TW201430056A - Liquid crystal aligning agent, liquid crystal aligning film and method for producing the same and liquid crystal display element - Google Patents

Abstract

The invention provides a liquid crystal aligning agent, which contains a compound (B') and a polymer component (wherein a compound corresponding to the compound (B') is excluded). A thermal weight reduction of the compound (B') obtained by measuring under a temperature-increasing condition of 20 DEG C /min from 40 DEG C is 30% or less at 120 DEG C, and is 90% or more at 250 DEG C. A liquid crystal aligning film is formed by using the liquid crystal aligning agent to obtain a liquid crystal display element having a high performance in every property such as reliability, leveling property, liquid crystal aligning property, and after image property. At least one polymer (A) and the like selected from a group consisting of a polyamic acid, a polyamic acid ester and a polyimide can be listed as an example of the polymer component.

Description

Liquid crystal alignment agent, liquid crystal alignment film, manufacturing method thereof, and liquid crystal display element

The present invention relates to a liquid crystal alignment agent, a liquid crystal alignment film, a method for producing the same, and a liquid crystal display element.

Conventionally, liquid crystal display elements have developed various driving methods in which electrode structures or physical properties of liquid crystal molecules used are different, and for example, Twisted Nematic (TN) type or Super Twisted Nematic (STN) is known. Various liquid crystal display elements such as a Vertical Alignment (VA) type, an InPlane Switching (IPS) type, and a Fringe Field Switching (FFS) type. These liquid crystal display elements have a liquid crystal alignment film for aligning liquid crystal molecules. In terms of various properties such as heat resistance, mechanical strength, and affinity with liquid crystal, the material of the liquid crystal alignment film is usually polyacrylic acid or polyimide. The liquid crystal alignment film is usually formed by applying a liquid crystal alignment agent obtained by dissolving a polymer such as polylysine in a solvent onto a substrate, and heating the coated surface.

In recent years, liquid crystal display elements have not only been used for personal computers, etc. as before. The terminal is used for various purposes such as a liquid crystal television or a car navigation system, a mobile phone, a smart phone, an information display, and the like. In addition, in order to satisfy the above requirements, various liquid crystal alignment agents have been proposed in order to satisfy the above-mentioned requirements (see, for example, Patent Document 1 or Patent Document 2).

For example, Patent Document 1 proposes that a very small amount of a compound having one carboxyl group in the molecule, a compound having one carboxylic acid anhydride group in the molecule, and one molecule in the molecule, in addition to poly-proline or polyimine. The compound of the tertiary amino group-containing compound is contained in the liquid crystal alignment agent, thereby improving the voltage holding ratio and afterimage characteristics of the formed liquid crystal display element. Further, Patent Document 2 proposes that the antioxidant and the epoxy group-containing compound are contained in the liquid crystal alignment agent together with the polyaminic acid or the polyimine, thereby improving not only the light stress, heat, moisture, and the like. The electrical characteristics in the case of long-term continuous driving under the environment, and the improvement of reworkability.

As a method of imparting a liquid crystal alignment ability to a polymer film formed by using a liquid crystal alignment agent, in recent years, a photo-alignment method using photo-isomerization, photodimerization, photodegradation, or the like has been proposed as a technique for replacing the rubbing method (for example, Patent Document 3). This photo-alignment method is a technique for controlling the alignment of liquid crystal molecules by irradiating polarized or non-polarized radiation to a radiation-sensitive polymer film formed on a substrate to impart anisotropy to the film. According to this method, generation of dust or static electricity in the step can be suppressed as compared with the conventional rubbing method, and thus occurrence of display failure or deterioration in yield due to dust or the like can be suppressed. In addition, it also has a pair formed on the substrate The coating film uniformly imparts the advantage of the liquid crystal alignment ability.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. Hei 8-76128

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2012-194538

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2003-307736

In recent years, the use range of liquid crystal display elements has been expanded, and it is conceivable to use liquid crystal display elements in a more severe environment than before. Therefore, the liquid crystal alignment film is required to be able to withstand the use in a more severe environment than the previous liquid crystal alignment film (high reliability). Further, from the viewpoint of improving the yield of the product, the liquid crystal alignment agent is required to form a uniform and smooth film in the coating range of the substrate, that is, the leveling property is good.

In addition, in the case of a photo-alignment method in which a chemical change occurs by irradiation with ultraviolet rays or the like, it tends to be inferior in the alignment control force of the liquid crystal as compared with the conventional liquid crystal alignment film which is subjected to the rubbing treatment. Therefore, when the alignment ability is imparted by the photo-alignment method, the liquid crystal alignment property is not sufficient, or for example, in the case of the lateral electric field type liquid crystal display element, the printing is problematic.

The present invention has been made in view of the above problems, and a main object thereof is to provide a liquid crystal alignment agent for obtaining a liquid crystal display element having high performance. Specifically, one of the objects is to provide a liquid crystal alignment agent for obtaining a liquid crystal alignment film having high reliability and good leveling property. Further, another object of the invention is to provide a liquid crystal alignment agent for obtaining a liquid crystal display element which is excellent in liquid crystal alignment and has less burnt.

The inventors of the present invention conducted active research in order to achieve the above-described problems of the prior art, and as a result, found that a specific compound can be contained in a liquid crystal alignment agent together with a polymer such as polyglycolic acid or polyamidene. In order to solve the above problems, the present invention has been completed. Specifically, the present invention provides the following liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element.

An aspect of the present invention provides a liquid crystal alignment agent comprising a compound (B') and a polymer component (excluding a compound corresponding to the above compound (B')), wherein the compound (B') is from 40 ° C The amount of thermal weight loss at 120 ° C measured by a temperature rise condition of 20 ° C /min was 30% or less, and the amount of thermal weight reduction at 250 ° C was 90% or more.

An aspect of the present invention provides a liquid crystal alignment agent containing at least one polymer (A) selected from the group consisting of polylysine, polyphthalate, and polyimine, and the following formula (b) Compound (B) represented.

(In the formula (b), X ¹ and Y ¹ are each independently a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 6 carbon atoms, a halogenated alkyl group having 1 to 6 carbon atoms, an amine group, an epoxy group, or an epoxy group. a group, a phenyl group, a vinyl group, a (meth) acrylonitrile group, a fluorenyl group or a carboxyl group; and R ¹ and R ² are each independently a hydrogen atom, a fluorine atom, an alkyl group having 1 to 6 carbon atoms, and a carbon number of 1 to 6; a halogenated alkyl group or a phenyl group. m is an integer of 1 to 5, and n is an integer of 2 to 20; wherein, when m is 2 or more, a plurality of R ¹ and R ² in the repeating unit may be the same or Different; R ¹ , R ² and m of each repeating unit may be the same or different.)

Another aspect of the present invention provides a liquid crystal alignment agent comprising, as the above polymer component, a polymer selected from the group consisting of polylysine, polylysine, and polyamidiamine. In at least one of the group, the polymer has a structure selected from the following formula (ph-1), a cyclobutane ring which may have a substituent, a carbon-carbon unsaturated bond, and an azobenzene in the main chain. At least one structure of the group consisting of skeletons.

Further, another aspect of the invention provides a method for producing a liquid crystal alignment film comprising: a film formation step of liquid crystal containing a compound (B') and a polymer component (excluding a compound corresponding to the compound (B')) The coating agent is applied to the substrate to form a coating film, and the amount of thermal weight reduction at 120 ° C of the compound (B') measured at a temperature rising condition of 20 ° C /min from 40 ° C is 30% or less, and 250 The amount of thermal weight reduction at ° C is 90% or more; and the light irradiation step, the coating film is irradiated with light to form a liquid crystal alignment film. In addition, a method for producing a liquid crystal alignment film is provided, wherein the film formation step includes: a prebaking step of preheating a liquid crystal alignment agent coated on the substrate; and a post-baking step after the prebaking The coating film is further heated; and the light irradiation step is a step of irradiating the coating film after the prebaking step and before the post-baking step.

Another aspect of the present invention provides a use of the above liquid crystal alignment agent. A liquid crystal alignment film formed. In addition, another aspect is to provide a liquid crystal display element including the liquid crystal alignment film.

By using the above liquid crystal alignment agent to form a liquid crystal alignment film, a high performance liquid crystal display element can be obtained. Specifically, according to the liquid crystal alignment agent, a liquid crystal alignment film having high reliability and uniformity (in-plane uniformity and smoothness) can be formed. In addition, by having a liquid crystal alignment film formed using the liquid crystal alignment agent, it is possible to produce a liquid crystal display element having less deterioration in display quality and high reliability.

Further, according to the above liquid crystal alignment agent, a liquid crystal display element having good liquid crystal alignment property can be obtained. Further, in the case of manufacturing a liquid crystal display element of a lateral electric field type, a liquid crystal display element having less burnt printing can be obtained.

11‧‧‧Electrode A

12‧‧‧Electrode B

FIG. 1 is a view showing an electrode pattern of a pair of electrodes patterned into a comb shape.

The liquid crystal alignment agent of the present invention contains a polymer component and a specific compound (B'). Hereinafter, each component contained in the liquid crystal alignment agent of the present invention and other components arbitrarily formulated as needed will be described.

[polymer composition]

Examples of the polymer contained in the liquid crystal alignment agent include polylysine, polyimine, polyphthalate, polyester, polyamine, polyorganosiloxane, cellulose derivative, and poly Acetal derivative, polystyrene derivative, poly(styrene-phenyl-n-butylene A polymer having a main skeleton such as a diquinone imine derivative or a poly(meth)acrylate derivative. The above-mentioned polymer can be used by appropriately selecting one or more kinds of polymers having a skeleton selected from the above polymers, depending on the use of the liquid crystal display element. Further, (meth) acrylate means acrylate and methacrylate.

The polymer contained in the liquid crystal alignment agent is preferably at least one polymer containing a group selected from the group consisting of polylysine, polyphthalate, and polyimine in the above polymer (A). .

<Polymer (A): Polylysine> "When the treatment of the alignment ability is not performed or the liquid crystal alignment ability is imparted by the rubbing treatment"

The polyamic acid as the polymer (A) can be obtained by reacting a tetracarboxylic dianhydride with a diamine.

[tetracarboxylic dianhydride]

Examples of the tetracarboxylic dianhydride used for the synthesis of polyamic acid include aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, and aromatic tetracarboxylic dianhydride. Specific examples of the tetracarboxylic dianhydride include aliphatic monocarboxylic dianhydride: 1,2,3,4-butanetetracarboxylic dianhydride; and alicyclic tetracarboxylic dianhydride. Listed: 1,2,3,4-cyclobutane tetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentyl acetic 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-six Hydrogen-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) -furyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 3,5,6-tricarboxy-2-carboxymethylnorbornane-2:3,5:6- Dihydride, 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-dianhydride, 4,9-dioxatricyclo[5.3.1.0 ^2,6 ] And undecane-3,5,8,10-tetraketone, cyclohexanetetracarboxylic dianhydride, etc., and the aromatic tetracarboxylic dianhydride is, for example, pyromellitic dianhydride, and the like. The tetracarboxylic dianhydride described in JP-A-2010-97188 is used. In addition, the above-mentioned tetracarboxylic dianhydride may be used alone or in combination of two or more.

From the viewpoints of transparency and solubility in a solvent, etc., it is preferred to contain an alicyclic tetracarboxylic dianhydride as a tetracarboxylic dianhydride for synthesis. Further, the alicyclic tetracarboxylic dianhydride preferably contains a compound selected from the group consisting of 2,3,5-tricarboxycyclopentyl acetic 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, 2,4,6, At least one of a group consisting of 8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-dianhydride and 1,2,3,4-cyclobutanetetracarboxylic dianhydride More preferably, it comprises at least one selected from the group consisting of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride and 1,2,3,4-cyclobutanetetracarboxylic dianhydride.

At least one selected from the group consisting of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride and 1,2,3,4-cyclobutanetetracarboxylic dianhydride as tetracarboxylic dianhydride In the case of the total amount of the tetracarboxylic dianhydride used for the synthesis of the polyamic acid, the total content of the compounds is preferably 10 mol% or more, more preferably 20 mol% to 100 mol%. %, especially preferably 50% by mole to 100% by mole.

[diamine]

Examples of the diamine used for the synthesis of the polyamic acid include an aliphatic diamine, an alicyclic diamine, an aromatic diamine, a diamine organic decane, and the like. Specific examples of the diamines include, for example, m-xylylenediamine, 1,3-propanediamine, tetramethylenediamine, and pentamethylenediamine. Hexamethylenediamine or the like; examples of the alicyclic diamine include 1,4-diaminocyclohexane, 4,4'-methylenebis(cyclohexylamine), and 1,3-bis(amine) Methyl)cyclohexane or the like; examples of the aromatic diamine include p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfide, and 1 , 5-diaminonaphthalene, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl)-4,4'-diamine linkage Benzene, 2,7-diaminoguanidine, 4,4'-diaminodiphenyl ether, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 9,9- Bis(4-aminophenyl)anthracene, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2-bis(4-aminophenyl)hexafluoro Propane, 4,4'-(p-phenylenediphenylene)diphenylamine, 4,4'-(meta-phenyldiisopropylidene)diphenylamine, 1,4-bis(4-amino Phenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine , 3,6-diamino acridine, 3,6-diamine Ketrazole, 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, 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-indole-5-amine, 1-( 4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-indol-6-amine, 3,5-diaminobenzoic acid, cholestyloxy-3 , cholestanyloxy-3,5-diaminobenzene, cholestenyloxy-3,5-diaminobenzene, cholestyloxy-2,4 -cholestanyyl-2,4-diaminobenzene,cholestenyloxy-2,4-diaminobenzene,3,5-diaminobenzoic acid cholesteric Cholestanyl 3,5-diaminobenzoate, cholestenyl 3,5-diaminobenzoate, lanyl alkyl 3,5-diaminobenzoate Lanostanyl 3,5-diaminobenzoate), 3,6-bis(4-aminobenzoyloxy)cholestane, 3,6-bis (4- Aminophenoxy)cholestane (3,6- Bis(4-aminophenoxy)cholestane), 4-(4'-trifluoromethoxybenzylideneoxy)cyclohexyl-3,5-diaminobenzoate, 4-(4'-trifluoromethyl Benzobenzyloxy)cyclohexyl-3,5-diaminobenzoate, 1,1-bis(4-((aminophenyl)methyl)phenyl)-4-butylcyclohexane Alkane, 1,1-bis(4-((aminophenyl)methyl)phenyl)-4-heptylcyclohexane, 1,1-bis(4-((aminophenoxy)methyl) Phenyl)-4-heptylcyclohexane, 1,1-bis(4-((aminophenyl)methyl)phenyl)-4-(4-heptylcyclohexyl)cyclohexane, 2 , 4-diamino-N,N-diallylaniline, 4-aminobenzylamine, 3-aminobenzylamine, 1,3-diamino-4-octadecyloxybenzene, 3-(3,5-diaminobenzimidyloxy)cholestane, 3,6-bis(4-aminobenzimidyloxy)cholestane, and the following formula (D-1) -1)~式(D-1-4)

Examples of the compound and the like which are respectively represented; examples of the diamine-based organodecane include 1,3-bis(3-aminopropyl)-tetramethyldioxane; and, in addition, Japanese patents can be used. The diamine described in JP-A-2010-97188. In addition, these diamines may be used alone or in combination of two or more.

The diamine used in the synthesis of the polyamic acid preferably contains 30 mol% or more of the aromatic diamine relative to the entire diamine, more preferably 50 mol% or more, and particularly preferably 80 mol% or more. .

"The case of imparting liquid crystal alignment capability by photo-alignment processing"

When the coating film formed using the liquid crystal alignment agent of the present invention is provided with a liquid crystal alignment ability by a photo-alignment method, it is preferred to contain the polymer (A-1) as the polymer (A) and the above polymer ( A-1) A structure (hereinafter also referred to as "photo-alignment structure") which exhibits optical alignment by photoisomerization, photodimerization, photodecomposition or the like. Preferable specific examples of the polymer (A-1) include, for example, a cyclopentane ring or a carbon-carbon which has a structure represented by the following formula (ph-1), a substituent which may have a substituent, and a carbon-carbon. At least one of a group consisting of a saturated bond and an azobenzene skeleton serves as a polymer of a photo-alignment structure or the like.

(In the formula (ph-1), X ³ is a sulfur atom, an oxygen atom or -NH-; "*" represents a bond, respectively; wherein at least one of the two "*" is bonded to the aromatic ring.)

Examples of the aromatic ring bonded to "*" in the above formula (ph-1) include a benzene ring, a naphthalene ring, an anthracene ring and the like. Among these aromatic rings, a benzene ring is preferred from the viewpoint of liquid crystal alignment and transparency. The structure which is bonded to the other "*" of the two "*"s in the above formula (ph-1) is not particularly limited, and examples thereof include a chain hydrocarbon structure, an aliphatic ring, an aromatic ring, a hetero ring, and the like. . In these structures, in terms of sensitivity to light, it is preferred that one of two "*"s is bonded to the aromatic ring, and the other is selected from the group consisting of an aromatic ring, an aliphatic ring, and a heterocyclic ring. At least one type of bond in the group, particularly preferably two "*"s are bonded to the aromatic ring. In terms of sensitivity to light, X ^{3 is} preferably a sulfur atom, and an oxygen atom is preferred in terms of a readily available aspect and a wide selection of monomers which can be used.

The cyclobutane ring introduced into the main chain of the polymer (A) may have a substituent, and specifically may be represented by the following formula (ph-2).

(In the formula (ph-2), R ⁴¹ , R ⁴² , R ⁴³ and R ⁴⁴ are each independently a hydrogen atom or an organic group having 1 to 4 carbon atoms; "*" represents a bond with -CO-, respectively.)

In the R ⁴¹ , R ⁴² , R ⁴³ and R ⁴⁴ of the above formula (ph-2), the organic group having 1 to 4 carbon atoms may, for example, be an alkyl group having 1 to 4 carbon atoms, an alkoxy group or an alkoxyalkyl group. Base. R ⁴¹ , R ⁴² , R ⁴³ and R ⁴⁴ may be the same or different from each other. In terms of liquid crystal alignment, R ⁴¹ , R ⁴² , R ⁴³ and R ^{44 are} preferably all hydrogen atoms.

In the case where the polymer (A-1) is a polymer having the above carbon-carbon unsaturated bond, it is preferred to, for example, give the following formula (ph-3-1) to formula (ph-3-7) Any one or more of the groups shown and the cinnamate structure represented by the following formula (ph-3-8) are introduced into the main chain of the polymer (A-1).

(In the formula, "*" indicates a binding key.)

(In the formula (ph-3-8), R ⁴⁵ is a substituent, and i is an integer of 0 to 4; "*" represents a bond.)

The substituent of R ⁴⁵ in the above formula (ph-3-8) may, for example, be an alkyl group having 1 to 10 carbon atoms or a halogen atom (such as a fluorine atom, a chlorine atom, a bromine atom or an iodine atom). i is an integer of 0 to 4, preferably 0 to 2.

The polylysine having the above photo-alignment structure in the main chain can be used in the reaction of a tetracarboxylic dianhydride with a diamine, using a tetracarboxylic dianhydride having the above photo-alignment structure, and having the above optical alignment structure At least one of the diamines is synthesized.

[tetracarboxylic dianhydride having a photo-alignment structure]

The tetracarboxylic dianhydride having a photo-alignment structure is preferably a tetracarboxylic acid dianhydride having a structure represented by the above formula (ph-1), and a tetrabutane ring having a substituent. At least one of a group consisting of a carboxylic acid dianhydride, a tetracarboxylic dianhydride having a carbon-carbon unsaturated bond, and a tetracarboxylic dianhydride having an azobenzene skeleton.

The tetracarboxylic dianhydride having a structure represented by the above formula (ph-1) is, for example, a compound represented by the following formula (t1).

(In the formula (t1), X ³ is a sulfur atom, an oxygen atom or -NH-; and R ⁶¹ and R ⁶² are each independently a monovalent organic group having one acid anhydride group, and at least one of R ⁶¹ and R ⁶² has an aromatic group; Ring; at least one bond of "-CO-X ³ -" is bonded to the aromatic ring.)

The monovalent organic group of R ⁶¹ and R ⁶² in the above formula (t1) is not particularly limited as long as it has an acid anhydride group. The structure of the moiety other than the acid anhydride group may, for example, be a hydrocarbon group having 1 to 40 carbon atoms, a hydrogen atom of the hydrocarbon group substituted with a halogen atom or the like, or a "-O-" between the carbon-carbon bonds of the hydrocarbon group. , "-S-", "-CO-", "-CO-O-", "-CO-S-", "-SO ₂ -", "-N=N-", "-NH-", A group such as "-CO-NH-".

Here, the "hydrocarbon group" in the present specification may be a saturated hydrocarbon group or an unsaturated hydrocarbon group, and means a chain hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. In addition, the "chain hydrocarbon group" means a linear hydrocarbon group and a branched hydrocarbon group which are not composed of a chain structure but a chain structure. The "alicyclic hydrocarbon group" means a structure containing only an alicyclic hydrocarbon and not containing a hydrocarbon group of an aromatic ring structure. Among them, it is not necessary to be composed only of the structure of the alicyclic hydrocarbon, and also includes a hydrocarbon group having a chain structure in a part thereof. The "aromatic hydrocarbon group" means a hydrocarbon group containing an aromatic ring structure as a ring structure. Among them, it is not necessary to be composed only of an aromatic ring structure, and a structure of a chain structure or an alicyclic hydrocarbon may be contained in a part thereof.

In particular, the compound represented by the above formula (t1) is preferably a compound represented by the following formula (t1-1).

[化8]

(In the formula (t1-1), X ⁵ is a single bond, *-COO-, *-OCO-, *-COS-, *-SCO-, -O-, *-NHCO-, *-CONH- or - NH-, X ⁶ is *-COO-, *-OCO-, *-COS- or *-SCO- (where "*" indicates a bond with R ⁶³ ); R ⁶³ is an alkane having a carbon number of 1-12 a diradical or a group in which one or more hydrogen atoms of the alkanediyl group are substituted by a fluorine atom, a 1,4-phenylene group or a 2,6-anthranyl group.

Examples of the alkanediyl group having 1 to 12 carbon atoms of R ⁶³ in the above formula (t1-1) include a methylene group, an ethylidene group, a propanediyl group, a butanediyl group, a pentanediyl group, and a hexane group. The base, heptanediyl, octanediyl, decanediyl, decanediyl, dodecanediyl, etc., may be linear or branched. It is preferably linear. In the case where a polymer having high photoreactivity can be obtained in combination with a diamine having a structure represented by the above formula (ph-1), R ^{63 is} preferably an alkane having 1 to 12 carbon atoms. The base is more preferably a linear alkanediyl group having 2 to 10 carbon atoms.

X ^{5 is} preferably *-COO-, *-OCO-, *-COS- or *-SCO-.

Specific examples of the compound represented by the above formula (t1) include compounds represented by the following formulas (t1-1-1) to (t1-1-18), and the like.

[Chemistry 9]

In the above formula (t1-1-1) to formula (t1-1-18), a compound represented by the above formula (t1-1) can be preferably used. For example, it is preferred to use the above formula (t1-1-). 5) A compound represented by the formula (t1-1-15) to the formula (t1-1-17), and the like.

Among them, the tetracarboxylic dianhydride having a cyclobutane ring which may have a substituent is preferably 1,2,3,4-cyclobutanetetracarboxylic dianhydride. In addition, examples of the tetracarboxylic dianhydride having an azobenzene skeleton include a compound represented by the above formula (t1-1-13).

Examples of the tetracarboxylic dianhydride having a carbon-carbon unsaturated bond include a compound represented by the following formula (t2).

(In the formula (t2), A ¹ and A ² are each independently a trivalent organic group, and Y ² is a divalent organic group containing a carbon-carbon unsaturated bond.)

Examples of the trivalent organic group of A ¹ and A ² in the above formula (t2) include a group obtained by removing three hydrogen atoms from an aromatic ring having 6 to 20 carbon atoms, and a trivalent group having 1 to 20 carbon atoms. A chain hydrocarbon group or a trivalent alicyclic hydrocarbon group having 5 to 20 carbon atoms. A ¹ and A ² may contain an oxy group or a carbonyl group between the bond with Y ² . Among these groups, in terms of photoreactivity and electrical properties, it is preferred to have an aromatic ring, and more preferably a benzene ring.

The carbon-carbon unsaturated bond of Y ² may be a form containing only a carbon-carbon double bond, a form containing only a carbon-carbon triple bond, and a form containing a carbon-carbon double bond and a carbon-carbon triple bond. One. The number of carbon-carbon unsaturated bonds is preferably one or two, and more preferably one, in terms of photoreactivity, photostability, and coloring properties. Further, the carbon-carbon triple bond is preferably from one to three, more preferably two or three. Preferable examples of Y ² include a group represented by the above formula (ph-3-1) to formula (ph-3-7), and the like.

Specific examples of the tetracarboxylic dianhydride having the above-described carbon-carbon unsaturated bond include compounds represented by the following formulas (t2-1) to (t2-5), and the like.

When the polymer (A-1) having a photo-alignment structure is synthesized, only the above-described tetracarboxylic dianhydride having a photo-alignment structure may be used, and other tetracarboxylic dianhydrides other than the compound may be used in combination. Specific examples of the other tetracarboxylic dianhydride include, for example, 2,3,5-tricarboxycyclopentyl acetic 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-A 5-(4-hydro-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, 2, 4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-dianhydride, 2,3,5,6-tetracarboxybicyclo[2.2.1]heptane-2:3 , 5:6-dianhydride, 4,9-dioxatricyclo[5.3.1.0 ^2,6 ]undecane-3,5,8,10-tetraone, pyromellitic dianhydride, 4,4 '-(hexafluoroisopropylidene) diphthalic anhydride or the like.

[Diamine having photo-alignment structure]

The diamine having a photo-alignment structure is preferably a diamine selected from the group consisting of the structure represented by the above formula (ph-1), a diamine having a carbon-carbon unsaturated bond, and two having an azobenzene skeleton. At least one of the groups consisting of amines.

The diamine having a structure represented by the above formula (ph-1) is, for example, a compound represented by the following formula (d1).

(In the formula (d1), X ³ is a sulfur atom or an oxygen atom; R ⁶⁴ and R ⁶⁵ are each independently a divalent organic group, and at least one of R ⁶⁴ and R ⁶⁵ has an aromatic ring; "-CO-X ³ -" At least one of the bonding bonds is bonded to the aromatic ring.)

Examples of the divalent organic group of R ⁶⁴ and R ⁶⁵ in the above formula (d1) include a hydrocarbon group having 1 to 30 carbon atoms, a group in which a hydrogen atom of the hydrocarbon group is substituted with a halogen atom or the like, and a carbon group at the hydrocarbon group. The carbon bond includes groups such as "-O-", "-S-", "-CO-", "-CO-O-", "-CO-S-", and "-N=N-". A group having a heterocyclic ring or the like.

A preferred example of the compound represented by the above formula (d1) is, for example, a compound represented by the following formula (d1-1).

(In the formula (d1-1), Ar ¹ , Ar ² and Ar ³ are each independently 1,4-phenylene, 2,6-anthranyl, 2,5-extended pyridyl, 2,4-extended Pyridyl or 3,5-extended pyridyl; X ⁷ is *-COO-, *-OCO-, *-COS-, *-SCO-, *-NHCO- or *-CONH- (where "*" indicates Binding bond to Ar ¹ ; X ⁸ is *-COO-, *-OCO-, *-COS-, *-SCO-, -OC _n H _2n -O- (n is an integer from 1 to 6), * -CH ₂ -S-, *-S-CH ₂ -, *-NHCO- or *-CONH- (where "*" indicates a bond to Ar ² ); p1 is an integer from 0 to 2.)

Among them, Ar ¹ , Ar ² and Ar ³ in the above formula (d1-1) are preferably a 1,4-phenylene group.

Specifically, the diamine having the structure represented by the above formula (ph-1) can be, for example Listed: 4-aminophenyl-4'-aminobenzoic acid ester (compound represented by the following formula (d-1-1)), 3,3'-dimethyl-4-aminophenyl -4'-Aminobenzoate, 3,3',5,5'-tetramethyl-4-aminophenyl-4'-aminobenzoate, 3-methyl-4-amine A phenylphenyl-4'-aminobenzoic acid ester, a compound represented by the following formula (d-1-2) to the formula (d-1-23), and the like. Further, the specific diamine may be used alone or in combination of two or more of these diamines.

[Chemistry 16]

In the above, in terms of high sensitivity to light, a diamine having a structure of "-aromatic ring-CO-X ³ -aromatic ring-" is preferable, and specifically, the above formula (d- is preferably used. 1-1), formula (d-1-3)~form (d-1-13), formula (d-1-15)~form (d-1-20), formula (d-1-23) respectively The compound represented. Among them, a diamine corresponding to the compound represented by the above formula (d1-1) is preferably used, and for example, it is preferred to use the above formula (d-1-1) and formula (d-1-5) to formula (d). -1-11), a compound represented by the formula (d-1-20) and the formula (d-1-23), respectively.

Examples of the diamine having a carbon-carbon unsaturated bond include a compound represented by the following formula (d2).

H ₂ NA ³ -Y ³ -A ⁴ -NH ₂ (d2)

(In the formula (d2), A ³ and A ⁴ are each independently a divalent organic group, and Y ³ is a divalent organic group containing a carbon-carbon unsaturated bond.)

Examples of the divalent organic group of A ³ and A ⁴ in the above formula (d2) include an aromatic hydrocarbon group having 6 to 20 carbon atoms, a chain hydrocarbon group having 1 to 20 carbon atoms, and an alicyclic group having 5 to 20 carbon atoms. Hydrocarbyl group and the like. A ³ and A ⁴ may contain an oxy group or a carbonyl group between the bond with Y ³ . Among these groups, in terms of photoreactivity, liquid crystal alignment, and electrical properties, A ³ and A ^{4 are} preferably an aromatic hydrocarbon group, and more preferably have a benzene ring.

The description of Y ² of the above formula (t2) can be applied to Y ³ .

Specific examples of the diamine having a carbon-carbon unsaturated bond include a compound represented by the above formula (d-1-17) and formula (d-1-18), and the following formula (d-2-1) - the compound represented by the formula (d-2-5), the compound represented by the above formula (d-1-2) to the formula (d-1-4), and the following formula (d-2-6)~ A compound represented by the formula (d-2-8) and the like.

[Chemistry 19]

Preferable specific examples of the diamine having an azobenzene skeleton include a compound represented by the above formula (d-1-15) and formula (d-1-16), and the following formula (d-3-1) a compound represented by the formula (d-3-7), and the like.

When the polymer (A-1) having a photo-alignment structure is synthesized, only the diamine having a photo-alignment structure may be used, and other diamines other than the diamine may be used in combination. Specific examples of the other diamines include: The diamine exemplified in the description of polylysine synthesis, or the nitrogen atom-containing diamine represented by the following formula (d-4-1) to formula (d-4-4), etc. .

The tetracarboxylic dianhydride having a photo-alignment structure and the above-mentioned light having a photo-alignment structure with respect to the total amount of monomers for synthesizing polyamic acid in terms of exhibiting sufficient liquid crystal alignment by light irradiation The total use ratio of the diamine of the alignment structure is preferably from 30 mol% to 100 mol%, more preferably from 50 mol% to 100 mol%.

Further, in the case where the polymer (A-1) has a plurality of the above-described photo-alignment structures, a plurality of photo-alignment structures may be contained in a single polymer or as a part of a plurality of photo-alignment structures. The polymer is used in a mixture with the polymer having the remaining portion. Further, as the polymer (A-1), three or more kinds of polyaminic acid may be used in combination, or two or more kinds of polyaminic acid having the same photo-alignment structure may be used in combination.

[Molecular weight regulator]

In the case of synthesizing polyamic acid, a terminally modified polymer can also be synthesized by using an appropriate molecular weight modifier together with the tetracarboxylic dianhydride and the diamine as described above. By When the terminal-modified polymer is produced, the coating property (printability) of the liquid crystal alignment agent can be further improved without impairing the effects of the present invention.

Examples of the molecular weight modifier include an acid monoanhydride, a monoamine compound, and a monoisocyanate compound. Specific examples of the compounds include, for example, maleic anhydride, phthalic anhydride, itaconic anhydride, n-decyl succinic anhydride, n-dodecyl succinic anhydride, and n-four. Examples of the alkyl succinic anhydride, n-hexadecyl succinic anhydride, and the like; and the monoamine compound may, for example, be aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine or n-octyl Examples of the monoamine, n-dodecylamine, n-octadecylamine, and the like; and examples of the monoisocyanate compound include phenyl isocyanate and naphthyl isocyanate.

The use ratio of the molecular weight modifier is preferably 20 parts by weight or less, more preferably 10 parts by weight or less, based on 100 parts by weight of the total of the tetracarboxylic dianhydride and the diamine to be used.

<Synthesis of polylysine>

The ratio of the tetracarboxylic dianhydride to the diamine to be used in the synthesis reaction of the polyglycolic acid of the present invention is preferably from 0.2 equivalents to 2 equivalents to the amine group of the diamine. The ratio of the equivalent is more preferably a ratio of 0.3 equivalent to 1.2 equivalent. Further, the synthesis reaction of polyamic acid is preferably carried out in an organic solvent. The reaction temperature at this time is preferably from -20 ° C to 150 ° C, more preferably from 0 ° C to 100 ° C. Further, the reaction time is preferably from 0.1 to 24 hours, more preferably from 0.5 to 12 hours.

Here, examples of the organic solvent used for the reaction include an aprotic polar solvent, a phenol solvent, an alcohol, a ketone, an ester, an ether, a halogenated hydrocarbon, and a hydrocarbon.

Specific examples of the organic solvent include, for example, N-methyl-2-pyrrolidone and 1,3-dimethyl-2-imidazolidinone (1,3-dimethyl-2). -imidazolidinone), N-ethyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl hydrazine, γ-butyrolactone, four Examples of the phenol solvent include m-cresol, xylenol, and halogenated phenol; and examples of the alcohol include methanol, ethanol, isopropanol, cyclohexanol, and B. Glycol, propylene glycol, 1,4-butanediol, triethylene glycol, ethylene glycol monomethyl ether, etc.; examples of the ketone include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc. Examples of the ester include ethyl lactate, butyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl methoxypropionate, ethyl ethoxy propionate, and diethyl oxalate. , diethyl malonate, isoamyl propionate, isoamyl isobutyrate, etc.; ethers, for example, diethyl ether, ethylene glycol methyl ether, ethylene glycol ether, ethylene glycol n-propyl ether, ethylene glycol Diisopropyl ether, ethylene glycol n-butyl ether, ethylene glycol 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, tetrahydrofuran, diisoamyl ether, etc.; halogenated hydrocarbons, for example, dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane Examples of the hydrocarbon include alkane, chlorobenzene, o-dichlorobenzene, and the like; and examples of the hydrocarbon include hexane, heptane, octane, benzene, toluene, xylene, and the like.

Among these organic solvents, one selected from the group consisting of an aprotic polar solvent and a phenol solvent (the first group of organic solvents) is preferably used. Or more than one or more selected from the group consisting of organic solvents of the first group and one or more selected from the group consisting of alcohols, ketones, esters, ethers, halogenated hydrocarbons, and hydrocarbons (organic solvents of the second group) mixture. In the latter case, the ratio of the organic solvent of the second group is preferably 50% by weight or less, more preferably 40% by weight based on the total amount of the organic solvent of the first group and the organic solvent of the second group. % or less, particularly preferably 30% by weight or less.

The amount (a) of the organic solvent used is preferably an amount of from 0.1% by weight to 50% by weight based on the total amount (a+b) of the reaction solution, and the total amount (b) of the tetracarboxylic dianhydride and the diamine.

As described above, a reaction solution obtained by dissolving polylysine was obtained. The reaction solution can be directly supplied to the preparation of the liquid crystal alignment agent, or the poly-proline acid contained in the reaction solution can be isolated and then supplied to the preparation of the liquid crystal alignment agent, or the isolated polylysine can be purified. Provided to the preparation of a liquid crystal alignment agent. In the case where polylysine is dehydrated and closed to form a polyimine, the above reaction solution can be directly supplied to a dehydration ring-closure reaction, and the polylysine contained in the reaction solution can be isolated and then supplied to dehydration. The ring closure reaction, or the isolated polylysine can be purified and then supplied to the dehydration ring closure reaction. The isolation and purification of polylysine can be carried out according to a known method.

<Polymer (A): Polyamide)

The polyglycolate which is the polymer (A) of the present invention can be obtained, for example, by the following method: [I] The polyamic acid obtained by the above synthesis reaction is esterified by using a hydroxyl group-containing compound or the like. To synthesize; [II] a method of reacting a tetracarboxylic acid diester with a diamine; and [III] a method of reacting a tetracarboxylic acid diester dichloride with a diamine.

Here, examples of the hydroxyl group-containing compound used in the method [I] include alcohols such as methanol, ethanol, and propanol; and phenols such as phenol and cresol. Further, examples of the halide include methyl bromide, ethyl bromide, octadecyl octadecyl, methyl chloride, chlorooctadecane, 1,1,1-trifluoro-2-iodoethane, and the like. Examples of the compound include propylene oxide and the like.

The tetracarboxylic acid diester used in the method [II] can be obtained, for example, by ring-opening the tetracarboxylic dianhydride exemplified in the synthesis of the above polyamic acid by using the above alcohol. The reaction of the method [II] is preferably carried out in the presence of a suitable dehydration catalyst. Examples of the dehydration catalyst include 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium halide, carbonylimidazole, and phosphorus-based condensing agent. Wait. The tetracarboxylic acid diester dihalide used in the method [III] can be obtained, for example, by reacting a tetracarboxylic acid diester obtained as described above with a suitable chlorinating agent such as sulfinium chloride.

The diamine used in the synthesis of the method [II] and the method [III] can be exemplified by the diamine exemplified in the synthesis of polylysine. In addition, the polyglycolate may have only a phthalate structure, and may also be a partial ester compound in which a valeric acid structure and a phthalate structure coexist.

<Polymer (A): Polyimine)

The polyimine which is the polymer (A) contained in the liquid crystal alignment agent of the present invention can be obtained by subjecting polylysine synthesized in the above manner to dehydration ring closure and imidization of ruthenium.

The polyimine may be a fully ruthenium imide obtained by dehydration ring closure of the proline structure of the polyamic acid as a precursor thereof, or may be a closed loop of only a part of the structure of the proline. And the structure of proline and ruthenium ring A part of the quinone imine compound. The polyimine of the present invention preferably has a sulfhydrylation ratio of 30% or more, more preferably 40% to 99%, and particularly preferably 50% to 99%. The ruthenium imidation ratio is a total of the number of the guanidine structure of the polyimine and the number of the quinone ring structure, and the ratio of the number of the quinone ring structure is expressed as a percentage. Here, a part of the quinone ring may be an isoindole ring.

The dehydration ring closure of polylysine is preferably carried out by a method of heating polylysine or by dissolving polylysine in an organic solvent, adding a dehydrating agent and a dehydration ring-closing catalyst to the solution. , the method of heating as needed. Among them, it is preferred to use the latter method.

In the method of performing hydrazine imidation by adding a dehydrating agent and a dehydration ring-closing catalyst to a solution of poly-proline, the dehydrating agent may be, for example, an acid anhydride such as acetic anhydride, propionic anhydride or trifluoroacetic anhydride. The amount of the dehydrating agent to be used is preferably from 0.01 mol to 20 mol based on 1 mol of the proline structure of the polyamic acid. As the dehydration ring-closing catalyst, for example, a tertiary amine such as pyridine, trimethylpyridine, dimethylpyridine or triethylamine can be used. The amount of the dehydration ring-closing catalyst used is preferably set to 0.01 mol to 10 mol with respect to the dehydrating agent used. The organic solvent used for the dehydration ring-closure reaction is exemplified as an organic solvent exemplified as a solvent used in the synthesis of polyglycine. The reaction temperature of the dehydration ring closure reaction is preferably from 0 ° C to 180 ° C, more preferably from 10 ° C to 150 ° C. The reaction time is preferably from 1.0 to 120 hours, more preferably from 2.0 to 30 hours.

A reaction solution containing polyienimine was obtained in the above manner. The reaction solution can be directly supplied to the preparation of the liquid crystal alignment agent, or can be prepared by removing the dehydrating agent and the dehydration ring-closing catalyst from the reaction solution, and then providing the liquid crystal alignment agent, and can also be used for the preparation of the liquid crystal alignment agent. The amine is isolated and then supplied to the preparation of the liquid crystal alignment agent, or the isolated polyimine may be purified and then supplied to the preparation of the liquid crystal alignment agent. These purification operations can be carried out in accordance with known methods.

The polylysine, polyphthalate and polyimine obtained in the above manner are preferably 10 mPa when it is made into a solution having a concentration of 10% by weight. s~800mPa. The solution viscosity of s is more preferably 15mPa. s~500mPa. s solution viscosity. Further, the solution viscosity (mPa.s) of the above polymer is a concentration of 10% by weight prepared for a good solvent (for example, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.) using the polymer. The polymer solution was measured at 25 ° C using an E-type rotational viscometer. Further, the poly-proline, polyphthalate, and polyimine contained in the liquid crystal alignment agent of the present invention are converted to polystyrene by gel permeation chromatography (GPC). The weight average molecular weight (Mw) is preferably from 500 to 100,000, more preferably from 1,000 to 50,000.

<compound (B')>

The liquid crystal alignment agent of the present invention contains the compound (B') in addition to the above polymer (A), and the compound (B') is measured at a temperature of 20 ° C/min from 40 ° C at 120 ° C. The amount of thermal weight loss is 30% or less, and the amount of thermal weight loss at 250 ° C is 90% or more.

The compound (B') may be a compound having a thermal weight loss amount measured under the above-described temperature rising conditions within a range of the above range. Specific examples of the compound (B') include a compound having a repeating unit represented by the following formula (c1), and a compound represented by the following formula (c2-1) to formula (c2-6).

(In the formula (c1), R ¹ and R ² each independently represent a hydrogen atom, a fluorine atom, an alkyl group having 1 to 6 carbon atoms, a halogenated alkyl group having 1 to 6 carbon atoms or a phenyl group; and X ⁴ is an oxygen atom; a carbonyl group, a carbonate group, a carbonyloxy group, -CH=N-, or -CR ¹³ (OH)- (wherein R ¹³ is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms); r1 is an integer of 1 to 6 Wherein, when r1 is 2 or more, a plurality of R ¹ and R ² in the repeating unit may be the same or different; R ¹ , R ² and r ¹ may be the same in all the repeating units, or may be between the repeating units. different.)

(In the formula (c2-1), R ⁵¹ is an alkyl group having 1 to 12 carbon atoms; and R ⁵² and R ⁵³ are each independently an alkyl group having 1 to 12 carbon atoms, or bonded to each other and to R ⁵² and R ⁵³ The bonded carbon atoms together form a divalent alicyclic hydrocarbon group; s is an integer of 1 to 4; R ⁵⁴ is an s-valent organic group in the case where s is 1, 3 or 4, and is s=2 in the case of s=2 Single bond or s-valent organic base.)

[Chem. 24]

(In the formula (c2-2), R ⁵⁵ and R ⁵⁶ are each independently an alkyl group having 1 to 12 carbon atoms, or are bonded to each other to form a monovalent ring together with a carbon atom to which R ⁵⁵ and R ⁵⁶ are bonded. An ether group; t is an integer of 1 to 4; and R ⁵⁷ is a t-valent organic group in the case where t is 1, 3 or 4, and is a single bond or a t-valent organic group in the case of t=2.

(In the formula (c2-3), R ³³ and R ³⁴ are each independently an alkyl group having 1 to 6 carbon atoms, and X ³¹ and X ³² are each independently a single bond, -O-, -COO- or -CO-. X ³³ and X ³⁴ are each independently a halogen atom; k1, k2, k3 and k4 are each independently an integer of 0 to 5, satisfying k1+k3≦5 and k2+k4≦5.

(In the formula (c2-4), R ³⁵ and R ³⁶ are each independently an alkyl group having 1 to 18 carbon atoms, and X ³⁵ and X ³⁶ are each independently a single bond, -O-, -COO- or -CO-. .)

(In the formula (c2-5), R ⁷¹ is a monovalent chain hydrocarbon group having 3 to 5 carbon atoms or a monovalent group containing "-O-" between the carbon-carbon bonds in the chain hydrocarbon group.)

(In the formula (c2-6), R ⁷² and R ⁷³ are each independently a hydrogen atom, a monovalent chain hydrocarbon group having 1 to 6 carbon atoms, or a "-O-" between the carbon-carbon bonds of the chain hydrocarbon group. The monovalent group, R ⁷² and R ⁷³ may be bonded to each other to form a ring structure; and R ⁷⁴ is an alkyl group having 1 to 6 carbon atoms.

[Compound having a repeating unit represented by the above formula (c1)]

With respect to R ¹ and R ² of the above formula (c1), examples of the alkyl group having 1 to 6 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, second propyl group, n-butyl group and isobutyl group. Base, second butyl, tert-butyl, n-pentyl, n-hexyl and the like. In addition, examples of the halogenated alkyl group having 1 to 6 carbon atoms include a group in which at least one hydrogen atom in an alkyl group having 1 to 6 carbon atoms is substituted with a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom or an iodine atom. Specific examples thereof include a monofluoromethyl group, a perfluoromethyl group, a monochloromethyl group, a monobromomethyl group, a monofluoroethyl group, a difluoroethyl group, and a perfluoroethyl group.

R ¹ and R ^{2 are} preferably a hydrogen atom, a fluorine atom or an alkyl group having 1 to 6 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, more preferably a hydrogen atom or a methyl group.

X ⁴ is an oxygen atom (-O-), a carbonyl group (-CO-), a carbonate group (-O-CO-O-), a carbonyloxy group (-CO-O-), -CH=N-, or - CR ¹³ (OH)-. Among these groups, in terms of a low thermal decomposition temperature, an oxygen atom, a carbonyloxy group or -CR ¹³ (OH)- is preferred, and an oxygen atom is more preferred.

Among the above compounds, the compound having a repeating unit represented by the above formula (c1) is preferably at least one selected from the group consisting of polyethylene glycol, polypropylene glycol, polyethylene glycol, and polypropylene glycol. A block copolymer; a compound having a repeating unit represented by the following formula (c1-1); and a compound having a repeating unit represented by the following formula (c1-2).

Among the compounds having the repeating unit represented by the above formula (c1), the weight thereof The number of complex units is preferably from 2 to 1,000. A more preferable range of values can be appropriately set depending on the use of the liquid crystal alignment agent or the desired effect. For example, in the case of producing a liquid crystal alignment agent for photoalignment, the number of repeating units is preferably from 5 to 1,000, more preferably from 5 to 500, still more preferably from 5 to 300.

The compound having a repeating unit represented by the above formula (c1) can be used as a synthetic compound or can be obtained as a commercially available product. Specific examples of the commercially available product include, for example, PEG 600 (manufactured by Wako Pure Chemical Industries, Ltd.), Epiol E-400, Epiol E-1000 (manufactured by Nippon Oil Co., Ltd.), SR-8EG, SR-TPG, SR-4PG (above manufactured by Sakamoto Pharmaceutical Co., Ltd.), Blaunon PEG-400, Blaunon 600, Blaunon P-172, Blaunon P-101M (above, manufactured by Aoki Oil & Fats Co., Ltd.); The vinyl alcohol can be exemplified by K-05, K-17E, K-17C, K-24E, H-12, H-17, H-24, B-05, B-17 (above by the electrical and chemical industry) ) Manufacturing), polyvinyl alcohol produced by Wako Pure Chemical Industries Co., Ltd. (degree of polymerization: about 500), and the like.

In the case where the compound (B') is a compound having a repeating unit represented by the above formula (c1), the compound (B) represented by the following formula (b) can be mentioned.

(In the formula (b), X ¹ and Y ¹ are each independently a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 6 carbon atoms, a halogenated alkyl group having 1 to 6 carbon atoms, an amine group, an epoxy group, or an epoxy group. a group (-CH ₂ -C ₂ H ₃ O), a phenyl group, a vinyl group, a (meth)acrylylene group, a fluorenyl group or a carboxyl group; m is an integer of 1 to 5, and n is an integer of 2 to 20; R ¹ and R ² has the same meaning as the above formula (c1); wherein, when m is 2 or more, a plurality of R ¹ and R ² in the repeating unit may be the same or different; and R ¹ , R ² and m may be used in all repeats. The same in the unit, but also between repeating units.)

With respect to X ¹ , Y ¹ , R ¹ and R ² of the above formula (b), an alkyl group having 1 to 6 carbon atoms and a halogenated alkyl group having 1 to 6 carbon atoms, R ¹ and R ^{2 of the} above formula (c1) can be used. instruction of. The (meth)acrylonitrile group in X ¹ and Y ¹ has the meaning of containing an acryloyl group and a methacryl group.

Among them, X ¹ and Y ^{1 are} preferably a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 3 carbon atoms or an amine group (-NH ₂ ). Further, in one molecule of the compound (B), X ¹ and Y ¹ may be the same or different. Further, R ¹ and R ^{2 are} preferably a hydrogen atom, a fluorine atom or an alkyl group having 1 to 3 carbon atoms, more preferably a hydrogen atom.

m is an integer of 1 to 5, preferably 2 to 4, more preferably 2 or 3.

n is an integer of 2 to 20, preferably 3 to 20. Further, in particular, in the case of performing heating at the time of film formation at a low temperature of, for example, less than 200 ° C, n is more preferably 4 or more, and particularly preferably 4 to 6 in terms of obtaining a highly reliable liquid crystal alignment film. . Further, n is more preferably 6 or more, and particularly preferably 6 to 12 in terms of the leveling property of the formed coating film. In the case where n=6, it is preferable in terms of the reliability of the film at the time of low-temperature heating and the leveling property of the coating film.

Here, when heat treatment at a high temperature is required in the formation of the liquid crystal alignment film, there are cases in which the following problems occur: application in, for example, a plastic substrate is restricted, or in the case of a color liquid crystal display element, color filter The dye contained in the sheet is discolored due to heat. On the other hand, if the heating temperature is lowered, the voltage holding ratio tends to decrease. In this respect, by setting the number of repeating units (n) of the compound (B) to 4 or more, it is preferable to perform the heating at the time of film formation at a relatively low temperature to ensure the reliability of the film. . Further, if a coating film formed at a low temperature can be formed, the total amount of heat in the manufacturing process can be reduced, and it is also preferable from the viewpoint of reducing the amount of CO ₂ emission or reducing the cost.

Specifically, examples of the compound represented by the above formula (b) include polyethylene glycol (m = 2, X ¹ = H, Y ¹ = OH), and polypropylene glycol (m = 3, X ¹ = H, Y). ¹ = OH), polyolefin diol alkyl ether (X ¹ = OH, Y ¹ = C _r H _r+1 (where r is an integer from 1 to 6)), polyetheramine (X ¹ = Y ¹ = NH ₂ ), ester glycol ether (X ¹ = (meth) propylene fluorenyl), aromatic glycol ether (X ¹ = phenyl), polyglycidyl ether (X ¹ = epoxy or ring) Oxymethyl), polyvinyl ether (X ¹ = vinyl), and the like.

Specific examples of the compounds include polyethylene glycol, triethylene glycol, tetraethylene glycol, pentaethylene glycol, hexaethylene glycol, heptaethylene glycol, and octaethylene glycol. , dodecaethylene glycol, tetradecyl glycol, etc.; polypropylene glycol, for example, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, pentapropylene glycol, six propanediol, heptapropanediol, octapropylene glycol, dodecapropanediol, tetradecanediol, etc.; Examples of the polyolefin diol alkyl ether include diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, dipropylene glycol monomethyl ether, triethylene glycol monomethyl ether, and tetraethylene glycol monomethyl ether. Hexaethylene glycol monomethyl ether, hexaethylene glycol monoethyl ether, heptaethylene glycol monomethyl ether, heptaethylene glycol monoethyl ether, octaethylene glycol monomethyl ether, octaethylene glycol monoethyl ether, etc.; Examples thereof include triethylene glycol diamine, tetraethylene glycol diamine, and diethylene glycol bis (3-aminopropyl) ether; and ester glycol ethers include, for example, diethylene glycol monomethyl ether B. Acid ester, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, etc.; Examples of the family glycol ether include diethylene glycol monophenyl ether, triethylene glycol monophenyl ether, dipropylene glycol monophenyl ether, and tripropylene glycol monophenyl ether; and polyglycidyl ether is exemplified. : diethylene glycol diglycidyl ether, triethylene glycol diglycidyl ether, tetraethylene glycol diglycidyl ether, etc.; polyvinyl ether, for example, diethylene glycol monovinyl ether, two Ethylene glycol divinyl ether, triethylene glycol monovinyl ether, triethylene glycol divinyl ether, tetraethylene glycol divinyl ether, and the like. In addition, the above-mentioned compound (B) may be used alone or in combination of two or more.

In the above compound, the above compound (B) is preferably at least one selected from the group consisting of polyethylene glycol, polypropylene glycol, polyolefin glycol alkyl ether, and polyether amine, and among these compounds, particularly preferred The compound having a repeat number (n) of 3 or more. Further, in terms of lowering the heating temperature at the time of film formation, it is preferably at least one selected from the group consisting of polyethylene glycol, polypropylene glycol, polyolefin glycol alkyl ether, and polyether amine. In the case where the number of repetitions (n) is 4 or more, it is preferably selected from polyethylene glycol, polypropylene glycol, and the like to improve the leveling property of the coating film. In at least one of the group consisting of a polyolefin diol alkyl ether and a polyether amine, the compound having a number (n) of 6 or more is repeated. Specifically, in terms of lowering the heating temperature at the time of film formation, it is preferably selected from the group consisting of tetraethylene glycol, hexaethylene glycol, dodecaethylene glycol, hexaethylene glycol monoethyl ether, octapropylene glycol, and tetraethylidene. At least one selected from the group consisting of glycol diamines is more preferably at least one selected from the group consisting of tetraethylene glycol, hexaethylene glycol, and tetraethylene glycol diamine. Further, in terms of improving the leveling property of the coating film, it is preferably selected from the group consisting of hexaethylene glycol, dodecaethylene glycol, hexaethylene glycol monoethyl ether, octapropylene glycol, and tetraethylene glycol diamine. At least one of the groups.

[Compound represented by the above formula (c2-1)]

The alkyl group having 1 to 12 carbon atoms of R ⁵¹ , R ⁵² and R ⁵³ in the above formula (c2-1) may be linear or branched, but is preferably linear. The carbon number is preferably from 1 to 6, more preferably from 1 to 3.

R ⁵² and R ⁵³ may form a divalent alicyclic hydrocarbon group together with the carbon atom to which R ⁵² and R ⁵³ are bonded. Examples of the divalent alicyclic hydrocarbon group include a group obtained by removing two hydrogen atoms from a cyclopentane ring, a cyclohexane ring, a cycloheptane ring or the like.

Examples of the organic group in R ⁵⁴ include an oxygen atom, a carbonyl group, a carbonyloxy group, a carbonate group, a hydrocarbon group having 1 to 12 carbon atoms, and at least one methylene group in the hydrocarbon group via an oxygen atom, a carbonyl group or a carbonyloxy group. a group such as a group substituted. In the case where R ⁵⁴ is a hydrocarbon group having 1 to 12 carbon atoms, the hydrocarbon group is preferably a chain hydrocarbon group or an alicyclic hydrocarbon group.

s is an integer of 1 to 4, preferably 2. Further, when s=2 and R ⁵⁴ is a single bond, the carbon atoms of the two carbonyloxy groups are bonded to each other.

Preferred specific examples of the compound represented by the above formula (c2-1) include, for example, the following A compound represented by the formula (c2-1-1) to the formula (c2-1-14), and the like.

(wherein R ⁵⁸ and R ⁶⁰ are each independently an alkyl group having 1 to 12 carbon atoms.)

Among the above compounds, the compound represented by the above formula (c2-1) preferably has a formula (c2-1-2), a formula (c2-1-3), a formula (c2-1-9), and a formula (c2). -1-10), a compound represented by the formula (c2-1-12) and the formula (c2-1-13), respectively.

[Compound represented by the above formula (c2-2)]

With respect to the alkyl group of R ⁵⁵ and R ⁵⁶ of the above formula (c2-2), the description of R ⁵² and R ⁵³ of the above formula (c2-1) can be applied. Examples of the monovalent cyclic ether group formed by the carbon atom bonded to R ⁵⁵ and R ⁵⁶ include a group in which one hydrogen atom is removed from oxetane, tetrahydrofuran, tetrahydropyran or the like. Mission and so on.

The description of R ⁵⁴ of the above formula (c2-1) can be applied to the organic group in R ⁵⁷ . t is an integer from 1 to 4, preferably 1 or 2.

Preferable specific examples of the compound represented by the above formula (c2-2) include compounds represented by the following formulas (c2-2-1) to (c2-2-6), and the like.

Among the above compounds, the compound represented by the above formula (c2-2) is preferably a compound represented by the formula (c2-2-4), the formula (c2-2-5), and the formula (c2-2-6), respectively. More preferably, a compound in which R ⁵⁸ and R ⁵⁹ in the formula are n-butyl groups can be used.

The alkyl group having 1 to 6 carbon atoms of R ³³ and R ³⁴ in the above formula (c2-3) may be linear or branched, but is preferably branched. It is preferable that k1+k2 is 1 or more.

Specific examples of the compound represented by the above formula (c2-3) include a compound represented by the following formula (c2-3-1) to formula (c2-3-5), and the like. In addition, specific examples of the compound represented by the above formula (c2-4) include a compound represented by the following formula (c2-4-1).

(In the formula (c2-4-1), R ⁶¹ and R ⁶² are each independently an alkyl group having 1 to 18 carbon atoms.)

[Compound represented by the above formula (c2-5)]

The monovalent chain hydrocarbon group having 3 to 5 carbon atoms of R ⁷¹ in the above formula (c2-5) is, for example, an alkyl group, an alkenyl group or an alkynyl group having 3 to 5 carbon atoms. In addition, examples of the monovalent group containing "-O-" between the carbon-carbon bonds in the chain hydrocarbon group include, for example, an alkoxyalkyl group having 3 to 5 carbon atoms.

Specific examples of the groups include a propyl group, a butyl group, a pentyl group and the like, and examples of the alkyl group having 3 to 5 carbon atoms; and an alkenyl group having 3 to 5 carbon atoms: 1-propenyl group, 2- Examples of the alkynyl group having 3 to 5 carbon atoms include a 2-propynyl group and a 2-butynyl group; and the alkoxyalkyl group having 3 to 5 carbon atoms is exemplified by the following: Methoxyethyl, methoxypropyl, methoxybutyl, ethoxymethyl, ethoxyethyl, etc.; these groups may be linear or branched. In the above group, R ^{71 is} preferably an alkyl group having 3 to 5 carbon atoms or an alkoxyalkyl group.

Specific examples of the compound represented by the above formula (c2-5) include N-(n-propyl)-2-pyrrolidone, N-(n-butyl)-2-pyrrolidone, and N-( Tributyl)-2-pyrrolidone, N-(n-pentyl)-2-pyrrolidone, N-methoxypropyl-2-pyrrolidone, N-ethoxyethyl-2-pyrrole Pyridone, N-methoxybutyl-2-pyrrolidone, and the like. Among these compounds, N-(n-pentyl)-2-pyrrolidone, N-(t-butyl)-2-pyrrolidone, and N-methoxypropyl-2-pyrrole are particularly preferably used. Pyridone. In addition, the compound represented by the above formula (c2-5) may be used alone or in combination of two or more kinds.

With respect to the compound represented by the above formula (c2-6), the monovalent chain hydrocarbon group having 1 to 6 carbon atoms of R ⁷² and R ⁷³ may, for example, be an alkyl group having 1 to 6 carbon atoms or an alkyl group having 2 to 6 carbon atoms. Base, alkynyl group having 2 to 6 carbon atoms, and the like. In addition, examples of the monovalent group containing "-O-" between the carbon-carbon bonds in the chain hydrocarbon group include an alkoxyalkyl group having 2 to 6 carbon atoms.

By bonding R ⁷² and R ^{73 to} each other, a ring may be formed together with the nitrogen atom to which R ⁷² and R ⁷³ are bonded. Examples of the ring formed by bonding R ⁷² and R ^{73 to} each other include a pyrrolidine ring and a piperidine ring. These rings may also bond a monovalent chain hydrocarbon group such as a methyl group.

R ⁷² and R ^{73 are} preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and particularly preferably a hydrogen atom or a methyl group.

[Compound represented by the above formula (c2-6)]

Specific examples of the compound represented by the above formula (c2-6) include 3-butoxy-N, N-dimethyl propanamide, and 3-methyl. oxy-N,N-dimethylpropanamide, 3-hexyloxy-N,N-dimethylpropanamide, isopropoxy Isopropoxy-N-isopropyl-propionamide, n-butoxy-N-isopropyl-propionamide, and the like. In addition, the compound represented by the above formula (c2-6) may be used alone or in combination of two or more.

One type of the above-mentioned compound (B') may be used alone or two or more types may be used in combination. The compound (B') is preferably selected from the group consisting of a compound having a repeating unit represented by the above formula (c1) and a compound represented by the above formula (c2-1) to formula (c2-4). At least one of them is more preferably a group selected from the group consisting of a compound having a repeating unit represented by the above formula (c1), a compound represented by the above formula (c2-1), and a compound represented by the above formula (c2-2). At least one of the groups.

When the total amount of the polymer component contained in the liquid crystal alignment agent (wherein the compound (B') is a polymer, except for the compound (B')) is 100 parts by weight, the above compound (B') The blending ratio is preferably from 0.1 part by weight to 50 parts by weight. By setting it as 0.1 part by weight or more, the effect by addition of the compound (B') can be suitably obtained, and if it is 50 parts by weight or less, the influence on the various properties of the liquid crystal alignment film can be reduced. More preferably, it is from 0.5 part by weight to 30 parts by weight, particularly preferably from 1 part by weight to 20 parts by weight, particularly preferably from 1 part by weight to 5 parts by weight.

When the compound (B) is used as the compound (B'), the compounding ratio of the compound (B) is preferably 0.1 part by weight based on 100 parts by weight of the total of the polymer contained in the liquid crystal alignment agent. 50 parts by weight. By setting the compounding ratio of the compound (B) within this range, it is possible to suitably obtain an effect of forming a liquid crystal alignment film having good leveling property and high reliability. More preferably 0.5 parts by weight ~ 30 It is especially preferably 1 part by weight to 20 parts by weight.

Further, the reason why a liquid crystal alignment film having high reliability and good leveling property can be obtained by using a liquid crystal alignment agent containing the above compound (B) is not clear, but one of the reasons is considered to be: by a liquid crystal alignment agent The compound (B) contained acts as a plasticizer, and the polymer (A) becomes easy to move. Therefore, it is presumed that, for example, a dehydration ring-closure reaction of a proline structure can be carried out during baking after coating of a substrate, and a more imidized coating film can be obtained, and as a result, the above effects can be exhibited. Further, the liquid crystal alignment agent for optical alignment is also unclear, but it is presumed that since the polymer (A) is easily moved, the polymer component around the photo-aligned portion follows, whereby the anisotropy of the alignment film is obtained. As a result, the liquid crystal alignment property or afterimage characteristics of the liquid crystal display element can be improved.

<Other ingredients>

The liquid crystal alignment agent of the present invention may contain other components as needed. Examples of the other component include a compound having at least one epoxy group in the molecule (hereinafter referred to as "epoxy group-containing compound"), a functional decane compound, and the like.

<epoxy group-containing compound>

The epoxy group-containing compound can be used to improve the adhesion or electrical properties of the liquid crystal alignment film to the surface of the substrate. As such an epoxy group-containing compound, for example, the following compounds are preferred: ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, and tripropylene glycol diglycidyl group. Ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerol diglycidyl ether, trimethylolpropane triglycidyl Ether, 2,2-dibromoneopentyl glycol diglycidyl ether, N,N,N',N'-tetraglycidyl-m-xylenediamine, 1,3-double (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. In addition to the above, examples of the epoxy group-containing compound may be the epoxy group-containing polyorganosiloxane having the disclosure of WO 2009/096598.

When the epoxy compound is added to the liquid crystal alignment agent, the compounding ratio of the epoxy compounds is preferably 40 parts by weight or less based on 100 parts by weight of the total of the polymers contained in the liquid crystal alignment agent. More preferably, it is 0.1 weight part - 30 weight part.

<Functional decane compound>

The above functional decane compound can be used for the purpose of improving the printability of the liquid crystal alignment agent. Examples of such a functional decane compound include 3-aminopropyltrimethoxydecane, 3-aminopropyltriethoxydecane, 2-aminopropyltrimethoxydecane, and 2-aminopropyl group. Triethoxy decane, N-(2-aminoethyl)-3-aminopropyltrimethoxydecane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxy Baseline, 3-ureidopropyltrimethoxydecane, 3-ureidopropyltriethoxydecane, N-ethoxycarbonyl-3-aminopropyltrimethoxydecane, N-triethoxy矽alkylpropyltriethylamine, 10-trimethoxydecyl-1,4,7-triazadecane, 9-trimethoxydecyl-3,6-diazepineacetic acid Ester, methyl 9-trimethoxydecyl-3,6-diazadecanoate, N-benzyl-3-aminopropyltrimethoxydecane, N-phenyl-3-aminopropyltrimethyl Oxaloxane, glycidoxymethyltrimethoxydecane, 2-glycidoxyethyltrimethoxydecane, 3-glycidoxypropyltrimethoxydecane, and the like.

When the functional decane compound is added to the liquid crystal alignment agent, the compounding ratio of the functional decane compound is preferably 2 parts by weight based on 100 parts by weight of the total of the polymer contained in the liquid crystal alignment agent. Hereinafter, it is more preferably 0.02 parts by weight to 0.2 parts by weight.

Further, in addition to the above compounds, a compound having at least one oxetanyl group in the molecule, an antioxidant, a photosensitizer or the like can be used as the other component.

<solvent>

The liquid crystal alignment agent of the present invention is preferably prepared by dissolving the above polymer component, the compound (B'), and other components optionally arbitrarily dissolved in an organic solvent.

Here, examples of the solvent for preparing the liquid crystal alignment agent of the present invention include N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactone, and N,N-dimethylmethyl. Indoleamine, N,N-dimethylacetamide, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionic acid Ester, ethyl ethoxy propionate, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol n-propyl ether, ethylene glycol isopropyl ether, ethylene glycol n-butyl ether (butyl cyproterone), ethylene Alcohol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, diisoamyl Ethyl ether, ethyl carbonate, propyl carbonate, and the like. These may be used alone or in combination of two or more.

The solid content concentration in the liquid crystal alignment agent of the present invention (the ratio of the total weight of the components other than the solvent of the liquid crystal alignment agent to the total weight of the liquid crystal alignment agent) is appropriately selected in consideration of viscosity, volatility, and the like. Good for 1% by weight~10 The range of % by weight. In other words, the liquid crystal alignment agent of the present invention is applied to the surface of the substrate as described later, and is preferably heated to form a coating film as a liquid crystal alignment film or a coating film for a liquid crystal alignment film. When it is less than 1% by weight, the film thickness of the coating film becomes too small, and a favorable liquid crystal alignment film cannot be obtained. On the other hand, when the solid content concentration exceeds 10% by weight, the film thickness of the coating film becomes too large, and a favorable liquid crystal alignment film cannot be obtained. Further, the viscosity of the liquid crystal alignment agent increases, and the coating properties are deteriorated.

The range of the particularly preferable solid content concentration differs depending on the method used when the liquid crystal alignment agent is coated on the substrate. For example, in the case of using the rotator method, the solid content concentration is particularly preferably in the range of 1.5% by weight to 4.5% by weight. In the case of using the printing method, it is particularly preferable to set the solid content concentration to a range of 3% by weight to 9% by weight, thereby setting the solution viscosity to 12 mPa. s~50mPa. The scope of s. In the case of using the inkjet method, it is particularly preferable to set the solid content concentration to a range of 1% by weight to 5% by weight, thereby setting the solution viscosity to 3 mPa. s~15mPa. The scope of s. The temperature at which the liquid crystal alignment agent is prepared is preferably from 10 ° C to 50 ° C, more preferably from 20 ° C to 30 ° C.

Preferred embodiments of the liquid crystal alignment agent of the present invention include the following forms.

[I] comprising at least one polymer (A) selected from the group consisting of polylysine, polyphthalate, and polyimine as a polymer component, and containing the above formula (b) Compound (B) is an embodiment of the compound (B').

[II] An embodiment comprising a polymer (A-1) having a photo-alignment structure as a polymer component and containing the compound (B').

In the above, [I] is preferably used as a liquid crystal alignment agent in the case where the coating film formed using the liquid crystal alignment agent is not subjected to the alignment ability imparting treatment or the liquid crystal alignment ability is imparted by the rubbing treatment, [II] It is preferably used as a liquid crystal alignment agent in the case where a liquid crystal alignment agent is used to impart a liquid crystal alignment ability to a coating film formed using a liquid crystal alignment agent.

<Liquid alignment film and liquid crystal display element>

The liquid crystal alignment film of the present invention is formed by using a liquid crystal alignment agent prepared in the above manner. Further, the liquid crystal display element of the present invention includes a liquid crystal alignment film formed using the liquid crystal alignment agent of the present invention. The driving mode of the liquid crystal display element to which the present invention is applied is not particularly limited, and can be applied to various driving modes such as TN type, STN type, IPS type, FFS type, VA type, and MVA type.

"When the treatment of the alignment ability is not performed or the liquid crystal alignment ability is imparted by the rubbing treatment"

The liquid crystal display element of the present invention can be produced, for example, by the following steps (1) to (3). Step (1) uses different substrates depending on the desired driving mode. Step (2) and step (3) are common to each drive mode.

[Step (1): Formation of coating film]

First, a coating film is formed on a substrate by applying the liquid crystal alignment agent of the present invention onto a substrate and then heating the coated surface.

(1-1) In the case of manufacturing a TN type, STN type or VA type liquid crystal display element, two substrates provided with a patterned transparent conductive film are formed as a pair, and a transparent conductive film is formed on each of the bulk substrates. On the surface, the liquid crystal alignment agent of the present invention is preferably applied by an offset printing method, a spin coating method, a roll coater method or an inkjet printing method, respectively. Here, as the substrate, for example, glass such as float glass or soda glass may be used; and polyethylene terephthalate, polybutylene terephthalate, polyether oxime, polycarbonate, poly ( A transparent substrate of plastic such as alicyclic olefin). As the transparent conductive film provided on one side of the substrate, a NESA film containing tin oxide (SnO ₂ ) (registered trademark of PPG, USA), an ITO film containing indium oxide-tin oxide (In ₂ O ₃ -SnO ₂ ), or the like can be used. In order to obtain a patterned transparent conductive film, for example, a transparent conductive film without a pattern may be used after the light is formed. A method of forming a pattern by etching, a method of using a mask having a desired pattern when forming a transparent conductive film, or the like. When the liquid crystal alignment agent is applied, in order to improve the adhesion between the surface of the substrate and the transparent conductive film and the coating film, the surface on which the coating film is formed on the surface of the substrate may be coated with a functional decane compound or a functional titanium compound. Pre-processing.

After the liquid crystal alignment agent is applied, preheating (prebaking) is preferably performed for the purpose of preventing sag of the applied alignment agent. The prebaking temperature is preferably from 30 ° C to 200 ° C, more preferably from 40 ° C to 150 ° C, and particularly preferably from 40 ° C to 100 ° C. The prebaking time is preferably from 0.25 minutes to 10 minutes, more preferably from 0.5 minutes to 5 minutes (in the example, 80 ° C, 1 minute). Then, for the purpose of completely removing the solvent, in addition, a calcination (post-baking) step is carried out for the purpose of thermally imidizing the proline structure present in the polymer as needed. The calcination temperature (post-baking temperature) at this time is preferably from 80 ° C to 250 ° C, more preferably from 120 ° C to 230 ° C. In particular, the liquid crystal alignment agent of the present invention can be made into a more imidized coating by performing a dehydration ring-closing reaction of a proline structure by heating for forming a coating film by using the compound (B) as an additive. membrane. The post-baking time is preferably from 5 minutes to 200 minutes, more preferably from 10 minutes to 100 minutes. As described above, the film thickness of the formed film is preferably 0.001 μm to 1 μm, more preferably 0.005 μm to 0.5 μm.

(1-2) In the case of manufacturing an IPS type or FFS type liquid crystal display element, an electrode forming surface of a substrate including an electrode including a transparent conductive film or a metal film patterned into a comb type, and The liquid crystal alignment agent of the present invention is applied to one surface of the opposite substrate of the electrode, and then each coated surface is heated to form a coating film. The material of the substrate and the transparent conductive film used at this time, the coating method, the heating conditions after coating, the patterning method of the transparent conductive film or the metal film, the pretreatment of the substrate, and the preferred film of the formed coating film Thick, the same as (1-1) above. As the metal film, for example, a film containing a metal such as chromium can be used.

In any of the above (1-1) and (1-2), after the liquid crystal alignment agent is applied onto the substrate, the organic solvent is removed to form a coating film to be an alignment film. In this case, in the case where the polymer contained in the liquid crystal alignment agent of the present invention is a polyamic acid or a quinone imidized polymer having a quinone ring structure and a guanine structure, After the coating film is formed, it is further heated to carry out a dehydration ring-closure reaction to prepare a more imidized coating film.

[Step (2): Friction treatment]

In the case of manufacturing a TN type, STN type, IPS type or FFS type liquid crystal display element, the following rubbing treatment is carried out: the above step (1) is carried out by, for example, a roll on which a cloth comprising fibers such as nylon, crepe or cotton is wound. The coating film formed in the middle is wiped in a predetermined direction. Thereby, the alignment ability of the liquid crystal molecules is imparted to the coating film to become a liquid crystal alignment film. another In the case of producing a VA liquid crystal display device, the coating film formed in the above step (1) can be directly used as a liquid crystal alignment film, but the coating film can also be subjected to a rubbing treatment.

Further, the liquid crystal alignment film after the rubbing treatment may be further subjected to a treatment of changing a pretilt angle of a partial region of the liquid crystal alignment film by irradiating a part of the liquid crystal alignment film with ultraviolet rays, or forming a part of the surface of the liquid crystal alignment film. After the resist film, the rubbing treatment is performed in a direction different from the previous rubbing treatment, and then the treatment of the resist film is removed; thereby, the liquid crystal alignment film has different liquid crystal alignment capabilities in each region. In this case, the visual field characteristics of the obtained liquid crystal display element can be improved.

[Step (3): Construction of liquid crystal cell]

By preparing two substrates on which the liquid crystal alignment film formed as described above is formed, liquid crystal is disposed between two substrates arranged in the opposite direction to manufacture a liquid crystal cell. For the production of the liquid crystal cell, for example, the following two methods are exemplified.

The first method is a previously known method. In this method, first, the two substrates are opposed to each other with a gap (cell gap) so that the liquid crystal alignment films face each other, and the peripheral portions of the two substrates are bonded together using a sealant, and the surface of the substrate and the sealant are bonded together. After filling the filled liquid crystal into the divided cell gap, the injection hole is sealed, thereby manufacturing a liquid crystal cell. In addition, the second method is a method called a One Drop Fill (ODF) method. In this method, for example, an ultraviolet curable sealing material is applied to a predetermined portion of one of the two substrates on which the liquid crystal alignment film is formed, and further added to a predetermined number of portions on the liquid crystal alignment film surface. After the liquid crystal, another substrate is bonded in such a manner that the liquid crystal alignment film faces each other. Then, the liquid crystal is on the entire surface of the substrate Spreading, and then irradiating the entire surface of the substrate with ultraviolet light to harden the sealant, thereby manufacturing a liquid crystal cell. In the case of using any of the methods, it is preferred to heat the liquid crystal cell produced in the above manner to a temperature at which the liquid crystal used becomes an isotropic phase, and then slowly cool to room temperature to remove the liquid crystal filling. The flow alignment at the time.

As the sealant, for example, an epoxy resin containing a hardener and an alumina ball as a spacer can be used.

The liquid crystal may, for example, be a nematic liquid crystal or a smectic liquid crystal, and among them, a nematic liquid crystal is preferable, and for example, Schiff base liquid crystal, oxidized azo may be used. (azoxy) liquid crystal, biphenyl liquid crystal, phenylcyclohexane liquid crystal, ester liquid crystal, terphenyl liquid crystal, biphenyl cyclohexane liquid crystal, pyrimidine liquid crystal, dioxane liquid crystal, A bicyclooctane liquid crystal, a cubane liquid crystal, or the like. In addition, the following substances may be added to the liquid crystals for use: for example , a cholesteric liquid crystal such as cholesteryl carbonate; a chiral agent sold under the trade names "C-15" and "CB-15" (manufactured by Merck); A ferroelectric liquid crystal such as p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate.

Next, a liquid crystal display element can be obtained by bonding a polarizing plate to the outer surface of the liquid crystal cell. The polarizing plate to be bonded to the outer surface of the liquid crystal cell may be a polarizing plate in which a polarizing film called an "H film" is sandwiched between a cellulose acetate protective film or A polarizing plate comprising the H film itself, wherein the "H film" is a polarizing film obtained by absorbing iodine while extending a polyvinyl alcohol. Further, in the case where the coating film is subjected to the rubbing treatment, the two substrates are disposed at a predetermined angle to each other in the rubbing direction of each of the coating films, for example, orthogonally or anti-parallel.

"The case of imparting liquid crystal alignment capability by photo-alignment processing"

When the liquid crystal alignment agent of the present invention is used and the liquid crystal alignment film is formed by a photo-alignment method, it can be preferably applied to a liquid crystal display device of a TN type, an STN type or a transverse electric field type. Among them, in particular, it is preferable to use a liquid crystal display element of a transverse electric field type such as an IPS type or an FFS type to maximize the effect of reducing the printing of the liquid crystal display element. The liquid crystal alignment film can be produced by a method including a film formation step of applying a liquid crystal alignment agent onto a substrate to form a coating film, and a light irradiation step of performing light irradiation on the formed coating film to form a liquid crystal. Orientation film.

[Film formation step]

In this step, a coating film is formed on the substrate by applying a liquid crystal alignment agent to the substrate and then heating the coated surface. The liquid crystal alignment agent used at this time is preferably a liquid crystal alignment agent containing a polymer (A-1) having a photo-alignment structure as a polymer component and containing the compound (B'). The material of the substrate and the transparent conductive film used at this time, the coating method, the heating conditions after coating, the material of the transparent conductive film or the metal film, the patterning method, the pretreatment of the substrate, and the film formed. The film thickness is the same as that of the above step (1).

[Light irradiation step]

In this step, the liquid crystal alignment ability is imparted by irradiating the coating film formed on the substrate with polarized or non-polarized radiation. The radiation irradiation can be carried out by the following methods: [1] a method of irradiating the coating film after the post-baking step; [2] a method of irradiating the coating film after the pre-baking step and before the post-baking step; [3] A method of irradiating a coating film in heating of a coating film in at least any of the prebaking step and the post-baking step. The method [2] is preferable in that the effect of reducing the burn-in of the liquid crystal display element is higher.

For the radiation, for example, ultraviolet rays including visible light having a wavelength of 150 nm to 800 nm and visible light rays can be used. In the case where the radiation is polarized, it may be linearly polarized or partially polarized. Further, when the radiation to be used is linearly polarized or partially polarized, the irradiation may be performed from a direction perpendicular to the substrate surface, or may be performed by irradiation from an oblique direction or by combining them. When the non-polarized radiation is irradiated, the direction of the irradiation is an oblique direction.

As the light source to be used, for example, a low pressure mercury lamp, a high pressure mercury lamp, a xenon lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, an excimer laser or the like can be used. The ultraviolet light in a preferred wavelength region can be obtained by a means for combining a light source with, for example, a filter, a diffraction grating, or the like. Radiation irradiation amount is preferably ^{100J / m 2 ~ 50,000J / m} 2, more preferably ^{300J / m 2 ~ 20,000J / m} 2. Further, in order to improve the reactivity, the coating film may be irradiated with light while heating the coating film. The temperature at the time of heating is usually from 30 ° C to 250 ° C, preferably from 40 ° C to 200 ° C, more preferably from 50 ° C to 150 ° C. Thus, a liquid crystal alignment film is formed on the substrate.

[Unit construction steps]

By preparing two substrates on which the liquid crystal alignment film formed as described above is formed, liquid crystal cells are disposed between two substrates arranged in the opposite direction to produce a liquid crystal cell. The method for producing a liquid crystal cell, a sealant, a liquid crystal, and a polarizing plate to be used are the same as in the above step (3).

The liquid crystal display element of the present invention can be effectively applied to various devices, for example, can be used for: a clock, a portable game, a word processor, a note type personal computer, a car navigation system. A display device such as a car navigation system, a camcorder, a personal digital assistant (PDA), a digital camera, a mobile phone, a smart phone, various monitors, and a liquid crystal television.

[Examples]

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

In the following examples and comparative examples, the ruthenium imidization ratio of the polyimine in the polymer solution and the solution viscosity of the polymer solution were measured by the following methods.

[醯Iminization rate of polyimine]

The solution of the polyimine is put into pure water, and the obtained precipitate is sufficiently dried under reduced pressure at room temperature, and then dissolved in dimethylated dimethyl hydrazine, and tetramethyl decane is used as a reference substance at room temperature. ¹ H- NMR measurement ^{(1 H-Nuclear magnetic resonance,} 1 H-NMR). From the obtained ¹ H-NMR spectrum, the oxime imidization ratio [%] was determined from the following formula (x).

醯imination rate [%]=(1-A ¹ /A ² ×α)×100...(x)

(In the formula (x), A ¹ is the peak area of the proton derived from the NH group appearing near the chemical shift of 10 ppm, A ² is the peak area derived from other protons, and α is the precursor of the other proton relative to the polymer ( The ratio of the number of protons of the NH group in the poly-proline).

[Solid viscosity of polymer solution]

The solution viscosity of the polymer solution was determined by using a prescribed solvent and using an E-type rotational viscometer at 25 ° C to prepare a solution having a polymer concentration of 10% by weight [mPa. s].

<Synthesis of Polymer (A) (1)> [Synthesis Example 1: Synthesis of Polyproline (A-1)]

98 g (0.50 mol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride as tetracarboxylic dianhydride and 109 g (0.50 mol) of pyromellitic dianhydride as 1, of diamine. 4-phenylenediamine 76g (0.7 moles), 1,3-diamino-4-octadecyloxybenzene 19g (0.05 moles), 4,4'-diaminodiphenylmethane 50g (0.25 Mohr was dissolved in a mixed solvent containing 230 g of N-methyl-2-pyrrolidone (NMP) and γ-butyrolactone 2,060 g, and the reaction was carried out at 40 ° C for 3 hours. After completion of the reaction, 1,350 g of γ-butyrolactone was added to obtain a solution containing 10% by weight of poly-proline (A-1). The solution has a solution viscosity of 125 mPa. s.

[Synthesis Example 2: Synthesis of Polyimine (A-2)]

110 g (0.50 mol) of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride as tetracarboxylic dianhydride, p-phenylenediamine 43 g (0.40 mol) and 3-(3,5) as diamine -diaminobenzimidyloxy)cholestane 52 g (0.10 mol) was dissolved in 830 g of NMP, and the reaction was carried out at 60 ° C for 6 hours. A small amount of the obtained polyaminic acid solution was added, NMP was added, and the viscosity was measured by a solution having a solid concentration of 10%, and the result was 60 mPa. s. Then, 1900 g of NMP was added to the obtained polyaminic acid solution, and 40 g of pyridine and 51 g of acetic anhydride were added, and dehydration ring closure was carried out at 110 ° C for 4 hours. After the imidization reaction, the solvent in the system is replaced with a new NMP solvent (by this operation, the pyridine and acetic anhydride used in the oxime imidization reaction are removed to the outside of the system), and about 15% by weight is obtained. A solution of polyamidiamine (A-2) having a ruthenium iodide ratio of about 50%. A small amount of the obtained polyimine solution was added, and NMP was added to prepare a solution having a polyimine concentration of 10% by weight, and the measured solution viscosity was 47 mPa. s.

[Synthesis Example 3: Synthesis of Polyimine (A-3)]

2,3,5-tricarboxycyclopentyl acetic acid dianhydride as tetracarboxylic dianhydride 110 g (0.50 mol) and 1,3,3a,4,5,9b-hexahydro-8-methyl-5 -(tetrahydro-2,5-dioxo-3-furanyl)naphtho[1,2-c]furan-1,3-dione 160g (0.50 mol), p-phenylenediamine as diamine 94 g (0.87 mol), 1,3-bis(3-aminopropyl)tetramethyldioxane 25 g (0.10 mol), and 3,6-bis(4-aminobenzimidyloxy) 6.2 g (0.015 mol) of choline, and 8.1 g (0.030 mol) of octadecylamine as a monoamine, dissolved in 960 g of NMP, and reacted at 60 ° C for 6 hours. A small amount of the obtained polyaminic acid solution was added, NMP was added, and the viscosity was measured using a solution having a solid concentration of 10%. The fruit is 60mPa. s. Then, 2700 g of NMP was added to the obtained polyaminic acid solution, and 400 g of pyridine and 410 g of acetic anhydride were added, and dehydration ring closure was carried out at 110 ° C for 4 hours. After the imidization reaction, the solvent in the system is subjected to solvent replacement with a new γ-butyrolactone to obtain a polyimine (A-3) containing about 15% by weight of a ruthenium iodide ratio of about 95%. The solution. A small amount of the obtained polyimine solution was added, and γ-butyrolactone was added to prepare a solution having a polyimine concentration of 10% by weight, and the obtained solution viscosity was 70 mPa. s.

[Synthesis Example 4: Synthesis of polyaminic acid (A-4)]

200 g (1.0 mol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride as tetracarboxylic dianhydride, 2,2'-dimethyl-4,4'-di as diamine 210 g (1.0 mol) of aminobiphenyl was dissolved in a mixed solvent of 370 g of NMP and γ-butyrolactone 3300 g, and the reaction was carried out at 40 ° C for 3 hours, thereby obtaining a polyglycine containing 10% by weight (A). -4) solution. The solution has a solution viscosity of 160 mPa. s.

<Example 1> [Preparation of Liquid Crystal Aligning Agent]

After adding NMP, γ-butyrolactone (BL) and butyl cyanidin (BC) as an organic solvent to a solution containing polyamic acid (A-1) as the polymer (A), relative to polymerization To 100 parts by weight of the total of the compound, 5 parts by weight of triethylene glycol as the compound (B) was added to prepare a solvent composition of NMP:BL:BC=30:30:40 (weight ratio), and a solid content concentration of 6.0% by weight. The solution. This solution was filtered using a filter having a pore size of 1 μm, thereby preparing a liquid crystal alignment agent.

[Manufacture of liquid crystal cell (1)]

The liquid crystal alignment agent prepared above was applied onto a transparent electrode surface of a glass substrate with a transparent electrode containing an ITO film using a liquid crystal alignment film printer (manufactured by Nippon Photoprint Co., Ltd.) on a hot plate at 80 ° C. After heating (prebaking) for 1 minute to remove the solvent, it was heated (post-baked) on a hot plate at 230 ° C for 10 minutes to form a coating film having an average film thickness of 100 nm.

This coating film was subjected to a rubbing treatment using a rubbing machine having a roll wound with a crepe cloth at a roll rotation speed of 500 rpm, a table moving speed of 3 cm/sec, and a hair press-in length of 0.4 mm to impart liquid crystal alignment ability. Then, ultrasonic cleaning was performed for 1 minute in ultrapure water, followed by drying in a 100 ° C clean oven for 10 minutes, thereby obtaining a substrate having a liquid crystal alignment film. This operation was repeated to obtain a pair of (two pieces) substrates having a liquid crystal alignment film.

Then, an epoxy resin adhesive having an alumina ball having a diameter of 5.5 μm is applied to the outer edges of the pair of substrates on the surface of the liquid crystal alignment film, and then the liquid crystal alignment film faces are overlapped and crimped. To harden the adhesive. Then, a positive liquid crystal (MLC-6221, manufactured by Merck & Co., Inc.) was filled between the pair of substrates from the liquid crystal injection port, and then the liquid crystal injection port was sealed with an acrylic photocurable adhesive to produce a liquid crystal cell (1).

[Manufacture of liquid crystal cell (2)]

The liquid crystal cell (2) was produced by performing the same operation as the above-described liquid crystal cell (1) except that the post-baking temperature was changed from 230 ° C to 170 ° C.

[Evaluation of Reliability of Liquid Crystal Alignment Film]

For the liquid crystal cell obtained above, with an application time of 60 microseconds, 167 milliseconds After a voltage of 5 V was applied to the span, the voltage holding ratio (VHR1) after 167 milliseconds from the release of the application was measured. Then, the liquid crystal cell was allowed to stand in an 80 ° C oven under irradiation with an LED lamp for 200 hours, and then allowed to stand at room temperature, and naturally cooled to room temperature. After cooling, a voltage of 5 V was applied to the liquid crystal cell with an application time of 60 microseconds and a span of 167 milliseconds, and then the voltage holding ratio (VHR2) after 167 milliseconds from the application release was measured. Further, the measuring device was "VHR-1" manufactured by Toyo Technica Co., Ltd. The VHR change rate (ΔVHR) before and after the stress application was calculated according to the following formula (y), and the reliability of the liquid crystal alignment film was evaluated based on ΔVHR. The evaluation was performed in such a manner that the reliability was "very good (?)" when ΔVHR was 5% or less, and the reliability was "good (○)" when it was more than 5% and not more than 10%. When it is more than 10% and less than 15%, it is evaluated as reliability "may (△)", and 15% or more is evaluated as reliability "bad (x)". Further, the liquid crystal cell (1) and the liquid crystal cell (2) were each evaluated for reliability of the liquid crystal alignment film. Their results are shown in Table 1 below.

△VHR[%]=(VHR1-VHR2)/(VHR1)×100...(y)

[Evaluation of surface roughness (leveling property) of coating film]

The liquid crystal alignment agent prepared above was applied onto a tantalum wafer using a liquid crystal alignment film printer (manufactured by Japan Photoprinting Co., Ltd.), and then prebaked on a hot plate at 80 ° C for 60 seconds. Then, it was baked on a hot plate at 230 ° C for 15 minutes to form a coating film having a film thickness of 100 nm. Use atomic force microscope Nano Scope IIIa The surface roughness Ra (arithmetic average height) of the obtained coating film was measured by the apparatus (Digital Instrument), and the leveling property was evaluated. The evaluation was carried out in such a manner that the case where the surface roughness Ra was 0.3 nm or less was evaluated as "very good (?)", and the case where the thickness was 0.3 nm to 0.6 nm was evaluated as "good (○)". The case of 0.6 nm or more was evaluated as the leveling "defect (x)". The results are shown in Table 1 below.

In Table 1, the "addition amount" of the compound (B) is a compounding ratio [parts by weight] based on 100 parts by weight of the total amount of the polymer contained in the liquid crystal alignment agent. n represents the number of repeating units, and m represents the number of carbons in the repeating unit. "Reliability (230 ° C)" indicates the evaluation result when the post-baking temperature was 230 ° C, and "reliability (170 ° C)" indicates the evaluation result when the post-baking temperature was 170 °C.

<Example 2 to Example 8, Comparative Example 1, Comparative Example 2>

A liquid crystal alignment agent was prepared in the same manner as in Example 1 except that the type of the polymer (A) to be used and the type and amount of the compound (B) were changed as shown in the above Table 1. Further, in Example 8, two polymers were used in such a manner that the solid content of the polymer became polyimine (A-3): polyamine (A-4) = 20:80 (weight ratio). (A) A solution obtained by mixing to prepare a liquid crystal alignment agent. Further, in Example 2, Example 4 to Example 8, and Comparative Example 1, a liquid crystal cell was produced in the same manner as in Example 1, and in Example 3 and Comparative Example 2, the liquid crystal used was changed to a negative type. A liquid crystal cell was produced in the same manner as in Example 1 except for liquid crystal (manufactured by Merck & Co., MLC-6608). Each of the liquid crystal cells produced was evaluated for various characteristics in the same manner as in Example 1. Their results are shown in Table 1 above.

As shown in Table 1, it can be seen that when the compound (B) is blended in the liquid crystal alignment agent, the reliability and the leveling property are improved as compared with the comparative example 1 and the comparative example 2 which do not contain the compound (B). Liquid crystal alignment film. In addition, regarding the reliability of the liquid crystal alignment film, the liquid crystal alignment agent of the example was used to obtain any results of "very good", "good", and "may" when the post-baking temperature was 170 °C. In particular, in Example 2, Example 3, and Example 8 containing tetraethylene glycol or hexaethylene glycol as the compound (B), the film was excellent in reliability. Further, the liquid crystal alignment agents of Examples 3 to 8 containing the polyether compound in which n is 6 or more as the compound (B) are excellent in leveling property.

<Synthesis of Polymer (A) (2)>

In each of the Synthesis Examples, the following compound was used to synthesize the polymer (A).

<tetracarboxylic dianhydride>

<Diamine>

[Synthesis Example 5: Synthesis of polyaminic acid (A-5)]

4.60 g of a compound (G-3-1) as a tetracarboxylic dianhydride, 2.44 g of a compound (G-1), and 7.96 g of a compound (H-2) as a diamine were dissolved in N-methyl-2-pyrrole. The reaction was carried out for 4 hours at room temperature in 85 g of ketone, whereby a solution containing 15% by weight of poly-proline (A-5) was obtained. The solution has a solution viscosity of 1,500 mPa. s.

[Synthesis Example 6 to Synthesis Example 18, Synthesis Example 20: Synthesis of Polyaminic Acid (A-6) ~ Polylysine (A-18), Polylysine (A-20)]

Polylysine was synthesized in the same manner as in Synthesis Example 5 except that the type and amount of the tetracarboxylic dianhydride to be used and the type and amount of the diamine to be used were changed as shown in Table 2 below. Further, in Table 2, the numerical value of the amount of the tetracarboxylic dianhydride input indicates the blending ratio [mol%] of each compound with respect to the total amount of the tetracarboxylic dianhydride used for the synthesis. The tetracarboxylic dianhydride (total amount) and the diamine are used in a molar amount.

[Synthesis Example 19: Synthesis of Polyimine (A-19)]

8.16 g of a compound (G-3-2) as a tetracarboxylic dianhydride and 6.84 g of a compound (H-2) as a diamine were dissolved in 85 g of N-methyl-2-pyrrolidone at room temperature. After reacting for 4 hours, 0.95 g of N-piperidine and 0.98 g of acetic anhydride were added, and the oxime imidization reaction was carried out at 120 ° C for 4 hours. Then, the reaction mixture was poured into a large amount of excess methanol to precipitate a reaction product. Then, the obtained precipitate was washed with methanol, and dried under reduced pressure for 15 hours, whereby 10 g of polyimine (A-19) was obtained. The ruthenium imidization ratio of polyimine (A-19) was 35%.

<Example 9> [Preparation of Liquid Crystal Aligning Agent]

In the solution containing the polyaminic acid (A-5) obtained in the above Synthesis Example 5, N-methyl-2-pyrrolidone (NMP), butyl quercetin (BC), and polyethylene glycol were added. (trade name "PEG600", a polyethylene glycol having a number average molecular weight of about 600 obtained from Wako Pure Chemical Industries Co., Ltd.), and sufficiently stirred to prepare a solvent composition of NMP: BC = 60: 40 (weight ratio), A solution having a solid content concentration of 2.5% by mass. This solution was filtered using a filter having a pore size of 1 μm, thereby preparing a liquid crystal alignment agent (E-1). Using the liquid crystal alignment agent (E-1), the following evaluation of liquid crystal alignment and evaluation of afterimage characteristics were performed.

[Evaluation of liquid crystal alignment]

. Manufacturing of liquid crystal display elements (1)

The liquid crystal alignment agent (E-1) prepared above was applied onto the transparent electrode surface of the glass substrate with a transparent electrode including the ITO film so that the film thickness was 0.1 μm at 80 ° C. Pre-bake on the hot plate for 1 minute. The surface of the coating film was irradiated with a polarized ultraviolet light of 8,000 J/m ² including a bright line of 254 nm from the normal direction of the substrate using an Hg-Xe lamp, and dried at 230 ° C for 1 hour (post-baking). Then, on the pair of substrates subjected to the light irradiation treatment, a liquid crystal injection port was left at the edge of the surface on which the liquid crystal alignment film was formed, and an epoxy resin adhesive having a diameter of 5.5 μm was added to the screen. After the printing and coating, the substrate was superposed on the substrate by the polarizing axis when the light was irradiated, and the substrate was placed on the substrate at 150 ° C for 1 hour to thermally cure the adhesive. Then, a nematic liquid crystal (MLC-7028, manufactured by Merck & Co., Inc.) was filled between the pair of substrates from the liquid crystal injection port, and then the liquid crystal injection port was sealed with an epoxy-based adhesive. Further, in order to eliminate the flow alignment during liquid crystal injection, the film was heated at 150 ° C and then slowly cooled to room temperature. Then, a polarizing plate was bonded to both sides of the substrate to produce a liquid crystal display element.

. Evaluation

For the liquid crystal display element manufactured above, a polarizing microscope is used to observe the connection. The presence or absence of an abnormal region when the voltage is turned off (ON.OFF) is applied, and the case where there is no abnormal region is judged as "good", and the case where only one abnormal region is determined is also determined as "poor". The liquid crystal alignment of the liquid crystal display element is "good".

[Evaluation of afterimage characteristics (burning characteristics)]

. Manufacturing of liquid crystal display elements (2)

A glass substrate having a two-system metal electrode, a electrode A (11), and an electrode B (12) patterned in a comb-tooth shape as shown in FIG. 1 and a counter-glass substrate not provided with an electrode Used as a pair of substrates, In the same operation as the "manufacturing (1) of the liquid crystal display element", a liquid crystal display element of a transverse electric field type is manufactured.

. Evaluation

The transverse electric field type liquid crystal display element produced above was placed in an environment of 25 ° C and 1 atmosphere, and no voltage was applied to the electrode B, and a combined voltage of an alternating current voltage of 3.5 V and a direct current voltage of 5 V was applied to the electrode A for 4 hours. Immediately thereafter, an alternating current of 4 V was applied to both the electrode A and the electrode B. The time from when the voltage of the alternating current of 4 V was applied to the two electrodes was reached, and the time until the light transmittance of the electrode A and the electrode B could not be confirmed by visual observation. The afterimage characteristics when the time is less than 100 seconds are evaluated as "excellent", and the afterimage characteristics when the time is 100 seconds or longer and 150 seconds or less are evaluated as "good", and the afterimage characteristics in the case of more than 150 seconds are evaluated as "good". bad". The afterimage characteristic of the liquid crystal display element is "excellent".

<Example 5 to Example 25, Comparative Example 3, and Comparative Example 4>

A liquid crystal alignment agent (E-2) was prepared in the same manner as in Example 5 except that the type of the polymer (A) to be used and the type and amount of the compound (B') were changed as described in Table 3 below. ~ Liquid crystal alignment agent (E-21), liquid crystal alignment agent (R-1), liquid crystal alignment agent (R-2). Further, two kinds of liquid crystal display elements were produced in the same manner as in Example 5 using the prepared liquid crystal alignment agent, and evaluation of liquid crystal alignment and afterimage characteristics was performed. Their results are shown in Table 4 below.

In Table 3, the abbreviations of the compound (B') are as follows.

PEG600: polyethylene glycol (trade name "PEG600", manufactured by Wako Pure Chemical Industries Co., Ltd.)

(c2-1-2): a compound represented by the above formula (c2-1-2)

(c1-1-1): polyvinyl alcohol (trade name "K24-E", manufactured by Electrochemical Industry Co., Ltd.)

(c2-3-1): a compound represented by the above formula (c2-3-1)

(c2-4-1): a compound of the above formula (c2-4-1) wherein R ⁶¹ and R ⁶² are each a n-hexyl group

As shown in Table 4, it was found that by blending the compound (B') in the liquid crystal alignment agent, a liquid crystal display element which can exhibit liquid crystal alignment properties and afterimage characteristics with good balance can be obtained. In contrast, liquid crystal alignment and afterimage characteristics in Comparative Example 3 All of them were "bad", and in Comparative Example 4, although the liquid crystal alignment property was "good", the afterimage characteristics were "poor".

11‧‧‧Electrode A

12‧‧‧Electrode B

Claims (12)

A liquid crystal alignment agent containing a compound (B') and a polymer component (excluding a compound corresponding to the above compound (B')), and the compound (B') is 20 ° C / min from 40 ° C The amount of thermal weight loss at 120 ° C obtained by measuring the temperature rising condition was 30% or less, and the amount of thermal weight loss at 250 ° C was 90% or more. The liquid crystal alignment agent according to claim 1, which comprises at least one polymer (A) selected from the group consisting of polylysine, polyphthalate, and polyimine as the above polymerization. Composition. The liquid crystal alignment agent according to claim 2, which comprises a cyclobutane ring having a substituent selected from the formula (ph-1) in the main chain, which may have a substituent, and carbon-carbon unsaturated A polymer having at least one structure selected from the group consisting of a bond and an azobenzene skeleton as the above polymer (A): (In the formula (ph-1), X ³ is a sulfur atom, an oxygen atom or -NH-; "*" represents a bond, respectively; wherein at least one of the two "*" is bonded to the aromatic ring). The liquid crystal alignment agent according to any one of claims 1 to 3, wherein the compound (B') is a compound having a repeating unit represented by the following formula (c1): [Chemical 2] (In the formula (c1), R ¹ and R ² each independently represent a hydrogen atom, a fluorine atom, an alkyl group having 1 to 6 carbon atoms, a halogenated alkyl group having 1 to 6 carbon atoms or a phenyl group; and X ⁴ is an oxygen atom; a carbonyl group, a carbonate group, a carbonyloxy group, -CH=N-, or -CR ¹³ (OH)- (wherein R ¹³ is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms); r1 is an integer of 1 to 6 Wherein, when r1 is 2 or more, a plurality of R ¹ and R ² in the repeating unit may be the same or different; R ¹ , R ² and r ¹ may be the same in all the repeating units, or may be between the repeating units. different). The liquid crystal alignment agent according to any one of claims 1 to 3, wherein the compound (B') is selected from the group consisting of the following formulas (c2-1) to (c2-4) At least one of the groups consisting of: (In the formula (c2-1), R ⁵¹ is an alkyl group having 1 to 12 carbon atoms; and R ⁵² and R ⁵³ are each independently an alkyl group having 1 to 12 carbon atoms, or bonded to each other and to R ⁵² and R ⁵³ The bonded carbon atoms together form a divalent alicyclic hydrocarbon group; s is an integer of 1 to 4; R ⁵⁴ is an s-valent organic group in the case where s is 1, 3 or 4, and is s=2 in the case of s=2 Single bond or s-valent organic base) (In the formula (c2-2), R ⁵⁵ and R ⁵⁶ are each independently an alkyl group having 1 to 12 carbon atoms, or are bonded to each other to form a monovalent ring together with a carbon atom to which R ⁵⁵ and R ⁵⁶ are bonded. Ether group; t is an integer from 1 to 4; R ⁵⁷ is a t-valent organic group in the case where t is 1, 3 or 4, and is a single bond or a t-valent organic group in the case of t=2) (In the formula (c2-3), R ³³ and R ³⁴ are each independently an alkyl group having 1 to 6 carbon atoms, and X ³¹ and X ³² are each independently a single bond, -O-, -COO- or -CO-. X ³³ and X ³⁴ are each independently a halogen atom; k1, k2, k3 and k4 are each independently an integer of 0 to 5, satisfying k1+k3≦5 and k2+k4≦5) [Chem. 6] (In the formula (c2-4), R ³⁵ and R ³⁶ are each independently an alkyl group having 1 to 18 carbon atoms, and X ³⁵ and X ³⁶ are each independently a single bond, -O-, -COO- or -CO-. ). The liquid crystal alignment agent according to any one of claims 1 to 4, wherein the compound (B') is a compound (B) represented by the following formula (b): (In the formula (b), X ¹ and Y ¹ are each independently a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 6 carbon atoms, a halogenated alkyl group having 1 to 6 carbon atoms, an amine group, an epoxy group, or an epoxy group. a group, a phenyl group, a vinyl group, a (meth) acryloxy group, a fluorenyl group or a carboxyl group; and R ¹ and R ² are each independently a hydrogen atom, a fluorine atom, an alkyl group having 1 to 6 carbon atoms, and a carbon number of 1 to 6; a halogenated alkyl group or a phenyl group; m is an integer of 1 to 5, and n is an integer of 2 to 20; wherein, when m is 2 or more, a plurality of R ¹ and R ² in the repeating unit may be the same Different; R ¹ , R ² and m may be the same in all repeating units, or may be different between repeating units). The liquid crystal alignment agent according to claim 6, wherein the content of the compound (B) is from 0.1 part by weight to 50 parts by weight based on 100 parts by weight of the total of the polymer component. The liquid crystal alignment agent according to Item 6 or Item 7, wherein the above n is an integer of 3 or more. A method for producing a liquid crystal alignment film, comprising: a film forming step of applying a liquid crystal alignment agent according to any one of claims 1 to 8 on a substrate to form a coating film; and light irradiation In the step, the coating film is irradiated with light to form a liquid crystal alignment film. The method for producing a liquid crystal alignment film according to claim 9, wherein the film forming step comprises: a prebaking step of preheating the liquid crystal alignment agent coated on the substrate; and a post-baking step, The coating film after the prebaking is further heated, and the light irradiation step is a step of irradiating the coating film after the prebaking step and before the post baking step. A liquid crystal alignment film formed by using the liquid crystal alignment agent according to any one of claims 1 to 8. A liquid crystal display element comprising the liquid crystal alignment film according to claim 11 of the patent application.