JP6696512B2 - Organic electroluminescence device, method for manufacturing organic electroluminescence device, and organic electroluminescence device material - Google Patents

Description

  The present invention relates to an organic electroluminescent element, a method for manufacturing an organic electroluminescent element, a display device, a lighting device, and an organic electroluminescent element material. In particular, the present invention has a small emission ratio of a component having a wavelength longer than the maximum emission wavelength, a high emission efficiency, a low driving voltage, a long emission lifetime, a small voltage increase during driving, and an excellent organic stability. The present invention relates to an electroluminescent element, a method for manufacturing the element, a display device and a lighting device including the element, and an organic electroluminescent element material used for the element.

  An organic electroluminescent element (hereinafter, also referred to as “organic EL element”) is a thin film type in which an organic thin film layer (single layer portion or multilayer portion) containing an organic light emitting substance is provided between an anode and a cathode. It is a solid-state device.

  When a voltage is applied to the organic EL element, electrons are injected into the organic thin film layer from the cathode and holes are injected from the anode, and these are recombined in the light emitting layer (organic light emitting material-containing layer) to generate excitons. The organic EL element is a light emitting element that utilizes the emission of light (fluorescence / phosphorescence) from these excitons, and is a technology that is expected as a next-generation flat display and illumination.

  Furthermore, since Princeton University reported an organic EL device that utilizes phosphorescence emission from excited triplets, which is in principle capable of achieving approximately four times the luminous efficiency of organic EL devices that utilize fluorescence, Starting with the development of materials that exhibit phosphorescence at room temperature, research and development of the layer structure of light-emitting elements and electrodes are being conducted around the world.

  As described above, the phosphorescence emission method has a very high potential, but in an organic EL device utilizing phosphorescence emission, it is significantly different from that utilizing fluorescence emission, and a method of controlling the position of the emission center, in particular, It is important to improve the luminous efficiency and the life of the organic EL element by how to perform the recombination inside the light emitting layer to stably emit light.

  Therefore, a multilayer laminated device including a hole transport layer located on the anode side of the light emitting layer and an electron transport layer located on the cathode side of the light emitting layer in a form adjacent to the light emitting layer, or a phosphor layer in the light emitting layer. Devices using a mixed layer containing a photoluminescent dopant and a host compound have been developed.

From the viewpoint of materials, heavy metal complexes such as iridium complex-based are being studied as materials that exhibit phosphorescence at room temperature. For example, tris (2-phenylpyridine) iridium complex is widely known, but sufficient device performance such as emission lifetime has not been obtained. Other than the tris (2-phenylpyridine) iridium complex, an iridium complex having a phenylimidazole ligand or a carbene ligand is known. With these ligands, the emission wavelength of the light emitting material has been shortened to achieve a blue color, and further, the emission efficiency and the emission lifetime have been significantly improved.
However, in recent years, an illumination light source having a high color temperature and a display having a wide color gamut have been demanded, and it has been demanded to reduce the y value measured using the CIE coordinates. In order to achieve these, it is conceivable to make the maximum wavelength of light emission shorter and to reduce the long-wave component of light emission. Until now, various efforts have been made to reduce the wavelength of the maximum emission wavelength, such as changing the substituents.However, while it is possible to reduce the wavelength to some extent, the emission efficiency and emission lifetime of the device are significantly degraded. There was a demand for improvement.

Phenyltriazole is known as a ligand that emits blue light (see, for example, Patent Document 1). These compounds can achieve a short-wavelength emission maximum wavelength, but their emission lifetime and emission efficiency were not sufficient values.
On the other hand, a metal complex having a triazole ligand in which a ring in which a metal atom is bonded to a carbon atom has a condensed ring structure is known (see, for example, Patent Documents 2 and 3). Further, a metal complex in which a ring coordinate-bonded to a metal atom has a triazole ligand having an alkyl group adjacent to the coordinate atom is known (for example, refer to Patent Document 4). Although these compounds have been able to achieve some improvement in emission lifetime, there is room for further improvement.

International Publication No. 2004/101707 Japanese Patent No. 5644050 Japanese Patent No. 5099013 JP, 2013-040159, A

  The present invention has been made in view of the above problems and circumstances, and the problem to be solved is that the emission ratio of long-wavelength components is smaller than the maximum emission wavelength, high emission efficiency, low drive voltage, and long emission life. , A small voltage increase during driving, an organic electroluminescence element excellent in stability over time, a method for manufacturing the element, a display device and a lighting device including the element, and an organic electroluminescence element material used for the element. Is to provide.

  In order to solve the above problems according to the present invention, as a result of examining the causes of the above problems, a metal complex having a 1H-1,2,4-triazole derivative as a ligand has a ring in which a metal atom is bonded to a carbon atom. Has a condensed ring structure containing a hetero atom, and the ring coordinate-bonded to the metal atom further has a specific substituent at the adjacent position of the coordination atom, thereby suppressing emission of light at a wavelength longer than the maximum emission wavelength. It was found that the emission efficiency and the emission lifetime can be improved while maintaining the short wavelength emission maximum wavelength to some extent. That is, according to the present invention, by suppressing the emission of long waves and reducing the y value measured using CIE coordinates, there is no trade-off between the shortening of the maximum emission wavelength and the emission efficiency / emission life of the device. It is possible to provide an organic EL element.

That is, the present inventors have made it possible for the organic layer to contain a compound having a structure represented by the following general formula (1) so that the emission ratio of a component having a wavelength longer than the maximum emission wavelength is small and the emission efficiency is high. It was found that it is possible to provide an organic electroluminescence device which has a low driving voltage, a long service life, a small voltage increase during driving, and is excellent in stability over time.
The problems relating to the present invention are solved by the following means.

1. An organic electroluminescence device comprising an organic layer sandwiched by at least one pair of an anode and a cathode,
The organic electroluminescent element, wherein the organic layer comprises at least one layer including a light emitting layer, and at least one layer of the organic layer contains a compound having a structure represented by the following general formula (1).

(In the general formula (1), R represents an alkyl group, a halogen atom, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an acyl group, a sulfinyl group, a sulfonyl group, a nitro group, a cyano group, a hydroxy group and a mercapto group. Ar represents an aromatic hydrocarbon group or an aromatic heterocyclic group, and R _{1 to} R ₄ each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, or an alkenyl group. , Alkynyl group, aromatic hydrocarbon group, heterocyclic group, aromatic heterocyclic group, halogen atom, alkoxy group, cycloalkoxy group, aryloxy group, alkylthio group, cycloalkylthio group, arylthio group, alkoxycarbonyl group, aryloxy Carbonyl group, sulfamoyl group, ureido group, acyl group, acyloxy group, amide group, carbamoyl group, sulfinyl group, alkylsulfonyl group, arylsulfonyl group, amino group, nitro group, cyano group, hydroxy group, mercapto group, alkylsilyl group , An arylsilyl group, an alkylphosphino group, an arylphosphino group, an alkylphosphoryl group, an arylphosphoryl group, an alkylthiophosphoryl group, and an arylthiophosphoryl group.
X ₁ -L ₁ -X ₂ represents a bidentate ligand, and X ₁ and X ₂ each independently represent a carbon atom, a nitrogen atom or an oxygen atom. L ₁ represents an atomic group forming a bidentate ligand with X ₁ and X ₂ . m represents an integer of 1 to 3, n represents an integer of 0 to 2, and m + n is 3.
However, at least two of adjacent R _{1 to} R ₄ are condensed to represent the structure of the following general formula (3) or (4 ) . )

(In the general formulas (3) and (4), Y _{1 to} Y ₄ each independently represent O, S or NR ′, and Y ₅ or Y ₆ represents CR ″ or N. 'Represents any group selected from an alkyl group, a cycloalkyl group, an aromatic hydrocarbon group, a heterocyclic group and an aromatic heterocyclic group, and R''represents a hydrogen atom, an alkyl group, a cycloalkyl group, It represents any group selected from an aromatic hydrocarbon group, a heterocyclic group, an aromatic heterocyclic group, a halogen atom, an amino group, a cyano group, an arylsilyl group and an arylphosphoryl group, wherein Z _{1 to} Z ₈ are each Independently represents C—Rx or N, and a plurality of Rx may be the same or different, and a plurality of Rx are each independently R _{1 to} R ₄ in the general formula (1). Represents an equivalent group, and * represents a bonding position with the structure represented by the general formula (1).

2. An organic electroluminescence device comprising an organic layer sandwiched by at least one pair of an anode and a cathode,
The organic layer is composed of at least one layer including a light emitting layer, and at least one of the organic layers contains a compound having a structure represented by any one of the following general formulas (5) and (7) to (10). organic electroluminescent device characterized by.

(In the general formulas (5) and (7) to (10), R represents an alkyl group, a halogen atom, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an acyl group, a sulfinyl group, a sulfonyl group, a nitro group, Represents any group selected from a cyano group, a hydroxy group and a mercapto group, and Ar represents an aromatic hydrocarbon group or an aromatic heterocyclic group. ₁ ~ R _Four Are each independently a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aromatic hydrocarbon group, a heterocyclic group, an aromatic heterocyclic group, a halogen atom, an alkoxy group, a cycloalkoxy group, an aryloxy group. Group, alkylthio group, cycloalkylthio group, arylthio group, alkoxycarbonyl group, aryloxycarbonyl group, sulfamoyl group, ureido group, acyl group, acyloxy group, amide group, carbamoyl group, sulfinyl group, alkylsulfonyl group, arylsulfonyl group, From amino, nitro, cyano, hydroxy, mercapto, alkylsilyl, arylsilyl, alkylphosphino, arylphosphino, alkylphosphoryl, arylphosphoryl, alkylthiophosphoryl and arylthiophosphoryl groups Represents any selected group.
X ₁ -L ₁ -X _Two Represents a bidentate ligand, X ₁ And X _Two Are each independently a carbon atom, a nitrogen atom or an oxygen atom. L ₁ Is X ₁ And X _Two And represents an atomic group forming a bidentate ligand. m represents an integer of 1 to 3, n represents an integer of 0 to 2, and m + n is 3.
Y ₁ Represents O, S or N-R '. R'represents any group selected from an alkyl group, a cycloalkyl group, an aromatic hydrocarbon group, a heterocyclic group and an aromatic heterocyclic group. Z ₁ ~ Z _Four Each independently represent C-Rx or N, and a plurality of Rx may be the same or different. A plurality of Rx are each independently R ₁ ~ R _Four Represents a group equivalent to. )

3 . Formula (1), or in the general formula (5) and (7) to (10), organic R is the first term, characterized in that an alkyl group or a cyano group, or according to paragraph 2 Electroluminescent device.

4 . In the general formula (1) or the general formulas (5) and (7) to (10) , Ar represents an aromatic hydrocarbon group or an aromatic heterocyclic group having a substituent at the 2-position. The organic electroluminescence device according to item 1 or 2, wherein

5 . In the general formula (1) or the general formulas (5) and (7) to (10) , n represents 0, and the organic electroluminescence device according to the first or second aspect .

6 . Item 1 or 2 wherein the light emitting layer contains a compound having a structure represented by the general formula (1) or the general formulas (5) and (7) to (10). the organic electroluminescent device according to.

7 . A compound having a structure represented by the general formula (1) or the general formulas (5) and (7) to (10), and a compound having a HOMO level of −5.4 eV or less. 7. The organic electroluminescence device according to item 6 , which contains at least two kinds of

8 . A method for manufacturing an organic electroluminescent element according to claim 1 or 2, wherein the organic electroluminescent element is manufactured by:
Among the organic layers, a layer containing a compound having a structure represented by the general formula (1) or the general formulas (5) and (7) to (10) is formed by a wet process. Method for manufacturing organic electroluminescent device.

9 . A display device comprising the organic electroluminescence element according to claim 1 or 2 .

10 . An illumination device comprising the organic electroluminescence element according to claim 1 or 2 .

11 . An organic electroluminescence device material comprising a compound having a structure represented by the following general formula (1).

(In the general formula (1), R represents an alkyl group, a halogen atom, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an acyl group, a sulfinyl group, a sulfonyl group, a nitro group, a cyano group, a hydroxy group and a mercapto group. Represents any group selected from Ar, and Ar represents an aromatic hydrocarbon group or an aromatic heterocyclic group. ₁ ~ R _Four Are each independently a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aromatic hydrocarbon group, a heterocyclic group, an aromatic heterocyclic group, a halogen atom, an alkoxy group, a cycloalkoxy group, an aryloxy group. Group, alkylthio group, cycloalkylthio group, arylthio group, alkoxycarbonyl group, aryloxycarbonyl group, sulfamoyl group, ureido group, acyl group, acyloxy group, amide group, carbamoyl group, sulfinyl group, alkylsulfonyl group, arylsulfonyl group, From amino, nitro, cyano, hydroxy, mercapto, alkylsilyl, arylsilyl, alkylphosphino, arylphosphino, alkylphosphoryl, arylphosphoryl, alkylthiophosphoryl and arylthiophosphoryl groups Represents any selected group.
  X ₁ -L ₁ -X _Two Represents a bidentate ligand, X ₁ And X _Two Are each independently a carbon atom, a nitrogen atom or an oxygen atom. L ₁ Is X ₁ And X _Two And represents an atomic group forming a bidentate ligand. m represents an integer of 1 to 3, n represents an integer of 0 to 2, and m + n is 3.
  However, adjacent R ₁ ~ R _Four At least two of them are condensed to represent the structure of the following general formula (3) or (4). )

(Y in general formulas (3) and (4) ₁ ~ Y _Four Each independently represent O, S or N-R ', and Y ₅ Or Y ₆ Represents CR ″ or N. R'represents any group selected from an alkyl group, a cycloalkyl group, an aromatic hydrocarbon group, a heterocyclic group and an aromatic heterocyclic group, and R '' represents a hydrogen atom, an alkyl group, a cycloalkyl group. Represents any group selected from an aromatic hydrocarbon group, a heterocyclic group, an aromatic heterocyclic group, a halogen atom, an amino group, a cyano group, an arylsilyl group and an arylphosphoryl group. Z ₁ ~ Z ₈ Each independently represent C-Rx or N, and a plurality of Rx may be the same or different. A plurality of Rx are each independently R in the general formula (1). ₁ ~ R _Four Represents a group equivalent to. * Represents a bonding position with the structure represented by the general formula (1). )

12. An organic electroluminescence device material containing a compound having a structure represented by any one of the following general formulas (5) and (7) to (10).

(In the general formulas (5) and (7) to (10), R represents an alkyl group, a halogen atom, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an acyl group, a sulfinyl group, a sulfonyl group, a nitro group, Represents any group selected from a cyano group, a hydroxy group and a mercapto group, and Ar represents an aromatic hydrocarbon group or an aromatic heterocyclic group. ₁ ~ R _Four Are each independently a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aromatic hydrocarbon group, a heterocyclic group, an aromatic heterocyclic group, a halogen atom, an alkoxy group, a cycloalkoxy group, an aryloxy group. Group, alkylthio group, cycloalkylthio group, arylthio group, alkoxycarbonyl group, aryloxycarbonyl group, sulfamoyl group, ureido group, acyl group, acyloxy group, amide group, carbamoyl group, sulfinyl group, alkylsulfonyl group, arylsulfonyl group, From amino, nitro, cyano, hydroxy, mercapto, alkylsilyl, arylsilyl, alkylphosphino, arylphosphino, alkylphosphoryl, arylphosphoryl, alkylthiophosphoryl and arylthiophosphoryl groups Represents any selected group.
X ₁ -L ₁ -X _Two Represents a bidentate ligand, X ₁ And X _Two Are each independently a carbon atom, a nitrogen atom or an oxygen atom. L ₁ Is X ₁ And X _Two And represents an atomic group forming a bidentate ligand. m represents an integer of 1 to 3, n represents an integer of 0 to 2, and m + n is 3.
  Y ₁ Represents O, S or N-R '. R'represents any group selected from an alkyl group, a cycloalkyl group, an aromatic hydrocarbon group, a heterocyclic group and an aromatic heterocyclic group. Z ₁ ~ Z _Four Each independently represent C-Rx or N, and a plurality of Rx may be the same or different. A plurality of Rx are each independently R ₁ ~ R _Four Represents a group equivalent to. )

  According to the present invention, the emission ratio of a component having a wavelength longer than the maximum emission wavelength is small, high emission efficiency, low driving voltage, long emission life, small increase in voltage during driving, and excellent stability over time. It is possible to provide a luminescent element and an organic electroluminescent element material used for the element. In addition, it is possible to improve the productivity of the device by the wet process. Further, a lighting device and a display device including the element can be provided.

Although the mechanism of action or mechanism of action of the present invention has not been clarified, it is presumed as follows.
The compound having a structure represented by the general formula (1) has a ring in which a metal atom is bonded to a carbon atom having a condensed ring structure, and a ring coordinately bonded to a metal atom has a specific substitution at a position adjacent to the coordination atom. It is a metal complex having a 1H-1,2,4-triazole derivative having a group as a ligand. As a result of diligent studies, the present inventors have found that the ring in which a metal atom is bonded to a carbon atom has a condensed ring structure containing a hetero atom, and thus an effect of suppressing emission of a component having a wavelength longer than the maximum emission wavelength is observed. I found it.
This is because the ring bonded to the metal atom with a carbon atom is condensed, thereby suppressing the distortion of the ring structure in the excited state, and further including a hetero atom in the condensed ring structure, resulting in a more rigid structure. It is speculated that the emission of long-wave components was suppressed. However, the condensed ring structure causes the π-plane to spread and easily aggregate, so that the light emission is broadened and the effect cannot be sufficiently exerted. Therefore, the present inventors further suppress the aggregation by allowing the ring coordinate-bonded to the metal atom to have a specific substituent (R in the general formula (1) of the present invention) adjacent to the coordinate atom. Furthermore, it was found that the effect of suppressing the emission of a component having a wavelength longer than the maximum emission wavelength is more remarkable by suppressing the vibration of the ligand.

  Further, the compound having the structure represented by the general formula (1) not only exhibits the effect of suppressing the emission of the component having a wavelength longer than the maximum emission wavelength, but also has high emission efficiency, low driving voltage, and long life. In addition, it is possible to provide an organic EL element that has a small voltage increase during driving and is excellent in stability over time. This is because the compound having a structure represented by the general formula (1) has a rigid structure due to the condensed ring structure containing a hetero atom in a ring bonded to a metal atom by a carbon atom, and thus is in an excited state. In that case, distortion is unlikely to occur, and because the crystallinity is suppressed by having a substituent at a specific position, the stability of the compound itself increases, and crystallization and decomposition over time become less likely to occur. it is conceivable that. This makes it possible to provide an organic EL element having a long life, a small voltage increase during driving, and excellent stability over time. Further, in the compound having the structure represented by the general formula (1), the ring in which a metal atom is bonded to a carbon atom contains a hetero atom, and therefore, unlike an aromatic condensed ring or fluorene, the charge transport property is improved. Therefore, it is possible to achieve high luminous efficiency and low driving voltage.

Schematic diagram showing an example of a display device composed of organic EL elements Schematic diagram of the display unit A in FIG. Schematic diagram showing the pixel circuit Schematic diagram of a passive matrix full-color display device according to the display unit A of FIG. Illumination device schematic Sectional view of lighting equipment Schematic diagram of organic EL full-color display device Schematic diagram of organic EL full-color display device Schematic diagram of organic EL full-color display device Schematic diagram of organic EL full-color display device Schematic diagram of organic EL full-color display device

The organic electroluminescent device of the present invention is an organic electroluminescent device comprising an organic layer sandwiched by at least one pair of an anode and a cathode, wherein the organic layer comprises at least one layer including a light emitting layer, and the organic layer At least one of the layers contains a compound having a structure represented by the general formula (1). This feature is a technical feature common to or corresponding to each claim.
In the present invention, the structure represented by the general formula (1) is preferably the structure represented by any of the general formulas (5) and (7) to (10) .
In the present invention, in the general formula (1), to display the structure of the formula with at least two condensed out of adjacent R ₁ to R ₄ (3) or (4).
In the present invention, it is preferable that R in the general formula (1) or the general formulas (5) and (7) to (10) represents an alkyl group or a cyano group. As a result, when R has an appropriate size, the effect of suppressing the vibration of the ligand is improved, and the emission of a component having a wavelength longer than the maximum emission wavelength can be suppressed more effectively.
Further, in the present invention, in the general formula (1) or the general formulas (5) and (7) to (10) , Ar is an aromatic hydrocarbon group or aromatic heterocycle having a substituent at the 2-position. Preferably it represents a group. As a result, the spread of the conjugated system with the ring coordinate-bonded to the metal atom can be cut, and the emission wavelength can be prevented from becoming longer.
Further, in the present invention, in the general formula (1) or the general formulas (5) and (7) to (10) , n preferably represents 0. As a result, light emission from the same ligand is obtained, so that the waveform of light emission becomes sharp, and it is possible to more effectively suppress light emission of a component having a wavelength longer than the maximum emission wavelength.
Further, in the present invention, it is preferable that the light emitting layer contains a compound having a structure represented by the general formula (1) or the general formulas (5) and (7) to (10) .
Further, in the present invention, the light emitting layer comprises a compound represented by the general formula (1) or the general formulas (5) and (7) to (10), and a compound having a HOMO level of -5.4 eV or less. It is preferable to contain at least two kinds of The compound having the structure represented by the general formula (1) or the general formulas (5) and (7) to (10) according to the present invention has a conventional 4H-1,2,4-triazole derivative as a ligand. Since the HOMO level is deeper than that of the metal complex possessed by, the use of a compound with a deep HOMO level of -5.4 eV or less makes the charge transfer smooth and further improves the luminous efficiency and the driving voltage. Connect

Moreover, the manufacturing method of the organic electroluminescent element of this invention is a manufacturing method of the organic electroluminescent element which manufactures the said organic electroluminescent element, Comprising: The said general formula (1) or general formula (5 ) among said organic layers. ) And (7) to (10) , the layer containing the compound having a structure is formed by a wet process. As a result, the organic electroluminescence device has a small emission ratio of components having a wavelength longer than the maximum emission wavelength, high emission efficiency, low driving voltage, long emission life, small voltage rise during driving, and excellent stability over time. Can be manufactured.

  A display device and a lighting device of the present invention are characterized by including the above-mentioned organic electroluminescence element.

Further, the organic electroluminescence device material of the present invention is characterized by containing a compound having a structure represented by the general formula (1) or the general formulas (5) and (7) to (10) . By using the organic electroluminescence element material, the emission ratio of components having a wavelength longer than the maximum emission wavelength is small, high emission efficiency, low driving voltage, and long emission life, small voltage rise during driving, and stable over time It is possible to obtain an excellent organic electroluminescence device.

  Hereinafter, the present invention, its components, and modes and modes for carrying out the present invention will be described in detail. In addition, in this application, "-" showing a numerical range is used in the meaning including the numerical value described before and after that as a lower limit and an upper limit.

<< Outline of organic electroluminescence device >>
The organic electroluminescent device of the present invention is an organic electroluminescent device comprising an organic layer sandwiched by at least one pair of an anode and a cathode, wherein the organic layer comprises at least one layer including a light emitting layer, and the organic layer At least one of the layers contains a compound having a structure represented by the general formula (1). The general formula (1) will be described later.

Typical element configurations of the organic EL element of the present invention include, but are not limited to, the following configurations.
(1) Anode / light emitting layer / cathode (2) Anode / light emitting layer / electron transport layer / cathode (3) Anode / hole transport layer / light emitting layer / cathode (4) Anode / hole transport layer / light emitting layer / electron Transport layer / cathode (5) Anode / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode (6) Anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / cathode ( 7) Anode / hole injecting layer / hole transporting layer / (electron blocking layer /) light emitting layer / (hole blocking layer /) electron transporting layer / electron injecting layer / cathode Among the above, the configuration of (7) is preferable. It is used, but is not limited thereto.

  The light emitting layer according to the present invention is composed of a single layer or a plurality of layers, and when it is composed of a plurality of layers, a non-light emitting intermediate layer may be provided between the respective light emitting layers.

  A hole blocking layer (also referred to as a hole blocking layer) or an electron injection layer (also referred to as a cathode buffer layer) may be provided between the light emitting layer and the cathode, if necessary. An electron blocking layer (also referred to as an electron barrier layer) and a hole injection layer (also referred to as an anode buffer layer) may be provided between the layers.

The electron transport layer used in the present invention is a layer having a function of transporting electrons, and in a broad sense, an electron injection layer and a hole blocking layer are also included in the electron transport layer. The electron transport layer may be composed of a plurality of layers.
The hole transport layer used in the present invention is a layer having a function of transporting holes, and in a broad sense, a hole injection layer and an electron blocking layer are also included in the hole transport layer. The hole transport layer may be composed of a plurality of layers.

  In the above-mentioned typical element structure, the layer excluding the anode and the cathode is referred to as an “organic layer”.

(Tandem structure)
Further, the organic EL device of the present invention may be a device having a so-called tandem structure in which a plurality of light emitting units including at least one light emitting layer are laminated.
Examples of typical tandem structure element configurations include the following configurations.

Anode / first light emitting unit / second light emitting unit / third light emitting unit / cathode Anode / first light emitting unit / intermediate layer / second light emitting unit / intermediate layer / third light emitting unit / cathode

  Here, the first light emitting unit, the second light emitting unit, and the third light emitting unit may all be the same or different. Further, the two light emitting units may be the same and the other one may be different.

  Further, the third light emitting unit may not be provided, while the light emitting unit and the intermediate layer may be further provided between the third light emitting unit and the cathode.

As in the above configuration example, the plurality of light emitting units may be directly laminated or may be laminated via an intermediate layer.
The intermediate layer is generally called an intermediate electrode, an intermediate conductive layer, a charge generation layer, an electron extraction layer, a connection layer or an intermediate insulating layer, and has electrons in the adjacent layer on the anode side and holes in the adjacent layer on the cathode side. Known materials and structures can be used as long as they have a function of supplying.

Examples of the material used for the intermediate layer include ITO (indium tin oxide), IZO (indium zinc oxide), ZnO ₂ , TiN, ZrN, HfN, TiO _x , VO _x , CuI, InN, GaN, and the like. A conductive inorganic compound layer such as CuAlO ₂ , CuGaO ₂ , SrCu ₂ O ₂ , LaB ₆ , RuO ₂ , and Al, a two-layer film such as Au / Bi ₂ O ₃ , SnO ₂ / Ag / SnO ₂ , ZnO / Multi-layer film of Ag / ZnO, Bi ₂ O ₃ / Au / Bi ₂ O ₃ , TiO ₂ / TiN / TiO ₂ , TiO ₂ / ZrN / TiO _2, etc., and fullerene such as C ₆₀ , and electroconductivity of oligothiophene etc. Examples include organic material layers, metal phthalocyanines, metal-free phthalocyanines, metal porphyrins, metal-free porphyrins, and other conductive organic compound layers, but the present invention is not limited thereto.

  Examples of preferable configurations in the light-emitting unit include those obtained by removing the anode and the cathode from the configurations (1) to (7) described in the above typical element configurations, but the present invention is not limited to these. Not done.

  Specific examples of the tandem organic EL device include, for example, US Pat. No. 6,337,492, US Pat. No. 7,420,203, US Pat. No. 7,473,923, US Pat. No. 6,872,472, US Pat. No. 6,107,734. Description, US Pat. No. 6,337,492, International Publication No. 2005/009087, JP 2006-228712 A, JP 2006-24791 A, JP 2006-49393 A, JP 2006-49394 A. , JP-A-2006-49396, JP-A-2011-96679, JP-A-2005-340187, JP 4711424, JP 3496681, JP 3884564, JP 4213169, JP Open 2010-192719, JP2009-076929A, JP2008-078414A, JP2007-059848A, JP2003-272860A, JP2003-045676A, International Publication No. Examples include element configurations and constituent materials described in 2005/094130, but the present invention is not limited to these.

  Each layer constituting the organic EL element of the present invention will be described.

<Light emitting layer>
The light emitting layer according to the present invention is a layer which emits light when the excitons generated by recombination of electrons and holes injected from the cathode or the electron transport layer or the anode or the hole transport layer are deactivated. The portion to be applied may be in the layer of the light emitting layer or at the interface between the light emitting layer and the adjacent layer.

  The total thickness of the light-emitting layer is not particularly limited, but the homogeneity of the film and preventing the application of an unnecessary high voltage during light emission, and from the viewpoint of improving the stability of the emission color with respect to the drive current, It is preferably adjusted to a range of 2 nm to 5 μm, more preferably adjusted to a range of 2 to 200 nm, and particularly preferably adjusted to a range of 5 to 100 nm.

  For the production of the light-emitting layer, a light-emitting dopant or a host compound described later, for example, vacuum deposition method, wet method (also referred to as wet process, for example, spin coating method, casting method, die coating method, blade coating method, roll coating method, An ink jet method, a printing method, a spray coating method, a curtain coating method, an LB method (Langmuir Blodgett method) and the like can be used to form a film. Preferably, the light emitting layer is a layer formed through a wet process. By forming the layer by a wet process, damage to the light emitting layer due to heat can be reduced as compared with the vacuum evaporation method.

The light emitting layer of the organic EL device of the present invention contains a light emitting dopant and a host compound, and at least one light emitting dopant is a phosphorescent organic metal having a structure represented by the general formula (1). A complex, preferably a phosphorescent organic metal complex having a structure represented by any one of the general formulas (5) and (7) to (10) .

Further, the light emitting layer according to the present invention may be used in combination with the compounds described in the following patent publications.
For example, WO 00/70655, JP 2002-280178 A, JP 2001-181616 A, JP 2002-280179 A, JP 2001-181617 A, JP 2002-280180 A, JP 2001-247859 A, JP 2002-299060 A, JP 2001-313178 A, JP 2002-302671 A, JP 2001-345183 A, JP 2002-324679 A, International publication. No. 02/15645, JP-A-2002-332291, JP-A-2002-50484, JP-A-2002-332292, JP-A-2002-83684, JP-A-2002-540572, JP-A-2002. No. 117978, No. 2002-338588, No. 2002-170684, No. 2002-352960, International Publication No. 01/93642, No. 2002-50483, No. 2002-100476. Japanese Patent Laid-Open No. 2002-173674, Japanese Patent Laid-Open No. 2002-359082, Japanese Patent Laid-Open No. 2002-175884, Japanese Patent Laid-Open No. 2002-363552, Japanese Patent Laid-Open No. 2002-184582, Japanese Patent Laid-Open No. 2003-7469, Japanese Unexamined Patent Publication No. 2002-525808, Japanese Unexamined Patent Publication No. 2003-7471, Japanese Unexamined Patent Publication No. 2002-525833, Japanese Unexamined Patent Publication No. 2003-31366, Japanese Unexamined Patent Publication No. 2002-226495, Japanese Unexamined Patent Publication No. 2002-234894, 2002-235076, JP2002-241751, JP2001-319779, JP2001-319780, JP2002-62824, JP2002-100474, JP2002-2002. No. 203679, No. 2002-343572, No. 2002-203678.

  Next, the compounds contained in the organic layer will be described and each layer will be described.

(1) Luminescent Dopant As a luminescent dopant, a fluorescent dopant (also referred to as a fluorescent compound) or a phosphorescent dopant (also referred to as a phosphorescent luminescent dopant, a phosphorescent compound, a phosphorescent luminescent compound, or the like) can be used. ..

(1.1) Phosphorescent Dopant The phosphorescent dopant according to the present invention is a compound in which light emission from an excited triplet is observed, specifically, a compound which emits phosphorescent light at room temperature (25 ° C.), A phosphorescence quantum yield is defined as a compound having a phosphorescence quantum yield of 0.01 or more at 25 ° C., but a preferable phosphorescence quantum yield is 0.1 or more.

  The phosphorescence quantum yield can be measured by the method described in Spectra II, 4th edition, Experimental Chemistry Course 7, page 398 (1992, Maruzen). The phosphorescence quantum yield in a solution can be measured using various solvents, but the phosphorescence dopant according to the present invention can achieve the above phosphorescence quantum yield (0.01 or more) in any of the solvents. Good.

  The principle of the light emission of the phosphorescent dopant is two. One is the recombination of carriers on the host compound where the carriers are transported to generate an excited state of the host compound, and the energy is transferred to the phosphorescent dopant. This is an energy transfer type in which light is emitted from the phosphorescent dopant by doing so. The other is a carrier trap type in which the phosphorescent dopant serves as a carrier trap, carriers are recombined on the phosphorescent dopant, and light emission from the phosphorescent dopant is obtained. In either case, the energy of the excited state of the phosphorescent dopant must be lower than the energy of the excited state of the host compound.

As the phosphorescent dopant in the embodiment of the present invention, it is preferable to use a phosphorescent organic metal complex having a structure represented by the general formula (1) described below.
By using the phosphorescent organic metal complex having the structure represented by the general formula (1) as the phosphorescent dopant, it is possible to suppress the long-wave emission component while maintaining the short-wavelength, and to obtain high emission brightness and low driving voltage. In addition, the emission life can be extended at the same time. In addition, the organic EL device produced by using the phosphorescent dopant of the present invention has a small voltage increase during driving, and is improved in terms of stability over time.

(1.1.1) Compound having structure represented by general formula (1)

In the general formula (1), R _{1 to} R ₄ are each independently a hydrogen atom, an alkyl group (for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, a (t) butyl group, a pentyl group, a hexyl group, Octyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, benzyl group, etc.), cycloalkyl group (eg, cyclopentyl group, cyclohexyl group, etc.), alkenyl group (eg, vinyl group, allyl group, etc.), alkynyl group ( For example, propargyl group, etc., aromatic hydrocarbon group (also referred to as aryl group, for example, phenyl group, p-chlorophenyl group, mesityl group, tolyl group, xylyl group, naphthyl group, anthryl group, azulenyl group, acenaphthenyl group, fluorenyl group. Group, phenanthryl group, indenyl group, pyrenyl group, biphenylyl group, etc., heterocyclic group (eg, epoxy ring, aziridine ring, thiirane ring, oxetane ring, azetidine ring, thietane ring, tetrahydrofuran ring, dioxolane ring, pyrrolidine ring, pyrazolidine) Ring, imidazolidine ring, oxazolidine ring, tetrahydrothiophene ring, sulfolane ring, thiazolidine ring, ε-caprolactone ring, ε-caprolactam ring, piperidine ring, hexahydropyridazine ring, hexahydropyrimidine ring, piperazine ring, morpholine ring, tetrahydropyran Ring, 1,3-dioxane ring, 1,4-dioxane ring, trioxane ring, tetrahydrothiopyran ring, thiomorpholine ring, thiomorpholine 1,1-dioxide ring, pyranose ring, diazabicyclo [2,2,2] -octane Ring, etc.), aromatic heterocyclic group (pyridyl group, pyrimidinyl group, furyl group, pyrrolyl group, imidazolyl group, benzimidazolyl group, pyrazolyl group, pyrazinyl group, triazolyl group (for example, 1,2,4-triazol-1-yl) Group, 1,2,3-triazol-1-yl group, etc.), oxazolyl group, benzoxazolyl group, thiazolyl group, isoxazolyl group, isothiazolyl group, flazanyl group, thienyl group, quinolyl group, benzofuryl group, dibenzofuryl group. , A benzothienyl group, a dibenzothienyl group, an indolyl group, a carbazolyl group, a carborinyl group, and a diazacarbazolyl group (in which one of the carbon atoms constituting the carboline ring of the carborinyl group is replaced with a nitrogen atom), Quinoxalinyl group, pyridazinyl group, triazinyl group, quinazolinyl group, phthalazinyl group, etc.), halogen atom (eg chlorine atom, odor) Elementary atom, iodine atom, fluorine atom, etc., alkoxy group (eg, methoxy group, ethoxy group, propyloxy group, pentyloxy group, hexyloxy group, octyloxy group, dodecyloxy group, etc.), cycloalkoxy group (eg, Cyclopentyloxy group, cyclohexyloxy group, etc.), aryloxy group (eg, phenoxy group, naphthyloxy group, etc.), alkylthio group (eg, methylthio group, ethylthio group, propylthio group, pentylthio group, hexylthio group, octylthio group, dodecylthio group) Etc.), cycloalkylthio groups (eg cyclopentylthio group, cyclohexylthio group etc.), arylthio groups (eg phenylthio group, naphthylthio group etc.), alkoxycarbonyl groups (eg methyloxycarbonyl group, ethyloxycarbonyl group, butyloxy) Carbonyl group, octyloxycarbonyl group, dodecyloxycarbonyl group, etc., aryloxycarbonyl group (eg, phenyloxycarbonyl group, naphthyloxycarbonyl group, etc.), sulfamoyl group (eg, aminosulfonyl group, methylaminosulfonyl group, dimethylamino) Sulfonyl group, butylaminosulfonyl group, hexylaminosulfonyl group, cyclohexylaminosulfonyl group, octylaminosulfonyl group, dodecylaminosulfonyl group, phenylaminosulfonyl group, naphthylaminosulfonyl group, 2-pyridylaminosulfonyl group, etc., ureido group (for example, , Methylureido group, ethylureido group, pentylureido group, cyclohexylureido group, octylureido group, dodecylureido group, phenylureido group, naphthylureido group, 2-pyridylaminoureido group, etc., acyl group (for example, acetyl group, ethyl group) Carbonyl group, propylcarbonyl group, pentylcarbonyl group, cyclohexylcarbonyl group, octylcarbonyl group, 2-ethylhexylcarbonyl group, dodecylcarbonyl group, phenylcarbonyl group, naphthylcarbonyl group, pyridylcarbonyl group, etc., acyloxy group (eg, acetyloxy) Group, ethylcarbonyloxy group, butylcarbonyloxy group, octylcarbonyloxy group, dodecylcarbonyloxy group, phenylcarbonyloxy group, etc.), amide group (eg, methylcarbonylamino group, ethylcarbonylamino group, dimethylcarbonylamino group, propyl) Carbonylamino group, pentylcarbo Nylamino group, cyclohexylcarbonylamino group, 2-ethylhexylcarbonylamino group, octylcarbonylamino group, dodecylcarbonylamino group, phenylcarbonylamino group, naphthylcarbonylamino group, etc., carbamoyl group (for example, aminocarbonyl group, methylaminocarbonyl group) , Dimethylaminocarbonyl group, propylaminocarbonyl group, pentylaminocarbonyl group, cyclohexylaminocarbonyl group, octylaminocarbonyl group, 2-ethylhexylaminocarbonyl group, dodecylaminocarbonyl group, phenylaminocarbonyl group, naphthylaminocarbonyl group, 2- Pyridylaminocarbonyl group, etc., sulfinyl group (for example, methylsulfinyl group, ethylsulfinyl group, butylsulfinyl group, cyclohexylsulfinyl group, 2-ethylhexylsulfinyl group, dodecylsulfinyl group, phenylsulfinyl group, naphthylsulfinyl group, 2-pyridylsulfinyl group) Etc.), alkylsulfonyl group or arylsulfonyl group (for example, methylsulfonyl group, ethylsulfonyl group, butylsulfonyl group, cyclohexylsulfonyl group, 2-ethylhexylsulfonyl group, dodecylsulfonyl group, phenylsulfonyl group, naphthylsulfonyl group, 2-pyridyl group Sulfonyl group, etc., amino group (for example, amino group, ethylamino group, dimethylamino group, butylamino group, cyclopentylamino group, 2-ethylhexylamino group, dodecylamino group, anilino group, diarylamino group (for example, diphenylamino Group, dinaphthylamino group, phenylnaphthylamino group, etc.), naphthylamino group, 2-pyridylamino group, etc.), nitro group, cyano group, hydroxy group, mercapto group, alkylsilyl group or arylsilyl group (for example, trimethylsilyl group, Triethylsilyl group, (t) butyldimethylsilyl group, triisopropylsilyl group, (t) butyldiphenylsilyl group, triphenylsilyl group, trinaphthylsilyl group, 2-pyridylsilyl group, etc.), alkylphosphino group or arylphosphine Phino group (dimethylphosphino group, diethylphosphino group, dicyclohexylphosphino group, methylphenylphosphino group, diphenylphosphino group, dinaphthylphosphino group, di (2-pyridyl) phosphino group), alkylphosphoryl group or aryl Phosphoryl group (dimethylphosphoryl group, die Tylphosphoryl group, dicyclohexylphosphoryl group, methylphenylphosphoryl group, diphenylphosphoryl group, dinaphthylphosphoryl group, di (2-pyridyl) phosphoryl group), alkylthiophosphoryl group or arylthiophosphoryl group (dimethylthiophosphoryl group, diethylthiophosphoryl group , A dicyclohexylthiophosphoryl group, a methylphenylthiophosphoryl group, a diphenylthiophosphoryl group, a dinaphthylthiophosphoryl group, a di (2-pyridyl) thiophosphoryl group). Here, groups other than the hydrogen atom are represented as a substituent. In addition, these substituents may be further substituted by the above-mentioned substituents, or may be condensed with each other to further form a ring.

  The specific examples in parentheses in these substituents are not limited to these. In addition, specific examples in parentheses in the alkyl group, halogen atom, alkoxy group, aryloxy group, alkylthio group, arylthio group, acyl group, sulfinyl group, sulfonyl group, nitro group, cyano group, hydroxy group, and mercapto group in the above substituents Examples include R alkyl group of formula (1), halogen atom, alkoxy group, aryloxy group, alkylthio group, arylthio group, acyl group, sulfinyl group, sulfonyl group, nitro group, cyano group, hydroxy group, mercapto. The same applies to the group. Further, the specific examples in the parentheses in the aromatic hydrocarbon group or the aromatic heterocyclic group in the above substituents are the same as in the aromatic hydrocarbon group or the aromatic heterocyclic group of Ar in the general formula (1). ..

When R _{1 to} R ₄ represent the above-mentioned substituents, an alkyl group, an aromatic hydrocarbon group, a heterocyclic group, an aromatic heterocyclic group, a halogen atom, an aryloxy group, an arylthio group, an amino group, a cyano group It is preferably any one, particularly preferably any one of an aromatic hydrocarbon group, an aromatic heterocyclic group, a halogen atom and a cyano group, and particularly preferably a halogen atom or a cyano group.

  In the general formula (1), R represents an alkyl group, a halogen atom, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an acyl group, a sulfinyl group, a sulfonyl group, a nitro group, a cyano group, a hydroxy group or a mercapto group. Represents any selected group. In addition, these groups may be further substituted with the above-mentioned substituents. R is preferably an alkyl group, a halogen atom, or a cyano group, and is particularly an alkyl group or a cyano group from the viewpoint of more effectively suppressing the emission of a component having a wavelength longer than the maximum emission wavelength. Are preferred, and an alkyl group having 1 to 6 carbon atoms is particularly preferred.

  In the general formula (1), Ar represents an aromatic hydrocarbon group or an aromatic heterocyclic group. In addition, these groups may be further substituted with the above-mentioned substituents, or they may be condensed with each other to further form a ring. Ar is preferably substituted with the above-mentioned substituent, and particularly substituted with any one of an alkyl group, a cycloalkyl group, a halogen atom, an aromatic hydrocarbon group, a heterocyclic group and an aromatic heterocyclic group. Are particularly preferable, and those substituted with an alkyl group, an aromatic hydrocarbon group or an aromatic heterocyclic group are particularly preferable. Further, the ortho position is substituted with respect to the bonding position with the 1H-1,2,4-triazole ring of the general formula (1) (1H-1,2,4-of the ring represented by Ar). It is preferable to have a substituent at the position adjacent to the bonding position with the triazole ring) from the viewpoint of shortening the emission wavelength, and it is particularly preferable that the substituent is substituted with an alkyl group.

In the general formula (1), X ₁ -L ₁ -X ₂ represents a bidentate ligand, and X ₁ and X ₂ each independently represent a carbon atom, a nitrogen atom or an oxygen atom. L ₁ represents an atomic group forming a bidentate ligand with X ₁ and X ₂ .

Specific examples of the bidentate ligand represented by X ₁ -L ₁ -X ₂ include substituted or unsubstituted phenylpyridine, phenylpyrazole, phenylimidazole, phenyltriazole, phenyltetrazole, pyrazabole, acetylacetone, picolinic acid. However, the present invention is not limited to these. The bidentate ligand represented by X ₁ -L ₁ -X ₂ is preferably phenylpyrazole or phenyltriazole, and particularly preferably phenyltriazole.

  In the general formula (1), m represents an integer of 1 to 3, n represents an integer of 0 to 2, and m + n is 3. n is preferably 0 or 1, and particularly preferably 0 from the viewpoint of more effectively suppressing the emission of a component having a wavelength longer than the emission maximum wavelength.

In the general formula (1), at least two of adjacent R _{1 to} R ₄ are condensed to represent the structure of either the general formula (3) or (4).

In formulas (3) and (4), Y _{1 to} Y ₄ each independently represent O, S or NR ′, and Y ₅ or Y ₆ represent CR ″ or N. Y ₁ or Y ₄ is particularly preferably N—R ′, Y ₂ or Y ₃ is preferably O or N—R ′, and particularly preferably N—R ′. Y ₅ is preferably CR ″, and Y ₆ is preferably N.

In the general formulas (3) and (4), R ′ represents any group selected from an alkyl group, a cycloalkyl group, an aromatic hydrocarbon group, a heterocyclic group and an aromatic heterocyclic group. In addition, these groups may be further substituted with the above-mentioned substituents, or they may be condensed with each other to further form a ring. R ′ is preferably any group selected from an aromatic hydrocarbon group, a heterocyclic group and an aromatic heterocyclic group, and particularly preferably an aromatic hydrocarbon group or an aromatic heterocyclic group.

In the general formulas (3) and (4), R ″ represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aromatic hydrocarbon group, a heterocyclic group, an aromatic heterocyclic group, a halogen atom, an amino group, a cyano group. Represents an arylsilyl group or an arylphosphoryl group. In addition, these groups may be further substituted with the above-mentioned substituents, or they may be condensed with each other to further form a ring. R ″ is preferably any group selected from a hydrogen atom, an aromatic hydrocarbon group and an aromatic heterocyclic group.

In formulas (3) and (4), Z _{1 to} Z ₈ each independently represent C—Rx or N, and a plurality of Rx may be the same or different. Z _{1 to} Z ₈ are preferably C-Rx. A plurality of Rx each independently represents a group equivalent to R _{1 to} R ₄ in the general formula (1). In addition, these groups may be further substituted with the above-mentioned substituents, or they may be condensed with each other to further form a ring. When one or more of a plurality of Rx represent the above substituents, Rx is selected from an alkyl group, an aromatic hydrocarbon group, a heterocyclic group, an aromatic heterocyclic group, a halogen atom, an amino group and a cyano group. It is preferably any group selected from the group consisting of alkyl group, aromatic hydrocarbon group, aromatic heterocyclic group, halogen atom and cyano group.

In the general formulas (3) and (4), * represents a bonding position with the structure represented by the general formula (1).

  The compound having the structure represented by the general formula (1) may be contained in an organic layer other than the light emitting layer.

(1.1.2) Compound Having Structure Represented by General Formulas (5) and (7) to (10) The structure represented by general formula (1) is represented by the following general formulas (5) and (7). The structure represented by any one of to (10) is preferable.

In the general formulas (5) and (7) to (10) , R, Ar, R _{1 to} R ₄ , Y ₁ , Z _{1 to} Z ₄ , X ₁ , X ₂ , L ₁ , m and n are the above general ones. equation (1), (3) and (4) R _{of, Ar, R 1 ~R 4,} Y 1, Z 1 ~Z 4, X 1, X 2, L 1, synonymous with m and n.

(1.1.3) Specific Examples Hereinafter, specific examples of the compound having a structure represented by the general formula (1) according to the present invention will be shown, but the invention is not limited thereto.

(1.1.4) Synthetic Example Hereinafter, a synthetic example of a compound having a structure represented by any one of the general formulas (1) to (10) will be described by taking the exemplified compound 3-3 as an example. It is not limited to this.
Exemplified compound 3-3 can be synthesized according to the following scheme.

  Under a nitrogen stream, 5.0 g (9.60 mmol) of intermediate 1, iridium chloride 3.39 g (9.60 mmol), 2-ethoxyethanol 40 mL and water 10 mL were placed in a flask and heated and stirred at 100 ° C. for 4 hours. .. The precipitated crystals were collected by filtration, and the collected crystals were washed with methanol to obtain 11.5 g of Intermediate 2.

In a flask under a nitrogen stream, 4.73 g (9.07 mmol) of intermediate 1, 11.5 g (4.54 mmol) of intermediate 2, 2.51 g (11.4 mmol) of silver trifluoroacetate and phenylacetate 230 mL Was added, and the mixture was heated and stirred at 180 ° C. for 9 hours. The reaction solution was allowed to cool to room temperature and then concentrated under reduced pressure, and the obtained crude product was purified by silica gel column chromatography to obtain 1.27 g (yield 8%) of Exemplified Compound 3-3. The structure of Exemplified Compound 3-3 was confirmed by mass spectrum and ¹ H-NMR. In addition, in the production of an organic EL device described later, a sublimation-purified product of this compound was used.

  Other compounds of the present invention can also be synthesized in good yield by using appropriate raw materials and reactions, as in the above-mentioned synthesis examples.

(1.2) Fluorescent Dopant As a fluorescent dopant (hereinafter, also referred to as a fluorescent compound), a coumarin dye, a pyran dye, a cyanine dye, a croconium dye, a squarylium dye, an oxobenzanthracene dye, and a fluorescein dye. Examples thereof include dyes, rhodamine-based dyes, pyrylium-based dyes, perylene-based dyes, stilbene-based dyes, polythiophene-based dyes or rare earth complex-based phosphors, and compounds having a high fluorescence quantum yield typified by laser dyes.

Further, in recent years, luminescent dopants utilizing delayed fluorescence have been developed, and these may be used.
Specific examples of the luminescent dopant utilizing delayed fluorescence include the compounds described in International Publication No. 2011/156793, JP 2011-213643 A, JP 2010-93181 A, and the like. Are not limited to these.

(1.3) Combined Use with Conventionally Known Luminescent Dopant The luminescent dopant according to the present invention may be used in combination of plural kinds of compounds, such as a combination of phosphorescent dopants having different structures, a phosphorescent dopant and fluorescence. You may use combining a dopant. Known phosphorescent dopants and fluorescent dopants can be used together.

(2) Host compound In the present invention, the host compound (hereinafter, also referred to as a light emitting host) has a mass ratio of 20% or more in the compound contained in the light emitting layer and at room temperature (25 ° C). ) Is defined as a compound having a phosphorescence quantum yield of phosphorescence emission of less than 0.1. The phosphorescence quantum yield is preferably less than 0.01. Further, among the compounds contained in the light emitting layer, the mass ratio in the layer is preferably 20% or more.

  The light emitting host that can be used in the present invention is not particularly limited, and compounds conventionally used in organic EL devices can be used. Typically, those having a basic skeleton such as a carbazole derivative, a triarylamine derivative, an aromatic derivative, a nitrogen-containing heterocyclic compound, a thiophene derivative, a furan derivative, an oligoarylene compound, or a carboline derivative or a diazacarbazole derivative (here , And the diazacarbazole derivative means that at least one carbon atom of the hydrocarbon ring constituting the carboline ring of the carboline derivative is substituted with a nitrogen atom).

  As a known light-emitting host that can be used in the present invention, a compound that has a hole-transporting ability and an electron-transporting ability, prevents the emission from having a long wavelength, and has a high Tg (glass transition temperature) is preferable.

  In the present invention, conventionally known light emitting hosts may be used alone or in combination of two or more kinds. By using a plurality of types of light emitting hosts, it is possible to adjust the movement of charges and improve the efficiency of the organic EL device. Further, by using a plurality of kinds of the metal complex of the present invention used as the phosphorescent dopant and / or a conventionally known compound, it is possible to mix different luminescence, and thereby an arbitrary luminescent color can be obtained.

  The luminescent host used in the present invention may be a low molecular compound, a high molecular compound having a repeating unit, or a low molecular compound having a polymerizable group such as a vinyl group or an epoxy group (polymerizable luminescent host). Of course, one or more such compounds may be used.

  Specific examples of known light emitting hosts include JP 2001-257076A, JP 2002-308855A, JP 2001-313179A, JP 2002-319491A, 2001-357977 and 2002-334786. No. 2002, No. 2002-8860, No. 2002-334787, No. 2002-15871, No. 2002-334788, No. 2002-43056, No. 2002-334789, No. 2002-75645. JP, 2002-338579, 2002-105445, 2002-343568, 2002-141173, 2002-352957, 2002-203683, 2002-363227. No. 2002-231453, No. 2003-3165, No. 2002-234888, No. 2003-27048, No. 2002-255934, No. 2002-260861, No. 2002-280183. The compounds described in documents such as JP-A Nos. 2002-299060, 2002-302516, 2002-305083, 2002-305084, and 2002-308837 are mentioned.

  Further, as described above, since the compound having the structure represented by the general formula (1) according to the present invention has a deep HOMO level, a host compound having a HOMO level of −5.4 eV or less is used. Preferably. As a result, the movement of the charges becomes smooth, which leads to further improvement of the luminous efficiency and the driving voltage.

  Next, the injection layer, the blocking layer, the electron transporting layer, the hole transporting layer and the like, which are preferably used as the constituent layers of the organic EL device of the present invention, will be described.

<Electron transport layer>
In the present invention, the electron transport layer is made of a material having a function of transporting electrons, and may have a function of transmitting the electrons injected from the cathode to the light emitting layer.

  The total thickness of the electron transport layer used in the present invention is not particularly limited, but is usually in the range of 2 nm to 5 μm, more preferably 2 to 500 nm, further preferably 5 to 200 nm.

Further, in the organic EL element, when the light generated in the light emitting layer is extracted from the electrode, the light directly extracted from the light emitting layer interferes with the light extracted after being reflected by the electrode that is opposite to the light extracting electrode. It is known to wake up. When the light is reflected by the cathode, it is possible to efficiently use this interference effect by appropriately adjusting the layer thickness of the electron transport layer within a range of several nm to several μm.
On the other hand, when the layer thickness of the electron transport layer is increased, the voltage is likely to increase. Therefore, especially when the layer thickness is large, the electron mobility of the electron transport layer is preferably 10 ⁻⁵ cm ² / Vs or more. ..

  The material used for the electron-transporting layer (hereinafter referred to as electron-transporting material) may have any of an electron injecting property or a transporting property and a hole blocking property. Any one can be selected and used.

  For example, nitrogen-containing aromatic heterocyclic derivatives (carbazole derivatives, azacarbazole derivatives (one or more of the carbon atoms constituting the carbazole ring are substituted with nitrogen atoms), pyridine derivatives, pyrimidine derivatives, pyrazine derivatives, pyridazine derivatives, Triazine derivative, quinoline derivative, quinoxaline derivative, phenanthroline derivative, azatriphenylene derivative, oxazole derivative, thiazole derivative, oxadiazole derivative, thiadiazole derivative, triazole derivative, benzimidazole derivative, benzoxazole derivative, benzthiazole derivative, etc.), dibenzofuran derivative, Examples thereof include dibenzothiophene derivatives, silole derivatives, aromatic hydrocarbon ring derivatives (naphthalene derivatives, anthracene derivatives, triphenylene, etc.).

  Further, a metal complex having a quinolinol skeleton or a dibenzoquinolinol skeleton as a ligand, for example, tris (8-quinolinol) aluminum (Alq3), tris (5,7-dichloro-8-quinolinol) aluminum, tris (5,7- Dibromo-8-quinolinol) aluminum, tris (2-methyl-8-quinolinol) aluminum, tris (5-methyl-8-quinolinol) aluminum, bis (8-quinolinol) zinc (Znq), and the like, and their metal complexes. A metal complex in which the central metal is replaced with In, Mg, Cu, Ca, Sn, Ga or Pb can also be used as the electron transport material.

  In addition, metal-free or metal phthalocyanine, or those whose terminal is substituted with an alkyl group, a sulfonic acid group, or the like can be preferably used as the electron transport material. Further, a distyrylpyrazine derivative can also be used as an electron transporting material, and an inorganic semiconductor such as n-type-Si or n-type-SiC can also be used as an electron transporting material as in the hole injection layer and the hole transporting layer. You can

  Further, a polymer material obtained by introducing these materials into a polymer chain or using these materials as a polymer main chain can also be used.

  In the electron transport layer used in the present invention, the electron transport layer may be doped with a doping material as a guest material to form an electron transport layer having a high n property (electron rich). Examples of the doping material include n-type dopants such as metal compounds such as metal complexes and metal halides. Specific examples of the electron transport layer having such a structure include, for example, JP-A-4-297076, JP-A-10-270172, JP-A-2000-196140, JP-A-2001-102175 and J. Appl. Phys. , 95, 5773 (2004) and the like.

Specific examples of the known preferable electron transport material used in the organic EL device of the present invention include the compounds described in the following documents, but the present invention is not limited thereto.
United States Patent No. 6528187, United States Patent No. 7230107, United States Patent Application Publication No. 2005/0025993, United States Patent Application Publication No. 2004/0036077, United States Patent Application Publication No. 2009/0115316. , U.S. Patent Application Publication No. 2009/0101870, U.S. Patent Application Publication No. 2009/0179554, International Publication No. 2003/060956, International Publication No. 2008/132085, Appl. Phys. Lett. , 75, 4 (1999), Appl. Phys. Lett. , 79, 449 (2001), Appl. Phys. Lett. , 81, 162 (2002), Appl. Phys. Lett. , 81, 162 (2002), Appl. Phys. Lett. , 79, 156 (2001), U.S. Patent No. 7,964,293, U.S. Patent Application Publication No. 2009/030202, International Publication No. 2004/080975, International Publication No. 2004/063159, International Publication No. 2005/085387. International Publication No. 2006/067931, International Publication No. 2007/086552, International Publication No. 2008/114690, International Publication No. 2009/06942, International Publication No. 2009/066779, International Publication No. 2009/054253, International Publication No. 2011/086935, International Publication No. 2010/150593, International Publication No. 2010/047707, European Patent No. 2311826, JP 2010-251675 A, JP 2009-209133 A, JP 2009-124114, JP 2008-277810 A, JP 2006-156445 A, JP 2005-340122 A, JP 2003-45662 A, JP 2003-31367 A, JP 2003-A. No. 2822270, International Publication No. 2012/115034 and the like.

  More preferable electron transporting materials in the present invention include pyridine derivatives, pyrimidine derivatives, pyrazine derivatives, triazine derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, carbazole derivatives, azacarbazole derivatives and benzimidazole derivatives.

  The electron transport materials may be used alone or in combination of two or more.

<Hole blocking layer>
The hole blocking layer is a layer having a function of an electron transporting layer in a broad sense, and is preferably made of a material having a function of transporting an electron and having a small ability to transport a hole. By blocking the holes, the recombination probability of electrons and holes can be improved. Further, the structure of the electron transport layer described above can be used as the hole blocking layer used in the present invention, if necessary. The hole blocking layer provided in the organic EL device of the present invention is preferably provided adjacent to the cathode side of the light emitting layer.

  The layer thickness of the hole blocking layer used in the present invention is preferably in the range of 3 to 100 nm, more preferably 5 to 30 nm.

  As the material used for the hole blocking layer, the material used for the electron transport layer described above is preferably used, and the material used as the host compound described above is also preferably used for the hole blocking layer.

<Electron injection layer>
The electron injection layer (also referred to as “cathode buffer layer”) used in the present invention is a layer provided between the cathode and the light emitting layer in order to lower the driving voltage and improve the light emission brightness. And its industrialization front line (November 30, 1998, NTS Co., Ltd.) ”, Volume 2, Chapter 2,“ Electrode Materials ”(pages 123 to 166).
In the present invention, the electron injection layer may be provided as necessary and may be present between the cathode and the light emitting layer or between the cathode and the electron transport layer as described above.

  The electron injection layer is preferably a very thin film, and the layer thickness is preferably in the range of 0.1 to 5 nm, although it depends on the material. Further, it may be a non-uniform film in which the constituent material is present intermittently.

Details of the electron injection layer are described in JP-A-6-325871, JP-A-9-17574, JP-A-10-74586, and the like, and specific examples of materials preferably used for the electron injection layer are as follows. , Metals such as strontium and aluminum, alkali metal compounds such as lithium fluoride, sodium fluoride and potassium fluoride, alkaline earth metal compounds such as magnesium fluoride and calcium fluoride, oxidation Examples thereof include metal oxides typified by aluminum and metal complexes typified by lithium 8-hydroxyquinolate (Liq). It is also possible to use the above-mentioned electron transport material.
The materials used for the electron injection layer may be used alone or in combination of two or more.

<Hole transport layer>
In the present invention, the hole transport layer is made of a material having a function of transporting holes, and may have a function of transmitting the holes injected from the anode to the light emitting layer.

  The total thickness of the hole transport layer used in the present invention is not particularly limited, but is usually in the range of 5 nm to 5 μm, more preferably 2 to 500 nm, and further preferably 5 to 200 nm.

  The material used for the hole transport layer (hereinafter, also referred to as a hole transport material) may have any of a hole injecting property, a hole transporting property, and an electron barrier property. Any of these can be selected and used.

  For example, porphyrin derivative, phthalocyanine derivative, oxazole derivative, oxadiazole derivative, triazole derivative, imidazole derivative, pyrazoline derivative, pyrazolone derivative, phenylenediamine derivative, hydrazone derivative, stilbene derivative, polyarylalkane derivative, triarylamine derivative, carbazole derivative. , Indolocarbazole derivatives, isoindole derivatives, acene derivatives such as anthracene and naphthalene, fluorene derivatives, fluorenone derivatives, and polyvinylcarbazole, polymer materials or oligomers containing aromatic amines introduced into the main chain or side chains, polysilane, conductive Polymers or oligomers (for example, PEDOT / PSS, aniline-based copolymers, polyaniline, polythiophene, etc.) and the like can be mentioned.

  Examples of triarylamine derivatives include benzidine type compounds represented by α-NPD (4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl) and starburst type compounds represented by MTDATA. Examples thereof include compounds having fluorene or anthracene in the triarylamine-linked core portion.

  Further, a hexaazatriphenylene derivative as described in JP-B-2003-515432, JP-A-2006-135145, etc. can be similarly used as the hole transport material.

  Further, a hole transport layer having a high p property doped with impurities can be used. Examples thereof include JP-A-4-297076, JP-A-2000-196140, and JP-A-2001-102175, J. Appl. Phys. , 95, 5773 (2004) and the like.

Further, JP-A No. 11-251067, J. Huang et. al. A so-called p-type hole transporting material or an inorganic compound such as p-type-Si or p-type-SiC as described in the literature (Appl. Phys. Lett., 80 (2002), p. 139) is used. You can also Furthermore, an orthometalated organometallic complex having Ir or Pt as a central metal, which is represented by Ir (ppy) ₃ , is also preferably used.

  As the hole-transporting material, the above-mentioned ones can be used, but a triarylamine derivative, a carbazole derivative, an indolocarbazole derivative, an azatriphenylene derivative, an organometallic complex, and an aromatic amine are introduced into the main chain or side chains. The polymer materials or oligomers mentioned above are preferably used.

Specific examples of known preferable hole transport materials used in the organic EL device of the present invention include the compounds described in the following documents in addition to the above-mentioned documents, but the present invention is not limited thereto. Not done.
For example, Appl. Phys. Lett. 69, 2160 (1996), J. Lumin. , 72-74, 985 (1997), Appl. Phys. Lett. , 78, 673 (2001), Appl. Phys. Lett. , 90, 183503 (2007), Appl. Phys. Lett. , 90, 183503 (2007), Appl. Phys. Lett. , 51, 913 (1987), Synth. Met. , 87, 171 (1997), Synth. Met. , 91, 209 (1997), Synth. Met. , 111, 421 (2000), SID Symposium Digest, 37, 923 (2006), J. Am. Mater. Chem. , 3,319 (1993), Adv. Mater. , 6,677 (1994), Chem. Mater. , 15, 3148 (2003), U.S. Patent Application Publication No. 2003/0162053, U.S. Patent Application Publication No. 2002/0158242, U.S. Patent Application Publication No. 2006/0240279, U.S. Patent Application Publication 2008. No. / 0220265, U.S. Pat. No. 5,061,569, WO 2007/002683, WO 2009/01809, European Patent 650955, US Patent Application Publication No. 2008/0124572, U.S. Patent Application Publication No. 2007/0278938, U.S. Patent Application Publication No. 2008/0106190, U.S. Patent Application Publication No. 2008/0018221, International Publication No. 2012/115034, and Japanese Patent Publication No. 2003-515432. Japanese Patent Laid-Open No. 2006-135145, US Patent Application No. 13/585981, and the like.

  The hole transport material may be used alone or in combination of two or more kinds.

<Electron blocking layer>
The electron blocking layer is a layer having a function of a hole transport layer in a broad sense, and is preferably made of a material having a function of transporting holes and having a small ability to transport electrons, while transporting holes. By blocking the electrons, the recombination probability of electrons and holes can be improved.
Further, the structure of the hole transport layer described above can be used as the electron blocking layer used in the present invention, if necessary.
The electron blocking layer provided in the organic EL device of the present invention is preferably provided adjacent to the anode side of the light emitting layer.

  The layer thickness of the electron blocking layer used in the present invention is preferably in the range of 3 to 100 nm, more preferably 5 to 30 nm.

  As the material used for the electron blocking layer, the material used for the hole transport layer described above is preferably used, and the material used as the host compound described above is also preferably used for the electron blocking layer.

<Hole injection layer>
The hole injecting layer (also referred to as “anode buffer layer”) used in the present invention is a layer provided between the anode and the light emitting layer for the purpose of lowering driving voltage and improving light emission brightness. Devices and their forefront of industrialization (published on Nov. 30, 1998, NTS Co., Ltd.), Volume 2, Chapter 2, "Electrode Materials" (pages 123 to 166).
In the present invention, the hole injection layer may be provided as necessary and may be present between the anode and the light emitting layer or between the anode and the hole transport layer as described above.

The hole injection layer is described in detail in JP-A-9-45479, JP-A-9-260062, JP-A-8-288069, and the like, and examples of the material used for the hole injection layer include: Examples thereof include the materials used for the hole transport layer.
Among them, a phthalocyanine derivative typified by copper phthalocyanine, a hexaazatriphenylene derivative as described in JP-A-2003-159432, JP-A-2006-135145, a metal oxide typified by vanadium oxide, and an amorphous carbon Conductive polymers such as polyaniline (emeraldine) and polythiophene, orthometallated complexes represented by tris (2-phenylpyridine) iridium complex, triarylamine derivatives and the like are preferable.

  The above-mentioned materials used for the hole injection layer may be used alone or in combination of two or more.

<Other additive compounds>
The organic layer in the present invention described above may further contain other additive compounds. Examples of the additive compound include halogen elements such as bromine, iodine and chlorine, halogenated compounds, alkali metal and alkaline earth metals such as Pd, Ca and Na, compounds and complexes of transition metals, salts and the like.

The content of the additive compound can be arbitrarily determined, but it is preferably 1000 ppm or less, more preferably 500 ppm or less, and further preferably 50 ppm or less based on the total mass% of the layer to be contained. ..
However, it is not within this range depending on the purpose of improving the transportability of electrons and holes, the purpose of favoring energy transfer of excitons, and the like.

<< Method of forming organic layer >>
The method for forming the organic layer (hole injection layer, hole transport layer, electron blocking layer, light emitting layer, hole blocking layer, electron transport layer, electron injection layer, etc.) used in the present invention will be described.

  The method for forming the organic layer used in the present invention is not particularly limited, and a conventionally known method such as a vacuum deposition method or a wet method (also referred to as a wet process) can be used, but the organic layer is wet. It is preferably a layer formed by the process. That is, it is preferable to manufacture the organic EL element by a wet process. By manufacturing the organic EL element by a wet process, it is possible to obtain an effect that a uniform film (coating film) is easily obtained and pinholes are not easily generated. In addition, the film (coating film) here is in a state of being dried after being applied by a wet process.

  Examples of the wet method include a spin coating method, a casting method, an inkjet method, a printing method, a die coating method, a blade coating method, a roll coating method, a spray coating method, a curtain coating method and an LB method (Langmuir-Blodgett method). A roll-to-roll method having high suitability such as a die coating method, a roll coating method, an ink jet method, and a spray coating method is preferable because a uniform thin film can be easily obtained and high productivity can be obtained.

  As a liquid medium for dissolving or dispersing the organic EL material of the present invention, for example, methyl ethyl ketone, ketones such as cyclohexanone, fatty acid esters such as ethyl acetate, halogenated hydrocarbons such as dichlorobenzene, toluene, xylene, mesitylene, Aromatic hydrocarbons such as cyclohexylbenzene, aliphatic hydrocarbons such as cyclohexane, decalin and dodecane, and organic solvents such as DMF and DMSO can be used.

  Further, as a dispersion method, it is possible to disperse by a dispersion method such as ultrasonic wave, high shearing force dispersion or media dispersion.

Furthermore, different film forming methods may be applied for each layer. When the vapor deposition method is adopted for film formation, the vapor deposition conditions vary depending on the type of compound used and the like, but generally, the boat heating temperature is 50 to 450 ° C., the degree of vacuum is 10 ⁻⁶ to 10 ⁻² Pa, the vapor deposition rate is 0.01 to It is desirable to appropriately select within a range of 50 nm / sec, a substrate temperature of -50 to 300 ° C., and a layer thickness of 0.1 nm to 5 μm, preferably 5 to 200 nm.

  In forming the organic layer according to the present invention, it is preferable to consistently form from the hole injection layer to the cathode by vacuuming once, but it is also possible to take out in the middle and perform a different film forming method. In that case, it is preferable to perform the work in a dry inert gas atmosphere.

"anode"
As the anode in the organic EL device, those having an electrode substance of a metal, an alloy, an electrically conductive compound and a mixture thereof having a large work function (4 eV or more, preferably 4.5 eV or more) are preferably used. Specific examples of such an electrode substance include a conductive transparent material such as metal such as Au, CuI, indium tin oxide (ITO), SnO ₂ and ZnO.
In addition, a material such as IDIXO (In ₂ O ₃ —ZnO) that can form an amorphous transparent conductive film may be used.

As a method for forming the anode, a thin film may be formed by a method such as vapor deposition or sputtering using these electrode substances, and a pattern having a desired shape may be formed by a photolithography method, or pattern accuracy is not required so much. If not (about 100 μm or more), a pattern may be formed through a mask having a desired shape during vapor deposition or sputtering of the electrode material.
Further, when a coatable substance such as an organic conductive compound is used, a wet film forming method such as a printing method or a coating method can be used. When the emitted light is taken out from this anode, it is desirable that the transmittance is greater than 10%, and the sheet resistance as the anode is preferably several hundred Ω / □ or less.

  Although the thickness of the anode depends on the material, it is generally selected in the range of 10 nm to 1 μm, preferably 10 to 200 nm.

"cathode"
As the cathode, a metal having a low work function (4 eV or less) (referred to as an electron injecting metal), an alloy, an electrically conductive compound, or a mixture thereof is used as an electrode material. Specific examples of such an electrode material include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide (Al ₂ O 3). ₃ ) Mixtures, indium, lithium / aluminum mixtures, aluminum, rare earth metals and the like. Among these, a mixture of an electron-injecting metal and a second metal which is a stable metal having a larger work function than that of the electron-injecting metal, for example, a magnesium / silver mixture, from the viewpoint of electron injecting property and durability against oxidation and the like. Suitable are magnesium / aluminum mixtures, magnesium / indium mixtures, aluminum / aluminum oxide (Al ₂ O ₃ ) mixtures, lithium / aluminium mixtures, aluminum and the like.

  The cathode can be produced by forming a thin film of these electrode substances by a method such as vapor deposition or sputtering. The sheet resistance as the cathode is preferably several hundreds Ω / □ or less, and the thickness is usually selected in the range of 10 nm to 5 μm, preferably 50 to 200 nm.

Since the emitted light is transmitted, if either the anode or the cathode of the organic EL element is transparent or semi-transparent, the emission brightness is improved, which is convenient.
In addition, a transparent or semitransparent cathode can be produced by producing the above-mentioned metal in a thickness of 1 to 20 nm on the cathode, and then producing the conductive transparent material mentioned in the explanation of the anode thereon, By applying this, an element in which both the anode and the cathode are transparent can be manufactured.

《Supporting substrate》
The supporting substrate (hereinafter, also referred to as a substrate, a substrate, a substrate, a support, etc.) that can be used in the organic EL device of the present invention is not particularly limited in the kind of glass, plastic, etc., and is transparent. Or it may be opaque. When the light is extracted from the supporting substrate side, the supporting substrate is preferably transparent. Examples of transparent support substrates that are preferably used include glass, quartz, and transparent resin films. A particularly preferable support substrate is a resin film that can give flexibility to the organic EL element.

  Examples of the resin film include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyethylene, polypropylene, cellophane, cellulose diacetate, cellulose triacetate (TAC), cellulose acetate butyrate, cellulose acetate propionate ( CAP), cellulose acetate phthalate, cellulose esters such as cellulose nitrate or derivatives thereof, polyvinylidene chloride, polyvinyl alcohol, polyethylene vinyl alcohol, syndiotactic polystyrene, polycarbonate, norbornene resin, polymethylpentene, polyether ketone, polyimide , Polyethersulfone (PES), Polyphenylene sulfide, Polysulfones, Polyetherimide, Polyetherketone imide, Polyamide, Fluorine resin, Nylon, Polymethylmethacrylate, Acrylic or polyarylates, Arton (product name JSR) or Apel Examples of the film include cycloolefin-based resins such as (trade name, manufactured by Mitsui Chemicals, Inc.).

On the surface of the resin film, an inorganic film, an organic film or a hybrid film of both of them may be formed, and the water vapor permeability (25 ± 0.5 ° C.) measured by the method according to JIS K 7129-1992. , Relative humidity (90 ± 2)%) is preferably 1 × 10 ⁻² g / (m ² · 24 h) or less gas barrier film, and further measured by a method according to JIS K 7126-1987. With a high gas barrier film having an oxygen permeability of 1 × 10 ⁻³ mL / (m ² · 24 h · atm) or less and a water vapor permeability of 1 × 10 ⁻⁵ g / (m ² · 24 h) or less. Preferably.

  As a material for forming the gas barrier film, any material may be used as long as it has a function of suppressing entry of moisture or oxygen, which causes deterioration of the element, but, for example, silicon oxide, silicon dioxide, silicon nitride or the like can be used. Further, in order to improve the brittleness of the film, it is more preferable to have a laminated structure of these inorganic layer and a layer made of an organic material. The order of laminating the inorganic layer and the organic layer is not particularly limited, but it is preferable to alternately laminate the both layers a plurality of times.

  The method for forming the gas barrier film is not particularly limited, and examples thereof include vacuum deposition method, sputtering method, reactive sputtering method, molecular beam epitaxy method, cluster ion beam method, ion plating method, plasma polymerization method, and atmospheric pressure plasma heavy. Although a method such as a conventional method, a plasma CVD method, a laser CVD method, a thermal CVD method, and a coating method can be used, the method by the atmospheric pressure plasma polymerization method as described in JP-A-2004-68143 is particularly preferable.

  Examples of the opaque support substrate include metal plates such as aluminum and stainless steel, films and opaque resin substrates, and ceramic substrates.

The external extraction quantum efficiency of light emission of the organic EL device of the present invention at room temperature is preferably 1% or more, and more preferably 5% or more.
Here, the external extraction quantum efficiency (%) = the number of photons emitted outside the organic EL element / the number of electrons flown into the organic EL element × 100.
Further, a hue improving filter such as a color filter or the like may be used together, or a color conversion filter that converts the emission color from the organic EL element into a multicolor by using as a phosphor may be used together.

《Sealing》
Examples of the sealing means used for sealing the organic EL element of the present invention include a method of bonding a sealing member, an electrode, and a support substrate with an adhesive. The sealing member only needs to be arranged so as to cover the display region of the organic EL element, and may have a concave plate shape or a flat plate shape. Moreover, the transparency and the electrical insulation are not particularly limited.

  Specific examples thereof include glass plates, polymer plates / films, metal plates / films, and the like. Examples of the glass plate include soda-lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, and quartz. Further, examples of the polymer plate include polycarbonate, acrylic, polyethylene terephthalate, polyether sulfide, polysulfone and the like. Examples of the metal plate include those made of one or more metals or alloys selected from the group consisting of stainless steel, iron, copper, aluminum, magnesium, nickel, zinc, chromium, titanium, molybdenum, silicon, germanium and tantalum.

In the present invention, a polymer film or a metal film can be preferably used because the organic EL device can be made thin. Further, the polymer film has an oxygen permeability of 1 × 10 ⁻³ mL / (m ² · 24 h · atm) or less measured by a method according to JIS K 7126-1987, and a method according to JIS K 7129-1992. the measured water vapor transmission rate (25 ± 0.5 ° C., relative humidity (90 ± 2)%) is preferably that of ^{1 × 10 -3 g / (m} 2 / 24h) or less.

  To process the sealing member into a concave shape, sandblasting, chemical etching, etc. are used.

Specific examples of the adhesive include photocurable and thermosetting adhesives having a reactive vinyl group of acrylic acid-based oligomer and methacrylic acid-based oligomer, and moisture-curable adhesives such as 2-cyanoacrylic acid ester. be able to. In addition, epoxy and other heat and chemical curing types (mixing of two liquids) can be used. Moreover, hot-melt type polyamide, polyester, and polyolefin can be mentioned. Further, a cation-curing type UV-curing type epoxy resin adhesive can be mentioned.
Since the organic EL element may be deteriorated by heat treatment, it is preferable that the adhesive can be cured from room temperature to 80 ° C. A desiccant may be dispersed in the adhesive. A commercially available dispenser may be used to apply the adhesive to the sealing portion, or printing such as screen printing may be performed.

In addition, it is also preferable to coat the electrode and the organic layer on the outside of the electrode facing the support substrate with the organic layer sandwiched therebetween, and form a layer of an inorganic material or an organic material in contact with the support substrate to form a sealing film. .. In this case, as the material for forming the film, any material may be used as long as it has a function of suppressing entry of moisture or oxygen, which causes deterioration of the element, but, for example, silicon oxide, silicon dioxide, silicon nitride or the like is used. it can.
Further, in order to improve the brittleness of the film, it is preferable to have a laminated structure of these inorganic layers and layers made of an organic material. The method for forming these films is not particularly limited, and examples thereof include vacuum deposition method, sputtering method, reactive sputtering method, molecular beam epitaxy method, cluster ion beam method, ion plating method, plasma polymerization method, and atmospheric pressure plasma heavy. A legal method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, or the like can be used.

In the gap between the sealing member and the display region of the organic EL element, an inert gas such as nitrogen or argon or an inert liquid such as fluorocarbon or silicon oil may be injected in the vapor phase and the liquid phase. preferable. A vacuum can also be used. Also, a hygroscopic compound can be enclosed inside.
Examples of the hygroscopic compound include metal oxides (eg, sodium oxide, potassium oxide, calcium oxide, barium oxide, magnesium oxide, aluminum oxide, etc.), sulfates (eg, sodium sulfate, calcium sulfate, magnesium sulfate, cobalt sulfate). Etc.), metal halides (eg, calcium chloride, magnesium chloride, cesium fluoride, tantalum fluoride, cerium bromide, magnesium bromide, barium iodide, magnesium iodide, etc.), perchloric acids (eg, perchloric acid) Barium, magnesium perchlorate, etc.) and the like, and anhydrous salts are preferably used for sulfates, metal halides and perchloric acids.

《Protective film, protective plate》
A protective film or a protective plate may be provided outside the encapsulating film or the encapsulating film on the side facing the support substrate with the organic layer sandwiched therebetween in order to enhance the mechanical strength of the device. In particular, when the sealing is performed by the sealing film, its mechanical strength is not necessarily high, so that it is preferable to provide such a protective film or protective plate.

  As a material that can be used for this, the same glass plate, polymer plate / film, metal plate / film, etc. as those used for the above-mentioned sealing can be used, but the polymer film is lightweight and thin. Is preferably used.

<Light extraction improvement technology>
The organic electroluminescence element emits light inside a layer having a higher refractive index than air (refractive index within a range of about 1.6 to 2.1), and accounts for about 15% to 20% of the light generated in the light emitting layer. It is generally said that only light can be extracted. This is because light incident on the interface (interface between the transparent substrate and air) at an angle θ equal to or greater than the critical angle causes total reflection and cannot be extracted to the outside of the device, and the light between the transparent electrode or the light emitting layer and the transparent substrate is This is because the light undergoes total internal reflection between them and the light is guided through the transparent electrode or the light emitting layer, and as a result, the light escapes toward the side surface of the device.

  As a method for improving the efficiency of extracting light, for example, a method of forming irregularities on the surface of a transparent substrate to prevent total internal reflection at the interface between the transparent substrate and the air (for example, US Pat. No. 4,774,435), is used. A method of improving efficiency by providing light condensing property (for example, Japanese Patent Laid-Open No. 63-314795), a method of forming a reflecting surface on a side surface of an element (for example, Japanese Patent Laid-Open No. 1-220394), substrate And a light-emitting body by introducing a flat layer having an intermediate refractive index to form an antireflection film (for example, Japanese Patent Application Laid-Open No. 62-172691), and a lower refractive index than the substrate between the substrate and the light-emitting body. (For example, Japanese Patent Laid-Open No. 2001-202827), a method of forming a diffraction grating between any of the substrate, the transparent electrode layer, and the light emitting layer (including the substrate and the outside) ( JP-A No. 11-283751) and the like.

In the present invention, these methods can be used in combination with the organic EL device of the present invention, but a method of introducing a flat layer having a lower refractive index than the substrate between the substrate and the light emitting body, or the substrate, the transparent A method of forming a diffraction grating between any of the electrode layers and the light emitting layer (including between the substrate and the outside) can be preferably used.
In the present invention, by combining these means, it is possible to obtain an element having higher brightness or durability.

When a medium with a low refractive index is formed between the transparent electrode and the transparent substrate with a thickness longer than the wavelength of light, the light emitted from the transparent electrode has a higher extraction efficiency to the outside as the refractive index of the medium is lower. Become.
Examples of the low refractive index layer include airgel, porous silica, magnesium fluoride, fluorine-based polymer and the like. Since the transparent substrate generally has a refractive index in the range of about 1.5 to 1.7, the low refractive index layer preferably has a refractive index of about 1.5 or less. Further, it is preferably 1.35 or less.
Moreover, it is desirable that the thickness of the low-refractive-index medium be at least twice the wavelength in the medium. This is because when the thickness of the low-refractive index medium reaches a wavelength of light and the electromagnetic wave exuded by evanescent penetrates into the substrate, the effect of the low-refractive index layer decreases.

  The method of introducing a diffraction grating into the interface that causes total internal reflection or into any one of the media is characterized by a high effect of improving the light extraction efficiency. This method uses the property that the diffraction grating can change the direction of light to a specific direction different from refraction by means of so-called Bragg diffraction such as first-order diffraction and second-order diffraction. The light that cannot go out due to total reflection between layers is diffracted by introducing a diffraction grating into any of the layers or into the medium (transparent substrate or transparent electrode). , Trying to get the light out.

The diffraction grating to be introduced preferably has a two-dimensional periodic refractive index. This is because the light emitted from the light emitting layer is randomly generated in all directions, so in a general one-dimensional diffraction grating that has a periodic refractive index distribution only in a certain direction, only the light traveling in a specific direction is diffracted. Therefore, the light extraction efficiency does not increase so much.
However, by making the refractive index distribution a two-dimensional distribution, light traveling in all directions is diffracted, and the light extraction efficiency is improved.

  The position where the diffraction grating is introduced may be between any layers or in the medium (in the transparent substrate or in the transparent electrode), but is preferably near the organic light emitting layer where light is generated. At this time, the period of the diffraction grating is preferably within a range of about 1/2 to 3 times the wavelength of the light in the medium. The array of the diffraction grating is preferably a two-dimensional array such as a square lattice shape, a triangular lattice shape, and a honeycomb lattice shape.

<Condensing sheet>
The organic EL element of the present invention is processed in a specific direction, for example, by processing so as to provide a microlens array-like structure on the light extraction side of a supporting substrate (substrate) or by combining it with a so-called condensing sheet. By condensing light in the front direction with respect to the light emitting surface of the device, it is possible to increase the brightness in a specific direction.

  As an example of the microlens array, square pyramids each having a side of 30 μm and an apex angle of 90 degrees are two-dimensionally arranged on the light extraction side of the substrate. One side is preferably in the range of 10 to 100 μm. If it is smaller than this range, the effect of diffraction occurs and it is colored, and if it is too large, the thickness becomes thick, which is not preferable.

As the light-condensing sheet, it is possible to use, for example, one that has been put to practical use in an LED backlight of a liquid crystal display device. As such a sheet, for example, a brightness enhancement film (BEF) manufactured by Sumitomo 3M Limited can be used. As the shape of the prism sheet, for example, a Δ-shaped stripe having an apex angle of 90 ° and a pitch of 50 μm may be formed on the base material, or the apex angle may be rounded or the pitch may be changed at random. It may have a different shape or another shape.
Further, a light diffusing plate / film may be used in combination with the light condensing sheet in order to control the light emission angle from the organic EL element. For example, a diffusion film (light up) manufactured by Kimoto Co., Ltd. can be used.

<< Use >>
The organic EL element of the present invention can be used as a display device, a display, and various light emitting light sources.

  Examples of light-emitting light sources include lighting devices (home lighting, vehicle interior lighting), clocks and liquid crystal backlights, billboard advertisements, traffic lights, light sources for optical storage media, light sources for electrophotographic copying machines, light sources for optical communication processors, and light sources. Examples of the light source include a light source of a sensor and the like, but the present invention is not limited thereto, and can be effectively used particularly as a backlight of a liquid crystal display device and a light source for illumination.

  In the organic EL element of the present invention, patterning may be carried out at the time of film formation by a metal mask, an inkjet printing method or the like, if necessary. When patterning, only the electrode may be patterned, the electrode and the light emitting layer may be patterned, or the entire element layer may be patterned. In the fabrication of the element, a conventionally known method is used. You can

《Display device》
The organic EL element of the present invention can be used in a display device.
One aspect of the display device of the present invention, which includes the organic EL element of the present invention, will be described. Although the display device may be monochromatic or multicolored, a multicolor display device will be described here.

In the case of a multicolor display device, a shadow mask is provided only when the light emitting layer is formed, and a film can be formed on one surface by a vapor deposition method, a casting method, a spin coating method, an inkjet method, a printing method, or the like.
When patterning only the light emitting layer, the method is not limited, but vapor deposition method, ink jet method, spin coating method, and printing method are preferable.

The configuration of the organic EL element included in the display device is selected from the above-described configuration examples of the organic EL element as needed.
The method for manufacturing the organic EL element is as shown in the above-described one aspect of manufacturing the organic EL element of the present invention.

  When a direct current voltage is applied to the thus obtained multicolor display device, light emission can be observed by applying a voltage of about 2 to 40 V with the anode having a positive polarity and the cathode having a negative polarity. Further, even if a voltage is applied with the opposite polarity, no current flows and no light emission occurs. Further, when an AC voltage is applied, light is emitted only when the anode is in the + state and the cathode is in the − state. The waveform of the alternating current applied may be arbitrary.

  The multicolor display device can be used as a display device, a display, and various light emitting sources. In the display device and the display, full-color display is possible by using three kinds of organic EL elements of blue, red, and green light emission.

  Examples of the display device and display include a television, a personal computer, a mobile device, an AV device, a teletext display, and an information display in a car. In particular, it may be used as a display device for reproducing a still image or a moving image, and a driving system for use as a display device for reproducing a moving image may be either a simple matrix (passive matrix) system or an active matrix system.

  Light-emitting light sources include home lighting, vehicle lighting, backlights for watches and liquid crystals, billboard advertisements, traffic lights, light sources for optical storage media, light sources for electrophotographic copying machines, light sources for optical communication processors, light sources for optical sensors, etc. However, the present invention is not limited thereto.

Hereinafter, an example of a display device having the organic EL element of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic diagram showing an example of a display device including an organic EL element. It is a schematic diagram of a display such as a mobile phone, which displays image information by light emission of an organic EL element.

The display 1 has a display section A having a plurality of pixels, a control section B that performs image scanning of the display section A based on image information, a wiring section C that electrically connects the display section A and the control section B, and the like. ..
The control unit B is electrically connected to the display unit A via the wiring unit C, sends a scanning signal and an image data signal to each of a plurality of pixels based on image information from the outside, and the pixels for each scanning line by the scanning signal. Emits light sequentially according to the image data signal to perform image scanning and display image information on the display unit A.

FIG. 2 is a schematic diagram of the display unit A in FIG.
The display section A has a wiring section including a plurality of scanning lines 5 and data lines 6, a plurality of pixels 3 and the like on a substrate. The main members of the display unit A will be described below.

FIG. 2 shows a case where the light emitted from the pixel 3 (emitted light) is extracted in the direction of the white arrow (downward).
The scanning lines 5 and the plurality of data lines 6 in the wiring portion are each made of a conductive material, and the scanning lines 5 and the data lines 6 are orthogonal to each other in a grid pattern and are connected to the pixels 3 at the orthogonal positions (details are shown in FIG. Not shown).

When the scanning signal is applied from the scanning line 5, the pixel 3 receives the image data signal from the data line 6 and emits light according to the received image data.
Full color display is possible by appropriately arranging pixels in the red region, pixels in the green region, and pixels in the blue region in parallel on the same substrate.

Next, the light emitting process of the pixel will be described. FIG. 3 is a schematic diagram showing a pixel circuit.
The pixel includes an organic EL element 10, a switching transistor 11, a drive transistor 12, a capacitor 13 and the like. Full-color display can be performed by using red, green, and blue light-emitting organic EL elements as the organic EL elements 10 in a plurality of pixels and arranging them in parallel on the same substrate.

  In FIG. 3, an image data signal is applied from the control unit B shown in FIG. 1 to the drain of the switching transistor 11 via the data line 6. Then, when a scanning signal is applied to the gate of the switching transistor 11 from the control unit B via the scanning line 5, the driving of the switching transistor 11 is turned on, and the image data signal applied to the drain is transferred to the capacitor 13 and the driving transistor 12. Is transmitted to the gate.

  By transmitting the image data signal, the capacitor 13 is charged according to the potential of the image data signal, and the driving of the drive transistor 12 is turned on. The drive transistor 12 has a drain connected to the power supply line 7 and a source connected to the electrode of the organic EL element 10. The drive transistor 12 is connected from the power supply line 7 to the organic EL element 10 according to the potential of the image data signal applied to the gate. Electric current is supplied.

  When the scanning signal moves to the next scanning line 5 by the sequential scanning of the control unit B, the driving of the switching transistor 11 is turned off. However, even if the driving of the switching transistor 11 is turned off, the capacitor 13 holds the potential of the charged image data signal, so that the driving of the driving transistor 12 is kept on and the next scanning signal is applied. The organic EL element 10 continues to emit light. When a scanning signal is applied next by sequential scanning, the driving transistor 12 is driven according to the potential of the next image data signal synchronized with the scanning signal, and the organic EL element 10 emits light.

  That is, the light emission of the organic EL element 10 is such that the switching transistor 11 and the drive transistor 12 which are active elements are provided for the organic EL element 10 of each of the plurality of pixels, and the organic EL element 10 of each of the plurality of pixels 3 emits light. It is carried out. Such a light emitting method is called an active matrix method.

  Here, the light emission of the organic EL element 10 may be light emission of a plurality of gradations by a multi-valued image data signal having a plurality of gradation potentials, or may be ON or OFF of a predetermined light emission amount by a binary image data signal. good. The potential of the capacitor 13 may be held continuously until the next scanning signal is applied, or may be discharged immediately before the next scanning signal is applied.

  The present invention is not limited to the active matrix system described above, but may be a passive matrix system light emission drive in which the organic EL element emits light according to the data signal only when the scanning signal is scanned.

FIG. 4 is a schematic diagram of a passive matrix full-color display device according to the display unit A of FIG. In FIG. 4, a plurality of scanning lines 5 and a plurality of image data lines 6 are provided in a grid pattern so as to face each other with the pixel 3 interposed therebetween.
When the scanning signal of the scanning line 5 is applied by sequential scanning, the pixels 3 connected to the applied scanning line 5 emit light according to the image data signal.
In the passive matrix method, the pixel 3 has no active element, and the manufacturing cost can be reduced.

  By using the organic EL element of the present invention, a display device having improved luminous efficiency can be obtained.

《Lighting device》
The organic EL element of the present invention can be used in a lighting device.
One aspect of the lighting device of the present invention, which includes the organic EL element of the present invention, will be described.

  The non-light-emitting surface of the organic EL device of the present invention is covered with a glass case, a glass substrate having a thickness of 300 μm is used as a sealing substrate, and an epoxy-based photocurable adhesive (Lux manufactured by Toagosei Co., Ltd. is used as a sealing material around the periphery. Track LC0629B) is applied, and this is stacked on the cathode and brought into close contact with the transparent supporting substrate, and UV light is irradiated from the glass substrate side to cure and seal the illumination as shown in FIGS. 5 and 6. The device can be made.

  FIG. 5 shows a schematic view of a lighting device, and the organic EL element 101 of the present invention is covered with a glass cover 102 (note that the sealing operation with the glass cover involves bringing the organic EL element 101 into contact with the atmosphere). Without using a glove box under a nitrogen atmosphere (under a high-purity nitrogen gas atmosphere with a purity of 99.999% or more).

  FIG. 6 shows a sectional view of the illuminating device. In FIG. 6, 105 is a cathode, 106 is an organic EL layer, and 107 is a glass substrate with a transparent electrode. The glass cover 102 is filled with nitrogen gas 108 and is provided with a water catching agent 109.

  Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In the examples, “part” or “%” is used, but “volume%” is indicated unless otherwise specified. The exemplified compounds 1-1 to 8-19 used in the examples correspond to the specific examples 1-1 to 8-19 of the compound having the structure represented by the general formula (1). Further, the structures of Comparative Compounds 1 to 4 used in Examples are shown.

Comparative Compound 1: Compound disclosed in WO 2004/101707 Comparative Compound 2: Compound disclosed in Japanese Patent No. 5644050 Comparative Compound 3: Compound disclosed in Japanese Patent No. 5099013 Comparative Compound 4: JP 2013-2013A Compounds disclosed in JP-A-040159

[Example 1]
<< Fabrication of Organic EL Element 1-1 >>
Patterning was performed on a substrate (NA-45 manufactured by AvanStrate Co., Ltd.) in which ITO (Indium Tin Oxide) was formed into a film with a thickness of 100 nm as an anode on a glass substrate of 100 mm × 100 mm × 1.1 mm. Then, the transparent support substrate provided with this ITO transparent electrode was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and UV ozone cleaned for 5 minutes.

  This transparent supporting substrate was fixed to a substrate holder of a commercially available vacuum evaporation system, while 200 mg of HT-1 as a hole injecting material was put in a resistance heating boat made of molybdenum, and HT-as a hole transporting material in another molybdenum resistance heating boat. 200 mg of 2 was put, 200 mg of the comparative compound 1 was put in another resistance heating boat made of molybdenum as a dopant, 200 mg of Host-1 was put as a host compound in the resistance heating boat made of molybdenum, and holes were put in another resistance heating boat made of molybdenum. 200 mg of ET-1 was placed as a blocking material, and 200 mg of ET-2 was placed as a electron transporting material in another resistance heating boat made of molybdenum, which was attached to a vacuum vapor deposition apparatus.

Next, after depressurizing the vacuum chamber to 4 × 10 ⁻⁴ Pa, the heating boat containing HT-1 is energized and heated, and vapor-deposited on a transparent support substrate at a vapor deposition rate of 0.1 nm / sec. A hole injection layer was formed.

  Further, the heating boat containing HT-2 was energized and heated, and vapor deposition was performed on the hole injection layer at a vapor deposition rate of 0.1 nm / sec to form a hole transport layer having a layer thickness of 30 nm.

  Further, a heating boat containing Comparative Compound 1 and Host-1 was energized and heated, and co-deposited on the hole transport layer at vapor deposition rates of 0.1 nm / sec and 0.010 nm / sec, respectively, to obtain a layer thickness of 40 nm. A light emitting layer was formed.

  Further, a heating boat containing ET-1 was energized and heated, and vapor deposition was performed on the light emitting layer at a vapor deposition rate of 0.1 nm / sec to form a hole blocking layer having a layer thickness of 10 nm.

  Further, the heating boat containing ET-2 was energized and heated, and vapor-deposited on the hole blocking layer at a vapor deposition rate of 0.1 nm / sec to form an electron transport layer having a layer thickness of 30 nm.

Subsequently, lithium fluoride is deposited on the electron transport layer to form an electron injection layer (cathode buffer layer) having a layer thickness of 0.5 nm, and aluminum is further deposited on the electron injection layer to form a cathode having a thickness of 110 nm. Then, the organic EL element 1-1 was formed.
The compounds used in this example are those having the following chemical structural formulas.

<< Fabrication of Organic EL Elements 1-2 to 1-10 >>
In the production of the organic EL element 1-1, the organic EL elements 1-2 to 1-10 were produced in the same manner except that the comparative compound 1 and the Host-1 were changed to the compounds shown in Table 1.
Host-2 in Table 1 has the following chemical structural formula.

<< Evaluation of Organic EL Elements 1-1 to 1-10 >>
When evaluating the obtained organic EL elements 1-1 to 1-10, the non-light emitting surface of each organic EL element after production was covered with a glass case, and a glass substrate having a thickness of 300 μm was used as a sealing substrate. An epoxy photocurable adhesive (Luxtrack LC0629B manufactured by Toagosei Co., Ltd.) was applied as a sealant to the surroundings, and this was stacked on the cathode to be in close contact with the transparent supporting substrate, and UV light was irradiated from the glass substrate side. After curing and sealing, a lighting device as shown in FIGS. 5 and 6 was produced.
The following evaluations were performed on each of the samples thus produced. The evaluation results are shown in Table 1.

(1) External extraction quantum efficiency (also called luminous efficiency)
Lighting at room temperature (about 23 to 25 ° C.) under a constant current condition of ^2.5 mA / cm ² using an organic EL element, and measuring the emission luminance (L) [cd / m ² ] immediately after the start of lighting. Then, the external extraction quantum efficiency (η) was calculated.
Here, the emission luminance was measured using CS-1000 (manufactured by Konica Minolta Sensing), and the external extraction quantum efficiency was represented by a relative value with the organic EL element 1-1 as 100.

(2) Half life The half life was evaluated according to the measurement method shown below. Each organic EL element was driven at a constant current with a current that gave an initial luminance of 1000 cd / m ^2, and the time at which the initial luminance was ½ (500 cd / m ² ) was obtained, and this was used as a measure of half-life. The half-life is expressed as a relative value with the organic EL element 1-1 as 100.

(3) Driving voltage The voltage when the organic EL element was driven at room temperature (about 23 ° C. to 25 ° C.) and a constant current condition of ^2.5 mA / cm ² was measured, and the measurement results were as shown below. , And the relative value with the organic EL element 1-1 as 100 was determined.
Drive voltage = (drive voltage of each element / drive voltage of organic EL element 1-1) × 100
It should be noted that the smaller the value, the lower the driving voltage as compared with the comparative example.

(4) Voltage rise during driving The organic EL device was measured at room temperature (about 23 ° C to 25 ° C) under constant current conditions of ^2.5 mA / cm ² , and the voltage was measured. The voltage rise during driving was calculated from the formula. The voltage increase during driving was expressed as a relative value with the organic EL element 1-1 as 100.
Voltage rise during driving (relative value) = driving voltage when luminance is halved−initial driving voltage Note that the smaller the value, the smaller the voltage increase during driving as compared with the comparative example.

(5) Temporal stability The organic EL device was stored under the conditions of 60 ° C. and 70% RH for one month, and the power efficiencies before and after storage were determined. A power efficiency ratio was obtained from each power efficiency according to the following formula, and this was used as a measure of stability over time.
Stability over time (%) = (power efficiency after storage / power efficiency before storage) x 100
The power efficiency was determined by measuring the front luminance and the luminance angle dependence of each organic EL element using a spectral radiance meter CS-1000 (manufactured by Konica Minolta Sensing Co., Ltd.) and determining the front luminance at 1000 cd / m ² . Using.

(6) Second wave ratio The emission spectrum of the metal complex used as a dopant in each organic EL element under a low temperature (about 77 K) in a 2-methyl THF solution was measured by a spectrofluorometer made by Hitachi High-Tech Science Co., Ltd. It measured using F-7000. The second wave ratio was calculated from the measurement result by the following calculation formula, and evaluated according to the following criteria. As a result, it was confirmed that the emission of the wavelength component on the long wave side of the maximum emission wavelength was suppressed.
Second wave ratio = amount of light emitted at peak wavelength next to emission maximum wavelength / amount of emission at emission maximum wavelength

◎: Second wave ratio is 0.4 or less ○: Second wave ratio is more than 0.4 and 0.6 or less △: Second wave ratio is more than 0.6 and less than 0.8 ×: Second wave ratio is 0.1. 8 or more

  As is clear from Table 1, it was found that when the compound having the structure represented by the general formula (1) according to the present invention was used, the second wave ratio was predominantly small. Furthermore, it is clear that the organic EL device using the compound having the structure represented by the general formula (1) is superior in light emission efficiency and light emission life and has a low driving voltage as compared with the organic EL device of the comparative example. It was also found that the voltage rise during driving was suppressed and the stability over time was excellent.

[Example 2]
<< Fabrication of Organic EL Element 2-1 >>
Patterning was performed on a substrate (NA-45 manufactured by AvanStrate Co., Ltd.) in which ITO (Indium Tin Oxide) was formed into a film with a thickness of 100 nm as an anode on a glass substrate of 100 mm × 100 mm × 1.1 mm. Then, the transparent support substrate provided with this ITO transparent electrode was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and UV ozone cleaned for 5 minutes.

  A solution obtained by diluting poly (3,4-ethylenedioxythiophene) -polystyrenesulfonate (PEDOT / PSS, manufactured by HC Starck Co., CLEVIO P VPAI 4083) with pure water to 70% by mass on the transparent supporting substrate. Was used to form a thin film by a spin coating method at 3000 rpm for 30 seconds, and then dried at 200 ° C. for 1 hour to form a first hole transport layer having a layer thickness of 20 nm.

  This transparent support substrate was fixed to a substrate holder of a commercially available vacuum vapor deposition apparatus, while 200 mg of HT-2 as a hole transport material was put in a resistance heating boat made of molybdenum, and a comparative compound 1 was used as a dopant in another resistance heating boat made of molybdenum. Was put in another resistance heating boat made of molybdenum, and 200 mg of Host-1 as a host compound was put in another resistance heating boat made of molybdenum, and 200 mg of ET-1 as an electron transport material was put in another resistance heating boat made of molybdenum, which was attached to a vacuum vapor deposition apparatus.

Next, after depressurizing the vacuum chamber to 4 × 10 ⁻⁴ Pa, electricity is applied to a heating boat containing HT-2 to heat it, and vapor deposition is carried out on a transparent support substrate at a vapor deposition rate of 0.1 nm / sec. To form a second hole transport layer.

  Further, a heating boat containing Comparative Compound 1 and Host-1 was energized and heated, and co-deposited on the second hole transport layer at vapor deposition rates of 0.1 nm / sec and 0.006 nm / sec, respectively. A 40 nm light emitting layer was formed.

  Further, a heating boat containing ET-1 was energized and heated, and vapor-deposited on the light emitting layer at a vapor deposition rate of 0.1 nm / sec to form an electron transport layer having a layer thickness of 30 nm. The substrate temperature during vapor deposition was room temperature.

  Subsequently, lithium fluoride is vapor-deposited on the light-emitting layer to form an electron injection layer having a layer thickness of 0.5 nm, and aluminum is further vapor-deposited on the electron injection layer to form a cathode having a thickness of 110 nm. 2-1 was produced.

<< Fabrication of Organic EL Elements 2-2 to 2-8 >>
In the production of the organic EL element 2-1, the organic EL elements 2-2 to 2-8 were produced in the same manner except that the comparative compound 1 and the Host-1 were changed to the compounds shown in Table 2.

<< Evaluation of Organic EL Elements 2-1 to 2-8 >>
When evaluating the obtained organic EL element, it was sealed in the same manner as the organic EL elements 1-1 to 1-10 of Example 1, and an illumination device as shown in FIGS. 5 and 6 was produced and evaluated. ..
Each sample thus produced was evaluated for external extraction quantum efficiency, half-life, driving voltage, voltage rise during driving, stability over time, and second wave ratio, as in Example 1. The evaluation results are shown in Table 2. The measurement results of the external extraction quantum efficiency, the half life, the driving voltage, and the voltage increase during driving in Table 2 are expressed as relative values with the measured value of the organic EL element 2-1 being 100.

  As is clear from Table 2, it was found that when the compound having the structure represented by the general formula (1) according to the present invention was used, the second wave ratio was predominantly small. Furthermore, it is clear that the organic EL device using the compound having the structure represented by the general formula (1) is superior in light emission efficiency and light emission life and has a low driving voltage as compared with the organic EL device of the comparative example. It was also found that the voltage rise during driving was suppressed and the stability over time was excellent.

[Example 3]
<< Fabrication of Organic EL Element 3-1 >>
Patterning was performed on a substrate (NA-45 manufactured by AvanStrate Co., Ltd.) in which ITO (Indium Tin Oxide) was formed into a film with a thickness of 100 nm as an anode on a glass substrate of 100 mm × 100 mm × 1.1 mm. Then, the transparent support substrate provided with this ITO transparent electrode was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and UV ozone cleaned for 5 minutes.

  On this transparent support substrate, a solution prepared by diluting poly (3,4-ethylenedioxythiophene) -polystyrenesulfonate (PEDOT / PSS, manufactured by Bayer, Baytron P Al 4083) with pure water to 70% by mass at 3000 rpm was used. After forming a thin film by a spin coating method for 30 seconds, it was dried at 200 ° C. for 1 hour to form a first hole transport layer having a layer thickness of 20 nm.

  This substrate was transferred to a nitrogen atmosphere, and a solution of 47 mg of HT-3 and 3 mg of HT-4 dissolved in 10 mL of toluene was used on the first hole transport layer under conditions of 1500 rpm and 30 seconds. A thin film was formed by spin coating. Ultraviolet light was irradiated at 120 ° C. for 90 seconds to perform photopolymerization / crosslinking, and vacuum drying was further performed at 60 ° C. for 1 hour to form a second hole transport layer having a layer thickness of about 20 nm.

  A solution prepared by dissolving 100 mg of Host-3, 20 mg of Comparative Compound 1, 0.5 mg of D-1, and 0.2 mg of D-2 in 10 mL of butyl acetate on the second hole transport layer. Was used to form a thin film by spin coating under the conditions of 600 rpm for 30 seconds. Further, it was vacuum dried at 60 ° C. for 1 hour to form a light emitting layer having a layer thickness of about 70 nm.

  Next, a thin film was formed on this light emitting layer by spin coating using a solution of 50 mg of ET-3 dissolved in 10 mL of hexafluoroisopropanol (HFIP) under conditions of 1500 rpm and 30 seconds. Furthermore, it vacuum-dried at 60 degreeC for 1 hour, and formed the electron carrying layer with a layer thickness of about 20 nm.

Subsequently, this substrate was fixed to a substrate holder of a vacuum vapor deposition apparatus, the vacuum chamber was depressurized to 4 × 10 ⁻⁴ Pa, potassium fluoride was vapor-deposited on the electron transport layer, and electron injection with a layer thickness of 0.4 nm was performed. A layer was formed, and aluminum was further vapor-deposited on the electron injection layer to form a cathode having a thickness of 110 nm, to fabricate an organic EL element 3-1.
The compounds used in this example are those having the following chemical structural formulas.

<< Fabrication of Organic EL Elements 3-2 to 3-8 >>
In the production of the organic EL element 3-1, the organic EL elements 3-2 to 3-8 were produced in the same manner except that the comparative compound 1 and the Host-3 were changed to the compounds shown in Table 3.
Comparative compound 5 and Host-4 in Table 3 have the following chemical structural formulas.

  Comparative compound 5: Compound disclosed in JP2013-040159A

<< Evaluation of Organic EL Elements 3-1 to 3-8 >>
When evaluating the obtained organic EL element, it was sealed in the same manner as the organic EL elements 1-1 to 1-10 of Example 1, and an illumination device as shown in FIGS. 5 and 6 was produced and evaluated. ..
Each sample thus produced was evaluated for external extraction quantum efficiency, half-life, driving voltage, voltage rise during driving, stability over time, and second wave ratio, as in Example 1. The evaluation results are shown in Table 3. The measurement results of the external extraction quantum efficiency, the half life, the driving voltage, and the voltage increase during driving in Table 3 are shown as relative values with the measured value of the organic EL element 3-1 being 100.

  As is clear from Table 3, it was found that when the compound having the structure represented by the general formula (1) according to the present invention was used, the second wave ratio was significantly small. Furthermore, it is clear that the organic EL device using the compound having the structure represented by the general formula (1) is superior in light emission efficiency and light emission life and has a low driving voltage as compared with the organic EL device of the comparative example. It was also found that the voltage rise during driving was suppressed and the stability over time was excellent.

[Example 4]
<< Fabrication of Organic EL Element 4-1 >>
Patterning was performed on a substrate (NA-45 manufactured by AvanStrate Co., Ltd.) in which ITO (Indium Tin Oxide) was formed into a film with a thickness of 100 nm as an anode on a glass substrate of 100 mm × 100 mm × 1.1 mm. Then, the transparent support substrate provided with this ITO transparent electrode was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and UV ozone cleaned for 5 minutes.

  On this transparent support substrate, a solution prepared by diluting poly (3,4-ethylenedioxythiophene) -polystyrene sulfonate (PEDOT / PSS, Baytron P Al4083 manufactured by Bayer Co., Ltd.) with pure water to 70 mass% was used, and spin was performed. After forming a thin film by the coating method, it was dried at 200 ° C. for 1 hour to form a first hole transport layer having a layer thickness of 30 nm.

  On the first hole transport layer, a hole transport material Poly (N, N'-bis (4-butylphenyl) -N, N'-bis (phenyl)) benzidine (ADS-, manufactured by American Dye Source, Inc.) is formed. A thin film was formed by the spin coating method using the chlorobenzene solution of 254). It heat-dried at 150 degreeC for 1 hour, and formed the 2nd positive hole transport layer with a layer thickness of 40 nm.

  On this second hole transport layer, a thin film was formed by a spin coating method using a butyl acetate solution of Host-3 as a host compound and Comparative Compound 1 as a dopant, and dried by heating at 120 ° C. for 1 hour to form a layer. A light emitting layer having a thickness of 30 nm was formed.

  A 1-butanol solution of ET-4 as an electron-transporting material was used to form a thin film on the light-emitting layer by a spin coating method to form an electron-transporting layer having a layer thickness of 20 nm.

This substrate was attached to a vacuum vapor deposition apparatus, and the vacuum chamber was depressurized to 4 × 10 ⁻⁴ Pa. Next, lithium fluoride is vapor-deposited on the electron transport layer to form an electron injection layer having a layer thickness of 1.0 nm, and aluminum is vapor-deposited on the electron injection layer to form a cathode having a thickness of 110 nm. -1 was produced.
The compounds used in this example are those having the following chemical structural formulas.

<< Fabrication of Organic EL Elements 4-2 to 4-10 >>
Organic EL elements 4-2 to 4-10 were produced in the same manner as in the production of the organic EL element 4-1, except that the compounds in Table 4 were used instead of the comparative compound 1 and Host-3.
Comparative compounds 6 and 7 in Table 4 have the following chemical structural formulas.

Comparative Compound 6: Compound disclosed in Japanese Patent No. 5644050 Comparative Compound 7: Compound disclosed in Japanese Patent No. 5099013

<< Evaluation of Organic EL Elements 4-1 to 4-10 >>
When evaluating the obtained organic EL element, it was sealed in the same manner as the organic EL elements 1-1 to 1-10 of Example 1, and an illumination device as shown in FIGS. 5 and 6 was produced and evaluated. ..
Each sample thus produced was evaluated for external extraction quantum efficiency, half-life, driving voltage, voltage rise during driving, stability over time, and second wave ratio, as in Example 1. The evaluation results are shown in Table 4. The measurement results of the external extraction quantum efficiency, the half life, the driving voltage, and the voltage increase during driving in Table 4 are expressed as relative values with the measured value of the organic EL element 4-1 being 100.

  As is clear from Table 4, it was found that when the compound having the structure represented by the general formula (1) according to the present invention was used, the second wave ratio was significantly small. Furthermore, it is clear that the organic EL device using the compound having the structure represented by the general formula (1) is superior in light emission efficiency and light emission life and has a low driving voltage as compared with the organic EL device of the comparative example. It was also found that the voltage rise during driving was suppressed and the stability over time was excellent.

[Example 5]
<< Fabrication of Organic EL Element 5-1 >>
Patterning was performed on a substrate (NA-45 manufactured by AvanStrate Co., Ltd.) in which ITO (Indium Tin Oxide) was formed into a film with a thickness of 100 nm as an anode on a glass substrate of 100 mm × 100 mm × 1.1 mm. Then, the transparent support substrate provided with this ITO transparent electrode was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and UV ozone cleaned for 5 minutes.

  This transparent support substrate was fixed to a substrate holder of a commercially available vacuum evaporation system, while 200 mg of HT-6 as a hole injection material was put in a resistance heating boat made of molybdenum, and HT-as a hole transport material in another molybdenum resistance heating boat. 200 mg of No. 5, 200 mg of Host-5 as a host compound in another molybdenum resistance heating boat, 200 mg of Comparative Compound 1 as a dopant in another molybdenum resistance heating boat, as a dopant in another molybdenum resistance heating boat 200 mg of D-3 was put, 200 mg of D-4 as a dopant was put in another resistance heating boat made of molybdenum, and 200 mg of ET-5 as an electron transport material was put in another resistance heating boat made of molybdenum, which was attached to a vacuum evaporation apparatus.

Next, after depressurizing the vacuum chamber to 4 × 10 ⁻⁴ Pa, the heating boat containing HT-6 was energized and heated, and vapor-deposited on the transparent support substrate at a vapor deposition rate of 0.1 nm / sec. A hole injection layer was formed.

  Further, a heating boat containing HT-5 was energized and heated, and vapor deposition was performed on the hole injection layer at a vapor deposition rate of 0.1 nm / sec to form a hole transport layer having a layer thickness of 20 nm.

  Further, the heating boat containing Host-5, Comparative Compound 1, D-3, and D-4 was energized and heated, and the vapor deposition rate was 0.1 nm / sec, 0.025 nm / sec, 0.0007 nm / sec, respectively. Co-evaporation was performed on the hole transport layer at 0.0002 nm / sec to form a light emitting layer having a layer thickness of 60 nm.

  Further, a heating boat containing ET-5 was energized and heated, and vapor-deposited on the light emitting layer at a vapor deposition rate of 0.1 nm / sec to form an electron transport layer having a layer thickness of 20 nm.

Subsequently, potassium fluoride is deposited on the electron transport layer to form an electron injection layer having a thickness of 0.5 nm, and aluminum is further deposited on the electron injection layer to form a cathode having a thickness of 110 nm. Element 5-1 was produced.
The compounds used in this example are those having the following chemical structural formulas.

<< Fabrication of Organic EL Elements 5-2 to 5-9 >>
Organic EL elements 5-2 to 5-9 were produced in the same manner as in the production of the organic EL element 5-1, except that the compounds of Comparative Example 1 and Host-5 were changed to the compounds shown in Table 5.
Host-6 in Table 5 has the following chemical structural formula.

<< Evaluation of Organic EL Elements 5-1 to 5-9 >>
When evaluating the obtained organic EL element, it was sealed in the same manner as the organic EL elements 1-1 to 1-10 of Example 1, and an illumination device as shown in FIGS. 5 and 6 was produced and evaluated. ..
Each sample thus produced was evaluated for external extraction quantum efficiency, half-life, driving voltage, voltage rise during driving, stability over time, and second wave ratio, as in Example 1. The evaluation results are shown in Table 5. The measurement results of the external extraction quantum efficiency, the half life, the driving voltage, and the voltage increase during driving in Table 5 are shown as relative values with the measured value of the organic EL element 5-1 as 100.

  As is clear from Table 5, it was found that when the compound having the structure represented by the general formula (1) according to the present invention was used, the second wave ratio was predominantly small. Furthermore, it is clear that the organic EL device using the compound having the structure represented by the general formula (1) is superior in light emission efficiency and light emission life and has a low driving voltage as compared with the organic EL device of the comparative example. It was also found that the voltage rise during driving was suppressed and the stability over time was excellent.

[Example 6]
<< Fabrication of Organic EL Element 6-1 >>
On a glass substrate having a thickness of 50 mm × 50 mm and a thickness of 0.7 mm, ITO (Indium Tin Oxide) was formed into a film having a thickness of 120 nm as an anode and patterned. After that, the transparent support substrate provided with the ITO transparent electrode is ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and UV ozone cleaned for 5 minutes, and then this transparent substrate is used as a substrate holder of a commercially available vacuum deposition apparatus. Fixed to.

  Each of the resistance heating boats in the vacuum vapor deposition apparatus was filled with the constituent material of each layer in an optimum amount for producing each element. As the resistance heating boat, one made of molybdenum or tungsten resistance heating material was used.

After decompressing to a vacuum degree of 1 × 10 ⁻⁴ Pa, the heating boat containing the compound HT-1 was energized and heated, and vapor-deposited on the ITO transparent electrode at a vapor deposition rate of 0.1 nm / sec. A hole injection layer was formed.

  Then, the compound HT-2 was similarly vapor-deposited on the hole injection layer to form a hole transport layer having a layer thickness of 30 nm.

  Next, Comparative Compound 1 and Host-5 were co-deposited on the hole transport layer at a vapor deposition rate of 0.1 nm / sec so as to be 90% by volume and 10% by volume, respectively, to form a light emitting layer having a layer thickness of 30 nm. ..

  Then, ET-1 is vapor-deposited on the light emitting layer at a vapor deposition rate of 0.1 nm / sec to form a first electron transport layer having a layer thickness of 10 nm, and ET-2 is vapor-deposited on the first electron transport layer at 0.1 nm / sec. Then, a second electron transport layer having a layer thickness of 45 nm was formed.

  Further, lithium fluoride was vapor-deposited on the second electron transport layer to form an electron injection layer having a layer thickness of 1.0 nm, and then aluminum was vapor-deposited on the electron injection layer to form a cathode having a thickness of 100 nm.

  An electrode lead-out wiring is installed on the above element, and the organic EL element is covered with a can glass case filled with an epoxy resin in a nitrogen glove box in an atmosphere of water and oxygen of 1 ppm or less, and a hygroscopic agent is incorporated in the package. 6-1 was produced.

<< Fabrication of Organic EL Devices 6-2 to 6-9 >>
Organic EL elements 6-2 to 6-9 were produced in the same manner as in the production of the organic EL element 6-1, except that the compounds of Comparative Example 1 and Host-5 were changed to the compounds shown in Table 6.
Comparative compound 8 in Table 6 has the following chemical structural formula.

  Comparative Compound 8: Compound disclosed in JP 2013-040159 A

<< Evaluation of Organic EL Elements 6-1 to 6-9 >>
When evaluating the obtained organic EL element, it was sealed in the same manner as the organic EL elements 1-1 to 1-10 of Example 1, and an illumination device as shown in FIGS. 5 and 6 was produced and evaluated. ..
Each sample thus produced was evaluated for external extraction quantum efficiency, half-life, driving voltage, voltage rise during driving, stability over time, and second wave ratio, as in Example 1. The evaluation results are shown in Table 6. The measurement results of the external extraction quantum efficiency, the half life, the driving voltage, and the voltage increase during driving in Table 6 are shown as relative values with the measured value of the organic EL element 6-1 as 100.

  As is clear from Table 6, it was found that when the compound having the structure represented by the general formula (1) according to the present invention was used, the second wave ratio was significantly small. Furthermore, it is clear that the organic EL device using the compound having the structure represented by the general formula (1) is superior in light emission efficiency and light emission life and has a low driving voltage as compared with the organic EL device of the comparative example. It was also found that the voltage rise during driving was suppressed and the stability over time was excellent.

[Example 7]
<< Fabrication of organic EL full-color display device >>
In this example, an organic EL full-color display device was manufactured and evaluated as shown in FIGS. 7A to 7E. 7A to 7E show schematic configuration diagrams of the organic EL full-color display device.

  After patterning at a pitch of 100 μm on a substrate (NH45 manufactured by NH Techno Glass Co., Ltd.) having a 100 nm ITO transparent electrode 202 formed as an anode on the glass substrate 201 (see FIG. 7A), A non-photosensitive polyimide partition wall 203 (width 20 μm, thickness 2.0 μm) was formed between the ITO transparent electrodes 202 by photolithography (see FIG. 7B).

  A hole injection layer composition having the following composition is ejected and injected between the partition walls 203 on the ITO electrode 202 using an inkjet head (manufactured by Epson Corp .; MJ800C), and irradiated with ultraviolet light for 200 seconds at 60 ° C. A hole injection layer 204 having a layer thickness of 40 nm was formed by a drying treatment for 10 minutes (see FIG. 7C).

(Hole injection layer composition)
HT-3: 20 parts by mass Cyclohexylbenzene: 50 parts by mass Isopropylbiphenyl: 50 parts by mass

  Onto this hole injecting layer 204, a blue light emitting layer composition, a green light emitting layer composition and a red light emitting layer composition having the following compositions, respectively, were similarly ejected and injected using an inkjet head, and the temperature was 60 ° C. for 10 minutes. Drying treatment was performed to form the light emitting layers 205B, 205G, and 205R of the respective colors (see FIG. 7D).

(Blue light emitting layer composition)
Host-2: 0.7 parts by mass Exemplified Compound 5-3: 0.04 parts by mass Cyclohexylbenzene: 50 parts by mass Isopropylbiphenyl: 50 parts by mass

(Green light emitting layer composition)
Host-1: 0.7 parts by mass D-3: 0.04 parts by mass Cyclohexylbenzene: 50 parts by mass Isopropylbiphenyl: 50 parts by mass

(Red light emitting layer composition)
Host-1: 0.7 parts by mass D-2: 0.04 parts by mass Cyclohexylbenzene: 50 parts by mass Isopropylbiphenyl: 50 parts by mass

  Next, an electron transport material is vapor-deposited so as to cover the light emitting layers 205B, 205G, and 205R to form an electron transport layer (not shown) having a layer thickness of 20 nm, and further lithium fluoride is vapor-deposited to have a layer thickness of 0.6 nm. An electron injection layer (not shown) was formed, and Al was vapor-deposited to form a cathode 206 having a film thickness of 130 nm to produce an organic EL device (see FIG. 7E).

  It was found that the manufactured organic EL elements emitted blue, green, and red light by applying a voltage to the electrodes, respectively, and could be used as a full-color display device.

As described above, when the compound having the structure represented by the general formula (1) according to the present invention is used, light emission having a significantly small second wave ratio can be obtained. Further, according to the present invention, there is provided an organic electroluminescence element, a lighting device and a display device which have high luminous efficiency, low driving voltage, long life, small voltage increase during driving, and further excellent stability over time. be able to.
Further, an organic EL element having the above effect can be manufactured by the wet process.

  As described above, the present invention has a small emission ratio of a component having a wavelength longer than the maximum emission wavelength, a high emission efficiency, a low driving voltage, a long emission lifetime, a small voltage increase during driving, and stability over time. It is suitable for providing an excellent organic electroluminescence element, a method for manufacturing the element, a display device and a lighting device including the element, and an organic electroluminescence element material used for the element.

1 Display 3 Pixel 5 Scanning Line 6 Data Line 7 Power Supply Line 10 Organic EL Element 11 Switching Transistor 12 Drive Transistor 13 Capacitor 101 Organic EL Element 102 Glass Cover 105 Cathode 106 Organic EL Layer 107 Glass Substrate with Substrate 108 Nitrogen Gas 109 Water Capture Agent 201 Glass substrate 202 ITO transparent electrode 203 Partition wall 204 Hole injection layer 205B, 205G, 205R Light emitting layer 206 Cathode A Display section B Control section C Wiring section

Claims (12)

An organic electroluminescence device comprising an organic layer sandwiched by at least one pair of an anode and a cathode,
The organic electroluminescent element, wherein the organic layer comprises at least one layer including a light emitting layer, and at least one layer of the organic layer contains a compound having a structure represented by the following general formula (1).

(In the general formula (1), R represents an alkyl group, a halogen atom, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an acyl group, a sulfinyl group, a sulfonyl group, a nitro group, a cyano group, a hydroxy group and a mercapto group. Ar represents an aromatic hydrocarbon group or an aromatic heterocyclic group, and R _{1 to} R ₄ each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, or an alkenyl group. , Alkynyl group, aromatic hydrocarbon group, heterocyclic group, aromatic heterocyclic group, halogen atom, alkoxy group, cycloalkoxy group, aryloxy group, alkylthio group, cycloalkylthio group, arylthio group, alkoxycarbonyl group, aryloxy Carbonyl group, sulfamoyl group, ureido group, acyl group, acyloxy group, amide group, carbamoyl group, sulfinyl group, alkylsulfonyl group, arylsulfonyl group, amino group, nitro group, cyano group, hydroxy group, mercapto group, alkylsilyl group , An arylsilyl group, an alkylphosphino group, an arylphosphino group, an alkylphosphoryl group, an arylphosphoryl group, an alkylthiophosphoryl group, and an arylthiophosphoryl group.
X ₁ -L ₁ -X ₂ represents a bidentate ligand, and X ₁ and X ₂ each independently represent a carbon atom, a nitrogen atom or an oxygen atom. L ₁ represents an atomic group forming a bidentate ligand with X ₁ and X ₂ . m represents an integer of 1 to 3, n represents an integer of 0 to 2, and m + n is 3.
However, at least two of adjacent R _{1 to} R ₄ are condensed to represent the structure of the following general formula (3) or (4 ) . )

(In the general formulas (3) and (4), Y _{1 to} Y ₄ each independently represent O, S or NR ′, and Y ₅ or Y ₆ represents CR ″ or N. 'Represents any group selected from an alkyl group, a cycloalkyl group, an aromatic hydrocarbon group, a heterocyclic group and an aromatic heterocyclic group, and R''represents a hydrogen atom, an alkyl group, a cycloalkyl group, It represents any group selected from an aromatic hydrocarbon group, a heterocyclic group, an aromatic heterocyclic group, a halogen atom, an amino group, a cyano group, an arylsilyl group and an arylphosphoryl group, wherein Z _{1 to} Z ₈ are each Independently represents C—Rx or N, and a plurality of Rx may be the same or different, and a plurality of Rx are each independently R _{1 to} R ₄ in the general formula (1). Represents an equivalent group, and * represents a bonding position with the structure represented by the general formula (1). An organic electroluminescence device comprising an organic layer sandwiched by at least one pair of an anode and a cathode,
The organic layer is composed of at least one layer including a light emitting layer, and at least one of the organic layers contains a compound having a structure represented by any one of the following general formulas (5) and (7) to (10). organic electroluminescent device characterized by.

(In the general formulas (5) and (7) to (10), R represents an alkyl group, a halogen atom, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an acyl group, a sulfinyl group, a sulfonyl group, a nitro group, Represents a group selected from a cyano group, a hydroxy group and a mercapto group, Ar represents an aromatic hydrocarbon group or an aromatic heterocyclic group, and R _{1 to} R ₄ are each independently a hydrogen atom or an alkyl group. Group, cycloalkyl group, alkenyl group, alkynyl group, aromatic hydrocarbon group, heterocyclic group, aromatic heterocyclic group, halogen atom, alkoxy group, cycloalkoxy group, aryloxy group, alkylthio group, cycloalkylthio group, arylthio Group, alkoxycarbonyl group, aryloxycarbonyl group, sulfamoyl group, ureido group, acyl group, acyloxy group, amide group, carbamoyl group, sulfinyl group, alkylsulfonyl group, arylsulfonyl group, amino group, nitro group, cyano group, hydroxy A group, a mercapto group, an alkylsilyl group, an arylsilyl group, an alkylphosphino group, an arylphosphino group, an alkylphosphoryl group, an arylphosphoryl group, an alkylthiophosphoryl group, and an arylthiophosphoryl group.
X ₁ -L ₁ -X ₂ represents a bidentate ligand, and X ₁ and X ₂ each independently represent a carbon atom, a nitrogen atom or an oxygen atom. L ₁ represents an atomic group forming a bidentate ligand with X ₁ and X ₂ . m represents an integer of 1 to 3, n represents an integer of 0 to 2, and m + n is 3.
Y ₁ represents O, S or NR ′. R'represents any group selected from an alkyl group, a cycloalkyl group, an aromatic hydrocarbon group, a heterocyclic group and an aromatic heterocyclic group. Z _{1 to} Z ₄ each independently represent C—Rx or N, and a plurality of Rx may be the same or different. A plurality of Rx's each independently represent the same group as R _{1 to} R ₄ . ) In the general formula (1) or the general formulas (5) and (7) to (10) , R represents an alkyl group or a cyano group, and the organic compound according to claim 1 or claim 2. Electroluminescent device. In the general formula (1) or the general formulas (5) and (7) to (10) , Ar represents an aromatic hydrocarbon group or an aromatic heterocyclic group having a substituent at the 2-position. The organic electroluminescent element according to claim 1 or 2 . In said General formula (1) or said General formula (5) and (7)-(10) , n represents 0 , The organic electroluminescent element of Claim 1 or Claim 2 characterized by the above-mentioned. The light-emitting layer is, the general formula (1) or the general formula (5) and (7) according to claim, characterized in that it contains a compound having a structure represented by - (10) 1 or claim 2 the organic electroluminescent device according to. A compound having a structure represented by the general formula (1) or the general formulas (5) and (7) to (10) , and a compound having a HOMO level of −5.4 eV or less. 7. The organic electroluminescence device according to claim 6, which contains at least two kinds of A method for manufacturing an organic electroluminescence device according to claim 1, which is a method for manufacturing the organic electroluminescence device according to claim 1.
Among the organic layers, a layer containing a compound having a structure represented by the general formula (1) or the general formulas (5) and (7) to (10) is formed by a wet process. method of manufacturing an organic electroluminescent element you. Display device comprising a call provided with an organic electroluminescence element according to claim 1 or claim 2. An illuminating device comprising the organic electroluminescent element according to claim 1 or 2 . An organic electroluminescence device material containing a compound having a structure represented by the following general formula (1) .

(In the general formula (1), R represents an alkyl group, a halogen atom, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an acyl group, a sulfinyl group, a sulfonyl group, a nitro group, a cyano group, a hydroxy group and a mercapto group. Ar represents an aromatic hydrocarbon group or an aromatic heterocyclic group, and R _{1 to} R ₄ each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, or an alkenyl group. , Alkynyl group, aromatic hydrocarbon group, heterocyclic group, aromatic heterocyclic group, halogen atom, alkoxy group, cycloalkoxy group, aryloxy group, alkylthio group, cycloalkylthio group, arylthio group, alkoxycarbonyl group, aryloxy Carbonyl group, sulfamoyl group, ureido group, acyl group, acyloxy group, amide group, carbamoyl group, sulfinyl group, alkylsulfonyl group, arylsulfonyl group, amino group, nitro group, cyano group, hydroxy group, mercapto group, alkylsilyl group , An arylsilyl group, an alkylphosphino group, an arylphosphino group, an alkylphosphoryl group, an arylphosphoryl group, an alkylthiophosphoryl group, and an arylthiophosphoryl group.
X ₁ -L ₁ -X ₂ represents a bidentate ligand, and X ₁ and X ₂ each independently represent a carbon atom, a nitrogen atom or an oxygen atom. L ₁ represents an atomic group forming a bidentate ligand with X ₁ and X ₂ . m represents an integer of 1 to 3, n represents an integer of 0 to 2, and m + n is 3.
However, at least two of R _{1 to} R ₄ adjacent to each other are condensed to represent the structure of the following general formula (3) or (4). )

(In the general formula (3) and _(4), Y 1 to Y ₄ are .R each independently, O, 'it represents, _{Y 5} or _{Y 6} is that CR' S or N-R represents a 'or N 'Represents any group selected from an alkyl group, a cycloalkyl group, an aromatic hydrocarbon group, a heterocyclic group and an aromatic heterocyclic group, and R''represents a hydrogen atom, an alkyl group, a cycloalkyl group, An aromatic hydrocarbon group, a heterocyclic group, an aromatic heterocyclic group, a halogen atom, an amino group, a cyano group, an arylsilyl group, or an arylphosphoryl group, and any one group selected from Z _{1 to} Z ₈ . independently represent C-Rx or N, more Rx may be different even in the same, respectively. plurality of Rx is independently a R ₁ to R ₄ in the general formula (1) Represents an equivalent group, and * represents a bonding position with the structure represented by the general formula (1). An organic electroluminescence device material comprising a compound having a structure represented by any one of the following general formulas (5) and (7) to (10) .

(In the general formulas (5) and (7) to (10) , R represents an alkyl group, a halogen atom, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an acyl group, a sulfinyl group, a sulfonyl group, a nitro group, Represents a group selected from a cyano group, a hydroxy group and a mercapto group, Ar represents an aromatic hydrocarbon group or an aromatic heterocyclic group, and R _{1 to} R ₄ are each independently a hydrogen atom or an alkyl group. Group, cycloalkyl group, alkenyl group, alkynyl group, aromatic hydrocarbon group, heterocyclic group, aromatic heterocyclic group, halogen atom, alkoxy group, cycloalkoxy group, aryloxy group, alkylthio group, cycloalkylthio group, arylthio Group, alkoxycarbonyl group, aryloxycarbonyl group, sulfamoyl group, ureido group, acyl group, acyloxy group, amide group, carbamoyl group, sulfinyl group, alkylsulfonyl group, arylsulfonyl group, amino group, nitro group, cyano group, hydroxy A group, a mercapto group, an alkylsilyl group, an arylsilyl group, an alkylphosphino group, an arylphosphino group, an alkylphosphoryl group, an arylphosphoryl group, an alkylthiophosphoryl group, and an arylthiophosphoryl group.
X ₁ -L ₁ -X ₂ represents a bidentate ligand, and X ₁ and X ₂ each independently represent a carbon atom, a nitrogen atom or an oxygen atom. L ₁ represents an atomic group forming a bidentate ligand with X ₁ and X ₂ . m represents an integer of 1 to 3, n represents an integer of 0 to 2, and m + n is 3.
Y ₁ represents O, S or NR ′. R'represents any group selected from an alkyl group, a cycloalkyl group, an aromatic hydrocarbon group, a heterocyclic group and an aromatic heterocyclic group. Z _{1 to} Z ₄ each independently represent C—Rx or N, and a plurality of Rx may be the same or different. A plurality of Rx's each independently represent the same group as R _{1 to} R ₄ . )

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