JP7375544B2 - Liquid crystal alignment agent, liquid crystal alignment film, method for producing liquid crystal alignment film, and liquid crystal display element - Google Patents

Description

The present invention provides a liquid crystal aligning agent that has high dimensional stability when applied by inkjet and is difficult to dry during flexographic printing, a liquid crystal aligning film obtained from the liquid crystal aligning agent, and a liquid crystal display element having the liquid crystal aligning film. Regarding.

As liquid crystal alignment films in liquid crystal display elements, so-called polyimide-based liquid crystal alignment films are widely used, which are made by coating and baking a liquid crystal aligning agent whose main component is a polyimide precursor such as polyamic acid (polyamic acid) or a solution of soluble polyimide. has been done. Spin coating, dip coating, flexo printing, etc. are generally known as methods for forming such liquid crystal alignment films. Flexographic printing allows for easy pattern formation of the alignment film and is highly productive. However, in order to form a uniform thin film, it is necessary to apply a liquid crystal aligning agent to the surfaces of the anilox roll and doctor roll. In order to prevent the alignment film material from drying on the surface of the substrate, a liquid crystal aligning agent must be supplied at regular intervals (Patent Document 1). Another drawback is that it is difficult to form an alignment film on a substrate with large irregularities or a curved surface.

Therefore, an inkjet method has been proposed as another method for applying a liquid crystal aligning agent in place of the above method. The inkjet method is a method in which fine droplets are dropped onto a substrate and a film is formed by wetting and spreading the liquid. Since printing patterns can be set freely, there is an advantage that alignment films can be formed on substrates with large irregularities or curved surfaces.

A liquid crystal alignment film formed by an inkjet method is required to have small unevenness in film thickness inside the coated surface and to have high film formation precision around the coated area. Generally, in a liquid crystal alignment film formed by an inkjet method, there is a trade-off between the uniformity of the film thickness within the coating surface and the film formation accuracy in the peripheral area of the coating. Normally, materials with high in-plane uniformity have poor dimensional stability around the coated area, resulting in the film protruding from the set dimensions. On the other hand, in the case of a material in which the peripheral portion of the coating is straight, the uniformity within the coating surface will be poor.
In order to improve the accuracy of film formation in the peripheral area of the coating, a method has been proposed in which the liquid crystal alignment film is confined within a predetermined range using a structure (Patent Document 2, Patent Document 3, Patent Document 4). However, these methods have the disadvantage of requiring additional structures.

Japanese Patent Publication No. 2001-042330 Japanese Patent Publication No. 2004-361623 Japanese Patent Publication No. 2008-145461 Japanese Patent Publication No. 2010-281925

In recent years, as the definition of liquid crystal display elements has become higher, TFTs with multilayer wiring are becoming mainstream. In this designed TFT, a contact hole (hereinafter also referred to as C/H) is formed on the TFT substrate to connect the lower layer wiring and the upper layer wiring. Accordingly, due to the influence of the wiring structure and C/H, the spreadability of the liquid is likely to be inhibited when applying the liquid crystal aligning agent by inkjet. As a result, non-uniform film thickness of the alignment film such as dot-like unevenness or streak-like unevenness may occur around the C/H and other parts, resulting in non-uniform display on the liquid crystal display element. Additionally, as production lines for liquid crystal alignment films become larger, a problem has arisen in that when a liquid crystal alignment agent is applied by flexographic printing, the liquid crystal alignment agent tends to dry out on the surfaces of the anilox roll and doctor roll. Furthermore, demands for improving the quality of display elements are becoming more severe, and in particular, liquid crystal alignment films are required that have better properties than ever before in terms of liquid crystal alignment.

In view of the above-mentioned problems, the present invention provides a liquid crystal aligning agent that can suppress coating defects of an alignment film caused by the influence of wiring structure and C/H, and can suppress defects that result in non-uniform display of a liquid crystal display element. An object of the present invention is to provide a liquid crystal alignment film and a liquid crystal display element using the same.
Another object of the present invention is to provide a liquid crystal aligning agent in which drying of the liquid crystal aligning agent that occurs during flexographic printing is suppressed, a liquid crystal aligning film using the same, and a method for manufacturing the liquid crystal aligning film. Furthermore, it is an object of the present invention to provide a liquid crystal aligning agent from which a liquid crystal alignment film having high liquid crystal alignment properties can be obtained.

As a result of intensive studies to solve the above problems, the present inventors have found that various properties can be simultaneously improved by combining a polymer into which a specific structure is introduced and a solvent containing a specific solvent. They discovered this and completed the present invention.

The present invention is based on this knowledge and has the following gist.
At least one selected from the group consisting of polyamic acid, polyamic acid ester (hereinafter, polyamic acid and polyamic acid ester are also collectively referred to as polyimide precursor) having the structure of the following formula [1], and polyimide which is an imidized product thereof. a seed polymer;
At least one solvent A selected from the group consisting of the following formulas (d-1) to (d-5), an alkylene glycol monoalkyl ether acetate, an alkylene glycol having the following formula (e) and a boiling point of 200 to 300 ° C. A liquid crystal aligning agent characterized by containing a solvent containing at least one solvent B selected from the group consisting of diacetate, alkylene glycol monoalkyl ether, and alkylene glycol dialkyl ether.

However, X is a single bond, -O-, -C(CH ₃ ) ₂ -, -NH-, -CO-, -NHCO-, -COO-, -(CH ₂ ) _m -, and -SO ₂ - represents a divalent organic group selected from the group consisting of, m represents an integer of 1 to 8. The two Y's independently represent a side chain structure selected from the group consisting of the following formulas [S1] to [S3] and a structure derived from tocopherol.

However, X ¹ and X ² are independently a single bond, -(CH ₂ ) _a - (a is an integer from 1 to 15), -CONH-, -NHCO-, -CON(CH ₃ )-, -NH-, -O-, -COO-, -OCO-, or ((CH ₂ ) _a1 -A ₁ ) _m1 - (a1 each independently represents an integer from 1 to 15, A ₁ is an oxygen atom , -COO or OCO, and m ₁ is 1 to 2). G ¹ and G ² are independently divalent cyclic groups selected from the group consisting of a divalent aromatic group having 6 to 12 carbon atoms or a divalent alicyclic group having 3 to 8 carbon atoms; Any hydrogen atom on the cyclic group is an alkyl group having 1 to 3 carbon atoms, an alkoxyl group having 1 to 3 carbon atoms, a fluorine-containing alkyl group having 1 to 3 carbon atoms, a fluorine-containing alkoxyl group having 1 to 3 carbon atoms, or It may be substituted with a fluorine atom, and m and n are independently integers of 0 to 3, and the sum of these is 1 to 4. R ¹ is alkyl having 1 to 20 carbon atoms, alkoxy having 1 to 20 carbon atoms, or alkoxyalkyl having 2 to 20 carbon atoms, and any hydrogen in these groups may be replaced with fluorine.
X ³ represents a single bond, -CONH-, -NHCO-, -CON(CH ₃ )-, -NH-, -O-, -CH ₂ O-, -COO-, or OCO-, and R ² represents carbon It is an alkyl group having 1 to 20 carbon atoms or an alkoxyalkyl group having 2 to 20 carbon atoms, and any hydrogen in these groups may be replaced with fluorine.
X ⁴ represents -CONH-, -NHCO-, -O-, -COO- or OCO-, and R ³ represents a structure having a steroid skeleton.

但し、Ｒ_１ａは炭素数２～８の１価の炭化水素基、又は該炭化水素基における炭素－炭素結合間に「－Ｏ－」を有する１価の基を示す。Ｒ_２ａ及びＲ_２ｂは独立して、炭素数１～６のアルキル基を示す。Ｒ_３ａはメチル基又はエチル基を示す。Ｒ_５ａは、炭素数１～６のアルキル基を示す。Ｒ_５ｂ及びＲ_５ｃは独立して、水素原子、炭素数１～６の１価の炭化水素基、又は該炭化水素基の炭素－炭素結合間に「－Ｏ－」を有する１価の基を示す。ｎは１又は２である。

However, R _1a represents a monovalent hydrocarbon group having 2 to 8 carbon atoms, or a monovalent group having "-O-" between carbon-carbon bonds in the hydrocarbon group. R _2a and R _2b independently represent an alkyl group having 1 to 6 carbon atoms. R _3a represents a methyl group or an ethyl group. R _5a represents an alkyl group having 1 to 6 carbon atoms. R _5b and R _5c independently represent a hydrogen atom, a monovalent hydrocarbon group having 1 to 6 carbon atoms, or a monovalent group having "-O-" between the carbon-carbon bonds of the hydrocarbon group. show. n is 1 or 2.

但し、ｒ_１ａ 及びｒ_１ｂ は独立して、水素原子又は炭素数１～６のアルキル基を示し、ｍは２～６の整数である。

However, r _1a and r _1b independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and m is an integer of 2 to 6.

According to the liquid crystal aligning agent of the present invention, it is possible to suppress coating defects of the alignment film caused by the influence of wiring structure and C/H, suppress defects that result in non-uniform display of liquid crystal display elements, and to perform flexographic printing. Also, drying of the liquid crystal aligning agent is suppressed. A liquid crystal alignment film having even higher liquid crystal alignment properties can be obtained.

The liquid crystal aligning agent of the present invention comprises at least one polymer (hereinafter also referred to as a specific polymer) selected from the group consisting of a polyimide precursor having the structure of formula [1] and polyimide which is an imidized product thereof. contains.

<Specific polymer>
Among others, it is preferable that the specific polymer has the structure of the formula [1] in the main chain of the polymer from the viewpoint of ease of synthesis. Here, in the present invention, the main chain of a polymer refers to a portion of the polymer consisting of the longest chain of atoms. Furthermore, in the specific polymer, it is not excluded that the structure of the formula [1] is also present in parts other than the main chain (for example, in the side chain part of the polymer).
X in the formula [1] is a single bond, -O-, -C(CH ₃ ) ₂ -, -NH-, -CO-, -NHCO-, -COO-, -(CH ₂ ) _m -, It represents a divalent organic group consisting of -SO ₂ - or a combination thereof, and m represents an integer of 1 to 8.

Examples of the above combinations include -O-(CH ₂ ) _m -O-, -OC(CH ₃ ) ₂ -, -CO-(CH ₂ ) _m -, -NH-(CH ₂ ) _m - , -SO ₂ -(CH ₂ ) _m -, -CONH-(CH ₂ ) _m -, -CONH-(CH ₂ ) _m -NHCO-, -COO-(CH ₂ ) _m -OCO-, and the like.
X is preferably a single bond, -O-, -NH-, or -O-(CH ₂ ) _m -O-.

式［Ｓ１］中、Ｘ^１及びＸ^２は、上記に定義したとりである。なかでも、原料の入手性や合成の容易さの点からの観点から、単結合、－（ＣＨ_２）_ａ－（ａは１～１５の整数である）、－Ｏ－、－ＣＨ_２Ｏ－又はＣＯＯ－が好ましい。より好まくは、単結合、－（ＣＨ_２）_ａ－（ａは１～１０の整数である）、－Ｏ－、－ＣＨ_２Ｏ－又はＣＯＯ－である。Y in formula [1] has a side chain structure selected from the following formulas [S1] to [S3] or a structure having a tocopherol skeleton.

In formula [S1], X ¹ and X ² are as defined above. Among these, from the viewpoint of availability of raw materials and ease of synthesis, single bonds, -(CH ₂ ) _a - (a is an integer from 1 to 15), -O-, -CH ₂ O- or COO- is preferred. More preferably a single bond, -(CH ₂ ) _a - (a is an integer from 1 to 10), -O-, -CH ₂ O- or COO-.

G ¹ and G ² are decoys as defined above.
Examples of the divalent aromatic group having 6 to 12 carbon atoms include phenylene, biphenylene, and naphthalene. Examples of the divalent alicyclic group having 3 to 8 carbon atoms include cyclopropylene and cyclohexylene.

Preferred specific examples of formula [S1] include structures of formulas [S1-x1] to [S1-x7] below.

However, R ¹ is an alkyl group having 1 to 20 carbon atoms, and X ^p is -(CH ₂ ) _a - (a is an integer of 1 to 15), -CONH-, -NHCO-, -CON( CH ₃ )-, -NH-, -O-, -CH ₂ O-, -CH ₂ OCO-, -COO-, or -OCO-. A ₁ is an oxygen atom or -COO-* (however, the bond marked with "*" bonds with (CH 2 ) _a2 ), and A ₂ is an oxygen atom or *-COO- (the bond marked with "*" is bonded to (CH ₂ ) a2). The bond bond is (CH ₂ ) _a2 ). a ₁ and a ₃ are independently an integer of 0 or 1, a ₂ is an integer of 1 to 10, and Cy is a 1,4-cyclohexylene group or a 1,4-phenylene group.

式［Ｓ２］中、Ｘ^３は、上記に定義したとりである。なかでも液晶配向性の観点から、－ＣＯＮＨ－、－ＮＨＣＯ－、－Ｏ－、－ＣＨ_２Ｏ－、－ＣＯＯ－又はＯＣＯ－が好ましい。
Ｒ^２は上記に定義したとりである。なかでも、液晶配向性の観点から、炭素数３～２０のアルキル又は炭素数２～２０のアルコキシアルキルが好ましい。
式［Ｓ２］の好ましい具体例として、－ＣＯＮＨ－（ＣＨ_２）_ｎ－ＣＨ_３（ｎ＝２～１７）、－ＮＨＣＯ－（ＣＨ_２）_ｎ－ＣＨ_３（ｎ＝２～１７）、－Ｏ－（ＣＨ_２）_ｎ－ＣＨ_３（ｎ＝２～１７）、－ＣＯＯ－（ＣＨ_２）_ｎ－ＣＨ_３（ｎ＝２～１７）、－ＣＨ_２Ｏ－（ＣＨ_２）_ｎ－ＣＨ_３（ｎ＝２～１７）が挙られる。

In the formula [S2], X ³ is defined above. Among them, from the viewpoint of liquid crystal orientation, -CONH-, -NHCO-, -O-, -CH ₂ O-, -COO- or OCO- are preferred.
R ² is as defined above. Among these, from the viewpoint of liquid crystal orientation, alkyl having 3 to 20 carbon atoms or alkoxyalkyl having 2 to 20 carbon atoms is preferred.
Preferred specific examples of formula [S2] include -CONH-(CH ₂ ) _n -CH ₃ (n=2 to 17), -NHCO-(CH ₂ ) _n -CH ₃ (n=2 to 17), -O -(CH ₂ ) _n -CH ₃ (n=2 to 17), -COO-(CH ₂ ) _n -CH ₃ (n=2 to 17), -CH ₂ O-(CH ₂ ) _n -CH ₃ ( n=2 to 17).

式［Ｓ３］中、Ｘ^４は、上記に定義したとりである。なかでも、液晶配向性の観点から、－Ｏ－、－ＣＯＯ－又は －ＯＣＯ－が好ましい。
ステロイド骨格を有する構造として、β－シトステロールやエルゴステロール等の化合物からヒドロキシ基を除いた構造、日本特開平４－２８１４２７号の［００２４］に記載のステロイド化合物からヒドロキシ基を除いた構造、［００３０］に記載のステロイド化合物から酸クロライド基を除いた構造、［００３８］に記載のステロイド化合物からアミノ基を除いた構造、［００４２］にステロイド化合物からハロゲン基を除いた構造や、日本特開平８－１４６４２１の［００１８］～［００２２］に記載の構造を挙げることができる。

In the formula [S3], X ⁴ is a bridge defined above. Among these, -O-, -COO-, or -OCO- is preferred from the viewpoint of liquid crystal orientation.
Structures having a steroid skeleton include a structure obtained by removing a hydroxy group from a compound such as β-sitosterol or ergosterol, a structure obtained by removing a hydroxy group from a steroid compound described in [0024] of Japanese Patent Application Publication No. 4-281427, and [0030 The structure obtained by removing the acid chloride group from the steroid compound described in ], the structure obtained by removing the amino group from the steroid compound described in [0038], the structure obtained by removing the halogen group from the steroid compound described in [0042], and the structure obtained by removing the halogen group from the steroid compound described in [0042], -146421, structures described in [0018] to [0022] can be mentioned.

（式中、＊は結合位置を示す）A preferred specific example of formula [S3] is the following formula [S3-x]. The definitions of X, Col, and G in formula [S3-x] are as follows, respectively.

(In the formula, * indicates the bonding position)

（式中、＊は結合位置を示す）More preferable examples of formula [S3] include structures represented by the following formulas [S3-1] to [S3-6].

(In the formula, * indicates the bonding position)

Examples of the structure having a tocopherol skeleton in formula [1] include structures derived from compounds such as α-tocopherol, β-tocopherol, γ-tocopherol, and δ-tocopherol. A specific example of the structure having the tocopherol skeleton is a structure represented by the following formula [T]. Note that "*" indicates the bonding position.

The specific polymer contained in the liquid crystal aligning agent of the present invention is a group consisting of a polyimide precursor having a divalent group represented by the above formula [1] and a polyimide that is an imidized product of the polyimide precursor. It may be synthesized by any method as long as it is at least one kind of polymer selected from the following.
Among these, the specific polymer is a tetracarboxylic dianhydride having the structure of the above formula [1] or a derivative thereof (hereinafter also referred to as a specific tetracarboxylic acid compound), or a tetracarboxylic acid containing the specific tetracarboxylic acid compound. A polyimide precursor obtained by reacting a component with a diamine component; a polyimide of the polyimide precursor; a tetracarboxylic acid component, and a diamine having the structure of the above formula [1] (hereinafter referred to as "specific diamine"). or a polyimide precursor obtained by reacting a diamine component containing a specific diamine; and a polyimide of the polyimide precursor.

[Tetracarboxylic acid component]
The tetracarboxylic acid component used to synthesize the specific polymer contains either or both of the specific tetracarboxylic acid compound and other tetracarboxylic acid compounds.
<Specific tetracarboxylic acid compound>
The specific tetracarboxylic acid compound is a tetracarboxylic acid compound having the structure of the above formula [1], and includes, for example, a compound represented by the formula [T] or a derivative thereof.

式［Ｔ］中、Ａは３価の基を示し、２つのＡは同一であっても異なってもよい。Ａの例としては、シクロブタン環構造、シクロペンタン環構造、シクロヘキサン環構造、ベンゼン環構造及び下記式（Ａ－１）よりなる群から選ばれる少なくとも一種を有する３価の有機基が挙げられる。Ｐは、上記式［１］の構造を有する２価の有機基を示す。

In formula [T], A represents a trivalent group, and two A's may be the same or different. Examples of A include a trivalent organic group having at least one member selected from the group consisting of a cyclobutane ring structure, a cyclopentane ring structure, a cyclohexane ring structure, a benzene ring structure, and the following formula (A-1). P represents a divalent organic group having the structure of the above formula [1].

前記テトラカルボン酸化合物の誘導体としては、テトラカルボン酸二無水物、テトラカルボン酸ジハライド、テトラカルボン酸ジアルキルエステル又はテトラカルボン酸ジアルキルエステルジハライドが挙げられる。

Examples of the derivatives of the tetracarboxylic acid compound include tetracarboxylic dianhydride, tetracarboxylic dihalide, tetracarboxylic acid dialkyl ester, and tetracarboxylic acid dialkyl ester dihalide.

<Other tetracarboxylic acid compounds>
Other tetracarboxylic acid compounds include 1,2,5,6-naphthalenetetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid, 1,2,5,6-anthracenetetracarboxylic acid, 3, 3',4,4'-biphenyltetracarboxylic acid, 2,3,3',4-biphenyltetracarboxylic acid, bis(3,4-dicarboxyphenyl)ether, 3,3',4,4'-benzophenone Tetracarboxylic acid, bis(3,4-dicarboxyphenyl)sulfone, bis(3,4-dicarboxyphenyl)methane, 2,2-bis(3,4-dicarboxyphenyl)propane, 1,1,1, 3,3,3-hexafluoro-2,2-bis(3,4-dicarboxyphenyl)propane, bis(3,4-dicarboxyphenyl)dimethylsilane, bis(3,4-dicarboxyphenyl)diphenylsilane , 2,3,4,5-pyridinetetracarboxylic acid, 2,6-bis(3,4-dicarboxyphenyl)pyridine, 3,3',4,4'-diphenylsulfonetetracarboxylic acid, 3,4, Acid dianhydride obtained from tetracarboxylic acid such as 9,10-perylenetetracarboxylic acid or 1,3-diphenyl-1,2,3,4-cyclobutanetetracarboxylic acid, tetracarboxylic acid represented by the following formula [4] Examples include acid dianhydrides, or derivatives thereof such as tetracarboxylic acid dihalides, tetracarboxylic acid dialkyl ester compounds, and tetracarboxylic acid dialkyl ester dihalides.

Ｚは、下記［４ａ］～［４ｋ］からなる群から選ばれる構造を示す。Among these, from the viewpoint of high solubility of the polymer, at least one type of tetracarboxylic dianhydride having a structure represented by formula [4] and its tetracarboxylic acid derivative is preferable.

Z represents a structure selected from the group consisting of [4a] to [4k] below.

（式中、＊１は一方の酸無水物基に結合する結合手であり、＊２は他方の酸無水物基に結合する結合手である。）

(In the formula, *1 is a bond that is bonded to one acid anhydride group, and *2 is a bond that is bonded to the other acid anhydride group.)

（＊１、＊２は、上記に定義したとおりである。）In formula [4a], Z ¹ to Z ⁴ independently represent a hydrogen atom, a methyl group, an ethyl group, a propyl group, a chlorine atom, or a benzene ring. Preferred specific examples of Z ¹ to Z ⁴ include the following formulas [4a-1] and [4a-2].

(*1 and *2 are as defined above.)

In formula [4g], Z ⁵ and Z ⁶ independently represent a hydrogen atom or a methyl group.
Among Z in formula [4], from the viewpoint of ease of synthesis and ease of polymerization reactivity when producing a polymer, formula [4a], formula [4c] to formula [4g] or formula [ 4k] is preferred. Formula [4a] or formula [4e] to formula [4g] are more preferred, and [4a], formula [4e] or formula [4f] is particularly preferred. Preferred specific examples include tetracarboxylic dianhydrides or tetracarboxylic acid derivatives thereof having structures represented by [4a-1], formula [4a-2], formula [4e], and formula [4f].

The tetracarboxylic acid compound represented by formula [4] in the polymer of the present invention is preferably 1 mol % or more based on 100 mol % of all the tetracarboxylic acid compounds from the viewpoint of increasing the solubility of the polymer. Among these, 5 mol% or more is preferable, and 10 mol% or more is more preferable.
The tetracarboxylic acid compound is selected depending on the properties such as solubility of the polymer of the present invention in a solvent, coatability of a liquid crystal alignment agent, alignment of liquid crystal when used as a liquid crystal alignment film, voltage holding rate, and accumulated charge. It is also possible to use one type or a mixture of two or more types.

[Diamine component]
The diamine component used to synthesize the specific polymer contains a specific diamine. The specific diamine is a diamine having the structure of the above formula [1], and includes, for example, a compound represented by the following formula [2].

式［２］中のＸ、Ｙは、それぞれ、上記式［１］におけるのと同じ意味である。
Ｘは、特定ジアミンの合成が容易である観点で、単結合、－Ｏ－、－ＮＨ－、又は－Ｏ－（ＣＨ_２）_ｍ－Ｏ－が好ましい。ｍは１～８の整数を示す。<Specific diamine>
The specific diamine used in the liquid crystal aligning agent of the present invention is represented by the following formula [2].

X and Y in formula [2] each have the same meaning as in formula [1] above.
From the viewpoint of easy synthesis of the specific diamine, X is preferably a single bond, -O-, -NH-, or -O-(CH ₂ ) _m -O-. m represents an integer from 1 to 8.

In formula [2], Y may be at the meta or ortho position from the position of X, but the ortho position is preferable from the viewpoint of high reactivity with the specific diamine. Specifically, the formula [2] is preferably the following formula [2'].

The above formula [2] preferably has a structure of one of the following formulas from the viewpoint of high reactivity of the specific diamine, and more preferably a structure represented by formula [2]-a1-1.

As a preferable form of Y in the above formula [2], the preferable form of Y in the above formula [1] can be applied. Among these, structures selected from the above formulas [S1-x3] to [S1-x4], [S1-x6] and formula [S3-x] are preferred from the viewpoint of improving liquid crystal orientation, and preferred specific examples include the following formulas: Examples include structures [W-1] to [W-6].

In the formula, X ^p1 to X ^p8 are independently -(CH ₂ ) _a - (a is an integer from 1 to 15), -CONH-, -NHCO-, -CON(CH ₃ )-, -NH -, -O-, -CH ₂ O-, -CH ₂ OCO-, -COO-, or -OCO-. X ^s1 to X ^s4 independently represent -O-, -COO- or -OCO-. X _a to X _f independently represent a single bond, -O-, -NH-, or -O-(CH ₂ ) _m -O-. R ^1a to R ^1h independently represent an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an alkoxyalkyl group having 2 to 20 carbon atoms. m represents an integer from 1 to 8.

The specific diamine is selected depending on the inkjet coating properties of the liquid crystal aligning agent, the liquid crystal alignment properties when used as a liquid crystal alignment film, the voltage holding characteristics, the accumulated charge, etc., and the response speed of the liquid crystal when used as a liquid crystal display element. It can be used as a species or as a mixture of two or more species.
The specific diamine is preferably used in an amount of 1 to 100 mol% of the diamine component used in the synthesis of the specific polymer, more preferably 2 to 100 mol%, particularly preferably 5 to 90 mol%.

As the diamine for synthesizing polyamic acid or polyamic acid ester, only the specific diamine may be used, or other diamines may be used in combination with the specific diamine. Here, other diamines include, for example, diamines having a pretilt angle development property other than the above (2), diamines having a function of polymerizing or generating radicals by light irradiation, and [0169 of WO (International Publication) 2015/046374. Diamines described in ], diamines having a carboxyl group or hydroxyl group described in [0171] to [0172], diamines having a nitrogen-containing heterocycle described in [0173] to [0188], and Japanese Patent Application Publication No. 2016-218149 Diamine having a nitrogen-containing structure as described in [0050], 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, 1,3-bis(4-aminobutyl) -1,1,3,3-tetramethyldisiloxane and other organosiloxane-containing diamines. Among these, in a PSA (Polymer Sustained Alignment) type liquid crystal display element, from the viewpoint of increasing the response speed, diamines having a function of polymerizing or generating radicals upon irradiation with light are preferred.

Preferred specific examples of other diamines include m-phenylenediamine, p-phenylenediamine, 4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-difluoro-4 , 4'-diaminodiphenyl, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylamine, N-methyl(4,4'-diaminodiphenyl)amine, 4,4'- Diaminobenzophenone, 1,4-diaminonaphthalene, 2,6-diaminonaphthalene, 1,2-bis(4-aminophenyl)ethane, 1,3-bis(4-aminophenyl)propane, 1,4-bis(4 -aminophenyl)butane, 1,4-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 1,4-bis (4-aminobenzyl)benzene, 1,3-bis(4-aminophenoxy)benzene, 4,4'-[1,4-phenylenebis(methylene)]dianiline, 1,4-phenylenebis[(4-amino phenyl)methanone], 1,4-phenylenebis(4-aminobenzoate), bis(4-aminophenyl)terephthalate, bis(4-aminophenyl)isophthalate, N,N'-(1,4-phenylene)bis (4-aminobenzamide), N,N'-bis(4-aminophenyl)terephthalamide, N,N'-bis(4-aminophenyl)isophthalamide, 9,10-bis(4-aminophenyl)anthracene, 2,2'-bis[4-(4-aminophenoxy)phenyl]propane, 2,2'-bis(4-aminophenyl)propane, 1,3-bis(4-aminophenoxy)propane, 1,4- Bis(4-aminophenoxy)butane, 1,5-bis(4-aminophenoxy)pentane, 1,6-bis(4-aminophenoxy)hexane, 1,7-bis(4-aminophenoxy)heptane, 1 , 8-bis(4-aminophenoxy)octane, 1,9-bis(4-aminophenoxy)nonane, 1,10-(4-aminophenoxy)decane, bis(4-aminocyclohexyl)methane, 1,3- Diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 2,4-diaminobenzoic acid, 2,5-diaminobenzoic acid, 3,5-diaminobenzoic acid, 4 , 4'-diaminobiphenyl-3-carboxylic acid, 4,4'-diaminodiphenylmethane-3-carboxylic acid, 4,4'-diaminodiphenylethane-3-carboxylic acid, 4,4'-diaminobiphenyl-3,3 '-dicarboxylic acid, 4,4'-diaminobiphenyl-2,2'-dicarboxylic acid, 3,3'-diaminobiphenyl-4,4'-dicarboxylic acid, 3,3'-diaminobiphenyl-2,4'- Dicarboxylic acid, 4,4'-diaminodiphenylmethane-3,3'-dicarboxylic acid, 4,4'-diaminodiphenylethane-3,3'-dicarboxylic acid, 4,4'-diaminodiphenyl ether-3,3'-dicarboxylic acid acid, 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,N'-bis(4-aminophenyl)-benzidine, N,N'-bis(4-aminophenyl)-N,N'-dimethylbenzidine, compounds represented by each of the following formulas (D-2-1) to (D-2-8),

更には、これらのアミノ基が２級のアミノ基であるジアミンが挙げられる。

Further examples include diamines in which these amino groups are secondary amino groups.

Examples of diamines having a pretilt angle development property other than the above formula (2) include diamines represented by the following structural formulas [V-1] to [V-7].

In the above formula, X ^v1 to X ^v4 are independently -(CH ₂ ) _a - (a is an integer from 1 to 15), -CONH-, -NHCO-, -CON(CH ₃ )-, - Indicates NH-, -O-, -CH ₂ O-, -CH ₂ OCO-, -COO-, or -OCO-. X ^v5 represents -O-, -CH ₂ O-, -CH ₂ OCO-, -COO-, or -OCO-. X ^V6 to X ^V7 independently represent -O-, -COO- or -OCO-.

Examples of diamines that have the function of polymerizing upon light irradiation include diamines in which structures represented by the following formulas [p1] to [p7] are bonded directly or via a linking group to an aromatic ring such as a benzene ring. It will be done.

Specific examples include diamines represented by the following formula [P-a] or [P-b].

The bonding positions of the two amino groups (-NH ₂ ) in formula [P-a] and formula [P-b] are not limited, but from the viewpoint of the reactivity of the diamine, the positions of the 2 and 4 positions and the 2 and 5 positions are or the 3rd and 5th positions are preferred. Considering the ease of synthesizing the diamine, the 2nd and 4th positions or the 3rd and 5th positions are more preferable.
In formula [P-a], R ⁸ is a single bond, -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, -CH ₂ O-, -N(CH ₃ )-, -CON(CH ₃ )-, or -N(CH ₃ )CO-. From the viewpoint of ease of synthesis, a single bond, -O-, -COO-, -NHCO-, or -CONH- is preferred.

R ⁹ is a divalent group selected from a single bond, an alkylene group having 1 to 20 carbon atoms optionally substituted with a fluorine atom, an aromatic ring having 6 to 12 carbon atoms such as a benzene ring and a naphthalene ring, and cyclohexane. Divalent alicyclic groups having 3 to 8 carbon atoms such as rings, 5-membered rings or more such as pyrrole, imidazole, pyridine, pyrimidine, pyrazine, pyridazine, triazine, indole, quinoline, carbazole, thiazole, purine, tetrahydrofuran, thiophene, etc. represents a divalent cyclic group selected from heterocycles. Here, -CH ₂ - of the alkylene group may be optionally substituted with -CF ₂ - or -CH=CH-. From the viewpoint of ease of synthesis, a single bond or an alkylene group having 1 to 12 carbon atoms is preferred. k is an integer from 0 to 4.
R ¹⁰ represents a structure selected from the group consisting of the above formulas [p1] to [p7]. From the viewpoint of photoreactivity, [p1], [p2], and [p4] are preferable.

In formula [P-b], Y ₁ and Y ₃ are independently -CH ₂ -, -O-, -CONH-, -NHCO-, -COO-, -OCO-, -NH-, or -CO - indicates. Y ₂ and Y ₅ independently have the same meaning as R ₉ in [Pa] above. Y ₄ represents a cinnamoyl group. Y ₆ represents a structure selected from the group consisting of the above formulas [p1] to [p7]. From the viewpoint of photoreactivity, [p1], [p2], or [p4] is preferable. m represents 0 or 1.

Diamines that have the ability to polymerize upon light irradiation are used depending on the characteristics such as liquid crystal orientation, pretilt angle, voltage holding characteristics, and accumulated charge when used as a liquid crystal alignment film, and the response speed of liquid crystal when used as a liquid crystal display element. , can be used alone or in combination of two or more.
The diamine having the function of polymerizing upon light irradiation is preferably used in an amount of 10 to 70 mol% of the diamine component used in the synthesis of the specific polymer, more preferably 10 to 60 mol%, particularly preferably 10 to 50 mol%. be.

Examples of diamines that have the function of generating radicals when irradiated with light include diamines that have a moiety in the side chain that has a radical-generating structure that decomposes and generates radicals when irradiated with ultraviolet light. For example, diamines represented by the following formula (R) Can be mentioned.

Ar, R ₁ , R ₂ , T ₁ , T ₂ , S and Q in the above formula (R) have the following definitions.
That is, Ar represents an aromatic hydrocarbon group selected from the group consisting of phenylene, naphthylene, and biphenylene, which may be substituted with an organic group, and the hydrogen atom may be substituted with a halogen atom.
R ₁ and R ₂ are independently an alkyl group or an alkoxy group having 1 to 10 carbon atoms.
T ₁ and T ₂ are independently a single bond or -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, -CH ₂ O-, -N(CH ₃ )- , -CON(CH ₃ )-, or -N(CH ₃ )CO-.
S has the same meaning as R ⁹ in [Pa] above.

（式中、＊は結合位置を示す。）Q is a structure selected from the group consisting of the following formulas [q-1] to [q-4] (R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R ₃ is -CH ₂ -, -NR -, -O-, or -S-).

(In the formula, * indicates the bonding position.)

In the above formula (R), Ar to which carbonyl is bonded preferably has a structure with a long conjugation length, such as naphthylene or biphenylene, from the viewpoint of efficient absorption of ultraviolet rays. Further, Ar may have a substituent, and the substituent is preferably an electron-donating organic group such as an alkyl group, a hydroxyl group, an alkoxy group, or an amino group. A phenyl group is most preferred because sufficient properties can be obtained with a phenyl group if the wavelength of ultraviolet rays is in the range of 250 to 380 nm.
Further, R ₁ and R ₂ are independently an alkyl group, an alkoxy group, a benzyl group, or a phenethyl group having 1 to 10 carbon atoms, and in the case of an alkyl group or an alkoxy group, R ₁ and R ₂ form a ring. It may be formed.

Q is more preferably a hydroxyl group or an alkoxyl group from the viewpoint of easy production of the specific polymer.
Diaminobenzene in formula (R) may be o-phenylenediamine, m-phenylenediamine, or p-phenylenediamine, but m-phenylenediamine or p-phenylenediamine is preferred in terms of high reactivity with the tetracarboxylic acid component. -Phenylene diamine is preferred.

Specifically, structures represented by the following formulas [R-1] to [R-4] are most preferred from the viewpoint of ease of synthesis, high versatility, properties, etc. Note that in the formula, n is an integer from 2 to 8.

The diamine having the function of generating radicals upon light irradiation is preferably used in an amount of 5 to 70 mol% of the diamine component used in the synthesis of the specific polymer, and more preferably 10 to 60 mol% from the viewpoint of maintaining liquid crystal orientation. and particularly preferably 10 to 50 mol%.

<Synthesis of specific polymer>
The specific polymer is obtained by reacting a diamine and a tetracarboxylic acid compound as described above. Examples of the method for obtaining polyamic acid include a method for obtaining polyamic acid by polycondensing a tetracarboxylic dianhydride and a diamine, or a method for obtaining polyamic acid by polycondensing a tetracarboxylic acid dihalide compound and a diamine compound. .

The specific polymer can be obtained by reacting it with a molecular weight regulator, if necessary. Examples of molecular weight modifiers include acid monoanhydrides such as maleic anhydride, phthalic anhydride, and itaconic anhydride, monoamines such as aniline, cyclohexylamine, and n-butylamine, and monoisocyanates such as phenyl isocyanate and naphthylisocyanate. be able to. The proportion of the molecular weight regulator used is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, based on the total of 100 parts by mass of the tetracarboxylic acid compound and diamine used.

Methods for obtaining polyamic acid esters include a method of polycondensing a tetracarboxylic acid dialkyl ester compound in which a carboxylic acid group is dialkyl esterified and a diamine, and a tetracarboxylic acid dialkyl ester dihalide in which a carboxylic acid group is dialkyl esterified and dihalidated. Examples include a method of polycondensing a compound and a primary or secondary diamine, or a method of converting a carboxyl group of a polyamic acid into an ester.

Examples of methods for obtaining polyimide include the method of ring-closing the polyimide precursor described above to obtain polyimide.
The reaction between the diamine and the tetracarboxylic acid compound is preferably carried out in a solvent. The solvent is not particularly limited as long as it dissolves the produced polymer. Specific examples of the solvent are listed below, but the solvent is not limited to these examples.

For example, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone or γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide or 1,3-dimethyl-2-imidazolidinone. can be mentioned. In addition, when the polymer has high solvent solubility, methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone or the following formulas [D-1] to [D-3] are used. Any solvent can be used.

（式［Ｄ－１］中、Ｄ^１は炭素数１～３のアルキレン基を示し、式［Ｄ－２］中、Ｄ^２は炭素数１～３のアルキレン基を示し、式［Ｄ－３］中、Ｄ^３は炭素数１～４のアルキレン基を示す）。

(In the formula [D-1], D ¹ represents an alkylene group having 1 to 3 carbon atoms, and in the formula [D-2], D ² represents an alkylene group having 1 to 3 carbon atoms, and the formula [D-3 ], D ³ represents an alkylene group having 1 to 4 carbon atoms).

These solvents may be used alone or in combination. Furthermore, even if the solvent does not dissolve the polymer, it may be used by mixing it with the above-mentioned solvent as long as the produced polymer does not precipitate. Further, since water in the solvent inhibits the polymerization reaction and further causes hydrolysis of the produced polymer, it is preferable to use a solvent that has been dehydrated and dried.
When reacting a diamine and a tetracarboxylic acid compound in a solvent, the reaction can be carried out at any concentration, but if the concentration is too low, it will be difficult to obtain a polymer with a high molecular weight; The viscosity of the reaction solution becomes too high, making uniform stirring difficult. Therefore, it is preferably 1 to 50% by weight, more preferably 5 to 30% by weight. The initial stage of the reaction can be carried out at a high concentration, and then the solvent can be added.

In the polycondensation reaction, the ratio of the total number of moles of diamine to the total number of moles of tetracarboxylic acid compound is preferably 0.8 to 1.2. As in normal polycondensation reactions, the closer this molar ratio is to 1.0, the greater the molecular weight of the specific polymer produced.
Polyimide is a polyimide obtained by ring-closing the polyimide precursor, and in this polyimide, the ring-closing rate (also referred to as imidization rate) of the amic acid group does not necessarily have to be 100%, and may vary depending on the use and purpose. It can be adjusted arbitrarily.

Examples of methods for imidizing the polyimide precursor include thermal imidization, in which the polyimide precursor solution is directly heated, and catalytic imidization, in which a catalyst is added to the polyimide precursor solution.
The temperature when thermally imidizing the polyimide precursor in a solution is 100 to 400°C, preferably 120 to 250°C, and it is preferable to carry out the process while removing water produced by the imidization reaction from the system.

Catalytic imidization of the polyimide precursor can be carried out by adding a basic catalyst and an acid anhydride to a solution of the polyimide precursor and stirring at -20°C to 250°C, preferably 0 to 180°C. . The amount of the basic catalyst is 0.5 to 30 times the mole of the amic acid group, preferably 2 to 20 times the mole, and the amount of the acid anhydride is 1 to 50 times the mole of the amic acid group, preferably 3 to 30 times the mole. It's double. Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine, etc. Among them, pyridine is preferred because it has an appropriate basicity to allow the reaction to proceed. Examples of the acid anhydride include acetic anhydride, trimellitic anhydride, and pyromellitic anhydride. Among them, acetic anhydride is preferably used because it facilitates purification after the reaction is completed. The imidization rate by catalytic imidization can be controlled by adjusting the amount of catalyst, reaction temperature, and reaction time.

When recovering the generated polyimide precursor or polyimide from the polyimide precursor or polyimide reaction solution, the reaction solution may be poured into a solvent and precipitated. Examples of the solvent used for precipitation include methanol, ethanol, isopropyl alcohol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, toluene, benzene, water, and the like. The polymer precipitated in a solvent can be collected by filtration and then dried under normal pressure or reduced pressure, at room temperature or by heating. Furthermore, by repeating the procedure of redissolving the precipitated and recovered polymer in a solvent and re-precipitating and recovering it 2 to 10 times, the amount of impurities in the polymer can be reduced. Examples of the solvent in this case include alcohols, ketones, and hydrocarbons, and it is preferable to use three or more types of solvents selected from these, since the efficiency of purification will further increase.

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

<Liquid crystal alignment agent>
The liquid crystal aligning agent of the present invention is constituted by dissolving in a solvent at least one polymer selected from the group consisting of polyimide precursors and polyimides as described above, and optional additive components used as necessary. .
As described above, the solvent used in the liquid crystal aligning agent of the present invention includes at least one solvent A selected from the group consisting of formulas (d-1) to (d-5), the formula (e), and the boiling point and at least one solvent B selected from the group consisting of alkylene glycol monoalkyl ether acetate, alkylene glycol diacetate, alkylene glycol monoalkyl ether, and alkylene glycol dialkyl ether, having a temperature of 200 to 300°C. Note that the boiling point in the present invention means the boiling point at 1 atmosphere.
Since drying of the liquid crystal aligning agent is suppressed by containing the solvent A, a change in concentration at the time of applying the liquid crystal aligning agent is suppressed, and a liquid crystal aligning agent with excellent coating properties is obtained. Furthermore, the solubility of the polymer in the solvent is high, and it is possible to suppress phenomena such as precipitation of the polymer occurring during firing and resulting in non-uniform film thickness. Containing solvent B reduces the boiling point difference with solvent A, and when baking the substrate coated with the liquid crystal aligning agent, the liquid crystal aligning agent can wet and spread, making it suitable for substrates with complex step structures. It becomes possible to uniformly apply the liquid crystal alignment film even when the liquid crystal alignment film is coated evenly, and a liquid crystal aligning film with excellent film thickness uniformity can be obtained.

In formula (d-1), the monovalent hydrocarbon group having 2 to 8 carbon atoms for R _1a includes a chain hydrocarbon group and an alicyclic hydrocarbon group, such as a chain hydrocarbon group having 2 to 8 carbon atoms. Examples include alkyl groups and cycloalkyl groups having 3 to 8 carbon atoms. Furthermore, examples of the monovalent group having "-O-" between carbon-carbon bonds in the hydrocarbon group include an alkoxyalkyl group having 2 to 8 carbon atoms.
Specific examples of these include chain alkyl groups having 2 to 8 carbon atoms, such as ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, and octyl group. Examples of the cycloalkyl group having 3 to 8 carbon atoms include cyclopropyl group, cyclobutyl group, cyclopentyl group, and cyclohexyl group. Examples of the alkoxyalkyl group having 2 to 8 carbon atoms include methoxymethyl group, methoxyethyl group, methoxypropyl group, methoxybutyl group, ethoxymethyl group, and ethoxyethyl group. These groups may be linear or branched.

In formulas (d-2), (d-5) and formula (e), examples of the alkyl group having 1 to 6 carbon atoms in R _2a , R _2b , R _5a , r _1a and r _1b include methyl group, ethyl group, etc. group, propyl group, butyl group, pentyl group, hexyl group, etc., and these may be linear or branched.
In formula (d-3), R _3a represents a methyl group or an ethyl group.
In formula (d-5), the monovalent hydrocarbon group having 1 to 6 carbon atoms for R _5b and R _5c includes a chain hydrocarbon group and an alicyclic hydrocarbon group, for example, a monovalent hydrocarbon group having 1 to 6 carbon atoms. Examples include a chain alkyl group, a cycloalkyl group having 3 to 6 carbon atoms, and the like. Further, examples of the monovalent group having "-O-" between carbon-carbon bonds in the hydrocarbon group include, for example, an alkoxyalkyl group having 1 to 6 carbon atoms. Specific examples of these include chain alkyl groups having 1 to 6 carbon atoms such as methyl, ethyl, propyl, butyl, pentyl, hexyl, etc.; cycloalkyl groups having 3 to 6 carbon atoms; , cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, etc.

Specific examples of formula (d-1) include N-ethyl-2-pyrrolidone, N-(n-propyl)-2-pyrrolidone, N-isopropyl-2-pyrrolidone, N-(n-butyl)-2- Pyrrolidone, N-(tert-butyl)-2-pyrrolidone, N-(n-pentyl)-2-pyrrolidone, N-(n-hexyl)-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, N-(n -octyl)-2-pyrrolidone, N-methoxypropyl-2-pyrrolidone, N-ethoxyethyl-2-pyrrolidone, N-methoxybutyl-2-pyrrolidone, and the like. Among these, from the viewpoint of solubility of specific polymers, N-ethyl-2-pyrrolidone, N-(n-pentyl)-2-pyrrolidone, N-(t-butyl)-2-pyrrolidone, N-(n Particularly preferred are -butyl)-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, N-(n-hexyl)-2-pyrrolidone, and N-methoxypropyl-2-pyrrolidone.

Specific examples of formula (d-2) include 1,3-dimethyl-2-imidazolidinone (DMI), 1,3-diethyl-2-imidazolidinone, and 1,3-dipropyl-2-imidazolidinone. , 1,3-diisopropyl-2-imidazolidinone, etc. Among these, DMI is preferred from the viewpoint of solubility of the specific polymer.
Specific examples of formula (d-5) include 3-butoxy-N,N-dimethylpropanamide, 3-methoxy-N,N-dimethylpropanamide, 3-hexyloxy-N,N-dimethylpropanamide, iso Examples include propoxy-N-isopropyl-propionamide and n-butoxy-N-isopropyl-propionamide. Among them, 3-butoxy-N,N-dimethylpropanamide and 3-methoxy-N,N-dimethylpropanamide are preferred from the viewpoint of solubility of the specific polymer.

Among solvent A, from the viewpoint of solubility of the specific polymer, N-ethyl-2-pyrrolidone, N-(n-pentyl)-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, N-(n-hexyl )-2-pyrrolidone, N-methoxypropyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, γ-butyrolactone, γ-valerolactone, γ-hexanolactone, 3-butoxy-N,N- At least one selected from the group consisting of dimethylpropanamide and 3-methoxy-N,N-dimethylpropanamide is preferred.
The content of the solvent A in the solvent is preferably 5 to 99% by mass, more preferably 10 to 99% by mass, based on the entire solvent contained in the liquid crystal aligning agent.

Specific examples of formula (e) include ethylene carbonate, propylene carbonate, butylene carbonate, pentylene carbonate, hexylene carbonate, 2-methyl-1,3-propylene carbonate, and 2,2-dimethyl-1,3-propylene carbonate. Examples include. Among these, propylene carbonate, ethylene carbonate, and butylene carbonate are preferred from the viewpoint of solubility of the specific polymer.
Specific examples of alkylene glycol monoalkyl ether acetate having a boiling point of 200 to 300°C include diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate, and the like.

Specific examples of alkylene glycol diacetate having a boiling point of 200 to 300°C include 1,3-butylene glycol diacetate, 1,6-hexanediol diacetate, and 1,2-propylene glycol dibutyrate.
Specific examples of alkylene glycol monoalkyl ethers having a boiling point of 200 to 300°C include ethylene glycol monohexyl ether, ethylene glycol monophenyl ether, ethylene glycol mono-2-ethyl butyl ether, propylene glycol phenyl ether, diethylene glycol monoethyl ether, and diethylene glycol. Examples include monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, dipropylene glycol monopropyl ether, tripropylene glycol methyl ether, and tripropylene glycol-n-butyl ether.

Specific examples of alkylene glycol dialkyl ethers having a boiling point of 200 to 300°C include diethylene glycol dibutyl ether, dipropylene glycol dibutyl ether, and tetraethylene glycol dimethyl ether.
Among solvent B, from the viewpoint of solubility of the specific polymer, propylene carbonate, ethylene carbonate, butylene carbonate, ethylene glycol monohexyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate, diethylene glycol At least one selected from the group consisting of monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, dipropylene glycol monopropyl ether, and tripropylene glycol methyl ether is preferred.

The solvent contained in the liquid crystal aligning agent of the present invention preferably contains one combination selected from the following MS1 to MS14 from the viewpoint of achieving both solubility of the specific polymer and wettability of the liquid crystal aligning agent;
・MS1: N-ethyl-2-pyrrolidone and propylene carbonate ・MS2: N-cyclohexyl-2-pyrrolidone and propylene carbonate ・MS3: N-(n-hexyl)-2-pyrrolidone and propylene carbonate ・MS4: γ-valerolactone and propylene carbonate ・MS5: N-ethyl-2-pyrrolidone and diethylene glycol monoethyl ether acetate ・MS6: N-ethyl-2-pyrrolidone and diethylene glycol monobutyl ether acetate

・MS7: N-ethyl-2-pyrrolidone and dipropylene glycol monomethyl ether acetate ・MS8: N-ethyl-2-pyrrolidone and ethylene glycol monohexyl ether ・MS9: N-ethyl-2-pyrrolidone and diethylene glycol monoethyl ether ・MS10 : N-ethyl-2-pyrrolidone and diethylene glycol monopropyl ether ・MS11: N-ethyl-2-pyrrolidone and diethylene glycol monobutyl ether ・MS12: N-ethyl-2-pyrrolidone and diethylene glycol monohexyl ether ・MS13: N-ethyl-2 -Pyrrolidone and dipropylene glycol monopropyl ether ・MS14: N-ethyl-2-pyrrolidone and tripropylene glycol methyl ether

The content of the solvent B in the solvent is preferably 1 to 95% by mass, more preferably 1 to 90% by mass, based on the entire solvent contained in the liquid crystal aligning agent.
The liquid crystal aligning agent of the present invention preferably further contains N-methyl-2-pyrrolidone as a solvent from the viewpoint of increasing the solubility of the specific polymer and ensuring printability. The content thereof is preferably 10 to 90% by weight, more preferably 20 to 90% by weight, particularly preferably 30 to 90% by weight based on the total amount of the solvent.

In the liquid crystal aligning agent of the present invention, other solvents may be used in combination with the above solvents. Here, other solvents include, for example, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, methyl methoxypropionate, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol-n - Propyl ether, ethylene glycol-i-propyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, the lower described in [0203] of WO2011/132751 Mention may be made of solvents that have surface tension.

The solid content concentration (ratio of the total weight of components other than the solvent in the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent) in the liquid crystal aligning agent of the present invention is selected in consideration of viscosity, volatility, etc. However, the particularly preferable solid content concentration range varies depending on the method used when applying the liquid crystal aligning agent to the substrate. For example, in the case of flexographic printing, it is particularly preferable that the solid content concentration is in the range of 3 to 9% by weight, and the solution viscosity is thereby in the range of 12 to 50 mPa·s. In the case of the inkjet method, it is particularly preferable that the solid content concentration is in the range of 1 to 5% by weight, and thereby the solution viscosity is in the range of 3 to 15 mPa·s.

The liquid crystal aligning agent of the present invention includes at least one substituent selected from the group consisting of a crosslinkable compound having an epoxy group, an isocyanate group, an oxetane group, or a cyclocarbonate group, a hydroxyl group, a hydroxyalkyl group, and a lower alkoxyalkyl group. or a crosslinkable compound having a polymerizable unsaturated bond may be introduced. It is preferable that the crosslinkable compound has two or more of these substituents and polymerizable unsaturated bonds.

Examples of the crosslinkable compound having an epoxy group or an isocyanate group include the compounds described in [0087] of WO2015/008846.
Specific examples of the crosslinkable compound having an oxetane group include crosslinkable compounds represented by formulas [4a] to [4k] listed on pages 58 to 59 of WO2011/132751. More preferable specific examples include compounds of formula [4b], formula [4d], and formula [4k] where n=5.
Specific examples of crosslinkable compounds having a cyclocarbonate group include crosslinkable compounds represented by formulas [5-1] to [5-42] listed on pages 76 to 82 of WO2012/014898. It will be done.

Examples of the crosslinkable compound having at least one substituent selected from the group consisting of a hydroxyl group and an alkoxyl group include the compounds described in [0090] to [0092] of WO2015/008846, and the compounds described in [0054] of WO2015/072554. Examples include a compound having a hydroxyalkylamide group, a compound described in [0126] of WO2015/156314, and the like. More preferable specific examples include crosslinkable compounds represented by formulas [6-1] to [6-48] listed in [181] to [185] of WO2011/132751, and those listed in [0054] of WO2015/072554. Examples include compounds having a hydroxyalkylamide group, and compounds described in [0126] of WO2015/156314.

Examples of the crosslinkable compound having a polymerizable unsaturated bond include the compounds described in [0186] of WO2011/132751.
In addition, a compound represented by formula [5] described in [0188] of WO2011/132751 can also be used.
The above compounds are examples of crosslinkable compounds, and the present invention is not limited thereto. Moreover, the number of the crosslinkable compounds used for the liquid crystal aligning agent of this invention may be one type, and may combine two or more types.

The content of the crosslinkable compound in the liquid crystal aligning agent of the present invention is preferably 0.1 to 150 parts by mass based on 100 parts by mass of all polymer components. Among these, in order for the crosslinking reaction to proceed and to exhibit the desired effect, the amount is preferably 0.1 to 100 parts by weight based on 100 parts by weight of all polymer components. More preferably, it is 1 to 50 parts by mass.
For the liquid crystal aligning agent of the present invention, a compound that improves the uniformity of the film thickness and surface smoothness of the liquid crystal aligning film when the liquid crystal aligning agent is applied can be used.

Examples of compounds that improve the uniformity of film thickness and surface smoothness of the liquid crystal alignment film include fluorine-based surfactants, silicone-based surfactants, and nonionic surfactants. More specifically, for example, FTOP EF301, EF303, EF352 (all manufactured by Tochem Products), Megafac F171, F173, R-30 (all manufactured by Dainippon Ink), Florado FC430, FC431 (all manufactured by Dainippon Ink), , manufactured by Sumitomo 3M), Asahi Guard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, and SC106 (all manufactured by Asahi Glass).
The proportion of these surfactants used is preferably 0.01 to 2 parts by mass, more preferably 0.01 to 1 part by mass, based on 100 parts by mass of all polymer components contained in the liquid crystal aligning agent. be.

Furthermore, the liquid crystal alignment agent of the present invention is described in pages 69 to 73 of WO2011/132751 (published on October 27, 2011) as a compound that promotes charge transfer in the liquid crystal alignment film and promotes charge loss in the device. Nitrogen-containing heterocyclic amine compounds represented by formulas [M1] to [M156] listed above can also be added. This amine compound may be added directly to the liquid crystal aligning agent, but it is preferable to add it after making it into a solution with a concentration of 0.1 to 10% by mass, preferably 1 to 7% by mass, in an appropriate solvent. This solvent is not particularly limited as long as it can dissolve the above-mentioned specific polymer.
In addition to the above-mentioned poor solvent, crosslinkable compound, compound that improves the uniformity of the film thickness and surface smoothness of the resin coating or liquid crystal alignment film, and the compound that promotes charge loss, the liquid crystal aligning agent of the present invention includes the liquid crystal aligning agent. A dielectric or conductive substance may be added for the purpose of changing the electrical properties such as dielectric constant and conductivity of the alignment film.

<Liquid crystal alignment film/liquid crystal display element>
The liquid crystal alignment agent of the present invention can be used as a liquid crystal alignment film by applying an alignment treatment on a substrate, baking it, and then subjecting it to alignment treatment by rubbing, light irradiation, or the like. Furthermore, in the case of vertical alignment applications, it can be used as a liquid crystal alignment film without alignment treatment. The substrate used in this case is not particularly limited as long as it is a highly transparent substrate, and in addition to glass substrates, plastic substrates such as acrylic substrates and polycarbonate substrates can also be used. From the viewpoint of process simplification, it is preferable to use a substrate on which ITO electrodes and the like for driving the liquid crystal are formed. Further, in a reflective liquid crystal display element, an opaque substrate such as a silicon wafer can be used as only one substrate, and in this case, a material that reflects light such as aluminum can also be used as the electrode.

The method for applying the liquid crystal aligning agent includes screen printing, offset printing, flexographic printing, inkjet method, dip method, roll coater method, slit coater method, spinner method, spray method, etc., but the manufacturing efficiency of the liquid crystal aligning film is limited. From the viewpoint of increasing the coating properties, flexographic printing or inkjet coating is preferred.

After the liquid crystal aligning agent is applied onto the substrate, the temperature is heated to 30 to 300°C, preferably 30°C, depending on the solvent used for the liquid crystal aligning agent, using a heating means such as a hot plate, a thermal circulation type oven, or an IR (infrared) type oven. A liquid crystal alignment film can be obtained by evaporating the solvent at a temperature of ~250°C. The thickness of the liquid crystal alignment film after firing is preferably 5 to 300 nm, more preferably 5 to 300 nm, because if it is too thick, it will be disadvantageous in terms of power consumption of the liquid crystal display element, and if it is too thin, the reliability of the liquid crystal display element may decrease. is 10 to 100 nm.

When the display mode of the liquid crystal display element to be manufactured is VA type, the coating film formed as described above can be used as a liquid crystal alignment film as it is, but if necessary, it may be subjected to rubbing treatment or PSA as described below. Processing may be performed. On the other hand, when the display mode of the liquid crystal display element to be manufactured is a vertical electric field type other than VA type or a horizontal electric field type, the formed coating surface is subjected to rubbing treatment or polarized ultraviolet irradiation. treatment and orientation treatment.

The liquid crystal aligning agent of the present invention has a liquid crystal layer between a pair of substrates provided with electrodes, and has a liquid crystal composition containing a polymerizable compound that is polymerized by at least one of active energy rays and heat between the pair of substrates. It is also preferably used for liquid crystal display elements manufactured through a step of arranging objects and polymerizing a polymerizable compound by at least one of irradiation with active energy rays and heating while applying a voltage between electrodes. Here, the applied voltage can be, for example, 5 to 50 V direct current or alternating current. Moreover, ultraviolet rays are suitable as active energy rays. The ultraviolet rays include ultraviolet rays having a wavelength of 300 to 400 nm, preferably ultraviolet rays including light having a wavelength of 310 to 360 nm. The amount of light irradiation is preferably 0.1 to 20 J/cm ² , more preferably 1 to 20 J/cm ² .

The above liquid crystal display element controls the pretilt of liquid crystal molecules using the PSA method. In the PSA method, a small amount of a photopolymerizable compound, such as a photopolymerizable monomer, is mixed into the liquid crystal material, and after the liquid crystal cell is assembled, the photopolymerizable compound is exposed to ultraviolet light while a predetermined voltage is applied to the liquid crystal layer. The pretilt of liquid crystal molecules is controlled by the polymer produced. Since the alignment state of the liquid crystal molecules when the polymer is generated is remembered even after the voltage is removed, the pretilt of the liquid crystal molecules can be adjusted by controlling the electric field formed in the liquid crystal layer. Furthermore, since the PSA method does not require a rubbing process, it is suitable for forming a vertically aligned liquid crystal layer in which it is difficult to control pretilt by a rubbing process.

The liquid crystal display element of the present invention is obtained by obtaining a substrate with a liquid crystal alignment film from the liquid crystal aligning agent of the present invention by the method described above, and then producing a liquid crystal cell by a known method to obtain a liquid crystal display element.
The method for manufacturing a liquid crystal cell is to prepare a pair of substrates on which a liquid crystal alignment film is formed, sprinkle spacers on the liquid crystal alignment film of one substrate so that the liquid crystal alignment film surface is on the inside, and then close the other substrate. Examples include a method in which the substrates are bonded together and liquid crystal is injected under reduced pressure for sealing, or a method in which liquid crystal is dropped onto the surface of a liquid crystal alignment film on which spacers have been sprinkled, and then the substrates are bonded together and sealing is carried out.

The liquid crystal may be mixed with a polymerizable compound that is polymerized by ultraviolet irradiation or heat, as described above. Examples of the polymerizable compound include compounds having one or more polymerizable unsaturated groups such as acrylate groups and methacrylate groups in the molecule, for example, polymerizable compounds represented by the following formulas (M-1) to (M-3). Can be mentioned.

The amount of the polymerizable compound used is preferably 0.01 to 10 parts by weight, more preferably 0.1 to 5 parts by weight, per 100 parts by weight of the liquid crystal component. If the amount of the polymerizable compound is less than 0.01 part by mass, the polymerizable compound will not polymerize, making it impossible to control the alignment of the liquid crystal, and if it exceeds 10 parts by mass, there will be a large amount of unreacted polymerizable compound, which may cause problems in the liquid crystal display element. The burn-in characteristics are reduced. After producing the liquid crystal cell, the polymerizable compound is polymerized by irradiating heat or ultraviolet rays while applying an alternating current or direct current voltage to the liquid crystal cell. Thereby, the alignment of liquid crystal molecules can be controlled.

In addition, the liquid crystal aligning agent of the present invention has a liquid crystal layer between a pair of substrates provided with electrodes, and a polymerizable group that is polymerized by at least one of active energy rays and heat between the pair of substrates. It may also be used for a liquid crystal display element manufactured through a process of arranging a liquid crystal alignment film containing the above and applying a voltage between electrodes, that is, an SC-PVA mode. Here, ultraviolet rays are suitable as the active energy rays. As the ultraviolet rays, the ultraviolet rays used in the above-mentioned PSA method can be applied, including preferred embodiments. In the case of polymerization by heating, the heating temperature is 40 to 120°C, preferably 60 to 80°C. Further, ultraviolet rays and heating may be applied simultaneously.

In order to obtain a liquid crystal alignment film containing a polymerizable group that is polymerized by at least one of active energy rays and heat, there is a method of adding a compound containing this polymerizable group to a liquid crystal aligning agent, a method of adding a compound containing this polymerizable group to a liquid crystal aligning agent, and a method of adding a polymer containing a polymerizable group. Examples include methods using components. Specific examples of polymers containing polymerizable groups include polymers obtained using the diamine that has the function of polymerizing upon irradiation with light.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples.
(Specific diamine)
W-A1: Compound represented by formula [W-A1], W-A2: Compound represented by formula [W-A2] W-A3: Compound represented by formula [W-A3]

(Other side chain diamine compounds)
A1: Compound represented by formula [A1]

C1: Compound represented by formula [C1], C2: Compound represented by formula [C2] C3: Compound represented by formula [C3]

(Tetracarboxylic acid compound)
D1: 1,2,3,4-cyclobutanetetracarboxylic dianhydride D2: Bicyclo[3,3,0]octane-2,4,6,8-tetracarboxylic dianhydride D3: Pyromellitic dianhydride thing

(solvent)
NEP: N-ethyl-2-pyrrolidone, GVL: γ-valerolactone,
GBL: γ-butyrolactone NMP: N-methyl-2-pyrrolidone,
CHP: N-cyclohexyl-2-pyrrolidone, NHP: N-(n-hexyl)-2-pyrrolidone 3BMP: 3-butoxy-N,N-dimethylpropanamide, PC: Propylene carbonate EC: Ethylene carbonate DEMBA: Diethylene glycol monobutyl ether Acetate DPMEA: Dipropylene glycol monomethyl ether acetate EMH: Ethylene glycol monohexyl ether

DEME: Diethylene glycol monoethyl ether DEMP: Diethylene glycol monopropyl ether DEMB: Diethylene glycol monobutyl ether DEMH: Diethylene glycol monohexyl ether DPMP: Dipropylene glycol monopropyl ether TPME: Tripropylene glycol methyl ether

(molecular weight measurement)
The molecular weights of the polyimide precursor and polyimide were determined as follows using a room temperature gel permeation chromatography (GPC) device (GPC-101) (manufactured by Showa Denko) and columns (KD-803, KD-805) (manufactured by Shodex). It was measured as follows.
Column temperature: 50℃
Eluent: N,N'-dimethylformamide (as additives, 30 mmol/L (liter) of lithium bromide-hydrate (LiBr.H ₂ O), 30 mmol of phosphoric acid/anhydrous crystal (o-phosphoric acid) /L, tetrahydrofuran (THF) is 10ml/L), flow rate: 1.0ml/min Standard sample for creating a calibration curve: TSK standard polyethylene oxide (molecular weight: approximately 900,000, 150,000, 100,000 and 30,000 ) (manufactured by Tosoh Corporation) and polyethylene glycol (molecular weight; approximately 12,000, 4,000, and 1,000) (manufactured by Polymer Laboratory Corporation).

(Measurement of imidization rate)
Put 20 mg of polyimide powder into an NMR (nuclear magnetic resonance) sample tube (NMR sampling tube standard, φ5 (manufactured by Kusano Kagaku)) and add deuterated dimethyl sulfoxide (DMSO-d6, 0.05% by mass TMS (tetramethylsilane)). Mixed product) (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 amic acid that appears around 9.5 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.

(Viscosity measurement)
The viscosity of the polyimide polymer was measured 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. did.

<Synthesis of specific diamine>
W-A1 to W-A3 are new compounds that have not been published in literature, etc., and were synthesized as follows.
The products described in Synthesis Examples 1 to 3 below were identified by ¹ H-NMR analysis under the following conditions.
Equipment: Varian NMR System 400 NB (400 MHz)
Measurement solvent: CDCl _3, DMSO-d ₆
Reference substance: Tetramethylsilane (TMS) (δ0.0 ppm for ¹ H)

<Synthesis Example 1 Synthesis of W-A1>

<Synthesis of compounds [1] and [2]>
4,4'-dinitro-1,1'-biphenyl-2,2'-dimethanol (41.1 g, 135 mmol) and triethylamine (31.5 g) in tetrahydrofuran (165.6 g) were added to a reaction vessel, and nitrogen was added. Compound [1] was obtained by adding methanesulfonyl chloride (33.2 g) dropwise under ice-cooled atmosphere and reacting for 1 hour. Subsequently, p-(trans-4-heptylcyclohexyl)phenol (77.8 g) dissolved in tetrahydrofuran (246.6 g) was added, and after stirring at 40°C for 1 hour, water dissolved in pure water (233 g) was added. Potassium oxide (41.0 g) was added at the same temperature and reacted for 21 hours. After the reaction was completed, a 1.0M aqueous hydrochloric acid solution (311 ml) and pure water (1050 g) were added to precipitate a crude substance, and the crude substance was collected by filtration. The obtained crude product was dissolved in tetrahydrofuran (574 g) by heating at 50°C, methanol (328 g) was added to precipitate crystals, and the compound [2] was obtained by filtration and drying (yield: 97.9 g, rate: 89%).

¹ H-NMR (400MHz) in CDCl ₃ : 0.87-0.90ppm (m, 6H), 0.96-1.05ppm (m, 4H), 1.19-1.39ppm (m, 30H), 1.80-1.85ppm (m, 8H), 2.33-2.40ppm (m, 2H), 4.77ppm (s, 4H), 6.66-6.70ppm (m, 4H), 7. 02-7.06ppm (m, 4H), 7.40ppm (d, 2H, 8.4), 8.25ppm (dd, 2H, J=2.4Hz, J=8.4Hz), 8.54ppm (d , 2H, J=2.4Hz).

<Synthesis of W-A1>
Tetrahydrofuran (1783 g), compound [2] (74.3 g, 90.9 mmol), and 3% platinum carbon (5.94 g) were added to a reaction vessel, and the mixture was reacted in a hydrogen atmosphere at room temperature. After the reaction was completed, the reaction mixture was filtered, and the filtrate was concentrated under reduced pressure to give a total internal weight of 145 g. Subsequently, methanol (297 g) was added to the concentrated solution, stirred under ice cooling, filtered, and dried to obtain W-A1 (yield: 59.2 g, yield: 86%).
¹ H-NMR (400MHz) in CDCl ₃ : 0.87-0.90ppm (m, 6H), 0.96-1.05ppm (m, 4H), 1.19-1.40ppm (m, 30H), 1.81-1.84ppm (m, 8H), 2.32-2.38ppm (m, 2H), 3.67ppm (s, 4H), 4.69ppm (d, 2H, J=12.0Hz), 4.74ppm (d, 2H, J=11.6Hz), 6.62ppm (dd, 2H, J=2.4Hz, J=8.0Hz), 6.70-6.75ppm (m, 4H), 6 .91ppm (d, 2H, J=2.4Hz), 6.97-7.03ppm (m, 6H).

<Synthesis Example 2 Synthesis of W-A2>

<Synthesis of compound [3]>
In a reaction vessel, tetrahydrofuran (327.2 g), 4,4'-dinitro-2,2'-diphenic acid (40.9 g, 123 mmol) and p-(trans-4-heptylcyclohexyl)phenol (72.1 g), 4 -Dimethylaminopyridine (1.50 g) was added, and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (56.6 g) was added under nitrogen atmosphere and room temperature conditions, and the mixture was allowed to react for 3 hours. After the reaction was completed, the reaction solution was poured into pure water (1226 g) to precipitate a crude product, which was collected by filtration. Subsequently, the crude material was slurried washed with methanol (245 g), filtered, and the obtained crude material was dissolved in tetrahydrofuran (245 g) by heating at 60°C. After removing insoluble materials by filtration, the total internal weight was reduced to 232 g by vacuum concentration, and methanol (163 g) was added to precipitate crystals. After stirring under ice-cooling conditions, filtration and drying yielded compound [3]. (Yield: 73.9 g, yield: 71%).

¹ H-NMR (400MHz) in CDCl ₃ : 0.87-0.90ppm (m, 6H), 0.98-1.06ppm (m, 4H), 1.18-1.43ppm (m, 30H), 1.83-1.86ppm (m, 8H), 2.41-2.47ppm (m, 2H), 6.89-6.92ppm (m, 4H), 7.17-7.20ppm (m, 4H) ), 7.48ppm (d, 2H, 8.4), 8.49ppm (dd, 2H, J = 2.4Hz, J = 8.4Hz), 9.11ppm (d, 2H, J = 2.4Hz) ．．

<Synthesis of W-A2>
Tetrahydrofuran (443 g), methanol (73.9 g), compound [3] (73.9 g, 87.4 mmol), and 5% palladium on carbon (8.80 g) were added to a reaction vessel and reacted under hydrogen atmosphere at room temperature. After the reaction was completed, palladium on carbon was removed by filtration, and the total internal weight was reduced to 171 g by vacuum concentration. Subsequently, methanol (222 g) was added to the concentrated solution to precipitate crystals, followed by ice-cooling stirring, filtration, and drying to obtain W-A2 (yield: 66.6 g, yield: 97%).
¹ H-NMR (400MHz) in CDCl ₃ : 0.87-0.90ppm (m, 6H), 0.96-1.05ppm (m, 4H), 1.17-1.42ppm (m, 30H), 1.82-1.85ppm (m, 8H), 2.38-2.44ppm (m, 2H), 3.77ppm (s, 4H), 6.80-6.87ppm (m, 6H), 7. 08-7.13ppm (m, 6H), 7.41ppm (d, 2H, J=2.4Hz).

<Synthesis Example 3 Synthesis of W-A3>

<Synthesis of compounds [4] and [5]>
Toluene (366 g), 4-(trans-4-heptylcyclohexyl)-benzoic acid (73.1 g, 242 mmol) and N,N-dimethylformamide (0.73 g) were added to a reaction vessel, and the mixture was heated under nitrogen atmosphere at 50°C. Thionyl chloride (35.9 g) was added dropwise. After the dropwise addition, the reaction solution was reacted at the same temperature for 1 hour, and the reaction solution was concentrated under reduced pressure to obtain compound [4]. Subsequently, 4,4'-dinitro-1,1'-biphenyl-2,2'-dimethanol (35.0 g, 115 mmol) and triethylamine (26.8 g) were charged in tetrahydrofuran (210 g), and the mixture was placed on ice under a nitrogen atmosphere. Compound [4] dissolved in tetrahydrofuran (73.1 g) was added dropwise under cold conditions. After the dropwise addition was completed, the reaction temperature was raised to room temperature and the reaction was continued for 18 hours. After the reaction was completed, triethylamine hydrochloride was removed by filtration, and then concentrated under reduced pressure to obtain an oily compound. The obtained oily compound was added to pure water (1015 g) to precipitate crystals, and the crude product was collected by filtration. Subsequently, the obtained crude product was slurried at room temperature with methanol (291 g), washed with ethyl acetate (175 g), filtered, and dried to obtain compound [5] (yield: 92.7 g, rate: 92%).

¹ H-NMR (400MHz) in CDCl ₃ : 0.89-0.91ppm (m, 6H), 0.99-1.09ppm (m, 4H), 1.20-1.47ppm (m, 30H), 1.85-1.88ppm (m, 8H), 2.46-2.52ppm (m, 2H), 5.14ppm (s, 4H), 7.23-7.26ppm (m, 4H), 7. 45ppm (d, 2H, J=8.4Hz), 7.83-7.86ppm (m, 4H), 8.27ppm (dd, 2H, J=2.4Hz, J=8.4Hz), 8.47ppm (d, 2H, J=2.4Hz).

<Synthesis of W-A3>
Tetrahydrofuran (484 g), methanol (161 g), compound [5] (80.5 g, 92.2 mmol), and 3% platinum carbon (6.44 g) were added to a reaction vessel and reacted under hydrogen atmosphere at room temperature. After the reaction was completed, platinum carbon was removed by filtration, and the solvent was removed by vacuum concentration to give a total internal weight of 96.6 g. Subsequently, methanol (322 g) was added to the concentrated solution to precipitate crystals, followed by ice-cooling stirring and filtration to obtain a crude product. Subsequently, the obtained crude product was dissolved in ethyl acetate (322 g) by heating at 60°C, methanol (700 g) was added, crystals were precipitated under ice-cooling conditions, and W-A3 was obtained by filtering and drying. (Yield: 67.9 g, yield: 91%).

¹ H-NMR (400MHz) in CDCl ₃ : 0.87-0.91ppm (m, 6H), 0.98-1.08ppm (m, 4H), 1.19-1.47ppm (m, 30H), 1.84-1.87ppm (m, 8H), 2.44-2.51ppm (m, 2H), 3.71ppm (s, 4H), 5.02ppm (d, 2H, J=12.8Hz), 5.09ppm (d, 2H, J = 12.4Hz), 6.66ppm (dd, 2H, J = 2.4Hz, J = 8.0Hz), 6.84ppm (d, 2H, J = 2.4Hz) , 7.03ppm (d, 2H, J=8.0Hz), 7.19-7.25ppm (m, 4H), 7.89-7.92ppm (m, 4H).

<Synthesis of polymer>
[Synthesis example 1]
D2 (2.50 g, 10.0 mmol), W-A1 (3.03 g, 4.00 mmol), and C1 (1.73 g, 16.0 mmol) were added to NMP (18.1 g) and NEP (18.1 g). After dissolving in a mixed solvent and reacting at 60°C for 3 hours, D1 (1.78 g, 9.10 mmol) was added and reacted at 40°C for 3 hours to form a polyamic acid solution with a resin solid content of 20% by mass (viscosity :840 mPa·s) was obtained.
After adding NMP to the obtained polyamic acid solution (20.0 g) and diluting it to 6.5% by mass, acetic anhydride (4.43 g) and pyridine (1.37 g) were added as imidization catalysts, and the mixture was heated at 80°C. The reaction was allowed to proceed for 3 hours. This reaction solution was poured into methanol (382 ml), and the resulting precipitate was filtered off. This precipitate was washed with methanol and dried under reduced pressure at 100°C to obtain polyimide powder (PI-1). The imidization rate of this polyimide was 76.4%, the Mn was 16,165, and the Mw was 49,988.

[Synthesis example 2]
D2 (2.50 g, 10.0 mmol), W-A2 (3.14 g, 4.00 mmol), and C1 (1.84 g, 16.0 mmol) were added to NMP (11.1 g) and PC (25.8 g). After dissolving in a mixed solvent and reacting at 60°C for 3 hours, D1 (1.84 g, 9.38 mmol) was added and reacted at 40°C for 3 hours to obtain a polyamic acid solution with a resin solid content of 20% by mass (viscosity :658 mPa·s) was obtained.
After adding NMP to the obtained polyamic acid solution (20.0 g) and diluting it to 6.5% by mass, acetic anhydride (4.38 g) and pyridine (1.36 g) were added as an imidization catalyst, and the mixture was heated at 80°C. The reaction was allowed to proceed for 3 hours. This reaction solution was poured into methanol (382 ml), and the resulting precipitate was filtered off. This precipitate was washed with methanol and dried under reduced pressure at 100°C to obtain polyimide powder (PI-2). The imidization rate of this polyimide was 75.8%, the Mn was 15,430, and the Mw was 45,756.

[Synthesis example 3]
D2 (2.50 g, 10.0 mmol), W-A3 (3.25 g, 4.00 mmol), and C1 (1.73 g, 16.0 mmol) were mixed in GVL (37.3 g) and heated at 60 °C. After reacting for 3 hours, D1 (1.84 g, 9.38 mmol) was added and reacted at 40° C. for 3 hours to obtain a polyamic acid solution (viscosity: 656 mPa·s) with a resin solid content concentration of 20% by mass.
After adding GVL to the obtained polyamic acid solution (20.0 g) and diluting it to 6.5% by mass, acetic anhydride (4.32 g) and pyridine (1.34 g) were added as imidization catalysts, and the mixture was heated at 80°C. The reaction was allowed to proceed for 3 hours. This reaction solution was poured into methanol (382 ml), and the resulting precipitate was filtered off. This precipitate was washed with methanol and dried under reduced pressure at 100°C to obtain polyimide powder (PI-3). The imidization rate of this polyimide was 74.7%, the Mn was 13,340, and the Mw was 41,948.

[Comparative synthesis example 1]
Add D2 (2.88 g, 11.5 mmol), A1 (0.60 g, 1.2 mmol), C2 (3.32 g, 21.8 mmol) and NMP to a set concentration of 20% by mass, and react at 60°C for 3 hours. After that, D1 (2.19 g, 11.2 mmol) and NMP were added to set the concentration to 20% by mass, and the mixture was reacted at 40°C for 3 hours to form a polyamic acid solution with a resin solid concentration of 20% by mass (viscosity: 600 mPa).・s) was obtained.
After adding NMP to the obtained polyamic acid solution (20.0 g) and diluting it to 6.5% by mass, acetic anhydride (4.64 g) and pyridine (1.44 g) were added as imidization catalysts, and the mixture was heated at 80°C. The reaction was allowed to proceed for 3 hours. This reaction solution was poured into methanol (382 ml), and the resulting precipitate was filtered off. This precipitate was washed with methanol and dried under reduced pressure at 100°C to obtain polyimide powder (PI-R1). The imidization rate of this polyimide was 57%, Mn was 13,100, and Mw was 33,200.

[Comparative synthesis example 2]
Polyimide powder (PI-R2) was obtained in the same manner as in Polymer Comparative Synthesis Example 1, except that the type and composition of the diamine used were changed as shown in Table 1 below. The imidization rate of this polyimide was 65%, Mn was 10,500, and Mw was 20,900.

[Example 1]
The polyimide (PI-1) obtained in the above polymer synthesis example 1 was dissolved in a mixed solvent consisting of NEP, GVL and PC (mixing ratio (weight ratio) = 20:50:30), and the solid content concentration was A liquid crystal aligning agent (S-1) containing 6.5% by mass was obtained. This was filtered through a filter with a pore size of 0.2 μm, and then subjected to the following evaluations of flexographic printability and liquid crystal orientation.

<Evaluation of inkjet coating properties>
As the substrate to which the liquid crystal aligning agent was applied, a step substrate (made of glass) having a height of 0.5 μm, a line width of 50 μm, and an inter-line space of 120 μm was used, which had just been cleaned with ultraviolet rays.
The liquid crystal alignment agent prepared above (after filtration) was applied onto the glass substrate using HIS-200 (manufactured by Hitachi Plant Technologies). The coating conditions at this time were a coating area of 70 mm x 70 mm, a nozzle pitch of 0.423 mm, a scan pitch of 0.5 mm, and a coating speed of 40 mm/sec. After application, the mixture was allowed to stand for 60 seconds and then heated at 70° C. to form a coating film with an average thickness of 100 nm. The obtained coating film was evaluated for coating properties and for linearity of the edges of the liquid crystal alignment film.

The coating properties are evaluated by observing with the naked eye under the irradiation of an interference fringe measurement lamp (sodium lamp).If neither unevenness nor repellency is observed, it is evaluated as excellent, and when at least one of unevenness and repellency is observed. Good, and cases where both unevenness and repellency were observed were evaluated as poor.
The linearity of the edge of the liquid crystal alignment film was evaluated by observing the coating film at the right edge with an optical microscope (ECLIPSE E600WPOL, manufactured by Nikon Corporation) with respect to the printing direction. Specifically, it was observed using an optical microscope at a magnification of 25 times, and evaluated according to the following evaluation criteria.
Excellent: A homogeneous line shape was obtained on all four sides.
Good: Disturbances in line width were observed on 1 to 3 sides.
Poor: Disturbances in line width were observed throughout.

<Evaluation of flexo printability>
A coating property test was conducted by flexographic printing the liquid crystal aligning agent prepared above onto a cleaned Cr plate using an alignment film printer ("Angstromer" manufactured by Nissha Printing Co., Ltd.). About 1.0 mL of liquid crystal aligning agent was dropped onto the anilox roll, and after 20 idle runs, the printing press was stopped for 10 minutes in the atmosphere to dry the printing plate. After that, printing was performed on one Cr substrate, and the printed substrate was heated to 70° C., and the film state was observed. Observations were made visually and with an optical microscope ("ECLIPSE ME600" manufactured by Nikon Corporation) at a magnification of 50 times. Excellent if no pinholes or uneven film thickness at the edges were observed; Good if either pinholes or uneven film thickness at the edges were observed; both pinholes or uneven film thickness at the edges were observed. It was evaluated as defective if it was.

<Manufacture of liquid crystal cells>
The liquid crystal aligning agent prepared above was filtered under pressure using a membrane filter with a pore diameter of 1 μm. The above inkjet coating of the obtained solution was performed on the ITO surface of a 40 mm x 30 mm glass substrate with an ITO electrode (length: 40 mm, width: 30 mm, thickness: 1.1 mm), which had been washed with pure water and IPA (isopropyl alcohol). Alternatively, a coating film is created by flexographic printing, and heat treated on a hot plate at 70°C for 90 seconds and in a thermal circulation clean oven at 230°C for 30 minutes to form a liquid crystal alignment film with a film thickness of 100 nm. An ITO substrate was obtained. Two ITO substrates with the obtained liquid crystal alignment film were prepared, and bead spacers with a diameter of 4 μm (manufactured by JGC Catalysts & Chemicals Co., Ltd., Shinshu Ball, SW-D1) were applied to the liquid crystal alignment film surface of one of the substrates.

Next, a sealant (XN-1500T manufactured by Mitsui Chemicals) was applied around the area. Next, the other substrate was bonded to the previous substrate with the surface on which the liquid crystal alignment film was formed facing inward, and then the sealing material was cured to create an empty cell. A negative liquid crystal MLC-3023 (trade name, manufactured by Merck & Co., Ltd.) was injected into this empty cell by a vacuum injection method to prepare a liquid crystal cell.
Thereafter, with a DC voltage of 15 V applied to the obtained liquid crystal cell, 15 J/cm ² of ultraviolet light with a wavelength of 365 nm and passed through a bandpass filter was irradiated using an ultraviolet irradiation device using a high-pressure mercury lamp as a light source. As a result, a vertical alignment type liquid crystal display element was obtained. In addition, to measure the amount of ultraviolet irradiation, a UV-M03A manufactured by ORC Co., Ltd. was connected to a UV-35 light receiver.

<Evaluation of liquid crystal orientation>
The liquid crystal orientation of the liquid crystal display element was observed using a polarizing microscope (ECLIPSE E600WPOL) (manufactured by Nikon Corporation) to confirm whether the liquid crystal was vertically aligned. Specifically, those in which no defects due to liquid crystal flow or bright spots due to alignment defects were observed were evaluated as good.
[Examples 2 to 19 and Comparative Examples 1 to 4]
Liquid crystal aligning agents (S-2) to (S-19), (RS-1) to (RS-4) were prepared respectively. Moreover, for each liquid crystal aligning agent, either flexographic printability, liquid crystal alignment, or inkjet coatability was evaluated. The results are shown in Table 2 below.

In Table 2, the numerical value of the polymer indicates the blending ratio (mass ratio) of each polymer with respect to the total amount of polymers used for preparing the liquid crystal aligning agent. The numerical value of the solvent composition indicates the blending ratio (mass ratio) of each compound to the total amount of the solvent used for preparing the liquid crystal aligning agent.
As can be seen from the above results, the liquid crystal alignment film obtained from the liquid crystal alignment agent of the example has better inkjet printability, flexographic printability, and liquid crystal alignment film than the liquid crystal alignment film obtained from the liquid crystal alignment agent of the comparative example. A liquid crystal alignment film that achieves all of the above can be obtained.

The liquid crystal aligning agent of the present invention can suppress coating defects of the alignment film caused by the influence of wiring structure and C/H, and can also suppress drying of the liquid crystal aligning agent when performing flexographic printing. It is. In addition, a liquid crystal display element having a liquid crystal alignment film obtained in this way can display high-quality images, and can be suitably used for large-screen, high-definition liquid crystal televisions, etc., and can be used for TN elements, STN elements, TFT liquid crystal It is particularly useful for vertically aligned liquid crystal display devices.

The entire contents of the specification, claims, drawings, and abstract of Japanese Patent Application No. 2017-223899 filed on November 21, 2017 are cited here as disclosure of the specification of the present invention. , is something to be taken in.

Claims (16)

At least one polymer selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide which is an imidized product thereof, having the structure of the following formula [1],
At least one solvent A selected from the group consisting of the following formulas (d-1) to (d-5), an alkylene glycol monoalkyl ether acetate, an alkylene glycol having the following formula (e) and a boiling point of 200 to 300 ° C. A solvent containing at least one solvent B selected from the group consisting of diacetate, alkylene glycol monoalkyl ether, and alkylene glycol dialkyl ether;
A liquid crystal aligning agent characterized by containing,
The polyamic acid, polyamic acid ester, and polyimide react with a tetracarboxylic acid compound and a diamine represented by the following formula [2], or a mixture of a diamine represented by the following formula [2] and other diamines. The liquid crystal aligning agent obtained by

X represents a single bond. The two Y's independently represent a side chain structure selected from the following formulas [S1] to [S3] or a structure derived from tocopherol.

X ¹ and X ² are independently a single bond, -(CH ₂ ) _a - (a is an integer from 1 to 15), -CONH-, -NHCO-, -CON(CH ₃ )-, -NH -, -O-, -COO-, -OCO-, or ((CH ₂ ) _a1 -A ₁ ) _m1 - (a1 represents an integer from 1 to 15, A ₁ represents an oxygen atom, -COO or OCO) and m ₁ is 1 to 2), and G ¹ and G ² are independently a divalent aromatic group having 6 to 12 carbon atoms or a divalent alicyclic group having 3 to 8 carbon atoms. A divalent cyclic group selected from the following, and any hydrogen atom on the cyclic group is an alkyl group having 1 to 3 carbon atoms, an alkyl group having 1 to 3 carbon atoms, or a fluorine-containing alkyl group having 1 to 3 carbon atoms. , may be substituted with a fluorine-containing alkoxyl group having 1 to 3 carbon atoms or a fluorine atom, m and n are independently integers of 0 to 3, the sum of these is 1 to 4, and R ¹ is alkyl having 1 to 20 carbon atoms, alkoxy having 1 to 20 carbon atoms, or alkoxyalkyl having 2 to 20 carbon atoms, and any hydrogen atom in these groups may be replaced with a fluorine atom.
X ³ represents -CONH- , -NHCO-, -CON(CH ₃ )-, -NH-, -O-, -CH ₂ O-, -COO-, or OCO-, and R ² has a carbon number of 1 to 20 alkyl or alkoxyalkyl having 2 to 20 carbon atoms, and any hydrogen in these groups may be replaced with fluorine.
X ⁴ represents -CONH-, -NHCO-, -O-, -COO- or OCO-, and R ³ represents a structure having a steroid skeleton.

R _1a represents a monovalent hydrocarbon group having 2 to 8 carbon atoms, or a monovalent group having "-O-" between the carbon-carbon bonds in the hydrocarbon group, and R _2a and R _2b are independently represents an alkyl group having 1 to 6 carbon atoms, R _3a represents a methyl group or an ethyl group, R _5a represents an alkyl group having 1 to 6 carbon atoms, and R _5b and R _5c independently represent a hydrogen atom. , a monovalent hydrocarbon group having 1 to 6 carbon atoms, or a monovalent group having "-O-" between the carbon-carbon bonds of the hydrocarbon group, and n is 1 or 2.

In the formula, r _1a and r _1b independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and m is an integer of 2 to 6.

(In the formula, X and Y have the same meanings as X and Y in the above formula [1].) The liquid crystal aligning agent according to claim 1, wherein the two Y's independently represent a side chain structure selected from the formulas [S1], [S3], or a structure derived from tocopherol. Solvent A is N-ethyl-2-pyrrolidone, N-(n-pentyl)-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, N-(n-hexyl)-2-pyrrolidone, N-methoxypropyl-2 -pyrrolidone, 1,3-dimethyl-2-imidazolidinone, γ-butyrolactone, γ-valerolactone, γ-hexanolactone, 3-butoxy-N,N-dimethylpropanamide, and 3-methoxy-N,N - The liquid crystal aligning agent according to claim 1, which is at least one solvent selected from the group consisting of dimethylpropanamide. Solvent B is propylene carbonate, ethylene carbonate, butylene carbonate, ethylene glycol monohexyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether The liquid crystal aligning agent according to any one of claims 1 to 3, which is at least one solvent selected from the group consisting of , diethylene glycol monohexyl ether, dipropylene glycol monopropyl ether, and tripropylene glycol methyl ether. The liquid crystal aligning agent according to any one of claims 1 to 4, wherein the solvent includes one combination selected from the group consisting of MS1 to MS14 below.
・MS1: N-ethyl-2-pyrrolidone and propylene carbonate ・MS2: N-cyclohexyl-2-pyrrolidone and propylene carbonate ・MS3: N-(n-hexyl)-2-pyrrolidone and propylene carbonate ・MS4: γ-valerolactone and propylene carbonate ・MS5: N-ethyl-2-pyrrolidone and diethylene glycol monoethyl ether acetate ・MS6: N-ethyl-2-pyrrolidone and diethylene glycol monobutyl ether acetate ・MS7: N-ethyl-2-pyrrolidone and dipropylene glycol monomethyl ether Acetate MS8: N-ethyl-2-pyrrolidone and ethylene glycol monohexyl ether MS9: N-ethyl-2-pyrrolidone and diethylene glycol monoethyl ether MS10: N-ethyl-2-pyrrolidone and diethylene glycol monopropyl ether MS11: N-ethyl-2-pyrrolidone and diethylene glycol monobutyl ether ・MS12: N-ethyl-2-pyrrolidone and diethylene glycol monohexyl ether ・MS13: N-ethyl-2-pyrrolidone and dipropylene glycol monopropyl ether ・MS14: N-ethyl- 2-pyrrolidone and tripropylene glycol methyl ether The liquid crystal aligning agent according to any one of claims 1 to 5, wherein the content of solvent B in the solvent is 1 to 95% by mass, and the content of solvent A in the solvent is 5 to 99% by mass. . The liquid crystal aligning agent according to any one of claims 1 to 6, wherein the solvent further contains N-methyl-2-pyrrolidone. The liquid crystal aligning agent according to claim 7, wherein the content of N-methyl-2-pyrrolidone is 10 to 90% by mass. 9. The tetracarboxylic acid compound according to any one of claims 1 to 8, wherein the tetracarboxylic acid compound is at least one of a tetracarboxylic dianhydride having a structure represented by the following formula [4] and a tetracarboxylic acid derivative thereof. Liquid crystal alignment agent.

Z represents a structure selected from the group consisting of [4a] to [4k] below.

(In the formula, *1 is a bond bonded to one acid anhydride group, and *2 is a bond bonded to the other acid anhydride group. In formula [4a], Z ¹ to Z ⁴ are (Independently represents a hydrogen atom, methyl group, ethyl group, propyl group, chlorine atom or benzene ring. In formula [4g], Z ⁵ and Z ⁶ independently represent a hydrogen atom or a methyl group.) The liquid crystal aligning agent according to claim 9 , wherein the tetracarboxylic acid compound represented by the formula [4] accounts for 5 mol% or more in 100 mol% of all the tetracarboxylic acid compounds. The liquid crystal aligning agent according to any one of claims 1 to 10, wherein the other diamine includes a diamine having a function of polymerizing or generating radicals upon irradiation with light. A method for producing a liquid crystal aligning film, comprising a step of applying the liquid crystal aligning agent according to any one of claims 1 to 11 onto a substrate surface by flexographic printing or an inkjet method, and baking the coated liquid crystal aligning agent. A liquid crystal aligning film obtained from the liquid crystal aligning agent according to any one of claims 1 to 11. A liquid crystal display element comprising the liquid crystal alignment film according to claim 13. A liquid crystal layer is provided between a pair of substrates provided with electrodes, a liquid crystal composition containing a polymerizable compound that is polymerized by at least one of active energy rays and heat is disposed between the pair of substrates, and the electrode The liquid crystal alignment film according to claim 13, which is used for a liquid crystal display element and is manufactured through a step of polymerizing the polymerizable compound while applying a voltage therebetween. A liquid crystal display element comprising the liquid crystal alignment film according to claim 15.