JP6701635B2 - Liquid crystal aligning agent, liquid crystal aligning film and liquid crystal display device - Google Patents

Description

The present invention relates to a liquid crystal aligning agent, relates to a liquid crystal alignment film and a liquid crystal display element.

  Conventionally, as a liquid crystal display element, various driving methods having different electrode structures, physical properties of liquid crystal molecules to be used, manufacturing processes, etc. have been developed. For example, TN (Twisted Nematic) type and STN (Super Twisted Nematic) type , VA (Vertical Alignment) type, IPS type (In-Plane Switching) type, FFS (fringe field switching) type and the like are known. These liquid crystal display elements have a liquid crystal alignment film for aligning liquid crystal molecules. As a material of the liquid crystal alignment film, polyamic acid or polyimide is generally used because it has various properties such as heat resistance, mechanical strength, and affinity with liquid crystal.

  In recent years, various liquid crystal aligning agents have been proposed in order to further improve the display performance of liquid crystal display elements. For example, it has been proposed to form a liquid crystal alignment film by using a liquid crystal alignment agent containing a polyimide having a nitrogen atom in addition to an imide group or a precursor thereof for the purpose of reducing an afterimage (for example, see Patent Document 1). .

  In Patent Document 1, a tetracarboxylic dianhydride containing 1,2,3,4-cyclobutanetetracarboxylic dianhydride is reacted with a diamine containing a diamine having an amide bond (—NH—CO—). The resulting polyamic acid, and an imidized polymer of a polyamic acid obtained by reacting a tetracarboxylic dianhydride and a diamine, and containing a liquid crystal aligning agent, and imidized polymer in the liquid crystal aligning agent It has been proposed that the ratio of the number of imide rings possessed by is within a specific range. In Patent Document 1, by using such a liquid crystal aligning agent, voltage holding performance and afterimage characteristics are improved.

JP, 2009-294274, A

  However, since the amide bond has a high polarity and the solubility of the liquid crystal aligning agent in the solvent component is not so good, the storage stability of the liquid crystal aligning agent and the coating property (printability) on the substrate tend to be poor. There is room for improvement.

  An object of the present invention is to provide a liquid crystal aligning agent which has a good solubility of the components contained in the liquid crystal aligning agent and which can provide a liquid crystal display device exhibiting good afterimage characteristics.

  The present inventors have conducted extensive studies to achieve the above-mentioned problems of the prior art, and found that the above problems can be solved by protecting the amide bond with a protecting group. Specifically, the following liquid crystal aligning agent, liquid crystal aligning film, liquid crystal display device, polymer and compound are provided.

  One aspect of the present invention provides a liquid crystal aligning agent containing a compound (P) having a partial structure represented by the following formula (1).

(In the formula (1), Y ¹ is a protecting group. “*” represents a bond.)

In another aspect, a liquid crystal alignment film formed using the above liquid crystal alignment agent is provided. Further, a liquid crystal display device including the liquid crystal alignment film is provided.
Further, in another one aspect, there is provided a polymer having polyamic acid, polyamic acid ester, polyimide or polyamide as a main skeleton and having a partial structure represented by the above formula (1). Further, a diamine having a partial structure represented by the above formula (1) and a tetracarboxylic acid dianhydride having a partial structure represented by the above formula (1) are provided.

  By protecting the amide bond in the compound having an amide bond (-NH-CO-) with a protective group and including it in the liquid crystal aligning agent, the solubility in a solvent can be improved. This makes it possible to obtain a liquid crystal aligning agent having excellent storage stability and printability. In addition, the protective group introduced into the amide bond is eliminated by, for example, heating during film formation, acid or base conditions, or light irradiation, whereby a structure with high liquid crystal alignment is reproduced after film formation. As a result, it is possible to obtain a liquid crystal display element having good afterimage characteristics.

It is explanatory drawing which shows the pattern of the transparent conductive film in the liquid crystal cell which has the patterned transparent conductive film manufactured in the Example and the comparative example.

Hereinafter, each component contained in the liquid crystal aligning agent according to the present invention and other components optionally blended as necessary will be described.
<Compound (P)>
The liquid crystal aligning agent according to the present invention contains a compound (P) having a partial structure represented by the following formula (1).
(In the formula (1), Y ¹ is a protecting group. “*” represents a bond.)

Y ¹ in the above formula (1) is not particularly limited as long as it is a protective group that protects an amide group, an imide group, an ureido group, a carbamate group, and is eliminated by at least one of heat, light, acid and base. Examples thereof include monovalent organic groups. Y ¹ is preferably a monovalent organic group which is at least released by heat, and specific examples thereof include a carbamate-based protecting group, an amide-based protecting group, an imide-based protecting group, and a sulfonamide-based protecting group. Be done. Of these, a carbamate-based protecting group is preferable, and specific examples thereof include t-butoxycarbonyl group, benzyloxycarbonyl group, 1,1-dimethyl-2-haloethyloxycarbonyl group, 1,1- Examples thereof include a dimethyl-2-cyanoethyloxycarbonyl group, a 9-fluorenylmethyloxycarbonyl group, an allyloxycarbonyl group, and a 2-(trimethylsilyl)ethoxycarbonyl group. Further specific examples of Y ^1, and the like groups represented by each of the following formulas (7-1) to (7-4).
(In the formula (7-1) to Formula (7- 4), Ar ¹ is a monovalent aromatic ring group having 6 to 10 carbon ^{atoms, R 14} is an alkyl group having 1 to 12 carbon atoms. "* "Indicates a bond that bonds to the nitrogen atom.)

Ar ^{1 in the} above formula (7-2) is a group obtained by removing one hydrogen atom from an aromatic ring having 6 to 10 carbon atoms, and specific examples thereof include a phenyl group and a naphthyl group. Examples of the alkyl group having 1 to 12 carbon atoms of R ^{14 in} the formula (7-4) include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, and the like, which may be linear. It may be branched . Na us, a group represented by each of the above formulas (7-1) to (7-4) can be deprotected by light well heat.
Among them, Y ¹ is preferably a carbamate-based protecting group because it has a high releasability by heat, and a compound derived from Y ¹ released by heating during film formation can be discharged as a gas out of the film. , T-butoxycarbonyl group is more preferred.
The atom to which the bond “*” in the above formula (1) is bonded is preferably a carbon atom.
The compound (P) may form at least a part of the polymer component of the liquid crystal aligning agent, or may be contained in the form of an additive separately from the polymer component serving as the base material.

[Polymer (P)]
When the compound (P) is a polymer having a partial structure represented by the above formula (1) (hereinafter, also referred to as “polymer (P)”), its main skeleton is not particularly limited, and examples thereof include polyamic acid. , Polyimide, polyamic acid ester, polysiloxane, polyester, polyamide, cellulose derivative, polyacetal, polystyrene derivative, poly(styrene-phenylmaleimide) derivative, poly(meth)acrylate, a polymer having an azobenzene derivative as a main skeleton, and the like. Be done. The polymer (P) is a polymer having a partial structure represented by the above formula (1) in the main chain from the viewpoint of improving the solubility of the polymer and the afterimage property of the obtained liquid crystal display device. Preferably.
Among them, the polymer (P) is at least one polymer selected from the group consisting of polyamic acid, polyamic acid ester, polyimide and polyamide from the viewpoint of heat resistance, mechanical strength, affinity with liquid crystal, and the like ( Hereinafter, it is also referred to as “specific polymer”), and the specific polymer is more preferably a polymer having a partial structure represented by the above formula (1) in the main chain. In addition, (meth)acrylate means containing an acrylate and a methacrylate.

(Polyamic acid)
When the polymer (P) is a polyamic acid, the polyamic acid can be obtained by reacting a tetracarboxylic dianhydride and a diamine. Specifically, [i] a method of synthesizing by tetrapolymeric dianhydride having a partial structure represented by the above formula (1) by polymerization containing a monomer composition, [ii] represented by the above formula (1) Method for synthesizing by polymerization containing diamine having partial structure in monomer composition, [iii] tetracarboxylic dianhydride having partial structure represented by the above formula (1), and partial structure represented by the above formula (1) And a method of synthesizing a diamine having a diamine having a monomer composition by polymerization. In the following, a tetracarboxylic dianhydride having a partial structure represented by the above formula (1) will be referred to as a “specific tetracarboxylic dianhydride”, and a diamine having a partial structure represented by the above formula (1) will be described. Also referred to as "specific diamine".

(Tetracarboxylic acid dianhydride)
The specific tetracarboxylic acid dianhydride used for the synthesis of the polyamic acid is not particularly limited as to the other structure as long as it has a partial structure represented by the above formula (1). The specific tetracarboxylic dianhydride preferably has a partial structure represented by the above formula (1) in the main chain when the main chain is a structural part connecting two acid anhydride groups. Specific examples thereof include compounds represented by the following formula (2).
(In the formula (2), R ¹ , R ² and R ⁴ are each independently a divalent organic group. R ³ is a single bond or a divalent organic group. Y ¹ is a protective group. Z ¹ and Z ² are each independently a trivalent organic group, m is an integer of 1 to 3, and k is 0 or 1.)

Examples of the divalent organic group represented by R ^{1 to} R ^{4 in} the above formula (2) include a divalent hydrocarbon group having 1 to 20 carbon atoms; a methylene group of the hydrocarbon group is —O—, —S—, — ^{CO -, - COO -, -} COS -, - NR a -, - CO-NR a -, - NR a -CO-NR a -, - Si (R a) 2 - ( provided that, ^{R a} is the number of carbon atoms 1 to 12 is a monovalent hydrocarbon group or a protecting group), - N = N -, - SO 2 - a divalent made by replacing the like groups;. a hydrogen atom bonded to a carbon atom of a hydrocarbon radical A divalent group in which at least one is substituted with a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom, etc.), a hydroxyl group, a cyano group, etc.; a divalent group having a heterocycle and the like can be mentioned.

  Here, in the present specification, the “hydrocarbon group” is meant to include a chain hydrocarbon group, an alicyclic hydrocarbon group and an aromatic hydrocarbon group. Among these, the "chain hydrocarbon group" means a straight chain hydrocarbon group and a branched hydrocarbon group that do not include a cyclic structure in the main chain and are composed of only a chain structure. However, it may be saturated or unsaturated. The “alicyclic hydrocarbon group” means a hydrocarbon group containing only an alicyclic hydrocarbon structure as a ring structure and not containing an aromatic ring structure. However, it does not need to be composed only of the structure of an alicyclic hydrocarbon, and a part thereof having a chain structure is also included. The “aromatic hydrocarbon group” means a hydrocarbon group containing an aromatic ring structure as a ring structure. However, the structure need not be composed of only the aromatic ring structure, and a part thereof may include a chain structure or an alicyclic hydrocarbon structure.

Specific examples of the divalent hydrocarbon group having 1 to 20 carbon atoms in R ^{1 to} R ⁴ include chain hydrocarbon groups such as methylene group, ethylene group, propanediyl group, butanediyl group, pentanediyl group, hexanediyl. Group, heptanediyl group, octanediyl group, nonanediyl group, decandiyl group, vinylene group, propenediyl group, butenediyl group and the like; alicyclic hydrocarbon group, for example, cyclohexylene group and the like; aromatic hydrocarbon group, for example, Examples thereof include a phenylene group and a biphenylene group.
The trivalent organic group of Z ¹ and Z ² is preferably a trivalent chain hydrocarbon group, an alicyclic hydrocarbon group or an aromatic ring group, and a benzene ring, a naphthalene ring, a cyclopentane ring and A cyclic group obtained by removing three hydrogen atoms from a ring selected from the group consisting of cyclohexane rings is more preferable.
It is preferable that m is 1.

Specific examples of the specific tetracarboxylic dianhydride include compounds represented by the following formulas (2-1) to (2-3).
(In the formula, TMS represents a trimethylsilyl group.)
When synthesizing the polyamic acid, the specific tetracarboxylic acid dianhydride may be used alone or in combination of two or more.

The specific tetracarboxylic dianhydride can be synthesized by appropriately combining conventional methods of organic chemistry. For example, by reacting a tetracarboxylic dianhydride having “—NH—CO—” with di-tert-butyl dicarbonate in the presence of a strong base such as dimethylaminopyridine, Y ¹ is t-butoxy. Specific carbonyl group tetracarboxylic dianhydride can be synthesized. However, the method for synthesizing the specific tetracarboxylic dianhydride is not limited to the above.

The tetracarboxylic acid dianhydride used in the methods [i] and [iii] may be only the specific tetracarboxylic acid dianhydride, but other tetracarboxylic acid dianhydrides other than the specific tetracarboxylic acid dianhydride may be used. You may use together an anhydride. Further, in the method [ii], another tetracarboxylic acid dianhydride is used as the tetracarboxylic acid dianhydride upon the synthesis of the polyamic acid.
Examples of other tetracarboxylic acid dianhydrides include aliphatic tetracarboxylic acid dianhydrides, alicyclic tetracarboxylic acid dianhydrides, aromatic tetracarboxylic acid dianhydrides, and the like. Specific examples thereof include aliphatic tetracarboxylic dianhydrides such as butanetetracarboxylic dianhydride;

Examples of the alicyclic tetracarboxylic acid dianhydride include 1,2,3,4-cyclobutanetetracarboxylic acid 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- 1,2-dicarboxylic anhydride, 3,5,6-tricarboxy-2-carboxymethylnorbornane-2:3,5:6-dianhydride, bicyclo[3.3.0]octane-2,4 6,8-Tetracarboxylic acid 2:4,6:8-dianhydride, bicyclo[2.2.1]heptane-2,3,5,6-tetracarboxylic acid 2:3,5:6-dianhydride 4,9-dioxatricyclo[5.3.1.0 ^2,6 ]undecane-3,5,8,10-tetraone, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, Bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, ethylenediaminetetraacetic acid dianhydride, cyclopentanetetracarboxylic dianhydride, ethylene glycol bis(ane Hydrotrimellitate), 1,3-propylene glycol bis (anhydrotrimellitate), p-phenylene bis (trimellitic acid monoester anhydride) and the like;
Examples of the aromatic tetracarboxylic dianhydrides include, for example, pyromellitic dianhydride; and the tetracarboxylic dianhydrides described in JP 2010-97188 A can be used. In addition, other tetracarboxylic dianhydride can be used individually by 1 type or in combination of 2 or more types.

  Other tetracarboxylic acid dianhydrides include 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, and 5 from the viewpoint of liquid crystal alignment and the like. -(2,5-Dioxotetrahydrofuran-3-yl)-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 5-(2,5-dioxotetrahydrofuran -3-yl)-8-methyl-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, bicyclo[3.3.0]octane-2,4,6 , 8-tetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, cyclohexanetetracarboxylic dianhydride, p-phenylene bis (trimellitic acid monoester anhydride), and pyromellitic dianhydride It preferably contains at least one compound selected from the group. The amount of these preferable other tetracarboxylic dianhydrides used (the total amount when two or more kinds are used) is 5 mol with respect to the total amount of the tetracarboxylic dianhydride used for the synthesis of the polyamic acid. % Or more, preferably 10 mol% or more, more preferably 20 mol% or more.

(Diamine)
The specific diamine is not particularly limited in the other structure as long as it has a partial structure represented by the above formula (1). A compound containing a partial structure represented by the above formula (1) in the main chain is preferable. Preferred specific examples include a compound represented by the following formula (3), a compound represented by the following formula (3A), and a compound represented by the following formula (3B).
(In the formula (3), R ⁵ , R ⁶ and R ⁸ are each independently a divalent organic group. R ⁷ is a single bond or a divalent organic group. Y ¹ is a protecting group. (t is an integer of 1 to 3, and s is 0 or 1.)

(In formula (3A), Y ² and Y ³ are each independently a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a protecting group. However, at least one of Y ² and Y ³ is a protecting group. R ¹¹ , R ¹² and R ¹⁴ are each independently a divalent organic group, R ¹³ is a single bond or a divalent organic group, v is an integer of 1 to 3, and u is u. It is 0 or 1.)

(In the formula (3B), R ²¹ , R ²² and R ²⁴ are each independently a divalent organic group. R ²³ is a single bond or a divalent organic group. Y ⁴ is a protecting group. x is an integer of 1 to 3.

R ^{5 to} R ⁸ divalent organic groups in the above formula (3), R ^{11 to} R ¹⁴ divalent organic groups in the above formula (3A) and R ^{21 to} R ²⁴ divalent in the above formula (3B). The description of the divalent organic group of R ^{1 to} R ^{4 in} the above formula (2) can be applied to the organic group. Among them, R ⁵ , R ⁸ , R ¹¹ , R ¹⁴ , R ²¹ and R ²⁴ are preferably a phenylene group or a substituted phenylene group. In addition, as a substituent, a C1-C3 alkyl group, a C1-C3 alkoxy group, a halogen atom etc. are mentioned, for example.
Each of t, v and x is preferably 1.
Specific examples of the specific diamine, the following formula (3-1) to (3-20), and formula (ADA1) to (ADA6) and compounds represented by the respective formulas (ADA8) and the like.
(In the formula, TMS represents a trimethylsilyl group.)

(In the formula, R ¹⁵ and R ¹⁶ are each independently a halogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, n is an integer of 2 to 12, and a 1 and a 2 are each independently. Is an integer of 0 to 4, and p is an integer of 1 to 12.)

When synthesizing the polyamic acid, the specific diamine may be used alone or in combination of two or more.

When Y ¹ in the above formula (1) is a group that is deprotected by light, for example, by using the reaction of the following scheme A, as a liquid crystal aligning agent for photoalignment by irradiation of polarized or unpolarized ultraviolet light, It can also be used.
(In Scheme A, "*" indicates a bond.)

The specific diamine can be synthesized by appropriately combining conventional methods of organic chemistry. For example, by reacting a diamine having “—NH—CO—” with di-tert-butyl dicarbonate in the presence of a strong base such as dimethylaminopyridine, Y ¹ can identify a t-butoxycarbonyl group. Diamines can be synthesized. However, the method for synthesizing the specific diamine is not limited to the above.

  The diamine used in the methods [ii] and [iii] may be only the specific diamine, but may be used in combination with another diamine other than the specific diamine. In the method [i], another diamine is used as the diamine during the synthesis of the polyamic acid.

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

As the aromatic diamine, for example, dodecanoxydiaminobenzene, tetradecanoxydiaminobenzene, pentadecanoxydiaminobenzene, hexadecanoxydiaminobenzene, octadecanoxydiaminobenzene, cholestanyloxydiaminobenzene, cholesteryloxydiaminobenzene. , Cholestanyl diaminobenzoate, cholesteryl diaminobenzoate, lanostanyl diaminobenzoate, 3,6-bis(4-aminobenzoyloxy)cholestane, 3,6-bis(4-aminophenoxy)cholestane, 1,1-bis(4 -((Aminophenyl)methyl)phenyl)-4-butylcyclohexane, 1,1-bis(4-((aminophenyl)methyl)phenyl)-4-heptylcyclohexane, 1,1-bis(4-((amino Phenoxy)methyl)phenyl)-4-heptylcyclohexane, 1,1-bis(4-((aminophenyl)methyl)phenyl)-4-(4-heptylcyclohexyl)cyclohexane, N-(2,4-diaminophenyl) -4-(4-heptylcyclohexyl)benzamide, the following formula (E-1)
(In formula (E-1), X ^I and X ^II are each independently a single bond, —O—, —COO— or —OCO—, 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 It is 0 or 1. However, a and b cannot be 0 at the same time.)
An orienting group-containing diamine such as a compound represented by:

p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfide, 4-aminophenyl-4'-aminobenzoate, 4,4'-diaminoazobenzene, 1,5-bis(4-amino) Phenoxy)pentane, 1,7-bis(4-aminophenoxy)heptane, bis[2-(4-aminophenyl)ethyl]hexanedioic acid, N,N-bis(4-aminophenyl)methylamine, 1,5 -Diaminonaphthalene, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 2,7-diaminofluorene, 4,4' -Diaminodiphenyl ether, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 9,9-bis(4-aminophenyl)fluorene, 2,2-bis[4-(4-aminophenoxy)phenyl ] Hexafluoropropane, 2,2-bis(4-aminophenyl)hexafluoropropane, 4,4'-(p-phenylenediisopropylidene)bisaniline, 4,4'-(m-phenylenediisopropylidene)bisaniline, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3, 6-diaminoacridine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N,N'- Bis(4-aminophenyl)-benzidine, N,N'-bis(4-aminophenyl)-N,N'-dimethylbenzidine, 1,4-bis-(4-aminophenyl)-piperazine, 3,5- Other diamines such as diaminobenzoic acid, etc.;
Examples of diaminoorganosiloxanes include 1,3-bis(3-aminopropyl)-tetramethyldisiloxane; and diamines described in JP 2010-97188 A can be used.

In the above formula (E-1) ^{"-X I - (R I -X II} ) d - " Examples of the divalent group represented by the alkanediyl group having 1 to 3 carbon atoms, * - O -, * It is preferably —COO— or *—O—C ₂ H ₄ —O— (however, the bond marked with “*” bonds to the diaminophenyl group). Examples of the group “—C _c H _2c+1 ” include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, dodecyl group, tridecyl group, tetradecyl group. Examples thereof include a group, a pentadecyl group, a hexadecyl group, a heptadecyl group, an octadecyl group, a nonadecyl group, and an eicosyl group, and these are preferably linear. The two amino groups in the diaminophenyl group are preferably in the 2,4-position or the 3,5-position with respect to the other groups.

Specific examples of the compound represented by the above formula (E-1) include compounds represented by the following formulas (E-1-1) to (E-1-4).
As the other diamine, one kind of these compounds may be used alone, or two or more kinds may be appropriately selected and used.

  When applied to a liquid crystal aligning agent for a TN type, STN type or vertical alignment type liquid crystal display device, a group (alignment group) capable of imparting a liquid crystal aligning ability to the coating film is introduced into the side chain of the polyamic acid. Good. Examples of the orientation group include an alkyl group having 4 to 20 carbon atoms, a fluoroalkyl group having 4 to 20 carbon atoms, an alkoxy group having 4 to 20 carbon atoms, a group having a steroid skeleton having 17 to 51 carbon atoms, and a polycyclic structure. And the like. The polyamic acid having an oriented group can be obtained by, for example, polymerization including an oriented group-containing diamine in the monomer composition. When the oriented group-containing diamine is used, its amount is preferably 3 mol% or more, and more preferably 5 to 70 mol%, based on all diamines used in the synthesis.

When the liquid crystal aligning ability is imparted to the coating film formed by the liquid crystal aligning agent by the photoalignment method, at least a part of the polyamic acid as the polymer (P) may be a polymer having a photoalignable structure. As a specific example of the photo-alignment structure, a group exhibiting photo-alignment property by photoisomerization, photodimerization, photolysis or the like can be adopted. Specifically, for example, an azo-containing group containing an azo compound or a derivative thereof as a basic skeleton, a cinnamic acid-containing group containing a cinnamic acid or a derivative thereof as a basic skeleton, and a chalcone-containing group containing a chalcone or a derivative thereof as a basic skeleton. A benzophenone-containing group containing benzophenone or a derivative thereof as a basic skeleton, a coumarin-containing group containing coumarin or a derivative thereof as a basic skeleton, a cyclobutane-containing structure containing cyclobutane or a derivative thereof as a basic skeleton, and bicyclo[2.2.2]. ] A bicyclo[2.2.2]octene-containing structure containing octene or a derivative thereof as a basic skeleton, the following formula (4):
(In the formula (4), X ³ is a sulfur atom, an oxygen atom or —NH—. “*” represents a bond, respectively, provided that at least one of the two “*” is bonded to the aromatic ring. is doing.)
And a structure containing a partial structure represented by as a basic skeleton.

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

(Synthesis of polyamic acid)
The polyamic acid can be obtained by reacting the above-mentioned tetracarboxylic acid dianhydride and diamine together with a molecular weight modifier, if necessary. The ratio of the tetracarboxylic dianhydride and the diamine used for the synthesis reaction of the polyamic acid is such that the acid anhydride group of the tetracarboxylic dianhydride is 0.2 to 2 with respect to 1 equivalent of the amino group of the diamine. The equivalent ratio is preferable, and the ratio of 0.8 to 1.2 equivalent is more preferable.
When synthesizing the polyamic acid as the polymer (P), the use ratio of the specific tetracarboxylic dianhydride and the specific diamine is determined from the viewpoint of sufficiently enhancing the solubility improving effect and the afterimage reducing effect of the polyamic acid. The total amount of the specific tetracarboxylic acid dianhydride and the specific diamine is preferably 10 mol% or more, more preferably 20 to 80 mol%, and more preferably 25 to 70, based on the total amount of the monomers used. More preferably, it is mol %.

  Examples of the molecular weight modifier include acid monoanhydrides such as maleic anhydride, phthalic anhydride and itaconic anhydride, monoamine compounds such as aniline, cyclohexylamine and n-butylamine, monoisocyanate compounds such as phenyl isocyanate and naphthyl isocyanate. Can be mentioned. The use ratio of the molecular weight modifier is preferably 20 parts by weight or less, and more preferably 10 parts by weight or less, based on 100 parts by weight of the total of tetracarboxylic dianhydride and diamine used.

  The synthesis reaction of polyamic acid is preferably carried out in an organic solvent. The reaction temperature at this time is preferably −20° C. to 150° C., more preferably 0 to 100° C. The reaction time is preferably 0.1 to 24 hours, more preferably 0.5 to 12 hours.

  Examples of the organic solvent used in the reaction include aprotic polar solvents, phenolic solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons and hydrocarbons. Of 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. And a mixture of at least one selected from the group consisting of alcohols, ketones, esters, ethers, halogenated hydrocarbons and hydrocarbons (organic solvent of the second group). In the latter case, the use ratio of the second group organic solvent is preferably 50% by weight or less, more preferably 40% by weight, based on the total amount of the first group organic solvent and the second group organic solvent. It is below, more preferably 30% by weight or less.

  Particularly preferred organic solvents are N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethylsulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphortriamide, m-cresol, xylenol. It is preferable to use one or more selected from the group consisting of and halogenated phenols as a solvent, or to use a mixture of one or more of these with other organic solvents in the range of the above ratio. The amount (a) of the organic solvent used is such that the total amount (b) of the tetracarboxylic dianhydride and the diamine becomes 0.1 to 50% by weight based on the total amount (a+b) of the reaction solution. Is good

  As described above, a reaction solution obtained by dissolving polyamic acid is obtained. This reaction solution may be directly used for the preparation of the liquid crystal aligning agent, or may be subjected to the preparation of the liquid crystal aligning agent after isolating the polyamic acid contained in the reaction solution, or the isolated polyamic acid is purified. Alternatively, the liquid crystal aligning agent may be prepared. Isolation and purification of the polyamic acid can be performed according to known methods.

(Polyamic acid ester)
The polyamic acid ester as the polymer (P) can be obtained by, for example, a method of reacting a tetracarboxylic acid diester dihalide with a diamine.
In the present specification, the “tetracarboxylic acid diester dihalide” means a compound in which two of the four carboxyl groups of tetracarboxylic acid are esterified and the remaining two are halogenated. “Tetracarboxylic acid diester” means a compound in which two of the four carboxyl groups of tetracarboxylic acid are esterified and the remaining two are carboxyl groups.

The tetracarboxylic acid diester dihalide used can be obtained by reacting the tetracarboxylic acid diester with a suitable chlorinating agent such as thionyl chloride. The tetracarboxylic acid diester is obtained by reacting the tetracarboxylic acid dianhydride (specific tetracarboxylic acid dianhydride and other tetracarboxylic acid dianhydride) exemplified in the synthesis of polyamic acid with alcohols such as methanol and ethanol. Can be obtained by
As the diamine to be reacted with the tetracarboxylic acid diester dihalide, in addition to the specific diamine and other diamines exemplified in the description of the synthesis of the polyamic acid, a compound obtained by protecting the primary amino group of the specific diamine and the other diamine with a protective group. (Hereinafter, also referred to as “diamine compound CA1”) and the like. Specific examples of the primary amino group-protected diamine compound (CA1) include compounds represented by the following formula (5).
(In the formula (5), R ⁹ is a divalent organic group and Y ¹ is a protective group. A plurality of Y ¹ may be the same or different.)

The description of the divalent organic group of R ⁹ in the above formula (5) can be applied to the description of the divalent organic group of R ^{1 to} R ^{4 in} the above formula (2). Specific examples of the compound represented by the above formula (5) include compounds represented by the following formulas (5-1) to (5-16).

The ratio of the tetracarboxylic acid diester dihalide and the diamine to be used for the synthesis reaction of the polymer (P) is such that the amount of the tetracarboxylic acid diester dihalide group “—COX (X is "Halogen atom)" is preferably 0.2 to 2 equivalents, and more preferably 0.8 to 1.2 equivalents.
The usage ratio of the tetracarboxylic acid diester dihalide having a partial structure represented by the above formula (1), the specific diamine and the above diamine compound (CA1) (when a plurality of types are used, the total amount thereof) is the same as that of the polyamic acid. From the viewpoint of sufficiently enhancing the effect of improving the solubility and the effect of reducing the residual image, the amount is preferably 10 mol% or more, more preferably 20 to 80 mol%, based on the total amount of the monomers used in the synthesis. It is more preferable to set it to 25 to 70 mol %.

  The reaction between the tetracarboxylic acid diester dihalide and the diamine is preferably carried out in the presence of a base in an organic solvent. The reaction temperature at this time is preferably −30° C. to 150° C., more preferably −10 to 100° C. The reaction time is preferably 0.1 to 48 hours, more preferably 0.5 to 36 hours. As the organic solvent used in the reaction, the description of the organic solvent that can be used in the synthesis reaction of polyamic acid can be applied. The amount of the organic solvent used is preferably such that the total amount of the tetracarboxylic acid diester dihalide and the diamine becomes 0.1 to 50% by weight based on the total amount of the reaction solution. Examples of the base used in the above reaction include tertiary amines such as pyridine, triethylamine and N-ethyl-N,N-diisopropylamine; sodium hydride, potassium hydride, sodium hydroxide, potassium hydroxide, sodium, potassium and the like. Alkali metals and the like can be preferably used. The amount of the base used is preferably 2 to 4 mol, and more preferably 2 to 3 mol, based on 1 mol of the diamine.

As described above, the reaction solution obtained by dissolving the polyamic acid ester is obtained. This reaction solution may be directly used for the preparation of the liquid crystal aligning agent, or may be subjected to the preparation of the liquid crystal aligning agent after isolating the polyamic acid ester contained in the reaction solution, or the isolated polyamic acid ester may be used. The liquid crystal aligning agent may be purified and then used for the preparation of the liquid crystal aligning agent. Isolation and purification of the polyamic acid ester can be performed according to known methods. The polyamic acid ester may have only an amic acid ester structure, or may be a partial esterified product in which an amic acid structure and an amic acid ester structure coexist.
The polyamic acid ester as the polymer (P) is not limited to the above-mentioned synthesis method, and for example, a method of reacting the polyamic acid as the polymer (P) with an alcohol, a reaction of a tetracarboxylic acid diester and a diamine It can also be obtained by a method such as.

(Polyimide)
The polyimide as the polymer (P) can be obtained, for example, by subjecting the polyamic acid synthesized as described above to dehydration ring closure to imidize. When the polyamic acid is dehydrated and ring-closed to form a polyimide, the reaction solution of the polyamic acid may be subjected to the dehydration ring-closing reaction as it is, and the polyamic acid contained in the reaction solution may be isolated and then subjected to the dehydration ring-closing reaction. Alternatively, the isolated polyamic acid may be purified and then subjected to a dehydration ring closure reaction.

  The polyimide may be a complete imidized product obtained by dehydration ring closure of all of the amic acid structure of the precursor polyamic acid, dehydration ring closure of only a portion of the amic acid structure, amic acid structure and imide It may be a partial imidized compound having a ring structure. The imidation ratio of the polyimide used in the reaction is preferably 20% or more, more preferably 30 to 99%, further preferably 40 to 99%. The imidization ratio is a percentage of the ratio of the number of imide ring structures to the total number of amic acid structures and imide ring structures of polyimide. Here, a part of the imide ring may be an isoimide ring.

  The dehydration ring closure of the polyamic acid is preferably carried out by a method of heating the polyamic acid or by dissolving the polyamic acid in an organic solvent and adding a dehydrating agent and a dehydration ring closure catalyst to the solution and heating the mixture as necessary. . Of these, the latter method is preferable.

  In the method of adding the dehydrating agent and the dehydration ring-closing catalyst to the solution of polyamic acid, an acid anhydride such as acetic anhydride, propionic anhydride, or trifluoroacetic anhydride can be used as the dehydrating agent. The amount of the dehydrating agent used is preferably 0.01 to 20 mol per 1 mol of the amic acid structure of the polyamic acid. As the dehydration ring-closing catalyst, for example, tertiary amines such as pyridine, collidine, lutidine, triethylamine and the like can be used. The amount of the dehydration ring-closing catalyst used is preferably 0.01 to 10 mol with respect to 1 mol of the dehydrating agent used. Examples of the organic solvent used for the dehydration ring closure 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 directly used for the preparation of the liquid crystal aligning agent, or may be used for the preparation of the liquid crystal aligning agent after removing the dehydrating agent and the dehydration ring-closing catalyst from the reaction solution. The alignment agent may be prepared, or the isolated polyimide may be purified and then used to prepare the liquid crystal alignment agent. These purification operations can be performed according to known methods.

(polyamide)
The polyamide of the polymer (P) can be obtained by, for example, a method of reacting a dicarboxylic acid and a diamine. Here, the dicarboxylic acid is preferably subjected to acid chloride formation using an appropriate chlorinating agent such as thionyl chloride and then subjected to the reaction with the diamine. In the present specification, the “dicarboxylic acid dihalide” means a compound in which two carboxyl groups of dicarboxylic acid are halogenated.

The dicarboxylic acid used for synthesizing the polyamide is not particularly limited, and examples thereof include oxalic acid, malonic acid, dimethylmalonic acid, succinic acid, glutaric acid, adipic acid, 2-methyladipic acid, trimethyladipic acid, pimelic acid, and 2 Aliphatic dicarboxylic acids such as 2,2-dimethylglutaric acid, 3,3-diethylsuccinic acid, azelaic acid, sebacic acid, suberic acid, fumaric acid, and muconic acid;
A dicarboxylic acid having an alicyclic structure such as cyclobutanedicarboxylic acid, 1-cyclobutenedicarboxylic acid, cyclopentanedicarboxylic acid, cyclohexanedicarboxylic acid;
Phthalic acid, isophthalic acid, terephthalic acid, 5-methylisophthalic acid, 5-tert-butylisophthalic acid, 2,5-dimethylterephthalic acid, naphthalenedicarboxylic acid, 4,4'-biphenyldicarboxylic acid, 4,4'-diphenylmethane Dicarboxylic acid, 4,4'-diphenylpropanedicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, 4,4'-carbonyldibenzoic acid, 4-carboxycinnamic acid, p-phenylenediacrylic acid, 3,3'- [4,4′-(Methylenedi-p-phenylene)]dipropionic acid, 4,4′-[4,4′-(oxydi-p-phenylene)]dibutyric acid,3,4-diphenyl-1,2- Dicarboxylic acids having an aromatic ring such as cyclobutanedicarboxylic acid and azobenzene-4,4′-dicarboxylic acid; The dicarboxylic acid dihalides may be used alone or in combination of two or more.
Examples of the diamine used for synthesizing the polyamide include the specific diamine and other diamines exemplified in the description of the synthesis of the polyamic acid, and the compound represented by the above formula (5). At this time, the polyamide as the polymer (P) can be obtained by using the specific diamine or the diamine compound (CA1) as at least a part of the monomer. The diamine may be used alone or in combination of two or more.

  The ratio of the dicarboxylic acid dihalide and the diamine to be used for the synthesis reaction of the polymer (P) is such that the dicarboxylic acid dihalide group “—COX (X is a halogen atom)” is equivalent to 1 equivalent of the amino group of the diamine. Is preferably 0.2 to 2 equivalents, more preferably 0.8 to 1.2 equivalents.

The reaction between the dicarboxylic acid dihalide and the diamine is preferably carried out in the presence of a base in an organic solvent. The reaction temperature at this time is preferably 0°C to 200°C, more preferably 10 to 100°C. The reaction time is preferably 0.5 to 48 hours, more preferably 1 to 36 hours.
As the organic solvent used in the reaction, it is preferable to use an organic solvent, for example, tetrahydrofuran, dioxane, toluene, chloroform, dimethylformamide, dimethylacetamide, dimethylsulfoxide, N-methyl-2-pyrrolidone and the like are preferably used. it can. The amount of the organic solvent used is preferably 400 to 900 parts by weight, and more preferably 500 to 700 parts by weight, based on 100 parts by weight of the total amount of the dicarboxylic acid dihalide and the diamine.
Examples of the base used in the above reaction include tertiary amines such as pyridine, triethylamine, N-ethyl-N,N-diisopropylamine; lithium hydride, sodium hydride, potassium hydride, lithium bis(trimethylsilyl)amide, sodium Alkali metals such as bis(trimethylsilyl)amide, potassium bis(trimethylsilyl)amide, lithium diisopropylamide, sodium diisopropylamide, potassium diisopropylamide and t-butyllithium; can be preferably used. The amount of the base used is preferably 2 to 4 mol, and more preferably 2 to 3 mol, based on 1 mol of the diamine.

  As described above, a reaction solution obtained by dissolving polyamide is obtained. This reaction solution may be directly used for the preparation of the liquid crystal aligning agent, or may be subjected to the preparation of the liquid crystal aligning agent after isolation of the polyamide contained in the reaction solution, or after the isolated polyamide is purified. You may use for preparation of a liquid crystal aligning agent. Isolation and purification of the polyamide can be performed according to a known method.

The solution viscosity and the weight average molecular weight (Mw) of the polymer (P) can be appropriately selected according to the main skeleton. For example, in the case of polyamic acid, polyamic acid ester, polyimide and polyamide, the solution viscosity of the polymer should have a solution viscosity of 10 to 800 mPa·s when the solution has a concentration of 10% by weight. Are preferable, and those having a solution viscosity of 15 to 500 mPa·s are more preferable. The solution viscosity (mPa·s) of the polymer (P) is 10% by weight when prepared using a good solvent for the polymer (P) (eg, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.). It is a value measured at 25° C. using a E-type rotational viscometer for the polymer solution.
The polystyrene-equivalent weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) is preferably 1,000 to 500,000, more preferably 2,000 to 300,000. The molecular weight distribution (Mw/Mn) represented by the ratio of Mw to the polystyrene-equivalent number average molecular weight (Mn) measured by GPC is preferably 15 or less, and more preferably 10 or less.

[Compound (P) as Additive]
When the compound (P) is used as an additive, the compound having a partial structure represented by the above formula (1) is a compound having a plurality of photopolymerizable groups (hereinafter, “photopolymerizable compound (P)”). (Also referred to as “)” can be preferably used. Preferred specific examples include compounds represented by the following formula (6).
(In Formula (6), X ⁴ and X ⁵ are photopolymerizable groups. R ¹⁰ , R ¹¹ and R ¹³ are each independently a divalent organic group, and R ¹² is a single bond or a divalent group. Is an organic group, Y ¹ is a protective group, f is an integer of 1 to 3, and g is 0 or 1.)

In the formula (6), examples of the photopolymerizable group for X ⁴ and X ⁵ include a group having a polymerizable unsaturated bond. Specifically, for example, (meth) acryloyloxy group, styryl group, (meth) acrylamide group, a vinyl _{group, CH 2 = C (CH 3} ) -, vinyloxy group _{(CH 2 = CH-O-)} , the following equation ( and a group represented by formula (x-1) or formula (x-2).
(Formula (x-1) in, ^{X 6} is an oxygen atom or -NH-. "*" Indicates a bond.)

  As the photopolymerizable group, a (meth)acryloyloxy group is particularly preferable from the viewpoint of high photoreactivity. The (meth)acryloyloxy group is meant to include "acryloyloxy group" and "methacryloyloxy group". The (meth)acrylamide group is meant to include "acrylamide group" and "methacrylamide group".

The description of the divalent organic group of R ^{10 to} R ¹³ can be applied to the description of the divalent organic group of R ^{1 to} R ⁴ of the above formula (2). The R ¹⁰ to R ^13, from the viewpoint of affinity with the liquid crystal, it is preferable that at least one of these is a phenylene group, cyclohexylene group or a biphenylene group, more than one R ¹⁰ to R ¹³ is It is more preferably a phenylene group, a cyclohexylene group or a biphenylene group. Further, from the viewpoint of solubility of the compound (P), it is preferable that at least one of R ^{10 to} R ¹³ is a cyclohexylene group.
It is preferable that f is 1.
Specific examples of the photopolymerizable compound (P) include compounds represented by the following formulas (6-1) to (6-30).
(In the formulas (6-1) to (6-20), R is a hydrogen atom or a methyl group, and n is an integer of 1 to 20. Boc represents a tert-butoxycarbonyl group.)
(In the formulas (6-21) to (6-24), n is an integer of 1 to 20. Boc represents a tert-butoxycarbonyl group.)
(In formula (6-25) to formula (6-30), R is a hydrogen atom or a methyl group, m and n are each independently an integer of 1 to 20. Boc is a tert-butoxycarbonyl group. Show.)

  In the liquid crystal aligning agent, the compounding ratio of the compound (P) as an additive is preferably 1 to 100 parts by weight, and 5 to 50 parts by weight based on 100 parts by weight of the total weight of the polymer components. Is more preferable. The compound (P) may be used alone or in combination of two or more. The molecular weight of the compound (P) is preferably 1,500 or less, more preferably 1,200 or less, even more preferably 1,000 or less.

<Other ingredients>
The liquid crystal aligning agent according to the present invention may contain other components than the compound (P), if necessary. Examples of other components include other polymers other than the polymer (P), compounds having at least one epoxy group in the molecule (hereinafter referred to as "epoxy group-containing compound"), functional silane compounds, and the like. Be done.

[Other polymers]
The above-mentioned other polymers can be used for the purpose of improving various properties such as solution properties, electrical properties, heat resistance, and mechanical strength, or for the purpose of cost reduction. Such other polymer is a polymer having no partial structure represented by the above formula (1), for example, polyamic acid, polyimide, polyamic acid ester, polyorganosiloxane, polyester, polyamide, cellulose derivative, polyacetal, polystyrene. Examples thereof include a derivative, a poly(styrene-phenylmaleimide) derivative, or a polymer having a poly(meth)acrylate as a main skeleton and not having the above specific structure. Among these, at least one polymer selected from the group consisting of polyamic acid, polyimide, polyamic acid ester, and polyamide can be preferably used as the other polymer.

When the other polymer is blended with the liquid crystal aligning agent, the blending ratio is preferably appropriately selected according to the type of the compound (P). For example, when the compound (P) is a polymer, the blending ratio of the other polymer is 100% by weight of the total of the polymers contained in the liquid crystal aligning agent (the total of the polymer (P) and the other polymer). The amount is preferably 50 parts by weight or less, more preferably 0.1 to 40 parts by weight, and even more preferably 0.1 to 30 parts by weight.
When the liquid crystal aligning agent of the present invention contains the compound (P) as an additive, the liquid crystal aligning agent is at least one selected from the group consisting of the polymer (P) and other polymers as a polymer component. Containing a polymer of. In such a case, the blending ratio of the other polymer can be arbitrarily set within the range of 100% by weight or less based on the total amount of the polymers contained in the liquid crystal aligning agent. It is preferably 10 to 100% by weight, more preferably 30 to 90% by weight.

[Epoxy group-containing compound]
The epoxy group-containing compound can be used to improve the adhesiveness of the liquid crystal alignment film to the substrate surface and the electrical characteristics. 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-xylylenediene Amine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, N,N-diglycidyl-benzylamine, N , N-diglycidyl-aminomethylcyclohexane, N,N-diglycidyl-cyclohexylamine and the like can be mentioned as preferable ones. In addition, as an example of the epoxy group-containing compound, the epoxy group-containing polyorganosiloxane described in WO 2009/096598 can be used.
When the epoxy group-containing compound is blended with the liquid crystal aligning agent, the blending ratio is preferably 40 parts by weight or less with respect to 100 parts by weight of the total amount of the polymer contained in the liquid crystal aligning agent, More preferably, it is 30 parts by weight.

[Functional silane compound]
The functional silane compound can be used for the purpose of improving the printability of the liquid crystal aligning agent. Examples of such a functional silane compound 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 Methyl-3,6-diazananoate, N-benzyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, glycidoxymethyltrimethoxysilane, 2-glycidoxyethyltrimethoxysilane , 3-glycidoxypropyltrimethoxysilane and the like.
When the other functional silane compound is added to the liquid crystal aligning agent, the mixing ratio is preferably 2 parts by weight or less based on 100 parts by weight of the total amount of the polymer contained in the liquid crystal aligning agent. It is more preferable that the amount is from 0.2 to 0.2 parts by weight.

  In addition to the above, other components include compounds having at least one oxetanyl group in the molecule, antioxidants, metal chelate compounds, curing accelerators, surfactants, fillers, dispersants, and photosensitizers. And so on.

The liquid crystal aligning agent according to the present invention may contain only one kind of polymer as a polymer component, or may contain two or more kinds of polymers. In the case of containing two or more kinds of polymers, for example, the following [1] to [3] are exemplified.
[1] An embodiment containing the polymer (P) and another polymer, wherein the polymer (P) and the other polymer are at least one selected from polyamic acid, polyamic acid ester, polyimide and polyamide.
[2] A mode in which a plurality of types of polymers (P) are contained, and the plurality of types of polymers (P) are at least one selected from polyamic acid, polyamic acid ester, polyimide and polyamide.
[3] A mode in which a plurality of other polymers are contained, and the other polymer is at least one selected from polyamic acid, polyamic acid ester, polyimide and polyamide (provided that the compound (P) is contained as an additive). ..).
Among these, in the aspect [1], the amino group in the amide bond of the polymer (P) is protected by Y ¹ , so that the polarity difference between the polymer (P) and the other polymer is increased. It is presumed that the size of the polymer becomes large and the distribution of the polymer in the liquid crystal alignment film can be sufficiently biased.

The compounding ratio of the compound (P) to the solid content (the component other than the solvent of the liquid crystal aligning agent) in the liquid crystal aligning agent is preferably appropriately selected according to the type of the compound (P). For example, when the compound (P) is a polymer, the compounding ratio of the polymer (P) is preferably 40 parts by weight or more based on 100 parts by weight of the total solid content of the liquid crystal aligning agent, and 50 The amount is preferably at least 60 parts by weight, more preferably at least 60 parts by weight.
In addition, the blending ratio of the polymer (P) in the above aspect [1] is 100 in terms of the total amount of the polymer (P) and other polymers from the viewpoint of cost reduction while sufficiently obtaining the effects of the present invention. The amount is preferably 1 to 99 parts by weight, more preferably 10 to 90 parts by weight, and further preferably 20 to 80 parts by weight with respect to parts by weight.
When the compound (P) is an additive, the compounding ratio of the compound (P) is preferably 0.5 to 50 parts by weight, based on 100 parts by weight of the total solid content in the liquid crystal aligning agent. The amount is preferably 30 parts by weight, more preferably 5 to 25 parts by weight.

<Solvent>
The liquid crystal aligning agent according to the present invention is prepared as a liquid composition in which the compound (P) and other components used as necessary are dispersed or dissolved in a suitable solvent.

  Examples of the organic solvent 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 ethoxy propionate, 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 diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diisobutyl ketone , Isoamyl propionate, isoamyl isobutyrate, diisopentyl ether, ethylene carbonate, propylene carbonate and the like. These may be used alone or in combination of two or more.

  The solid content concentration in the liquid crystal aligning agent (the ratio of the total weight of components other than the solvent of the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent) is appropriately selected in consideration of viscosity, volatility, etc., but is preferably It is in the range of 1 to 10% by weight. That is, the liquid crystal aligning agent is applied to the surface of the substrate as described later and preferably heated to form a coating film which is a liquid crystal alignment film or a coating film which becomes a liquid crystal alignment film. At this time, if 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, the film thickness of the coating film becomes excessively large, and it is difficult to obtain a good liquid crystal alignment film, and the viscosity of the liquid crystal alignment agent increases and the coating property deteriorates. There is a tendency.

  The particularly preferable range of the solid content concentration depends on the method used when the liquid crystal aligning agent is applied to the substrate. For example, when applied to a substrate by a spinner method, the solid content concentration (the ratio of the total weight of all components other than the solvent in the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent) is 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 thus the solution viscosity is in the range of 12 to 50 mPa·s. In the case of using the inkjet method, it is particularly preferable that the solid content concentration is in the range of 1 to 5% by weight, and thus the solution viscosity is in the range of 3 to 15 mPa·s. The temperature for preparing the liquid crystal aligning agent is preferably 10 to 50°C, more preferably 20 to 30°C.

<Liquid crystal display element>
The liquid crystal display element according to the present invention includes a liquid crystal alignment film formed using the liquid crystal alignment agent described above. The operation mode of the liquid crystal display device is not particularly limited, and includes, for example, TN type, STN type, VA type (including VA-MVA type, VA-PVA type, etc.), IPS type, FFS type, OCB (Optically Compensated Bend) type. It can be applied to various operation modes.

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

[Step (1): Formation of coating film]
First, a liquid crystal aligning agent is applied onto a substrate, and then the applied surface is heated to form a coating film on the substrate.
(1-A) When manufacturing a TN-type, STN-type or VA-type liquid crystal display device, first, two substrates provided with a patterned transparent conductive film are made into a pair, and each transparent conductive film is formed. A liquid crystal aligning agent is applied onto each surface, preferably by an offset printing method, a spin coating method, a roll coater method or an inkjet printing method. As the substrate, for example, a glass such as float glass or soda glass; a transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyether sulfone, polycarbonate, poly (alicyclic olefin) can be used. As the transparent conductive film provided on one surface of the substrate, a NESA film made of tin oxide (SnO ₂ ) (registered trademark of PPG Co., USA), an ITO film made of indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ ) and the like are used. Can be used. To obtain a patterned transparent conductive film, for example, a method of forming a pattern-free transparent conductive film and then forming a pattern by photo-etching; a method of using a mask having a desired pattern when forming the transparent conductive film; You can 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 on which the coating film is formed. You may perform the pre-processing which applies in advance.

  After applying the liquid crystal aligning agent, preheating (prebaking) is preferably carried out for the purpose of preventing liquid dripping of the applied liquid crystal aligning agent. The prebaking temperature is preferably 30 to 200°C, more preferably 40 to 150°C, and particularly preferably 40 to 100°C. The pre-baking time is preferably 0.25 to 10 minutes, more preferably 0.5 to 5 minutes. Then, a baking (post-baking) step is carried out for the purpose of completely removing the solvent and, if necessary, thermal imidization of the amic acid structure present in the polymer. The baking temperature (post-baking temperature) at this time is preferably 80 to 300°C, more preferably 120 to 250°C. The post-baking 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-B) When manufacturing an IPS-type or FFS-type liquid crystal display element, an electrode formation surface of a substrate provided with an electrode made of a comb-shaped patterned transparent conductive film or a metal film, and an electrode are provided. A liquid crystal aligning agent is applied to one surface of the counter substrate which is not formed, and then each applied surface is heated to form a coating film. The materials of the substrate and the transparent conductive film used at this time, the coating method, the heating conditions after coating, the patterning method of the transparent conductive film or the metal film, the pretreatment of the substrate, and the preferable film thickness of the coating film formed are as described above. It is the same as (1-A). As the metal film, for example, a film made of a metal such as chromium can be used.

  In any of the above (1-A) and (1-B), a liquid crystal alignment film or a coating film to be a liquid crystal alignment film is formed by removing the organic solvent after applying the liquid crystal alignment agent on the substrate. To be done. At this time, the polymer contained in the liquid crystal aligning agent is a polyamic acid, is a polyamic acid ester, or when it contains an imidized polymer having an imide ring structure and an amic acid structure, a coating film The coating may be further imidized by further heating after formation to allow the dehydration ring closure reaction to proceed.

[Step (2): Alignment treatment]
When manufacturing a TN-type, STN-type, IPS-type or FFS-type liquid crystal display device, a treatment (alignment treatment) for imparting a liquid crystal aligning ability to the coating film formed in the step (1) is carried out. As a result, the alignment ability of the liquid crystal molecules is imparted to the coating film to form a liquid crystal alignment film. As the orientation treatment, for example, a rubbing treatment for imparting a liquid crystal orientation ability to the coating film by rubbing the coating film in a certain direction with a roll wound with a cloth made of fibers such as nylon, rayon and cotton, a coating film formed on a substrate A photo-alignment treatment for imparting a liquid crystal aligning ability to the coating film by irradiating the film with light is given. On the other hand, when manufacturing a vertical alignment type liquid crystal display device, the coating film formed in the above step (1) can be used as it is as a liquid crystal alignment film, but the coating film may be subjected to an alignment treatment. .

  Light irradiation in the photo-alignment treatment includes (1a) a method of irradiating a coating film after post-baking, (2a) a method of irradiating a coating film after pre-baking and before post-baking, (3a) pre-baking and It can be carried out by a method of irradiating the coating film while heating the coating film in at least one of post-baking.

The light that illuminates the coating can be polarized or unpolarized 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, the irradiation may be performed in a direction perpendicular to the substrate surface, an oblique direction, or a combination thereof. When irradiating non-polarized radiation, the irradiation direction is an oblique direction.
As the light source used, for example, a low pressure mercury lamp, a high pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, an excimer laser, etc. can be used. Ultraviolet rays in a preferable wavelength range can be obtained by means of using a light source in combination with a filter, a diffraction grating, or the like. The irradiation amount of light is preferably 100 to 50,000 J/m ² , and more preferably 300 to 20,000 J/m ² . The coating film may be irradiated with light while heating the coating film in order to increase the reactivity. The temperature at the time of heating is usually 30 to 250°C, preferably 40 to 200°C, and more preferably 50 to 150°C.

  Note that the liquid crystal alignment film after the rubbing treatment is further irradiated with a part of the liquid crystal alignment film to change the pretilt angle of a partial region of the liquid crystal alignment film, or a part of the liquid crystal alignment film surface is changed. A resist film may be formed on each part and then a rubbing process may be performed in a direction different from the previous rubbing process, and then the resist film may be removed so that the liquid crystal alignment film has different liquid crystal aligning ability for each region. .. In this case, it is possible to improve the visual field characteristics of the obtained liquid crystal display element.

  When a PSA (Polymer sustained alignment) type liquid crystal display element is manufactured, or when a coating film is formed using a liquid crystal aligning agent containing a polymerizable group-containing component, the coating film formed in the above step (1) is used. Although the following step (3) may be carried out as it is, an alignment treatment such as a weak rubbing treatment may be carried out for the purpose of controlling the collapse of liquid crystal molecules and performing alignment division by a simple method. The liquid crystal alignment film suitable for the VA type liquid crystal display element can be also suitably used for the PSA type liquid crystal display element.

[Step (3): Construction of liquid crystal cell]
(3-A) Two substrates on which the liquid crystal alignment film is formed as described above are prepared, and a liquid crystal cell is manufactured by arranging liquid crystal between the two substrates which are arranged to face each other. To manufacture a liquid crystal cell, for example, the following two methods can be mentioned. The first method is a conventionally known method. First, two substrates are arranged to face each other with a gap (cell gap) so that the respective liquid crystal alignment films face each other, and the peripheral portions of the two substrates are bonded together by using a sealant, and the substrate surface and the sealant are attached. A liquid crystal cell is manufactured by injecting and filling a liquid crystal into the cell gap partitioned by, and then sealing the injection hole. The second method is a method called ODF (One Drop Fill) method. For example, an ultraviolet light curable sealant is applied to a predetermined place on one of the two substrates having the liquid crystal alignment film formed thereon, and liquid crystal is dripped at predetermined places on the liquid crystal alignment film surface. After that, the other substrate is bonded so that the liquid crystal alignment films face each other, the liquid crystal is spread over the entire surface of the substrate, and then the entire surface of the substrate is irradiated with ultraviolet light to cure the sealant, thereby manufacturing a liquid crystal cell. . In either method, the liquid crystal cell manufactured as described above is further heated to a temperature at which the liquid crystal used has an isotropic phase, and then gradually cooled to room temperature to remove the flow orientation at the time of filling the liquid crystal. It is desirable to do.

  As the sealant, for example, a curing agent and an epoxy resin containing aluminum oxide spheres as a spacer can be used. Examples of the liquid crystal include nematic liquid crystal and smectic liquid crystal, and 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. A biphenylcyclohexane liquid crystal, a pyrimidine liquid crystal, a dioxane liquid crystal, a bicyclooctane liquid crystal, a cubane liquid crystal, or the like can be used. In addition to these liquid crystals, for example, cholesteric liquid crystals such as cholesteryl chloride, cholesteryl nonaate and cholesteryl carbonate; chiral agents such as those sold under the product names "C-15" and "CB-15" (manufactured by Merck). A ferroelectric liquid crystal such as p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate or the like may be added and used.

(3-B) In the case of manufacturing a PSA type liquid crystal display element, a liquid crystal cell is constructed in the same manner as in the above (3-A) except that a photopolymerizable compound is injected or dropped together with the liquid crystal. After that, the liquid crystal cell is irradiated with light while a voltage is applied between the conductive films of the pair of substrates. The voltage applied here can be a direct current or an alternating current of 5 to 50 V, for example. Further, as the light to be applied, for example, ultraviolet rays and visible rays containing light with a wavelength of 150 to 800 nm can be used, but ultraviolet rays containing light with a wavelength of 300 to 400 nm are preferable. As the light source of the irradiation light, for example, a low pressure mercury lamp, a high pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, an excimer laser or the like can be used. The ultraviolet rays in the above preferable wavelength range can be obtained by means of using a light source in combination with a filter diffraction grating or the like. The irradiation dose of light, preferably 1,000~200,000J / ^{m 2,} more preferably from 1,000~100,000J / ^{m 2.}

  (3-C) When a coating film is formed on a substrate using a liquid crystal aligning agent containing a compound having a photopolymerizable group as a polymer component or an additive, a liquid crystal cell is formed in the same manner as in (3-A) above. A method of manufacturing a liquid crystal display element may be adopted by performing a process of irradiating the liquid crystal cell with light after applying a voltage between the conductive films of the pair of substrates. According to this method, the merit of the PSA mode can be realized with a small light irradiation amount. The description in (3-B) can be applied to the applied voltage and the conditions of the irradiation light.

  Then, a liquid crystal display element can be obtained by attaching a polarizing plate to the outer surface of the liquid crystal cell. As a polarizing plate to be attached to the outer surface of a liquid crystal cell, a polarizing plate in which a polarizing film called "H film" in which polyvinyl alcohol is stretched and oriented to absorb iodine and sandwiched between cellulose acetate protective films or the H film itself is used. A polarizing plate consisting of

  The liquid crystal display device of the present invention can be effectively applied to various devices, for example, watches, portable games, word processors, notebook computers, car navigation systems, camcorders, PDAs, digital cameras, mobile phones, smartphones, and various types. It can be used for various display devices such as a monitor, a liquid crystal television, and an information display.

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

In the following examples, the weight average molecular weight Mw of the polymer, the imidization ratio, and the solution viscosity of the polymer solution were measured by the following methods. In the following, the compound represented by the formula X may be simply referred to as “compound X”.
[Weight average molecular weight Mw of polymer]
Mw is a polystyrene conversion value measured by GPC under the following conditions.
Column: Tosoh Corp., TSKgelGRCXLII
Solvent: Tetrahydrofuran Temperature: 40°C
Pressure: 68 kgf/cm ²
[Imidization rate of polymer]
A solution containing a polyimide was poured into pure water, and the obtained precipitate was sufficiently dried under reduced pressure at room temperature and then dissolved in deuterated dimethyl sulfoxide, and ¹ H-NMR was measured at room temperature using tetramethylsilane as a reference substance. did. From the obtained ¹ H-NMR spectrum, the imidization ratio was calculated using the following mathematical formula (1).
Imidization rate (%)=(1−A ¹ /A ² ×α)×100 (1)
(In Formula (1), A ¹ is a peak area derived from a proton of an NH group appearing near a chemical shift of 10 ppm, A ² is a peak area derived from another proton, and α is a precursor of a polymer (polyamic acid). The ratio of the number of other protons to one proton of the NH group in ).
[Solution viscosity of polymer solution]
The solution viscosity (mPa·s) of the polymer solution was measured at 25° C. using an E-type rotational viscometer.
[Surface contact angle of film]
Using a contact angle meter DM-700 manufactured by Kyowa Interface Science Co., Ltd., about 2.0 μL of ultrapure water droplets was dropped on a mold (ASL-400), and the state of the droplets was processed 30 seconds after the dropping. Then, the surface contact angle of the film was measured.

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

2.5 g of 4-nitro-N-(4-nitrophenyl)benzamide was suspended in 30 mL of THF, and 1.5 g of N,N-dimethylaminopyridine was added thereto. To the solution was added 3.95 g of di-tert-butyl dicarbonate (Boc ₂ O). After stirring at room temperature for 3 hours, the suspended solid was filtered and the solid was washed with ethanol. This solid was dried to obtain 2.2 g of compound (i-1) with a purity of 99%.
A three-necked flask containing 0.3 g of Pd/C was purged with nitrogen, and 40 ml of oxygen-degassed THF was added thereto and stirred. 2.2 g of the compound (i-1) was put in the container, cooled to 0° C., and stirred for 5 minutes. Hydrogen gas was introduced there to reduce the nitro group. After stirring under a hydrogen gas atmosphere for 3 hours, 50 mL of THF was added, the reaction solution was filtered, and then the reaction solution was concentrated. The precipitated solid was collected and dried to obtain 1.7 g of the desired compound (I) with a purity of 99%.

[Synthesis Example 1-2: Synthesis of compound (II)]
Compound (II) was synthesized according to the following scheme 2.

N ^{1, N 6} - bis (4-Nitorofenechiru) a adipamide 2.8g was suspended in 40 mL of THF, N Thereto was placed N- dimethylaminopyridine 2.5 g. 16 g of di-tert-butyl dicarbonate (Boc ₂ O) was added to the solution. After stirring at room temperature for 3 hours, the suspended solid was filtered and the solid was washed with ethanol. This solid was dried to obtain 3.5 g of compound (ii-1) with a purity of 98%.
The three-necked flask containing 0.5 g of Pd/C was replaced with nitrogen, and 100 ml of THF degassed with oxygen was added thereto and stirred. 3.5 g of compound (ii-1) was put in the container, cooled to 0° C., and stirred for 5 minutes. Hydrogen gas was introduced there to reduce the nitro group. After stirring in a hydrogen gas atmosphere for 6 hours, 50 mL of THF was added, the reaction solution was filtered, and then the reaction solution was concentrated. The precipitated solid was collected and dried to obtain 2.8 g of the target compound (II) with a purity of 99%.

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

2.5 g of 4-nitro-N-(4-nitrophenyl)benzamide was suspended in 30 mL of THF, and 1.5 g of N,N-dimethylaminopyridine was added thereto. To the solution was added 10.4 g of N-[2-(trimethylsilyl)ethoxycarbonyloxy]succinimide. After stirring at room temperature for 3 hours, the suspended solid was filtered and the solid was washed with ethanol. This solid was dried to obtain 1.8 g of compound (iii-1) with a purity of 98%.
A three-necked flask containing 0.3 g of Pd/C was purged with nitrogen, and 40 ml of oxygen-degassed THF was added thereto and stirred. 1.8 g of the compound (iii-1) was placed in the container, cooled to 0° C., and stirred for 5 minutes. Hydrogen gas was introduced there to reduce the nitro group. After stirring under a hydrogen gas atmosphere for 3 hours, 50 mL of THF was added, the reaction solution was filtered, and then the reaction solution was concentrated. The precipitated solid was collected and dried to obtain 1.5 g of the desired compound (III) with a purity of 99%.

[Synthesis Example 1-4: Synthesis of compound (IV)]
Compound (IV) was synthesized according to the following scheme 4.

5.0 g of bis(1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylic acid)=1,1′-biphenyl-4,4′-diyl was suspended in 60 mL of THF, and N,N was added thereto. -Add 0.5 g of dimethylaminopyridine. To the solution was added 40 g of di-tert-butyl dicarbonate (Boc ₂ O). After stirring for 7 hours at room temperature, 10 mL of acetic anhydride was added and the reaction was carried out for 5 hours. The suspended solid formed during the reaction was filtered and the solid was washed with ethyl acetate. The solid was dried to obtain 4.5 g of compound (IV) with a purity of 97%.

[Synthesis Example 1-5: Synthesis of compound (V)]
Compound (V) was synthesized according to the following scheme 5.

3.7 g of 4,4′-(pentane-1,5-diylbis(oxy)bis(N-(4-nitrophenyl)benzamide) was suspended in 60 mL of THF, and 2.7 g of N,N-dimethylaminopyridine was added thereto. 20 g of di-tert-butyl dicarbonate (Boc ₂ O) was added to the solution.After stirring for 5 hours at room temperature, the suspended solid was filtered and the solid was washed with ethanol. , Compound (v-1) 3.7 g were obtained with a purity of 98%.
The three-necked flask containing 0.3 g of Pd/C was replaced with nitrogen, and 100 mL of oxygen-degassed THF was added thereto and stirred. 3.7 g of the compound (v-1) was put in the container, cooled to 0° C., and stirred for 5 minutes. Hydrogen gas was introduced there to reduce the nitro group. After stirring in a hydrogen gas atmosphere for 6 hours, 80 mL of THF was added, the reaction solution was filtered, and then the reaction solution was concentrated. The precipitated solid was collected and dried to obtain 3.0 g of the desired compound (V) with a purity of 99%.

[Synthesis Example 1-6: Synthesis of compound (VI)]
Compound (VI) was synthesized according to the following scheme 6.

To a 1 L eggplant flask, 25.4 g of compound (vi-1), 300 mL of acetonitrile, 48.0 g of t-butyl dicarbonate (Boc ₂ O), and 1.22 g of N,N-dimethylaminopyridine were added, and the mixture was allowed to stand at 6 at room temperature. Reacted for hours. After the reaction was completed, the reaction solution was concentrated to 100 mL, reprecipitated in 1 L of water, and the resulting precipitate was collected by filtration and dried to obtain 40.9 g of compound (VI).

[Synthesis Example 1-7; Synthesis of compound (VII)]
Compound (VII) was synthesized according to the following scheme 7.

To a 1 L eggplant flask, 51.2 g of compound (vii-1), 500 mL of acetonitrile, 48.0 g of t-butyl dicarbonate (Boc ₂ O) and 1.22 g of N,N-dimethylaminopyridine were added, and the mixture was kept at room temperature for 6 hours. It was made to react. After completion of the reaction, the reaction solution was concentrated to 150 mL, reprecipitated in 1 L of water, and the resulting precipitate was collected by filtration and dried to obtain 64.2 g of compound (VII).

[Synthesis Example 1-8: Synthesis of compound (VIII)]
Compound (VIII) was synthesized according to the following scheme 8.

4.54 g of 4-methacryloxybenzoic acid and 1.08 g of 1,4-diaminobenzene were suspended in 30 mL of dichloromethane and cooled with ice. Then, 5.76 g of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and 0.488 g of N,N-dimethyl-4-aminopyridine were added. After stirring for 6 hours at room temperature, the suspended solid was filtered and washed with ethanol. This solid was dried to obtain 3.4 g of compound (viii-1) with a purity of 99%.
3.0 g of the compound (viii-1) was suspended in 30 mL of THF, and 2.0 g of di-tert-butyl dicarbonate (Boc ₂ O) was dissolved in 30 mL of THF in the solution. To the solution was added 1.49 g of di-tert-butyl dicarbonate (Boc ₂ O). After stirring at room temperature for 3 hours, the solution was concentrated and the solid was dried to obtain 3.4 g of compound (VIII) with a purity of 99%.

[Synthesis Example 1-9: Synthesis of compound (C-1)]
Compound (C-1) was synthesized according to the following scheme 9.

  To a 500 mL round-bottomed flask equipped with a nitrogen introducing tube and a reflux tube, 30.2 g of compound (C-1a), 200 mL of thionyl chloride and 0.1 mL of N,N-dimethylformamide were added and refluxed for 1 hour. After completion of the reaction, the viscous liquid obtained by concentrating and drying was recrystallized from cyclohexane, filtered and dried to obtain 27.1 g of compound (C-1).

[Synthesis Example 1-10; Synthesis of compound (ADBA1)]
A compound (ADBA1) was synthesized according to the following scheme 13.

To a 1 L eggplant flask, 28.6 g of compound (DA1), 300 mL of acetonitrile, 45.8 g of -t-butyl dicarbonate (Boc ₂ O), and 1.01 g of triethylamine were added, and they were reacted at room temperature for 6 hours. After completion of the reaction, the reaction solution was concentrated to 100 mL, reprecipitated in 1 L of water, and the resulting precipitate was collected by filtration and dried to obtain 43.8 g of compound (ADBA1).

[Synthesis Example 1-11; Synthesis of compound (ADC1)]
A compound (ADC1) was synthesized according to the following scheme 14.

  To a 500 mL round-bottomed flask equipped with a nitrogen introduction tube and a reflux tube, 27.0 g of compound (DC1), thionyl chloride (200 mL) and N,N-dimethylformamide (0.1 mL) were added, and the mixture was refluxed for 1 hour. After completion of the reaction, the viscous liquid obtained by concentrating and drying was recrystallized from cyclohexane, filtered and dried to obtain 27.6 g of compound (ADC1).

[Synthesis Example 1-12; Synthesis of compound (3-7)]
Compound (3-7) was synthesized according to Scheme 17 below.

· Eggplant flask 1L compound (3-7A), nitrophenethylamine 16.6 g, acetonitrile 200 mL, dicarbonate -t- butyl _(Boc 2 O) _43.7g, and N, N- dimethylaminopyridine 1.22g Was added and reacted at room temperature for 6 hours. After completion of the reaction, the reaction solution was concentrated to 100 mL, reprecipitated in 1 L of water, and the resulting precipitate was collected by filtration and dried to obtain 24.0 g of compound (3-7A).
-Synthesis of compound (3-7C) 24.0 g of compound (3-7A), 17.3 g of compound (3-7B) and 500 mL of dichloromethane were added to a 1 L three-necked flask equipped with a reflux tube and a nitrogen introducing tube. The mixture was refluxed for 20 hours. After completion of the reaction, the mixture was concentrated under reduced pressure to 100 mL, eluted with an alumina column (developing solvent hexane:ethyl acetate=6:4), concentrated and dried to obtain 22.9 g of compound (3-7C).
-Synthesis of compound (3-7) 22.9 g of compound (3-7C), 200 mL of tetrahydrofuran, 200 mL of ethanol and 1.15 g of 5% Pd/C were charged in a 2 L autoclave. Next, hydrogen was blown to make the pressure 1.4 kg/cm ^2, and the reaction was performed at room temperature for 20 hours. After completion of the reaction, the filtrate obtained by performing Celite filtration was concentrated under reduced pressure to 50 mL, and the obtained solution was reprecipitated with 1 L of water. The precipitate was collected by filtration, washed with methanol, and dried in vacuum to obtain 17.9 g of compound (3-7).

<Synthesis of polymer>
[Synthesis Example 2-1: Synthesis of Polymer (P1)]
100 mol parts of pyromellitic dianhydride (PMDA) and 100 mol parts of compound (I) as a diamine are dissolved in N-methyl-2-pyrrolidone (NMP) and reacted at room temperature for 6 hours to give 20 polyamic acid. A solution containing wt% was obtained. A small amount of the obtained polyamic acid solution was sampled, NMP was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10 wt% was 92 mPa·s. The polyamic acid obtained here was used as a polymer (P1).

[Synthesis Example 2-2 to Synthesis Example 2-23, Synthesis Example 2-27 and Synthesis Example 2-28]
Polyamic acids were synthesized in the same manner as in Synthesis Example 2-1 except that the types and amounts of the tetracarboxylic dianhydride and diamine used were changed as shown in Table 1 below. Regarding Synthesis Examples 2-2, 2-5, 2-6, 2-8, 2-10-2-12, 2-14-2-18, 2-20-2-23, the obtained polyamic acid was used. Polymer (P2), polymer (P5), polymer (P6), polymer (P8), polymer (P10) to polymer (P12), polymer (P14) to polymer (P18), The polymers (R2) to (R5) were used.
In addition, regarding Synthesis Examples 2-3, 2-4, 2-7, 2-9, 2-13, 2-19, 2-27, 2-28, pyridine and acetic anhydride were added to the obtained polyamic acid solution. It was added and chemically imidized. The reaction solution after chemical imidization was concentrated and prepared by NMP so that the concentration was 10% by weight.

In Table 1, the value in () of tetracarboxylic dianhydride represents the ratio [mol part] of the tetracarboxylic dianhydride used for the synthesis of the polymer to 100 mol parts in total. The numerical value in the parentheses of the diamine represents the usage ratio [mol part] with respect to 100 mol parts in total of the tetracarboxylic dianhydride used for the synthesis of the polymer. Abbreviations of acid anhydrides and diamines in Table 1 represent the following compounds, respectively.
<Tetracarboxylic acid dianhydride>
A-1: Pyromellitic dianhydride A-2: 1,2,3,4-cyclobutanetetracarboxylic dianhydride A-3: 2,3,5-tricarboxycyclopentyl acetic acid dianhydride A-4: 1R,2S,4S,5R-1,2,4,5-Cyclohexanetetracarboxylic dianhydride A-5: p-phenylene bis (trimellitic acid monoester anhydride)
<Diamine>
D-1: p-phenylenediamine D-2: 4-aminophenyl-4′-aminobenzamide D-3: N-(4-aminophenyl)-N-phenylbenzene-1,4-diamine D-4:4 -Aminophenyl-4'-aminobenzoate D-5:3-(3,5-diaminobenzoyloxy)cholestane

[Synthesis Example 2-24: Synthesis of polymer (P19)]
A polymer (P19) was synthesized according to the following scheme 10.

  To a 100 mL three-necked flask equipped with a nitrogen introducing tube and a thermometer, 4.55 g of compound (VI), 50 mL of tetrahydrofuran and 0.2 mL of N,N-dimethylformamide were added and ice-cooled to 5°C or lower. Next, after adding 3.39 g of the compound (C-1), 2.84 g of N-ethyl-N,N-diisopropylamine was slowly added, and then the mixture was returned to room temperature and polymerized overnight. After completion of the reaction, 100 mL of cyclopentanone was added, and liquid separation washing was performed three times with 100 mL of water, and then 100 mL of N-methyl-2-pyrrolidone was added to the organic layer and concentrated to 70 g, and then again N-methyl- 2-Pyrrolidone (100 mL) was added, and then the mixture was concentrated to 70 g to obtain an N-methyl-2-pyrrolidone solution of the polymer (P19) (solid content concentration 10%). The weight average molecular weight of the polymer (P19) was 5,500.

[Synthesis Example 2-25: Synthesis of polymer (P20)]
A polymer (P20) was synthesized according to the following scheme 11.

  To a 100 mL three-necked flask equipped with a nitrogen introducing tube and a thermometer, 7.12 g of compound (VII), 70 mL of tetrahydrofuran and 0.2 mL of N,N-dimethylformamide were added and ice-cooled to 5°C or lower. Next, after adding 3.25 g of the compound (A-6), 2.84 g of N-ethyl-N,N-diisopropylamine was slowly added, and then the mixture was returned to room temperature and polymerized overnight. After completion of the reaction, 140 mL of cyclopentanone was added, and the mixture was separated and washed three times with 140 mL of water, then 140 mL of N-methyl-2-pyrrolidone was added to the organic layer and concentrated to 92 g, and then again N-methyl- 2-Pyrrolidone (140 mL) was added and the mixture was concentrated to 92 g to obtain an N-methyl-2-pyrrolidone solution of the polymer (P20) (solid content concentration 10%). The weight average molecular weight of the polymer (P20) was 6,100.

[Synthesis Example 2-26: Synthesis of polymer (R6)]
A polymer (R6) was synthesized according to the following scheme 12.

  To a 200 mL three-necked flask equipped with a thermometer and a nitrogen inlet tube, 2.54 g of compound (vi-1), 50 mL of chloroform, 50 mL of water and 0.8 g of sodium hydroxide were charged, and the mixture was ice-cooled to 5°C or lower. Next, when 3.39 g of compound (C-1) was added and vigorously stirred for 4 hours, a white precipitate was obtained. This precipitate was insoluble in tetrahydrofuran and N-methyl-2-pyrrolidone.

[Synthesis Example 2-29; Synthesis of polymer (AP3)]
A polymer (AP3) was synthesized according to the following scheme 15.

  To a 100 mL three-necked flask equipped with a dropping funnel, a nitrogen introducing tube and a thermometer, 4.87 g of the compound (ADBA1), 25 mL of tetrahydrofuran and 4.8 of sodium hydride were added and ice-cooled to 5°C or lower. Next, a solution prepared by dissolving 2.70 g of compound (ADC1) in 25 mL of tetrahydrofuran was slowly added dropwise, and then the mixture was returned to room temperature and polymerized overnight. After completion of the reaction, 100 mL of cyclopentanone was added, 100 mL of water was used for liquid separation and washing three times, and then 100 mL of cyclopentanone was added to the organic layer to concentrate the mixture to 61 g. Then, 100 mL of cyclopentanone was added again, and then concentrated to 61 g to obtain a cyclopentanone solution of the polymer (AP3) (solid content concentration 10%). The weight average molecular weight of the polymer (AP3) was 5,000.

[Synthesis Example 2-30; Synthesis of polymer (AP4)]
A polymer (AP4) was synthesized according to the following scheme 16.

  A 500 mL three-necked flask equipped with an oxygen introduction tube and a thermometer was charged with 60 mL of N,N-dimethylacetamide, 0.5 g of copper chloride, 20 mL of pyridine and 7.24 g of compound (V). Then, 248 mL of oxygen was introduced, and it was made to react at room temperature for 2 hours. After completion of the reaction, 100 mL of cyclopentanone was added, and liquid separation washing was performed with 100 mL of water three times. Next, after adding 72 g of cyclopentanone to the organic layer and concentrating the mixture to 72 g by vacuum concentration, 72 g of cyclopentanone was added again and the mixture was concentrated to 72 g to give a solution of the polymer (AP4) in cyclopentanone ( A solid content concentration of 10%) was obtained. The weight average molecular weight of the polymer (AP4) was 14,000.

[Synthesis Example 2-31; Synthesis of polymer (P21)]
100 parts by mole of 1R,2S,4S,5R-1,2,4,5-cyclohexanetetracarboxylic acid dianhydride as tetracarboxylic acid dianhydride, and 70 parts by mole of compound (I) and compound (3-7) as diamine. ) 30 mol parts were dissolved in N-methyl-2-pyrrolidone (NMP) and reacted at room temperature for 6 hours to obtain a solution containing 20% by weight of polyamic acid. A small amount of the obtained polyamic acid solution was sampled, NMP was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 89 mPa·s. The polyamic acid obtained here was used as a polymer (P21).

[Example 1]
<Preparation of liquid crystal aligning agent>
To the polymer (P1) obtained in Synthesis Example 2-1 as a polymer, NMP and butyl cellosolve (BC) were added as an organic solvent, the solvent composition was NMP:BC=50:50 (weight ratio), and the solid content concentration was 5 It was a 0.0 wt% solution. A liquid crystal aligning agent was prepared by filtering this solution with a filter having a pore size of 1 μm.

<Evaluation of storage stability>
The liquid crystal aligning agent prepared above was put in a sample bottle and left in an oven at a temperature of 40° C. for 1 week to measure the change in viscosity (mPa·s). The viscosity was measured at 25° C. using an E type rotational viscometer. Looking at the increase/decrease change in viscosity after 1 week, the storage stability was "good (○)" when it was less than 5%, and the storage stability was "good (△)" when it was 5% or more and less than 10%. When it was 10% or more, the storage stability was evaluated as "poor (x)". As a result, the storage stability was determined to be "good" in this example.

<Manufacture of liquid crystal display device for rubbing alignment>
As a substrate, a liquid crystal aligning agent prepared above was applied by a spinner on a glass substrate having two systems of metal electrodes (electrode A and electrode B) consisting of comb-patterned chromium on one surface, After prebaking on a hot plate for 1 minute, post baking was performed on a hot plate at 230° C. for 10 minutes to form a coating film having a film thickness of about 800Å. Using a rubbing machine having a roll around which a nylon cloth is wound on the formed coating film surface, the roll rotation speed is 1,000 rpm, the stage moving speed is 25 mm/sec, and the pushing length is 0.4 mm. Rubbing treatment was performed to impart liquid crystal alignment ability. Further, this substrate was ultrasonically cleaned in ultrapure water for 1 minute and dried in a 100° C. clean oven for 10 minutes to manufacture a substrate having a liquid crystal alignment film on the surface having the comb-teeth-shaped chromium electrode. The substrate having this liquid crystal alignment film was referred to as “substrate A”.

Separately from this, on one surface of a glass substrate having a thickness of 1 mm without electrodes, a coating film of a liquid crystal aligning agent is formed and rubbed in the same manner as described above, washed and dried, and liquid crystal alignment is performed on one surface. A substrate having a membrane was manufactured. The substrate having this liquid crystal alignment film was referred to as “substrate B”.
Next, after applying an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm to the outer edge of the surface of the substrate having the rubbing-treated liquid crystal alignment film, the rubbing directions in each liquid crystal alignment film are antiparallel. Then, the two substrates A and B were opposed to each other with a gap therebetween, and the outer edge portions were brought into contact with each other and pressure-bonded to cure the adhesive. Then, after filling a nematic liquid crystal (MLC-2042, manufactured by Merck & Co., Inc.) between the pair of substrates through the liquid crystal injection port, the liquid crystal injection port is sealed with an acrylic photo-curing adhesive to form a horizontal electric field liquid crystal cell. Was manufactured.

<Evaluation of afterimage characteristic (image sticking characteristic)>
A horizontal electric field type liquid crystal display element was manufactured by using the same method as the above-mentioned "manufacturing of liquid crystal display element for rubbing alignment". This in-plane switching mode liquid crystal display element was placed in an environment of 25° C. and 1 atm, and a voltage of 3.5 V and 5 V of AC voltage was applied to the electrode A for 2 hours without applying voltage to the electrode B. Immediately thereafter, a voltage of 4 V AC was applied to both the electrodes A and B. The time from when the voltage of 4 V 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. If the time is less than 100 seconds, the afterimage characteristic is “good (◯)”, if the time is 100 seconds or more and less than 150 seconds, the afterimage characteristic is “OK”, and if it exceeds 150 seconds. Was evaluated as “poor (x)”. As a result, this example was evaluated as “good”.

[Examples 2 to 9, 27 and Comparative Examples 2, 3, 5]
Liquid crystal aligning agents were prepared in the same manner as in Example 1 except that the types and amounts of the polymers used were as shown in Table 2 below. Using the prepared liquid crystal aligning agent, the storage stability was evaluated, the liquid crystal display device for rubbing alignment was manufactured, and the residual image property was evaluated in the same manner as in Example 1. The results are shown in Table 2 below.

  In Table 2, the numerical value of the compounding ratio of the polymer indicates the orientation ratio [parts by weight] with respect to 100 parts by weight in total of the polymer components used for the preparation of the liquid crystal aligning agent.

[Examples 10 to 22, 28, 32, 33, 36 and Comparative Examples 1 and 4]
Liquid crystal aligning agents were prepared in the same manner as in Example 1 except that the types and amounts of the polymers used were as shown in Table 2 above. Using the prepared liquid crystal aligning agent, the storage stability was evaluated, the liquid crystal display device for rubbing alignment was manufactured, and the residual image property was evaluated in the same manner as in Example 1. The results are shown in Table 2 above.

<Phase separation evaluation>
With respect to the liquid crystal aligning agent obtained by blending two kinds of polymers, the phase separation between the polymers was evaluated. First, two kinds of liquid crystal aligning agents having different kinds of contained polymers were prepared by performing the same operation as in Example 1 except that only one kind of the two kinds of polymers was used. Next, a fired film was prepared for each of the prepared liquid crystal aligning agents and the surface contact angle (reference contact angle A1, A2 [°]) of the film was measured. Further, with respect to the liquid crystal aligning agent prepared above, a fired film was prepared by the same operation, and the surface contact angle B [°] of the film was measured. When the phase separation property of the polymer is good, the two types of polymers are divided into the upper layer and the lower layer, so that the surface contact angle B of the fired film containing the two types of polymers is the same as that of the two types of polymers. While it is close to one surface contact angle (A1 or A2), when the phase separation property is not so good, it is considered to be a value close to the middle of the two kinds of polymers. Therefore, when the surface contact angle B of the fired film containing two kinds of polymers is close to either of the reference contact angles A1 and A2, the phase separation property is considered to be good, and the surface contact angle B and the two reference contact angles are considered. If the difference Δθ from either of the angles A1 or A2 is less than 5%, the phase separation property is “good”, and if it is 5% or more and less than 10%, “OK”, 10% or more. When it was, it was set as "poor (x)". The evaluation results of each example are shown in Table 2 above. A value represented by the following equation (2) was used as Δθ.
Δθ [%]=(|B−A|/B)×100 (2)
(In the formula (2), A is one of the reference contact angles A1 and A2, and B is the surface contact angle of the fired film produced using the liquid crystal aligning agent containing two kinds of polymers.)

[Example 23]
<Preparation of liquid crystal aligning agent>
A liquid crystal aligning agent was prepared in the same manner as in Example 1 except that the type and amount of the polymer used were as shown in Table 2 above.
<Evaluation of storage stability>
Using the prepared liquid crystal aligning agent, the storage stability of the liquid crystal aligning agent was evaluated in the same manner as in Example 1 above. As a result, this example was evaluated as “OK”.

<Production of liquid crystal display element for photo-alignment (1)>
The surface of the glass substrate having the liquid crystal aligning agent prepared as described above on one surface of two metal electrodes (electrode A and electrode B) made of chromium patterned in a comb shape, and the surface of the counter glass substrate on which no electrode is provided. A spinner was applied so that the film thickness would be 0.1 μm, and the coating was formed by drying on a hot plate at 80° C. for 1 minute and in a clean oven at 200° C. for 1 hour. The surface of the coating film was irradiated with 10,000 J/m ² of ultraviolet rays of polarized light including a bright line of 254 nm from the direction normal to the substrate using a Hg-Xe lamp to form a liquid crystal alignment film. Next, with respect to the pair of substrates that have been subjected to the light irradiation treatment, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm and having a diameter of 5.5 μm is applied by screen printing, leaving a liquid crystal injection port at the edge of the surface on which the liquid crystal alignment film is formed. The substrates were stacked and pressure-bonded so that the projection directions of the polarization axes on the substrate surface during light irradiation were antiparallel, and the adhesive was thermoset at 150° C. for 1 hour. Next, after filling a nematic liquid crystal (MLC-7028, manufactured by Merck & Co., Inc.) between the pair of substrates through the liquid crystal injection port, the liquid crystal injection port was sealed with an epoxy adhesive. Further, in order to remove the flow orientation at the time of injecting liquid crystal, this was heated at 150° C. and then gradually cooled to room temperature. Next, a polarizing plate was attached to both outer surfaces of the substrate to prepare a horizontal electric field type liquid crystal display element.

<Evaluation of afterimage characteristics>
A lateral electric field type liquid crystal display element was manufactured by the same method as in the above-mentioned “Production of liquid crystal display element for optical alignment (1)”, and afterimage characteristics were evaluated by the same method as in Example 1. As a result, in this example, an afterimage was less likely to occur and the evaluation was “good”.

[Examples 24 to 26]
Liquid crystal aligning agents were prepared in the same manner as in Example 1 except that the types and amounts of the polymers used were as shown in Table 2 above. Further, the storage stability was evaluated in the same manner as in Example 1 using the prepared liquid crystal aligning agent. Further, a liquid crystal display device for optical alignment was manufactured in the same manner as in Example 23 except that the used liquid crystal aligning agent was changed. The characteristics were evaluated respectively. In Examples 25 and 26 in which two types of polymers were blended to prepare a liquid crystal aligning agent, the phase separation properties of the two types of polymers were evaluated by the same method as in the above <Phase separation evaluation>. The results are shown in Table 2 above.

[Examples 29 and 30]
<Preparation of liquid crystal aligning agent>
A liquid crystal aligning agent was prepared in the same manner as in Example 1 except that the type and amount of the polymer used were as shown in Table 2 above.
<Evaluation of storage stability>
The storage stability was evaluated in the same manner as in Example 1 using the prepared liquid crystal aligning agent. As a result, both Examples 29 and 30 were evaluated as “good”.

<Manufacturing of liquid crystal display element for photo-alignment (2)>
Each of the liquid crystal aligning agents prepared above was provided with a glass substrate having two systems of metal electrodes (electrode A and electrode B) made of chrome patterned in a comb shape on one surface, and a counter glass substrate having no electrodes. Was applied to the surface of the substrate using the above as a pair using a spinner so as to have a film thickness of 0.1 μm, and baked for 1 minute on a hot plate at 80° C. Next, this coating film surface was irradiated with polarized UV rays of 10,000 J/m ² including a bright line of 254 nm using a Hg-Xe lamp from the substrate normal direction, and then dried in a clean oven at 200° C. for 1 hour. A liquid crystal alignment film was formed. Next, an epoxy resin adhesive containing 5.5 μm diameter aluminum oxide spheres with an epoxy resin adhesive having a diameter of 5.5 μm was screen-printed on the pair of substrates, leaving a liquid crystal injection port at the edge of the surface on which the liquid crystal alignment film was formed, and then polarized at the time of light irradiation. The substrates were stacked and pressure-bonded so that the projection directions of the axes on the substrate surface were antiparallel, and the adhesive was thermoset at 150° C. for 1 hour. Next, after filling a nematic liquid crystal (MLC-7028, manufactured by Merck & Co., Inc.) between the pair of substrates through the liquid crystal injection port, the liquid crystal injection port was sealed with an epoxy adhesive. Further, in order to remove the flow orientation at the time of liquid crystal injection, this was heated at 150° C. and then gradually cooled to room temperature. After that, polarizing plates were attached to both outer surfaces of the substrate to manufacture a horizontal electric field type liquid crystal display element.

<Evaluation of afterimage characteristics>
A lateral electric field type liquid crystal display element was manufactured by the same method as in the above-mentioned "Production of liquid crystal display element for optical alignment (2)", and the afterimage characteristics were evaluated by the same method as in Example 1 above. As a result, Example 29 was evaluated as “good” and Example 30 was evaluated as “OK”.
<Phase separation evaluation>
Using the prepared liquid crystal aligning agent, the phase separation properties of the two types of polymers were evaluated by the same operation as the above <Evaluation of phase separation property>. As a result, both Examples 29 and 30 were evaluated as “good”.

As shown in Table 2, by using the polymer (P) in which the amide bond was protected, the storage stability could be improved while the afterimage characteristics were not impaired. Further, even when a polymer having a high imidization ratio (for example, a polymer having an imidization ratio of 90% or more) was used, good results were obtained with respect to storage stability. Further, a polymer having a strong hydrogen bonding property such as the polymer (P20) does not have a very good storage stability, but by introducing a protective group, the solubility in a solvent is improved and the storage stability can be improved. I understood. In addition, good results were obtained as the afterimage characteristics of the liquid crystal display device. It is presumed that this is because the protective group introduced into the polymer was removed by heat, and the highly oriented structure was regenerated after post-baking.
Regarding the phase separation property of the system in which a plurality of kinds of polymers were blended, all of the examples were good. It is presumed that this is because the hydrophobicity of the polymer (P) was increased by the effect of introducing the protective group and a polarity difference was generated between the polymer (P) and the polymer having no protective group, and thus the phase separation property was improved. Further, for these reasons, the phase separation is induced even when a polymer such as the polymer (R1) which does not have very good liquid crystal orientation and tends to deteriorate the afterimage characteristic of the liquid crystal display device is added. As a result of the uneven distribution of the highly oriented film on the upper layer, it is presumed that good results were obtained in the evaluation of the afterimage characteristics.

[Example 31]
<Preparation of liquid crystal aligning agent>
To the solution containing the polymer (R5) obtained in Synthesis Example 2-23 as a polymer component, NMP and butyl cellosolve (BC) were added as organic solvents, and the compound synthesized in Synthesis Example 1-8 as an additive. 20 parts by weight of (VIII) was added to 100 parts by weight of the polymer (R5) to obtain a solution having a solvent composition of NMP:BC=50:50 (weight ratio) and a solid content concentration of 6.0% by weight. A liquid crystal aligning agent was prepared by filtering this solution with a filter having a pore size of 1 μm.

<Evaluation of printability>
The liquid crystal aligning agent prepared above was applied to the transparent electrode surface of the glass substrate with a transparent electrode made of an ITO film using a liquid crystal aligning film printer (manufactured by Nissha Printing Co., Ltd.), and on a hot plate at 80° C. After heating (pre-baking) for 1 minute to remove the solvent, heating (post-baking) was performed for 10 minutes on a hot plate at 200° C. to form a coating film having an average film thickness of 600Å. The coating film was observed under a microscope with a magnification of 20 to check for print unevenness and pinholes. The evaluation is printability “good” when neither print unevenness nor pinholes were observed, and printability “good” when at least one of print unevenness and pinholes was slightly observed, print unevenness and pins. When at least one of the holes was frequently seen, the printability was “poor”. In this example, neither print unevenness nor pinholes were observed, and the printability was “good”.

<Manufacture of liquid crystal display element>
A liquid crystal alignment film printer is provided on each electrode surface of a pair of glass substrates each having an ITO electrode divided into a plurality of regions by patterning the liquid crystal alignment agent prepared above into a slit shape as shown in FIG. (Nissha Printing Co., Ltd.) is applied, and the solvent is removed by heating (pre-baking) on a hot plate at 80° C. for 1 minute, and then heating (post-baking) on a hot plate at 200° C. for 10 minutes. To form a coating film having an average film thickness of 600Å. The coating film was rubbed with a rubbing machine having a roll around which a rayon cloth was wound, at a roll rotation speed of 400 rpm, a stage moving speed of 3 cm/sec, and a foot pushing length of 0.1 mm. After that, ultrasonic cleaning was performed in ultrapure water for 1 minute, and then drying was performed in a 100° C. clean oven for 10 minutes to obtain a substrate having a liquid crystal alignment film. This operation was repeated to obtain a pair (two) of substrates having a liquid crystal alignment film. The rubbing treatment performed above is a weak rubbing treatment performed for the purpose of controlling the collapse of the liquid crystal and performing alignment division by a simple method.
Next, after applying an epoxy resin adhesive containing 5.5 μm diameter aluminum oxide spheres to the outer edge of the surface having the liquid crystal alignment film on one of the pair of substrates, The adhesive was cured by stacking and pressing so as to face each other. Then, a nematic liquid crystal (MLC-6608 manufactured by Merck & Co., Inc.) was filled between the pair of substrates through the liquid crystal injection port, and then the liquid crystal injection port was sealed with an acrylic photo-curing adhesive to manufacture a liquid crystal cell. With respect to the obtained liquid crystal cell, an alternating current of 10 Hz with a frequency of 60 Hz was applied between the electrodes, and while the liquid crystal was being driven, an ultraviolet ray irradiation device using a metal halide lamp as a light source was used to emit an ultraviolet ray of 10,000 J/m ^2. The irradiation amount was Note that this irradiation amount is a value measured by using a photometer that measures the wavelength of 365 nm.

<Evaluation of afterimage characteristics>
The liquid crystal display element manufactured as described above was placed in an environment of 25° C. and 1 atm, and an AC voltage of 10 V was applied to the electrode A for 300 hours without applying a voltage to the electrode B. Immediately after 300 hours had elapsed, a voltage of AC 3 V was applied to both the electrode A and the electrode B, and the difference ΔT [%] in light transmittance between both electrodes was measured. At this time, when the ΔT is less than 2%, the afterimage characteristic is “good (◯)”, and when it is 2% or more and less than 4%, the afterimage characteristic is “acceptable (Δ)” and when it is 4% or more. The afterimage characteristic was evaluated as "poor (x)". As a result, this example was evaluated as “good”.

[Comparative Examples 6 and 7]
A liquid crystal aligning agent was prepared in the same manner as in Example 31 except that the types and amounts of the additives used were as shown in Table 3 below. Further, using the prepared liquid crystal aligning agent, the printability was evaluated, the liquid crystal display device was manufactured, and the afterimage characteristic was evaluated in the same manner as in Example 31. The results are shown in Table 3 below.

In Table 3, the numerical value of the blending ratio of the polymer and the additive shows the blending ratio [parts by weight] with respect to 100 parts by weight in total of the polymer components used for the preparation of the liquid crystal aligning agent. The abbreviations of additives are as follows.
Add-1: Compound represented by the following formula (Add-1) Add-2: Compound represented by the following formula (Add-2)

  As shown in Table 3, in Example 31, by using a compound having a protective group introduced into the amide bond portion as the photopolymerizable compound, it is possible to improve the printability while maintaining the afterimage characteristics of the liquid crystal display device. I was able to. On the other hand, in Comparative Example 6 in which the protective group was not introduced into the amide bond portion, the printability was “poor”, and in Comparative Example 7 having no nitrogen atom, the afterimage characteristic was inferior to that of the example.

Example 34
<Preparation of liquid crystal aligning agent>
To the polymer (AP3) obtained in Synthesis Example 2-29 above as a polymer, NMP and butyl cellosolve (BC) were added as an organic solvent, and the solvent composition was NMP:BC:cyclopentanone=20:50:30 (weight ratio). ) And a solid content concentration of 5.0% by weight. A liquid crystal aligning agent was prepared by filtering this solution with a filter having a pore size of 1 μm.
<Evaluation of storage stability>
Using the prepared liquid crystal aligning agent, the storage stability of the liquid crystal aligning agent was evaluated in the same manner as in Example 1 above. As a result, in this example, the storage stability was evaluated as “good”.

<Manufacturing of liquid crystal display element for photo-alignment (3)>
The surface of the glass substrate having the liquid crystal aligning agent prepared as described above on one surface of two metal electrodes (electrode A and electrode B) made of chromium patterned in a comb shape, and the surface of the counter glass substrate on which no electrode is provided. A spinner was applied to the above to a film thickness of 0.1 μm and dried in a clean oven at 200° C. for 1 hour to form a coating film.
The surface of this coating film was irradiated with polarized ultraviolet rays of 5,000 J/m ² including a bright line of 365 nm from the substrate normal direction using an Hg-Xe lamp to form a liquid crystal alignment film. Next, with respect to the pair of substrates that have been subjected to the light irradiation treatment, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm and having a diameter of 5.5 μm is applied by screen printing, leaving a liquid crystal injection port at the edge of the surface on which the liquid crystal alignment film is formed. The substrates were stacked and pressure-bonded so that the projection directions of the polarization axes on the substrate surface during light irradiation were antiparallel, and the adhesive was thermoset at 150° C. for 1 hour. Next, after filling a nematic liquid crystal (MLC-7028, manufactured by Merck & Co., Inc.) between the pair of substrates through the liquid crystal injection port, the liquid crystal injection port was sealed with an epoxy adhesive. Further, in order to remove the flow orientation at the time of injecting liquid crystal, this was heated at 150° C. and then gradually cooled to room temperature. Next, a polarizing plate was attached to both outer surfaces of the substrate to prepare a horizontal electric field type liquid crystal display element.

<Evaluation of afterimage characteristics>
A horizontal electric field type liquid crystal display element was manufactured by the same method as in the above-mentioned "Production of liquid crystal display element for optical alignment (3)", and the afterimage characteristics were evaluated by the same method as in Example 1. As a result, in this example, an afterimage was less likely to occur and the evaluation was “good”.

Example 35
A liquid crystal aligning agent was prepared in the same manner as in Example 34, except that the polymer (AP4) was used instead of the polymer (AP3). Further, evaluation was performed in the same manner as in Example 34 using the obtained liquid crystal aligning agent. The results are shown in Table 4 below.

  As shown in Table 4, the storage stability of the liquid crystal aligning agent was good even when a polymer having an azobenzene structure in its main chain was used as the polymer (P). Also, good results were obtained in the evaluation of the afterimage characteristics of the liquid crystal display device.

  A, B: Glass substrate.

Claims (6)

A compound (P) having a partial structure represented by the following formula (1) in the main chain (excluding polyamic acid, polyamic acid ester and polyimide having the structure represented by the following formula (8)) is contained. Liquid crystal aligning agent.
(In the formula (1), Y ¹ is a monovalent organic group that is eliminated by at least ^one of heat, light, acid, and base. “*” represents a bond.)
(In the formula (8), R ¹ and R ² are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or a group represented by the following formula (9), at least one of which is represented by the following formula: It is a group represented by (9).)
(In the formula (9), A is a single bond or a divalent group which is a hydrocarbon group having 1 to 4 carbon atoms.)   The liquid crystal aligning agent according to claim 1, wherein the compound (P) is a polymer having a partial structure represented by the formula (1).   The liquid crystal aligning agent according to claim 2, wherein the compound (P) is at least one selected from the group consisting of polyamic acid, polyamic acid ester, polyimide and polyamide. Containing at least one polymer selected from the group consisting of polyamic acid, polyamic acid ester, polyimide and polyamide , and a compound (P) having as an additive a partial structure represented by the following formula (1) in the main chain Liquid crystal aligning agent.
(In the formula (1), Y ¹ is a protecting group. “*” represents a bond.)   A liquid crystal alignment film formed using the liquid crystal alignment agent according to claim 1.   A liquid crystal display device comprising the liquid crystal alignment film according to claim 5.