JPWO2019202853A1 - Liquid crystal alignment agent, liquid crystal alignment film, liquid crystal element, polymer and compound - Google Patents

Abstract

The liquid crystal aligning agent contains a polymer (P) having at least one selected from the group consisting of the partial structures represented by the formulas (1) to (4). In formula (1), R1 is a monovalent group having a partial structure represented by formula (11). In formula (11), A1 is a divalent aromatic ring group. One of L1 and L2 is a hydroxyl group, a halogen atom, or a monovalent leaving group having 1 or more carbon atoms that is eliminated by heat, and the other is a hydrogen atom.

Description

Cross-reference of related applications

This application is based on Japanese Application No. 2018-80880 filed on April 19, 2018, the contents of which are incorporated herein by reference.

The present disclosure relates to liquid crystal alignment agents, liquid crystal alignment films, liquid crystal devices, polymers and compounds.

Liquid crystal elements are used in various applications such as display devices such as televisions, personal computers, and smartphones. These liquid crystal elements include a liquid crystal alignment film having a function of orienting liquid crystal molecules in a certain direction. The liquid crystal alignment film is generally formed on a substrate by applying a liquid crystal alignment agent in which a polymer component is dissolved in an organic solvent onto the substrate and preferably heating the substrate. As the polymer component of the liquid crystal alignment agent, polyamic acid and soluble polyimide are widely used because they are excellent in mechanical strength, liquid crystal orientation, and affinity with liquid crystal.

As a method for imparting liquid crystal alignment ability to a polymer thin film formed by a liquid crystal alignment agent, a photoalignment method has been proposed as a technique alternative to the rubbing method. The photoalignment method is a method of controlling the orientation of a liquid crystal by irradiating a radiation-sensitive organic thin film formed on a substrate with polarized or unpolarized radiation to give anisotropy to the film. According to this method, as compared with the conventional rubbing method, it is possible to suppress the generation of dust and static electricity in the process, and it is possible to suppress the occurrence of display defects and the decrease in yield. In addition, there is an advantage that the liquid crystal alignment ability can be uniformly imparted to the organic thin film formed on the substrate.

As a liquid crystal alignment agent for forming a liquid crystal alignment film by a photoalignment method, various polymer compositions have been conventionally proposed (see, for example, Patent Document 1 and Patent Document 2). Patent Document 1 discloses that a liquid crystal alignment agent contains a polyamic acid or polyimide having a synnamate structure in a side chain. Further, Patent Document 2 discloses that a liquid crystal aligning agent contains a polyamic acid, a polyamic acid ester, or a polyimide having a β-hydroxy ester structure in a side chain.

International Publication No. 2014/030587 JP-A-2017-105828

If the solubility of the polymer in the solvent is not sufficient and the polymer is not uniformly dissolved in the solvent, uneven coating (uneven film thickness) or pinholes may occur in the liquid crystal alignment film formed on the substrate, or the film surface may be flattened. There are times when it cannot be done. In this case, there is a concern that the product yield may decrease or the display performance such as liquid crystal orientation and electrical characteristics may be affected.

In recent years, in the liquid crystal display field, standards with an increased number of pixels such as 4K (for example, 3840 pixels x 2160 pixels) and 8K (for example, 7680 pixels x 4320 pixels) have been introduced in order to obtain a sense of presence by further improving the display quality. It is made. As the number of pixels in the display device increases and the pixel size decreases, the pixel electrodes have a finer structure, and the surface on which the pixel electrodes are formed has a higher uneven density per unit area. In that case, when the liquid crystal alignment agent is applied to the forming surface of the pixel electrode to form the alignment film, the liquid crystal alignment agent is difficult to wet and spread with respect to the fine uneven structure of the pixel electrode, and sufficient coatability to the substrate is ensured. There is concern that it cannot be done. In order to obtain good coatability even when the liquid crystal alignment agent is applied to a fine uneven structure, it is necessary to develop a new polymer that is more soluble in solvent components than before. is there.

The present disclosure has been made in view of the above circumstances, and one of the purposes thereof is to provide a liquid crystal alignment agent capable of forming a liquid crystal alignment film having excellent surface uniformity and having excellent coatability on uneven surfaces. is there.

According to the present disclosure, the following means are provided.

（式（１）〜式（４）中、Ｒ^１、Ｒ^２、Ｒ^１０及びＲ^１４は、それぞれ独立して、下記式（１１）で表される部分構造を有する１価の基であり、Ｒ^３及びＲ^１１は、それぞれ独立して、水素原子又は炭素数１以上の１価の有機基である。Ｒ^６〜Ｒ^９、Ｒ^１２、Ｒ^１３、Ｒ^１６及びＲ^１７は、それぞれ独立して水素原子又はメチル基である。Ｘ^１０及びＸ^１１のうち一方は単結合であり、他方はメチレン基である。）

（式（１１）中、Ｘ^１は、酸素原子又は−ＮＲ^４−（ただし、Ｒ^４は、水素原子若しくは炭素数１以上の１価の有機基であるか、又は、Ｒ^４が他の基に結合してＲ^４が結合する窒素原子と共に環構造を形成する基である。）である。Ａ^１は２価の芳香環基である。Ｌ^１及びＬ^２のうち一方は、水酸基、ハロゲン原子、又は熱により脱離する炭素数１以上の１価の脱離基であり、他方は水素原子である。）
［２］ 上記［１］の液晶配向剤を用いて形成された液晶配向膜。
［３］ 上記［２］の液晶配向膜を具備する液晶素子。
［４］ 上記式（１）で表される部分構造、上記式（２）で表される部分構造、上記式（３）で表される部分構造及び上記式（４）で表される部分構造よりなる群から選ばれる少なくとも一種を有する重合体。
［５］ 下記式（５）、式（６）、式（７）又は式（８）で表される化合物。

（式（５）〜式（８）中、Ｒ^１、Ｒ^２、Ｒ^１０及びＲ^１４は、上記式（１１）で表される部分構造を有する１価の基であり、Ｒ^３及びＲ^１１は、水素原子又は炭素数１以上の１価の有機基である。Ｒ^６〜Ｒ^９、Ｒ^１２、Ｒ^１３、Ｒ^１６及びＲ^１７は、それぞれ独立して水素原子又はメチル基である。Ｘ^１０及びＸ^１１のうち一方は単結合であり、他方はメチレン基である。）[1] Partial structure represented by the following formula (1), partial structure represented by the following formula (2), partial structure represented by the following formula (3), and partial structure represented by the following formula (4). A liquid crystal alignment agent containing a polymer (P) having at least one selected from the group consisting of.

(In formulas (1) to (4), R ¹ , R ² , R ¹⁰ and R ¹⁴ are monovalent groups having a partial structure represented by the following formula (11) independently. R ³ and R ¹¹ are independent hydrogen atoms or monovalent organic groups having 1 or more carbon atoms. R ^{6 to} R ⁹ , R ¹² , R ¹³ and R ¹⁶ and R ¹⁷ are independent of each other. A hydrogen atom or a methyl group. One of X ¹⁰ and X ¹¹ is a single bond and the other is a methylene group.)

(In the formula (11), ^{X 1} represents an oxygen atom or -NR ⁴ - (provided that, ^{R 4} is a hydrogen atom or a monovalent organic group having 1 or more carbon atoms, or, ^{R 4} is other group It is a group that forms a ring structure together with the nitrogen atom to which R ⁴ is bonded.) A ¹ is a divalent aromatic ring group. One of L ¹ and L ² is a hydroxyl group and a halogen. It is an atom or a monovalent desorbing group having 1 or more carbon atoms that is desorbed by heat, and the other is a hydrogen atom.)
[2] A liquid crystal alignment film formed by using the liquid crystal alignment agent of the above [1].
[3] A liquid crystal element provided with the liquid crystal alignment film of the above [2].
[4] The partial structure represented by the above formula (1), the partial structure represented by the above formula (2), the partial structure represented by the above formula (3), and the partial structure represented by the above formula (4). A polymer having at least one selected from the group consisting of.
[5] A compound represented by the following formula (5), formula (6), formula (7) or formula (8).

(In formulas (5) to (8), R ¹ , R ² , R ¹⁰ and R ¹⁴ are monovalent groups having a partial structure represented by the above formula (11), and R ³ and R ¹¹ Is a hydrogen atom or a monovalent organic group having one or more carbon atoms. R ^{6 to} R ⁹ , R ¹² , R ¹³ , R ¹⁶ and R ¹⁷ are independently hydrogen atoms or methyl groups, respectively. ^{One of 10} and X ¹¹ is a single bond and the other is a methylene group.)

According to the liquid crystal alignment agent containing the polymer (P), a liquid crystal alignment film having excellent surface uniformity can be formed. In addition, the liquid crystal alignment agent has excellent coatability on uneven surfaces, so that a high-quality liquid crystal alignment film can be formed even on a substrate having a pixel electrode having a fine structure.

FIG. 1 is a diagram showing a schematic configuration of an ITO electrode substrate for evaluation. (A) is a plan view, and (b) is a partially enlarged sectional view.

≪Liquid crystal alignment agent≫
The liquid crystal alignment agent of the present disclosure has a partial structure represented by the above formula (1), a partial structure represented by the above formula (2), a partial structure represented by the above formula (3), and the above formula (4). It contains a polymer (P) having at least one partial structure (hereinafter, also referred to as “specific structure”) selected from the group consisting of the partial structures represented by. Hereinafter, the components contained in the liquid crystal aligning agent of the present disclosure and other components optionally blended will be described.

In addition, in this specification, a "hydrocarbon group" means a chain hydrocarbon group, an alicyclic hydrocarbon group and an aromatic hydrocarbon group. The "chain hydrocarbon group" means a linear hydrocarbon group and a branched hydrocarbon group which do not contain a cyclic structure in the main chain and are composed only of a chain structure. However, it may be saturated or unsaturated. The "alicyclic hydrocarbon group" means a hydrocarbon group containing only the alicyclic hydrocarbon structure as the ring structure and not containing the aromatic ring structure. However, it does not have to be composed only of the alicyclic hydrocarbon structure, and some of them have a chain structure. The "aromatic hydrocarbon group" means a hydrocarbon group containing an aromatic ring structure as a ring structure. However, it does not have to be composed of only an aromatic ring structure, and a chain structure or an alicyclic hydrocarbon structure may be included in a part thereof.

<Polymer (P)>
^{R 1} in the formula (1), ^{R 2} in the formula (2), ^{R 14} in the formula (3) ^{R 10} and the formula in (4) in the above formula (11) It is a monovalent group having a partial structure. When X ¹ in the formula (11) is −NR ⁴ −, the monovalent organic group having 1 or more carbon atoms in R ⁴ is preferably an alkyl group having 1 to 3 carbon atoms or a protecting group. Examples of the protecting group include a carbamate-based protecting group, an amide-based protecting group, an imide-based protecting group, a sulfonamide-based protecting group, and the like. Of these, the t-butoxycarbonyl group (BOC group) is particularly preferable because it has high heat desorption and the residual amount of the compound derived from the desorbed protecting group in the membrane can be reduced as much as possible. When R ⁴ is a group that is bonded to another group to form a ring structure together with a nitrogen atom to which R ⁴ is bonded, the ring structure is, for example, 2 from a nitrogen-containing heterocycle such as a piperidine ring or a piperazine ring. Examples include groups from which hydrogen atoms have been removed.
The X ^1, in that it can form a higher liquid crystal alignment film light reactivity, oxygen atom, or -NR 4 ^- R ⁴ is a hydrogen atom, a group is a methyl group or a protecting group is preferably an oxygen atom Is particularly preferred.

In the formula (11), the divalent aromatic ring group of A ¹ is a group obtained by removing two hydrogen atoms from the ring portion of the substituted or unsubstituted aromatic ring. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as a benzene ring, a biphenylene ring, a terphenylene ring, a naphthalene ring, and an anthracene ring; Examples include group heterocycles. When the aromatic ring group of A ¹ has a substituent on the ring portion, examples of the substituent include an alkyl group such as a methyl group and an ethyl group, an alkoxy group such as a methoxy group and an ethoxy group, and the like, which is preferable. Is an alkyl group or an alkoxy group having 1 to 3 carbon atoms.
Among the above, the aromatic ring contained in A ¹ is preferably a substituted or unsubstituted benzene ring or a pyridine ring, more preferably a substituted or unsubstituted benzene ring, and an unsubstituted benzene ring (that is, A ^1). Is a phenylene group).

For L ¹ and L ^2, either one of L ¹ and L ² represents a hydroxyl group, a halogen atom, or a heat by a monovalent leaving group of one or more carbon atoms capable of leaving (hereinafter, simply "heat leaving group The other is a hydrogen atom. In the following, the case where L ¹ is a hydroxyl group, a halogen atom or a thermal leaving group and L ² is a hydrogen atom is “α-form”, L ¹ is a hydrogen atom and L ² is a hydroxyl group. , Halogen atom or thermal leaving group is called "β-form".

When ^one of L ¹ and L ² is a thermal leaving group, the thermal leaving group is preferably "-OR ⁵ (where R ⁵ is a monovalent organic group having 1 or more carbon atoms". ) ”. Specific examples of R ⁵ include an alkyl group having 1 to 20 carbon atoms, -SO ₂ R ²¹ , -COR ²¹ , -Si (R ²¹ ) ₃ , or a monovalent aromatic ring group (where R ²¹ is carbon. It is a monovalent hydrocarbon group of numbers 1 to 20 or a hydrocarbon group substituted with fluorine, and a plurality of R ^21s in the monofunctional group may be the same or different from each other). From the viewpoint of thermal desorption, R ²¹ preferably has 1 to 10 carbon atoms, more preferably 1 to 7 carbon atoms, and is a monovalent hydrocarbon group or fluorinated group having 1 to 6 carbon atoms. It is more preferably a hydrocarbon group, and particularly preferably an alkyl group or a fluoroalkyl group having 1 to 5 carbon atoms.
When R ⁵ is a monovalent aromatic ring group, the aromatic ring group is a group obtained by removing one hydrogen atom from the ring portion of the substituted or unsubstituted aromatic ring. Specific examples of the case where R ⁵ is a monovalent aromatic ring group include, for example, a benzyl group, a p-methoxybenzyl group, a nitrophenyl group, a dinitrophenyl group and the like.

When either ^one of L ¹ and L ² is a halogen atom, specific examples thereof include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, and a fluorine atom or a chlorine atom is preferable.
L ¹ and L ² are desorbed by heating at a lower temperature to form a photoreactive group (cinnamate structure) in the side chain of the polymer (P), and a portion represented by the above formula (11). It is preferably a thermal leaving group or a halogen atom in that it has a higher conversion rate from structure to cinnamate structure. Of these, -OSO ₂ R ²¹ , -OCOR ²¹ , -OSi (R ²¹ ) ₃ , a nitrophenyloxy group, a dinitrophenyloxy group, or a halogen atom is more preferable.
The partial structure of the polymer (P) represented by the above formula (11) may be either an α-form or a β-form, but a maleimide-based monomer having a partial structure represented by the above formula (11) during polymerization, When an itaconimide-based monomer is used, the α-form is preferable because the monomer has better solubility in a solvent and the polymer (P) can have higher solubility in a solvent.

（式（１１−１）中、Ｙ^１は２価の連結基であり、Ｂ^１は、単結合、酸素原子、硫黄原子、炭素数１〜３のアルカンジイル基、−ＣＨ＝ＣＨ−、−ＮＨ−、＊^１−ＣＯＯ−、＊^１−ＯＣＯ−、＊^１−ＮＨ−ＣＯ−、＊^１−ＣＯ−ＮＨ−、＊^１−ＣＨ_２−Ｏ−又は＊^１−Ｏ−ＣＨ_２−（ただし、「＊^１」はＡ^１との結合手を示す。）である。Ａ^３は、フェニレン基、ビフェニレン基、ターフェニレン基若しくはシクロヘキシレン基であるか、又は、フェニレン基、ビフェニレン基、ターフェニレン基若しくはシクロヘキシレン基が有する水素原子の少なくとも一部が、ハロゲン原子、炭素数１〜１０のアルキル基、炭素数１〜１０のアルコキシ基若しくはシアノ基で置換された基である。Ｂ^２は、単結合、酸素原子又は−ＮＲ^２４−（ただし、Ｒ^２４は、水素原子又は炭素数１以上の１価の有機基である。）である。Ｒ^２３は、炭素数１〜２０のアルキル基又はハロゲン化アルキル基である。ａは０〜３の整数である。ただし、ａが０の場合、Ｒ^２３は炭素数４以上である。ａが２又は３の場合、式中の複数のＢ^１、Ａ^３は互いに同じでも異なっていてもよい。Ｘ^１、Ａ^１、Ｌ^１及びＬ^２は、それぞれ上記式（１１）と同義である。「＊^２」は、式（１）、式（２）、式（３）又は式（４）中の窒素原子に結合する結合手であることを示す。）When the liquid crystal aligning agent of the present disclosure is used for manufacturing a vertically oriented liquid crystal element, it is preferable that R ¹ , R ² , R ¹⁰ and R ¹⁴ further have a vertically oriented group. The vertically oriented group is a group capable of vertically orienting a liquid crystal molecule when it is used as a liquid crystal alignment film, and specific examples thereof include an alkyl group having 4 to 20 carbon atoms, a fluoroalkyl group, and an alkoxy. Group or fluoroalkoxy group; a group having a structure in which an alkyl group having 1 to 20 carbon atoms, a fluoroalkyl group, an alkoxy group or a fluoroalkoxy group is bonded to a ring; two or more rings form a direct or divalent linking group. Groups having a structure linked via a group; a group having a steroid skeleton, and the like can be mentioned. Preferred specific examples of R ¹ , R ² , R ¹⁰ and R ¹⁴ include groups represented by the following formula (11-1).

(In formula (11-1), Y ¹ is a divalent linking group, and B ¹ is a single bond, an oxygen atom, a sulfur atom, an alkanediyl group having 1 to 3 carbon atoms, -CH = CH-,-. ^{NH -, * 1 -COO -,} * 1 -OCO -, * 1 -NH-CO -, * 1 -CO-NH -, * 1 -CH 2 -O- or ^* 1 -O-CH ₂ - (provided that , "* ^1" is .A a.) indicating the bond between a ^{1 3,} phenylene group, biphenylene group, or a terphenylene group or cyclohexylene group, or a phenylene group, biphenylene group, terphenylene B ² is a group in which at least a part of the hydrogen atom of the group or cyclohexylene group is substituted with a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a cyano group. It is a single bond, an oxygen atom or −NR ^24- (where R ²⁴ is a hydrogen atom or a monovalent organic group having 1 or more carbon atoms). R ²³ is an alkyl group having 1 to 20 carbon atoms or an alkyl group. a halogenated alkyl group .a is an integer of 0 to 3. However, when a is ^0, when ^{R 23} is 4 or more carbon atoms .a is 2 or 3, a plurality of the formula ^{B 1} , A ³ may be the same as or different from each other. X ¹ , A ¹ , L ¹ and L ² are synonymous with the above equation (11), respectively. “* ² ” is the equation (1) and the equation (1). 2), it indicates that it is a bond that binds to a nitrogen atom in the formula (3) or the formula (4).

In formula (11-1), the divalent linking group of Y ¹ is a divalent hydrocarbon group having 1 to 20 carbon atoms or an oxygen atom, −CO−, between carbon-carbon bonds of the hydrocarbon group. It is preferably a divalent group having −COO− or −NH—CO−. Y ¹ is preferably a divalent aromatic hydrocarbon group in that the liquid crystal orientation and electrical characteristics of the liquid crystal alignment film formed by using the polymer (P) can be sufficiently ensured. It is more preferably a divalent aromatic ring group, and particularly preferably a phenylene group or a biphenylene group.
R ²³ is preferably linear, more preferably an alkyl halide group, and particularly preferably a fluoroalkyl group, in that the liquid crystal orientation can be improved. The carbon number of R ²³ is preferably 2 or more, and more preferably 3 or more.
a is preferably 1 or 2 from the viewpoint of achieving both liquid crystal orientation and coatability.

Examples of the monovalent organic group of R ³ in the formula (2) and R ¹¹ in the formula (3) include a monovalent hydrocarbon group having 1 to 30 carbon atoms and at least one methylene of the hydrocarbon group. Group in which the group is substituted with -O-, -CO-, -COO- or -NR ^16- (where R ¹⁶ is a hydrogen atom or a monovalent hydrocarbon group), 1 of 1 to 30 carbon atoms. Examples thereof include a group in which at least one hydrogen atom of a valent hydrocarbon group is replaced with a halogen atom. Of these, R ³ and R ¹¹ are preferably hydrogen atoms or hydrocarbon groups having 1 to 10 carbon atoms, and hydrogen, in that the polymer (P) has higher solubility in a solvent and liquid crystal orientation. More preferably, it is an atom or an alkyl group having 1 to 5 carbon atoms.

The specific structure of the polymer (P) may have only one of the above formulas (1) to (4), or may have two or more of these. From the viewpoint of obtaining a polymer in which the polymerization reaction easily proceeds and the molecular weight is sufficiently large, the specific structure is preferably at least one selected from the group consisting of the above formulas (1) to (3), and the above formula ( It is more preferable that it is at least one selected from the group consisting of 1) and the formula (2).

(Synthesis of polymer (P))
The method for synthesizing the polymer (P) is not particularly limited. For example, the following methods [1] to [3] can be mentioned.
[1] From the group consisting of the compound represented by the above formula (5), the compound represented by the above formula (6), the compound represented by the above formula (7) and the compound represented by the above formula (8). A method for polymerizing a monomer containing at least one selected compound (hereinafter, also referred to as "specific monomer A").
[2] A precursor Pr1 of the polymer (P) was obtained by polymerizing a monomer containing a maleimide-based compound having no partial structure represented by the above formula (11), and then the obtained precursor was obtained. A method of reacting Pr1 with a reactive compound having a partial structure represented by the above formula (11) to introduce the partial structure represented by the above formula (11) into the side chain of the precursor Pr1.
[3] By polymerizing a monomer containing maleic anhydride, a precursor Pr2 having a partial structure derived from maleic anhydride is obtained, and then the obtained precursor Pr2 and the above formula (11) are used. A method for reacting with an amino group-containing compound having the represented partial structure.
Of these, the method of [1] is preferably used because the efficiency of introducing the partial structure represented by the above formula (11) into the polymer side chain is high.

（式（５−１）〜式（５−１８）、式（７−１）〜式（７−８）、式（８−１）及び式（８−２）中、ｎは１〜２０の整数である。）For the specific monomer A, R ¹ , R ⁶ and R ^{7 in} the formula (5), R ² , R ³ , R ⁸ and R ^{9 in} the formula (6), R ^{10 to} R ¹³ in the formula (7), In addition, the explanations of the above equations (1), (2), (3) and (4) are applied to the explanations of R ¹⁴ , R ¹⁶ and R ^{17 in} the equation (8), respectively. Specific examples of the specific monomer A include compounds represented by the following formulas (5-1) to (5-18), ring-opened compounds of the compounds (that is, "-NH-CO" based on a maleimide group. -CH = CH-COOH "), compounds represented by the following formulas (7-1) to (7-8), and the following formulas (8-1) and (8-2). Examples thereof include compounds represented by each. In the synthesis of the polymer (P), one type of the specific monomer A may be used alone, or two or more types may be used in combination.

(In formulas (5-1) to (5-18), formulas (7-1) to formulas (7-8), formulas (8-1) and formulas (8-2), n is 1 to 20. It is an integer.)

In synthesizing the polymer (P), only the specific monomer A may be used as the polymerization monomer, but a monomer other than the specific monomer A (hereinafter, also referred to as “other monomer B”) may be used in combination. The other monomer B is not particularly limited as long as it is a monomer that can be polymerized with the specific monomer A, but for example, a styrene compound, a (meth) acrylic compound (however, the compound corresponding to the specific monomer A is excluded), and a conjugate. Examples thereof include a diene compound, a maleimide compound having no partial structure represented by the above formula (11), and an itaconimide compound having no partial structure represented by the above formula (11).
In the present specification, the "maleimide-based compound" means a compound having a maleimide ring and a compound having a structure in which the maleimide ring is open. The "itaconimide-based compound" is meant to include a compound having an itaconimide structure and a compound having a ring-opened structure having an itaconimide structure. "(Meta) acrylic" is meant to include "acrylic" and "methacryl". The "(meth) acrylic compound" as a monomer means a compound having only one (meth) acrylic group in one molecule, and is distinguished from a maleimide-based compound and an itaconimide-based compound in the present specification.

The polymer (P) is different from the specific monomer A and the other monomer B in that the coatability (printability) of the liquid crystal aligning agent to the substrate can be improved while ensuring good liquid crystal orientation and electrical characteristics. It is more preferable that the other monomer B is at least one selected from the group consisting of a styrene compound, a (meth) acrylic compound, a maleimide compound and an itaconimide compound. Among these, the polymer (P) is particularly preferably a copolymer of the specific monomer A and at least one selected from the group consisting of a styrene compound and a (meth) acrylic compound.

When synthesizing the polymer (P), the proportion of the specific monomer A used is such that a sufficiently high liquid crystal alignment ability can be imparted to the formed organic film by the photo-alignment method, which is used for the synthesis of the polymer (P). It is preferably 1 to 70 mol%, more preferably 3 to 60 mol%, and further preferably 5 to 60 mol% with respect to the total amount of the monomers used.
Further, in the above polymerization, a maleimide-based compound and an itaconimide-based compound (however, as the other monomer B together with the specific monomer A, a maleimide-based compound and an itaconimide-based compound having no partial structure represented by the above formula (11) are used. When used, the usage ratio of (the total amount thereof) is preferably 1 to 85 mol% with respect to the total amount of the monomers used for the polymerization. If it is less than 1 mol%, it is difficult to sufficiently obtain the effect of improving the solubility in the solvent and the coatability on the substrate, while if it exceeds 85 mol%, the liquid crystal orientation and the voltage holding ratio of the obtained liquid crystal element become low. Tend. The ratio of the maleimide-based compound and the itaconimide-based compound to be used is more preferably 3 to 75 mol%, still more preferably 5 to 65 mol%, based on the total amount of the monomers used for the polymerization.
When at least one of a styrene compound and a (meth) acrylic compound is used as the other monomer B in the polymerization, the usage ratio (the total amount when two or more kinds are used) is the liquid crystal orientation of the liquid crystal element and the liquid crystal orientation. From the viewpoint of ensuring sufficient electrical properties, the content is preferably 15 to 99 mol%, more preferably 25 to 97 mol%, and 35 to 95 mol% with respect to the total amount of the monomers used for the polymerization. It is more preferable to do so.

The liquid crystal alignment agent of the present disclosure forms a liquid crystal alignment film having excellent coatability on uneven surfaces and excellent surface uniformity by using a polymer having a specific structure in a side chain as at least a part of the polymer component. It can be done. The polymer (P) has the above formula (11) in that the solubility of the polymer (P) in a solvent can be sufficiently improved while sufficiently ensuring the liquid crystal orientation and electrical characteristics of the obtained liquid crystal element. It is preferable to have at least one of the following (x1) and (x2) in the side chain together with the partial structure represented by), and it is particularly preferable to have both (x1) and (x2) in the side chain. ..
(X1) At least one functional group of an oxetanyl group and an oxylanyl group (hereinafter, also referred to as "functional group (x1)").
(X2) A functional group that reacts with at least one of an oxetanyl group and an oxylanyl group by heating (hereinafter, also referred to as "functional group (x2)").
In the following, at least one of the oxetanyl group and the oxylanyl group is also simply referred to as an “epoxy group”.

(About functional group (x2))
Examples of the functional group (x2) include a carboxyl group, a hydroxyl group, an isocyanate group and an amino group, a group in which each of these groups is protected by a protective group, an alkoxymethyl group and the like. The functional group (x2) has good storage stability and high reactivity with the oxetane ring and the oxylan ring by heating. Among these, a carboxyl group and a protected carboxyl group (hereinafter, "protected carboxyl") are used. It is preferably at least one selected from the group consisting of a "group"), an amino group, and a protected amino group (hereinafter, also referred to as a "protected amino group"), and is composed of a carboxyl group and a protected carboxyl group. More preferably, it is at least one selected from the group. The amino group here includes a primary amino group, a secondary amino group and a tertiary amino group. When the functional group (x2) is an amino group, it is preferably a primary amino group in that it has a higher effect of improving liquid crystal orientation and electrical characteristics.

（式（１２）中、Ｒ^３１，Ｒ^３２及びＲ^３３は、それぞれ独立に炭素数１〜１０のアルキル基若しくは炭素数３〜２０の１価の脂環式炭化水素基であるか、又は、Ｒ^３１とＲ^３２とが相互に結合してＲ^３１及びＲ^３２が結合している炭素原子とともに炭素数４〜２０の２価の脂環式炭化水素基又は環状エーテル基を形成し、かつＲ^３３が炭素数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示す。）The protective carboxyl group is not particularly limited as long as it is desorbed by heat to generate a carboxyl group. Preferred specific examples of the protected carboxyl group include a structure represented by the following formula (12), an acetal ester structure of a carboxylic acid, a ketal ester structure of a carboxylic acid, and the like.

(In the formula (12), R ³¹ , R ³² and R ³³ are independently alkyl groups having 1 to 10 carbon atoms or monovalent alicyclic hydrocarbon groups having 3 to 20 carbon atoms, respectively, or R ³¹ and R ³² are bonded to each other to form a divalent alicyclic hydrocarbon group or cyclic ether group having 4 to 20 carbon atoms together with the carbon atom to which R ³¹ and R ³² are bonded, and R ³³ 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. "*" Indicates a bond.)

The protected amino group is not particularly limited as long as it is desorbed by heat to form a primary amino group. Examples of the protecting group include a carbamate-based protecting group, an amide-based protecting group, an imide-based protecting group, a sulfonamide-based protecting group, and the like. Of these, the t-butoxycarbonyl group (BOC group) is particularly preferable because it has high heat desorption and the residual amount of the compound derived from the desorbed protecting group in the membrane can be reduced as much as possible.

The method for introducing at least one of the functional group (x1) and the functional group (x2) into the polymer (P) is not particularly limited, but the amount of the functional group (x1) and the functional group (x2) introduced can be easily adjusted. In addition, it is preferable that the other monomer B is introduced into the polymer (P) because the degree of freedom in selecting the monomer is high. The other monomer B used for introducing the functional group (x1) or the functional group (x2) into the polymer (P) is a group consisting of a styrene compound, a (meth) acrylic compound, a maleimide compound and an itaconimide compound. It is preferable that it is at least one selected from, and it is particularly preferable that it is at least one selected from the group consisting of styrene-based compounds and (meth) acrylic-based compounds.

Specific examples of the monomer having a functional group (x1) include, for example, N- (4-glycidyloxyphenyl) maleimide, N-glycidylmaleimide and the like as maleimide compounds.
Examples of the styrene compound include 3- (glycidyloxymethyl) styrene, 4- (glycidyloxymethyl) styrene, 4-glycidyl-α-methylstyrene and the like.
Examples of the (meth) acrylic compound include (meth) glycidyl acrylate, α-ethyl acrylate glycidyl, α-n-propyl acrylate glycidyl, α-n-butyl acrylate glycidyl, and (meth) acrylic acid 3,4-. Epoxybutyl, α-ethylacrylic acid 3,4-epoxybutyl, (meth) acrylic acid 3,4-epoxycyclohexylmethyl, (meth) acrylic acid 6,7-epoxyheptyl, α-ethylacrylic acid 6,7-epoxy Heptyl, 4-hydroxybutylglycidyl ether acrylate, methyl (3-ethyloxetane-3-yl) methyl (meth) acrylate and the like can be mentioned respectively. As the monomer having a functional group (x1), one of these may be used alone, or two or more thereof may be used in combination.

（式（ｍ２−１）〜式（ｍ２−１２）中、Ｒ^１５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；（メタ）アクリルアミド、（メタ）アクリル酸２−（ジメチルアミノ）エチル、（メタ）アクリル酸２−（ジエチルアミノ）エチル、（メタ）アクリル酸２−（ｔ−ブトキシカルボニルアミノ）エチル、（メタ）アクリル酸２−（ｔ−ブトキシカルボニルメチルアミノ）エチル等のアミノ基又は保護アミノ基含有化合物等を、それぞれ挙げることができる。なお、官能基（ｘ２）を有するモノマーとしては、これらの１種を単独で又は２種以上を組み合わせて使用することができる。Specific examples of the monomer having a functional group (x2) include, for example, 3- (2,5-dioxo-3-pyrroline-1-yl) benzoic acid and 4- (2,5-dioxo-3) as maleimide compounds. -Pyrroline-1-yl) benzoic acid, 4- (2,5-dioxo-3-pyroline-1-yl) methyl benzoate, maleimide, etc.
Examples of styrene compounds include 3-vinylbenzoic acid, 4-vinylbenzoic acid, 4-aminostyrene, 3-aminostyrene, 4- (t-butoxycarbonylamino) styrene, and the like.
Examples of the (meth) acrylic compound include (meth) acrylic acid, α-ethylacrylic acid, maleic acid, fumaric acid, vinyl benzoic acid, crotonic acid, citraconic acid, mesaconic acid, itaconic acid, 3-maleimide benzoic acid, 3-. Carboxyl group-containing compounds such as maleimide propionic acid; the following formulas (m2-1) to (m2-12)

(In the formula (m2-1) ~ formula ^{(m2-12), R 15} is hydrogen atom or a methyl group.)
Protected carbonyl group-containing compounds represented by: (meth) acrylamide, 2- (dimethylamino) ethyl (meth) acrylate, 2- (diethylamino) ethyl (meth) acrylate, 2-(meth) acrylate Amino group or protected amino group-containing compounds such as t-butoxycarbonylamino) ethyl and 2- (t-butoxycarbonylmethylamino) ethyl (meth) acrylate can be mentioned, respectively. As the monomer having a functional group (x2), one of these can be used alone or in combination of two or more.

In the synthesis of the polymer (P), the proportion of the monomer having a functional group (x1) is preferably 1 to 70 mol% with respect to the total amount of the monomers used in the synthesis of the polymer (P). It is more preferably 5 to 60 mol%, and even more preferably 10 to 55 mol%. The proportion of the monomer having a functional group (x2) is preferably 1 to 90 mol%, preferably 5 to 80 mol%, based on the total amount of the monomers used for the synthesis of the polymer (P). More preferably, it is more preferably 10 to 70 mol%.

In synthesizing the polymer (P), as the other monomer B, a monomer having neither a functional group (x1) nor a functional group (x2) may be used. Examples of the monomer include (meth) acrylic compounds such as alkyl (meth) acrylate, cycloalkyl (meth) acrylate, benzyl (meth) acrylate, and -2-ethylhexyl (meth) acrylate; styrene and methyl. Aromatic vinyl compounds such as styrene and divinylbenzene; conjugated diene compounds such as 1,3-butadiene, 2-methyl-1,3-butadiene; maleimides such as N-methylmaleimide, N-cyclohexylmaleimide and N-phenylmaleimide Examples include compounds, maleic anhydride and the like. The proportion of the monomer used is preferably 20 mol% or less, more preferably 10 mol% or less, and 3 mol% or less, based on the total amount of the monomers used in the synthesis of the polymer (P). It is more preferable to do so.

The method for synthesizing the polymer (P) is not particularly limited, but for example, it is carried out by radically polymerizing the above-mentioned monomer in an organic solvent in the presence of a polymerization initiator. The polymerization initiator used is 2,2'-azobis (isobutyronitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (4-methoxy-2, An azo compound such as 4-dimethylvaleronitrile) is preferred. 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 the organic solvent used include alcohols, ethers, ketones, amides, esters, hydrocarbon compounds and the like.

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 should be 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 preferable. The reaction solution obtained by dissolving the polymer is known, for example, a method of pouring the reaction solution into a large amount of a poor solvent and drying the precipitate under reduced pressure, a method of distilling off the reaction solution under reduced pressure with an evaporator, and the like. The polymer (P) contained in the reaction solution may be isolated using the separation method and then used for preparation of the liquid crystal alignment agent. The synthesis of the polymer (P) is not limited to the above, and may be carried out by, for example, living radical polymerization using a RAFT reagent.

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 7 or less, more preferably 5 or less. The polymer (P) used for preparing the liquid crystal alignment agent may be only one type or a combination of two or more types.

The content ratio of the polymer (P) in the liquid crystal alignment agent is 0.1% by mass or more with respect to the total amount of the polymer components contained in the liquid crystal alignment agent in that the coatability to the substrate can be sufficiently high. It is preferable, it is more preferably 0.5% by mass or more, and further preferably 1% by mass or more. Further, the content ratio of the polymer (P) is low in order to sufficiently obtain the effect of improving various properties (for example, liquid crystal orientation, electrical properties, etc.) by using a polymer different from the polymer (P) in combination. In order to achieve the conversion, the content is preferably 90% by mass or less, more preferably 70% by mass or less, still more preferably 50% by mass or less, based on the total polymer contained in the liquid crystal alignment agent. ..
In the state of the polymer (P) contained in the liquid crystal alignment agent, ^one of L ¹ and L ² is a specific functional group (hydroxyl group, halogen atom or thermo-eliminating group), and the other is a hydrogen atom. Therefore, the symmetry of the polymer structure is lowered, and thus the solubility in the solvent is high. On the other hand, after the coating on the substrate, the specific functional group is eliminated by heating at the time of film formation to form a synnate structure. It is presumed that the formation made it possible to form a liquid crystal alignment film having excellent liquid crystal orientation and electrical characteristics.

（上記スキーム中のＲ^１、Ｒ^６、Ｒ^７、Ｒ^２３、Ａ^１、Ａ^３、Ｂ^１、Ｂ^２、Ｙ^１及びａは、上記式（５）、式（１１−１）と同義である。）(Synthesis of specific monomer A)
The method for synthesizing the specific monomer A is not particularly limited, and can be obtained by appropriately combining conventional methods of organic chemistry according to the desired molecular structure of the compound. For example, a compound represented by the formula (5) is a compound represented by "R ¹ -NH _2", by reacting with maleic anhydride (a compound represented by the following formula (8-1)) , The compound represented by the following formula (5-1) is obtained, and then the obtained compound is dehydrated and ring-closed. The compound represented by the following formula (5-1) is a compound in which R ³ in the above formula (6) is a hydrogen atom. Further, by using itaconic anhydride instead of maleic anhydride, the compound represented by the above formula (7) can be obtained. Further, in the reaction of compound and maleic acid represented by "R ¹ -NH _2", by using the itaconic anhydride instead of maleic anhydride, to obtain a compound represented by the above formula (8) Can be done.
As a method for obtaining the compound represented by "R ^1- NH ₂ ", for example, as shown in the following scheme A, the compound represented by the following formula (9-1) is reacted with Meldrum's acid, and then obtained. After reacting the obtained reaction product (9-2) with the compound represented by the following formula (9-3), the ring was opened by Meldrum's acid and the ketone moiety was reduced to obtain "R ^1- NH ₂ ". As the represented compound, a compound (β form) represented by the following formula (9-5) can be obtained.
Further, as shown in Scheme B below, the compound represented by the following formula (10-1) is reacted with the compound represented by the following formula (9-3), and then the ketone moiety is reduced. As the compound represented by "R ^1- NH ₂ ", a compound (α form) represented by the following formula (10-3) can be obtained. However, the method for synthesizing the specific monomer A is not limited to the above.

(R ¹ , R ⁶ , R ⁷ , R ²³ , A ¹ , A ³ , B ¹ , B ² , Y ¹ and a in the above scheme are synonymous with the above formulas (5) and (11-1). is there.)

<Other ingredients>
The liquid crystal alignment agent of the present disclosure may contain other components other than the polymer (P), if necessary. The other components are not particularly limited as long as the effects of the present disclosure are not impaired, and examples thereof include the following components.

(Polymer (Q))
The liquid crystal alignment agent of the present disclosure contains at least one polymer selected from the group consisting of polyamic acid, polyamic acid ester and polyimide (hereinafter, also referred to as "polymer (Q)") together with the polymer (P). It is preferable to do so. In this case, it is preferable that the polymer (P) is unevenly distributed in the upper layer in that a film having higher liquid crystal orientation can be obtained. In the embodiment containing the polymer (P) and the polymer (Q), the polymer (P) is a polymer having a halogen atom or a silicon atom from the viewpoint of promoting phase separation of the polymer, and the polymer. It is preferable that (Q) is a combination of a polymer having no partial structure represented by the above formula (3), a halogen atom and a silicon atom.

The polymer (Q) can be synthesized according to a conventionally known method. For example, a polyamic acid can be obtained by reacting a tetracarboxylic dianhydride with a diamine. In addition, in this specification, "tetracarboxylic acid derivative" means including tetracarboxylic dianhydride, tetracarboxylic acid diester and tetracarboxylic acid diester dihalide.

The tetracarboxylic dianhydride used for the polymerization is not particularly limited, and various tetracarboxylic dianhydrides can be used. Specific examples thereof include aliphatic tetracarboxylic acid dianhydrides such as butanetetracarboxylic acid dianhydride and ethylenediamine tetraacetichydride dianhydride; 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1, 3-Dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetichydride, 5- (2,5-dioxotetracarboxylic acid dianhydride)- 3a, 4,5,9b-tetrahydronaphtho [1,2-c] furan-1,3-dione, 5- (2,5-dioxotetrahydride-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 Alicyclic tetracarboxylic dianhydrides such as cyclopentanetetracarboxylic hydrides, cyclohexanetetracarboxylic hydrides; pyromellitic dianhydrides, 4,4'-(hexafluoroisopropyridene) diphthalic acid. Aromatic tetracarboxylic acid dianhydride, p-phenylene bis (trimeritic acid monoester anhydride), ethylene glycol bis (anhydro trimellitate), 1,3-propylene glycol bis (anhydrotrimeritate), etc. Anhydrides, etc. can be mentioned, and the tetracarboxylic dianhydrides described in JP-A-2010-97188 can be used. As the tetracarboxylic dianhydride, one type may be used alone, or two or more types may be used in combination.

Examples of the diamine used for the above polymerization include aliphatic diamines such as ethylenediamine and tetramethylenediamine; alicyclic diamines such as p-cyclohexanediamine and 4,4′-methylenebis (cyclohexylamine); hexadecanoxidiaminobenzene. , Cholestanyloxydiaminobenzene, Cholestanyl diaminobenzoate, Cholesteryl diaminobenzoate, Ranostanyl diaminobenzoate, 3,6-bis (4-aminobenzoyloxy) cholestan, 3,6-bis (4-aminophenoxy) cholestan, 1, , 1-bis (4-((aminophenyl) methyl) phenyl) -4-butylcyclohexane, 2,5-diamino-N, N-diallylaniline, the following formulas (2-1) to (2-3)

Side-chain type aromatic diamines such as compounds represented by each of the above; p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylamine, 4-aminophenyl-4'-aminobenzoate, 4 , 4'-diaminoazobenzene, 3,5-diaminobenzoic acid, 2,4-diaminobenzoic acid, 2,5-diaminobenzoic acid, 4,4'-diaminobiphenyl-3-carboxylic 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 (trifluoromethyl) -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- Non- (4-aminophenoxycarbonyl) -1- (4-aminophenyl) piperidine, 4,4'-[4,4'-propane-1,3-diylbis (piperidin-1,4-diyl)] dianiline, etc. Side-chain type aromatic diamines; diaminoorganosiloxanes such as 1,3-bis (3-aminopropyl) -tetramethyldisiloxane, and the like, as well as diamines described in JP-A-2010-97188. Can be used. As the diamine, one type may be used alone, or two or more types may be used in combination.

The polyamic acid synthesis reaction is preferably carried out in an organic solvent. The reaction temperature at this time is preferably −20 ° C. to 150 ° C., and the reaction time is preferably 0.1 to 24 hours. Examples of the organic solvent used in the reaction include 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 contains, for example, the polyamic acid obtained above and an esterifying agent (for example, methanol, ethanol, N, N-dimethylformamide diethylacetal, etc.). Obtaining by a method of reacting, a method of reacting a tetracarboxylic acid diester with a diamine compound in the presence of an appropriate dehydration catalyst, a method of reacting a tetracarboxylic acid diester dihalide with a diamine in the presence of an appropriate base, or the like. 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 imidization ratio of polyimide is preferably 20 to 95%, more preferably 30 to 90%. This imidization ratio represents the ratio of the number of imide ring structures to the total of the number of amic acid structures and the number of imide ring structures of polyimide as a percentage.

For the polymer (Q), the polystyrene-equivalent weight average molecular weight (Mw) measured by GPC is preferably 1,000 to 500,000, more preferably 2,000 to 300,000. The molecular weight distribution (Mw / Mn) is preferably 7 or less, more preferably 5 or less. The polymer (Q) contained in the liquid crystal alignment agent may be only one type or a combination of two or more types.

The blending ratio of the polymer (Q) is 40 with respect to 100 parts by mass of the polymer (P) used for preparing the liquid crystal alignment agent from the viewpoint of expressing the coatability, the liquid crystal orientation and the electrical characteristics to the substrate in a well-balanced manner. It is preferably parts by mass or more. It is more preferably 50 to 1500 parts by mass, and even more preferably 60 to 1000 parts by mass. As the polymer (Q), one type may be used alone, or two or more types may be used in combination.

(solvent)
The liquid crystal alignment agent of the present disclosure is prepared as a solution-like composition in which a polymer component and, if necessary, a component arbitrarily blended are preferably dissolved in an organic solvent. Examples of the organic solvent include aprotic polar solvents, phenolic solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons, hydrocarbons and the like. The solvent component may be one of these or a mixed solvent of two or more.

As the solvent component of the liquid crystal aligning agent, a solvent having high solubility and leveling property of the polymer (hereinafter, also referred to as "first solvent") and a solvent having good wettability and spreading property (hereinafter, also referred to as "second solvent"). ), And a mixed solvent thereof.
Specific examples of the solvent include, for example, N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N, N-dimethylformamide, N, N-dimethylacetamide, 4-hydroxy-4-methyl as the first solvent. -2-Pentanone, diisobutylketone, ethylene carbonate, propylene carbonate, N-ethyl-2-pyrrolidone, N- (n-pentyl) -2-pyrrolidone, N- (t-butyl) -2-pyrrolidone, N-methoxypropyl -2-Pyrrolidone, 1,3-dimethyl-2-imidazolidinone, 3-butoxy-N, N-dimethylpropanamide, 3-methoxy-N, N-dimethylpropanamide, etc.;
As the second solvent, for example, ethylene glycol monobutyl ether (butyl cellosolve), ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, diacetone alcohol, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, propylene glycol monomethyl Ether, propylene glycol monomethyl ether acetate, 3-methoxy-1-butanol, cyclopentanone, butyl lactate, butyl acetate, methylmethoxypropionate, ethylethoxypropionate, isoamylpropionate, isoamylisobutyrate, Examples thereof include propylene glycol diacetate, dipropylene glycol monomethyl ether, propylene glycol monobutyl ether, and diisopentyl ether. As the solvent, one of these may be used alone, or two or more of them may be mixed and used.

When the solvent component of the liquid crystal aligning agent is a mixed solvent of the first solvent and the second solvent, the content ratio of the first solvent is preferably 10% by mass or more with respect to the total amount of the solvent components, 15 to 15 It is more preferably 85% by mass.

Other components to be contained in the liquid crystal aligning agent include, for example, a polymer different from the polymer (P) and the polymer (Q), and a low molecular weight of 1000 or less having at least one epoxy group in the molecule. Molecular compounds (eg, ethylene glycol diglycidyl ether, N, N, N', N'-tetraglycidyl-m-xylene diamine, N, N, N', N'-tetraglycidyl-4,4'-diaminodiphenylmethane, etc. ), Functional silane compounds, polyfunctional (meth) acrylates, antioxidants, metal chelate compounds, curing accelerators, surfactants, fillers, dispersants, photosensitizers and the like. The blending ratio of the other components can be appropriately selected according to each compound as long as the effects of the present disclosure are not impaired.

The solid content concentration in the liquid crystal alignment agent (the ratio of the total mass of the components other than the solvent of the liquid crystal alignment agent to the total mass of the liquid crystal alignment agent) is appropriately selected in consideration of viscosity, volatility, etc., but is preferable. It is in the range of 1 to 10% by mass. When the solid content concentration is less than 1% by mass, the film thickness of the coating film becomes too small and it becomes difficult to obtain a good liquid crystal alignment film. On the other hand, when the solid content concentration exceeds 10% by mass, the film thickness of the coating film becomes excessive and it is difficult to obtain a good liquid crystal alignment film, and the viscosity of the liquid crystal alignment agent increases and the coatability deteriorates. There is a tendency.

≪Liquid crystal alignment film and liquid crystal element≫
The liquid crystal alignment film of the present disclosure is formed by the liquid crystal alignment agent prepared as described above. Further, the liquid crystal element of the present disclosure includes a liquid crystal alignment film formed by using the liquid crystal alignment agent described above. The operation mode of the liquid crystal in the liquid crystal element is not particularly limited, and for example, TN type, STN type, VA type (including VA-MVA type, VA-PVA type, etc.), IPS (In-Plane Switching) type, FFS (Fringe). It can be applied to various modes such as Field Switching) type, OCB (Optically Compensated Bend) type, and PSA type (Polymer Sustained Alignment). The liquid crystal element can be manufactured, for example, by a method including the following steps 1 to 3. In step 1, the substrate used differs depending on the desired operation mode. Steps 2 and 3 are common to each operation mode.

<Step 1: Formation of coating film>
First, a liquid crystal alignment agent is applied onto the substrate, and preferably the coated surface is heated to form a coating film on the substrate. As the substrate, for example, glass such as float glass and soda glass; a transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyether sulfone, polycarbonate, and poly (aliphatic olefin) can be used. Examples of the transparent conductive film provided on one surface of the substrate include a NESA film (registered trademark of PPG, USA) made of tin oxide (SnO ₂ ) and an ITO film made of indium tin oxide (In ₂ O _3- SnO ₂ ). Can be used. When manufacturing a TN type, STN type or VA type liquid crystal element, two substrates provided with a patterned transparent conductive film 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 patterned in a comb-teeth shape and a counter substrate not provided with electrodes are used. The liquid crystal alignment agent is applied to the substrate on the electrode forming surface, preferably by an offset printing method, a flexographic printing method, a spin coating method, a roll coater method, or an inkjet printing method.

After applying the liquid crystal alignment agent, preheating is preferably performed for the purpose of preventing the applied liquid crystal alignment agent from dripping. The pre-baking temperature is preferably 30 to 200 ° C., and the pre-baking time is preferably 0.25 to 10 minutes. Then, a firing (post-baking) step is carried out for the purpose of completely removing the solvent and, if necessary, thermally imidizing the amic acid structure present in the polymer. The firing temperature (post-baking temperature) at this time is preferably 80 to 250 ° C, more preferably 80 to 200 ° C. The post-bake time is preferably 5 to 200 minutes. The film thickness of the film thus formed is preferably 0.001 to 1 μm.

<Step 2: Orientation treatment>
When manufacturing a TN type, STN type, IPS type or FFS type liquid crystal element, a treatment (alignment treatment) for imparting a liquid crystal alignment ability to the coating film formed in the above step 1 is performed. As a result, the alignment ability of the liquid crystal molecules is imparted to the coating film to form a liquid crystal alignment film. Here, when an organic film is formed on the substrate using a liquid crystal alignment agent containing a polymer (P), L ¹ or L ² is desorbed by heating at the time of film formation, and the polymer (P) in the film is desorbed. A synnamate structure is formed in R ¹ or R ^{2 of the above} , and the obtained organic film has photoreactivity. Therefore, in this step, it is preferable to use a photo-alignment treatment in which the coating film formed on the substrate is irradiated with light to impart the liquid crystal alignment ability to the coating film. In the case of manufacturing a vertically oriented liquid crystal element, the coating film formed in step 1 can be used as it is as a liquid crystal alignment film, but in order to further enhance the liquid crystal alignment ability, the coating film is subjected to an orientation treatment. It is preferable to apply.

The light irradiation for photo-orientation includes 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, a pre-baking process and a post-baking process. At least one of them can be carried out by a method of irradiating the coating film while heating the coating film, or the like. As the radiation to irradiate the coating film, for example, ultraviolet rays including light having a wavelength of 150 to 800 nm and visible light can be used. Preferably, it is ultraviolet light containing light having a wavelength of 200 to 400 nm. When the radiation is polarized, it may be linearly polarized or partially polarized. When the radiation used is linearly polarized light or partially polarized light, the irradiation may be performed from a direction perpendicular to the substrate surface, may be performed from an oblique direction, or may be performed in combination thereof. In the case of unpolarized radiation, the irradiation direction is diagonal.

Examples of the light source used include a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, an excimer laser, and the like. The irradiation amount of radiation is preferably 400 to 50,000 J / m ² , and more preferably 1,000 to 20,000 J / m ² . After light irradiation for imparting orientation ability, the surface of the substrate is washed with, for example, water, an organic solvent (for example, methanol, isopropyl alcohol, 1-methoxy-2-propanol acetate, butyl cellosolve, ethyl lactate, etc.) or a mixture thereof. Or a process of heating the substrate may be performed.

<Step 3: Construction of liquid crystal cell>
A liquid crystal cell is manufactured by preparing two substrates on which the liquid crystal alignment film is formed as described above and arranging the liquid crystal between the two substrates arranged opposite to each other. In order to manufacture a liquid crystal cell, for example, two substrates are arranged to face each other with a gap so that the liquid crystal alignment films face each other, and the peripheral portions of the two substrates are bonded to each other using a sealant to form a surface of the substrate. Examples thereof include a method of injecting and filling a liquid crystal in a cell gap surrounded by a sealing agent to seal the injection hole, a method of using the ODF method, and the like. As the sealing agent, for example, an epoxy resin containing an aluminum oxide sphere as a curing agent and a spacer can be used. Examples of the liquid crystal include a nematic liquid crystal and a smectic liquid crystal, and among them, the nematic liquid crystal is preferable. In the PSA mode, after the liquid crystal cell is constructed, the liquid crystal cell is irradiated with light while a voltage is applied between the conductive films of the pair of substrates.

Subsequently, if necessary, a polarizing plate is attached to the outer surface of the liquid crystal cell to form a liquid crystal element. Examples of the polarizing plate include a polarizing plate in which a polarizing film called "H film" in which polyvinyl alcohol is stretch-oriented and iodine is absorbed is sandwiched between a cellulose acetate protective film, or a polarizing plate made of the H film itself.

The liquid crystal elements of the present disclosure can be effectively applied to various applications, for example, clocks, portable games, word processors, notebook computers, car navigation systems, camcorders, PDAs, digital cameras, mobile phones, smartphones, various monitors. , LCD televisions, information displays and other display devices, dimming films, retardation films and the like.

Hereinafter, the contents of the present disclosure will be described in detail with reference to Examples, but the contents of the present disclosure are not limited to the following Examples.
In the following examples, the weight average molecular weight (Mw), number average molecular weight (Mn) and molecular weight distribution (Mw / Mn) of the polymer were measured by the following methods.
<Weight average molecular weight, number average molecular weight and molecular weight distribution>
Mw and Mn were measured by gel permeation chromatography (GPC) under the following conditions. The molecular weight distribution (Mw / Mn) was calculated from the obtained Mw and Mn.
Equipment: Showa Denko Corporation "GPC-101"
GPC column: Combines "GPC-KF-801", "GPC-KF-802", "GPC-KF-803" and "GPC-KF-804" manufactured by Shimadzu GLC Co., Ltd. Mobile phase: tetrahydrofuran (THF) ), Or N, N-dimethylformamide solution containing lithium bromide and phosphoric acid Column temperature: 40 ° C.
Flow velocity: 1.0 mL / min Sample concentration: 1.0 mass%
Sample injection volume: 100 μL
Detector: Differential Refractometer Standard Material: Monodisperse Polystyrene

<Synthesis of monomer>
[Synthesis Example 1-1: Synthesis of compound (MI-1)]
Compound (MI-1) was synthesized according to the scheme below. In the following, for convenience, the "compound represented by the formula X" (where X is a number, a symbol or a combination thereof) may be simply referred to as "compound X".

To compound 1 (24.4 g, 50 mmol), 50 ml of thionyl chloride and 2 ml of N, N-dimethylformamide (DMF) were added, and the mixture was reacted at 60 ° C. for 2 hours under a nitrogen atmosphere. After the reaction, thionyl chloride was distilled off under reduced pressure to obtain a solid. To this, 200 ml of tetrahydrofuran (THF) was added to obtain a uniform solution (referred to as "solution A").
Apart from the above, Meldrum's acid (5.7 g, 50 mmol) and N, N-dimethylaminopyridine (DMAP) (12.2 g, 100 mmol) were dissolved in THF 200 ml, cooled to 0 ° C., and chloride of compound 1 was prepared therein. A THF solution (solution A) of the compound was slowly added dropwise, and the reaction was carried out for 20 hours after the addition was completed. After the reaction, 500 ml of ethyl acetate was added, and the organic layer was separated 3 times with 1N hydrochloric acid and 3 times with water. Further, the organic layer was dried over sodium sulfate, and after drying, sodium sulfate was collected by filtration. The solvent of the obtained filtrate was distilled off under reduced pressure to obtain Compound 2 (19.6 g, 32 mmol).

Compound 2 (19.6 g, 32 mmol) and 4- (BOC-amino) phenol (8.0 g, 38 mmol) were reacted in 200 ml of acetonitrile at 80 ° C. for 4 hours. After the reaction, the solvent was distilled off under reduced pressure and dissolved in a mixed solvent of 100 ml of THF, 100 ml of ethanol and 50 ml of water. Then, the solvent was slowly distilled off under reduced pressure to precipitate crystals. The obtained solid was collected by filtration and dried to obtain Compound 3 (18.4 g, 25.9 mmol).

50 ml of trifluoroacetic acid was added to Compound 3 (18.4 g, 25.9 mmol), and the mixture was stirred for 20 minutes. The remaining trifluoromethanesulfonic acid was distilled off under reduced pressure, and 150 ml of THF and 100 ml of ethyl acetate were added to the obtained solid to dissolve it. Then, the obtained organic layer was separated twice with a saturated aqueous sodium hydrogen carbonate solution and twice with water. Further, the organic layer was dried over sodium sulfate, and after drying, sodium sulfate was collected by filtration. The solvent of the obtained filtrate was distilled off under reduced pressure to obtain Compound 4 (16.0 g, 25.3 mmol).

Compound 4 (16.0 g, 25.3 mmol) was dissolved in 100 ml of THF and cooled to 0 ° C. Then, sodium borohydride (454 mg, 12 mmol) was slowly added while maintaining 0 ° C., and the mixture was stirred for 20 minutes. Then, a saturated aqueous solution of ammonium chloride was added so as not to exceed 5 ° C. for neutralization. 200 ml of ethyl acetate was added thereto, and the mixture was stirred to remove the aqueous layer. Then, the solution was separated twice with water to wash the organic layer. The solvent of the obtained organic layer was distilled off under reduced pressure to obtain Compound 5 (13.6 g, 21.7 mmol).

Compound 5 (13.6 g, 21.7 mmol) was dissolved in 200 ml of THF, maleic anhydride (2.2 g, 22 mmol) was added, and the mixture was stirred. After 15 hours, 200 ml of THF, 200 ml of ethyl acetate and 200 ml of water were added to separate the liquids. The obtained organic layer was distilled off under reduced pressure to obtain Compound 6 (14.9 g, 20.6 mmol).

Compound 6 (14.9 g, 20.6 mmol), zinc chloride (4.2 g, 30.9 mmol) and bis (trimethylsilyl) amine (6.6 g, 41 mmol) were added to 100 ml of toluene, and the mixture was stirred at 80 ° C. for 5 hours. After the reaction, 100 ml of ethyl acetate and 100 ml of THF were added, and the mixture was separated 3 times with 1N hydrochloric acid and 8 times with water. The obtained organic layer was dried over sodium sulfate, and after drying, sodium sulfate was collected by filtration. The solvent of the obtained filtrate was distilled off under reduced pressure to obtain compound (MI-1) (8.7 g, 12.4 mmol).

[Synthesis Example 1-2: Synthesis of compound (MI-2)]
Compound (MI-2) was synthesized according to the scheme below.

Add 50 mmol of DMF to compound (MI-1) (7.0 g, 9.9 mmol), ethyl iodide (1.9 g, 12.2 mmol), potassium carbonate (2.1 g, 15.2 mmol) and at 50 ° C. for 8 hours. It was reacted. After the reaction, 300 ml of water was added, the solid was collected by filtration, and the solid was washed well with water. The solid was dried to give compound (MI-2) (6.6 g, 9 mmol).

[Synthesis Example 1-3: Synthesis of compound (MI-3)]
Compound (MI-3) was synthesized according to the scheme below.

200 ml of acetonitrile was added to compound (MI-1) (7.1 g, 10.1 mmol) and pyridine (1.0 g, 12.6 mmol), and then acetic anhydride (1.2 g, 11.7 mmol) was slowly added dropwise. After stirring for 24 hours, 200 ml of ethyl acetate was added, and the organic layer was separated twice with 1N hydrochloric acid. Further, the solution was separated with water three times, and the solvent of the obtained organic layer was distilled off under reduced pressure. The obtained solid was dissolved in a mixed solvent of 100 ml of THF, 100 ml of ethanol and 50 ml of water. Then, the solvent was slowly distilled off under reduced pressure to precipitate crystals. The obtained solid was collected by filtration and dried to obtain compound (MI-3) (5.4 g, 7.2 mmol).

[Synthesis Example 1-4: Synthesis of compound (MI-4)]
Compound (MI-4) was synthesized according to the scheme below.

100 ml of pyridine was added to compound (MI-1) (7.1 g, 10.1 mmol), the mixture was stirred, and the mixture was cooled to 0 ° C. Tosyl chloride (2.3 g, 12.1 mmol) was added thereto, and the mixture was reacted at room temperature for 68 hours. After the reaction, 100 ml of ethyl acetate and 100 ml of THF were added. Then, it was separated 3 times with 1N hydrochloric acid, 5 times with saturated aqueous sodium hydrogen carbonate solution, and finally 3 times with water. Then, the organic layer was distilled off under reduced pressure, and the obtained solid was dissolved in THF. Hexane was added along the wall of the flask and allowed to stand for 16 hours. The precipitated crystals were collected by filtration and dried to obtain compound (MI-4) (3.3 g, 3.8 mmol).

[Synthesis Example 1-5: Synthesis of compound (MI-5)]
Compound (MI-5) was synthesized according to the scheme below.

To compound 7 (36.8 g, 100 mmol), 80 ml of thionyl chloride and 3 ml of DMF were added, and the mixture was reacted at 60 ° C. for 2 hours under a nitrogen atmosphere. After the reaction, thionyl chloride was distilled off under reduced pressure to obtain a chloride of compound 7. 200 ml of THF was added thereto to obtain a uniform solution (referred to as "solution B").
Separately from the above, 300 ml of pyridine was added to 4-hydroxyphenylpyruvate (21.6 g, 119.9 mmol), cooled to 0 ° C., and a THF solution (solution B) of chloride of compound 7 was slowly added dropwise. After the dropping was completed, the reaction was carried out for 18 hours. After the reaction, 500 ml of ethyl acetate was added, and the organic layer was separated 3 times with 1N hydrochloric acid and 3 times with water. Next, the solvent of the organic layer was distilled off under reduced pressure, and a mixed solvent of 300 ml of THF, 200 ml of ethanol, and 100 ml of water was added to the solid to dissolve it. Then, the solvent was slowly distilled off under reduced pressure to precipitate crystals. The obtained solid was collected by filtration and dried to obtain Compound 8 (33.4 g, 63.0 mmol).

Add 300 ml of methylene chloride to compound 8 (33.4 g, 63.0 mmol), 4- (BOC-amino) phenol (13.2 g, 65.0 mmol), DMAP (1.5 g, 12.3 mmol) and bring to 0 ° C. Cooled. Then, 1- (3-dimethylaminopropyl) -3-) ethylcarbodiimide (11.7 g, 75.3 mmol) was added, and the mixture was stirred at 5 ° C. or lower for 20 hours. After the reaction, the solution was separated once with 1N hydrochloric acid and twice with water. The solvent of the obtained organic layer was distilled off under reduced pressure to obtain Compound 9 (44.2 g, 61.2 mmol).

150 ml of trifluoroacetic acid was added to compound 9 (44.2 g, 61.2 mmol), and the mixture was stirred for 20 minutes. The remaining trifluoromethanesulfonic acid was distilled off under reduced pressure, and 400 ml of THF and 200 ml of ethyl acetate were added to the obtained solid to dissolve it. Then, the obtained organic layer was separated twice with a saturated aqueous sodium hydrogen carbonate solution and twice with water. Further, the organic layer was dried over sodium sulfate, and after drying, sodium sulfate was collected by filtration. The solvent of the obtained filtrate was distilled off under reduced pressure to obtain Compound 10 (36.9 g, 59.4 mmol).

Compound 10 (36.9 g, 59.4 mmol) was dissolved in 400 ml of THF and cooled to 0 ° C. Then, sodium borohydride (1.134 g, 30.0 mmol) was slowly added while maintaining 0 ° C., and the mixture was stirred for 20 minutes. Then, a saturated aqueous solution of ammonium chloride was added so as not to exceed 5 ° C. for neutralization. The aqueous layer was then extracted twice with 400 ml of ethyl acetate. The solvent of the obtained organic layer was distilled off under reduced pressure to obtain Compound 11 (32.2 g, 51.6 mmol).

500 ml of THF was added to compound 11 (32.2 g, 51.6 mmol), maleic anhydride (5.1 g, 52.0 mmol) was further added, and the mixture was stirred. After 18 hours, 300 ml of THF, 300 ml of ethyl acetate, and 500 ml of water were added and the liquids were separated. The obtained organic layer was distilled off under reduced pressure to obtain Compound 12 (36.1 g, 50.0 mmol).

Compound 12 (35.1 g, 48.6 mmol), zinc chloride (10.2 g, 74.8 mmol) and bis (trimethylsilyl) amine (16.6 g, 102.9 mmol) were added to 500 ml of toluene and stirred at 80 ° C. for 5 hours. did. After the reaction, 300 ml of ethyl acetate and 300 ml of THF were added, and the mixture was separated 3 times with 1N hydrochloric acid and 8 times with water. The obtained organic layer was dried over sodium sulfate, and after drying, sodium sulfate was collected by filtration. The solvent of the filtrate was distilled off under reduced pressure, and the obtained solid was dissolved in a mixed solvent of 500 ml of THF, 100 ml of ethanol and 100 ml of water. Then, the solvent was slowly distilled off under reduced pressure to precipitate crystals, and the resulting solid was collected by filtration and dried to obtain compound (MI-5) (18.9 g, 26.9 mmol).

[Synthesis Example 1-6: Synthesis of compound (MI-6)]
Compound (MI-6) was synthesized according to the scheme below.

2 ml of pyridine and 20 ml of DMF were added to compound (MI-5) (3.5 g, 4.9 mmol), and the mixture was cooled to 0 ° C. Then, trimethylsilyl chloride (0.81 g, 7.46 mmol) was slowly added dropwise, and the mixture was stirred for 2 hours. After the reaction, 200 ml of water was added, and the resulting solid was collected by filtration. The obtained solid was dissolved in a mixed solvent of 100 ml of THF, 30 ml of ethanol and 10 ml of water. Then, the solvent was slowly distilled off under reduced pressure to precipitate crystals, and the resulting solid was collected by filtration and dried to obtain compound (MI-6) (1.5 g, 1.9 mmol).

[Synthesis Example 1-7: Synthesis of compound (MI-7)]
Compound (MI-7) was synthesized according to the scheme below.

To compound (MI-5) (3.6 g, 5.1 mmol), 15 ml of thionyl chloride and 1 ml of DMF were added, and the mixture was reacted at 60 ° C. for 2 hours under a nitrogen atmosphere. After the reaction, thionyl chloride was distilled off under reduced pressure to obtain compound (MI-7) (3.5 g, 4.9 mmol).

[Synthesis Example 1-8: Synthesis of compound (MI-8)]
Compound (MI-8) was synthesized according to the scheme below.

Add 20 ml of DMF to compound (MI-5) (3.5 g, 4.9 mmol), 2,4-dinitrofluorobenzene (1.0 g, 5.4 mmol), potassium carbonate (1.36 g, 9.9 mmol), and add 50. The mixture was stirred at ° C. for 16 hours. After the reaction, 300 ml of water was added, and the resulting solid was collected by filtration. The obtained solid was dissolved in a mixed solvent of 150 ml of THF, 50 ml of ethanol and 15 ml of water. Then, the solvent was slowly distilled off under reduced pressure to precipitate crystals, and the resulting solid was collected by filtration and dried to obtain compound (MI-8) (1.4 g, 1.6 mmol).

[Synthesis Example 1-9: Synthesis of compound (MI-9)]
Compound (MI-9) was synthesized by the same method as in Synthesis Example 1-5, except that the starting material was changed to compound 13 instead of compound 7.

<Synthesis of polymer (P)>
[Synthesis Example 2-1]
In a 100 mL two-necked flask, 0.524 g (0.75 mmol) of compound (MI-1), 0.841 g (4.29 mmol) of 3,4-epoxycyclohexylmethylmethacrylate, 0.635 g (4.29 mmol) of 4-vinylbenzoic acid. ), 2,2'-Azobis (2,4-dimethylvaleronitrile) (0.06 g, 0.24 mmol), 2,4-diphenyl-4-methyl-1-pentene 0.10 g (0.42 mmol), and 8 g of N-methyl-2-pyrrolidone was added, and the mixture was polymerized under nitrogen at 70 ° C. for 5 hours. After reprecipitation in n-hexane, the precipitate was filtered and vacuum dried at room temperature for 8 hours to obtain the desired polymer (StMI-1). The weight average molecular weight Mw of the obtained polymer measured by GPC in terms of polystyrene was 28300, and the molecular weight distribution Mw / Mn was 2.7.
[Synthesis Example 2-2-2-10 and Comparative Synthesis Example 1-1]
Polymerization was carried out in the same manner as in Synthesis Example 2-1 except that the types and amounts of the monomers used for the polymerization were as shown in Table 1 below, and the polymers (StMI-2) to (StMI-10) and ( SMA-1) was synthesized. The numerical value in the "monomer ratio" column in Table 1 represents the amount [mol%] of each monomer charged with respect to all the monomers used in the synthesis of the polymer.

In Table 1, the abbreviations of the compounds represent the following compounds.
MI-1 to MI-9: Compound represented by each of the above formulas (MI-1) to (MI-9) MI-10: Compound represented by the above formula 6 (Compound 6)
MA-1: Compound represented by the following formula (MA-1) M-100: 3,4-epoxycyclohexylmethylmethacrylate VBA: 4-vinylbenzoic acid

<Synthesis of polyamic acid>
[Comparative Synthesis Example 2-1]
Compound (DA-1) (5.7 g, 7.98 mmol), paraphenylenediamine (0.086 g, 0.8 mmol), and 2,3,5-tri to 31 g of N-methyl-2-pyrrolidone (NMP). Carboxycyclopentyl acetate dianhydride (2.0 g, 8.8 mol) was added and dissolved, and this was reacted at 60 ° C. for 6 hours to obtain a solution containing 10% by mass of polyamic acid (PAA-1). .. The weight average molecular weight Mw of the obtained polymer measured by GPC in terms of polystyrene was 67,000, and the molecular weight distribution Mw / Mn was 5.3.
[Comparative Synthesis Example 2-2 and Synthesis Example 3-1 to 3-3]
Polyamic acids (PAA-2) to (PAA-5) are synthesized by polymerizing in the same manner as in Synthesis Example 3-1 except that the types and amounts of the monomers used for the polymerization are as shown in Table 2 below. did. The numerical value in the "diamine" column in Table 2 represents the amount [mol%] of each monomer charged with respect to the total amount of diamine used in the synthesis of the polymer. When synthesizing the polymer, the amount of acid dianhydride used was 8.8 mol.

In Table 2, the abbreviations of the compounds are as follows.
(Tetracarboxylic dianhydride)
T-1: 2,3,5-tricarboxycyclopentyl acetate dianhydride T-2: 1,2,3,4-cyclobutanetetracarboxylic dianhydride T-3: pyromellitic dianhydride (diamine)
DA-1: Compound represented by the following formula (DA-1) DA-2: Compound represented by the following formula (DA-2) DA-3: Paraphenylenediamine DA-4: The following formula (DA-4) Compound DA-5: 3,5-diaminobenzoate cholestanyl represented by

<Evaluation of monomers and polymers>
[Example 1-1]
1. 1. Evaluation of Monomer Solubility The compound (MI-1) was added to NMP so that the solid content concentration was 5% by mass and stirred, and the monomer solubility was evaluated according to the following criteria. In this example, "2" It was an evaluation.
<Evaluation of monomer solubility>
Insoluble at 1: 70 ° C, partially soluble at 2: 70 ° C, soluble at 3: 70 ° C, 4: soluble at room temperature

2. 2. Evaluation of Desorption Temperature of Polymer The polymer (StMI-1) synthesized in Synthesis Example 2-1 using a thermogravimetric differential thermal analyzer (TG-DTA) (TG / DTA7300, manufactured by Hitachi High-Tech Science Co., Ltd.). The desorption behavior in the process of raising the temperature from 50 ° C. to 300 ° C. was measured. When the temperature at which the weight reduction and the endothermic peak occurred was defined as the desorption temperature, the desorption temperature was 200 ° C.

[Examples 1-2 to 1-10 and Comparative Examples 1-1 to 1-3]
The same evaluation as in Example 1-1 was carried out except that the monomers and polymers used were changed as shown in Table 3 below. The results are shown in Table 3 below. In the example shown in the desorption temperature column of "-" in Table 3 below, no desorption behavior was observed even when the polymer was heated.

As can be seen from Table 3, the compounds (MI-1) to (MI-10) were evaluated as having a solubility in NMP of "2", "3" or "4", and had good solubility in a solvent. .. Among these, compounds in which ^one of L ¹ and L ² is a thermal leaving group or a halogen atom ((MI-2) to (MI-4), (MI-6) to (MI-8), (MI-) 10)) was an evaluation of "3" or "4", and was excellent in solubility in a solvent. Further, in the polymers (StMI-1) to (StMI-10), the desorption temperature was 200 ° C. or lower. In particular, the polymers (StMI-3), (StMI-4), and (StMI-6) to (StMI-8) have a desorption temperature of 180 ° C. or lower, which is higher than that of the polymer (PAA-1) of the comparative example. It can be said that the elimination reaction (that is, conversion to a polymer structure) occurs at low temperatures.

<Evaluation of liquid crystal alignment agent>
[Example 2-1]
1. 1. Preparation of liquid crystal alignment agent (A-1) 20 parts by mass of the polymer (StMI-1) obtained in Synthesis Example 2-1 and 80 parts by mass of the polyamic acid (PAA-3) obtained in Synthesis Example 3-1. N-Methyl-2-pyrrolidone (NMP) and butyl cellosolve (BC) were added as solvents to prepare a solution having a solvent composition of NMP / BC = 50/50 (mass ratio) and a solid content concentration of 4.0% by mass. .. A liquid crystal alignment agent (A-1) was prepared by filtering this solution through a filter having a pore size of 1 μm.

2. 2. Evaluation of coating uniformity Above 1. The liquid crystal alignment agent (A-1) prepared in the above was applied onto a glass substrate using a spinner, prebaked on a hot plate at 80 ° C. for 1 minute, and then the inside of the refrigerator was replaced with nitrogen in an oven at 200 ° C. 1 A coating film having an average film thickness of 0.1 μm was formed by heating (post-baking) for a time. The surface of the obtained coating film was observed with an atomic force microscope (AFM), the center average roughness (Ra) was measured, and the uniformity of the coating film surface was evaluated. When Ra was 5 nm or less, the coating uniformity was evaluated as “good (◯)”, when it was larger than 5 nm and less than 10 nm, it was evaluated as “possible (Δ)”, and when it was 10 nm or more, it was evaluated as “poor (×)”. As a result, the evaluation was "good" in this example.

3. 3. Evaluation of Applicability to Fine Concavo-convex Surface The applicability of the liquid crystal alignment agent to the fine concavo-convex surface was evaluated using the evaluation ITO electrode substrate 10 shown in FIG. As the evaluation ITO electrode substrate 10, a plurality of striped ITO electrodes 12 were arranged on one surface of the glass substrate 11 at predetermined intervals (see FIG. 1). The electrode width A was 50 μm, the distance between the electrodes B was 2 μm, and the electrode height C was 0.2 μm. A wettability evaluation device LSE-A100T (manufactured by Nick) was used on the electrode forming surface of the evaluation ITO electrode substrate 10, and the above 1. The liquid crystal alignment agent (A-1) prepared in the above was added dropwise, and the ease of adapting to the uneven surface of the substrate was evaluated. At this time, it can be said that the larger the wet spread of the droplets (the larger the wet spread area S (mm ² / μL) of the droplets with respect to the amount of liquid), the better the applicability of the liquid crystal aligning agent to the fine uneven surface.
The evaluation is "very good (○○)" when the area S is 15 mm ² / μL or more, and “good (○)” when the area S is 10 mm ² / μL or more and less than 15 mm ² / μL. S has a "good (△)", "poor (×)" when the area S is less than 5 mm ² / [mu] L if it is greater than 10 mm ² / [mu] L than 5 mm ² / [mu] L. As a result, in this example, the area S was 10 mm ² / μL, and the applicability to the fine uneven surface was judged to be “good”.

4. Evaluation of printability (flatness of film) Except for the solid content concentration of 7.0% by mass, the above 1. A liquid crystal alignment agent was prepared in the same manner as in the above. This liquid crystal alignment agent was applied onto a glass substrate using a liquid crystal alignment film printing machine (manufactured by Nissha Printing Co., Ltd., model S40). Next, after prebaking on a hot plate at 80 ° C. for 1 minute, the inside of the chamber was heated (post-baked) in an oven at 200 ° C. with nitrogen substitution for 1 hour to form a coating film having an average film thickness of 100 nm. With respect to the obtained coating film, the in-plane film thickness deviation σ was determined by a mapping ellipsometry apparatus (ME-210 manufactured by Photonic Lattice), and the flatness of the film was evaluated according to the following criteria. As a result, in this example, the evaluation was "3", and a film having good flatness was obtained.
<Evaluation of film flatness>
1: σ> 0.80
2: 0.50 <σ ≤ 0.80
3: 0.30 <σ ≤ 0.50
4: σ ≤ 0.30

[Examples 2-1 to 2-10 and Comparative Examples 2-1 to 2-3]
Preparations were carried out at the same solid content concentration as in Example 2-1 except that the compounding composition was changed as shown in Table 4 below to obtain liquid crystal alignment agents. In Examples 2-3, 2-6 and 2-8, the types and amounts of additives shown in Table 4 below were blended. Moreover, the same evaluation as in Example 2-1 was performed using each liquid crystal alignment agent. The results are shown in Table 4 below.

In Table 4, the abbreviations of additives indicate the following compounds.
K-1: Monobutyltrimellitic acid K-2: N, N, N', N'-tetraglycidyl-m-xylylenediamine K-3: 3-aminomethylpyridine

Comparing Examples 2-1 to 2-10 with Comparative Examples 2-2 and 2-3, Examples 2-1 to 2-10 were superior in coating uniformity. Moreover, the result was equivalent to that of Comparative Example 2-1.
Regarding the unevenness coating property, the evaluation was "very good" or "good" in Examples 2-1 to 2-10, whereas it was "OK" or "poor" in Comparative Examples 2-1 to 2-3. , And all of the examples were superior to the comparative examples. In particular, in Examples 2-3, 2-4, 2-6 to 2-10, the evaluation was "very good", and the unevenness coating property was excellent. Further, in terms of printability, all of Examples 2-1 to 2-10 were superior to Comparative Examples.
From these results, it was found that the liquid crystal alignment agent containing the polymer (P) can form a liquid crystal alignment film having excellent coating uniformity, uneven coating property and printability.

10 ... Evaluation ITO electrode substrate, 11 ... Glass substrate, 12 ... ITO electrode

Claims (10)

A group consisting of a partial structure represented by the following formula (1), a partial structure represented by the following formula (2), a partial structure represented by the following formula (3), and a partial structure represented by the following formula (4). A liquid crystal alignment agent containing a polymer (P) having at least one selected from the above.

(In formulas (1) to (4), R ¹ , R ² , R ¹⁰ and R ¹⁴ are monovalent groups having a partial structure represented by the following formula (11) independently. R ³ and R ¹¹ are independent hydrogen atoms or monovalent organic groups having 1 or more carbon atoms. R ^{6 to} R ⁹ , R ¹² , R ¹³ and R ¹⁶ and R ¹⁷ are independent of each other. It is a hydrogen atom or a methyl group. One of X ¹⁰ and X ¹¹ is a single bond and the other is a methylene group.)

(In the formula (11), ^{X 1} represents an oxygen atom or -NR ⁴ - (provided that, ^{R 4} is a hydrogen atom or a monovalent organic group having 1 or more carbon atoms, or, ^{R 4} is other group It is a group that forms a ring structure together with the nitrogen atom to which R ⁴ is bonded.) A ¹ is a divalent aromatic ring group. One of L ¹ and L ² is a hydroxyl group and a halogen. It is an atom or a monovalent desorbing group having 1 or more carbon atoms that is desorbed by heat, and the other is a hydrogen atom.) The liquid crystal alignment agent according to claim 1, wherein the polymer (P) has at least one of an oxetanyl group and an oxylanyl group. The liquid crystal alignment agent according to claim 2, wherein the polymer (P) has a functional group that reacts with at least one of an oxetanyl group and an oxylanyl group when heated. The liquid crystal alignment agent according to any one of claims 1 to 3, wherein the polymer (P) has at least one selected from the group consisting of a carboxyl group and a protected carboxyl group. The liquid crystal alignment agent according to any one of claims 1 to 4, further containing at least one polymer selected from the group consisting of polyamic acid, polyamic acid ester and polyimide. The polymer (P) is represented by a compound represented by the following formula (5), a compound represented by the following formula (6), a compound represented by the following formula (7), and a compound represented by the following formula (8). The liquid crystal alignment agent according to any one of claims 1 to 5, which is a polymer having a partial structure derived from at least one compound selected from the group consisting of compounds.

(In formulas (5) to (8), R ^{1 to} R ³ , R ^{6 to} R ¹⁴ , R ¹⁶ and R ¹⁷ are synonymous with the above formulas (1) to (4), respectively.) A liquid crystal alignment film formed by using the liquid crystal alignment agent according to any one of claims 1 to 6. A liquid crystal element comprising the liquid crystal alignment film according to claim 7. A group consisting of a partial structure represented by the following formula (1), a partial structure represented by the following formula (2), a partial structure represented by the following formula (3), and a partial structure represented by the following formula (4). A polymer having at least one selected from.

(In formulas (1) to (4), R ¹ , R ² , R ¹⁰ and R ¹⁴ are monovalent groups having a partial structure represented by the following formula (11) independently. R ³ and R ¹¹ are independent hydrogen atoms or monovalent organic groups having 1 or more carbon atoms. R ^{6 to} R ⁹ , R ¹² , R ¹³ and R ¹⁶ and R ¹⁷ are independent of each other. It is a hydrogen atom or a methyl group. One of X ¹⁰ and X ¹¹ is a single bond and the other is a methylene group.)

(In the formula (11), ^{X 1} represents an oxygen atom or -NR ⁴ - (provided that, ^{R 4} is a hydrogen atom or a monovalent organic group having 1 or more carbon atoms, or, ^{R 4} is other group It is a group that forms a ring structure together with the nitrogen atom to which R ⁴ is bonded.) A ¹ is a divalent aromatic ring group. One of L ¹ and L ² is a hydroxyl group and a halogen. It is an atom or a monovalent desorbing group having 1 or more carbon atoms that is desorbed by heat, and the other is a hydrogen atom.) A compound represented by the following formula (5), formula (6), formula (7) or formula (8).

(In formulas (5) to (8), R ¹ , R ² , R ¹⁰ and R ¹⁴ are monovalent groups having a partial structure represented by the following formula (11), and R ³ and R ¹¹ Is a hydrogen atom or a monovalent organic group having one or more carbon atoms. R ^{6 to} R ⁹ , R ¹² , R ¹³ , R ¹⁶ and R ¹⁷ are independently hydrogen atoms or methyl groups, respectively. ^{One of 10} and X ¹¹ is a single bond and the other is a methylene group.)

(In the formula (11), ^{X 1} represents an oxygen atom or -NR ⁴ - (provided that, ^{R 4} is a hydrogen atom or a monovalent organic group having 1 or more carbon atoms, or, ^{R 4} is other group It is a group that forms a ring structure together with the nitrogen atom to which R ⁴ is bonded.) A ¹ is a divalent aromatic ring group. One of L ¹ and L ² is a hydroxyl group and a halogen. It is an atom or a monovalent desorbing group having 1 or more carbon atoms that is desorbed by heat, and the other is a hydrogen atom.)

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