TW201708316A - Liquid crystal aligning agent, liquid crystal alignment film and liquid crystal display element - Google Patents

Abstract

Provided are: a liquid crystal aligning agent for obtaining a liquid crystal alignment film for photo-alignment methods, which enables the achievement of good afterimage characteristics without producing bright dots even in cases where negative liquid crystals are used; a liquid crystal alignment film; and a liquid crystal display element. A liquid crystal aligning agent which contains at least one polymer selected from the group consisting of polyimide precursors that have a structure represented by formula (1) in the main chain and imidized polymers of the polyimide precursors. (In formula (1), each of R1 and R2 represents a single bond, -O-, -S-, -NR12- or the like; R12 represents a hydrogen atom or the like; A represents an alkylene group having 2-20 carbon atoms; and each of B1 and B2 independently represents a divalent organic group selected from among structures (AA), provided that B1 and B2 are different from each other.) (In structures (AA), R4 represents an alkylene group having 1-5 carbon atoms; and R5 represents a hydrogen atom or the like).

Description

Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element

The present invention relates to a liquid crystal alignment agent used for the production of a liquid crystal display element having excellent afterimage characteristics, a liquid crystal alignment film obtained from the liquid crystal alignment agent, and a liquid crystal display element having the liquid crystal alignment film.

The photo-alignment method is a non-friction alignment treatment method, and is also a simple manufacturing process in the industry. In particular, in a liquid crystal display device of an IPS (In-Plane-Switching) driving method or an FFS (Flinge-field-Switching) driving method, by using the liquid crystal alignment film obtained by the above-described photoalignment method, compared with rubbing The liquid crystal alignment film obtained by the treatment method can be expected to have an improvement in contrast or viewing angle characteristics of the liquid crystal display element. Thereby, the performance of the liquid crystal display element can be improved, and attention is paid as a liquid crystal alignment processing method which is worthy of expectation.

However, the liquid crystal alignment film obtained by the photo-alignment method has a problem that the anisotropy of the alignment direction of the polymer film is small as compared with the friction. When the anisotropy is small, sufficient liquid crystal alignment property cannot be obtained, and when it is a liquid crystal display element, there is a problem that an afterimage or the like occurs.

On the other hand, as a liquid crystal alignment obtained by the optical alignment method In the method of anisotropic film formation, a low molecular weight component which is formed by cutting a main chain of the polyimine by light irradiation is proposed, and is removed after light irradiation.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. Hei 9-297313

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2011-107266

[Non-patent literature]

[Non-Patent Document 1] "Liquid Crystal Light Alignment Film", Kimo Kasumi, Shimura Functional Materials Vol.17(1997) No.11 p.13-22

In the liquid crystal display device of the IPS driving method or the FFS driving method, a positive liquid crystal has been conventionally used. However, by using a negative liquid crystal, the transmission loss at the upper portion of the electrode can be made small, and the contrast can be improved.

When the liquid crystal alignment film obtained by the photo-alignment method is used for a liquid crystal display device using an IPS driving method or an FFS driving method of a negative liquid crystal, it is expected to have higher display performance than conventional liquid crystal display elements. However, as a result of the investigation by the present inventors, it has been found that the decomposition of the polymer by light irradiation produces anisotropy, and when the liquid crystal alignment is used, a photodegradable liquid crystal alignment film and a negative liquid crystal are used to produce a liquid crystal display element. By composition The occurrence rate of display defects (bright spots) due to the decomposition product of the polymer of the liquid crystal alignment film produced by the ultraviolet light irradiation is high.

An object of the present invention is to provide a liquid crystal alignment agent for obtaining a liquid crystal alignment film for a photo-alignment method which does not cause a bright spot even when a negative-type liquid crystal is used, and a liquid crystal alignment agent obtained by the liquid crystal alignment agent. An alignment film and a liquid crystal display element including the liquid crystal alignment film.

The inventors of the present invention have completed the present invention in an effort to solve the above problems. That is, the present invention is as follows.

A liquid crystal aligning agent comprising a fluorene imidized polymer selected from the group consisting of a polyimine precursor having a structure represented by the following formula (1) in the main chain and the polyimine precursor. At least one polymer of the group; [Chemical 1]-B ₁ -R ₁ -AR ₂ -B ₂ - (1)

(wherein R ₁ and R ₂ are each independently a single bond, -O-, -S-, -NR ₁₂ -, an ester bond, a guanamine bond, a thioester bond, a urea bond, a carbonate bond, or an amine. a carbamate bond, R ₁₂ is a hydrogen atom or a methyl group; A is an alkylene group having 2 to 20 carbon atoms; and B ₁ and B ₂ are each independently a divalent organic group selected from the following structures. B ₁ and B _{2 are} not the same structure);

(wherein R ₄ is an alkylene group having 1 to 5 carbon atoms; and R ₅ is a hydrogen atom, a methyl group, a hydroxyl group or a methoxy group).

2. The liquid crystal alignment agent according to 1, wherein the polyimine precursor is a polymer containing a structural unit of the following formula (2);

(Wherein, X ₁ is selected from the group consisting of the following formulas (X1-1) and (X1-2) represents at least one kind of structure formed by the group; the Y ₁ is the formula (1) represents the divalent organic group; R ₃ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; and Z ₁ and Z ₂ are each independently a hydrogen atom or may have a substituent, an alkyl group having 1 to 10 carbon atoms, and a carbon number of 2 to 10; Alkenyl or alkynyl having 2 to 10 carbon atoms).

3. The liquid crystal alignment agent according to 2 above, wherein the polyimine precursor has a structural unit represented by the above formula (2) in an amount of 20 to 100 mol% based on the total structural unit.

4. The liquid crystal alignment agent according to 2 or 3 above, wherein X ₁ is the following formula (X1-2);

5. The liquid crystal alignment agent according to any one of the above 1 to 4, wherein the structure of the above formula (1) has the following structure.

(wherein A, R ₁ and R ₂ are the same as defined above.)

A liquid crystal alignment film obtained by applying and baking a liquid crystal alignment agent according to any one of the above 1 to 5, and irradiating the polarized ultraviolet light.

A liquid crystal display element comprising the liquid crystal alignment film of the above-described item 6.

8. A diamine represented by the following formula;

(Wherein, R ₁ is and R ₂ are each independently a single bond lines, -O -, - S -, - NR 12 -, an ester bond, acyl amine linkage, a thioester bond, a urea bond, a carbonate bond, or an amine a carbamate bond, R ₁₂ is a hydrogen atom or a methyl group, and A is a C 2 to 20 alkyl group).

By using the liquid crystal alignment agent of the present invention, it is possible to suppress the bright spots caused by the decomposition products from the liquid crystal alignment film which are generated during the photoalignment treatment, and to obtain a liquid crystal alignment film having high irradiation sensitivity and excellent liquid crystal alignment. It can provide liquid crystal display elements with no display defects and high reliability.

Although the reason why the above effect can be obtained by using the liquid crystal alignment agent of the present invention is not clear, it is presumed that the diamine used as a raw material of the polymer constituting the liquid crystal alignment agent has a specific asymmetric structure due to light. The solubility and crystallinity of the decomposition product generated by the irradiation change.

<specific construction>

The main chain of the polymer constituting the liquid crystal alignment agent of the present invention contains a specific structure represented by the above formula (1) (hereinafter also referred to as a specific structure).

[Chem. 8]-B ₁ -R ₁ -AR ₂ -B ₂ - (1)

In the above formula (1), R ₁ and R ₂ are each independently a single bond, -O-, -S-, -NR ₁₂ -, an ester bond, a guanamine bond, a thioester bond, a urea bond, or a carbonate bond. Or a urethane bond, and R ₁₂ is a hydrogen atom or a methyl group. A is an alkylene group having a carbon number of 2 to 20. The B ₁ and B ₂ systems are each independently a divalent organic group selected from the following structures, and B ₁ and B _{2 are} not the same structure. Further, B ₁ and B ₂ do not have the same structure, and the solubility and crystallinity of the decomposition product due to light irradiation change, and the bright spots derived from the decomposition component of the polymer can be suppressed.

In the above formula, R ₄ is an alkylene group having 1 to 5 carbon atoms. R ₅ is a hydrogen atom, a methyl group, a hydroxyl group or a methoxy group).

Further, in the above formula (1), from the viewpoint of liquid crystal alignment, R ₁ and R _{2 are} particularly preferably a single bond, -O-, -S-, -NR ₁₂ -, an ester bond or a guanamine bond; Good for -O-. Further, from the viewpoint of liquid crystal alignment, A is preferably an alkyl group having 2 to 6 carbon chains, and particularly preferably an alkyl group having 2 to 4 carbon chains.

In the above formula, R _{4 is} preferably an alkylene group having 1 to 3 carbon atoms from the viewpoint of liquid crystal alignment. From the viewpoint of liquid crystal alignment, R _{5 is} preferably a hydrogen atom or a methyl group.

The above specific structure is preferably contained in the diamine of the raw material of the polyimide precursor. Specific examples of the diamine having the above specific structure include the following diamines, but are not limited thereto.

(R ₅ is the same as defined above).

In the above formula, R ₅ and R ₁₂ also include the preferred examples of each, and are the same as defined above.

The diamine having the specific structure described above is preferably a diamine having the following structure from the viewpoints of the alignment property and the reduction of the bright spot when the liquid crystal display element is used.

In the above formula, R ₁ , R ₂ and A, each including a preferred example thereof, are as described above. The diamine having the above specific configuration is preferably the following diamine.

<Synthesis of diamine>

The main synthesis of the above diamines is detailed below. Furthermore, the method described below is an example and is not limited thereto.

The diamine of the present invention is obtained by reducing a dinitro compound and converting a nitro group into an amine group, as shown in the following reaction formula. In addition, the following reaction formula is a diamine described in the Example, as an example.

The method for reducing the dinitro compound is not particularly limited, and examples thereof include palladium-carbon, platinum oxide, Raney nickel, platinum black, lanthanum-alumina, and platinum sulfide carbon as catalysts. A method of reducing a solvent such as an ester, toluene, tetrahydrofuran, dioxane or an alcohol by hydrogen, helium, hydrogen chloride or the like. It can also be carried out using an autoclave as needed, under pressure. On the other hand, when an unsaturated bond site is contained in the substituent structure of the hydrogen atom of the substituted benzene ring or the saturated hydrocarbon moiety, when palladium carbon or platinum carbon or the like is used, the unsaturated bond site is reduced and becomes a saturated bond. After that. Therefore, it is preferred to use a reducing metal such as reduced iron, tin, or tin chloride as a reducing condition of the catalyst.

In the synthesis of the dinitro compound, the dinitro compound can be obtained by reacting a commercially available biphenyl derivative with a nitrobenzene substituted with a leaving group X such as a halogen, as shown in the following reaction formula. . Preferred examples of the leaving group X include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a tosylate (-OTs), a mesylate (-OMs), and the like.

The above reaction can be carried out in the presence of a base. The base to be used is not particularly limited as long as it can be synthesized, and examples thereof include inorganic bases such as potassium carbonate, sodium carbonate, cesium carbonate, sodium alkoxide, potassium alkoxide, sodium hydroxide, potassium hydroxide, and sodium hydride; and pyridine; An organic base such as dimethylaminopyridine, trimethylamine, triethylamine or tributylamine. Further, depending on the case, when a palladium catalyst such as dibenzylideneacetone palladium or diphenylphosphinoferrocene palladium or a copper catalyst is used in combination, the yield can be improved. From the viewpoint of easiness of synthesis, a method using potassium carbonate is preferred, but it can be synthesized in addition to the method. Therefore, the synthesis method is not particularly limited.

<polymer>

The polyimine precursor constituting the liquid crystal alignment agent of the present invention contains a structural unit of the following formula (2).

X ₁ is at least one selected from the group consisting of structures represented by the following formulas (X1-1) and (X1-2). Among them, from the viewpoint of liquid crystal alignment, the following formula (X1-2) is particularly preferable.

Y ₁ is a divalent organic group represented by the formula (1).

R ₃ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. Specific examples thereof include a methyl group, an ethyl group, a propyl group, an i-propyl group, an n-butyl group, an i-butyl group, an s-butyl group, a t-butyl group, an n-pentyl group and the like. From the viewpoint of easy imidization by heat, R _{3 is} preferably a hydrogen atom or a methyl group.

Z ₁ and Z ₂ are each independently a hydrogen atom or a substituent having an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms or an alkynyl group having 2 to 10 carbon atoms. Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a t-butyl group, a hexyl group, an octyl group, a decyl group, a cyclopentyl group, a cyclohexyl group, a bicyclohexyl group and the like. The alkenyl group may be a structure in which one or more CH ₂ -CH ₂ structures present in the above alkyl group are substituted with a CH=CH structure. Specific examples thereof include a vinyl group, an allyl group, a 1-propenyl group, an isopropenyl group, a 2-butenyl group, a 1,3-butadienyl group, a 2-pentenyl group, a 2-hexenyl group, and a ring. Propylene, cyclopentenyl, cyclohexenyl and the like. The alkynyl group may be a structure in which one or more CH ₂ -CH ₂ structures present in the above alkyl group are substituted with a C≡C structure. Specific examples thereof include an ethynyl group, a 1-propynyl group, and a 2-propynyl group.

The above alkyl group, alkenyl group, and alkynyl group may have a substituent, and further, a substituent may form a ring structure. Further, by forming a ring structure by a substituent, it means that the substituents are each other or the substituent and the parent skeleton A part of the bond is formed into a ring structure.

Examples of the substituent include a halogen group, a hydroxyl group, a thiol group, a nitro group, an aryl group, an organic oxy group, an organic thio group, an organic decyl group, a decyl group, an ester group, a thioester group, a phosphate group, and a decylamine. Base, alkyl, alkenyl, alkynyl and the like.

The halogen group may, for example, be a fluorine atom, a chlorine atom, a bromine atom or an iodine atom.

The aryl group may be a phenyl group. The other substituents described above may be further substituted on the aryl group.

The organooxy group may represent a structure represented by O-R. The R may be the same or different, and the above-mentioned alkyl group, alkenyl group, alkynyl group, aryl group and the like can be exemplified. The above substituents may be further substituted for R on these. Specific examples thereof include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group and the like.

The organic sulfur group may represent a structure represented by -S-R. The R may be exemplified by the above-mentioned alkyl group, alkenyl group, alkynyl group, aryl group or the like. The above substituents may be further substituted for R on these. Specific examples thereof include a methylthio group, an ethylthio group, a propylthio group, a butylthio group, a pentylthio group, a hexylthio group, a heptylthio group, an octylthio group and the like.

The organic decyl group may represent a structure represented by -Si-(R) ₃ . The R may be the same or different, and the above-mentioned alkyl group, alkenyl group, alkynyl group, aryl group and the like can be exemplified. The above substituents may be further substituted for R on these. Specific examples include trimethyldecylalkyl, triethyldecylalkyl, tripropyldecylalkyl, tributyldecylalkyl, tripentyldecylalkyl, trihexyldecylalkyl, pentyldimethyldecyl, hexyl Methyl decyl group and the like.

The fluorenyl group may represent a structure represented by -C(O)-R. The R can be exemplified above An alkyl group, an alkenyl group, an aryl group or the like. The above substituents may be further substituted for R on these. Specific examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, an isobutyl group, a pentamidine group, an isovaleryl group, a benzindenyl group and the like.

The ester group may represent a structure represented by -C(O)O-R or -OC(O)-R. The R may be exemplified by the above-mentioned alkyl group, alkenyl group, alkynyl group, aryl group or the like. The above substituents may be further substituted for R on these.

The thioester group may represent a structure represented by -C(S)O-R or -OC(S)-R. The R may be exemplified by the above-mentioned alkyl group, alkenyl group, alkynyl group, aryl group or the like. The above substituents may be further substituted for R on these.

The phosphate group may represent a structure represented by -OP(O)-(OR) ₂ . The R may be the same or different, and the above-mentioned alkyl group, alkenyl group, alkynyl group, aryl group and the like can be exemplified. The above substituents may be further substituted for R on these.

The guanamine group may be represented by -C(O)NH ₂ or -C(O)NHR, -NHC(O)R, -C(O)N(R) ₂ , -NRC(O)R. The R may be the same or different, and the above-mentioned alkyl group, alkenyl group, alkynyl group, aryl group and the like can be exemplified. The above substituents may be further substituted for R on these.

The aryl group may be the same as the above-mentioned aryl group. The other substituents described above may be further substituted on the aryl group.

The alkyl group may be the same as the alkyl group described above. The other substituents described above may be further substituted on the alkyl group.

The alkenyl group may be the same as the above-mentioned alkenyl group. The other substituents described above may be further substituted on the alkenyl group.

The alkynyl group may be the same as the alkynyl group described above. The other substituents described above may be further substituted on the alkynyl group.

In general, when a structure having a large volume is introduced, there is a possibility that the reactivity of the amine group or the liquid crystal alignment property is lowered. Therefore, as Z ₁ and Z _{2 ,} a hydrogen atom or a carbon number which may have a substituent is more preferable. An alkyl group of 5; particularly preferably a hydrogen atom, a methyl group or an ethyl group.

The structural unit represented by the above formula (2) having a total structural unit of 20 to 100 mol% is preferably 30 to 100 mol% from the viewpoint of liquid crystal alignment.

<Other construction units>

When the polymer constituting the liquid crystal alignment agent of the present invention contains a structural unit other than the structural unit of the above formula (2), the structural unit thereof is represented by the following formula (3).

The definitions of R ₃ , Z ₁ and Z _{2 are} the same as those of the above formula (2).

X ₂ is a tetravalent organic group, and Y ₂ is a divalent organic group.

X ₂ is a tetravalent organic group derived from a tetracarboxylic acid derivative, and its structure is not particularly limited. In the polyimine precursor, two or more kinds of X ₂ may be mixed and mixed. Specific examples of X ₂ include the structures of the following formulas (X-1) to (X-44).

R ₈ to R ₁₁ in the above formula (X-1) are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, and a carbon number of 2 to 6. Alkynyl or phenyl. When R ₈ to R ₁₁ are a bulky structure, there is a possibility of lowering the liquid crystal alignment property, and therefore it is more preferably a hydrogen atom, a methyl group or an ethyl group; particularly preferably a hydrogen atom or a methyl group.

In the formula (3), Y ₂ is a divalent organic group derived from a diamine, and the structure thereof is not particularly limited. Specific examples of the structure of Y ₂ include the following (Y-1) to (Y-118).

(In the formula (Y-109), m and n are each independently an integer from 1 to 11, and m+n is an integer from 2 to 12. In the formula (Y-114), h is an integer from 1 to 3, In (Y-111) and (Y-117), j is an integer from 0 to 3.

The polyimine precursor used in the present invention is obtained by a reaction of a diamine component and a tetracarboxylic acid derivative, and examples thereof include polyglycine or polydecylamine.

<polyimine precursor (polyglycine)>

The polyamic acid used in the polyimine precursor of the present invention is produced by the following method.

Specifically, the reaction can be carried out by reacting tetracarboxylic dianhydride with a diamine in the presence of an organic solvent at -20 to 150 ° C, preferably at 0 to 50 ° C for 30 minutes to 24 hours, preferably 1 reaction. ~12 hours to synthesize.

The reaction of the diamine component with the tetracarboxylic acid component is usually carried out in an organic solvent. The organic solvent used at this time is not particularly limited as long as it is dissolved in the produced polyimide precursor. The following series of specific examples of the organic solvent used in the reaction are not limited to these examples. For example, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, γ-butyrolactone, N,N-dimethylformamide, N,N-dimethyl B can be cited. Guanidine, dimethyl hydrazine or 1,3-dimethyl-imidazolidinone.

Further, when the solubility of the polyimide precursor is high, methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone or the following formula [D- can be used. 1]~ The organic solvent represented by the formula [D-3].

In the formula [D-1], D ¹ represents an alkyl group having 1 to 3 carbon atoms, and in the formula [D-2], D ² represents an alkyl group having 1 to 3 carbon atoms, and in the formula [D-3], D ³ It represents an alkyl group having 1 to 4 carbon atoms.

These solvents may be used singly or in combination. Further, even if the solvent of the polyimine precursor is not dissolved, it may be used in the solvent in the range in which the produced polyimide precursor is not precipitated. Further, since the water in the solvent hinders the polymerization reaction and further causes the polyimine precursor formed by the hydrolysis, the solvent is preferably used by dehydration.

The concentration of the poly-proline polymer in the reaction system is preferably from 1 to 30% by mass, more preferably from 5 to 20% by mass, from the viewpoint that the precipitation of the polymer is less likely to occur and the high molecular weight body is easily obtained.

The polyamic acid obtained as described above can be injected into a poor solvent while sufficiently stirring the reaction solution to precipitate a polymer and collect it. Further, it can be obtained by several times of precipitation, washing with a poor solvent, and then drying at room temperature or by heating to obtain a powder of purified polylysine. The poor solvent is not particularly limited, and examples thereof include water, methanol, ethanol, hexane, butyl quercetin, acetone, toluene, and the like.

<polyimine precursor (polyphthalate)>

The polyphthalate ester of the polyimine precursor used in the present invention can be produced by the production method of (1), (2) or (3) shown below.

(1) Cases made of polylysine

Polyammonium esters can be produced by esterifying a polyamic acid produced as described above. Specifically, the polyglycine and the esterifying agent can be reacted at -20 to 150 ° C, preferably at 0 to 50 ° C for 30 minutes to 24 hours, preferably in the presence of an organic solvent. ~4 hours to manufacture.

The esterifying agent is preferably one which can be easily removed by purification, and examples thereof include N,N-dimethylformamide dimethyl acetal, N,N-dimethylformamide diethyl acetal, and N. , N-dimethylformamide dipropyl acetal, N,N-dimethylformamide dineopentyl butyl acetal, N,N-dimethylformamide di-t-butyl Acetal, 1-methyl-3-p-tolyltriazene, 1-ethyl-3-p-tolyltriazene, 1-propyl-3-p-tolyltriazene, 4- (4,6-Dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride or the like. The amount of the esterifying agent to be added is preferably 2 to 6 mol equivalents based on 1 mol of the repeating unit of polylysine.

The organic solvent may, for example, be N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone or γ-butyrolactone, N,N-dimethylformamide, N,N-dimethyl Ethyl acetamide, dimethyl hydrazine or 1,3-dimethyl-imidazolidinone. Further, when the solvent solubility of the polyimide precursor is high, methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, or the above formula [D] can be used. -1]~ The solvent represented by the formula [D-3].

These solvents may be used singly or in combination. Further, even if the solvent of the polyimide precursor is not dissolved, it may be used in the solvent in a range in which the produced polyimide precursor does not precipitate. Further, since the water in the solvent hinders the polymerization reaction and further causes the polyimine precursor formed by the hydrolysis, the solvent is preferably dried by dehydration. Dry.

The solvent used in the above reaction is preferably N,N-dimethylformamide, N-methyl-2-pyrrolidone or γ-butyrolactone from the viewpoint of solubility of the polymer. It is used in one type or in combination of two or more types. The concentration at the time of production is preferably from 1 to 30% by mass, more preferably from 5 to 20% by mass, from the viewpoint that the precipitation of the polymer is less likely to occur and the high molecular weight body is easily obtained.

(2) Manufactured by the reaction of a tetracarboxylic acid diester dichloride with a diamine

Polyammonium esters can be made from tetracarboxylic acid diester dichlorides and diamines.

Specifically, the reaction can be carried out by reacting a tetracarboxylic acid diester dichloride with a diamine in the presence of a base and an organic solvent at -20 to 150 ° C, preferably at 0 to 50 ° C, for 30 minutes to 24 hours. It is produced in an hour, preferably in a reaction time of 1 to 4 hours.

As the base, pyridine, triethylamine or 4-dimethylaminopyridine can be used, and in order to carry out the reaction gently, pyridine is preferred. The amount of the base to be added is preferably from 2 to 4 moles per mole of the tetracarboxylic acid diester dichloride from the viewpoint of easy removal of the amount and easy availability of a high molecular weight body.

The solvent used for the above reaction is preferably N-methyl-2-pyrrolidone or γ-butyrolactone from the solubility of the monomer and the polymer. These may be used alone or in combination of two or more. use. The polymer concentration at the time of production is preferably from 1 to 30% by mass, more preferably from 5 to 20% by mass, from the viewpoint that the precipitation of the polymer is less likely to occur and the high molecular weight body is easily obtained. Further, in order to prevent hydrolysis of the tetracarboxylic acid diester dichloride, it is preferred that the solvent used for the production of the polyphthalate is dehydrated as much as possible, and it is preferred to prevent external air from entering in a nitrogen atmosphere.

(3) Cases of tetracarboxylic acid diester and diamine

Polyammonium esters can be produced by polycondensation of a tetracarboxylic acid diester with a diamine.

Specifically, the tetracarboxylic acid diester and the diamine can be reacted in the presence of a condensing agent, a base, and an organic solvent at 0 to 150 ° C, preferably at 0 to 100 ° C, for 30 minutes to 24 minutes. It is produced in an hour, preferably in a reaction time of 3 to 15 hours.

As the condensing agent, triphenyl phosphite, dicyclohexylcarbodiimide, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, N, N'-carbonyldiimidazole, dimethoxy-1,3,5-triazinylmethylmorpholinium, O-(benzotriazol-1-yl)-N,N,N',N'- Tetramethyluronium tetrafluoroborate, O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate, (2,3-dihydrogen) Diphenyl 2-thio-3-benzoxazolyl)phosphonate and the like. The amount of the condensing agent to be added is preferably 2 to 3 moles per mole of the tetracarboxylic acid diester.

As the base, a tertiary amine such as pyridine or triethylamine can be used. The amount of the base to be added is preferably from 2 to 4 times the molar amount of the diamine component from the viewpoint of easy removal of the amount and easy availability of a high molecular weight body.

Further, in the above reaction, the reaction proceeds efficiently by adding Lewis acid as an additive. As the Lewis acid, lithium halide such as lithium chloride or lithium bromide is preferred. The amount of Lewis acid added is preferably from 0 to 1.0 times the molar amount of the diamine component.

In the method for producing the above three polyglycolates, since a high molecular weight polyglycolate can be obtained, the method of the above (1) or (2) is particularly Very good.

The solution of the polyglycolate obtained as described above can be poured into a poor solvent while being sufficiently stirred to precipitate a polymer. The precipitation is carried out several times, and after washing with a poor solvent, it is dried at room temperature or by heating to obtain a powder of the purified polyphthalate. The poor solvent is not particularly limited, and examples thereof include water, methanol, ethanol, hexane, butyl quercetin, acetone, toluene, and the like.

<polyimine]

The polyimine used in the present invention can be produced by subjecting the aforementioned polyphthalate or polylysine to ruthenium.

When a polyimine is produced from a polyphthalate, the chemistry of adding a basic catalyst to a polyphthalic acid solution obtained by dissolving a polyphthalate solution or a polyphthalate resin powder in an organic solvent The hydrazine imidization system is simple. The chemical imidization is preferred because the ruthenium imidization reaction is carried out at a lower temperature and the molecular weight of the polymer is less likely to be lowered during the imidization.

The imidization of the chemical hydrazine can be carried out by stirring the polyamine phthalate imidized in an organic solvent in the presence of a basic catalyst. As the organic solvent, the solvent used in the above polymerization reaction can be used. Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, and trioctylamine. Among them, triethylamine is preferred because it has sufficient alkalinity for the reaction.

The temperature at which the ruthenium imidization reaction is carried out is -20 to 140 ° C, preferably 0 to 100 ° C, and preferably the reaction time is 1 to 100 hours. The amount of the alkaline catalyst is 0.5 to 30 moles, preferably 2 to 20 moles, per mole of the amidate group. The yield of the obtained imidization of the polymer can be adjusted by adjusting the amount of the catalyst, Temperature, reaction time, etc. are controlled. Since the added catalyst or the like remains in the solution after the imidization reaction, it is preferred to recover the obtained quinone imidized polymer and dissolve it in an organic solvent by the means described below. As the liquid crystal alignment agent of the present invention.

When the polyimine is produced from polylysine, the chemical ruthenium imidization of the catalyst in the solution of the polyamic acid obtained by the reaction of the diamine component and the tetracarboxylic dianhydride is simple. The chemical imidization is preferred because the ruthenium imidization reaction is carried out at a lower temperature and the molecular weight of the polymer is less likely to be lowered during the imidization.

The chemical hydrazine imidization can be carried out by stirring the polyaminic acid to be imidized in an organic solvent in the presence of a basic catalyst and an acid anhydride. As the organic solvent, the solvent used in the above polymerization reaction can be used. Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, and trioctylamine. Among them, pyridine is preferred because it has an appropriate basicity for allowing the reaction to proceed. Further, examples of the acid anhydride include acetic anhydride, trimellitic anhydride, and pyromellitic anhydride. Among them, acetic anhydride is preferred because it is easy to refine after completion of the reaction.

The temperature at which the ruthenium imidization reaction is carried out is -20 to 140 ° C, preferably 0 to 100 ° C, and preferably the reaction time is 1 to 100 hours. The amount of the alkaline catalyst is 0.5 to 30 moles, preferably 2 to 20 moles, of the proline group, and the amount of the acid anhydride is 1 to 50 moles of the proline group, preferably 3 to 30 moles. The ruthenium imidization ratio of the obtained polymer can be controlled by adjusting the amount of the catalyst, the temperature, the reaction time, and the like.

In the solution after the imidization reaction of the polyperurethane or polylysine, the added catalyst or the like remains, so that it is preferably the following In the above manner, the obtained ruthenium imidized polymer is recovered and redissolved in an organic solvent to obtain a liquid crystal alignment agent of the present invention.

The solution of the polyimine obtained as described above can be poured into a poor solvent while being sufficiently stirred to precipitate a polymer. After several times of precipitation, washing with a poor solvent, and drying at room temperature or under heating, a purified polyimine powder can be obtained.

The poor solvent is not particularly limited, and examples thereof include methanol, acetone, hexane, butyl cyanidin, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, and benzene.

<Liquid alignment agent>

The liquid crystal alignment agent of the present invention contains at least one polymer selected from the group consisting of a polyimide intermediate having a specific structure in a main chain and a ruthenium imidized polymer of the polyimide precursor. The molecular weight of the polymer, based on the weight average molecular weight (Mw), is preferably 2,000 to 500,000, more preferably 5,000 to 300,000, still more preferably 10,000 to 100,000. Further, the number average molecular weight (Mn) is preferably from 1,000 to 250,000, more preferably from 2,500 to 150,000, still more preferably from 5,000 to 50,000.

The concentration of the polymer in the liquid crystal alignment agent of the present invention can be appropriately changed depending on the thickness of the coating film to be formed. However, from the viewpoint of forming a uniform coating film having no defects, it is preferably 1% by mass or more. The storage stability of the solution is preferably 10% by mass or less. The concentration of the polymer is preferably from 2 to 7% by mass.

Polymerization contained in the liquid crystal alignment agent used in the present invention The organic solvent in which the substance is dissolved (hereinafter also referred to as a good solvent) is not particularly limited as long as the polymer is uniformly dissolved.

For example, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, and dimethyl Kea, γ-butyrolactone, 1,3-dimethyl-imidazolidinone, methyl ethyl ketone, cyclohexanone, cyclopentanone or 4-hydroxy-4-methyl-2-pentanone. Among them, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, or γ-butyrolactone is particularly preferred.

Further, when the solubility of the polymer of the present invention in a solvent is high, it is preferred to use a solvent represented by the above formula [D-1] to formula [D-3].

The content of the good solvent in the liquid crystal alignment agent of the present invention is preferably from 20 to 99% by mass based on the total amount of the solvent contained in the liquid crystal alignment agent. Especially preferred is 20 to 90% by mass. More preferably 30 to 80% by mass.

The liquid crystal alignment agent of the present invention can be used as a solvent (also referred to as a poor solvent) for improving the coating property or surface smoothness of the liquid crystal alignment film after applying the liquid crystal alignment agent as long as the effects of the present invention are not impaired. Specific examples of the poor solvent are listed, but are not limited to these examples.

For example, ethanol, isopropanol, 1-butanol, 2-butanol, isobutanol, tert-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1 can be cited. -butanol, isoamyl alcohol, tert-pentanol, 3-methyl-2-butanol, neopentyl alcohol, 1-hexanol, 2-methyl-1-pentanol, 2-methyl-2-pentyl Alcohol, 2-ethyl-1-butanol, 1-heptanol, 2-heptanol, 3-heptanol, 1-octanol, 2-octanol, 2-ethyl-1-hexanol, cyclohexanol , 1-methylcyclohexanol, 2-methylcyclohexanol, 3-methylcyclohexanol, 1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, 1,2-butyl Glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 2-methyl-2,4-pentanediol, 2-ethyl- 1,3-hexanediol, dipropyl ether, dibutyl ether, dihexyl ether, dioxane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, 1,2-butoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol dibutyl ether, 2-pentyl Ketone, 3-pentanone, 2-hexanone, 2-heptanone, 4-heptanone, 3-ethoxybutyl acetate, 1-methylpentyl acetate, 2-ethylbutyl acetate, acetic acid 2- Ethylhexyl ester, ethylene glycol monoacetate, ethylene glycol diacetate, propyl carbonate, ethyl carbonate, 2-(methoxymethoxy)ethanol, ethylene glycol monobutyl ether , ethylene glycol monoisoamyl ether, ethylene glycol monohexyl ether, 2-(hexyloxy)ethanol, furan methanol, diethylene glycol, propylene glycol, propylene glycol monobutyl ether, 1-(butoxyethoxy Propyl alcohol, propylene glycol monomethyl ether acetate, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, tripropylene glycol monomethyl ether, ethylene glycol Monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monoacetate, ethylene glycol diacetate, diethylene glycol Monoethyl ether acetate, diethylene glycol monobutyl ether acetate, 2-(2-ethoxyethoxy)ethyl acetate, diethylene glycol acetate, triethylene glycol, three Ethylene glycol monomethyl ether, triethylene glycol monoethyl ether, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether, methyl pyruvate , ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxy Propionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate, milk The acid isoamyl ester, the solvent represented by the above formula [D-1] to the formula [D-3], and the like.

Among them, 1-hexanol, cyclohexanol, 1,2-ethanediol, 1,2-propanediol, propylene glycol monobutyl ether, ethylene glycol monobutyl ether or dipropylene glycol dimethyl ether is preferred.

The content of such a poor solvent is preferably from 1 to 80% by mass based on the total amount of the solvent contained in the liquid crystal alignment agent. Among them, 10 to 80% by mass is preferred, and more preferably 20 to 70% by mass.

In the liquid crystal alignment agent of the present invention, a polymer other than the polymer described in the present invention may be added in addition to the above, and the dielectric constant or conductivity of the liquid crystal alignment film may be added as long as the effect of the present invention is not impaired. For the purpose of improving the hardness or density of the film when the liquid crystal alignment film is used as a liquid crystal alignment film, the dielectric property or the conductive material is changed for the purpose of improving the adhesion between the liquid crystal alignment film and the substrate. The bismuth imidization accelerator for the purpose of ruthenium imidization by heating of the polyimide precursor is efficiently carried out when the coating film is fired.

<Liquid alignment film>

The liquid crystal alignment film of the present invention is a film obtained by applying the liquid crystal alignment agent to a substrate, drying and baking. The substrate to which the liquid crystal alignment agent of the present invention is applied is not particularly limited as long as it is a substrate having high transparency, and a plastic substrate such as a glass substrate, a tantalum nitride substrate, an acrylic substrate, or a polycarbonate substrate can be used. From the viewpoint of simplification, it is preferred to use a substrate on which an ITO electrode or the like for liquid crystal driving is formed. Further, in the reflective liquid crystal display device, if it is only a single-sided substrate, opaque or the like may be used. For the electrode at this time, a material such as aluminum which reflects light can be used.

The coating method of the liquid crystal alignment agent of the present invention includes a spin coating method, a printing method, an inkjet method, and the like.

The drying and baking steps after coating the liquid crystal alignment agent may be selected to any temperature and time. Usually, in order to sufficiently remove the organic solvent contained, the drying temperature is preferably from 50 to 120 ° C, and the drying time is preferably from 1 to 10 minutes. Further, the firing temperature is preferably from 150 to 300 ° C, and the firing time is preferably from 5 to 120 minutes.

The thickness of the film after firing is not particularly limited. However, when it is too thin, the reliability of the liquid crystal display element may be impaired. Therefore, it is preferably 5 to 300 nm, more preferably 10 to 120 nm.

The method of the light alignment treatment of the liquid crystal alignment film may be a method in which the surface of the coating film is irradiated with radiation polarized in a certain direction, and further heated at a temperature of 150 to 250 ° C to impart a liquid crystal alignment ability. For the radiation, ultraviolet rays and visible rays having a wavelength of 100 to 800 nm can be used. Among them, ultraviolet rays having a wavelength of from 100 to 400 nm, particularly preferably having a wavelength of from 200 to 400 nm, are preferred. Further, in order to improve the liquid crystal alignment property, the coated substrate may be heated while being heated at 50 to 250 ° C while irradiating the radiation. The irradiation amount of the radiation is preferably from 1 to 10,000 mJ/cm ² , particularly preferably from 100 to 5,000 mJ/cm ² . The liquid crystal alignment film produced as described above can stably align liquid crystal molecules in a certain direction.

Since higher anisotropy can be imparted, the higher the extinction ratio of the polarized ultraviolet light, the better. Specifically, the extinction ratio of the ultraviolet light which is linearly polarized is preferably 10:1 or more, more preferably 20:1 or more.

a film that is irradiated with polarized radiation, and then by The contact treatment is carried out by containing at least one solvent selected from water and an organic solvent.

The solvent to be used in the contact treatment is not particularly limited as long as it dissolves the decomposition product generated by light irradiation. Specific examples include water, methanol, ethanol, 2-propanol, acetone, methyl ethyl ketone, 1-methoxy-2-propanol, 1-methoxy-2-propanol acetate, and butyl. Kesaisusu, ethyl lactate, methyl lactate, diacetone alcohol, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propyl acetate, butyl acetate, cyclohexyl acetate, etc. . These solvents may be used in combination of two or more kinds. From the viewpoint of versatility or safety, it is more preferably at least one selected from the group consisting of water, 2-propanol, 1-methoxy-2-propanol, and ethyl lactate. Particularly preferred is water, 2-propanol, or a mixed solvent of water and 2-propanol.

In the present invention, the contact treatment of the film irradiated with the polarized radiation and the solution containing the organic solvent may be immersion treatment, spray (spraying) treatment or the like, and it is preferred that the membrane be in sufficient contact with the liquid. More preferably, it is 10 seconds to 1 hour, more preferably 1 to 30 minutes, and preferably a method of immersing the film in a solution containing an organic solvent. The contact treatment may be normal temperature or heating, but is preferably carried out at 10 to 80 ° C, more preferably at 20 to 50 ° C. Further, a means for improving contact such as ultrasonic waves may be applied as needed.

After the contact treatment, it is also possible to rinse (wash) with a low boiling point solvent such as water, methanol, ethanol, 2-propanol, acetone or methyl ethyl ketone for the purpose of removing the organic solvent in the solution used. Any of the dry, or both.

Further, the film subjected to the solvent contact treatment can also be heated at 150 ° C or higher for the purpose of drying the solvent and realigning the molecular chains in the film. The heating temperature is preferably from 150 to 300 °C. The higher the temperature, the more the reorientation of the molecular chain is promoted, but when the temperature is too high, there is a entanglement with the decomposition of the molecular chain. Therefore, the heating temperature is preferably 180 to 250 ° C, and particularly preferably 200 to 230 ° C.

When the heating time is too short, there is a possibility that the molecular chain realignment effect cannot be obtained. When the temperature is too long, the molecular chain may be decomposed, so it is preferably 10 seconds to 30 minutes, more preferably 1 to 10 minutes. Minute.

<Liquid crystal display element>

In the liquid crystal display device of the present invention, after a substrate having a liquid crystal alignment film formed of the liquid crystal alignment agent of the present invention is obtained, a liquid crystal cell is produced by a known method, and the cell is used as a component.

As an example of a method of fabricating a liquid crystal cell, a liquid crystal display device having a passive matrix structure will be described below as an example. Further, a liquid crystal display element having an active matrix structure of a switching element such as a TFT (Thin Film Transistor) may be provided in each pixel portion constituting the image display.

First, a transparent glass substrate is prepared, and a common electrode is provided on one of the substrates, and a segment electrode is provided on the other substrate. Such electrodes, for example, may be ITO electrodes, patterned in such a manner as to display a desired image. Next, an insulating film is provided on each of the substrates so as to cover the common electrode and the segment electrodes. The insulating film may be, for example, a film made of SiO ₂ -TiO ₂ formed by a sol-gel method.

Next, a liquid crystal alignment film of the present invention is formed on each substrate. Next, the other substrate is superimposed on one of the substrates so that the alignment films of the substrates face each other, and the periphery is followed by a sealing material. In order to control the substrate gap, it is generally preferred to incorporate a spacer into the sealing material. Moreover, it is preferable to disperse the spacer for substrate gap control in advance in the in-plane portion where the sealing material is not provided. Further, in one portion of the sealing material, an opening portion which can fill the liquid crystal from the outside is usually provided.

Next, a liquid crystal material is injected into a space surrounded by the two substrates and the sealing material by being provided in the opening of the sealing material. Thereafter, the opening is sealed with an adhesive. The injection can be carried out by vacuum injection or by using a capillary phenomenon in the atmosphere. Next, the setting of the polarizing plate is performed. Specifically, a pair of polarizing plates are attached to the surface of the two substrates opposite to the liquid crystal layer. By the above steps, the liquid crystal display element of the present invention can be obtained.

In the present invention, as the sealant, for example, a reactive group having an epoxy group, an acryloyl group, a methacryloyl group, a hydroxyl group, an allyl group, an ethyl fluorenyl group or the like can be used, which is hardened by ultraviolet irradiation or heating. Resin. In particular, a hardening resin having a reactive group having both an epoxy group and a (meth)acryl fluorenyl group is preferably used.

The inorganic filler may be blended in the above-mentioned sealant for the purpose of improving adhesion, moisture resistance and the like. The inorganic filler to be used is not particularly limited, and specific examples thereof include spherical cerium oxide, molten cerium oxide, crystalline cerium oxide, titanium oxide, titanium black, cerium carbide, cerium nitride, and boron nitride. Calcium carbonate, magnesium carbonate, barium sulfate, calcium sulfate, mica, talc, Clay, alumina, magnesia, zirconia, aluminum hydroxide, calcium citrate, aluminum silicate, lithium aluminum silicate, zirconium silicate, barium titanate, glass fiber, carbon fiber, molybdenum disulfide, asbestos, and the like. Preferred are spherical cerium oxide, molten cerium oxide, crystalline cerium oxide, titanium oxide, titanium black, cerium nitride, boron nitride, calcium carbonate, barium sulfate, calcium sulfate, mica, talc, clay, alumina. , aluminum hydroxide, calcium citrate, aluminum citrate and the like. The above-mentioned inorganic filler may be used in combination of two or more kinds.

[Examples]

The invention will be described in more detail below by way of examples, but the invention is not limited thereto. The abbreviations of the compounds used are as follows.

NMP: N-methyl-2-pyrrolidone, BCS: butyl cycas

[Synthesis of DA-1 (4'-(2-(4-Aminophenoxy)ethoxy)-[1,1'-biphenyl]-4-amine)] Step 1: 4-Nitrate Synthesis of keto-4'-(2-(4-nitrophenoxy)ethoxy)-1,1'-biphenyl (DA-1-1)

4-Hydroxy-4'-nitrobiphenyl (10.0 g, 46.5 mmol) was dissolved in DMF (40.0 g), and potassium carbonate (17.2 g, 69.7 mmol) was added to give β-bromo-4-nitrophenylethyl ether ( 17.2 g, 69.7 mmol) of DMF solution (40.0 g) was added dropwise at 80 °C.

The mixture was stirred at 80 ° C for 2 hours, and the disappearance of the starting material was confirmed by high-speed liquid chromatography (hereinafter abbreviated as HPLC). Thereafter, the reaction solution was allowed to cool to room temperature, water (500.0 g) was added, and the precipitate was filtered, and the filtrate was washed twice with water (100.0 g). The resulting filtrate was washed twice with MeOH (500.0 g). The precipitate was filtered and dried under reduced pressure at 50 ° C to give 4-nitro-4'-(2-(4-nitrophenoxy)ethoxy)-1,1'-biphenyl (DA-1) -1) (white powder, yield: 17.6 g, yield: 99%).

¹ H NMR (DMSO-d ₆ ): δ 8.22-8.29 (m, 4H, C ₆ H ₄ ), 7.94 (d, J = 7.2 Hz, 2H, C ₆ H ₄ ), 7.79 (d, J = 8.8 Hz) , 2H, C ₆ H ₄ ), 7.25-7.15 (m, 4H, C ₆ H ₄ ) 4.54-4.45 (m, 4H, CH ₂ ). ¹³ C{ ¹ H} NMR (DMSO-d ₆ ): δ 164.1 , 159.6, 146.6, 146.5, 141.4, 130.7, 129.1, 127.5, 126.4, 124.5, 115.7, 115.6, 67.8, 66.7 (each s).

Melting point (DSC): 193 ° C

Step 2: Synthesis of 4'-(2-(4-aminophenoxy)ethoxy)-[1,1'-biphenyl]-4-amine (DA-1)

DA-1-1 (5.0 g, 13.1 mmol) was dissolved in tetrahydrofuran (100.0 g), and 5 mass% of palladium-carbon (0.1 g) was added thereto, and the mixture was stirred at room temperature for 2 hours under a hydrogen atmosphere. After confirming the disappearance of the starting material by HPLC, the reaction solution was dissolved in tetrahydrofuran (800.0 g), the catalyst was removed by filtration, and the filtrate was concentrated. The precipitated solid was stirred in heptane (200.0 g), washed, and filtered. DA-1 (white powder, yield: 4.0 g, yield: 94%) was obtained by drying the obtained solid.

¹ H NMR (DMSO-d ₆ ): δ 7.45 (d, J = 8.8 Hz, 2H, C ₆ H ₄ ), 7.29 (d, J = 8.8 Hz, 2H, C ₆ H ₄ ), 6.97 (d, J = 8.8 Hz, 2H, C ₆ H ₄ ), 6.70 (d, J = 8.8 Hz, 2H, C ₆ H ₄ ), 6.62 (d, J = 8.8 Hz, 2H, C ₆ H ₄ ), 6.52 (d, J = 8.8 Hz, 2H, C ₆ H ₄ ), 5.14 (s, 2H, NH ₂ ), 4.64 (s, 2H, NH ₂ ), 4.24 (br, 2H, CH ₂ ), 4.16 (br, 2H, CH) ₂ ). ¹³ C{ ¹ H} NMR (DMSO-d ₄ ): δ 157.2, 150.0, 148.2, 143.1, 133.9, 127.7, 126.2, 116.3, 115.9, 115.5, 115.0, 114.4, 67.2, 66.9 (each s).

Melting point (DSC): 156 ° C

Further, the hydrogen nuclear magnetic resonance ( ¹ H NMR, 500 MHz) of the synthesis example was measured in a solvent of dimethyl hydrazine (DMSO-d6), and the chemical shift showed a δ value (ppm) when tetramethyl decane was used as an internal standard. ).

[viscosity]

The viscosity of each solution was measured using an E-type viscometer (TVE-22H, manufactured by Toki Sangyo Co., Ltd.) at a sample amount of 1.1 mL, a conical rotor TE-1 (1°34', R24), and a temperature of 25 °C.

[molecular weight]

GPC device: manufactured by Shodex Co., Ltd. (GPC-101), pipe column: manufactured by Shodex Co., Ltd. (inline of KD803, KD805), column temperature: 50 ° C, eluent: N,N-dimethylformamide (as additive, Lithium bromide-hydrate (LiBr.H ₂ O) 30 mmol/L, phosphoric acid, anhydrous crystals (o-phosphoric acid) 30 mmol/L, tetrahydrofuran (THF) 10 ml/L), flow rate: 1.0 ml/min.

Standard sample for the production of calibration lines: TSK standard polyethylene oxide (weight average molecular weight (Mw); about 900,000, 150,000, 100,000 and 30,000) made by Tosoh Corporation, and polyethylene glycol (Polymer) manufactured by Polymer Laboratories Molecular weight (Mp); about 12,000, 4,000 and 1,000).

In order to avoid peak overlap, the determination system is 900,000, Samples of 4 types mixed with 100,000, 12,000, and 1,000; 2 samples mixed with 150,000, 30,000, and 4,000 of the 3 types.

[Production of liquid crystal cell]

A liquid crystal cell having a structure of a fringe field switching (FFS) mode liquid crystal display element was fabricated.

A glass substrate with an electrode of a size of 30 mm × 50 mm and a thickness of 0.7 mm was prepared. An ITO electrode having a monolithic pattern as a counter electrode and having an integral shape as a first layer was formed on the substrate. On the counter electrode of the first layer, a SiN (tantalum nitride) film formed as a second layer by a CVD method is formed. The SiN film of the second layer has a film thickness of 500 nm and functions as an interlayer insulating film. On the SiN film of the second layer, as the third layer, a comb-shaped pixel electrode formed by patterning an ITO film is disposed to form two pixels of the first pixel and the second pixel. The size of each pixel is 10 mm in length and 5 mm in width. At this time, the counter electrode of the first layer and the pixel electrode of the third layer are electrically insulated by the action of the SiN film of the second layer.

The third layer of the pixel electrode has a comb-tooth shape in which a plurality of electrode elements having a U-shaped central portion are curved. The width of each electrode element in the short-side direction was 3 μm, and the interval between the electrode elements was 6 μm. The pixel electrodes forming the respective pixels are formed by arranging a plurality of electrode elements having a U-shaped central portion in a curved shape. Therefore, the shape of each pixel is not a rectangular shape, and the shape is similar to that of the electrode element. The shape of the word. In addition, each pixel is curved at its center. It is divided into upper and lower divisions, and has a first region on the upper side of the curved portion and a second region on the lower side.

When the first region and the second region of each pixel are compared, the direction in which the electrode elements constituting the pixel electrodes are formed is different. In other words, when the rubbing direction of the liquid crystal alignment film described later is used as a reference, in the first region of the pixel, the electrode elements of the pixel electrode are formed at an angle of +10° (clockwise), in the pixel. In the second region, the electrode elements of the pixel electrodes are formed at an angle of -10° (clockwise). In other words, in the first region and the second region of each pixel, the direction of the rotation (in-plane switching) of the liquid crystal in the plane of the substrate induced by the voltage application between the pixel electrode and the counter electrode is They are formed in a way that they are opposite to each other.

Next, the liquid crystal alignment agent was filtered through a 1.0 μm filter, and then a glass substrate having a columnar spacer having a height of 4 μm and having an ITO film formed thereon was spin-coated on the substrate on which the electrode was prepared. After coating, it was dried on a hot plate at 80 ° C for 5 minutes, and then fired in a hot air circulating oven at 230 ° C for 20 minutes to form a coating film having a film thickness of 100 nm. The coating film surface was irradiated with ultraviolet rays having a wavelength of 254 nm of a linearly polarized light having an extinction ratio of 10:1 or more via a polarizing plate. The substrate is immersed in at least one solvent selected from water and an organic solvent for 3 minutes, and then immersed in pure water for 1 minute, and then heated on a hot plate at 150 to 300 ° C for 5 minutes to obtain a liquid crystal alignment. The substrate of the film.

The sealing agent is printed on one of the two substrates, and the other substrate is bonded to each other with the liquid crystal alignment film facing each other and the alignment direction is 0°, and then the sealing agent is cured. Making an air crystal Cell. Liquid crystal MLC-7026-100 (manufactured by Merck) was injected into the empty cell by a vacuum injection method, and the injection port was sealed to obtain an FFS-driven liquid crystal cell. Thereafter, the obtained liquid crystal cell was heated at 110 ° C for 1 hour, and left for one night and used for each evaluation.

[Long-term AC-driven afterimage evaluation]

A liquid crystal cell having the same structure as that of the above liquid crystal cell was prepared, and an AC voltage of ±5 V was applied at a frequency of 60 Hz for 120 hours in a constant temperature environment of 60 °C. Thereafter, the pixel electrode between the liquid crystal cell and the counter electrode were short-circuited, and were allowed to stand at room temperature for one day.

After being placed, the liquid crystal cell is placed between two polarizing plates arranged orthogonally with the polarization axis, and the backlight is preliminarily illuminated in a state where the voltage is not applied, and the arrangement angle of the liquid crystal cell is adjusted to minimize the luminance of the transmitted light. . Then, a rotation angle when the liquid crystal cell is rotated from the angle at which the second region of the first pixel is the darkest to the darkest angle of the first region is calculated as the angle Δ. In the second pixel, the second region and the first region are compared in the same manner as in the case of the first pixel, and the same angle Δ is calculated.

[Evaluation of bright spot of liquid crystal cell (comparative)]

The evaluation of the bright spots of the above liquid crystal cell is performed. The evaluation of the bright spot of the liquid crystal cell was carried out by observing the liquid crystal cell with a polarizing microscope (ECLIPSE E600WPOL) (manufactured by Nikon Corporation). Specifically, the liquid crystal cell is arranged in a crossed nibble, and the liquid crystal cell is observed by a polarizing microscope having a magnification of 5 times, and the number of bright spots confirmed is counted, and the number of bright spots is less than 10 Good, and the above is "bad".

<Synthesis Example 1>

In a 50 mL four-necked flask equipped with a stirring device and a nitrogen introduction tube, 1.44 g (4.50 mmol) of DA-1 and 0.49 g (4.53 mmol) of DA-2 were weighed, and 25.38 g of NMP was added thereto, and nitrogen was fed thereto. Stir and dissolve. While stirring the diamine solution, 1.92 g (8.56 mmol) of 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride was added, and the solid content concentration was further 12% by mass. In a manner of adding 2.82 g of NMP, it was stirred at room temperature for 24 hours to obtain a polyaminic acid solution (A). The polyamic acid solution has a viscosity of 1680 mPa at a temperature of 25 ° C. s. Further, the molecular weight of the polyamic acid was Mn = 14,700 and Mw = 35,000.

<Synthesis Example 2>

In a 50 mL four-necked flask equipped with a stirring device and a nitrogen introduction tube, 2.24 g (7.00 mmol) of DA-1 was weighed, and 24.64 g of NMP was added thereto, and the mixture was stirred and dissolved while supplying nitrogen. While stirring the diamine solution, 1.49 g (6.65 mmol) of 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride was added, and the solid content concentration was further 12% by mass. 2.73 g of NMP was added and stirred at room temperature for 24 hours to obtain a polyaminic acid solution (B). The polyamic acid solution has a viscosity of 2650 mPa at a temperature of 25 ° C. s. Further, the molecular weight of the polyamic acid was Mn = 21,300 and Mw = 52,300.

<Synthesis Example 3>

Into a 50 mL four-necked flask equipped with a stirring device and a nitrogen introduction tube, 1.51 g (4.71 mmol) of DA-1 and 1.14 g (4.71 mmol) of DA-3 were weighed, and 16.99 g of NMP was added thereto, and nitrogen was fed thereto. Stir and dissolve. While stirring the diamine solution, 2.07 g (9.23 mmol) of 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride was added, and the solid content concentration was further 20% by mass. In a manner of 1.89 g of NMP, it was stirred at 40 ° C for 24 hours to obtain a polyaminic acid solution (C). The polyamic acid solution has a viscosity of 5000 mPa at a temperature of 25 ° C. s. Further, the molecular weight of the polyamic acid was Mn = 13900 and Mw = 34,100.

<Synthesis Example 4>

Into a 50 mL four-necked flask equipped with a stirring device and a nitrogen introduction tube, 1.75 g (6.51 mmol) of DA-4 and 0.70 g (6.47 mmol) of DA-2 were weighed, and 33.07 g of NMP was added thereto, and nitrogen was fed thereto. Stir and dissolve. While stirring the diamine solution, 2.71 g (12.09 mmol) of 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride was added, and the solid content concentration was further 12% by mass. In a manner of adding 3.67 g of NMP, the mixture was stirred at room temperature for 24 hours to obtain a polyamic acid solution (D). The polyamic acid solution has a viscosity of 360 mPa at a temperature of 25 ° C. s. Further, the molecular weight of the polyamic acid was Mn = 14,500 and Mw = 30,200.

<Synthesis Example 5>

50mL four-necked flask with stirring device and nitrogen inlet tube In the above, 3.59 g (16.01 mmol) of 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride was weighed, and 34.18 g of NMP was added thereto, and the mixture was stirred and dissolved while supplying nitrogen. . While stirring the acid dianhydride solution, 1.59 g (14.70 mmol) of DA-2 was added, and 3.80 g of NMP was added so that the solid content concentration became 12 mass%, and the mixture was stirred at room temperature for 24 hours to obtain a polyamidonic acid solution. (E). The polyamic acid solution has a viscosity of 200 mPa at a temperature of 25 ° C. s. Further, the molecular weight of the polyamic acid was Mn = 12,600 and Mw = 30,500.

<Example 1>

The amount of the 1% by mass of 12% by mass of the polyamidic acid solution (A) was placed in a 100 ml Erlenmeyer flask, and 9.00 g of NMP and 6.00 g of BCS were added, and the mixture was mixed at 25 ° C for 8 hours to obtain a liquid crystal alignment agent (1). No abnormality such as turbidity or precipitation was observed in the liquid crystal alignment agent, and it was confirmed that it was a uniform solution.

<Example 2>

The liquid crystal alignment agent (2) was obtained in the same manner as in Example 1 except that the polyamic acid solution (B) was used instead of the polyamic acid solution (A). No abnormality such as turbidity or precipitation was observed in the liquid crystal alignment agent, and it was confirmed that it was a uniform solution.

<Example 3>

20 mass% polyamic acid solution (C) 9.00g was weighed into a 100ml conical flask, NMP 15.00g, BCS 6.00g was added, mixed at 25 ° C After 8 hours, a liquid crystal alignment agent (3) was obtained. No abnormality such as turbidity or precipitation was observed in the liquid crystal alignment agent, and it was confirmed that it was a uniform solution.

<Comparative Example 1>

The liquid crystal alignment agent (4) was obtained in the same manner as in Example 1 except that the polyamic acid solution (D) was used instead of the polyamic acid solution (A). No abnormality such as turbidity or precipitation was observed in the liquid crystal alignment agent, and it was confirmed that it was a uniform solution.

<Comparative Example 2>

The liquid crystal alignment agent (5) was obtained in the same manner as in Example 1 except that the polyamic acid solution (E) was used instead of the polyamic acid solution (A). No abnormality such as turbidity or precipitation was observed in the liquid crystal alignment agent, and it was confirmed that it was a uniform solution.

<Example 4>

The liquid crystal alignment agent (1) was filtered through a 1.0 μm filter, and then a glass substrate having a columnar spacer having a height of 4 μm and having an ITO film formed thereon was spin-coated on the substrate on which the electrode was attached. Subsequently, it was dried on a hot plate at 80 ° C for 5 minutes, and fired in a hot air circulating oven at 230 ° C for 20 minutes to form a coating film having a film thickness of 100 nm. The coating film surface was irradiated with ultraviolet rays having a wavelength of 254 nm of a linear polarization of 0.2 J/cm ² at an extinction ratio of 0.2 J/cm ² through a polarizing plate. Thereafter, it was heated on a hot plate at 230 ° C for 14 minutes to obtain a substrate with a liquid crystal alignment film.

The sealing agent was printed on one of the two substrates, and the other substrate was bonded to each other with the liquid crystal alignment film faces facing each other and the alignment direction was 0°. Thereafter, the sealant is cured to form an empty unit cell. Liquid crystal MLC-7026-100 (manufactured by Merck) was injected into the empty cell by a vacuum injection method, and then the injection port was sealed to obtain an FFS-driven liquid crystal cell. Thereafter, the obtained liquid crystal cell was heated at 110 ° C for 1 hour, and allowed to stand overnight to carry out long-term AC drive afterimage evaluation. After long-term AC driving, the angle Δ of the liquid crystal cell is 0.01°. Further, as a result of observing the bright spots in the liquid crystal cell, the number of bright spots was less than 10, which was good.

<Example 5>

A coating film was formed in the same manner as in Example 4 except that the above liquid crystal alignment agent (2) was used. The coating film surface was irradiated with ultraviolet rays having a wavelength of 254 nm of a linear polarization of 26:1 at an extinction ratio of 0.5 J/cm ² through a polarizing plate. Thereafter, it was heated on a hot plate at 230 ° C for 14 minutes to obtain a substrate with a liquid crystal alignment film. An FFS-driven liquid crystal cell was produced in the same manner as in Example 4 except that the substrate with the liquid crystal alignment film was used, and the same evaluation as in Example 4 was carried out for the obtained liquid crystal cell. As a result, the value of the angle Δ was 0.03°. Moreover, the number of bright spots is less than 10, and the system is good.

<Example 6>

In addition to the above liquid crystal alignment agent (3), it is the same as in Example 4. In the same manner, a coating film is formed, irradiated with ultraviolet rays, and heated to obtain a substrate with a liquid crystal alignment film. An FFS-driven liquid crystal cell was produced in the same manner as in Example 4 except that the substrate with the liquid crystal alignment film was used, and the same evaluation as in Example 4 was carried out for the obtained liquid crystal cell. As a result, the value of the angle Δ was 0.02°. Moreover, the number of bright spots is less than 10, and the system is good.

<Comparative Example 3>

A coating film was formed in the same manner as in Example 4 except that the liquid crystal alignment agent (4) was used, and the substrate was coated with a liquid crystal alignment film by irradiation with ultraviolet rays. An FFS-driven liquid crystal cell was produced in the same manner as in Example 4 except that the substrate with the liquid crystal alignment film was used, and the same evaluation as in Example 4 was carried out for the obtained liquid crystal cell. As a result, the value of the angle Δ was 0.10°. Moreover, the number of bright spots is 10 or more, and it is bad.

<Comparative Example 4>

A coating film was formed in the same manner as in Example 4 except that the liquid crystal alignment agent (5) was used, and ultraviolet rays of 0.5 J/cm ^{2 were} irradiated thereto to obtain a substrate having a liquid crystal alignment film. An FFS-driven liquid crystal cell was produced in the same manner as in Example 4 except that the substrate with the liquid crystal alignment film was used, and the same evaluation as in Example 4 was carried out for the obtained liquid crystal cell. As a result, the value of the angle Δ was 0.19°. Moreover, the number of bright spots is 10 or more, and it is bad.

[Industrial availability]

The liquid crystal alignment agent of the present invention can form a liquid crystal alignment film for a light alignment method which does not cause bright spots even when a negative liquid crystal is used, and has a good afterimage characteristic, and can be used for a liquid crystal display element of a FFS driving method of high display quality. Wait.

In addition, the entire contents of the specification, the scope of the patent application, and the Abstract of the Japanese Patent Application No. 2015-061095, filed on Mar.

Claims (8)

A liquid crystal alignment agent containing a group selected from the group consisting of a polyimine precursor having a structure represented by the following formula (1) in a main chain and a ruthenium imidized polymer of the polyimide precursor At least one polymer; [Chemical Formula 1]-B ₁ -R ₁ -AR ₂ -B ₂ - (1) (wherein R ₁ and R ₂ are each independently a single bond, -O-, -S- , -NR ₁₂ -, ester bond, guanamine bond, thioester bond, urea bond, carbonate bond, or urethane bond, R ₁₂ is a hydrogen atom or a methyl group; A is a carbon number of 2 to 20 The alkyl group; the B ₁ and B ₂ systems are each independently a divalent organic group selected from the following structures, and B ₁ and B _{2 are} not the same structure); (wherein R ₄ is an alkylene group having 1 to 5 carbon atoms; and R ₅ is a hydrogen atom, a methyl group, a hydroxyl group or a methoxy group). The liquid crystal alignment agent of claim 1, wherein the polyimine precursor is a polymer containing a structural unit of the following formula (2); (wherein X ₁ is at least one selected from the group consisting of the structures represented by the following formulas (X1-1) and (X1-2); and Y ₁ is a divalent organic group represented by the above formula (1), R ₃ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; and Z ₁ and Z ₂ are each independently a hydrogen atom or may have a substituent, an alkyl group having 1 to 10 carbon atoms, and a carbon number of 2 to 10; Alkenyl or alkynyl having 2 to 10 carbon atoms; The liquid crystal alignment agent of claim 2, wherein the polyimine precursor has a structural unit represented by the above formula (2) in an amount of 20 to 100 mol% with respect to all structural units. The liquid crystal alignment agent of claim 2 or 3, wherein X ₁ is the following formula (X1-2); The liquid crystal alignment agent according to any one of claims 1 to 4, wherein the configuration of the above formula (1) is the following configuration; (wherein A, R ₁ and R ₂ are the same as defined above). A liquid crystal alignment film which is obtained by coating a film obtained by firing a liquid crystal alignment agent according to any one of claims 1 to 5, and irradiating the polarized ultraviolet light. A liquid crystal display element comprising the liquid crystal alignment film of claim 6. a diamine represented by the following formula; (wherein R ₁ and R ₂ are each independently a single bond, -O-, -S-, -NR ₁₂ -, an ester bond, a guanamine bond, a thioester bond, a urea bond, a carbonate bond, or an amine. a carbamate bond, R ₁₂ is a hydrogen atom or a methyl group, and A is a C 2 to 20 alkyl group).