JP2015005768A - Organic electroluminescent device, method for manufacturing the same, luminaire, and display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic electroluminescent device having a long life and a high external extraction quantum efficiency by use of an organic electroluminescent device material which is usable in a wet process and higher in the abilities to charge and transport electric charges and the stability in a solvent in comparison to conventional organic EL device materials.SOLUTION: An organic electroluminescent device comprises organic compound layers sandwiched and held between a positive electrode and a negative electrode and including a light-emitting layer and an electron transport layer. In the organic electroluminescent device, at least one of the organic compound layers includes a polymer electron transport material including a repeating unit expressed by the following general formula (1).

Description

  The present invention relates to an organic electroluminescence element, a method for manufacturing the same, a lighting device, and a display device.

  An organic electroluminescence element (hereinafter also referred to as an organic EL element) is an all-solid-state element composed of an organic material film having a thickness of only about 0.1 μm between electrodes, and emits light of 2V to 20V. Since it can be achieved at a relatively low voltage, it is a technology expected as a next-generation flat display and illumination.

  The discovery of an organic EL device using phosphorescence emission enables a light emission efficiency of about 4 times in principle compared to the previous method using fluorescence emission. Research and development regarding the structure is performed all over the world (for example, see Patent Document 1 and Non-Patent Documents 1 to 3).

  On the other hand, there are roughly two methods for manufacturing organic EL elements, known as film formation by vapor deposition (dry process) and solution application / film formation (wet process). An excellent wet process is attracting attention in terms of high productivity. In the organic EL elements having a multi-layer structure which is currently the mainstream, development of a lamination method by coating and a material that can be laminated by coating is required, and in terms of solution stability, film formability, etc., particularly from a practical viewpoint. It is still inadequate and further improvement techniques are essential.

US Pat. No. 6,097,147

M.M. A. Baldo et al. , Nature, 395, 151-154 (1998) M.M. A. Baldo et al. , Nature, 403, 17, 750-753 (2000) S. Lamansky et al. , J .; Am. Chem. Soc. 123, 4304 (2001)

  The object of the present invention is to provide an organic electroluminescence device material that has higher charge injection / transport performance and higher solvent stability than conventional organic EL device materials and can be used in a wet process. An object of the present invention is to provide an organic electroluminescence device having high quantum efficiency and a long lifetime.

The above-described object of the present invention can be achieved by the following configuration. In particular, according to the present invention, in Configuration 1, Ar ₁ represents a partial structure represented by the following General Formula (3) in General Formula (1). In the general formula (3), when a plurality of R ₅ are present, they may be the same or different, and they are not bonded to each other to form a ring. Features.

  1. In an organic electroluminescence device having a plurality of organic compound layers including a light emitting layer and an electron transport layer sandwiched between an anode and a cathode, a repeating unit represented by the following general formula (1) is provided in at least one of the organic compound layers An organic electroluminescence device comprising a polymer electron transport material comprising:

(In the formula, X represents a boron-containing compound residue selected from a divalent group having a partial structure represented by the following general formula (2), and Ar ₁ represents an arylene group or a heteroarylene group.)

(In the formula, R _{1 to} R ₄ are each independently an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an alkylthio group, an aryl group, an aryloxy group, an arylthio group, an arylalkyl group, an arylalkoxy group, an arylalkylthio group. , Arylalkenyl group, arylalkynyl group, heteroaryl group, heteroaryloxy group, heteroarylthio group, heteroarylalkyl group, heteroarylalkoxy group, heteroarylalkylthio group, heteroarylalkenyl group, heteroarylalkynyl group, amino group , Substituted amino group, silyl group, substituted silyl group, halogen atom, acyl group, acyloxy group, imine residue, amide group, acid imide group, monovalent heterocyclic group, carboxy group, substituted carboxy group, cyano group or nitro Group, halo Represents a sulfonyl group or a linking group,, _{R 1} and _R 3, _{R 2} and _{R 4} and _{R 3} and _{R 4} each may form a ring together. Also, a, b are each independently And an integer selected from 0 to _{3. When a} plurality of R ₁ and R ₂ are present, they may be the same or different, and may be bonded to each other to form a ring.
2. 2. The organic electroluminescence device according to 1 above, wherein in the general formula (1), Ar ₁ is a divalent group having a partial structure represented by the following general formulas (3) to (9).

(Wherein R _{5 to} R ₂₀ each independently represents an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an alkylthio group, an aryl group, an aryloxy group, an arylthio group, an arylalkyl group, an arylalkoxy group, an arylalkylthio group) Group, arylalkenyl group, arylalkynyl group, heteroaryl group, heteroaryloxy group, heteroarylthio group, heteroarylalkyl group, heteroarylalkoxy group, heteroarylalkylthio group, heteroarylalkenyl group, heteroarylalkynyl group, amino Group, substituted amino group, silyl group, substituted silyl group, halogen atom, acyl group, acyloxy group, imine residue, amide group, acid imide group, monovalent heterocyclic group, carboxy group, substituted carboxy group, cyano group or Nitro group, Represents Rogeniru group, _{R 6} and _R 8, _{R 7} and _{R 9} may each also be bonded to each other to form a ring .c is an integer selected from Less than six, f, g are each independently 0 An integer selected from 5, d, e, and h are each independently an integer selected from 0 to 4, and i and j are each independently an integer selected from 0 to 3. R _{5 to} R ₇ , R ₁₀ , R _{14 to} R ₁₇ , and R ₁₉ may be the same or different, and may be bonded to each other to form a ring. In 9), two groups selected from the substituents each have become a bond.)
3. 3. The organic electroluminescent device according to 1 or 2 above, wherein a polymer electron transport material comprising a repeating unit represented by the general formula (1) is contained in at least one layer of the electron transport layer.

  4). 4. The organic electroluminescent device according to 3 above, wherein at least one of the light emitting layers contains a phosphorescent organometallic complex compound.

  5. 5. The organic electroluminescent device according to 4 above, wherein at least one of the phosphorescent organic metal complex compounds is a compound represented by the following general formula (10).

(In the formula, P and Q represent a carbon atom or a nitrogen atom, A1 represents an atomic group which forms an aromatic hydrocarbon ring or an aromatic heterocycle with PC, and A2 represents an aromatic hydrocarbon with QN. P1-L1-P2 represents a bidentate ligand, P1 and P2 each independently represent a carbon atom, a nitrogen atom, or an oxygen atom, and L1 represents P1. , P2 represents an atomic group forming a bidentate ligand, r represents an integer of 1 to 3, s represents an integer of 0 to 2, r + s is 2 or 3. M is an element period (Represents group 8-10 metal elements in the table.)
6). An illuminating device comprising the organic electroluminescence element according to any one of 1 to 5 above.

  7). 6. A display device comprising the organic electroluminescence element according to any one of 1 to 5 above.

  8). When manufacturing the organic electroluminescent element of any one of said 1-5, the layer containing the polymeric electron transport material shown by the said General formula (1) among this organic compound layer is a wet method (wet process). The method of manufacturing an organic electroluminescence element, comprising the steps of forming a film and forming a film by the above method.

  Compared to conventional organic EL element materials, the organic EL element material according to the present invention has higher charge injection / transport performance, stability to solvents, and high organic EL suitability with good amorphous properties by wet process. As a result, an organic EL element having high cost performance and high performance (high external extraction quantum efficiency, low driving voltage, and long life) can be provided.

It is the schematic diagram which showed an example of the display apparatus comprised from an organic EL element. 4 is a schematic diagram of a display unit A. FIG. It is a schematic diagram of a pixel. It is a schematic diagram of a passive matrix type full color display device. It is the schematic of an illuminating device. It is a schematic diagram of an illuminating device. The schematic block diagram of an organic electroluminescent full color display apparatus is shown.

  Hereinafter, the best mode for carrying out the present invention will be described in detail, but the present invention is not limited thereto.

  The organic EL device material according to the present invention has high charge injection / transport performance and high stability in solution by molecularly designing the compounds represented by the general formulas (1) to (9). Thus, a polymer electron transport material capable of forming a thin film could be obtained.

  In addition, when the polymer electron transport material composed of the repeating unit represented by the general formula (1) of the present invention is used, an organic EL device having high external extraction quantum efficiency, low driving voltage, and long emission lifetime can be provided. In addition, an organic EL element manufactured by the manufacturing method, a display device including the element, and a lighting device can be provided.

  First, the compound represented by General formula (1) of this invention is demonstrated.

<< Polymer Electron Transport Material Represented by Formula (1) >>
In the general formula (1), Ar ₁ represents an arylene group or a heteroarylene group. In the present invention, an arylene group is an aromatic hydrocarbon in which two hydrogen atoms are removed. As an aromatic hydrocarbon, an aromatic monocyclic hydrocarbon, a condensed polycyclic hydrocarbon, an independent A combination of a plurality of aromatic monocyclic hydrocarbons or condensed polycyclic hydrocarbons is also included. Examples thereof include a phenylene group, naphthalenediyl group, anthracenediyl group, biphenylene group, fluorenediyl group, and binaphthalenediyl group.

  The heteroarylene group is a heteroaromatic hydrocarbon in which two hydrogen atoms are removed. As the heteroaromatic hydrocarbon, the elements constituting the aromatic hydrocarbon ring described above are carbon atoms. Refers to one or more atoms substituted with heteroatoms such as oxygen, sulfur, nitrogen, phosphorus, boron, heteroaromatic monocyclic hydrocarbons, heterocondensed polycyclic hydrocarbons, independent Those in which aromatic monocyclic hydrocarbons or hetero-fused polycyclic hydrocarbons are bonded are also included. Examples thereof include pyridinediyl group, thiophenediyl group, bipyridyldiyl group, phenylpyridinediyl group, carbazolediyl group, azacarbazolediyl group, imidazolediyl group, dibenzofurandiyl group, isoquinolinediyl group, dibenzophospholediyl group and the like.

  The arylene group or heteroarylene group may have a substituent, and examples of the substituent include an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an alkylthio group, an aryl group, an aryloxy group, an arylthio group, an arylalkyl group, Arylalkoxy group, arylalkylthio group, arylalkenyl group, arylalkynyl group, heteroaryl group, heteroaryloxy group, heteroarylthio group, heteroarylalkyl group, heteroarylalkoxy group, heteroarylalkylthio group, heteroarylalkenyl group, Heteroarylalkynyl group, amino group, silyl group, halogen atom, acyl group, acyloxy group, imine residue, amide group, acid imide group, monovalent heterocyclic group, carboxy group, substituted carboxy group, cyano group or nitro group Group, halogenyl group.

  X represents a boron-containing compound residue selected from a divalent group having a partial structure represented by the general formula (2).

In the general formula (2), R _{1 to} R ₄ are each independently an alkyl group, alkenyl group, alkynyl group, alkoxy group, alkylthio group, aryl group, aryloxy group, arylthio group, arylalkyl group, arylalkoxy group. , Arylalkylthio group, arylalkenyl group, arylalkynyl group, heteroaryl group, heteroaryloxy group, heteroarylthio group, heteroarylalkyl group, heteroarylalkoxy group, heteroarylalkylthio group, heteroarylalkenyl group, heteroarylalkynyl Group, amino group, silyl group, halogen atom, acyl group, acyloxy group, imine residue, amide group, acid imide group, monovalent heterocyclic group, carboxy group, substituted carboxy group, cyano group or nitro group, halogenyl group , The other represents a linking group. R ₁ and R ₃ , R ₂ and R _4, and R ₃ and R ₄ may be bonded to each other to form a ring. A and b each independently represents an integer selected from 0 to 3; When a plurality of R ₁ and R ₂ are present, they may be the same or different, and may be bonded to each other to form a ring. Preferred examples of the group represented by R _{1 to} R ₄ include an alkyl group, an aryl group, and a halogenyl group.

  Although the specific example of the polymeric electron transport material which consists of a repeating unit shown by General formula (1) of this invention is shown, this invention is not limited to these.

(Synthesis example)
<Method of synthesizing boron unit>

  Benzaldehyde (8.6 g, 0.08 mol) p-iodoacetophenone (20.0 g, 0.08 mol) was heated and stirred in a basic water / methanol solvent and treated in the usual manner to obtain intermediate IN-1a. Yield 96% (26.2 g). Next, the intermediate IN-1a (26.0 g, 0.08 mol) and nitromethane were heated and stirred in basic ethanol and then subjected to a conventional treatment to obtain an intermediate IN-1b in a yield of 83% (25.7 g). Got in. After dissolving the obtained intermediate IN-1b in butanol, a large excess of ammonium acetate was added, and after heating and stirring, the usual treatment was performed to obtain intermediate IN-1c in a yield of 25% (6.2 g). Obtained.

  Boron trifluoride-ether complex (19.9 g, 0.13 mol) was stirred in a dichloromethane solution of a large excess of triethylamine and intermediate IN-1c (6.0 g, 8.56 mmol) under a nitrogen atmosphere. Slowly dripped. After completion of the dropwise addition, the mixture was heated to reflux for 48 hours and returned to room temperature, and then the solid was collected by filtration and washed with dichloromethane and methanol to obtain the target boron unit B-1 (3.5 g, 55%).

《Polymer synthesis method》
Synthesis Example 1 (Synthesis of poly-12 (R = —O— (CH ₂ CH ₂ O) ₃ —CH ₃ ))
Poly-12 was synthesized according to the following scheme.

Boron unit B-1 (61 mg, 82 μmol), 2,5-bis (2- (2- (2-methoxyethoxy) ethoxy) ethoxy) -1,4-phenylenediboronic acid (40 mg, 82 μmol), Pd ₂ ( dba) ₃ (0.7 mg, 0.8 μmol), S-Phos (1.3 mg, 3.3 μmol), and cesium carbonate (270 mg, 0.8 mmol) were dissolved in 1 ml THF, and further 0.2 ml water was added. . This solution was subjected to a polymerization reaction at 60 ° C. for 72 hours in a nitrogen atmosphere. After completion of the reaction, the objective polymer poly-12 [M _n = 4400 (DMF)] was obtained in 68% yield (50 mg) by reprecipitation from methanol.

  Other compounds can be synthesized in the same manner.

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

<< Method for Manufacturing Organic EL Element >>
As an example of a method for producing an organic EL element, a method for producing an element comprising an anode / hole injection layer / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode will be described.

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

  Next, a thin film containing an organic compound such as a hole injection layer, a hole transport layer, a light emitting layer, a hole blocking layer, or an electron transport layer, which is an element material, is formed thereon.

  Here, as the wet method, there are a spin coating method, a casting method, a die coating method, a blade coating method, a roll coating method, an ink jet method, a printing method, a spray coating method, a curtain coating method, etc., but a precise thin film can be formed. In view of high productivity, a method having high suitability for a roll-to-roll method such as a die coating method, a roll coating method, an ink jet method, or a spray coating method is preferable. Different film forming methods may be applied for each layer.

  After the formation of these layers, a thin film made of a cathode material is formed thereon so as to have a thickness of 1 μm or less, preferably in the range of 50 to 200 nm, and a desired organic EL device can be obtained by providing a cathode. .

  Further, the order can be reversed, and the cathode, the electron transport layer, the hole blocking layer, the light emitting layer, the hole transport layer, the hole injection layer, and the anode can be formed 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.

  The organic EL device of the present invention is preferably produced from the hole injection layer to the cathode consistently by a single evacuation, but may be taken out halfway and subjected to different film forming methods. At that time, it is necessary to consider that the work is performed in a dry inert gas atmosphere.

<< Method for Manufacturing Organic EL Element >>
As an example of a method for producing an organic EL element, a method for producing an element comprising an anode / hole injection layer / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode will be described.

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

  Next, a thin film containing an organic compound such as a hole injection layer, a hole transport layer, a light emitting layer, a hole blocking layer, or an electron transport layer, which is an element material, is formed thereon.

  Here, as the wet method, there are a spin coating method, a casting method, a die coating method, a blade coating method, a roll coating method, an ink jet method, a printing method, a spray coating method, a curtain coating method, etc., but a precise thin film can be formed. In view of high productivity, a method having high suitability for a roll-to-roll method such as a die coating method, a roll coating method, an ink jet method, or a spray coating method is preferable. Different film forming methods may be applied for each layer.

  After the formation of these layers, a thin film made of a cathode material is formed thereon so as to have a thickness of 1 μm or less, preferably in the range of 50 to 200 nm, and a desired organic EL device can be obtained by providing a cathode. .

  Further, the order can be reversed, and the cathode, the electron transport layer, the hole blocking layer, the light emitting layer, the hole transport layer, the hole injection layer, and the anode can be formed 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.

  The organic EL device of the present invention is preferably produced from the hole injection layer to the cathode consistently by a single evacuation, but may be taken out halfway and subjected to different film forming methods. At that time, it is necessary to consider that the work is performed in a dry inert gas atmosphere.

<< 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 / hole transport layer / light emitting layer / electron transport layer / cathode (ii) Anode / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode (iii) Anode / hole transport layer / Light emitting layer / hole blocking layer / electron transport layer / cathode buffer layer / cathode (iv) anode / anode buffer layer / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode buffer layer / cathode << Organic compound layer (also called 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, and examples of the organic compound layer include a hole transport layer, a light emitting layer, and a hole blocking layer in the above-described layer configuration. As the organic compound layer according to the present invention, an organic compound contained in a constituent layer of the organic EL element, such as a hole injection layer or an electron injection layer, is included. Defined.

  Further, when an organic compound is used for the anode buffer layer, the cathode buffer layer, and the like, the anode buffer layer, the cathode buffer layer, and the like 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 thickness of the light emitting layer is not particularly limited, but from the viewpoint of improving the uniformity of the film, preventing unnecessary application of a high voltage during light emission, and improving the stability of the emission color with respect to the drive current. It is preferable to adjust in the range of 2 nm to 5 μm, more preferably in the range of 2 nm to 200 nm, and particularly preferably in the range of 10 nm to 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. it can.

  The light emitting layer of the organic EL device of the present invention preferably contains a light emitting host compound and at least one kind of light emitting dopant (phosphorescent dopant (also referred to as phosphorescent dopant) or fluorescent dopant). . Moreover, you may mix and use the hole transport material and electron transport material which are mentioned later.

(Host compound (also called luminescent host))
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, the compound having the carbazole ring as a partial structure, the compound having a polymerizable group and having the carbazole ring as a partial structure, and a polymer of the compound are 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 luminescent 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.

(Luminescent 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 (also referred to as a fluorescent compound) or a phosphorescent dopant (also referred to as a phosphorescent emitter, a phosphorescent compound, a phosphorescent compound, or the like) can be used. From the viewpoint of obtaining an organic EL device having higher luminous efficiency, the above-mentioned host compound may be used as the luminescent dopant (simply referred to as a luminescent material) used in the light emitting layer or the light emitting unit of the organic EL device of the present invention. It is preferable to contain a phosphorescent dopant at the same time as containing.

(Phosphorescent compound (phosphorescent dopant)) The phosphorescent compound (phosphorescent dopant) according to the present invention will be described.

  The phosphorescent compound according to the present invention is a compound in which light emission from an excited triplet is observed. Specifically, it is a compound that emits phosphorescence at room temperature (25 ° C.) and has a phosphorescence quantum yield. The phosphorescence quantum yield is preferably 0.1 or more, although it is defined as a compound of 0.01 or more at 25 ° C.

  The phosphorescence quantum yield can be measured by the method described in Spectroscopic II, page 398 (1992 edition, 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 compound 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 compounds. In principle, the recombination of carriers occurs on the host compound to which carriers are transported, and an excited state of the host compound is generated. This energy is phosphorescent. An energy transfer type that obtains light emission from the phosphorescent compound by transferring to the phosphorescent compound, and the other is that the phosphorescent compound becomes a carrier trap, and recombination of carriers on the phosphorescent compound is performed. And a carrier trap type in which light emission from the phosphorescent compound is obtained.

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

  The phosphorescent compound can be appropriately selected from known compounds used for the light emitting layer of the organic EL device.

  The phosphorescent compound according to the present invention 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 compounds) and rare earth complexes, with iridium compounds (Ir complexes) being most preferred among them.

<< Phosphorescent Compound Represented by Formula (10) >>
As the phosphorescent compound according to the present invention, a compound represented by the general formula (10) is preferably used.

  In the general formula (10), the aromatic hydrocarbon ring represented by A1 includes a benzene ring, biphenyl ring, naphthalene ring, azulene ring, anthracene ring, phenanthrene ring, pyrene ring, chrysene ring, naphthacene ring, triphenylene ring, o-terphenyl ring, m-terphenyl ring, p-terphenyl ring, acenaphthene ring, coronene ring, fluorene ring, fluoranthrene ring, naphthacene ring, pentacene ring, perylene ring, pentaphen ring, picene ring, pyrene ring, Examples include a pyranthrene ring and anthraanthrene ring. These rings may further have a substituent described later.

  In the general formula (10), examples of the aromatic heterocycle represented by A1 include a furan ring, a thiophene ring, an oxazole ring, a pyrrole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, and a benzimidazole. Ring, oxadiazole ring, triazole ring, imidazole ring, pyrazole ring, thiazole ring, indazole ring, indazole ring, benzimidazole ring, benzothiazole ring, benzoxazole ring, quinoxaline ring, quinazoline ring, cinnoline ring, quinoline ring, isoquinoline Ring, phthalazine ring, naphthyridine ring, carbazole ring, carboline ring, diazacarbazole ring (showing a ring in which one of the carbon atoms constituting the carboline ring is further substituted with a nitrogen atom) and the like. These rings may further have a substituent described later.

<< Substituent >>
Examples of the substituent that the aromatic hydrocarbon ring or aromatic heterocyclic ring represented by A1 may have 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 (eg, ethynyl group, propargyl group, etc.), aromatic hydrocarbon group (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) Groups (for example, 1,2,4-triazol-1-yl group, 1,2,3-triazol-1-yl group, etc.), oxazolyl group, benzoxazolyl group, thiazolyl group, isoxazolyl group, isothiazolyl group, Flazanyl group, thienyl group, quinolyl group, benzofuryl group, dibenzofuryl group, benzothienyl group, dibenzothienyl group, indolyl group, carbazolyl group, carbolinyl group, diazacarbazolyl group (carbon constituting the carboline ring of the carbolinyl group) One of the atoms is 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.), alkoxy group (eg, methoxy Group, ethoxy group, propyloxy group, pentyloxy group, hexyloxy group, octyloxy group, dodecyloxy group, etc.), cycloalkoxy group (for example, cyclopentyloxy group, cyclohexyloxy group, etc.), aryloxy group (for example, phenoxy) Group, naphthyloxy group, etc.), alkylthio group (eg, methylthio group, ethylthio group, propylthio group, pentylthio group, hexylthio group, octylthio group, dodecylthio group, etc.), cycloalkylthio group (eg, cyclopentylthio group, cyclyl). Rohexylthio group, etc.), arylthio group (eg, phenylthio group, naphthylthio group, etc.), alkoxycarbonyl group (eg, methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, octyloxycarbonyl group, dodecyloxycarbonyl group, etc.) An aryloxycarbonyl group (eg, phenyloxycarbonyl group, naphthyloxycarbonyl group, etc.), a sulfamoyl group (eg, aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group, butylaminosulfonyl group, hexylaminosulfonyl group, cyclohexyl) Aminosulfonyl group, octylaminosulfonyl group, dodecylaminosulfonyl group, phenylaminosulfonyl group, naphthylaminosulfonyl group, 2-pyridylamino Sulfonyl 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 etc.), acyloxy group (eg acetyloxy group, ethylcarbonyloxy group, butylcarbonyloxy group, octylcarbonyloxy group, dodecylcarbonyloxy group, phenylcarbonyloxy group etc.), amide group (eg methylcarbonyl) Amino group, ethylcarbonylamino group, dimethylcarbonylamino group, propylcarbonylamino group, pentylcarbonylamino group, cyclohexylcarbonylamino group, 2-ethyl Xylcarbonylamino group, octylcarbonylamino group, dodecylcarbonylamino group, phenylcarbonylamino group, naphthylcarbonylamino group, etc.), carbamoyl group (for example, aminocarbonyl group, methylaminocarbonyl group, dimethylaminocarbonyl group, propylaminocarbonyl group) Pentylaminocarbonyl group, cyclohexylaminocarbonyl group, octylaminocarbonyl group, 2-ethylhexylaminocarbonyl group, dodecylaminocarbonyl group, phenylaminocarbonyl group, naphthylaminocarbonyl group, 2-pyridylaminocarbonyl group, etc.), ureido group (for example, , Methylureido group, ethylureido group, pentylureido group, cyclohexylureido group, octylureido group, dodecylureido group, phenyl Ureido group naphthylureido group, 2-pyridylaminoureido group, etc.), sulfinyl group (for example, methylsulfinyl group, ethylsulfinyl group, butylsulfinyl group, cyclohexylsulfinyl group, 2-ethylhexylsulfinyl group, dodecylsulfinyl group, phenylsulfinyl group, naphthyl) Sulfinyl group, 2-pyridylsulfinyl group, etc.), alkylsulfonyl group (for example, methylsulfonyl group, ethylsulfonyl group, butylsulfonyl group, cyclohexylsulfonyl group, 2-ethylhexylsulfonyl group, dodecylsulfonyl group, etc.), arylsulfonyl group or hetero An arylsulfonyl group (eg, phenylsulfonyl group, naphthylsulfonyl group, 2-pyridylsulfonyl group, etc.), amino group (eg, amino group, ethyl Amino group, dimethylamino 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.), phosphono group and the like.

  In addition, 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.

  In general formula (10), the aromatic hydrocarbon ring and aromatic heterocycle represented by A2 are respectively synonymous with the aromatic hydrocarbon ring and aromatic heterocycle represented by A1 in general formula (10). is there.

  In the general formula (10), examples of the bidentate ligand represented by P1-L1-P2 include substituted or unsubstituted phenylpyridine, phenylpyrazole, phenylimidazole, phenyltriazole, phenyltetrazole, pyrazabol, acetylacetone. And picolinic acid.

  In the general formula (10), M1 is a transition metal element of group 8 to 10 in the periodic table of elements (also simply referred to as a transition metal). Among them, iridium and platinum are preferable, and iridium is particularly preferable.

  Specific examples of the compound used as the phosphorescent compound are shown below, but the present invention is not limited thereto. These compounds are described, for example, in Inorg. Chem. 40, 1704-1711, and the like.

(Fluorescent dopant (also called fluorescent compound))
Fluorescent dopants (fluorescent compounds) include coumarin dyes, pyran dyes, cyanine dyes, croconium dyes, squalium dyes, oxobenzanthracene dyes, fluorescein dyes, rhodamine dyes, pyrylium dyes, perylene dyes Examples thereof include dyes, stilbene dyes, polythiophene dyes, and 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) in detail, 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 10 nm 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. The probability of recombination of electrons and holes can be improved by blocking.

  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 an electron 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) Gaussian 98 (Gaussian 98, Revision A.11.4, MJ Frisch, et al, Gaussian, Inc., Pittsburgh PA, 2002.), which is molecular orbital calculation software manufactured by Gaussian, USA, is used as a keyword. The ionization potential can be obtained as a value obtained by rounding off the second decimal place of a value (eV unit converted 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 recombination probability 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 3 nm to 100 nm, and more preferably 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.

  The above-mentioned materials can be used as the hole transport material, but it is preferable to use a porphyrin compound, an aromatic tertiary amine compound and a styrylamine compound, particularly an aromatic tertiary amine compound.

  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 also two of those described in US Pat. No. 5,061,569. Having a condensed aromatic ring in the molecule, for example, 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPD), JP-A-4-3086 4,4 ', 4 "-tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine in which three triphenylamine units described in Japanese Patent No. 8 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 as described in a book (Applied Physics Letters 80 (2002), p. 139) can also be used.

  In the present invention, since a higher performance light emitting device can be obtained, the present invention contains a polymerizable compound represented by the general formula (1) or a polymer compound having a structural unit derived from the polymerizable compound. These organic EL element materials are preferably used, and the above materials may be used in combination.

  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. However, in the present invention, it is preferably produced by a coating method (wet process). 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, JP-A-2001-102175, J. Pat. 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.

  It is preferable that at least one layer of the electron transport layer of the present invention contains a compound represented by the general formula (1) of the present invention.

  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 material can be selected from conventionally known compounds.

  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 derivative, a thiadiazole derivative in which the oxygen atom of the oxadiazole ring is substituted with a sulfur atom, and a quinoxaline derivative having a quinoxaline ring known as an electron withdrawing group can also be used as an 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, Metal complexes replaced with Cu, Ca, Sn, Ga or Pb can also be used as the 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 transporting 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 also 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 an electron transport layer having such a high n property because an element with lower power consumption can be manufactured.

"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, wet 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 one of 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 by the film thickness of 1 nm-20 nm to 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. 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 Cycloolefin resins such as polyetherimide, polyetherketoneimide, polyamide, fluororesin, nylon, polymethylmethacrylate, acrylic or polyarylate, Arton (trade name, manufactured by JSR) or Appel (trade name, manufactured by Mitsui Chemicals) Can be mentioned.

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 JISK 7129-1992) It is preferably a barrier film having a relative humidity (90 ± 2)% RH) of 0.01 g / (m ² · 24 h) or less, and further, oxygen permeability measured by a method according to JISK 7126-1987. However, it is preferable that it is a high barrier film whose 10 < ^-3 > ml / (m < ² > 24h * MPa) or less and water-vapor permeability are 10 < ^-5 > g / (m < ² > 24h) or less.

  As a material for forming the barrier film, any material may be used as long as it has a function of suppressing entry 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, the vacuum deposition method, sputtering method, reactive sputtering method, molecular beam epitaxy method, cluster ion beam method, ion plating method, plasma polymerization method, atmospheric pressure plasma weight A combination method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, and the like can be used. However, 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 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. 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>
As a sealing means used for this invention, the method of adhere | attaching a sealing member, an electrode, and a support substrate with an adhesive agent can be mentioned, for example.

  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 JISK 7126-1987 or less, measured by a method according to JISK 7129-1992, below 1 × 10 ⁻³ ml / (m ² · 24 h · MPa). The water vapor permeability (25 ± 0.5 ° C., relative humidity (90 ± 2)% RH) 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. be able to.

  Moreover, 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 adhesive-hardened from room temperature to 80 degreeC 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 preferable that the electrode and the organic layer are coated on the outside of the electrode facing the support substrate with the organic layer interposed therebetween, and an inorganic or organic layer is formed in contact with the support substrate to form a sealing film. . 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. it can. Further, in order to improve the brittleness of the film, it is preferable to have a laminated structure of these inorganic layers and layers made of organic materials.

  The method for forming these films is not particularly limited. For example, vacuum deposition, sputtering, reactive sputtering, molecular beam epitaxy, cluster-ion beam method, ion plating method, plasma polymerization method, atmospheric pressure plasma A polymerization 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, an inert gas such as nitrogen or argon, or an inert liquid such as fluorinated hydrocarbon or silicon oil can be injected in the gas phase and liquid phase. preferable. A vacuum is also possible. 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, and the like), 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, and the like used for the sealing can be used, but the polymer film is light and thin. Is preferably used.

《Light extraction》
The organic EL element emits light inside a layer having a refractive index higher than that of air (refractive index is about 1.7 to 2.1) and can extract only about 15% to 20% of the light generated in the light emitting layer. It is generally said.

  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 taken out of the device, or between the transparent electrode or light emitting layer and the transparent substrate. This is because the light is totally reflected between the light 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 element side surface.

  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. Light that cannot be emitted due to total internal reflection between layers is diffracted by introducing a diffraction grating in any layer or medium (in 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 device light emitting surface. By condensing 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 μm 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, which are organic EL element materials, is formed thereon.

  As a method for forming each of these layers, there are a vapor deposition method and a wet process (spin coating method, casting method, ink jet method, printing method) as described above, but it is easy to obtain a uniform film and a pinhole is generated. In view of difficulty, etc., 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, the layer containing a compound having a carbazole ring as a partial structure according to the present invention, the compound having a polymerizable group, and a polymer of the compound is preferably formed by the above-described coating method. 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 be able to.

  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 1 μm or less, preferably by a method such as vapor deposition or sputtering so that the film thickness is in the range of 50 nm to 200 nm. By providing, a desired organic EL element can be obtained.

  Further, it is also possible to reverse the production order and produce the cathode, the electron injection layer, the electron transport layer, the hole blocking layer, the light emitting layer, the hole transport layer, the hole injection layer, and the anode 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 to 40 V with the positive polarity of the anode and the negative polarity of the cathode. 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 emission 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 Although the light source of a sensor etc. are mentioned, It is not limited to this, Especially, it can use effectively for the use as a backlight of a liquid crystal display device, and a light source for illumination.

  In the organic EL element of the present invention, patterning may be 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. Can do.

  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 when the 2 ° viewing angle front luminance is measured by the above method. = 0.33 ± 0.07 and Y = 0.33 ± 0.1.

<Display device>
The display device of the present invention will be described. The display device of the present invention comprises the organic EL element of the present invention.

  Although the display device of the present invention may be single color or multicolor, the multicolor display device will be described here. In the case of a multicolor display device, a shadow mask is provided only at the time of forming a light emitting layer, and a film can be formed on one surface by vapor deposition, casting, spin coating, ink jet, printing, or the like.

  In the case of patterning only the light emitting layer, the method is not limited. However, the vapor deposition method, the ink jet method, the spin coating method, and the printing method are preferable.

  The configuration of the organic EL element provided in the display device is selected from the above-described configuration examples of the organic EL element as necessary.

  Moreover, the manufacturing method of an organic EL element is as having shown to the one aspect | mode of manufacture of the organic EL element of said invention.

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

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

  Examples of the display device and display include a television, a personal computer, a mobile device, an AV device, a character broadcast display, and an information display in an automobile. In particular, it may be used as a display device for reproducing still images and moving images, and the driving method when used as a display device for reproducing moving images may be either a simple matrix (passive matrix) method or an active matrix method.

  Light sources include home lighting, interior lighting, clock and liquid crystal backlights, billboard advertisements, traffic lights, light sources for optical storage media, light sources for electrophotographic copying machines, light sources for optical communication processors, light sources for optical sensors, etc. The present invention is not limited to these examples.

  Hereinafter, an example of a display device having the organic EL element of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic view showing an example of a display device composed of organic EL elements. It is a schematic diagram of a display such as a mobile phone that displays image information by light emission of an organic EL element.

  The display 1 includes a display unit A having a plurality of pixels, a control unit B that performs image scanning of the display unit A based on image information, and the like.

  The control unit B is electrically connected to the display unit A, and sends a scanning signal and an image data signal to each of a plurality of pixels based on image information from the outside, and the pixels for each scanning line respond to the image data signal by the scanning signal. The image information is sequentially emitted to scan the image and display the image information on the display unit A.

  FIG. 2 is a schematic diagram of the display unit A.

  The display unit A includes a wiring unit including a plurality of scanning lines 5 and data lines 6, a plurality of pixels 3 and the like on a substrate. The main members of the display unit A will be described below.

  In the figure, the light emitted from the pixel 3 is extracted in the direction of the white arrow (downward).

  The scanning line 5 and the plurality of data lines 6 in the wiring portion are each made of a conductive material, and the scanning lines 5 and the data lines 6 are orthogonal to each other in a grid pattern and are connected to the pixels 3 at the orthogonal positions (details are illustrated). Not) When a scanning signal is applied from the scanning line 5, the pixel 3 receives an image data signal from the data line 6 and emits light according to the received image data.

  Full-color display is possible by appropriately arranging pixels in the red region, the green region, and the blue region on the same substrate.

  Next, the light emission process of the pixel will be described.

  FIG. 3 is a schematic diagram of a pixel.

  The pixel includes an organic EL element 10, a switching transistor 11, a driving transistor 12, a capacitor 13, and the like. A full color display can be performed by using red, green, and blue light emitting organic EL elements as the organic EL elements 10 in a plurality of pixels, and juxtaposing them on the same substrate.

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

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

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

  That is, the light emission of the organic EL element 10 is performed by providing the switching transistor 11 and the drive transistor 12 which are active elements with respect to the organic EL element 10 of each of the plurality of pixels. It is carried out. Such a light emitting method is called an active matrix method.

  Here, the light emission of the organic EL element 10 may be light emission of a plurality of gradations by a multi-value image data signal having a plurality of gradation potentials, or by turning on / off a predetermined light emission amount by a binary image data signal. Good. The potential of the capacitor 13 may be maintained until the next scanning signal is applied, or may be discharged immediately before the next scanning signal is applied.

  In the present invention, not only the active matrix method described above, but also a passive matrix light emission drive in which the organic EL element emits light according to the data signal only when the scanning signal is scanned.

  FIG. 4 is a schematic diagram of a passive matrix display device. In FIG. 4, a plurality of scanning lines 5 and a plurality of image data lines 6 are provided in a lattice shape so as to face each other with the pixel 3 interposed therebetween.

  When the scanning signal of the scanning line 5 is applied by sequential scanning, the pixels 3 connected to the applied scanning line 5 emit light according to the image data signal.

  In the passive matrix system, the pixel 3 has no active element, and the manufacturing cost can be reduced.

《Lighting device》
The lighting device of the present invention will be described. The illuminating device of this invention has the said organic EL element.

  The organic EL element of the present invention may be used as an organic EL element having a resonator structure. The purpose of use of the organic EL element having such a resonator structure is as follows. The light source of a machine, the light source of an optical communication processing machine, the light source of a photosensor, etc. are mentioned, However, It is not limited to these. Moreover, you may use for the said use by making a laser oscillation.

  Further, the organic EL element of the present invention may be used as a kind of lamp for illumination or exposure light source, a projection device for projecting an image, or a display for directly viewing a still image or a moving image. It may be used as a device (display).

  The driving method when used as a display device for moving image reproduction may be either a simple matrix (passive matrix) method or an active matrix method. Alternatively, a full-color display device can be manufactured by using two or more organic EL elements of the present invention having different emission colors. The organic EL material of the present invention can be applied as an illumination device to an organic EL element that emits substantially white light. A plurality of light emitting colors are simultaneously emitted by a plurality of light emitting materials to obtain white light emission by color mixing. The combination of a plurality of emission colors may include three emission maximum wavelengths of the three primary colors of blue, green, and blue, or two using the relationship of complementary colors such as blue and yellow, blue green and orange, etc. The thing containing the light emission maximum wavelength may be used.

  In addition, a combination of light emitting materials for obtaining a plurality of emission colors is a combination of a plurality of phosphorescent or fluorescent materials, a light emitting material that emits fluorescence or phosphorescence, and light from the light emitting material as excitation light. Any of those combined with a dye material that emits light may be used, but in the white organic EL device according to the present invention, only a combination of a plurality of light-emitting dopants may be mixed.

  It is only necessary to provide a mask only when forming a light emitting layer, a hole transport layer, an electron transport layer, etc., and simply arrange them separately by coating with the mask. Since other layers are common, patterning of the mask etc. is unnecessary, In addition, for example, an electrode film can be formed by a vapor deposition method, a cast method, a spin coating method, an ink jet method, a printing method, or the like, and productivity is also improved.

  According to this method, unlike a white organic EL device in which light emitting elements of a plurality of colors are arranged in parallel in an array, the elements themselves are luminescent white.

  There is no restriction | limiting in particular as a luminescent material used for a light emitting layer, For example, if it is a backlight in a liquid crystal display element, the metal complex which concerns on this invention so that it may suit the wavelength range corresponding to CF (color filter) characteristic, Any one of known luminescent materials may be selected and combined to whiten.

<< One Embodiment of Lighting Device of the Present Invention >>
One aspect of the lighting device of the present invention that includes the organic EL element of the present invention will be described.

  The non-light emitting surface of the organic EL device of the present invention is covered with a glass case, a glass substrate having a thickness of 300 μm is used as a sealing substrate, and an epoxy-based photocurable adhesive (LUX TRACK manufactured by Toagosei Co., Ltd.) is used as a sealing material. LC0629B) is applied, and this is overlaid on the cathode and brought into close contact with the transparent support substrate, irradiated with UV light from the glass substrate side, cured and sealed, and an illumination device as shown in FIGS. Can be formed.

  FIG. 5 shows a schematic diagram of a lighting device, and the organic EL element 201 of the present invention is covered with a glass cover 202 (in addition, the sealing operation with the glass cover is to bring the organic EL element 201 into contact with the atmosphere. And a glove box under a nitrogen atmosphere (in an atmosphere of high-purity nitrogen gas having a purity of 99.999% or more).

  6 shows a cross-sectional view of the lighting device. In FIG. 6, 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.

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited thereto.

  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.

Example 1
<< Formation of thin film by wet process and evaluation of film stability >>
A quartz substrate of 30 mm × 30 mm × 1.1 mm was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, subjected to UV ozone cleaning for 5 minutes, then attached to a commercially available spin coater, and 20 mg of Poly-1 was added to 2 ml. A solution dissolved in toluene was formed into a film by spin coating under conditions of 1500 rpm and 30 seconds, and further dried under vacuum at 25 ° C. for 1 hour to obtain a thin film. In the same manner as in the case of Poly-1, the polymer material of the present invention shown in Table 1 and a thin film such as BCP were prepared. The results are shown in Table 1. The thin film was evaluated by visual inspection, and indicated as “◯” only when it was smooth and transparent, and “x (NG)” otherwise.

Alq ₃ which is a typical electron transporting material has poor stability in a solution and cannot form a wet film, and thus cannot be evaluated. In addition, BCP and B-2, which is a boron unit, had no problem in appearance immediately after film formation, but changed rapidly with time, resulting in white turbidity and partial shrinkage, resulting in NG.

  On the other hand, when the thin film was prepared from the polymer material of the present invention and visually observed, white turbidity, unevenness and the like were not observed and a good appearance was exhibited. When this film was allowed to stand at room temperature for 24 hours and then the state of the thin film was visually confirmed again, no cloudiness or unevenness was observed, and the polymer material of the present invention had good film stability. I understood it. From the above points, it is clear that the conventional material has a big problem with respect to the stability over time. In the compound of the present invention, a great improvement was recognized for such a problem.

Example 2
<< Evaluation of electron transportability >>
Production of an electron-only device (EOD) After patterning a substrate (NA-45 manufactured by NH Techno Glass Co., Ltd.) formed by depositing 100 nm of ITO (indium tin oxide) on a glass substrate of 100 mm × 100 mm × 1.1 mm as an anode The transparent support substrate provided with the ITO transparent electrode was subjected to ultrasonic cleaning with isopropyl alcohol, dried with dry nitrogen gas, and UV ozone cleaning was performed for 5 minutes. This transparent support substrate was attached to a vacuum deposition apparatus, the vacuum chamber was depressurized to 4 × 10 ⁻⁴ Pa, and 5 nm of Ca was deposited as a hole blocking layer. A solution obtained by dissolving 20 mg of Poly-X in 1 ml of toluene on a transparent support substrate on which Ca was vapor-deposited was formed by spin coating at 1000 rpm for 30 seconds, dried at 120 ° C. for 1 hour, and a film thickness of 80 nm. The electron transport layer was provided. This was again attached to the vacuum deposition apparatus, and the vacuum chamber was depressurized to 4 × 10 ⁻⁴ Pa. Lithium fluoride 1 nm was deposited as a cathode buffer layer and aluminum 110 nm was deposited as a cathode to form a cathode, thereby producing an electron-only device (EOD) EOD-1.

EOD-2 to 5 were produced in the same manner as EOD-1, except that Poly-1 used in EOD-1 was changed to the material shown in Table 2. In the Alq ₃ shown in EOD-5, because of the wet film formation it was impossible, was deposited by vacuum evaporation method described below.

<< EOD evaluation >>
When evaluating the EOD produced in the above-described examples, the non-light-emitting surface of each EOD after production was sealed with a glass case, and an illumination device as shown in FIGS. 5 and 6 was formed and evaluated. The sealing method is as follows. In a nitrogen atmosphere, a glass case having a thickness of 300 μm was used as a sealing substrate, and an epoxy photocurable adhesive (Lux Track LC0629B manufactured by Toagosei Co., Ltd.) was applied as a sealing material around the glass case. It was made to adhere | attach with the said transparent support substrate again, was hardened with UV light from the glass substrate side, and sealed. Using these elements, charge transport characteristics were evaluated from current-voltage characteristics. The evaluation method is shown below.

  About produced EOD, the current-voltage characteristic in the range of the applied voltage 0-30V in 23 degreeC and dry-nitrogen gas atmosphere was measured using the source meter 6430 by Kessley. Using the slope α of the current-voltage curve at this time, −logα was calculated, and an integer value obtained by rounding was used as an index of mobility. The results are shown in Table 2.

From the above results, the polymer material having the boron unit of the present invention has excellent electron transport performance as compared with Alq ₃ which is very well known as an electron transport material for organic EL (EOD-5). Is clear. Moreover, since the polymer material which has the boron unit of this invention shows the outstanding advantage compared with BP-1 (EOD-4) which is the same boron polymer, it is an excellent electron for organic EL It is clear that it is a transport material.

Example 3
<< Organic EL element >>
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, BaytronP Al 4083) to 70% with pure water at 3000 rpm for 30 seconds. After film formation by spin coating, the film was dried at 200 ° C. for 1 hour to provide a 30 nm-thick hole transport layer.

On this hole transport layer, a solution prepared by dissolving 30 mg of polyvinylcarbazole (PVK; VP-6) and 1.5 mg of D-1 in 3 ml of dichloroethane was formed by spin coating under the conditions of 2000 rpm and 30 seconds. The film was dried at 120 ° C. for 1 hour under nitrogen to obtain a light-emitting layer having a thickness of 50 nm. On this light emitting layer, a solution in which 10 mg of poly-12 was dissolved in 3 ml of dehydrated butanol was formed by spin coating under conditions of 1000 rpm and 30 seconds. It was heated and dried at 120 ° C. for 1 hour, an electron transport layer having a film thickness of 20 nm was provided, this was attached to a vacuum deposition apparatus, and the vacuum chamber was decompressed to 4 × 10 ⁻⁴ Pa. A cathode was formed by vapor-depositing 3 nm of potassium fluoride as a cathode buffer layer and 110 nm of aluminum as a cathode, and an organic EL device 1-1 was produced. When the produced organic EL element 1-1 was driven, green light emission due to the light emission of D-1 was recognized, and it was confirmed that poly-12 functions as an electron transport material in the organic EL element.

Organic EL elements 1-2 to 1-6 were prepared in the same manner except that poly-12 used for the electron transport material was changed to the material shown in Table 3. Note that the organic EL device 1-7, since Alq ₃ is a material that was impossible wet film formation, a film was formed by vacuum evaporation.

<< Evaluation of Organic EL Elements 1-1 to 1-7 >>
When evaluating the obtained organic EL elements 1-1 to 1-7, 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 photo-curing adhesive (Lux Track LC0629B manufactured by Toagosei Co., Ltd.) is applied as a sealant around the periphery, and this is placed on the cathode so as 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. 3 and 4 was formed and evaluated.

(External quantum efficiency)
About the produced organic EL element, external extraction quantum efficiency (%) when ^2.5 mA / cm ² constant current was applied in a dry nitrogen gas atmosphere at 23 ° C. was measured. For the measurement, a spectral radiance meter CS-1000 (manufactured by Konica Minolta Sensing) was used.

<Drive voltage>
The voltage at the start of light emission was measured at a temperature of 23 ° C. and in a dry nitrogen gas atmosphere. Note that the voltage value at the start of light emission was measured when the luminance was 50 cd / m ² or more. A spectral radiance meter CS-1000 (manufactured by Minolta) was used for the measurement of luminance.

(Luminescence life)
When driving at a constant current of ^2.5 mA / cm ^{2 in} a dry nitrogen gas atmosphere at 23 ° C., the time required for the luminance to drop to half of the luminance immediately after the start of light emission (initial luminance) was measured. Was used as an index of life as half-life time (τ0.5). For the measurement, a spectral radiance meter CS-1000 (manufactured by Konica Minolta Sensing) was used in the same manner.

  The measurement results of the external extraction quantum efficiency, drive voltage, and light emission lifetime of the organic EL elements 1-1 to 1-7 were evaluated relative to the organic EL element 1-7 as 100.

When the polymer material having the boron unit of the present invention is used for the electron transport layer, compared to the case of using Alq ₃ which is well known in the past, in any case of external extraction quantum efficiency, driving voltage, and emission lifetime. It is clear that it also shows very good performance. In particular, the results show very good performance at the driving voltage. On the other hand, when compared with BP-1 (organic EL element 1-5) having a boron analog, it shows a significant difference in driving voltage and emission lifetime, and compared with BP-2 (organic EL element 1-6). Then, it showed a superior difference with respect to external extraction quantum efficiency. Moreover, in comparison with B-2 (organic EL element 1-7) which is a low molecular boron unit, a significant difference is shown with respect to the light emission lifetime, and a result showing a superior difference of the polymer material having the specific boron unit of the present invention. Obviously.

Example 4
<Production of full-color display device>
(Blue light emitting organic EL device)
Blue light-emitting organic EL element 1-1B was produced in the same manner as in the production of organic EL element 1-1 produced in Example 3, except that D-1 was changed to D-12.

(Green light-emitting organic EL device)
As the green light-emitting organic EL element, the organic EL element 1-1 produced in Example 3 was used.

(Red light emitting organic EL device)
In the production of the organic EL element 1-1 produced in Example 3, red light-emitting organic EL element 1-1R was produced in the same manner except that D-1 was changed to D-10.

Example 5
<< Production of white light-emitting lighting device >>
In the production of the organic EL element 1-1 produced in Example 3, the white light-emitting organic EL element was similarly obtained except that D-1 was changed to a ternary mixture of D-1, D-10, and D-12. 1-1W was produced. D-10 and D-12 were prepared in the same manner as the D-1 solution of Example 3, and the obtained three solutions were mixed. The obtained organic EL element 1-1W was covered with a glass case on a non-light emitting surface to obtain a lighting device. The illuminating device could be used as a thin illuminating device that emits white light with high luminous efficiency and long emission life.

DESCRIPTION OF SYMBOLS 1 Display 3 Pixel 5 Scan line 6 Data line 7 Power line 10 Organic EL element 11 Switching transistor 12 Drive transistor 13 Capacitor A Display part B Control part 101 Glass substrate 102 ITO transparent electrode 103 Partition 104 Hole injection layer 105B, 105G, 105R Light emitting layer 207 Glass substrate with transparent electrode 206 Organic EL layer 205 Cathode 202 Glass cover 208 Nitrogen gas 209 Water catching agent

Claims (7)

In an organic electroluminescence device having a plurality of organic compound layers including a light emitting layer and an electron transport layer sandwiched between an anode and a cathode, a repeating unit represented by the following general formula (1) is provided in at least one of the organic compound layers An organic electroluminescence device comprising a polymer electron transport material comprising:

(Wherein X represents a boron-containing compound residue selected from a divalent group having a partial structure represented by the following general formula (2), Ar ₁ has a partial structure represented by the following general formula (3) Represents a divalent group.)

(In the formula, R _{1 to} R ₄ are each independently an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an alkylthio group, an aryl group, an aryloxy group, an arylthio group, an arylalkyl group, an arylalkoxy group, an arylalkylthio group. , Arylalkenyl group, arylalkynyl group, heteroaryl group, heteroaryloxy group, heteroarylthio group, heteroarylalkyl group, heteroarylalkoxy group, heteroarylalkylthio group, heteroarylalkenyl group, heteroarylalkynyl group, amino group , Substituted amino group, silyl group, substituted silyl group, halogen atom, acyl group, acyloxy group, imine residue, amide group, acid imide group, monovalent heterocyclic group, carboxy group, substituted carboxy group, cyano group or nitro Group, halo Represents a sulfonyl group or a linking group,, _{R 1} and _R 3, _{R 2} and _{R 4} and _{R 3} and _{R 4} each may form a ring together. Also, a, b are each independently And an integer selected from 0 to _{3. When a} plurality of R ₁ and R ₂ are present, they may be the same or different, and may be bonded to each other to form a ring.

Wherein R ₅ is an alkyl group, alkenyl group, alkynyl group, alkoxy group, alkylthio group, aryl group, aryloxy group, arylthio group, arylalkyl group, arylalkoxy group, arylalkylthio group, arylalkenyl group, aryl Alkynyl group, heteroaryl group, heteroaryloxy group, heteroarylthio group, heteroarylalkyl group, heteroarylalkoxy group, heteroarylalkylthio group, heteroarylalkenyl group, heteroarylalkynyl group, amino group, substituted amino group, silyl Group, substituted silyl group, halogen atom, acyl group, acyloxy group, imine residue, amide group, acid imide group, monovalent heterocyclic group, carboxy group, substituted carboxy group, cyano group or nitro group, halogenyl group C is 0 Represents an integer selected from ˜6, when there are a plurality of R _{5 s} , they may be the same or different and do not bond to each other to form a ring, in general formula (3), Two groups selected from the substituents each have become a bond.)   2. The organic electroluminescence device according to claim 1, wherein at least one layer of the electron transport layer contains a polymer electron transport material composed of the repeating unit represented by the general formula (1).   The organic electroluminescence device according to claim 2, wherein at least one of the light emitting layers contains a phosphorescent organometallic complex compound. The organic electroluminescence device according to claim 3, wherein at least one of the phosphorescent organometallic complex compounds is a compound represented by the following general formula (10).

(In the formula, P and Q represent a carbon atom or a nitrogen atom, A1 represents an atomic group which forms an aromatic hydrocarbon ring or an aromatic heterocycle with PC, and A2 represents an aromatic hydrocarbon with QN. P1-L1-P2 represents a bidentate ligand, P1 and P2 each independently represent a carbon atom, a nitrogen atom, or an oxygen atom, and L1 represents P1. , P2 represents an atomic group forming a bidentate ligand, r represents an integer of 1 to 3, s represents an integer of 0 to 2, r + s is 2 or 3. M is an element period (Represents group 8-10 metal elements in the table.)   An illuminating device comprising the organic electroluminescent element according to any one of claims 1 to 4.   A display device comprising the organic electroluminescence element according to claim 1.   When manufacturing the organic electroluminescent element as described in any one of Claim 1- Claim 4, the layer containing the polymeric electron transport material shown by the said General formula (1) among this organic compound layer is wet. A method for producing an organic electroluminescence element, comprising a step of forming and forming a film by a method (wet process).

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