JP2016206274A - Liquid crystal alignment agent, liquid crystal alignment film and manufacturing method of the same, liquid crystal display, phase difference film and manufacturing method of the same, polymer, and compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal alignment agent with which a liquid crystal display that has an excellent coating property on a substrate and excellent liquid crystal alignment property and reliability can be obtained.SOLUTION: A polymer (A) having a partial structure represented by the following formula (1) is made contained in a liquid crystal alignment agent. In the formula (1), Ris a hydrogen atom or a protective group of an amino group, and Ris a halogen atom or a monovalent organic group. N is an integer of 0 to 3. "*" indicates a coupling hand.SELECTED DRAWING: None

Description

  The present invention relates to a liquid crystal aligning agent, a liquid crystal alignment film and a production method thereof, a liquid crystal display element, a retardation film and a production method thereof, a polymer, and a compound.

  In liquid crystal display elements widely used in televisions, mobile devices, various monitors, etc., a liquid crystal alignment film is used to control the alignment of liquid crystal molecules in the liquid crystal cell. As a method for producing a liquid crystal alignment film, conventionally, a method of rubbing an organic film, a method of obliquely depositing silicon oxide, a method of forming a monomolecular film having a long chain alkyl group, and light irradiation to a photosensitive organic film A method (photo-alignment method) is known. Among these, the photo-alignment method can impart uniform liquid crystal alignment to the photosensitive organic film while suppressing the generation of static electricity and dust, and also enables precise control of the liquid crystal alignment direction. Various studies are underway (see, for example, Patent Document 1).

  Patent Document 1 discloses a liquid crystal alignment film made of a polymer having a main skeleton selected from the group consisting of polybenzoxazole, polybenzothiazole and polybenzimidazole and having a photoactive group as a functional group. Yes. In Patent Document 1, the use of such a polymer makes it possible to apply a photo-alignment technique, while suppressing a decrease in display quality in a high-temperature environment.

  In recent years, large-screen high-definition liquid crystal televisions are mainly used, and small display terminals such as smartphones and tablet PCs are widely used, and the demand for high-definition liquid crystal panels is increasing. Based on this background, improvements in the display quality and reliability of liquid crystal panels have become more important than ever.

  In addition, various optical materials are used for liquid crystal display elements. Above all, retardation films eliminate the object of viewing color dependency and the viewing angle dependency that the display color and contrast ratio change depending on the visual direction. It is used for the purpose. As such retardation films, those having a liquid crystal alignment film formed on the surface of a substrate such as a TAC film and a liquid crystal layer formed by curing a polymerizable liquid crystal on the surface of the liquid crystal alignment film are known. ing. In recent years, a liquid crystal alignment film in a retardation film has been produced by using a photo-alignment method that imparts liquid crystal alignment ability by irradiating a radiation-sensitive organic thin film formed on the substrate surface with polarized or non-polarized radiation. Various liquid crystal aligning agents for retardation films for producing a liquid crystal aligning film by such a method have been proposed (for example, see Patent Document 2).

Japanese Patent No. 4429334 JP 2012-37868 A

  However, the liquid crystal aligning agent described in Patent Document 1 has poor applicability to the substrate, which may cause a decrease in product yield or affect the display quality of the obtained liquid crystal display element. .

  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 display element excellent in application properties to a substrate and having excellent liquid crystal alignment properties and reliability. To do. Another object is to provide a liquid crystal aligning agent capable of obtaining a retardation film excellent in liquid crystal alignment and adhesion.

  The present inventors diligently studied to solve the problems of the prior art as described above, and found that when the polymer having a specific partial structure was contained in the liquid crystal aligning agent, the problems could be solved, and the present invention. It came to complete. Specifically, the present invention provides the following liquid crystal aligning agent, liquid crystal alignment film and method for producing the same, liquid crystal display element, retardation film and method for producing the same, polymer and compound.

[1] A liquid crystal aligning agent containing a polymer (A) having a partial structure represented by the following formula (1).

(In Formula (1), R ¹ is a hydrogen atom or an amino-protecting group, R ² is a halogen atom or a monovalent organic group, n is an integer of 0 to ^3. “*” is a bond. Indicates that it is a hand.)
[2] A liquid crystal alignment film formed using the liquid crystal aligning agent of [1].
[3] A liquid crystal alignment film obtained by applying the liquid crystal aligning agent of [1] to a substrate to form a coating film, and irradiating the coating film with light.
[4] A liquid crystal alignment film obtained by applying the liquid crystal aligning agent of [1] to a substrate and then rubbing.
[5] A liquid crystal alignment film containing a polymer having a partial structure represented by the following formula (2).
(In Formula (2), R ² is a halogen atom or a monovalent organic group. N is an integer of 0 to ^3. “*” indicates a bond.)
[6] Manufacture of a liquid crystal alignment film comprising: a step of applying the liquid crystal aligning agent of [1] above onto a substrate to form a coating film; and a step of irradiating the coating film with light to impart liquid crystal alignment ability. Method.
[7] A liquid crystal display device comprising the liquid crystal alignment film according to any one of [2] to [4].
[8] A retardation film comprising the liquid crystal alignment film of [2] or [3].
[9] A step of coating the liquid crystal aligning agent according to [1] on a substrate to form a coating film, a step of irradiating the coating film with light, and a polymerizable property on the coating film after the light irradiation. And a step of applying and curing a liquid crystal.
[10] A polymer having a partial structure represented by the above formula (1).
[11] A polyimide having a partial structure represented by the above formula (2) or a precursor thereof.
[12] A diamine having a partial structure represented by the above formula (1).

  According to the liquid crystal aligning agent containing the said polymer (A), the liquid crystal display element excellent in the applicability | paintability with respect to a board | substrate, and excellent in liquid crystal aligning property and reliability can be obtained. In addition, a retardation film having good adhesion to the substrate can be obtained.

The figure which shows the result of the thermogravimetric analysis of a compound (Model-1). The figure which shows the result of the thermogravimetric analysis of a compound (Model-2). ¹ H-NMR spectrum of the compound (Model-1). ¹ H-NMR spectrum of the compound (Model-2). ¹ H-NMR spectrum of the compound (Model-1) after heating at 230 ° C. ¹ H-NMR spectrum of 230 ° C. After heating the compound (Model-2). The schematic block diagram of a FFS type liquid crystal display element. The plane schematic diagram of the top electrode used for manufacture of a photo-alignment type liquid crystal display element. (A) is a top view of a top electrode, (b) is the elements on larger scale of a top electrode. The figure which shows the drive electrode of 4 systems. The plane schematic diagram of the top electrode used for manufacture of a rubbing alignment type liquid crystal display element. (A) is a top view of a top electrode, (b) is the elements on larger scale of a top electrode.

  The liquid crystal aligning agent of the present invention is a liquid polymer composition in which a polymer component is preferably dissolved or dispersed in an organic solvent. Below, each component contained in the liquid crystal aligning agent of this invention and the other component arbitrarily mix | blended as needed are demonstrated.

  In the present specification, the “hydrocarbon group” means a chain hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. The “chain hydrocarbon group” means a linear hydrocarbon group and a branched hydrocarbon group that are composed only of a chain structure without including a cyclic structure in the main chain. However, it may be saturated or unsaturated. The “alicyclic hydrocarbon group” means a hydrocarbon group that includes only an alicyclic hydrocarbon structure as a ring structure and does not include an aromatic ring structure. However, it is not necessary to be comprised only by the structure of an alicyclic hydrocarbon, The thing which has a chain structure in the part is also included. “Aromatic hydrocarbon group” means a hydrocarbon group containing an aromatic ring structure as a ring structure. However, it is not necessary to be composed only of an aromatic ring structure, and a part thereof may include a chain structure or an alicyclic hydrocarbon structure. “Organic group” means a group containing a carbon atom, and the structure may contain a heteroatom.

<Polymer (A)>
The polymer (A) of the present invention contains a polymer (A) having a partial structure represented by the following formula (1) (hereinafter also referred to as “specific partial structure”).
(In Formula (1), R ¹ is a hydrogen atom or an amino-protecting group, R ² is a halogen atom or a monovalent organic group, n is an integer of 0 to ^3. “*” is a bond. Indicates that it is a hand.)

With respect to R ¹ in the above formula (1), the protecting group for the amino group is not particularly limited as long as it is a functional group capable of temporarily making the amino group an inactive functional group. And monovalent organic groups which are eliminated by at least one of an acid and a base. R ¹ is preferably an amino-protecting group from the viewpoint of storage stability of the liquid crystal aligning agent, and is a monovalent organic group that is at least desorbed by heat because it can be desorbed by heating during post-baking. It is more preferable. Specifically, for example, carbamate protecting groups, amide protecting groups, imide protecting groups, sulfonamide protecting groups, groups represented by the following formulas (1-1) to (1-5), etc. Can be mentioned.
(In Formula (1-1) to Formula (1-5), Ar ¹ is a monovalent aromatic ring group having 6 to 10 carbon atoms, R ¹¹ is an alkyl group having 1 to 12 carbon atoms, and R ¹² Is a monovalent organic group. “*” 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. Examples of the monovalent organic group for R ¹² include an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aralkyl group having 7 to 10 carbon atoms. Can be mentioned. Among these, R ¹² is preferably an aryl group having 6 to 10 carbon atoms, and more preferably an aromatic ring group such as a phenyl group or a naphthyl group.

R ¹ is preferably a carbamate-based protecting group because of its high ability to leave by heat. Specific examples thereof include tert-butoxycarbonyl group, benzyloxycarbonyl group, 1,1-dimethyl-2-halo group. Examples include ethyloxycarbonyl group, 1,1-dimethyl-2-cyanoethyloxycarbonyl group, 9-fluorenylmethyloxycarbonyl group, allyloxycarbonyl group, 2- (trimethylsilyl) ethoxycarbonyl group and the like. Among these, it is a tert-butoxycarbonyl group (BOC group) in that it has a high desorption property by heat and a compound derived from R ¹ desorbed by heating during film formation can be discharged out of the film as a gas. It is preferable.

Examples of the halogen atom for R ² include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the monovalent organic group for R ² include an alkyl group having 1 to 5 carbon atoms and a group “—NHR ¹ ”. n is preferably 0 or 1.

The specific partial structure of the polymer (A) is represented by the partial structure represented by the following formula (1-1) or the formula (1-2) in that the effect of improving the reliability of the liquid crystal display element is high. The partial structure is preferable.
(In Formula (1-1) and Formula (1-2), R ³ and R ⁴ are a halogen atom or an alkyl group having 1 to 5 carbon atoms. R and s are integers of 0 to 2. R ¹ and “*” have the same meanings as in the above formula (1).)

In the above formula (1-1) and formula (1-2), the explanation of R ² can be applied to the examples of the halogen atoms of R ³ and R ⁴ . Examples of the alkyl group having 1 to 5 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group, and these may be linear or branched. r and s are preferably 0 or 1, more preferably 0.

The main skeleton of the polymer (A) is not particularly limited. For example, a polyimide precursor, 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. Examples of the polyimide precursor include polyamic acid and polyamic acid ester, and examples of the polybenzoxazole precursor include polyhydroxyamide. As the polymer (A), one type may be used alone, or two or more types may be used in combination.
Among these, the polymer (A) is preferably at least one selected from the group consisting of a polyimide precursor, polyimide, polybenzoxazole precursor and polybenzoxazole, and selected from the group consisting of polyimide precursor and polyimide. More preferably, it is at least one polymer (A1).

The polymer (A) may have the specific partial structure in either the main chain or the side chain of the polymer. Here, the “main chain” of the polymer in the present specification refers to a “trunk” portion composed of the longest chain of atoms in the polymer. It is allowed that the “trunk” portion includes a ring structure. Therefore, “having a specific partial structure in the main chain” means that this structure constitutes a part of the main chain. The “side chain” of the polymer refers to a portion branched from the “trunk” of the polymer.
The polymer (A) preferably has the above-mentioned specific partial structure in the main chain in that the effect of improving the reliability of the obtained liquid crystal display element is high. However, when the polymer (A) has a specific partial structure in the main chain, it does not exclude that the structure exists also in the side chain.
Hereinafter, the case where the polymer (A) is each of a polyimide precursor, a polyimide, a polybenzoxazole precursor, and a polybenzoxazole will be described in more detail.

[Polyamic acid]
The polyamic acid as the polymer (A) can be obtained, for example, by reacting tetracarboxylic dianhydride with diamine. Specifically, the polyamic acid is a monomer comprising at least one of a tetracarboxylic dianhydride having a partial structure represented by the above formula (1) and a diamine having a partial structure represented by the above formula (1). It can be obtained by polymerization included in the composition. It is preferable to use a diamine having a partial structure represented by the above formula (1) (hereinafter also referred to as “specific diamine”) in terms of a high degree of freedom in selecting a compound.

(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 like, respectively, and JP 2010-97188 A The tetracarboxylic dianhydride described in 1. can be used. In addition, as tetracarboxylic dianhydride used for the synthesis | combination of a polyamic acid, these 1 type can be used individually or in combination of 2 or more types.

  As tetracarboxylic dianhydride, among others, bicyclo [2.2.1] heptane-2,3,5,6-tetracarboxylic acid 2: 3,5: 6-dianhydride, 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, bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic acid 2: 4,6: 8-dianhydride, cyclohexanetetracarboxylic dianhydride And pyromellitic dianhydride Preferably contains at least one compound selected from the group consisting of. The amount of these preferred compounds used (the total amount when two or more are used) is preferably 5 mol% or more based on the total amount of tetracarboxylic dianhydride used for the synthesis of polyamic acid. It is more preferable to set it as 10 mol% or more, and it is more preferable to set it as 20 mol% or more.

(Diamine)
As long as the specific diamine has a partial structure represented by the above formula (1), the remaining structure is not particularly limited, but preferred specific examples include, for example, compounds represented by the following formula (X). It is done.
(In Formula (X), Y ¹ and Y ² are each independently a single bond or a divalent linking group. R ¹ , R ² and n have the same meanings as in Formula (1) above.)

In the above formula (X), examples of the divalent linking group for Y ¹ include —O—, —S—, —CO—, —COO—, —COS—, —NR ⁵ —, —CONR ⁵ —, — CO—NR ⁵ —CO— (wherein R ⁵ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms), a divalent hydrocarbon group having 1 to 20 carbon atoms, at least one of the hydrocarbon groups the number of methylene groups -O -, - S -, - CO -, - COO -, - COS -, - NR 5 -, - CONR 5 -, - CONR 5 -CO- ( provided that, ^{R 5} is A hydrogen atom or an alkyl group having 1 to 3 carbon atoms). In the divalent linking group, a hydrogen atom of the hydrocarbon group may be further substituted with, for example, a halogen atom. Y ¹ is preferably * ¹ -COO-, * ¹ -R ⁶ -COO- (R ⁶ is an alkanediyl group having 1 to 3 carbon atoms, a cyclohexylene group, or a phenylene group. "* ¹ " is amino. A bond with a phenyl group is shown.).

Examples of the divalent linking group for Y ² include a divalent hydrocarbon group having 1 to 20 carbon atoms and at least one methylene group of the hydrocarbon group represented by —O—, —S—, —CO—, — Groups substituted by COO-, -COS-, -NR ^5- , -CONR ^5- , -CO-NR ⁵ -CO-, etc., and the like. The hydrogen atom of the hydrocarbon group is substituted by a halogen atom or the like. May be. Preferably, a single bond or —R ⁷ —X ¹ — * ² (R ⁶ is an alkanediyl group having 1 to 3 carbon atoms, a cyclohexylene group, or a phenylene group, and X ¹ is a single bond, —O—, — COO— or —OCO—, where “* ² ” represents a bond with an aminophenyl group.

Specific examples of the specific diamine include compounds represented by the following formulas (X-1) and (X-2). In addition, specific diamine can be used individually by 1 type or in combination of 2 or more types.
(In the formula, Boc represents a tert-butoxycarbonyl group.)

  The specific diamine can be synthesized by appropriately combining organic chemistry methods. As an example, a dinitro intermediate having a nitro group is synthesized in place of the primary amino group of the diamine having the partial structure represented by the above formula (1), and then the nitro group of the obtained dinitro intermediate is synthesized. A method of amination using an applicable reduction system can be mentioned.

The method for synthesizing the dinitro intermediate can be appropriately selected according to the target compound. As an example, first, a phenol compound having a group “—NHR ¹ ” is synthesized, and then the obtained phenol compound and an acid chloride such as nitrobenzoyl chloride are preferably used in an organic solvent, if necessary. The method of making it react in presence is mentioned.
The reduction reaction of the dinitro intermediate can be preferably carried out in an organic solvent using a catalyst such as palladium carbon, platinum oxide, zinc, iron, tin, nickel or the like. Examples of the organic solvent used here include ethyl acetate, toluene, tetrahydrofuran, and alcohols. However, the synthesis procedure of the specific diamine is not limited to the above method.

  Although the specific diamine may be sufficient as the diamine used for the synthesis | combination of the polyamic acid as a polymer (A), other diamines other than a specific diamine may be used together.

  Examples of other diamines include aliphatic diamines, alicyclic diamines, aromatic diamines, and diaminoorganosiloxanes. Specific examples of these include aliphatic diamines such as m-xylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, and 1,3-bis (aminomethyl) cyclohexane. An alicyclic diamine such as 1,4-diaminocyclohexane, 4,4′-methylenebis (cyclohexylamine);

Aromatic diamines such as dodecaoxydiaminobenzene, tetradecaoxydiaminobenzene, pentadecaoxydiaminobenzene, hexadecaoxydiaminobenzene, octadecaoxydiaminobenzene, cholestanyloxydiaminobenzene, 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-((aminophenoxy) 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—, and R ^I is an alkanediyl group having 1 to 3 carbon atoms. R ^II is a single bond or an alkanediyl group having 1 to 3 carbon atoms, a is 0 or 1, b is an integer of 0 to 2, c is an integer of 1 to 20, and d is 0 or 1, provided that 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′-diaminodiphenylamine, 4,4′-diaminodiphenyl sulfide, 4-aminophenyl-4′-aminobenzoate, 4,4′-diaminoazobenzene, 1 , 5-bis (4-aminophenoxy) pentane, 1,7-bis (4-aminophenoxy) heptane, bis [2- (4-aminophenyl) ethyl] hexanedioic acid, N, N-bis (4-amino) Phenyl) methylamine, 1,5-diaminonaphthalene, 2,2′-dimethyl-4,4′-diaminobiphenyl, 2,2′-bis (trifluoromethyl) -4,4′-diaminobiphenyl, 4,4 '-Diaminodiphenyl ether, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 9,9-bis (4-aminophen Fluorene, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4 '-(p-phenylenediisopropyl Riden) bisaniline, 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) biphenyl, 2,6-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diamino Acridine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, N, N′-bis (4-aminophenyl) -benzidine, N, N′-bis (4-aminophenyl) -N, N′-dimethylbenzidine, 1,4-bis- (4-aminophenyl) -piperazine, 3,5-diaminobenzoic acid, benzene-1,4- Diylbis (4-aminobenzoate), 4,4 ′-[4,4′-propane-1,3-diylbis (piperidine-1,4-diyl)] dianiline and the like;
Examples of the diaminoorganosiloxane include 1,3-bis (3-aminopropyl) -tetramethyldisiloxane; and the diamines described in JP-A 2010-97188 can be used.

Examples of the divalent group represented by “—X ^I — (R ^I —X ^II ) _d —” in the above formula (E-1) include alkanediyl groups having 1 to 3 carbon atoms, * —O—, * —COO— or * —O—C ₂ H ₄ —O— (however, a bond marked with “*” is bonded to a diaminophenyl group) is preferred. Examples of the group “—C _c H _{2c + 1} ” include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, a dodecyl group, a tridecyl group, and a tetradecyl group. Group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, eicosyl group and the like, and these are preferably linear. The two amino groups in the diaminophenyl group are preferably in the 2,4-position or 3,5-position with respect to other groups.

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). .
In addition, as another diamine used for the synthesis | combination of a polyamic acid, 1 type of these compounds can be used individually or in combination of 2 or more types as appropriate.

  When the liquid crystal aligning agent of the present invention is used for a TN type, STN type or vertical alignment type liquid crystal display element, it is preferable to introduce an alignment group into the side chain of the polyamic acid. Here, the orientation group is a group capable of imparting a pretilt angle characteristic to the coating film without depending on light irradiation. Specifically, for example, an alkyl group having 4 to 20 carbon atoms, a fluoro having 4 to 20 carbon atoms, and the like. Examples thereof include an alkyl group, an alkoxy group having 4 to 20 carbon atoms, a group having a steroid skeleton having 17 to 51 carbon atoms, and a group in which a plurality of rings are bonded directly or via a linking group. The polyamic acid having an orientation group can be obtained, for example, by polymerization containing the above side chain type diamine in the monomer composition. When using the said side chain type diamine, it is preferable that the compounding quantity shall be 3 mol% or more with respect to all the diamine used for a synthesis | combination from a viewpoint of expressing favorable liquid crystal orientation. It is more preferable to set it as mol%.

  The proportion of the specific diamine used is that of the diamine used for the synthesis of the polyamic acid from the viewpoint of improving the liquid crystal orientation when the photo-alignment method is applied and obtaining the sufficient effect of improving the reliability of the liquid crystal display element. The total amount is preferably 0.5 mol% or more, more preferably 2 mol% or more, and even more preferably 5 mol% or more. Moreover, the upper limit in particular of the usage rate of specific diamine is not restrict | limited, It can select arbitrarily according to the usage rate of other diamine.

(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. The use ratio of the molecular weight modifier is preferably 20 parts by weight or less, and more preferably 10 parts by weight or less with respect to 100 parts by weight of the total of the tetracarboxylic dianhydride and diamine 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, more preferably 0 to 100 ° C. The reaction time is preferably from 0.1 to 24 hours, more preferably from 0.5 to 12 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. Or less, more preferably 30% by weight or less.

  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 (x) of the organic solvent used is such that the total amount (y) of tetracarboxylic dianhydride and diamine is 0.1 to 50% by weight with respect to the total amount (x + y) 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 as it is for the preparation of the liquid crystal aligning agent, may be used for the preparation of the liquid crystal aligning agent after isolating the polyamic acid contained in the reaction solution, or the isolated polyamic acid was purified. You may use for preparation of a liquid crystal aligning agent. When polyamic acid is dehydrated and cyclized into a polyimide, the above reaction solution may be directly subjected to dehydration and cyclization reaction, or may be subjected to dehydration and cyclization reaction after isolating the polyamic acid contained in the reaction solution. Alternatively, the isolated polyamic acid may be purified and then subjected to a dehydration ring closure reaction. Isolation and purification of the polyamic acid can be performed according to known methods.

[Polyamic acid ester]
The polyamic acid ester as the polymer (A) is, for example, [I] a method of reacting a polyamic acid having a partial structure represented by the above formula (1) with an esterifying agent, and [II] a tetracarboxylic acid diester. It can be obtained by a method of reacting diamine, a method of reacting [III] tetracarboxylic acid diester dihalide and diamine, or the like.
In this specification, “tetracarboxylic acid diester” means a compound in which two of the four carboxyl groups of tetracarboxylic acid are esterified and the remaining two are carboxyl groups. “Tetracarboxylic acid diester dihalide” means a compound in which two of the four carboxyl groups of tetracarboxylic acid are esterified and the remaining two are halogenated.

  Examples of the esterifying agent used in Method [I] include a hydroxyl group-containing compound, an acetal compound, a halide, an epoxy group-containing compound, and the like. Specific examples thereof include hydroxyl group-containing compounds such as alcohols such as methanol, ethanol and propanol; phenols such as phenol and cresol; and acetal compounds such as N, N-dimethylformamide diethyl acetal, N, N-diethylformamide diethyl acetal and the like; halides such as methyl bromide, ethyl bromide, stearyl bromide, methyl chloride, stearyl chloride, 1,1,1-trifluoro-2-iodoethane and the like; epoxy group-containing Examples of the compound include propylene oxide.

The tetracarboxylic acid diester used in the method [II] can be obtained, for example, by ring-opening the tetracarboxylic dianhydride exemplified in the synthesis of the polyamic acid with alcohols such as methanol and ethanol. The tetracarboxylic acid derivative used in method [II] may be only a tetracarboxylic acid diester, but may also be used in combination with tetracarboxylic dianhydride. Examples of the diamine to be used include the specific diamine exemplified in the synthesis of polyamic acid and other diamines.
The reaction of Method [II] is preferably carried out in an organic solvent in the presence of a suitable dehydration catalyst. As an organic solvent, the organic solvent illustrated as what is used for the synthesis | combination of a polyamic acid can be mentioned. Examples of the dehydration catalyst include 4- (4,6-dimethoxy-1,3,5-triazin-2-yl) -4-methylmorpholinium halide, carbonylimidazole, a phosphorus condensing agent, and the like. The reaction temperature at this time is preferably -20 to 150 ° C, more preferably 0 to 100 ° C. The reaction time is preferably from 0.1 to 24 hours, more preferably from 0.5 to 12 hours.

The tetracarboxylic acid diester dihalide used in Method [III] can be obtained, for example, by reacting the tetracarboxylic acid diester obtained as described above with an appropriate chlorinating agent such as thionyl chloride. The tetracarboxylic acid derivative used in the method [III] may be only a tetracarboxylic acid diester dihalide, or a tetracarboxylic dianhydride may be used in combination. Examples of the diamine to be used include the specific diamine exemplified in the synthesis of polyamic acid and other diamines.
The reaction of Method [III] is preferably carried out in an organic solvent in the presence of a suitable base. As an organic solvent, the organic solvent illustrated as what is used for the synthesis | combination of a polyamic acid can be mentioned. As the base, for example, tertiary amines such as pyridine and triethylamine; alkali metals such as sodium hydride, potassium hydride, sodium hydroxide, potassium hydroxide, sodium and potassium can be preferably used. The reaction temperature at this time is preferably -20 to 150 ° C, more preferably 0 to 100 ° C. The reaction time is preferably from 0.1 to 24 hours, more preferably from 0.5 to 12 hours.

  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. The reaction solution obtained 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. Alternatively, the isolated polyamic acid ester may be purified and then used for the preparation of the liquid crystal aligning agent. Isolation and purification of the polyamic acid ester can be performed according to a known method.

[Polyimide]
The polyimide as the polymer (A) can be obtained, for example, by dehydrating and ring-closing a polyamic acid having a partial structure represented by the above formula (1) to imidize.

  The polyimide may be a completely imidized product obtained by dehydrating and cyclizing all of the amic acid structure possessed by the polyamic acid that is the precursor, and only a part of the amic acid structure may be dehydrated and cyclized. It may be a partially imidized product in which a ring structure coexists. The polyimide used for the reaction preferably has an imidization ratio of 20% or more, more preferably 30 to 99%, and still more preferably 40 to 99%. 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. .
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 20 to 1,800 mPa · s when this is made into a solution having a concentration of 15% by weight. More preferably, it has a solution viscosity of ˜1,500 mPa · s. In addition, the solution viscosity (mPa · s) of the above polymer is based on a polymer solution having a concentration of 15% 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 gel permeation chromatography (GPC) of the polyamic acid, polyamic acid ester and polyimide is preferably 1,000 to 500,000, more preferably 2,000. ~ 300,000. Moreover, the molecular weight distribution (Mw / Mn) represented by the ratio of Mw and the number average molecular weight (Mn) in terms of polystyrene measured by GPC is preferably 7 or less, more preferably 5 or less. By being in such a molecular weight range, it is possible to ensure good orientation and stability of the liquid crystal display element.

[Polybenzoxazole precursor]
The polybenzoxazole precursor as the polymer (A) is, for example, [1] a dicarboxylic acid having a partial structure represented by the above formula (1) (hereinafter also referred to as “specific dicarboxylic acid”) or a specific dicarboxylic acid. A method of reacting a mixture of other dicarboxylic acid with a bis (o-aminophenol) compound; [2] a method of reacting a dicarboxylic acid, a bis (o-aminophenol) compound and a specific diamine, and the like. Can be obtained.

  In the method [1], the dicarboxylic acid having a partial structure represented by the formula (1) is not particularly limited. For example, the partial structure represented by the formula (1-1) or the formula (1) -Dicarboxylic acid having a partial structure represented by -2). Specific dicarboxylic acid can be used individually by 1 type or in combination of 2 or more types.

The other dicarboxylic acid used in the method [1] and the dicarboxylic acid used in the method [2] are not particularly limited. For example, oxalic acid, malonic acid, dimethylmalonic acid, succinic acid, glutaric acid, Aliphatic dicarboxylic acids such as adipic acid, 2-methyladipic acid, 2,2-dimethylglutaric acid, 3,3-diethylsuccinic acid, sebacic acid, fumaric acid, muconic acid; cyclobutanedicarboxylic acid, 1-cyclobutenedicarboxylic acid Dicarboxylic acids having an alicyclic structure such as cyclopentanedicarboxylic acid and cyclohexanedicarboxylic acid; phthalic acid, isophthalic acid, terephthalic acid, 2,5-dimethylterephthalic acid, naphthalenedicarboxylic acid, 4,4′-biphenyldicarboxylic acid, 4,4'-diphenylmethane dicarboxylic acid, 4,4'-diphenyl ether dica Boronic acid, 4,4′-carbonyldibenzoic acid, 4-carboxycinnamic acid, p-phenylenediacrylic acid, 3,3 ′-[4,4 ′-(methylenedi-p-phenylene)] dipropionic acid, 3 , 4-diphenyl-1,2-cyclobutanedicarboxylic acid and other dicarboxylic acids having an aromatic ring; In addition, dicarboxylic acid can be used individually by 1 type or in combination of 2 or more types. In the method [2], a specific dicarboxylic acid may be included in the monomer component.
The dicarboxylic acid may be subjected to the polymerization reaction as it is, but may be subjected to the polymerization reaction after acid chloride using an appropriate chlorinating agent such as thionyl chloride or oxalyl chloride.

Examples of the bis (o-aminophenol) compound used in the above methods [1] and [2] include 2,4-diamino-1,5-benzenediol and 2,5-diamino-1,4-benzenediol. 2,5-diamino-3-fluoro-1,4-benzenediol, 2,6-diamino-1,5-dihydroxynaphthalene, 3,3′-diamino-4,4′-dihydroxybiphenyl, 4,4 ′ -Diamino-3,3'-dihydroxybiphenyl, 4,4'-diamino-3,3'-dihydroxy-6,6'-ditrifluoromethylbiphenyl, bis (4-amino-3-hydroxyphenyl) methane, bis ( 4-amino-3-hydroxyphenyl) ether, bis (4-amino-3-hydroxyphenyl) ketone and the like. The bis (o-aminophenol) compound may be subjected to a polymerization reaction as it is. However, in order to further improve the reactivity and reaction selectivity, it is polymerized after being activated using a silylating agent such as trimethylsilyl chloride. You may use for reaction. A bis (o-aminophenol) compound can be used individually by 1 type or in combination of 2 or more types.
About the specific diamine used by the method of said [2], description of the specific diamine used for the synthesis | combination of a polyamic acid is applicable.

  The polymerization reactions [1] and [2] are preferably performed in an organic solvent in the presence of a condensing agent as necessary. As an organic solvent, the organic solvent illustrated as what is used for the synthesis | combination of a polyamic acid can be mentioned. Examples of the condensing agent include dicyclohexylcarbodiimide (DCC), 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide, (2,3-dihydro-2-thioxo-3-benzoxazolyl) phosphonic acid diphenyl, oxy Examples thereof include phosphorus chloride.

The ratio of the dicarboxylic acid and the bis (o-aminophenol) compound used in the reaction is preferably 0.5 to 2 mol of dicarboxylic acid with respect to 1 mol of the bis (o-aminophenol) compound. It is more preferable to set it as 7-1.5 mol. In addition, when using specific diamine in the case of reaction, it is preferable to prepare so that the sum total of a bis (o-aminophenol) compound and specific diamine may become the said ratio.
The proportion of the compound having a specific partial structure (total of specific diamine and specific carboxylic acid) is preferably 0.25 mol% or more based on the total amount of monomers used for the synthesis of the polybenzoxazole precursor. More preferably, it is 1 mol% or more.

In the polymerization reaction, a terminal blocking agent may be used for the purpose of adjusting the molecular weight or introducing a functional group. Examples of the terminal blocking agent include acid monoanhydrides such as maleic anhydride, phthalic anhydride, and itaconic anhydride, monoamine compounds such as aniline, cyclohexylamine, n-butylamine, 4-aminostyrene, and 2-aminohydroxybenzene. Is mentioned.
0-100 degreeC is preferable and, as for the reaction temperature in the said polymerization reaction, 5-60 degreeC is more preferable. The reaction time is preferably 0.5 to 100 hours, more preferably 1 to 50 hours.

  In this way, a reaction solution containing a polybenzoxazole precursor is obtained. This reaction solution may be used as it is for the preparation of the liquid crystal aligning agent, may be used for the preparation of the liquid crystal aligning agent after isolating the polybenzoxazole precursor contained in the reaction solution, or the isolated poly You may use for preparation of a liquid crystal aligning agent, after refine | purifying a benzoxazole precursor. Isolation and purification of the polybenzoxazole precursor can be performed according to known methods.

  The weight average molecular weight (Mw) in terms of polystyrene measured by gel permeation chromatography (GPC) of the polybenzoxazole precursor used for preparing the liquid crystal aligning agent is preferably 1,000 to 500,000, more preferably. Is 2,000 to 300,000.

[Polybenzoxazole]
The polybenzoxazole as the polymer (A) is, for example, a method in which a part of a specific partial structure of the polybenzoxazole precursor synthesized as described above is dehydrated and cyclized; dicarboxylic acid and bis (o-aminophenol) ) Based compounds can be obtained, for example, by a condensation polymerization reaction in an environment of 100 to 300 ° C. The description of the polybenzoxazole precursor can be applied to each condition such as a monomer and a solvent used for the reaction when the condensation polymerization reaction is performed in a high temperature environment.

The polymer (A) undergoes a structural change by heating to produce a polymer (A ^* ) having a partial structure represented by the formula (2) in the following scheme A. In addition, although such a structural change is one hypothesis, for example, when R ¹ is an amino-protecting group, a primary amino group is generated by removing the protecting group by a deprotection treatment such as heating, It is presumed that the generated primary amino group attacked the carbonyl group to cause a thermal rearrangement reaction. Thereby, it is considered that a polymer (A ^* ) having an amide bond was obtained.
(In Scheme A, R ¹ , R ² , n, and “*” have the same meanings as in the above formula (1).)

<Other ingredients>
Although the liquid crystal aligning agent of this invention contains the above polymers (A) as a polymer component, it may contain other polymers other than a polymer (A) as needed. The other polymer may be a polymer that does not have the partial structure represented by the above formula (1), and the main skeleton is not particularly limited. Specifically, for example, polyamic acid, polyimide, polyamic acid ester, polyorganosiloxane, polyester, polyamide, cellulose derivative, polyacetal, polystyrene derivative, poly (styrene-phenylmaleimide) derivative, poly (meth) acrylate and the like as the main skeleton Can be mentioned. Among these, at least one polymer selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, polyorganosiloxane, polybenzoxazole precursor, and polybenzoxazole is preferable.
When other polymers are blended in the liquid crystal aligning agent, the blending ratio is preferably 30 parts by weight or less with respect to a total of 100 parts by weight of the polymer contained in the liquid crystal aligning agent. It is more preferable to set it as 20 weight part, and it is still more preferable to set it as 0.3-10 weight part.

  The liquid crystal aligning agent of this invention may contain components other than a polymer as other components. Examples of such components include a compound having at least one epoxy group in the molecule, a compound having at least one oxetanyl group in the molecule, a functional silane compound, a photopolymerizable compound, a metal chelate compound, a curing accelerator, an interface Activators, antioxidants, sensitizers, preservatives, stabilizers, viscosity modifiers and the like can be mentioned. These blending proportions can be appropriately selected according to various compounds within a range not impairing the effects of the present invention.

<Solvent>
The liquid crystal aligning agent in the present invention is prepared as a liquid composition in which the polymer (A) and other components used as necessary are preferably dispersed or dissolved in an appropriate solvent.

  Examples of the organic solvent to be used include N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N, N-dimethylformamide, N, N-dimethylacetamide, 4-hydroxy-4-methyl-2-pentanone, Ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether , Ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol Recall 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, etc. be able to. These can be used alone or in admixture of two or more.

  The solid content concentration in the liquid crystal aligning agent (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, etc. It is in the range of 1 to 10% by weight. That is, the liquid crystal aligning agent is applied to the substrate surface as will be described later, and 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, 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 particularly preferable solid content concentration range varies depending on the use of the liquid crystal aligning agent and the method used when the liquid crystal aligning agent is applied to the substrate. For example, when a liquid crystal aligning agent for a liquid crystal display element is applied to a substrate by a spinner method, the solid content concentration (the ratio of the total weight of all components other than the solvent in the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent) Is particularly preferably in the range of 1.5 to 4.5% by weight. In the case of the printing method, it is particularly preferable that the solid content concentration is in the range of 3 to 9% by weight, and thereby the solution viscosity is in the range of 12 to 50 mPa · s. In the case of the inkjet method, it is particularly preferable that the solid content concentration is in the range of 1 to 5% by weight, and thereby the solution viscosity is in the range of 3 to 15 mPa · s. The temperature when preparing the liquid crystal aligning agent is preferably 10 to 50 ° C, more preferably 20 to 30 ° C. Moreover, about the liquid crystal aligning agent for retardation films, the solid content density | concentration of a liquid crystal aligning agent is 0.2 to 10 weight% from a viewpoint which makes the applicability | paintability of a liquid crystal aligning agent, and the film thickness of the coating film formed moderate. It is preferable that it is the range of 3-10 weight%.

<Liquid crystal display element and retardation film>
A liquid crystal alignment film can be manufactured by using the liquid crystal aligning agent described above. Moreover, the liquid crystal aligning film formed using the said liquid crystal aligning agent can be applied to the liquid crystal aligning film for liquid crystal display elements, and the liquid crystal aligning film for retardation films. Below, a liquid crystal display element and retardation film are demonstrated.

[Liquid crystal display element]
The liquid crystal display element of this invention comprises the liquid crystal aligning film formed using the said liquid crystal aligning agent. The operation mode of the liquid crystal display element is not particularly limited. For example, various operation modes such as a TN type, STN type, VA type (including VA-MVA type, VA-PVA type, etc.), IPS type, FFS type, OCB type, etc. Can be applied to.

  A liquid crystal display element can be manufactured by the method of including the following processes (1-1)-processes (1-3), for example. In the step (1-1), a substrate to be used is different depending on a desired operation mode. Step (1-2) and step (1-3) are common to each operation mode.

[Step (1-1): Formation of coating film]
First, a liquid crystal aligning agent is apply | coated on a board | substrate and a coating film is formed on a board | substrate.
(1-1A) When manufacturing a TN-type, STN-type, or VA-type liquid crystal display element, for example, first, a pair of two substrates provided with patterned transparent conductive films is formed, and each transparent conductive film is formed. A liquid crystal aligning agent is preferably applied onto the surface by an offset printing method, a spin coating method, a roll coater method or an ink jet printing method. 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 order to obtain a patterned transparent conductive film, for example, after forming a transparent conductive film without a pattern, a method of forming a pattern by photo-etching; a method of using a mask having a desired pattern when forming a transparent conductive film; And so on. 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 applying the liquid crystal aligning agent to form a coating film, preheating (pre-baking) is preferably performed for the purpose of preventing dripping of the applied liquid crystal aligning agent. The pre-baking temperature is preferably 30 to 200 ° C, more preferably 40 to 150 ° C, and particularly preferably 40 to 100 ° C. The pre-bake time is preferably 0.25 to 10 minutes, and more preferably 0.5 to 5 minutes. Then, a baking (post-baking) process is implemented for the purpose of removing a solvent completely and heat imidating the amic acid structure which exists in a polymer as needed. The firing temperature (post-bake temperature) at this time is preferably 80 to 300 ° C, more preferably 120 to 250 ° C. The post-bake time is preferably 5 to 200 minutes, more preferably 10 to 100 minutes. The thickness of the film thus formed is preferably 0.001 to 1 μm, more preferably 0.005 to 0.5 μm.

  (1-1B) When manufacturing an IPS type or FFS type liquid crystal display 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 applied to one surface of the counter substrate that is not formed to form a coating film. 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 (1-1A). As the metal film, for example, a film made of a metal such as chromium can be used.

In both cases (1-1A) and (1-1B), after applying a liquid crystal aligning agent on the substrate, the organic solvent is removed to form a liquid crystal alignment film or an organic thin film that becomes a liquid crystal alignment film. The At this time, when at least one of polyamic acid, polyamic acid ester and polyimide is blended in the liquid crystal aligning agent, the polyamic acid and polyamic acid blended in the liquid crystal aligning agent are further heated after the coating film is formed. It is good also as a coating film made more imidized by advancing the dehydration ring-closing reaction of ester and polyimide. A liquid crystal alignment film containing the polymer (A ^* ) or an organic thin film that becomes a liquid crystal alignment film is obtained by applying a liquid crystal aligning agent on the substrate and then performing a heat treatment.

[Step (1-2): Orientation ability imparting treatment]
When manufacturing a TN type, STN type, IPS type, or FFS type liquid crystal display element, the process which provides liquid crystal aligning ability to the coating film formed at the said process (1-1) is implemented. 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 orientation-imparting treatment include rubbing treatment in which the 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 (1-1) can be used as it is as a liquid crystal alignment film. May be. Since the liquid crystal aligning agent of the present invention has a partial structure represented by the above formula (1), at least a part of the polymer component can use a photo-alignment method when imparting liquid crystal aligning ability to the coating film, This is preferable in that the merit of the photo-alignment method can be obtained.

  The light irradiation in the photo-alignment treatment is [1] a method of irradiating the coating film after the post-baking process, [2] a method of irradiating the coating film after the pre-baking process and before the post-baking process, [3 ] It can carry out by the method of irradiating with respect to a coating film during the heating of a coating film in at least any one of a prebaking process and a post-baking process. Of these, the method [2] is preferable in that the reliability of the obtained liquid crystal display element can be sufficiently secured.

In the photo-alignment treatment, ultraviolet rays and visible rays including light having a wavelength of 150 to 800 nm can be used as the radiation applied to the coating film, for example. 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 non-polarized radiation is irradiated, the irradiation direction 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. Ultraviolet rays in a preferable wavelength region can be obtained by means of using a light source in combination with, for example, a filter or a diffraction grating. 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, More preferably, it is 50-150 degreeC.

  In addition, the liquid crystal alignment film after the rubbing treatment is further subjected to a process for changing the pretilt angle of a part of the liquid crystal alignment film by irradiating a part of the liquid crystal alignment film with ultraviolet rays or a surface of the liquid crystal alignment film. A resist film is formed on the part, and a rubbing process is performed in a direction different from the previous rubbing process, followed by a process of removing the resist film, so that the liquid crystal alignment film has different liquid crystal alignment capabilities for each region. . In this case, it is possible to improve the visibility characteristics of the obtained liquid crystal display element. A liquid crystal alignment film suitable for a VA liquid crystal display element can also be suitably used for a PSA (Polymer sustained alignment) type liquid crystal display element.

[Step (1-3): Construction of liquid crystal cell]
(1-3A) Two substrates on which the liquid crystal alignment film is formed as described above are prepared, and a liquid crystal cell is manufactured by disposing a liquid crystal between the two substrates facing each other. In order to manufacture a liquid crystal cell, the following two methods are mentioned, for example. The first method is a conventionally known method. First, two substrates are arranged opposite to each other through a gap (cell gap) so that the respective liquid crystal alignment films are opposed to each other, and the peripheral portions of the two substrates are bonded together using a sealant, and the substrate surface and the sealant are bonded. A liquid crystal cell can be manufactured by injecting and filling liquid crystal into the cell gap partitioned by the step, and then sealing the injection hole. The second method is a method called an ODF (One Drop Fill) method. For example, an ultraviolet light curable sealant is applied to a predetermined location on one of the two substrates on which the liquid crystal alignment film is formed, and liquid crystal is dropped to a predetermined location on the liquid crystal alignment film surface. After that, the other substrate is bonded so that the liquid crystal alignment film faces, and the liquid crystal is spread over the entire surface of the substrate, and then the entire surface of the substrate is irradiated with ultraviolet light to cure the sealant, thereby manufacturing a liquid crystal cell. can do. Regardless of which method is used, the liquid crystal cell produced as described above is further heated to a temperature at which the used liquid crystal takes an isotropic phase, and then slowly cooled to room temperature, thereby removing the flow alignment at the time of filling the liquid crystal. It is desirable to do.

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 crystals and smectic liquid crystals. Among them, nematic liquid crystals are preferable. For example, Schiff base liquid crystals, azoxy liquid crystals, biphenyl liquid crystals, phenylcyclohexane liquid crystals, ester liquid crystals, terphenyl liquid crystals, biphenyls. A cyclohexane liquid crystal, a pyrimidine liquid crystal, a dioxane liquid crystal, a bicyclooctane liquid crystal, a cubane liquid crystal, or 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.

(1-3B) When manufacturing a PSA type liquid crystal display element, a liquid crystal cell is constructed in the same manner as in the above (1-3A) except that a photopolymerizable compound is injected or dropped together with 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 can be, for example, 5 to 50 V direct current or alternating current. Moreover, as light to irradiate, the ultraviolet-ray and visible light which contain light with a wavelength of 150-800 nm can be used, for example, However, The ultraviolet-ray containing light with a wavelength of 300-400 nm is preferable. As a light source of irradiation light, 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. In addition, the ultraviolet rays in the above preferable wavelength region can be obtained by means of using a light source in combination with, for example, a filter diffraction grating. The irradiation dose of light, preferably 1,000~200,000J / ^{m 2,} more preferably from 1,000~100,000J / ^{m 2.}

  (1-3C) When a coating film is formed on a substrate using a liquid crystal aligning agent containing a compound (polymer or additive) having a photopolymerizable group, a liquid crystal cell is formed in the same manner as (1-3A) above. Then, a method of manufacturing a liquid crystal display element may be adopted by performing a step of irradiating light to the liquid crystal cell in a state where a voltage is applied between the conductive films of the pair of substrates. The applied voltage can be, for example, 0.1 to 30 V direct current or alternating current. The description of (1-3B) above can be applied to the conditions of light to be irradiated.

  And a liquid crystal display element can be obtained by sticking a polarizing plate on the outer surface of a 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.

[Phase difference film]
Next, a method for producing a retardation film using a liquid crystal aligning agent will be described. In the production of the retardation film, it is possible to form a uniform liquid crystal alignment film while suppressing the generation of dust and static electricity during the process, and by using a suitable photomask during radiation irradiation, the substrate It is preferable to use a photo-alignment method in that a plurality of regions having different liquid crystal alignment directions can be formed arbitrarily. Specifically, it can be produced through the following steps (2-1) to (2-3).

[Step (2-1): Formation of coating film by liquid crystal aligning agent]
First, a liquid crystal aligning agent is apply | coated on a board | substrate and a coating film is formed. As a substrate used here, a transparent substrate made of a synthetic resin such as triacetyl cellulose (TAC), polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polyamide, polyimide, polymethyl methacrylate, polycarbonate, etc. is preferably exemplified. Can do. Of these, TAC is generally used as a protective layer for a polarizing film in a liquid crystal display device. In addition, polymethyl methacrylate can be preferably used as a substrate for a retardation film in that the hygroscopicity of the solvent is low, the optical properties are good, and the cost is low. In addition, for the substrate used for the application of the liquid crystal aligning agent, in order to further improve the adhesion between the substrate surface and the coating film, a conventionally known pretreatment is performed on the surface of the substrate surface on which the coating film is formed. May be implemented.

  In many cases, the retardation film is used in combination with a polarizing film. At this time, it is necessary to attach the retardation film by precisely controlling the angle with respect to the polarization axis of the polarizing film in a specific direction so that the desired optical characteristics can be exhibited. Accordingly, by forming a liquid crystal alignment film having a liquid crystal alignment ability in a predetermined angle direction on a substrate such as a TAC film or polymethyl methacrylate, the angle of the retardation film is controlled on the polarizing film. The step of bonding can be omitted. Thereby, it can contribute to the improvement of productivity of a liquid crystal display element. In order to form a liquid crystal alignment film having a liquid crystal alignment ability in a predetermined angle direction, it is preferable to carry out by a photo-alignment method using a liquid crystal alignment agent.

The liquid crystal aligning agent can be applied onto the substrate by an appropriate application method such as a roll coater method, a spinner method, a printing method, an ink jet method, a bar coater method, an extrusion die method, a direct gravure coater method, a chamber. Doctor coater method, offset gravure coater method, single roll kiss coater method, reverse kiss coater method using small diameter gravure roll, 3 reverse roll coater method, 4 reverse roll coater method, slot die method, air doctor coater method A positive rotation roll coater method, a blade coater method, a knife coater method, an impregnation coater method, an MB coater method, an MB reverse coater method, and the like can be employed.
After coating, the coated surface is heated (baked) to form a coating film. The heating temperature at this time is preferably 40 to 150 ° C, more preferably 80 to 140 ° C. The heating time is preferably 0.1 to 15 minutes, and more preferably 1 to 10 minutes. The film thickness of the coating film formed on the substrate is preferably 1 to 1,000 nm, more preferably 5 nm to 500 nm.

[Step (2-2): Light irradiation step]
Next, the coating film formed on the substrate as described above is irradiated with light, thereby imparting liquid crystal alignment ability to the liquid crystal alignment film. The description of the photo-alignment process in the step (1-2) can be applied to the type, wavelength, irradiation direction, and light source of the light to be irradiated. The dose of light is preferably in a 0.1~1,000mJ / cm ^2, more preferably to 1 to 500 mJ / cm ^2, and more preferably be 2~200mJ / cm ^2.

[Step (2-3): Formation of Liquid Crystal Layer]
Next, a polymerizable liquid crystal is applied and cured on the coating film after the light irradiation as described above. Thereby, the coating film (liquid crystal layer) containing a polymerizable liquid crystal is formed. The polymerizable liquid crystal used here is a liquid crystal compound or a liquid crystal composition that is polymerized by at least one treatment of heating and light irradiation. As such a polymerizable liquid crystal, a conventionally known liquid crystal can be used. Specifically, for example, Non-Patent Document 1 ("UV curable liquid crystal and its application", Liquid Crystal, Vol. 3, No. 1 (1999). Year), pp 34-42). Further, cholesteric liquid crystal; discotic liquid crystal; twisted nematic alignment type liquid crystal to which a chiral agent is added may be used. The polymerizable liquid crystal may be a mixture of a plurality of liquid crystal compounds. The polymerizable liquid crystal may further be a composition containing a known polymerization initiator, an appropriate solvent, and the like.
In order to apply the polymerizable liquid crystal as described above on the formed liquid crystal alignment film, for example, an appropriate application method such as a bar coater method, a roll coater method, a spinner method, a printing method, or an ink jet method can be employed. .

Next, the coating film of the polymerizable liquid crystal formed as described above is subjected to at least one treatment selected from heating and light irradiation to cure the coating film to form a liquid crystal layer. It is preferable to perform these treatments in a superimposed manner because good alignment can be obtained.
The heating temperature of the coating film is appropriately selected depending on the type of polymerizable liquid crystal used. For example, when using RMS03-013C manufactured by Merck, it is preferable to heat at a temperature in the range of 40 to 80 ° C. The heating time is preferably 0.5 to 5 minutes.
As irradiation light, non-polarized ultraviolet rays having a wavelength in the range of 200 to 500 nm can be preferably used. The irradiation dose of light, preferably in the 50~10,000mJ / cm ^2, and more preferably a 100~5,000mJ / cm ^2.
The thickness of the liquid crystal layer to be formed is appropriately set depending on desired optical characteristics. For example, when manufacturing a half-wave plate for visible light having a wavelength of 540 nm, a thickness is selected such that the retardation of the formed retardation film is 240 to 300 nm. The thickness is selected such that the phase difference is 120 to 150 nm. The thickness of the liquid crystal layer from which the desired retardation is obtained varies depending on the optical characteristics of the polymerizable liquid crystal used. For example, when RMS03-013C manufactured by Merck is used, the thickness for manufacturing a quarter-wave plate is in the range of 0.6 to 1.5 μm.

  The retardation film obtained as described above can be preferably applied as a retardation film of a liquid crystal display element. The liquid crystal display element to which the retardation film manufactured using the liquid crystal aligning agent of the present invention is applied is not limited in its operation mode. For example, TN type, STN type, IPS type, FFS type, VA type and the like are known. It can be applied to various modes. The retardation film is used by attaching the substrate-side surface of the retardation film to the outer surface of the polarizing plate disposed on the viewing side of the liquid crystal display element. Therefore, it is preferable that the retardation film substrate is made of TAC or an acrylic base, and the retardation film substrate also functions as a protective film for the polarizing film.

  Here, there is a roll-to-roll method as a method for producing a retardation film on an industrial scale. In this method, a film is unwound from a wound body of a long base film, a liquid crystal alignment film is formed on the unwound film, and a polymerizable liquid crystal is applied and cured on the liquid crystal alignment film. It is the method of performing the process and the process which laminates | stacks a protective film as needed in the continuous process, and collect | recovering the film after passing through these processes as a wound body. The retardation film formed using the liquid crystal aligning agent in the present invention has good adhesion to the substrate, and the liquid crystal alignment film and the substrate are hardly peeled even when stored as a wound body. Therefore, it is possible to suppress a decrease in product yield when producing a retardation film by a roll-to-roll method, which is preferable from the viewpoint of productivity.

  The liquid crystal display 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, The present invention can be used for various display devices such as various monitors, liquid crystal televisions, and information displays.

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

In the following examples, the polymer weight average molecular weight Mw, imidization rate, epoxy equivalent, and solution viscosity of the polymer solution were measured by the following methods. Hereinafter, the compound represented by Formula X may be simply referred to as “Compound X”.
[Weight average molecular weight Mw of polymer]
Mw is a polystyrene equivalent value measured by GPC under the following conditions.
Column: Tosoh Co., Ltd., TSKgelGRCXLII
Solvent: Tetrahydrofuran Temperature: 40 ° C
Pressure: 68 kgf / cm ²
[Imidation rate of polymer]
A solution containing polyimide is poured into pure water, and the resulting precipitate is sufficiently dried at room temperature under reduced pressure, then dissolved in deuterated dimethyl sulfoxide, and ¹ H-NMR is measured at room temperature using tetramethylsilane as a reference substance. did. From the obtained ¹ H-NMR spectrum, the imidation ratio was determined using the following formula (EX-1).
Imidation ratio (%) = (1-A ¹ / A ² × α) × 100 (EX-1)
(In Formula (EX-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 ( It is the number ratio of other protons to one NH group proton in the polyamic acid).
[Epoxy equivalent]
The epoxy equivalent was measured by the hydrochloric acid-methyl ethyl ketone method described in JIS C 2105.
[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.

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

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

[Synthesis Example 1-3; Synthesis of Compound (Model-1)]
A compound (Model-1) was synthesized according to the following scheme 3.

[Synthesis Example 1-4; Synthesis of Compound (Model-2)]
A compound (Model-2) was synthesized according to the following scheme 4.

<Synthesis of polymer>
[Synthesis Example 2-1; Synthesis of Polymer (PA-1)]
12.16 g of 1,3-propylene glycol bis (anhydrotrimellitate) as tetracarboxylic dianhydride (93 mol parts with respect to 100 mol parts of the total amount of diamine compounds used in the synthesis), and compound as diamine compound 17.33 g (100 mole parts) of (X-1) was dissolved in a mixed solvent of 85 g of N-methyl-2-pyrrolidone (NMP) and 85 g of γ-butyrolactone (GBL) and reacted at 30 ° C. for 6 hours. It was. The reaction mixture was then poured into a large excess of methanol to precipitate the reaction product. The recovered precipitate was washed with methanol and then dried under reduced pressure at 40 ° C. for 15 hours to obtain 28.5 g of polyamic acid (hereinafter referred to as polymer (PA-1)). The obtained polymer (PA-1) was prepared so as to be 15% by weight with a solvent composition of NMP: GBL = 50: 50 (weight ratio), and the viscosity of this solution was measured to be 360 mPa · s. It was. Further, when this polymer solution was allowed to stand at 20 ° C. for 3 days, it did not gel and the storage stability was good.

[Synthesis Example 2-2 to Synthesis Example 2-6]
A polyamic acid was obtained in the same manner as in Synthesis Example 2-1, except that the types and amounts of tetracarboxylic dianhydride and amine compound used in the reaction were changed as shown in Table 1 below. When each of the polymer solutions obtained in Synthesis Examples 2-2 to 2-6 was allowed to stand at 20 ° C. for 3 days, none of them was gelled, and the storage stability was good.

The numerical values in Table 1 indicate the usage ratio (mol%) with respect to the total amount of tetracarboxylic dianhydride used for the reaction for tetracarboxylic dianhydride, and for the diamine compound, The use ratio (mol%) with respect to the total amount is shown. Abbreviations of tetracarboxylic dianhydride and diamine compound in Table 1 are as follows.
(Tetracarboxylic dianhydride)
AN-1; 1,2,3,4-cyclobutanetetracarboxylic dianhydride AN-2; pyromellitic dianhydride AN-3; 2,3,5-tricarboxycyclopentylacetic dianhydride AN-4; 1,3-propylene glycol bis (anhydrotrimellitate)
AN-5; 1,4-phenylenebis (anhydrotrimellitate)
AN-6; bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic acid 2: 4,6: 8-dianhydride (diamine compound)
DA-1; Compound DA-2 represented by Formula (X-1); Compound DA-3 represented by Formula (X-2); Benzene-1,4-diylbis (4-aminobenzoate)
DA-4; 4,4 ′-[4,4′-propane-1,3-diylbis (piperidine-1,4-diyl)] dianiline DA-5; bis [2- (4-aminophenyl) ethyl] hexane Diacid DA-6; 4,4'-diaminodiphenylamine DA-7; 3,5-diaminobenzoic acid DA-8; N- (2,4-diaminophenyl) -4- (4-heptylcyclohexyl) benzamide DA- 9; 4- (Tetradecaoxy) benzene-1,3-diamine DA-10; Cholestanyl 3,5-diaminobenzoate DA-11; 4,4′-diaminodiphenylmethane In addition, the polymer (PA-4) is particularly It is suitable for a TN liquid crystal display element, and the polymer (PA-5) is particularly suitable for a VA liquid crystal display element (including a PSA display system).

[Synthesis Example 3-1; Synthesis of Polymer (PI-1)]
20.62 g of bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic acid 2: 4,6: 8-dianhydride as a tetracarboxylic dianhydride (diamine compound used in the synthesis) 98 mol parts with respect to 100 mol parts in total), and 4.86 g (10 mol parts) of the compound (X-1) as a diamine compound, 4,4 ′-[4,4′-propane-1, 3-diylbis (piperidine-1,4-diyl)] dianiline 3.3 g (10 mol parts), bis [2- (4-aminophenyl) ethyl] hexanedioic acid 16.17 g (50 mol parts) and 4 , 4′-diaminodiphenylamine (5.02 g, 30 mol parts) was dissolved in 200 g of NMP and reacted at room temperature for 6 hours. Next, 250 g of NMP was added, 6.52 g of pyridine and 8.42 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 100 ° C. for 5 hours. The reaction mixture was then poured into a large excess of methanol to precipitate the reaction product. The recovered precipitate was washed with methanol and then dried under reduced pressure at 40 ° C. for 15 hours to obtain a polyimide having an imidation ratio of about 50% (hereinafter referred to as polymer (PI-1)). The obtained polymer (PI-1) was prepared to be 15% by weight with NMP. The viscosity of this solution was measured and found to be 530 mPa · s. Moreover, when the obtained polymer solution was allowed to stand at 20 ° C. for 3 days, it did not gel and the storage stability was good.

[Synthesis Example 4-1; Synthesis of Polymer (p-1)]
The following operation was performed with reference to the method described in Japanese Patent No. 4894729 to obtain a polymer (p-1). First, 10 mmol of 4,6-diaminoresorcinol was dissolved in 40 mL of NMP in a well-dried sealed reaction vessel with a stirrer, and 44 mmol of pyridine was further added and dissolved. Next, while stirring the resulting solution, 0.4 g of lithium chloride (LiCl) was added, and then 10 mmol of 1,5-pentanedioic acid chloride was added and dissolved in two portions as a powder. By stirring at room temperature for 24 hours, a solution containing a polybenzoxazole precursor was obtained. Next, after the obtained polymer solution was appropriately diluted with NMP, the polybenzoxazole precursor was reprecipitated by adding dropwise to a large amount of diluted hydrochloric acid aqueous solution. Thereafter, the precipitate was repeatedly washed with water and then vacuum-dried at 80 ° C. for 24 hours to obtain a polymer (p-1) powder which is a polybenzoxazole precursor.

[Synthesis Example 4-2; Synthesis of Polymer (p-2)]
The following operation was performed with reference to Japanese Patent No. 4429334 to obtain a polymer (p-2). First, (E) -2- (cinnamoyloxy) terephthalic acid and diaminobenzenediol dihydrochloride were mixed and subjected to a polycondensation reaction in an environment of 300 ° C. Then, a process of dehydrochlorination (-HCl) and dried _(-H 2 O), to give the polybenzoxazole polymer and is a polymer of (p-2).

[Synthesis Example 5-1; Synthesis of Polymer (PSi-1)]
A reaction vessel equipped with a stirrer, thermometer, dropping funnel and reflux condenser was charged with 100.0 g of 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 500 g of methyl isobutyl ketone and 10.0 g of triethylamine, and room temperature. Mixed with. 100 g of deionized water was added dropwise from the dropping funnel over 30 minutes, and the reaction was carried out at 80 ° C. for 6 hours while mixing under reflux. After completion of the reaction, the organic layer is taken out, washed with 0.2 wt% ammonium nitrate aqueous solution until the water after washing becomes neutral, and then the solvent and water are distilled off under reduced pressure to have an oxiranyl group. Polyorganosiloxane was obtained as a viscous transparent liquid. When ¹ H-NMR analysis was performed on the polyorganosiloxane having an oxiranyl group, a peak based on the oxiranyl group was obtained in the vicinity of the chemical shift (δ) = 3.2 ppm according to the theoretical intensity. It was confirmed that no side reaction occurred. The epoxy equivalent of the polyorganosiloxane having an oxiranyl group was measured and found to be 186 g / equivalent.
Next, in a 100 mL three-necked flask, 9.3 g of the polyorganosiloxane having the oxiranyl group obtained above, 26 g of methyl isobutyl ketone, 3 g of 4-phenoxycinnamic acid and UCAT 18X (trade name, manufactured by San Apro Co., Ltd.) 0.10 g Was reacted at 80 ° C. for 12 hours with stirring. After completion of the reaction, the reaction mixture was poured into methanol to collect a precipitate, which was dissolved in ethyl acetate to form a solution. The solution was washed with water three times, and then the solvent was distilled off to remove the oxiranyl group. 6.3 g of polyorganosiloxane (PSi-1) having a cinnamic acid structure was obtained as a white powder. The weight average molecular weight Mw in terms of polystyrene measured by GPC for this polyorganosiloxane (PSi-1) was 3,500.

[Confirmation of rearrangement reaction by heating]
・ Thermogravimetric analysis (TGA)
For each of the compound (Model-1) and the compound (Model-2) obtained above, the change in weight was measured when the temperature was raised to 400 ° C at a rate of 10 ° C / min using a thermogravimetric analyzer. . The measurement result of the compound (Model-1) is shown in FIG. 1, and the measurement result of the compound (Model-2) is shown in FIG. First, with respect to the compound (Model-1), a weight reduction occurred from around 180 ° C., and a weight reduction (theoretical value: 36.5%) corresponding to 2 molecules of the Boc group was confirmed (see FIG. 1). On the other hand, the weight loss of the compound (Model-2) was not confirmed until around 230 ° C., and a weight decrease estimated to be sublimation or decomposition / volatilization of the compound after 230 ° C. was confirmed (see FIG. 2). As the thermogravimetric analyzer, TG / DTA7300 manufactured by SII Nano Technology Co., Ltd. was used.

・ Structural analysis by ¹ H-NMR Separately, each compound (Model-1) and compound (Model-2) was heated to 230 ° C. at a rate of 10 ° C./min, and then cooled to room temperature to obtain a residue. It was collected. Structural analysis was performed by ¹ H-NMR for the compound before the temperature increase and the residue collected after the temperature increase. The results are shown in FIGS. 3 shows the compound (Model-1) before the temperature rise, FIG. 4 shows the residue of the compound (Model-1) recovered after the temperature rise, FIG. 5 shows the compound (Model-2) before the temperature rise, and FIG. is the ¹ H-NMR measurement results of the residue of the compound recovered after heating (Model-1). From these results, it was confirmed that the structure of the compound (Model-1) was changed to the compound (Model-2) by heating. When the structure of the compound (Model-1) changes, the amino group having high nucleophilicity attacks the carbonyl group, possibly via an intermediate structure represented by the following formula (M′-1), and the compound ( It is presumed that it became Model-2) (see the following scheme 5). On the other hand, in the compound (Model-2), no structural change due to heating was confirmed.

<Preparation and evaluation of liquid crystal aligning agent>
[Example 1: Photo-alignment FFS type liquid crystal display element]
(1) Preparation of liquid crystal aligning agent The polymer (PA-1) obtained in Synthesis Example 2-1 as a polymer was obtained from γ-butyrolactone (GBL), N-methyl-2-pyrrolidone (NMP) and butyl cellosolve (BC). In a mixed solvent (GBL: NMP: BC = 40: 40: 20 (weight ratio)) to obtain a solution having a solid content concentration of 4.5% by weight. The liquid crystal aligning agent (R-1) was prepared by filtering this solution through a filter having a pore diameter of 0.2 μm.

(2) Evaluation of applicability The liquid crystal aligning agent (R-1) prepared above was applied on a glass substrate using a spinner, prebaked on a hot plate at 80 ° C. for 1 minute, and then the interior was filled with nitrogen. A coating film having an average film thickness of 0.1 μm was formed by heating (post-baking) in a substituted 200 ° C. oven for 1 hour. This coating film was observed with a microscope having a magnification of 100 times and 10 times to examine the presence or absence of film thickness unevenness and pinholes. In the evaluation, when neither film thickness unevenness nor pinhole was observed even when observed with a 100 × microscope, the coating property was “good”, and with a 100 × microscope, at least one of film thickness unevenness and pinhole was observed. However, when both the film thickness unevenness and the pinhole were not observed with a 10 × microscope, the coating property was “Yes”. When the film thickness unevenness and / or pinhole was clearly observed with a 10 × microscope Was defined as “poor”. In this example, neither film thickness unevenness nor pinhole was observed even with a 100 × microscope, and the coating property was “good”.

(3) Evaluation of liquid crystal alignment Using the Hg-Xe lamp and the Grand Taylor prism, the coating film obtained above was irradiated with polarized ultraviolet rays of 1,000 mJ / cm ² containing a 313 nm emission line from the normal direction of the substrate. Were subjected to orientation treatment. The refractive index anisotropy α (nm) of this glass substrate with an alignment film was measured using a liquid crystal alignment film inspection apparatus (RayScan) manufactured by MORITEX. In the evaluation, when α was 0.020 nm or more, “good”, when less than 0.020 nm and 0.010 nm or more were “good”, and when α was less than 0.010 nm, “bad”. As a result, in this substrate, α = 0.035 nm, and the orientation was “good”.

(4) Manufacture of FFS type liquid crystal display element by photo-alignment method FFS type liquid crystal display element 10 shown in FIG. 7 was produced. First, a glass substrate 11a having an electrode pair on one side of which a bottom electrode 15 having no pattern, a silicon nitride film as an insulating layer 14, and a top electrode 13 patterned in a comb shape are formed in this order, and an electrode The liquid crystal aligning agent (R-1) prepared in the above (1) is paired with the opposite glass substrate 11b not provided with the glass substrate 11a, and the surface of the glass substrate 11a having the transparent electrode and one surface of the opposite glass substrate 11b. The film was applied using a spinner, and then pre-baked on an 80 ° C. hot plate for 1 minute to form a coating film. Next, each surface of these coatings is irradiated with polarized ultraviolet rays of 1,000 mJ / cm ² including a 313 nm emission line from the normal direction of the substrate using a Hg-Xe lamp and a Grand Taylor prism, thereby having a liquid crystal alignment film. A pair of substrates was obtained. At this time, the irradiation direction of the polarized ultraviolet light is from the normal direction of the substrate, and the polarization plane direction is set so that the direction of the line segment in which the polarization plane of the polarized ultraviolet light is projected onto the substrate is the direction of the double-headed arrow in FIG. The light irradiation process was performed. Then, it heated for 15 minutes at 230 degreeC in the oven which substituted the inside with nitrogen (post-baking), and formed the coating film with an average film thickness of 0.1 micrometer.
A schematic plan view of the top electrode 13 used here is shown in FIG. 8A is a top view of the top electrode 13, and FIG. 8B is an enlarged view of a portion C1 surrounded by a broken line in FIG. 8A. In this example, a substrate having a top electrode having a line width d1 of electrodes of 4 μm and a distance d2 between the electrodes of 6 μm was used. In addition, as the top electrode 13, four systems of drive electrodes of electrode A, electrode B, electrode C, and electrode D were used. FIG. 9 shows the configuration of the drive electrode used. In this case, the bottom electrode 15 functions as a common electrode that acts on all of the four drive electrodes, and each of the four drive electrode regions serves as a pixel region.

Next, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm is applied to the outer periphery of the surface having one liquid crystal alignment film of the above substrates by screen printing, and then the liquid crystal alignment film surfaces of a pair of substrates Were placed so that the planes of polarization of polarized ultraviolet rays projected onto the substrate were parallel and pressure bonded, and the adhesive was heat cured at 150 ° C. for 1 hour. Next, a liquid crystal “MLC-6221” manufactured by Merck & Co. was filled into the gap between the liquid crystal injection port and the liquid crystal injection port was sealed with an epoxy resin adhesive. Then, in order to remove the flow alignment at the time of liquid crystal injection, this was heated to 150 ° C. and then gradually cooled to room temperature.
Next, an FFS type liquid crystal display element was manufactured by laminating polarizing plates on both outer surfaces of the substrate. At this time, one of the polarizing plates is stuck so that the polarization direction thereof is parallel to the direction of projection of the polarization plane of the polarized ultraviolet light of the liquid crystal alignment film onto the substrate surface, and the other one has the polarization direction first. The polarizing plate was stuck so as to be orthogonal to the polarization direction of the polarizing plate.

(5) Evaluation of liquid crystal alignment The presence / absence of an abnormal domain in a change in brightness when a voltage of 5 V is turned ON / OFF (applied / released) is measured with a microscope at a magnification of 50 for the FFS type liquid crystal display device manufactured in (4) Observed at double. In the evaluation, when the abnormal domain was not observed, the liquid crystal alignment was “good”, and when the abnormal domain was observed, the liquid crystal alignment was “bad”. In this liquid crystal display element, the liquid crystal orientation was “good”.
(6) Evaluation of voltage holding ratio For the FFS type liquid crystal display device manufactured in (4) above, a voltage of 5 V was applied at 23 ° C. with an application time of 60 microseconds and a span of 167 milliseconds. When the voltage holding ratio (VHR) after 1,000 milliseconds was measured, it was 94.9%. In addition, as a measuring apparatus, Toyo Technica Co., Ltd. make and VHR-1 were used.

(7) per FFS type liquid crystal display device manufactured in heat-resistant evaluation above (4), to measure the voltage holding ratio similarly to the above (6), and its value as an initial VHR _{(VHR BF).} Next, the liquid crystal display element after the initial VHR measurement was left in an oven at 100 ° C. for 500 hours. Thereafter, this was allowed to cool to room temperature a liquid crystal display device was allowed to stand at room temperature, in the same manner as in the above (6) to measure the voltage holding ratio, which was used as a post-heat stress VHR (VHR _AFH). Further, the rate of change in voltage holding ratio (ΔVHR (%)) before and after application of thermal stress was determined by the following mathematical formula (EX-2).
ΔVHR _HT = ((VHR _BF −VHR _AFH ) ÷ VHR _BF ) × 100 (EX−2)
In the evaluation of heat resistance, when the rate of change ΔVHR _HT is less than 5%, the heat resistance is “good”, when 5% or more but less than 10% is “good”, and when it is 10% or more “Bad”. As a result, ΔVHR _HT of the liquid crystal display element of this example was 3.9%, and the heat resistance was “good”.

(8) Evaluation of light resistance With respect to the FFS type liquid crystal display device produced in the above (4), the voltage holding ratio was measured in the same manner as in the above (6), and the value was defined as the initial VHR (VHR _BF ). Next, the liquid crystal display element after the initial VHR measurement was allowed to stand in an 80 ° C. oven under LED lamp irradiation for 500 hours, and then allowed to stand at room temperature and naturally cooled to room temperature. With respect to the liquid crystal cell after light irradiation, the voltage holding ratio was measured by the same method as in (6) above, and this value was defined as VHR (VHR _AFB ) after light stress. The decrease amount ΔVHR _BL (%) of the voltage holding ratio was obtained from the following formula (EX-3) and evaluated as light resistance.
ΔVHR _BL = ((VHR _BF −VHR _AFB ) ÷ VHR _BF ) × 100 (EX-3)
When ΔVHR _BL was less than 3%, the light resistance was judged as “good”, when it was 3% or more but less than 5%, “good”, and when it was 5% or more, “bad”. As a result, ΔVHR _BL of the liquid crystal display element of this example was 1.8%, and the light resistance was “good”.

(9) Evaluation of afterimage characteristics (DC afterimage evaluation)
The liquid crystal display element produced in the above (4) was placed in an environment of 25 ° C. and 1 atmosphere. The bottom electrode was set as a common electrode for all four drive electrodes, and the potential of the bottom electrode was set to 0 V potential (ground potential). The electrode B and the electrode D were short-circuited with the common electrode to be in a 0 V application state, and a composite voltage composed of an AC voltage of 3.5 V and a DC voltage of 1 V was applied to the electrodes A and C for 2 hours. Immediately after 2 hours, an AC voltage of 1.5 V was applied to all of the electrodes A to D. Then, from the start of applying an AC voltage of 1.5 V to all drive electrodes, a drive stress application region (pixel region of electrode A and electrode C) and a drive stress non-application region (pixel region of electrode B and electrode D) The time until the difference in brightness with the eye could not be visually confirmed was measured, and this was defined as the afterimage erasing time. Note that the shorter this time, the less likely an afterimage is generated. The case where the afterimage erasing time was less than 30 seconds was evaluated as “good”, the case where it was 30 seconds or more and less than 120 seconds was evaluated as “good”, and the case where it was 120 seconds or more was evaluated as “bad”. The afterimage erasing time of the liquid crystal display element was 1 second, and the afterimage characteristics were evaluated as “good”.

[Examples 2-6, Comparative Examples 1-3]
In Example 1 above, the liquid crystal aligning agent is prepared in the same manner as in Example 1 except that the type and amount of solids (polymer and additive) contained in the liquid crystal aligning agent are changed as shown in Table 2 below. At the same time, FFS type liquid crystal display elements were manufactured by a photo-alignment method and various evaluations were performed. The evaluation results are shown in Table 2 below.

  In Table 2, the numerical value of the polymer indicates the blending ratio (part by weight) of each component with respect to 100 parts by weight of the total of the polymer components. “-” Indicates that the component corresponding to the column was not used. In Comparative Example 2, the liquid crystal orientation of the coating film was poor, and visual evaluation in the afterimage characteristics of the liquid crystal display element could not be performed.

  As shown in Table 2, in Examples 1 to 6, all the coating properties and liquid crystal alignment properties of the liquid crystal aligning agent, and the liquid crystal alignment properties, voltage holding ratio, heat resistance, light resistance, and afterimage characteristics of the liquid crystal display element are “ The result was “good”, and various characteristics were balanced. On the other hand, Comparative Examples 1-3 were inferior to the Example in several evaluation items.

The reason why the above result is obtained when the liquid crystal aligning agent containing the polymer (A) having the partial structure represented by the above formula (1) is used is not clear, but as one hypothesis, first, radiation The orientation vector of the polymer is determined by the irradiation, and the protecting group (R ¹ ) in the partial structure represented by the above formula ( ¹ ) is eliminated by the subsequent heating (post-bake), and the amino group (—NH ₂ ) As a result of the rearrangement reaction (thermal rearrangement) by the generated amino group attacking the carbonyl group and the formation of an amide bond, it is presumed that excellent reliability was expressed. Further, it is presumed that the polymer was aligned with the previously determined alignment vector by heating after radiation irradiation, thereby exhibiting excellent liquid crystal alignment. On the other hand, it is presumed that the polybenzoxazole precursor used in Comparative Example 2 did not react with light and the liquid crystal alignment was poor.

[Example 7: rubbing alignment FFS type liquid crystal display element]
(1) Preparation of liquid crystal aligning agent The polymer (PA-2) obtained in Synthesis Example 2-2 as a polymer was obtained from γ-butyrolactone (GBL), N-methyl-2-pyrrolidone (NMP) and butyl cellosolve (BC). To a solution having a solid content concentration of 4.5% by weight. A liquid crystal aligning agent (R-7) was prepared by filtering this solution through a filter having a pore size of 0.2 μm.

(2) Evaluation of applicability The liquid crystal aligning agent (R-7) prepared above was applied onto a glass substrate using a spinner, pre-baked for 1 minute on a hot plate at 80 ° C., and then the interior was filled with nitrogen. A coating film having an average film thickness of 0.1 μm was formed by heating (post-baking) in a substituted 200 ° C. oven for 1 hour. Using the obtained coating film, coatability was evaluated in the same manner as in (2) of Example 1 above. As a result, the coating property of this coating film was “good”.
(3) Evaluation of rubbing resistance With respect to the coating film obtained in the above (2), a rubbing machine having a roll wound with a cotton cloth was used, and the roll rotation speed was 1000 rpm, the stage moving speed was 20 cm / sec, and the length of pushing the hair foot was set to 0. The rubbing process was performed 7 times at 4 mm. Foreign matter (a piece of coating film) due to rubbing scraping on the obtained substrate was observed with an optical microscope, and the number of foreign matters in a 500 μm × 500 μm region was measured. In the evaluation, the rubbing resistance was “good” when the number of foreign substances was 3 or less, and the rubbing resistance was “good” when 4 or more and 7 or less, and the rubbing resistance “bad” when 8 or more. As a result, the rubbing resistance of this coating film was “good”.

(4) Manufacture of FFS type liquid crystal display element by rubbing process First, the liquid crystal aligning agent prepared by said (1) on each surface of a pair of glass substrate 11a, 11b similar to (4) of the said Example 1 ( R-8) was applied using a spinner to form a coating film. Next, this coating film was pre-baked for 1 minute on an 80 ° C. hot plate, and then heated (post-baked) for 15 minutes at 230 ° C. in an oven in which the inside of the chamber was purged with nitrogen, so that the average film thickness was 0.1 μm. A coating film was formed. A schematic plan view of the top electrode 13 used here is shown in FIG. 10A is a top view of the top electrode 13, and FIG. 10B is an enlarged view of a portion C1 surrounded by a broken line in FIG. 10A. In this example, the line width d1 of the electrodes was 4 μm, and the distance d2 between the electrodes was 6 μm. As the top electrode 13, four drive electrodes of electrode A, electrode B, electrode C, and electrode D were used as in Example 1 (see FIG. 9).

  Subsequently, the surface of the coating film formed on the glass substrates 11 a and 11 b was rubbed with cotton to form the liquid crystal alignment film 12. In FIG.10 (b), the rubbing direction with respect to the coating film formed on the glass substrate 11a is shown by the arrow. Next, after applying the product name “XN-21-S” (manufactured by Mitsui Chemicals) as a sealant to the outer edge of the surface having the liquid crystal alignment film in one of the pair of substrates, Then, the substrates were bonded together via a spacer having a diameter of 3.5 μm so that the rubbing directions of the substrates 11a and 11b were antiparallel, and the sealant was cured. Next, liquid crystal MLC-6221 (manufactured by Merck & Co., Inc.) was injected between the pair of substrates through the liquid crystal injection port to form the liquid crystal layer 16. Furthermore, the liquid crystal display element 10 was produced by bonding a polarizing plate (not shown) on both outer surfaces of the substrates 11a and 11b so that the polarization directions of the two polarizing plates were orthogonal to each other.

(5) Evaluation of liquid crystal alignment The rubbing FFS type liquid crystal display device produced in (4) above was evaluated for liquid crystal alignment in the same manner as in (5) of Example 1 above. As a result, this liquid crystal display element had “good” liquid crystal alignment.
(6) Evaluation of voltage holding ratio The voltage holding ratio (VHR) of the rubbing type FFS liquid crystal display device manufactured in (4) was measured in the same manner as in (6) of Example 1. As a result, VHR = 97.2%.

[Example 8: retardation film]
(1) Preparation of liquid crystal aligning agent 100 parts by weight of the polymer (PSi-1) obtained in Synthesis Example 5-1 and 5 parts by weight of the polymer (PA-2) obtained in Synthesis Example 2-2 were mixed with propylene glycol. It is dissolved in a mixed solvent (PGMEA: MEK: BTLAC = 30: 30: 40 (weight ratio)) composed of monomethyl ether acetate (PGMEA), 2-butanone (MEK) and butyl acetate (BTLAC), and the solid content concentration is 4. A 5% by weight solution was obtained. A liquid crystal aligning agent (R-8) was prepared by filtering this solution through a filter having a pore size of 0.2 μm.

(2) Manufacture of retardation film The liquid crystal aligning agent (R-8) prepared above is applied to one surface of a TAC film as a substrate with a bar coater, and baked in an oven at 120 ° C for 2 minutes to form a film. A coating film having a thickness of 100 nm was formed. Next, the surface of the coating film was irradiated perpendicularly from the substrate normal line with polarized ultraviolet rays of 10 mJ / cm ² containing an emission line of 313 nm using a Hg—Xe lamp and a Grand Taylor prism. Next, the polymerizable liquid crystal (RMS03-013C, manufactured by Merck & Co., Inc.) was filtered through a filter having a pore size of 0.2 μm, and this polymerizable liquid crystal was applied onto the coated film after light irradiation by a bar coater. A coating film was formed. After baking for 1 minute in an oven adjusted to a temperature of 50 ° C., an unpolarized ultraviolet ray containing 365 nm emission line was irradiated at 1,000 mJ / cm ² from a direction perpendicular to the coating surface using an Hg-Xe lamp. A retardation film was produced by curing a polymerizable liquid crystal to form a liquid crystal layer.

(3) Evaluation of liquid crystal orientation About the retardation film manufactured by said (2), liquid crystal orientation is observed by observing the presence or absence of an abnormal domain by visual observation under crossed Nicols and a polarizing microscope (magnification 2.5 times). evaluated. Evaluation is that the liquid crystal orientation is “good” when no abnormal domain is observed visually and with a polarizing microscope, and the liquid crystal orientation is when abnormal domain is observed with a polarizing microscope when no abnormal domain is visually observed. “Yes”, the case where an abnormal domain was observed visually and with a polarizing microscope was defined as “Poor” for liquid crystal alignment. As a result, this retardation film was evaluated as “good” for liquid crystal alignment.

(4) Adhesiveness Using the retardation film produced in (2) above, the adhesiveness of the coating film formed with the liquid crystal aligning agent to the substrate was evaluated. First, using an equally spaced spacer with a guide, a cutter knife was used to cut from the surface on the liquid crystal layer side of the retardation film to form 10 × 10 lattice patterns within a range of 1 cm × 1 cm. The depth of each cut was made to reach the middle of the substrate thickness from the surface of the liquid crystal layer. Next, after attaching a cellophane tape so as to cover the entire surface of the lattice pattern, the cellophane tape was peeled off. The notches in the lattice pattern after peeling were observed visually under crossed Nicols to evaluate the adhesion. The evaluation was that the adhesion was “good” when no peeling was observed at the portion along the cut line and at the intersection of the lattice pattern, and the number of lattices where peeling was observed in the above portion was the number of the entire lattice pattern. On the other hand, when the amount is less than 15%, the adhesion is “possible”, and when the number of lattices where peeling is observed in the above portion is 15% or more with respect to the total number of lattice patterns, the adhesion is “bad”. went. As a result, this retardation film had good adhesion.

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

Claims (15)

The liquid crystal aligning agent containing the polymer (A) which has a partial structure represented by following formula (1).
(In Formula (1), R ¹ is a hydrogen atom or an amino-protecting group, R ² is a halogen atom or a monovalent organic group, n is an integer of 0 to ^3. “*” is a bond. Indicates that it is a hand.) The liquid crystal aligning agent according to claim 1, wherein the polymer (A) is a polymer having a partial structure represented by the following formula (1-1) or formula (1-2).
(In Formula (1-1) and Formula (1-2), R ³ and R ⁴ are a halogen atom or an alkyl group having 1 to 5 carbon atoms. R and s are integers of 0 to 2. R ¹ and “*” have the same meanings as in the above formula (1).)   The liquid crystal aligning agent of Claim 1 or 2 containing at least 1 type of polymer chosen from the group which consists of a polyimide precursor, a polyimide, a polybenzoxazole precursor, and a polybenzoxazole as said polymer (A). The polymer (A) includes at least one polymer (A1) selected from the group consisting of a polyimide precursor and polyimide,
The polymer (A1) is bicyclo [2.2.1] heptane-2,3,5,6-tetracarboxylic acid 2: 3,5: 6-dianhydride, 1,2,3,4-cyclobutane. Tetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentyl acetic 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, bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic acid 2: 4,6: 8-dianhydride, cyclohexanetetracarboxylic dianhydride and pyromerit Selected from the group consisting of acid dianhydrides Having a partial structure derived from at least one compound, a liquid crystal aligning agent according to any one of claims 1-3.   The liquid crystal aligning film formed using the liquid crystal aligning agent as described in any one of Claims 1-4.   The liquid crystal aligning film obtained by apply | coating the liquid crystal aligning agent as described in any one of Claims 1-4 to a board | substrate, forming a coating film, and light-irradiating this coating film.   The liquid crystal aligning film obtained by apply | coating the liquid crystal aligning agent as described in any one of Claims 1-4 to a board | substrate, and carrying out a rubbing process. The liquid crystal aligning film containing the polymer which has a partial structure represented by following formula (2).
(In Formula (2), R ² is a halogen atom or a monovalent organic group. N is an integer of 0 to ^3. “*” indicates a bond.)   The process of apply | coating the liquid crystal aligning agent as described in any one of Claims 1-4 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 are included. A method for producing a liquid crystal alignment film.   A liquid crystal display element provided with the liquid crystal aligning film as described in any one of Claims 5-8.   A retardation film comprising the liquid crystal alignment film according to claim 6.   The process of apply | coating the liquid crystal aligning agent as described in any one of Claims 1-4 on a board | substrate, forming a coating film, the process of light-irradiating the said coating film, and the coating film after the said light irradiation A method for producing a retardation film, comprising: applying a polymerizable liquid crystal thereon and curing the liquid crystal. A polymer having a partial structure represented by the following formula (1).
(In Formula (1), R ¹ is a hydrogen atom or an amino-protecting group, R ² is a halogen atom or a monovalent organic group, n is an integer of 0 to ^3. “*” is a bond. Indicates that it is a hand.) A polyimide having a partial structure represented by the following formula (2) or a precursor thereof.
(In Formula (2), R ² is a halogen atom or a monovalent organic group. N is an integer of 0 to ^3. “*” indicates a bond.) Diamine which has the partial structure represented by following formula (1).
(In Formula (1), R ¹ is a hydrogen atom or an amino-protecting group, R ² is a halogen atom or a monovalent organic group, n is an integer of 0 to ^3. “*” is a bond. Indicates that it is a hand.)