JP2022161796A - Liquid crystal alignment agent, liquid crystal alignment film, manufacturing therefor, and liquid crystal element - Google Patents

Abstract

To provide a liquid crystal element which has a stable pretilt angle and excels in long-term heat resistance.SOLUTION: A liquid crystal alignment agent includes a polymer [P] that is an additional polymer including, at its side chain, a partial structure capable of expressing at least either a radical generation function to generate radicals by light irradiation or a photosensitization function to indicate photosensitization action by light irradiation, or a polymerizable carbon-carbon unsaturated bond, the polymer including at least one of structure units represented by formulas (1) to (4), where X1 to X4 each represent a monovalent group including a partial structure capable of expressing at least either a radical generation function to generate radicals by light irradiation or a photosensitization function to indicate photosensitization action by light irradiation, or a polymerizable carbon-carbon unsaturated bond.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a liquid crystal aligning agent, a liquid crystal aligning film, a method for producing the same, and a liquid crystal element.

As the polymer component of the liquid crystal alignment film, polyimide is generally used because of its high heat resistance. On the other hand, polyimides have low solubility in solvents, so when relatively large hydrophobic groups (such as mesogenic structures) are introduced into the side chains of the polymer, the solubility is insufficient and the applicability may be reduced. be done. Therefore, as a substitute for polyimide, it has been proposed to use an acrylic polymer or a styrene-maleimide polymer as a material for a liquid crystal alignment film (see, for example, Patent Document 1).

WO2018/074547

A liquid crystal alignment film is usually formed on a substrate by applying a liquid crystal alignment agent obtained by dissolving or dispersing a polymer component in a solvent onto a substrate and heating the substrate at a high temperature (for example, 200 to 250°C). For this reason, if the heat resistance of the polymer component is not sufficient, the polymer component will thermally decompose during the heat treatment during film formation, causing poor display, or the components generated by thermal decomposition will become impurities, reducing reliability. It is feared that It is considered that such concern is particularly likely to occur in a region where the thickness of the liquid crystal alignment film is reduced due to coating failure or the like. On the other hand, liquid crystal elements are required to have higher quality, and even when the thickness of the liquid crystal alignment film is thinned due to poor coating at the time of forming the alignment film, etc., the characteristic that shows the desired pretilt angle (hereinafter, " Also referred to as "pretilt angle stability") is required.

In addition, if the components generated by thermal decomposition due to heating at a relatively high temperature remain in the film as impurities, the liquid crystal element will be exposed to a high temperature environment for a long time, resulting in performance deterioration due to the impurities in the film. There is a concern that the heat resistance may be lowered, that is, the long-term heat resistance may be deteriorated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a liquid crystal device having a stable pretilt angle and excellent long-term heat resistance even when the film thickness of the liquid crystal alignment film is reduced due to poor coating or the like. A main object of the present invention is to provide a liquid crystal aligning agent capable of

The present invention employs the following means to solve the above problems.

（式（１）中、Ｒ^１及びＲ^２は、それぞれ独立して、水素原子、ハロゲン原子、炭素数１～１０の１価の炭化水素基、若しくは炭化水素基の任意の水素原子がハロゲン原子に置き換えられてなる炭素数１～１０の１価の基であるか、又は、Ｒ^１及びＲ^２が互いに結合してＲ^１及びＲ^２が結合する炭素原子と共に構成される環構造を表す。Ｘ^１は、光照射によりラジカルを発生するラジカル発生機能及び光照射により増感作用を示す光増感機能のうち少なくともいずれかの機能を発現可能な部分構造を有するか、又は重合性炭素－炭素不飽和結合を有する１価の基である。Ｒ^３は、１価の置換基である。ｍ１は０～４の整数である。ｎ１は０～２の整数である。ｍ１が２以上の場合、複数のＲ^３は互いに同一又は異なる。「＊」は結合手であることを表す。
式（２）中、Ｒ^４及びＲ^５は、それぞれ独立して、水素原子、ハロゲン原子、炭素数１～１０の１価の炭化水素基、若しくは炭化水素基の任意の水素原子がハロゲン原子に置き換えられてなる炭素数１～１０の１価の基であるか、又は、Ｒ^４及びＲ^５が互いに結合してＲ^４及びＲ^５が結合する炭素原子と共に構成される環構造を表す。Ｒ^６は、水素原子又は１価の有機基である。Ｘ^２は、光照射によりラジカルを発生するラジカル発生機能及び光照射により増感作用を示す光増感機能のうち少なくともいずれかの機能を発現可能な部分構造を有するか、又は重合性炭素－炭素不飽和結合を有する１価の基である。Ｒ^７は、１価の置換基である。ｍ２は０～４の整数である。ｎ２は０～２の整数である。ｍ２が２以上の場合、複数のＲ^７は互いに同一又は異なる。「＊」は結合手であることを表す。
式（３）中、Ｒ^８は、水素原子、ハロゲン原子、炭素数１～１０の１価の炭化水素基、若しくは炭化水素基の任意の水素原子がハロゲン原子に置き換えられてなる炭素数１～１０の１価の基である。Ｘ^３は、光照射によりラジカルを発生するラジカル発生機能及び光照射により増感作用を示す光増感機能のうち少なくともいずれかの機能を発現可能な部分構造を有するか、又は重合性炭素－炭素不飽和結合を有する１価の基である。Ｒ^９は、１価の置換基である。ｍ３は０～４の整数である。ｍ３が２以上の場合、複数のＲ^９は互いに同一又は異なる。「＊」は結合手であることを表す。
式（４）中、Ｒ^１０は、水素原子、ハロゲン原子、炭素数１～１０の１価の炭化水素基、若しくは炭化水素基の任意の水素原子がハロゲン原子に置き換えられてなる炭素数１～１０の１価の基である。Ｚ^１は、酸素原子又は－ＮＨ－である。Ｘ^４は、光照射によりラジカルを発生するラジカル発生機能及び光照射により増感作用を示す光増感機能のうち少なくともいずれかの機能を発現可能な部分構造を有するか、又は重合性炭素－炭素不飽和結合を有する１価の基である。「＊」は結合手であることを表す。） <1> A partial structure capable of exhibiting at least one of a radical generating function of generating radicals by light irradiation and a photosensitizing function of exhibiting a sensitizing effect by light irradiation, or a polymerizable carbon- It contains a polymer [P] which is an addition polymer having a carbon unsaturated bond, and the polymer [P] is a structural unit represented by the following formula (1), a structure represented by the following formula (2) A liquid crystal aligning agent having at least one selected from the group consisting of a unit, a structural unit represented by the following formula (3), and a structural unit represented by the following formula (4).

(In formula (1), R ¹ and R ² are each independently a hydrogen atom, a halogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms, or any hydrogen atom of a hydrocarbon group is a halogen atom. is a monovalent group having 1 to 10 carbon atoms substituted with or represents a ring structure composed of R ¹ and R ² bonded together and the carbon atoms to which R ¹ and R ² are bonded. X ¹ has a partial structure capable of exhibiting at least one of a radical generating function of generating radicals by light irradiation and a photosensitizing function of exhibiting a sensitizing effect by light irradiation, or polymerizable carbon-carbon a monovalent group having an unsaturated bond, R ³ is a monovalent substituent, m1 is an integer of 0 to 4, n1 is an integer of 0 to 2, and m1 is 2 or more , a plurality of R ³ are the same or different, and "*" represents a bond.
In formula (2), R ⁴ and R ⁵ are each independently a hydrogen atom, a halogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms, or any hydrogen atom of a hydrocarbon group is a halogen atom. It is a monovalent group having 1 to 10 carbon atoms to be substituted, or represents a ring structure composed of R ⁴ and R ⁵ bonded together and the carbon atom to which R ⁴ and R ⁵ are bonded. ^R6 is a hydrogen atom or a monovalent organic group. X ² has a partial structure capable of exhibiting at least one of a radical generating function of generating radicals by light irradiation and a photosensitizing function of exhibiting a sensitizing effect by light irradiation, or polymerizable carbon-carbon It is a monovalent group having an unsaturated bond. ^R7 is a monovalent substituent. m2 is an integer of 0-4. n2 is an integer of 0-2. When m2 is 2 or more, multiple ^R7s are the same or different. "*" represents a bond.
In formula (3), R ⁸ is a hydrogen atom, a halogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms, or a hydrocarbon group having 1 to 1 carbon atoms in which any hydrogen atom of the hydrocarbon group is replaced with a halogen atom. It is a 10 monovalent group. X ³ has a partial structure capable of exhibiting at least one of a radical generating function of generating radicals by light irradiation and a photosensitizing function of exhibiting a sensitizing effect by light irradiation, or polymerizable carbon-carbon It is a monovalent group having an unsaturated bond. ^R9 is a monovalent substituent. m3 is an integer of 0-4. When m3 is 2 or more, multiple ^R9s are the same or different. "*" represents a bond.
In formula (4), R ¹⁰ is a hydrogen atom, a halogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms, or a hydrocarbon group having 1 to 1 carbon atoms in which any hydrogen atom is replaced with a halogen atom. It is a 10 monovalent group. Z ¹ is an oxygen atom or -NH-. X ⁴ has a partial structure capable of exhibiting at least one of a radical generating function of generating radicals by light irradiation and a photosensitizing function of exhibiting a sensitizing effect by light irradiation, or polymerizable carbon-carbon It is a monovalent group having an unsaturated bond. "*" represents a bond. )

<2> A liquid crystal alignment film formed using the liquid crystal alignment agent of <1> above.
<3> A liquid crystal device comprising the liquid crystal alignment film of <2> above.
<4> A step of applying the liquid crystal aligning agent of the above <1> onto each conductive film in a pair of substrates having a conductive film to form a coating film; A method for manufacturing a liquid crystal element, comprising the steps of: constructing a liquid crystal cell by arranging the coating films so as to face each other across the conductive film; and irradiating the liquid crystal cell with light while a voltage is applied between the conductive films. .

According to the liquid crystal aligning agent of the present invention, it is possible to obtain a liquid crystal element having a stable pretilt angle and excellent long-term heat resistance even when the film thickness of the liquid crystal alignment film is reduced due to poor coating or the like.

Matters relating to aspects of the present disclosure are described in detail below. As used herein, the term "hydrocarbon group" includes a chain hydrocarbon group, an alicyclic hydrocarbon group and an aromatic hydrocarbon group. A "chain hydrocarbon group" means a straight-chain hydrocarbon group or a branched hydrocarbon group that does not contain a cyclic structure and is composed only of a chain structure. However, it may be saturated or unsaturated. The “alicyclic hydrocarbon group” means a hydrocarbon group containing only an alicyclic hydrocarbon structure as a ring structure and not containing an aromatic ring structure. However, it does not have to be composed only of an alicyclic hydrocarbon structure, and includes those having a chain structure in part thereof. An "aromatic hydrocarbon group" means a hydrocarbon group containing an aromatic ring structure as a ring structure. However, it does not have to be composed only of an aromatic ring structure, and may partially contain a chain structure or an alicyclic hydrocarbon structure. The "main chain" of a polymer refers to the longest "stem" portion of the atomic chain of the polymer. A "side chain" of a polymer refers to a portion branched from the "trunk" of the polymer. An "organic group" refers to an atomic group obtained by removing an arbitrary hydrogen atom from a compound containing carbon (ie, an organic compound).

（式（１）中、Ｒ^１及びＲ^２は、それぞれ独立して、水素原子、ハロゲン原子、炭素数１～１０の１価の炭化水素基、若しくは炭化水素基の任意の水素原子がハロゲン原子に置き換えられてなる炭素数１～１０の１価の基であるか、又は、Ｒ^１及びＲ^２が互いに結合してＲ^１及びＲ^２が結合する炭素原子と共に構成される環構造を表す。Ｘ^１は、光照射によりラジカルを発生するラジカル発生機能及び光照射により増感作用を示す光増感機能のうち少なくともいずれかの機能を発現可能な部分構造を有するか、又は重合性炭素－炭素不飽和結合を有する１価の基である。Ｒ^３は、１価の置換基である。ｍ１は０～４の整数である。ｎ１は０～２の整数である。ｍ１が２以上の場合、複数のＲ^３は互いに同一又は異なる。「＊」は結合手であることを表す。
式（２）中、Ｒ^４及びＲ^５は、それぞれ独立して、水素原子、ハロゲン原子、炭素数１～１０の１価の炭化水素基、若しくは炭化水素基の任意の水素原子がハロゲン原子に置き換えられてなる炭素数１～１０の１価の基であるか、又は、Ｒ^４及びＲ^５が互いに結合してＲ^４及びＲ^５が結合する炭素原子と共に構成される環構造を表す。Ｒ^６は、水素原子又は１価の有機基である。Ｘ^２は、光照射によりラジカルを発生するラジカル発生機能及び光照射により増感作用を示す光増感機能のうち少なくともいずれかの機能を発現可能な部分構造を有するか、又は重合性炭素－炭素不飽和結合を有する１価の基である。Ｒ^７は、１価の置換基である。ｍ２は０～４の整数である。ｎ２は０～２の整数である。ｍ２が２以上の場合、複数のＲ^７は互いに同一又は異なる。「＊」は結合手であることを表す。
式（３）中、Ｒ^８は、水素原子、ハロゲン原子、炭素数１～１０の１価の炭化水素基、若しくは炭化水素基の任意の水素原子がハロゲン原子に置き換えられてなる炭素数１～１０の１価の基である。Ｘ^３は、光照射によりラジカルを発生するラジカル発生機能及び光照射により増感作用を示す光増感機能のうち少なくともいずれかの機能を発現可能な部分構造を有するか、又は重合性炭素－炭素不飽和結合を有する１価の基である。Ｒ^９は、１価の置換基である。ｍ３は０～４の整数である。ｍ３が２以上の場合、複数のＲ^９は互いに同一又は異なる。「＊」は結合手であることを表す。
式（４）中、Ｒ^１０は、水素原子、ハロゲン原子、炭素数１～１０の１価の炭化水素基、若しくは炭化水素基の任意の水素原子がハロゲン原子に置き換えられてなる炭素数１～１０の１価の基である。Ｚ^１は、酸素原子又は－ＮＨ－である。Ｘ^４は、光照射によりラジカルを発生するラジカル発生機能及び光照射により増感作用を示す光増感機能のうち少なくともいずれかの機能を発現可能な部分構造を有するか、又は重合性炭素－炭素不飽和結合を有する１価の基である。「＊」は結合手であることを表す。） 《Liquid crystal aligning agent》
The liquid crystal aligning agent of the present disclosure contains the following polymer [P].
Polymer [P]: a partial structure capable of exhibiting at least one of a radical generating function of generating radicals by light irradiation and a photosensitizing function of exhibiting a sensitizing effect by light irradiation in the side chain of the polymer, or polymerization a structural unit represented by the following formula (1), a structural unit represented by the following formula (2), and a structure represented by the following formula (3). and at least one structural unit (hereinafter also referred to as "first structural unit") selected from the group consisting of structural units represented by the following formula (4).

(In formula (1), R ¹ and R ² are each independently a hydrogen atom, a halogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms, or any hydrogen atom of a hydrocarbon group is a halogen atom. is a monovalent group having 1 to 10 carbon atoms substituted with or represents a ring structure composed of R ¹ and R ² bonded together and the carbon atoms to which R ¹ and R ² are bonded. X ¹ has a partial structure capable of exhibiting at least one of a radical generating function of generating radicals by light irradiation and a photosensitizing function of exhibiting a sensitizing effect by light irradiation, or polymerizable carbon-carbon a monovalent group having an unsaturated bond, R ³ is a monovalent substituent, m1 is an integer of 0 to 4, n1 is an integer of 0 to 2, and m1 is 2 or more , a plurality of R ³ are the same or different, and "*" represents a bond.
In formula (2), R ⁴ and R ⁵ are each independently a hydrogen atom, a halogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms, or any hydrogen atom of a hydrocarbon group is a halogen atom. It is a monovalent group having 1 to 10 carbon atoms to be substituted, or represents a ring structure composed of R ⁴ and R ⁵ bonded together and the carbon atom to which R ⁴ and R ⁵ are bonded. ^R6 is a hydrogen atom or a monovalent organic group. X ² has a partial structure capable of exhibiting at least one of a radical generating function of generating radicals by light irradiation and a photosensitizing function of exhibiting a sensitizing effect by light irradiation, or polymerizable carbon-carbon It is a monovalent group having an unsaturated bond. ^R7 is a monovalent substituent. m2 is an integer of 0-4. n2 is an integer of 0-2. When m2 is 2 or more, multiple ^R7s are the same or different. "*" represents a bond.
In formula (3), R ⁸ is a hydrogen atom, a halogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms, or a hydrocarbon group having 1 to 1 carbon atoms in which any hydrogen atom of the hydrocarbon group is replaced with a halogen atom. It is a 10 monovalent group. X ³ has a partial structure capable of exhibiting at least one of a radical generating function of generating radicals by light irradiation and a photosensitizing function of exhibiting a sensitizing effect by light irradiation, or polymerizable carbon-carbon It is a monovalent group having an unsaturated bond. ^R9 is a monovalent substituent. m3 is an integer of 0-4. When m3 is 2 or more, multiple ^R9s are the same or different. "*" represents a bond.
In formula (4), R ¹⁰ is a hydrogen atom, a halogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms, or a hydrocarbon group having 1 to 1 carbon atoms in which any hydrogen atom is replaced with a halogen atom. It is a 10 monovalent group. Z ¹ is an oxygen atom or -NH-. X ⁴ has a partial structure capable of exhibiting at least one of a radical generating function of generating radicals by light irradiation and a photosensitizing function of exhibiting a sensitizing effect by light irradiation, or polymerizable carbon-carbon It is a monovalent group having an unsaturated bond. "*" represents a bond. )

<First structural unit>
In the above formulas (1) to (4), X ¹ , X ² , X ³ and X ⁴ are among the radical generating function of generating radicals by light irradiation and the photosensitizing function of showing sensitization by light irradiation. In the case of a group having a partial structure capable of exhibiting at least one function (hereinafter also referred to as "partial structure A"), the partial structure A is a group having a photoinitiator structure that absorbs light and generates radicals. is preferably Examples of the photoinitiator structure include structures derived from known photoradical generators. Examples of the photoradical generator include radical-generating group-containing compounds such as alkylphenone-based compounds, benzoin-based compounds, ketal-based compounds, acetophenone-based compounds, benzophenone-based compounds, thioxanthone-based compounds, and anthraquinone-based compounds.

（式（ａ－１）中、Ａｒ^１及びＡｒ^２は、Ａｒ^１が２価の芳香環基であり、かつＡｒ^２がアルキル基又は１価の芳香環基であるか、又は、Ａｒ^１とＡｒ^２とが互いに合わせられ、Ａｒ^１及びＡｒ^２が結合するカルボニル基と共に構成される環構造を表す。Ｒ^３１は、単結合又は２価の有機基である。「＊」は結合手であることを表す。）

（式（ａ－２）中、Ａｒ^３は２価の芳香環基である。Ｒ^３２及びＲ^３３は、それぞれ独立して１価の有機基であるか、又はＲ^３２とＲ^３３とが合わせられ、Ｒ^３２及びＲ^３３が結合する炭素原子と共に構成される環構造を表す。Ｒ^３４は、水酸基又は１価の有機基である。Ｒ^３５は、単結合又は２価の有機基である。「＊」は結合手であることを表す。） When X ¹ , X ² , X ³ and X ⁴ are groups having partial structure A, X ¹ , X ² , X ³ and X ⁴ are groups represented by formula (a-1) below, or A group represented by formula (a-2) is preferred.

(In the formula (a- ¹ ), Ar ¹ and Ar ² are a divalent aromatic ring group and Ar ² is an alkyl group or a monovalent aromatic ring group, or Ar ¹ and and Ar ² together represent a ring structure formed with the carbonyl group to which Ar ¹ and Ar ² are bonded, R ³¹ is a single bond or a divalent organic group, and "*" is a bond represents.)

(In formula (a-2), Ar ³ is a divalent aromatic ring group. R ³² and R ³³ are each independently a monovalent organic group, or R ³² and R ³³ are represents a ring structure formed with the carbon atoms to which R ³² and R ³³ are bonded, R ³⁴ is a hydroxyl group or a monovalent organic group, and R ³⁵ is a single bond or a divalent organic group. "*" indicates a bond.)

The divalent aromatic ring group represented by Ar ¹ and Ar ² in the above formula (a-1) and Ar ³ in the above formula (a-2) is a substituted or unsubstituted aromatic ring having 2 It is a group from which one hydrogen atom has been removed. Examples of the aromatic ring include benzene ring, naphthalene ring, anthracene ring and the like, preferably benzene ring. Examples of substituents that the aromatic ring may have include alkyl groups having 1 to 6 carbon atoms, alkoxy groups, fluoroalkyl groups, fluorine atoms, and hydroxyl groups. The ring structure formed by combining Ar ¹ and Ar ² includes two benzene rings of —O—, —S—, a carbonyl group or —NR ³⁶ — (R ³⁶ is a hydrogen atom or a carbon number 1 to 10 hydrocarbon groups (the same shall apply hereinafter).

Examples of monovalent organic groups represented by R ³² to R ³⁴ in formula (a-2) include alkyl groups having 1 to 20 carbon atoms, alkoxy groups having 1 to 20 carbon atoms, benzyl groups, and phenethyl groups. , a phenyloxy group, a phenylalkyloxy group, —NR ³⁹ R ⁴⁰ (wherein R ³⁹ and R ⁴⁰ are each independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms), a nitrogen-containing heterocyclic group etc., and any hydrogen atom of these groups may be substituted. Examples of such substituents include fluorine atoms and hydroxyl groups. Examples of the ring structure formed by combining R ³² and R ³³ include a cycloalkyl group having 4 to 10 carbon atoms.

In R ³¹ in formula (a-1) and R ³⁵ in formula (a-2), the divalent organic group includes, for example, a divalent hydrocarbon group having 1 to 20 carbon atoms, a carbon A group having 2 to 20 carbon atoms in which any methylene group in the hydrogen group is replaced with -O-, -S- or -NR ³⁶ -, any hydrogen atom in the hydrocarbon group is a fluorine atom, an alkoxy group, or a hydroxyl group and groups having 2 to 20 carbon atoms substituted with, and the like. When R ³¹ and R ³⁵ are divalent organic groups, they preferably have 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms.

From the viewpoint of achieving both pretilt angle stability and manufacturing easiness in the liquid crystal alignment film when the film thickness is reduced, preferable examples of R ³¹ and R ³⁵ are represented by the following formula (r-1). groups.
* ¹ -R ³⁸ -Z ² -* (r-1)
(In formula (r-1), R ³⁸ is a divalent organic group. Z ² is —O—, * ² —COO-, * ² —OCO-, * ² —NH—CO—, * ² —CO—NH— or * ² —NH—COO— “* ² ” represents a bond with R ^38. “* ¹ ” represents a bond with Z ¹ . "*" indicates a bond.)

（式中、Ｒ^３１は、単結合又は２価の基である。「＊」は結合手であることを表す。）

（式中、Ｒ^３５は、単結合又は２価の基である。「＊」は結合手であることを表す。） When X ¹ , X ² , X ³ and X ⁴ have the partial structure A, specific examples of X ¹ , X ² , X ³ and X ⁴ are partial structures represented by the above formula (a-1) as a group represented by the following formulas (a-1-1) to (a-1-5); as a group represented by the above formula (a-2), the following formula ( Groups represented by formulas (a-2-1) to (a-2-9) and the like can be respectively exemplified.

(In the formula, R ³¹ is a single bond or a divalent group. "*" represents a bond.)

(In the formula, R ³⁵ is a single bond or a divalent group. "*" represents a bond.)

When X ¹ , X ² , X ³ and X ⁴ are monovalent groups having a polymerizable carbon-carbon unsaturated bond, X ¹ , X ² , X ³ and X ⁴ are represented by the following formula (a -3).
*-R ³⁷ -D ¹ (a-3)
(In formula (a-3), D ¹ is a (meth)acryloyl group, vinyl group, vinylphenyl group or vinyl ether group. R ³⁷ is a single bond or a divalent organic group.)

In R ³⁷ in the above formula (a-3), the divalent organic group includes, for example, a divalent hydrocarbon group having 1 to 20 carbon atoms, any methylene group possessed by the hydrocarbon group is —O—, — a group having 2 to 20 carbon atoms substituted with S— or —NR ³⁶ —, a group having 2 to 20 carbon atoms in which any hydrogen atom of a hydrocarbon group is substituted with a fluorine atom, an alkoxy group, a hydroxyl group, or the like; mentioned. In addition, in this specification, "(meth)acryl" is meant to include "acryl" and "methacryl". "(Meth)acryloyl" is meant to include "acryloyl" and "methacryloyl".

In R ¹ and R ² in the formula (1) and R ⁴ and R ⁵ in the formula (2), the hydrocarbon group having 1 to 10 carbon atoms is a chain or branched hydrocarbon group having 1 to 10 carbon atoms. Examples include an alkyl group, a cycloalkyl group having 4 to 10 carbon atoms, a phenyl group, a methylphenyl group, and the like. Examples of the ring structure formed by bonding R ¹ and R ² or R ³ and R ⁴ together include a cycloalkyl group having 4 to 10 carbon atoms. From the viewpoint of further improving the long-term heat resistance and pretilt angle stability of the liquid crystal element, n1 and n2 are preferably single bonds.

When R ⁶ in the above formula (2) is a monovalent organic group, the monovalent organic group includes, for example, a monovalent hydrocarbon group having 1 to 30 carbon atoms, and at least one of the hydrocarbon groups methylene group is substituted with —O—, —CO—, —COO— or —NR ²⁰ — (where R ²⁰ is a hydrogen atom or a monovalent hydrocarbon group) (hereinafter also referred to as “group α” ), a monovalent hydrocarbon group having 1 to 30 carbon atoms, or a group in which at least one hydrogen atom in the group α is substituted with a fluorine atom or a cyano group.

The monovalent substituents of R ³ in the above formula (1), R ⁷ in the above formula (2), and R ⁹ in the above formula (3) include an alkyl group having 1 to 10 carbon atoms, Examples include 4-10 cycloalkyl groups, phenyl groups, alkoxy groups having 1-10 carbon atoms, halogen atoms, cyano groups and the like. Each of m1 to m3 is preferably 0 to 2, more preferably 0 or 1.
R ⁸ in formula (3) and R ¹⁰ in formula (4) are preferably a hydrogen atom, a fluorine atom, an alkyl group having 1 to 3 carbon atoms, or a fluoroalkyl group having 1 to 3 carbon atoms.

From the viewpoint of further enhancing the long-term heat resistance improvement effect of the liquid crystal element, the first structural unit includes the partial structure represented by the above formula (1), the partial structure represented by the above formula (2), and the above formula ( It is preferably at least one selected from the group consisting of partial structures represented by 3). In addition, the first structural unit is represented by the above formula (a-1) or the above formula (a-2) in that it is possible to obtain a liquid crystal alignment film exhibiting a desired pretilt angle even when a thin film is formed. and more preferably have a group represented by the above formula (a-2).

（式中、Ｘ^５は、上記式（ａ－１－１）～式（ａ－１－５）及び上記式（ａ－２－１）～式（ａ－２－９）のいずれかで表される１価の基である。「＊」は結合手であることを表す。） Specific examples of the first structural unit include structural units represented by the following formulas (U1-1) to (U1-21).

(Wherein, X ⁵ is represented by any of the above formulas (a-1-1) to (a-1-5) and the above formulas (a-2-1) to (a-2-9) is a monovalent group that is bound."*" represents a bond.)

In the polymer [P], the preferred range of the content of the first structural unit differs depending on whether the polymer [P] contains the following second structural unit. When the polymer [P] contains the second structural unit together with the first structural unit, the content of the first structural unit in the polymer [P] is It is preferably 1 mol % or more, more preferably 2 mol % or more, and even more preferably 5 mol % or more. In addition, the content of the first structural unit is preferably 50 mol% or less, more preferably 40 mol% or less, more preferably 30 mol%, relative to the total amount of structural units constituting the polymer [P]. % or less. When the content of the first structural unit is within the above range, the desired pretilt angle can be exhibited even when the thickness of the liquid crystal alignment film is reduced due to poor coating or the like during the formation of the alignment film, and the long-term heat resistance of the liquid crystal element can be obtained. It is suitable in that the improvement effect of can be enhanced.

When the polymer [P] does not contain the second structural unit, the content of the first structural unit in the polymer [P] is 10 mol% or more with respect to the total amount of the structural units constituting the polymer [P]. is preferably 20 mol % or more, and even more preferably 25 mol % or more. Also, the content of the first structural unit is preferably 80 mol % or less, more preferably 70 mol % or less, relative to the total amount of the structural units constituting the polymer [P]. When the polymer [P] does not contain the second structural unit and the content ratio of the first structural unit is within the above range, the desired pretilt angle is exhibited even when the thickness of the liquid crystal alignment film is thin, It is suitable for improving the long-term heat resistance of the liquid crystal element.

<Second structural unit>
The polymer [P] is the following (a) and (b) together with the first structural unit:
(a) a non-photosensitive monovalent group having a total of two or more of at least one of an aromatic ring and an aliphatic ring (hereinafter also referred to as "non-photosensitive group B");
(b) a non-photosensitive monovalent group having an alkyl group, alkoxy group, fluoroalkyl group or fluoroalkoxy group having 5 or more carbon atoms (excluding groups corresponding to (a); hereinafter referred to as "non-photosensitive Also referred to as “base C”),
It is preferable to further include a structural unit having at least one of (hereinafter also referred to as "second structural unit"). By further including the second structural unit in the polymer [P], even when the film thickness of the liquid crystal alignment film is reduced due to poor coating or the like, the desired pretilt angle is exhibited more stably, resulting in a highly reliable liquid crystal device. It is preferable in that it is possible to obtain

The total number of aromatic rings and aliphatic rings that the non-photosensitive group B has is preferably 2 or more, more preferably 2 to 6, from the viewpoint of achieving both liquid crystal orientation and solubility of the polymer [A]. preferable. In addition, when the ring which the non-photosensitive group B has is a condensed ring, the number of single rings constituting the condensed ring represents the total number of aromatic rings and aliphatic rings which the non-photosensitive group B has. For example, a cholestanyl group is a group having four aliphatic rings and corresponds to a non-photosensitive monovalent group having two or more of at least one of an aromatic ring and an aliphatic ring in total.

Preferred specific examples of the non-photosensitive group B include groups represented by the following formula (8). The group represented by the following formula (8) is less likely to be thermally decomposed, and is preferable in that the long-term heat resistance of the liquid crystal element can be increased.
A ¹ -B ¹ -L ¹ -B ² -L ² -* (8)
(In formula (8), A ¹ is a hydrogen atom, a fluorine atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a fluoroalkyl group having 1 to 20 carbon atoms, or a fluoroalkyl group having 1 to 20 carbon atoms, or 1 to 20. B ¹ is a divalent group represented by any one of the following formulas (1-1) to (1-8), L ¹ is a single bond or , or a divalent group represented by any one of the following formulas (2-1) to (2-6), B ² is a single bond or a divalent aromatic ring group, L ² is a divalent group represented by any one of the following formulas (3-1) to (3-9)."*" represents a bond.)

In the above formula (8), when A ¹ is an alkyl group having 1 to 20 carbon atoms, an alkoxy group, a fluoroalkyl group or a fluoroalkoxy group, it is preferably linear. A ¹ is preferably an alkyl group, an alkoxy group, a fluoroalkyl group or a fluoroalkoxy group having 2 to 20 carbon atoms, and an alkyl group having 3 to 15 carbon atoms, alkoxy more preferably a group, a fluoroalkyl group or a fluoroalkoxy group.

When B2 is a ^divalent aromatic ring group, the aromatic ring group is preferably a substituted or unsubstituted phenylene group or naphthalene group, more preferably a phenylene group. A methyl group, a halogen atom, etc. are mentioned as a substituent which an aromatic ring group has.

（式（ｍ２－１）～式（ｍ２－１６）中、Ａ^１は、上記式（８）と同義である。「＊」は結合手であることを表す。） Specific examples of the group represented by formula (8) include groups represented by formulas (m2-1) to (m2-16) below.

(In formulas (m2-1) to (m2-16), A ¹ has the same definition as in formula (8) above. “*” represents a bond.)

The non-photosensitive group C is a non-photosensitive monovalent group having an alkyl group, alkoxy group, fluoroalkyl group or fluoroalkoxy group having 5 or more carbon atoms. The alkyl group, alkoxy group, fluoroalkyl group and fluoroalkoxy group of the non-photosensitive group C are preferably linear. Specific examples of these alkyl groups include n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, n-dodecyl, n-tetradecyl and n-hexadecyl groups. , n-octadecyl group, n-nonadecyl group and the like. Examples of alkoxy groups include groups in which the above-exemplified alkyl groups and oxygen atoms are bonded. Examples of fluoroalkyl groups include groups in which at least one hydrogen atom in the above-exemplified alkyl groups is substituted with a fluorine atom. Examples of fluoroalkoxy groups include groups in which at least one hydrogen atom in the above-exemplified groups in which an alkyl group and an oxygen atom are bonded is substituted with a fluorine atom.

The non-photosensitive group C may be a monovalent group in which an alkyl group, alkoxy group, fluoroalkyl group or fluoroalkoxy group having 5 or more carbon atoms is bonded to an aromatic ring or an aliphatic ring. The ring possessed by the non-photosensitive group C is preferably a benzene ring or a cyclohexane ring, more preferably a benzene ring. However, the number of rings which the non-photosensitive group C has is one.

The alkyl group, alkoxy group, fluoroalkyl group and fluoroalkoxy group possessed by the non-photosensitive group C preferably have 6 or more carbon atoms in that the pretilt angle stability of the liquid crystal alignment film can be further increased when a thin film is formed. Those having 8 or more carbon atoms are particularly preferred.

（式（５）中、Ｒ^１１及びＲ^１２は、それぞれ独立して、水素原子、ハロゲン原子、炭素数１～１０の１価の炭化水素基、若しくは炭化水素基の任意の水素原子がハロゲン原子に置き換えられてなる炭素数１～１０の１価の基であるか、又は、Ｒ^１１及びＲ^１２が互いに結合してＲ^１１及びＲ^１２が結合する炭素原子と共に構成される環構造を表す。Ｙ^１は、芳香族環及び脂肪族環のうち少なくともいずれかを合計２個以上有する非感光性の１価の基である。Ｒ^１３は、１価の置換基である。ｍ４は０～４の整数である。ｎ３は０～２の整数である。ｍ４が２以上の場合、複数のＲ^１３は互いに同一又は異なる。「＊」は結合手であることを表す。
式（６）中、Ｒ^１４及びＲ^１５は、それぞれ独立して、水素原子、ハロゲン原子、炭素数１～１０の１価の炭化水素基、若しくは炭化水素基の任意の水素原子がハロゲン原子に置き換えられてなる炭素数１～１０の１価の基であるか、又は、Ｒ^１４及びＲ^１５が互いに結合してＲ^１４及びＲ^１５が結合する炭素原子と共に構成される環構造を表す。Ｒ^１６は、水素原子又は１価の有機基である。Ｙ^２は、芳香族環及び脂肪族環のうち少なくともいずれかを合計２個以上有する非感光性の１価の基である。Ｒ^１７は、１価の置換基である。ｍ５は０～４の整数である。ｎ４は０～２の整数である。ｍ５が２以上の場合、複数のＲ^１７は互いに同一又は異なる。「＊」は結合手であることを表す。
式（７）中、Ｒ^１８は、水素原子、ハロゲン原子、炭素数１～１０の１価の炭化水素基、若しくは炭化水素基の任意の水素原子がハロゲン原子に置き換えられてなる炭素数１～１０の１価の基である。Ｙ^３は、芳香族環及び脂肪族環のうち少なくともいずれかを合計２個以上有する非感光性の１価の基である。Ｒ^１９は、１価の置換基である。ｍ６は０～４の整数である。ｍ６が２以上の場合、複数のＲ^１９は互いに同一又は異なる。「＊」は結合手であることを表す。） The second structural unit possessed by the polymer [P] is advantageous in that a desired pretilt angle can be expressed more stably even when the thickness of the liquid crystal alignment film is reduced, and a highly reliable liquid crystal device can be obtained. preferably has a non-photosensitive group B, consisting of a structural unit represented by the following formula (5), a structural unit represented by the following formula (6), and a structural unit represented by the following formula (7) At least one structural unit selected from the group is particularly preferred.

(In the formula (5), R ¹¹ and R ¹² are each independently a hydrogen atom, a halogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms, or any hydrogen atom of the hydrocarbon group is a halogen atom. is a monovalent group having 1 to 10 carbon atoms substituted with or represents a ring structure composed of R ¹¹ and R ¹² bonded to each other and the carbon atoms to which R ¹¹ and R ¹² are bonded. Y ¹ is a non-photosensitive monovalent group having a total of two or more of at least one of an aromatic ring and an aliphatic ring, R ¹³ is a monovalent substituent, m4 is 0 to 4 n3 is an integer of 0 to 2. When m4 is 2 or more, a plurality of R ¹³ are the same or different, and "*" represents a bond.
In formula (6), R ¹⁴ and R ¹⁵ are each independently a hydrogen atom, a halogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms, or any hydrogen atom of a hydrocarbon group is a halogen atom. It is a monovalent group having 1 to 10 carbon atoms to be substituted, or represents a ring structure composed of R ¹⁴ and R ¹⁵ bonded together and the carbon atom to which R ¹⁴ and R ¹⁵ are bonded. ^R16 is a hydrogen atom or a monovalent organic group. Y2 is a non-photosensitive monovalent group having ^two or more of at least one of an aromatic ring and an aliphatic ring in total. R ¹⁷ is a monovalent substituent. m5 is an integer of 0-4. n4 is an integer of 0-2. When m5 is 2 or more, multiple R ¹⁷ are the same or different. "*" represents a bond.
In formula (7), R ¹⁸ is a hydrogen atom, a halogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms, or a hydrocarbon group having 1 to 1 carbon atoms in which any hydrogen atom is replaced with a halogen atom. It is a 10 monovalent group. Y3 is a non ^- photosensitive monovalent group having two or more of at least one of an aromatic ring and an aliphatic ring in total. R ¹⁹ is a monovalent substituent. m6 is an integer of 0-4. When m6 is 2 or more, multiple ^R19s are the same or different. "*" represents a bond. )

Y ¹ in the above formula (5), Y ² in the above formula (6), and Y ³ in the above formula (7) have a total of two or more of at least one of an aromatic ring and an aliphatic ring It is a non-photosensitive monovalent group (non-photosensitive group B). Specific examples and preferred examples of the non-photosensitive group B are the same as those of the non-photosensitive group B possessed by the second structural unit.

The descriptions of R ¹ , R ² , R ³ , n1 and m1 in formula (1) apply to R ¹¹ , R ¹² , R ¹³ , n3 and m4 in formula (5) above.
R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , n4 and m5 in the above formula (6) are the same as R ⁴ , R ⁵ , R ⁶ , R ⁷ , n2 and m2 in the above formula (2) Applies.
The description of R ⁸ , R ⁹ and m3 in the formula (3) applies to R ¹⁸ , R ¹⁹ and m6 in the formula (7) respectively.

As specific examples of the second structural unit, for example, in structural units represented by the above formulas (U1-1) to (U1-17), X ⁵ in the formula is the above formula (m2-1) to the formula (m2-16) in a structural unit that is a group represented by any of the above formulas (U1-1) to (U1-17), in which X ⁵ is the number of carbon atoms Structural units of 5 or more alkyl groups, alkoxy groups, fluoroalkyl groups or fluoroalkoxy groups are included. Preferred specific examples of the second structural unit are the structural units represented by the above formulas (U1-1) to (U1-17), wherein X ⁵ in the formulas is the above formulas (m2-1) to ( It is a structural unit of a group represented by any one of m2-16).

When the polymer [P] contains the second structural unit, the content of the second structural unit is preferably 1 mol% or more with respect to the total amount of the structural units constituting the polymer [P]. It is more preferably mol % or more, and even more preferably 5 mol % or more. Further, when the polymer [P] contains the second structural unit, the content of the second structural unit is preferably 40 mol% or less with respect to the total amount of the structural units constituting the polymer [P]. , is more preferably 35 mol % or less, and even more preferably 30 mol % or less. When the content of the second structural unit is within the above range, it is preferable in that the effect of improving pretilt angle stability and long-term heat resistance can be further improved.

<Third Structural Unit>
Polymer [P] preferably further has a structural unit (hereinafter also referred to as "third structural unit") having at least one selected from the group consisting of a cyclic ether group and a cyclic carbonate group. When the polymer [P] has a third structural unit, the cyclic ether group or cyclic carbonate group in the third structural unit reacts with the carboxy group, hydroxyl group, amino group, etc. of the component contained in the liquid crystal aligning agent. is suitable in that the pretilt angle stability and heat resistance of the liquid crystal alignment film can be improved by The cyclic ether group preferably has 3 to 7 ring members, and more preferably at least one of an oxetanyl group and an oxiranyl group in terms of high reactivity. In the present specification, an oxetanyl group and an oxiranyl group are also collectively referred to as an "epoxy group".

The polymer [P] having the third structural unit is, for example, a non-uniform having at least one of a cyclic ether group and a cyclic carbonate group as a monomer that provides the third structural unit when synthesizing the polymer [P]. It can be obtained by using a saturated monomer (hereinafter also referred to as "third monomer"). Examples of the third monomer include maleimide-based compounds, styrene-based compounds, (meth)acrylic-based compounds, and the like.

Specific examples of the third monomer include compounds having a cyclic ether group such as (3-ethyloxetan-3-yl)methyl (meth)acrylate, N-(4-glycidyloxyphenyl)maleimide, N-glycidyl Maleimide, 3-(glycidyloxymethyl)styrene, 4-(glycidyloxymethyl)styrene, 4-glycidyl-α-methylstyrene, glycidyl (meth)acrylate, glycidyl α-ethylacrylate, α-n-propyl acrylate glycidyl, α-n-butyl glycidyl acrylate, 3,4-epoxybutyl (meth)acrylate, 3,4-epoxybutyl α-ethylacrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, (meth) ) 6,7-epoxyheptyl acrylate, 6,7-epoxyheptyl α-ethyl acrylate, 4-hydroxybutyl glycidyl ether (meth)acrylate, and the like;
(2-oxo-1,3-dioxolan-4-yl)methyl (meth)acrylate, 2-((2-oxo-1,3-dioxolan-4-yl)methoxy)ethyl as compounds having a cyclic carbonate group (meth)acrylates, etc.; In addition, when synthesizing the polymer [P], as the third monomer, one of these may be used alone, or two or more thereof may be used in combination.

When the polymer [P] contains the third structural unit, the content of the third structural unit is preferably 5 mol% or more with respect to the total amount of the structural units constituting the polymer [P]. It is more preferably mol % or more, and even more preferably 20 mol % or more. Further, when the polymer [P] contains the third structural unit, the content of the third structural unit is preferably 80 mol% or less with respect to the total amount of the structural units constituting the polymer [P]. , is more preferably 75 mol % or less, and even more preferably 70 mol % or less. When the content of the third structural unit is within the above range, a crosslinked structure can be appropriately formed between the components, pretilt angle stability can be secured even when the liquid crystal alignment film is thinned, and long-term heat resistance can be achieved. This is preferable in that the effect of improving the properties can be enhanced.

<Fourth Structural Unit>
The polymer [P] is a functional group capable of forming a bond between compounds, and is a structural unit (hereinafter referred to as (also referred to as "fourth structural unit"). Examples of the reactive functional group possessed by the fourth structural unit include a functional group that reacts with at least one of an oxetanyl group and an oxiranyl group by heating (hereinafter also referred to as "functional group D"). When the polymer [P] has the functional group D, it is preferable in that the effect of improving the liquid crystal orientation (especially the pretilt angle stability in a thin film) can be sufficiently obtained.

Examples of the functional group D include a carboxy group, a protected carboxy group, a hydroxyl group, a protected hydroxyl group, an isocyanate group, a protected isocyanate group, an amino group, a protected amino group, an alkoxymethyl group, and the like. The functional group D has good storage stability and high reactivity with the oxetane ring and the oxirane ring upon heating. At least one selected from the group consisting of is preferred.

When the reactive functional group possessed by the fourth structural unit is at least one selected from the group consisting of a carboxy group, a protected carboxy group, an amino group, and a protected amino group, it is included in the liquid crystal aligning agent. A functional group possessed by the component (for example, an oxetanyl group or oxiranyl group possessed by the polymer [P], or an amino group, hydroxyl group, carboxyl group possessed by a polymer different from the polymer [P], etc.) reacts to form a crosslinked structure. is preferable in that the pretilt angle stability and heat resistance of the liquid crystal alignment film can be improved.

（式（４）中、Ｒ^４１、Ｒ^４２及びＲ^４３は、次の（１）又は（２）を満たす。
（１）Ｒ^４１、Ｒ^４２及びＲ^４３は、それぞれ独立して、炭素数１～１０のアルキル基又は炭素数３～２０の１価の脂環式炭化水素基である。
（２）Ｒ^４１及びＲ^４２は、互いに合わせられＲ^４１及びＲ^４２が結合する炭素原子とともに構成される炭素数４～２０の脂環式炭化水素構造又は環状エーテル構造を表す。Ｒ^４３は、炭素数１～１０のアルキル基、炭素数２～１０のアルケニル基又は炭素数６～２０のアリール基である。
「＊」は結合手であることを表す。） The protected carboxyl group is not particularly limited as long as it is released by heat to form a carboxyl group. Preferred specific examples of the protected carboxy group include a structure represented by the following formula (4), a carboxylic acid acetal ester structure, a carboxylic acid ketal ester structure, and the like.

(In formula (4), R ⁴¹ , R ⁴² and R ⁴³ satisfy the following (1) or (2).
(1) R ⁴¹ , R ⁴² and R ⁴³ are each independently an alkyl group having 1 to 10 carbon atoms or a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms.
(2) R ⁴¹ and R ⁴² represent an alicyclic hydrocarbon structure or cyclic ether structure having 4 to 20 carbon atoms combined with the carbon atoms to which R ⁴¹ and R ⁴² are bonded. R ⁴³ is an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms or an aryl group having 6 to 20 carbon atoms.
"*" represents a bond. )

Specific examples of the structure represented by the above formula (4) include a tert-butoxycarbonyl group, 1-cyclopentylethoxycarbonyl group, 1-cyclopentyl-2-methylpropoxycarbonyl group, 1-cyclohexylethoxycarbonyl group, 1-nor Bornylethoxycarbonyl group, 1-phenylethoxycarbonyl group, 1-(1-naphthyl)ethoxycarbonyl group, 1-benzylethoxycarbonyl group, 1-phenethylethoxycarbonyl group and the like can be mentioned.

Specific examples of acetal ester structures of carboxylic acids include, for example, 1-methoxyethoxycarbonyl group, 1-ethoxyethoxycarbonyl group, 1-propoxyethoxycarbonyl group, 1-butoxyethoxycarbonyl group, 1-cyclohexyloxyethoxycarbonyl group, 2-tetrahydropyranyloxycarbonyl group, 1-phenoxyethoxycarbonyl group, 2-tetrahydrofuranyloxycarbonyl group, 2-tetrahydropyranyloxycarbonyl group and the like.

Specific examples of ketal ester structures of carboxylic acids include 1-methyl-1-methoxyethoxycarbonyl group, 1-methyl-1-ethoxyethoxycarbonyl group, 1-methyl-1-propoxyethoxycarbonyl group, 1-methyl-1 -butoxyethoxycarbonyl group, 1-methyl-1-cyclohexyloxyethoxycarbonyl group, 2-(2-methyltetrahydrofuranyl)oxycarbonyl group, 2-(2-methyltetrahydropyranyl)oxycarbonyl group, 1-methoxycyclopentyloxy A carbonyl group, a 1-methoxycyclohexyloxycarbonyl group and the like can be mentioned.

A protected amino group is one that is thermally eliminated to yield an amino group. Specific examples of thermally-leaving groups that are detached by heat include, for example, tert-butoxycarbonyl group, benzyloxycarbonyl group, 1,1-dimethylpropynyloxycarbonyl group, 1,1-dimethyl-2-haloethyloxy carbonyl group, allyloxycarbonyl group, vinyloxycarbonyl group, cyclohexyloxycarbonyl group, methylcyclohexyloxycarbonyl group, 2-(trimethylsilyl)ethoxycarbonyl group, 9-fluorenylmethyloxycarbonyl group, 2,2,2-trichloro ethoxycarbonyl group, phthaloyl group, p-toluenesulfonyl group, 2-nitrobenzenesulfonyl group and the like. Among these, a tert-butoxycarbonyl group and a 9-fluorenylmethyloxycarbonyl group are preferable from the viewpoint of desorption by heating during film formation, and are excellent in desorption property by heat, and in the desorbed structure of the film. A tert-butoxycarbonyl group (Boc group) is particularly preferred in that the residual amount in can be reduced.

When the polymer [P] contains the fourth structural unit, the reactive functional group possessed by the fourth structural unit has high reactivity with the cyclic ether group and the cyclic carbonate group, and good storage stability of the liquid crystal aligning agent. A carboxy group or a protected carboxy group is preferred, and a protected carboxy group is more preferred.

The polymer [P] having the fourth structural unit can be obtained, for example, by performing a polymerization reaction using an unsaturated monomer having a reactive functional group (hereinafter also referred to as "fourth monomer"). can be done. Examples of the fourth monomer include maleimide-based compounds, styrene-based compounds, (meth)acrylic-based compounds, and vinyl-based compounds.

（式（ｍ４－１）～式（ｍ４－１２）中、Ｒ^５０は水素原子又はメチル基である。）
のそれぞれで表される保護カルボニル基含有化合物等を；
ビニル系化合物として、例えばビシクロ［２．２．１］ヘプト－５－エン－２－カルボン酸等を；挙げることができる。なお、重合体［Ｐ］の合成に際し、第４単量体としては１種を単独で使用してもよく、２種以上を組み合わせて使用してもよい。 Specific examples thereof include maleimide compounds such as 3-(2,5-dioxo-3-pyrrolin-1-yl)benzoic acid, 4-(2,5-dioxo-3-pyrrolin-1-yl) Benzoic acid, 4-(2,5-dioxo-3-pyrrolin-1-yl) methyl benzoate, tert-butyl 4-(2,5-dioxopyrrol-1-yl) benzoate and the like;
Examples of styrene compounds include 3-vinylbenzoic acid, 4-vinylbenzoic acid, 4-aminostyrene, 4-(N-tert-butoxycarbonyl)styrene, and the like;
Examples of (meth)acrylic compounds include (meth)acrylic acid, α-ethylacrylic acid, maleic acid, fumaric acid, vinylbenzoic acid, crotonic acid, citraconic acid, mesaconic acid, itaconic acid, 3-maleimidobenzoic acid, 3 -maleimidopropionic acid, 2-aminoethyl (meth)acrylate, the following formulas (m4-1) to (m4-12)

(In formulas (m4-1) to (m4-12), R ⁵⁰ is a hydrogen atom or a methyl group.)
A protected carbonyl group-containing compound represented by each of;
Vinyl compounds include, for example, bicyclo[2.2.1]hept-5-ene-2-carboxylic acid; In synthesizing the polymer [P], as the fourth monomer, one type may be used alone, or two or more types may be used in combination.

When the polymer [P] contains the fourth structural unit, the content of the fourth structural unit is preferably 2 mol% or more with respect to the total amount of the structural units constituting the polymer [P]. It is more preferably mol % or more, and even more preferably 10 mol % or more. Further, when the polymer [P] contains the fourth structural unit, the content of the fourth structural unit is preferably 65 mol% or less with respect to the total amount of the structural units constituting the polymer [P]. , is more preferably 60 mol % or less, and even more preferably 55 mol % or less. When the content of the fourth structural unit is within the above range, a crosslinked structure is appropriately formed between the functional group of the third structural unit or the functional group of a polymer different from the polymer [P]. , the pretilt angle stability and long-term heat resistance of the liquid crystal element can be improved.

<Other structural units>
The polymer [P] may further have structural units different from the first to fourth structural units (hereinafter also referred to as "other structural units"). Examples of monomers that provide other structural units (hereinafter also referred to as "other monomers") include alkyl (meth)acrylates, cycloalkyl (meth)acrylates, benzyl (meth)acrylates, ( (Meth) acrylic compounds such as 2-hydroxyethyl acrylate; aromatic vinyl compounds such as styrene, methylstyrene and divinylbenzene; conjugated dienes such as 1,3-butadiene and 2-methyl-1,3-butadiene compounds; maleimide compounds such as N-methylmaleimide, N-cyclohexylmaleimide and N-phenylmaleimide; Other monomers may be used singly or in combination of two or more.

In the polymer [P], the content ratio of other structural units varies depending on whether the polymer [P] contains the second structural unit. When the polymer [P] contains the second structural unit together with the first structural unit, the ratio of the other structural units in the polymer [P] is 20% with respect to the total amount of the structural units constituting the polymer [P]. It is preferably mol % or less, more preferably 15 mol % or less.

When the polymer [P] does not contain the second structural unit together with the first structural unit, the ratio of other structural units in the polymer [P] is, with respect to the total amount of structural units constituting the polymer [P], It is preferably 40 mol % or less, more preferably 35 mol % or less.

In the polymer [P], the ratio of structural units derived from maleimide compounds (that is, the ratio of structural units derived from maleimide compounds among the first to fourth structural units and other structural units) is It is preferably 20 mol % or more relative to the total amount of structural units constituting [P]. When it is 20 mol % or more, it is preferable in that the effect of improving the pretilt angle stability of the liquid crystal alignment film can be sufficiently obtained while ensuring the solubility of the polymer [P] and the coatability to the substrate. . From the above viewpoint, the ratio of the structural units derived from the maleimide compound is more preferably 25 mol% or more, more preferably 30 mol% or more, relative to the total amount of the structural units constituting the polymer [P]. is more preferred. In addition, from the viewpoint of suppressing a decrease in the liquid crystal orientation and the voltage holding ratio of the liquid crystal element, the ratio of the structural units derived from the maleimide compound is more preferable with respect to the total amount of the structural units constituting the polymer [P]. is 95 mol % or less, more preferably 90 mol % or less.

When introducing a structural unit derived from a styrenic compound into the polymer [P], the ratio of structural units derived from the styrenic compound (that is, the first to fourth structural units and other structural units to the styrenic compound The proportion of structural units derived from) is preferably 1 mol% or more with respect to the total amount of structural units constituting the polymer [P] from the viewpoint of enhancing the effect of improving the heat resistance of the liquid crystal alignment film. It is more preferably 2 mol or more, and even more preferably 5 mol % or more. Further, the ratio of the structural units derived from the styrene compound is preferably 90 mol% or less, more preferably 80 mol% or less, relative to the total amount of the structural units constituting the polymer [P]. . Furthermore, when the polymer [P] is a copolymer of a styrene-based compound and a maleimide-based compound, the styrene-based compound and the maleimide-based compound are alternately copolymerized to form a main chain structure with high heat resistance, This is preferable in that it is possible to further improve long-term heat resistance due to the reduction of unreacted monomers after polymerization and the heat resistance of the main chain. In addition, from the above viewpoint, the ratio of the styrene compound and the maleimide compound constituting the polymer [P] is 0.8 to 1.2 mol of the maleimide compound per 1 mol of the styrene compound. It is preferable to

Ratio of structural units derived from (meth)acrylic compound in polymer [P] (that is, ratio of structural units derived from (meth)acrylic compound among first to fourth structural units and other structural units) is, from the viewpoint of forming a liquid crystal alignment film with high heat resistance and sufficiently ensuring the liquid crystal alignment and electrical properties of the liquid crystal element, relative to the total amount of structural units possessed by the polymer [A], 30 mol% or less. is preferably 25 mol % or less, and even more preferably 20 mol % or less.

<Synthesis of polymer [P]>
Polymer [P] is a polymer obtained by addition polymerization, and the details of its synthesis method are not particularly limited. Polymer [P] can be obtained, for example, by polymerizing (addition polymerization) monomers in an organic solvent in the presence of a polymerization initiator. As the polymerization initiator, a radical polymerization initiator can be preferably used. Specific examples thereof include 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2,4-dimethylvalero nitrile), 2,2′-azobis(4-methoxy-2,4-dimethylvaleronitrile) and other azo compounds. The proportion of the polymerization initiator used is preferably 0.01 to 30 parts by mass with respect to 100 parts by mass of all the monomers used in the reaction. Examples of organic solvents to be used include alcohols, ethers, ketones, amides, esters and hydrocarbon compounds.

In the above polymerization reaction, the reaction temperature is preferably 30° C. to 120° C., and the reaction time is preferably 1 to 36 hours. The amount (a) of the organic solvent used is such that the total amount (b) of the monomers used in the reaction is 0.1 to 60% by mass with respect to the total amount (a+b) of the reaction solution. is preferred. For the reaction solution obtained by dissolving the polymer, known methods such as a method of pouring the reaction solution into a large amount of poor solvent and drying the precipitate obtained under reduced pressure, a method of distilling off the reaction solution under reduced pressure with an evaporator, etc. By applying the isolation method, the polymer [P] contained in the reaction solution may be isolated and used for the preparation of the liquid crystal aligning agent.

The polystyrene equivalent weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) of the polymer [P] is preferably 1,000 to 300,000, more preferably 2,000 to 100,000. is. The molecular weight distribution (Mw/Mn) represented by the ratio of Mw to the polystyrene equivalent number average molecular weight (Mn) measured by GPC is preferably 10 or less, more preferably 8 or less. In addition, only 1 type may be sufficient as the polymer [P] used for preparation of a liquid crystal aligning agent, and 2 or more types may be combined.

A preferable content ratio of the polymer [P] in the liquid crystal aligning agent varies depending on whether the polymer [P] contains the second structural unit. When the polymer [P] contains the second structural unit together with the first structural unit, even if the liquid crystal alignment film becomes thinner than the desired film thickness due to coating failure or the like, the pretilt angle characteristics are improved and the long-term heat resistance is improved. From the viewpoint of obtaining an excellent liquid crystal element, it is preferably 2 parts by mass or more, more preferably 3 parts by mass or more with respect to a total of 100 parts by mass of the solid components (that is, components other than the solvent) in the liquid crystal aligning agent. Yes, more preferably 5 parts by mass or more. Further, the content of the polymer [P] in the liquid crystal aligning agent is preferably 40 parts by mass or less, more preferably 30 parts by mass or less with respect to the total 100 parts by mass of the solid components in the liquid crystal aligning agent. Yes, more preferably 25% by mass or less.

When the polymer [P] does not contain the second structural unit, the content of the polymer [P] is preferably It is 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, and still more preferably 0.1 parts by mass or more. Further, the content of the polymer [P] in the liquid crystal aligning agent is preferably 10 parts by mass or less, more preferably 5 parts by mass or less with respect to the total 100 parts by mass of the solid components in the liquid crystal aligning agent. Yes, more preferably 3% by mass or less.

<Other ingredients>
The liquid crystal aligning agent of the present disclosure may further contain components other than the polymer [P] (hereinafter also referred to as "other components").

(Polymer [Q])
The liquid crystal aligning agent of the present disclosure, for the purpose of further improving the liquid crystal aligning properties and electrical properties of the liquid crystal aligning film formed using the liquid crystal aligning agent, contains a polymer different from the polymer [P] as another component. That is, it may further contain a polymer that does not contain the first structural unit (hereinafter also referred to as "polymer [Q]").

The main skeleton of the polymer [Q] is not particularly limited, but examples include polyamic acid, polyamic acid ester, polyimide, polyorganosiloxane, polyester, polyenamine, polyurea, polyamide, polyamideimide, polybenzoxazole precursor, polybenzoxazole, Cellulose derivatives, polyacetal and the like can be mentioned. Among these, the polymer [Q] is preferably at least one selected from the group consisting of polyamic acids, polyamic acid esters and polyimides. According to the blend system of the polyamic acid or the like and the polymer [P], phase separation between the polymer [P] and the polymer [Q] can easily occur in the liquid crystal alignment film. P] can be easily unevenly distributed in the upper layer. As a result, it is considered that a liquid crystal alignment film exhibiting high pretilt angle stability, which is hardly affected by the difference in film thickness, can be obtained.

Polymer [Q] can be synthesized according to a conventionally known method. For example, polyamic acid can be obtained by reacting tetracarboxylic dianhydride and diamine. In this specification, the term "tetracarboxylic acid derivative" includes tetracarboxylic dianhydrides, tetracarboxylic diesters and tetracarboxylic diester dihalides.

The tetracarboxylic dianhydride used for polymerization is not particularly limited, and various tetracarboxylic dianhydrides can be used. Specific examples thereof include aliphatic tetracarboxylic dianhydrides such as butanetetracarboxylic dianhydride and ethylenediaminetetraacetic dianhydride; 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1, 3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, 5-(2,5-dioxotetrahydrofuran-3-yl)- 3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 5-(2,5-dioxotetrahydrofuran-3-yl)-8-methyl-3a,4,5 ,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-dianhydride cyclopentanetetracarboxylic dianhydride, cyclohexanetetracarboxylic dianhydride and other alicyclic tetracarboxylic dianhydrides; pyromellitic dianhydride, 4,4'-(hexafluoroisopropylidene)diphthalic acid Anhydrides, p-phenylene bis (trimellitic acid monoester anhydride), ethylene glycol bis (anhydro trimellitate), 1,3-propylene glycol bis (anhydro trimellitate) and other aromatic tetracarboxylic acid di anhydride; In addition, tetracarboxylic dianhydrides described in JP-A-2010-97188 can be used. In addition, tetracarboxylic dianhydride may be used individually by 1 type, and may be used in combination of 2 or more type.

（式（５－０）～式（５－４）中、ｎは１～２０の整数である。）

Examples of diamines used in the above polymerization include aliphatic diamines such as ethylenediamine and tetramethylenediamine; alicyclic diamines such as p-cyclohexanediamine and 4,4′-methylenebis(cyclohexylamine);
dodecanoxydiaminobenzene, pentadecanoxydiaminobenzene, hexadecanoxydiaminobenzene, octadecanoxydiaminobenzene, cholestanyloxydiaminobenzene, cholestanyl diaminobenzoate, cholesteryl diaminobenzoate, lanostanyl diaminobenzoate, 3, 6-bis(4-aminobenzoyloxy)cholestane, 3,6-bis(4-aminophenoxy)cholestane, 1,1-bis(4-((aminophenyl)methyl)phenyl)-4-butylcyclohexane, 2, 5-diamino-N,N-diallylaniline, p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylamine, 4-aminophenyl-4'-aminobenzoate, 4,4'-diaminoazobenzene , 3,5-diaminobenzoic acid, 1,5-bis(4-aminophenoxy)pentane, bis[2-(4-aminophenyl)ethyl]hexanedioic acid, bis(4-aminophenyl)amine, N,N -bis(4-aminophenyl)methylamine, N,N'-bis(4-aminophenyl)-benzidine, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-bis(trifluoro methyl)-4,4'-diaminobiphenyl, 4,4'-diaminodiphenyl ether, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 4,4'-(phenylenediisopropylidene)bisaniline, 1,4-bis(4-aminophenoxy)benzene, 4-(4-aminophenoxycarbonyl)-1-(4-aminophenyl)piperidine, 4,4'-[4,4'-propane-1,3- aromatic diamines such as diylbis(piperidine-1,4-diyl)]dianiline and compounds represented by the following formulas (5-0) to (5-10);
Diaminoorganosiloxanes such as 1,3-bis(3-aminopropyl)-tetramethyldisiloxane can be used, and diamines described in JP-A-2010-97188 can be used. As the diamine, a diamine in which any one of the above formulas (m2-1) to (m2-16) is bonded to diaminobenzene can also be used. In addition, diamine may be used individually by 1 type, and may be used in combination of 2 or more type.

(In formulas (5-0) to (5-4), n is an integer of 1 to 20.)

The synthesis reaction of polyamic acid is preferably carried out in an organic solvent. At this time, the reaction temperature is preferably −20° C. to 150° C., and the reaction time is preferably 0.1 to 24 hours. Organic solvents used in the reaction include, for example, aprotic polar solvents, phenolic solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons, hydrocarbons and the like. The amount of the organic solvent used is preferably such that the total amount of the tetracarboxylic dianhydride and the diamine compound is 0.1 to 50% by mass with respect to the total amount of the reaction solution.

When the polymer [Q] is a polyamic acid ester, the polyamic acid ester is obtained by, for example, mixing the polyamic acid obtained above with an esterifying agent (e.g., methanol, ethanol, N,N-dimethylformamide diethyl acetal, etc.). Obtained by a method of reacting, a method of reacting a tetracarboxylic acid diester and a diamine compound in the presence of a suitable dehydration catalyst, a method of reacting a tetracarboxylic acid diester dihalide and a diamine in the presence of a suitable base, etc. can be done.

When the polymer [Q] is a polyimide, the polyimide can be obtained, for example, by dehydrating and ring-closing the polyamic acid obtained above to imidize it. The polyimide preferably has an imidization rate of 20 to 95%, more preferably 30 to 85%, even more preferably 40 to 80 mol%. The imidization rate is expressed as a percentage of the ratio of the number of imide ring structures to the sum of the number of amic acid structures and the number of imide ring structures of the polyimide.

The solution viscosity of the polymer [Q] preferably has a solution viscosity of 10 to 800 mPa s when the solution has a concentration of 10% by mass, and has a solution viscosity of 15 to 500 mPa s. is more preferable. The solution viscosity (mPa s) is E It is a value measured at 25° C. using a type rotational viscometer.

The polystyrene equivalent weight average molecular weight (Mw) of the polymer [Q] measured by GPC is preferably 1,000 to 500,000, more preferably 5,000 to 100,000. The molecular weight distribution (Mw/Mn) represented by the ratio of Mw to the polystyrene-equivalent number average molecular weight (Mn) measured by GPC is preferably 15 or less, more preferably 10 or less. In addition, the polymer [Q] contained in the liquid crystal aligning agent may be used alone or in combination of two or more.

When the polymer [P] does not contain the second structural unit, the liquid crystal aligning agent of the present disclosure, together with the polymer [P] (that is, the polymer containing the first structural unit and not containing the second structural unit), As the polymer [Q], a polymer having a non-photosensitive group of at least one of the above-described non-photosensitive B and non-photosensitive C and not containing the first structural unit (hereinafter referred to as "polymer [Q1] ”) is preferably contained. When the polymer [P] does not contain the second structural unit, by containing the polymer [Q1] together with the polymer [P], the resulting liquid crystal alignment film can exhibit good pretilt angle characteristics.

The non-photosensitivity of the polymer [Q1] is particularly preferably the non-photosensitivity B in that the effect of improving the pretilt angle stability in the thinned liquid crystal alignment film is higher. Specific examples and preferable examples of the non-photosensitive group B and the non-photosensitive group C are the same as described above.

The polymer [Q1] is selected from the group consisting of polyamic acids, polyamic acid esters and polyimides in that it can facilitate phase separation between the polymer [P] and the polymer [Q1] in the liquid crystal alignment film. is preferably at least one. When the polymer [Q1] is at least one selected from the group consisting of polyamic acids, polyamic acid esters and polyimides, the polymer is, for example, a non-photosensitive B or a diamine having a non-photosensitive C (hereinafter referred to as It can be obtained by polymerization using a "vertical alignment diamine").

When the polymer [Q1] is at least one selected from the group consisting of polyamic acids, polyamic acid esters and polyimides, the content of the structural unit derived from the vertically aligned diamine in the polymer [Q1] is It is preferably 5 mol % or more, more preferably 10 mol % or more, and even more preferably 20 mol % or more, relative to the total amount of diamines constituting the coalescence [Q1]. In addition, the content ratio of the structural unit derived from the vertically aligned diamine is preferably 80 mol% or less, more preferably 70 mol% or less, and 60 mol% or less with respect to the total amount of the diamine constituting the polymer [Q1]. is more preferred.

When the polymer [Q] is blended in the liquid crystal aligning agent of the present disclosure, the ratio of the polymer [Q] and the polymer [P] in the liquid crystal aligning agent is such that the polymer [P] contains the second structural unit The preferred range differs depending on the type. When the polymer [P] contains the second structural unit together with the first structural unit, the ratio of the polymer [P] to the content of the polymer [Q] is 1 per 100 parts by mass of the polymer [Q]. It is preferably at least 2 parts by mass, more preferably at least 2 parts by mass, and even more preferably at least 5 parts by mass. The content of the polymer [P] is preferably 40 parts by mass or less, more preferably 30 parts by mass or less, and even more preferably 25 parts by mass or less with respect to 100 parts by mass of the polymer [Q]. By setting the content of the polymer [P] within the above range, a stable pretilt angle can be expressed even when the thickness of the liquid crystal alignment film is thinner than the desired film thickness, and long-term heat resistance of the liquid crystal element can be improved. It is suitable in that it can be made excellent.

When the polymer [P] does not contain the second structural unit together with the first structural unit, the ratio of the polymer [P] to the content of the polymer [Q] (preferably polymer [Q1]) is Q] With respect to 100 parts by mass, 0.05 parts by mass or more is preferable, 0.1 parts by mass or more is more preferable, and 0.2 parts by mass or more is even more preferable. The content of the polymer [P] is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, and even more preferably 10 parts by mass or less with respect to 100 parts by mass of the polymer [Q]. By setting the content of the polymer [P] within the above range, a stable pretilt angle can be expressed even when the thickness of the liquid crystal alignment film is thinner than the desired film thickness, and long-term heat resistance of the liquid crystal element can be improved. It is suitable in that it can be made excellent.

Other components that the liquid crystal aligning agent of the present disclosure may contain include, in addition to the polymer [Q], for example, a compound having one or more epoxy groups in the molecule, and two or more methylols in the molecule. group-containing compounds, functional silane compounds, compounds containing one or more (meth)acryloyl groups in the molecule, antioxidants, metal chelate compounds, curing accelerators, surfactants, fillers, dispersants, light enhancers sensitizers and the like. These mixing ratios can be appropriately selected according to each compound within a range that does not impair the effects of the present disclosure.

(solvent)
The liquid crystal aligning agent is usually prepared as a liquid composition in which the polymer [P] and optionally other components are preferably dispersed or dissolved in a suitable solvent.

Organic solvents to be used include, for example, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 1,2-dimethyl-2-imidazolidinone, γ-butyrolactone, γ-butyrolactam, N,N-dimethyl Formamide, N,N-dimethylacetamide, 4-hydroxy-4-methyl-2-pentanone (diacetone alcohol), ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate , ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether, ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, Diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, diisopentyl ether, ethylene carbonate, propylene carbonate and the like. be able to. These can be used individually or in mixture of 2 or more types.

The solid content concentration in the liquid crystal aligning agent (ratio of the total mass of components other than the solvent of the liquid crystal aligning agent to the total mass of the liquid crystal aligning agent) is appropriately selected in consideration of viscosity, volatility, etc., but is preferably It is in the range of 1 to 10% by mass. That is, the liquid crystal aligning agent is applied to the surface of the substrate as described later, and preferably heated to form a coating film which is a liquid crystal alignment film or a coating film which becomes a liquid crystal alignment film. At this time, when the solid content concentration is 1% by mass or more, the film thickness of the coating film can be sufficiently secured, and it is preferable in that a good liquid crystal alignment film can be easily obtained. In addition, when the solid content concentration is 10% by mass or less, the film thickness of the coating film is not excessively large, and a good liquid crystal alignment film can be obtained, and the viscosity of the liquid crystal alignment agent can be appropriately secured, and the coating property is improved. can be made better.

Preferred embodiments of the liquid crystal aligning agent of the present disclosure include the following embodiments <1> to <4>. However, the aspect of the liquid crystal aligning agent of this indication is not limited to the following.
<1> The polymer [P] contains a polymer containing a first structural unit, a second structural unit and a third structural unit, and optionally further containing other structural units, and the polymer [Q ], the aspect containing a polyamic acid, a polyamic acid ester, or a polyimide.
<2> The polymer [P] contains a polymer containing a first structural unit, a second structural unit, a third structural unit and a fourth structural unit, and optionally further containing other structural units, and , an embodiment containing polyamic acid, polyamic acid ester or polyimide as the polymer [Q].
<3> The polymer [P] contains a polymer containing the first structural unit, the second structural unit and the fourth structural unit, and optionally further containing other structural units, and the polymer [Q ], the aspect containing a polyamic acid, a polyamic acid ester, or a polyimide.
<4> The polymer [P] contains a polymer containing the first structural unit and the fourth structural unit and optionally further contains other structural units, and the polymer [Q1] contains a polyamic acid , polyamic acid ester or polyimide.
<5> The polymer [P] contains a polymer containing a first structural unit, a third structural unit and a fourth structural unit, and optionally further containing other structural units, and the polymer [Q1 ], the aspect containing a polyamic acid, a polyamic acid ester, or a polyimide.
<6> The polymer [P] contains a polymer containing the first structural unit and the third structural unit and optionally further contains other structural units, and the polymer [Q1] contains a polyamic acid , polyamic acid ester or polyimide.

Among the above aspects, <1>, <2>, <4>, and <5> have the effect of expressing a stable pretilt angle even when the thickness of the liquid crystal alignment film is thinner than the desired film thickness. It is preferable in that it is high and the long-term heat resistance of the liquid crystal element can be made excellent.

<<Liquid crystal alignment film and liquid crystal element>>
The liquid crystal alignment film of the present disclosure is formed from the liquid crystal alignment agent prepared as described above. Moreover, the liquid crystal element of this indication is equipped with the liquid crystal aligning film formed using the liquid crystal aligning agent demonstrated above. The operation mode of the liquid crystal in the liquid crystal element is not particularly limited. It can be applied to various modes such as IPS (In-Plane Switching) type, FFS (Fringe Field Switching) type, OCB (Optically Compensated Bend) type, and PSA type (Polymer Sustained Alignment) type. A liquid crystal element can be manufactured, for example, by a method including steps 1 to 3 below. Step 1 uses different substrates depending on the desired mode of operation. Steps 2 and 3 are common to each operation mode.

(Step 1: Formation of coating film)
First, a liquid crystal aligning agent is applied onto a substrate, and preferably the coated surface is heated to form a coating film on the substrate. Examples of substrates that can be used include glass such as float glass and soda glass; and transparent substrates made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, and poly(alicyclic olefin). As the transparent conductive film provided on the substrate surface, an NESA film (registered trademark of PPG, USA) made of tin oxide (SnO ₂ ), an ITO film made of indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ ), or the like is used. be able to. When manufacturing a TN-type, STN-type or VA-type liquid crystal element, two substrates provided with patterned transparent conductive films are used. On the other hand, in the case of manufacturing an IPS-type or FFS-type liquid crystal element, a substrate provided with electrodes made of a transparent conductive film or a metal film patterned in a comb shape and a counter substrate provided with no electrodes are used. Use As the metal film, for example, a film made of metal such as chromium can be used. Application of the liquid crystal aligning agent to the substrate is preferably performed on the electrode forming surface by an offset printing method, a spin coating method, a roll coater method or an inkjet printing method.

After applying the liquid crystal aligning agent, preheating (pre-baking) is preferably carried out for the purpose of preventing dripping of the applied liquid crystal aligning agent. The pre-baking temperature is preferably 30-150°C, more preferably 40-120°C. The prebake time is preferably 0.25 to 10 minutes.

Thereafter, the solvent is further removed and, if necessary, a baking (post-baking) step is performed in order to thermally imidize the amic acid structures present in the polymer. The baking temperature (post-baking temperature) at this time is preferably 280° C. or lower, more preferably 250° C. or lower. In addition, from the viewpoint of suppressing deterioration of liquid crystal orientation and reliability due to the influence of solvent components remaining in the film, the post-baking temperature is preferably 80° C. or higher, more preferably 90° C. or higher. The post-bake time is preferably 5-150 minutes. The thickness of the film thus formed is preferably 0.001 to 1 μm. After apply|coating a liquid crystal aligning agent on a board|substrate, the coating film used as a liquid crystal aligning film or a liquid crystal aligning film is formed by removing an organic solvent.

(Step 2: Orientation treatment)
When manufacturing a TN-type, STN-type, IPS-type, or FFS-type liquid crystal element, the coating film formed in step 1 above is subjected to a treatment (orientation treatment) for imparting liquid crystal orientation ability. As a result, the coating film is provided with the ability to align liquid crystal molecules to form a liquid crystal alignment film. As the alignment treatment, it is preferable to use a rubbing treatment in which the surface of the coating film formed on the substrate is rubbed with cotton or the like, or a photo-alignment treatment in which the coating film is irradiated with light to impart liquid crystal alignment ability. In the case of manufacturing a vertically aligned liquid crystal element, the coating film formed in the above step 1 may be used as a liquid crystal alignment film as it is. good too.

The light irradiation in the photo-alignment treatment is a method of irradiating the coating film after the post-baking process, a method of irradiating the coating film after the pre-baking process and before the post-baking process, at least the pre-baking process and the post-baking process. In any one of them, it can be carried out by a method of irradiating the coating film while the coating film is being heated, or the like. In the photo-alignment treatment, ultraviolet rays and visible rays including light having a wavelength of 150 to 800 nm can be used as the radiation to irradiate the coating film. Ultraviolet rays including light with a wavelength of 200 to 400 nm are preferred. When the radiation is polarized, it may be linearly polarized or partially polarized. Further, when the radiation used is linearly polarized or partially polarized, irradiation may be performed in a direction perpendicular to the substrate surface, may be performed in an oblique direction, or may be performed in combination. When non-polarized radiation is applied, the direction of irradiation is oblique.

Examples of light sources that can be used include low-pressure mercury lamps, high-pressure mercury lamps, deuterium lamps, metal halide lamps, argon resonance lamps, xenon lamps, and excimer lasers. The dose of radiation is preferably 400 to 20,000 J/m ² , more preferably 1,000 to 5,000 J/m ² . The light irradiation to the coating film may be performed while heating the coating film in order to increase the reactivity.

In the production of the liquid crystal alignment film, the organic film that has been subjected to the light irradiation treatment may be further heated. The method may further include a contacting step of contacting the light-irradiated organic film with water, a water-soluble organic solvent, or a mixed solvent of water and a water-soluble organic solvent. Examples of water-soluble organic solvents include methanol, ethanol, 1-propanol, isopropanol, 1-methoxy-2-propanol acetate, butyl cellosolve, ethyl lactate, acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclopentanone. After the contacting step, the organic film may be heat-treated.

(Step 3: Construction of liquid crystal cell)
A liquid crystal cell is manufactured by preparing two substrates on which a liquid crystal alignment film is formed as described above and arranging a liquid crystal between the two substrates facing each other. In order to manufacture a liquid crystal cell, for example, (1) two substrates are arranged facing each other with a gap (spacer) interposed so that the liquid crystal alignment films face each other, and the periphery of the two substrates is sealed using a sealant. A method of sealing the injection hole after injecting liquid crystal into the cell gap partitioned by the substrate surface and the sealing agent, (2) Sealing at a predetermined place on one of the substrates on which the liquid crystal alignment film is formed. After applying the agent and dropping the liquid crystal on several predetermined places on the surface of the liquid crystal alignment film, the other substrate is attached so that the liquid crystal alignment film faces each other and the liquid crystal is spread over the entire surface of the substrate (ODF method ) and the like. The liquid crystal cell thus produced is preferably heated to a temperature at which the liquid crystal used assumes an isotropic phase, and then slowly cooled to room temperature to remove the flow alignment during liquid crystal filling.

As the sealant, for example, an epoxy resin containing a curing agent and aluminum oxide spheres as spacers can be used. A photospacer, a bead spacer, or the like can be used as the spacer.

As the liquid crystal, either positive type or negative type may be used. When negative liquid crystal is used in the IPS type and FFS type liquid crystal elements, it is preferable in that the transmission loss above the electrodes can be reduced and the contrast can be improved. Liquid crystals to be used include nematic liquid crystals and smectic liquid crystals, among which nematic liquid crystals are preferred. Examples of nematic liquid crystals include Schiff base liquid crystals, azoxy liquid crystals, biphenyl liquid crystals, phenylcyclohexane liquid crystals, ester liquid crystals, terphenyl liquid crystals, biphenylcyclohexane liquid crystals, pyrimidine liquid crystals, dioxane liquid crystals, bicyclooctane liquid crystals, A Cuban liquid crystal or the like can be used. Further, these liquid crystals may be used by adding, for example, cholesteric liquid crystals, chiral agents, ferroelectric liquid crystals, and the like.

In the PSA mode, a polymerizable compound (for example, a polyfunctional (meth)acrylate compound, etc.) is filled in the cell gap together with the liquid crystal, and after the liquid crystal cell is constructed, a voltage is applied between the conductive films of the pair of substrates. , a process of irradiating the liquid crystal cell with light is performed. In producing a PSA mode liquid crystal device, the proportion of the polymerizable compound used is 0.01 to 3 parts by weight, preferably 0.1 to 1 part by weight, per 100 parts by weight of liquid crystal in total.

In the manufacturing process of the PSA mode liquid crystal element, it is necessary to irradiate the liquid crystal cell with a relatively large amount of light in order to react the polymerizable compound in the liquid crystal. There is concern that the display quality may be degraded due to decomposition. On the other hand, when the amount of light irradiation to the liquid crystal cell is reduced, unreacted polymerizable compounds remain in the film or liquid crystal. If the unreacted polymer component remains as an impurity in the film or in the liquid crystal, there is a concern that the quality of the liquid crystal element may be deteriorated by exposing the liquid crystal element to a high-temperature environment for a long time. In this respect, by forming a liquid crystal alignment film using the liquid crystal alignment agent of the present disclosure, the polymerizable compound in the liquid crystal can be efficiently reacted with a small amount of light irradiation, and a high liquid crystal alignment regulating force can be expressed. As a result, it is considered that a stable pretilt angle can be obtained even in the thin film region and the long-term heat resistance can be improved.

Subsequently, a polarizing plate is attached to the outer surface of the liquid crystal cell as required. Examples of the polarizing plate include a polarizing plate in which a polarizing film called "H film" in which iodine is absorbed while stretching orientation of polyvinyl alcohol is sandwiched between cellulose acetate protective films, or a polarizing plate composed of the H film itself. A liquid crystal element is thus obtained.

The liquid crystal element of the present disclosure can be effectively applied to various uses, such as watches, portable game machines, word processors, notebook computers, car navigation systems, camcorders, PDAs, digital cameras, mobile phones, smart phones, and various other applications. It can be used for various display devices such as monitors, liquid crystal televisions and information displays, and light control films. Moreover, the liquid crystal element formed using the liquid crystal aligning agent of this indication can also be applied to optical films, such as a retardation film.

The present invention will be described in more detail with reference to examples below, but the present invention is not limited to these examples.

<Measurement method>
In the following examples, the solution viscosity, weight average molecular weight (Mw) and imidization rate of the polymer were measured by the following methods.
[Polymer Solution Viscosity]
The solution viscosity of the polymer was measured at 25°C using an E-type viscometer.
[Polymer weight average molecular weight (Mw)]
Mw was measured under the following conditions by gel permeation chromatography (GPC).
Apparatus: "GPC-101" of Showa Denko K.K.
GPC column: Shimadzu GLC Co., Ltd. "GPC-KF-801", "GPC-KF-802", "GPC-KF-803" and "GPC-KF-804" combined Mobile phase: tetrahydrofuran (THF )
Column temperature: 40°C
Flow rate: 1.0 mL/min Sample concentration: 1.0% by mass
Sample injection volume: 100 μL
Detector: Differential refractometer Standard substance: Monodisperse polystyrene

[Imidation rate of polyimide]
The polyimide solution was poured into pure water, and the resulting precipitate was thoroughly dried under reduced pressure at room temperature, dissolved in deuterated dimethylsulfoxide, and subjected to ¹ H-NMR measurement at room temperature using tetramethylsilane as a reference substance. . From the obtained ¹ H-NMR spectrum, the imidization rate [%] was determined by the following formula (1).
Imidation rate [%]=(1−(β ¹ /(β ² ×α)))×100 (1)
(In formula (1), β ¹ is the peak area derived from protons of the NH group appearing near the chemical shift of 10 ppm, β ² is the peak area derived from other protons, and α is the precursor of the polymer (polyamic acid ) is the number ratio of other protons to one proton of the NH group.)

<Compound abbreviation>
The abbreviations of the compounds used in the examples below are shown below. In the following description, for the sake of convenience, "the compound represented by formula (X)" (where X is a symbol) may be simply referred to as "compound (X)".

[Photoreactive monomer]

[Vertical alignment monomer]

[Cyclic group-containing monomer]

[Reactive functional group-containing monomer]

[Other monomers]

[Tetracarboxylic dianhydride]

[Diamine]

[Additive]

<Synthesis of compound>
1. Synthesis of liquid crystal alignment monomer [Synthesis Example 1-1: Synthesis of compound (M-01)]

3.05 g of 4-(chloromethyl)styrene, 4.93 g of 4-(4-pentylcyclohexyl)phenol, and 5.48 g of potassium carbonate were dissolved in 40 mL of dimethylformamide and reacted at 60° C. for 12 hours. After confirming the disappearance of the raw materials by HPLC, the reaction solution was added dropwise to 400 mL of water, and the resulting solid was collected by filtration. Thereafter, recrystallization was performed with a THF solvent, and the obtained solid was collected by filtration and dried to obtain 5.80 g of compound (M-01).

[Synthesis Example 1-2: Synthesis of compound (M-02)]

2.46 g of 4-(4-pentylcyclohexyl)phenol, 12.5 g of 2-bromoethanol and 16.6 g of potassium carbonate were dissolved in 200 mL of dimethylformamide and reacted at 100° C. for 5 hours. After the reaction, the reaction mixture was poured into 1 L of water, and the resulting solid was collected by filtration and dried to obtain 28.1 g of compound (M-02-1).
Next, 26.1 g of compound (M-02-1) was dissolved in 200 ml of dichloromethane, 10 mL of pyridine was further added, and the solution was ice-cooled to 0°C. 100 mL of dichloromethane in which 17.2 g of tosyl chloride was dissolved was added dropwise thereto, and the mixture was allowed to react overnight at room temperature. After the reaction, liquid separation was performed three times with 200 mL of water, and the solvent was distilled off from the organic layer. The obtained solid was purified by column chromatography to obtain 17.2 g of compound (M-02-2).
13.3 g of the compound (M-02-2), 5.68 g of 4-hydroxyphenylmaleimide and 3.33 g of triethylamine were dissolved in 200 mL of tetrahydrofuran and reacted under reflux for 4 hours. After the reaction, 200 mL of ethyl acetate was added, and the mixture was separated twice with 200 mL of 1N hydrochloric acid and 3 times with 200 mL of water. The organic layer was evaporated under reduced pressure. The obtained solid was dissolved in 150 mL of THF, and 60 mL of ethanol and 50 mL of water were added thereto. The good solvent was slowly distilled off using a rotary evaporator, and the precipitated solid was collected by filtration and dried to obtain 8.58 g of compound (M-02).

[Synthesis Example 1-3: Synthesis of compound (M-03)]

20 mL of thionyl chloride and a catalytic amount of DMF were added to 2.74 g of 4-(4-pentylcyclohexyl)benzoic acid and reacted at 60° C. for 2 hours. After the reaction, thionyl chloride was distilled off under reduced pressure. The obtained solid was dissolved in 20 mL of dehydrated THF to obtain a solution A. On the other hand, 1.90 g of 4-hydroxyphenylmaleimide and 1.20 g of triethylamine were dissolved in 20 mL of dehydrated THF and ice-cooled to 0°C. Solution A was added dropwise thereto and reacted overnight at room temperature. After the reaction, the reaction solution was partitioned twice with 1N hydrochloric acid and three times with water, and the organic layer was distilled off under reduced pressure. Furthermore, the obtained solid was dissolved in 50 mL of THF, and 30 mL of ethanol and 10 mL of water were added thereto. The good solvent was slowly distilled off using a rotary evaporator, and the precipitated solid was collected by filtration and dried to obtain 3.81 g of compound (M-03).

[Synthesis Example 1-4: Synthesis of compound (M-04)]
In Synthesis Example 1-3, 4'-pentyl-[1,1'-bi(cyclohexane)]-4-carboxylic acid was used in place of 4-(4-pentylcyclohexyl)benzoic acid to obtain 4-hydroxyphenylmaleimide. 9.25 g of compound (M-04) was obtained in the same manner as in Synthesis Example 1-3 except that 4-(2-hydroxyethyl)phenylmaleimide was used instead.

[Synthesis Example 1-5: Synthesis of compound (M-05)]
12.1 g of compound (M-05) was obtained in the same manner as in Synthesis Example 1-2, except that 4-hydroxystyrene was used instead of 4-hydroxyphenylmaleimide in Synthesis Example 1-2.

[Synthesis Example 1-6: Synthesis of compound (M-06)]
8.08 g of compound (M-06) was obtained in the same manner as in Synthesis Example 1-1, except that β-cholestanol was used instead of 4-(4-pentylcyclohexyl)phenol in Synthesis Example 1-1. Obtained.

[Synthesis Example 1-7: Synthesis of compound (M-07)]
In Synthesis Example 1-2, 4-(4'-pentyl-[1,1'-bicyclohexan]-4-yl)phenol was used in place of 4-(4-pentylcyclohexyl)phenol to produce 4-hydroxyphenylmaleimide. 5.82 g of compound (M-07) was obtained in the same manner as in Synthesis Example 1-2, except that 4-hydroxy-3-methylphenylmaleimide was used instead of .

[Synthesis Example 1-8: Synthesis of compound (M-08)]
Synthesis Example except that 4-(4'-pentyl-[1,1'-bicyclohexane]-4-yl)phenol was used instead of 4-(4-pentylcyclohexyl)phenol in Synthesis Example 1-1. 7.11 g of compound (M-08) was obtained in the same manner as in 1-1.

[Synthesis Example 1-9: Synthesis of compound (M-09)]

10.0 g of 4-(4-heptylcyclohexyl)phenol, 8.8 g of 1-(4-fluorophenethyl)-1H-pyrrole-2,5-dione, and 5 potassium carbonate were placed in a 500 mL three-necked flask equipped with a stirrer. .6 g and 200 mL of N,N-dimethylformamide were added and stirred at room temperature for 30 minutes. After confirming the dissolution of the raw materials, the reaction was carried out at 80° C. for 12 hours. After the reaction, the reaction solution was poured into 1500 mL of distilled water, and the precipitated solid was collected by filtration. Thereafter, the solid was vacuum dried and recrystallized to obtain 13.7 g of compound (M-09). 1-(4-fluorophenethyl)-1H-pyrrole-2,5-dione was synthesized according to the method described in Molecules, 2016, 21, 1198.

[Synthesis Example 1-10: Synthesis of compound (M-10)]
In Synthesis Example 1-1, 4-(2-(4'-pentyl-[1,1'-bicyclohexane]-4-yl)ethyl)phenol was used in place of 4-(4-pentylcyclohexyl)phenol. 7.56 g of compound (M-10) was obtained in the same manner as in Synthesis Example 1-1, except that 4-(2-(4′-pentyl-[1,1′-bicyclohexane]-4-yl)ethyl)phenol was synthesized according to the method described in JP-A-2013-228672.

[Synthesis Example 1-11: Synthesis of compound (M-11)]
In Synthesis Example 1-3, 4-(4'-(4,4,4-trifluorobutyl)-[1,1'-bicyclohexane]-4- in place of 4-(4-pentylcyclohexyl)benzoic acid yl) 6.49 g of compound (M-11) was obtained in the same manner as in Synthesis Example 1-3 except that benzoic acid was used and 4-hydroxy-3-methylphenylmaleimide was used instead of 4-hydroxyphenylmaleimide. Obtained.

[Synthesis Example 1-12: Synthesis of compound (M-12)]

The same method as in Synthesis Example 1-9, except that 1-fluoro-3-nitrobenzene was used in place of 1-(4-fluorophenethyl)-1H-pyrrole-2,5-dione in Synthesis Example 1-9. 12.1 g of compound (M-12-1) was obtained.
Next, 12.0 g of compound (M-12-1), 1.94 g of 5% palladium on carbon, 60 mL of tetrahydrofuran, and 60 mL of ethanol were added to a 500 mL three-necked flask containing a stirrer, and the mixture was heated to 80°C. After 9.11 g of hydrazine monohydrate was added dropwise thereto, the mixture was heated under reflux for 6 hours. After cooling to room temperature, the filtered solution was reprecipitated with 600 mL of water. The resulting solid was filtered, washed with water, and dried in a vacuum to obtain 9.8 g of compound (M-12-2).
It was taken in a 500 mL three-necked flask containing a stirring bar, 100 mL of tetrahydrofuran was added, and the mixture was placed in an ice bath. A solution of 2.15 g of maleic anhydride and 50 mL of tetrahydrofuran was added dropwise thereto and stirred at room temperature for 3 hours. After that, the precipitated solid was collected by filtration. The obtained solid was vacuum dried to obtain 9.5 g of compound (M-12).

[Synthesis Example 1-13: Synthesis of compound (M-13)]

In Synthesis Example 1-12, using 4'-(4,4,4-trifluorobutyl)-[1,1'-bicyclohexane]-4-ol instead of 4-(4-heptylcyclohexyl)phenol, 11.1 g of compound (M-13-1) was obtained in the same manner as compound (M-12-1) except that 1-fluoro-4-nitrobenzene was used instead of 1-fluoro-3-nitrobenzene. . Then, compound (M-13-2) was prepared in the same manner as for compound (M-12-2) except that compound (M-13-1) was used instead of compound (M-12-1). .5 g was obtained.
3.00 g of monomethyl maleate, 15 g of thionyl chloride, and 0.01 g of N,N-dimethylformamide were added to a 300 mL eggplant flask containing a stirrer, and the mixture was stirred at 60° C. for 2 hours. Thereafter, excess thionyl chloride was removed with a diaphragm pump, and 30 g of tetrahydrofuran was added to obtain solution A. 8.84 g of the compound (M-13-2), 100 g of tetrahydrofuran, and 4.7 g of triethylamine were added to a 500 mL three-necked flask containing a stirrer and placed in an ice bath. Solution A was added dropwise thereto, and the mixture was stirred at room temperature for 8 hours. The reaction solution was reprecipitated with 750 mL of water, and the obtained white solid was vacuum-dried to obtain 9.8 g of compound (M-13).

[Synthesis Example 1-17: Synthesis of compound (M-17)]
Compound (M-17) was prepared in the same manner as in Synthesis Example 1-1, except that 4-(4-pentylcyclohexyl)phenol was replaced with 4-pentylcyclohexanol. 58 g was obtained.

[Synthesis Examples 1-14 to 1-16, 1-18, 1-19: Synthesis of Compounds (M-14 to M-16, M-18, M-19)]
Compounds (M-14 to M-16, M-18, M-19) were synthesized according to the methods described in the following documents.
Compound (M-14): JP-A-2006-178149 Compound (M-15): JP-A-2004-2373 Compound (M-16): JP-A-2004-99446 Compound (M-18): Patent JP 2008-191337 A Compound (M-19): International Publication No. 2006/001096

[Synthesis Example 1-20: Synthesis of compound (E-2)]
In Synthesis Example 1-1, 2-hydroxy-4′-(2-hydroxyethoxy)-2-methylpropiophenone and sodium hydride were used in place of 4-(4-pentylcyclohexyl)phenol and potassium carbonate, respectively. 4.76 g of compound (E-2) was obtained in the same manner as in Synthesis Example 1-1 except that the compound (E-2) was used.

[Synthesis Example 1-21: Synthesis of compound (E-3)]
Synthesis Example 1-2 except that 2-hydroxy-4′-(2-hydroxyethoxy)-2-methylpropiophenone was used instead of the compound (M-02-1) in Synthesis Example 1-2. By the same method, 4.68 g of compound (E-3) was obtained.

[Synthesis Example 1-22: Synthesis of compound (E-4)]

7.93 g of 4-hydroxybenzophenone, 5.0 g of 2-bromoethanol, and 11.06 g of potassium carbonate were dissolved in 80 mL of dimethylformamide and reacted at 100° C. for 10 hours. After confirming the disappearance of the raw materials by HPLC, the reaction solution was added dropwise to 500 mL of water, and the resulting solid was collected by filtration and dried to obtain 9.21 g of intermediate (E-4-1).
Then, 2.42 g of intermediate (E-4-1) was dissolved in 20 mL of dimethylformamide and stirred at 0°C. After that, 0.60 g of sodium hydride (60%, liquid paraffin dispersion) was added and stirred at 0°C for 30 minutes. After that, 1.53 g of 4-(chloromethyl)styrene was added and reacted at 0° C. for 3 hours. After confirming the disappearance of the raw materials by HPLC, the reaction solution was added dropwise to 150 mL of water, and liquid separation and purification were performed with ethyl acetate. The separated organic layer was evaporated under reduced pressure and dried to obtain 3.40 g of compound (E-4).

[Synthesis Example 1-23: Synthesis of compound (E-5)]
Compound (E-5) was prepared in the same manner as in Synthesis Example 1-1, except that 4'-hydroxyacetophenone was used in place of 4-(4-pentylcyclohexyl)phenol in Synthesis Example 1-1. Got 50g.

<Synthesis of polymer>
1. Synthesis of Polymer [P] [Synthesis Example 2-1]
Under nitrogen, in a 100 mL two-necked flask, as polymerization monomers, compound (M-01) 10 mol parts, compound (E-2) 10 mol parts, compound (A-5) 30 mol parts, compound (A-6) 10 mol parts, compound (B-3) 20 mol parts, and compound (B-6) 20 mol parts, 2,2'-azobis (2,4-dimethylvaleronitrile) as a radical polymerization initiator 2 mol parts, and a solvent 50 ml of tetrahydrofuran was added as a solution and polymerized at 70° C. for 6 hours. After reprecipitation in methanol, the precipitate was filtered and vacuum-dried at room temperature for 8 hours to obtain a styrene-maleimide copolymer (referred to as polymer (P-1)). The weight average molecular weight Mw measured in terms of polystyrene by GPC was 92700, and the molecular weight distribution Mw/Mn was 4.78.

[Synthesis Examples 2-2 to 2-10, 2-12 to 2-24: Polymers (P-2) to (P-10), (P-12), (p-13), (P-16) Synthesis of ~ (P-19), (P-20) ~ (P-26)]
Polymerization was carried out in the same manner as in Synthesis Example 2-1 except that the types and amounts of the monomers used in the polymerization were changed as shown in Table 1 to obtain polymers (P-2) to (P-10), (P- 12), (P-16) to (P-19), and (P-20) to (P-26) were obtained, respectively.

[Synthesis Example 2-11: Synthesis of polymer (P-11)]
Polymerization was carried out in the same manner as in Synthesis Example 2-1 except that the types and amounts of the monomers used in the polymerization were changed as shown in Table 1 to obtain a solution containing the polymer (P-11-1). Next, to this polymer solution, 1 mol of a compound represented by the following formula (MO-1) is added with respect to 2-hydroxyethyl methacrylate in the polymer, and reacted at 50° C. for 6 hours to obtain a polymer. A solution containing (P-11) was obtained. After reprecipitation in methanol, the precipitate was filtered and vacuum-dried at room temperature for 8 hours to obtain a polymer (P-11).

[Comparative Synthesis Examples 2-1 to 2-3: Synthesis of Polymers (P-14), (P-15) and (P-27)]
Polymerization was carried out in the same manner as in Synthesis Example 2-1 except that the types and amounts of the monomers used in the polymerization were changed as shown in Table 1 to obtain polymers (P-14), (P-15), (P- 27) were obtained, respectively.

2. Synthesis of Polymer [Q] [Synthesis Example 2-25]
30 mol parts of compound (DA-1), 50 mol parts of compound (DA-8), and 20 mol parts of compound (DA-9) as diamines are dissolved in N-methyl-2-pyrrolidone (NMP), and tetracarboxylic acid 100 mol parts of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride was added as a dianhydride, and reacted at 40° C. for 24 hours to obtain a solution containing 20% by mass of polyamic acid. Next, NMP is added to the resulting polyamic acid solution, pyridine and acetic anhydride are added in 1.80 molar equivalents to the carboxylic acid dianhydride-derived carboxyl groups of the polyamic acid, and the mixture is heated at 80° C. for 4 hours. A dehydration ring closure reaction was carried out. After the dehydration ring-closure reaction, the solvent in the system is replaced with new NMP and further concentrated to obtain a polyimide having an imidization rate of 70% (this is referred to as a polymer (PI-1)) containing 20% by mass. A solution was obtained. A small amount of this solution was taken and NMP was added to obtain a solution with a concentration of 10% by mass.

[Synthesis Examples 2-26, 2-27, 2-29 to 2-36]
Polymerization was carried out in the same manner as in Synthesis Example 2-18 except that the types and amounts of the tetracarboxylic dianhydride and diamine used in the polymerization were changed as shown in Table 2 to obtain a polyimide polymer (PI-2). , (PI-3), (PI-5) to (PI-12) were obtained respectively. In addition, the polymerization is such that the viscosity of the NMP solution with a polymer concentration of 10% by mass is 40 to 60 mPa s, the molar ratio of diamine and tetracarboxylic dianhydride (diamine / tetracarboxylic dianhydride) It was carried out to 0.95-1.00. In Table 2, the numerical value of the acid anhydride represents the ratio (parts by moles) of each compound to 100 parts by moles of the total amount of tetracarboxylic dianhydride used in the synthesis. The numerical value of the diamine represents the ratio (mol parts) of each compound to 100 mol parts of the total amount of diamines used in the synthesis.

[Synthesis Example 2-28]
30 mol parts of compound (DA-1), 50 mol parts of compound (DA-3), and 20 mol parts of compound (DA-8) as diamines are dissolved in N-methyl-2-pyrrolidone (NMP), and tetracarboxylic acid 100 mol parts of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride is added as a dianhydride and reacted at 40° C. for 24 hours to obtain 20 mass of polyamic acid (this is polymer (PI-4)). % was obtained.

<Production and Evaluation of Liquid Crystal Device>
[Example 1: PSA type liquid crystal display device]
(1) Preparation of liquid crystal aligning agent (AL-1) In a solution containing 100 parts by mass of the polymer (PI-1) obtained in Synthesis Example 2-25, the polymer obtained in Synthesis Example 2-1 (P-1 ) 10 parts by mass, and NMP and butyl cellosolve (BC) as solvents were added to prepare a solution having a solvent composition of NMP/BC = 50/50 (mass ratio) and a solid content concentration of 4.0 mass%. A liquid crystal aligning agent (AL-1) was prepared by filtering this solution through a filter having a pore size of 0.2 μm.

(2) Preparation of liquid crystal composition Per 10 g of nematic liquid crystal (MLC-6608, manufactured by Merck Ltd.), 5% by mass of a liquid crystalline compound represented by the following formula (L1-1) and the following formula (L2-1) 0.3 mass % of the photopolymerizable compound represented by was added and mixed to obtain a liquid crystal composition LC1.

(3) Manufacture of PSA-type liquid crystal display element The liquid crystal aligning agent (AL-1) prepared above is applied to the electrode surfaces of two glass substrates each having a conductive film made of ITO electrodes patterned into slits. Apply using a liquid crystal alignment film printer (manufactured by Nissha Printing Co., Ltd.), heat (pre-bake) on a hot plate at 80 ° C. for 2 minutes to remove the solvent, and then heat on a hot plate at 230 ° C. for 30 minutes. Heating (post-baking) was performed to form a coating film having an average film thickness of 100 nm. These coating films were subjected to ultrasonic cleaning in ultrapure water for 1 minute and then dried in a 100° C. clean oven for 10 minutes to obtain a pair (2 sheets) of substrates having liquid crystal alignment films. The electrode pattern used is the same as the electrode pattern in the PSA mode.
Next, an epoxy resin adhesive containing aluminum oxide spheres with a diameter of 5.5 μm was applied to the outer edge of the surface of one of the pair of substrates having the liquid crystal alignment film, and then the substrates were stacked so that the liquid crystal alignment film surfaces faced each other. They were pressed together and the adhesive cured. Then, the liquid crystal composition LC1 prepared above was filled between the pair of substrates through the liquid crystal injection port, and then the liquid crystal injection port was sealed with an acrylic photocurable adhesive to manufacture a liquid crystal cell. After that, an AC voltage of 10 V with a frequency of 60 Hz was applied between the conductive films of the liquid crystal cell, and while the liquid crystal was being driven, an irradiation amount of 100,000 J/m ² was obtained using an ultraviolet irradiation device using a metal halide lamp as a light source. was irradiated with UV light. Note that this irradiation amount is a value measured using a photometer that measures at a wavelength of 365 nm. After that, polarizing plates are attached to both outer surfaces of the substrate so that their polarization directions are orthogonal to each other and form an angle of 45° with the direction of projection of the optical axis of the ultraviolet rays of the liquid crystal alignment film onto the substrate surface. , a PSA-type liquid crystal display device was manufactured.

(4) Evaluation of liquid crystal orientation (normal film thickness)
For the PSA type liquid crystal display element produced in the above (3), the presence or absence of anomalous domains in the change in brightness when a voltage of 5 V was turned on and off (applied and released) was observed with an optical microscope, and the liquid crystal orientation was evaluated. . The evaluation is “excellent (◎)” when there is no abnormal domain or unevenness, “good (○)” when there is no abnormal domain and some unevenness, and “good (△)” when there is some abnormal domain )”, and “bad (×)” when there is an abnormal domain as a whole. As a result, in this example, the liquid crystal orientation was evaluated as "excellent (⊚)".

(5) Evaluation of liquid crystal orientation (thin film)
A PSA type liquid crystal display device was produced in the same manner as in (3) above, except that the average film thickness of the coating film was changed from 100 nm to 30 nm in (3) above. The presence or absence of anomalous domains in the change in brightness when a voltage of 5 V was turned ON/OFF (applied/released) was observed with an optical microscope for the PSA-type liquid crystal display element thus produced, and the four-level evaluation was performed in the same manner as in (4) above. was used to evaluate the liquid crystal orientation. As a result, in this example, the liquid crystal orientation in the thin film was evaluated as "excellent (⊚)".

(6) Evaluation of electrical properties based on voltage holding ratio (VHR) After applying a voltage of 5 V for an application time of 60 microseconds for a span of 167 milliseconds, the voltage of 5 V was applied to the PSA type liquid crystal display element manufactured above, and then 167 seconds after the application was released. The voltage holding ratio after milliseconds was measured. VHR-1 manufactured by Toyo Technica Co., Ltd. was used as a measuring device. At this time, when the voltage holding rate was 98% or more, it was "good (○)", when it was 95% or more and less than 98%, it was "good (△)", and when it was less than 95%, it was "poor (x)". . As a result, in this example, the electrical properties were evaluated as "good (○)".

(7) Evaluation of long-term heat resistance A PSA-type liquid crystal cell was produced in the same manner as in (3) above, except that the polarizing plates were not adhered to both outer sides of the substrate. This PSA-type liquid crystal cell was subjected to the same operation as in (6) above, and the voltage holding ratio was measured. Further, after the obtained liquid crystal cell was stored in a constant temperature bath at 100° C. for 21 days (about 500 hours), the voltage holding ratio was measured again. If the decrease in voltage holding ratio due to storage in a constant temperature bath at 100 ° C. (voltage holding ratio after liquid crystal cell production (%) - voltage holding ratio after storage in a constant temperature bath (%)) is less than 20%, it is evaluated as “good ( ◯)”, 20% or more and less than 40% as “Fair (Δ)”, and 40% or more as “Poor (X)”. As a result, in this example, the evaluation was "good (○)".

[Examples 2 to 35 and Comparative Examples 1 to 5]
Liquid crystal aligning agents (AL-2) to (AL-40) were prepared with the same solvent composition and solid content concentration as in Example 1 except that the formulation composition was changed as shown in Tables 3 and 4. Moreover, using each liquid crystal aligning agent, while manufacturing a PSA-type liquid crystal display element like Example 1, various evaluations were performed. Evaluation results are shown in Tables 3 and 4.

As shown in Table 3, all of the liquid crystal aligning agents of Examples 1 to 18 were evaluated for liquid crystal alignment (normal film thickness, thin film), voltage holding ratio and long-term heat resistance as "◎", "○" or " Δ”, and various characteristics were well-balanced. In particular, in Examples 1 to 14 using a polymer containing a vertically oriented monomer unit having a group represented by the above formula (8) as the polymer [P], the group represented by the above formula (8) As compared with Examples 15 to 18 using a polymer that does not contain a monomer unit having , the evaluation of the liquid crystal orientation of the thin film was excellent or good. This is because by using the polymer [P] having a specific main chain structure having the partial structure A as the polymer component of the liquid crystal aligning agent, the photopolymerizable compound mixed in the liquid crystal layer reacts efficiently, resulting in alignment. This is considered to be due to the fact that the immobilization ability could be enhanced.

Further, as shown in Table 4, for the liquid crystal aligning agents of Examples 19 to 35, the evaluation of liquid crystal alignment (normal film thickness, thin film), voltage holding ratio and long-term heat resistance is all "◎" or "○ ”, and the various characteristics were well balanced. In particular, when a polymer containing a homeotropic alignment monomer unit having two or more ring structures was used as the polymer [Q], excellent results tended to be obtained in the evaluation of the liquid crystal orientation of the thin film.

On the other hand, the liquid crystal aligning agents of Comparative Examples 1 to 3, which do not contain the polymer [P] of the present disclosure, show good liquid crystal alignment with a normal film thickness (0.1 μm), but the thickness of the liquid crystal alignment film If the thickness is too thin, the orientation of the liquid crystal cannot be sufficiently controlled, and the evaluation of the orientation of the liquid crystal of the thin film is unsatisfactory. Further, the liquid crystal aligning agent of Comparative Example 4 was a poor result in the evaluation of the liquid crystal alignment of the thin film, and the liquid crystal aligning agent of Comparative Example 5 was a poor result in the evaluation of the liquid crystal alignment of both the normal film thickness and the thin film. was the result.

Claims (13)

A partial structure capable of exhibiting at least one of a radical generating function of generating radicals by light irradiation and a photosensitizing function of exhibiting a sensitizing effect by light irradiation, or a polymerizable carbon-carbon unsaturated structure in the side chain of the polymer. Containing a polymer [P] that is an addition polymer having a bond,
The polymer [P] includes a structural unit represented by the following formula (1), a structural unit represented by the following formula (2), a structural unit represented by the following formula (3), and a structural unit represented by the following formula (4) Liquid crystal aligning agent having at least one selected from the group consisting of structural units represented by.

(In formula (1), R ¹ and R ² are each independently a hydrogen atom, a halogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms, or any hydrogen atom of a hydrocarbon group is a halogen atom. is a monovalent group having 1 to 10 carbon atoms substituted with or represents a ring structure composed of R ¹ and R ² bonded together and the carbon atoms to which R ¹ and R ² are bonded. X ¹ has a partial structure capable of exhibiting at least one of a radical generating function of generating radicals by light irradiation and a photosensitizing function of exhibiting a sensitizing effect by light irradiation, or polymerizable carbon-carbon a monovalent group having an unsaturated bond, R ³ is a monovalent substituent, m1 is an integer of 0 to 4, n1 is an integer of 0 to 2, and m1 is 2 or more , a plurality of R ³ are the same or different, and "*" represents a bond.
In formula (2), R ⁴ and R ⁵ are each independently a hydrogen atom, a halogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms, or any hydrogen atom of a hydrocarbon group is a halogen atom. It is a monovalent group having 1 to 10 carbon atoms to be substituted, or represents a ring structure composed of R ⁴ and R ⁵ bonded together and the carbon atom to which R ⁴ and R ⁵ are bonded. ^R6 is a hydrogen atom or a monovalent organic group. X ² has a partial structure capable of exhibiting at least one of a radical generating function of generating radicals by light irradiation and a photosensitizing function of exhibiting a sensitizing effect by light irradiation, or polymerizable carbon-carbon It is a monovalent group having an unsaturated bond. ^R7 is a monovalent substituent. m2 is an integer of 0-4. n2 is an integer of 0-2. When m2 is 2 or more, multiple ^R7s are the same or different. "*" represents a bond.
In formula (3), R ⁸ is a hydrogen atom, a halogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms, or a hydrocarbon group having 1 to 1 carbon atoms in which any hydrogen atom of the hydrocarbon group is replaced with a halogen atom. It is a 10 monovalent group. X ³ has a partial structure capable of exhibiting at least one of a radical generating function of generating radicals by light irradiation and a photosensitizing function of exhibiting a sensitizing effect by light irradiation, or polymerizable carbon-carbon It is a monovalent group having an unsaturated bond. ^R9 is a monovalent substituent. m3 is an integer of 0-4. When m3 is 2 or more, multiple ^R9s are the same or different. "*" represents a bond.
In formula (4), R ¹⁰ is a hydrogen atom, a halogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms, or a hydrocarbon group having 1 to 1 carbon atoms in which any hydrogen atom is replaced with a halogen atom. It is a 10 monovalent group. Z ¹ is an oxygen atom or -NH-. X ⁴ has a partial structure capable of exhibiting at least one of a radical generating function of generating radicals by light irradiation and a photosensitizing function of exhibiting a sensitizing effect by light irradiation, or polymerizable carbon-carbon It is a monovalent group having an unsaturated bond. "*" represents a bond. ) As the polymer [P] or a polymer different from the polymer [P], the following (a) and (b):
(a) a non-photosensitive monovalent group having a total of two or more of at least one of an aromatic ring and an aliphatic ring;
(b) a non-photosensitive monovalent group having an alkyl group, alkoxy group, fluoroalkyl group or fluoroalkoxy group having 5 or more carbon atoms (excluding groups corresponding to (a));
The liquid crystal aligning agent according to claim 1, comprising a polymer having at least one of The liquid crystal aligning agent according to claim 2, wherein the (a) non-photosensitive monovalent group is a group represented by the following formula (8).
A ¹ -B ¹ -L ¹ -B ² -L ² -* (8)
(In formula (8), A ¹ is a hydrogen atom, a fluorine atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a fluoroalkyl group having 1 to 20 carbon atoms, or a fluoroalkyl group having 1 to 20 carbon atoms, or 1 to 20. B ¹ is a divalent group represented by any one of the following formulas (1-1) to (1-8), L ¹ is a single bond or , or a divalent group represented by any one of the following formulas (2-1) to (2-6), B ² is a single bond or a divalent aromatic ring group, L ² is a divalent group represented by any one of the following formulas (3-1) to (3-9)."*" represents a bond.)

The polymer [P] is the (a) polymer having a non-photosensitive monovalent group, and is a structural unit represented by the following formula (5) or a structural unit represented by the following formula (6). , and the liquid crystal aligning agent according to claim 2 or 3, comprising at least one selected from the group consisting of structural units represented by the following formula (7).

(In the formula (5), R ¹¹ and R ¹² are each independently a hydrogen atom, a halogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms, or any hydrogen atom of the hydrocarbon group is a halogen atom. is a monovalent group having 1 to 10 carbon atoms substituted with or represents a ring structure composed of R ¹¹ and R ¹² bonded to each other and the carbon atoms to which R ¹¹ and R ¹² are bonded. Y ¹ is a non-photosensitive monovalent group having a total of two or more of at least one of an aromatic ring and an aliphatic ring, R ¹³ is a monovalent substituent, m4 is 0 to 4 n3 is an integer of 0 to 2. When m4 is 2 or more, a plurality of R ¹³ are the same or different, and "*" represents a bond.
In formula (6), R ¹⁴ and R ¹⁵ are each independently a hydrogen atom, a halogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms, or any hydrogen atom of a hydrocarbon group is a halogen atom. It is a monovalent group having 1 to 10 carbon atoms to be substituted, or represents a ring structure composed of R ¹⁴ and R ¹⁵ bonded together and the carbon atom to which R ¹⁴ and R ¹⁵ are bonded. ^R16 is a hydrogen atom or a monovalent organic group. Y2 is a non-photosensitive monovalent group having ^two or more of at least one of an aromatic ring and an aliphatic ring in total. R ¹⁷ is a monovalent substituent. m5 is an integer of 0-4. n4 is an integer of 0-2. When m5 is 2 or more, multiple R ¹⁷ are the same or different. "*" represents a bond.
In formula (7), R ¹⁸ is a hydrogen atom, a halogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms, or a hydrocarbon group having 1 to 1 carbon atoms in which any hydrogen atom is replaced with a halogen atom. It is a 10 monovalent group. Y3 is a non ^- photosensitive monovalent group having two or more of at least one of an aromatic ring and an aliphatic ring in total. R ¹⁹ is a monovalent substituent. m6 is an integer of 0-4. When m6 is 2 or more, multiple ^R19s are the same or different. "*" represents a bond. ) The liquid crystal aligning agent according to any one of claims 1 to 4, further comprising a polymer [Q] different from the polymer [P]. Further containing a polymer [Q] different from the polymer [P],
4. The liquid crystal according to claim 2, wherein the polymer [Q] has at least one of the (a) non-photosensitive monovalent group and the (b) non-photosensitive monovalent group. Alignment agent. The liquid crystal aligning agent according to claim 5 or 6, wherein the polymer [Q] is at least one selected from the group consisting of polyamic acid, polyamic acid ester and polyimide. The liquid crystal aligning agent according to any one of claims 1 to 7, wherein said X ¹ , X ² , X ³ and X ⁴ are groups having a photoinitiator structure that absorbs light and generates radicals. The liquid crystal aligning agent according to any one of claims 1 to 8, wherein the polymer [P] has at least one selected from the group consisting of cyclic ether groups and cyclic carbonate groups. The polymer [P] according to any one of claims 1 to 9, having at least one selected from the group consisting of a carboxy group, a protected carboxy group, an amino group, and a protected amino group. The liquid crystal aligning agent described. A liquid crystal alignment film formed using the liquid crystal alignment agent according to any one of claims 1 to 10. A liquid crystal device comprising the liquid crystal alignment film according to claim 11 . A step of applying the liquid crystal aligning agent according to any one of claims 1 to 12 on each conductive film in a pair of substrates having a conductive film to form a coating film;
A step of constructing a liquid crystal cell by arranging a pair of substrates on which the coating film is formed so that the coating films face each other with a liquid crystal layer interposed therebetween;
a step of irradiating the liquid crystal cell with a voltage applied between the conductive films;
A method for manufacturing a liquid crystal element, comprising: