JP5609641B2 - Organic electroluminescence element, display device and lighting device - Google Patents

Description

  The present invention relates to an organic electroluminescence element, a display device, and a lighting device. More specifically, the present invention relates to an organic electroluminescence element that suppresses unevenness in light emission and achieves a long life and high efficiency, and a display device and a lighting device including the element.

  Conventionally, there is an electroluminescence display (ELD) as a light-emitting electronic display device. Examples of the constituent elements of ELD include inorganic electroluminescent elements and organic electroluminescent elements (hereinafter also referred to as organic EL elements). Inorganic electroluminescent elements have been used as planar light sources, but an alternating high voltage is required to drive the light emitting elements.

  On the other hand, an organic EL element has a configuration in which a light emitting layer containing a compound that emits light is sandwiched between a cathode and an anode, and injects electrons and holes into the light emitting layer to recombine excitons. It is an element that emits light by utilizing light emission (fluorescence / phosphorescence) when the exciton is deactivated.

  Between the electrodes, the thickness is only about 0.1 μm, the light emission is possible at a relatively low voltage of several V to several tens V, and the field of view is self-luminous. Since it is rich in corners, has high visibility, and is a thin-film type completely solid element, it has attracted attention as a next-generation flat display and illumination from the viewpoint of space saving and portability.

  Currently, an organic EL element is composed of a plurality of organic layers having functions other than light emission, in addition to a light emitting layer, in order to realize low voltage, high luminous efficiency, and high luminance. Yes.

  In addition, it is known that an organic EL element can emit light more efficiently by adding a trace amount of a dopant compound to the host compound in the light emitting layer. As the dopant molecule, a fluorescent dopant represented by a quinacridone derivative (for example, JP-A-3-255190) and a phosphorescent dopant represented by iridium (III) tris (2-phenylpyridine) are known, Studies on phosphorescent dopants having higher luminous efficiency and host molecules for efficiently emitting phosphorescent dopants have been actively conducted (for example, see Patent Documents 1 to 3).

In addition, vapor deposition and coating methods (wet methods) are known as methods for producing organic EL elements, which can be easily applied to increase the area of organic EL elements and will be manufactured at low cost in the future. Since it is estimated that it can be done, research on organic EL device fabrication by a coating method has been extensively conducted in recent years. (For example, JP 2008-13700 A)
However, when organic EL elements are applied to lighting applications or large-area electronic displays, especially when large-area elements are created using a coating method, leakage current and dark spots are more prominent than small-area elements. There is a problem of becoming.

  The organic EL element is known to have a significantly reduced light emission lifetime due to a very few dark spots, which is a major obstacle to increasing the area of the organic EL element. Further, as a problem specific to the increase in area of the light emitting element, there is light emission unevenness in the light emitting element.

  The uneven light emission in the element is difficult to solve by controlling the current and voltage, and this also becomes a factor that hinders the increase in area of the organic EL element.

  As means for solving the light emission unevenness, a method using a metal mesh plate subjected to etching (for example, see Patent Document 4) is known.

  However, Patent Document 1 is for suppressing uneven light emission between a plurality of light emitting elements, and does not suppress uneven light emission within a single element, which is the subject of the present invention. Moreover, although the method (for example, refer patent document 5) of moving the vapor deposition source in a vacuum chamber is known, it was not suitable for manufacture of organic EL by the apply | coating method.

International publication 07/198116 pamphlet International Publication No. 07/069569 Pamphlet JP 2008-016827 A JP 2008-047355 A JP 2007-305439 A

  This invention is made | formed in view of the subject which concerns, and the objective of this invention is providing an organic EL element, an illuminating device, and a display apparatus with few dark spots, a leakage current, and the light emission nonuniformity in a light emitting element.

The above object of the present invention is achieved by the following constitutions 1 to 16. In particular, according to the present invention, in constitutions 1 to 3 , each of the compounds represented by the following general formula (1) and the following general formula There is provided an organic electroluminescence device characterized in that the compound represented by (2) is contained in at least one layer of the organic layer. (However, the compound represented by the general formula (1) and the compound represented by the general formula (2) may be contained in the same layer or in different layers).
In the following general formula (1), R _{11 to} R ₁₅ , R ₁₇ , R ₁₈ and R ₂₁ , R ₂₂ , R _{24 to} R ₂₈ each represent a hydrogen atom. R ₁₆ and R ₂₃ are used for connection with X. X represents an arylene group or a heteroarylene group. At least one of X is represented by the following general formula (3) or a phenylene group. However, X directly linked to R ₁₆ and R ₂₃ is a dibenzofuranylene group, a fluorenylene group, a pyridylene group or a phenylene group. n represents an integer of 1 or more. When n is 2 or more, Xs may be the same or different.
In the following general formula (3), R _{30 to} R ₃₈ are each linked to a hydrogen atom, a substituent, or R ₁₆ and R ₂₃ .

1. In an organic electroluminescence device having a plurality of organic layers including a light emitting layer sandwiched between an anode and a cathode,
Each of the organic electroluminescence devices, wherein each of the organic layers contains a compound represented by the following general formula (1) and a compound represented by the following general formula (2) independently of each other . (However, the compound represented by the general formula (1) and the compound represented by the general formula (2) may be contained in the same layer or in different layers).

[Wherein, R _{11 to} R ₁₈ and R _{21 to} R ₂₈ each represent a hydrogen atom or a substituent. However, at least one of R _{11 to} R ₁₈ and at least one of R _{21 to} R ₂₈ are used for connection with X. X represents an arylene group or a heteroarylene group. n represents an integer of 0 or more, and when n is 2 or more, Xs may be the same or different. ]

_Wherein, R 1 to R ₅ represents a substituent. B ₁ .about.B ₃ represents a carbon atom or a nitrogen atom, _{L A} is to form a bidentate ligand with _{B 2} and _{B 3.} Z _A , Z _B and Z _C each independently represents an atomic group necessary for forming a hydrocarbon ring group or a heterocyclic group. n ₁ represents an integer of 0 to 5, n ₂ represents an integer of 0 to ₃ , and n ₃ represents an integer of 0 to 4. M represents a group 8-10 transition metal element of the periodic table. m ₁ represents an integer of 1 to 3, m ₂ represents an integer of 0 to 2, and m ₁ + m ₂ represents 2 or 3. ]
2. 2. The organic electroluminescence device according to 1 above, wherein in the general formula (1), X is bonded to R ₁₆ and R ₂₃ .

  3. 3. In the general formula (1), n is 1 or more, and at least one kind of X is represented by the following general formula (3).

[Wherein Y represents O, S or —N (R ₃₀ ) —. R _{30 to} R ₃₈ are each linked to a hydrogen atom, a substituent, or at least one of R _{11 to} R ₁₈ and at least one of R _{21 to} R ₂₈ . ]
4). In the general formula (3), R ₃₃ and R ₃₆ are respectively connected to at least one of R _{11 to} R ₁₈ and at least one of R _{21 to} R ₂₈ , Electroluminescence element.

5. In the general formula (3), Y represents —N (R ₃₀ ) — (wherein R ₃₀ represents a hydrogen atom or a substituent, provided that R _{11 to} R ₁₈ and R _{21 to} R ₂₈ are connected to each other). The organic electroluminescence device according to 3 or 4 above, wherein any two of R _{30 to} R ₃₈ are represented.

  6). Any of the above 1 to 5, wherein the compound represented by the general formula (1) is a compound represented by the following general formula (4) or a compound represented by the following general formula (5) 2. The organic electroluminescence device according to item 1.

_Wherein, R 11 _{to R 18} and _R 21 _{to R 28} are each the formula in (1) have _the same meanings as R 11 _{to R 18} and _R 21 _{to R 28.} ]

_Wherein, R 11 _{to R 18} and _R 21 _{to R 28} are each the formula in (1) have _the same meanings as R 11 _{to R 18} and _R 21 _{to R 28.} ]
7). 7. The organic electroluminescence device according to any one of 1 to 6, wherein the compound represented by the general formula (2) is a compound represented by the following general formula (6).

_Wherein, R 6 _{to R 10} represents a substituent. and n ₆ represents an integer of 0 to 4, _{n 7} represents an integer of 0 to 2, _{n 8} is an integer of 0 to 3. M represents a group 8-10 transition metal element of the periodic table. ]
8). 8. The organic electroluminescence device as described in 1 or 7 above, wherein M in the general formula (2) is iridium.

  9. 9. The organic according to any one of 1 to 8, wherein the compound represented by the general formula (1) and the compound represented by the general formula (2) are contained in the same organic layer. Electroluminescence element.

  10. 10. The organic electroluminescence device as described in 9 above, wherein the same organic layer is a light emitting layer.

  11. In any one of 1 to 10 above, an organic layer containing the compound represented by the general formula (1) or the compound represented by the general formula (2) is formed by a coating method. The organic electroluminescent element of description.

  12 The organic layer containing the compound represented by the general formula (1) and the compound represented by the general formula (2) and any one layer adjacent to the organic layer are formed by a coating method. 12. The organic electroluminescence device as described in 11 above.

  13. An organic layer containing the compound represented by the general formula (1) and the compound represented by the general formula (2) and two layers adjacent to the organic layer are formed by a coating method. 13. The organic electroluminescence device as described in 11 or 12 above.

  14 14. The organic electroluminescence element according to any one of 1 to 13, which emits white light.

  15. 15. A display device comprising the organic electroluminescence element according to any one of 1 to 14 above.

  16. 15. An illumination device comprising the organic electroluminescence element according to any one of 1 to 14 above.

  The organic EL element of the present invention can provide a highly durable organic EL element, and a lighting device and a display device using the element.

It is a conceptual diagram which shows the relationship between a roughness curve and centerline average roughness Ra. It is the schematic of an illuminating device. It is sectional drawing of an illuminating device. The schematic block diagram of an organic electroluminescent full color display apparatus is shown.

  In the organic EL device of the present invention, an organic EL device having high durability (long life) can be obtained by having the configuration according to any one of claims 1 to 14.

  Moreover, it succeeded also in obtaining the display apparatus and the illuminating device which comprised the said organic EL element.

  Hereinafter, details of each component according to the present invention will be sequentially described.

  As a result of intensive studies, the present inventors have clarified that the cause of light emission unevenness is closely related to the likelihood of aggregation of the compounds constituting the organic layer. Especially when trying to form a layer using a coating method, if the compound to be applied is easy to agglomerate, the compound in the organic thin film that constitutes the organic layer becomes partially dense and the organic thin film becomes uniform. It could not be formed, causing not only unevenness of light emission but also a leakage current, and it was found that it caused a decrease in durability of the element.

  As a result of further studies, the above problem can be solved by incorporating the compound represented by the general formula (1) and the compound represented by the general formula (2) into at least one layer constituting the organic EL. The route was found and the present invention was reached.

  That is, the organic EL device produced using the compound represented by the general formula (1) and the compound represented by the general formula (2) was able to obtain a highly durable device.

  This is because the compound represented by the general formula (1) and the compound represented by the general formula (2) have an appropriate molecular weight and a three-dimensional bulk, so that the molecules are less likely to aggregate, It is presumed that a uniform and smooth film can be formed, and the flow of electricity is made uniform.

  Further, the compounds represented by the general formula (1) and the general formula (2) are considered to be able to form a film having a uniform and smooth density in the organic layer when mixed with other compounds. In particular, an organic EL device is manufactured using the compound represented by the general formula (1) as a host compound (also simply referred to as a host) and the compound represented by the general formula (2) as a light-emitting dopant (also simply referred to as a dopant). As a result, a highly durable (long life) organic EL element could be produced. The host compound, the light-emitting dopant, etc. will be described later in detail at the constituent layers of the organic EL element.

<< Compound Represented by Formula (1) >>
The compound represented by the general formula (1) according to the present invention will be described.

In the general formula (1), examples of the substituent represented by R _{11 to} R ₁₈ , R _{21 to} R ₂₈ and R _{30 to} R ₃₈ include an alkyl group (for example, a methyl group, an ethyl group, a propyl group, an isopropyl group). Group, tert-butyl group, pentyl group, hexyl group, octyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, etc.), cycloalkyl group (for example, cyclopentyl group, cyclohexyl group, etc.), alkenyl group (for example, vinyl) Group, allyl group, etc.), alkynyl group (for example, ethynyl group, propargyl group, etc.), aromatic hydrocarbon ring group (aromatic carbocyclic group, aryl group, etc.), for example, phenyl group, p-chlorophenyl group, mesityl Group, tolyl group, xylyl group, naphthyl group, anthryl group, azulenyl group, acenaphthenyl group, fluorenyl Group, phenanthryl group, indenyl group, pyrenyl group, biphenylyl group, etc.), aromatic heterocyclic group (for example, 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, furazanyl Group, thienyl group, quinolyl group, benzofuryl group, dibenzofuryl group, benzothienyl group, dibenzothienyl group, indolyl group, carbazolyl group, carbolinyl group, diazacarbazolyl group (carbon atoms constituting the carboline ring of the carbolinyl group) One of which is replaced by a nitrogen atom ), Quinoxalinyl group, pyridazinyl group, triazinyl group, quinazolinyl group, phthalazinyl group, etc.), heterocyclic group (for example, pyrrolidyl group, imidazolidyl group, morpholyl group, oxazolidyl group, etc.), alkoxy group (for example, 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.) Group), alkylthio group (for example, methylthio group, ethylthio group, propylthio group, pentylthio group, hexylthio group, octylthio group, dodecylthio group, etc.), cycloalkylthio group (for example, cyclopentylthio group, cyclohexyl group) Group), arylthio group (eg, phenylthio group, naphthylthio group, etc.), alkoxycarbonyl group (eg, methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, octyloxycarbonyl group, dodecyloxycarbonyl group, etc.), Aryloxycarbonyl group (eg, phenyloxycarbonyl group, naphthyloxycarbonyl group, etc.), sulfamoyl group (eg, aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group, butylaminosulfonyl group, hexylaminosulfonyl group, cyclohexylamino) Sulfonyl group, octylaminosulfonyl group, dodecylaminosulfonyl group, phenylaminosulfonyl group, naphthylaminosulfonyl group, 2-pyridylaminosulfonyl group, etc. ), Acyl group (for example, acetyl group, ethylcarbonyl group, propylcarbonyl group, pentylcarbonyl group, cyclohexylcarbonyl group, octylcarbonyl group, 2-ethylhexylcarbonyl group, dodecylcarbonyl group, phenylcarbonyl group, naphthylcarbonyl group, pyridylcarbonyl) Group), acyloxy group (for example, acetyloxy group, ethylcarbonyloxy group, butylcarbonyloxy group, octylcarbonyloxy group, dodecylcarbonyloxy group, phenylcarbonyloxy group, etc.), amide group (for example, methylcarbonylamino group, Ethylcarbonylamino group, dimethylcarbonylamino group, propylcarbonylamino group, pentylcarbonylamino group, cyclohexylcarbonylamino group, 2-ethylhexylcarbo group Ruamino group, octylcarbonylamino group, dodecylcarbonylamino group, phenylcarbonylamino group, naphthylcarbonylamino group, etc.), carbamoyl group (for example, aminocarbonyl group, methylaminocarbonyl group, dimethylaminocarbonyl group, propylaminocarbonyl group, pentyl) Aminocarbonyl group, cyclohexylaminocarbonyl group, octylaminocarbonyl group, 2-ethylhexylaminocarbonyl group, dodecylaminocarbonyl group, phenylaminocarbonyl group, naphthylaminocarbonyl group, 2-pyridylaminocarbonyl group, etc.), ureido group (eg methyl Ureido group, ethylureido group, pentylureido group, cyclohexylureido group, octylureido group, dodecylureido group, phenylureido group Tilureido group, 2-pyridylaminoureido 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 (eg methylsulfonyl group, ethylsulfonyl group, butylsulfonyl group, cyclohexylsulfonyl group, 2-ethylhexylsulfonyl group, dodecylsulfonyl group etc.), arylsulfonyl group or heteroarylsulfonyl group (For example, phenylsulfonyl group, naphthylsulfonyl group, 2-pyridylsulfonyl group, etc.), amino group (for example, amino group, ethylamino group, di Methylamino group, butylamino group, cyclopentylamino group, 2-ethylhexylamino group, dodecylamino group, anilino group, naphthylamino group, 2-pyridylamino group, etc., halogen atom (for example, fluorine atom, chlorine atom, bromine atom, etc.) ), Fluorinated hydrocarbon group (eg, fluoromethyl group, trifluoromethyl group, pentafluoroethyl group, pentafluorophenyl group, etc.), cyano group, nitro group, hydroxy group, mercapto group, silyl group (eg, trimethylsilyl group) , Triisopropylsilyl group, triphenylsilyl group, phenyldiethylsilyl group, etc.).

  These substituents may be further substituted with the above substituents. In addition, a plurality of these substituents may be bonded to each other to form a ring.

  Among these, a hydrogen atom, an aromatic hydrocarbon ring group, or an aromatic heterocyclic group is preferable.

  In the general formula (1), examples of the arylene group represented by X include o-phenylene group, m-phenylene group, p-phenylene group, naphthalenediyl group, anthracenediyl group, naphthacenediyl group, pyrenediyl group, and naphthylnaphthalene. Diyl group, biphenyldiyl group (for example, [1,1′-biphenyl] -4,4′-diyl group, 3,3′-biphenyldiyl group, 3,6-biphenyldiyl group, etc.), terphenyldiyl group, Quaterphenyldiyl group, kinkphenyldiyl group, sexiphenyldiyl group, septiphenyldiyl group, octiphenyldiyl group, nobiphenyldiyl group, deciphenyldiyl group, etc.).

  In the general formula (1), examples of the heteroarylene group represented by X include a carbazole ring, a carboline ring, a diazacarbazole ring (also referred to as a monoazacarboline ring, and one of carbon atoms constituting the carboline ring). Derived from the group consisting of triazole ring, pyrrole ring, pyridine ring, pyrazine ring, quinoxaline ring, thiophene ring, oxadiazole ring, dibenzofuran ring, dibenzothiophene ring, indole ring) And the like, and the like. These substituents may be further substituted with the above substituents.

  In-(X) n- of the general formula (1), n is preferably 1 or more, more preferably at least one is a heteroarylene group, and more preferably a carbazole ring, a carboline ring, or a diazacarbazole ring. (Also referred to as a monoazacarboline ring, which is a divalent group derived from a ring structure in which one of the carbon atoms constituting the carboline ring is replaced with a nitrogen atom), and particularly preferred is the general formula (3 ).

(Group represented by general formula (3))
The group represented by the general formula (3) will be described.

  In-(X) n- of the general formula (1), when n is 2 or more, X may be different, but at least one X is preferably the above heteroarylene group, more preferably. Is a group represented by the general formula (3).

In the general formula (3), the substituents represented by R _{30 to} R ₃₈ are represented by R _{11 to} R ₁₈ , R _{21 to} R _28, and R _{30 to} R ₃₈ in the general formula (1). It is synonymous with a substituent.

In the general formula (3) Y is, -N _{(R 30)} - group.

Furthermore, R ₃₀ is preferably a substituent. Examples of the substituent are the same as those of R _{11 to} R ₁₈ and R _{21 to} R _28, and among them, an aromatic hydrocarbon ring group or an aromatic heterocyclic group is preferable, and among them, a phenyl group is preferable.

_May also be used in connection with any one or ₂₁ to R ₂₈ of _R 11 _{to R 18} substituents of _{R 30} is the formula (1).

  Among the compounds represented by the general formula (1), the compound represented by the general formula (4) or the compound represented by the general formula (5) is preferable.

<< Compound Represented by General Formula (4) or General Formula (5) >>
In the compound represented by the general formula (4) and the compound represented by the general formula (5), R _{11 to} R ₁₈ and R _{21 to} R ₂₈ are R _{11 to} R ₁₈ in the general formula (1), respectively. And R _{21 to} R ₂₈ .

  In the compound represented by the general formula (1), the general formula (4) or the general formula (5) according to the present invention, the molecular weight is not specified, but preferably the molecular weight is in the range of 700 to 5,000, Furthermore, it is the range of 800-3000.

  The number of n is not particularly limited, but is preferably 50 or less, more preferably 20 or less, and particularly preferably 10 or less.

  Hereinafter, although the specific example of a compound represented by General formula (1) is shown, this invention is not limited to these.

<< Synthesis of Exemplified Compound H-4 >>
Hereinafter, although an example (example compound H-4) of the synthesis | combination of the compound represented by General formula (1) based on this invention is shown, this invention is not limited to these.

  (Process 1)

To 20 g of raw material 1, 23.1 g of bis (pinacolato) diboron, 12.2 g of potassium acetate, and 1.0 g of PdCl ₂ (dppf) CH ₂ Cl ₂ were added 300 ml of dimethyl sulfoxide, and the mixture was heated and stirred at 100 ° C. for 16 hours in a nitrogen stream.

  The reaction solution was cooled to room temperature, insolubles were filtered, water was added, and the mixture was extracted with ethyl acetate. The organic layer was repeatedly washed with water and concentrated under reduced pressure.

  The resulting mixture was purified by silica gel column chromatography to obtain 18.8 g of Intermediate 2. The yield was 80%.

  The structure of the obtained intermediate 2 was confirmed by nuclear magnetic resonance spectrum and mass spectrum.

  (Process 2)

550 ml of 1,2-dimethoxyethane and 70 ml of water were added to 20.7 g of intermediate 2, 13.7 g of intermediate 3, 23.1 g of potassium carbonate, 0.64 g of Pd (dba) ₂ and 0.62 g of dppf for 5 hours. Heating to reflux was performed.

  The reaction mixture was cooled to room temperature, insolubles were filtered, water was added, and the mixture was extracted with ethyl acetate. The organic layer was repeatedly washed with water and concentrated under reduced pressure.

  The resulting mixture was purified by silica gel column chromatography to obtain 13.9 g of intermediate 4. The yield was 72%.

  The structure of the obtained intermediate 4 was confirmed by nuclear magnetic resonance spectrum and mass spectrum.

  (Process 3)

  To 0.29 g of palladium acetate, 2.1 g of a 50 mass% toluene solution of tert-butylphosphine and 10 ml of xylene (dehydrated) were added, and the mixture was stirred at room temperature for 1 hour in a nitrogen stream. Subsequently, Intermediate 4 6.7 g, 1,3-diiodobenzene 2.9 g, sodium t-butoxide 2.1 g, and xylene (dehydrated) 120 ml were added, and the mixture was heated to reflux for 5 hours under a nitrogen stream.

  After cooling the reaction solution to room temperature, insolubles were filtered, water was added, and the mixture was extracted with toluene. The organic layer was repeatedly washed with water and concentrated under reduced pressure.

  The resulting mixture was purified by silica gel column chromatography and recrystallized from toluene to obtain 5.7 g of Exemplified Compound H-4. The yield was 83%.

  The obtained exemplary compound H-4 was confirmed in structure by nuclear magnetic resonance spectrum and mass spectrum.

<< Compound Represented by General Formula (2) or General Formula (6) (also referred to as metal complex) >>
The compound represented by formula (2) or formula (6) according to the present invention will be described.

  In the organic EL device of the present invention, at least one of the organic layers constituting the device contains a compound represented by the general formula (2) (also referred to as a metal complex), preferably the general formula (6) The compound represented by these is used.

  In addition, it is preferable that the compound represented by General formula (2) or General formula (6) which concerns on this invention is used as a light emission dopant in the light emitting layer of the organic EL element of this invention. The constituent layers and constituent materials of the elements such as the light emitting layer and the light emitting dopant will be described in detail in the constituent layers of the organic EL element described later.

In General Formula (2) and General Formula (6), the substituents represented by R _{1 to} R ₁₀ are R _{11 to} R ₁₈ , R _{21 to} R _28, and R _{30 to} R ₃₈ in General Formula (1). It is synonymous with the kind of substituent in.

Furthermore, the substituent represented by R _{1 to} R ₁₀ is preferably a hydrogen atom, an aromatic hydrocarbon ring group, or an aromatic heterocyclic group.

In the general formula (2), Z _A , Z _B , and Z _C each independently represent a hydrocarbon ring group or a heterocyclic group, for example, an aromatic hydrocarbon ring group (both aromatic carbocyclic group and 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, phenanthryl group, indenyl group, pyrenyl group, biphenylyl group, etc.) An aromatic heterocyclic group (for example, pyridyl group, pyrimidinyl group, furyl group, pyrrolyl group, imidazolyl group, benzoimidazolyl 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, Soxazolyl group, isothiazolyl group, furazanyl group, thienyl group, quinolyl group, benzofuryl group, dibenzofuryl group, benzothienyl group, dibenzothienyl group, indolyl group, carbazolyl group, carbolinyl group, diazacarbazolyl group One of the carbon atoms constituting the carboline ring is replaced by a nitrogen atom), quinoxalinyl group, pyridazinyl group, triazinyl group, quinazolinyl group, phthalazinyl group, etc.), heterocyclic group (eg, pyrrolidyl group, imidazolidyl group, morpholyl) Group, oxazolidyl group, etc.), aryloxy group (eg, phenoxy group, naphthyloxy group, etc.), arylthio group (eg, phenylthio group, naphthylthio group, etc.), aryloxycarbonyl group (eg, phenyloxycarbonyl group, Naphthyloxycarbonyl group, etc.), arylsulfonyl group or heteroarylsulfonyl group (eg, phenylsulfonyl group, naphthylsulfonyl group, 2-pyridylsulfonyl group, etc.).

In the general formula (2), the Z _A, for example, a phenyl group, a naphthyl group, a pyridyl group, a pyrimidyl group, a pyrrolyl group, a thienyl group, a pyrazolyl group, an imidazolyl group, preferably a oxazolyl group and thiazolyl group, more preferably, They are a phenyl group, a naphthyl group, and a pyridyl group, and most preferably a phenyl group.

In the general formula (2), the Z _B, a pyridyl group, a pyrimidyl group, a pyrrolyl group, an imidazolyl group, a benzimidazolyl group, a pyrazolyl group, pyrazinyl group, triazolyl group, oxazolyl group and thiazolyl group, more preferably a pyridyl group , A pyrimidyl group, an imidazolyl group, a benzimidazolyl group and a triazolyl group, and most preferably a pyridyl group and an imidazolyl group.

In the general formula (2), the Z _C, a phenyl group, a naphthyl group, a pyridyl group, a pyrimidyl group, a pyrrolyl group, a thienyl group, a pyrazolyl group, an imidazolyl group, an oxazolyl group, a thiazolyl group, a carbazolyl group and a diaza-carbazolyl Group is preferred, more preferably a phenyl group, a naphthyl group, a pyridyl group and a carbazolyl group, and most preferably a phenyl group and a carbazolyl group.

In the general formula (2), L _A represents an atomic group that forms a bidentate ligand together with B ₂ and B ₃ . Specific examples of ligands of B ₂ -L _A -B ₃ in bidentate represented, for example, a substituted or unsubstituted phenyl pyridine, phenylpyrazole, phenylimidazole, phenyl triazole, phenyl tetrazole, include pyrazabole etc. It is done.

These groups may be further substituted with the same substituents as R _{11 to} R ₁₈ , R _{21 to} R ₂₈ and R _{30 to} R ₃₈ .

In the general formula (2), m ₁ represents an integer of ₁ to 3, m ₂ represents an integer of 0 to 2, and m ₁ + m ₂ is 2 or 3. Above all, when _{m 2} is 0 are preferred.

  In the general formula (2), as the metal represented by M, a transition metal element of group 8 to group 10 of the periodic table (also simply referred to as a transition metal) is used, among which iridium and platinum are preferable, Iridium is preferred.

  In addition, the compound represented by General formula (2) may or may not have a polymerizable group or a reactive group.

  Specific examples of the compound (metal complex) represented by the general formula (2) or the compound (metal complex) represented by the general formula (6) are shown below, but the present invention is not limited thereto. These compounds are described, for example, in Inorg. Chem. It can be synthesized by referring to the method described in Volume 40, 1704 to 1711.

  Although the synthesis example of the metal complex based on this invention is shown below, this invention is not limited to these.

  << Synthesis of Exemplary Compound D-21 >>

(Step 1: Synthesis of Complex A)
In a solution of 18 g (0.06861 mol) of 2-phenyl- (2,4,6-trimethylphenyl) -1H-imidazole in 350 ml of 2-ethoxyethanol under a nitrogen atmosphere, iridium chloride trihydrate, 8. 1 g (0.02297 mol) and 100 ml of water were added and refluxed for 5 hours under a nitrogen atmosphere. The reaction solution was cooled, 500 ml of methanol was added, and the precipitated crystals were collected by filtration. The obtained crystals were further washed with methanol and dried to obtain 15.2 g (yield: 88.4%) of Complex A.

(Step 2: Synthesis of Exemplified Compound D-21)
6.0 g (0.003998 mol) of complex A and 1.85 g (0.008396 mol) of silver trifluoroacetate obtained in step 1 were refluxed in 500 ml of methylene chloride for 1 hour while carrying out nitrogen bubbling.

  After cooling the reaction solution, the salt was filtered off, the filtrate was concentrated, 500 ml of tetrahydrofuran was added, 3.2 g (0.007996 mol) of carbene precursor and 1.35 g of tert-butoxy potassium were added, and the mixture was refluxed for 5 hours. . After cooling the reaction solution, the insoluble material was filtered off and the filtrate was concentrated. The obtained residue was separated and produced by silica gel column chromatography (hexane / tetrahydrofuran) to obtain 5.33 g (65.0%) of Exemplary Compound D-21.

  The above synthesis method is an example, and the present invention is not limited thereto. For example, various compounds can be synthesized by changing the solvent to be used to a polar solvent having a high boiling point such as phenyl acetate, changing the amount of the reaction substrate, or changing the reaction temperature.

  Further, the dopant used in the present invention is not limited to the one according to the present invention, and by combining with other dopants, the emission intensity can be increased and the emission peak can be shifted. In particular, an organic EL element that emits white light can be achieved by mixing a plurality of dopants.

  Although an example of the dopant which may be used for this invention below is shown, the dopant which can be used is not limited to these.

<< Constitutional layer of organic EL element, organic compound layer >>
The constituent layers and organic compound layers of the organic EL device of the present invention will be described. Although the preferable specific example of the layer structure of the organic EL element of this invention is shown below, this invention is not limited to these.

(I) Anode / light emitting layer / electron transport layer / cathode (ii) Anode / hole transport layer / light emitting layer / electron transport layer / cathode (iii) Anode / hole transport layer / light emitting layer / hole blocking layer / electron Transport layer / cathode (iv) Anode / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode buffer layer / cathode (v) Anode / anode buffer layer / hole transport layer / light emitting layer / hole Blocking layer / electron transport layer / cathode buffer layer / cathode << organic compound layer (also referred to as organic layer) >>
The organic compound layer according to the present invention will be described.

  The organic EL device of the present invention preferably has a plurality of organic compound layers as a constituent layer. Examples of the organic compound layer include a hole transport layer, a light emitting layer, and a hole blocking layer in the above layer constitution. In addition, an organic compound layer according to the present invention is defined as long as it contains an organic compound contained in a constituent layer of an organic EL element, such as a hole injection layer or an electron injection layer. Is done.

  Furthermore, when an organic compound is used for the anode buffer layer, the cathode buffer layer, etc., the anode buffer layer, the cathode buffer layer, etc. each form an organic compound layer.

  The organic compound layer includes a layer containing “organic EL element material that can be used for a constituent layer of an organic EL element” or the like.

  In the organic EL device of the present invention, the light emitting maximum wavelength of the blue light emitting layer is preferably 430 nm to 480 nm, the green light emitting layer has a light emitting maximum wavelength of 510 nm to 550 nm, and the red light emitting layer has a light emitting maximum wavelength of 600 nm to 640 nm. A monochromatic light emitting layer in the range is preferable, and a display device using these is preferable.

  Alternatively, a white light emitting layer may be formed by laminating at least three light emitting layers. Further, a non-light emitting intermediate layer may be provided between the light emitting layers.

  The organic EL element of the present invention is preferably a white light emitting layer, and is preferably a lighting device using these.

  Each layer which comprises the organic EL element of this invention is demonstrated.

<Light emitting layer>
The light emitting layer according to the present invention is a layer that emits light by recombination of electrons and holes injected from the electrode, the electron transport layer, or the hole transport layer, and the light emitting portion is in the layer of the light emitting layer. May be the interface between the light emitting layer and the adjacent layer.

  The total film thickness of the light emitting layer is not particularly limited, but it is 2 nm to from the viewpoint of preventing the application of a high voltage unnecessary for the film homogeneity and light emission and improving the stability of the emission color with respect to the drive current. It is preferable to adjust to the range of 5 micrometers, More preferably, it adjusts to the range of 2 nm-200 nm, Most preferably, it is the range of 10 nm-20 nm.

  For the production of the light-emitting layer, a light-emitting dopant or a host compound, which will be described later, is formed by a known thinning method such as a vacuum deposition method, a spin coating method, a casting method, an LB method, or an ink-jet method. I can do it.

  The light emitting layer of the organic EL device of the present invention preferably contains a host compound and at least one kind of light emitting dopant (phosphorescent dopant, fluorescent dopant, etc.).

(Host compound)
The host compound used in the present invention will be described.

  Here, the host compound in the present invention is a phosphorescent quantum yield of phosphorescence emission at a room temperature (25 ° C.) having a mass ratio of 20% or more in the compound contained in the light emitting layer. Is defined as a compound of less than 0.1. The phosphorescence quantum yield is preferably less than 0.01. Moreover, it is preferable that the mass ratio in the layer is 20% or more among the compounds contained in a light emitting layer.

  In the present invention, a compound having a structure represented by general formula (1), general formula (4), or general formula (5) is particularly preferably used as the host compound.

  In addition, as a host compound, a well-known host compound may be used together, and may be used in combination of multiple types. By using a plurality of types of host compounds, it is possible to adjust the movement of charges, and the organic EL element can be made highly efficient. Moreover, it becomes possible to mix different light emission by using multiple types of light emission dopants mentioned later, and, thereby, arbitrary light emission colors can be obtained.

  A conventionally known host compound that may be used in combination is preferably a compound that has a hole transporting ability and an electron transporting ability, prevents the emission of light from becoming longer, and has a high Tg (glass transition temperature).

  Specific examples of conventionally known host compounds include compounds described in the following documents.

  JP-A-2001-257076, 2002-308855, 2001-313179, 2002-319491, 2001-357777, 2002-334786, 2002-8860, 2002-334787, 2002-15871, 2002-334788, 2002-43056, 2002-334789, 2002-75645, 2002-338579, 2002-105445 gazette, 2002-343568 gazette, 2002-141173 gazette, 2002-352957 gazette, 2002-203683 gazette, 2002-363227 gazette, 2002-231453 gazette, No. 003-3165, No. 2002-234888, No. 2003-27048, No. 2002-255934, No. 2002-286061, No. 2002-280183, No. 2002-299060, No. 2002. -302516, 2002-305083, 2002-305084, 2002-308837, and the like.

《Light emitting dopant》
The light emitting dopant according to the present invention will be described.

  As the light emitting dopant according to the present invention, a fluorescent dopant or a phosphorescent light emitting dopant can be used. From the viewpoint of obtaining an organic EL element with higher luminous efficiency, the light emitting layer or light emitting unit of the organic EL element of the present invention. As the luminescent dopant used in the above, it is preferable to contain the above-mentioned host compound and at the same time a phosphorescent dopant.

  In the present invention, a compound (metal complex) having a structure represented by the general formula (2) is preferred as a phosphorescent dopant, and particularly preferably a compound (metal complex) represented by the general formula (6). Is mentioned.

《Phosphorescent dopant》
The phosphorescent dopant will be described.

  The phosphorescent dopant is a compound in which light emission from an excited triplet is observed. Specifically, the phosphorescent dopant is a compound that emits phosphorescence at room temperature (25 ° C.), and the phosphorescence quantum yield is 25 ° C. Although defined as 0.01 or more compounds, the preferred phosphorescence quantum yield is 0.1 or more.

  The phosphorescent quantum yield can be measured by the method described in Spectroscopic II, page 398 (1992 version, Maruzen) of Experimental Chemistry Course 4 of the 4th edition. Although the phosphorescence quantum yield in a solution can be measured using various solvents, the phosphorescence emitting dopant according to the present invention achieves the above phosphorescence quantum yield (0.01 or more) in any solvent. It only has to be done.

  There are two types of light emission of phosphorescent dopants in principle. One is the recombination of carriers on the host compound to which carriers are transported to generate an excited state of the host compound. The energy transfer type is to obtain light emission from the phosphorescent dopant by transferring to the phosphorescent dopant, and the other is that the phosphorescent dopant becomes a carrier trap, and carrier recombination occurs on the phosphorescent dopant to cause phosphorescence. There is a carrier trap type in which light emission from a photoluminescent dopant can be obtained.

  In any of the above cases, it is a condition that the excited state energy of the phosphorescent dopant is lower than the excited state energy of the host compound.

  The phosphorescent dopant is appropriately selected from known compounds used for the light emitting layer of the organic EL device and the compound represented by the general formula (2) or the general formula (6) of the present invention. It is possible to use a compound represented by general formula (2) or general formula (6).

  The phosphorescent dopant is preferably a complex compound containing a group 8-10 metal in the periodic table, more preferably an iridium compound (Ir complex), an osmium compound, or a platinum compound (platinum complex compound). ), Rare earth complexes, and most preferred among these are iridium compounds (Ir complexes).

<Fluorescent dopant>
As fluorescent dopants, coumarin dyes, pyran dyes, cyanine dyes, croconium dyes, squalium dyes, oxobenzanthracene dyes, fluorescein dyes, rhodamine dyes, pyrylium dyes, perylene dyes, stilbene dyes , Polythiophene dyes, or rare earth complex phosphors.

  Next, an injection layer, a blocking layer, an electron transport layer, and the like used as a constituent layer of the organic EL element of the present invention will be described.

<< Injection layer: electron injection layer, hole injection layer >>
The injection layer is provided as necessary, and there are an electron injection layer and a hole injection layer, and as described above, it exists between the anode and the light emitting layer or the hole transport layer and between the cathode and the light emitting layer or the electron transport layer. May be.

  An injection layer is a layer provided between an electrode and an organic layer in order to reduce drive voltage and improve light emission luminance. “Organic EL element and its forefront of industrialization (issued by NTT Corporation on November 30, 1998) 2), Chapter 2, “Electrode Materials” (pages 123 to 166), and includes a hole injection layer (anode buffer layer) and an electron injection layer (cathode buffer layer).

  The details of the anode buffer layer (hole injection layer) are described in JP-A-9-45479, JP-A-9-260062, JP-A-8-288069 and the like. As a specific example, copper phthalocyanine is used. Examples thereof include a phthalocyanine buffer layer represented by an oxide, an oxide buffer layer represented by vanadium oxide, an amorphous carbon buffer layer, and a polymer buffer layer using a conductive polymer such as polyaniline (emeraldine) or polythiophene.

  The details of the cathode buffer layer (electron injection layer) are described in JP-A-6-325871, JP-A-9-17574, JP-A-10-74586, and the like. Specifically, strontium, aluminum, etc. Metal buffer layer typified by lithium, alkali metal compound buffer layer typified by lithium fluoride, alkaline earth metal compound buffer layer typified by magnesium fluoride, oxide buffer layer typified by aluminum oxide, etc. . The buffer layer (injection layer) is preferably a very thin film, and the film thickness is preferably in the range of 0.1 nm to 5 μm although it depends on the material.

<Blocking layer: hole blocking layer, electron blocking layer>
The blocking layer is provided as necessary in addition to the basic constituent layer of the organic compound thin film as described above. For example, it is described in JP-A Nos. 11-204258, 11-204359, and “Organic EL elements and their forefront of industrialization” (issued by NTT, Inc. on November 30, 1998). There is a hole blocking (hole blocking) layer.

  The hole blocking layer has a function of an electron transport layer in a broad sense, and is made of a hole blocking material that has a function of transporting electrons and has a remarkably small ability to transport holes. By blocking this, the recombination probability of electrons and holes can be improved.

  Moreover, the structure of the electron carrying layer mentioned later can be used as a hole-blocking layer concerning this invention as needed.

  The hole blocking layer of the organic EL device of the present invention is preferably provided adjacent to the light emitting layer.

  In the present invention, when a plurality of light emitting layers having different light emission colors are provided, the light emitting layer having the shortest wavelength of light emission is preferably closest to the anode among all the light emitting layers. In this case, it is preferable to additionally provide a hole blocking layer between the shortest wave layer and the light emitting layer next to the anode next to the anode.

  Furthermore, it is preferable that 50% by mass or more of the compound contained in the hole blocking layer provided at the position has an ionization potential of 0.3 eV or more larger than the host compound of the shortest wave emitting layer.

  The ionization potential is defined by the energy required to emit electrons at the HOMO (highest occupied molecular orbital) level of the compound to the vacuum level, and can be obtained by the following method, for example.

  (1) Using Gaussian 98 (Gaussian 98, Revision A.11.4, MJ Frisch, et al, Gaussian, Inc., Pittsburgh PA, 2002.), a molecular orbital calculation software manufactured by Gaussian, USA The ionization potential can be obtained as a value obtained by rounding off the second decimal place of the value (eV unit conversion value) calculated by performing structural optimization using B3LYP / 6-31G *. This calculation value is effective because the correlation between the calculation value obtained by this method and the experimental value is high.

  (2) The ionization potential can also be obtained by a method of directly measuring by photoelectron spectroscopy. For example, a method known as ultraviolet photoelectron spectroscopy can be suitably used by using a low energy electron spectrometer “Model AC-1” manufactured by Riken Keiki Co., Ltd.

  On the other hand, the electron blocking layer has a function of a hole transport layer in a broad sense, and is made of a material that has a function of transporting holes and has an extremely small ability to transport electrons, and transports electrons while transporting holes. By blocking, the probability of recombination of electrons and holes can be improved.

  Moreover, the structure of the positive hole transport layer mentioned later can be used as an electron blocking layer as needed. The film thickness of the hole blocking layer and the electron transport layer according to the present invention is preferably in the range of 3 nm to 100 nm, more preferably in the range of 5 nm to 30 nm.

《Hole transport layer》
The hole transport layer is made of a hole transport material 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 can be provided as a single layer or a plurality of layers.

  The hole transport material has any one of hole injection or transport and electron barrier properties, and may be either organic or inorganic. For example, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, Examples thereof include stilbene derivatives, silazane derivatives, aniline copolymers, and conductive polymer oligomers, particularly thiophene oligomers. Furthermore, the compounds represented by the general formula (1), general formula (4) and general formula (5) of the present invention can also be used as the hole transport material.

  As the hole transport material, those described above can be used. Porphyrin compounds, aromatic tertiary amine compounds and styrylamine compounds, particularly aromatic tertiary amine compounds, the general formula (1) of the present invention, It is preferable to use the compounds represented by general formula (4) and general formula (5).

  Representative examples of aromatic tertiary amine compounds and styrylamine compounds include N, N, N ', N'-tetraphenyl-4,4'-diaminophenyl; N, N'-diphenyl-N, N'- Bis (3-methylphenyl)-[1,1′-biphenyl] -4,4′-diamine (TPD); 2,2-bis (4-di-p-tolylaminophenyl) propane; 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane; N, N, N ′, N′-tetra-p-tolyl-4,4′-diaminobiphenyl; 1,1-bis (4-di-p-tolyl) Aminophenyl) -4-phenylcyclohexane; bis (4-dimethylamino-2-methylphenyl) phenylmethane; bis (4-di-p-tolylaminophenyl) phenylmethane; N, N'-diphenyl-N, N ' − (4-methoxyphenyl) -4,4'-diaminobiphenyl; N, N, N ', N'-tetraphenyl-4,4'-diaminodiphenyl ether; 4,4'-bis (diphenylamino) quadriphenyl; N, N, N-tri (p-tolyl) amine; 4- (di-p-tolylamino) -4 '-[4- (di-p-tolylamino) styryl] stilbene; 4-N, N-diphenylamino- (2-diphenylvinyl) benzene; 3-methoxy-4′-N, N-diphenylaminostilbenzene; N-phenylcarbazole, and two more described in US Pat. No. 5,061,569 Having a condensed aromatic ring of, for example, 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPD), JP-A-4-308 4,4 ', 4 "-tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine in which three triphenylamine units described in Japanese Patent No. 88 are linked in a starburst type ( MTDATA) and the like.

  Furthermore, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used. In addition, inorganic compounds such as p-type-Si and p-type-SiC can also be used as the hole injection material and the hole transport material.

  JP-A-11-251067, J. Org. Huang et. al. A so-called p-type hole transport material described in a book (Applied Physics Letters 80 (2002), p. 139) can also be used. In the present invention, these materials are preferably used because a light-emitting element with higher efficiency can be obtained.

  The hole transport layer can be formed by thinning the hole transport material by a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an ink jet method, or an LB method. I can do it. Although there is no restriction | limiting in particular about the film thickness of a positive hole transport layer, Usually, 5 nm-about 5 micrometers, Preferably it is 5 nm-200 nm. The hole transport layer may have a single layer structure composed of one or more of the above materials.

  Alternatively, 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; Appl. Phys. 95, 5773 (2004), and the like.

  In the present invention, it is preferable to use a hole transport layer having such a high p property because a device with lower power consumption can be produced.

《Electron transport layer》
The electron transport layer is made of a material 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 can be provided as a single layer or a plurality of layers.

  Conventionally, in the case of a single electron transport layer and a plurality of layers, an electron transport material (also serving as a hole blocking material) used for an electron transport layer adjacent to the light emitting layer on the cathode side is injected from the cathode. Any material may be used as long as it has a function of transferring electrons to the light-emitting layer, and any of known materials can be selected for use.

  Examples include nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, carbodiimides, fluorenylidenemethane derivatives, anthraquinodimethane and anthrone derivatives, oxadiazole derivatives, and the like.

  Furthermore, in the above oxadiazole derivatives, thiadiazole derivatives in which the oxygen atom of the oxadiazole ring is substituted with a sulfur atom, and quinoxaline derivatives having a quinoxaline ring known as an electron-withdrawing group can also be used as the electron transport material. Furthermore, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used.

  In addition, metal complexes of 8-quinolinol derivatives such as tris (8-quinolinol) aluminum (Alq), 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 the central metals of these metal complexes are In, Mg, A metal complex replaced with Cu, Ca, Sn, Ga, or Pb can also be used as an electron transport material.

  In addition, metal-free or metal phthalocyanine, or those having terminal ends substituted with an alkyl group or a sulfonic acid group can be preferably used as the electron transport material. In addition, the distyrylpyrazine derivative exemplified as the material of the light emitting layer can also be used as an electron transport material, and an inorganic semiconductor such as n-type-Si, n-type-SiC, etc. as in the case of the hole injection layer and the hole transport layer. Can also be used as an electron transporting material.

  The electron transport layer can be formed by thinning the electron transport material by a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an ink jet method, or an LB method.

  Although there is no restriction | limiting in particular about the film thickness of an electron carrying layer, Usually, 5 nm-about 5 micrometers, Preferably it is 5 nm-200 nm. The electron transport layer may have a single layer structure composed of one or more of the above materials.

  Further, an electron transport layer having a high n property doped with impurities can be used. Examples thereof include JP-A-4-297076, JP-A-10-270172, JP-A-2000-196140, 2001-102175, J.A. Appl. Phys. 95, 5773 (2004), and the like.

  In the present invention, it is preferable to use such an electron transport layer having a high n property because an element with lower power consumption can be produced.

"anode"
As the anode in the organic EL element, an electrode material made of a metal, an alloy, an electrically conductive compound, or a mixture thereof having a high work function (4 eV or more) is preferably used.

Specific examples of such electrode materials include metals such as Au, and conductive transparent materials such as CuI, indium tin oxide (ITO), SnO ₂ , and ZnO.

Alternatively, an amorphous material such as IDIXO (In ₂ O ₃ —ZnO) capable of forming a transparent conductive film may be used. For the anode, these electrode materials may be formed into a thin film by a method such as vapor deposition or sputtering, and a pattern having a desired shape may be formed by a photolithography method, or when pattern accuracy is not so high (about 100 μm or more) A pattern may be formed through a mask having a desired shape at the time of vapor deposition or sputtering of the electrode material.

  Or when using the substance which can be apply | coated like an organic electroconductivity compound, the coating film-forming methods, such as a printing system and a coating system, can also be used.

  When light emission is extracted from the anode, it is desirable that the transmittance be greater than 10%, and the sheet resistance as the anode is preferably several hundred Ω / □ or less. Further, although the film thickness depends on the material, it is usually selected in the range of 10 nm to 1000 nm, preferably 10 nm to 200 nm.

"cathode"
On the other hand, as the cathode, a material having a low work function (4 eV or less) metal (referred to as an electron injecting metal), an alloy, an electrically conductive compound, and a mixture thereof as an electrode material is used. Specific examples of such electrode materials 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 ) Mixtures, indium, lithium / aluminum mixtures, rare earth metals and the like.

Among these, from the point of durability against electron injection and oxidation, etc., a mixture of an electron injecting metal and a second metal which is a stable metal having a larger work function than this, for example, a magnesium / silver mixture, Magnesium / aluminum mixtures, magnesium / indium mixtures, aluminum / aluminum oxide (Al ₂ O ₃ ) mixtures, lithium / aluminum mixtures, aluminum and the like are preferred. The cathode can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering.

  The sheet resistance as a cathode is preferably several hundred Ω / □ or less, and the film thickness is usually selected in the range of 10 nm to 5 μm, preferably 50 nm to 200 nm.

  In order to transmit the emitted light, if either the anode or the cathode of the organic EL element is transparent or translucent, the light emission luminance is improved, which is convenient.

  Moreover, after producing the said metal with a film thickness of 1 nm-20 nm on a cathode, the transparent or semi-transparent cathode can be produced by producing the electroconductive transparent material quoted by description of the anode on it, By applying this, an element in which both the anode and the cathode are transmissive can be manufactured.

《Support substrate》
As a support substrate (hereinafter also referred to as a substrate, substrate, substrate, support, etc.) that can be used in the organic EL device of the present invention, there is no particular limitation on the type of glass, plastic, etc., and it is transparent. May be opaque. When extracting light from the support substrate side, the support substrate is preferably transparent.

  Examples of the transparent support substrate preferably used include glass, quartz, and a transparent resin film. A particularly preferable support substrate is a resin film capable of giving 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, cellulose acetate butyrate, cellulose acetate propionate (CAP), Cellulose esters such as cellulose acetate phthalate (TAC) and 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, polyether ketone imide, polyamide, fluorine resin, nylon, polymethyl methacrylate, acrylic or polyarylates, and cycloolefin resins such as ARTON (JSR Corp.) or APEL (manufactured by Mitsui Chemicals, Inc.).

On the surface of the resin film, an inorganic film, an organic film, or a hybrid film of both may be formed. Water vapor permeability (25 ± 0.5 ° C.) measured by a method according to JIS K 7129-1992. , Relative humidity (90 ± 2)% RH) is preferably 0.01 g / (m ² · 24 h) or less, and further, oxygen measured by a method according to JIS K 7126-1987. A high barrier film having a permeability of 10 ⁻³ ml / (m ² · 24 h · MPa) or less and a water vapor permeability of 10 ⁻⁵ g / (m ² · 24 h) or less is preferable.

  As a material for forming the barrier film, any material may be used as long as it has a function of suppressing intrusion of elements that cause deterioration of elements such as moisture and oxygen. 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 layers and organic material layers.

  Although there is no restriction | limiting in particular about the lamination | stacking order of an inorganic layer and an organic layer, It is preferable to laminate | stack both alternately several times.

  The method for forming the barrier film is not particularly limited. For example, vacuum deposition, sputtering, reactive sputtering, molecular beam epitaxy, cluster ion beam, ion plating, plasma polymerization, atmospheric pressure plasma polymerization A plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, or the like can be used, but an 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, opaque resin substrates, and ceramic substrates.

  The external extraction quantum efficiency at room temperature of light emission of the organic EL device of the present invention is preferably 1% or more, more preferably 5% or more.

  Here, the external extraction quantum efficiency (%) = the number of photons emitted to the outside of the organic EL element / the number of electrons sent to the organic EL element × 100.

  In addition, a hue improvement filter such as a color filter may be used in combination, or a color conversion filter that converts the emission color from the organic EL element into multiple colors using a phosphor may be used in combination. In the case of using a color conversion filter, the λmax of light emission of the organic EL element is preferably 480 nm or less.

<Sealing>
Examples of the sealing means used in the present invention include a method of bonding a sealing member, an electrode, and a support substrate with an adhesive.

  As a sealing member, it should just be arrange | positioned so that the display area | region of an organic EL element may be covered, and concave plate shape or flat plate shape may be sufficient. Further, transparency and electrical insulation are not particularly limited.

  Specific examples include a glass plate, a polymer plate / film, and a metal plate / film. Examples of the glass plate include soda-lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, and quartz. Examples of the polymer plate include polycarbonate, acrylic, polyethylene terephthalate, polyether sulfide, and polysulfone. 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 and a metal film can be preferably used because the element can be thinned. Furthermore, the polymer film has an oxygen permeability measured by a method according to JIS K 7126-1987 of 1 × 10 ⁻³ ml / (m ² · 24 h · MPa) or less, and a method according to JIS K 7129-1992. The water vapor permeability (25 ± 0.5 ° C., relative humidity (90 ± 2)% RH) measured in (1) is preferably 1 × 10 ⁻³ g / (m ² · 24 h) or less.

  For processing the sealing member into a concave shape, sandblasting, chemical etching, or the like is used.

  Specific examples of the adhesive include photocuring and thermosetting adhesives having reactive vinyl groups such as acrylic acid oligomers and methacrylic acid oligomers, and moisture curing adhesives such as 2-cyanoacrylates. I can do it.

  Moreover, the heat | fever and chemical curing types (two-component mixing), such as an epoxy type, can be mentioned. Moreover, hot-melt type polyamide, polyester, and polyolefin can be mentioned. Moreover, a cationic curing type ultraviolet curing epoxy resin adhesive can be mentioned.

  In addition, since an organic EL element may deteriorate by heat processing, what can be adhesively cured from room temperature to 80 degrees is preferable. A desiccant may be dispersed in the adhesive. Application | coating of the adhesive agent to a sealing part may use commercially available dispenser, and may print like screen printing.

  In addition, it is also possible to suitably form an inorganic or organic layer as a sealing film by covering the electrode and the organic layer on the outer side of the electrode facing the support substrate with the organic layer interposed therebetween, and in contact with the support substrate. . In this case, the material for forming the film may be any material that has a function of suppressing intrusion of elements that cause deterioration of elements such as moisture and oxygen. For example, silicon oxide, silicon dioxide, silicon nitride, or the like may be used. I can do it. 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 organic materials.

  There are no particular limitations on the method of forming these films. For example, vacuum deposition, sputtering, reactive sputtering, molecular beam epitaxy, cluster ion beam, ion plating, plasma polymerization, atmospheric pressure plasma A combination 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 area of the organic EL element, it is preferable to inject an inert gas such as nitrogen or argon, or an inert liquid such as fluorinated hydrocarbon or silicon oil in the gas phase and the liquid phase. . A vacuum can also be used. Moreover, a hygroscopic compound can also be enclosed inside.

  Examples of the hygroscopic compound include metal oxides (for example, sodium oxide, potassium oxide, calcium oxide, barium oxide, magnesium oxide, aluminum oxide) and sulfates (for example, 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 anhydrous salts are preferably used in sulfates, metal halides and perchloric acids.

《Protective film, protective plate》
In order to increase the mechanical strength of the element, a protective film or a protective plate may be provided on the outer side of the sealing film on the side facing the support substrate with the organic layer interposed therebetween or on the sealing film.

  In particular, when the sealing is performed by the sealing film, the mechanical strength is not necessarily high, and thus it is preferable to provide such a protective film and a protective plate.

  As a material that can be used for this, the same glass plate, polymer plate / film, metal plate / film, etc. as used for the sealing can be used. It is preferable to use a film.

《Light extraction》
The organic EL element emits light inside a layer having a higher refractive index than air (refractive index is about 1.7 to 2.1), and only about 15% to 20% of the light generated in the light emitting layer can be extracted. It is generally said that there is no.

  This is because light incident on the interface (interface between the transparent substrate and air) at an angle θ greater than the critical angle causes total reflection and cannot be extracted outside the device. This is because the light undergoes total reflection between them and the light is guided through the transparent electrode or the light emitting layer, and as a result, the light escapes in the direction of the side surface of the device.

  As a method for improving the light extraction efficiency, for example, a method of forming irregularities on the surface of the transparent substrate to prevent total reflection at the interface between the transparent substrate and the air (US Pat. No. 4,774,435), A method of improving efficiency by providing a light collecting property to a substrate (Japanese Patent Laid-Open No. 63-314795), a method of forming a reflective surface on a side surface of an element (Japanese Patent Laid-Open No. 1-220394), and light emission from a substrate A method of forming an antireflection film by introducing a flat layer having an intermediate refractive index between the bodies (Japanese Patent Laid-Open No. 62-172691), a flat having a lower refractive index between the substrate and the light emitter than the substrate A method of introducing a layer (Japanese Patent Laid-Open No. 2001-202827), a method of forming a diffraction grating between any one of a substrate, a transparent electrode layer and a light emitting layer (including between the substrate and the outside) (Japanese Patent Laid-Open No. 11-283951) Gazette).

  In the present invention, these methods can be used in combination with the organic EL device of the present invention. However, a method of introducing a flat layer having a lower refractive index than the substrate between the substrate and the light emitter, or a substrate, transparent A method of forming a diffraction grating between any layers of the electrode layer and the light emitting layer (including between the substrate and the outside) can be suitably used.

  In the present invention, by combining these means, it is possible to obtain an element having higher luminance or durability.

  When a medium having 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 extracted from the transparent electrode has a higher extraction efficiency to the outside as the refractive index of the medium is lower.

  Examples of the low refractive index layer include aerogel, porous silica, magnesium fluoride, and a fluorine-based polymer. Since the refractive index of the transparent substrate is generally 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.

  The thickness of the low refractive index medium is preferably at least twice the wavelength in the medium. This is because the effect of the low refractive index layer is diminished when the thickness of the low refractive index medium is about the wavelength of light and the electromagnetic wave that has exuded by evanescent enters the substrate.

  The method of introducing a diffraction grating into an interface or any medium that causes total reflection is characterized by a high effect of improving 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 so-called Bragg diffraction such as first-order diffraction and second-order diffraction. Of this, light that cannot be emitted due to total reflection between layers, etc. is diffracted by introducing a diffraction grating into any layer or medium (inside a transparent substrate or transparent electrode), and the light is removed. I want to take it out.

  The introduced diffraction grating desirably has a two-dimensional periodic refractive index. This is because light emitted from the light-emitting layer is randomly generated in all directions, so in a general one-dimensional diffraction grating having a periodic refractive index distribution only in a certain direction, only 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 light extraction efficiency is increased.

  As described above, the position where the diffraction grating is introduced may be in any of the layers or in the medium (in the transparent substrate or in the transparent electrode), but is preferably in the vicinity of the organic light emitting layer where light is generated.

  At this time, the period of the diffraction grating is preferably about 1/2 to 3 times the wavelength of light in the medium.

  The arrangement of the diffraction grating is preferably two-dimensionally repeated, such as a square lattice, a triangular lattice, or a honeycomb lattice.

<Condenser sheet>
The organic EL device of the present invention is processed on the light extraction side of the substrate so as to provide, for example, a microlens array structure, or combined with a so-called condensing sheet, for example, with respect to a specific direction, for example, the light emitting surface By condensing light in the front direction, the luminance in a specific direction can be increased.

  As an example of the microlens array, quadrangular pyramids 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 10 to 100 μm. If it becomes smaller than this, the effect of diffraction will generate | occur | produce and color, and if too large, thickness will become thick and is not preferable.

  As the condensing sheet, for example, a sheet that is put into practical use in an LED backlight of a liquid crystal display device can be used. 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, the base material may be formed by forming a △ -shaped stripe having a vertex angle of 90 degrees and a pitch of 50 μm, or the vertex angle is rounded and the pitch is changed randomly. Other shapes may be used.

  Moreover, in order to control the light emission angle from a light emitting element, you may use together a light diffusing plate and a film with a condensing sheet. For example, a diffusion film (light-up) manufactured by Kimoto Co., Ltd. can be used.

<< Method for producing organic EL element >>
As an example of the method for producing the organic EL device of the present invention, a method for producing an organic EL device comprising an anode / hole injection layer / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / electron injection layer / cathode Will be explained.

  First, a desired electrode material, for example, a thin film made of an anode material is formed on a suitable substrate so as to have a film thickness of 1 μm or less, preferably 10 nm to 200 nm, to form an anode.

  Next, an organic compound thin film of a hole injection layer, a hole transport layer, a light emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer is formed thereon.

  As a method for forming each of these layers, there are a vapor deposition method and a coating method (spin coating method, casting method, ink jet method, printing method) as described above, but it is easy to obtain a homogeneous film and it is difficult to generate pinholes. In view of the above, film formation by a coating method such as a spin coating method, an ink jet method, or a printing method is preferable in the present invention.

  In particular, in the present invention, the layer containing the compound having the structure represented by the general formula (1) is preferably formed by the above coating method, and the layer is preferably a light emitting layer.

  Further, when the total number of layers (the constituent layers of the organic EL element) existing between the anode and the cathode is 100%, 50% or more of the total number of layers is preferably formed by a coating method. .

  For example, in the anode / hole injection layer / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / electron injection layer / cathode mentioned as an example of the organic EL element, the hole injection layer In the case where the total number of layers / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / electron injection layer is 6, it is preferable that at least three layers are formed by a coating method.

  When the constituent layers of the organic EL device of the present invention are formed by coating, examples of the liquid medium for dissolving or dispersing various organic EL materials used for coating include ketones such as methyl ethyl ketone and cyclohexanone, and fatty acid esters such as ethyl acetate. , Halogenated hydrocarbons such as dichlorobenzene, aromatic hydrocarbons such as toluene, xylene, mesitylene and cyclohexylbenzene, aliphatic hydrocarbons such as cyclohexane, decalin and dodecane, and organic solvents such as DMF and DMSO I can do it.

  Moreover, as a dispersion method, it can disperse | distribute by dispersion methods, such as an ultrasonic wave, high shear force dispersion | distribution, and media dispersion | distribution.

  After these layers are formed, a thin film made of a cathode material is formed thereon by a method such as vapor deposition or sputtering so as to have a film thickness of 1 μm or less, preferably in the range of 50 nm to 200 nm, and a cathode is provided. Thus, a desired organic EL element can be obtained.

  In addition, it is also possible to reverse the production order and produce a cathode, an electron injection layer, an electron transport layer, a hole blocking layer, a light emitting layer, a hole transport layer, a hole injection layer, an anode, and the like in this order.

  When a DC voltage is applied to the multicolor display device thus obtained, light emission can be observed by applying a voltage of about 2 V to 40 V with the anode as + and the cathode as-. An alternating voltage may be applied. The alternating current waveform to be applied may be arbitrary.

<Application>
The organic EL element of the present invention can be used as a display device, a display, and various light sources. For example, lighting devices (home lighting, interior lighting), clock and liquid crystal backlights, billboard advertisements, traffic lights, light sources of optical storage media, light sources of electrophotographic copying machines, light sources of optical communication processors, light Examples include, but are not limited to, a light source of a sensor. In particular, the light source can be effectively used as a backlight of a liquid crystal display device or a light source for illumination.

  In the organic EL element of the present invention, patterning may be performed by a metal mask, an ink jet printing method, or the like as needed during film formation. In the case of patterning, only the electrode may be patterned, the electrode and the light emitting layer may be patterned, or the entire layer of the element may be patterned. In the fabrication of the element, a conventionally known method is used. I can do it.

  The light emission color of the organic EL device of the present invention and the compound according to the present invention is shown in FIG. 4.16 on page 108 of “New Color Science Handbook” (edited by the Japan Color Society, University of Tokyo Press, 1985). It is determined by the color when the result measured with the total CS-1000 (manufactured by Konica Minolta Sensing) is applied to the CIE chromaticity coordinates.

Further, when the organic EL element of the present invention is a white element, white means that the chromaticity in the CIE 1931 color system at 1000 Cd / m ² is X = It is in the region of 0.33 ± 0.07, Y = 0.33 ± 0.1.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these. In addition, although the display of "%" is used in an Example, unless otherwise indicated, "mass%" is represented.

Reference example 1
<< Preparation of model thin film 1 of light emitting layer of organic EL element >>
A quartz substrate of 30 mm × 30 mm × 1.1 mm was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and subjected to UV ozone cleaning for 5 minutes, then attached to a commercially available spin coater, H-1 (50 mg) and Ir -3 (5 mg) dissolved in 10 ml of toluene was formed by spin coating at 1500 rpm for 30 seconds, and further vacuum dried at 25 ° C. for 1 hour to obtain a model thin film 1 having a thickness of 25 nm. Produced.

<< Preparation of model thin films 2 to 9 of light emitting layer of organic EL element >>
In the production of the model thin film 1 described above, the model thin films 2 to 9 were prepared in the same manner except that the host compound H-1 and the phosphorescent dopant (also referred to as phosphorescent compound) were changed as shown in Table 1. Each was produced.

<< Ra measurement, P-to-V measurement >>
About the obtained model thin films 1-9, the apparatus name: SPI3800N DFM made from SII, cantilever: SI-DF20 was used, and the surface roughness was measured by measurement area: 50 micrometers x 50 micrometers, 10 micrometers x 10 micrometers. Thereby, Ra measurement value and P-to-V measurement value were obtained.

Here, Ra is a kind of JIS roughness shape parameter (JIS B0601-1994) and represents the centerline average roughness. The roughness curve is folded from the center line, and the value obtained by dividing the area obtained by the roughness curve and the center line by the length L is expressed in micrometers (μm). (See Figure 1)
P-to-V is the same as Ry, which is a kind of JIS roughness shape parameter (JIS B0601-1994), and represents the height from the lowest valley bottom to the highest mountain peak for each reference length. The maximum height of the section from which the reference length L is extracted from the cross-sectional curve is obtained and expressed in micrometers (μm), which is defined as a P-to-V value or an Ry value.

  Here, the cross-sectional curve represents a contour that appears at the cut end when the surface to be measured is cut along a plane perpendicular to the surface to be measured. Ra and P-to-V were obtained based on the obtained surface roughness data.

  The obtained Ra measurement values and P-to-V measurement values are shown in Table 1.

  Based on the above results, a thin film containing a compound represented by general formula (1) and a compound represented by general formula (2) can be formed into a thin film having a low P-to-V value and high smoothness. I understood.

Example 2
<< Production of Organic EL Element 1-1 >>
After patterning on a substrate (NH-Techno Glass NA-45) formed by depositing 100 nm of ITO (indium tin oxide) on a 100 mm × 100 mm × 1.1 mm glass substrate as an anode, this ITO transparent electrode was provided. The transparent support substrate was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and subjected to UV ozone cleaning for 5 minutes.

  On this transparent support substrate, a solution obtained by diluting poly (3,4-ethylenedioxythiophene) -polystyrene sulfonate (PEDOT / PSS, Bayer, Baytron P Al 4083) to 70% with pure water at 3000 rpm for 30 seconds. Then, the film was formed by spin coating and then dried at 200 ° C. for 1 hour to provide a 20 nm-thick hole transport layer.

  This substrate was transferred to a nitrogen atmosphere, and a solution in which 50 mg of the hole transport material 1 was dissolved in 10 ml of toluene was formed on the hole transport layer by spin coating at 1500 rpm for 30 seconds. In a nitrogen atmosphere, ultraviolet light was irradiated for 180 seconds to carry out photopolymerization and crosslinking to form a second hole transport layer having a thickness of about 20 nm.

  On this second hole transport layer, a solution obtained by dissolving 100 mg of Comparative Compound 1 and 10 mg of Compound Ir-3 in 10 ml of toluene was formed by spin coating at 1000 rpm for 30 seconds. It vacuum-dried at 120 degreeC for 1 hour, and was set as the light emitting layer with a film thickness of about 50 nm.

  Next, a solution obtained by dissolving 50 mg of the electron transport material 1 in 10 ml of 1-butanol was formed on this light emitting layer by spin coating under the condition of 5000 rpm for 30 seconds. It vacuum-dried at 60 degreeC for 1 hour, and was set as the electron carrying layer with a film thickness of about 15 nm.

Subsequently, this substrate is fixed to a substrate holder of a vacuum deposition apparatus, the vacuum chamber is decompressed to 4 × 10 ⁻⁴ Pa, lithium fluoride 1.0 nm is deposited as a cathode buffer layer, and aluminum 110 nm is deposited as a cathode to form a cathode. Then, an organic EL element 1-1 was produced.

<< Production of Organic EL Elements 1-2 to 1-11 >>
In the production of the organic EL element 1-1, the organic EL elements 1-2 to 1-11 were prepared in the same manner as the organic EL element 1-1 except that the comparative compound 1 and the compound Ir-3 were replaced with the compounds shown in Table 2. Each was produced.

<< Evaluation of Organic EL Elements 1-1 to 1-11 >>
When evaluating the obtained organic EL elements 1-1 to 1-11, 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-based photo-curing adhesive (Lux Track LC0629B manufactured by Toagosei Co., Ltd.) is applied as a sealing material in the periphery, and this is placed on the cathode to be in close contact with the transparent support substrate and irradiated with UV light from the glass substrate side. Then, it was cured and sealed, and an illumination device as shown in FIGS. 2 and 3 was formed and evaluated.

  FIG. 2 is a schematic diagram of the lighting device, and the organic EL element 201 is covered with a glass cover 202. Note that the sealing operation with the glass cover was performed in a glove box in a nitrogen atmosphere without bringing the organic EL element 201 into contact with the atmosphere (in a high purity nitrogen gas atmosphere with a purity of 99.999% or more).

  FIG. 3 is a cross-sectional view illustrating one embodiment of the lighting device of the present invention. In FIG. 3, reference numeral 205 denotes a cathode, 206 denotes an organic EL layer, and 207 denotes a glass substrate with a transparent electrode. The glass cover 202 is filled with nitrogen gas 208 and a water catching agent 209 is provided.

  Subsequently, the light emission lifetime was measured as follows.

(lifespan)
When driving at a constant current of ^2.5 mA / cm ² , the time required for the luminance to drop to half of the luminance immediately after the start of light emission (initial luminance) was measured, and this was calculated as the half-life time (τ ^0.5 ) As an index of life.

  For the measurement, a spectral radiance meter CS-1000 (manufactured by Konica Minolta) was used.

  The lifetime measurement results in Table 1 are expressed as relative values when the organic EL element 1-1 is taken as 100.

  The obtained results are shown in Table 2.

  From Table 2, it is clear that the organic EL device of the present invention has a longer emission lifetime than the comparative device.

Reference example 3
<< Production of organic EL full-color display device >>
FIG. 4 shows a schematic configuration diagram of an 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 thick ITO transparent electrode (102) formed on a glass substrate 101 as an anode, non-between the ITO transparent electrodes on this glass substrate. A photosensitive polyimide partition 103 (width 20 μm, thickness 2.0 μm) was formed by photolithography.

  A hole injection layer composition having the following composition is ejected and injected between polyimide partition walls on the ITO electrode using an inkjet head (manufactured by Epson; MJ800C), irradiated with ultraviolet light for 2 minutes, and dried at 60 ° C. for 10 minutes. A hole injection layer 104 having a thickness of 40 nm was produced by the treatment.

  On the hole injection layer, the following blue light-emitting layer composition, green light-emitting layer composition, and red light-emitting layer composition were similarly discharged and injected using an inkjet head, and dried at 60 ° C. for 10 minutes. Each light emitting layer (105B, 105G, 105R) was formed. Finally, Al (106) was vacuum-deposited as a cathode so as to cover the light emitting layer 105, and an organic EL element was produced.

  It was found that the produced organic EL element exhibited blue, green, and red light emission by applying a voltage to each electrode, and could be used as a full-color display device.

(Hole injection layer composition)
Hole transport material 1 20 parts by mass Cyclohexylbenzene 50 parts by mass Isopropyl biphenyl 50 parts by mass (Blue light emitting layer composition)
H-3 0.7 parts by mass D-3 0.04 parts by mass Cyclohexylbenzene 50 parts by mass Isopropylbiphenyl 50 parts by mass (green light emitting layer composition)
H-3 0.7 parts by mass D-20 0.04 parts by mass cyclohexylbenzene 50 parts by mass Isopropylbiphenyl 50 parts by mass (red light emitting layer composition)
H-3 0.7 parts by mass D-38 0.04 parts by mass Cyclohexylbenzene 50 parts by mass Isopropylbiphenyl 50 parts by mass (electron transport layer composition)
Electron transport material 1 20 parts by mass 1-butanol 50 parts by mass Isopropyl biphenyl 50 parts by mass An organic EL device produced by using compounds H-4, 14, and 19 instead of H-3 can also be used as a full-color display device. I understood that.

Reference example 4
<< Production of White Organic EL Element 3-1 >>
On the transparent electrode substrate of Example 2, a hole transport layer / second hole transport layer was formed by spin coating as in Example 2, and 100 mg of Compound Example H-3, 10 mg as a light emitting layer was further formed. A solution of D-3 and 0.1 mg of D-38 dissolved in 10 ml of toluene was formed into a film by spin coating under conditions of 1000 rpm and 30 seconds. It vacuum-dried at 120 degreeC for 1 hour, and was set as the light emitting layer with a film thickness of about 50 nm.

  Next, in the same manner as in Example 2, an electron transport layer, a lithium fluoride layer, and an aluminum cathode were formed to produce a white light-emitting organic EL element 3-1. The obtained organic EL element 3-1 was sealed in the same manner as in Example 2.

  When this organic EL element 3-1 was energized, almost white light was obtained, and it was found that it could be used as a lighting device. In addition, it turned out that white light emission is obtained similarly even if it replaces a host compound with the other compound which concerns on this invention.

DESCRIPTION OF SYMBOLS 101 Glass substrate 102 ITO transparent electrode 103 Partition 104 Hole injection layer 105B, 105G, 105R Light emitting layer 201 Organic EL element 207 Glass substrate with a transparent electrode 206 Organic EL layer 205 Cathode 202 Glass cover 208 Nitrogen gas 209 Water capturing agent

Claims (11)

In an organic electroluminescence device having a plurality of organic layers including a light emitting layer sandwiched between an anode and a cathode,
Each of the organic electroluminescence devices, wherein each of the organic layers contains a compound represented by the following general formula (1) and a compound represented by the following general formula (2) independently of each other . (However, the compound represented by the general formula (1) and the compound represented by the general formula (2) may be contained in the same layer or in different layers).
[In formula, R < ₁₁ > -R < ₁₅ >, R < ₁₇ >, R < ₁₈ > and R < ₂₁ >, R < ₂₂ >, R < ₂₄ > -R < ₂₈ > represent a hydrogen atom respectively. R ₁₆ and R ₂₃ are used for connection with X. X represents an arylene group or a heteroarylene group. At least one of X is represented by the following general formula (3) or a phenylene group. However, X directly linked to R ₁₆ and R ₂₃ is a dibenzofuranylene group, a fluorenylene group, a pyridylene group or a phenylene group. n represents an integer of 1 or more. When n is 2 or more, Xs may be the same or different. ]
_Wherein, R 1 to R ₅ represents a substituent. B ₁ .about.B ₃ represents a carbon atom or a nitrogen atom, _{L A} is to form a bidentate ligand with _{B 2} and _{B 3.} Z _A , Z _B and Z _C each independently represents an atomic group necessary for forming a hydrocarbon ring group or a heterocyclic group. n ₁ represents an integer of 0 to 5, n ₂ represents an integer of 0 to ₃ , and n ₃ represents an integer of 0 to 4. M represents a group 8-10 transition metal element of the periodic table. m ₁ represents an integer of 1 to 3, m ₂ represents an integer of 0 to 2 , and m ₁ + m ₂ represents 2 or 3. ]
[Wherein Y represents O, S or —N (R ₃₀ ) —. R _{30 to} R ₃₈ are each linked to a hydrogen atom, a substituent, or R ₁₆ and R ₂₃ . ] The organic electroluminescent device according to claim 1, wherein the compound represented by the general formula (2) is a compound represented by the following general formula (6).
_Wherein, R 6 _{to R 10} represents a substituent. and n ₆ represents an integer of 0 to 4, _{n 7} represents an integer of 0 to 2, _{n 8} is an integer of 0 to 3. M represents a group 8-10 transition metal element of the periodic table. ]   3. The organic electroluminescence device according to claim 1, wherein M in the general formula (2) is iridium.   The compound represented by the general formula (1) and the compound represented by the general formula (2) are contained in the same organic layer, according to any one of claims 1 to 3. Organic electroluminescence device.   The organic electroluminescence device according to claim 4, wherein the same organic layer is a light emitting layer.   6. The organic layer containing the compound represented by the general formula (1) or the compound represented by the general formula (2) is formed by a coating method. The organic electroluminescent element of description.   The organic layer containing the compound represented by the general formula (1) and the compound represented by the general formula (2) and any one layer adjacent to the organic layer are formed by a coating method. The organic electroluminescence device according to claim 6.   An organic layer containing the compound represented by the general formula (1) and the compound represented by the general formula (2) and two layers adjacent to the organic layer are formed by a coating method. The organic electroluminescent element according to claim 6 or 7.   The organic electroluminescence element according to claim 1, which emits white light.   A display device comprising the organic electroluminescence element according to claim 1.   An illuminating device comprising the organic electroluminescence element according to claim 1.