WO2020027262A1

WO2020027262A1 - Charge-transporting composition

Info

Publication number: WO2020027262A1
Application number: PCT/JP2019/030221
Authority: WO
Inventors: 歳幸遠藤
Original assignee: 日産化学株式会社
Priority date: 2018-08-03
Filing date: 2019-08-01
Publication date: 2020-02-06
Also published as: CN112534599A; TWI837158B; JP7414001B2; KR20210040081A; TW202018059A; JPWO2020027262A1

Abstract

Provided, for example, is a charge-transporting composition including the aniline derivative shown in the formula that follows. (In the formula, Ph is a phenyl group.)

Description

Charge transporting composition

The present invention relates to a charge transporting composition.

In recent years, a charge transporting thin film used in an organic electroluminescence (hereinafter, also referred to as an organic EL) device has been transmitted in a visible region in recent years due to the fact that the coloring deteriorates the color purity and color reproducibility of the organic EL device. It is desired that the ratio is high and the transparency is excellent (Patent Document 1). In view of this, the present applicant has already found a material for a wet process that provides a charge transporting thin film with excellent transparency and suppressed coloring in the visible region (Patent Documents 1 and 2).

On the other hand, various approaches have been taken so far to improve the performance of the organic EL element, but efforts have been made to adjust the refractive index of the functional film to be used for the purpose of improving the light extraction efficiency. . Specifically, by using a hole injection layer or a hole transport layer having a relatively high or low refractive index in consideration of the entire configuration of the element and the refractive index of other adjacent members, high efficiency of the element can be obtained. Attempts have been made to achieve this (for example, Patent Documents 3 and 4). As described above, the refractive index is an important factor in the design of the organic EL element, and the material for the organic EL element is considered to be an important physical property value in which the refractive index should also be considered.

International Publication No. WO 2013/046233 WO 2008/032616 Tokuyo 2007-536718 JP-T-2017-501585

The present invention has been made in view of the above circumstances, and provides a thin film having good charge transportability, low extinction coefficient (k), good transparency, and high refractive index (n). It is an object of the present invention to provide a charge transporting composition capable of realizing an organic EL device having excellent characteristics when applied to a hole injection layer or the like.

The present inventors have conducted intensive studies to achieve the above object, and as a result, have found that certain anilines having an N, N, N ', N'-tetra (carbazol-2-yl) -paraphenylenediamine structure in the molecule The charge-transporting composition containing the derivative only provides a charge-transporting thin film having a low extinction coefficient (k), good transparency, and a high refractive index (n), as compared with the case of using an aniline derivative having a similar structure. In addition, the present inventors have found that the composition itself has excellent storage stability, and that the present invention provides an organic EL device having excellent characteristics when the charge transporting thin film is applied to a hole injection layer or the like. I let it.

Therefore, the present invention provides the following charge transporting composition.
1. A charge transport composition containing an aniline derivative represented by the following formula (1).

[In the formula, each Ar is independently a group represented by any of the following formulas (Ar1) to (Ar9).

(Wherein, R ¹ to R ²¹ each independently represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may be substituted by Z ¹ , or a C 2 to 20 carbon atom which may be substituted by Z ¹ alkenyl groups, Z ¹ at carbon atoms which may be substituted have 2-20 alkynyl group, which may prime be substituted by an aryl group, or Z ² of which may 6 carbon atoms also be ~ 20 substituted by Z ² 2-20 heteroaryl groups,
Z ¹ is a halogen atom, a nitro group, a cyano group, a heteroaryl group aryl or Z ³ which do 2-20 carbon atoms substituted with Z ³ are carbon atoms that may 6 to be 20 substituted with Yes,
Z ² is a halogen atom, a nitro group, a cyano group, Z ^{3-substituted} of having 1 to 20 carbon atoms in the alkyl group, an alkenyl group of Z ³ is 1-2 carbon atoms which may be 20 substituted by or Z An alkynyl group having 2 to 20 carbon atoms which may be substituted by ³ ,
Z ³ is a halogen atom, a nitro group or a cyano group. )]
2. 1. The charge transporting composition according to 1, wherein Ar is the same group.
3. 2. The charge transporting composition according to 2, wherein Ar is a group represented by any one of formulas (Ar1) to (Ar5).
4. 3. The charge transporting composition according to 3, wherein Ar is a group represented by the formula (Ar1).
5. The charge transporting composition according to any one of 1 to 4, further comprising a dopant.
6. 5. The charge transporting composition according to 5, wherein the dopant is an arylsulfonic acid ester compound.
7. A charge transporting thin film produced using the charge transporting composition of any one of 1 to 5.
An organic EL device comprising the charge transporting thin film of 8.7.

By using the charge transporting composition of the present invention, compared to the case of using a composition containing an aniline derivative having a similar structure, a charge having high transparency (low extinction coefficient (k)) and high refractive index (n) is used. A transportable thin film can be manufactured. Further, the charge transporting composition of the present invention is superior in storage stability to a composition containing an aniline derivative having a similar structure. The charge transporting thin film obtained from the charge transporting composition of the present invention can be suitably used as a thin film for an electronic element such as an organic EL element, and is provided between an anode and a light emitting layer of the organic EL element. An organic EL device having excellent characteristics can be obtained by using it as a functional layer, in particular, a hole injection layer.

[Charge transporting composition]
The charge transporting composition of the present invention contains an aniline derivative represented by the following formula (1).

In the formula (1), each Ar is independently a group represented by any of the following formulas (Ar1) to (Ar9).

In the formulas (Ar1) to (Ar9), R ¹ to R ²¹ each independently represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may be substituted by Z ¹ , and which may be substituted by Z ^1. an alkenyl group having 2 to 20 carbon atoms, substituted with an aryl group, or Z ² alkynyl group, Z ² is optionally carbon atoms 6 to be 20 substituted with Z ¹ to 2 carbon atoms which may be ~ 20 substituted by And a heteroaryl group having 2 to 20 carbon atoms. Z ¹ is a halogen atom, a nitro group, a cyano group, a heteroaryl group aryl or Z ³ which do 2-20 carbon atoms substituted with Z ³ are carbon atoms that may 6 to be 20 substituted with is there. Z ² is a halogen atom, a nitro group, a cyano group, Z ^{3-substituted} of having 1 to 20 carbon atoms in the alkyl group, an alkenyl group of Z ³ is 1-2 carbon atoms which may be 20 substituted by or Z An alkynyl group having 2 to 20 carbon atoms which may be substituted by ³ ; Z ³ is a halogen atom, a nitro group or a cyano group.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.

The alkyl group having 1 to 20 carbon atoms may be linear, branched, or cyclic, and specific examples thereof include methyl, ethyl, n-propyl, isopropyl, n-butyl, and isobutyl. Group having 1 to 20 carbon atoms, such as a s-butyl group, a s-butyl group, a t-butyl group, a n-pentyl group, a n-hexyl group, a n-heptyl group, a n-octyl group, a n-nonyl group and a n-decyl group. A chain or branched alkyl group; and a cyclic alkyl group having 3 to 20 carbon atoms such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, and a cyclodecyl group.

The alkenyl group having 2 to 20 carbon atoms may be linear, branched or cyclic, and specific examples thereof include ethenyl, n-1-propenyl, n-2-propenyl, 1-methylethenyl Group, n-1-butenyl group, n-2-butenyl group, n-3-butenyl group, 2-methyl-1-propenyl group, 2-methyl-2-propenyl group, 1-ethylethenyl group, 1-methyl- Examples thereof include a 1-propenyl group, a 1-methyl-2-propenyl group, an n-1-pentenyl group, and an n-1-decenyl group.

The alkynyl group having 2 to 20 carbon atoms may be linear, branched or cyclic, and specific examples thereof include an ethynyl group, an n-1-propynyl group, an n-2-propynyl group, and an n-1 -Butynyl group, n-2-butynyl group, n-3-butynyl group, 1-methyl-2-propynyl group, n-1-pentynyl group, n-2-pentynyl group, n-3-pentynyl group, n- 4-pentynyl group, 1-methyl-n-butynyl group, 2-methyl-n-butynyl group, 3-methyl-n-butynyl group, 1,1-dimethyl-n-propynyl group, n-1-hexynyl group, and n-1-decynyl group.

Specific examples of the aryl group having 6 to 20 carbon atoms include phenyl, tolyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl, 9-anthryl, and 1-phenanthryl. , 2-phenanthryl, 3-phenanthryl, 4-phenanthryl, 9-phenanthryl and the like.

Specific examples of the heteroaryl group having 2 to 20 carbon atoms include a 2-thienyl group, a 3-thienyl group, a 2-furanyl group, a 3-furanyl group, a 2-oxazolyl group, a 4-oxazolyl group, and a 5-oxazolyl group. , 3-isoxazolyl, 4-isoxazolyl, 5-isoxazolyl and other oxygen-containing heteroaryl groups, 2-thiazolyl, 4-thiazolyl, 5-thiazolyl, 3-isothiazolyl, 4-isothiazolyl, 5-isothiazolyl, Sulfur-containing heteroaryl groups such as isothiazolyl group, 2-imidazolyl group, 4-imidazolyl group, 2-pyridyl group, 3-pyridyl group, 4-pyridyl group, 2-pyrazyl group, 3-pyrazyl group, 5-pyrazyl group, 6-pyrazyl group, 2-pyrimidyl group, 4-pyrimidyl group, 5-pyrimidyl group, 6-pyrimidyl group, 3-pyridazyl group, -Pyridazyl group, 5-pyridazyl group, 6-pyridazyl group, 1,2,3-triazin-4-yl group, 1,2,3-triazin-5-yl group, 1,2,4-triazin-3- Yl, 1,2,4-triazin-5-yl, 1,2,4-triazin-6-yl, 1,3,5-triazin-2-yl, 1,2,4,5- Tetrazin-3-yl, 1,2,3,4-tetrazin-5-yl, 2-quinolinyl, 3-quinolinyl, 4-quinolinyl, 5-quinolinyl, 6-quinolinyl, 7-quinolinyl Group, 8-quinolinyl group, 1-isoquinolinyl group, 3-isoquinolinyl group, 4-isoquinolinyl group, 5-isoquinolinyl group, 6-isoquinolinyl group, 7-isoquinolinyl group, 8-isoquinolinyl group, 2-quinoxanyl group, 5-quinoxanyl A 6-quinoxanyl group, -Quinazolinyl group, 4-quinazolinyl group, 5-quinazolinyl group, 6-quinazolinyl group, 7-quinazolinyl group, 8-quinazolinyl group, 3-cinnolinyl group, 4-cinnolinyl group, 5-cinnolinyl group, 6-cinnolinyl group, 7 And nitrogen-containing heteroaryl groups such as -cinnolinyl group and 8-cinnolinyl group.

Among these, as R ¹ - R ^21, an aryl group Z ² are carbon atoms 6 also be ~ 20 substituted with a heteroaryl group Z ² is optionally 2-20 carbon atoms preferably substituted with, Z more preferably an aryl group which may having 6 to 20 carbon atoms optionally substituted by ² phenyl group which may be substituted with Z ^2, which may be substituted with Z ² 1-naphthyl group, substituted with Z ² An optionally substituted 2-naphthyl group is even more preferred. As the Z ^2, a halogen atom, an alkyl group of Z ³ are optionally to 1 to 20 carbon atoms substituted with an alkenyl group Z ³ are optionally 2-20 carbon atoms substituted with preferred. As Z ³ , a halogen atom is preferable, and a fluorine atom is more preferable.

In the present invention, from the viewpoint of ease of synthesis of the aniline derivative, it is preferable that Ars are all the same. Further, from the viewpoint of improving the solubility of the aniline derivative in an organic solvent and obtaining a highly uniform composition with good reproducibility, a group represented by any one of formulas (Ar1) to (Ar5) is preferable. The group represented by Ar1) is optimal.

Hereinafter, specific examples of the aniline derivative suitable for the present invention will be described, but the present invention is not limited thereto.

(In the formula, Ph is a phenyl group.)

The aniline derivative used in the present invention may be a paraphenylenediamine (1,4-phenylenediamine) and a halogenated or pseudohalogenated carbazole derivative Ar-X (where Ar is the same as described above; X is a halogen atom) in the presence of a catalyst. Or a pseudohalogen group).

Examples of the halogen atom include the same as described above, but a chlorine atom, a bromine atom and an iodine atom are preferable. Examples of the pseudohalogen group include a (fluoro) alkylsulfonyloxy group such as a methanesulfonyloxy group, a trifluoromethanesulfonyloxy group, and a nonafluorobutanesulfonyloxy group; and an aromatic sulfonyloxy group such as a benzenesulfonyloxy group and a toluenesulfonyloxy group. And the like.

The charge ratio of the 1,4-phenylenediamine to the halogenated or pseudohalogenated carbazole derivative is such that the halogenated or pseudohalogenated carbazole derivative is at least equivalent to the total amount of NH groups in 1,4-phenylenediamine. However, about 1 to 1.2 equivalents are preferred.

Examples of the catalyst used in the reaction include copper catalysts such as copper chloride, copper bromide, and copper iodide; tetrakis (triphenylphosphine) palladium (Pd (PPh ₃ ) ₄ ), bis (triphenylphosphine) dichloropalladium (Pd (PPh ₃ ) ₂ Cl ₂ ), bis (dibenzylideneacetone) palladium (Pd (dba) ₂ ), tris (dibenzylideneacetone) dipalladium (Pd ₂ (dba) ₃ ), bis [tri (t-butyl) Phosphine)] palladium catalysts such as palladium (Pd (Pt-Bu ₃ ) ₂ ) and palladium acetate (Pd (OAc) ₂ ). These catalysts may be used alone or in combination of two or more.

These catalysts may be used together with a known suitable ligand. Such ligands include triphenylphosphine, tri-o-tolylphosphine, diphenylmethylphosphine, phenyldimethylphosphine, trimethylphosphine, triethylphosphine, tributylphosphine, tri-t-butylphosphine, di-t-butyl ( Phenyl) phosphine, di-t-butyl (4-dimethylaminophenyl) phosphine, 1,2-bis (diphenylphosphino) ethane, 1,3-bis (diphenylphosphino) propane, 1,4-bis (diphenyl) Examples include tertiary phosphines such as phosphino) butane and 1,1′-bis (diphenylphosphino) ferrocene, and tertiary phosphites such as trimethyl phosphite, triethyl phosphite and triphenyl phosphite.

The amount of the catalyst used can be about 0.01 to 0.2 mol, preferably about 0.15 mol, per 1 mol of the halogenated or pseudohalogenated carbazole derivative.
When a ligand is used, the amount of the ligand used can be 0.1 to 5 equivalents to the catalyst to be used, but is preferably 1 to 2 equivalents.

場合 Each of the above-mentioned reactions is carried out in a solvent when all the starting compounds are solid or from the viewpoint of efficiently obtaining the desired aniline derivative. When a solvent is used, its type is not particularly limited as long as it does not adversely affect the reaction. Specific examples include aliphatic hydrocarbons (pentane, n-hexane, n-octane, n-decane, decalin, etc.), halogenated aliphatic hydrocarbons (chloroform, dichloromethane, dichloroethane, carbon tetrachloride, etc.), aromatics Aromatic hydrocarbons (benzene, nitrobenzene, toluene, o-xylene, m-xylene, p-xylene, mesitylene, etc.), halogenated aromatic hydrocarbons (chlorobenzene, bromobenzene, o-dichlorobenzene, m-dichlorobenzene, p-dichlorobenzene, etc.), ethers (diethyl ether, diisopropyl ether, t-butyl methyl ether, tetrahydrofuran, dioxane, 1,2-dimethoxyethane, 1,2-diethoxyethane, etc.), ketones (acetone, methyl ethyl ketone, Methyl isobutyl ketone, di-n Butyl ketone, cyclohexanone, etc.), amides (N, N-dimethylformamide, N, N-dimethylacetamide, etc.), lactams and lactones (N-methylpyrrolidone, γ-butyrolactone, etc.), ureas (N, N-dimethylimidazo) Examples include, but are not limited to, ridinone, tetramethylurea, etc., sulfoxides (dimethylsulfoxide, sulfolane, etc.), nitriles (acetonitrile, propionitrile, butyronitrile, etc.). These solvents may be used alone or in a combination of two or more.

The reaction temperature may be appropriately set in the range from the melting point to the boiling point of the solvent to be used, but is usually in the range of about 0 to 200 ° C, preferably in the range of 20 to 150 ° C. After completion of the reaction, a post-treatment is carried out according to a conventional method to obtain a desired aniline derivative.

電荷 The charge transporting composition of the present invention contains an organic solvent. As such an organic solvent, a highly soluble solvent that can satisfactorily dissolve the aniline derivative represented by the formula (1), which is a charge transporting substance, can be used. Specific examples of the highly soluble solvent include, for example, cyclohexanone, N, N-dimethylformamide, N, N-dimethylacetamide, N, N-dimethylisobutyramide, N-methylpyrrolidone, 1,3-dimethyl-2-imidazo Examples include, but are not limited to, organic solvents such as lydinone and diethylene glycol monomethyl ether. These solvents may be used alone or in a combination of two or more. The amount used can be 5 to 100% by mass based on the whole solvent used in the composition.

Further, the composition has a viscosity of 10 to 200 mPa · s at 25 ° C., particularly 35 to 150 mPa · s, and a high viscosity organic solvent having a boiling point of 50 to 300 ° C., particularly 150 to 250 ° C. at normal pressure (atmospheric pressure). , The viscosity of the composition can be easily adjusted, and as a result, it is possible to prepare a composition that gives a highly planar thin film with good reproducibility and that is suitable for the application method used. Examples of the high-viscosity organic solvent include cyclohexanol, ethylene glycol, ethylene glycol diglycidyl ether, 1,3-octylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, 1,3-butanediol, Examples include, but are not limited to, 2,3-butanediol, 1,4-butanediol, propylene glycol, hexylene glycol, and the like. These solvents may be used alone or in a combination of two or more. The addition ratio of the high-viscosity organic solvent to the entire solvent used in the composition is preferably within a range in which no solid precipitates, and as long as no solid precipitates, the addition ratio is preferably 5 to 80% by mass.

Further, for the purpose of improving the wettability to the substrate, adjusting the surface tension of the solvent, adjusting the polarity, adjusting the boiling point, and the like, another solvent is used in an amount of 1 to 90% by mass, preferably 1 to 90% by mass based on the whole solvent used in the composition. Can be mixed at a ratio of 1 to 50% by mass. Examples of such a solvent include propylene glycol monomethyl ether, ethylene glycol monobutyl ether, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, diethylene glycol. Examples include, but are not limited to, monoethyl ether, diacetone alcohol, γ-butyrolactone, ethyl lactate, n-hexyl acetate, and the like. These solvents may be used alone or in a combination of two or more.

Further, when the aniline derivative represented by the formula (1) has an aryl group on the nitrogen atom at the 9-position of the carbazole moiety in the molecule, the aniline derivative is substituted on at least one nitrogen atom in the molecule. In the case of having a group, preferably in the case of having a substituent on all nitrogen atoms, preparation of a composition using only a low-polarity solvent is facilitated. Specific examples of such low-polarity solvents include chlorinated solvents such as chloroform and chlorobenzene; aromatic hydrocarbon-based solvents such as toluene, xylene, tetralin, cyclohexylbenzene, and decylbenzene; 1-octanol, 1-nonanol, -Aliphatic alcohol solvents such as decanol; tetrahydrofuran, dioxane, anisole, 4-methoxytoluene, 3-phenoxytoluene, dibenzyl ether, diethylene glycol dimethyl ether, diethylene glycol butyl methyl ether, triethylene glycol dimethyl ether, triethylene glycol butyl methyl ether, etc. Ether solvents: methyl benzoate, ethyl benzoate, butyl benzoate, dimethyl phthalate, diethyl maleate, isoamyl benzoate, bis (2 -Ethylhexyl), dibutyl maleate, dibutyl oxalate, hexyl acetate, ester solvents such as diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, and the like, but are not limited thereto. These solvents may be used alone or in a combination of two or more.

The charge transporting composition of the present invention may contain water as a solvent, but when the charge transporting thin film obtained from the composition is used as a hole injection layer of an organic EL device, a highly durable device can be reproducibly prepared. From the viewpoint of obtaining, the content of water is preferably 10% by mass or less, more preferably 5% by mass or less of the whole solvent, and it is optimal to use only an organic solvent as the solvent. In this case, "only organic solvent" means that only the organic solvent is used as the solvent, and denies the existence of "water" contained in a trace amount in the organic solvent or solid content used. It does not do. In the present invention, the solid content means components other than the solvent contained in the charge transporting composition.

電荷 The charge transporting composition of the present invention may contain other charge transporting substances in addition to the charge transporting substance comprising the aniline derivative represented by the formula (1).

The charge transporting composition of the present invention contains a charge transporting substance composed of the aniline derivative represented by the formula (1) and an organic solvent. The charge transporting ability is improved depending on the use of the obtained thin film. It may contain a dopant (charge-accepting substance) for the purpose.

The dopant is not particularly limited as long as it is soluble in at least one kind of solvent used in the composition, and either an inorganic dopant or an organic dopant can be used. Further, the inorganic and organic dopants may be used alone or in combination of two or more. Further, during the process of obtaining a charge-transporting thin film as a solid film from the composition, for example, the function as a dopant is expressed for the first time because a part of the molecule comes off due to an external stimulus such as heating during baking. Alternatively, a substance capable of improving, for example, an arylsulfonic acid ester compound in which a sulfonic acid group is protected with a group which is easily eliminated may be used.

The amount of the dopant substance in the composition cannot be specified unconditionally because it differs depending on the desired degree of charge transporting property and the kind of the dopant substance, but usually, the amount of the dopant substance is based on the mass of the aniline derivative 1 represented by the formula (1). The ratio is in the range of 0.0001 to 100.

In the present invention, heteropolyacid is preferred as the inorganic dopant. The heteropolyacid typically has a structure in which a hetero atom is located at the center of a molecule, represented by a Keggin-type chemical structure represented by the following formula (H1) or a Dawson-type chemical structure represented by the following formula (H2). Further, it is a polyacid obtained by condensing isopolyacid which is an oxygen acid such as vanadium (V), molybdenum (Mo), and tungsten (W) with oxygen acid of a different element. Examples of such different types of oxyacids include oxyacids of silicon (Si), phosphorus (P), and arsenic (As).

具体 Specific examples of the heteropolyacid include phosphomolybdic acid, silicomolybdic acid, phosphotungstic acid, silicotungstic acid, and phosphorus tungstomolybdic acid. These heteropoly acids may be used alone or in combination of two or more. These heteropoly acids are available as commercial products, and can also be synthesized by known methods.

Especially, when one kind of heteropolyacid is used, the one kind of heteropolyacid is preferably phosphotungstic acid or phosphomolybdic acid, and most preferably phosphotungstic acid. When two or more heteropoly acids are used, one of the two or more heteropoly acids is preferably phosphotungstic acid or phosphomolybdic acid, more preferably phosphotungstic acid.

In addition, the heteropolyacid, in a quantitative analysis such as elemental analysis, the number of elements is large or small from the structure represented by the general formula, even if it is obtained as a commercial product, or a known synthetic As long as it is appropriately synthesized according to the method, it can be used in the present invention. That is, for example, phosphotungstic acid is generally represented by the chemical formula H ₃ (PW ₁₂ O ₄₀ ) · nH ₂ O, and phosphomolybdic acid is generally represented by the chemical formula H ₃ (PMo ₁₂ O ₄₀ ) · nH ₂ O. In quantitative analysis, even if the number of P (phosphorus), O (oxygen) or W (tungsten) or Mo (molybdenum) in this formula is large or small, it is obtained as a commercial product; Alternatively, it can be used in the present invention as long as it is appropriately synthesized according to a known synthesis method. In this case, the mass of the heteropolyacid specified in the present invention is not the mass of pure phosphotungstic acid (phosphotungstic acid content) in a synthetic product or a commercial product, but a commercially available product and a known synthetic polytungstic acid. In the form that can be isolated by the method, it means the total mass in the state containing water of hydration and other impurities.

When a heteropolyacid is used as a dopant, the amount of the heteropolyacid can be about 0.001 to 50.0 in terms of a mass ratio with respect to the aniline derivative 1 represented by the formula (1). It is about 0.01 to 20.0, more preferably about 0.1 to 10.0.

On the other hand, preferable organic dopants include a tetracyanoquinodimethane derivative and a benzoquinone derivative. Specific examples of the tetracyanoquinodimethane derivative include 7,7,8,8-tetracyanoquinodimethane (TCNQ) and halotetracyanoquinodimethane represented by the following formula (H3). Specific examples of the benzoquinone derivative include tetrafluoro-1,4-benzoquinone (F4BQ), tetrachloro-1,4-benzoquinone (chloranil), tetrabromo-1,4-benzoquinone, 2,3-dichloro-5, 6-dicyano-1,4-benzoquinone (DDQ) and the like.

In the formula (H3), R ¹⁰¹ to R ¹⁰⁴ independently represent a hydrogen atom or a halogen atom, but at least one is a halogen atom, preferably at least two are halogen atoms, and at least three are halogen atoms. More preferably, all are halogen atoms. Examples of the halogen atom include the same as described above, but a fluorine atom or a chlorine atom is preferable, and a fluorine atom is more preferable.

Specific examples of such halotetracyanoquinodimethane include 2-fluoro-7,7,8,8-tetracyanoquinodimethane, 2-chloro-7,7,8,8-tetracyanoquinodimethane 2,5-difluoro-7,7,8,8-tetracyanoquinodimethane, 2,5-dichloro-7,7,8,8-tetracyanoquinodimethane, 2,3,5,6-tetra Chloro-7,7,8,8-tetracyanoquinodimethane, 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) and the like.

When a tetracyanoquinodimethane derivative or a benzoquinone derivative is used as a dopant, the amount thereof is 0.01 to 20.0 in terms of the amount (mol) of the aniline derivative 1 represented by the formula (1). Although it can be about 0.1 to 10.0, it is preferably about 0.1 to 10.0, and more preferably about 0.5 to 5.0.

Other preferred organic dopants include aryl sulfonic acid compounds. Specific examples thereof include benzenesulfonic acid, tosylic acid, p-styrenesulfonic acid, 2-naphthalenesulfonic acid, 4-hydroxybenzenesulfonic acid, 5-sulfosalicylic acid, p-dodecylbenzenesulfonic acid, dihexylbenzenesulfonic acid, and 5,5-dihexylbenzenesulfonic acid, dibutylnaphthalenesulfonic acid, 6,7-dibutyl-2-naphthalenesulfonic acid, dodecylnaphthalenesulfonic acid, 3-dodecyl-2-naphthalenesulfonic acid, hexylnaphthalenesulfonic acid, 4-hexyl-1 -Naphthalenesulfonic acid, octylnaphthalenesulfonic acid, 2-octyl-1-naphthalenesulfonic acid, hexylnaphthalenesulfonic acid, 7-hexyl-1-naphthalenesulfonic acid, 6-hexyl-2-naphthalenesulfonic acid, dinonylnaphthalene Rufonic acid, 2,7-dinonyl-4-naphthalenesulfonic acid, dinonylnaphthalenedisulfonic acid, 2,7-dinonyl-4,5-naphthalenedisulfonic acid, 1,4-benzodioxane described in WO 2005/000832 Disulfonic acid compounds, aryl sulfonic acid compounds described in WO 2006/025342, and aryl sulfonic acid compounds described in WO 2009/096352.

More specifically, an arylsulfonic acid compound represented by the following formula (H4) or (H5) can be mentioned.

In the formula (H4), A ¹ represents O or S, and O is preferable. A ² is a (q + 1) -valent group derived from naphthalene or anthracene (that is, a group obtained by removing (q + 1) hydrogen atoms from naphthalene or anthracene), and a group derived from naphthalene is preferable. A ³ is a p-valent group derived from perfluorobiphenyl (that is, a group obtained by removing p fluorine atoms from perfluorobiphenyl). p represents the number of bonds between A ¹ and A ³ and is an integer satisfying 2 ≦ p ≦ 4, preferably 2. At this time, A ³ is a perfluorobiphenyldiyl group, preferably a perfluorobiphenyl-4,4′-diyl group. q represents the number of sulfonic acid groups bonded to A ² and is an integer satisfying 1 ≦ q ≦ 4, and 2 is most preferable.

In the formula (H5), A ⁴ to A ⁸ each independently represent a hydrogen atom, a halogen atom, a cyano group, an alkyl group having 1 to 20 carbon atoms, a halogenated alkyl group having 1 to 20 carbon atoms or a group having 2 to 2 carbon atoms. Among the 20 alkenyl halide groups, at least three of A ⁴ to A ⁸ are halogen atoms.

Examples of the halogenated alkyl group having 1 to 20 carbon atoms include trifluoromethyl, 2,2,2-trifluoroethyl, 1,1,2,2,2-pentafluoroethyl, 3,3,3-trifluoropropyl 2,2,3,3,3-pentafluoropropyl, 1,1,2,2,3,3,3-heptafluoropropyl, 4,4,4-trifluorobutyl, 3,3,4,4 , 4-pentafluorobutyl, 2,2,3,3,4,4,4-heptafluorobutyl, 1,1,2,2,3,3,4,4,4-nonafluorobutyl and the like Can be Examples of the halogenated alkenyl group having 2 to 20 carbon atoms include a perfluorovinyl group, a perfluoro-1-propenyl group, a perfluoro-2-propenyl group, a perfluorobutenyl group, and the like. In addition, examples of the halogen atom and the alkyl group having 1 to 20 carbon atoms include the same as described above, and the halogen atom is preferably a fluorine atom.

Among them, A ⁴ to A ⁸ include a hydrogen atom, a halogen atom, a cyano group, an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, and a halogenated alkenyl having 2 to 10 carbon atoms. And at least three of A ⁴ to A ⁸ are preferably a fluorine atom, such as a hydrogen atom, a fluorine atom, a cyano group, an alkyl group having 1 to 5 carbon atoms, and a fluorine atom having 1 to 5 carbon atoms. It is an alkyl group or an alkenyl fluoride group having 2 to 5 carbon atoms, and at least three of A ⁴ to A ⁸ are more preferably a fluorine atom, and a hydrogen atom, a fluorine atom, a cyano group, a carbon atom More preferably, it is a perfluoroalkyl group having 1 to 5 or a perfluoroalkenyl group having 1 to 5 carbon atoms, and A ⁴ , A ⁵ and A ⁸ are fluorine atoms. Note that a perfluoroalkyl group is a group in which all hydrogen atoms of an alkyl group are substituted with fluorine atoms, and a perfluoroalkenyl group is a group in which all hydrogen atoms of an alkenyl group are substituted with fluorine atoms.

ＲIn the formula (H5), r represents the number of sulfonic acid groups bonded to the naphthalene ring, and is an integer satisfying 1 ≦ r ≦ 4, preferably 2 to 4, and most preferably 2.

Hereinafter, specific examples of preferred arylsulfonic acid compounds will be described, but the invention is not limited thereto.

When an aryl sulfonic acid compound is used as a dopant, the amount of the aryl sulfonic acid compound is preferably about 0.01 to 20.0 in terms of a substance amount (mole) ratio to the aniline derivative 1 represented by the formula (1). It is preferably about 0.4 to 5.0. The arylsulfonic acid compound may be a commercially available product, but can also be synthesized by a known method described in International Publication No. WO 2006/025342, International Publication No. 2009/096352, and the like.

Other preferred organic dopants include arylsulfonic acid ester compounds. Specific examples thereof include an arylsulfonic acid ester compound disclosed in International Publication No. 2017/217455 and an arylsulfonic acid ester compound disclosed in International Publication No. 2017/217457.

More specifically, as the arylsulfonic acid ester compound, a compound represented by any of the following formulas (H6) to (H8) is preferable.

中 In the formulas (H6) to (H8), m is an integer satisfying 1 ≦ m ≦ 4, preferably 2. n is an integer satisfying 1 ≦ n ≦ 4, preferably 2.

In the formula (H6), A ¹¹ is an m-valent group derived from perfluorobiphenyl. A ¹² is —O— or —S—, preferably —O—. A ¹³ is a (n + 1) -valent group derived from naphthalene or anthracene, and is preferably a group derived from naphthalene.

R ^s1 to R ^s4 each independently represent a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms, and R ^s5 represents an ^optionally substituted 2 to 20 carbon atoms. Is a multivalent hydrocarbon group. Examples of the linear or branched alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an s-butyl group and a t-butyl group. , N-hexyl group and the like. Among these, an alkyl group having 1 to 3 carbon atoms is preferable. The monovalent hydrocarbon group having 2 to 20 carbon atoms may be linear, branched, or cyclic, and specific examples thereof include an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, and an isobutyl group. And an alkyl group such as a t-butyl group; and an aryl group such as a phenyl, naphthyl and phenanthryl group.

In particular, among R ^s1 to R ^s4 , R ^s1 or R ^s3 is a straight-chain alkyl group having 1 to 3 carbon atoms, and the remainder is a hydrogen atom, or R ^s1 is a straight-chain alkyl group having 1 to 3 carbon atoms. And it is preferred that R ^s2 to R ^s4 are hydrogen atoms. In this case, the straight-chain alkyl group having 1 to 3 carbon atoms is preferably a methyl group. Further, as R ^s5 , a linear alkyl group having 2 to 4 carbon atoms or a phenyl group is preferable.

In the formula (H7), A ¹⁴ is an optionally substituted m-valent hydrocarbon group having 6 to 20 carbon atoms and containing one or more aromatic rings, wherein the hydrocarbon group is one or more A group obtained by removing m hydrogen atoms from a hydrocarbon compound having 6 to 20 carbon atoms including an aromatic ring. Examples of such a hydrocarbon compound include benzene, toluene, xylene, ethylbenzene, biphenyl, naphthalene, anthracene, and phenanthrene. In the hydrocarbon group, part or all of the hydrogen atoms may be further substituted with a substituent. Examples of such a substituent include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and a nitro atom. Group, cyano group, hydroxy group, amino group, silanol group, thiol group, carboxy group, sulfonic acid ester group, phosphoric acid group, phosphoric acid ester group, ester group, thioester group, amide group, monovalent hydrocarbon group, organo Examples include an oxy group, an organoamino group, an organosilyl group, an organothio group, an acyl group, and a sulfo group. Among them, A ¹⁴ is preferably a group derived from benzene, biphenyl and the like.

In the formula (H7), A ¹⁵ is —O— or —S—, preferably —O—.

In the formula (H7), A ¹⁶ is a (n + 1) -valent aromatic hydrocarbon group having 6 to 20 carbon atoms, and the aromatic hydrocarbon group is an aromatic hydrocarbon compound having 6 to 20 carbon atoms. It is a group obtained by removing (n + 1) hydrogen atoms from the ring. Examples of such aromatic hydrocarbon compounds include benzene, toluene, xylene, biphenyl, naphthalene, anthracene, and pyrene. Among them, A ¹⁶ is preferably a group derived from naphthalene or anthracene, and more preferably a group derived from naphthalene.

In the formula (H7), R ^s6 and R ^s7 are each independently a hydrogen atom or a linear or branched monovalent aliphatic hydrocarbon group, and R ^s8 is a linear or branched monovalent aliphatic hydrocarbon group. It is a valent aliphatic hydrocarbon group. However, the total number of carbon atoms of R ^s6 , R ^s7 and R ^s8 is 6 or more. The upper limit of the total number of carbon atoms of R ^s6 , R ^s7 and R ^s8 is not particularly limited, but is preferably 20 or less, and more preferably 10 or less. Specific examples of the linear or branched monovalent aliphatic hydrocarbon group include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t- C1-C20 alkyl groups such as butyl group, n-hexyl group, n-octyl group, 2-ethylhexyl group and decyl group; vinyl group, 1-propenyl group, 2-propenyl group, isopropenyl group, 1- Examples thereof include an alkenyl group having 2 to 20 carbon atoms such as a methyl-2-propenyl group, a 1-butenyl group, a 2-butenyl group, a 3-butenyl group, and a hexenyl group. Among them, R ^s6 is preferably a hydrogen atom, and R ^s7 and R ^s8 are each independently preferably an alkyl group having 1 to 6 carbon atoms.

In the formula (H8), R ^s9 to R ^s13 each independently represent a hydrogen atom, a nitro group, a cyano group, a halogen atom, an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, or It is a halogenated alkenyl group having 2 to 10 carbon atoms.

The alkyl group having 1 to 10 carbon atoms may be linear, branched or cyclic, and specific examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group and an isobutyl group. Group, s-butyl group, t-butyl group, n-pentyl group, cyclopentyl group, n-hexyl group, cyclohexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group and the like. Can be

The halogenated alkyl group having 1 to 10 carbon atoms is not particularly limited as long as part or all of the hydrogen atoms of the alkyl group having 1 to 10 carbon atoms are substituted with halogen atoms. Specific examples thereof include a trifluoromethyl group, a 2,2,2-trifluoroethyl group, a 1,1,2,2,2-pentafluoroethyl group, a 3,3,3-trifluoropropyl group, 2,3,3,3-pentafluoropropyl group, 1,1,2,2,3,3,3-heptafluoropropyl group, 4,4,4-trifluorobutyl group, 3,3,4,4 , 4-pentafluorobutyl group, 2,2,3,3,4,4,4-heptafluorobutyl group, 1,1,2,2,3,3,4,4,4-nonafluorobutyl group, etc. Is mentioned.

The halogenated alkenyl group having 2 to 10 carbon atoms is not particularly limited as long as part or all of the hydrogen atoms of the alkenyl group having 2 to 10 carbon atoms are substituted with halogen atoms. Specific examples thereof include a perfluorovinyl group, a perfluoro-1-propenyl group, a perfluoro-2-propenyl group, a perfluoro-1-butenyl group, a perfluoro-2-butenyl group, and a perfluoro-3-butenyl group. And the like.

Among them, as R ^s9 , a nitro group, a cyano group, a halogenated alkyl group having 1 to 10 carbon atoms and an alkenyl halide group having 2 to 10 carbon atoms are preferable, and a nitro group, a cyano group, and a carbon atom having 1 to 4 carbon atoms are preferable. Are more preferable, and a nitro group, a cyano group, a trifluoromethyl group and a perfluoropropenyl group are more preferable.

In the formula (H8), R ^s10 to R ^s13 are preferably a halogen atom, more preferably a fluorine atom.

In the formula (H8), A ¹⁷ is —O—, —S— or —NH—, preferably —O—.

In the formula (H8), A ¹⁸ is an (n + 1) -valent aromatic hydrocarbon group having 6 to 20 carbon atoms, and this aromatic hydrocarbon group is an aromatic hydrocarbon compound having 6 to 20 carbon atoms. It is a group obtained by removing (n + 1) hydrogen atoms from the ring. Examples of such aromatic hydrocarbon compounds include benzene, toluene, xylene, biphenyl, naphthalene, anthracene, and pyrene. Among these, A ¹⁸ is preferably a group derived from naphthalene or anthracene, and more preferably a group derived from naphthalene.

In the formula (H8), R ^s14 to R ^s17 each independently represent a hydrogen atom or a linear or branched monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms. Specific examples of the monovalent aliphatic hydrocarbon group include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, C1-C20 alkyl groups such as cyclopentyl group, n-hexyl group, cyclohexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group and n-dodecyl group A group having 2 to 2 carbon atoms such as a vinyl group, a 1-propenyl group, a 2-propenyl group, an isopropenyl group, a 1-methyl-2-propenyl group, a 1-butenyl group, a 2-butenyl group, a 3-butenyl group and a hexenyl group; And 20 alkenyl groups. Among these, an alkyl group having 1 to 20 carbon atoms is preferable, an alkyl group having 1 to 10 carbon atoms is more preferable, and an alkyl group having 1 to 8 carbon atoms is still more preferable.

In the formula (H8), R ^s18 is a linear or branched monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms or OR ^s19 . R ^s19 is an ^optionally substituted monovalent hydrocarbon group having 2 to 20 carbon atoms. ^Examples of the linear or branched monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms represented by R ^s18 include the same as described above. When R ^s18 is a monovalent aliphatic hydrocarbon group, R ^s18 is preferably an alkyl group having 1 to 20 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms, and an alkyl group having 1 to 8 carbon atoms. Even more preferred. ^Examples of the monovalent hydrocarbon group having 2 to 20 carbon atoms represented by R ^s19 include the above-mentioned monovalent aliphatic hydrocarbon groups other than methyl group, and aryl groups such as phenyl group, naphthyl group and phenanthryl group. And the like. Among them, R ^s19 is preferably a straight-chain alkyl group having 2 to 4 carbon atoms or a phenyl group. Examples of the substituent which the monovalent hydrocarbon group may have include a fluorine atom, an alkoxy group having 1 to 4 carbon atoms, a nitro group and a cyano group.

Specific examples of suitable arylsulfonic acid ester compounds include, but are not limited to, the following.

When an arylsulfonic acid ester compound is used as a dopant, the amount of the arylsulfonic acid ester compound to be used is about 0.01 to 20.0 based on the aniline derivative 1 represented by the formula (1) in a substance amount (molar) ratio. However, it is preferably about 0.1 to 10.0, more preferably about 0.5 to 5.0.

When an organic dopant is used as the dopant, its molecular weight is not particularly limited, but when used together with the aniline derivative represented by the formula (1), good solubility in an organic solvent is ensured, and uniformity is ensured. From the viewpoint of obtaining a high composition with good reproducibility, it is preferably 5,000 or less, more preferably 3,000 or less, and even more preferably 2,000 or less. In particular, the molecular weight of the arylsulfonic acid compound used as the dopant is preferably 2,000 or less, more preferably 1,500 or less from the same viewpoint.

In the present invention, considering that a thin film with high charge transportability can be obtained with good reproducibility, availability of dopants, etc., as the dopant, arylsulfonic acid compounds, arylsulfonic acid ester compounds, halotetracyanoquinodimethane and benzoquinone It is preferable to use at least one derivative, and in view of obtaining a more transparent charge-transporting thin film with good reproducibility, it is more preferable to use at least one of arylsulfonic acid compounds and arylsulfonic acid ester compounds, When further considering obtaining a charge transporting composition having excellent stability, it is more preferable to use an arylsulfonic acid ester compound.

電荷 The charge transporting substance and the dopant are preferably completely dissolved or uniformly dispersed in the solvent, and most preferably completely dissolved.

The charge transporting composition of the present invention is used for improving the injection property into the hole transporting layer when the obtained thin film is used as a hole injecting layer of an organic EL device, and improving the life characteristics of the device. It may contain a compound or a nonionic fluorinated surfactant, and its content is usually about 1 to 30 parts by mass based on 100 parts by mass of the total of the charge transporting substance and the dopant.

The concentration of the solid content in the charge transporting composition of the present invention is generally about 0.1 to 20% by mass, preferably 0.5, from the viewpoint of securing a sufficient film thickness while suppressing the deposition of the charge transporting substance. １５15% by mass.

The viscosity of the charge transporting composition of the present invention is usually 1 to 50 mPa · s at 25 ° C., and the surface tension is usually 20 to 50 mN / m at 25 ° C. The viscosity and surface tension of the charge transporting composition of the present invention are determined by changing the type of the organic solvent used, their ratio, the solid content, and the like, in consideration of various factors such as a coating method to be used and a desired film thickness. Can be adjusted.

電荷 The charge transporting composition of the present invention can be produced by dissolving the aniline derivative represented by the formula (1) in an organic solvent. The aniline derivative may be dissolved in an organic solvent in advance, and the other organic solvent may be sequentially added thereto. Alternatively, a mixed solvent of all the solvents to be used may be prepared in advance, and the aniline derivative may be dissolved therein. If necessary, the components contained in the composition may be heated so as to accelerate the dissolution of the aniline derivative and the like, while taking care not to decompose or deteriorate the components. The same method is followed when the charge transporting composition of the present invention contains components other than the aniline derivative and the solvent. Furthermore, the charge transporting composition of the present invention is obtained by dissolving the charge transporting substance in an organic solvent from the viewpoint of obtaining a thinner film having higher flatness with good reproducibility, and then filtering using a submicrometer-order filter or the like. May be.

[Charge transporting thin film]
By applying the charge transporting composition of the present invention on a substrate and baking it, a charge transporting thin film can be formed on the substrate.

塗布 The method of applying the composition is not particularly limited, and examples thereof include a dipping method, a spin coating method, a transfer printing method, a roll coating method, an ink jet method, a spray method, and a slit coating method. It is preferable to adjust the viscosity and surface tension of the composition according to the application method.

The firing atmosphere is not particularly limited, and a uniform thin film surface and a thin film having a charge transporting property can be obtained not only in an air atmosphere (under air) but also in an inert gas such as nitrogen or in a vacuum. Bake in an atmosphere.

焼成 Also, firing conditions are not particularly limited. For example, heating and firing are performed using a hot plate. In general, the firing temperature is appropriately determined within the range of 100 to 260 ° C., and the firing time is appropriately determined within the range of 1 minute to 1 hour in consideration of the desired charge transporting property. Further, if necessary, multi-stage firing may be performed at two or more different temperatures.

The thickness of the charge transporting thin film is not particularly limited, but is preferably 5 to 300 nm when used as a functional layer of an organic EL device. As a method of changing the film thickness, for example, there is a method of changing a solid concentration in the charge transporting composition or a method of changing a liquid amount at the time of application.

[Organic EL device]
The organic EL device of the present invention has a pair of electrodes, and has the charge transporting thin film of the present invention as a functional layer between these electrodes.

Representative configurations of the organic EL device include the following (a) to (f), but are not limited thereto. In the following configuration, an electron block layer or the like may be provided between the light emitting layer and the anode, and a hole (hole) block layer or the like may be provided between the light emitting layer and the cathode as necessary. Further, the hole injection layer, the hole transport layer, or the hole injection / transport layer may also have a function as an electron blocking layer or the like, and the electron injection layer, the electron transport layer, or the electron injection / transport layer may be a hole (hole). It may have a function as a block layer or the like. Further, an optional functional layer can be provided between the layers as needed.
(A) anode / hole injection layer / hole transport layer / emission layer / electron transport layer / electron injection layer / cathode (b) anode / hole injection layer / hole transport layer / emission layer / electron injection transport layer / Cathode (c) anode / hole injection / transport layer / emission layer / electron transport layer / electron injection layer / cathode (d) anode / hole injection / transport layer / emission layer / electron injection / transport layer / cathode (e) anode / positive Hole injection layer / hole transport layer / emission layer / cathode (f) anode / hole injection / transport layer / emission layer / cathode

“Hole injection layer”, “hole transport layer” and “hole injection transport layer” are layers formed between the light emitting layer and the anode, and transport holes from the anode to the light emitting layer. It has a function. When only one layer of the hole transporting material is provided between the light emitting layer and the anode, it is a “hole injection / transport layer”, and the layer of the hole transporting material is provided between the light emitting layer and the anode. Is provided, two or more layers are a "hole injection layer" and a layer near the anode is a "hole transport layer". In particular, as the hole injection (transport) layer, a thin film that is excellent in not only the property of accepting holes from the anode but also the property of injecting holes into the hole transport (emission) layer is used.

"Electron injection layer", "electron transport layer" and "electron injection transport layer" are layers formed between the light emitting layer and the cathode, and have a function of transporting electrons from the cathode to the light emitting layer. It is. When only one layer of the electron transporting material is provided between the light emitting layer and the cathode, it is an “electron injection and transport layer”, and two layers of the electron transporting material are provided between the light emitting layer and the cathode. When provided as described above, the layer close to the cathode is an “electron injection layer”, and the other layers are “electron transport layers”.

The “light-emitting layer” is an organic layer having a light-emitting function, and includes a host material and a dopant material when a doping system is employed. At this time, the host material mainly has a function of promoting recombination of electrons and holes and confining excitons in the light-emitting layer, and the dopant material efficiently emits excitons obtained by the recombination. Has functions. In the case of a phosphorescent element, a host material has a function of mainly confining excitons generated by a dopant in a light-emitting layer.

The charge transporting thin film of the present invention is suitable as a functional layer provided between an anode and a light emitting layer in an organic EL device, and is more suitable as a hole injection layer, a hole transport layer, and a hole injection transport layer. It is even more suitable as a hole injection layer.

材料 Materials and methods for producing an organic EL device using the charge transporting composition of the present invention include, but are not limited to, the following.

の一 An example of a method for producing an OLED device having a hole transport layer comprising a thin film obtained from the charge transport composition of the present invention is as follows. Note that the electrode is preferably subjected to cleaning with alcohol, pure water, or the like, or surface treatment such as UV ozone treatment or oxygen-plasma treatment in advance within a range that does not adversely affect the electrode.

(4) On the anode substrate, a hole injection layer composed of the charge transporting thin film of the present invention is formed by the method described above. This is introduced into a vacuum evaporation apparatus, and a hole transport layer, a light emitting layer, an electron transport layer, an electron transport layer / hole block layer, and a cathode metal are sequentially deposited. Alternatively, instead of forming the hole transporting layer and the light emitting layer by vapor deposition in the method, a composition for forming a hole transporting layer containing a hole transporting polymer and a composition for forming a light emitting layer containing a light emitting polymer Are used to form these layers by a wet process. Note that, if necessary, an electron block layer may be provided between the light emitting layer and the hole transport layer.

Examples of the anode material include a transparent electrode typified by indium tin oxide (ITO) and indium zinc oxide (IZO), and a metal anode composed of a metal typified by aluminum, an alloy thereof, and the like. It is preferable that the material has been subjected to a chemical treatment. A polythiophene derivative or a polyaniline derivative having a high charge transporting property can also be used. The other metal constituting the metal anode includes, but is not limited to, gold, silver, copper, indium and alloys thereof.

Examples of the material for forming the light emitting layer include aluminum complexes of 8-hydroxyquinoline such as tris (8-quinolinolato) aluminum (III) (Alq ₃ ) and bis (8-quinolinolato) zinc (II), and metal complexes such as zinc complex. Low molecular light emitting materials such as metal complexes of 10,10-hydroxybenzo [h] quinoline, bisstyrylbenzene derivatives, bisstyrylarylene derivatives, metal complexes of (2-hydroxyphenyl) benzothiazole, and silole derivatives; poly (p-phenylenevinylene) ), Poly [2-methoxy-5- (2-ethylhexyloxy) -1,4-phenylenevinylene], poly (3-alkylthiophene), polyvinylcarbazole, and other high molecular compounds mixed with a light emitting material and an electron transfer material And the like, but are not limited thereto. When the light emitting layer is formed by vapor deposition, the light emitting layer may be co-deposited with a light emitting dopant. The light emitting dopant may be a metal complex such as tris (2-phenylpyridine) iridium (III) (Ir (PPy) ₃ ). And naphthacene derivatives such as rubrene, quinacridone derivatives, condensed polycyclic aromatic rings such as perylene, and the like, but are not limited thereto.

材料 Materials for forming the electron transport layer / hole block layer include, but are not limited to, oxydiazole derivatives, triazole derivatives, phenanthroline derivatives, phenylquinoxaline derivatives, benzimidazole derivatives, and pyrimidine derivatives.

Materials for forming the electron injection layer include metal oxides such as lithium oxide (Li ₂ O), magnesium oxide (MgO), and alumina (Al ₂ O ₃ ), lithium fluoride (LiF), and sodium fluoride (NaF). But not limited to metal fluorides

Examples of the cathode material include, but are not limited to, aluminum, magnesium-silver alloy, aluminum-lithium alloy and the like.

材料 A material for forming the electron blocking layer includes, but is not limited to, tris (phenylpyrazole) iridium and the like.

As the hole transporting polymer, poly [(9,9-dihexylfluorenyl-2,7-diyl) -co- (N, N'-bis {p-butylphenyl} -1,4-diaminophenylene] )], Poly [(9,9-dioctylfluorenyl-2,7-diyl) -co- (N, N′-bis {p-butylphenyl} -1,1′-biphenylene-4,4-diamine )], Poly [(9,9-bis {1′-penten-5′-yl} fluorenyl-2,7-diyl) -co- (N, N′-bis {p-butylphenyl} -1,4 -Diaminophenylene)], poly [N, N'-bis (4-butylphenyl) -N, N'-bis (phenyl) -benzidine] -end-capped {with polysilsesquioxane, poly [(9,9 -Didioctylfluorenyl-2,7-diyl) -co- (4,4 '-(N- (p-butylphenyl)) diphenylamine)].

Examples of the luminescent polymer include polyfluorene derivatives such as poly (9,9-dialkylfluorene) (PDAF), poly (2-methoxy-5- (2′-ethylhexoxy) -1,4-phenylenevinylene) (MEH- Polyphenylene vinylene derivatives such as PPV); polythiophene derivatives such as poly (3-alkylthiophene) (PAT); and polyvinyl carbazole (PVCz).

(4) The materials constituting the anode, the cathode, and the layers formed between them differ depending on whether an element having a bottom emission structure or a top emission structure is manufactured. Therefore, the material is appropriately selected in consideration of this point.

Normally, in a bottom emission structure element, a transparent anode is used on the substrate side, and light is extracted from the substrate side, whereas in a top emission structure element, a reflective anode made of metal is used, and in a direction opposite to the substrate. Since light is extracted from a certain transparent electrode (cathode) side, regarding the anode material, a transparent anode such as ITO is used when manufacturing a device having a bottom emission structure, and Al / is used when manufacturing a device having a top emission structure. A reflective anode such as Nd is used.

有機 The organic EL device of the present invention may be sealed together with a water catching agent, if necessary, according to a standard method, in order to prevent deterioration in characteristics.

Hereinafter, the present invention will be described more specifically with reference to Examples, but the present invention is not limited to the following Examples. In addition, the used apparatus is as follows.
(1) LDI-MS: Bruker AutoFlex
(2) ¹ H-NMR: JNM-ECP300 FT NMR SYSTEM manufactured by JEOL Ltd.
(3) Substrate cleaning: Choshu Sangyo Co., Ltd. substrate cleaning system (reduced pressure plasma method)
(4) Application of the composition: Spin coater MS-A100 manufactured by Mikasa Corporation
(5) Film thickness measurement: Surfcorder ET-4000, a fine shape measuring instrument manufactured by Kosaka Laboratory Co., Ltd.
(6) Fabrication of element: Choshu Sangyo Co., Ltd. multifunctional vapor deposition system C-E2L1G1-N
(7) Measurement of element current density, etc .: Multi-channel IVL measurement device manufactured by EC Corporation (8) Measurement of refractive index (n) and extinction coefficient (k): manufactured by JA Woollam Japan Multi-entry angle spectroscopic ellipsometer VASE

[1] Production of Compound [Synthesis Example 1]

0.502 g of 1,4-phenylenediamine, 6.26 g of 2-bromo-9-phenyl-9H-carbazole, 0.106 g of bis (dibenzylideneacetone) palladium and 2.24 g of sodium t-butoxide were placed in a flask. The atmosphere in the flask was replaced with nitrogen. Thereto, 10 mL of toluene and 1.3 mL (concentration: 62.5 g / L) of a toluene solution of phenyldi-t-butylphosphine separately prepared in advance were added, and the mixture was stirred at 90 ° C. for 3 hours. After the reaction mixture was cooled to room temperature, toluene and a saturated saline solution were put into a separatory funnel together with the cooled reaction mixture, and liquid separation treatment was performed to collect an organic layer. Activated carbon was added to the collected organic layer, and the mixture was stirred at room temperature for 0.5 hour, followed by silica gel filtration, and the obtained filtrate was concentrated.
The obtained concentrated liquid was dropped into a mixed solvent of methanol and ethyl acetate, and stirred for a while. The obtained slurry solution was filtered, and the obtained residue was dried to obtain 2.96 g of the desired aniline derivative A (yield: 59%). The obtained target product was identified by ¹ H-NMR.
¹ H-NMR (500 MHz, DMSO-d6) δ [ppm]: 8.09-8.15 (m, 8H), 7.54-7.57 (m, 8H), 7.43-7.47 (m, 12H), 7.33-7.37 (m, 4H ), 7.24-7.30 (m, 8H), 7.05 (m, 8H), 6.92-6.94 (m, 4H).

[2] Preparation of charge transporting composition and evaluation of its storage stability [Example 1-1]
To a mixture of 0.243 g of the aniline derivative A and 0.283 g of the arylsulfonic acid ester B represented by the following formula, 10 g of xylene was added and dissolved by stirring at room temperature. The resulting solution was passed through a syringe filter having a pore size of 0.2 μm. After filtration, a charge transporting composition was obtained. The aryl sulfonic acid ester B was synthesized according to the method described in International Publication No. 2017/217457 (the same applies hereinafter).

[Example 1-2]
To a mixture of 0.243 g of the aniline derivative A and 0.283 g of the arylsulfonic acid ester B, 5 g of triethylene glycol butyl methyl ether, 3 g of butyl benzoate and 2 g of dimethyl phthalate were added and stirred at room temperature to dissolve the resulting solution. The mixture was filtered through a syringe filter having a pore size of 0.2 μm to obtain a charge transporting composition.

[Example 1-3]
To a mixture of 0.243 g of the aniline derivative A and 0.283 g of the arylsulfonic acid ester B, 3 g of 3-phenoxytoluene and 7 g of butyl benzoate were added, and the mixture was stirred and dissolved at room temperature to obtain a solution having a pore size of 0.2. The mixture was filtered with a 2 μm syringe filter to obtain a charge transporting composition.

[Comparative Example 1-1]
Preparation of a charge transporting composition was attempted in the same manner as in Example 1-1, except that an aniline derivative C represented by the following formula was used instead of the aniline derivative A. However, the solid content did not dissolve even when stirred at room temperature, and the solid content did not dissolve even when heated and stirred at 50 ° C., and the solid content was dissolved when heated and stirred at 80 ° C. The obtained solution was filtered with a syringe filter having a pore size of 0.2 μm to obtain a charge transporting composition. In addition, the aniline derivative C was synthesized according to the method described in International Publication No. 2015/137395.

[Comparative Example 1-2]
An attempt was made to prepare a charge transporting composition in the same manner as in Example 1-2, except that aniline derivative C was used instead of aniline derivative A. However, the solid content does not dissolve even when stirred at room temperature, and does not dissolve even when heated and stirred at any temperature of 50 ° C. or 80 ° C., so that a charge transporting thin film can be produced. A uniform charge transporting composition was not obtained.

[Comparative Example 1-3]
An attempt was made to prepare a charge transporting composition in the same manner as in Example 1-3, except that aniline derivative C was used instead of aniline derivative A. However, the solid content did not dissolve even when stirred at room temperature, and the solid content did not dissolve even when heated and stirred at 50 ° C., and the solid content was dissolved when heated and stirred at 80 ° C. The obtained solution was filtered with a syringe filter having a pore size of 0.2 μm to obtain a charge transporting composition.

(4) The obtained composition was stored at 0 ° C. for one week, and it was confirmed whether or not solid content of the composition after storage was precipitated. The results are shown in Table 1 together with the solubility of the solids in the preparation of each composition.

とおり As is clear from Table 1, no precipitation was confirmed in any of the solvent compositions in the composition of the present invention. On the other hand, in the composition of the comparative example containing the aniline derivative C having a structure similar to the aniline derivative A used in the present invention, precipitation was confirmed. From these results, it was found that the composition of the present invention was superior in storage stability to the composition of the comparative example.

[3] Evaluation of optical properties of thin film [Example 2 and Comparative Example 2]
Each of the charge transporting compositions obtained in Example 1-1 and Comparative Example 1-1 was applied to a quartz substrate using a spin coater, and then dried at 80 ° C. for 1 minute in an air atmosphere. Firing at 15 ° C. for 15 minutes produced a uniform thin film of 60 nm on the substrate.
The extinction coefficient k (average extinction coefficient at a wavelength of 400 nm to 800 nm) and the refractive index n (average refractive index at a wavelength of 400 nm to 800 nm) of each thin film were measured. Table 2 shows the results.

As is clear from Table 2, the thin film obtained from the composition of the present invention exhibited a lower extinction coefficient, was highly transparent, and had a high refractive index, as compared with the thin film obtained from the composition of the comparative example. Was.

[4] Production and Evaluation of Hole-Only Element In the following examples, a 25 mm × 25 mm × 0.7 t glass substrate in which indium tin oxide (ITO) was patterned with a thickness of 150 nm on the surface was used as the ITO substrate. Before use, impurities on the surface were removed by an O ₂ plasma cleaning apparatus (150 W, 30 seconds).

[Example 3]
The composition obtained in Example 1-1 was applied to an ITO substrate using a spin coater, dried at 80 ° C. for 1 minute in the air, and baked at 200 ° C. for 15 minutes to obtain a film having a thickness of 60 nm. Was prepared.
On top of that, α-NPD (N, N′-di (1-naphthyl) was used as a hole transport layer using a vapor deposition device (vacuum degree: 1.0 × 10 ⁻⁵ Pa, vapor deposition rate: 0.2 nm / sec). ) -N, N'-diphenylbenzidine) was formed at a thickness of 0.2 nm / sec to form a 30 nm film, and an 80 nm aluminum thin film was further formed thereon to produce a device.

[Comparative Example 3]
A device was produced in the same manner as in Example 3, except that the composition obtained in Comparative Example 1-1 was used instead of the composition obtained in Example 1-1.

[Example 4]
In the same manner as in Example 3, a charge transporting thin film was formed on an ITO substrate.
A 0.6% by mass xylene solution of a TFB polymer (LT-N148, manufactured by Luminescence Technology) was applied thereon by spin coating in a glove box under a nitrogen atmosphere, and then baked at 130 ° C. for 10 minutes to obtain a charge of 20 nm. A transportable thin film was formed as a hole transport layer. Further, an 80 nm aluminum thin film was formed thereon in the same manner as in Example 3 to fabricate a device.

[Comparative Example 4]
A device was manufactured in the same manner as in Example 4, except that the composition obtained in Comparative Example 1-1 was used instead of the composition obtained in Example 1-1.

(4) The current density when the fabricated device was driven at a driving voltage of 5 V was measured. Table 3 shows the results.

As shown in Table 3, the charge transporting thin film obtained from the composition of the present invention was more excellent in hole injection into the hole transporting layer than the charge transporting thin film obtained from the composition of Comparative Example. . By using the charge transporting thin film obtained from the composition of the present invention, an organic EL device having high characteristics can be expected.

Claims

A charge transport composition containing an aniline derivative represented by the following formula (1).

[In the formula, each Ar is independently a group represented by any of the following formulas (Ar1) to (Ar9).

(Wherein, R 1 to R 21 each independently represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may be substituted by Z 1 , or a C 2 to 20 carbon atom which may be substituted by Z 1 alkenyl groups, Z 1 at carbon atoms which may be substituted have 2-20 alkynyl group, which may prime be substituted by an aryl group, or Z 2 of which may 6 carbon atoms also be ~ 20 substituted by Z 2 2-20 heteroaryl groups,
Z 1 is a halogen atom, a nitro group, a cyano group, a heteroaryl group aryl or Z 3 which do 2-20 carbon atoms substituted with Z 3 are carbon atoms that may 6 to be 20 substituted with Yes,
Z 2 is a halogen atom, a nitro group, a cyano group, Z 3-substituted of having 1 to 20 carbon atoms in the alkyl group, an alkenyl group of Z 3 is 1-2 carbon atoms which may be 20 substituted by or Z An alkynyl group having 2 to 20 carbon atoms which may be substituted by 3 ,
Z 3 is a halogen atom, a nitro group or a cyano group. )]
The charge transporting composition according to claim 1, wherein Ar is the same group.
3. The charge transport composition according to claim 2, wherein Ar is a group represented by any one of formulas (Ar1) to (Ar5).
The charge transport composition according to claim 3, wherein Ar is a group represented by the formula (Ar1).
(5) The charge transporting composition according to any one of (1) to (4), further comprising a dopant.
The charge transporting composition according to claim 5, wherein the dopant is an arylsulfonic acid ester compound.
[6] A charge transporting thin film produced using the charge transporting composition according to any one of [1] to [5].
An organic electroluminescent device comprising the charge transporting thin film according to claim 7.