JP2017187647A - Liquid crystal aligning agent, liquid crystal alignment film and production method of the same, liquid crystal clement, polymer and compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal aligning agent with which a liquid crystal clement having good afterimage characteristics and contrast characteristics can be obtained.SOLUTION: The liquid crystal aligning agent comprises a polymer [A] having at least one structure selected from the group consisting of a partial structure represented by formula (1) and a partial structure represented by formula (2). In formula (1), Yrepresents a tetravalent organic group represented by formula (3); Zrepresents a divalent organic group; and Rand Rrepresent a hydrogen atom or a monovalent organic group. In formula (3), Rto Rrepresent a hydrogen atom or a monovalent organic group; Arepresents -NR-, a carbonyl group, an oxygen atom or a sulfur atom; Arepresents -C(RR)-, -NR-, a carbonyl group, an oxygen atom or a sulfur atom, where Rand Reach independently represent a hydrogen atom or a monovalent organic group and Rrepresents a monovalent organic group; and n is 0 or 1.SELECTED DRAWING: None

Description

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

  The liquid crystal element includes a liquid crystal alignment film formed using a polymer composition containing a polymer such as polyamic acid or polyimide as an organic film for controlling the alignment of liquid crystal molecules in the liquid crystal cell. As a method for obtaining an organic film having alignment regulating ability of liquid crystal molecules, conventionally, a method of rubbing an organic film, a method of obliquely depositing silicon oxide, a method of forming a monomolecular film having a long chain alkyl group, and photosensitivity A method of irradiating the organic film with light (photo-alignment method) or the like is known. For example, the photo-alignment method can impart uniform liquid crystal alignment to a photosensitive organic film while suppressing the generation of static electricity and dust, and also enables precise control of the liquid crystal alignment direction. Various studies are underway.

  The characteristics required for the liquid crystal panel include a high voltage holding ratio and a small afterimage, and various liquid crystal aligning agents for improving these characteristics have been proposed (for example, Patent Document 1). reference). Patent Document 1 discloses a tetracarboxylic dianhydride having a structure in which two cyclobutane rings are bonded by a single bond or an alkanediyl group, or a condensed ring structure comprising a total of three cycloalkanes including two cyclobutane rings. It is disclosed that a liquid crystal alignment film is formed using a liquid crystal aligning agent containing a polyamic acid obtained by reacting a tetracarboxylic dianhydride compound containing a product with a diamine compound, or a derivative thereof. Patent Document 1 describes that according to this liquid crystal aligning agent, a liquid crystal display element having improved voltage holding ratio and residual DC can be obtained.

Japanese Patent No. 4561607

  In recent years, large-screen and high-definition liquid crystal televisions are mainly used, and small display terminals such as smartphones and tablet PCs are widely used, and the demand for high-definition liquid crystal panels is increasing. For example, the fact that afterimages are less likely to occur (afterimage characteristics) and that the contrast is good (contrast characteristics) is important for ensuring the display quality of a liquid crystal device, and improving these characteristics is more important than before. It is becoming important. In particular, when the liquid crystal alignment regulating force is applied by the photo-alignment process, the alignment regulating force is weaker than that of the rubbing process, so that there is a problem that image sticking called “AC afterimage” is likely to occur.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a liquid crystal aligning agent capable of obtaining a liquid crystal element having excellent afterimage characteristics and contrast characteristics.

  As a result of intensive studies to achieve the above-described problems of the prior art, the present inventors have found that the above-described problems can be solved by including a polymer having a specific partial structure in the liquid crystal aligning agent. The headline and the present invention were completed. Specifically, the following means are provided.

（式（１）中、Ｙ^１は、下記式（３）で表される４価の有機基であり、Ｚ^１は２価の有機基であり、Ｒ^１及びＲ^２は、それぞれ独立して水素原子又は１価の有機基である。）

（式（３）中、Ｒ^３〜Ｒ^１０は、それぞれ独立して水素原子又は１価の有機基であり、Ａ^１は、−ＮＲ^１３−、カルボニル基、酸素原子又は硫黄原子であり、Ａ^２は、−Ｃ（Ｒ^１１Ｒ^１２）−、−ＮＲ^１３−、カルボニル基、酸素原子又は硫黄原子である。Ｒ^１１及びＲ^１２は、それぞれ独立して水素原子又は１価の有機基であり、Ｒ^１３は１価の有機基である。ｎは０又は１である。「＊」は結合手を示す。）
＜２＞ 上記＜１＞の液晶配向剤を基板上に塗布して塗膜を形成する工程と、前記塗膜に光照射する工程と、を含む液晶配向膜の製造方法。
＜３＞ 上記＜１＞の液晶配向剤を用いて形成された液晶配向膜。
＜４＞ 上記＜３＞の液晶配向膜を具備する液晶素子。
＜５＞ 上記式（１）で表される部分構造及び上記式（２）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。
＜６＞ 下記式（４）で表されるテトラカルボン酸二無水物。

（式（４）中、Ｒ^３〜Ｒ^１０は、それぞれ独立して水素原子又は１価の有機基であり、Ａ^１は、−ＮＲ^１３−、カルボニル基、酸素原子又は硫黄原子であり、Ａ^２は、−Ｃ（Ｒ^１１Ｒ^１２）−、−ＮＲ^１３−、カルボニル基、酸素原子又は硫黄原子である。Ｒ^１１及びＲ^１２は、それぞれ独立して水素原子又は１価の有機基であり、Ｒ^１３は１価の有機基である。ｎは０又は１である。） <1> A liquid crystal aligning agent comprising a polymer [A] having at least one selected from the group consisting of a partial structure represented by the following formula (1) and a partial structure represented by the following formula (2).

(In formula (1), Y ¹ is a tetravalent organic group represented by the following formula (3), Z ¹ is a divalent organic group, and R ¹ and R ² are each independently It is a hydrogen atom or a monovalent organic group.)

(In Formula (3), R ^{3 to} R ¹⁰ are each independently a hydrogen atom or a monovalent organic group, A ¹ is —NR ¹³ —, a carbonyl group, an oxygen atom, or a sulfur atom; ² is —C (R ¹¹ R ¹² ) —, —NR ¹³ —, a carbonyl group, an oxygen atom or a sulfur atom, and R ¹¹ and R ¹² are each independently a hydrogen atom or a monovalent organic group. , R ¹³ is a monovalent organic group, n is 0 or 1. “*” represents a bond.)
<2> A method for producing a liquid crystal alignment film, comprising: a step of applying the liquid crystal aligning agent of <1> above onto a substrate to form a coating film; and a step of irradiating the coating film with light.
<3> A liquid crystal alignment film formed using the liquid crystal aligning agent according to <1>.
<4> A liquid crystal element comprising the liquid crystal alignment film of <3> above.
<5> A polymer having at least one selected from the group consisting of a partial structure represented by the above formula (1) and a partial structure represented by the above formula (2).
<6> A tetracarboxylic dianhydride represented by the following formula (4).

(In Formula (4), R ^{3 to} R ¹⁰ are each independently a hydrogen atom or a monovalent organic group, A ¹ is —NR ¹³ —, a carbonyl group, an oxygen atom, or a sulfur atom; ² is —C (R ¹¹ R ¹² ) —, —NR ¹³ —, a carbonyl group, an oxygen atom or a sulfur atom, and R ¹¹ and R ¹² are each independently a hydrogen atom or a monovalent organic group. R ¹³ is a monovalent organic group, and n is 0 or 1.)

  According to the liquid crystal aligning agent containing the polymer [A], it is possible to obtain a liquid crystal element in which an afterimage (particularly an AC afterimage) hardly occurs and the contrast is good.

The schematic block diagram of a FFS type liquid crystal display element. The plane schematic diagram of the top electrode used for manufacture of the liquid crystal display element by a photo-alignment method. (A) is a top view of a top electrode, (b) is the elements on larger scale of a top electrode. The figure which shows the drive electrode of 4 systems. The plane schematic diagram of the top electrode used for manufacture of the liquid crystal display element by a rubbing method. (A) is a top view of a top electrode, (b) is the elements on larger scale of a top electrode.

  Below, each component contained in the liquid crystal aligning agent of this indication and the other component arbitrarily mix | blended as needed are demonstrated.

≪Polymer [A] ≫
The liquid crystal aligning agent of this indication contains polymer [A] which has at least 1 type chosen from the group which consists of the partial structure represented by the said Formula (1), and the partial structure represented by the said Formula (2). This polymer [A] has a skeleton represented by the above formula (3) at Y ¹ in the above formulas (1) and (2). In the present specification, the “organic group” is a concept including a group of reactive or non-reactive atoms contained in an organic compound and a single atom that gives reactivity to the organic compound. Therefore, the organic group may be a hydrocarbon atomic group, an atomic group containing a hetero atom in the structure, or a hetero atom.

The monovalent organic group, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, fluoroalkyl group having 1 to 10 carbon atoms ^R 3 ^{to R 10} in the formula (3), the number of carbon atoms A cycloalkyl group having 3 to 10 carbon atoms, a cycloalkylalkyl group having 4 to 10 carbon atoms, an alkylcycloalkyl group having 4 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aralkyl group having 7 to 10 carbon atoms, and an epoxy group , Alkylsilyl group, alkoxysilyl group, halogen atom and the like. R ^{3 to} R ¹⁰ are preferably a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms.
With respect to —C (R ¹¹ R ¹² ) — of A ¹ , the description of R ^{3 to} R ¹⁰ is applied to specific examples of the monovalent organic groups of R ¹¹ and R ¹² . R ¹¹ and R ¹² are preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and more preferably a hydrogen atom or a methyl group.
With respect to —NR ¹³ — of A ¹ and A ² , examples of the monovalent organic group represented by R ¹³ include an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, and a cyclohexane having 4 to 10 carbon atoms. Examples thereof include an alkylalkyl group, an alkylcycloalkyl group having 4 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aralkyl group having 7 to 10 carbon atoms, and a protecting group. When R ¹³ is a protecting group, a tert-butoxycarbonyl group is preferred.
In particular, A ¹ and A ² are preferably —NR ¹³ —, a carbonyl group, or an oxygen atom.

The divalent organic group of Z ¹ is a residue obtained by removing two primary amino groups of the diamine compound. Examples of the monovalent organic group for R ¹ and R ² include an alkyl group having 1 to 20 carbon atoms, a fluoroalkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, and a 4 to 20 carbon atom. A cycloalkylalkyl group, an alkylcycloalkyl group having 4 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, an alkoxysilyl group, a monovalent group having a cinnamic acid structure, and the like. It is done.

  The polymer [A] is a polymer having a main skeleton of polyamic acid, polyamic acid ester, or polyimide. The polymer [A] can be obtained by a synthesis method corresponding to the main skeleton. When the polymer [A] is a polyamic acid, for example, a tetracarboxylic dianhydride containing a compound represented by the above formula (4) (hereinafter also referred to as “specific acid dianhydride”), a diamine compound, Can be obtained by reacting.

For certain dianhydride, description of ^R 3 ^{to R 10,} A 1, ^{A 2} and n in the above formula (4) is, ^R 3 ^{to R} 10, ^{A 1} in the above formula (1) and (2) , A ² and n apply respectively.
Specific examples of the specific acid dianhydride include compounds represented by the following formulas (a-1) to (a-15), for example. In addition, specific acid dianhydride may be used individually by 1 type, and may be used in combination of 2 or more type.

The specific acid dianhydride can be synthesized by appropriately combining conventional methods of organic chemistry. As an example, the specific acid dianhydride is obtained by light-emitting 1,4-cyclohexadiene derivative having groups corresponding to A ¹ and A ² in the above formula (4), and substituted or unsubstituted maleic anhydride. It can obtain by making it react. However, the method for synthesizing the specific acid dianhydride is not limited to the above.

  In the synthesis of the polyamic acid as the polymer [A], only the specific acid dianhydride may be used as the tetracarboxylic dianhydride, but other tetracarboxylic dianhydrides other than the specific acid dianhydride may be used. May be used. Specific examples of other tetracarboxylic dianhydrides include aliphatic tetracarboxylic dianhydrides such as butanetetracarboxylic dianhydride and ethylenediaminetetraacetic acid dianhydride;

  As the alicyclic tetracarboxylic dianhydride, for example, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 5- (2,5-dioxotetrahydrofuran-3-yl) -3a, 4,5,9b-tetrahydronaphtho [1,2-c] furan-1 , 3-dione, 5- (2,5-dioxotetrahydrofuran-3-yl) -8-methyl-3a, 4,5,9b-tetrahydronaphtho [1,2-c] furan-1,3-dione, 2,4,6,8-tetracarboxybicyclo [3.3.0] octane-2: 4,6: 8-dianhydride, cyclopentanetetracarboxylic dianhydride, cyclohexanetetracarboxylic dianhydride, etc. An aromatic tetracarboxylic dianhydride such as pyromellitic dianhydride, 4,4 ′-(hexafluoroisopropylidene) diphthalic anhydride, p-phenylenebis (trimellitic acid monoester anhydride), ethylene Glycol bis (anhydrotrimellitate), 1,3-propylene glycol bis (anhydrotrimellitate), etc .; in addition to tetracarboxylic dianhydrides described in JP 2010-97188 A Can be used. Other tetracarboxylic dianhydrides may be used alone or in combination of two or more.

  The diamine compound used in the synthesis of the polyamic acid is not particularly limited. Specific examples include aliphatic diamines such as metaxylylenediamine, ethylenediamine, 1,3-propanediamine, tetramethylenediamine, hexamethylenediamine, and the like; alicyclic diamines such as p-cyclohexanediamine and 4,4. '-Methylenebis (cyclohexylamine) and the like;

（式（Ｅ−１）中、Ｘ^I及びＸ^IIは、それぞれ独立に、単結合、−Ｏ−、−ＣＯＯ−又は−ＯＣＯ−であり、Ｒ^Ｉは炭素数１〜３のアルカンジイル基であり、Ｒ^ＩＩは単結合又は炭素数１〜３のアルカンジイル基であり、ａは０又は１であり、ｂは０〜２の整数であり、ｃは１〜２０の整数であり、ｄは０又は１である。ただし、ａ及びｂが同時に０になることはない。）
で表される化合物等の側鎖型ジアミン：
ｐ−フェニレンジアミン、４，４’−ジアミノジフェニルメタン、４，４’−エチレンジアニリン、４，４’−ジアミノジフェニルアミン、４，４’−ジアミノジフェニルスルフィド、４−アミノフェニル−４’−アミノベンゾエート、４，４’−ジアミノアゾベンゼン、３，５−ジアミノ安息香酸、１，２−ビス（４−アミノフェノキシ）エタン、１，５−ビス（４−アミノフェノキシ）ペンタン、ビス［２−（４−アミノフェニル）エチル］ヘキサン二酸、ビス（４−アミノフェニル）アミン、Ｎ，Ｎ−ビス（４−アミノフェニル）メチルアミン、１，４−ビス（４−アミノフェニル）−ピペラジン、Ｎ，Ｎ’−ビス（４−アミノフェニル）−ベンジジン、２，２’−ジメチル−４，４’−ジアミノビフェニル、２，２’−ビス（トリフルオロメチル）−４，４’−ジアミノビフェニル、４，４’−ジアミノジフェニルエーテル、２，２−ビス［４−（４−アミノフェノキシ）フェニル］プロパン、４，４’−（フェニレンジイソプロピリデン）ビスアニリン、１，４−ビス（４−アミノフェノキシ）ベンゼン、４−（４−アミノフェノキシカルボニル）−１−（４−アミノフェニル）ピペリジン、４，４’−［４，４’−プロパン−１，３−ジイルビス（ピペリジン−１，４−ジイル）］ジアニリン等の非側鎖型ジアミンを；
ジアミノオルガノシロキサンとして、例えば、１，３−ビス（３−アミノプロピル）−テトラメチルジシロキサン等を；それぞれ挙げることができるほか、特開２０１０−９７１８８号公報に記載のジアミン化合物を用いることができる。 Examples of aromatic diamines include dodecanoxydiaminobenzene, hexadecanoxydiaminobenzene, octadecanoxydiaminobenzene, cholestanyloxydiaminobenzene, cholesteryloxydiaminobenzene, cholesteryl diaminobenzoate, cholesteryl diaminobenzoate, and diaminobenzoic acid. Lanostanyl, 3,6-bis (4-aminobenzoyloxy) cholestane, 3,6-bis (4-aminophenoxy) cholestane, 1,1-bis (4-((aminophenyl) methyl) phenyl) -4-butyl Cyclohexane, 2,5-diamino-N, N-diallylaniline, the following formula (E-1)

(In formula (E-1), X ^I and X ^II are each independently a single bond, —O—, —COO— or —OCO—, and R ^I is an alkanediyl group having 1 to 3 carbon atoms. R ^II is a single bond or an alkanediyl group having 1 to 3 carbon atoms, a is 0 or 1, b is an integer of 0 to 2, c is an integer of 1 to 20, and d is 0 or 1. However, a and b are not 0 at the same time.)
Side-chain diamines such as compounds represented by:
p-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-ethylenedianiline, 4,4′-diaminodiphenylamine, 4,4′-diaminodiphenyl sulfide, 4-aminophenyl-4′-aminobenzoate, 4,4′-diaminoazobenzene, 3,5-diaminobenzoic acid, 1,2-bis (4-aminophenoxy) ethane, 1,5-bis (4-aminophenoxy) pentane, bis [2- (4-amino Phenyl) ethyl] hexanedioic acid, bis (4-aminophenyl) amine, N, N-bis (4-aminophenyl) methylamine, 1,4-bis (4-aminophenyl) -piperazine, 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- (4-aminophenoxycarbonyl) -1- (4-aminophenyl) piperidine, 4,4 ′-[4,4′-propane-1,3-diylbis ( Piperidine-1,4-diyl)] non-side chain diamines such as dianiline;
Examples of the diaminoorganosiloxane include 1,3-bis (3-aminopropyl) -tetramethyldisiloxane, and the like. In addition, a diamine compound described in JP 2010-97188 A can be used. .

ジアミン化合物は、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 compound represented by the formula (E-1) include compounds represented by the following formula (E-1-1) and formula (E-1-2), for example.

A diamine compound can be used individually by 1 type or in combination of 2 or more types.

(Synthesis of polyamic acid)
A polyamic acid is obtained by reacting a tetracarboxylic dianhydride and a diamine compound as described above together with a molecular weight modifier (for example, acid monoanhydride, monoamine compound, monoisocyanate compound, etc.) as necessary. Can do. The ratio of the tetracarboxylic dianhydride and the diamine compound used for the polyamic acid synthesis reaction is such that the acid anhydride group of the tetracarboxylic dianhydride is 0.2 with respect to 1 equivalent of the amino group of the diamine compound. A ratio of ˜2 equivalents is preferred. When synthesizing polyamic acid, the amount of the specific acid dianhydride is compared to the total amount of tetracarboxylic dianhydride used in the synthesis from the viewpoint of imparting sufficiently high liquid crystal alignment ability to the coating film by irradiation with polarized radiation. Thus, it is preferably 5 mol% or more, more preferably 10 mol% or more, and further preferably 20 mol% or more.

  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, phenol solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons, hydrocarbons and the like. Particularly preferred organic solvents are N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphortriamide, m-cresol, xylenol. And one or more selected from the group consisting of halogenated phenols, or a mixture of one or more of these and another organic solvent (for example, butyl cellosolve, diethylene glycol diethyl ether, etc.). The amount of the organic solvent used is preferably such that the total amount of tetracarboxylic dianhydride and diamine compound is 0.1 to 50% by mass relative to the total amount of the reaction solution. The reaction solution obtained by dissolving the polyamic acid may be used for preparing the liquid crystal aligning agent as it is, or may be used for preparing the liquid crystal aligning agent after isolating the polyamic acid contained in the reaction solution.

  The polyamic acid ester as the polymer [A] is, for example, [I] a method of reacting the polyamic acid obtained above with an esterifying agent (for example, methanol, ethanol, N, N-dimethylformamide diethyl acetal, etc.), [II] A tetracarboxylic acid diester and a diamine compound are mixed with an appropriate dehydration catalyst (for example, 4- (4,6-dimethoxy-1,3,5-triazin-2-yl) -4-methyl, preferably in an organic solvent. A method of reacting in the presence of morpholinium halide, carbonyl imidazole, phosphorus condensing agent, etc., [III] tetracarboxylic acid diester dihalide and diamine, preferably in an organic solvent, preferably in a suitable base (eg pyridine, triethylamine) Tertiary amines such as sodium hydride, potassium hydride, sodium hydroxide A method of reacting in the presence of potassium hydroxide, sodium, alkali metals such as potassium) can be obtained by such. The polyamic acid ester contained in the liquid crystal aligning agent may have only an amic acid ester structure, or may be a partially esterified product in which an amic acid structure and an amic acid ester structure coexist. In addition, when the polyamic acid ester is obtained as a solution by the above reaction, the solution may be used for the preparation of the liquid crystal aligning agent as it is, and after isolating the polyamic acid ester contained in the reaction solution, You may use for preparation.

  The polyimide as the polymer [A] can be obtained, for example, by dehydrating and ring-closing the polyamic acid synthesized as described above to imidize. The polyimide may be a completely imidized product obtained by dehydrating and cyclizing all of the amic acid structure possessed by the polyamic acid that is the precursor, and only a part of the amic acid structure may be dehydrated and cyclized. It may be a partially imidized product in which a ring structure coexists. The polyimide used for the reaction preferably has an imidation ratio of 20 to 99%, more preferably 30 to 90%. This imidation ratio represents the ratio of the number of imide ring structures to the total of the number of polyimide amic acid structures and the number of imide ring structures in percentage. Here, a part of the imide ring may be an isoimide ring.

  The polyamic acid is preferably dehydrated and closed by a method in which the polyamic acid is dissolved in an organic solvent, a dehydrating agent and a dehydrated ring-closing catalyst are added to the solution, and the mixture is heated as necessary. As the dehydrating agent, for example, acid anhydrides such as acetic anhydride, propionic anhydride, and trifluoroacetic anhydride can be used. It is preferable that the usage-amount of a dehydrating agent shall be 0.01-20 mol with respect to 1 mol of the amic acid structure of a polyamic acid. As the dehydration ring closure catalyst, for example, tertiary amines such as pyridine, collidine, lutidine, triethylamine and the like can be used. It is preferable that the usage-amount of a dehydration ring-closing catalyst shall be 0.01-10 mol with respect to 1 mol of dehydrating agents to be used. As an organic solvent to be used, the organic solvent illustrated as what is used for the synthesis | combination of a polyamic acid can be mentioned. The reaction temperature of the dehydration ring closure reaction is preferably 0 to 180 ° C., and the reaction time is preferably 1.0 to 120 hours. The reaction solution containing the polyimide thus obtained may be directly used for the preparation of the liquid crystal aligning agent, or may be used for the preparation of the liquid crystal aligning agent after the polyimide is isolated.

The solution viscosity of the polymer [A] preferably has a solution viscosity of 10 to 800 mPa · s when a 10% by mass concentration solution is obtained, and has a solution viscosity of 15 to 500 mPa · s. It is more preferable. The solution viscosity (mPa · s) is E for a polymer solution having a concentration of 10% by mass prepared using a good solvent for the polymer [A] (for example, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.). It is a value measured at 25 ° C. using a mold rotational viscometer.
The weight average molecular weight (Mw) in terms of polystyrene measured by gel permeation chromatography (GPC) of the polymer [A] is preferably 1,000 to 500,000, more preferably 2,000 to 300,000. It is. The molecular weight distribution (Mw / Mn) represented by the ratio between Mw and the polystyrene-equivalent number average molecular weight (Mn) measured by GPC is preferably 15 or less, more preferably 10 or less. In addition, the polymer [A] contained in the liquid crystal aligning agent may be only one kind, or two or more kinds may be combined.

  By using a liquid crystal aligning agent containing the polymer [A] as the polymer component, it is possible to obtain a liquid crystal element exhibiting good afterimage characteristics and contrast characteristics. This is because, by using the skeleton represented by the above formula (3) as a photosensitive group, sufficient anisotropy is expressed in the film by photolysis accompanying ultraviolet irradiation, and the anisotropy is stable for a long time. This is thought to be due to being maintained. Thereby, even when the liquid crystal element is driven for a long time, the deviation of the liquid crystal alignment direction from the initial state can be reduced, and the AC afterimage can be reduced and the contrast can be improved. However, this is just a guess and does not limit the content of the present disclosure.

≪Other ingredients≫
The liquid crystal aligning agent of the present disclosure contains the polymer [A] as described above, but may contain other components as necessary. As other components, for example, a polymer having neither the partial structure represented by the above formula (1) nor the partial structure represented by the above formula (2) (hereinafter referred to as “other polymer”). , Compounds having at least one epoxy group in the molecule, functional silane compounds, photopolymerizable compounds, antioxidants, metal chelate compounds, curing accelerators, surfactants, fillers, dispersants, photosensitizers, etc. Is mentioned. The main skeleton of the other polymer is not particularly limited. For example, polyamic acid, polyimide, polyamic acid ester, polyamide, polysiloxane, polyester, cellulose derivative, polyacetal, polystyrene derivative, poly (styrene-phenylmaleimide) derivative, Examples thereof include polymers having poly (meth) acrylate or the like as a main skeleton. 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 content ratio of the polymer [A] in the liquid crystal aligning agent is a solid component (component other than the solvent) in the liquid crystal aligning agent from the viewpoint of sufficiently increasing the contrast characteristics and AC afterimage characteristics of the liquid crystal element obtained by the photo-alignment treatment. ) Is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and still more preferably 20 parts by mass or more.

<Solvent>
The liquid crystal aligning agent of the present disclosure is prepared as a liquid composition in which the polymer [A] and other components used as necessary are preferably dispersed or dissolved in an appropriate solvent.
Examples of the organic solvent used include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 1,2-dimethyl-2-imidazolidinone, γ-butyrolactone, γ-butyrolactam, and N, N-dimethylformamide. N, N-dimethylacetamide, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol methyl ether, Ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether, ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether Ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, diisopentyl ether, ethylene carbonate, A propylene carbonate etc. can be mentioned. These can be used individually by 1 type or in mixture of 2 or more types.

  The solid content concentration in the liquid crystal aligning agent (the ratio of the total mass of components other than the solvent of the liquid crystal aligning agent to the total mass of the liquid crystal aligning agent) is appropriately selected in consideration of viscosity, volatility, etc. It is the range of 1-10 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, it is difficult to obtain a good liquid crystal alignment film because the film thickness is excessive, and the viscosity of the liquid crystal aligning agent increases and the applicability decreases. 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 aligning agent prepared as described above. Moreover, the liquid crystal element of this indication comprises the liquid crystal aligning film formed using the liquid crystal aligning agent demonstrated above. The operation mode of the liquid crystal in the liquid crystal element is not particularly limited, and includes, for example, a TN (Twisted Nematic) type, STN (Super Twisted Nematic) type, VA (Vertical Alignment) type (including VA-MVA type, VA-PVA type, etc.). It can be applied to various modes such as IPS (In-Plane Switching) type, FFS (fringe field switching) type, OCB (Optically Compensated Bend) type. A liquid crystal element can be manufactured by the method including the following processes 1 to 3, for example. In step 1, the substrate to be used varies depending on the desired operation mode. Step 2 and step 3 are common to each operation mode.

(Step 1: Formation of coating film)
First, a liquid crystal aligning agent is applied on a substrate, and a coating film is preferably formed on the substrate by heating the coated surface. As the substrate, for example, glass such as float glass or soda glass; a transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, poly (cycloaliphatic olefin) can be used. As a transparent conductive film provided on one surface of the substrate, an NESA film (registered trademark of PPG, USA) made of tin oxide (SnO ₂ ), an ITO film made of indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ ), etc. Can be used. In the case of 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 an electrode patterned in a comb shape and a counter substrate provided with no electrode are used. Application of the liquid crystal aligning agent to the substrate is preferably performed on the electrode forming surface by an offset printing method, a spin coating method, a roll coater method or an ink jet printing method.

  After applying the liquid crystal aligning agent, preheating (pre-baking) is preferably performed for the purpose of preventing dripping of the applied liquid crystal aligning agent. The prebake temperature is preferably 30 to 200 ° C., and the prebake time is preferably 0.25 to 10 minutes. Thereafter, the solvent is completely removed, and if necessary, a baking (post-baking) step is performed for the purpose of thermally imidizing the amic acid structure present in the polymer. The firing temperature (post-bake temperature) at this time is preferably 80 to 300 ° C., and the post-bake time is preferably 5 to 200 minutes. The 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 (orientation treatment) for imparting liquid crystal alignment ability to the coating film formed in Step 1 is performed. Thereby, the orientation ability of a liquid crystal molecule is provided to a coating film, and it becomes a liquid crystal aligning film. As the alignment treatment, for example, a rubbing treatment that imparts liquid crystal alignment ability to the coating film by rubbing the coating film in a certain direction with a roll wrapped with a cloth made of fibers such as nylon, rayon, cotton, etc., a coating film formed on the substrate And a photo-alignment process for imparting liquid crystal alignment ability to the coating film, and the photo-alignment method can be particularly preferably applied. On the other hand, when manufacturing a vertical alignment type liquid crystal element, the coating film formed in the above step 1 can be used as it is as a liquid crystal alignment film, but the coating film may be subjected to an alignment treatment.

  Light irradiation for photo-alignment is a method of irradiating the coating film after the post-baking process, a method of irradiating the coating film after the pre-baking process and before the post-baking process, a pre-baking process and a post-baking process. At least one of the methods can be performed by a method of irradiating the coating film while the coating film is heated. As the radiation applied to the coating film, for example, ultraviolet rays and visible rays including light having a wavelength of 150 to 800 nm can be used. Preferably, it is an ultraviolet ray containing light having a wavelength of 200 to 400 nm. When the radiation is polarized light, it may be linearly polarized light or partially polarized light. When the radiation to be used is linearly polarized light or partially polarized light, irradiation may be performed from a direction perpendicular to the substrate surface, may be performed from an oblique direction, or a combination thereof. The irradiation direction in the case of non-polarized radiation is an oblique direction.

As a light source to be used, for example, 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, or the like can be used. The radiation dose is preferably 400 to 50,000 J / m ² , more preferably 1,000 to 20,000 J / m ² . After light irradiation for imparting alignment 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) or a mixture thereof. You may perform the process to heat and the process to heat a board | substrate.

(Process 3: Construction of liquid crystal cell)
Two substrates on which the liquid crystal alignment film is formed as described above are prepared, and a liquid crystal cell is manufactured by disposing a liquid crystal between the two substrates disposed to face 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 together using a sealant, Examples thereof include a method of injecting and filling liquid crystal in a cell gap surrounded by a sealing agent to seal the injection hole, a method using an ODF method, and the like. As the sealant, for example, an epoxy resin containing a curing agent and aluminum oxide spheres as a spacer can be used. Examples of the liquid crystal include nematic liquid crystals and smectic liquid crystals. Among them, nematic liquid crystals are preferable.

  Subsequently, if necessary, a polarizing plate is bonded to the outer surface of the liquid crystal cell to obtain a liquid crystal element. Examples of the polarizing plate include a polarizing plate comprising a polarizing film called an “H film” in which iodine is absorbed while stretching and orientation of polyvinyl alcohol is sandwiched between cellulose acetate protective films, or a polarizing plate made of the H film itself.

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

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

In the following examples, the weight average molecular weight Mw of the polymer was measured by the following method.
[Weight Average Molecular Weight Mw of Polymer]: A polystyrene conversion value measured by GPC under the following conditions.
Column: Tosoh Co., Ltd., TSKgelGRCXLII
Solvent: Tetrahydrofuran Temperature: 40 ° C
Pressure: 68 kgf / cm ²
Hereinafter, the “compound represented by the formula (X)” may be simply referred to as “compound (X)”.

<Synthesis of compounds>
[Example 1-1]
Compound (a-1) was synthesized according to the following scheme 1.

For the first stage of Scheme 1, see References Organic Synthesis, 1977, Vol. The synthesis was performed by the method described in 57,92-94, and 10.0 g of intermediate (a-1-1) was obtained with a purity of 99%. Next, 10.0 g of intermediate (a-1-1), 9.8 g of maleic anhydride, 0.1 g of benzophenone, and ethyl acetate were added to a 200 ml internal irradiation type Pyrex (registered trademark) glass four-necked reactor. 111 ml was charged, and the outer wall of the reactor was covered with aluminum foil and dissolved by stirring for 15 minutes at room temperature while bubbling nitrogen. The solution was then cooled to 5 ° C. and irradiated with stirring using a 400 W high pressure mercury lamp in a Pyrex (registered trademark) glass light source condenser in the center of the reactor. After completion of the reaction, the solid was separated by filtration, washed with ethyl acetate, and dried to obtain 3.0 g of intermediate (a-1-2) with a purity of 99%.
3.0 g of the obtained intermediate (a-1-2) was added to a mixed solvent of 25.5 ml of pure water, 51 ml of tetrahydrofuran, and 102 ml of acetic acid, and stirred at 45 ° C. for 4 hours. Then it was concentrated. To the obtained residue, 15 ml of acetic anhydride was added and stirred at 100 ° C. for 5 hours. Thereafter, the mixture was cooled to room temperature, and the precipitated white solid was filtered and dried to obtain 2.1 g of compound (a-1) with a purity of 99%.

[Example 1-2]
Synthesis was performed in the same manner as in Example 1-1 except that maleic anhydride was changed to 2,3-dimethylmaleic anhydride in the second stage of Scheme 1 in Example 1-1, and compound (a- 2) was obtained.

[Example 1-3]
The first stage of Scheme 1 in Example 1-1 was changed to the following Scheme 2, and the second and subsequent stages of the above Scheme 1 using the compound (intermediate (a-3-1)) obtained in the following Scheme 2 The compound (a-3) was obtained in the same manner as in Example 1-1 except that the above procedure was performed.

  For Scheme 2, 15.0 g of γ-pyrone, 0.25 g of ammonium nitrate, and 49.7 g of trimethyl orthoformate were added to 120 ml of methanol and stirred at room temperature for 5 minutes. Subsequently, it stirred at 50 degreeC for 10 hours. Thereafter, the reaction solution was added to 150 ml of a 4% by mass aqueous sodium hydrogen carbonate solution, and after separating with ethyl acetate, the organic layer was separated with pure water and saturated brine. Then, it is dried over magnesium sulfate, the solution is concentrated, and the residue is purified by column chromatography (silica gel / containing 0.1% by mass of triethylamine, hexane: ethyl acetate mixed solvent (volume ratio 2: 1)). Intermediate (a-3-1) was obtained in 12.0 g with a purity of 99%.

[Example 1-4]
Compound (a-4) was synthesized according to the following scheme 3.

  A 200 ml internal irradiation type pyrex (registered trademark) glass four-necked reactor was charged with 10.0 g of 1-methyl-4-pyridone, 18.0 g of maleic anhydride, 0.17 g of benzophenone, and 150 ml of ethyl acetate. The outer wall of the vessel was covered with aluminum foil and dissolved by stirring for 15 minutes at room temperature while bubbling nitrogen. The solution was then cooled to 5 ° C. and irradiated with stirring using a 400 W high pressure mercury lamp in a Pyrex (registered trademark) glass light source condenser in the center of the reactor. After completion of the reaction, the solid was separated by filtration, and the solid was added to a mixed solvent of 70 ml of tetrahydrofuran and 35 ml of ethyl acetate and stirred at 80 ° C. for 30 minutes. Then, after cooling to room temperature, the precipitated white solid was filtered and dried to obtain 5.1 g of Compound (a-4) with a purity of 99%.

[Example 1-5]
Compound (b-1) was synthesized according to the following scheme 4.

  Compound (a-1) 10.0g and pyridine 0.26g were added to ethyl acetate 34ml, and it stirred at room temperature for 5 minutes. To this solution, 32 ml of methanol was added dropwise over 1 hour so that the internal temperature was 25 ° C. or lower. After completion of the dropwise addition, the mixture was stirred at room temperature for 2 hours to obtain a uniform solution. After concentrating this solution, 70 ml of ethyl acetate was added, heated to 80 ° C. and refluxed for 30 minutes, and then allowed to cool to room temperature. Next, the precipitated white solid was filtered, washed twice with 15 ml of ethyl acetate, and dried to obtain 8.4 g of Compound (b-1) with a purity of 99%.

<Synthesis of polymer>
[Example 2-1]
100 mol parts of compound (a-1) as tetracarboxylic dianhydride and 100 mol parts of p-phenylenediamine as diamine compound are dissolved in N-methyl-2-pyrrolidone (NMP) and reacted at 60 ° C. for 4 hours. And a solution containing 20% by mass of polyamic acid was obtained. The weight average molecular weight Mw of the obtained polyamic acid (hereinafter referred to as “polymer (A-1)”) was 30,000.
[Examples 2-2, 2-3, 2-5, 2-6 and Synthesis Examples 1 and 2]
A polyamic acid (polymer (A-2), (A-3) was obtained in the same manner as in Example 2-1 except that the types and amounts of tetracarboxylic dianhydride and diamine compound used were changed as shown in Table 1 below. ), (A-5), (A-6) and polymers (B-1), (B-2)) were synthesized respectively.
[Example 2-4]
10.0 g of compound (b-1) was added to 20 ml of thionyl chloride, a catalytic amount of N, N-dimethylformamide was added, and then the mixture was stirred at 80 ° C. for 1 hour. Thereafter, the reaction solution was concentrated, and the residue was dissolved in 88.4 g of γ-butyrolactone (GBL) (this solution was used as the reaction solution (A)). Separately, 3.1 g of p-phenylenediamine was added to 5.4 g of pyridine, 34.8 g of NMP, and 26.2 g of GBL, dissolved, and cooled to 0 ° C. Next, the reaction solution (A) was slowly added dropwise to this solution over 1 hour. After completion of dropping, the mixture was stirred at room temperature for 4 hours. The obtained polyamic acid ester solution was added dropwise to 650 ml of pure water with stirring, the deposited precipitate was filtered, washed with 300 ml of isopropyl alcohol (IPA) five times, and dried to obtain a polymer. 11.6 g of powder was obtained. The obtained polyamic acid ester (hereinafter referred to as “polymer (A-4)”) had a weight average molecular weight Mw of 40,000.

In Table 1, the numbers in parentheses of the tetracarboxylic acid derivative and diamine represent the usage ratio [mole part] of each compound with respect to a total of 100 mole parts of the tetracarboxylic acid derivative used for the synthesis of the polymer. Abbreviations in Table 1 have the following meanings.
<Tetracarboxylic acid derivative>
d-1: 1,2,4,5-cyclohexanetetracarboxylic dianhydride d-2: 1,2,3,4-cyclobutanetetracarboxylic dianhydride d-3: in the following formula (d-3) Compound represented <diamine>
c-1: p-phenylenediamine c-2: 1,4-bis (4-aminophenyl) -piperazine c-3: 1,5-bis (4-aminophenoxy) pentane c-4: 2,2′- Bis (trifluoromethyl) -p-biphenylenediamine c-5: 4,4′-diaminodiphenylamine

[Example 3-1]
1. Preparation of liquid crystal aligning agent As a polymer component, NMP and butyl cellosolve (BC) are added to the solution containing the polymer (A-1) obtained in Example 2-1 above, and the mixture is sufficiently stirred. : BC = 70: 30 (mass ratio) and a solid content concentration of 3.0% by mass. A liquid crystal aligning agent was prepared by filtering this solution using a filter having a pore diameter of 0.45 μm.

2. Production of Optical FFS Type Liquid Crystal Display Element The FFS type liquid crystal display element 10 shown in FIG. 1 was produced. First, a glass substrate 11a having an electrode pair on one side of which a bottom electrode 15 having no pattern, a silicon nitride film as an insulating layer 14, and a top electrode 13 patterned in a comb shape are formed in this order, and an electrode The counter glass substrate 11b not provided with a pair of the glass substrate 11a and the surface of the glass substrate 11a having a transparent electrode and one surface of the counter glass substrate 11b are respectively 1. The liquid crystal aligning agent prepared in (1) was applied using a spinner to form a coating film.
A schematic plan view of the used top electrode 13 is shown in FIG. 2A is a top view of the top electrode 13, and FIG. 2B is an enlarged view of a portion C1 surrounded by a broken line in FIG. 2A. In this example, the line width d1 of the electrodes was 4 μm, and the distance d2 between the electrodes was 6 μm. Further, as the top electrode 13, four systems of drive electrodes of electrode A, electrode B, electrode C, and electrode D were used (FIG. 3). The bottom electrode 15 functions as a common electrode that acts on all of the four systems of drive electrodes, and each of the four systems of drive electrodes serves as a pixel area.
After the coating film was formed by the spinner, the coating film was pre-baked for 1 minute on an 80 ° C. hot plate, and heated (post-baked) at 230 ° C. for 1 hour in an oven in which the inside of the chamber was replaced with nitrogen. Thereafter, each surface of the coating film was irradiated with polarized ultraviolet rays of 3,000 J / m ² using a Hg—Xe lamp and a Grand Taylor prism to obtain a pair of substrates having a liquid crystal alignment film. At this time, the irradiation direction of the polarized ultraviolet rays is from the normal direction of the substrate, and the polarization plane direction is set so that the direction of the line segment in which the polarization plane of the polarized ultraviolet rays is projected onto the substrate is the direction of the double-headed arrow in FIG. The light irradiation process was performed after setting. After light irradiation, it was heated at 230 ° C. for 1 hour (addition bake) in an oven in which the inside of the chamber was replaced with nitrogen to form a coating film having an average film thickness of 0.1 μm.

Next, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 3.5 μm is applied to the outer periphery of the surface of the substrate having the liquid crystal alignment film by screen printing, and the liquid crystal alignment film surfaces of the pair of substrates are then applied. It was made to oppose and it piled up and crimped | bonded so that the direction which the polarization plane of polarized ultraviolet rays projected on the board | substrate might become parallel, and the adhesive was thermoset at 150 degreeC over 1 hour. Next, after filling the substrate gap from the liquid crystal injection port with liquid crystal “MLC-7028” manufactured by Merck, the liquid crystal injection port was sealed with an epoxy resin adhesive. Then, in order to remove the flow alignment at the time of liquid crystal injection, this was heated to 150 ° C. and then gradually cooled to room temperature. Next, an FFS type liquid crystal display element was manufactured by attaching polarizing plates to both outer surfaces of the substrate. At this time, one of the polarizing plates is stuck so that the polarization direction thereof is parallel to the direction of projection of the polarization plane of the polarized ultraviolet light of the liquid crystal alignment film onto the substrate surface, and the other one has the polarization direction first. The polarizing plate was stuck so as to be orthogonal to the polarization direction of the polarizing plate.
In addition, by performing the above series of operations by changing the ultraviolet irradiation amount after post-baking within the range of 500 to 20,000 J / m ² , three or more liquid crystal display elements having different ultraviolet irradiation amounts can be obtained. Manufactured.

3. Evaluation of liquid crystal display element 2. The following (1) was evaluated using the liquid crystal display device manufactured in (1). Further, the above 2. except that the polarizing plate was not bonded. A liquid crystal display element (a liquid crystal cell in which a polarizing plate was not bonded) was manufactured by performing the same operation as described above, and the following (2) and (3) were evaluated. In addition, about the evaluation result, the best result was selected from the 3 or more liquid crystal display elements from which ultraviolet irradiation amount differs, and it used for evaluation of the liquid crystal display element.
(1) Evaluation of AC afterimage characteristics The FFS type liquid crystal display device manufactured in the above was placed in an environment of 25 ° C. and 1 atmosphere. The bottom electrode was set as a common electrode for all four drive electrodes, and the potential of the bottom electrode was set to 0 V potential (ground potential). While the electrodes B and D were short-circuited with the common electrode to be in a 0 V application state, a composite voltage consisting of an AC voltage of 5 V was applied to the electrodes A and C for 100 hours. Immediately after 100 hours, an AC voltage of 1.5 V was applied to all of the electrodes A to D. Then, from the time when the voltage of AC 1.5V starts to be applied to all of the electrodes A to D, the driving stress application region (pixel region of the electrodes A and C) and the driving stress non-application region (electrode B and electrode D). The time until the luminance difference from the pixel area) cannot be visually confirmed is measured, and this is defined as an afterimage erasing time Ts. Note that the shorter this time, the less likely an afterimage is generated. The case where the afterimage erasing time Ts is less than 30 seconds is “good (◯)”, the case where it is 30 seconds or more and less than 120 seconds is “good (Δ)”, and the case where it is 120 seconds or more is “bad” (× ) ", The liquid crystal display device of this example was evaluated as having good afterimage characteristics.

(2) Evaluation of contrast after driving stress The liquid crystal display device manufactured in (1) is driven at an AC voltage of 10 V for 30 hours, and then a device in which a polarizer and an analyzer are arranged between the light source and the light amount detector is used. The transmittance (%) was measured.
Minimum relative transmittance (%) = (β−B ⁰ ) / (B ¹⁰⁰ −B ⁰ ) × 100 (1)
(In Formula (1), B ⁰ is the transmission amount of light under the crossed Nicols in the blank. B ¹⁰⁰ is the transmission amount of the light in the blanks and under the Paranicol. Β is the polarizer under the crossed Nicols. (The liquid crystal display element is sandwiched between the analyzers, and this is the minimum light transmission amount.)
The black level in the dark state is represented by the minimum relative transmittance of the liquid crystal display element, and the smaller the black level in the dark state, the better the contrast. A sample with a minimum relative transmittance of less than 0.5% is defined as “Good (◯)”, a sample having a minimum relative transmittance of less than 0.5% and less than 1.0% is defined as “Yes”, and a sample having a minimum relative transmittance of 1.0% or more “Bad (×)”. As a result, the contrast evaluation of this liquid crystal display element was determined to be “good”.

(3) Evaluation of sensitivity to ultraviolet rays In the evaluation of (2), the sensitivity to ultraviolet rays of a coating film formed using a liquid crystal aligning agent was evaluated based on the ultraviolet ray irradiation amount of the liquid crystal display element having the best contrast evaluation result. . In addition, it can be said that the sensitivity with respect to the ultraviolet-ray of a coating film is so favorable that there is little ultraviolet irradiation amount. Evaluation, when the amount of ultraviolet irradiation is less than 4,000J / ^{m 2} the sensitivity "good (○)", the sensitivity "Yes case was 4,000J / ^{m 2} or more 10,000 J / ^m less than ² ( Δ) ”The sensitivity was“ bad (×) ”when the density was 10,000 J / m ² or more. As a result, the sensitivity of the coating film of this example to ultraviolet rays was determined to be “good”.

[Examples 3-2 and 3-6 and Comparative Example 1-1]
A liquid crystal aligning agent was prepared at the same solvent ratio and solid content concentration as in Example 3-1, except that the type of polymer used was changed as shown in Table 2 below. Moreover, while producing a liquid crystal display element like Example 3-1, using each liquid crystal aligning agent, various evaluation was performed using the obtained liquid crystal display element. The results are shown in Table 2 below. In Table 2, the numerical value in parentheses in the polymer column indicates the blending ratio [parts by mass] of each polymer with respect to 100 parts by mass in total of the polymer components used for preparing the liquid crystal aligning agent.

[Example 3-3]
The liquid crystal aligning agent was prepared by the same solvent ratio and solid content concentration as the said Example 3-1, except the point which changed the kind of polymer to be used into the polymer (A-3). Further, in place of the point of using the liquid crystal aligning agent prepared in this example and the procedure of additional baking after performing the photo-alignment treatment with polarized ultraviolet rays, the substrate was subjected to pure water after performing the photo-alignment treatment with polarized ultraviolet rays. / IPA = 1/1 (mass ratio) liquid crystal display in the same manner as in Example 3-1 except that it was immersed in a mixed solution for 3 minutes and then further baked after being immersed in pure water for 1 minute. While producing an element, various evaluation was performed using the obtained liquid crystal display element. The results are shown in Table 2 below.

[Example 3-4]
As a polymer component, 3.0 g of the powder polymer (A-4) obtained in Example 2-4 above was added to a mixed solution of 19.4 g of NMP and 67.9 g of GBL, and sufficiently stirred to dissolve. . Next, 9.7 g of BC was added and stirred to obtain a solution having a solvent composition of NMP: GBL: BC = 20: 70: 10 (mass ratio) and a solid content concentration of 3.0 mass%. A liquid crystal aligning agent was prepared by filtering this solution using a filter having a pore diameter of 0.45 μm.
Regarding the production and evaluation of the liquid crystal display element, a liquid crystal display element was produced in the same manner as in Example 3-1 using the liquid crystal aligning agent prepared in this example, and various evaluations were performed using the obtained liquid crystal display element. Went. The results are shown in Table 2 below.

[Example 3-5]
1.5 g of the polymer (A-4) was added to a mixed solution of 13.4 g of NMP and 67.9 g of GBL and sufficiently stirred to dissolve. Polymer solution (B-1) 7.5g and BC9.7g are added and stirred to the solution, solvent composition is NMP: GBL: BC = 20: 70: 10 (weight ratio), solid content concentration 3. A liquid crystal aligning agent was prepared by preparing a 0 wt% solution and filtering the solution using a filter having a pore size of 0.45 μm.
Moreover, regarding manufacture and evaluation of a liquid crystal display element, while manufacturing a liquid crystal display element like Example 3-4 using the liquid crystal aligning agent prepared in the present Example, using the obtained liquid crystal display element Various evaluations were performed. The results are shown in Table 2 below.

[Example 3-7]
1. Preparation of liquid crystal aligning agent As a polymer component, NMP and BC are added to the solution containing the polymer (A-5) obtained in Example 2-5, and the mixture is sufficiently stirred. The solvent composition is NMP: BC = 70. : 30 (mass ratio), and a solid content concentration of 3.0 mass%. A liquid crystal aligning agent was prepared by filtering this solution using a filter having a pore diameter of 0.45 μm.

2. Production of FFS-type liquid crystal display element aligned by rubbing method Using the liquid crystal aligning agent prepared above, a coating film was formed on a substrate using a spinner in the same manner as in Example 3-1, and then the coating film was coated with 80 Pre-baking was performed for 1 minute on a hot plate at 0 ° C., and heating (post-baking) was performed at 230 ° C. for 1 hour in an oven in which the inside of the chamber was replaced with nitrogen to form a coating film having a thickness of about 0.1 μm. Using a rubbing machine having a roll around which a nylon cloth is wound on the formed coating film surface, the rotation speed of the roll is 1,000 rpm, the moving speed of the stage is 25 mm / second, and the indentation length is 0.4 mm. A rubbing treatment was performed to impart liquid crystal alignment ability. Further, this substrate was ultrasonically cleaned in ultrapure water for 1 minute and dried in a clean oven at 100 ° C. for 10 minutes to obtain a pair of substrates having a liquid crystal alignment film.
Next, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 3.5 μm is applied to the outer periphery of the surface of the substrate having the liquid crystal alignment film by screen printing, and the liquid crystal alignment film surfaces of the pair of substrates are then applied. It was made to oppose and it overlap | superposed and pressure-bonded so that the rubbing direction in each liquid crystal aligning film might become antiparallel, and the adhesive was thermoset at 150 degreeC over 1 hour. Next, after filling the substrate gap from the liquid crystal injection port with liquid crystal “MLC-7028” manufactured by Merck, the liquid crystal injection port was sealed with an epoxy resin adhesive. Then, in order to remove the flow alignment at the time of liquid crystal injection, this was heated to 150 ° C. and then gradually cooled to room temperature. Next, a liquid crystal display element was manufactured by bonding polarizing plates on both outer surfaces of the substrate so that the polarization directions thereof were orthogonal to each other and in the rubbing direction of the liquid crystal alignment film.

3. Evaluation of liquid crystal display element 2. The liquid crystal display element obtained in (1) was evaluated for (1) AC afterimage characteristics and (2) contrast after driving stress in the same manner as in Example 3-1. In the evaluation of (2), a liquid crystal cell without a polarizing plate was used. As a result, the AC afterimage characteristics and the contrast evaluation after driving stress were both “good (◯)”.
Moreover, the voltage holding ratio (VHR) was evaluated using the liquid crystal cell which has not bonded the polarizing plate. Specifically, for a liquid crystal cell, a voltage of 5 V was applied at 60 ° C. with an application time of 60 microseconds and a span of 167 milliseconds, and then the voltage holding ratio after 167 milliseconds from the application release was measured. The measuring device used was “VHR-1” manufactured by Toyo Corporation. As a result, the VHR of the liquid crystal display element of this example was 99.2%.

  As can be seen from the results of Examples 3-1 to 3-7 above, the liquid crystal display element produced using the liquid crystal aligning agent containing the polymer [A] is that of the comparative example not containing the polymer [A]. As compared with the above, it was excellent in AC afterimage characteristics and contrast characteristics. Moreover, also about the photosensitivity of the coating film, in Examples 3-1 to 3-7, it was superior to the comparative example.

  DESCRIPTION OF SYMBOLS 10 ... Liquid crystal display element, 11a, 11b ... Glass substrate, 12 ... Liquid crystal aligning film, 13 ... Top electrode, 14 ... Insulating layer, 15 ... Bottom electrode, 16 ... Liquid crystal layer

Claims (6)

A liquid crystal aligning agent comprising a polymer [A] having at least one selected from the group consisting of a partial structure represented by the following formula (1) and a partial structure represented by the following formula (2).

(In formula (1), Y ¹ is a tetravalent organic group represented by the following formula (3), Z ¹ is a divalent organic group, and R ¹ and R ² are each independently It is a hydrogen atom or a monovalent organic group.)

(In Formula (3), R ^{3 to} R ¹⁰ are each independently a hydrogen atom or a monovalent organic group, A ¹ is —NR ¹³ —, a carbonyl group, an oxygen atom, or a sulfur atom; ² is —C (R ¹¹ R ¹² ) —, —NR ¹³ —, a carbonyl group, an oxygen atom or a sulfur atom, and R ¹¹ and R ¹² are each independently a hydrogen atom or a monovalent organic group. , R ¹³ is a monovalent organic group, n is 0 or 1. “*” represents a bond.)   A method for producing a liquid crystal alignment film, comprising: applying a liquid crystal aligning agent according to claim 1 on a substrate to form a coating film; and irradiating the coating film with light.   The liquid crystal aligning film formed using the liquid crystal aligning agent of Claim 1.   A liquid crystal device comprising the liquid crystal alignment film according to claim 3. A polymer having at least one selected from the group consisting of a partial structure represented by the following formula (1) and a partial structure represented by the following formula (2).

(In formula (1), Y ¹ is a tetravalent organic group represented by the following formula (3), Z ¹ is a divalent organic group, and R ¹ and R ² are each independently It is a hydrogen atom or a monovalent organic group.)

(In Formula (3), R ^{3 to} R ¹⁰ are each independently a hydrogen atom or a monovalent organic group, A ¹ is —NR ¹³ —, a carbonyl group, an oxygen atom, or a sulfur atom; ² is —C (R ¹¹ R ¹² ) —, —NR ¹³ —, a carbonyl group, an oxygen atom or a sulfur atom, and R ¹¹ and R ¹² are each independently a hydrogen atom or a monovalent organic group. , R ¹³ is a monovalent organic group, n is 0 or 1. “*” represents a bond.) A compound represented by the following formula (4).

(In Formula (4), R ^{3 to} R ¹⁰ are each independently a hydrogen atom or a monovalent organic group, A ¹ is —NR ¹³ —, a carbonyl group, an oxygen atom, or a sulfur atom; ² is —C (R ¹¹ R ¹² ) —, —NR ¹³ —, a carbonyl group, an oxygen atom or a sulfur atom, and R ¹¹ and R ¹² are each independently a hydrogen atom or a monovalent organic group. R ¹³ is a monovalent organic group, and n is 0 or 1.)

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