JP2016200798A - Liquid crystal aligning agent, liquid crystal alignment film, method for producing liquid crystal alignment film, liquid crystal element, method for manufacturing liquid crystal element and compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal aligning agent that can give a liquid crystal element having excellent image persistence characteristics and voltage retention characteristics.SOLUTION: The liquid crystal aligning agent comprises a polymer component and a compound [A] having the following groups (1) and (2): (1) a group having a structure in which two or more rings are connected directly or via a connecting group, and at least one group selected from a set consisting of groups having a condensed ring; and (2) at least one group selected from a set consisting of -NRR(where Rand Reach independently represent a hydrogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms, or a protective group), a protective isocyanate group, a protective isothiocyanate group, a group having an oxazoline ring structure, a group having a Meldrum's acid structure, and a group represented by formula (g-1) below.SELECTED DRAWING: None

Description

  The present 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.

  2. Description of the Related Art Conventionally, as liquid crystal display elements, various drive systems having different electrode structures and physical properties of liquid crystal molecules to be used have been developed. For example, TN (Twisted Nematic) type, STN (Super Twisted Nematic) type, VA Various liquid crystal display elements such as (Vertical Alignment) type, IPS (In-Plane Switching) type, FFS (fringe field switching) type, and optical compensation bent type (OCB type) are known. These liquid crystal display elements are provided with a liquid crystal alignment film for aligning liquid crystal molecules. As a material for the liquid crystal alignment film, polyimide, a precursor thereof, or the like is used because various properties such as heat resistance, mechanical strength, and affinity with liquid crystal are good (see, for example, Patent Document 1). . Patent Document 1 contains, as a liquid crystal alignment film, a polymer obtained by reacting a polyamic acid having a specific partial structure with p-pentenoxybenzoic acid (p-cyanophenyl) oxide, and liquid crystal. A composite membrane is disclosed.

Japanese Patent Laid-Open No. 11-64856

  In recent years, liquid crystal display elements are used not only in display devices such as personal computers as in the past, but also in various applications such as liquid crystal televisions, car navigation systems, mobile phones, smartphones, information displays, and the like. It is becoming. With such diversification of liquid crystal display elements, demands for display quality have become stricter than before, and there is a demand for liquid crystal display elements with less image sticking and higher voltage holding ratio.

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

  As a result of intensive studies to achieve the above-described problems of the prior art, the present inventors have found that the above problems can be solved by blending a specific compound into the liquid crystal aligning agent. It came to be completed. Specifically, the present invention provides the following liquid crystal aligning agent, liquid crystal alignment film, liquid crystal alignment film manufacturing method, liquid crystal element, liquid crystal element manufacturing method and compound.

In one aspect, the present invention provides a liquid crystal aligning 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 in which two or more rings are linked directly or via a linking group, and a group having a condensed ring.
(2) -NR ¹ R ² (wherein R ¹ and R ² are each independently a hydrogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms or a protecting group), a protected isocyanate group, a protected iso At least one group selected from the group consisting of a thiocyanate group, 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).

(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, 3 alkyl group or “* ^2- CH ₂ —O—R ¹¹ ” (R ¹¹ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. “* ² ” is a bond between R ⁴ and R ⁵ . (It indicates a bond with a carbon atom.) “* ¹ ” indicates a bond.)

In one aspect, the present invention provides a liquid crystal aligning agent obtained by blending a polymer component and the compound [A] having the groups (1) and (2).
In another aspect, a liquid crystal alignment film formed using the liquid crystal alignment agent is provided. Furthermore, the manufacturing method of the liquid crystal aligning film including the process of apply | coating the said liquid crystal aligning agent on a board | substrate and forming a coating film, and the process of light-irradiating the said coating film and providing liquid crystal aligning ability is provided. Furthermore, a liquid crystal element comprising the liquid crystal alignment film or the liquid crystal alignment film obtained by the manufacturing method is provided.

  In one aspect, the present invention provides a process for forming a coating film by applying the liquid crystal aligning agent on the conductive film of a pair of substrates having a conductive film, and a pair of substrates on which the coating film is formed. Manufacturing a liquid crystal element comprising: a step of constructing a liquid crystal cell by facing each other so that the coating film faces each other through a layer; and a step of irradiating the liquid crystal cell with a voltage applied between conductive films Provide a method. In another aspect, the present invention provides a compound [A] having the above groups (1) and (2).

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

The figure which shows the electrode structure used in the Example.

≪Liquid crystal aligning agent≫
The liquid crystal aligning agent of this invention is a polymer composition obtained using a polymer component and a specific additive component. Below, each component used for preparation of the liquid crystal aligning agent of this invention, and the other component arbitrarily mix | blended as needed are demonstrated.
<Polymer component>
The liquid crystal aligning agent of this invention contains a polymer component. The main skeleton of the polymer is not particularly limited. For example, polyamic acid, polyamic acid ester, polyimide, polysiloxane, polyester, polyamide, polybenzoxazole precursor, polybenzoxazole, cellulose derivative, polyacetal, polystyrene derivative, poly (styrene- Main skeletons such as phenylmaleimide) derivatives and poly (meth) acrylates. In addition, (meth) acrylate means containing an acrylate and a methacrylate. In preparing the liquid crystal aligning agent, one type of polymer may be used alone, or two or more types may be used in combination.

  From the viewpoint of sufficiently exhibiting the effect of reduction in image sticking (particularly, reduction of AC afterimage) by the following compound [A], the polymer component of the liquid crystal aligning agent is selected from the group consisting of polyamic acid, polyamic acid ester and polyimide. It is preferably at least one (hereinafter also referred to as “polymer [P]”). The polymer [P] is obtained, for example, by reacting a diamine with a tetracarboxylic acid derivative which is at least one selected from the group consisting of tetracarboxylic dianhydride, tetracarboxylic diester and tetracarboxylic diester dihalide. Can be obtained.

[Polyamic acid]
The polyamic acid in the present invention can be obtained, for example, by reacting a tetracarboxylic dianhydride and a diamine.
(Tetracarboxylic dianhydride)
Examples of tetracarboxylic dianhydrides used for the synthesis of polyamic acid include aliphatic tetracarboxylic dianhydrides, alicyclic tetracarboxylic dianhydrides, aromatic tetracarboxylic dianhydrides, and the like. it can. Specific examples of these include aliphatic tetracarboxylic dianhydrides such as butane tetracarboxylic dianhydride;
Examples of the alicyclic tetracarboxylic dianhydride include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 5- (2,5-di Oxotetrahydrofuran-3-yl) -3a, 4,5,9b-tetrahydronaphtho [1,2-c] furan-1,3-dione, 5- (2,5-dioxotetrahydrofuran-3-yl) -8 -Methyl-3a, 4,5,9b-tetrahydronaphtho [1,2-c] furan-1,3-dione, 3-oxabicyclo [3.2.1] octane-2,4-dione-6-spiro -3 ′-(tetrahydrofuran-2 ′, 5′-dione), 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride, 3 , 5,6-To Carboxy-2-carboxymethylnorbornane-2: 3,5: 6-dianhydride, bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic acid 2: 4,6: 8-di Anhydride, 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-cyclohexane tetracarboxylic dianhydride, bicyclo [2.2.2] oct-7-ene -2, 3,5,6-tetracarboxylic dianhydride, ethylenediaminetetraacetic acid dianhydride, cyclopentanetetracarboxylic dianhydride, ethylene glycol bis (anhydro trimellitate), 1,3-propylene glycol bis (anhydro Trimellitate ) Etc .;

Examples of the aromatic tetracarboxylic dianhydride include pyromellitic dianhydride, 4,4 ′-(hexafluoroisopropylidene) diphthalic anhydride, and the following formulas (H-1-1) to (H-1- In addition to the compounds represented by each of 4), tetracarboxylic dianhydrides described in JP 2010-97188 A can be used.
In addition, the said tetracarboxylic dianhydride can be used individually by 1 type or in combination of 2 or more types.

The tetracarboxylic dianhydride used for the synthesis preferably includes an alicyclic tetracarboxylic dianhydride, and is at least one partial structure selected from the group consisting of a cyclobutane ring structure, a cyclopentane ring structure, and a cyclohexane ring structure It is more preferable to contain a tetracarboxylic dianhydride having the following (hereinafter also referred to as “specific tetracarboxylic dianhydride”). Specifically, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 5- (2,5-dioxotetrahydrofuran-3-yl) -3a, 4,5,9b-tetrahydronaphtho [1,2-c] furan-1,3-dione, 5- (2,5-dioxotetrahydrofuran-3-yl) -8-methyl-3a, 4 5,9b-tetrahydronaphtho [1,2-c] furan-1,3-dione, cyclopentanetetracarboxylic dianhydride, bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic It is particularly preferable to include at least one compound selected from the group consisting of acid dianhydride and cyclohexanetetracarboxylic dianhydride.
The amount of the specific tetracarboxylic dianhydride used (the total amount when two or more are used) is 10 mol% or more based on the total amount of the tetracarboxylic dianhydride used for the synthesis of the polyamic acid. Preferably, it is more preferably 20 mol% or more, and even more preferably 30 mol% or more.

(Diamine)
Examples of the diamine used for the synthesis of the polyamic acid include aliphatic diamine, alicyclic diamine, aromatic diamine, and diaminoorganosiloxane. Specific examples thereof include aliphatic diamines such as metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, 1,3-bis (aminomethyl) cyclohexane; Examples of alicyclic diamines include 1,4-diaminocyclohexane, 4,4′-methylenebis (cyclohexylamine) and the like;

Examples of aromatic diamines include dodecanoxydiaminobenzene, tetradecanoxydiaminobenzene, pentadecanoxydiaminobenzene, hexadecanoxydiaminobenzene, octadecanoxydiaminobenzene, cholestanyloxydiaminobenzene, and cholesteryloxydiaminobenzene. Cholestanyl diaminobenzoate, cholesteryl diaminobenzoate, lanostannyl diaminobenzoate, 3,6-bis (4-aminobenzoyloxy) cholestane, 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-((amino Phenoxy Methyl) phenyl) -4-heptylcyclohexane, 1,1-bis (4-((aminophenyl) methyl) phenyl) -4- (4-heptylcyclohexyl) cyclohexane, N- (2,4-diaminophenyl) -4 -(4-Heptylcyclohexyl) benzamide, the following formula (E-1)
(In Formula (E-1), X ^I and X ^II are each independently a single bond, —O—, * —COO— or * —OCO— (where “*” 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, and b is 0 ) Is an integer of ˜2, c is an integer of 1 to 20, and d is 0 or 1. However, a and b are not 0 at the same time.)
Side chain type diamines such as compounds represented by:

p-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl sulfide, 4-aminophenyl-4′-aminobenzoate, 4,4′-diaminoazobenzene, 1,5-bis (4-amino) Phenoxy) pentane, 1,7-bis (4-aminophenoxy) heptane, bis [2- (4-aminophenyl) ethyl] hexanedioic 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) fluorene, 2,2-bis [4- (4-aminophenoxy) phenyl] Hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4 ′-(p-phenylenediisopropylidene) bisaniline, 4,4 ′-(m-phenylenediisopropylidene) bisaniline, 1 , 4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) biphenyl, etc .;
Examples of the diaminoorganosiloxane include 1,3-bis (3-aminopropyl) -tetramethyldisiloxane; and the diamines described in JP-A 2010-97188 can be used.

Specific examples of the compound represented by the formula (E-1) include, for example, compounds represented by the following formulas (E-1-1) to (E-1-4). .

  As the diamine used for the synthesis of the polyamic acid, a diamine having at least one structure selected from the group consisting of a nitrogen-containing heterocyclic ring, a secondary amino group and a tertiary amino group (hereinafter also referred to as “nitrogen-containing structure”); Examples thereof include diamine having a carboxyl group. A polymer using a diamine having a nitrogen-containing structure as at least a part of the raw material is preferable in that the effect of improving the reduction in image sticking due to the DC voltage of the liquid crystal display element can be enhanced. In addition, according to the polymer using the carboxyl group-containing diamine as at least a part of the raw material, the interaction with the following compound [A] is increased, and the improvement effect of reducing the image sticking due to the AC voltage of the liquid crystal display element can be enhanced. It is suitable.

In the diamine having a nitrogen-containing structure, examples of the nitrogen-containing heterocyclic ring that the diamine may have include pyrrole, imidazole, pyrazole, triazole, pyridine, pyrimidine, pyridazine, pyrazine, indole, benzimidazole, purine, quinoline, Examples include isoquinoline, naphthyridine, quinoxaline, phthalazine, triazine, carbazole, acridine, piperidine, piperazine, pyrrolidine, hexamethyleneimine and the like. Among them, it is preferable to have at least one selected from the group consisting of pyridine, pyrimidine, pyrazine, piperidine, piperazine, quinoline, carbazole and acridine.
The secondary amino group and the tertiary amino group that the diamine having a nitrogen-containing structure may have are represented, for example, by the following formula (N-1).
(In formula (N-1), R ²³ represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. “*” Represents a bond bonded to the hydrocarbon group.)

In the above formula (N-1), examples of the monovalent hydrocarbon group for R ²³ include an alkyl group such as a methyl group, an ethyl group, and a propyl group; a cycloalkyl group such as a cyclohexyl group; a phenyl group, a methylphenyl group, and the like And aryl groups. 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-diaminocarbazole, N-methyl-3,6-diamino. Carbazole, 1,4-bis- (4-aminophenyl) -piperazine, 3,6-diaminoacridine, N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N, N ′ -Bis (4-aminophenyl) -benzidine, N, N'-bis (4-aminophenyl) -N, N'-dimethylbenzidine, the following formula (N-1-1) to formula (N-1-8) And the like.

In the synthesis of the polyamic acid, the proportion of the diamine having a nitrogen-containing structure is 0.1 mol% or more based on the total amount of the diamine used in the synthesis from the viewpoint of sufficiently obtaining the improvement effect of reducing the burn-in of the liquid crystal display element. Preferably, the content is 1 mol% or more, more preferably 2 mol% or more. Further, the upper limit of the use ratio is preferably 60 mol% or less, more preferably 50 mol% or less, and further preferably 40 mol% or less. Diamines having a nitrogen-containing structure can be used alone or in combination of two or more.
In the synthesis of the polyamic acid, a polyamic acid as a polymer having a nitrogen-containing structure is obtained by using a diamine having a nitrogen-containing structure as at least a part of the raw material. However, the method for obtaining a 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 with a diamine.

The carboxyl group-containing diamine may have at least one carboxyl group and two primary amino 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, 4,4′-diaminobiphenyl-3-carboxylic acid, Monocarboxylic acids such as 4'-diaminodiphenylmethane-3-carboxylic acid, 4,4'-diaminodiphenylethane-3-carboxylic acid;
4,4′-diaminobiphenyl-3,3′-dicarboxylic acid, 4,4′-diaminobiphenyl-2,2′-dicarboxylic acid, 3,3′-diaminobiphenyl-4,4′-dicarboxylic acid, 3, 3'-diaminobiphenyl-2,4'-dicarboxylic acid, 4,4'-diaminodiphenylmethane-3,3'-dicarboxylic acid, 4,4'-diaminodiphenylethane-3,3'-dicarboxylic acid, 4,4 And dicarboxylic acids such as' -diaminodiphenyl ether-3,3'-dicarboxylic acid;

  In the synthesis of the polyamic acid, the use ratio of the carboxyl group-containing diamine is preferably 1 mol% or more, preferably 5 mol% or more, based on the total amount of diamine used in the synthesis, from the viewpoint of image sticking characteristics. More preferably, it is more preferably 10 mol% or more. In addition, the upper limit value of the usage rate is not particularly limited, but from the viewpoint of voltage holding ratio, it is preferably 80 mol% or less, and preferably 70 mol% or less with respect to the total amount of diamine used for synthesis. Is more preferable. In addition, a carboxyl group-containing diamine can be used by selecting one of the above alone or by appropriately selecting two or more.

When the liquid crystal alignment ability is imparted to the coating film formed with the liquid crystal aligning agent by light irradiation, a polymer having a photo-alignment structure may be used as at least a part of the polymer component. As a specific example of the photoalignment structure, a group exhibiting photoalignment by photoisomerization, photodimerization, photolysis, or the like can be employed. Specifically, for example, an azo-containing group containing an azo compound or derivative thereof as a basic skeleton, a cinnamic acid-containing group containing cinnamic acid or a derivative thereof as a basic skeleton, or a chalcone-containing group containing chalcone or a derivative thereof as a basic skeleton A benzophenone-containing group containing benzophenone or a derivative thereof as a basic skeleton, a coumarin-containing group containing coumarin or a derivative thereof as a basic skeleton, a cyclobutane-containing structure containing cyclobutane or a derivative thereof as a basic skeleton, bicyclo [2.2.2 ] Bicyclo [2.2.2] octene-containing structure containing octene or a derivative thereof as a basic skeleton, the following formula (4)
(In Formula (4), X ³ is a sulfur atom or an oxygen atom. “*” Represents a bond, respectively, provided that at least one of the two “*” is bonded to an aromatic ring. )
The structure containing the partial structure represented by these as a basic skeleton, etc. are mentioned.

  The polyamic acid having a photoalignment structure can be obtained, for example, by polymerization containing at least one of a tetracarboxylic dianhydride having a photoalignment structure and a diamine having a photoalignment structure in the monomer composition. In this case, from the viewpoint of photoreactivity, the proportion of the monomer having a photo-alignment structure is preferably 20 mol% or more based on the total amount of monomers used for polymer synthesis, and is 30 to 80 mol. % Is more preferable.

(Synthesis of polyamic acid)
The polyamic acid can be obtained by reacting the above tetracarboxylic dianhydride and diamine together with a molecular weight adjusting agent as necessary. The ratio of the tetracarboxylic dianhydride and the diamine used in the polyamic acid synthesis reaction is 0.2 to 2 for the tetracarboxylic dianhydride acid anhydride group to 1 equivalent of the amino group of the diamine. The ratio which becomes an equivalent is preferable, and the ratio which becomes 0.3-1.2 equivalent is more preferable.
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, and monoisocyanate compounds such as phenyl isocyanate and naphthyl isocyanate. Can be mentioned. It is preferable that the usage-amount of a molecular weight modifier shall be 20 weight part or less with respect to a total of 100 weight part of tetracarboxylic dianhydride and diamine to be used.

The polyamic acid synthesis reaction is preferably carried out in an organic solvent. The reaction temperature at this time is preferably −20 ° C. to 150 ° C., and the reaction time is preferably 0.1 to 24 hours.
Examples of the organic solvent used in the reaction include aprotic polar solvents, phenol solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons, hydrocarbons, and the like. Among these organic solvents, one or more selected from the group consisting of an aprotic polar solvent and a phenolic solvent (first group organic solvent), or one or more selected from the first group of organic solvents And a mixture of at least one selected from the group consisting of alcohols, ketones, esters, ethers, halogenated hydrocarbons and hydrocarbons (second-group organic solvent). In the latter case, the proportion of the second group organic solvent used is preferably 50% by weight or less, more preferably 40% by weight, based on the total amount of the first group organic solvent and the second group organic solvent. It is as follows.

Particularly preferred organic solvents are N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphortriamide, m-cresol, xylenol. And at least one selected from the group consisting of halogenated phenols is used as a solvent, or a mixture of one or more of these and another organic solvent is preferably used in the above range. The amount of organic solvent used (a) is such that the total amount (b) of tetracarboxylic dianhydride and diamine is 0.1 to 50% by weight based on the total amount (a + b) of the reaction solution. Is preferred.
As described above, a reaction solution obtained by dissolving polyamic acid is obtained. This reaction solution may be used for the preparation of the liquid crystal aligning agent as it is, or may be used for the preparation of the liquid crystal aligning agent after isolating the polyamic acid contained in the reaction solution. Isolation and purification of the polyamic acid can be performed according to known methods.

[Polyamic acid ester]
The polyamic acid ester in the present invention is, for example, [I] a polyamic acid obtained by the above synthesis reaction and an esterifying agent (for example, methanol, ethanol, N, N-dimethylformamide diethyl acetal, N, N-diethylformamide diethyl acetal). Etc.), [II] a method of reacting a tetracarboxylic acid diester and a diamine, [III] a method of reacting a tetracarboxylic acid diester dihalide and a diamine, and the like.
The polyamic acid ester contained in the liquid crystal aligning agent may have only an amic acid ester structure, or may be a partially esterified product in which an amic acid structure and an amic acid ester structure coexist. In addition, the reaction solution formed by dissolving the polyamic acid ester may be used for the preparation of the liquid crystal aligning agent as it is, or may be used for the preparation of the liquid crystal aligning agent after isolating the polyamic acid ester contained in the reaction solution. Good.

[Polyimide]
The polyimide in the present invention can be obtained, for example, by dehydrating and ring-closing imidized polyamic acid synthesized as described above.

  The polyimide may be a completely imidized product obtained by dehydrating and cyclizing all of the amic acid structure possessed by the polyamic acid that is the precursor, and only a part of the amic acid structure may be dehydrated and cyclized. It may be a partially imidized product in which a ring structure coexists. The polyimide used for the reaction preferably has an imidization ratio of 10% or more, more preferably 20 to 99%, and still more preferably 20 to 85%. This imidation ratio represents the ratio of the number of imide ring structures to the total of the number of polyimide amic acid structures and the number of imide ring structures in percentage. Here, a part of the imide ring may be an isoimide ring.

The polyamic acid is preferably dehydrated and closed by heating the polyamic acid, or by dissolving the polyamic acid in an organic solvent, adding a dehydrating agent and a dehydrating ring-closing catalyst to the solution, and heating the solution as necessary. . Of these, the latter method is preferred.
In the method of adding a dehydrating agent and a dehydrating ring-closing catalyst to a polyamic acid solution, as the dehydrating agent, for example, acid anhydrides such as acetic anhydride, propionic anhydride, and trifluoroacetic anhydride can be used. It is preferable that the usage-amount of a dehydrating agent shall be 0.01-20 mol with respect to 1 mol of the amic acid structure of a polyamic acid. As the dehydration ring closure catalyst, for example, tertiary amines such as pyridine, collidine, lutidine, triethylamine and the like can be used. It is preferable that the usage-amount of a dehydration ring-closing catalyst shall be 0.01-10 mol with respect to 1 mol of dehydrating agents to be used. Examples of the organic solvent used in the dehydration ring-closing reaction include the organic solvents exemplified as those used for the synthesis of polyamic acid. The reaction temperature of the dehydration ring closure reaction is preferably 0 to 180 ° C, more preferably 10 to 150 ° C. The reaction time is preferably 1.0 to 120 hours, more preferably 2.0 to 30 hours.

  In this way, a reaction solution containing polyimide is obtained. This reaction solution may be used for the preparation of the liquid crystal aligning agent as it is, may be used for the preparation of the liquid crystal aligning agent after removing the dehydrating agent and the dehydrating ring-closing catalyst from the reaction solution, and the liquid crystal after isolating the polyimide. You may use for preparation of an aligning agent, or you may use for preparation of a liquid crystal aligning agent, after purifying the isolated polyimide. These purification operations can be performed according to known methods. In addition, polyimide can also be obtained by imidation of polyamic acid ester.

  The polyamic acid, polyamic acid ester and polyimide obtained as described above preferably have a solution viscosity of 10 to 800 mPa · s, when this is made into a solution having a concentration of 10% by weight, and 15 to 500 mPa · s. More preferably, it has a solution viscosity of s. In addition, the solution viscosity (mPa · s) of the above polymer is based on a polymer solution having a concentration of 10% by weight prepared using a good solvent for the polymer (eg, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.). The value measured at 25 ° C. using an E-type rotational viscometer.

  The polystyrene-equivalent weight average molecular weight (Mw) measured by polyamic acid, polyamic acid ester and polyimide gel permeation chromatography (GPC) is preferably 1,000 to 500,000, more preferably 2,000 to 300,000. Moreover, the molecular weight distribution (Mw / Mn) represented by the ratio of Mw to the number average molecular weight (Mn) in terms of polystyrene measured by GPC is preferably 10 or less, more preferably 7 or less. By being in such a molecular weight range, it is possible to ensure good alignment and stability of the liquid crystal element.

<Compound [A]>
In preparing the liquid crystal aligning agent of the present invention, the compound [A] having the following groups (1) and (2) is used in addition to the polymer component.
(1) At least one selected from the group consisting of a group having a structure in which two or more rings are connected directly or via a linking group (hereinafter also referred to as “polycyclic structure”), and a group having a condensed ring. Group.
(2) -NR ¹ R ² (wherein R ¹ and R ² are each independently a hydrogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms or a protecting group), a protected isocyanate group, a protected iso At least one group selected from the group consisting of a thiocyanate group, a group containing an oxazoline ring structure, a group containing a Meldrum's acid structure, and a group represented by the above 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 the ring which the said group has is two or more, it will not specifically limit, It is preferable that it is 2-4. The plurality of rings constituting the polycyclic structure may be the same or different from each other. 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 carbon atoms, or a protecting group.) , At least one methylene group of an alkanediyl group having 1 to 10 carbon atoms or an alkanediyl group having 1 to 10 carbon atoms by —O—, —CO—, —COO—, —NR ^b — or —CONR ^b —. And substituted divalent groups.

^Examples of the protecting group for R ^b include a monovalent organic group which can be eliminated by at least one of heat, light, acid and base. R ^b is preferably a monovalent organic group that is at least eliminated by heat. Specific examples thereof include carbamate-based protecting groups, amide-based protecting groups, imide-based protecting groups, sulfonamide-based protecting groups, Examples include groups represented by each of (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. "Represents a bond bonded to a nitrogen atom.)

Ar ^{1 in the} above formula (1-2) is a group obtained by removing one hydrogen atom from an aromatic ring having 6 to 10 carbon atoms. Specific examples thereof include a phenyl group and a naphthyl group. Examples of the alkyl group having 1 to 12 carbon atoms of R ^{11 in} the formula (1-4) include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group. It may be branched.
R ^b is preferably a carbamate-based protecting group because it is highly removable by heat. Specific examples thereof include tert-butoxycarbonyl group, benzyloxycarbonyl group, 1,1-dimethyl-2-haloethyloxycarbonyl group, 1,1-dimethyl-2-cyanoethyloxycarbonyl group, 9-fluorenyl. Examples thereof include a methyloxycarbonyl group, an allyloxycarbonyl group, and a 2- (trimethylsilyl) ethoxycarbonyl group. Among them, it is a tert-butoxycarbonyl group (BOC group) in that it has a high desorption property due to heat and a compound derived from R ^b desorbed by heating during film formation can be discharged out of the film as a gas. preferable.

Specific examples of the polycyclic structure include, for example, 4,4′-biphenylene group, 4,4′-bicyclohexylene group, and groups represented by the following formulas (6-1) to (6-9). Etc.
(In the formula, “BOC” represents a tert-butoxycarbonyl group. “*” Represents a bond.)

  In the group (1), the condensed ring is not particularly limited as long as it has a cyclic structure having two or more rings and each ring sharing two or more atoms. For example, a naphthalene ring, anthracene Ring, phenanthrene ring, steroid nucleus and the like. Of these, the group having a condensed ring is preferably a group having a steroid skeleton. The group having a steroid skeleton preferably has 17 to 51 carbon atoms, and examples thereof include a cholesteryl group, a cholestanyl group, a lanostannyl group, a cholestanyloxycarbonyl group, a cholesteryloxycarbonyl group, a cholesteryloxy group, and a cholesteryloxy group. It is done.

Regarding the group (2), examples of the hydrocarbon group having 1 to 10 carbon atoms of R ¹ and R ² in the group “—NR ¹ R ² ” include a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group. A linear or branched alkyl group such as a hexyl group; an alicyclic hydrocarbon group such as a cyclohexyl group or a methylcyclohexyl group; an aromatic hydrocarbon group such as a phenyl group, a methylphenyl group, or a benzyl group; Can be mentioned. As specific examples in the case where R ¹ and R ² are protecting groups, the explanations given as examples for R ^b can be applied. Among these, R ¹ and R ² are preferably a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a tert-butoxycarbonyl group. R ¹ and R ² may be the same or different from each other.

  The protected iso (thio) cyanate group in the group (2) is preferably a group that regenerates the iso (thio) cyanate group by deprotection with at least one of heat, light, acid, and base. Specific examples include groups obtained by reacting an iso (thio) cyanate group with a compound having an active hydrogen (blocking agent). “Active hydrogen” means a hydrogen atom having high detachability, and preferably refers to an acid dissociation constant pKa in water of 20 or less. In addition, an iso (thio) cyanate group is a meaning containing an isocyanate group and an isothiocyanate group.

Known blocking agents can be used, for example, alcohol compounds, phenol compounds, active methylene compounds, mercaptan compounds, acid amide compounds, acid imide compounds, imidazole compounds, pyrazole compounds, urea systems. Examples include compounds, oxime compounds, amine compounds, imine compounds, pyridine compounds, and the like. Specific examples thereof include alcohol compounds such as methanol, ethanol, propanol, butanol, 2-ethylhexanol, methyl cellosolve, butyl cellosolve, methyl carbitol, benzyl alcohol, cyclohexanol and the like;
Examples of phenolic compounds include phenol, cresol, ethylphenol, butylphenol, nonylphenol, dinonylphenol, styrenated phenol, hydroxybenzoate, and the like;

Examples of active methylene compounds include dimethyl malonate, diethyl malonate, methyl acetoacetate, ethyl acetoacetate, and acetylacetone; mercaptan compounds such as butyl mercaptan and dodecyl mercaptan; acid amide compounds such as acetanilide, Acetic acid amide, ε-caprolactam, δ-valerolactam, γ-butyrolactam and the like; acid imide compounds such as succinimide, maleic imide and the like;
Examples of imidazole compounds include imidazole and 2-methylimidazole; examples of pyrazole compounds include 3-methylpyrazole, 3,5-dimethylpyrazole, and 3,5-ethylpyrazole; examples of urea compounds include urea, Thiourea, ethyleneurea, etc .; oxime compounds such as formaldoxime, acetoaldoxime, acetoxime, methyl ethyl ketoxime, cyclohexanone oxime, etc .; amine compounds such as diphenylamine, aniline, carbazole, etc .; imine compounds Examples include ethyleneimine and polyethyleneimine; examples of the pyridine compound include 2-hydroxypyridine and 2-hydroxyquinoline.

  The protected iso (thio) cyanate group in the group (2) is preferably a group that is 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 protecting group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, and more preferably 1 to 4 carbon atoms. Some are more preferred.

  Examples of the group containing an oxazoline ring structure include a group obtained by removing any one hydrogen atom from the oxazoline ring. Examples of the group containing a Meldrum acid structure include a group obtained by removing any one hydrogen atom from Meldrum acid.

In the above formula ^(g-1), the alkyl group having 1 to 3 carbon atoms R 3, ^{R 6} and ^{R 11,} for example a methyl group, an ethyl group, n- propyl group, an isopropyl group. R ⁶ and R ¹¹ are preferably a hydrogen atom or a methyl group, more preferably a hydrogen atom, from the viewpoint of improving the image sticking property of the liquid crystal display element.
Examples of the alkyl group having 1 to 3 carbon atoms of R ⁴ and R ⁵ include the groups exemplified above for R ³ . From the viewpoint of improving the image sticking property, a hydrogen atom, * ³ —CH ₂ —OH, or * ³ —CH ₂ —OCH ₃ is preferable. 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 coating property of the liquid crystal aligning agent on the substrate, the molecular weight is more preferably 1,500 or less, further preferably 1,200 or less, and 1,000 or less. It is particularly preferred.
Preferable examples of the compound [A] include, for example, “R ⁸ —C _m H _2m —R ⁹ ” (where R ⁸ is the group (1) above and R ⁹ is the group (2) above). m is an integer of 1 to 20.). Here, R ⁹ is preferably a group represented by any of the following formulas (r-1) to (r-7). R ⁸ is “* -X ¹ -R ¹⁰ -R ¹¹ ” (where X ¹ is a single bond, an oxygen atom, —CO— or —COO—, R ¹⁰ is a polycyclic structure, and R ¹¹ is , A hydrogen atom, an alkyl group or a fluoroalkyl group, “*” indicates a bond, or “* -X ² -R ¹² ” (where X ¹ is a single bond, an oxygen atom, − CO— or —COO—, and R ¹² is a cholesteryl group, a cholestanyl group, or a lanostannyl group, and “*” represents a bond.

Specific examples of the compound [A] include compounds represented by the following formulas (A1-1) to (A1-22).
(In Formula (A1-1) to Formula (A1-22), R ⁷ is a group represented by any of the following Formulas (r-1) to (r-7), and m is 1 to 20. It is an integer, n is an integer of 0-20, and l and k are each independently an integer of 0-10.)
(In the formula, “*” indicates a bond.)

  The compounding ratio of the compound [A] is preferably 0.1 to 50 parts by weight with respect to 100 parts by weight of the total polymer components in the liquid crystal aligning agent. When the compounding ratio of the compound [A] is less than 0.1 parts by weight, it is difficult to obtain a sufficient effect of improving the image sticking reduction of the liquid crystal display element. When the compounding ratio is more than 50 parts by weight, the compound [A] is excessive. Along with this, there is a possibility that the film strength of the liquid crystal alignment film, the liquid crystal alignment property, and the electric holding characteristics of the liquid crystal display element are deteriorated. About the minimum of the compounding ratio of compound [A], More preferably, it is 1 weight part or more with respect to a total of 100 weight part of the polymer component in a liquid crystal aligning agent, More preferably, it is 3 weight part or more, Especially Preferably it is 5 parts by weight or more. Moreover, about the upper limit of the compounding ratio of compound [A], More preferably, it is 40 weight part or less, More preferably, it is 30 weight part or less. In addition, compound [A] can be used individually by 1 type or in combination of 2 or more types. These compounds [A] can be synthesized by appropriately combining organic chemistry methods.

  In the liquid crystal aligning agent, at least a part of the compound [A] may interact with the polymer component, or may exist in the liquid crystal aligning agent in a state where it does not interact with the polymer component. When the liquid crystal aligning agent contains the compound [A], for example, a polymer having a functional group (for example, a carboxyl group) that reacts with the group (2) by heating during post-baking (hereinafter referred to as “specific polymer”). It is speculated that an interaction occurs between the compound [A] and the compound [A], and the effect of reducing the image sticking and improving the voltage holding ratio can be increased. In the present specification, the term “interaction” refers to an intermolecular force that forms a covalent bond between molecules or is weaker than a covalent bond (eg, ion-dipole interaction, dipole-dipole interaction, It means the formation of electromagnetic force between molecules such as hydrogen bonds and van der Waals forces.

<Other ingredients>
The liquid crystal aligning agent of this invention may mix | blend other components other than a polymer component and compound [A] in the range which does not prevent the objective and effect of this invention. Examples of such other components include compounds having at least one photopolymerizable group in the molecule (hereinafter also referred to as “photopolymerizable compounds”).

(Photopolymerizable compound)
The photopolymerizable compound can be used for the purpose of increasing the alignment regulating 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 a group having a polymerizable unsaturated bond, and specifically, (meth) acryloyloxy group, styryl group, (meth) acrylamide group, vinyl group, vinylidene group, vinyloxy group. (CH ₂ ═CH—O—), maleimide group, and the like. The number of photopolymerizable groups contained in the photopolymerizable compound may be one or more, preferably two or more, and more preferably 2 to 4. The molecular weight of the photopolymerizable compound is preferably 2,000 or less, and more preferably 1,500 or less.

As such a photopolymerizable compound, a (meth) acrylate compound can be preferably used in terms of high photoreactivity. 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 , Monofunctional (meth) acrylates such as methoxytriethylene glycol (meth) acrylate, glycidyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate; ethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) ) Acrylate, pentaerythritol tri (meth) acrylate, polyether (meth) acrylate, ethoxylated bisphenol A di (meth) acrylate, 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.)
And polyfunctional (meth) acrylates such as compounds represented by each of the above.
When mix | blending a photopolymerizable compound with a liquid crystal aligning agent, it is preferable that the mixture ratio shall be 40 weight part or less with respect to a total of 100 weight part of the polymer contained in a liquid crystal aligning agent, 0.5- It is more preferable to set it as 30 weight part, and it is still more preferable to set it as 1-20 weight part.

  As 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, an antifoaming agent, a sensitizer, a dispersing agent, an oxidizing agent Inhibitors, adhesion assistants, antistatic agents, leveling agents, antibacterial agents and the like can be mentioned. These blending ratios can be set as appropriate in a range not impeding the effects of the present invention, depending on the compound to be blended.

[solvent]
The liquid crystal aligning agent of the present invention is prepared as a liquid composition in which the polymer component, the compound [A] and other components used as necessary are preferably dispersed or dissolved in an appropriate organic solvent. The
Examples of the organic solvent to be used include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 1,3-dimethyl-1-imidazolidinone, γ-butyrolactone, γ-butyrolactam, N, N-dimethylformamide. N, N-dimethylacetamide, 3-methoxy-N, N-dimethylpropanamide, 3-butoxy-N, N-dimethylpropanamide, N, N, 2-trimethylpropanamide, 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 methoxypropionate, ethyl ethoxypropionate G, ethylene grease Coal methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether, ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl Ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, diisopentyl ether, ethylene carbonate, propylene carbonate And the like can be given Boneto. These can be used individually by 1 type or in mixture of 2 or more types.

  The solid content concentration in the liquid crystal aligning agent of the present invention (the ratio of the total weight of components other than the solvent of the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent) is appropriately selected in consideration of viscosity, volatility, and the like. The range is preferably 1 to 10% by weight. That is, the liquid crystal aligning agent of this invention is apply | coated to a substrate surface so that it may mention later, Preferably the coating film which becomes a liquid crystal aligning film or a coating film used as a liquid crystal aligning film is formed by heating. At this time, when the solid content concentration is less than 1% by weight, the film thickness of the coating film becomes too small, and it becomes difficult to obtain a good liquid crystal alignment film. On the other hand, when the solid content concentration exceeds 10% by weight, it is difficult to obtain a good liquid crystal alignment film because the film thickness is excessive, and the viscosity of the liquid crystal aligning agent increases and the applicability decreases. There is a tendency. The temperature when preparing the liquid crystal aligning agent is preferably 10 to 50 ° C, more preferably 20 to 30 ° C.

≪Liquid crystal alignment film and liquid crystal element≫
The liquid crystal alignment film of the present invention is formed by the liquid crystal aligning agent prepared as described above. Moreover, the liquid crystal element of this invention comprises the liquid crystal aligning film formed using said liquid crystal aligning agent. The driving mode of the liquid crystal element is not particularly limited, and can be applied to various driving modes such as a TN type, STN type, IPS type, FFS type, VA type, MVA type, and PSA (Polymer sustained alignment) type.

  The liquid crystal element of the present invention can be produced, for example, by a method including the following steps 1 to 3. In step 1, the substrate to be used varies depending on the desired drive mode. Step 2 and step 3 are common to each drive mode.

[Step 1: Formation of coating film]
First, a liquid crystal aligning agent is apply | coated on a board | substrate, Then, a coating film is formed on a board | substrate by heating an application surface.
(1-1) When manufacturing a TN type, STN type, VA type, MVA type or PSA type liquid crystal element, a pair of two substrates provided with a patterned transparent conductive film is used as a pair, and each substrate is transparent. A liquid crystal aligning agent is preferably applied to the surface on which the conductive conductive film is formed by an offset printing method, a spin coating method, a roll coater method, or an ink jet printing method, respectively. Here, as the substrate, for example, glass such as float glass or soda glass; a transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, poly (cycloaliphatic olefin) can be used. As a transparent conductive film provided on one surface of the substrate, an NESA film (registered trademark of PPG, USA) made of tin oxide (SnO ₂ ), an ITO film made of indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ ), etc. Can be used. In applying the liquid crystal aligning agent, in order to further improve the adhesion between the substrate surface and the transparent conductive film and the coating film, a functional silane compound or a functional titanium compound is formed on the surface of the substrate surface on which the coating film is formed. It is also possible to perform a pretreatment to apply the above in advance.

  After the application of the liquid crystal aligning agent, preheating (pre-baking) is preferably performed for the purpose of preventing dripping of the applied aligning agent. The prebake temperature is preferably 30 to 200 ° C., and the prebake time is preferably 0.25 to 10 minutes. Thereafter, a firing (post-baking) step is carried out for the purpose of completely removing the solvent and, if necessary, for thermal imidization of the amic acid structure present in the polymer. The firing temperature (post-bake temperature) at this time is preferably 80 to 300 ° C., and the post-bake time is preferably 5 to 200 minutes. The thickness of the film thus formed is preferably 0.001 to 1 μm, more preferably 0.005 to 0.5 μm.

(1-2) When manufacturing an IPS type or FFS type liquid crystal element, an electrode forming surface of a substrate provided with an electrode made of a transparent conductive film or a metal film patterned in a comb shape, and an electrode are provided. A liquid crystal aligning agent is apply | coated to one surface of the counter substrate which is not, respectively, Then, a coating film is formed by heating each application surface. Regarding the material used for the substrate and the transparent conductive film, the coating method, the heating conditions after coating, the patterning method for the transparent conductive film or the metal film, the pretreatment of the substrate, and the preferred film thickness of the coating film to be formed The same as (1-1). As the metal film, for example, a film made of a metal such as chromium can be used.
In both cases (1-1) and (1-2), a liquid crystal alignment film or a coating film that becomes a liquid crystal alignment film is formed by applying a liquid crystal aligning agent on the substrate and then removing the organic solvent. Is done.

[Step 2: Orientation ability imparting treatment]
In the case of manufacturing a TN type, STN type, IPS type, or FFS type liquid crystal element, a treatment for imparting liquid crystal alignment ability to the coating film formed in Step 1 is performed. Thereby, the orientation ability of a liquid crystal molecule is provided to a coating film, and it becomes a liquid crystal aligning film. Examples of the alignment ability imparting treatment include a rubbing treatment in which a coating film is rubbed in a fixed direction with a roll wound with a cloth made of fibers such as nylon, rayon, and cotton, and photo-alignment in which the coating film is irradiated with polarized or non-polarized radiation. Processing. On the other hand, when manufacturing a VA type liquid crystal display element, the coating film formed in the above step 1 can be used as it is as a liquid crystal alignment film, but the coating film may be subjected to alignment ability imparting treatment.

When the liquid crystal alignment ability is imparted to the coating film by the photo-alignment treatment, for example, ultraviolet rays and visible rays including light having a wavelength of 150 to 800 nm can be used as the radiation applied to the coating film. When the radiation is polarized light, it may be linearly polarized light or partially polarized light. When the radiation used is linearly polarized light or partially polarized light, irradiation may be performed from a direction perpendicular to the substrate surface, an oblique direction, or a combination thereof. When irradiating non-polarized radiation, the direction of irradiation is an oblique direction.
As a light source to be used, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, an excimer laser, or the like can be used. The radiation dose is preferably 100 to 50,000 J / m ² , more preferably 300 to 20,000 J / m ² . Moreover, you may perform light irradiation with respect to a coating film, heating a coating film, in order to improve the reactivity. The temperature at the time of heating is 30-250 degreeC normally, Preferably it is 40-200 degreeC. A liquid crystal alignment film suitable for a VA liquid crystal display element can also be suitably used for a PSA liquid crystal display element.

[Step 3: Construction of liquid crystal cell]
(3-1) A liquid crystal cell is manufactured by preparing two substrates on which a liquid crystal alignment film is formed as described above and disposing a liquid crystal between the two substrates facing each other. In order to manufacture a liquid crystal cell, for example, two substrates are arranged to face each other with a gap so that the liquid crystal alignment films face each other, and the peripheral portions of the two substrates are bonded together using a sealant, and the substrate surface and A method of injecting and filling liquid crystal into a cell gap defined by a sealing agent and then sealing the injection hole; applying a sealing agent to a predetermined place on one substrate on which the liquid crystal alignment film is formed; For example, a method of dropping the liquid crystal at a predetermined number of locations on the surface and then bonding the other substrate so that the liquid crystal alignment film faces each other and spreading the liquid crystal over the entire surface of the substrate (ODF method). The manufactured liquid crystal cell is preferably heated to a temperature at which the used liquid crystal takes an isotropic phase, and then slowly cooled to room temperature to remove the flow alignment at the time of filling the liquid crystal.

  As the sealing agent, for example, an epoxy resin containing a curing agent and aluminum oxide spheres as a spacer can be used. Examples of the liquid crystal include nematic liquid crystal and smectic liquid crystal. Among them, nematic liquid crystal is preferable. For example, Schiff base liquid crystal, azoxy liquid crystal, biphenyl liquid crystal, phenylcyclohexane liquid crystal, ester liquid crystal, terphenyl liquid crystal, biphenyl. Cyclohexane liquid crystals, pyrimidine liquid crystals, dioxane liquid crystals, bicyclooctane liquid crystals, cubane liquid crystals, and the like can be used. Further, cholesteric liquid crystals such as cholestyl chloride, cholesteryl nonate, and cholesteryl carbonate; chiral agents such as those sold under the trade names “C-15” and “CB-15” (manufactured by Merck & Co., Inc.). A ferroelectric liquid crystal such as p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate may be added and used.

(3-2) When manufacturing a PSA type liquid crystal display element, a liquid crystal cell is constructed in the same manner as in the above (3-1) except that a photopolymerizable compound is injected or dropped together with a liquid crystal. Thereafter, 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 to 50 V direct current or alternating current. As light to irradiate, the ultraviolet-ray containing light with a wavelength of 300-400 nm is preferable. The irradiation dose of light is preferably 1,000~200,000J / ^{m 2,} more preferably 1,000~100,000J / ^{m 2.}

  (3-3) When a coating film is formed on a substrate using a liquid crystal aligning agent containing a photopolymerizable compound, a liquid crystal cell is constructed in the same manner as in (3-1) above, and then the pair of substrates has You may employ | adopt the method of manufacturing a liquid crystal display element by passing through the process of light-irradiating a liquid crystal cell in the state which applied the voltage between electrically conductive films. According to this method, the merit of the PSA mode can be realized with a small amount of light irradiation. The applied voltage can be, for example, 0.1 to 30 V direct current or alternating current. The description of (3-2) above can be applied to the condition of the light to be irradiated.

  A liquid crystal element can be obtained by attaching a polarizing plate to the outer surface of the liquid crystal cell. As a polarizing plate to be bonded to the outer surface of the liquid crystal cell, a polarizing film or an H film itself in which a polarizing film called an “H film” in which iodine is absorbed while stretching and aligning polyvinyl alcohol is sandwiched between cellulose acetate protective films The polarizing plate which consists of can be mentioned.

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

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

In the following examples and comparative examples, the imidization ratio of polyimide in the polymer solution, the solution viscosity of the polymer solution, and the weight average molecular weight of the polymer were measured by the following methods. Hereinafter, the compound represented by Formula X may be simply referred to as “Compound X”.
[Imidation rate of polyimide]
The polyimide solution was poured into pure water, and the resulting precipitate was sufficiently dried under reduced pressure at room temperature, then dissolved in deuterated dimethyl sulfoxide, and ¹ H-NMR was measured at room temperature using tetramethylsilane as a reference substance. From the obtained ¹ H-NMR spectrum, the imidation ratio [%] was determined by the following mathematical formula (1).
Imidation ratio [%] = (1-A ¹ / A ² × α) × 100 (1)
(In Formula (1), A ¹ is a peak area derived from protons of NH groups appearing near a chemical shift of 10 ppm, A ² is a peak area derived from other protons, and α is a precursor of a polymer (polyamic acid). The number ratio of other protons to one proton of NH group in)
[Solution viscosity of polymer solution]
The solution viscosity [mPa · s] of the polymer solution was measured at 25 ° C. using an E-type rotational viscometer for a solution prepared to a polymer concentration of 10% by weight using a predetermined solvent.
[Weight average molecular weight of polymer]
The weight average molecular weight is a polystyrene equivalent value measured by gel permeation chromatography under the following conditions.
Column: Tosoh Co., Ltd., TSKgelGRCXLII
Solvent: Tetrahydrofuran Temperature: 40 ° C
Pressure: 68 kgf / cm ²

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

  In a 2000 mL three-necked flask containing a stir bar, 17.8 g of 4- (2- (4′-pentyl- [1,1′-bicyclohexane] -4-yl) ethyl) phenol, 2-((tert-butoxy) 8.76 g of carbonyl) amino) acetic acid was taken and 500 g of dichloromethane was added and stirred. Thereafter, the mixture was cooled to 0 ° C., 11.5 g of 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride and 1.22 g of N, N-dimethylaminopyridine were added thereto, and the mixture was stirred at room temperature for 20 hours. . Thereafter, the reaction solution was separated and washed three times with 800 mL of water, and then the organic layer was dried over magnesium sulfate. Then, it concentrated slowly by the concentration by a rotary evaporator until the internal volume became 100g, and collect | recovered the white solid which precipitated on the way by filtration. This white solid was vacuum-dried to obtain 18.0 g of compound (a-1).

[Synthesis Example 1-2]
Compound (a-2) was synthesized according to the following scheme 2.

-Synthesis | combination of compound (a-2-1) Compound (a-2-1) was obtained by the synthesis method similar to compound (a-1) using (beta) -cholestanol as a starting material.
-Synthesis of compound (a-2-2) 16.4 g of compound (a-2-1), 300 g of dichloromethane, and 17.1 g of trifluoroacetic acid were added to a 200 mL eggplant flask containing a stir bar, and the mixture was stirred at room temperature for 1 hour. Stir. Then, it cooled to 0 degreeC, 50 mL of saturated sodium hydrogencarbonate aqueous solution was added slowly and liquid-separated, and the organic layer was liquid-separated and washed 3 times with 100 mL of water. Then, it concentrated slowly by the concentration by a rotary evaporator until the internal volume became 30g, and collect | recovered the white solid which precipitated in the middle by filtration. This white solid was vacuum-dried to obtain 13.1 g of compound (a-2-2).
Synthesis of compound (a-2) To a 200 mL three-necked flask containing a stirrer, 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 ° C. . Thereto, methyl chloroformate was slowly added dropwise and stirred at room temperature for 2 hours. Thereafter, the reaction solution was extracted three times with 50 mL of ethyl acetate, and the obtained organic layer was separated and washed three times with 100 mL of distilled water. Then, it concentrated slowly by the concentration by a rotary evaporator until the internal volume became 30g, and collect | recovered the white solid which precipitated in the middle by filtration. This white solid was vacuum-dried to obtain 5.53 g of compound (a-2).

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

Synthesis of compound (a-3-1) 16.4 g of 4- (4′-pentyl- [1,1′-bicyclohexane] -4-yl) phenol, 9 mol / L in a 100 mL three-necked flask containing a stirrer 20 mL of potassium hydroxide aqueous solution was added, and it stirred at room temperature for 5 minutes. Thereafter, the mixture was heated to boiling, and 14.1 g of 50% aqueous acetic acid chloride solution was added dropwise thereto and refluxed for 5 hours. Thereafter, the reaction solution was cooled to room temperature, 200 mL of a 1 mol / L hydrochloric acid aqueous solution was dropped, and the mixture was extracted three times with 150 mL of ethyl acetate. The obtained organic layer was separated and washed with 100 mL of distilled water three times. Then, it concentrated slowly by the concentration by a rotary evaporator until the internal volume became 40g, and collect | recovered the white solid which precipitated on the way by filtration. This white solid was vacuum-dried to obtain 13.7 g of compound (a-3-1).
-Synthesis | combination of compound (a-3) 11.6g of compounds (a-3-1), 7.38g of 2-bromoethylamine hydrobromide, 300mL of methanol, and N- 3.64 g of methylmorpholine was added and stirred, and 9.96 g of DMT-MM was added thereto. After stirring at room temperature for 1 hour, 120 g of 1 mol / L potassium hydroxide-methanol solution was added and refluxed for 2 hours. Thereafter, the reaction solution was poured into 500 mL of water and extracted three times with 300 mL of diethyl ether. Thereafter, the organic layer was separated and washed once with 300 mL of 1 mol / L hydrochloric acid, once with 200 mL of saturated aqueous sodium hydrogen carbonate solution, and three times with 200 mL of water. Then, the organic layer was slowly concentrated by concentration using a rotary evaporator until the organic layer became 50 g, and a white solid precipitated during the course was collected by filtration. This white solid was vacuum-dried to obtain 9.01 g of compound (a-3).

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

-Synthesis | combination of compound (a-4) 5.14g of compound (a-1), 30mL of dichloromethane, and 5.7g of trifluoroacetic acid were added to the 100 mL eggplant flask which put the stirring element, and it stirred at room temperature for 2 hours. . Thereafter, the reaction solution was neutralized with an aqueous potassium carbonate solution and extracted three times with 100 mL of ethyl acetate. The obtained organic layer was separated and washed three times with 100 mL of distilled water. Then, it concentrated slowly until the internal volume became 30g by the concentration by a rotary evaporator, and the white solid which precipitated on the way was collect | recovered by filtration. This white solid was vacuum-dried to obtain 3.93 g of compound (a-4).

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

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

[Synthesis Example 1-6]
Compound (a-6) was synthesized according to the following scheme 6.

Synthesis of Compound (a-6-1) Using 4- (2- (4′-pentyl- [1,1′-bicyclohexane] -4-yl) ethyl) phenol as a starting material, compound (a- Compound (a-6-1) was obtained by the same synthesis method as in 3-1).
Synthesis of Compound (a-6) In a 100 mL three-necked flask containing a stirrer, 7.73 g of Compound (a-6-1), 2.88 g of Meldrum's acid, 2.44 g of N, N-dimethylaminopyridine, 50 mL of dichloromethane was added and cooled to 0 ° C. Thereto was added N, N′-dicyclohexylcarbodiimide (4.12 g), followed by stirring at 0 ° C. for 2 hours. Thereafter, the reaction solution was filtered through Celite, and the filtrate was separated and washed once with 50 mL of 1 mol / L hydrochloric acid aqueous solution and three times with 50 mL of water. Then, it concentrated slowly until the internal volume became 20g by the concentration by a rotary evaporator, and the white yellow solid which precipitated on the way was collect | recovered by filtration. This solid was vacuum-dried to obtain 9.30 g of compound (a-6).

[Synthesis Example 1-7]
Compound (a-7) was synthesized according to the following scheme 7.

Synthesis of compound (a-7) (E) -3- (4 ((4- (4,4,4-trifluorobutoxy) benzoyl) oxy) phenyl) acrylic acid and 3- (dimethylamino) as starting materials ) Using ethanol, compound (a-7) was obtained by the same synthesis method as compound (a-1).

[Synthesis Example 1-8]
Compound (c-1) was synthesized according to the following scheme 8.

Synthesis of Compound (c-1) 7.13 g of 4- (2- (4′-pentyl- [1,1′-bicyclohexane] -4-yl) ethyl) phenol was added to a 300 mL three-necked flask containing a stirrer. Ethanol (120 mL) and sodium hydroxide (0.96 g) were added, and the mixture was stirred at room temperature for 20 minutes. Epichlorohydrin 5.55g was dripped there, and it stirred at room temperature for 9 hours. Thereafter, 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 separated and washed with 100 mL of water three times, and the solvent was distilled off by a rotary evaporator. The residue was subjected to column purification with silica gel to obtain 6.60 g of a compound (c-1) that was a white yellow solid.

[Synthesis Example 1-9]
Compound (c-2) was synthesized according to the following scheme 9.

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

<Synthesis of polymer>
[Synthesis Example 2-1]
100 mol parts of 1,2,3,4-cyclobutanetetracarboxylic dianhydride as tetracarboxylic dianhydride and 100 mol parts of p-phenylenediamine as diamine were dissolved in N-methyl-2-pyrrolidone (NMP). The reaction was performed at room temperature for 6 hours to obtain a solution containing 20% by weight of polyamic acid. The polyamic acid obtained here was used as a polymer (PA-1).

[Synthesis Example 2-2 to Synthesis Example 2-7]
A polyamic acid (polymer (PA-2) to polymer (PA-7) was prepared 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 shown in Table 1 below. )) Was synthesized.

In Table 1, the numbers in parentheses of tetracarboxylic dianhydride and diamine represent the usage ratio [mole part] of each compound with respect to 100 mol parts in total of the tetracarboxylic dianhydride used for the synthesis of the polymer. Abbreviations of the compounds in Table 1 have the following meanings, respectively.
<Tetracarboxylic dianhydride>
T-1: 1,2,3,4-cyclobutanetetracarboxylic dianhydride T-2: 2,3,5-tricarboxycyclopentylacetic acid dianhydride T-3: bicyclo [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 (piperidine-1,4-diyl)] dianiline (compound represented by the above formula (N-1-1))
D-6: Cholestanyl 3,5-diaminobenzoate

[Synthesis Example 2-8]
A polyamic acid was 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 shown in Table 1 above. Next, 80 mol parts of N, N-dimethylformamide diethyl acetal was dropped into this reaction solution, and then reacted at 50 ° C. for 2 hours to give a polyamic acid ester (referred to as “polymer (PAE-1)”). A solution containing was obtained. The weight average molecular weight of the polymer (PAE-1) was 30,000.

[Synthesis Example 2-9]
A polyamic acid was 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 shown in Table 1 above. Next, 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 with NMP so that the concentration would be 10% by weight. The imidation ratio of the obtained polyimide (polymer (PI-1)) was about 50%.

<Example 1>
(1) Preparation of liquid crystal aligning agent In a solution containing polymer (PA-1) as a polymer component, an NMP solution of compound (a-1) as compound [A] is mixed with a compounding ratio of compound [A]. Add NMP and butyl cellosolve (BC) as a solvent and stir well with 100 parts by weight of the combined component. The solvent composition is NMP: BC = 50: 50 (weight ratio), solid A solution having a partial concentration of 5.0% by weight was obtained. A liquid crystal aligning agent (J-1) was prepared by filtering this solution using a filter having a pore size of 1 μm.

(2) Manufacture of liquid crystal display element Two glass substrates having two transparent electrodes (electrode A and electrode B) made of ITO film on one side and capable of independently applying a voltage to electrode A and electrode B are provided. I prepared a sheet. The liquid crystal aligning agent (J-1) prepared above was applied to each electrode forming surface of the pair of glass substrates with a spinner, and prebaked for 1 minute on an 80 ° C. hot plate. Subsequently, it was post-baked for 10 minutes on a 230 ° C. hot plate to form a coating film having a thickness of about 0.08 μm. Subsequently, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm was applied to the outer edge of the surface of one of the substrates having the coating film, and then the two substrates were placed opposite to each other with a gap between them. The parts were brought into contact with each other and pressed to cure the adhesive. Next, a nematic liquid crystal (MLC-6608, manufactured by Merck & Co., Inc.) was filled between the pair of substrates from the liquid crystal injection port, and then the liquid crystal injection port was sealed with an acrylic photo-curing adhesive.

(3) Evaluation of image sticking characteristics (AC afterimage characteristics) The liquid crystal display device manufactured as described above was placed in an environment of 25 ° C. and 1 atm, no voltage was applied to electrode B, and an AC voltage of 3.5 V was applied to electrode A. A combined voltage of DC voltage 5V was applied for 2 hours. Immediately thereafter, an AC voltage of 4 V was applied to both electrode A and electrode B. The time from when the voltage of 4V AC was started to be applied to both electrodes until the difference in light transmittance between the electrodes A and B could not be visually confirmed was measured. When this time is less than 20 seconds, the burn-in characteristic “good 1 (◎)”, when it is 20 seconds or more and less than 60 seconds, the burn-in characteristic “good 2 (◯)”, 60 seconds or more and less than 100 seconds The seizure property “possible 1 (Δ)” when it is present, the seizure property “possible 2 (ΔΔ)” when it is 100 seconds or more and less than 150 seconds, and the seizure property “defective (×)” when it is 150 seconds or more. As a result, the image sticking property of this liquid crystal display element was “good 2 (◯)”.

(4) Evaluation of voltage holding ratio With respect to the liquid crystal display device manufactured as described above, a voltage of 1 V was applied at 60 ° C. with an application time of 60 microseconds and a span of 167 milliseconds, and 1,000 milliseconds after application cancellation. The voltage holding ratio (VHR) of was measured. As a measuring apparatus, VHR-1 manufactured by Toyo Corporation was used. The case where the measured voltage holding ratio was 96% or more was “good (◯)”, the case where it was 92% or more and less than 96% was “good (Δ)”, and the case where it was less than 92% was “bad”. When evaluated as “x)”, the voltage holding ratio of this liquid crystal display element was 96.5%, which was “good (◯)”.

<Examples 5, 6, 8, 9 and Comparative Examples 1-3>
Liquid crystal aligning agents (J-5), (J-6), (J-8), (J) as in Example 1 except that the types and amounts of the polymers and additives used were changed as shown in Table 2 below. J-9) and (R-1) to (R-3) were respectively prepared. Further, using each of the prepared liquid crystal aligning agents, a liquid crystal display element was produced in the same manner as in Example 1, and the image sticking characteristics and the voltage holding ratio were evaluated. The results are shown in Table 2 below.

<Example 2>
(1) Preparation of liquid crystal aligning agent The liquid crystal aligning agent (J-2) was prepared like Example 1 except having changed the kind and quantity of the polymer and additive which were used as Table 2 below.
(2) Preparation of liquid crystal composition LC1 To 10 g of nematic liquid crystal (MLC-6608, manufactured by Merck & Co.), 0.3% by weight of a photopolymerizable compound represented by the following formula (b-3-1) was added. By mixing, a liquid crystal composition LC1 was obtained.

(3) Manufacture of liquid crystal display element On each electrode surface of two glass substrates each patterned with a slit shape as shown in FIG. 1 and having ITO electrodes (electrode A and electrode B) partitioned into a plurality of regions. The liquid crystal aligning agent (J-2) prepared above was applied using a liquid crystal alignment film printer (Nissha Printing Co., Ltd.). Next, after removing the solvent by heating (pre-baking) for 1 minute on an 80 ° C. hot plate, heating (post-baking) for 10 minutes on a hot plate at 150 ° C. to form a coating film having an average film thickness of 0.06 μm. Formed. The coating film was subjected to ultrasonic cleaning in ultrapure water for 1 minute and then dried in a clean oven at 100 ° C. for 10 minutes to obtain a substrate having a liquid crystal alignment film. This operation was repeated to obtain a pair (two) of substrates having a liquid crystal alignment film. The used electrode pattern is the same type as the electrode pattern in the PSA mode.
Next, after applying an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm to the outer edges of the pair of substrates having the liquid crystal alignment film, the surfaces having the liquid crystal alignment film are overlapped and pressed together. And the adhesive was cured. Next, after filling the liquid crystal composition LC1 prepared above between a pair of substrates from the liquid crystal injection port, the liquid crystal injection port was sealed with an acrylic photo-curing adhesive. With respect to the obtained liquid crystal cell, an alternating current of 10 Hz is applied between the electrodes, and the liquid crystal is driven, and an ultraviolet ray irradiation device using a metal halide lamp as a light source is used to emit ultraviolet rays of 100,000 J / m ² . Irradiated at a dose. In addition, this irradiation amount is the value measured using the light meter measured on the basis of wavelength 365nm.
(4) Evaluation of liquid crystal display element The liquid crystal display element obtained above was evaluated for image sticking characteristics and voltage holding ratio in the same manner as in Example 1. As a result, in this example, the seizure characteristics “good 2 (◯)” and the voltage holding ratio “good (◯)” were evaluated.

<Examples 3 and 4>
Liquid crystal aligning agents (J-3) and (J-4) were prepared in the same manner as in Example 1 except that the types and amounts of the polymers and additives used were changed as shown in Table 2 below. Further, the same procedure as in Example 2 was performed except that the liquid crystal aligning agent to be used was changed, and that instead of the liquid crystal composition LC1, nematic liquid crystal “MLC-6608” manufactured by Merck was filled between a pair of substrates. A liquid crystal display element was manufactured, and image sticking characteristics and voltage holding ratio were evaluated. The results are shown in Table 2 below.

<Example 7>
(1) Preparation of liquid crystal aligning agent The liquid crystal aligning agent (J-7) was prepared like Example 1 except having changed the kind and quantity of the polymer and additive which were used as Table 2 below.
(2) Manufacture of a liquid crystal display element The liquid crystal aligning agent (J-7) prepared above is transparent for each of two glass substrates (a pair) with two transparent electrodes (electrode A and electrode B) made of an ITO film. It apply | coated using the spinner on the electrode surface. Subsequently, heating (pre-baking) was performed at 80 ° C. for 1 minute, and then heating (post-baking) was performed at 200 ° C. for 1 hour in an oven in which the inside of the chamber was replaced with nitrogen to form a coating film having a thickness of 0.1 μm. Next, a pair of substrates having a liquid crystal alignment film by irradiating the surface of these coating films with polarized ultraviolet rays 50 mJ / cm ² including a 313 nm emission line from the direction perpendicular to the substrate surface using a Hg-Xe lamp and a Grand Taylor prism. Got. In addition, this irradiation amount is the value measured using the light meter measured on the basis of wavelength 365nm.
Next, with respect to one of the pair of substrates subjected to the light irradiation treatment, an epoxy resin containing aluminum oxide spheres having a diameter of 5.5 μm is provided at the outer peripheral edge of the surface on which the liquid crystal alignment film is formed, leaving a liquid crystal injection port. After screen printing application of the adhesive, a pair of substrates are stacked and pressure-bonded at 150 ° C. so that the liquid crystal alignment film forming surfaces face each other and the projection directions onto the substrate surface of the polarization plane at the time of light irradiation coincide. The adhesive was heat cured by heating for 1 hour.
Next, a nematic liquid crystal (MLC-6608, manufactured by Merck & Co., Inc.) was filled between the pair of substrates from the liquid crystal injection port, and then 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, this was heated to 150 ° C. and then gradually cooled to room temperature.
(3) Evaluation of liquid crystal display element The liquid crystal display element obtained above was evaluated for image sticking characteristics and voltage holding ratio in the same manner as in Example 1. As a result, in this example, the seizure characteristics “good 2 (◯)” and the voltage holding ratio “good (◯)” were evaluated.

In Table 2, the numerical values in parentheses of the polymer component and the additive indicate the blending ratio (parts by weight) of each compound with respect to 100 parts by weight of the total polymer components used for the preparation of the liquid crystal aligning agent. “-” Means that the compound in the corresponding column was not used. Among the additives in Table 2, “b-1” and “b-2” mean the following compounds, respectively, and the others are the above formulas (a-1) to (a-7), (c- The compound represented by each of 1) and (c-2) is meant.
<Additives>
b-1: Compound represented by the following formula (b-1) b-2: Compound represented by the following formula (b-2)

  As shown in Table 2, in each of Examples 1 to 9, the image sticking characteristics of the obtained liquid crystal display elements were evaluated as “good”. The voltage holding characteristics were evaluated as “good” or “good”. On the other hand, in Comparative Example 3 using a liquid crystal aligning agent that includes a polymer using a side chain type diamine and does not include the compound [A], the image sticking property and the voltage holding property are “good” evaluations, The example was superior. In Comparative Example 1 and Comparative Example 2, the voltage holding characteristic was evaluated as “defective”. From these results, according to the liquid crystal aligning agent in which an additive having a reactive group (the group of (1) above) and a group showing the vertical alignment (the group of (2) above) is mixed with the polymer component, It was found that the AC afterimage can be sufficiently reduced without impairing the electrical characteristics of the display element.

  A, B: Electrode

Claims (12)

A liquid crystal aligning agent comprising 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 in which two or more rings are linked directly or via a linking group, and a group having a condensed ring.
(2) -NR ¹ R ² (wherein R ¹ and R ² are each independently a hydrogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms or a protecting group), a protected isocyanate group, a protected iso At least one group selected from the group consisting of a thiocyanate group, 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).
(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, 3 alkyl group or “* ^2- CH ₂ —O—R ¹¹ ” (R ¹¹ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. “* ² ” is a bond between R ⁴ and R ⁵ . (It indicates a bond with a carbon atom.) “* ¹ ” indicates a bond.)   The liquid crystal aligning agent of Claim 1 containing at least 1 type of polymer [P] chosen from the group which consists of a polyamic acid, a polyamic acid ester, and a polyimide as said polymer component.   As the polymer [P], a polymer having at least one nitrogen-containing structure selected from the group consisting of a nitrogen-containing heterocyclic ring (excluding the imide ring of polyimide), a secondary amino group, and a tertiary amino group The liquid crystal aligning agent of Claim 2 containing.   As the polymer [P], a tetracarboxylic acid derivative which is at least one selected from the group consisting of tetracarboxylic dianhydride, tetracarboxylic diester and tetracarboxylic diester dihalide, a carboxyl group and two primary grades The liquid crystal aligning agent of Claim 2 or 3 containing the polymer obtained by making the diamine containing the compound which has an amino group react.   The liquid crystal alignment as described in any one of Claims 1-4 whose compounding ratio of the said compound [A] is 0.1-50 weight part with respect to a total of 100 weight part of the compounding quantity of the said polymer component. Agent.   Furthermore, the liquid crystal aligning agent as described in any one of Claims 1-5 containing the compound which has a photopolymerizable group. Liquid crystal aligning agent obtained by mix | blending a polymer component and the compound [A] which has the following (1) and group of (2).
(1) At least one group selected from the group consisting of a group having a structure in which two or more rings are linked directly or via a linking group, and a group having a condensed ring.
(2) -NR ¹ R ² (wherein R ¹ and R ² are each independently a hydrogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms or a protecting group), a protected isocyanate group, a protected iso At least one group selected from the group consisting of a thiocyanate group, 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).
(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, 3 alkyl group or “* ^2- CH ₂ —O—R ¹¹ ” (R ¹¹ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. “* ² ” is a bond between R ⁴ and R ⁵ . (It indicates a bond with a carbon atom.) “* ¹ ” indicates a bond.)   The liquid crystal aligning film formed using the liquid crystal aligning agent as described in any one of Claims 1-7.   The process of apply | coating the liquid crystal aligning agent as described in any one of Claims 1-7 on a board | substrate, and forming a coating film, and the process of light-irradiating the said coating film and providing liquid crystal aligning ability is included. A method for producing a liquid crystal alignment film.   A liquid crystal device comprising the liquid crystal alignment film according to claim 8. A step of applying a liquid crystal aligning agent according to any one of claims 1 to 7 to form a coating film on the conductive film of a pair of substrates having a conductive film;
A step of constructing a liquid crystal cell by arranging the pair of substrates on which the coating film is formed so as to face each other with the coating film facing each other through a liquid crystal layer;
Irradiating the liquid crystal cell with a voltage applied between the conductive films; and
A method for manufacturing a liquid crystal element comprising: Compounds having the following groups (1) and (2):
(1) At least one group selected from the group consisting of a group having a structure in which two or more rings are linked directly or via a linking group, and a group having a condensed ring.
(2) -NR ¹ R ² (wherein R ¹ and R ² are each independently a hydrogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms or a protecting group), a protected isocyanate group, a protected iso At least one group selected from the group consisting of a thiocyanate group, 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).
(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, 3 alkyl group or “* ^2- CH ₂ —O—R ¹¹ ” (R ¹¹ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. “* ² ” is a bond between R ⁴ and R ⁵ . (It indicates a bond with a carbon atom.) “* ¹ ” indicates a bond.)