TWI685543B - Liquid crystal alignment agent, liquid crystal alignment film and its manufacturing method, liquid crystal element and its manufacturing method, compound - Google Patents

Abstract

The present invention provides a liquid crystal alignment agent capable of obtaining a liquid crystal element having excellent image retention characteristics and voltage retention characteristics, which contains a polymer component and a compound [A] having the following groups (1) and (2). (1) At least one group selected from the group consisting of a group having a structure having two or more rings connected directly or via a linking group, and a group having a condensed ring. (2) Selected from -NR ¹ R ² (wherein R ¹ and R ² are each independently a hydrogen atom, a C 1-10 monovalent hydrocarbon group or a protecting group), protected isocyanate group, protected isothiocyanate group , At least one group from the group consisting of a group containing an oxazoline ring structure, a group containing a Mienic acid structure, and a group represented by the following formula (g-1).

Description

Liquid crystal alignment agent, liquid crystal alignment film and its manufacturing method, liquid crystal element and its manufacturing method, compound

The invention relates to a liquid crystal alignment agent, a liquid crystal alignment film, a method for manufacturing a liquid crystal alignment film, a liquid crystal element, a method for manufacturing a liquid crystal element, and a compound.

Previously, as liquid crystal display devices, various driving methods having different electrode structures, physical properties of liquid crystal molecules used, etc. have been developed, for example, known as twisted nematic (TN) type or super twisted nematic (Super Twisted) Nematic, STN), Vertical Alignment (VA), In-Plane Switching (IPS), Fringe Field Switching (FFS), Optically Compensation Bend (OCB) ) Type and other liquid crystal display elements. These liquid crystal display elements include liquid crystal alignment films for aligning liquid crystal molecules. In terms of good heat resistance, mechanical strength, and affinity with liquid crystals, the material of the liquid crystal alignment film is polyimide or a precursor thereof (see, for example, Patent Document 1). Patent Literature 1 discloses a composite film as a liquid crystal alignment film, the composite film containing a polyamic acid having a specific partial structure and p-pentenyloxybenzoic acid (p-cyanophenyl) oxide to react The obtained polymer is made of liquid crystal. [Prior Art Literature]

[Patent Literature] [Patent Literature 1] Japanese Patent Laid-Open No. 11-64856

[Problems to be solved by the invention]

In recent years, liquid crystal display elements have been used not only for display devices such as personal computers as before, but also for various purposes such as liquid crystal televisions or car navigation systems, mobile phones, smart phones, and information displays. As the liquid crystal display device becomes more versatile, the requirements for display quality become stricter than before, and a liquid crystal display device that requires less image retention and a higher voltage retention rate is required.

The present invention has been made in view of the aforementioned problems, and one of the objects is to provide a liquid crystal alignment agent that can obtain a liquid crystal element having excellent image retention characteristics and voltage retention characteristics. [Technical means to solve the problem]

The inventors conducted intensive research in order to achieve the above-mentioned problems of the prior art, and as a result, they found that by mixing a specific compound in the liquid crystal alignment agent, the above-mentioned problems can be solved, and the present invention has been completed. Specifically, the present invention provides the following liquid crystal alignment agent, liquid crystal alignment film, method for producing liquid crystal alignment film, liquid crystal element, method for producing liquid crystal element, and compound.

In one aspect, the present invention provides a liquid crystal alignment agent containing a polymer component and a compound [A] having the following groups (1) and (2). (1) At least one group selected from the group consisting of a group having a structure having two or more rings connected directly or via a linking group, and a group having a condensed ring. (2) Selected from -NR ¹ R ² (wherein R ¹ and R ² are each independently a hydrogen atom, a C 1-10 monovalent hydrocarbon group or a protecting group), protected isocyanate group, protected isothiocyanate group , At least one group of a group consisting of a group containing an oxazoline ring structure, a group containing a Meldrum's acid structure, and a group represented by the following formula (g-1).

（式（g-1）中，R³ 及R⁶ 分別獨立地為氫原子或碳數1～3的烷基，R⁴ 及R⁵ 分別獨立地為氫原子、碳數1～3的烷基或者“*² -CH₂ -O-R¹¹ ”（R¹¹ 為氫原子或碳數1～3的烷基；“*² ”表示與R⁴ 及R⁵ 所鍵結的碳原子的結合鍵）；“*¹ ”表示結合鍵）[Chemical 1]

(In formula (g-1), R ³ and R ⁶ are each independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R ⁴ and R ⁵ are each independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. Or "* ² -CH ₂ -OR ¹¹ "(R ¹¹ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms; "* ² " represents a bonding bond to the carbon atom bonded to R ⁴ and R ⁵ );" * ¹ "means the combination key)

In one aspect, the present invention provides a liquid crystal alignment agent obtained by mixing a polymer component and a compound [A] having the groups (1) and (2). In addition, in another aspect, there is provided a liquid crystal alignment film formed using the liquid crystal alignment agent. Furthermore, there is provided a method for manufacturing a liquid crystal alignment film, comprising: a step of applying the liquid crystal alignment agent on a substrate to form a coating film; and a step of imparting liquid crystal alignment capability by irradiating the coating film with light. In addition, there is provided a liquid crystal element including the liquid crystal alignment film or the liquid crystal alignment film obtained by the manufacturing method.

In one aspect, the present invention provides a method for manufacturing a liquid crystal element, comprising: a step of applying the liquid crystal alignment agent to form a coating film on the conductive films of a pair of substrates having a conductive film; the coating film is formed A pair of substrates, a step of constructing a liquid crystal cell facing each other through the liquid crystal layer and facing the coating film; and a step of irradiating the liquid crystal cell with a voltage applied between the conductive films. In addition, in another aspect, the present invention provides a compound [A] having the groups (1) and (2). [Effect of invention]

According to the liquid crystal alignment agent containing the compound [A], a liquid crystal element excellent in image retention characteristics and voltage retention characteristics can be obtained.

<<Liquid crystal alignment agent>> The liquid crystal alignment agent of the present invention is a polymer composition obtained using a polymer component and a specific additive component. Hereinafter, each component used for preparing the liquid crystal aligning agent of this invention, and other components arbitrarily mixed as needed are demonstrated. <Polymer component> The liquid crystal alignment agent of the present invention contains a polymer component. The main skeleton of the polymer is not particularly limited, and examples include polyamic acid, polyamic acid ester, polyimide, polysiloxane, polyester, polyamidoamine, polybenzoxazole precursor, Main skeletons such as polybenzoxazole, cellulose derivatives, polyacetals, polystyrene derivatives, poly(styrene-phenyl maleimide) derivatives, poly(meth)acrylates, etc. In addition, (meth)acrylate refers to including acrylate and methacrylate. When preparing the liquid crystal alignment agent, one kind of polymer may be used alone, or two or more kinds may be used in combination.

From the viewpoint of fully exhibiting the effect of reducing the image sticking (especially the reduction of the alternating current (AC) afterimage) caused by the following compound [A], the polymerization of the liquid crystal alignment agent The material component is preferably at least one selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide (hereinafter also referred to as "polymer [P]"). The polymer [P] can be obtained, for example, by using at least one tetracarboxylic acid derivative and diamine selected from the group consisting of tetracarboxylic dianhydride, tetracarboxylic acid diester, and tetracarboxylic acid diester dihalide. Obtained through the reaction.

[Polyamide] The polyamide in the present invention can be obtained by reacting tetracarboxylic dianhydride and diamine, for example. (Tetracarboxylic dianhydride) Examples of the tetracarboxylic dianhydride used in the synthesis of polyamic acid include aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, and aromatic tetracarboxylic dianhydride. . As specific examples of these tetracarboxylic dianhydrides, for example, aliphatic tetracarboxylic dianhydrides include butane tetracarboxylic dianhydride and the like; and alicyclic tetracarboxylic dianhydrides include, for example, 1,2,3,4- Cyclobutane tetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 5-(2,5-dioxotetrahydrofuran-3-yl)-3a,4,5,9b-tetra Hydronaphtho[1,2-c]furan-1,3-dione, 5-(2,5-dioxotetrahydrofuran-3-yl)-8-methyl-3a,4,5,9b-tetra Hydronaphtho[1,2-c]furan-1,3-dione, 3-oxabicyclo[3.2.1]octane-2,4-dione-6-spiro-3'-(tetrahydrofuran- 2',5'-dione), 5-(2,5-bi-oxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 3, 5,6-tricarboxy-2-carboxymethylnorbornane-2:3,5:6-dianhydride, bicyclo[3.3.0]octane-2,4,6,8-tetracarboxylic acid 2:4 ,6:8-dianhydride, bicyclo[2.2.1]heptane-2,3,5,6-tetracarboxylic acid 2:3,5:6-dianhydride, 4,9-dioxatricyclo[5.3 .1.0 ^2,6 ]undecane-3,5,8,10-tetraone, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, bicyclo[2.2.2]oct-7-ene- 2,3,5,6-tetracarboxylic dianhydride, ethylenediaminetetraacetic dianhydride, cyclopentanetetracarboxylic dianhydride, ethylene glycol bis(trimellitic anhydride), 1,3-propanediol bis(trimellitic anhydride), etc.;

此外，所述四羧酸二酐可單獨使用一種或者將兩種以上組合使用。Examples of the aromatic tetracarboxylic dianhydride include pyromellitic dianhydride, 4,4′-(hexafluoroisopropylidene) diphthalic anhydride, and the following formula (H-1-1) to formula (H-1-4) Respectively represented compounds, etc.; In addition, the tetracarboxylic dianhydride described in Japanese Patent Laid-Open No. 2010-97188 can be used. [Chem 2]

In addition, the tetracarboxylic dianhydride may be used alone or in combination of two or more.

The tetracarboxylic dianhydride used in the synthesis preferably contains an alicyclic tetracarboxylic dianhydride, and more preferably contains a group selected from the group consisting of a cyclobutane ring structure, a cyclopentane ring structure and a cyclohexane ring structure At least one type of tetracarboxylic dianhydride in the group (hereinafter also referred to as "specific tetracarboxylic dianhydride"). Specifically, it is particularly preferable to include a group selected from 1,2,3,4-cyclobutane tetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, 5-(2,5-di Pendant tetrahydrofuran-3-yl)-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 5-(2,5-dideoxytetrahydrofuran-3 -Yl)-8-methyl-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, cyclopentanetetracarboxylic dianhydride, bicyclo[3.3. 0] At least one compound in the group consisting of octane-2,4,6,8-tetracarboxylic dianhydride and cyclohexanetetracarboxylic dianhydride. The use amount of the specific tetracarboxylic dianhydride (total amount when two or more kinds are used) is preferably set to 10 mol relative to the total amount of tetracarboxylic dianhydride used in the synthesis of polyamic acid. Ear% or more, more preferably 20 mole% or more, particularly preferably 30 mole% or more.

(Diamine) Examples of the diamine used in the synthesis of polyamic acid include aliphatic diamines, alicyclic diamines, aromatic diamines, and diamine-based organosiloxanes. As specific examples of these diamines, aliphatic diamines include, for example, m-xylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, and hexamethylenediamine. , 1,3-bis(aminomethyl)cyclohexane, etc.; alicyclic diamines include, for example: 1,4-diaminocyclohexane, 4,4'-methylenebis(cyclohexylamine )Wait;

（式（E-1）中，X^I 及X^II 分別獨立地為單鍵、-O-、*-COO-或*-OCO-（其中，“*”表示與X^I 的結合鍵），R^I 為碳數1～3的烷二基，R^II 為單鍵或碳數1～3的烷二基，a為0或1，b為0～2的整數，c為1～20的整數，d為0或1；其中，a及b不會同時為0） 所表示的化合物等側鏈型的二胺：Examples of the aromatic diamine include dodecyloxydiaminobenzene, tetradecyloxydiaminobenzene, pentadecyloxydiaminobenzene, hexadecyloxydiaminobenzene, and 18 Alkoxydiaminobenzene, cholesteryloxydiaminobenzene, cholesteryloxydiaminobenzene, diaminobenzoic acid cholesteryl ester, diaminobenzoic acid cholesteryl ester, Lanolin alkyl diaminobenzoate, 3,6-bis(4-aminobenzyloxy)cholesterane, 3,6-bis(4-aminophenoxy)cholestane, 1,1-bis(4-((aminophenyl)methyl)phenyl)-4-butylcyclohexane, 1,1-bis(4-((aminophenyl)methyl)phenyl )-4-heptylcyclohexane, 1,1-bis(4-((aminophenoxy)methyl)phenyl)-4-heptylcyclohexane, 1,1-bis(4-( (Aminophenyl)methyl)phenyl)-4-(4-heptylcyclohexyl)cyclohexane, N-(2,4-diaminophenyl)-4-(4-heptylcyclohexyl ) Benzoamide, the following formula (E-1)

(In formula (E-1), X ^I and X ^II are independently a single bond, -O-, *-COO- or *-OCO- (wherein "*" represents a bond with X ^I ), 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, and c is an integer of 1 to 20, d is 0 or 1; wherein, a and b will not be 0 at the same time) Compounds such as side chain type diamines represented by:

P-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfide, 4-aminophenyl-4'-aminobenzoate, 4 ,4'-diaminoazobenzene, 1,5-bis(4-aminophenoxy)pentane, 1,7-bis(4-aminophenoxy)heptane, bis[2-( 4-aminophenyl)ethyl]adipic acid, N,N-bis(4-aminophenyl)methylamine, 3,5-diaminobenzoic acid, 2,4-diaminobenzoic acid , 2,5-diaminobenzoic acid, 4,4'-diaminobiphenyl-3-carboxylic acid, 1,5-diaminonaphthalene, 2,2'-dimethyl-4,4'- Diaminobiphenyl, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 2,7-diaminofluorene, 4,4'-diaminodiphenyl Ether, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 9,9-bis(4-aminophenyl) stilbene, 2,2-bis[4-(4- (Aminophenoxy)phenyl)hexafluoropropane, 2,2-bis(4-aminophenyl)hexafluoropropane, 4,4'-(p-phenylene diisopropylidene)bisaniline, 4 ,4'-(m-phenylene diisopropylidene)bisaniline, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl Benzene and the like; diaminoorganosiloxanes include, for example, 1,3-bis(3-aminopropyl)-tetramethyldisilaxane, etc.; in addition, Japanese Patent Laid-Open No. 2010-97188 can be used The diamine described in No. Gazette.

Specific examples of the compound represented by the formula (E-1) include, for example, compounds represented by the following formulae (E-1-1) to (E-1-4), respectively. [Chemical 4]

Examples of the diamine used in the synthesis of polyamic acid include at least one structure selected from the group consisting of a nitrogen-containing heterocyclic ring, a secondary amine group, and a tertiary amine group (hereinafter also referred to as "nitrogen-containing structure" ") diamines; diamines with carboxyl groups, etc. According to the use of a diamine having a nitrogen-containing structure as a polymer in at least a part of the raw material, it is preferable that the improvement effect of the reduction in image sticking caused by the DC voltage of the liquid crystal display element can be improved. In addition, the use of a carboxyl group-containing diamine as a polymer in at least a part of the raw material improves the interaction with the following compound [A], and can improve the reduction in image retention caused by the AC voltage of the liquid crystal display element. The effect is better.

（式（N-1）中，R²³ 為氫原子或碳數1～10的一價烴基；“*”為鍵結於烴基上的結合鍵）Among the diamines having a nitrogen-containing structure, examples of nitrogen-containing heterocycles that the diamine may have include pyrrole, imidazole, pyrazole, triazole, pyridine, pyrimidine, pyridazine, pyrazine, indole, benzimidazole, Purine, quinoline, isoquinoline, naphthyridine, quinoxaline, phthalazine, triazine, carbazole, acridine, pyridine, pyrazine, pyrrolidine, hexamethyleneimine, etc. Among them, it is preferable to have at least one selected from the group consisting of pyridine, pyrimidine, pyrazine, pyridine, pyrazine, quinoline, carbazole, and acridine. The secondary amine group and tertiary amine group which the diamine having a nitrogen-containing structure may have are represented by the following formula (N-1), for example. [Chem 5]

(In formula (N-1), R ²³ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms; "*" is a bonding bond bonded to the hydrocarbon group)

In the formula (N-1), examples of the monovalent hydrocarbon group of R ²³ include alkyl groups such as methyl, ethyl, and propyl; cycloalkyl groups such as cyclohexyl; aryl groups such as phenyl and methylphenyl; . R ^{23 is} preferably a hydrogen atom or a methyl group.

Specific examples of the diamine having a nitrogen-containing structure include, for example, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diamine group Carbazole, N-methyl-3,6-diaminocarbazole, 1,4-bis-(4-aminophenyl)-pyrazine, 3,6-diaminoacridine, N-ethyl -3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N,N'-bis(4-aminophenyl)-benzidine, N,N'-bis (4-Aminophenyl)-N,N'-dimethylbenzidine, compounds represented by the following formula (N-1-1) to formula (N-1-8), etc., respectively. [化6]

When synthesizing a polyamic acid, the use ratio of the diamine having a nitrogen-containing structure relative to the total amount of the diamine used in the synthesis is preferably from the viewpoint of sufficiently obtaining the improvement effect of reducing the image sticking of the liquid crystal display element is It is set to 0.1 mol% or more, more preferably 1 mol% or more, and particularly preferably 2 mol% or more. In addition, the upper limit of the use ratio is preferably 60 mol% or less, more preferably 50 mol% or less, and particularly preferably 40 mol% or less. The diamine having a nitrogen-containing structure may be used alone or in combination of two or more. When synthesizing a polyamic acid, by using a diamine having a nitrogen-containing structure in at least a part of the raw material, a polyamic acid as a polymer having a nitrogen-containing structure is obtained. However, the method of obtaining the polyamic acid having a nitrogen-containing structure is not limited to the above, and for example, it can also be obtained by a method of reacting a tetracarboxylic dianhydride having a nitrogen-containing structure and a diamine.

The carboxyl group-containing diamine only needs to have at least one carboxyl group and two primary amine groups in the molecule, and the remaining structure is not particularly limited. Specific examples of the carboxyl group-containing diamine include, for example, 3,5-diaminobenzoic acid, 2,4-diaminobenzoic acid, 2,5-diaminobenzoic acid, and 4,4′-diamine Monocarboxylic acids such as aminobiphenyl-3-carboxylic acid, 4,4'-diaminodiphenylmethane-3-carboxylic acid, 4,4'-diaminodiphenylethane-3-carboxylic acid ; 4,4'-diaminobiphenyl-3,3'-dicarboxylic acid, 4,4'-diaminobiphenyl-2,2'-dicarboxylic acid, 3,3'-diaminobiphenyl Benzene-4,4'-dicarboxylic acid, 3,3'-diaminobiphenyl-2,4'-dicarboxylic acid, 4,4'-diaminodiphenylmethane-3,3'-di Carboxylic acid, 4,4'-diaminodiphenylethane-3,3'-dicarboxylic acid, 4,4'-diaminodiphenyl ether-3,3'-dicarboxylic acid and other dicarboxylic acids Acid and so on.

When synthesizing polyamic acid, from the viewpoint of image retention characteristics, the use ratio of the carboxyl group-containing diamine relative to the total amount of the diamine used in the synthesis is preferably 1 mol% or more, more preferably It is set to 5 mol% or more, and particularly preferably 10 mol% or more. In addition, the upper limit of the use ratio is not particularly limited. From the viewpoint of the voltage retention rate, it is preferably 80 mol% or less relative to the total amount of diamine used in the synthesis, and more preferably It is below 70 mol%. In addition, the carboxyl group-containing diamine may be used alone or two or more of them may be appropriately selected and used.

（式（4）中，X³ 為硫原子或氧原子；“*”分別表示結合鍵；其中，2個“*”中的至少一個鍵結於芳香環上） 所表示的部分結構作為基本骨架的結構等。In the case where the liquid crystal alignment ability is imparted to the coating film formed using the liquid crystal alignment agent by light irradiation, a polymer having a light alignment structure may be used in at least a part of the polymer component. As a specific example of the photo-alignment structure, a group exhibiting photo-alignment by photo-isomerization, photo-dimerization, photo-decomposition, or the like can be used. Specifically, for example, an azo-containing group containing an azo compound or its derivative as a basic skeleton, a cinnamic acid-containing group containing a cinnamic acid or its derivative as a basic skeleton, and chalcone or Chalcone-containing groups whose derivatives are the basic skeleton, benzophenone-containing groups containing the benzophenone or its derivatives as the basic skeleton, and those containing the coumarin or its derivatives as the basic skeleton Coumarin group, cyclobutane-containing structure containing cyclobutane or its derivatives as the basic skeleton, and bicyclic-containing [2.2.2] containing bicyclo[2.2.2]octene or its derivatives as the basic skeleton The structure of octene contains the following formula (4)

(In formula (4), X ³ is a sulfur atom or an oxygen atom; "*" represents a bonding bond; wherein, at least one of the two "*" is bonded to an aromatic ring.) The partial structure represented as the basic skeleton Structure etc.

The polyamic acid having a photo-alignment structure can be obtained, for example, by polymerizing at least one of a tetracarboxylic dianhydride having a photo-alignment structure and a diamine having a photo-alignment structure in the monomer composition. . In this case, from the viewpoint of photoreactivity, the use ratio of the monomer having a photo-alignment structure relative to the total amount of monomers used in the synthesis of the polymer is preferably 20 mol% or more. More preferably, it is set to 30 mol% to 80 mol%.

(Synthesis of Polyamic Acid) Polyamic acid can be obtained by reacting the above-mentioned tetracarboxylic dianhydride and diamine with a molecular weight modifier as necessary. The use ratio of the tetracarboxylic dianhydride and the diamine provided for the synthesis reaction of the polyamic acid is preferably 1 equivalent to the amine group of the diamine, and the acid anhydride group of the tetracarboxylic dianhydride becomes a ratio of 0.2 equivalent to 2 equivalents It is more preferably a ratio of 0.3 to 1.2 equivalents. Examples of the molecular weight modifier include acid monoanhydrides such as maleic anhydride, phthalic anhydride, and itaconic anhydride, monoamine compounds such as aniline, cyclohexylamine, and n-butylamine, phenyl isocyanate, and naphthyl isocyanate. Monoisocyanate compounds, etc. The use ratio of the molecular weight modifier is preferably 20 parts by weight or less relative to 100 parts by weight of the total amount of tetracarboxylic dianhydride and diamine used.

The synthesis reaction of polyamic acid 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 hour to 24 hours. Examples of organic solvents used in the reaction include aprotic polar solvents, phenolic solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons, and hydrocarbons. Among these organic solvents, it is preferable to use one or more selected from the group consisting of aprotic polar solvents and phenolic solvents (organic solvents of the first group), or selected from the organic solvents of the first group A mixture of more than one type and one or more types selected from the group consisting of alcohols, ketones, esters, ethers, halogenated hydrocarbons, and hydrocarbons (organic solvents of the second group). In the latter case, the use ratio of the organic solvent of the second group is preferably 50% by weight or less, and more preferably 40% by weight relative to the total amount of the organic solvent of the first group and the organic solvent of the second group %the following.

Particularly preferred organic solvents are preferably selected from the group consisting of N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethylsulfoxide, γ- One or more of the group consisting of butyrolactone, tetramethylurea, hexamethylphosphoryltriamine, m-cresol, xylenol, and halogenated phenol are used as solvents, or these solvents are used in the range of the ratio A mixture of more than one type with other organic solvents. The amount of use of the organic solvent (a) is preferably such that the total amount of tetracarboxylic dianhydride and diamine (b) is 0.1% to 50% by weight relative to the total amount of the reaction solution (a+b). . As described above, a reaction solution obtained by dissolving polyamide acid is obtained. The reaction solution can be directly provided to the preparation of the liquid crystal alignment agent, or the polyamic acid contained in the reaction solution can be separated and then provided to the preparation of the liquid crystal alignment agent. The isolation and purification of polyamide can be performed according to a known method.

[Polyamidate] The polyamic acid ester in the present invention can be obtained by, for example, the following method: [I] Polyamide acid obtained by the synthesis reaction and an esterifying agent (such as methanol and ethanol) , N,N-dimethylformamide diethyl acetal, N,N-diethylformamide diethyl acetal, etc.); [II] Tetracarboxylic acid diester and di Method of reacting amine; [III] Method of reacting tetracarboxylic diester dihalide with diamine. The polyamic acid ester contained in the liquid crystal alignment agent may have only the amide acid ester structure, or may be a partial esterified product in which the amide acid structure and the amide acid ester structure coexist. In addition, the reaction solution obtained by dissolving the polyamic acid ester may be directly provided to the preparation of the liquid crystal alignment agent, or the polyamic acid ester contained in the reaction solution may be separated and then provided to the preparation of the liquid crystal alignment agent.

[Polyimide] The polyimide in the present invention can be obtained by, for example, dehydrating and ring-closing the polyacrylic acid synthesized in the above-described manner, and then performing imidization.

The polyimide may be a complete imide compound obtained by dehydrating and ring-closing all the amidic acid structures of the polyamic acid as a precursor thereof, or may be dehydrating and ring-closing only a part of the amidic acid structure. , And a part of the imidate compound that coexists with the imidate structure and the imidate ring structure. The polyimide used in the reaction preferably has an imidization ratio of 10% or more, more preferably 20% to 99%, and particularly preferably 20% to 85%. The imidate ratio is the sum of the number of amide acid structures of the polyimide and the number of amide imine ring structures, and expresses the ratio of the number of amide imine ring structures as a percentage. Here, a part of the amide imide ring may be an isoamide imide ring.

The dehydration and ring closure of the polyamic acid is preferably carried out by the following method: heating the polyamic acid; or dissolving the polyamic acid in an organic solvent, adding a dehydrating agent and a dehydration ring-closing catalyst to the solution, The method of heating as needed. Among them, the latter method is preferred. In the method of adding a dehydrating agent and a dehydration ring-closing catalyst to the solution of polyamic acid, for example, an anhydride such as acetic anhydride, propionic anhydride, trifluoroacetic anhydride, etc. can be used as the dehydrating agent. The use amount of the dehydrating agent is preferably 0.01 mol to 20 mol relative to 1 mol of the amic acid structure of the polyamic acid. As the dehydration ring-closure catalyst, for example, tertiary amines such as pyridine, trimethylpyridine, lutidine, and triethylamine can be used. The use amount of the dehydration ring-closing catalyst is preferably 0.01 mol to 10 mol relative to 1 mol of the dehydrating agent used. Examples of the organic solvent used in the dehydration ring-closure reaction include organic solvents exemplified as users in the synthesis of polyamide. The reaction temperature of the dehydration ring-closure reaction is preferably 0°C to 180°C, more preferably 10°C to 150°C. The reaction time is preferably 1.0 hour to 120 hours, and more preferably 2.0 hours to 30 hours.

In this way, a reaction solution containing polyimide was obtained. The reaction solution can be directly provided to the preparation of the liquid crystal alignment agent, or can be provided to the preparation of the liquid crystal alignment agent after removing the dehydrating agent and the dehydration ring-closing catalyst from the reaction solution, or the polyimide can be separated and then provided to the liquid crystal alignment agent. Preparation of the agent, or the separated polyimide can be purified and then provided to the preparation of the liquid crystal alignment agent. These purification operations can be carried out according to known methods. In addition to this, polyimide can also be obtained by the imidization of polyimide.

The polyamic acid, polyamic acid ester and polyimide obtained in the above-mentioned manner are preferably solutions having a concentration of 10 mPa·s to 800 mPa·s when they are made into a solution with a concentration of 10% by weight The viscosity is more preferably a solution viscosity of 15 mPa·s to 500 mPa·s. In addition, the solution viscosity (mPa·s) of the polymer is prepared with a concentration of 10% by weight for a good solvent using the polymer (such as γ-butyrolactone, N-methyl-2-pyrrolidone, etc.) The polymer solution is a value measured at 25°C using an E-type viscometer.

Polystyrene-converted weight average molecular weight (Mw) of polyacrylic acid, polyamic acid ester and polyimide determined by gel permeation chromatography (GPC) is preferably 1,000 to 500,000 , More preferably from 2,000 to 300,000. In addition, the molecular weight distribution (Mw/Mn) represented by the ratio of Mw to the polystyrene equivalent number average molecular weight (Mn) measured by GPC is preferably 10 or less, and more preferably 7 or less. By being within the molecular weight range as described above, it is possible to ensure good alignment and stability of the liquid crystal element.

<Compound [A]> In preparing the liquid crystal alignment agent of the present invention, in addition to the polymer component, the compound [A] having the following groups (1) and (2) is used. (1) At least one selected from the group consisting of a group having a structure having two or more rings connected directly or via a linking group (hereinafter also referred to as "polycyclic structure") and a group having a condensed ring A group. (2) Selected from -NR ¹ R ² (wherein R ¹ and R ² are each independently a hydrogen atom, a C 1-10 monovalent hydrocarbon group or a protecting group), protected isocyanate group, protected isothiocyanate group , At least one group from the group consisting of a group containing an oxazoline ring structure, a group containing a Mienic acid structure, and a group represented by the formula (g-1).

Regarding the group (1), the ring constituting the polycyclic structure is preferably a benzene ring or a cyclohexane ring. If the number of rings possessed by this group is 2 or more, it is not particularly limited, but preferably 2 to 4. In addition, the plurality of rings constituting the multi-ring structure may be the same as each other or may be different. When the ring is a benzene ring or a cyclohexane ring, the bonding position of the ring is preferably para to the other group. Examples of the linking group include -O-, -CO-, -COO-, -NR ^b -, -CONR ^b- (R ^b is a hydrogen atom, an alkyl group having 1 to 6 carbons or a protecting group), and carbon number 1 ~10 alkanediyl group, bivalent substitution of at least one methylene group of a C1-10 alkanediyl group with -O-, -CO-, -COO-, -NR ^b -or -CONR ^b- Base etc.

（式（1-1）～式（1-4）中，Ar¹ 為碳數6～10的一價芳香環基，R¹¹ 為碳數1～12的烷基；“*”表示鍵結於氮原子上的結合鍵）The protecting group of R ^b may include a monovalent organic group that is detached by at least any one of heat, light, acid, and base. R ^{b is} preferably a monovalent organic group that is detached by at least heat. Specific examples thereof include, for example, carbamate-based protective groups, amide-based protective groups, amide-based protective groups, and sulfonamides. Amine-based protecting group, groups represented by the following formula (1-1) to formula (1-4), etc., respectively. [Chem 8]

(In formula (1-1) to formula (1-4), Ar ¹ is a C 6-10 monovalent aromatic ring group, R ¹¹ is a C 1-12 alkyl group; "*" means bonded to Bond on the nitrogen atom)

Ar ^{1 in} the formula (1-2) is a group obtained by removing one hydrogen atom from an aromatic ring having 6 to 10 carbon atoms. Specific examples include phenyl and naphthyl. Examples of the alkyl group having 1 to 12 carbon atoms in R ¹¹ of formula (1-4) include methyl, ethyl, propyl, butyl, pentyl, and hexyl groups. These alkyl groups may be linear, or Can be branched. In terms of high thermal detachability, R ^{b is} preferably a carbamate-based protective group. Specific examples thereof include, for example, a third butoxycarbonyl group, benzyloxycarbonyl group, 1,1-dimethyl-2-haloethyloxycarbonyl group, and 1,1-dimethyl-2-cyano Ethyloxycarbonyl, 9-oxylmethyloxycarbonyl, allyloxycarbonyl, 2-(trimethylsilyl)ethoxycarbonyl, etc. Among them, the third butoxy group is preferred in that it has high detachability due to heat and that the compound derived from R ^b detached by heating during film formation can be discharged out of the film as a gas. Carbonyl (BOC group).

（式中，“BOC”表示第三丁氧基羰基；“*”表示結合鍵）Specific examples of the polycyclic structure include, for example, 4,4'-biphenylene, 4,4'-bicyclohexyl, and the following formulas (6-1) to (6-9). Represented groups, etc. [化9]

(In the formula, "BOC" means the third butoxycarbonyl group; "*" means the bond)

In the group of (1), if the condensed ring has a ring structure having two or more rings and each ring shares two or more atoms, it is not particularly limited, and examples include naphthalene rings, anthracene rings, and phenanthrenes. Ring, steroid core, etc. Among these, the group having a condensed ring is preferably a group having a steroid skeleton. The group having a steroid skeleton preferably has a carbon number of 17 to 51, and examples thereof include cholesteryl group, cholesteryl group, lanosteryl group, cholesteryloxycarbonyl group, cholesteryloxycarbonyl group, and cholesteric group. Alkyloxy, cholesteryloxy, etc.

Regarding the group of the above (2), R ¹ and R ² in the group “—NR ¹ R ² ”have a C 1-10 hydrocarbon group, for example, methyl, ethyl, propyl, butyl, Linear or branched alkyl groups such as pentyl and hexyl; alicyclic hydrocarbon groups such as cyclohexyl and methylcyclohexyl; aromatic hydrocarbon groups such as phenyl, methylphenyl and benzyl. For a specific example in the case where R ¹ and R ² are protecting groups, the illustrations listed in the above R ^b can be applied. In the above, R ¹ and R ^{2 are} preferably a hydrogen atom, a C 1-3 alkyl group or a third butoxycarbonyl group. In addition, R ¹ and R ² may be the same as or different from each other.

The protected iso(thio)cyanate group in the group of (2) is preferably a regenerated iso(thio)cyanate by deprotection using at least any one of heat, light, acid and alkali Radical group. Specific examples include groups obtained by reacting an iso(thio)cyanate group with a compound (blocking agent) having active hydrogen. In addition, the "active hydrogen" refers to a hydrogen atom with high detachability, and preferably refers to one having an acid dissociation constant pKa of 20 or less in water. In addition, the iso(thio)cyanate group means that the isocyanate group and the isothiocyanate group are included.

As the blocking agent, known ones can be used, and examples thereof include alcohol-based compounds, phenol-based compounds, active methylene-based compounds, thiol-based compounds, acid amide-based compounds, acid imide-based compounds, imidazole-based compounds, and pyridines. An azole compound, urea compound, oxime compound, amine compound, imine compound, pyridine compound, etc. As specific examples of these compounds, alcohol compounds include, for example, methanol, ethanol, propanol, butanol, 2-ethylhexanol, methyl cellosolve, butyl cellosolve, methyl carbitol, and benzyl alcohol. , Cyclohexanol, etc.; Examples of phenolic compounds include phenol, cresol, ethylphenol, butylphenol, nonylphenol, dinonylphenol, styrenated phenol, hydroxybenzoate, etc.;

Examples of active methylene-based compounds include dimethyl malonate, diethyl malonate, methyl acetoacetate, ethyl acetoacetate, and acetone acetone. Examples of thiol-based compounds include: Butyl mercaptan, dodecyl mercaptan, etc.; Acetamide compounds include, for example, acetanilide, acetamide acetate, ε-caprolactam, δ-valerolactam, γ-butylactam Etc.; acid imide-based compounds include, for example, succinic acid imide, maleimide succinate, etc.; imidazole-based compounds include, for example, imidazole, 2-methylimidazole, etc.; pyrazole-based compounds such as Examples include: 3-methylpyrazole, 3,5-dimethylpyrazole, 3,5-ethylpyrazole; urea-based compounds include, for example, urea, thiourea, ethidium urea, etc.; oxime-based Examples of the compound include formaldehyde oxime, acetaldehyde oxime, acetone oxime, methyl ethyl ketoxime, cyclohexanone oxime, etc.; amine compounds include diphenylamine, aniline, carbazole, etc.; imine compounds For example, ethylidene imide, polyethylidene imide, etc. may be mentioned; for pyridine-based compounds, for example, 2-hydroxypyridine, 2-hydroxyquinoline, etc. may be mentioned.

The protective iso(thio)cyanate group in the group of (2) is preferably a group deprotected by heating during post-baking. From the viewpoint of reducing the remaining amount of the compound derived from the protecting group in the film, the carbon number of the protecting group is preferably 1-10, more preferably 1-6, and particularly preferably 1-4 carbons.

The group containing an oxazoline ring structure may be a group in which any one hydrogen atom is removed from the oxazoline ring. In addition, the group containing the Mie acid structure may include a group in which any one hydrogen atom is removed from the Mie acid.

In the above formula (g-1), the C 1-3 alkyl group for R ³ , R ⁶ and R ¹¹ may, for example, be methyl, ethyl, n-propyl or isopropyl. From the viewpoint of improving the image retention characteristics of the liquid crystal display element, R ⁶ and R ^{11 are} preferably a hydrogen atom or a methyl group, and more preferably a hydrogen atom. The alkyl groups having 1 to 3 carbon atoms in R ⁴ and R ⁵ include the groups exemplified in R ³ above. From the viewpoint of improving image retention characteristics, a hydrogen atom, * ³ -CH ₂ -OH or * ³ -CH ₂ -OCH _{3 is} preferred. In addition, R ⁴ and R ⁵ may be the same as or different from each other.

The molecular weight of the compound [A] is preferably 2,000 or less. From the viewpoint of improving the solubility in the solvent and the applicability of the liquid crystal alignment agent to the substrate, the molecular weight is more preferably 1,500 or less, particularly preferably 1,200 or less, and particularly preferably 1,000 or less. As a preferable example of the compound [A], for example, "R ⁸ -C _m H _2m -R ⁹ "(wherein R ⁸ is the group of (1) above, R ⁹ is the group of (2) above Group; m is an integer from 1 to 20). Here, R ^{9 is} preferably a group represented by any one of the following formula (r-1) to formula (r-7). R ^{8 is} preferably "*-X ¹ -R ¹⁰ -R ¹¹ "(wherein X ¹ is a single bond, an oxygen atom, -CO- or -COO-, R ¹⁰ is a polycyclic structure, R ¹¹ is a hydrogen atom, Alkyl or fluoroalkyl; "*" represents a bond), or "*-X ² -R ¹² "(wherein X ¹ is a single bond, an oxygen atom, -CO- or -COO-, and R ¹² is cholesterol Base, cholesteryl or lanosteryl; "*" means a bond).

[化11]

[化12]

（式（A1-1）～式（A1-22）中，R⁷ 為下述式（r-1）～式（r-7）的任一者所表示的基團，m為1～20的整數，n為0～20的整數，l及k分別獨立地為0～10的整數） [化13]

（式中，“*”表示結合鍵）Specific examples of the compound [A] include, for example, compounds represented by the following formula (A1-1) to formula (A1-22), respectively. [化10]

[Chem 11]

[化12]

(In formula (A1-1) to formula (A1-22), R ⁷ is a group represented by any of the following formula (r-1) to formula (r-7), and m is 1 to 20 Integer, n is an integer from 0 to 20, l and k are independently integers from 0 to 10) [Chem 13]

(In the formula, "*" represents the bond)

The compounding ratio of the compound [A] is preferably 0.1 parts by weight to 50 parts by weight with respect to a total of 100 parts by weight of the polymer components in the liquid crystal alignment agent. If the compounding ratio of the compound [A] is less than 0.1 parts by weight, it is difficult to sufficiently obtain the improvement effect of the image retention reduction of the liquid crystal display element, and if it is more than 50 parts by weight, the liquid crystal is present as the compound [A] becomes an excessive amount. There is a concern that the film strength of the alignment film, the liquid crystal alignment property, and the electrical retention characteristics of the liquid crystal display element may decrease. The lower limit of the compounding ratio of the compound [A] is more preferably 1 part by weight or more, more preferably 3 parts by weight or more, and particularly preferably 5 parts by weight with respect to the total 100 parts by weight of the polymer components in the liquid crystal alignment agent. the above. In addition, the upper limit of the compounding ratio of the compound [A] is more preferably 40 parts by weight or less, and particularly preferably 30 parts by weight or less. In addition, the compound [A] may be used alone or in combination of two or more. These compounds [A] can be synthesized by appropriately combining ordinary methods of organic chemistry.

In the liquid crystal alignment agent, the compound [A] may interact with at least a part of the polymer component, or may exist in the liquid crystal alignment agent without interacting with the polymer component. It is presumed that the liquid crystal alignment agent contains the compound [A], and for example, a polymer having a functional group (such as a carboxyl group) that reacts with the group (2) by heating during post-baking (for example, Hereinafter also referred to as "specific polymer") and the compound [A] interact to further improve the effect of reducing image retention and voltage retention. In addition, the "interaction" in this specification refers to the formation of covalent bonds between molecules, or the formation of intermolecular forces that are weaker than covalent bonds (eg, ion-dipole interaction, dipole-dipole interaction, (Hydrogen bonding, van der Waals force and other electromagnetic forces acting between molecules).

<Other Components> The liquid crystal alignment agent of the present invention may contain other components than the polymer component and the compound [A] within a range that does not hinder the purpose and effect of the present invention. Examples of the other components include compounds having at least one photopolymerizable group in the molecule (hereinafter also referred to as "photopolymerizable compound") and the like.

(Photopolymerizable Compound) The photopolymerizable compound can be used for the purpose of improving the alignment restricting force of the liquid crystal alignment film when the coating film formed using the liquid crystal alignment agent is irradiated with light. Examples of the photopolymerizable group include groups having a polymerizable unsaturated bond, and specific examples include (meth)acryloyloxy, styryl, (meth)acryloylamino, and vinyl groups. , Vinyl group, vinyloxy group (CH ₂ =CH-O-), maleimide group, etc. The number of photopolymerizable groups included in the photopolymerizable compound may be one or more, preferably two or more, and more preferably two to four. The molecular weight of the photopolymerizable compound is preferably 2,000 or less, and more preferably 1,500 or less.

（式（B1-1）～式（B1-3）中，R^x 為氫原子或者甲基） 分別所表示的化合物等多官能(甲基)丙烯酸酯等。 在將光聚合性化合物調配於液晶配向劑中的情況下，其調配比例相對於液晶配向劑中所含的聚合物的合計100重量份，較佳為設為40重量份以下，更佳為設為0.5重量份～30重量份，尤佳為設為1重量份～20重量份。In terms of high photoreactivity, as the photopolymerizable compound, a (meth)acrylate compound can be preferably used. Specifically, for example, methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, lauryl (meth)acrylate, cyclohexyl (meth)acrylate, ( Benzyl meth)acrylate, 2-methoxyethyl (meth)acrylate, methoxytriethylene glycol (meth)acrylate, glycidyl (meth)acrylate, 2-(meth)acrylic acid Monofunctional (meth)acrylates such as hydroxyethyl ester; ethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, pentaerythritol tri(meth)acrylate, polyether (Meth)acrylate, ethoxylated bisphenol A di(meth)acrylate, the following formula (B1-1) to formula (B1-3)

(In Formula (B1-1) to Formula (B1-3), R ^x is a hydrogen atom or a methyl group) Multifunctional (meth)acrylates such as compounds represented by each. When the photopolymerizable compound is compounded in the liquid crystal alignment agent, the compounding ratio is preferably 40 parts by weight or less relative to the total of 100 parts by weight of the polymer contained in the liquid crystal alignment agent, more preferably It is 0.5 to 30 parts by weight, particularly preferably 1 to 20 parts by weight.

In addition, as the other components, in addition to the above, for example, a compound having at least one epoxy group in the molecule, a functional silane compound, a surfactant, a filler, a defoamer, a sensitizer, a dispersant, an anti-oxidant Oxidizing agent, adhesion aid, antistatic agent, leveling agent, antibacterial agent, etc. The compounding ratio of these compounds can be appropriately set according to the compound to be compounded, within a range that does not hinder the effect of the present invention.

[Solvent] The liquid crystal alignment agent of the present invention is prepared as a polymer component, a compound [A], and other components used as needed, and is preferably a liquid composition dispersed or dissolved in an appropriate organic solvent. Examples of the organic solvent used include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 1,3-dimethyl-1-imidazolidinone, γ-butyrolactone, and γ-butyrol Endoamide, N,N-dimethylformamide, N,N-dimethylacetamide, 3-methoxy-N,N-dimethylpropionamide, 3-butoxy-N ,N-dimethylpropylamide, N,N,2-trimethylpropylamide, 1-butoxy-2-propanol, diacetone alcohol, propylene glycol diacetate, dipropylene glycol monomethyl ether, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxy propionate, ethyl ethoxy propionate, ethylene glycol Dimethyl ether, ethylene glycol ether, ethylene glycol-n-propyl ether, ethylene glycol-isopropyl ether, ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ether acetate Ester, 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 ether Acid ester, diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, diisoamyl ether, ethyl carbonate, propyl carbonate, etc. These solvents can be used alone or in combination of two or more.

The solid content concentration in the liquid crystal alignment agent of the present invention (the ratio of the total weight of components other than the solvent of the liquid crystal alignment agent to the total weight of the liquid crystal alignment agent) is appropriately selected in consideration of viscosity, volatility, etc. It is preferably in the range of 1% by weight to 10% by weight. That is, the liquid crystal alignment agent of the present invention is applied to the surface of the substrate by the method described below, and is preferably heated to form a coating film that is a liquid crystal alignment film or a coating film that becomes a liquid crystal alignment film. At this time, when the solid content concentration is less than 1% by weight, the film thickness of the coating film becomes too small, making it difficult to obtain a good liquid crystal alignment film. On the other hand, when the solid content concentration exceeds 10% by weight, the film thickness of the coating film becomes too large, making it difficult to obtain a good liquid crystal alignment film. In addition, there is an increase in viscosity of the liquid crystal alignment agent and a decrease in coatability tendency. The temperature when preparing the liquid crystal alignment agent is preferably 10°C to 50°C, more preferably 20°C to 30°C.

<<Liquid crystal alignment film and liquid crystal element>> The liquid crystal alignment film of the present invention is formed using the liquid crystal alignment agent prepared as described above. In addition, the liquid crystal element of the present invention includes a liquid crystal alignment film formed using the liquid crystal alignment agent. The driving mode of the liquid crystal element is not particularly limited, and can be applied to: TN type, STN type, IPS type, FFS type, VA type, multi-domain vertical alignment (Multi-domain Vertical Alignment, MVA) type, polymer stable alignment (Polymer Various driving modes such as sustained alignment (PSA).

The liquid crystal element of the present invention can be manufactured by a method including the following steps 1 to 3, for example. Step 1 uses different substrates according to the required driving mode. Steps 2 and 3 are common to each drive mode.

[Step 1: Formation of coating film] First, a coating film is formed on the substrate by applying a liquid crystal alignment agent on the substrate, and then heating the coating surface. (1-1) In the case of manufacturing a TN type, STN type, VA type, MVA type or PSA type liquid crystal element, two substrates provided with a patterned transparent conductive film are used as a pair, in each substrate On the forming surface of the transparent conductive film, it is preferable to apply the liquid crystal alignment agent by an offset printing method, a spin coating method, a roll coater method, or an inkjet printing method, respectively. Here, as the substrate, for example, glass such as float glass and soda glass; including polyethylene terephthalate, polybutylene terephthalate, polyether ash, polycarbonate, poly(alicyclic olefin) ) And other plastic transparent substrates. The transparent conductive film provided on one side of the substrate can be used: a NESA film containing tin oxide (SnO ₂ ) (registered trademark of the US PPG company), and containing indium oxide-tin oxide (In ₂ O ₃ -SnO ₂ ) Indium Tin Oxide (ITO) film, etc. When applying the liquid crystal alignment agent, in order to improve the adhesion between the substrate surface and the transparent conductive film and the coating film, the surface on the substrate surface where the coating film is formed may be pre-coated with a functional silane compound, a functional titanium compound, etc. Pre-treatment.

After the liquid crystal alignment agent is applied, for the purpose of preventing sagging of the applied alignment agent and the like, it is preferable to perform preheating (prebaking). The pre-baking temperature is preferably 30°C to 200°C, and the pre-baking time is preferably 0.25 minutes to 10 minutes. Then, for the purpose of completely removing the solvent, and additionally for the purpose of thermally imidizing the amide acid structure present in the polymer as necessary, a sintering (post-baking) step is performed. The burning temperature (post-baking temperature) at this time is preferably 80°C to 300°C, and the post-baking time is preferably 5 minutes to 200 minutes. The film thickness of the film formed in this way is preferably 0.001 μm to 1 μm, and more preferably 0.005 μm to 0.5 μm.

(1-2) In the case of manufacturing an IPS-type or FFS-type liquid crystal element, by forming an electrode-forming surface on a substrate provided with an electrode including a transparent conductive film or metal film patterned into a comb-teeth type, and not providing On one side of the counter substrate of the electrode, a liquid crystal alignment agent is applied separately, and then each applied surface is heated, thereby forming a coating film. The material of the substrate and the transparent conductive film used at this time, the coating method, the heating conditions after coating, the patterning method of the transparent conductive film or the metal film, the pretreatment of the substrate, and the preferred film thickness of the formed coating film Same as the above (1-1). As the metal film, for example, a film containing metal such as chromium can be used. In any of the above (1-1) and (1-2), after applying the liquid crystal alignment agent on the substrate, the organic solvent is removed to form the liquid crystal alignment film or the coating film that becomes the liquid crystal alignment film.

[Step 2: Alignment ability-imparting treatment] In the case of manufacturing a TN-type, STN-type, IPS-type, or FFS-type liquid crystal element, a process of imparting liquid-crystal aligning ability to the coating film formed in the above step 1 is performed. By this, the alignment ability of liquid crystal molecules is imparted to the coating film to become a liquid crystal alignment film. Examples of the alignment ability-imparting treatment include rubbing treatment and photo-alignment treatment. The rubbing treatment uses a roll wound with a cloth containing fibers such as nylon, rayon, and cotton to wipe the coating film in a certain direction; The treatment is to irradiate the coating film with polarized or unpolarized radiation. On the other hand, in the case of manufacturing a VA-type liquid crystal display element, the coating film formed in the above step 1 may be directly used as a liquid crystal alignment film, but the coating film may also be subjected to an alignment ability-imparting treatment.

In the case where the liquid crystal alignment ability is imparted to the coating film by the photo-alignment process, the radiation irradiated to the coating film can use, for example, ultraviolet rays and visible rays including light having a wavelength of 150 nm to 800 nm. When the radiation is polarized light, it may be linearly polarized light or partially polarized light. In addition, when the radiation used is linearly polarized light or partially polarized light, the substrate surface may be irradiated from a vertical direction, or may be irradiated from an oblique direction, or these irradiations may be combined. In the case of irradiating unpolarized light, the direction of irradiation is set to an oblique direction. As the light source 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, etc. can be used. The radiation dose is preferably 100 J/m ² to 50,000 J/m ² , and more preferably 300 J/m ² to 20,000 J/m ² . In addition, in order to improve the reactivity, the coating film may be irradiated with light while being heated. The temperature during heating is usually 30°C to 250°C, preferably 40°C to 200°C. The liquid crystal alignment film suitable for the VA type liquid crystal display element can also be suitably used for the PSA type liquid crystal display element.

[Step 3: Construction of liquid crystal cell] (3-1) By preparing the two substrates on which the liquid crystal alignment film is formed in the above-described manner, liquid crystal is arranged between the two substrates facing each other to manufacture a liquid crystal cell. In order to manufacture a liquid crystal cell, for example, the following method may be mentioned: the two substrates are opposed to each other with a gap so that the liquid crystal alignment film is opposed, and the peripheral portions of the two substrates are bonded together using a sealant. A method of sealing the injection hole after injecting and filling liquid crystal into the cell gap defined by the agent; applying a sealant to a predetermined portion on one of the substrates on which the liquid crystal alignment film is formed, and then a predetermined number of liquid crystal alignment film surfaces After the liquid crystal is dropped on the part, the other substrate is bonded with the liquid crystal alignment film facing, and the liquid crystal is spread on the entire surface of the substrate (liquid crystal drop (One Drop Filling, ODF) method). Preferably, the manufactured liquid crystal cell is further heated until the used liquid crystal obtains the temperature of the isotropic phase, and then slowly cooled to room temperature, thereby removing the flow alignment when the liquid crystal is filled.

As the sealant, for example, an epoxy resin containing a hardener and alumina balls as spacers can be used. Liquid crystals include nematic liquid crystals and discotic liquid crystals. Among them, nematic liquid crystals are preferred. For example, Schiff base liquid crystals, azoxy liquid crystals, biphenyl liquid crystals, and phenyl rings can be used. Hexane liquid crystal, ester liquid crystal, terphenyl liquid crystal, biphenyl cyclohexane liquid crystal, pyrimidine liquid crystal, dioxane liquid crystal, bicyclooctane liquid crystal, cubane liquid crystal, etc. In addition, these liquid crystals can also be used by adding the following substances: for example, cholesteric liquid crystals such as cholesteryl chloride, cholesteryl nonanoate, cholesteryl carbonate, etc.; under the trade names "C-15", "CB-15" (Merk (Merck) company) to sell the chiral agent; p-decyloxybenzylidene-p-amino-2-methylbutyl cinnamate and other ferroelectric liquid crystals.

(3-2) In the case of manufacturing a PSA type liquid crystal display element, a liquid crystal cell is constructed in the same manner as in (3-1) above except that the photopolymerizable compound is injected or dropped together with the liquid crystal. Then, the liquid crystal cell is irradiated with light while a voltage is applied between the conductive films of the pair of substrates. The voltage applied here is, for example, 5 V to 50 V DC or AC. The light to be irradiated is preferably ultraviolet light including light having a wavelength of 300 nm to 400 nm. The irradiation amount of light is preferably 1,000 J/m ² to 200,000 J/m ² , and more preferably 1,000 J/m ² to 100,000 J/m ² .

(3-3) In the case where a coating film is formed on a substrate using a liquid crystal alignment agent containing a photopolymerizable compound, a liquid crystal cell is constructed in the same manner as in (3-1) above, and then the following method may also be adopted : A liquid crystal display element is manufactured through a step of irradiating liquid crystal cells with a voltage applied between the conductive films of a pair of substrates. According to this method, the advantages of the PSA mode can be realized with a small amount of light irradiation. The applied voltage may be, for example, 0.1 V to 30 V DC or AC. Regarding the conditions of the irradiated light, the description of (3-2) above can be applied.

Then, a liquid crystal element can be obtained by attaching a polarizing plate to the outer surface of the liquid crystal cell. Examples of the polarizing plate attached to the outer surface of the liquid crystal cell include a polarizing plate formed by sandwiching a polarizing film called "H film" with a cellulose acetate protective film or a polarizing plate containing the H film itself. The "H film" is formed by absorbing iodine while extending the polyvinyl alcohol.

The liquid crystal element of the present invention can be effectively applied to various devices, such as: watches, portable game consoles, word processors, notebook personal computers, car navigation systems, camcorders, personal digital assistants (PDAs) ), digital cameras, mobile phones, smart phones, various monitors, LCD TVs, information displays and other display devices, or dimming films. In addition, the liquid crystal element formed using the liquid crystal alignment agent of the present invention can also be applied to a retardation film. [Example]

Hereinafter, the present invention will be further specifically described by examples, but the present invention is not limited to these examples.

In the following examples and comparative examples, the following method was used to measure the imidate ratio of polyimide in the polymer solution, the solution viscosity of the polymer solution, and the weight average molecular weight of the polymer. In the following, the compound represented by the formula X may only be shown as "compound X". [Amidation rate of polyimide] The solution of polyimide was poured into pure water, the obtained precipitate was sufficiently dried under reduced pressure at room temperature, and then dissolved in deuterated dimethyl sulfoxide, Using tetramethylsilane as a reference substance, ¹ H-nuclear magnetic resonance (NMR) was measured at room temperature. Based on the obtained ¹ H-NMR spectrum, the imidate ratio [%] was determined using the following mathematical formula (1). Acetylimidization rate [%] = (1-A ¹ /A ² ×α)×100…(1) (In the mathematical formula (1), A ¹ is derived from the NH group near the chemical shift of 10 ppm The peak area of protons, A ² is the peak area derived from other protons, and α is the ratio of the number of other protons to one proton of the NH group in the polymer precursor (polyamide) (polymer) Solution viscosity of the solution] The solution viscosity of the polymer solution [mPa·s] is a solution prepared with a predetermined solvent at a polymer concentration of 10% by weight and measured at 25°C using an E-type viscometer. [Weight average molecular weight of polymer] The weight average molecular weight is a polystyrene conversion value measured by gel permeation chromatography under the following conditions. Column: manufactured by Tosoh (share), TSKgelGRCXLII Solvent: Tetrahydrofuran Temperature: 40°C Pressure: 68 kgf/cm ² <Synthesis of Compound (A)>

[Synthesis Example 1-1] The compound (a-1) was synthesized according to the following scheme 1. [化15]

Take 17.8 g of 4-(2-(4'-pentyl-[1,1'-bicyclohexane]-4-yl)ethyl)phenol, 8.76 g of 2-((third butoxycarbonyl) Amino)acetic acid was added to a 2000 mL three-necked flask with a stir bar, and 500 g of dichloromethane was added to stir. Then, it was cooled to 0°C, and 11.5 g of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and 1.22 g of N,N-dimethyl were added thereto. The aminoaminopyridine was stirred at room temperature for 20 hours. Then, the reaction solution was washed with 800 mL of water three times, and the organic layer was dried with magnesium sulfate. Then, by concentration using a rotary evaporator, the concentration was gradually reduced until the content became 100 g, and the white solid precipitated in the middle was recovered by filtration. This white solid was vacuum dried, thereby obtaining 18.0 g of compound (a-1).

[Synthesis Example 1-2] The compound (a-2) was synthesized according to the following scheme 2. [Chem 16]

·Synthesis of compound (a-2-1) Using β-cholestanol as a starting material, compound (a-2-1) was obtained by the same synthesis method as compound (a-1). ·Synthesis of Compound (a-2-2) In a 200 mL eggplant-shaped flask with a stir bar, 16.4 g of Compound (a-2-1), 300 g of methylene chloride, and 17.1 g of trifluoroacetic acid were added , Stir at room temperature for 1 hour. Then, it was cooled to 0° C., 50 mL of a saturated sodium bicarbonate aqueous solution was slowly added for liquid separation, and the organic layer was washed with 100 mL of water three times for liquid separation. Then, by concentration using a rotary evaporator, the concentration was gradually reduced until the content became 30 g, and the white solid precipitated in the middle was recovered by filtration. The white solid was vacuum dried to obtain 13.1 g of compound (a-2-2). ·Synthesis of Compound (a-2) In a 200 mL three-necked flask equipped with a stir bar, 8.91 g of Compound (a-2-2), 20 mL of tetrahydrofuran, and 2 mol/L potassium carbonate aqueous solution were added and cooled to 0℃. Methyl chloroformate was slowly added dropwise thereto and stirred at room temperature for 2 hours. Then, the reaction liquid was extracted three times with 50 mL of ethyl acetate, and the obtained organic layer was subjected to liquid separation washing three times with 100 mL of distilled water. Then, by concentration using a rotary evaporator, the concentration was gradually reduced until the content became 30 g, and the white solid precipitated in the middle was recovered by filtration. The white solid was vacuum dried, thereby obtaining 5.53 g of compound (a-2).

[Synthesis Example 1-3] The compound (a-3) was synthesized according to the following scheme 3. [化17]

·Synthesis of Compound (a-3-1) In a 100 mL three-necked flask with a stir bar, 16.4 g of 4-(4'-pentyl-[1,1'-bicyclohexane]-4-yl) was added Phenol and 20 mL of 9 mol/L potassium hydroxide aqueous solution were stirred at room temperature for 5 minutes. Then, the mixture was heated to boil, 14.1 g of a 50% aqueous solution of chloroacetic acid was added dropwise thereto, and refluxed for 5 hours. Then, the reaction solution was cooled to room temperature, 200 mL of a 1 mol/L hydrochloric acid aqueous solution was added dropwise, and extraction was performed three times with 150 mL of ethyl acetate. The obtained organic layer was separated and washed 3 times with 100 mL of distilled water. Then, by concentration using a rotary evaporator, the concentration was gradually reduced until the content became 40 g, and the white solid precipitated in the middle was recovered by filtration. The white solid was vacuum dried to obtain 13.7 g of compound (a-3-1). ·Synthesis of compound (a-3) In a 500 mL three-necked flask with a stir bar, 11.6 g of compound (a-3-1), 7.38 g of 2-bromoethylamine hydrobromide, 300 mL of Methanol and 3.64 g of N-methylmorpholine were stirred, and 9.96 g of DMT-MM was added thereto. After stirring at room temperature for 1 hour, 120 g of a 1 mol/L potassium hydroxide-methanol solution was added and refluxed for 2 hours. Then, the reaction solution was poured into 500 mL of water, and extracted with 300 mL of diethyl ether three times. Then, the organic layer was subjected to one liquid separation washing with 300 mL of 1 mol/L hydrochloric acid water, one liquid separation washing with 200 mL of saturated sodium bicarbonate aqueous solution, and three liquid separation washings with 200 mL of water. Then, by concentration using a rotary evaporator, the organic layer was gradually concentrated until the organic layer became 50 g, and the white solid precipitated in the middle was recovered by filtration. This white solid was vacuum dried, thereby obtaining 9.01 g of compound (a-3).

[Synthesis Example 1-4] The compound (a-4) was synthesized according to the following scheme 4. [Chemical 18]

·Synthesis of Compound (a-4) In a 100 mL eggplant-shaped flask with a stir bar, 5.14 g of Compound (a-1), 30 mL of methylene chloride, and 5.7 g of trifluoroacetic acid were added at room temperature Stir for 2 hours. Then, the reaction solution was neutralized with potassium carbonate aqueous solution, and extracted three times with 100 mL of ethyl acetate. The obtained organic layer was separated and washed 3 times with 100 mL of distilled water. Then, by concentration using a rotary evaporator, the concentration was gradually reduced until the content became 30 g, and the white solid precipitated in the middle was recovered by filtration. This white solid was vacuum dried, thereby obtaining 3.93 g of compound (a-4).

[Synthesis Example 1-5] The compound (a-5) was synthesized according to the following scheme 5. [Chem 19]

·Synthesis of compound (a-5) uses 4-(4-heptylcyclohexyl)benzoic acid and 3-amino-1-propanol as starting materials, using the same synthesis method as compound (a-1) Compound (a-5) is obtained.

[Synthesis Example 1-6] The compound (a-6) was synthesized according to the following scheme 6. [化20]

·Synthesis of compound (a-6-1) uses 4-(2-(4'-pentyl-[1,1'-bicyclohexane]-4-yl)ethyl)phenol as the starting material. Compound (a-3-1) is synthesized in the same way as compound (a-6-1). ·Synthesis of compound (a-6) In a 100 mL three-necked flask with a stir bar, 7.73 g of compound (a-6-1), 2.88 g of Mie acid, and 2.44 g of N,N-dimethyl were added Aminopyridine, 50 mL of dichloromethane, cooled to 0 °C. 4.12 g of N,N'-dicyclohexylcarbodiimide was added thereto, and the mixture was stirred at 0°C for 2 hours. Then, the reaction solution was filtered through diatomaceous earth, and the filtrate was washed with 50 mL of a 1 mol/L hydrochloric acid aqueous solution once, and washed with 50 mL of water three times. Then, by concentration using a rotary evaporator, the concentration was gradually reduced until the content became 20 g, and the white-yellow solid precipitated in the middle was recovered by filtration. This solid was vacuum dried, thereby obtaining 9.30 g of compound (a-6).

[Synthesis Example 1-7] The compound (a-7) was synthesized according to the following scheme 7. [化21]

·The synthesis of compound (a-7) uses (E)-3-(4((4-(4,4,4-trifluorobutoxy)benzyl)oxy)phenyl)acrylic acid and 3 -(Dimethylamino) ethanol is used as a starting material to obtain compound (a-7) by the same synthesis method as compound (a-1).

[Synthesis Example 1-8] The compound (c-1) was synthesized according to the following scheme 8. [化22]

·Synthesis of Compound (c-1) In a 300 mL three-necked flask with a stirring bar, 7.13 g of 4-(2-(4'-pentyl-[1,1'-bicyclohexane]-4-yl was added ) Ethyl) phenol, 120 mL of ethanol, and 0.96 g of sodium hydroxide, and stirred at room temperature for 20 minutes. 5.55 g of epichlorohydrin was added dropwise thereto and stirred at room temperature for 9 hours. Then, the solvent was distilled off by concentration using a rotary evaporator, and the residue was extracted three times with 100 mL of ethyl acetate. The obtained organic layer was washed with 100 mL of water three times, and the solvent was distilled off using a rotary evaporator. The residue was subjected to column purification using silica gel, thereby obtaining 6.60 g of compound (c-1) as a white-yellow solid.

[Synthesis Example 1-9] The compound (c-2) was synthesized according to the following scheme 9. [化23]

·Synthesis of compound (c-2) Using 4-(4-heptylcyclohexyl)benzoic acid and glycerol 1,2-carbonate as starting materials, the compound was obtained by the same synthesis method as compound (a-1) (C-2).

<Synthesis of Polymer> [Synthesis Example 2-1] 100 mole parts of 1,2,3,4-cyclobutane tetracarboxylic dianhydride as tetracarboxylic dianhydride and 100 moles of diamine Ears of p-phenylenediamine were dissolved in N-methyl-2-pyrrolidone (NMP) and reacted at room temperature for 6 hours to obtain a compound containing 20% by weight of polyamic acid Solution. The polyamide obtained here was used as a polymer (PA-1).

[Synthesis Example 2-2 to Synthesis Example 2-7] In the same manner as Synthesis Example 2-1, except that the types and amounts of tetracarboxylic dianhydride and diamine used were changed as described in Table 1 below. Synthesis of polyamide (polymer (PA-2) ~ polymer (PA-7)).

[Table 1]

In Table 1, the numerical value in parentheses of tetracarboxylic dianhydride and diamine shows the use ratio of each compound with respect to a total of 100 mol parts of tetracarboxylic dianhydride used for synthesizing a polymer [mol parts] . The abbreviations of the compounds in Table 1 have the following meanings, respectively. <Tetracarboxylic dianhydride> T-1: 1,2,3,4-cyclobutane tetracarboxylic dianhydride T-2: 2,3,5-tricarboxycyclopentylacetic acid dianhydride T-3: bicyclic [3.3.0] Octane-2,4,6,8-tetracarboxylic dianhydride T-4: pyromellitic dianhydride <diamine> D-1: p-phenylenediamine D-2: 4,4 '-Diaminodiphenyl ether D-3: 4,4'-diaminodiphenylmethane D-4: 3,5-diaminobenzoic acid D-5: 4,4'-[4, 4'-propane-1,3-diylbis(pyridin-1,4-diyl)]diphenylamine (the compound represented by the formula (N-1-1)) D-6: 3,5- Cholesteryl diaminobenzoate

[Synthesis Example 2-8] Polyamides were synthesized in the same manner as in Synthesis Example 2-1, except that the types and amounts of tetracarboxylic dianhydride and diamine used were changed as described in Table 1 above. Amino acid. Then, 80 mol portions of N,N-dimethylformamide diethyl acetal was added dropwise to the reaction solution, and then the reaction was carried out at 50°C for 2 hours to obtain a polyamidate (containing As a "polymer (PAE-1)") solution. The weight average molecular weight of the polymer (PAE-1) was 30,000.

[Synthesis Example 2-9] Polyamides were synthesized in the same manner as in Synthesis Example 2-1, except that the types and amounts of tetracarboxylic dianhydride and diamine used were changed as described in Table 1 above. Amino acid. Then, pyridine and acetic anhydride were added to the obtained polyamic acid solution to perform chemical imidization. The reaction solution after chemical imidization was concentrated and prepared by NMP so that the concentration became 10% by weight. The polyimide (polymer (PI-1)) obtained had an imidization rate of about 50%.

<Example 1> (1) Preparation of liquid crystal alignment agent In a solution containing a polymer (PA-1) as a polymer component, the compounding ratio of the compound [A] was 10 parts by weight with respect to 100 parts by weight of the polymer component Add NMP solution of compound (a-1) as compound [A] in one part, and then add NMP and butyl cellosolve (BC) as a solvent, and stir well to make the solvent composition as NMP: BC=50: 50 (weight ratio), with a solid content concentration of 5.0% by weight. This solution was filtered using a filter with a pore size of 1 μm, thereby preparing a liquid crystal alignment agent (J-1).

(2) Manufacture of liquid crystal display elements Two glass substrates having two-system transparent electrodes (electrode A and electrode B) including an ITO film on one side and capable of independently applying voltages to electrode A and electrode B were prepared. On each electrode forming surface of the pair of glass substrates, the prepared liquid crystal alignment agent (J-1) was applied using a spinner, and pre-baking was performed on a hot plate at 80° C. for 1 minute. Then, after baking for 10 minutes on a hot plate at 230°C, a coating film having a film thickness of about 0.08 μm was formed. Then, on the outer edge of the surface of the coating film of any substrate, an epoxy resin adhesive with an alumina ball with a diameter of 5.5 μm added was applied, and the two substrates were arranged facing each other with a gap so that the outer edge portion Abut against each other and press to harden the adhesive. Then, after nematic liquid crystal (MLC-6608 manufactured by Merck) was filled between the pair of substrates from the liquid crystal injection port, the liquid crystal injection port was sealed with an acrylic photohardening adhesive.

(3) Evaluation of image sticking characteristics (AC image sticking characteristics) The liquid crystal display device manufactured as described above was placed in an environment of 25° C. and 1 atmosphere, no voltage was applied to electrode B, and AC voltage 3.5 V and DC were applied to electrode A Combined voltage of 5 V for 2 hours. Then, an alternating voltage of 4 V was applied to both electrode A and electrode B. The time from when the application of a voltage of 4 V AC was started to both electrodes until the difference in light transmittance between the electrodes A and B could not be confirmed visually. The case where the time is less than 20 seconds is evaluated as the image retention characteristic "good 1 (◎)", and the case where the period is 20 seconds or longer and less than 60 seconds is evaluated as the image retention characteristic "good 2 (○)", and the period is more than 60 seconds and less than The case of 100 seconds is evaluated as the image retention characteristic "OK 1 (△)", the image retention characteristic of 100 seconds or more and less than 150 seconds is evaluated as "OK 2 (△△)", and the case of 150 seconds or more is evaluated as The image sticking characteristic was “bad (×)”. As a result, the image sticking characteristic of the liquid crystal display element was “good 2 (○)”.

(4) Evaluation of voltage retention rate For the manufactured liquid crystal display element, after applying a voltage of 1 V at 60 microseconds and a span of 167 milliseconds at 60° C., a voltage of 1,000 milliseconds after the release of the application was measured. Voltage Holding Ratio (VHR). The measuring device is VHR-1 manufactured by Toyo Technica (share). A case where the measured voltage retention rate was 96% or more was evaluated as "good (○)", a case of 92% or more and less than 96% was evaluated as "possible (△)", and a case of less than 92% was evaluated as " Bad (×)”. As a result, the voltage retention rate of the liquid crystal display element was 96.5%, which was “good (○)”.

<Example 5, Example 6, Example 8, Example 9, and Comparative Examples 1 to 3> In addition to changing the types and amounts of polymers and additives used as described in Table 2 below, the The liquid crystal alignment agent (J-5), the liquid crystal alignment agent (J-6), the liquid crystal alignment agent (J-8), the liquid crystal alignment agent (J-9) and the liquid crystal alignment agent (R- 1)～Liquid crystal alignment agent (R-3). In addition, using the prepared liquid crystal alignment agents, a liquid crystal display element was manufactured in the same manner as in Example 1 described above, and evaluation of image retention characteristics and voltage retention was performed. The results are shown in Table 2 below.

<Example 2> (1) Preparation of liquid crystal alignment agent The liquid crystal alignment agent (J) was prepared in the same manner as in Example 1 except that the type and amount of the polymer and additives used were changed as described in Table 2 below. -2). (2) Preparation of liquid crystal composition LC1 For 10 g of nematic liquid crystal (Merck (Merck), MLC-6608), 0.3 wt% of photopolymerization represented by the following formula (b-3-1) was added The liquid compounds are mixed to obtain a liquid crystal composition LC1. [化24]

(3) Manufacturing of liquid crystal display elements on each electrode surface of two glass substrates each having ITO electrodes (electrode A and electrode B) patterned into slits and divided into a plurality of regions as shown in FIG. 1 On the above, the liquid crystal alignment agent (J-2) prepared above was applied using a liquid crystal alignment film printer (manufactured by Japan Photographic Printing Co., Ltd.). Subsequently, the solvent was removed by heating (pre-baking) for 1 minute on an 80°C hot plate, and then heating (post-baking) for 10 minutes on a 150° C hot plate to form a coating film with an average film thickness of 0.06 μm. After this coating film was subjected to ultrasonic cleaning in ultrapure water for 1 minute, it was dried in a clean oven at 100°C for 10 minutes to obtain a substrate with a liquid crystal alignment film. This operation is repeated to obtain a pair (two pieces) of substrates with liquid crystal alignment films. In addition, the pattern of the electrode used is the same kind of pattern as the electrode pattern in the PSA mode. Then, on each outer edge of the pair of substrates having the liquid crystal alignment film, an epoxy resin adhesive with an alumina ball of 5.5 μm in diameter added was applied, and then the layers with the liquid crystal alignment film faced each other. To harden the adhesive. Then, after filling the prepared liquid crystal composition LC1 between a pair of substrates from the liquid crystal injection port, the liquid crystal injection port was sealed with an acrylic photohardening adhesive. To the obtained liquid crystal cell, an AC 10 V with a frequency of 60 Hz was applied between the electrodes, and in the state of liquid crystal driving, an ultraviolet irradiation device using a metal halide lamp as the light source was irradiated at an irradiation amount of 100,000 J/m ² Ultraviolet rays. In addition, this irradiation amount is the value measured using the photometer which measured based on the wavelength 365 nm reference. (4) Evaluation of liquid crystal display element The liquid crystal display element obtained above was evaluated in the same manner as in Example 1 for image retention characteristics and voltage retention. As a result, in this example, the image sticking characteristic “good 2 (○)” and the voltage retention rate “good (○)” were evaluated.

<Example 3, Example 4> A liquid crystal alignment agent (J-3) was prepared in the same manner as in Example 1, except that the types and amounts of the polymers and additives used were changed as described in Table 2 below. 、Liquid crystal alignment agent (J-4). In addition to the aspect of changing the liquid crystal alignment agent used and the substitution of the liquid crystal composition LC1, the nematic liquid crystal "MLC-6608" manufactured by Merck (Merck) is filled between a pair of substrates, A liquid crystal display element was manufactured in the same manner as in Example 2, and evaluation of image retention characteristics and voltage retention was performed. These results are shown in Table 2 below.

<Example 7> (1) Preparation of liquid crystal alignment agent The liquid crystal alignment agent (J) was prepared in the same manner as in Example 1 except that the type and amount of the polymer and additives used were changed as described in Table 2 below. -7). (2) Manufacture of liquid crystal display elements Using a spinner, the prepared liquid crystal alignment agent (J-7) was applied to two pieces (one electrode of a two-system transparent electrode (electrode A and electrode B) containing an ITO film Yes) Each transparent electrode surface of the glass substrate. Then, it was heated at 80°C for 1 minute (pre-baking), and then heated in an oven with nitrogen substitution in the store at 200°C (post-baking) for 1 hour to form a film with a thickness of 0.1 μm Coated film. Then, for these coated film surfaces, using a Hg-Xe lamp and a Gran-Taylor prism, 50 mJ/cm ² of polarized ultraviolet rays containing 313 nm bright lines were irradiated from the vertical direction of the substrate surface to obtain a pair of liquid crystal alignment films Substrate. In addition, this irradiation amount is the value measured using the photometer which measured based on the wavelength 365 nm reference. Then, for one of the pair of substrates subjected to the light irradiation treatment, a liquid crystal injection port remained on the outer peripheral edge of the surface where the liquid crystal alignment film was formed, and a screen printing coating was added with a diameter of 5.5 μm. After the epoxy resin adhesive of the alumina ball, a pair of substrates are laminated and heated at 150° C. so that the liquid crystal alignment film forming surfaces face each other and the projection direction of the polarized surface on the substrate surface coincides with light irradiation. The adhesive is thermally hardened in 1 hour. Then, after filling the nematic liquid crystal (made by Merck Co., Ltd., MLC-6608) between the pair of substrates from the liquid crystal injection port, the liquid crystal injection port was sealed with an epoxy adhesive. Furthermore, in order to remove the flow alignment at the time of liquid crystal injection, it was heated to 150°C, and then slowly cooled to room temperature. (3) Evaluation of liquid crystal display element With respect to the obtained liquid crystal display element, evaluation of image retention characteristics and voltage retention rate was performed in the same manner as in Example 1. As a result, in this example, the image sticking characteristic “good 2 (○)” and the voltage retention rate “good (○)” were evaluated.

[Table 2]

In Table 2, the numerical value in parentheses of the polymer component and the additive represents the compounding ratio (parts by weight) of each compound with respect to a total of 100 parts by weight of the polymer component used to prepare the liquid crystal alignment agent. "-" refers to compounds that do not use this column. Among the additives in Table 2, "b-1" and "b-2" refer to the following compounds, and in addition to the above formula (a-1) to formula (a-7) and formula (c -1) and compounds represented by formula (c-2), respectively. <Additive> b-1: Compound represented by the following formula (b-1) b-2: Compound represented by the following formula (b-2) [Chem. 25]

As shown in Table 2, in Examples 1 to 9, the image retention characteristics of the obtained liquid crystal display elements were all evaluated as "good". In addition, the voltage retention characteristics were evaluated as "good" or "acceptable". On the other hand, in Comparative Example 3 using a liquid crystal alignment agent containing a polymer using a side chain type diamine and containing no compound [A], the evaluation of the image retention characteristic and the voltage retention characteristic was “ok”, and the example was excellent . In addition, in Comparative Example 1 and Comparative Example 2, the voltage retention characteristics were evaluated as "poor". From these results, it can be seen that liquid crystals prepared by mixing additives having a reactive group (the group of (1)) and a group exhibiting vertical alignment (the group of (2)) with a polymer component The alignment agent can sufficiently reduce the AC afterimage without impairing the electrical characteristics of the liquid crystal display element.

A, B‧‧‧electrode ITO‧‧‧Indium Tin Oxide

FIG. 1 is a diagram showing an electrode structure used in Examples.

A, B‧‧‧electrode

ITO‧‧‧Indium Tin Oxide

Claims (11)

A liquid crystal alignment agent containing a polymer component and a compound [A] having the following groups (1) and (2), (1) selected from those having two or more rings directly or via a linking group At least one group in the group consisting of a group having a structure and a group having a condensed ring, wherein the ring is a benzene ring or a cyclohexane ring, and the linking group is -O-, -CO-, -COO-, -NR ^b -, -CONR ^b -, C1-C10 alkanediyl group, C1-C10 alkanediyl group of at least one methylene group from -O-, -CO-,- A bivalent group substituted by COO-, -NR ^b -or -CONR ^b -, wherein R ^b is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or a protecting group, and the protecting group is selected from the group consisting of carbamates At least one of the group consisting of a protecting group, an amide-based protecting group, an imidate-based protecting group, a sulfonamide-based protecting group, and groups represented by formula (1-1) to formula (1-4) Group,

In formula (1-1) to formula (1-4), Ar ¹ is a monovalent aromatic ring group having 6 to 10 carbon atoms, and R ¹¹ is an alkyl group having 1 to 12 carbon atoms; * indicates a bond to a nitrogen atom Bond of (2) selected from -NR ¹ R ² , protected isocyanate group, protected isothiocyanate group, group containing oxazoline ring structure, group containing Mie acid structure, and the following formula At least one group in the group consisting of the group represented by (g-1), wherein R ¹ and R ² are each independently a hydrogen atom, a C 1-3 alkyl group or a third butoxy group Carbonyl

In formula (g-1), R ³ and R ⁶ are each independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms; R ⁴ and R ⁵ are independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms or * ² -CH ₂ -OR ¹¹ , where R ¹¹ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms; * ² represents a bond to the carbon atom to which R ⁴ and R ⁵ are bonded; * ¹ represents a bond . The liquid crystal alignment agent as described in item 1 of the patent application scope, which contains at least one polymer [P] selected from the group consisting of polyamic acid, polyamic acid ester and polyimide as the said Polymer component. The liquid crystal aligning agent as described in item 2 of the scope of the patent application, which contains as a polymer a polymer having at least one nitrogen-containing structure selected from the group consisting of a nitrogen-containing heterocyclic ring, a secondary amine group, and a tertiary amine group The polymer [P], wherein the nitrogen-containing heterocyclic ring does not include the amide imide ring which the polyimide has. The liquid crystal alignment agent according to item 2 or item 3 of the patent application scope, which contains a compound selected from the group consisting of tetracarboxylic dianhydride, tetracarboxylic acid diester, and tetracarboxylic acid diester dihalide The polymer obtained by reacting at least one kind of tetracarboxylic acid derivative with a diamine containing a compound having a carboxyl group and two primary amine groups is the polymer [P]. The liquid crystal aligning agent according to any one of claims 1 to 3, wherein the compounding ratio of the compound [A] is 0.1 with respect to a total of 100 parts by weight of the compounding amount of the polymer component Parts by weight ~ 50 parts by weight. The liquid crystal aligning agent as described in any one of claims 1 to 3, further contains a compound having a photopolymerizable group. A liquid crystal alignment film formed using the liquid crystal alignment agent as described in any one of claims 1 to 6. A method for manufacturing a liquid crystal alignment film, comprising: the step of applying the liquid crystal alignment agent as described in any one of claims 1 to 6 to a substrate to form a coating film; and coating the coating The step of irradiating the film with light to give the liquid crystal alignment ability. A liquid crystal element comprising the liquid crystal alignment film as described in item 7 of the patent application. A method of manufacturing a liquid crystal element, comprising: forming a liquid crystal alignment agent as described in any one of the first to sixth patent application ranges on such a conductive film of a pair of substrates having a conductive film A step of coating a film; a step of constructing a liquid crystal cell by arranging a pair of substrates on which the coating film is opposed via the liquid crystal layer so that the coating films face each other; and applying voltage between the conductive films The step of irradiating the liquid crystal cell with light in a state. A compound having the following groups (1) and (2), wherein: (1) is selected from a group having a structure having two or more rings connected directly or via a linking group, and a group having a condensed ring At least one group in the group consisting of, wherein the ring is a benzene ring or a cyclohexane ring, and the linking group is -O-, -CO-, -COO-, -NR ^b -, -CONR ^b -, a C1-C10 alkanediyl group, a C1-C10 alkanediyl group with at least one methylene group from -O-, -CO-, -COO-, -NR ^b -or -CONR ^b- Substituted divalent group, wherein R ^b is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or a protecting group, the protecting group is selected from the group consisting of a carbamate-based protecting group, an amide-based protecting group, and an amide imine At least one group from the group consisting of a protective group, a sulfonamide-based protective group, and groups represented by formula (1-1) to formula (1-4),

In formula (1-1) to formula (1-4), Ar ¹ is a monovalent aromatic ring group having 6 to 10 carbon atoms, and R ¹¹ is an alkyl group having 1 to 12 carbon atoms; * indicates a bond to a nitrogen atom Bond of (2) selected from -NR ¹ R ² , protected isocyanate group, protected isothiocyanate group, group containing oxazoline ring structure, group containing Mie acid structure, and the following formula At least one group in the group consisting of the group represented by (g-1), wherein R ¹ and R ² are each independently a hydrogen atom, a C 1-3 alkyl group or a third butoxy group Carbonyl

In formula (g-1), R ³ and R ⁶ are each independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms; R ⁴ and R ⁵ are independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms or * ² -CH ₂ -OR ¹¹ , where R ¹¹ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms; * ² represents a bond to the carbon atom to which R ⁴ and R ⁵ are bonded; * ¹ represents a bond .

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