TWI646098B - Charge-transporting varnish, charge-transporting film, and organic electroluminescent device - Google Patents

Abstract

The present invention provides a charge-transporting varnish, a charge-transporting film, and an organic EL element that provide a thin film capable of achieving excellent brightness characteristics when applied to a hole injection layer of an organic EL element.

The charge-transporting varnish of the film of the present invention is characterized by containing a charge-transporting substance composed of a thiophene derivative represented by formula (1), a dopant, and an organic solvent.

(In the formula, Ar represents the following formulae (2-1) to (2-10)

A divalent group represented by any one, and R ¹ to R ³⁶ each independently represent hydrogen, halogen, nitro, cyano, aldehyde, hydroxyl, thiol, carboxylic acid, alkyl, alkenyl, alkynyl, aromatic Group, -C (O) Y ¹ group, -OY ² group, -SY ³ group, -C (O) OY ⁴ group, -OC (O) Y ⁵ group, -C (O) NHY ⁶ group, or -C (O) NY ⁷ Y ⁸ base).

Description

Charge-transporting varnish, charge-transporting film, and organic electroluminescent device

The present invention relates to a charge-transporting varnish, a charge-transporting film, and an organic electroluminescence (hereinafter referred to as an organic EL) element.

In the organic EL device, a charge-transporting thin film made of an organic compound can be used as a light-emitting layer or a charge-injection layer. In particular, the hole injection layer serves as the transfer of charge between the anode and the hole transporting layer or the light emitting layer, and achieves low voltage driving and high brightness of the organic EL element, and has important functions.

The formation method of the hole injection layer can be roughly divided into a dry process represented by the evaporation method and a wet process represented by the spin coating method. Compared to these processes, the wet process can efficiently produce a large area. High flatness film. Therefore, with the development of large-scale organic EL displays, a hole injection layer that can be formed by a wet process is expected.

In view of this situation, the present inventors have developed a charge-transporting material that can be applied to various wet processes and also provides a hole injection layer suitable for an organic EL device, and can realize excellent EL device characteristics. Compounds with good solubility in organic solvents used for such materials (see, for example, Patent Documents 1 to 4).

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] International Publication No. 2008/032616

[Patent Document 2] International Publication No. 2008/129947

[Patent Document 3] International Publication No. 2006/025342

[Patent Document 4] International Publication No. 2010/058777

[Summary of Invention]

The present invention is the same as the technology of the above-mentioned patent documents developed in the past, and an object of the present invention is to provide a charge-transporting varnish that imparts a thin film capable of achieving excellent characteristics when applied to a hole injection layer of an organic EL element.

In order to achieve the above-mentioned object, the present inventors have conducted careful research and found that a thin film obtained from a varnish containing a charge-transporting substance composed of a specific thiophene derivative, a dopant, and an organic solvent has high charge-transporting properties, and the film is suitable In the hole injection layer of the organic EL element, excellent brightness characteristics and excellent durability can be achieved, and the present invention has been completed.

That is, the present invention provides the following charge-transporting varnish, charge-transporting film, and organic EL device.

A charge-transporting varnish comprising a charge-transporting substance, a dopant, and an organic solvent composed of a thiophene derivative represented by formula (1).

(In the formula, Ar represents the following formulae (2-1) to (2-10) A divalent group represented by any one, and R ¹ to R ³⁶ each independently represent a hydrogen atom, a halogen atom, a nitro group, a cyano group, an aldehyde group, a hydroxyl group, a thiol group, a carboxylic acid group, and a carbon number which may be substituted by Z ¹ Alkyl groups ¹ to 20, alkenyl groups 2 to 20 carbons that can be substituted by Z ¹ , alkynyl groups 2 to 20 carbons that can be substituted by Z ¹ , and aromatics 6 to 20 carbons that can be substituted by Z ² Group, -C (O) Y ¹ group, -OY ² group, -SY ³ group, -C (O) OY ⁴ group, -OC (O) Y ⁵ group, -C (O) NHY ⁶ group, or -C (O) NY ⁷ Y ⁸ group, R ³ to R ⁶ are alkyl, alkenyl, alkynyl, aryl, -C (O) Y ¹ group, -OY ² group, -SY ³ group, -C (O When OY ⁴ group, -OC (O) Y ⁵ group, -C (O) NHY ⁶ group or -C (O) NY ⁷ Y ⁸ group, R ³ and R ⁴ and / or R ⁵ and R ^{6 are} mutually bonded junction may form a divalent group, Y ¹ ~ Y ⁸ each independently represent Z ¹ may be substituted having 1 to 20 carbon atoms of the alkyl group, may be substituted with Z ¹ of the carbon atoms of the alkenyl group having 2 to 20, may be substituted with Z ¹ An alkynyl group having 2 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms which can be substituted by Z ² , Z ¹ represents a halogen atom, a nitro group, a cyano group, an aldehyde group, a hydroxyl group, a thiol group, a sulfonic acid group, carboxylic acid group or Z ³ may be substituted having 6 to 20 carbon atoms of the aryl group, Z ² represents a halogen atom, a nitro group, a cyano group, an aldehyde group, a hydroxyl group, a thiol Carbon, sulfonic acid group, a carboxylic acid group, Z ³ may be substituted with alkyl of 1 to 20 carbon atoms, the Z ³ may be substituted with the carbon atoms of the alkenyl group having 2 to 20, or Z ³ may be substituted with the 2 to 20 Alkynyl, Z ³ represents a halogen atom, a nitro group, a cyano group, an aldehyde group, a hydroxyl group, a thiol group, a sulfonic acid group, or a carboxylic acid group).

2. The charge-transporting varnish according to the aforementioned item 1, wherein the dopant contains a heteropolyacid.

3. The charge-transporting varnish according to item 1 or 2 above, further comprising an organosilane compound.

4. The charge-transporting varnish according to any one of items 1 to 3 above, which further comprises a tetracyanobenzoquinone dimethane compound represented by the following formula (5), (In the formula, R ¹⁰¹ to R ¹⁰⁴ each independently represent a hydrogen atom or a halogen atom, but at least one is a halogen atom.)

5. A charge-transporting film characterized by using the charge-transporting varnish according to any one of items 1 to 4 above.

6. An organic electroluminescence device, comprising the charge-transporting film according to item 5 above.

7. The organic electroluminescent device according to the aforementioned item 6, wherein the charge transporting film is a hole injection layer or a hole transport layer.

8. A method for producing a charge-transporting film, characterized in that a charge-transporting varnish according to any one of the foregoing items 1 to 4 is applied to a substrate and fired.

9. A method for manufacturing an organic electroluminescence device, characterized by using the charge-transporting film as described in item 5 above.

10. A charge-transporting material characterized by containing a charge-transporting substance and a dopant composed of a thiophene derivative represented by formula (1), (In the formula, Ar represents the following formulae (2-1) to (2-10) A divalent group represented by any one, and R ¹ to R ³⁶ each independently represent a hydrogen atom, a halogen atom, a nitro group, a cyano group, an aldehyde group, a hydroxyl group, a thiol group, a carboxylic acid group, and a carbon number which may be substituted by Z ¹ Alkyl groups ¹ to 20, alkenyl groups 2 to 20 carbons that can be substituted by Z ¹ , alkynyl groups 2 to 20 carbons that can be substituted by Z ¹ , and aromatics 6 to 20 carbons that can be substituted by Z ² Group, -C (O) Y ¹ group, -OY ² group, -SY ³ group, -C (O) OY ⁴ group, -OC (O) Y ⁵ group, -C (O) NHY ⁶ group, or -C (O) NY ⁷ Y ⁸ group, R ³ to R ⁶ are alkyl, alkenyl, alkynyl, aryl, -C (O) Y ¹ group, -OY ² group, -SY ³ group, -C (O When OY ⁴ group, -OC (O) Y ⁵ group, -C (O) NHY ⁶ group or -C (O) NY ⁷ Y ⁸ group, R ³ and R ⁴ and / or R ⁵ and R ^{6 are} mutually bonded junction may form a divalent group, Y ¹ ~ Y ⁸ each independently represent Z ¹ may be substituted having 1 to 20 carbon atoms of the alkyl group, may be substituted with Z ¹ of the carbon atoms of the alkenyl group having 2 to 20, may be substituted with Z ¹ An alkynyl group having 2 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms which can be substituted by Z ² , Z ¹ represents a halogen atom, a nitro group, a cyano group, an aldehyde group, a hydroxyl group, a thiol group, a sulfonic acid group, carboxylic acid group or Z ³ may be substituted having 6 to 20 carbon atoms of the aryl group, Z ² represents a halogen atom, a nitro group, a cyano group, an aldehyde group, a hydroxyl group, a thiol Carbon, sulfonic acid group, a carboxylic acid group, Z ³ may be substituted with alkyl of 1 to 20 carbon atoms, the Z ³ may be substituted with the carbon atoms of the alkenyl group having 2 to 20, or Z ³ may be substituted with the 2 to 20 Alkynyl, Z ³ represents a halogen atom, a nitro group, a cyano group, an aldehyde group, a hydroxyl group, a thiol group, a sulfonic acid group, or a carboxylic acid group).

The thiophene derivative used in the present invention is easily soluble in an organic solvent, and the thiophene derivative is dissolved in an organic solvent together with the dopant, and the charge-transporting varnish can be easily prepared.

Since the thin film produced from the charge-transporting varnish of the present invention exhibits high charge-transporting properties, it can be applied to films for electronic devices including organic EL elements. In particular, this film is suitable for a hole injection layer of an organic EL element, and an organic EL element having excellent brightness characteristics and durability can be obtained.

In addition, since the charge-transporting varnish of the present invention contains an organic silane compound or a tetracyanobenzoquinone dimethane compound, it can be fired at a lower temperature than in the past. The film produced at this time has high flatness and high charge-transportability.

In addition, the charge-transporting varnish of the present invention has good reproducibility and produces a film having excellent charge-transportability even when various wet processes capable of forming a large area are formed using a spin coating method, a slit coating method, or the like. , Can also fully In response to recent progress in the field of organic EL elements.

In addition, the film obtained from the charge-transporting varnish of the present invention can also be used as an antistatic film or an anode buffer layer of an organic thin-film solar cell.

[Form of Implementing Invention] [Charge Transporting Substance]

The charge-transporting varnish of the present invention contains a charge-transporting substance composed of a thiophene derivative represented by the following formula (1).

In the present invention, the charge transportability is synonymous with conductivity and synonymous with hole transportability. The charge-transporting substance may be a substance having a charge-transporting property in itself or a substance having a charge-transporting property when used with an electron-accepting substance. The charge-transporting varnish may be one having a charge-transporting property by itself, or a solid film obtained by using the charge-transporting varnish.

(In the formula, Ar represents a divalent group represented by any one of the formulae (2-1) to (2-10).

R ¹ to R ³⁶ each independently represent a hydrogen atom, a halogen atom, a nitro group, a cyano group, an aldehyde group, a hydroxyl group, a thiol group, a carboxylic acid group, an alkyl group having 1 to 20 carbon atoms which may be substituted by Z ¹ , Z ¹ substituted alkenyl group with 2 to 20 carbon atoms, Z ¹ substituted carbon group with 2 to 20 alkynyl group, Z ² substituted carbon group with 6 to 20 aryl group, -C (O) Y ¹ Group, -OY ² group, -SY ³ group, -C (O) OY ⁴ group, -OC (O) Y ⁵ group, -C (O) NHY ⁶ group, or -C (O) NY ⁷ Y ⁸ group, R ³ to R ⁶ are alkyl, alkenyl, alkynyl, aryl, -C (O) Y ¹ group, -OY ² group, -SY ³ group, -C (O) OY ⁴ group, -OC (O When Y ⁵ group, -C (O) NHY ⁶ group or -C (O) NY ⁷ Y ⁸ group, R ³ and R ⁴ and / or R ⁵ and R ⁶ may be bonded to each other to form a divalent group.

Y ¹ ~ Y ⁸ each independently represent an alkyl group may be substituted with Z ¹ of the carbon atoms of 1 to 20, Z ¹ may be substituted with the carbon atoms of the alkenyl group having 2 to 20, may be substituted with Z ¹ of the 2 to 20 carbon atoms Alkynyl or aryl having 6 to 20 carbon atoms which may be substituted by Z ² .

Z ¹ represents a halogen atom, a nitro group, a cyano group, an aldehyde group, a hydroxyl group, a thiol group, a sulfonic acid group, a carboxylic acid group, or an aryl group having 6 to 20 carbon atoms which may be substituted by Z ³ .

Z ² represents a halogen atom, a nitro group, a cyano group, an aldehyde group, a hydroxyl group, a thiol group, a sulfonic acid group, a carboxylic acid group, Z ³ may be substituted with an alkyl group of 1 to 20 carbon atoms, the substituent of Z ³ may be Alkenyl group having 2 to 20 carbon atoms or alkynyl group having 2 to 20 carbon atoms which can be substituted by Z ³ .

Z ³ represents a halogen atom, a nitro group, a cyano group, an aldehyde group, a hydroxyl group, a thiol group, a sulfonic acid group, or a carboxylic acid group.

Examples of the halogen atom include fluorine, chlorine, bromine, and iodine atoms.

The alkyl group having 1 to 20 carbon atoms may be linear, branched, or cyclic. Examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, and iso. Butyl, s-butyl, t-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, etc. Chain or branched chain alkyl; cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, bicyclobutyl, dicyclopentyl, dicyclohexyl, Bicycloheptyl, bicyclooctyl, bicyclononyl, bicyclodecyl, and the like having a cyclic alkyl group having 3 to 20 carbon atoms.

Specific examples of alkenyl groups having 2 to 20 carbon atoms include vinyl, n-1-propenyl, n-2-propenyl, 1-methylvinyl, n-1-butenyl, and n-2 -Butenyl, n-3-butenyl, 2-methyl-1-propenyl, 2-methyl-2-propenyl, 1-ethylvinyl, 1-methyl-1-propenyl, 1-methyl-2-propenyl, n-1-pentenyl, n-1-decenyl, n-1-icosenyl, and the like.

Specific examples of the alkynyl group having 2 to 20 carbon atoms include ethynyl, n-1-propynyl, n-2-propynyl, n-1-butynyl, n-2-butynyl, n-3-butynyl, 1-methyl-2-propynyl, n-1-pentynyl, n-2-pentynyl , N-3-pentynyl, n-4-pentynyl, 1-methyl-n-butynyl, 2-methyl-n-butynyl, 3-methyl-n-butynyl , 1,1-dimethyl-n-propynyl, n-1-hexynyl, n-1-decynyl, n-1-pentadeynyl, n-1-icosynyl and the like.

Specific examples of aryl groups having 6 to 20 carbon atoms include phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl, 9-anthryl, 1-phenanthryl, 2- Fickey, 3-Ficky, 4-Ficky, 9-Ficky, etc.

When R ³ and R ⁴ and / or R ⁵ and R ^{6 are} bonded to each other to form a divalent group, the divalent group includes, for example, ethylidene, propylidene, butylidene, methylenedioxy, 1,2 -Ethylenedioxy, 1,3-propyldioxy and the like.

R ¹ to R ^{6 are} preferably a hydrogen atom, an alkyl group having 1 to 20 carbon atoms that can be substituted by Z ¹ , -OY ² group, -SY ³ group, more preferably a hydrogen atom, and a carbon number that can be substituted by Z ¹ An alkyl group of 1 to 20, a -OY ² group, and more preferably a hydrogen atom or an alkyl group of 1 to 20 carbon atoms which can be substituted by Z ¹ , and more preferably R ¹ to R ³ and R ⁶ are hydrogen atoms, And R ⁴ and R ^{5 are} both an alkyl group having 1 to 20 carbon atoms, -OY ² group or -SY ³ group which may be substituted by Z ¹ , or R ¹ and R ² are hydrogen atoms, and R ³ and R ⁴ and R ⁵ and R ⁶ together form 1,2-ethylenedioxy.

R ⁷ to R ^{36 are} preferably a hydrogen atom or an alkyl group having 1 to 20 carbon atoms which may be substituted by Z ¹ , and most preferably a hydrogen atom.

When R ¹ to R ³⁶ and Y ¹ to Y ⁸ are an alkyl group, an alkenyl group, an alkynyl group, or an aryl group, Z ^{1 is} preferably a halogen atom or an aryl group having 6 to 20 carbon atoms which may be substituted by Z ³ , More preferred is phenyl which may be substituted by Z ³ , most preferred is absent (ie, unsubstituted).

Z ² is preferably a halogen atom or an alkyl group substituted by Z ³ of the carbon atoms of 1 to 20, more preferably a carbon number of Z ³ may be substituted with the alkyl group of 1 to 10, and more preferably may be substituted with Z ³ The alkyl group having 1 to 8 carbon atoms, and more preferably the alkyl group having 1 to 6 carbon atoms which can be substituted by Z ³ , is most preferably absent (ie, non-substituted).

Z ^{3 is} preferably a halogen atom, more preferably a fluorine atom, and most preferably non-existent (ie, non-substituted).

Specific examples of the thiophene derivative represented by the formula (1) are listed below, but the invention is not limited thereto. In the formula, "Me" represents a methyl group, "Et" represents an ethyl group, "n-Pr" represents an n-propyl group, "n-Bu" represents an n-butyl group, and "n-Pen" represents an n-pentyl group. "N-Hex" means n-hexyl.

[Production method of thiophene derivative]

The thiophene derivative used in the present invention can be based on, for example, Chemistry of Materials 2010, 22, pp. 5314-5318, Chemistry of Materials 2012, 24, pp. 3964-3971, Tetrahedron Letters 2005, 46, pp. 8153-8157, Journal of American Chemical Society 2007, 129, pp. 12386-12387, etc., but it is not limited to these methods.

Specifically, the thiophene derivative used in the present invention is, for example, a compound represented by the following formulae (2'-1) to (2'-10) and thiophene or a derivative thereof as starting materials, and can be coupling ), Right field ‧ Kosugi ‧ Stille Coupling, Negishi coupling, Suzuki ‧ Miyaura coupling, Laoshan coupling and other coupling reactions to synthesize.

(Wherein R ⁷ to R ³⁶ are the same as above).

As the compounds represented by the formulae (2'-1) to (2'-10), commercially available products can be used, and known compounds (Synthetic Communications, 1991, 21 (1), pp. 145-9, Bulletin of the Chemical) can be used. Society of Japan, 1993, 66 (7), pp. 2034-41, Heterocycles, 2000, 52 (2), pp. 761-774, Tetrahedron Letters, 1997, 38 (26), pp. 4581-4582, Zhurnal Obshchei Khimii, 1986, 56 (9), pp. 2087-91, Chemistry of Materials, 2010, 22 (18), pp. 5314-5318, ARKIVOC (Gainesville, FL, United States), 2008, (5), 90- 101, Organic Reactions (Hoboken, NJ, United States), 1984, 30, No pp. Given, Chemicala Scripta, 1977, 12 (2-3), pp. 57-67, Journal of Heterocyclic Chemistry, 1990, 27 (7 ), pp. 1867-71, Journal of Organic Chemistry, 2005, 70, pp. 10569-10571, Journal of Organic Chemistry, 1994, 59, pp. 3077-3081, Journal of the Chemical Society, Perkin Transactions 1983, pp. 2813-2819, etc.).

For example, a compound represented by the formula (2'-1) is subjected to halogenation or tinylation, etc. In order to make a cross-coupling reaction with the compound, the thiophenes represented by the formulae (3) and (4) The derivative may be subjected to tinization or the like, or halogenated, and the coupling reaction may be performed. The same applies when a compound represented by the formula (2'-1) is replaced with a compound represented by the formula (2'-2) to (2'-10).

(In the formula, R ¹ to R ⁸ are the same as above.)

At this time, the input ratio of the thiophene or its derivative represented by the formulae (3) and (4) is usually relative to the triphenylamine or its derivative represented by the formulae (2'-1) to (2'-10), They are about 0.5 to 1.5 equivalents, preferably about 0.6 to 1.0 equivalents.

The compounds represented by the formulae (3) and (4) may be commercially available products or may be synthesized by a known method.

[Dopant]

The charge-transporting varnish of the present invention contains a dopant. The dopant is not particularly limited, and either an organic dopant or an inorganic dopant can be used. By.

Among them, in the best aspect, the charge-transporting varnish of the present invention contains a heteropoly acid as a dopant, and therefore, it is possible to obtain not only the transparency represented by indium tin oxide (ITO), indium zinc oxide (IZO), etc. A thin film having high hole-receiving energy of an electrode and excellent charge-transporting property of high hole-receiving energy of a metal anode represented by aluminum.

Heteropolyacid refers to a chemical structure represented by a Keggin type represented by formula (A1) or a Dawson type represented by formula (A2), having a structure in which a heteroatom is located at the center of a molecule, and vanadium (V), molybdenum (Mo ), Tungsten (W), oxoacid, isopoly acid, isopoly acid, and polyacids formed by condensation with oxoacids of different elements. The oxyacids of such heterogeneous elements include, for example, oxyacids of silicon (Si), phosphorus (P), and arsenic (As).

Specific examples of the heteropoly acid include, for example, phosphomolybdic acid, silomomolybdic acid, phosphotungstic acid, silototungstic acid, phosphotungstic molybdic acid, and the like. These can be used alone or in combination of two or more. The heteropolyacid used in the present invention can be obtained from a commercially available product, and can also be synthesized by a conventional method.

Especially when the dopant is composed of one type of heteropoly acid, the one type of heteropoly acid is preferably phosphotungstic acid or phosphomolybdic acid, and more preferably phosphorous tungsten acid. When the dopant is composed of two or more types of heteropolyacid, at least one of the two or more types of heteropolyacid is preferably phosphotungstic acid or phosphomolybdic acid, and more preferably phosphotungstic acid.

In addition, the heteropolyacid has a structure represented by a general formula in quantitative analysis such as elemental analysis, and even if the number of elements is large or small, as long as it is obtained from a commercially available product or appropriately synthesized according to a conventional synthesis method In either case, it can be used in the present invention.

That is, for example, the general phosphotungstic acid is represented by the chemical formula H ₃ (PW ₁₂ O ₄₀ ) ‧nH ₂ O, and the phosphomolybdic acid is represented by the chemical formula H ₃ (PMo ₁₂ O ₄₀ ) ‧nH ₂ O, but in the quantitative analysis , Even if the amount of P (phosphorus), O (oxygen), W (tungsten), or Mo (molybdenum) in this formula is more or less, as long as it is obtained from a commercially available product, or according to a conventional synthesis method, it is appropriate All synthesizers can be used in the present invention. At this time, the mass of the heteropolyacid specified in the present invention does not refer to the mass of pure phosphotungstic acid (phosphotungstic acid content) in the composition or the commercially available product, but refers to the form and commercially available product. In the form that can be separated by the conventional synthesis method, it contains the full mass of hydrated water or other impurities.

The heteropoly acid contained in the charge-transporting varnish of the present invention is expressed by mass ratio, and can be set to about 1.0 to 70.0, preferably about 2.0 to 60.0, and more preferably about 2.5 to 55.0 relative to the charge transporting substance 1. , And more preferably about 2.5 ~ 25.0.

〔Organic solvents〕

Organic solvents used in the preparation of charge-transporting varnishes. A highly soluble solvent that dissolves charge-transporting substances and dopants well.

As such a highly soluble solvent, for example, N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, 1,3-dimethyl-2-imidazoline can be used. Organic solvents such as ketones and diethylene glycol monomethyl ether. These solvents can be used singly or in combination of two or more kinds. The amount of the solvent used is 5 to 100% by mass based on the entire solvent used in the varnish.

Moreover, it is preferable that both the charge transporting substance and the dopant are completely dissolved in the solvent.

In the present invention, the varnish contains at least one kind having a viscosity of 10 to 200 mPa · s, especially 35 to 150 mPa · s at 25 ° C, and a boiling point of 50 to 300 ° C at normal pressure (atmospheric pressure) In particular, a high-viscosity organic solvent at 150 to 250 ° C makes it easy to adjust the viscosity of the varnish. As a result, it has good reproducibility and provides a film with high flatness. The varnish can be prepared according to the coating method used.

The high-viscosity organic solvent is not particularly limited, and examples thereof include cyclohexanol, ethylene glycol, ethylene glycol diglycidyl ether, 1,3-octanediol, diethylene glycol, dipropylene glycol, triethylene glycol, and tripropylene glycol. , 1,3-butanediol, 2,3-butanediol, 1,4-butanediol, propylene glycol, hexanediol, and the like. These solvents can be used singly or in combination of two or more.

The addition ratio of the high-viscosity organic solvent to the entire solvent used in the varnish of the present invention is preferably in a range where solids do not precipitate, and in a range where solids do not precipitate, the addition ratio is preferably 5 to 80% by mass.

In addition, in order to improve the wettability of the substrate, adjust the surface tension of the solvent, adjust the polarity, and adjust the boiling point, etc., compared with varnish The entire solvent used is preferably a mixture of 1 to 90% by mass, and more preferably a mixture of 1 to 50% by mass of other solvents.

Examples of such a solvent include ethylene glycol monobutyl ether, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol monoethyl ether acetate, and diethylene glycol monoethyl ether. Butyl ether acetate, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether, diacetone alcohol, γ-butyrolactone, ethyl lactate, n- Hexyl acetate, propylene glycol monomethyl ether, and the like, but are not limited thereto. These solvents can be used alone or in combination of two or more.

The viscosity of the varnish of the present invention is suitable for the thickness of the film to be produced or the solid content concentration, but it is usually 1 to 50 mPa · s at 25 ° C.

The solid content concentration of the charge-transporting varnish in the present invention is appropriately set in consideration of the viscosity and surface tension of the varnish or the thickness of the film to be produced, but it is usually about 0.1 to 10.0% by mass. In the case of coatability, it is preferably 0.5 to 5.0% by mass, and more preferably 1.0 to 3.0% by mass.

[Organic Silane Compound]

The charge-transporting varnish of the present invention preferably contains an organic silane compound. The organic silane compound is, for example, a dialkoxysilane compound, a trialkoxysilane compound, or a tetraalkoxysilane compound. These can be used individually by 1 type or in combination of 2 or more types.

In particular, the organic silane compound preferably contains one selected from a dialkoxysilane compound and a trialkoxysilane compound, and more preferably It is a trialkoxysilane-containing compound.

Examples of the dialkoxysilane compound, trialkoxysilane compound, and tetraalkoxysilane compound include formulas (B1) to (B3).

SiR ' ₂ (OR) ₂ (B1)

SiR '(OR) ₃ (B2)

Si (OR) ₄ (B3)

In the formula, R each independently represents an alkyl group may be substituted with Z ¹⁰¹ carbon atoms of 1 to 20, the sum may be substituted with Z ¹⁰¹ carbon atoms, alkenyl having 2 to 20, the sum may be substituted with Z ¹⁰¹ carbon atoms, alkynyl of 2 to 20 Group, an aryl group having 6 to 20 carbon atoms which may be substituted by Z ¹⁰² or a heteroaryl group having 2 to 20 carbon atoms which may be substituted by Z ¹⁰² .

R 'each independently represent an alkyl group may be substituted with Z 1 of ¹⁰³ to 20 carbon atoms, the substituents Z may be the ¹⁰³ carbon atoms of the alkenyl group having 2 to 20, Z may be a substituted alkynyl group of ¹⁰³ carbon atoms of 2 to 20, the heteroaryl may be 2 to 20 substituted aryl group of Z ¹⁰⁴ carbon atoms, an aryl group of 6 to 20 may be substituted with Z ¹⁰⁴ or the number of carbon atoms.

Z ¹⁰¹ represents a halogen atom, an aryl group having 6 to 20 carbon atoms which may be substituted with Z ¹⁰⁵ or a heteroaryl group having 2 to 20 carbon atoms which may be substituted with Z ¹⁰⁵ .

Z ¹⁰² represents a halogen atom, an alkyl group may be substituted by Z ¹⁰⁵ of 1 to 20 carbon atoms, the sum may be substituted with Z ¹⁰⁵ carbon atoms of the alkenyl group having 2 to 20 or ¹⁰⁵ may be substituted with Z alkynyl of 2 to 20 carbon atoms of the group .

Z ¹⁰³ represents a halogen atom, an aryl group having 6 to 20 carbon atoms which can be substituted by Z ¹⁰⁵ , a heteroaryl group having 2 to 20 carbon atoms which can be substituted by Z ¹⁰⁵ , epoxycyclohexyl, glycidyloxy, methyl Propylene fluorenyloxy, propylene fluorenyloxy, ureido (-NHCONH ₂ ), thiol, isocyanate (-NCO), amine, -NHY ¹⁰¹ or -NY ¹⁰² Y ¹⁰³ .

Z ¹⁰⁴ represents a halogen atom, an alkyl group may be substituted with Z ¹⁰⁵ of 1 to 20 carbon atoms, the substituents Z may be the ¹⁰⁵ carbon atoms of the alkenyl group having 2 to 20, Z ¹⁰⁵ may be substituted alkynyl of 2 to 20 carbon atoms of the group , Epoxycyclohexyl, glycidyloxy, methacryloxy, propyleneoxy, ureido (-NHCONH ₂ ), thiol, isocyanate (-NCO), amine, -NHY ¹⁰¹ Base or -NY ¹⁰² Y ¹⁰³ base.

Y ¹⁰¹ ~ Y ¹⁰³ each independently represent an alkyl group may be substituted with Z ¹⁰⁵ of 1 to 20 carbon atoms, the sum may be substituted with Z ¹⁰⁵ carbon atoms of the alkenyl group having 2 to 20, carbon atoms can be substituted by Z 2 to 20 of the ¹⁰⁵ alkynyl group, Z ¹⁰⁵ may be a substituted aryl group of a carbon number of 6 to 20 aryl or heteroaryl group substituted by Z ¹⁰⁵ of the 2 to 20 carbon atoms.

Z ¹⁰⁵ represents a halogen atom, an amine group, a nitro group, a cyano group, or a thiol group.

Halogen atoms in formulas (B1) to (B3), alkyl groups having 1 to 20 carbon atoms, alkenyl groups having 2 to 20 carbon atoms, alkynyl groups having 2 to 20 carbon atoms, and aryl groups having 6 to 20 carbon atoms, for example There are the same as above.

R is preferably an alkyl group may be substituted by the Z ¹⁰¹ of 1 to 20 carbon atoms, may be substituted with the group Z ¹⁰¹ carbon atoms, alkenyl of 2 to 20, or it may be substituted with Z ¹⁰² carbon atoms of the aryl group having 6 to 20, more Jia Z ¹⁰¹ is substituted it may be an alkyl group having 1 to 6 carbon atoms, the substituents may be the Z ¹⁰¹ carbon atoms of the alkenyl group having 2 to 6 or, more preferably and Z ¹⁰¹ may be substituted by a substituted phenyl group of Z ¹⁰² An alkyl group having 1 to 4 carbon atoms or a phenyl group which may be substituted with Z ¹⁰² , and more preferably a methyl group or ethyl group which may be substituted with Z ¹⁰¹ .

Further, R ′ is preferably an alkyl group having 1 to 20 carbon atoms that can be substituted by Z ¹⁰³ or an aryl group having 6 to 20 carbon atoms that can be substituted by Z ¹⁰⁴ , and more preferably 1 to 20 carbon atoms that can be substituted by Z ¹⁰³ . An alkyl group of 10 or an aryl group having 6 to 14 carbon atoms that can be substituted by Z ¹⁰⁴ , and an alkyl group of 1 to 6 carbon atoms that can be substituted by Z ¹⁰³ or 6 to 10 carbon atoms that can be substituted by Z ¹⁰⁴ The aryl group is more preferably an alkyl group having 1 to 4 carbon atoms which may be substituted by Z ¹⁰³ or a phenyl group which may be substituted by Z ¹⁰⁴ .

Moreover, all of the plural R's may be the same or different, and all of the plural R's may be the same or different.

Z ^{101 is} preferably a halogen atom or an aryl group having 6 to 20 carbon atoms which can be substituted by Z ¹⁰⁵ , more preferably a fluorine atom or a phenyl group which can be substituted by Z ¹⁰⁵ , and most preferably is absent (ie, non-substituted).

In addition, Z ^{102 is} preferably a halogen atom or an alkyl group having 6 to 20 carbon atoms which may be substituted with Z ¹⁰⁵ , more preferably a fluorine atom or an alkyl group having 1 to 10 carbon atoms which may be substituted with Z ¹⁰⁵ , and most preferably not Exists (ie, non-substituted).

Further, Z ¹⁰³ is preferably a halogen atom, a phenyl group may be substituted by Z of ^{105, 105} may be substituted with Z of furanyl, epoxy cyclohexyl group, glycidoxy group, Bing Xixi methyl group, an oxygen Bing Xixi Group, urea group, thiol group, isocyanate group, amine group, phenylamino group which can be substituted by Z ¹⁰⁵ or diphenylamino group which can be substituted by Z ¹⁰⁴ , more preferably a halogen atom, and more preferably a fluorine atom Or does not exist (ie, non-substituted).

And, Z ¹⁰⁴ is preferably a halogen atom, an alkyl group may be substituted by Z ¹⁰⁵ of 1 to 20 carbon atoms, the substituents Z may be the ¹⁰⁵ furanyl, epoxy cyclohexyl group, glycidoxy group, methyl Bing Xixi group, Bing Xixi group, a ureido group, a thiol group, isocyanate group, amino group, Z may be a substituted phenyl group of ¹⁰⁵ or ¹⁰⁵ may be substituted with Z bis phenyl group, more preferably a halogen atom, Still more preferably, a fluorine atom is absent (ie, non-substituted).

Further, Z ^{105 is} preferably a halogen atom, more preferably a fluorine atom or is absent (ie, non-substituted).

Specific examples of the organosilane compound that can be used in the present invention are listed below, but are not limited thereto.

Specific examples of the dialkoxysilane compound include dimethyldimethoxysilane, dimethyldiethoxysilane, methylethyldimethoxysilane, diethyldimethoxysilane, Diethyldiethoxysilane, methylpropyldimethoxysilane, methylpropyldiethoxysilane, diisopropyldimethoxysilane, phenylmethyldimethoxysilane, ethylene Methylmethyldimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3- (3,4- (Epoxycyclohexyl) ethylmethyldimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldiethoxy Silane, 3-mercaptopropylmethyldimethoxysilane, 3-aminopropylmethyldiethoxysilane, N- (2-aminoethyl) aminopropylmethyldimethoxysilane , 3,3,3-trifluoropropylmethyldimethoxysilane.

Specific examples of the trialkoxysilane compound include, for example, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane, Propyltriethoxysilane, butyltrimethoxysilane, butyltriethoxysilane, pentyltrimethoxysilane, pentyltriethoxysilane, heptyltrimethoxysilane, heptyltriethoxy Silane, octyltrimethoxysilane, octyltriethoxysilane, dodecyltrimethoxysilane, dodecyltriethoxysilane, hexadecyltrimethoxysilane, hexadecyltriethyl Oxysilane, octadecyltrimethoxysilane, octadecyltriethoxysilane, phenyltrimethoxysilane, Phenyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-epoxy Propoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyl Triethoxysilane, triethoxy (4- (trifluoromethyl) phenyl) silane, dodecyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, ( (Triethoxysilyl) cyclohexane, perfluorooctylethyltriethoxysilane, triethoxyfluorosilane, tridecyl-1,1,2,2-tetrahydrooctyltriethoxy Silane, pentafluorophenyltrimethoxysilane, pentafluorophenyltriethoxysilane, 3- (heptafluoroisopropoxy) propyltriethoxysilane, heptafluoro-1,1,2,2 -Tetrahydrodecyltriethoxysilane, triethoxy-2-thienylsilane, 3- (triethoxysilyl) furan, and the like.

Specific examples of the tetraalkoxysilane compound include tetramethoxysilane, tetraethoxysilane, and tetrapropoxysilane.

Among these, 3,3,3-trifluoropropylmethyldimethoxysilane, triethoxy (4- (trifluoromethyl) phenyl) silane, and 3,3,3- Trifluoropropyltrimethoxysilane, perfluorooctylethyltriethoxysilane, pentafluorophenyltrimethoxysilane, pentafluorophenyltriethoxysilane, etc.

The content of the organosilane compound in the charge-transporting varnish of the present invention is generally about 0.1 to 50% by mass relative to the total mass of the charge-transporting substance and the dopant, but if consideration is given to suppressing the charge-transportability of the obtained film When it is lowered and the hole injection energy of the layer laminated on the opposite side of the anode such as the hole transport layer or the light emitting layer by contacting the hole injection layer is improved, it is preferably about 0.5 to 40% by mass. Preferably 0.8 to 30% by mass About 1 to 20% by mass is more preferable.

[Tetracyanobenzoquinone dimethane compound]

The charge-transporting varnish of the present invention preferably contains a tetracyanoquinodimethane compound represented by formula (5). When the obtained thin film is used as a hole injection layer of an organic EL element by containing a tetracyanobenzoquinone dimethane compound, the characteristics such as brightness are further improved. In addition, when the varnish is fired at a low temperature, a film having high flatness and high charge transportability can be produced with good reproducibility.

In the formula, R ¹⁰¹ to R ¹⁰⁴ each independently represent a hydrogen atom or a halogen atom, but at least one of them is a halogen atom. The halogen atom is, for example, the same as described above, preferably a fluorine atom or a chlorine atom, and more preferably a fluorine atom. In addition, at least two of R ¹⁰¹ to R ¹⁰⁴ are preferably halogen atoms, more preferably at least three are halogen atoms, and all of them are most preferably halogen atoms.

Specific examples of the tetracyanobenzoquinone dimethane compound include tetrafluorotetracyanobenzoquinone dimethane (F4TCNQ), tetrachlorotetracyanobenzoquinone dimethane, 2-fluorotetracyanobenzoquinone dimethane, 2 -Chlorotetracyanobenzoquinone dimethane, 2,5-difluorotetracyanobenzoquinone dimethane, 2,5-dichlorotetracyanobenzoquinone dimethane, and the like. Tetracyanobenzoquinone dimethane compound, particularly preferred is F4TCNQ.

Tetracyanobenzoquinone di in the charge-transporting varnish of the present invention The content of the methane compound is preferably 0.0001 to 1 equivalent, more preferably 0.001 to 0.5 equivalent, and still more preferably 0.01 to 0.2 equivalent with respect to the thiophene derivative.

[Other ingredients]

The charge-transporting varnish of the present invention may contain other charge-transporting substances in addition to the above-mentioned thiophene derivative as long as the effect of the present invention is not impaired. The charge-transporting varnish of the present invention may contain other substances in place of the heteropoly acid as a dopant.

Examples of other charge-transporting substances include the oligoaniline derivatives described in Japanese Patent Application Laid-Open No. 2002-151272, the oligoaniline compounds described in International Publication No. 2004/105446, and the oligoaniline compounds described in International Publication No. 2005/043962. A compound of 1,4-dithiin ring, an oligoaniline compound described in International Publication No. 2008/032617, an oligoaniline compound described in International Publication No. 2008/032616, and International Publication No. 2013 / An aryldiamine compound described in No. 042623.

In particular, other charge-transporting substances are preferably aniline derivatives. When considering the solubility in organic solvents, the molecular weight is preferably 4,000 or less, more preferably 3,000 or less, and even more preferably 2,000 or less.

In the present invention, examples of the aniline derivative suitable for use as another charge transporting substance include those represented by formula (6).

B ¹ represents a single bond, -NH-, -CH _2- , -S-, or -O-, and is preferably a single bond or -NH-.

R ²⁰¹ ~ R ²⁰⁶ each independently represent a hydrogen atom, a halogen atom, an alkyl group may be substituted with Z ²⁰¹ carbon atoms of 1 to 20, Z ²⁰¹ may be substituted by an alkenyl group having a carbon number of 2 to 20, may be Z ²⁰¹ substituted alkynyl group having a carbon number of 2 to 20, Z ²⁰² may be substituted having 6 to 20 carbon atoms of the aryl group may be substituted with Z ²⁰² 2 to 20 carbon atoms of the hetero aryl group, -OY ²⁰¹ group, -SY ²⁰² group, -NHY ²⁰³ , -NY ²⁰⁴ Y ²⁰⁵ group, or -NHC (O) Y ²⁰⁶ group. Y ²⁰¹ ~ Y ²⁰⁶ each independently represent an alkyl group may be substituted with Z ²⁰¹ 1 to 20 of carbon atoms, may be substituted with Z ²⁰¹ carbon atoms of the alkenyl group having 2 to 20, Z ²⁰¹ may be replaced by 2 carbon atoms ~ 20 alkynyl group, the heteroatoms may be the aryl group having 2 to 20 substituted by Z ²⁰² carbon atoms, an aryl group of 6 to 20 or may be substituted with Z ²⁰² carbon atoms. Specific examples of such a halogen atom, an alkyl group, an alkenyl group, an alkenyl group, an aryl group, and a heteroaryl group may be the same as those described above.

Z ²⁰¹ represents a halogen atom, a nitro group, a cyano group, an aldehyde group, a hydroxyl group, a thiol group, a sulfonic acid group, a carboxylic acid group, may be substituted with Z ²⁰³ carbon atoms of an aryl group of 6 to 20 or Z ²⁰³ may be the Heteroaryl groups having 2 to 20 carbon atoms.

Z ²⁰² represents a halogen atom, a nitro group, a cyano group, an aldehyde group, a hydroxyl group, a thiol group, a sulfonic acid group, a carboxylic acid group, an alkyl group may be substituted by the Z ²⁰³ carbon atoms of 1 to 20, Z ²⁰³ may be the Alkenyl having 2 to 20 carbon atoms substituted or alkynyl having 2 to 20 carbon atoms substituted by Z ²⁰³ .

Z ²⁰³ represents a halogen atom, a nitro group, a cyano group, an aldehyde group, a hydroxyl group, a thiol group, a sulfonic acid group, or a carboxylic acid group.

R ²⁰¹ to R ^{204 are} preferably a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms that can be substituted by Z ²⁰¹ , an aryl group having 6 to 20 carbon atoms that can be substituted by Z ²⁰² , and Z ²⁰¹ The substituted alkoxy group having 1 to 20 carbons (that is, Y ²⁰¹ is a -OY ²⁰¹ group having 1 to 20 alkyl groups which can be substituted by Z ²⁰¹ ), more preferably a hydrogen atom, a fluorine atom, or Alkyl groups having 1 to 10 carbon atoms replaced by Z ²⁰¹ , aryl groups having 6 to 14 carbon atoms that can be replaced by Z ²⁰² , alkoxy groups 1 to 10 carbon atoms that can be replaced by Z ²⁰¹ , and more It is preferably a hydrogen atom, a fluorine atom, an alkyl group having 1 to 6 carbon atoms that can be replaced by Z ²⁰¹ , an aryl group having 6 to 10 carbon atoms that can be replaced by Z ²⁰² , and 1 to 6 carbon atoms that can be replaced by Z ²⁰¹ The alkoxy group is more preferably a hydrogen atom, a fluorine atom, an alkyl group having 1 to 6 carbon atoms which can be substituted by Z ²⁰¹ , and an alkoxy group having 1 to 6 carbon atoms which can be substituted by Z ²⁰¹ . Is a hydrogen atom.

In addition, R ²⁰⁵ and R ^{206 are} preferably a hydrogen atom, a halogen atom, and each alkyl group is a dialkylamino group having 1 to 20 carbon atoms which may be substituted by Z ²⁰¹ (ie, Y ²⁰⁴ and Y ²⁰⁵ (A group of -NY ²⁰⁴ Y ^{205 which is} an alkyl group having 1 to 20 carbon atoms which may be substituted by Z ²⁰¹ ), or a diaryl group whose respective aryl group is an aryl group having 6 to 20 carbon atoms which may be substituted by Z ²⁰² Amine group (i.e., Y ²⁰⁴ and Y ²⁰⁵ are -NY ²⁰⁴ Y ²⁰⁵ groups having 6 to 20 aryl groups which can be substituted by Z ²⁰¹ ), more preferably a hydrogen atom, a fluorine atom, and their respective alkyl groups may be The dialkylamino group of the alkyl group having 1 to 20 carbon atoms substituted by Z ²⁰¹ , or the respective aryl group is a diarylamino group of the aryl group having 6 to 20 carbon atoms that can be substituted by Z ²⁰² , and More preferably, it is a hydrogen atom, and each aryl group is a diarylamino group having 6 to 20 carbon aryl groups which can be substituted by Z ²⁰² , and more preferably, a simultaneous hydrogen atom or each aryl group is capable of passing Z ²⁰² Diarylamino group with 6 to 20 carbon atoms.

In formula (6), p and q each independently represent an integer of 0 or more, and satisfy 2 ≦ p + q ≦ 20, preferably 2 ≦ p + q ≦ 8, more preferably 2 ≦ p + q ≦ 6, and More preferably, it is 2 ≦ p + q ≦ 4.

In particular R ²⁰¹ ~ R ²⁰⁶ and Y ²⁰¹ ~ Y ²⁰⁶ In, Z ²⁰¹ is a substituted preferably Z ²⁰² may be the carbon atoms of the aryl group having 6 to 20, more preferably the substituted phenyl group may be Z ^202, most preferably Does not exist (ie, non-substituted).

And, Z is preferably ²⁰² may be substituted by an alkyl group having a carbon number of 1 to ²⁰¹ Z of 20, more preferably a carbon number of Z may be substituted alkyl group having 1 to ²⁰¹ of the 10, and more preferably ²⁰¹ Z may be substituted by the The alkyl group having 1 to 8 carbons, and more preferably the alkyl group having 1 to 6 carbons which can be substituted by Z ²⁰¹ , is most preferably absent (ie, non-substituted).

Z ^{203 is} preferably a halogen atom, more preferably fluorine, and most preferably non-existent (ie, non-substituted).

Hereinafter, in the present invention, specific examples of aniline derivatives suitable as other charge-transporting substances are listed, but the invention is not limited thereto.

In addition, other substances that become a dopant include, for example, Benzenesulfonic acid, tosic acid, p-styrenesulfonic acid, 2-naphthalenesulfonic acid, 4-hydroxybenzenesulfonic acid, 5-sulfosalicylic acid, p-dodecyl Benzenesulfonic acid, dihexylbenzenesulfonic acid, 2,5-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, dinonylnaphthalenesulfonic acid, 2,7-dinonyl-4-naphthalenesulfonic acid, dinonylnaphthalenesulfonic acid, 2,7- Dinonyl-4,5-naphthalene disulfonic acid, 1,4-benzodioxane disulfonic acid compound described in International Publication No. 2005/000832, and arylsulfonic acid described in International Publication No. 2006/025342 Acid compounds, arylsulfonic acid compounds such as arylsulfonic acid compounds and polystyrenesulfonic acids described in International Publication No. 2009/096352; non-arylfluorene compounds such as 10-camphorsulfonic acid; 7,7,8, 8-tetracyanoquinone dimethane (TCNQ), 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and other organic oxidants.

In particular, other dopants are preferably arylsulfonic compounds. When considering the solubility in organic solvents, the molecular weight is preferably 3,000 or less, more preferably 2,000 or less, and even more preferably 1,000 or less.

Among these, an arylsulfonic acid compound suitable for use as another substance as a dopant includes, for example, those represented by formula (7) or (8).

In Formula (7), A ¹ represents -O- or -S-, and is preferably -O-. A ² represents a naphthalene ring or an anthracene ring, and is preferably a naphthalene ring. A ³ represents a di- to tetravalent perfluorobiphenyl, j represents the number of bonds between A ¹ and A ³ , and satisfies the integer of 2 ≦ j ≦ 4, and A ³ is a divalent perfluorobiphenyl, preferably Is perfluorobiphenyl-4,4-diyl, and j is preferably 2. m represents the number of sulfonic acid groups bonded to A ² and is an integer satisfying 1 ≦ m ≦ 4, but is preferably 2.

In formula (8), 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 halogen group having 2 to 20 carbon atoms. Alkenyl, at least three of A ⁴ to A ⁸ are halogen atoms. k represents the number of sulfonic acid groups bonded to the naphthalene ring, and is an integer satisfying 1 ≦ k ≦ 4, but is preferably 2 to 4, and more preferably 2.

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. Examples of the halogenated alkenyl group having 2 to 20 carbon atoms include perfluorovinyl group, 1-perfluoropropenyl group, perfluoroallyl group, and perfluorobutenyl group.

Examples of the halogen atom and the alkyl group having 1 to 20 carbon atoms are the same as those described above. The halogen atom is preferably a fluorine atom.

Among these, A ⁴ to A ^{8 are} preferably 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, or a halogenation group having 2 to 10 carbon atoms. Alkenyl, and at least 3 of A ⁴ to A ⁸ are fluorine atoms, more preferably hydrogen atom, fluorine atom, cyano group, alkyl group having 1 to 5 carbon atoms, fluorinated alkyl group having 1 to 5 carbon atoms or carbon Fluorinated alkenyl groups of 2 to 5, and at least 3 of A ⁴ to A ⁸ are fluorine atoms, and more preferably hydrogen atoms, fluorine atoms, cyano groups, perfluoroalkyl groups or carbon numbers of 1 to 5 Perfluoroalkenyl of 1 to 5, and A ⁴ , A ⁵ and A ⁸ are fluorine atoms.

In addition, a perfluoroalkyl group means a group in which all hydrogen atoms of an alkyl group are replaced by fluorine atoms, and a perfluoroalkenyl group means a group in which all hydrogen atoms of an alkenyl group are replaced by fluorine atoms.

Specific examples of the arylsulfonic acid compound suitable as the dopant of the present invention are exemplified, but are not limited thereto.

[Charge Transporting Material]

The charge-transporting material of the present invention contains a charge-transporting substance and a dopant composed of a thiophene derivative represented by formula (1). Such a charge-transporting material exhibits good solubility in an organic solvent. As described above, by dissolving the charge-transporting material in an organic solvent, a charge-transporting varnish can be easily produced.

[Charge Transporting Film]

The charge-transporting varnish of the present invention is coated on a substrate, and a charge-transporting film can be formed on the substrate by firing.

The coating method of the varnish is not particularly limited. For example, there are a dipping method, a spin coating method, a transfer printing method, a roll coating method, a bristle coating method, an inkjet method, and a spray method. Better.

In addition, when the varnish of the present invention is used, the firing environment is not particularly limited, and a thin film having a uniform film-forming surface and a high charge-transporting property can be obtained not only in the atmospheric environment but also in an inert gas such as nitrogen or in a vacuum. .

The use of the obtained thin film in consideration of the firing temperature and the degree of charge transport properties imparted to the obtained thin film can be appropriately set within a range of 100 to 260 ° C. However, when the obtained thin film is used as a hole injection layer of an organic EL device, It is preferably about 140 to 250 ° C, and more preferably about 145 to 240 ° C.

One of the characteristics of the varnish of the present invention is that it can be fired at a low temperature of less than 200 ° C. Even under such firing conditions, the film produced has high flatness and high charge transportability.

In addition, during firing, a temperature change of two or more stages may be applied for the purpose of exhibiting a higher uniform film-forming property or allowing a reaction to proceed on the substrate. Heating may be performed using a suitable device such as a hot plate or an oven.

The thickness of the charge-transporting thin film is not particularly limited. When used as a hole injection layer in an organic EL device, it is preferably 5 to 200 nm. The method of changing the film thickness includes, for example, a method of changing the solid content concentration in the varnish, or changing the amount of the solution on the substrate during coating.

[Organic EL element]

Examples of the materials or manufacturing methods used in the production of OLED elements using the charge-transporting varnish of the present invention include the following, but are not limited thereto.

The electrode substrate used is preferably cleaned by washing with liquid such as lotion, alcohol, pure water in advance. For example, the anode substrate is preferably surface treated with UV ozone treatment, oxygen-plasma treatment, etc. before use. . However, when the anode material is mainly composed of organic matter, the surface treatment may not be performed.

An example of a method for manufacturing an OLED device having a hole injection layer composed of a thin film obtained from the charge-transporting varnish of the present invention is shown below.

According to the method described above, the charge-transporting varnish of the present invention is coated on the anode substrate, and a hole injection layer is formed on the electrode after firing. This was introduced into a vacuum evaporation device, and a hole transporting layer, a light emitting layer, an electron transporting layer, an electron transporting layer / hole blocking layer, an electron injection layer, and a cathode metal were sequentially vapor-deposited to form an OLED element. In addition, if necessary, an electron blocking layer may be provided between the light emitting layer and the hole transporting layer.

Examples of the anode material include metal anodes such as transparent electrodes represented by indium tin oxide (ITO), indium zinc oxide (IZO), metals represented by aluminum, or alloys thereof, and the like is preferred.化 Processor. It is also possible to use a polythiophene derivative or a polyaniline derivative having a high charge-transporting property.

In addition, other metals constituting the metal anode include rhenium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, gallium, yttrium, zirconium, niobium, molybdenum, ruthenium, rhodium, palladium, cadmium, Indium, thallium, lanthanum, cerium, praseodymium, neodymium, giant, thorium, thorium, thorium, thorium, thorium, ', thorium, thorium, thorium, thorium, thorium, tungsten, thallium, thallium, thallium, iridium, platinum, gold, titanium, Lead, bismuth, or the like, but not limited thereto.

Examples of the material forming the hole transporting layer include (triphenylamine) dimer derivatives, [(triphenylamine) dimer] spiro dimers, N, N'-bis (naphthalene-1- Group) -N, N'-bis (phenyl) -benzidine (α-NPD), N, N'-bis (naphthalene-2-yl) -N, N'-bis (phenyl) -benzidine, N, N'-bis (3-methylphenyl) -N, N'-bis (phenyl) -benzidine, N, N'-bis (3-methylphenyl) -N, N'-bis (Phenyl) -9,9-spirobifluorene, N, N'-bis (naphthalene-1-yl) -N, N'-bis (phenyl) -9,9-spirobifluorene, N, N ' -Bis (3-methylphenyl) -N, N'-bis (phenyl) -9,9-dimethyl-fluorene, N, N'-bis (naphthalene-1-yl) -N, N ' -Bis (phenyl) -9,9-dimethyl-fluorene, N, N'-bis (3-methylphenyl) -N, N'-bis (phenyl) -9,9-diphenyl -Fluorene, N, N'-bis (naphthalene-1-yl) -N, N'-bis (phenyl) -9,9-diphenyl-fluorene, N, N'-bis (naphthalene-1-yl) ) -N, N'-bis (phenyl) -2,2'-dimethylbenzidine, 2,2 ', 7,7'-tetra (N, N-diphenylamino) -9,9 -Spirobifluorene, 9,9-bis [4- (N, N-bis-biphenyl-4-yl-amino) phenyl] -9H-fluorene, 9,9-bis [4- (N, N-bis-naphthalene-2-yl-amino) phenyl] -9H-fluorene, 9,9-bis [4- (N-naphthalene-1-yl-N-phenylamino) -phenyl]- 9H-fluorene, 2,2 ', 7,7'-tetrakis [N-naphthyl (phenyl) -amino] -9,9-spirobifluorene, N, N'-bis ( -9-yl) -N, N'-bis (phenyl) -benzidine, 2,2'-bis [N, N-bis (biphenyl-4-yl) amino] -9,9-spiro Difluorene, 2,2'-bis (N, N-diphenylamino) -9,9-spirobifluorene, di- [4- (N, N-bis (p-tolyl) amino)- Phenyl] cyclohexane, 2,2 ', 7,7'-tetrakis (N, N-bis (p-tolyl)) amino-9,9-spirobifluorene, N, N, N', N '-Tetra-naphthalen-2-yl-benzidine, N, N, N', N'-Tetra- (3-methylphenyl) -3,3'-dimethylbenzidine, N, N'- Bis (naphthyl) -N, N'-bis (naphthyl-2-yl) -benzidine, N, N, N ', N'-tetrakis (naphthyl) -benzidine, N, N'-bis (naphthalene -2-yl) -N, N'-diphenylbenzidine-1,4-diamine, N ¹ , N ⁴ -diphenyl-N ¹ , N ⁴ -bis (m-tolyl) benzene-1 , 4-diamine, N ² , N ² , N ⁶ , N ⁶ -tetraphenylnaphthalene-2,6-diamine, tris (4- (quinolin-8-yl) phenyl) amine, 2,2 '-Bis (3- (N, N-bis (p-tolyl) amino) phenyl) biphenyl, 4,4', 4 "-tri [3-methylphenyl (phenyl) amino] Triphenylamine (m-MTDATA), 4,4 ', 4 "-tri [1-naphthyl (phenyl) amino] triphenylamine (1-TNATA), and other triarylamines, 5,5 "-Bis- {4- [bis (4-methylphenyl) amino] phenyl} -2,2 ': 5', 2" -Trithiophene (BMA-3T) and the like.

Materials for forming the light-emitting layer include, for example, ginseng (8-hydroxyquinoline) aluminum (III) (Alq ₃ ), bis (8-hydroxyquinoline) zinc (II) (Znq ₂ ), and bis (2-methyl- 8-hydroxyquinoline) -4- (p-phenylphenol) aluminum (III) (BAlq), 4,4'-bis (2,2-diphenylvinyl) biphenyl, 9,10-bis ( Naphthalene-2-yl) anthracene, 2-t-butyl-9,10-bis (naphthalene-2-yl) anthracene, 2,7-bis [9,9-bis (4-methylphenyl) -fluorene -2-yl] -9,9-bis (4-methylphenyl) fluorene, 2-methyl-9,10-bis (naphthalene-2-yl) anthracene, 2- (9,9-cyclocyclobis (Fluoren-2-yl) -9,9-cyclocyclobifluorene, 2,7-bis (9,9-cyclocyclobifluoren-2-yl) -9,9-cyclocyclobifluorene, 2- [9, 9-bis (4-methylphenyl) -fluoren-2-yl] -9,9-bis (4-methylphenyl) fluorene, 2,2'-difluorenyl-9,9-cyclocyclobis Samarium, 1,3,5-ginsyl (fluoren-1-yl) benzene, 9,9-bis [4- (fluorenyl) phenyl] -9H-fluorene, 2,2'-bi (9,10-di Phenylanthracene), 2,7-difluorenyl-9,9-cyclocyclobifluorene, 1,4-bis (fluoren-1-yl) benzene, 1,3-bis (fluoren-1-yl) benzene, 6,13-bis (biphenyl-4-yl) fused pentabenzene, 3,9-bis (naphthalene-2-yl) fluorene, 3,10-bis (naphthalene-2-yl) fluorene, reference [4- ( Fluorenyl) -phenyl] amine, 10,10'-bis (biphenyl-4-yl) -9,9'-bisanthracene, N, N'-bis (naphthalene-1-yl) -N, N ' -Diphenyl- [1,1 ': 4', 1 ": 4", 1 "'-terphenyl ] -4,4 "'-diamine, 4,4'-bis [10- (naphthalene-1-yl) anthracene-9-yl] biphenyl, dibenzo {[f, f']-4,4 ', 7,7'-tetraphenyl} diindenyl [1,2,3-cd: 1', 2 ', 3'-lm] fluorene, 1- (7- (9,9'-bisanthracene- 10-yl) -9,9-dimethyl-9H-fluoren-2-yl) fluorene, 1- (7- (9,9'-bisanthracene-10-yl) -9,9-dihexyl-9H -Fluoren-2-yl) fluorene, 1,3-bis (carbazole-9-yl) benzene, 1,3,5-ginsyl (carbazole-9-yl) benzene, 4,4 ', 4 "-gin (Carbazole-9-yl) triphenylamine, 4,4'-bis (carbazole-9-yl) biphenyl (CBP), 4,4'-bis (carbazole-9-yl) -2, 2'-dimethylbiphenyl, 2,7-bis (carbazole-9-yl) -9,9-dimethylfluorene, 2,2 ', 7,7'-(carbazole-9-yl ) -9,9-cyclocyclobifluorene, 2,7-bis (carbazole-9-yl) -9,9-bis (p-tolyl) fluorene, 9,9-bis (4- (carbazole- 9-yl) -phenyl] fluorene, 2,7-bis (carbazole-9-yl) -9,9-cyclobifluorene, 1,4-bis (triphenylsilyl) benzene, 1,3 -Bis (triphenylsilyl) benzene, bis (4-N, N-diethylamino-2-methylphenyl) -4-methylphenylmethane, 2,7-bis (carbazole- 9-yl) -9,9-dioctylfluorene, 4,4 "-bis (triphenylsilyl) -p-terphenyl, 4,4'-bis (triphenylsilyl) biphenyl, 9 -(4-t-butylphenyl) -3,6-bis (triphenylsilyl) -9H-carbazole, 9- (4-t-butylbenzene ) -3,6-bis (trityl) -9H-carbazole, 9- (4-t-butylphenyl) -3,6-bis (9- (4-methoxyphenyl) -9H-fluoren-9-yl) -9H-carbazole, 2,6-bis (3- (9H-carbazole-9-yl) phenyl) pyridine, triphenyl (4- (9-phenyl- 9H-fluoren-9-yl) phenyl) silane, 9,9-dimethyl-N, N-diphenyl-7- (4- (1-phenyl-1H-benzo [d] imidazole-2 -Yl) phenyl) -9H-fluoren-2-amine, 3,5-bis (3- (9H-carbazole-9-yl) phenyl) pyridine, 9,9-cyclobifluoren-2-yl -Diphenyl-phosphine oxide, 9,9 '-(5- (triphenylsilyl) -1,3-phenylene) bis (9H-carbazole), 3- (2,7-bis ( Diphenylphosphonium) -9-phenyl-9H-fluoren-9-yl) -9-phenyl-9H-carbazole, 4,4,8,8,12,12-hexa (p-tolyl) ) -4H-8H-12H-12C-azadibenzo [cd, mn] pyrene, 4,7-bis (9H-carbazole-9-yl) -1,10-morpholine, 2,2'- Bis (4- (carbazole-9-yl) phenyl) biphenyl, 2,8-bis (diphenylphosphonium) dibenzo [b, d] thiophene, bis (2-methylphenyl) Diphenylsilane, bis [3,5-bis (9H-carbazole-9-yl) phenyl] diphenylsilane, 3,6-bis (carbazole-9-yl) -9- (2-ethyl -Hexyl) -9H-carbazole, 3- (diphenylphosphonium) -9- (4- (diphenylphosphonium) phenyl) -9H-carbazole, 3,6-bis [( 3,5-diphenyl) phenyl] -9-benzene It is also possible to form a light-emitting layer by co-evaporation with a light-emitting dopant, such as carbazole.

Examples of the light-emitting dopant include 3- (2-benzothiazolyl) -7- (diethylamino) coumarin, 2,3,6,7-tetrahydro-1,1,7,7 -Tetramethyl-1H, 5H, 11H-10- (2-benzothiazolyl) quinazino (9,9a, 1gh) coumarin, quinacridone, N, N'-dimethyl -Quinacridone, tris (2-phenylpyridine) iridium (III) (Ir (ppy) ₃ ), bis (2-phenylpyridine) (acetylacetonate) iridium (III) (Ir ( ppy) ₂ (acac)), tris [2- (p-tolyl) pyridine] iridium (III) (Ir (mppy) ₃ ), 9,10-bis (N, N-bis (p-tolyl) amine Yl] anthracene, 9,10-bis [phenyl (m-tolyl) amino] anthracene, bis [2- (2-hydroxyphenyl) thiazolato] zinc (II), N ¹⁰ , N ¹⁰ , N ¹⁰ , N ¹⁰ -tetra (p-tolyl) -9,9'-bianthracene-10,10'-diamine, N ¹⁰ , N ¹⁰ , N ¹⁰ , N ¹⁰ -tetraphenyl -9,9'-bianthracene-10,10'-diamine, N ¹⁰ , N ¹⁰ -diphenyl-N ¹⁰ , N ¹⁰ -dinaphthyl-9,9'-bianthryl-10,10'- Diamine, 4,4'-bis (9-ethyl-3-carbazole vinylidene) -1,1'-biphenyl, fluorene, 2,5,8,11-tetra-t-butylfluorene, 1,4-bis [2- (3-N-ethylcarbazolyl) vinyl] benzene, 4,4'-bis [4- (di-p-tolylamino) styryl] biphenyl, 4- (di-p-toluene Amine) -4 '-[(di-p-tolylamino) styryl] fluorene, bis [3,5-difluoro-2- (2-pyridyl) phenyl- (2-carboxypyridyl )] Iridium (III), 4,4'-bis [4- (diphenylamino) styryl] biphenyl, bis (2,4-difluorophenylpyridine) tetra (1-pyrazolyl) Borate iridium (III), N, N'-bis (naphthalene-2-yl) -N, N'-bis (phenyl) -tris (9,9-dimethylarylene), 2,7 -Bis {2- [phenyl (m-tolyl) amino] -9,9-dimethyl-fluoren-7-yl} -9,9-dimethyl-fluorene, N- (4-(( E) -2- (6 ((E) -4- (diphenylamino) styryl) naphthalene-2-yl) vinyl) phenyl) -N-phenylaniline, fac-iridium (III) Ginseng (1-phenyl-3-methylbenzimidazoline-2-ylidene-C, C ² ), mer-iridium (III) ginseng (1-phenyl-3-methylbenzimidazoline-2 -Subunit-C, C ² ), 2,7-bis [4- (diphenylamino) styryl] -9,9-cyclobifluorene, 6-methyl-2- (4- ( 9- (4- (6-methylbenzo [d] thiazol-2-yl) phenyl) anthracene-10-yl) phenyl) benzo [d] thiazole, 1,4-bis [4- (N , N-diphenyl) amino] styrylbenzene, 1,4-bis (4- (9H-carbazole-9-yl) styryl) benzene, (E) -6- (4- (di Phenylamino) styryl) -N, N-diphenylnaphthalene-2-amine, bis (2,4-difluorophenylpyridine) (5- ( Pyridin-2-yl) -1H-tetrazole) iridium (III), bis (3-trifluoromethyl-5- (2-pyridyl) pyrazole) ((2,4-difluorobenzyl) diphenyl Bisphosphonate) iridium (III), bis (3-trifluoromethyl-5- (2-pyridyl) pyrazole) (benzyldiphenylphosphonate) iridium (III), bis (1 -(2,4-difluorobenzyl) -3-methylbenzimidazolium) (3- (trifluoromethyl) -5- (2-pyridyl) -1,2,4-triazole) iridium (III), bis (3-trifluoromethyl-5- (2-pyridyl) pyrazole) (4 ', 6'-difluorophenylpyridyl ester) iridium (III), bis (4', 6 ' -Difluorophenylpyridine) (3,5-bis (trifluoromethyl) -2- (2'-pyridyl) pyrrole) iridium (III), bis (4 ', 6'-difluorophenylpyridine) (3- (trifluoromethyl) -5- (2-pyridyl) -1,2,4-triazole) iridium (III), (Z) -6-trimethylphenyl-N- (6-trimethylbenzene) (Mesityl) quinoline-2 (1H) -subunit) quinoline-2-amine-BF ₂ , (E) -2- (2- (4- (dimethylamino) styryl) -6 -Methyl-4H-pyran-4-ylidene) malononitrile, 4- (dicyanomethylene) -2-methyl-6-julonidyl-9-alkenyl-4H-pyran , 4- (dicyanomethylene) -2-methyl-6- (1,1,7,7-tetramethyljulonidin-9-alkenyl) -4H-pyran, 4- ( Dicyanomethylene) -2-t-butyl-6- (1,1,7,7-tetramethyljulonidin-4-yl-vinyl) -4H-pyran, tris ( Benzamidine methane) phenanthroline hydrazone (III), 5,6,11,12-tetraphenyltetrabenzene, bis (2-benzo [b] thien-2-yl-pyridine) (acetamidineacetone ) Iridium (III), tris (1-phenylisoquinoline) iridium (III), bis (1-phenylisoquinoline) (acetamidineacetone) iridium (III), bis (1- (9,9- Dimethyl-9H-fluoren-2-yl) -isoquinoline] (acetamidineacetone) iridium (III), bis [2- (9,9-dimethyl-9H-fluoren-2-yl) quinoline ] (Ethylacetone) Iridium (III), Tris [4,4'-di-t-butyl- (2,2 ')-dipyridine] Ruthenium (III) ‧Bis (hexafluorophosphate), Tris ( 2-phenylquinoline) iridium (III), bis (2-phenylquinoline) (acetamidineacetone) iridium (III), 2,8-di-t-butyl-5,11-bis (4- t-butylphenyl) -6,12-diphenyltetrane, bis (2-phenylbenzothiazole) (acetamidineacetone) iridium (III), 5,10,15,20- Tetraphenyltetrabenzoporphyrin platinum, fluorene (II) bis (3-trifluoromethyl-5- (2-pyridine) -pyrazole) dimethylphenylphosphine, fluorene (II) bis (3- ( Trifluoromethyl) -5- (4-t-butylpyridyl) -1,2,4-triazole) diphenylmethylphosphine, fluorene (II) bis (3- (trifluoromethyl)- 5- (2-pyridyl) -1,2,4-triazole) dimethylphenylphosphine, fluorene (II) bis (3- (trifluoromethyl) -5- (4-t-butylpyridine) ) -1,2,4-triazole) dimethylphenylphosphine Bis [2- (4-n-hexylphenyl) quinoline] (acetamidineacetone) iridium (III), tris [2- (4-n-hexylphenyl) quinoline] iridium (III), tris [2 -Phenyl-4-methylquinoline] iridium (III), bis (2-phenylquinoline) (2- (3-methylphenyl) pyridine ester) iridium (III), bis (2- (9 , 9-diethyl-fluoren-2-yl) -1-phenyl-1H-benzo [d] imidazolato (ethylacetone) iridium (III), bis (2-phenylpyridine) (3 -(Pyridin-2-yl) -2H-chromene-2-onate) iridium (III), bis (2-phenylquinoline) (2,2,6,6-tetramethylheptane -3,5-dionitri) iridium (III), bis (phenylisoquinoline) (2,2,6,6-tetramethylheptane-3,5-dionitri) iridium (III), Iridium (III) bis (4-phenylthieno [3,2-c] pyridine-N, C ² ) acetamidineacetone, (E) -2- (2-t-butyl-6- (2- ( 2,6,6-trimethyl-2,4,5,6-tetrahydro-1H-pyrrolo [3,2,1-ij] quinoline-8-yl) vinyl) -4H-pyran- 4-Subunit) malononitrile, bis (3-trifluoromethyl-5- (1-isoquinolinyl) pyrazole) (methyldiphenylphosphine) ruthenium, bis [(4-n-hexylbenzene Base) isoquinoline] (acetamidineacetone) iridium (III), platinum (II) octaethylporphine, bis (2-methyldibenzo [f, h] quinoxaline) (acetamidineacetone) (III), tris [(4-n-hexylphenyl) hydroxyquinoline] iridium (III )Wait.

Examples of the material forming the electron transporting layer / hole blocking layer include 8-hydroxyquinoline-lithium, 2,2 ', 2 "-(1,3,5-benzyltolyl) -tris (1-phenyl) -1-H-benzimidazole), 2- (4-biphenyl) 5- (4-t-butylphenyl) -1,3,4-oxadiazole, 2,9-dimethyl- 4,7-diphenyl-1,10-phenanthroline, 4,7-diphenyl-1,10-phenanthroline, bis (2-methyl-8-quinoline) -4- (phenyl Phenolato) aluminum, 1,3-bis [2- (2,2'-dipyridin-6-yl) -1,3,4-oxadiazol-5-yl] benzene, 6,6'- Bis [5- (biphenyl-4-yl) -1,3,4-oxadiazol-2-yl] -2,2'-dipyridine, 3- (4-biphenyl) -4-phenyl -5-t-butylphenyl-1,2,4-triazole, 4- (naphthalene-1-yl) -3,5-diphenyl-4H-1,2,4-triazole, 2, 9-bis (naphthalene-2-yl) -4,7-diphenyl-1,10-phenanthroline, 2,7-bis [2- (2,2'-dipyridine-6-yl) -1 , 3,4-oxadiazol-5-yl] -9,9-dimethylfluorene, 1,3-bis [2- (4-t-butylphenyl) -1,3,4-oxadi Azole-5-yl] benzene, tris (2,4,6-trimethyl-3- (pyridin-3-yl) phenyl) borane, 1-methyl-2- (4- (naphthalene-2- (Phenyl) phenyl) -1H-imidazole [4,5f] [1,10] phenanthroline, 2- (naphthalene-2-yl) -4,7-diphenyl-1,10-phenanthroline, benzene -Difluorenylphosphine oxide, 3,3 ', 5,5'-Tetra (m-pyridyl) -phenyl-3-yl] biphenyl, 1,3,5-tri [(3-pyridyl) -phenyl-3-yl] benzene, 4,4'-bis (4,6- Diphenyl-1,3,5-triazin-2-yl) biphenyl, 1,3-bis [3,5-bis (pyridine Pyridin-3-yl) phenyl] benzene, bis (10-hydroxybenzo [h] quinoline) beryllium, diphenylbis (4- (pyridin-3-yl) phenyl) silane, 3,5-di (Fluoren-1-yl) pyridine and the like.

Examples of the material for forming the electron injection layer include lithium oxide (Li ₂ O), magnesium oxide (MgO), aluminum oxide (Al ₂ O ₃ ), lithium fluoride (LiF), sodium fluoride (NaF), and fluoride Magnesium (MgF ₂ ), cesium fluoride (CsF), strontium fluoride (SrF ₂ ), molybdenum trioxide (MoO ₃ ), aluminum, Li (acac), lithium acetate, lithium benzoate, and the like.

Examples of the cathode material include aluminum, magnesium-silver alloy, aluminum-lithium alloy, lithium, sodium, potassium, and cesium.

Examples of the material forming the electron blocking layer include tris (phenylpyrazole) iridium.

The method for producing the PLED element using the charge-transporting varnish of the present invention is not particularly limited, and examples thereof include the following methods.

In the above-mentioned OLED device manufacturing, instead of performing a vacuum evaporation operation of a hole transporting layer, a light emitting layer, an electron transporting layer, and an electron injection layer, by sequentially forming a hole transporting polymer layer and a light emitting polymer layer, A PLED element having a charge-transporting film formed of the charge-transporting varnish of the present invention is produced.

Specifically, an anode substrate is coated with the charge-transporting varnish of the present invention, a hole injection layer is prepared by the above method, and a hole-transporting polymer layer and a light-emitting polymer layer are sequentially formed thereon, and then A cathode electrode was evaporated to form a PLED element.

The cathode and anode materials used can be used with the above OLED The components are the same at the time of manufacturing, and can perform the same cleaning treatment and surface treatment.

Methods for forming the hole-transporting polymer layer and the light-emitting polymer layer include, for example, adding a solvent to the hole-transporting polymer material or the light-emitting polymer material, or adding a dopant to the solvent to dissolve the material. Or a method of uniformly dispersing and coating on a hole injection layer or a hole-transporting polymer layer, and then firing to form a film.

Examples of hole-transporting polymer materials include poly [(9,9-dihexylfluorene-2,7-diyl) -co- (N, N'-bis {p-butylphenyl} -1 , 4-diaminophenylene)], poly [(9,9-dioctylfluorene-2,7-diyl) -co- (N, N'-bis {p-butylphenyl} -1 , 1'-biphenylene-4,4-diamine)], poly [(9,9-bis {1'-pentene-5'-yl} fluorene-2,7-diyl) -co- ( N, N'-bis {p-butylphenyl} -1,4-diaminophenylene)], poly [N, N'-bis (4-butyl (Phenyl) -N, N'-bis (phenyl) -benzidine], poly [(9,9-bis (dioctyl) fluorene-2,7-diyl) -co- (4,4'- (N- (p-butylphenyl)) diphenylamine)] and the like.

Light-emitting polymer materials include, for example, polyfluorene derivatives such as poly (9,9-dialkylfluorene) (PDAF), and poly (2-methoxy-5- (2'-ethylhexyloxy)- Polyphenylene vinylene derivatives such as 1,4-phenylene vinylene (MEH-PPV), polythiophene derivatives such as poly (3-alkylthiophene) (PAT), polyvinylcarbazole ( PVCz) and so on.

Examples of the solvent include toluene, xylene, and chloroform. Examples of the dissolution or uniform dispersion method include methods such as stirring, heating and stirring, and ultrasonic dispersion.

The coating method is not particularly limited, and examples thereof include an inkjet method, a spray method, a dipping method, a spin coating method, a transfer printing method, a roll coating method, and a bristle coating method. The coating is preferably performed under an inert gas such as nitrogen or argon.

Examples of the firing method include a method of heating in an oven or a hot plate under an inert gas or in a vacuum.

[Example]

Hereinafter, the present invention will be described more specifically with reference to synthesis examples and examples, but the present invention is not limited to the following examples. The equipment used is as follows.

(1) Substrate cleaning: Substrate cleaning device made by Changzhou Industry Co., Ltd. (decompression plasma system)

(2) Coating of varnish: Mikasa (strand), spin coater MS-A100

(3) Measurement of film thickness: Surfcorder ET-4000, a micro shape measuring machine manufactured by Kosaka Laboratory

(4) Production of EL elements: Multi-function vapor deposition system C-E2L1G1-N made by Changzhou Industry Co., Ltd.

(5) Measurement of EL element brightness, etc .: (with) Tech world, I-V-L measurement system

(6) Lifetime measurement (durability evaluation) of EL element: Organic EL brightness life evaluation system PEL-105S made by Eetch Sea

(7) NMR measurement: JNM-ECX300 made by Japan Electronics Co., Ltd. FT NMR SYSTEM

(8) MS measurement: Bruker (flex) autoflex III smartbem

[Synthesis Example 1] Synthesis of Thiophene Derivative 1 (Formula (1-1))

Thiophene derivative 1 was synthesized according to the following reaction formula.

2.00 g of thienothiophene (manufactured by Tokyo Chemical Industry Co., Ltd.) and 30 mL of dimethylformamide (DMF) were placed in a reaction vessel, and after stirring at room temperature to confirm dissolution, N-bromosuccinimide (Bromosuccinimide: NBS) 6.10 g (2.4 eq) was charged in a powder state. After confirming the disappearance of the raw materials, n-hexane and ion-exchanged water were added to the reaction solution, and liquid separation was performed. The organic layer was washed once with ion-exchanged water and saturated brine, and then dried with Na ₂ SO ₄ . The solvent was distilled off under reduced pressure and dried to obtain 4.21 g of the intended thienothiophene dibromide (yield: 99%).

Next, under a nitrogen environment, 1.93 g of thienothiophene dibromide, Pd (PPh ₃ ) ₄ 0.75 g (10 mol%), 3-hexylthiophene borate pinacol ester (manufactured by Aldrich) 4.00 g, 43 mL of dimethoxyethane (DME) and 16.2 mL (5 eq) of a 2 mol / L K ₂ CO ₃ aqueous solution were stirred under reflux for 5 hours to react. After the reaction was completed, n-hexane was added, and after stirring at room temperature for 30 minutes, insoluble matters were removed by filtration, and the filtrate was washed twice with ion-exchanged water and once with saturated saline. After drying with Na ₂ SO ₄ , the solvent was distilled off under reduced pressure, and the residue was separated and purified by column chromatography to obtain the desired thiophene derivative 1 (yield: 85%). The measurement results of ¹ H-NMR are shown below.

¹ H-NMR (300 MHz, CDCl ₃ ) δ [ppm]: 7.24 (s, 2H), 7.21 (d, J = 5.1 Hz, 2H), 6.96 (d, J = 5.3 Hz, 2H), 2.79 (t, J = 7.4Hz, 4H), 1.60-1.70 (m, 4H), 1.27-1.42 (m, 12H), 0.88 (t, J = 6.9Hz, 6H).

[Synthesis Example 2] Synthesis of Thiophene Derivative 2 (Formula (1-2))

Thiophene derivative 2 was synthesized according to the following reaction formula.

Under a nitrogen environment, 1.50 g of benzodithiophene (manufactured by Tokyo Chemical Industry Co., Ltd.) was placed in a reaction vessel, 50 mL of tetrahydrofuran (THF) was added, and then cooled to -78 ° C. To which n-butyllithium is dropped After 19.2 mL of n-hexane solution (concentration 1.64 mol / L, 4 eq), it was stirred for 1.5 hours. Then, 8.6 mL (4 eq) of tri-n-butylchlorostannane was dropped, and after reacting at -78 ° C for 1 hour, the cooling bath was removed and the temperature was raised to room temperature. After reaching room temperature, the solvent was distilled off under reduced pressure. The precipitate in the obtained slurry was filtered and obtained, and dried to obtain 11.84 g of a mixture containing the intended benzodithiophene bistinyl body. In addition, no further purification was performed. When the yield of this step was 100% (theoretical yield 6.07 g), the calculated purity (6.07 / 11.84 × 100 = 51.3%) was used as the raw material for the next step.

Next, under a nitrogen environment, 5.92 g of the mixture containing the obtained benzodithiophene dimethylstannyl body and 2.15 g (2.2 eq) of 2-bromo-3-n-hexylthiophene (manufactured by Tokyo Chemical Industry Co., Ltd.) 25 mL of toluene and 0.230 g (5 mol%) of Pd (PPh ₃ ) _{4 were} placed in a reaction vessel, and the reaction was stirred for 4.5 hours under heating and refluxing conditions. After leaving to cool to room temperature, chloroform and ion-exchanged water were added for liquid separation. The solvent of the obtained organic layer was distilled off under reduced pressure. After adding methanol to the obtained yellow slurry, insoluble matters were filtered off. After the filtrate was subjected to activated carbon treatment, the solvent was distilled off under reduced pressure. Ethanol and toluene were added to the residue, and the mixture was stirred under heating and refluxing conditions. After confirming complete dissolution, it was allowed to cool to room temperature. After stirring at room temperature overnight in this state, the desired thiophene derivative 2 was obtained by filtration and drying (yield: 1.40 g, two-stage yield: 68%). The measurement results of ¹ H-NMR and TOF-MS are shown below.

¹ H-NMR (300 MHz, CDCl ₃ ) δ [ppm]: 8.16 (s, 2H), 7.34 (s, 2H), 7.26 (d, J = 5.1 Hz, 2H), 6.98 (d, J = 5.1 Hz. 2H), 2.87 (t, J = 8.0Hz, 4H), 1.63-1.74 (m, 4H), 1.30-1.42 (m, 12H), 0.88 (t, J = 6.6Hz, 6H).

MALDI-TOF-MS m / Z found: 521.87 ((M) ⁺ calcd: 522.15)

[Example 1-1]

The thiophene derivative 1 (0.034 g), 0.17 g of phosphotungstic acid (PTA, manufactured by Kanto Chemical Co., Ltd.), and 0.020 g of F4TCNQ (made by Tokyo Chemical Industry Co., Ltd.) were dissolved in 1,3-dimethylformaldehyde in a nitrogen environment. 2 g of imidazolinone (DMI). 1 g of diethylene glycol monomethyl ether (DEGME) and 7 g of propylene glycol monoethyl ether (PGME) were added to the obtained solution, and after stirring, 0.007 g of trifluoropropyltrimethoxysilane and phenyltrimethoxy were added thereto. Based on 0.014 g of silane, a charge-transporting varnish was prepared by stirring.

[Example 1-2]

Thiophene derivative 2 (0.034 g), PTA (0.17 g), and F4TCNQ (0.031 g) were dissolved in DMI (2 g) under a nitrogen environment. To the obtained solution, DEGME (1 g) and PGME (7 g) were added and stirred, and 0.007 g of trifluoropropyltrimethoxysilane and 0.014 g of phenyltrimethoxysilane were added to the solution, and the charge-transporting varnish was prepared by stirring.

[Examples 1-3]

Thiophene derivative 1 (0.034 g) and PTA (0.17 g) were dissolved in DMI (2 g) under a nitrogen environment. DEGME (1g) and PGME (7g) were added to the obtained solution, and the charge-transporting varnish was prepared by stirring.

[Example 1-4]

Thiophene derivative 1 (0.034 g) and PTA (0.17 g) were dissolved in DMI (2 g) under a nitrogen environment. To the obtained solution, DEGME (1 g) and PGME (7 g) were added and stirred, and 0.007 g of trifluoropropyltrimethoxysilane and 0.014 g of phenyltrimethoxysilane were added to the solution, and the charge-transporting varnish was prepared by stirring.

[Example 2-1]

The varnish obtained in Example 1-1 was applied to an ITO substrate using a spin coater, and dried at 50 ° C for 5 minutes, and then fired at 160 ° C for 10 minutes in an atmospheric environment to form 30 nm on the ITO substrate. A uniform film. The ITO substrate is a 25mm × 25mm × 0.7t glass substrate formed by patterning indium tin oxide (ITO) with a film thickness of 150nm on the surface. Before use, it is cleaned by an O ₂ plasma cleaning device (150W, 30 seconds) to remove impurities from the surface.

Next, N, N'-bis (1-naphthyl) -N, N'-bisphenyl was sequentially laminated on the ITO substrate on which the thin film was formed using a vapor deposition apparatus (vacuum degree: 1.0 × 10 ^-5 Pa). Thin films of benzidine (α-NPD), ginseng (8-hydroxyquinoline) aluminum (III) (Alq ₃ ), lithium fluoride, and aluminum to obtain an organic EL device. At this time, regarding the evaporation rate, α-NPD, Alq _3, and aluminum were performed at 0.2 nm / sec, and lithium fluoride was performed at 0.02 nm / sec. The film thicknesses were 30 nm, 40 nm, 0.5 nm, and 120 nm, respectively.

In addition, in order to prevent deterioration of characteristics due to the influence of oxygen, water, and the like in the air, the organic EL element was sealed with a sealing substrate and evaluated. Its characteristics. Sealing is performed in the following order.

In a nitrogen environment with an oxygen concentration of 2 ppm or less and a dew point of -85 ° C or less, an organic EL element is housed between the sealing substrates, and the sealing substrate is bonded with an adhesive material (XNR5516Z-B1 made by Nagase Chemtex). At this time, a water-capturing agent (HD-071010W-40, manufactured by Dynac Co., Ltd.) was housed in the sealed substrate together with the organic EL element.

The bonded sealing substrate was irradiated with UV light (wavelength: 365 nm, irradiation amount: 6000 mJ / cm ² ), and then annealed at 80 ° C. for 1 hour to harden the adhesive material.

[Examples 2-2 to 2-4]

An organic EL device was produced in the same manner as in Example 2-1, except that the varnish obtained in Examples 1-2 to 1-4 was used instead of the varnish obtained in Example 1-1.

Measure the current density and brightness when the driving voltage of each element is 5V. The results are shown in Table 1.

As shown in Table 1, the varnish of the present invention can realize an organic EL element having excellent brightness characteristics.

The element manufactured in Example 2-1 was subjected to a durability test. The half-life of luminance (initial luminance 5,000 cd / m ² ) is shown in Table 2.

As shown in Table 2, an organic EL device having excellent durability can be realized by the varnish of the present invention.

Claims (10)

A charge-transporting varnish comprising a charge-transporting substance, a dopant, and an organic solvent composed of a thiophene derivative represented by formula (1), (In the formula, Ar represents the following formulae (2-1) to (2-10) A divalent group represented by any one, and R ¹ to R ³⁶ each independently represent a hydrogen atom, a halogen atom, a nitro group, a cyano group, an aldehyde group, a hydroxyl group, a thiol group, a carboxylic acid group, and a carbon number which may be substituted by Z ¹ Alkyl groups ¹ to 20, alkenyl groups 2 to 20 carbons that can be substituted by Z ¹ , alkynyl groups 2 to 20 carbons that can be substituted by Z ¹ , and aromatics 6 to 20 carbons that can be substituted by Z ² Group, -C (O) Y ¹ group, -OY ² group, -SY ³ group, -C (O) OY ⁴ group, -OC (O) Y ⁵ group, -C (O) NHY ⁶ group, or -C (O) NY ⁷ Y ⁸ group, R ³ to R ⁶ are alkyl, alkenyl, alkynyl, aryl, -C (O) Y ¹ group, -OY ² group, -SY ³ group, -C (O When OY ⁴ group, -OC (O) Y ⁵ group, -C (O) NHY ⁶ group or -C (O) NY ⁷ Y ⁸ group, R ³ and R ⁴ and / or R ⁵ and R ^{6 are} mutually bonded junction may form a divalent group, Y ¹ ~ Y ⁸ each independently represent Z ¹ may be substituted having 1 to 20 carbon atoms of the alkyl group, may be substituted with Z ¹ of the carbon atoms of the alkenyl group having 2 to 20, may be substituted with Z ¹ An alkynyl group having 2 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms which can be substituted by Z ² , Z ¹ represents a halogen atom, a nitro group, a cyano group, an aldehyde group, a hydroxyl group, a thiol group, a sulfonic acid group, carboxylic acid group or Z ³ may be substituted having 6 to 20 carbon atoms of the aryl group, Z ² represents a halogen atom, a nitro group, a cyano group, an aldehyde group, a hydroxyl group, a thiol Carbon, sulfonic acid group, a carboxylic acid group, Z ³ may be substituted with alkyl of 1 to 20 carbon atoms, the Z ³ may be substituted with the carbon atoms of the alkenyl group having 2 to 20, or Z ³ may be substituted with the 2 to 20 Alkynyl, Z ³ represents a halogen atom, a nitro group, a cyano group, an aldehyde group, a hydroxyl group, a thiol group, a sulfonic acid group, or a carboxylic acid group). For example, the charge-transporting varnish according to item 1 of the application, wherein the dopant includes a heteropoly acid. For example, the charge-transporting varnish according to item 1 of the patent application scope further comprises an organic silane compound. For example, the charge-transporting varnish according to any one of claims 1 to 3, which further comprises a tetracyanobenzoquinone dimethane compound represented by the following formula (5), (In the formula, R ¹⁰¹ to R ¹⁰⁴ each independently represent a hydrogen atom or a halogen atom, but at least one is a halogen atom.) A charge-transporting film characterized by using a charge-transporting varnish according to any one of claims 1 to 4 of the scope of patent application. An organic electroluminescence device is characterized by having a charge-transporting film as described in item 5 of the patent application scope. For example, the organic electroluminescence device according to item 6 of the patent application, wherein the charge transporting film is a hole injection layer or a hole transport layer. A method for manufacturing a charge-transporting film, which is characterized in that a charge-transporting varnish according to any one of claims 1 to 4 is applied to a substrate and fired. A method for manufacturing an organic electroluminescence device, which is characterized by using a charge-transporting film such as the item 5 in the scope of patent application. A charge transporting material characterized by containing a charge transporting substance and a dopant composed of a thiophene derivative represented by formula (1), (In the formula, Ar represents the following formulae (2-1) to (2-10) A divalent group represented by any one, and R ¹ to R ³⁶ each independently represent a hydrogen atom, a halogen atom, a nitro group, a cyano group, an aldehyde group, a hydroxyl group, a thiol group, a carboxylic acid group, and a carbon number which may be substituted by Z ¹ Alkyl groups ¹ to 20, alkenyl groups 2 to 20 carbons that can be substituted by Z ¹ , alkynyl groups 2 to 20 carbons that can be substituted by Z ¹ , and aromatics 6 to 20 carbons that can be substituted by Z ² Group, -C (O) Y ¹ group, -OY ² group, -SY ³ group, -C (O) OY ⁴ group, -OC (O) Y ⁵ group, -C (O) NHY ⁶ group, or -C (O) NY ⁷ Y ⁸ group, R ³ to R ⁶ are alkyl, alkenyl, alkynyl, aryl, -C (O) Y ¹ group, -OY ² group, -SY ³ group, -C (O When OY ⁴ group, -OC (O) Y ⁵ group, -C (O) NHY ⁶ group or -C (O) NY ⁷ Y ⁸ group, R ³ and R ⁴ and / or R ⁵ and R ^{6 are} mutually bonded junction may form a divalent group, Y ¹ ~ Y ⁸ each independently represent Z ¹ may be substituted having 1 to 20 carbon atoms of the alkyl group, may be substituted with Z ¹ of the carbon atoms of the alkenyl group having 2 to 20, may be substituted with Z ¹ An alkynyl group having 2 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms which can be substituted by Z ² , Z ¹ represents a halogen atom, a nitro group, a cyano group, an aldehyde group, a hydroxyl group, a thiol group, a sulfonic acid group, carboxylic acid group or Z ³ may be substituted having 6 to 20 carbon atoms of the aryl group, Z ² represents a halogen atom, a nitro group, a cyano group, an aldehyde group, a hydroxyl group, a thiol Carbon, sulfonic acid group, a carboxylic acid group, Z ³ may be substituted with alkyl of 1 to 20 carbon atoms, the Z ³ may be substituted with the carbon atoms of the alkenyl group having 2 to 20, or Z ³ may be substituted with the 2 to 20 Alkynyl, Z ³ represents a halogen atom, a nitro group, a cyano group, an aldehyde group, a hydroxyl group, a thiol group, a sulfonic acid group, or a carboxylic acid group).