratio (parts by mass) of each organic solvent is expressed with respect to 100 parts by mass of the total amount of organic solvents used for preparing the liquid crystal aligning agent.

<Production of liquid crystal display element>
A substrate with electrodes was prepared. The substrate is a glass substrate measuring 30 mm x 35 mm and having a thickness of 0.7 mm. On the substrate, an IZO electrode with a solid pattern is formed as a first layer and constitutes a counter electrode. A SiN (silicon nitride) film formed by CVD is formed as a second layer on the first layer of counter electrode. The second layer SiN film has a thickness of 500 nm and functions as an interlayer insulating film. A comb-shaped pixel electrode formed by patterning an IZO film as a third layer is arranged on the second layer of SiN film, forming two pixels, a first pixel and a second pixel. ing. The size of each pixel is 10 mm in height and approximately 5 mm in width. At this time, the first-layer counter electrode and the third-layer pixel electrode are electrically insulated by the action of the second-layer SiN film.

The pixel electrode of the third layer has a comb-like shape formed by arranging a plurality of "dogleg"-shaped electrode elements whose central portions are bent at an internal angle of 160 degrees. The width of each electrode element in the lateral direction is 3 μm, and the interval between electrode elements is 6 μm. The pixel electrode that forms each pixel is constructed by arranging multiple electrode elements in the shape of a dogleg with a bent central part, so the shape of each pixel is not rectangular, but in the same way as the electrode element. It has a shape similar to the bold ``dog'' character, which bends at some points. Each pixel is divided into upper and lower parts with the central bent part as a boundary, and has a first area above the bent part and a second area below the bent part.
In addition, in addition to the above-mentioned glass substrate with electrodes (hereinafter also referred to as the first glass substrate), a columnar spacer with a height of 3.5 μm is formed on the surface, and an ITO film for antistatic purpose is formed on the back surface. A second glass substrate was prepared, and a set of liquid crystal cells was manufactured.

A liquid crystal aligning agent filtered through a filter with a pore size of 1.0 μm was applied on the surface of each of the above pair of glass substrates by spin coating, and dried on a hot plate at 80° C. for 2 minutes. After that, the coated film surface was irradiated with a predetermined amount of linearly polarized ultraviolet light with a wavelength of 254 nm with an extinction ratio of 26:1 through a polarizing plate, and then baked in a hot air circulation oven at 230°C for 30 minutes to form a liquid crystal film with a thickness of 100 nm. A substrate with an alignment film was obtained. The liquid crystal alignment film formed on the first glass substrate is aligned so that the direction that equally divides the internal angle of the pixel bend and the alignment direction of the liquid crystal are perpendicular to each other, and the liquid crystal alignment film formed on the second glass substrate is The film was subjected to alignment treatment such that the alignment direction of the liquid crystal on the first substrate and the alignment direction of the liquid crystal on the second substrate coincided with each other when the liquid crystal cell was produced.
Next, a sealant was printed on one of the above-mentioned pair of glass substrates with a liquid crystal alignment film, and the other substrate was bonded so that the liquid crystal alignment film surfaces faced each other, and the sealant was cured to prepare an empty cell. Liquid crystal MLC-3019 (manufactured by Merck & Co., Ltd.) was injected into this empty cell by a reduced pressure injection method, and the injection port was sealed to obtain an FFS-driven liquid crystal cell. Thereafter, the obtained liquid crystal cell was heated at 120° C. for 1 hour, left overnight, and then used for evaluation.

[evaluation]
<In-plane uniformity of contrast>
The twist angle of the liquid crystal display element was evaluated using OPTIPRO-micro manufactured by Shintech. The manufactured liquid crystal display element was placed on a measurement stage, and with no voltage applied, measurements were taken at 20 points within the first pixel plane, and the standard deviation was calculated. The evaluation was made as "poor" when the twist angle standard deviation was 0.4 or more, and as "good" when it was less than 0.4.

<Stability evaluation of liquid crystal alignment>
Using the liquid crystal display element used in the above evaluation, an AC voltage of 10 VPP was applied at a frequency of 30 Hz for 168 hours in a constant temperature environment of 60°C. Thereafter, the pixel electrode and counter electrode of the liquid crystal display element were short-circuited, and the liquid crystal display element was left at room temperature for one day.
After leaving it for a while, the liquid crystal display element was placed between two polarizing plates arranged so that the polarization axes were perpendicular to each other, and the backlight was turned on with no voltage applied so that the brightness of the transmitted light was minimized. The arrangement angle of the liquid crystal display element was adjusted. Then, the rotation angle when the liquid crystal display element was rotated from the angle at which the second region of the first pixel was the darkest to the angle at which the first region was the darkest was calculated as the angle Δ. Similarly, for the second pixel, the second area and the first area were compared, and a similar angle Δ was calculated. Then, the average value of the angle Δ values of the first pixel and the second pixel was calculated as the angle Δ of the liquid crystal display element. If the value of the angle Δ of this liquid crystal display element exceeded 0.1 degree, it was evaluated as "poor". When the value of the angle Δ of this liquid crystal cell did not exceed 0.1 degree, it was evaluated as "good".

<Evaluation of relaxation characteristics of accumulated charge>
Afterimages were evaluated using the following optical system. The fabricated liquid crystal display element was installed between two polarizing plates arranged so that the polarization axes were perpendicular to each other, and the LED backlight was turned on with no voltage applied so that the brightness of the transmitted light was minimized. , the arrangement angle of the liquid crystal display element was adjusted.
Next, a VT curve (voltage-transmittance curve) was measured while applying an AC voltage with a frequency of 30 Hz to this liquid crystal display element, and the AC voltage at which the relative transmittance was 23% was calculated as the driving voltage.
In the afterimage evaluation, while driving the liquid crystal display element by applying an alternating current voltage with a frequency of 30 Hz giving a relative transmittance of 23%, a direct current voltage of 1 V was simultaneously applied and the device was driven for 40 minutes. Thereafter, the applied DC voltage value was set to 0 V, and only the application of the DC voltage was stopped, and the device was driven in that state for an additional 15 minutes.
The evaluation was rated as "good" if the relative transmittance decreased to 27% or less within 45 minutes from the time when the application of the DC voltage was started. If it took 45 minutes or more for the relative transmittance to decrease to 27% or less, it was evaluated as "poor".
The afterimage evaluation according to the method described above was performed under a temperature condition in which the temperature of the liquid crystal display element was 23°C.

<Evaluation of seal adhesion>
[Sample preparation]
The liquid crystal aligning agent produced above was applied to an ITO substrate of 30 mm x 40 mm by spin coating. After drying on a hot plate at 80°C for 2 minutes, the coating surface was irradiated with 254 nm ultraviolet rays through a polarizing plate, and then baked in a hot air circulation oven at 230°C for 20 minutes to form a coating with a thickness of 100 nm. A film was formed. Two substrates obtained in this way were prepared, and after applying bead spacers with a diameter of 4 μm on the liquid crystal alignment film surface of one substrate, a sealing agent (XN-1500T manufactured by Kyoritsu Chemical Co., Ltd.) was dropped. . Next, the other substrate was bonded with the liquid crystal alignment film surface facing inward so that the overlapping width of the substrates was 1 cm. At that time, the amount of the sealant dropped was adjusted so that the diameter of the sealant after bonding was 3 mm. After fixing the two bonded substrates with a clip, they were thermally cured at 150° C. for 1 hour to prepare a sample for adhesion evaluation.

[Measurement of adhesion]
After fixing the edge portions of the upper and lower substrates using a tabletop precision universal testing machine (AGS-X 500N, manufactured by Shimadzu Corporation), the sample substrate produced above was pressed from the top of the center of the substrate and peeled off. The actual strength (N) was measured. The value obtained by standardizing this peel strength (N) by the adhesive area (mm ² ) was taken as the seal adhesion (N/mm ² ) for each sample, and when it was greater than 5 N/mm ² , it was evaluated as "good". . When it was less than 5 N/mm ² , it was evaluated as "poor".

The evaluation results for each of the liquid crystal display elements of Examples 1 to 4 and Comparative Example 1 are shown in Table 3 below.

The liquid crystal aligning agent of the present invention is useful for forming a liquid crystal aligning film in a wide range of liquid crystal display elements such as IPS drive type and FFS drive type.
The entire contents of the specification, claims, drawings, and abstract of Japanese Patent Application No. 2018-227376 filed on December 4, 2018 are cited here as disclosure of the specification of the present invention. , is something to be taken in.

Claims (19)

A liquid crystal aligning agent characterized by containing the following components (A) and (B).
Component (A): A polymer (A) having a repeating unit represented by the following formula (1) and a repeating unit represented by the following formula (2).
Component (B): A polymer (B) having a repeating unit represented by the following formula (3).

(R ₁ to R ₄ each independently contain a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, and a fluorine atom. is a monovalent organic group having 1 to 6 carbon atoms, or a phenyl group, and at least one of R ₁ to R ₄ represents a group other than a hydrogen atom in the above definition. Y ₁ is represented by the following formula (H): Represents a divalent organic group having the indicated partial structure.)

(Q ³ is a structure represented by -(CH ₂ ) _n - (n is an integer from 2 to 20), and any -CH ₂ - may be replaced with -O-. (However, , oxygen atoms do not bond directly to each other), any hydrogen atoms on the two benzene rings may be replaced with a monovalent organic group. * represents a bond.)

(X ₂ represents a tetravalent organic group having a 5-membered ring or more alicyclic structure. _{Y 2} represents a divalent organic group having a partial structure represented by the above formula (H).)

(X ₃ represents a tetravalent organic group derived from an aromatic acid dianhydride. Y ₃ is a divalent organic group having a partial structure represented by the following formula (m), and * is a bond. R ₃₀ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Z ₃₁ and Z ₃₂ each independently represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms which may have a substituent. group, an alkenyl group having 2 to 10 carbon atoms which may have a substituent, an alkynyl group having 2 to 10 carbon atoms which may have a substituent, a tert-butoxycarbonyl group, or 9-fluorenylmethoxycarbonyl (Represents a group.)

The liquid crystal aligning agent according to claim 1, wherein X ₂ in the formula (2) is a tetravalent organic group represented by any one of the following formulas (X2-1) to (X2-12).

A liquid crystal aligning agent characterized by containing the following components (A) and (B).
Component (A): A polymer (A) having a repeating unit represented by the following formula (1) and a repeating unit represented by the following formula (2).
Component (B): A polymer (B) having a repeating unit represented by the following formula (3).

(R ₁ ～R ₄ each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, and a fluorine atom containing 1 to 6 carbon atoms. is a monovalent organic group or phenyl group, R ₁ ～R ₄ At least one of represents a group other than a hydrogen atom in the above definition. Y ₁ represents a divalent organic group having a partial structure represented by the following formula (H). )

(Q ³ Ha-(CH ₂ ) _n - (n is an integer from 2 to 20), and any -CH ₂ - may be replaced with -O- (however, oxygen atoms are not directly bonded to each other), and any hydrogen atoms on the two benzene rings may be replaced with a halogen atom or a carbon number of 1 to 6. It may be replaced with an alkyl group, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, or a monovalent organic group having 1 to 6 carbon atoms having a fluorine atom. * represents a bond. )

(X ₂ represents a tetravalent organic group having an alicyclic structure of 5 or more members. Y ₂ represents a divalent organic group having a partial structure represented by the above formula (H). )

(X ₃ represents a tetravalent organic group derived from an aromatic acid dianhydride. Y ₃ is a divalent organic group having a partial structure represented by the following formula (m), and * is a bond. R ₃₀ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Z ₃₁ ,Z ₃₂ each independently represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may have a substituent, an alkenyl group having 2 to 10 carbon atoms which may have a substituent, and a hydrogen atom having a substituent. represents an alkynyl group having 2 to 10 carbon atoms, a tert-butoxycarbonyl group, or a 9-fluorenylmethoxycarbonyl group. )

Y ₁ and Y ₂ in the formulas (1) and (2) each independently have a partial structure represented by any of the following formulas (H-1) to (H-6). The liquid crystal aligning agent according to claim 3 , which is a group.

Y ₁ and Y ₂ in the formulas (1) and (2) are each independently a divalent organic group represented by any of the following formulas (h-1) to (h-7), The liquid crystal aligning agent according to claim 3 .

A claim in which the polymer (A) further has at least one type of repeating unit selected from the group consisting of a repeating unit represented by the following formula (4) and a repeating unit represented by the following formula (5). 6. The liquid crystal aligning agent according to any one of 1 to 5 .

(R ₄₁ to R ₄₄ have the same meanings as R ₁ to R ₄ in formula (1), respectively, and Y ₄ and Y ₅ represent a divalent organic group represented by the following formula (I) _. It is synonymous with X ₂ in the above formula (2).)

(Q represents a single bond or an oxygen atom, and n represents 0 to 2. Any hydrogen atom on the benzene ring may be replaced with a monovalent organic group.) Claim 6 , wherein Y ₄ in the formula (4) and Y ₅ in the formula (5) are divalent organic groups represented by any of the following formulas (I-1) to (I-3). The liquid crystal aligning agent described in .

(* represents a bond.) Claim 1, wherein the polymer (A) further has at least one type of repeating unit selected from the group consisting of a repeating unit represented by the following formula (6) and a repeating unit represented by the following formula (7). - 7. The liquid crystal aligning agent according to any one of 7 .

(R ₆₁ to R ₆₄ have the same meanings as R ₁ to R ₄ in the above formula (1), and Y ₆ and Y ₇ each independently have a partial structure represented by the following formula (J-1). represents a valent organic group or a divalent organic group represented by the following formula (J-2). X ₇ has the same meaning as X ₂ in the above formula (2).)

(Q ₅ is a single bond, -(CH ₂ ) _n - (n is an integer from 1 to 20), or -O under the condition that any -CH ₂ - of -(CH ₂ ) _n - are not adjacent to each other. -, -COO-, -OCO-, -NQ ₉ -, -NQ ₉ CO-, -CONQ ₉ -, -NQ ₉ CONQ ₁₀ -, -NQ ₉ COO-, -OCOO-, and Q ₉ and Q ₁₀ each independently represent a hydrogen atom or a monovalent organic group;
Q ₆ and Q ₇ each independently represent a group having -H, -NHD, -N(D) ₂ or -NHD, or a group having -N(D) ₂ . Q ₈ represents -NHD, -N(D) ₂ , a group having -NHD, or a group having -N(D) ₂ . D represents a carbamate-based protecting group. However, at least one of Q ₅ , Q ₆ and Q ₇ has a carbamate protecting group in the group. *1 represents a bond. ), 9. The partial structure represented by the formula (J-1) is a partial structure represented by any of the following formulas (J-1-a) to (J-1-d) according to claim 8 . Liquid crystal alignment agent.

The liquid crystal aligning agent according to any one of claims 1 to 9 , wherein X ₃ in the formula (3) is selected from the following formulas (X3-1) to (X3-2).

(x and y are each independently a single bond, ether, carbonyl, ester, alkanediyl group having 1 to 5 carbon atoms, 1,4-phenylene, sulfonyl, or amide group. j and k are each independently , 0 or 1. * represents a bond.) The liquid crystal aligning agent according to any one of claims 1 to 9 , wherein Y ₃ in the formula (3) is a divalent organic group represented by (Y3-1) or (Y3-2).

The polymer (B) has at least one type of repeating unit selected from the group consisting of a repeating unit represented by the following formula (8) and a repeating unit represented by the following formula (9). 12. The liquid crystal aligning agent according to any one of Item 11 .

(X ₈ is a tetravalent organic group having an alicyclic structure of 5 or more members, and X ₉ is derived from a tetravalent organic group having an alicyclic structure of 5 or more members or an aromatic acid dianhydride. Represents a tetravalent organic group. Y ₈ has the same meaning as Y ₃ in the above formula (3). _{Y 9} represents a divalent organic group having a partial structure represented by the following formula (n-1) or (n-2). Z ₈₁ , Z ₈₂ , Z ₉₁ , and Z ₉₂ have the same meanings as Z ₃₁ and Z ₃₂ in formula (3) above. R ₈ and R ₉ each independently represent a hydrogen atom or a carbon It is an alkyl group of numbers 1 to 4, and Q ₁ and Q ₂ represent a hydrogen atom or a methyl group.)

Claims 1 to 12 , wherein the content ratio of the polymer (A) and the polymer (B) is 5/95 to 95/5 in weight ratio of polymer (A)/polymer (B). The liquid crystal aligning agent according to any one of the items. A liquid crystal aligning film obtained from the liquid crystal aligning agent according to any one of claims 1 to 13 . A liquid crystal display element comprising the liquid crystal alignment film according to claim 14 . A method for producing a liquid crystal alignment film, comprising the following steps (A) to (C).
Step (A): A step of applying the liquid crystal aligning agent according to any one of claims 1 to 13 onto a substrate.
Step (B): A step of heating the coating film of the liquid crystal aligning agent obtained in step (A) to obtain a film.
Step (C): A step of irradiating the film obtained in step (B) with polarized ultraviolet rays. The method for manufacturing a liquid crystal alignment film according to claim 16 , further comprising the following step (D).
Step (D): A step of firing the film obtained in step (C) at a temperature of 100° C. or higher and higher than that in step (B). The method for producing a liquid crystal aligning film according to claim 16 or 17 , wherein the coating film is heated in the temperature range of 40 to 180° C. in the step (B). A liquid crystal display element comprising a liquid crystal alignment film obtained by the method for producing a liquid crystal alignment film according to any one of claims 16 to 18 .