KR20230097217A - Liquid crystal aligning agent, liquid crystal alignment film and liquid crystal display element - Google Patents

Abstract

(R₁, R₂ 는 단결합, -O-, -S-, -NR₁₂- 등이고, R₁₂ 는 수소 원자 등이고, A 는 탄소수 2 ∼ 20 의 알킬렌기이고, B₁, B₂ 는 각각 독립적으로 하기 구조에서 선택되는 2 가의 유기기이고, B₁ 과 B₂ 는 동일하지 않다.)

(R₄ 는 탄소수 1 ∼ 5 의 알킬렌기를 나타내고, R₅ 는 수소 원자 등을 나타낸다.)Even when a negative liquid crystal is used, a liquid crystal aligning agent for obtaining a liquid crystal aligning film for a photo-alignment method in which a luminescent point does not occur and good afterimage characteristics are obtained, a liquid crystal aligning film, and a liquid crystal display element are provided.
The liquid crystal aligning agent containing the at least 1 sort(s) of polymer chosen from the group which consists of the imidation polymer of the polyimide precursor which has a structure represented by Formula (1) in a main chain, and this polyimide precursor.

(R ₁ , R ₂ is a single bond, -O-, -S-, -NR ₁₂ -, etc., R ₁₂ is a hydrogen atom, etc., A is an alkylene group having 2 to 20 carbon atoms, B ₁ and B ₂ are each independently is a divalent organic group selected from the following structures, and B ₁ and B ₂ are not the same.)

(R ₄ represents an alkylene group having 1 to 5 carbon atoms, and R ₅ represents a hydrogen atom or the like.)

Description

Liquid crystal aligning agent, liquid crystal aligning film, and liquid crystal display element {LIQUID CRYSTAL ALIGNING AGENT, LIQUID CRYSTAL ALIGNMENT FILM AND LIQUID CRYSTAL DISPLAY ELEMENT}

This invention relates to the liquid crystal display element which has the liquid crystal aligning agent used for manufacture of the liquid crystal display element with favorable afterimage characteristics, the liquid crystal aligning film obtained from this liquid crystal aligning agent, and this liquid crystal aligning film.

The photo-alignment method is an alignment treatment method for rubbing and is an industrially simple manufacturing process. In particular, in a liquid crystal display element of an IPS (In-Plane-Switching) driving method or a FFS (Flinge-field-Switching) driving method, by using a liquid crystal aligning film obtained by the optical alignment method, compared to a liquid crystal aligning film obtained by a rubbing treatment method. , improvement in the contrast and viewing angle characteristics of the liquid crystal display element can be expected. Thereby, the performance of a liquid crystal display element can be improved, and it attracts attention as a promising liquid-crystal alignment treatment method.

However, the liquid crystal alignment film obtained by the photo-alignment method has a problem that the anisotropy with respect to the alignment direction of the polymer film is small compared to that obtained by rubbing. When anisotropy is small, sufficient liquid-crystal orientation will not be obtained, and when it is set as a liquid crystal display element, problems, such as generation|occurrence|production of an afterimage, arise.

On the other hand, as a method of increasing the anisotropy of a liquid crystal aligning film obtained by the photo-alignment method, removing the low molecular weight component produced by cutting the main chain of the polyimide by photo-irradiation after photo-irradiation has been proposed.

Japanese Unexamined Patent Publication No. 9-297313 Japanese Unexamined Patent Publication No. 2011-107266

"Liquid Crystal Optical Alignment Film" Kidowaki, Ichimura Functional Materials Vol.17 (1997) No.11 p.13-22

Although positive type liquid crystals have conventionally been used in liquid crystal display elements of the IPS drive system or the FFS drive system, by using negative liquid crystals, the transmission loss at the top of the electrode can be reduced and the contrast can be improved.

When the liquid crystal aligning film obtained by the photo-alignment method is used for a liquid crystal display element of an IPS drive system using a negative liquid crystal or an FFS drive system, it is expected to have higher display performance than conventional liquid crystal display elements. However, as a result of investigation by the present inventors, when a liquid crystal display element is produced using a so-called photodegradable liquid crystal alignment film and negative liquid crystal, which exhibits anisotropy by decomposition of polymer by light irradiation and orients liquid crystal, polarized ultraviolet irradiation It has been clarified that the incidence of display defects (bright spots) derived from decomposition products of polymers constituting the liquid crystal aligning film produced by this is high.

The subject of this invention does not generate|occur|produce a luminescent point and the liquid crystal aligning agent for obtaining the liquid crystal aligning film for photo-alignment methods from which favorable afterimage characteristics are acquired even when a negative type liquid crystal is used, the liquid crystal aligning film obtained from this liquid crystal aligning agent, and its liquid crystal It is providing a liquid crystal display element provided with an alignment film.

The present inventors came to complete this invention, as a result of earnestly examining in order to solve the said subject. That is, this invention is as showing below.

1. The liquid crystal aligning agent containing the at least 1 sort(s) of polymer chosen from the group which consists of the imidation polymer of the polyimide precursor which has a structure represented by following formula (1) in a principal chain, and this polyimide precursor.

[Formula 1]

(Wherein, R ₁ and R ₂ are each independently a single bond, -O-, -S-, -NR ₁₂ -, an ester bond, an amide bond, a thioester bond, a urea bond, a carbonate bond, or a carbamate bond And, R ₁₂ is a hydrogen atom or a methyl group, A is an alkylene group having 2 to 20 carbon atoms, B ₁ and B ₂ are each independently a divalent organic group selected from the following structures, and B ₁ and B ₂ are the same It is not structured.)

[Formula 2]

(In the 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.)

2. Said liquid crystal aligning agent as described in 1 which is a polymer in which the said polyimide precursor contains the structural unit of following formula (2).

[Formula 3]

(In the formula, X ₁ is at least one selected from the group consisting of structures represented by the following formulas (X1-1) and (X1-2). Y ₁ is a divalent organic group represented by the formula (1). R ₃ is a hydrogen atom or an alkyl group of 1 to 5 carbon atoms Z ₁ and Z ₂ are each independently a hydrogen atom or an alkyl group of 1 to 10 carbon atoms which may have a substituent, an alkenyl group of 2 to 10 carbon atoms or a carbon atom of 2 It is an alkynyl group of to 10.)

[Formula 4]

3. Said liquid crystal aligning agent as described in 2 in which the said polyimide precursor has 20-100 mol% of structural units represented by said Formula (2) with respect to all structural units.

4. Liquid crystal aligning agent for photo-alignment as described in said 2 or 3 whose X _<1> is a following formula (X1-2).

[Formula 5]

5. The liquid crystal aligning agent in any one of said 1-4 whose structure of said Formula (1) is a following structure.

[Formula 6]

(In the formula, A, R ₁ and R ₂ have the same definition as above.)

6. The liquid crystal aligning film obtained by irradiating the ultraviolet-ray which polarized to the film|membrane obtained by apply|coating and baking the liquid crystal aligning agent in any one of said 1-5.

7. Liquid crystal display element provided with said liquid crystal aligning film of 6.

8. Diamine represented by the following formula.

[Formula 7]

(Wherein, R ₁ and R ₂ are each independently a single bond, -O-, -S-, -NR ₁₂ -, an ester bond, an amide bond, a thioester bond, a urea bond, a carbonate bond, or a carbamate bond , R ₁₂ is a hydrogen atom or a methyl group, and A is an alkylene group having 2 to 20 carbon atoms.)

By using the liquid crystal aligning agent of this invention, the bright spot by the decomposition product derived from the liquid crystal aligning film which generate|occur|produces at the time of photo-alignment process can be suppressed, irradiation sensitivity is high, the liquid crystal aligning film which has excellent liquid-crystal orientation can be obtained, and display defect Without this, it is possible to provide a highly reliable liquid crystal display element.

Although it is not necessarily clear whether the above-mentioned effect is obtained by using the liquid crystal aligning agent of the present invention, when diamine used as a raw material of a polymer constituting the liquid crystal aligning agent has a specific asymmetric structure, by light irradiation It is guessed that this is because the solubility and crystallinity of the generated decomposition product changed.

<Specific structure>

In the principal chain of the polymer which comprises the liquid crystal aligning agent of this invention, the specific structure (henceforth a specific structure) represented by said Formula (1) is contained.

[Formula 8]

In the above formula (1), R ₁ and R ₂ are each independently a single bond, -O-, -S-, -NR ₁₂ -, an ester bond, an amide bond, a thioester bond, a urea bond, a carbonate bond, or It is a carbamate bond, and R ₁₂ is a hydrogen atom or a methyl group. A is an alkylene group having 2 to 20 carbon atoms. B ₁ and B ₂ are each independently a divalent organic group selected from the following structures, and B ₁ and B ₂ do not have the same structure. In addition, when B ₁ and B ₂ do not have the same structure, the solubility and crystallinity of decomposition products generated by light irradiation change, and bright spots derived from decomposition components of the polymer can be suppressed.

[Formula 9]

(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.)

In the above formula (1), among others, R ₁ and R ₂ are preferably single bonds, -O-, -S-, -NR ₁₂ -, ester bonds or amide bonds from the viewpoint of liquid crystal orientation, and -O - is particularly preferred. Moreover, from a viewpoint of liquid-crystal orientation, A is preferably an alkylene group of 2 to 6 carbon chains, and particularly preferably an alkylene group of 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 orientation. R ₅ is preferably a hydrogen atom or a methyl group from the viewpoint of liquid crystal orientation.

It is preferable to contain said specific structure in the diamine which is a raw material of a polyimide precursor. Specific examples of the diamine having the specific structure described above include, but are not limited to, the following diamines.

[Formula 10]

[Formula 11]

(R ₅ is the same definition as above.)

[Formula 12]

[Formula 13]

In the above formula, R ₅ and R ₁₂ have the same definitions as above, including each preferred example.

It is preferable that the diamine which has the said specific structure is diamine which has the following structure from a viewpoint of orientation property and the luminescent point reduction when it is used as a liquid crystal display element especially.

[Formula 14]

In the above formula, R ₁ , R ₂ , and A are as described above, including each preferred example. As diamine which has the said specific structure, the following diamine is especially preferable.

[Formula 15]

<Synthesis of diamine>

The main synthesis method of the diamine is described in detail below. In addition, the method demonstrated below is an example, and is not limited to this.

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

[Formula 16]

The method for reducing the dinitro compound is not particularly limited, and palladium-carbon, platinum oxide, Raney nickel, platinum black, rhodium-alumina, platinum sulfide carbon, etc. are used as catalysts, and ethyl acetate, toluene, tetrahydrofuran, dioxane , a method of performing reduction with hydrogen gas, hydrazine, hydrogen chloride or the like in a solvent such as alcohol can be exemplified. You may carry out under pressure using an autoclave etc. as needed. On the other hand, when an unsaturated bond site is included in the structure of a substituent substituting a hydrogen atom in a benzene ring or a saturated hydrocarbon moiety, when palladium carbon or platinum carbon is used, the unsaturated bond site is reduced and becomes a saturated bond. there is Therefore, reduction conditions using a transition metal such as reduced iron, tin, or tin chloride as a catalyst are preferred.

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

[Formula 17]

The 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, but inorganic bases such as potassium carbonate, sodium carbonate, cesium carbonate, sodium alkoxide, potassium alkoxide, sodium hydroxide, potassium hydroxide, sodium hydride, pyridine, dimethylaminopyridine, trimethylamine, trimethylamine organic bases such as ethylamine and tributylamine; and the like. In some cases, the yield can be improved by using a palladium catalyst such as dibenzylideneacetone palladium or diphenylphosphinoferrocene palladium or a copper catalyst in combination. From the viewpoint of ease of synthesis, a method using potassium carbonate is preferable, but since synthesis is possible other than this method, the synthesis method is not particularly limited.

<Polymer>

The polyimide precursor which comprises the liquid crystal aligning agent of this invention contains the structural unit of following formula (2).

[Formula 18]

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

[Formula 19]

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

R ₃ is a hydrogen atom or an alkyl group of 1 to 5 carbon atoms. A methyl group, an ethyl group, a propyl group, i-propyl group, n-butyl group, i-butyl group, s-butyl group, t-butyl group, n-pentyl group etc. are mentioned as a specific example. From the viewpoint of the ease of imidation by heating, R ₃ is preferably a hydrogen atom or a methyl group.

Z ₁ and Z ₂ are each independently a hydrogen atom or an alkyl group of 1 to 10 carbon atoms, an alkenyl group of 2 to 10 carbon atoms, or an alkynyl group of 2 to 10 carbon atoms which may have a substituent. 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, and a bicyclohexyl group. As an alkenyl group, what substituted the 1 or more _CH2 - _CH2 structure which exists in the said alkyl group by the CH=CH structure is mentioned. Specifically, vinyl group, allyl group, 1-propenyl group, isopropenyl group, 2-butenyl group, 1,3-butadienyl group, 2-pentenyl group, 2-hexenyl group, cyclopropenyl group, cyclopentenyl group , cyclohexenyl group, etc. are mentioned. As an alkynyl group, what substituted the 1 or more _CH2 - _CH2 structure which exists in the said alkyl group with C≡C structure is mentioned. Specifically, an ethynyl group, 1-propynyl group, 2-propynyl group, etc. are mentioned.

The said alkyl group, an alkenyl group, and an alkynyl group may have a substituent, and also may form ring structure depending on a substituent. Further, forming a ring structure by substituents means that substituents or substituents and a part of the mother skeleton are bonded to form a ring structure.

Examples of the substituent include a halogen group, a hydroxyl group, a thiol group, a nitro group, an aryl group, an organooxy group, an organothio group, an organosilyl group, an acyl group, an ester group, a thioester group, a phosphate ester group, an amide group, and an alkyl group. , an alkenyl group, an alkynyl group, etc. are mentioned.

As a halogen group, a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom is mentioned.

A phenyl group is mentioned as an aryl group. This aryl group may be further substituted with the other substituents described above.

As an organooxy group, the structure represented by O-R can be shown. This R may be the same or different, and can illustrate an alkyl group, an alkenyl group, an alkynyl group, an aryl group, etc. which were mentioned above. These Rs may be further substituted by the substituents described above. A methoxy group, an ethoxy group, a propyloxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group etc. are mentioned as a specific example.

As an organothio group, the structure represented by -S-R can be shown. As this R, the above-mentioned alkyl group, alkenyl group, alkynyl group, aryl group, etc. can be illustrated. These Rs may be further substituted by the substituents described above. As a specific example, a methylthio group, an ethylthio group, a propylthio group, a butylthio group, a pentylthio group, a hexylthio group, a heptylthio group, an octylthio group, etc. are mentioned.

As an organosilyl group, the structure represented by -Si-(R) ₃ can be shown. This R may be the same or different, and can illustrate an alkyl group, an alkenyl group, an alkynyl group, an aryl group, etc. which were mentioned above. These Rs may be further substituted by the substituents described above. Specific examples include a trimethylsilyl group, a triethylsilyl group, a tripropylsilyl group, a tributylsilyl group, a tripentylsilyl group, a trihexylsilyl group, a pentyldimethylsilyl group, and a hexyldimethylsilyl group.

As an acyl group, the structure represented by -C(O)-R can be shown. As this R, the above-mentioned alkyl group, alkenyl group, aryl group, etc. can be illustrated. These Rs may be further substituted by the substituents described above. As a specific example, a formyl group, an acetyl group, a propionyl group, a butyryl group, an isobutyryl group, a valeryl group, an isovaleryl group, a benzoyl group, etc. are mentioned.

As an ester group, the structure represented by -C(O)O-R or -OC(O)-R can be shown. As this R, the above-mentioned alkyl group, alkenyl group, alkynyl group, aryl group, etc. can be illustrated. These Rs may be further substituted by the substituents described above.

As a thioester group, the structure represented by -C(S)O-R or -OC(S)-R can be shown. As this R, the above-mentioned alkyl group, alkenyl group, alkynyl group, aryl group, etc. can be illustrated. These Rs may be further substituted by the substituents described above.

As a phosphoric acid ester group, the structure represented by -OP(O)-(OR) ₂ can be shown. This R may be the same or different, and can illustrate an alkyl group, an alkenyl group, an alkynyl group, an aryl group, etc. which were mentioned above. These Rs may be further substituted by the substituents described above.

As the amide group, structures represented by -C(O)NH ₂ , or -C(O)NHR, -NHC(O)R, -C(O)N(R) ₂ , or -NRC(O)R can be represented. there is. This R may be the same or different, and can illustrate an alkyl group, an alkenyl group, an alkynyl group, an aryl group, etc. which were mentioned above. These Rs may be further substituted by the substituents described above.

Examples of the aryl group include the same ones as the aryl group described above. This aryl group may be further substituted with the other substituents described above.

As an alkyl group, the same thing as the above-mentioned alkyl group is mentioned. This alkyl group may be further substituted with the other substituents described above.

Examples of the alkenyl group include the same ones as the alkenyl group described above. The alkenyl group may be further substituted with the other substituents described above.

As an alkynyl group, the same thing as the alkynyl group mentioned above is mentioned. The alkynyl group may be further substituted with the other substituents described above.

In general, introducing a bulky structure may lower the reactivity of the amino group or the liquid crystal orientation, so as Z ₁ and Z ₂ , a hydrogen atom or an alkyl group having 1 to 5 carbon atoms which may have a substituent is more preferable and a hydrogen atom, a methyl group or an ethyl group is particularly preferred.

It is preferable to have 20-100 mol% of the structural unit represented by said Formula (2) with respect to all structural units, and 30-100 mol% is especially preferable from a viewpoint of liquid-crystal orientation.

＜Other structural units＞

When the polymer which comprises the liquid crystal aligning agent of this invention contains structural units other than the structural unit of said formula (2), the structural unit is represented by following formula (3).

[Formula 20]

The definitions of R ₃ , Z ₁ and Z ₂ are the same as in Formula (2) above.

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. Among the polyimide precursors, two or more types of X ₂ may be mixed. If a specific example of X ₂ is shown, structures of the following formulas (X-1) to (X-44) will be exemplified.

[Formula 21]

[Formula 22]

[Formula 23]

[Formula 24]

R ₈ to R ₁₁ in the formula (X-1) are each independently a hydrogen atom, a halogen atom, an alkyl group of 1 to 6 carbon atoms, an alkenyl group of 2 to 6 carbon atoms, an alkynyl group of 2 to 6 carbon atoms, or a phenyl group. . When R ₈ to R ₁₁ have a bulky structure, since there is a possibility of lowering the liquid crystal orientation, a hydrogen atom, a methyl group, or an ethyl group is more preferable, and a hydrogen atom or a methyl group is particularly preferable.

In Formula (3), Y ₂ is a divalent organic group derived from diamine, and the structure is not particularly limited. If the specific example of the structure of _Y2 is shown, the following (Y-1) - (Y-118) will be mentioned.

[Formula 25]

[Formula 26]

[Formula 27]

[Formula 28]

[Formula 29]

[Formula 30]

[Formula 31]

[Formula 32]

[Formula 33]

[Formula 34]

[Formula 35]

[Formula 36]

[Formula 37]

[Formula 38]

[Formula 39]

[Formula 40]

[Formula 41]

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

The polyimide precursor used in the present invention is obtained from reaction between a diamine component and a tetracarboxylic acid derivative, and examples thereof include polyamic acid and polyamic acid ester.

<Polyimide precursor (polyamic acid)>

The polyamic acid, which is a polyimide precursor used in the present invention, is manufactured by the following method.

Specifically, tetracarboxylic dianhydride and diamine are reacted in the presence of an organic solvent at -20 to 150°C, preferably 0 to 50°C for 30 minutes to 24 hours, preferably 1 to 12 hours can be synthesized.

Reaction of a diamine component and a tetracarboxylic acid component is normally performed in an organic solvent. The organic solvent used in that case is not particularly limited as long as the produced polyimide precursor dissolves therein. Below, although the specific example of the organic solvent used for reaction is given, it is not limited to these examples. For example, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide or and 1,3-dimethyl-imidazolidinone.

Moreover, when the solubility of a polyimide precursor is high, methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, or the following formula [D-1] - formula [D- 3] can be used.

[Formula 42]

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

These solvents may be used alone or in combination. Moreover, even if it is a solvent which does not dissolve a polyimide precursor, you may mix with the said solvent and use it within the range in which the produced|generated polyimide precursor does not precipitate. Further, since moisture in the solvent inhibits the polymerization reaction and causes the resulting polyimide precursor to be hydrolyzed, it is preferable to use a solvent obtained by dehydration and drying.

The concentration of the polyamic acid 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 precipitation of the polymer does not occur and a high molecular weight product is easily obtained.

The polyamic acid obtained in the above manner can precipitate and recover a polymer by injecting the reaction solution into a poor solvent while stirring it well. Further, a purified polyamic acid powder can be obtained by performing precipitation several times, washing with a poor solvent, and drying at room temperature or by heat. Although a poor solvent is not specifically limited, Water, methanol, ethanol, hexane, a butyl cellosolve, acetone, toluene, etc. are mentioned.

<Polyimide precursor (polyamic acid ester)>

The polyamic acid ester which is a polyimide precursor used for this invention can be manufactured by the manufacturing method of (1), (2) or (3) shown below.

(1) In the case of manufacturing with polyamic acid

Polyamic acid ester can be manufactured by esterifying the polyamic acid manufactured as mentioned above. Specifically, it can be produced by reacting a polyamic acid and an esterification agent in the presence of an organic solvent at -20 to 150°C, preferably 0 to 50°C for 30 minutes to 24 hours, preferably 1 to 4 hours. .

The esterifying agent is preferably one that can be easily removed by purification, and N,N-dimethylformamide dimethyl acetal, N,N-dimethylformamide diethyl acetal, N,N-dimethylformamide dipropyl acetal, N,N-dimethylformamidedineopentylbutylacetal, N,N-dimethylformamidedi-t-butylacetal, 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, and the like. The addition amount of the esterifying agent is preferably 2 to 6 molar equivalents per 1 mol of the repeating unit of the polyamic acid.

Examples of the organic solvent include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone or γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide or 1,3-dimethyl-imidazolidinone. Moreover, when the solvent solubility of a polyimide precursor is high, methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, or the said formula [D-1] - formula [ D-3] can be used.

These solvents may be used alone or in combination. Moreover, even if it is a solvent which does not dissolve a polyimide precursor, you may mix with the said solvent and use it within the range in which the produced|generated polyimide precursor does not precipitate. In addition, since moisture in the solvent inhibits the polymerization reaction and consequently causes the produced polyimide precursor to hydrolyze, it is preferable to use a solvent obtained by dehydration and drying.

The solvent used for the above reaction is preferably N,N-dimethylformamide, N-methyl-2-pyrrolidone, or γ-butyrolactone from the viewpoint of polymer solubility, and these are one type or a mixture of two or more types. You may use it. 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 precipitation of the polymer does not occur and it is easy to obtain a high molecular weight body.

(2) When produced by the reaction of tetracarboxylic acid diester dichloride and diamine

Polyamic acid ester can be manufactured from tetracarboxylic acid diester dichloride and diamine.

Specifically, tetracarboxylic diester dichloride and diamine are mixed in the presence of a base and an organic solvent at -20 to 150°C, preferably 0 to 50°C for 30 minutes to 24 hours, preferably 1 to 150°C. It can be manufactured by reacting for 4 hours.

As the base, pyridine, triethylamine, 4-dimethylaminopyridine and the like can be used, but pyridine is preferred because the reaction proceeds mildly. The added amount of the base is preferably from 2 to 4 moles per mole of tetracarboxylic acid diester dichloride, from the viewpoint of easy removal and easy obtaining of a high molecular weight body.

The solvent used for the above reaction is preferably N-methyl-2-pyrrolidone or γ-butyrolactone from the viewpoint of the solubility of the monomer and polymer, and these may be used alone or in combination of two or more. 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 precipitation of the polymer does not occur and it is easy to obtain a high molecular weight body. In addition, in order to prevent hydrolysis of tetracarboxylic acid diester dichloride, it is preferable that the solvent used for production of polyamic acid ester is dehydrated as much as possible, and it is preferable to prevent mixing of outside air in a nitrogen atmosphere. .

(3) When produced with tetracarboxylic acid diester and diamine

Polyamic acid ester can be manufactured by polycondensing tetracarboxylic-acid diester and diamine.

Specifically, a tetracarboxylic diester and a diamine are mixed in the presence of a condensing agent, a base, and an organic solvent at 0 to 150°C, preferably 0 to 100°C, for 30 minutes to 24 hours, preferably 3 It can be produced by reacting for about 15 hours.

The condensing agent includes triphenylphosphite, 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-(benzotriazole- 1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate, (2,3-dihydro-2-thioxo-3-benzooxazolyl)phosphonic acid diphenyl, etc. can As for the addition amount of a condensing agent, 2-3 times mole is preferable with respect to the tetracarboxylic-acid diester.

As the base, tertiary amines such as pyridine and triethylamine can be used. The addition amount of the base is a quantity that is easy to remove and is preferably 2 to 4 times mole with respect to the diamine component from the viewpoint of easy obtaining of a high molecular weight body.

In the above reaction, the reaction proceeds efficiently by adding a Lewis acid as an additive. As the Lewis acid, lithium halides such as lithium chloride and lithium bromide are preferable. As for the addition amount of a Lewis acid, 0-1.0 times mole is preferable with respect to the diamine component.

Since polyamic acid ester of high molecular weight is obtained among the manufacturing methods of said 3 types of polyamic acid ester, the manufacturing method of said (1) or (2) is especially preferable.

A polymer can be deposited by inject|pouring into a poor solvent, stirring well the solution of the polyamic acid ester obtained by performing it above. Precipitation is performed several times, and after washing with a poor solvent, it is dried at room temperature or by heat, and a purified polyamic acid ester powder can be obtained. Although a poor solvent is not specifically limited, Water, methanol, ethanol, hexane, a butyl cellosolve, acetone, toluene, etc. are mentioned.

<Polyimide>

The polyimide used in the present invention can be produced by imidizing the polyamic acid ester or polyamic acid described above.

When manufacturing a polyimide from polyamic acid ester, chemical imidation which adds a basic catalyst to the polyamic acid ester solution or the polyamic acid solution obtained by dissolving polyamic acid ester resin powder in an organic solvent is simple. Chemical imidation is preferable because the imidation reaction proceeds at a relatively low temperature and it is difficult to reduce the molecular weight of the polymer in the process of imidation.

Chemical imidation can be performed by stirring the polyamic acid ester to be imidated in basic catalyst presence in an organic solvent. As the organic solvent, the solvent used in the polymerization reaction described above can be used. Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, and trioctylamine. Among them, triethylamine is preferred because it has sufficient basicity to advance the reaction.

The temperature at the time of performing the imidation reaction is -20 to 140°C, preferably 0 to 100°C, and the reaction time is preferably 1 to 100 hours. The amount of the basic catalyst is 0.5 to 30 mole times of the amic acid ester group, preferably 2 to 20 mole times. The imidation rate of the resulting polymer can be controlled by adjusting the catalyst amount, temperature, reaction time and the like. Since the catalyst etc. which were added remain|survive in the solution after imidation reaction, it collect|recovers the obtained imidation polymer by the means described below, it is dissolved again in an organic solvent, and it is preferable to set it as the liquid crystal aligning agent of this invention.

When manufacturing a polyimide with polyamic acid, chemical imidation which adds a catalyst to the solution of the polyamic acid obtained by reaction of a diamine component and tetracarboxylic dianhydride is simple. Chemical imidation is preferable because the imidation reaction proceeds at a relatively low temperature and it is difficult to reduce the molecular weight of the polymer in the process of imidation.

Chemical imidation can be performed by stirring the polyamic acid to be imidated in the presence of a basic catalyst and an acid anhydride in an organic solvent. As the organic solvent, the solvent used in the polymerization reaction described above can be used. Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, and trioctylamine. Among them, pyridine is preferable because it has a suitable basicity for advancing the reaction. Moreover, as an acid anhydride, acetic anhydride, a trimellitic anhydride, a pyromellitic anhydride, etc. are mentioned. Among them, acetic anhydride is preferable because it facilitates purification after completion of the reaction.

The temperature at the time of carrying out the imidation reaction is -20 to 140°C, preferably 0 to 100°C, and the reaction time is preferably 1 to 100 hours. The amount of the basic catalyst is 0.5 to 30 mole times, preferably 2 to 20 mole times, the amount of the amic acid group, and the amount of the acid anhydride is 1 to 50 mole times, preferably 3 to 30 mole times the amic acid group. The imidation rate of the resulting polymer can be controlled by adjusting the catalyst amount, temperature, reaction time and the like.

Since the added catalyst and the like remain in the solution after the imidation reaction of the polyamic acid ester or the polyamic acid, the obtained imidized polymer is recovered by the means described below, re-dissolved in an organic solvent, and the liquid crystal of the present invention It is preferable to use it as an orientation agent.

A polymer can be deposited by inject|pouring into a poor solvent, stirring well the solution of the polyimide obtained by performing it above. Precipitation is performed several times, followed by washing with a poor solvent and drying at room temperature or by heating to obtain a purified polyimide powder.

Although it does not specifically limit as a poor solvent, Methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, etc. are mentioned.

<liquid crystal aligning agent>

The liquid crystal aligning agent of this invention contains at least 1 sort(s) of polymer chosen from the group which consists of the imidation polymer of the polyimide precursor which has a specific structure in a main chain, and this polyimide precursor. The molecular weight of the polymer is preferably from 2,000 to 500,000, more preferably from 5,000 to 300,000, still more preferably from 10,000 to 100,000 in terms of weight average molecular weight (Mw). Also, 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 aligning agent of the present invention can be appropriately changed according to the setting of the thickness of the coating film to be formed, but from the viewpoint of forming a uniform and defect-free coating film, it is preferably 1% by mass or more, and preservation of the solution From the point of stability, it is preferable to set it as 10 mass % or less. The concentration of the polymer is preferably 2 to 7% by mass.

The organic solvent (henceforth, also referred to as a good solvent) which dissolves a polymer contained in the liquid crystal aligning agent used for this invention is not specifically limited if a polymer melt|dissolves uniformly.

For example, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethylsulfoxide, γ-butyrolactone, 1,3-dimethyl-imidazolidinone, methyl ethyl ketone, cyclohexanone, cyclopentanone or 4-hydroxy-4-methyl-2-pentanone. Especially, it is preferable to use N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, or γ-butyrolactone.

Moreover, when the solubility to the solvent of the polymer of this invention is high, it is preferable to use the solvent represented by the said formula [D-1] - formula [D-3].

It is preferable that content of the good solvent in the liquid crystal aligning agent of this invention is 20-99 mass % of the whole solvent contained in the liquid crystal aligning agent. Especially, 20-90 mass % is preferable. More preferably, it is 30-80 mass %.

The liquid crystal aligning agent of the present invention can use a solvent (also referred to as a poor solvent) that improves the coating properties and surface smoothness of the liquid crystal aligning film when the liquid crystal aligning agent is applied, unless the effect of the present invention is impaired. Although the specific example of a poor solvent is given, it is not limited to these examples.

For example, ethanol, isopropyl alcohol, 1-butanol, 2-butanol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, Isopentyl alcohol, tert-pentyl alcohol, 3-methyl-2-butanol, neopentyl alcohol, 1-hexanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-ethyl-1- Butanol, 1-heptanol, 2-heptanol, 3-heptanol, 1-octanol, 2-octanol, 2-ethyl-1-hexanol, cyclohexanol, 1-methylcyclohexanol, 2-methyl Cyclohexanol, 3-methylcyclohexanol, 1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 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-pentanone, 3-pentanone, 2-hexanone, 2-heptanone, 4-heptanone, 3-ethoxybutylacetate, 1-methylpentylacetate, 2-ethylbutylacetate, 2-ethylhexyl Acetate, ethylene glycol monoacetate, ethylene glycol diacetate, propylene carbonate, ethylene carbonate, 2-(methoxymethoxy)ethanol, ethylene glycol monobutyl ether, ethylene glycol monoisoamyl ether, ethylene glycol monohexyl ether, 2-( Hexyloxy)ethanol, furfuryl alcohol, diethylene glycol, propylene glycol, propylene glycol monobutyl ether, 1-(butoxyethoxy)propanol, 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 di Acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, 2-(2-ethoxyethoxy)ethyl acetate, diethylene glycol acetate, triethylene glycol, triethylene 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, ethyl 3-ethoxymethylpropionate, 3 -Methoxyethylpropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, 3-methoxypropylpropionate, 3-methoxybutylpropionate, methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate Ester, lactic acid isoamyl ester, the solvent represented by said formula [D-1] - formula [D-3], etc. are mentioned.

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 preferable.

It is preferable that content of these poor solvents is 1-80 mass % of the whole solvent contained in a liquid crystal aligning agent. Especially, 10-80 mass % is preferable and 20-70 mass % is more preferable.

In the liquid crystal aligning agent of the present invention, as long as the effect of the present invention is not impaired other than the above, polymers other than the polymer described in the present invention, dielectric constant or conductive material for the purpose of changing electrical properties such as dielectric constant or conductivity of the liquid crystal aligning film, A silane coupling agent for the purpose of improving the adhesion between the liquid crystal alignment film and the substrate, a crosslinkable compound for the purpose of increasing the hardness and density of the film when used as a liquid crystal alignment film, and also imidation by heating a polyimide precursor when firing a coating film You may add an imidation promoter etc. for the purpose of advancing efficiently.

<Liquid crystal alignment film>

The liquid crystal aligning film of this invention is a film|membrane obtained by apply|coating the said liquid crystal aligning agent to a board|substrate, making it dry, and baking. The substrate to which the liquid crystal aligning agent of the present invention is coated is not particularly limited as long as it is a substrate having high transparency, and plastic substrates such as glass substrates, silicon nitride substrates, acrylic substrates, and polycarbonate substrates can be used, and ITO for driving liquid crystals It is preferable to use a substrate on which electrodes and the like are formed from the viewpoint of simplifying the process. In addition, in the reflective liquid crystal display element, as long as it is a substrate on one side, even an opaque material such as a silicon wafer can be used, and a material that reflects light such as aluminum can also be used for the electrode in this case.

As a coating method of the liquid crystal aligning agent of this invention, the spin coat method, the printing method, the inkjet method, etc. are mentioned.

The drying and baking process after apply|coating a liquid crystal aligning agent can select arbitrary temperature and time. Usually, in order to sufficiently remove the contained organic solvent, the drying temperature is preferably 50 to 120°C, and the drying time is preferably 1 to 10 minutes. Further, the firing temperature is preferably 150 to 300°C, and the firing time is preferably 5 to 120 minutes.

The thickness of the film after baking is not particularly limited, but is preferably 5 to 300 nm, more preferably 10 to 120 nm, since reliability of the liquid crystal display element may be impaired if it is too thin.

As a method of photo-alignment treatment of the liquid crystal aligning film, radiation deflected in a certain direction is irradiated to the surface of the coating film, and in some cases, further heat treatment is performed at a temperature of 150 to 250 ° C. to impart liquid crystal orientation ability way can be As the radiation, ultraviolet rays and visible rays having a wavelength of 100 to 800 nm can be used. Among these, ultraviolet rays having a wavelength of 100 to 400 nm are preferred, and those having a wavelength of 200 to 400 nm are particularly preferred. Moreover, in order to improve liquid-crystal orientation, you may irradiate a radiation, heating a coating-film board|substrate at 50-250 degreeC. The dose of radiation is preferably from 1 to 10,000 mJ/cm 2 , particularly preferably from 100 to 5,000 mJ/cm 2 . The liquid crystal aligning film produced as mentioned above can stably orientate liquid crystal molecules in a fixed direction.

Since a higher anisotropy can be imparted, a higher extinction ratio of polarized ultraviolet rays is preferable. Specifically, the extinction ratio of linearly polarized ultraviolet rays is preferably 10:1 or higher, and more preferably 20:1 or higher.

The film irradiated with polarized radiation may then be subjected to contact treatment with a solvent containing at least one selected from water and organic solvents.

The solvent used for the contact treatment is not particularly limited as long as it dissolves the decomposed 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, butyl cellosolve, ethyl lactate, methyl lactate , diacetone alcohol, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propyl acetate, butyl acetate, cyclohexyl acetate, and the like. These solvents may use 2 or more types together. At least one selected from the group consisting of water, 2-propanol, 1-methoxy-2-propanol, and ethyl lactate is more preferred from the viewpoint of versatility and safety. Water, 2-propanol, or a mixed solvent of water and 2-propanol is particularly preferred.

In the present invention, contact treatment between a film irradiated with polarized radiation and a solution containing an organic solvent includes immersion treatment, spray (spray) treatment, and the like, and a treatment in which the film and the liquid come into sufficient contact is preferable. Among them, a method in which the film is immersed in a solution containing an organic solvent for preferably 10 seconds to 1 hour, more preferably 1 to 30 minutes is preferable. The contact treatment may be performed at room temperature or heated, but is preferably carried out at 10 to 80°C, more preferably 20 to 50°C. In addition, if necessary, means for enhancing the contact of ultrasonic waves or the like can be implemented.

After the contact treatment, rinsing with a low boiling point solvent such as water, methanol, ethanol, 2-propanol, acetone, methyl ethyl ketone, or drying, or both, may be performed for the purpose of removing the organic solvent in the used solution. do.

In addition, a film subjected to contact treatment with a solvent may be heated at 150°C or higher for the purpose of drying the solvent and reorienting molecular chains in the film. As heating temperature, 150-300 degreeC is preferable. The higher the temperature promotes the reorientation of molecular chains, however, too high a temperature may result in decomposition of the molecular chains. Therefore, the heating temperature is more preferably 180 to 250°C, particularly preferably 200 to 230°C.

The heating time is preferably 10 seconds to 30 minutes, and more preferably 1 to 10 minutes, since there is a possibility that the molecular chain reorientation effect may not be obtained if it is too short, and the molecular chains may be decomposed if it is too long.

<Liquid crystal display element>

After the liquid crystal display element of this invention obtained the board|substrate which has a liquid crystal aligning film formed with the liquid crystal aligning agent of this invention, it produced a liquid crystal cell by a well-known method, and used the cell as an element.

As an example of the manufacturing method of a liquid crystal cell, below, the liquid crystal display element of a passive matrix structure is taken as an example and demonstrated. Alternatively, it may be a liquid crystal display element having an active matrix structure in which switching elements such as TFT (Thin Film Transistor) are formed in each pixel portion constituting the image display.

First, a transparent glass substrate is prepared, and a common electrode is formed on one substrate and a segment electrode is formed on the other substrate. These electrodes can be, for example, ITO electrodes, and are patterned so that desired image display is possible. Next, an insulating film is formed on each substrate so as to cover the common electrode and the segment electrode. The insulating film can be, for example, a film made of SiO ₂ -TiO ₂ formed by a sol-gel method.

Next, the liquid crystal aligning film of this invention is formed on each board|substrate. Next, the other substrate is superimposed on one substrate so that the orientation film faces face each other, and the periphery is bonded with a sealant. In order to control the gap between the substrates, it is preferable to incorporate a spacer into the sealing material. Further, it is preferable to spread spacers for controlling the gap between the substrates also in the in-plane portion where the sealing member is not formed. In addition, an opening capable of being filled with liquid crystal from the outside is usually formed in a part of the sealing material.

Next, the liquid crystal material is injected into the space surrounded by the two substrates and the sealant through the opening formed in the sealant. After that, the opening is sealed with an adhesive. For injection, a vacuum injection method may be used, or a method using a capillary phenomenon in the air may be used. Next, the polarizing plate is installed. Specifically, a pair of polarizing plates are attached to the surfaces of the two substrates opposite to the liquid crystal layer. By passing through the above process, the liquid crystal display element of this invention is obtained.

In the present invention, a resin curable by ultraviolet irradiation or heating having a reactive group such as an epoxy group, an acryloyl group, a methacryloyl group, a hydroxyl group, an allyl group, or an acetyl group is used as the sealing agent. In particular, it is preferable to use a cured resin system having a reactive group of both an epoxy group and a (meth)acryloyl group.

An inorganic filler may be blended with the sealant for the purpose of improving adhesiveness, moisture resistance, and the like. The usable inorganic filler is not particularly limited, but specifically, spherical silica, fused silica, crystalline silica, titanium oxide, titanium black, silicon carbide, silicon nitride, boron nitride, calcium carbonate, magnesium carbonate, barium sulfate, calcium sulfate, mica, talc, clay, alumina, magnesium oxide, zirconium oxide, aluminum hydroxide, calcium silicate, aluminum silicate, lithium aluminum silicate, zirconium silicate, barium titanate, glass fiber, carbon fiber, molybdenum disulfide, asbestos, and the like. . Preferably, spherical silica, fused silica, crystalline silica, titanium oxide, titanium black, silicon nitride, boron nitride, calcium carbonate, barium sulfate, calcium sulfate, mica, talc, clay, alumina, aluminum hydroxide, calcium silicate, aluminum silicate, etc. am. You may mix and use 2 or more types of the said inorganic filler.

Example

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

NMP: N-methyl-2-pyrrolidone, BCS: Butyl cellosolve

[Formula 43]

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

Step 1: Synthesis of 4-nitro-4'-(2-(4-nitrophenoxy)ethoxy)-1,1'-biphenyl (DA-1-1)

[Formula 44]

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

It stirred at 80 degreeC as it was for 2 hours, and the disappearance of the raw material was confirmed by high-performance liquid chromatography (hereinafter abbreviated as HPLC). Then, the reaction liquid was allowed to cool to room temperature, water (500.0 g) was added, the precipitate was filtered, and the filtrate was washed twice with water (100.0 g). The obtained filtrate was washed twice with MeOH (500.0 g). The precipitate was filtered and dried under reduced pressure at 50°C to obtain 4-nitro-4'-(2-(4-nitrophenoxy)ethoxy)-1,1'-biphenyl (DA-1-1) ( White powder, quantity: 17.6 g, yield: 99%).

Melting Point (DSC): 193℃

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

[Formula 45]

DA-1-1 (5.0 g, 13.1 mmol) was dissolved in tetrahydrofuran (100.0 g), 5% by mass palladium-carbon (0.1 g) was added, and the mixture was stirred at room temperature under a hydrogen atmosphere for 2 hours. After confirming disappearance of the raw 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 was obtained by drying the obtained solid (white powder, yield: 4.0 g, yield: 94%).

Melting Point (DSC): 156℃

In addition, hydrogen nuclear magnetic resonance ( ¹ HNMR, 500 MHz) of the Synthesis Example was measured in a deuterated dimethyl sulfoxide (DMSO-d6) solvent, and the chemical shift was calculated as a δ value (ppm) when tetramethylsilane was used as an internal standard. showed up

[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 cone rotor TE-1 (1° 34', R24), and a temperature of 25°C.

[Molecular Weight]

GPC device: manufactured by Shodex (GPC-101), column: manufactured by Shodex (KD803, KD805 in series), column temperature: 50 ° C, eluent: N, N-dimethylformamide (lithium bromide-hydrate (LiBr as an additive) H ₂ O) was 30 mmol/L, phosphoric acid/anhydrous crystalline (o-phosphoric acid) was 30 mmol/L, tetrahydrofuran (THF) was 10 ml/L), flow rate: 1.0 ml/min.

Standard samples for calibration curve: TSK standard polyethylene oxide manufactured by Tosoh Corporation (weight average molecular weight (Mw); about 900,000, 150,000, 100,000 and 30,000), and polyethylene glycol manufactured by Polymer Laboratories (peak top molecular weight (Mp); about 12,000) , 4,000 and 1,000).

In order to avoid overlapping peaks, two samples were separately measured: a sample in which four types of 900,000, 100,000, 12,000, and 1,000 were mixed, and a sample in which three types of 150,000, 30,000, and 4,000 were mixed.

[Production of liquid crystal cell]

A liquid crystal cell having a configuration of a fringe field switching (FFS) mode liquid crystal display element is manufactured.

A glass substrate having a size of 30 mm × 50 mm and a thickness of 0.7 mm on which an electrode was formed was prepared. On the substrate, as a first layer, an ITO electrode comprising a counter electrode and having a solid pattern is formed. On the counter electrode of the first layer, as a second layer, a SiN (silicon nitride) film formed by the CVD method is formed. The film thickness of the second layer SiN film is 500 nm, and functions as an interlayer insulating film. On the SiN film of the 2nd layer, the comb-tooth-shaped pixel electrode formed by patterning the ITO film as a 3rd layer is arrange|positioned, forming two pixels, a 1st pixel and a 2nd pixel. The size of each pixel is 10 mm in length and about 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 pixel electrode has a comb-like shape formed by arranging a plurality of ""-shaped electrode elements with bent central portions. The width of each electrode element in the short direction is 3 μm, and the interval between the electrode elements is 6 μm. Since the pixel electrodes constituting each pixel are constituted by arranging a plurality of z-shaped electrode elements with curved central portions, the shape of each pixel is not rectangular, but is bent in the central portion similarly to the electrode element. It has a shape similar to the character く. Further, each pixel is divided up and down with the central curved portion as a boundary, and has a first region above the curved portion and a second region below the curved portion.

Comparing the 1st area and the 2nd area|region of each pixel, the formation direction of the electrode element of the pixel electrode which comprises them differs. That is, when the rubbing direction of the liquid crystal alignment film described later is used as a reference, in the first area of the pixel, the electrode element of the pixel electrode is formed so as to form an angle of +10 ° (clockwise direction), and in the second area of the pixel, the pixel electrode The electrode elements of are formed to form an angle of -10° (clockwise). That is, in the first region and the second region of each pixel, directions of rotational motion (in-plane switching) of the liquid crystal caused by application of a voltage between the pixel electrode and the opposite electrode within the substrate plane are opposite to each other. has been

Next, after filtering the liquid crystal aligning agent with a 1.0 μm filter, it is applied by spin coating to the prepared substrate on which the electrode is formed and a glass substrate having a columnar spacer having a height of 4 μm and having an ITO film formed on the back surface thereof did After coating, after drying on a hot plate at 80°C for 5 minutes, it was baked in a hot air circulation oven at 230°C for 20 minutes to form a coating film having a thickness of 100 nm. The coated film surface was irradiated with ultraviolet light having a wavelength of 254 nm that was linearly polarized at an extinction ratio of 10:1 or more through a polarizing plate. This board|substrate was made to immerse this board|substrate in at least 1 sort(s) of solvent chosen from water and organic solvent for 3 minutes, then was immersed in pure water for 1 minute, and heated after that on a 150-300 degreeC hot plate for 5 minutes, A board|substrate with a liquid crystal aligning film formed got

After setting two board|substrates as one set, printing a sealing compound on one board|substrate, and attaching the other board|substrate so that the liquid crystal aligning film surface may face each other and orientation direction becoming 0 degree, the sealing compound is hardened and empty cell was made. Liquid crystal MLC-7026-100 (manufactured by Merck & Co., Ltd.) was injected into this empty cell by a reduced pressure injection method, the injection port was sealed, and an FFS drive liquid crystal cell was obtained. Then, after heating the obtained liquid crystal cell at 110 degreeC for 1 hour and leaving it to stand overnight, it used for each evaluation.

[Evaluation of afterimage by long-term alternating current drive]

A liquid crystal cell having the same structure as the liquid crystal cell described above was prepared, and an alternating voltage of ±5 V was applied at a frequency of 60 Hz in a constant temperature environment of 60°C for 120 hours. Then, it was set as the state which shorted between the pixel electrode of a liquid crystal cell and a counter electrode, and it was left to stand at room temperature for one day as it was.

After standing, the liquid crystal cell was installed between two polarizing plates arranged so that the polarization axes were orthogonal, the backlight was turned on in a voltage-free state, and the angle of arrangement of the liquid crystal cell was adjusted so that the luminance of the transmitted light was minimized. And the rotation angle at the time of rotating the liquid crystal cell from the angle at which the 2nd area|region of a 1st pixel becomes the darkest to the angle at which 1st area|region becomes the darkest was computed as angle (DELTA). Also in the second pixel, the same angle Δ was calculated by comparing the second area and the first area as in the case of the first pixel.

[Evaluation of bright point of liquid crystal cell (contrast)]

The luminescent point evaluation of the above liquid crystal cell was performed. Evaluation of the luminescent point of the liquid crystal cell was performed by observing the liquid crystal cell with a polarization microscope (ECLIPSE E600WPOL) (manufactured by Nikon Corporation). Specifically, a liquid crystal cell was installed with cross nicol, the liquid crystal cell was observed with a polarizing microscope with a magnification of 5 times, and the number of confirmed bright spots was counted. 」

<Synthesis Example 1>

Into a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, 1.44 g (4.50 mmol) of DA-1 and 0.49 g (4.53 mmol) of DA-2 were weighed and taken, and 25.38 g of NMP was added, It was stirred and dissolved while sending nitrogen. While stirring this diamine solution, 1.92 g (8.56 mmol) of 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride was added, and NMP was further added so that the solid concentration was 12% by mass. It added 2.82g, stirred at room temperature for 24 hours, and obtained the polyamic acid solution (A). The viscosity in the temperature of 25 degreeC of this polyamic-acid solution was 1680 mPa*s. Moreover, the molecular weight of this polyamic acid was Mn = 14700 and Mw = 35000.

<Synthesis Example 2>

2.24 g (7.00 mmol) of DA-1 was weighed out in a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, 24.64 g of NMP was added, and the mixture was stirred and dissolved while blowing nitrogen. While stirring this diamine solution, 1.49 g (6.65 mmol) of 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride was added, and NMP was further added so that the solid concentration was 12% by mass. It added 2.73g, stirred at room temperature for 24 hours, and obtained the polyamic acid solution (B). The viscosity in the temperature of 25 degreeC of this polyamic-acid solution was 2650 mPa*s. Moreover, the molecular weight of this polyamic acid was Mn = 21300 and Mw = 52300.

<Synthesis Example 3>

Into a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, 1.51 g (4.71 mmol) of DA-1 and 1.14 g (4.71 mmol) of DA-3 were weighed and taken, and 16.99 g of NMP was added, It was stirred and dissolved while sending nitrogen. While stirring this diamine solution, 2.07 g (9.23 mmol) of 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride was added, and NMP was further added so that the solid concentration was 20% by mass. It added 1.89g, stirred at 40 degreeC for 24 hours, and obtained the polyamic-acid solution (C). The viscosity in the temperature of 25 degreeC of this polyamic-acid solution was 5000 mPa*s. Moreover, the molecular weight of this polyamic acid was Mn = 13900 and Mw = 34100.

<Synthesis Example 4>

In a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, 1.59 g (6.51 mmol) of DA-4 and 0.70 g (6.47 mmol) of DA-2 were weighed and taken, 33.07 g of NMP was added, It was stirred and dissolved while sending nitrogen. While stirring this diamine solution, 2.71 g (12.09 mmol) of 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride was added, and NMP was further added so that the solid concentration was 12% by mass. It added 3.67g, stirred at room temperature for 24 hours, and obtained the polyamic acid solution (D). The viscosity in the temperature of 25 degreeC of this polyamic-acid solution was 360 mPa*s. Moreover, the molecular weight of this polyamic acid was Mn = 14500 and Mw = 30200.

<Synthesis Example 5>

Into a 50 mL four-necked flask equipped with a stirring device and a nitrogen inlet tube, 3.59 g (16.01 mmol) of 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride was weighed and taken, 34.18g of NMP was added, and it stirred and dissolved, sending nitrogen. While stirring this 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 was 12% by mass, stirred at room temperature for 24 hours, and a polyamic acid solution (E ) was obtained. The viscosity in the temperature of 25 degreeC of this polyamic-acid solution was 200 mPa*s. Moreover, the molecular weight of this polyamic acid was Mn = 12600 and Mw = 30500.

<Example 1>

15.00 g of a 12 mass % polyamic acid solution (A) was weighed and taken into a 100 ml Erlenmeyer flask, NMP 9.00 g and BCS 6.00 g were added, it mixed at 25 degreeC for 8 hours, and the liquid crystal aligning agent (1) was obtained. Abnormality, such as muddiness and precipitation, was not looked at by the liquid crystal aligning agent, but it was confirmed that it is a uniform solution.

<Example 2>

Except having used the polyamic-acid solution (B) instead of the polyamic-acid solution (A), it processed similarly to Example 1, and obtained the liquid crystal aligning agent (2). Abnormality, such as muddiness and precipitation, was not looked at by the liquid crystal aligning agent, but it was confirmed that it is a uniform solution.

<Example 3>

9.00 g of a 20 mass % polyamic acid solution (C) was taken in a 100 ml Erlenmeyer flask, NMP 15.00 g and BCS 6.00 g were added, it mixed at 25 degreeC for 8 hours, and the liquid crystal aligning agent (3) was obtained. Abnormality, such as muddiness and precipitation, was not looked at by the liquid crystal aligning agent, but it was confirmed that it is a uniform solution.

<Comparative Example 1>

Except having used the polyamic-acid solution (D) instead of the polyamic-acid solution (A), it processed similarly to Example 1, and obtained the liquid crystal aligning agent (4). Abnormality, such as muddiness and precipitation, was not looked at by the liquid crystal aligning agent, but it was confirmed that it is a uniform solution.

<Comparative Example 2>

Except having used the polyamic-acid solution (E) instead of the polyamic-acid solution (A), it processed similarly to Example 1, and obtained the liquid crystal aligning agent (5). Abnormality, such as muddiness and precipitation, was not looked at by the liquid crystal aligning agent, but it was confirmed that it is a uniform solution.

<Example 4>

After filtering the liquid crystal aligning agent (1) with a 1.0 μm filter, it was coated by spin coating on a glass substrate having a columnar spacer with a height of 4 μm and an ITO film formed on the substrate and the back surface of which the electrode was formed. . Then, it was dried on an 80 degreeC hot plate for 5 minutes, and it baked in a 230 degreeC hot-air circulation type oven for 20 minutes, and the coating film of 100 nm thickness was formed. 0.2 J/cm 2 of ultraviolet rays having a wavelength of 254 nm that were linearly polarized at an extinction ratio of 26:1 was irradiated to this coating film surface through a polarizing plate. Then, it heated for 14 minutes on a 230 degreeC hotplate, and obtained the board|substrate with a liquid crystal aligning film.

Two board|substrates were made into 1 set, the sealing compound was printed on one board|substrate, and the liquid crystal aligning film surface faced the other board|substrate, and it affixed so that an orientation direction might become 0 degree. After that, the sealing compound was cured to produce an empty cell. Liquid crystal MLC-7026-100 (manufactured by Merck & Co., Ltd.) was injected into this empty cell by a reduced pressure injection method, and then the injection port was sealed to obtain an FFS drive liquid crystal cell. Then, the obtained liquid crystal cell was heated at 110 degreeC for 1 hour, left to stand overnight, and residual image evaluation by long-term alternating current drive was performed. The value of angle Δ of this liquid crystal cell after long-term AC drive was 0.01°. Moreover, as a result of observing the bright spot in the liquid crystal cell, the number of bright spots was less than 10 and was good.

<Example 5>

A coating film was formed by the method similar to Example 4 except having used the said liquid crystal aligning agent (2). 0.5 J/cm 2 of ultraviolet rays having a wavelength of 254 nm that were linearly polarized at an extinction ratio of 26:1 was irradiated to the surface of the coated film through a polarizing plate. Then, it heated for 14 minutes on a 230 degreeC hotplate, and obtained the board|substrate with a liquid crystal aligning film. Evaluation similar to Example 4 was performed about the liquid crystal cell obtained by producing the FFS drive liquid crystal cell by the method similar to Example 4 except having used this board|substrate with a liquid crystal aligning film. As a result, the value of the angle Δ was 0.03°. Moreover, the number of bright spots was less than 10, which was good.

<Example 6>

Except having used the said liquid crystal aligning agent (3), the coating film was formed by the method similar to Example 4, ultraviolet-ray was irradiated, it heated, and the board|substrate with a liquid crystal aligning film was obtained. Evaluation similar to Example 4 was performed about the liquid crystal cell obtained by producing the FFS drive liquid crystal cell by the method similar to Example 4 except having used this board|substrate with a liquid crystal aligning film. As a result, the value of the angle Δ was 0.02°. Moreover, the number of bright spots was less than 10, which was good.

<Comparative Example 3>

Except having used the said liquid crystal aligning agent (4), the coating film was formed by the method similar to Example 4, ultraviolet-ray was irradiated, it heated, and the board|substrate with a liquid crystal aligning film was obtained. Evaluation similar to Example 4 was performed about the liquid crystal cell obtained by producing the FFS drive liquid crystal cell by the method similar to Example 4 except having used the board|substrate with this liquid crystal aligning film. As a result, the value of the angle Δ was 0.10°. Moreover, the number of bright spots was 10 or more, and it was defective.

<Comparative Example 4>

Except having used the said liquid crystal aligning agent (5), the coating film was formed by the method similar to Example 4, 0.5 J/cm<2> of ultraviolet rays were irradiated, it heated, and the board|substrate with a liquid crystal aligning film was obtained. Evaluation similar to Example 4 was performed about the liquid crystal cell obtained by producing the FFS drive liquid crystal cell by the method similar to Example 4 except having used this board|substrate with a liquid crystal aligning film. As a result, the value of the angle Δ was 0.19°. Moreover, the number of bright spots was 10 or more, and it was defective.

industrial applicability

The liquid crystal aligning agent of the present invention does not generate a bright spot even when a negative type liquid crystal is used, and it is possible to form a liquid crystal alignment film for an optical alignment method having good afterimage characteristics, and a high display quality, FFS drive type liquid crystal display. It can be used for elements and the like.

In addition, all the content of the JP Patent application 2015-061095, the claim, and the abstract for which it applied on March 24, 2015 is referred here, and it takes in as an indication of the specification of this invention.

Claims (9)

Diamine represented by the following formula (1b).
[Formula 1]

(Wherein, R ₁ and R ₂ are each independently a single bond, -O-, -S-, -NR ₁₂ -, an ester bond, an amide bond, a thioester bond, a urea bond, a carbonate bond, or a carbamate bond , R ₁₂ is a hydrogen atom or a methyl group, and A is an alkylene group having 2 to 20 carbon atoms.) According to claim 1,
In the above formula (1b), R ₁ and R ₂ are each independently a single bond, -O-, -S-, -NR ₁₂ -, an ester bond or an amide bond, and A is an alkylene group having 2 to 6 carbon atoms; diamine. According to claim 1,
In the formula (1b), R ₁ and R ₂ are -O-, and A is a diamine having an alkylene group of 2 to 4 carbon atoms. Diamine represented by any of the following formulas (1a-1) to (1a-15).

(In the formula, R ₅ is a hydrogen atom, a methyl group, a hydroxyl group or a methoxy group. R ₁₂ is a hydrogen atom or a methyl group.) A polymer obtained by using the diamine according to any one of claims 1 to 4 as a raw material. According to claim 5,
A polymer that is a polyamic acid obtained by a polycondensation reaction of the diamine according to any one of claims 1 to 4 and tetracarboxylic dianhydride. According to claim 5,
The polymer which is a polyimide obtained by imidating the polyamic acid obtained by the polycondensation reaction of the diamine and tetracarboxylic dianhydride of any one of Claims 1-4. According to any one of claims 5 to 7,
A polymer for a liquid crystal aligning agent. According to any one of claims 1 to 4,
Diamines used in the synthesis of polymers.