JP6287577B2 - Liquid crystal aligning agent, liquid crystal aligning film, manufacturing method thereof, and liquid crystal display element - Google Patents

Description

The present invention relates to a liquid crystal aligning agent, a liquid crystal alignment film and a method of manufacturing the same, and relates to a liquid crystal display element, a technique suitable in particular for applying a liquid crystal alignment capability to the membrane by optical alignment techniques.

  Conventionally, as a liquid crystal display element, various driving methods having different electrode structures and physical properties of liquid crystal molecules to be used have been developed. For example, vertical electric field methods such as TN type, STN type, VA type, IPS type, and FFS type. Various liquid crystal display elements such as a horizontal electric field method are known. Among these, in a vertical electric field type liquid crystal display element, an electrode is formed on each of a pair of substrates arranged opposite to each other to generate an electric field in a direction perpendicular to the substrate, whereas in a horizontal electric field type liquid crystal display element, An electrode is formed on one of the pair of substrates, and an electric field is generated in a direction parallel to the substrate. Thereby, it is known that the liquid crystal display element of the horizontal electric field type can improve the contrast and viewing angle characteristics as compared with the conventional vertical electric field type.

  In the liquid crystal display element, the alignment state of liquid crystal molecules is controlled by a liquid crystal alignment film formed on a substrate. As a material for the liquid crystal alignment film, polyamic acid or polyimide is generally used from the viewpoints of various properties such as heat resistance, mechanical strength, and affinity with liquid crystal. In addition, as a method for imparting liquid crystal alignment ability to a polymer thin film formed with a liquid crystal aligning agent, a photo-alignment method using photoisomerization, photodimerization, photolysis, etc. has recently been proposed as an alternative to the rubbing method. Has been. This photo-alignment method is a method in which the radiation-sensitive organic thin film formed on the substrate is irradiated with polarized or non-polarized radiation to make the film anisotropic, thereby controlling the alignment of liquid crystal molecules. is there. According to this method, it is possible to suppress the generation of dust and static electricity in the process as compared with the conventional rubbing method, and therefore it is possible to suppress the occurrence of display defects and the decrease in yield due to dust and the like. It is. Further, there is an advantage that the liquid crystal alignment ability can be uniformly imparted to the organic thin film formed on the substrate.

  Various liquid crystal aligning agents to which the photo-alignment method can be applied have been proposed (see, for example, Patent Documents 1 to 5). Among these, in Patent Document 1, a polyimide film is formed using a polymer solution containing a polyimide precursor obtained by reaction of 1,2,3,4-cyclobutanetetracarboxylic dianhydride and diamine, It is disclosed that liquid crystal alignment ability is imparted to the film by irradiating the surface of the polyimide film with ultraviolet rays. Patent Documents 2 and 3 disclose a liquid crystal alignment film containing polyimide having a structure in which a halogen atom is bonded to a cyclobutane ring. Patent Documents 3 to 5 disclose a structure in which an alkyl group is bonded to a cyclobutane ring. A liquid crystal alignment film containing a polyimide having the above is disclosed. Although Patent Document 1 discloses a polyimide having a structure in which a monovalent organic group having 1 to 4 carbon atoms is bonded to a cyclobutane ring, there is no specific description regarding the monovalent organic group.

Japanese Patent No. 3893659 Japanese Patent No. 4504665 International Publication No. 2012-176822 Japanese Patent No. 5368250 JP 2013-235130 A

  A lateral electric field type liquid crystal display element such as an IPS mode or an FFS mode has a wide viewing angle characteristic and a good contrast characteristic, but an afterimage (image burn-in) due to accumulation of residual charges may be a problem.

  In addition, by applying a liquid crystal alignment film obtained by a photo-alignment method to a liquid crystal display element of a horizontal electric field type, it can be expected to obtain merits when the alignment treatment is performed by the photo-alignment method. However, in the case of a photo-alignment method in which a chemical change is caused by irradiation with ultraviolet rays or the like, there is a general tendency that the electrical properties are inferior compared with a liquid crystal alignment film by a conventional rubbing treatment. In particular, when accompanied by photodecomposition of the polymer, there is a problem that impurity ions increase in the liquid crystal cell and the voltage holding ratio tends to decrease. In addition, it is presumed that the liquid crystal alignment film obtained by the photo-alignment method does not have sufficient liquid crystal alignment control force, and is a cause of image sticking in a horizontal electric field type liquid crystal display element. On the other hand, with the recent improvement in quality of liquid crystal panels, liquid crystal display elements that are superior in the electrical characteristics and afterimage characteristics of liquid crystal display elements are required than conventional ones.

  The present invention has been made in view of the above problems, and provides a liquid crystal aligning agent capable of obtaining a liquid crystal display element with a small residual charge accumulation amount, a high voltage holding ratio, and a good afterimage characteristic. Main purpose.

  The present inventors diligently studied to achieve the above-described problems of the prior art, and solved the above problems by using a polymer having a specific structure as at least a part of the polymer component in the liquid crystal aligning agent. The inventors have found that this is possible and have completed the present invention. Specifically, the present invention provides the following liquid crystal aligning agent, liquid crystal aligning film and method for producing the same, liquid crystal display element, polymer and compound.

  In one aspect, the present invention provides a polymer having at least one partial structure (a) selected from the group consisting of a partial structure represented by the following formula (1) and a partial structure represented by the following formula (2) ( A liquid crystal aligning agent containing A) is provided.

（式（１）及び式（２）中、Ｒ^１は脂環式構造を有する４価の基であり、Ｒ^２は２価の有機基であり、Ｒ^２５及びＲ^２６は、それぞれ独立に水素原子又は１価の有機基である。ただし、Ｒ^１、Ｒ^２５及びＲ^２６の少なくともいずれかに、フッ化アルキル基、フッ化アルコキシ基、フッ化アルキルエステル基及び−Ｓｉ（ＯＲ^３０）_３（ただし、Ｒ^３０は炭素数１〜４のアルキル基である。）よりなる群から選ばれる少なくとも一種である特定原子含有基を有する。）

(In Formula (1) and Formula (2), R ¹ is a tetravalent group having an alicyclic structure, R ² is a divalent organic group, and R ²⁵ and R ²⁶ are each independently hydrogen. An atomic or monovalent organic group, provided that at least one of R ¹ , R ^25, and R ²⁶ includes a fluorinated alkyl group, a fluorinated alkoxy group, a fluorinated alkyl ester group, and —Si (OR ³⁰ ) ₃ ( However, R < ³⁰ > is a C1-C4 alkyl group. It has a specific atom containing group which is at least 1 type chosen from the group which consists of.)

  In another aspect of the present invention, a step of applying a liquid crystal aligning agent containing the polymer (A) on a substrate to form a coating film, and irradiating the coating film formed on the substrate with light. And providing a liquid crystal alignment ability to the coating film.

  In another aspect, the present invention provides a liquid crystal alignment film formed using the liquid crystal alignment agent and a liquid crystal display device including the same. In another aspect, there is provided a polymer having at least one selected from the group consisting of a partial structure represented by the following formula (1A) and a partial structure represented by the following formula (2A).

（式（１Ａ）及び式（２Ａ）中、Ｒ^３１は、フッ化アルキル基、フッ化アルコキシ基及びフッ化アルキルエステル基よりなる群から選ばれる少なくとも一種である特定フッ素含有基が結合した脂環式構造を有する４価の基であり、Ｒ^２は２価の有機基であり、Ｒ^２５及びＲ^２６は、それぞれ独立に水素原子又は１価の有機基である。）

(In Formula (1A) and Formula (2A), R ³¹ is an alicyclic ring bonded with a specific fluorine-containing group that is at least one selected from the group consisting of a fluorinated alkyl group, a fluorinated alkoxy group, and a fluorinated alkyl ester group. A tetravalent group having a formula structure, R ² is a divalent organic group, and R ²⁵ and R ²⁶ are each independently a hydrogen atom or a monovalent organic group.)

  In still another aspect, provided is a compound represented by the following formula (3A) and a compound represented by the following formula (4A).

（式（３Ａ）中、Ｒ^３１は、フッ化アルキル基、フッ化アルコキシ基及びフッ化アルキルエステル基よりなる群から選ばれる少なくとも一種である特定フッ素含有基が結合した脂環式構造を有する４価の基である。）

(In Formula (3A), R ³¹ has an alicyclic structure in which a specific fluorine-containing group that is at least one selected from the group consisting of a fluorinated alkyl group, a fluorinated alkoxy group, and a fluorinated alkyl ester group is bonded. Valent group.)

（式（４Ａ）中、Ｒ^３１は、フッ化アルキル基、フッ化アルコキシ基及びフッ化アルキルエステル基よりなる群から選ばれる少なくとも一種である特定フッ素含有基が結合した脂環式構造を有する４価の基であり、Ｒ^２５及びＲ^２６は、それぞれ独立に水素原子又は１価の有機基であり、Ｘ^１は、水酸基又はハロゲン原子である。）

(In Formula (4A), R ³¹ has an alicyclic structure in which a specific fluorine-containing group that is at least one selected from the group consisting of a fluorinated alkyl group, a fluorinated alkoxy group, and a fluorinated alkyl ester group is bonded. R ²⁵ and R ²⁶ are each independently a hydrogen atom or a monovalent organic group, and X ¹ is a hydroxyl group or a halogen atom.)

  The liquid crystal alignment film obtained using the liquid crystal aligning agent of the present invention can reduce the accumulation of residual charges that are likely to occur in a horizontal electric field type liquid crystal display element, and exhibits a high voltage holding ratio. Further, the liquid crystal display element including the liquid crystal alignment film is less likely to cause an afterimage and has excellent display characteristics.

The present invention will be described below.
[Liquid crystal aligning agent]
The liquid crystal aligning agent of this invention is at least 1 type of a polymer component chosen from the group which consists of the partial structure represented by the said Formula (1), and the partial structure represented by the said Formula (2) as at least 1 type. A polymer (A) having (a) is contained.

R ¹ in the above formulas (1) and (2) is a tetravalent group having an alicyclic structure. The alicyclic structure of R ¹ includes a fluorinated alkyl group, a fluorinated alkoxy group, a fluorinated alkyl ester group, and —Si (OR ³⁰ ) ₃ (where R ³⁰ is an alkyl group having 1 to 4 carbon atoms). It is preferable to have at least one specific atom-containing group selected from the group consisting of:
Here, the fluorinated alkyl group possessed by R ¹ preferably has 1 to 10 carbon atoms. Specific examples thereof include, for example, a trifluoromethyl group, a perfluoroethyl group, and 2,2,2-trifluoroethyl. Group, 1,1-difluoroethyl group, 3,3,3-trifluoropropyl group, perfluoropropyl group, 4,4,4-trifluorobutyl group, 5,5,5-trifluoropentyl group, 4, Examples include 4,5,5,5-pentafluoropentyl group and 6,6,6-trifluorohexyl group. From the viewpoint of liquid crystal orientation, the fluorinated alkyl group that R ¹ has is more preferably 1 to 5 carbon atoms, and further preferably 1 to 3 carbon atoms.
In the fluorinated alkoxy group possessed by R ^1, the examples of the fluorinated alkyl group and the explanation of the preferred examples can be applied as the alkyl structure moiety.
The fluorinated alkyl ester group is a group represented by “* —CO—O—Rf” (where Rf is a fluorinated alkyl group, and * represents a bond bonded to the alicyclic structure). . With respect to Rf, the examples of the fluorinated alkyl group and the description of the preferred examples can be applied.
Examples of R ³⁰ in the group “—Si (OR ³⁰ ) ₃ ” include a methyl group, an ethyl group, a propyl group, and a butyl group, which may be linear or branched.
Among the above, the specific atom-containing group is at least one group selected from the group consisting of a fluorinated alkyl group, a fluorinated alkoxy group, and a fluorinated alkyl ester group (hereinafter also referred to as “specific fluorine-containing group”). It is preferable that

A tetravalent group having an alicyclic structure has a structure derived from an alicyclic tetracarboxylic acid. Examples of the alicyclic structure of R ¹ include a monocyclic cycloalkane such as a cyclobutane ring, a cyclopentane ring, a cyclohexane ring, and a cyclooctane ring; a bicyclo [2.2.0] hexane ring, a decahydronaphthalene ring, and a bicyclo Bicyclic alkanes such as [2.2.1] heptane ring and bicyclo [2.2.2] octane ring. Among these, the alicyclic structure of R ¹ is preferably a cyclobutane ring, a cyclopentane ring, a cyclohexane ring, or a bicyclo [2.2.0] hexane ring, and is a cyclobutane ring because of high photoalignment. It is particularly preferred.

（式（３−１）〜式（３−４）中、Ｒ^３〜Ｒ^２３は、それぞれ独立に水素原子又は１価の有機基である。ただし、Ｒ^３〜Ｒ^６の少なくとも１個は上記特定フッ素含有基であり、Ｒ^７〜Ｒ^１１の少なくとも１個は上記特定フッ素含有基であり、Ｒ^１２〜Ｒ^１７の少なくとも１個は上記特定フッ素含有基であり、Ｒ^１８〜Ｒ^２３の少なくとも１個は上記特定フッ素含有基である。「＊」は結合手を示す。） R ¹ is preferably a tetravalent group having an alicyclic structure to which a specific fluorine-containing group is bonded, and preferred specific examples thereof include, for example, those represented by the following formulas (3-1) to (3-4): Examples include groups represented by each.

(In Formula (3-1) to Formula (3-4), R ^{3 to} R ²³ are each independently a hydrogen atom or a monovalent organic group, provided that at least one of R ^{3 to} R ⁶ is the above-mentioned A specific fluorine-containing group, at least one of R ^{7 to} R ¹¹ is the specific fluorine-containing group, at least one of R ^{12 to} R ¹⁷ is the specific fluorine-containing group, and at least one of R ^{18 to} R ²³ One is the specific fluorine-containing group. “*” Represents a bond.)

The monovalent organic group in R ^{3 to} R ²³ is, for example, a monovalent hydrocarbon group or at least one methylene group of a monovalent hydrocarbon group represented by —O—, —CO—, —COO—, —NH—. , -NHCO- and the like, a trialkylsilyl group, a trialkoxysilyl group, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc.) and the like. In these groups, a hydrogen atom bonded to a carbon atom may be substituted with a halogen atom, a trialkylsilyl group, a trialkoxysilyl group, or the like.
Here, the “hydrocarbon group” in this specification may be a saturated hydrocarbon group or an unsaturated hydrocarbon group, a chain hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. The meaning includes a group. Further, the “chain hydrocarbon group” means a linear hydrocarbon group and a branched hydrocarbon group which are composed only of a chain structure without including a cyclic structure in the main chain. 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.

In the groups represented by the formulas (3-1) to (3-4), one or more of the specific fluorine-containing groups are bonded to a ring portion of an alicyclic structure such as a cyclobutane ring. The number of the specific fluorine-containing groups in each group can be appropriately set according to the number of fluorine atoms per specific fluorine-containing group, the number of ring members of the alicyclic structure, and the like.
The specific fluorine-containing group in the above formulas (3-1) to (3-4) is, among others, a trifluoromethyl group, a perfluoroethyl group, a 2,2,2-trifluoroethyl group, or a 1,1-difluoroethyl group. Are preferable, and a trifluoromethyl group or a 2,2,2-trifluoroethyl group is more preferable.

R ² in the above formulas (1) and (2) is a divalent organic group. For example, at least one methylene group of a divalent hydrocarbon group or a divalent hydrocarbon group may be represented by —O—, —CO—, —COO—, —NH—, —NHCO—, — Examples include groups substituted with Si (R ³⁰ ) ₂ —, —Si (OR ³⁰ ) ₂ —, etc., groups having a heterocyclic ring, and the like. In R ² , the hydrogen atom bonded to the carbon atom of the hydrocarbon group may be substituted with a halogen atom, an alkylsilyl group, an alkoxysilyl group, or the like.
R ²⁵ and R ²⁶ are a hydrogen atom or a monovalent organic group. As the monovalent organic group, for example, at least one methylene group of a monovalent hydrocarbon group having 1 to 18 carbon atoms or a monovalent hydrocarbon group having 1 to 18 carbon atoms is represented by —O— or —CO. —, —COO—, —NR—, —NRCO— (wherein R is an alkyl group), —Si (R ³⁰ ) ₂ —, —Si (OR ³⁰ ) ₂ —, etc. And a group obtained by substituting a hydrogen atom bonded to a carbon atom of 18 monovalent hydrocarbon group with a halogen atom, an alkylsilyl group, an alkoxysilyl group, or the like. R ²⁵ and R ²⁶ may be the same as or different from each other.
In the polymer (A) contained in the liquid crystal aligning agent of the present invention, when R ¹ does not have the specific atom-containing group, at least one of R ²⁵ and R ²⁶ is the specific atom-containing group. Have The description of R ¹ can be applied to the specific and preferred specific examples of the specific atom-containing group possessed by R ²⁵ and R ²⁶ .

The polymer (A) is at least one polymer selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide.
[Polyamic acid]
The polyamic acid (hereinafter also referred to as “polyamic acid (A)”) as the polymer (A) can be obtained, for example, by reacting a tetracarboxylic dianhydride with a diamine.

(Tetracarboxylic dianhydride)
The tetracarboxylic dianhydride used for the synthesis of the polyamic acid (A) preferably contains a compound represented by the above formula (3A) (hereinafter also referred to as “specific tetracarboxylic dianhydride”). As for R ³¹ in the formula (3A), said R ¹ is can be applied to the description of the case is a tetravalent group having an alicyclic structure that certain fluorine-containing group attached.

Preferable specific examples of the specific tetracarboxylic dianhydride include, for example, compounds represented by the following formulas (3-1) to (3-14). In addition, specific tetracarboxylic dianhydride can be used individually by 1 type or in combination of 2 or more types.

  In the synthesis of the polyamic acid (A), only the specific tetracarboxylic dianhydride may be used, but other tetracarboxylic dianhydrides may be used in combination with the specific tetracarboxylic dianhydride.

Examples of other tetracarboxylic dianhydrides that can be used here include aliphatic tetracarboxylic dianhydrides, alicyclic tetracarboxylic dianhydrides, aromatic tetracarboxylic dianhydrides, and the like. .
Specific examples thereof include aliphatic tetracarboxylic dianhydrides such as 1,2,3,4-butanetetracarboxylic dianhydride;
Examples of the alicyclic tetracarboxylic dianhydride include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 1,3,3a, 4, 5,9b-Hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5,9b- Hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [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- No 1,2-dicarboxylic acid 3,5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5: 6-dianhydride, 2,4,6,8-tetracarboxybicyclo [3.3.0] octane-2 : 4,6: 8-dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^2,6 ] undecane-3,5,8,10-tetraone, cyclohexanetetracarboxylic dianhydride Cyclopentanetetracarboxylic dianhydride and the like;
Examples of aromatic tetracarboxylic dianhydrides include pyromellitic dianhydride and 4,4 ′-(hexafluoroisopropylidene) diphthalic anhydride;
In addition to the above, tetracarboxylic dianhydrides described in JP 2010-97188 A can be used. In addition, the said other tetracarboxylic dianhydride can be used individually by 1 type or in combination of 2 or more types.

  In the synthesis of the polyamic acid (A), the use ratio of the specific tetracarboxylic dianhydride is the total amount of tetracarboxylic dianhydrides used for the synthesis of the polyamic acid from the viewpoint of sufficiently obtaining the effect of improving the voltage holding ratio. On the other hand, it is preferably 5 mol% or more, more preferably 10 mol% or more, further preferably 20 mol% or more, and particularly preferably 30 mol% or more.

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

（式（Ｄ−１）中、Ｘ^I及びＸ^IIは、それぞれ独立に、単結合、−Ｏ−、−ＣＯＯ−又は−ＯＣＯ−であり、Ｒ^Ｉは炭素数１〜３のアルカンジイル基であり、Ｒ^ＩＩは単結合又は炭素数１〜３のアルカンジイル基であり、ａは０又は１であり、ｂは０〜２の整数であり、ｃは１〜２０の整数であり、ｄは０又は１である。但し、ａ及びｂが同時に０になることはない。）
で表される化合物などのほか、 Examples of aromatic diamines include p-phenylenediamine, 4,4′-ethylenedianiline, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl sulfide, 1,5-diaminonaphthalene, and 2,2′-dimethyl. -4,4'-diaminobiphenyl, 4,4'-diamino-2,2'-bis (trifluoromethyl) biphenyl, 4,4'-diaminodiphenyl ether, 2- (4-aminophenyl) ethylamine, bis (4 -Aminophenyl) amine, N, N-bis (4-aminophenyl) methylamine, 4,4'-diaminobenzophenone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2- Bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexaph Oropropane, 4,4 ′-(p-phenylenediisopropylidene) bisaniline, 4,4 ′-(m-phenylenediisopropylidene) bisaniline, 1,4-bis (4-aminophenoxy) benzene, 4,4′- Bis (4-aminophenoxy) biphenyl, N, N′-bis (4-aminophenyl) -benzidine, N, N′-bis (4-aminophenyl) -N, N′-dimethylbenzidine, dodecanoxy-2,4 -Diaminobenzene, tetradecanoxy-2,4-diaminobenzene, octadecanoxy-2,5-diaminobenzene, cholestanyloxy-3,5-diaminobenzene, cholestenyloxy-3,5-diaminobenzene, cholestanyloxy-2, 4-diaminobenzene, cholestenyloxy-2,4-diaminobenzene, 3,5-dia Cholestanyl benzoate, cholestenyl 3,5-diaminobenzoate, lanostannyl 3,5-diaminobenzoate, 3,6-bis (4-aminobenzoyloxy) cholestane, 3,6-bis (4-aminophenoxy) cholestane, 4- (4′-trifluoromethoxybenzoyloxy) cyclohexyl-3,5-diaminobenzoate, {4- [2- (3,5-diaminophenoxy) -ethoxy] -phenyl} -ethanone, 3,4-diamino Benzophenone, {4- [2- (3,5-diaminophenoxy) -ethoxy] -phenyl} -phenyl-methanone, {4- [2- (2,4-diaminophenoxy) -ethoxy] -phenyl} -p- Toluyl-methanone, 2,7-diaminofluorenone, 2,7-diaminofluorene, and 9,9-bis (4- Minofeniru) fluorene, formula (D-1)

(In Formula (D-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.)
In addition to the compounds represented by

のそれぞれで表される化合物等の窒素含有複素環ジアミン：下記式（ｄ−４）〜式（ｄ−７）

のそれぞれで表される化合物などを； 3,5-diaminobenzoic acid, 2,4-diaminobenzoic acid, 2,5-diaminobenzoic acid, 4,4′-diaminobiphenyl-3,3′-dicarboxylic acid, 4,4′-diaminobiphenyl-2, 2'-dicarboxylic acid, 3,3'-diaminobiphenyl-2,4'-dicarboxylic acid, 4,4'-diaminodiphenylmethane-3,3'-dicarboxylic acid, 4,4'-diaminobiphenyl-3-carboxylic acid 4,4′-diaminodiphenylmethane-3-carboxylic acid, 4,4′-diaminodiphenylethane-3,3′-dicarboxylic acid, 4,4′-diaminodiphenylethane-3-carboxylic acid, and 4,4 ′ -Carboxyl group-containing diamine such as diaminodiphenyl ether-3,3'-dicarboxylic acid:
2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminoacridine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, 1,4- Bis- (4-aminophenyl) -piperazine, the following formulas (d-1) to (d-3)

A nitrogen-containing heterocyclic diamine such as a compound represented by each of the following formulas (d-4) to (d-7):

A compound represented by each of the above;

  Examples of the diaminoorganosiloxane include 1,3-bis (3-aminopropyl) -tetramethyldisiloxane, 3,3 ′-[1,4-phenylenebis (dimethylsilanediyl)] bis (1-propanamine), and the like. In addition, diamines described in JP 2010-97188 A can be used.

The divalent group represented by “—X ^I — (R ^I —X ^II ) _d —” in the formula (D-1) is an alkanediyl group having 1 to 3 carbon atoms, * —O—, * — COO— or * —O—C ₂ H ₄ —O— (however, a bond marked with “*” binds to a diaminophenyl group) is preferable. The group “—C _c H _{2c + 1} ” is 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 (D-1) include, for example, compounds represented by the following formulas (D-1-1) to (D-1-5).

In the synthesis of the polyamic acid (A), diamines can be used singly or in combination of two or more. In addition, R ² in the above formulas (1) and (2) is a divalent organic group derived from these diamines.

<Synthesis of polyamic acid>
The polyamic acid (A) can be obtained by reacting the above tetracarboxylic dianhydride and diamine together with a molecular weight regulator as necessary. The ratio of the tetracarboxylic dianhydride and diamine used in the synthesis reaction of the polyamic acid (A) is such that the acid anhydride group of the tetracarboxylic dianhydride is 0. A ratio of 2 to 2 equivalents is preferable, and a ratio of 0.3 to 1.2 equivalents is more preferable.
Examples of the molecular weight regulator 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 regulator 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 of organic solvents), or one or more selected from the first group of organic solvents, It is preferable to use a mixture with one or more 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 are N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphortriamide, m-cresol, xylenol and halogen. It is preferable to use one or more selected from the group consisting of fluorinated phenols as a solvent, or to use a mixture of one or more of these and another organic solvent in the above range.
The amount (a) of the organic solvent used is such that the total amount (b) of the tetracarboxylic dianhydride and diamine and the molecular weight regulator used as necessary is 0. 0 relative to the total amount (a + b) of the reaction solution. The amount is preferably 1 to 50% by weight.

  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 may be purified. In addition, you may use for preparation of a liquid crystal aligning agent. 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 the polyamic acid (A) obtained by the above synthesis reaction with an esterifying agent, [II] a tetracarboxylic acid diester and a diamine. And [III] a method of reacting a tetracarboxylic acid diester dihalide with a diamine.

  Here, examples of the esterifying agent used in the method [I] include a hydroxyl group-containing compound, an acetal compound, a halide, and an epoxy group-containing compound. 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 Method [II] can be obtained by a method of ring-opening by reacting a tetracarboxylic dianhydride with an alcohol, a method of esterifying a tetracarboxylic acid, or the like. The tetracarboxylic acid diester dihalide used in the method [III] can be obtained by reacting the tetracarboxylic acid diester obtained as described above with an appropriate halogenating agent such as thionyl chloride. When the polyamic acid ester having the partial structure (a) is synthesized, a compound represented by the above formula (4A) can be preferably used.

  Examples of the diamine used in the methods [II] and [III] include the compounds exemplified as the diamine used for the synthesis of the polyamic acid (A). The polyamic acid ester 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.

<Synthesis of compounds>
The compound represented by the above formula (3A) and the compound represented by the above formula (4A) can be synthesized by appropriately combining conventional methods of organic chemistry. As an example, a method using a photodimerization reaction can be mentioned. Specifically, for example, a compound in which R ³¹ in the above formula (3A) has a cyclobutane ring is contained in a solvent with respect to a maleic anhydride derivative. And can be obtained by a method of irradiating light having a wavelength of 250 nm or more. Moreover, the tetracarboxylic-acid diester represented by the said Formula (4A) is obtained by ring-opening the compound represented by the said Formula (3A), for example by alcohol, such as methanol, ethanol, and phenol, or phenols. Can do. Moreover, the tetracarboxylic-acid diester dihalide represented by the said Formula (4A) can be obtained by making the tetracarboxylic-acid diester obtained by the above react with halogenating agents, such as thionyl chloride. However, the synthesis method of the compound represented by the above formula (3A) and the compound represented by the above formula (4A) is not limited to the above.

[Polyimide]
The polyimide as the polymer (A) can be obtained, for example, by dehydrating and ring-closing the polyamic acid (A) synthesized as described above to imidize.

  The polyimide may be a completely imidized product obtained by dehydrating and cyclizing all of the amic acid structure possessed by the polyamic acid that is the precursor, and only a part of the amic acid structure is dehydrated and cyclized, It may be a partially imidized product in which an imide ring structure coexists. When manufacturing a liquid crystal aligning film using the said polymer composition, it is preferable to set it as 30% or more from a viewpoint of an electrical property, and it is preferable to set it as 50% or more, and 65% or more as for polyimide. More preferably. On the other hand, from the viewpoint of ensuring the solubility of the polymer and improving the coating property, the imidation ratio is preferably 65% or less, and more preferably 30% or less. 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 dehydration ring closure of the polyamic acid is preferably performed by (i) a method of heating the polyamic acid, or (ii) dissolving the polyamic acid in an organic solvent, adding a dehydrating agent and a dehydration ring closure catalyst to this solution, and if necessary It is performed by the method of heating.
The reaction temperature in the method (i) is preferably 50 to 200 ° C, more preferably 60 to 170 ° C. When the reaction temperature is less than 50 ° C., the dehydration ring-closure reaction does not proceed easily, and when the reaction temperature exceeds 200 ° C., the molecular weight of the resulting polymer may decrease. The reaction time is preferably 1.0 to 24 hours, more preferably 1.0 to 12 hours.
In the method (ii), as the dehydrating agent, for example, acid anhydrides such as acetic anhydride, propionic anhydride, and trifluoroacetic anhydride can be used. Although the usage-amount of a dehydrating agent is based on the desired imidation rate, it is preferable to set it as 0.01-20 mol with respect to 1 mol of the amic acid structure of a polyamic acid. Moreover, as a dehydration ring closure catalyst, tertiary amines, such as a pyridine, a collidine, a lutidine, a triethylamine, can be used, for example. 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.

The polymer (A) preferably has a solution viscosity of 10 to 800 mPa · s when it is made into a 10% by weight solution, and has a solution viscosity of 15 to 500 mPa · s. More preferably. In addition, the solution viscosity (mPa · s) of the above polymer is based on a polymer solution having a concentration of 10% by weight prepared using a good solvent for the polymer (eg, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.). The value measured at 25 ° C. using an E-type rotational viscometer.
The polymer (A) preferably has a polystyrene-equivalent weight average molecular weight of 500 to 500,000, more preferably 1,000 to 300,000, as measured by gel permeation chromatography (GPC). . Moreover, the molecular weight distribution (Mw / Mn) represented by the ratio between Mw and the polystyrene-equivalent number average molecular weight (Mn) measured by GPC is preferably 15 or less, more preferably 10 or less. By being in such a molecular weight range, it is possible to ensure good orientation and stability of the liquid crystal display element.

(Composition of polymer component)
The liquid crystal aligning agent of this invention may contain only 1 type in the polymer (A) as a polymer component, and may contain 2 or more types in the polymer (A). Or the polymer (B) which does not have the said partial structure (a) may be included with the polymer (A) as a polymer chosen from the group which consists of a polyamic acid, a polyamic acid ester, and a polyimide.

  When the liquid crystal aligning agent of the present invention is a blend system in which two or more kinds of polymers are blended, the liquid crystal aligning agent is a polymer selected from the group consisting of polyamic acid, polyamic acid ester and polyimide, fluorine atom and Two types of polymers having different specific atom contents (however, in the case of having both a fluorine atom and a silicon atom) different from each other may be included. Generally, when a coating film is formed by blending multiple types of polymers with different specific atom contents, the polymer with the higher specific atom content is unevenly distributed in the upper layer due to the difference in surface energy. It is known that a polymer having a lower atomic content is unevenly distributed in the lower layer. In view of such a phenomenon, it is presumed that the distribution of polymers in the liquid crystal alignment film can be biased by blending two or more kinds of polymers having different specific atom contents.

As a preferable aspect when the polymer component of the liquid crystal aligning agent is two or more kinds, for example,
[1] An embodiment in which at least two kinds of polymers are included as the polymer (A), and the contents of the specific atoms in the two kinds of polymers are different from each other.
[2] An embodiment comprising the polymer (A) and the polymer (B), wherein the content of the specific atom in the polymer (B) is lower than that of the polymer (A).
Etc. Hereinafter, of the two types of polymers having different specific atom contents, the polymer having the higher specific atom content is referred to as a polymer (F1), and the specific atom content is lower. The polymer may be referred to as a polymer (F2).

The polymer (F1) has the partial structure (a). In the polymer (F1), the content ratio of the partial structure (a) is based on the total partial structure of the polymer (F1) from the viewpoint of sufficiently causing the uneven distribution of the polymer in the liquid crystal alignment film. Thus, it is preferably 20 mol% or more, more preferably 30 mol% or more, and further preferably 40 mol% or more.
In addition, the polymer (F2) is the polymer (A) in the embodiment [1], and is the polymer (B) in the embodiment [2]. In the above aspect [1], the content ratio of the partial structure (a) of the polymer (F2) is preferably 20 mol% or less with respect to the total partial structure of the polymer (F2). It is more preferable to set it to -15 mol%, and it is further more preferable to set it as 1-10 mol%.

（式（４−１）中、Ｒ^２７は、ハロゲン原子、炭素数１〜１０のアルキル基又は炭素数１〜１０のアルコキシ基であり、ｒ１は１又は２であり、ｒ２は０〜３の整数であり、ｒ１＋ｒ２≦４を満たす。複数のＲ^２７は同じでも異なっていてもよい。「＊」は結合手を示す。式（４−２）中、Ｒ^２８は、水素原子又は炭素数１〜６のアルキル基である。「＊」は結合手を示す。） When blending polymers having different fluorine atom contents as the polymer component of the liquid crystal aligning agent, the polymer (F2) having the lower specific atom content is from the viewpoint of improving the electrical characteristics of the liquid crystal display element. , A structure represented by the following formula (4-1), a structure represented by the following formula (4-2) (excluding those contained in an amide bond formed by polymerization of monomers) and nitrogen-containing It preferably has at least one structure (Z) selected from the group consisting of heterocyclic rings.

(In the formula ^{(4-1), R 27} is a halogen atom, an alkyl group or an alkoxy group having 1 to 10 carbon atoms having 1 to 10 carbon atoms, r1 is 1 or 2, r2 is 0 to 3 It is an integer and satisfies r1 + r2 ≦ 4, a plurality of R ²⁷ may be the same or different, “*” represents a bond, R ²⁸ is a hydrogen atom or a carbon number of 1 in formula (4-2) (It is an alkyl group of ˜6. “*” Represents a bond.)

Examples of the alkyl group having 1 to 10 carbon atoms of R ²⁷ include a methyl group, an ethyl group, a propyl group, and a butyl group, and these may be linear or branched. Examples of the alkoxy group having 1 to 10 carbon atoms include groups in which an alkyl group having 1 to 10 carbon atoms and an oxygen atom are bonded. Specifically, for example, a methoxy group, an ethoxy group, a propoxy group, and the like. Groups and the like. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
r1 is preferably 1, and r2 is preferably 0 or 1.
R ²⁸ is preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and more preferably a hydrogen atom or a methyl group, from the viewpoint of a high effect of improving electrical characteristics.
Examples of the nitrogen-containing heterocycle include a piperidine ring, a pyrrolidine ring, a pyridine ring, a pyrazine ring, a piperazine ring, a pyrimidine ring, and a homopiperazine ring. Among these, a piperidine ring or a piperazine ring is preferable, and a piperidine ring is more preferable in that the effect of relaxing the accumulated residual charge is high.
The structure (Z) is preferably a structure represented by the above formula (4-2) or a nitrogen-containing heterocyclic ring because it has a high effect of improving electrical characteristics.

The polymer having the structure (Z) can be synthesized by appropriately combining organic chemistry methods. For example, a polymer having a structure represented by the above formula (4-1) can be obtained by using a carboxyl group-containing diamine during the synthesis of the polymer. In addition, a diamine having “—NR ²⁸ —” such as bis (4-aminophenyl) amine, N, N-bis (4-aminophenyl) methylamine, and a compound represented by the above formula (d-4), etc. A polymer having a structure represented by the above formula (4-2) can be obtained by polymerization included in the monomer composition. Moreover, the polymer which has said nitrogen containing heterocyclic diamine in a monomer composition can obtain the polymer which has a nitrogen containing heterocyclic ring.
In the synthesis of the polymer (F2), the proportion of the monomer containing the structure (Z) is preferably 1 to 25 mol%, and 2 to 20 mol%, based on the total amount of monomers used for the synthesis. More preferably.

  When the polymer (B) is a polyamic acid, the polymer (B) can be obtained, for example, by reacting tetracarboxylic dianhydride and diamine. Examples of the tetracarboxylic dianhydride used at this time include compounds exemplified as other tetracarboxylic dianhydrides that can be used for the synthesis of the polymer (A). Among these, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, bicyclo [3.3.0] octane-2,4,6, 8-tetracarboxylic acid 2: 4,6: 8-dianhydride, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -Naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1 , 2-c] furan-1,3-dione, cyclohexanetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, and at least one tetracarboxylic acid selected from the group consisting of pyromellitic dianhydride It is preferable to use an anhydride. In addition, in the synthesis | combination of a polymer (B), 1 type of said tetracarboxylic dianhydride can be used individually or in combination of 2 or more types.

  Examples of the diamine used for the synthesis of the polymer (B) include the compounds exemplified as the diamine that can be used for the synthesis of the polymer (A). The description of the polymer (A) can be applied to various reaction conditions when synthesizing the polyamic acid as the polymer (B). Further, the polyamic acid ester and polyimide as the polymer (B) can also be obtained according to the method described in the polymer (A). In addition, the polymer (B) contained in a liquid crystal aligning agent can be used individually by 1 type or in combination of 2 or more types.

The explanation of the polymer (A) can be applied to the preferable numerical ranges of the solution viscosity, the weight average molecular weight and the number average molecular weight of the polymer (B).
When the blending mode of the polymer is [1], the blending ratio of the two types of polymers (A) having different specific atom contents improves the sensitivity to light, electrical characteristics, afterimage characteristics, and contrast characteristics in a well-balanced manner. From this viewpoint, the weight ratio (F1 / F2) is preferably 2/8 to 8/2, and more preferably 3/7 to 7/3. In the case of the above-mentioned [2], for the same reason, the content ratio of the polymer (A) and the polymer (B) in the liquid crystal aligning agent is 2/8 to 2 by weight ratio (A / B). It is preferably 8/2, and more preferably 3/7 to 7/3.

<Other ingredients>
The liquid crystal aligning agent of this invention may contain the other component further as needed. As other components that may be blended in the liquid crystal aligning agent, for example, other polymers other than the polymer (A) and the polymer (B), a compound having at least one epoxy group in the molecule (hereinafter, "Epoxy group-containing compound"), functional silane compounds and the like.

[Other polymers]
The above other polymers can be used for improving solution properties and electrical properties. Examples of such other polymers include polyorganosiloxane, polyester, polyamide, cellulose derivative, polyacetal, polystyrene derivative, poly (styrene-phenylmaleimide) derivative, and poly (meth) acrylate.
When other polymers are added to the liquid crystal aligning agent, the blending ratio is preferably 20 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. More preferably.

[Epoxy group-containing compound]
The epoxy group-containing compound can be used to improve the adhesion and electrical properties with the substrate surface in the liquid crystal alignment film. Examples of such epoxy group-containing compounds include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1 , 6-hexanediol diglycidyl ether, glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, N, N, N ′, N′-tetraglycidyl-m-xylylene diene Amine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ′, N′-tetraglycidyl-4,4′-diamy Diphenylmethane, N, N-diglycidyl - benzylamine, N, N-diglycidyl - aminomethyl cyclohexane, N, N-diglycidyl - may be mentioned as being preferred and cyclohexylamine. In addition, as an example of the epoxy group-containing compound, an epoxy group-containing polyorganosiloxane described in International Publication No. 2009/096598 can be used.
When mix | blending these epoxy compounds with a liquid crystal aligning agent, it is preferable that the mixture ratio shall be 40 weight part or less with respect to a total of 100 weight part of the polymer contained in a liquid crystal aligning agent, 0.1-30 More preferred are parts by weight.

[Functional silane compounds]
The functional silane compound can be used for the purpose of improving the printability of the liquid crystal aligning agent. Examples of such functional silane compounds include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-aminoethyl). ) -3-Aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3- Aminopropyltrimethoxysilane, N-triethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-trimethoxysilyl -3,6- Methyl azananoate, N-benzyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, glycidoxymethyltrimethoxysilane, 2-glycidoxyethyltrimethoxysilane, 3-glycid And xylpropyltrimethoxysilane.
When these functional silane compounds are blended in the liquid crystal aligning agent, the blending ratio is preferably 2 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 to -0.2 weight part.

  In addition to the above, examples of other components include compounds having at least one oxetanyl group in the molecule, antioxidants, surfactants, and photosensitizers.

<Solvent>
The liquid crystal aligning agent of the present invention is prepared as a liquid composition in which a polymer component 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 individually or in mixture of 2 or more types.

  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. 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 range of the solid content concentration varies depending on the method used when the liquid crystal aligning agent is applied to the substrate. For example, when applied to a substrate by the 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 1.5 to 4.5% by weight. It is particularly preferable that the range is 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.

<Liquid crystal alignment film and liquid crystal display element>
The liquid crystal aligning film of this invention can be manufactured by the method including the process of apply | coating the liquid crystal aligning agent demonstrated above on a board | substrate, and forming a coating film. Moreover, 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 of the present invention is not particularly limited, and various modes such as TN type, STN type, VA type (including VA-MVA type and VA-PVA type), IPS type, FFS type, OCB type, and the like. Applicable to operation mode.

  The liquid crystal display element of this invention can be manufactured by the process including the following processes (1)-(3), for example. In step (1), the substrate to be used varies depending on the desired operation mode. Step (2) and step (3) are common to each operation mode.

[Step (1): Formation of coating film]
First, the liquid crystal aligning agent is applied on a substrate, and then the coated surface is preferably heated to form a coating film on the substrate.
(1-1) For example, when manufacturing a TN type, STN type, or VA type liquid crystal display element, first, a pair of two substrates on which a patterned transparent conductive film is provided, and each transparent conductive film is formed. On the surface, a liquid crystal aligning agent is preferably applied by an offset printing method, a spin coating method, a roll coater method or an ink jet printing method, respectively. 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 the transparent conductive film provided on one surface of the substrate, a 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. When 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, 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.

  (1-2) In the case of 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 respectively applied to one surface of the counter substrate that is not formed, and then each coated surface is preferably heated 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 (1-1). As the metal film, for example, a film made of a metal such as chromium can be used.

  In both cases (1-1) and (1-2), after applying a liquid crystal aligning agent on the substrate, the organic solvent is removed to form a liquid crystal alignment film or a liquid crystal alignment film. The At this time, by further heating after the coating film is formed, the dehydration ring-closing reaction of the polyamic acid, polyamic acid ester and polyimide compounded in the liquid crystal aligning agent is advanced to obtain a more imidized coating film.

[Step (2): Orientation treatment]
When manufacturing a TN type, STN type, IPS type, or FFS type liquid crystal display element, the process (orientation process) which provides liquid crystal aligning ability to the coating film formed at the said process (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 alignment treatment include rubbing treatment in which the coating film is rubbed in a certain direction with a roll wound with a cloth made of fibers such as nylon, rayon, and cotton, and photo-alignment treatment for irradiating the coating film with light. Among these, taking into account that the polymer (A) has high photodegradability and exhibits good liquid crystal orientation by light irradiation, it is preferable to use photo-alignment treatment. On the other hand, when manufacturing a vertical alignment type liquid crystal display element, the coating film formed in the above step (1) can be used as it is as a liquid crystal alignment film, but the coating film may be subjected to an alignment treatment. .

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.
The light applied to the coating film can be polarized or non-polarized radiation. As the radiation, for example, ultraviolet rays and visible rays including light having a wavelength of 150 to 800 nm can be used. 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 amount of light irradiation 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.

  Note that the liquid crystal alignment film after the rubbing treatment is further subjected to a treatment for changing the pretilt angle of a part of the liquid crystal alignment film by irradiating a part of the liquid crystal alignment film, 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 (3): Construction of liquid crystal cell]
Two substrates on which the liquid crystal alignment film is formed as described above are prepared, and a liquid crystal cell is manufactured by disposing a liquid crystal between the two substrates disposed to face each other. In order to manufacture a liquid crystal cell, the following two methods are mentioned, for example. The first method is a conventionally known method. First, two substrates are arranged to face 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 sealing material. A liquid crystal cell is manufactured by injecting and filling the liquid crystal into the cell gap partitioned by the step of sealing the injection hole. The second method is a method called an ODF (One Drop Fill) method. In this method, for example, an ultraviolet light curable sealing material is applied to a predetermined place on one of the two substrates on which the liquid crystal alignment film is formed, and a predetermined number of places on the liquid crystal alignment film surface are applied. After the liquid crystal is dropped on the liquid crystal, 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 sealing material. Manufacture the cell. Regardless of which method is used, the liquid crystal cell produced as described above is further heated to a temperature at which the liquid crystal used takes an isotropic phase and then gradually cooled to room temperature. It is desirable to remove.

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

  And the liquid crystal display element of this invention can be obtained by bonding 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.

  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, cellular phones, smartphones, various types. It can be suitably applied as a liquid crystal display element used in a display device such as a monitor, a liquid crystal television, or an information display.

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

The weight average molecular weight of each polymer and the solution viscosity of each polymer solution in the synthesis examples were measured by the following methods.
[Weight average molecular weight of polymer]
The weight average molecular weight Mw of the polymer is a polystyrene equivalent value measured by gel permeation chromatography under the following conditions.
Column: Tosoh Co., Ltd., TSKgelGRCXLII
Solvent: Tetrahydrofuran Temperature: 40 ° C
Pressure: 68 kgf / cm ²
[Solution viscosity of polymer solution]
The solution viscosity [mPa · s] of the polymer solution was measured at 25 ° C. using an E-type rotational viscometer for a solution prepared with N-methyl-2-pyrrolidone (NMP) to a polymer concentration of 10% by weight. did.

≪Synthesis of polymer≫
Polymers were synthesized using the following compounds in each example. Hereinafter, the compound represented by Formula X may be simply referred to as “Compound X”.

<Specific tetracarboxylic dianhydride>

<Other tetracarboxylic dianhydrides>

<Diamine>

<Synthesis of polymer (A)>
[Example 1: Synthesis of polymer (A-1)]
100 mol parts of compound (a-1) as tetracarboxylic dianhydride and 100 mol parts of compound (b-1) as diamine were dissolved in NMP and reacted at room temperature for 8 hours. As a result, a polyamic acid solution having a solid content concentration of 15% by weight was obtained. The obtained polyamic acid was used as the polymer (A-1). The weight average molecular weight Mw of the polymer (A-1) was 80,000.

[Examples 2 to 9: Synthesis of polymers (A-2) to (A-9)]
Except having changed the kind and quantity of the tetracarboxylic dianhydride and diamine to be used as shown in Table 1 below, the same operation as in Example 1 was performed to obtain a polyamic acid solution having a solid content concentration of 15% by weight. Table 1 below shows the weight average molecular weight Mw of each polymer.

  In Table 1, the numerical value in parentheses in each column of the compound indicates a blending ratio (mole part) with respect to a total of 100 parts by mole of the tetracarboxylic dianhydride used. “-” Means that the compound was not used (the same applies to the following table).

<Synthesis of polymer (B)>
[Synthesis Examples 1 and 2: Synthesis of Polymers (B-1) to (B-7)]
Except having changed the kind and quantity of the tetracarboxylic dianhydride and diamine to be used as shown in Table 2 below, the same operation as in Example 1 was performed to obtain a polyamic acid solution having a solid content concentration of 15%. The weight average molecular weight Mw of each polymer is shown in Table 2 below.

≪Preparation of liquid crystal aligning agent and production and evaluation of liquid crystal display element≫
[Example 10]
1. Preparation of liquid crystal aligning agent As a polymer component, NMP and butyl cellosolve (BC) are added to the solution containing the polymer (A-1) obtained in Example 1 above, and the mixture is sufficiently stirred, and the solvent composition is NMP: BC. = 70:30 (weight ratio), and a solid content concentration of 3.0% by weight. A liquid crystal aligning agent was prepared by filtering this solution using a filter having a pore diameter of 0.45 μm.

2. Manufacture of liquid crystal display element aligned by light irradiation treatment It has two metal electrodes (electrode A and electrode B) made of chromium patterned in a comb shape, and voltage is applied independently to these electrodes A and B A glass substrate that can be applied was prepared. A pair of this glass substrate and a counter glass substrate on which no electrode is provided, and the liquid crystal aligning agent prepared above on each of the surface having the electrode of the glass substrate and one surface of the counter glass substrate, respectively, using a spin coater Applied. Next, prebaking was performed for 1 minute on a hot plate at 80 ° C., and heating (post baking) was performed at 250 ° C. for 1 hour in an oven in which the inside of the chamber was replaced with nitrogen. Thereafter, the substrate surface on the side coated with the liquid crystal aligning agent was irradiated with polarized ultraviolet rays of 1,000 J / m ² from the direction perpendicular to the substrate surface using a Hg—Xe lamp and a Grand Taylor prism. This obtained a pair of board | substrate which has a liquid crystal aligning film with a film thickness of 0.1 micrometer.
Next, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 3.5 μm is applied to the outer periphery of the surface having one liquid crystal alignment film of the pair of substrates by screen printing, and then the liquid crystal alignment film surfaces of the pair of substrates Were placed so that the directions of the respective substrates would be reversed when irradiated with polarized ultraviolet rays, and then pressure-bonded, and the adhesive was thermally cured at 150 ° C. for 1 hour. Next, liquid crystal “MLC-7028” manufactured by Merck was filled in the gap between the substrates from the liquid crystal injection port, and then the liquid crystal injection port was sealed with an epoxy adhesive. Furthermore, in order to remove the flow alignment at the time of liquid crystal injection, this was heated at 150 ° C. and then gradually cooled to room temperature. Next, a polarizing plate is bonded to both outer surfaces of the substrate so that the polarization directions thereof are orthogonal to each other, and the liquid crystal alignment film is bonded so that the optical axis of polarized ultraviolet light is orthogonal to the projection direction onto the substrate surface. Manufactured. In addition, by performing the above series of operations by changing the ultraviolet irradiation amount after post-baking within the range of 1,000 to 5,000 J / m ² , three or more liquid crystal displays having different ultraviolet irradiation amounts. A device was manufactured.

3. Evaluation of liquid crystal display element The following (1)-(5) was evaluated using the liquid crystal display element manufactured above. In (2) to (4), based on the sensitivity evaluation result in (1), an optimal sensitivity is selected from three or more liquid crystal display elements having different ultraviolet irradiation amounts, and the liquid crystal display having the optimal sensitivity is selected. The evaluation results of the device are shown.

(1) Evaluation of sensitivity to ultraviolet rays Using the liquid crystal display element produced as described above, the presence or absence of abnormal domains in the change in brightness when a voltage of 5 V was applied / released was observed with an optical microscope. It can be said that the sensitivity of the coating film to ultraviolet rays is better as the amount of ultraviolet irradiation when the liquid crystal orientation is observed (when no abnormal domain is observed) is smaller. In the evaluation, when no abnormal domain was observed at any UV irradiation dose, the sensitivity was “excellent (◎)”. Although an abnormal domain was observed at an ultraviolet irradiation dose of 1,000 J / m ² , it was 2,000 J / m. If abnormal domain was not observed in ² and ultraviolet irradiation amount of 3,000 J / ^{m 2} the sensitivity "good (○)", the abnormal domain in the ultraviolet irradiation amount of 1,000 J / ^{m 2} and 2,000 J / ^{m 2} However, the sensitivity was “good (Δ)” when no abnormal domain was observed at the ultraviolet irradiation doses of 3,000 J / m ² and 5,000 J / m ^2. When observed, the sensitivity was “bad (×)”. As a result, the sensitivity of the liquid crystal display element to ultraviolet rays was determined to be “excellent”.

(2) Evaluation of voltage holding ratio Using the liquid crystal display device manufactured as described above, a voltage of 5 V was applied at 60 ° C. with an application time of 60 microseconds and a span of 167 milliseconds, and 167 milliseconds after the application release. The voltage holding ratio was measured. The measuring device used was “VHR-1” manufactured by Toyo Corporation. The voltage holding ratio of this liquid crystal display element was 99%.
(3) Measurement of Charge Accumulation (RDC) Using the liquid crystal display device manufactured above, a DC voltage of 2 V was applied at 71 ° C. for 10 minutes, then shorted for 0.2 seconds, and then opened for 10 minutes. The voltage accumulated in the liquid crystal display element when kept was measured by a dielectric absorption method. The evaluation is “good (）)” when the charge accumulation amount is 0.1 V or less, and “good (◯)” when the charge accumulation amount is greater than 0.1 V and 0.2 V or less. The case where the charge accumulation amount was larger than 0.2 V was defined as “defective (×)”. As a result, the evaluation of the charge accumulation amount of this liquid crystal display element was “OK”.

(4) Evaluation of AC afterimage characteristics Using the liquid crystal display device produced above, AC afterimage characteristics (burn-in characteristics) were evaluated. First, the liquid crystal display element was placed in an environment of 25 ° C. and 1 atmosphere, and an AC voltage of 4 V was applied to the electrode A for 2 hours without applying a voltage to the electrode B. Immediately thereafter, an AC voltage of 4 V was applied to both electrode A and electrode B. The time from when the voltage of 4V AC was started to be applied to both electrodes until the difference in light transmittance between the electrodes A and B could not be visually confirmed was measured. When this time is less than 60 seconds, the image sticking property is “good (◯)”, when it is 60 seconds or more and less than 100 seconds, the image sticking property is “good (Δ)”, and when it is 100 seconds or more, the image sticking property is “Bad (×)”. As a result, this liquid crystal display element had “good” image sticking characteristics.

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

[Examples 11 and 12 and Comparative Examples 1 and 2]
A liquid crystal aligning agent was prepared in the same manner as in Example 10 except that the type of polymer used was changed as shown in Table 3 below, and a liquid crystal display device was produced. Further, various evaluations of the manufactured liquid crystal display element were performed in the same manner as in Example 10. The evaluation results are shown in Table 3 below.

[Example 13]
1. Preparation of liquid crystal aligning agent As a polymer component, NMP and butyl cellosolve (BC) are added to the solution containing the polymer (A-8) obtained in Example 8, and the mixture is sufficiently stirred, and the solvent composition is NMP: BC = A solution having a solid content concentration of 3.0% by weight was prepared at 70:30 (weight ratio). A liquid crystal aligning agent was prepared by filtering this solution using a filter having a pore diameter of 0.45 μm.

2. Manufacture of liquid crystal display element subjected to alignment treatment by rubbing treatment A pair of glass substrates provided with electrodes A and B is prepared in the same manner as in Example 10, and prepared on the surface having the electrodes of the glass substrate and one surface of the counter glass substrate as described above. Each of the liquid crystal aligning agents was applied using a spin coater. Next, after pre-baking for 1 minute on a hot plate at 80 ° C., it was post-baked for 10 minutes on a hot plate at 250 ° C. to form a coating film having a thickness of about 0.1 μm. Using a rubbing machine having a roll around which a nylon cloth is wound on the formed coating surface, the roll rotation speed is 1,000 rpm, the stage moving speed is 25 mm / second, and the length of pushing the hair foot is 0.4 mm. A rubbing treatment was performed to give liquid crystal alignment ability. Further, this substrate was ultrasonically cleaned in ultrapure water for 1 minute and dried in a 100 ° C. clean oven for 10 minutes to obtain a pair of substrates having a liquid crystal alignment film.
Next, after applying an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 3.5 μm to the outer periphery of the surface having one liquid crystal alignment film of the pair of substrates, the liquid crystal alignment film surfaces of the pair of substrates are formed. It was made to oppose and it overlap | superposed and pressure-bonded so that the rubbing direction in each liquid crystal aligning film might become antiparallel, and the adhesive was thermoset at 150 degreeC over 1 hour. Next, liquid crystal “MLC-7028” manufactured by Merck was filled in the gap between the substrates from the liquid crystal injection port, and then the liquid crystal injection port was sealed with an epoxy adhesive. Furthermore, in order to remove the flow alignment at the time of liquid crystal injection, this was heated at 150 ° C. and then gradually cooled to room temperature. Next, a liquid crystal display element was manufactured by sticking polarizing plates on both outer surfaces of the substrate so that the polarization directions thereof were orthogonal to each other and in the rubbing direction of the liquid crystal alignment film.

  About the various evaluation of the liquid crystal display element manufactured by this Example, (2)-(5) of the evaluation items of Example 10 were implemented. The respective evaluation results are shown in Table 4 below.

[Comparative Example 3]
A liquid crystal aligning agent was prepared in the same manner as in Example 13 except that the type of polymer used was changed as shown in Table 4 above, and a liquid crystal display device was produced. In addition, various evaluations of the manufactured liquid crystal display element were performed in the same manner as in Example 13. The evaluation results are shown in Table 4 above.

[Example 14]
1. Preparation of liquid crystal aligning agent As polymer components, 50 parts by weight of polymer (A-2) obtained in Example 1 and 50 parts by weight of polymer (B-1) obtained in Synthesis Example 1 were used. NMP and butyl cellosolve (BC) were added to the contained solution and stirred sufficiently to obtain a solution having a solvent composition of NMP: BC = 70: 30 (weight ratio) and a solid content concentration of 3.0% by weight. A liquid crystal aligning agent was prepared by filtering this solution using a filter having a pore diameter of 0.45 μm.

2. Production and Evaluation of Liquid Crystal Display Element A liquid crystal display element was produced by performing an alignment treatment by light irradiation treatment in the same manner as in Example 10 except that the liquid crystal aligning agent prepared above was used. Further, various evaluations of the manufactured liquid crystal display element were carried out in the same manner as in Example 10. The evaluation results are shown in Table 5 below.

  In Table 5, the numerical value in the column of the blending amount of the polymer indicates the blending ratio (parts by weight) of each polymer with respect to the total 100 parts by weight of the polymer used for preparing the liquid crystal aligning agent (also for the following Table 6). the same).

[Examples 15 to 17 and Comparative Examples 4 and 5]
A liquid crystal aligning agent was prepared in the same manner as in Example 14 except that the type of polymer used was changed as shown in Table 5 above, and a liquid crystal display device was produced. Further, various evaluations of the manufactured liquid crystal display element were performed in the same manner as in Example 10. The evaluation results are shown in Table 5 above.

[Example 18]
1. Preparation of Liquid Crystal Alignment Agent As polymer components, 50 parts by weight of the polymer (A-8) obtained in Example 8 and 50 parts by weight of the polymer (B-1) obtained in Synthesis Example 1 were used. NMP and butyl cellosolve (BC) were added to the contained solution and stirred sufficiently to obtain a solution having a solvent composition of NMP: BC = 70: 30 (weight ratio) and a solid content concentration of 3.0% by weight. A liquid crystal aligning agent was prepared by filtering this solution using a filter having a pore diameter of 0.45 μm.

2. Production and Evaluation of Liquid Crystal Display Element A liquid crystal display element was produced by performing an alignment treatment by rubbing treatment in the same manner as in Example 13 except that the liquid crystal aligning agent prepared above was used. Further, various evaluations of the manufactured liquid crystal display element were performed in the same manner as in Example 13. The evaluation results are shown in Table 6 below.
[Comparative Example 6]
A liquid crystal aligning agent was prepared in the same manner as in Example 18 except that the type and amount of the polymer used were changed as shown in Table 6 below, and a liquid crystal display device was produced. In addition, various evaluations of the manufactured liquid crystal display element were performed in the same manner as in Example 13. The evaluation results are shown in Table 6 below.

In the liquid crystal alignment film containing only one kind of polymer component, the voltage holding ratio was 99% or more regardless of the alignment treatment method (Examples 10 to 13). Further, the charge accumulation amount, the AC afterimage characteristic, and the contrast characteristic were evaluated as “good”, and the sensitivity to ultraviolet rays was evaluated as “excellent”, and various characteristics were balanced.
Moreover, also in the liquid crystal aligning film containing 2 types of polymers as a polymer component, the voltage holding rate was 99% or more irrespective of the alignment processing method (Examples 14-18). In addition, the charge accumulation amount was as small as 0.1 V or less, and the AC afterimage characteristics and contrast characteristics were evaluated as “good”, and the sensitivity to ultraviolet rays was evaluated as “excellent or good”.
On the other hand, in Comparative Examples 1 to 3 in which only one polymer component was used, the voltage holding ratio was as low as 96% or less. Of the systems containing two types of polymers as polymer components, Comparative Example 4 had a voltage holding ratio of 93%, and Comparative Examples 5 and 6 had a low 97%. In the comparative example, AC afterimage characteristics, contrast characteristics, and sensitivity to ultraviolet rays were low.

Claims (13)

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

(In Formula (1) and Formula (2), R ¹ is a tetravalent group having an alicyclic structure, R ² is a divalent organic group, and R ²⁵ and R ²⁶ are each independently hydrogen. is an atom or a monovalent organic group. However, at least one selected at least one of R ^1, R ²⁵ and R ^26, fluoroalkyl group, a fluorinated alkoxy group and fluorinated alkyl ester group by Li Cheng group Having a specific atom-containing group.) R ¹ is a tetravalent group having an alicyclic structure to which a specific fluorine-containing group that is at least one selected from the group consisting of a fluorinated alkyl group, a fluorinated alkoxy group, and a fluorinated alkyl ester group is bonded. The liquid crystal aligning agent of Claim 1. 3. The liquid crystal aligning agent according to claim 2, wherein R ¹ is a kind selected from the group consisting of groups represented by the following formulas (3-1) to (3-3).

(In the formula (3-1) to formula ^{(3- 3), R 3 ~R} 17 are each independently a hydrogen atom or a monovalent organic group. ^However, at least one of R 3 to R ⁶ are the is a specific fluorine-containing ^group, at least one of R 7 ^{to R 11} is the specific fluorine-containing ^group, at least one of R 12 ^{to R 17} is the specific fluorine-containing group. "*" and the bond Show.) Wherein R ¹ is a group represented by the formula (3-1), the liquid crystal aligning agent of claim 3. Including at least two polymers as polymer components;
The two types of polymers are at least one polymer selected from the group consisting of the polymer (A) and a polyamic acid, a polyamic acid ester and a polyimide, and a heavy polymer having no partial structure (a). The liquid crystal aligning agent as described in any one of Claims 1-4 containing a unification | combination (B).   The liquid crystal aligning agent of Claim 5 whose content ratio of the said polymer (A) and the said polymer (B) is 2/8-8/2 by weight ratio (A / B).   The polymer (B) includes 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, bicyclo [3.3.0] octane-2, 4,6,8-tetracarboxylic acid 2: 4,6: 8-dianhydride, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo- 3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -At least one selected from the group consisting of naphtho [1,2-c] furan-1,3-dione, cyclohexanetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, and pyromellitic dianhydride Mono compounds It is a polymer obtained by polymerization comprising the chromatography composition, the liquid crystal alignment agent according to claim 5 or 6. Including at least two polymers as polymer components;
As the two kinds of polymers, two kinds of the above-mentioned polymers having different contents of specific atoms which are at least either fluorine atoms or silicon atoms (however, in the case of having both fluorine atoms and silicon atoms, the total amount thereof) The liquid crystal aligning agent as described in any one of Claims 1-4 containing (A). As the two kinds of polymers, containing polymers having different contents of specific atoms that are at least one of fluorine atoms and silicon atoms (however, in the case of having both fluorine atoms and silicon atoms, the total amount thereof),
Among the two kinds of polymers, the polymer having the lower content of the specific atom is a structure represented by the following formula (4-1) or a structure represented by the following formula (4-2) (however, And at least one structure (Z) selected from the group consisting of nitrogen-containing heterocycles, excluding those contained in amide bonds formed by polymerization of monomers). Liquid crystal aligning agent as described in.

(In the formula ^{(4-1), R 27} is a halogen atom, an alkyl group or an alkoxy group having 1 to 10 carbon atoms having 1 to 10 carbon atoms, r1 is 1 or 2, r2 is 0 to 3 It is an integer and satisfies r1 + r2 ≦ 4.When r2 is 2 or 3, a plurality of R ²⁷ may be the same or different, “*” represents a bond, and R ^{28 in} formula (4-2) Is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. “*” Represents a bond.)   The polymer which has the said structure (Z) WHEREIN: The usage-ratio of the monomer which has the said structure (Z) used for the synthesis | combination of this polymer is 1-25 mol% with respect to all the monomers. Liquid crystal aligning agent. A liquid crystal aligning agent comprising a polymer (A) having at least one partial structure (a) selected from the group consisting of a partial structure represented by the following formula (1) and a partial structure represented by the following formula (2) A liquid crystal comprising: a step of applying a coating on a substrate to form a coating film; and a step of irradiating the coating film formed on the substrate with light to impart liquid crystal alignment ability to the coating film. A method for producing an alignment film.

(In Formula (1) and Formula (2), R ¹ is a tetravalent group having an alicyclic structure, R ² is a divalent organic group, and R ²⁵ and R ²⁶ are each independently hydrogen. is an atom or a monovalent organic group. However, at least one selected at least one of R ^1, R ²⁵ and R ^26, fluoroalkyl group, a fluorinated alkoxy group and fluorinated alkyl ester group by Li Cheng group Having a specific atom-containing group.)   The liquid crystal aligning film formed using the liquid crystal aligning agent as described in any one of Claims 1-10.   A liquid crystal display device comprising the liquid crystal alignment film according to claim 12.