JP5532563B2 - ORGANIC ELECTROLUMINESCENT ELEMENT MATERIAL, ORGANIC ELECTROLUMINESCENT ELEMENT, DISPLAY DEVICE AND LIGHTING DEVICE - Google Patents

Description

  The present invention relates to an organic electroluminescence element material, an organic electroluminescence element, a display device, and a lighting device.

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

  On the other hand, an organic EL element has a configuration in which a light emitting layer containing a compound that emits light is sandwiched between a cathode and an anode, and injects electrons and holes into the light emitting layer to recombine excitons. This is an element that emits light by utilizing the emission of light (fluorescence / phosphorescence) when this exciton is deactivated, and can emit light at a voltage of several volts to several tens of volts. Therefore, it has a wide viewing angle, high visibility, and since it is a thin-film type complete solid-state device, it is attracting attention from the viewpoints of space saving and portability.

  For the development of organic EL elements for practical application, M.M. A. Baldo et al. Since 1993, Nature, 395, 151-154 (1998), Princeton University reported on organic EL devices using phosphorescence emission from excited triplets. A. Baldo et al. , Nature, 403, 17, 750-753 (2000) and US Pat. No. 6,097,147, research on materials that exhibit phosphorescence at room temperature has become active.

  In addition, recently discovered organic EL devices that use phosphorescence can realize a luminous efficiency that is approximately four times that of previous devices that use fluorescence. Research and development of light-emitting element layer configurations and electrodes are performed all over the world. For example, S.M. Lamansky et al. , J .; Am. Chem. Soc. , 123, 4304 (2001), a number of compounds have been studied for synthesis centering on heavy metal complexes such as iridium complexes.

  On the other hand, there are roughly two methods for manufacturing organic EL elements, known as film formation by vacuum evaporation (dry process) and solution coating / film formation (wet process). In addition, a wet process that is excellent in terms of high productivity and the like has attracted attention. However, from the viewpoint of practical use, it is still insufficient in terms of performance deterioration during high-temperature storage, and further improvement techniques are required.

  On the other hand, as an example in which a carbazole derivative is applied as the host compound in an element having a light emitting layer each containing a host compound and a phosphorescent compound as a dopant compound, 4,4′-N, N′— Dicarbazole-biphenyl (CBP) and the like are the most common, but even when these conventional carbazole derivatives are used, the compatibility between luminous efficiency and durability has not been achieved. In particular, satisfactory light emission efficiency is not obtained for light emission shorter than green.

As carbazole derivatives other than CBP, polymer types are disclosed in JP-A Nos. 2001-257076, 2002-105445, etc., JP-A Nos. 2001-313179, 2002-75645, 2002-100476, etc. Describes carbazole derivatives having a specific structure and carbazole ring-containing polymers (see, for example, Patent Documents 1 to 4), but in any case, a structure capable of achieving both the light emission efficiency and durability of the device is obtained. Not.
International Publication No. 06/70185 Pamphlet JP 2003-212850 A JP 2005-71909 A JP 2006-257196 A

  An object of the present invention is to provide an organic electroluminescence element having a long lifetime and high luminous efficiency, in particular, high luminous efficiency even at high temperature storage, a display device using the element, and a lighting device.

  The above object of the present invention is achieved by the following configurations.

1 . A polymer compound having a repeating unit structure represented by the following general formula (2 ) , wherein the polymer compound has a repeating unit structure represented by the following general formula (3) in an amount of 0% by mass to 50% by mass. It comprises in the range of organic electroluminescence element material, wherein the number-average molecular weight of the polymer compound is in the range of 900 or more to 160,000 or less.

(In the general formula (2), R _{1 to} R ₇ represent a hydrogen atom, an alkyl group, an alkoxy group, or an aryl group, and R ₁ and R ₂ , R ₂ and R ₃ , R ₃ and R ₄ are bonded to each other. A 6-membered aromatic ring may be formed, except that R _{1 to} R ₇ are simultaneously hydrogen atoms, wherein R _{8 to} R ₁₂ are hydrogen atoms, alkyl groups, alkoxy groups. R ₈ and R ₉ , R ₉ and R ₁₀ , R ₁₀ and R ₁₁ may be bonded to each other to form a 6-membered aromatic ring, and k and m are macromolecules. The ratio of the repeating unit structure constituting the compound is represented, and 50 ≦ k ≦ 100 % by mass and 0 ≦ m ≦ 50 % by mass.)

2 . An organic electroluminescent device having a plurality of organic layers between the opposed electrodes, the organic electroluminescent element in which at least layer of the organic layer and having containing an organic electroluminescence device material according to the 1.

3 . 3. The organic electroluminescence device according to 2 above, wherein at least one of the organic layers is a hole transport layer.

4 . 3. The organic electroluminescent element according to 2 above, wherein at least one of the organic layers is a light emitting layer.

5 . 5. The organic electroluminescence device according to any one of 2 to 4 , wherein the organic electroluminescence device emits white light.

6 . A display device comprising the organic electroluminescence element according to any one of 2 to 5 above.

7 . A lighting device comprising the organic electroluminescence element according to any one of 2 to 5 above.

  The organic electroluminescent element material of the present invention can provide an organic electroluminescent element having a long lifetime and high luminous efficiency, particularly high luminous efficiency even at high temperature storage, a display device using the element, and a lighting apparatus.

  Hereinafter, the present invention will be described in detail.

  The organic electroluminescent element of this invention has the organic electroluminescent element material of any one of Claims 1-3, It is characterized by the above-mentioned. Further, the present invention is characterized by a display device and a lighting device provided with the organic electroluminescence element.

In the general formula (1), R _{1 to} R ₇ represent a hydrogen atom, an alkyl group, an aryl group, or a heteroaryl group, and R ₁ and R ₂ , R ₂ and R ₃ , R ₃ and R ₄ are bonded to each other. A 5-membered or 6-membered aromatic ring may be formed. Note that the alkyl group, aryl group, or heteroaryl group may have a substituent, and the substituent may be a cycloalkyl group, an alkynyl group, an aromatic hydrocarbon ring group (also referred to as an aromatic carbocyclic group, an aryl group, or the like). 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), aromatic Group heterocyclic group (for example, pyridyl group, pyrimidinyl group, furyl group, pyrrolyl group, imidazolyl group, benzoimidazolyl group, pyrazolyl group, pyrazinyl group, triazolyl group (for example, 1,2,4-triazol-1-yl group, 1 , 2,3-triazol-1-yl group), oxazolyl group, benzoxazo Group, thiazolyl group, isoxazolyl group, isothiazolyl group, furazanyl group, thienyl group, quinolyl group, benzofuryl group, dibenzofuryl group, benzothienyl group, dibenzothienyl group, indolyl group, carbazolyl group, carbolinyl group, diazacarbazolyl A group (in which one of the carbon atoms constituting the carboline ring of the carbolinyl group is replaced by a nitrogen atom), a quinoxalinyl group, a pyridazinyl group, a triazinyl group, a quinazolinyl group, a phthalazinyl group, etc.), a heterocyclic group (for example, pyrrolidyl Group, imidazolidyl group, morpholyl group, oxazolidyl group, etc.), alkoxy group, cycloalkoxy group, aryloxy group, alkylthio group, cycloalkylthio group, arylthio group, alkoxycarbonyl group, aryloxycarbonyl group, sulfo group Amoyl group, acyl group, acyloxy group, amide group, carbamoyl group, ureido group, sulfinyl group, alkylsulfonyl group, arylsulfonyl group or heteroarylsulfonyl group, amino group, halogen atom, fluorinated hydrocarbon group, cyano group, nitro Group, hydroxy group, mercapto group, silyl group and the like.

  The average degree of polymerization n represents 3 ≦ n ≦ 1000, preferably 3 ≦ n ≦ 500, more preferably 5 ≦ n ≦ 100.

  Hereinafter, although the repeating unit of the high molecular compound which has the partial structure represented by General formula (1) is shown, it is not limited to these.

  Moreover, it shows below as a high molecular compound which has the partial structure represented by General formula (1).

In the copolymer comprising the general formula (2) and the general formula (3), in the general formula (2), R _{1 to} R ₇ represent a hydrogen atom, an alkyl group, an aryl group, or a heteroaryl group, and R ₁ and R ₂ , R ₂ and R ₃ , R ₃ and R ₄ may be bonded to each other to form a 5-membered or 6-membered aromatic ring. In General Formula (3), R _{8 to} R ₁₂ represent a hydrogen atom, an alkyl group, an aryl group, or a heteroaryl group, R ₈ and R ₉ , R ₉ and R ₁₀ , R ₁₀ and R ₁₁ are bonded to each other, A 5-membered or 6-membered aromatic ring may be formed. The alkyl group, aryl group or heteroaryl group represented by R _{1 to} R ₇ in the general formula (2), and the alkyl group, aryl group or heteroaryl group represented by R _{8 to} R ₁₂ in the structural formula (2) are all You may have a substituent and as a substituent, it is mentioned by General formula (1).

  K and m represent copolymerization ratios, 0 <k ≦ 100 mass%, 0 ≦ m <100 mass%, and n represents an average degree of polymerization calculated from the number average molecular weight, and 3 ≦ n ≦ 1000. The copolymer ratio of the copolymer composed of the general formula (2) and the general formula (3) is 0 <(1) ≦ 100 mass% of the general formula (2) and 0 ≦ (2) <100 mass% of the general formula. (3), preferably 50 ≦ (1) ≦ 100 mass% general formula (2) and 0 ≦ (2) ≦ 50 mass% general formula (3), more preferably (1) = 100 % By mass.

  The copolymer comprising the general formula (2) and the general formula (3) according to the present invention may be either a random copolymer or a block polymer.

  Specific examples of the repeating unit of the general formula (3) are shown below.

In addition, since general formula (2) is the same as general formula (1), the specific example of the copolymer which consists of general formula (2) and general formula (3) is the combination of the said Chemical formula 3, 4 and Chemical formula 6 Yes, as shown below.

  Hereinafter, synthesis examples of the polymer compound (polymer) according to the present invention will be shown.

Synthesis example (PCz-1)
3-Bromocarbazole (492 mg, 2 mmol), palladium acetate (45 mg, 0.2 mmol), tri-t-butylphosphine (80 mg, 0.4 mmol), sodium-t-butoxide (231 mg, 2.4 mmol) in 50 ml of xylene In addition, heating and refluxing was performed for 3 hours under a nitrogen stream. After completion of the reaction, insoluble matters were filtered off, and 10 ml of hexane was added to the resulting solution for reprecipitation. Further, the obtained compound was dissolved in 20 ml of xylene while heating, and 10 ml of hexane was added for reprecipitation. By repeating the same operation twice, 80 mg of the desired PCz-1 could be obtained.

  About molecular weight, molecular weight distribution, etc., it determined by HPLC (high performance liquid chromatography) using the following GPC (gel permeation chromatography) column. As a result, the number average molecular weight was 4500.

Measuring device: HLC-8220 GPC (high-speed GPC device)
Column used: TSKgel SuperHM-M (exclusion limit: 4 × 10 ⁶ )
Solvent amount: Tetrahydrofuran (THF)
Measurement temperature: 40 ° C
Column flow rate: 0.6 ml / min Calibration curve: A calibration curve was prepared using standard polystyrene.

  The polymer according to the present invention can be synthesized in the same manner as described above. Further, other known synthesis / polymerization reactions may be used in combination. Further, after the polymerization reaction, the polymer terminal may be treated by N-arylation reaction or aryl halide reduction reaction.

  The polymer compound (polymer) according to the present invention is specifically used as a light emitting layer material and a hole transport material.

  Hereinafter, the detail of each component of the organic EL element of this invention is demonstrated sequentially.

<< Constituent layers of organic EL elements >>
The constituent layers of the organic EL element of the present invention will be described. In this invention, although the preferable specific example of the layer structure of an organic EL element is shown below, this invention is not limited to these.

(I) Anode / light emitting layer / electron transport layer / cathode (ii) Anode / hole transport layer / light emitting layer / electron transport layer / cathode (iii) Anode / hole transport layer / light emitting layer / hole blocking layer / electron Transport layer / cathode (iv) Anode / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode buffer layer / cathode (v) Anode / anode buffer layer / hole transport layer / light emitting layer / hole Blocking layer / electron transport layer / cathode buffer layer / cathode In the organic EL device of the present invention, the blue light emitting layer preferably has a light emission maximum wavelength of 430 to 480 nm, and the green light emitting layer has a light emission maximum wavelength of 510 to 550 nm, The red light emitting layer is preferably a monochromatic light emitting layer having a light emission maximum wavelength in the range of 600 to 640 nm, and is preferably a display device using these. Alternatively, a white light emitting layer may be formed by laminating at least three light emitting layers. Further, a non-light emitting intermediate layer may be provided between the light emitting layers. The organic EL element of the present invention is preferably a white light emitting layer, and is preferably a lighting device using these.

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

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

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

  The light emitting layer of the organic EL device of the present invention contains a light emitting dopant (phosphorescent dopant (also referred to as phosphorescent dopant group) or fluorescent dopant) compound and a light emitting host compound.

(Luminescent dopant compound)
The luminescent dopant compound will be described.

  As the light-emitting dopant compound, a fluorescent dopant compound (also referred to as a fluorescent compound) or a phosphorescent dopant compound (also referred to as a phosphorescent emitter, a phosphorescent compound, a phosphorescent compound, or the like) can be used.

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

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

  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 dopant compound according to the present invention achieves the phosphorescence quantum yield (0.01 or more) in any solvent. Just do it.

  There are two types of light emission of the phosphorescent dopant compound in principle. One is the recombination of carriers on the host compound to which carriers are transported to generate an excited state of the luminescent host compound, and this energy is phosphorescent. Energy transfer type that obtains light emission from phosphorescent dopant by transferring to dopant, the other is phosphorescent dopant compound becomes carrier trap, recombination of carriers on phosphorescent dopant causes light emission from phosphorescent dopant compound In either case, the excited state energy of the phosphorescent dopant compound is required to be lower than the excited state energy of the host compound.

  Although the specific example of the well-known compound used as a phosphorescence dopant below is shown, this invention is not limited to these. These compounds are described, for example, in Inorg. Chem. 40, 1704-1711, and the like.

(Fluorescent dopant (also called fluorescent compound))
Fluorescent dopant compounds (fluorescent compounds) include coumarin dyes, pyran dyes, cyanine dyes, croconium dyes, squalium dyes, oxobenzanthracene dyes, fluorescein dyes, rhodamine dyes, pyrylium dyes, perylene And dyes, stilbene dyes, polythiophene dyes, rare earth complex phosphors, and the like.

(Luminescent host compound (also referred to as luminescent host))
The light emitting host compound used in the light emitting layer or light emitting unit of the organic EL device of the present invention is a condensed product of 5 aromatic rings having the aromatic heterocycle containing a chalcogen atom of the present invention as one of the constituent elements. A compound having a ring as a partial structure is contained as a luminescent host compound.

  In the present invention, the host compound has a mass ratio of 20% or more among the compounds contained in the light emitting layer, and a phosphorescence quantum yield of phosphorescence emission at a room temperature (25 ° C.) of 0. Defined as less than 1 compound. 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.

  As the host compound, the above host compounds may be used alone or in combination of two or more. 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 well-known compounds used as the said phosphorescence dopant, and, thereby, arbitrary luminescent colors can be obtained.

  In addition, in the present invention, in addition to a compound having a partial structure of a condensed ring obtained by condensing five aromatic rings each having an aromatic heterocycle containing a chalcogen atom as a constituent element, an organic EL element A known light-emitting host compound used in the light-emitting layer can be used in combination.

  Known light-emitting host compounds typically include those having a basic skeleton such as carbazole derivatives, triarylamine derivatives, aromatic derivatives, nitrogen-containing heterocyclic compounds, thiophene derivatives, furan derivatives, oligoarylene compounds, or carbolines. Derivatives and diazacarbazole derivatives (herein, diazacarbazole derivatives are those in which at least one carbon atom of the hydrocarbon ring constituting the carboline ring of the carboline derivative is substituted with a nitrogen atom). It is done.

  As a known host compound that may be used in combination, a compound that has a hole transporting ability and an electron transporting ability, prevents the emission of light from being increased in wavelength, and has a high Tg (glass transition temperature) is preferable.

  Specific examples of 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.

  Hereinafter, although the specific example which can be used together with the compound of Table 1 is given as a host compound of the light emitting layer of the organic EL element of this invention, this invention is not limited to these.

  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 5 μm although it depends on the material.

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

  The hole blocking layer has a function of an electron transport layer in a broad sense, and is made of a hole blocking material that has a function of transporting electrons and has a remarkably small ability to transport holes. 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.

  The hole blocking layer preferably contains the carbazole derivative, carboline derivative or diazacarbazole derivative mentioned as the host compound.

  In the present invention, when a plurality of light emitting layers having different light emission colors are provided, the light emitting layer having the shortest wavelength of light emission is preferably closest to the anode among all the light emitting layers. In this case, it is preferable to additionally provide a hole blocking layer between the shortest wave layer and the light emitting layer next to the anode next to the anode. Furthermore, it is preferable that 50% by mass or more of the compound contained in the hole blocking layer provided at the position has an ionization potential of 0.3 eV or more larger than the host compound of the shortest wave emitting layer.

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

  (1) Using Gaussian 98 (Gaussian 98, Revision A.11.4, MJ Frisch, et al, Gaussian, Inc., Pittsburgh PA, 2002.), a molecular orbital calculation software manufactured by Gaussian, USA The ionization potential can be obtained as a value obtained by rounding off the second decimal place of the value (eV unit 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 using a low energy electron spectrometer “Model AC-1” manufactured by Riken Keiki.

  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 transporting layer according to the present invention is preferably 3 to 100 nm, and more preferably 5 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.

  As the hole transport material, it is preferable to use a compound having, as a partial structure, a condensed ring obtained by condensing five aromatic rings each having an aromatic heterocycle containing a chalcogen atom of the present invention as one of the constituent elements.

  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, these materials are preferably used because a light-emitting element with higher efficiency can be obtained.

  The hole transport layer can be formed by thinning the hole transport material by a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an ink jet method, or an LB method. it can. 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 5-200 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, 2001-102175, J. Pat. Appl. Phys. 95, 5773 (2004), and the like.

  Specific examples of the hole transport material for the organic EL device of the present invention that can be used in combination with the compounds shown in Table 1 include the above-mentioned chemical formulas 10 to 13.

  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.

  As the electron transport material, it is preferable to use a compound having, as a partial structure, a condensed ring obtained by condensing five aromatic rings each having an aromatic heterocycle containing a chalcogen atom of the present invention as one of the constituent elements.

  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. As long as it has a function of transferring electrons to the light-emitting layer, any material can be selected and used from among conventionally known compounds. For example, nitro-substituted fluorene derivatives, diphenylquinone derivatives Thiopyrandioxide 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 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 5-200 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 produced.

"anode"
As the anode in the organic EL element, an electrode material made of a metal, an alloy, an electrically conductive compound, or a mixture thereof having a high work function (4 eV or more) is preferably used. Specific examples of such electrode materials include metals such as Au, and conductive transparent materials such as CuI, indium tin oxide (ITO), SnO ₂ , and ZnO. Alternatively, an amorphous material such as IDIXO (In ₂ O ₃ —ZnO) capable of forming a transparent conductive film may be used.

  For the anode, these electrode materials may be formed into a thin film by a method such as vapor deposition or sputtering, and a pattern having a desired shape may be formed by a photolithography method, or when pattern accuracy is not so high (about 100 μm or more) A pattern may be formed through a mask having a desired shape at the time of vapor deposition or sputtering of the electrode material. Or when using the substance which can be apply | coated like an organic electroconductivity compound, 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 in the range of 10 to 1000 nm, preferably in the range of 10 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 the 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 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 with a film thickness of 1-20 nm on a cathode, a transparent or semi-transparent cathode can be produced by producing the electroconductive transparent material quoted by description of the anode on it, By applying this, an element in which both the anode and the cathode are transmissive can be manufactured.

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

  Examples of the resin film include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyethylene, polypropylene, cellophane, cellulose diacetate, cellulose triacetate, cellulose acetate butyrate, cellulose acetate propionate (CAP), Cellulose esters such as cellulose acetate phthalate (TAC) and cellulose nitrate or derivatives thereof, polyvinylidene chloride, polyvinyl alcohol, polyethylene vinyl alcohol, syndiotactic polystyrene, polycarbonate, norbornene resin, polymethylpentene, polyether ketone, polyimide , Polyethersulfone (PES), polyphenylene sulfide, polysulfones Polyetherimide, polyether ketone imide, polyamide, fluorine resin, nylon, polymethyl methacrylate, acrylic or polyarylates, and cycloolefin resins such as ARTON (manufactured by JSR) or APEL (manufactured by Mitsui Chemicals).

On the surface of the resin film, an inorganic film, an organic film, or a hybrid film of both may be formed. Water vapor permeability (25 ± 0.5 ° C.) measured by a method according to JIS K 7129-1992. , Relative humidity (90 ± 2)% RH) is preferably 0.01 g / (m ² · 24 h) or less, and further, oxygen measured by a method according to JIS K 7126-1987. A high barrier film having a permeability of 10 ⁻³ cm ³ / (m ² · 24 h · atm) or less and a water vapor permeability of 10 ⁻³ g / (m ² · 24 h) or less is preferable. More preferably, the degree is 10 ⁻⁵ g / (m ² · 24 h) 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, vacuum deposition, sputtering, reactive sputtering, molecular beam epitaxy, cluster ion beam, ion plating, plasma polymerization, atmospheric pressure plasma polymerization A plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, or the like can be used, but an atmospheric pressure plasma polymerization method as described in JP-A-2004-68143 is particularly preferable.

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

  The external extraction quantum efficiency at room temperature of light emission of the organic EL device of the present invention is preferably 1% or more, more preferably 5% or more. Here, the external extraction quantum efficiency (%) = the number of photons emitted to the outside of the organic EL element / the number of electrons sent to the organic EL element × 100.

  In addition, a hue improvement filter such as a color filter may be used in combination, or a color conversion filter that converts the emission color from the organic EL element into multiple colors using a phosphor. 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. Further, the polymer film has an oxygen permeability measured by a method according to JIS K 7126-1987 of 1 × 10 ⁻³ cm ³ / (m ² · 24 h · atm) or less, and conforms to JIS K 7129-1992. The water vapor permeability (25 ± 0.5 ° C., relative humidity (90 ± 2)% RH) measured by the method 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, ion plating, plasma polymerization, atmospheric pressure plasma A combination method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, or the like can be used.

  In the gap between the sealing member and the display area of the organic EL element, 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, etc.), and sulfates, metal halides, and perchloric acids are preferably anhydrous salts.

《Protective film, protective plate》
In order to increase the mechanical strength of the element, a protective film or a protective plate may be provided on the outer side of the sealing film on the side facing the support substrate with the organic layer interposed therebetween or on the sealing film. In particular, when the sealing is performed by the sealing film, the mechanical strength is not necessarily high, and thus it is preferable to provide such a protective film and a protective plate. As a material that can be used for this, the same glass plate, polymer plate / film, metal plate / film, etc. used for the sealing can be used. It is preferable to use a film.

《Light extraction》
The organic EL element emits light inside a layer having a 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 or second-order diffraction, and light generated from the light-emitting layer. The light that cannot go out due to total reflection between layers, etc. is diffracted by introducing a diffraction grating in any layer or medium (in the transparent substrate or transparent electrode). It is intended to be taken out.

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

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

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

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

<Condenser sheet>
The organic EL device of the present invention is processed on the light extraction side of the substrate so as to provide, for example, a microlens array structure, or combined with a so-called condensing sheet, for example, with respect to a specific direction, for example, the light emitting surface By condensing 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 / electron transport layer / electron injection layer / cathode will be described.

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

  Next, an organic compound thin film of a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and a hole blocking 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, a wet process (spin coating method, casting method, ink jet method, printing method) and the like as described above. In view of the above, in the present invention, a wet process is preferable, and film formation by a coating method such as a spin coating method, an ink jet method, or a printing method is particularly preferable.

  Examples of the liquid medium for dissolving or dispersing the organic EL device material of the present invention include ketones such as methyl ethyl ketone and cyclohexanone, fatty acid esters such as ethyl acetate, halogenated hydrocarbons such as dichlorobenzene, toluene, xylene, and mesitylene. Aromatic hydrocarbons such as cyclohexylbenzene, aliphatic hydrocarbons such as cyclohexane, decalin, and dodecane, and organic solvents such as DMF and DMSO can be used. Moreover, as a dispersion method, it can disperse | distribute by dispersion methods, such as an ultrasonic wave, high shear force dispersion | distribution, and media dispersion | distribution.

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

  In addition, it is also possible to reverse the production order and produce the cathode, the electron injection layer, the electron transport 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 device may be patterned. 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.

When the organic EL element of the present invention is a white element, white means that the chromaticity in the CIE1931 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.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these.

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

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

On this 1st positive hole transport layer, the film which melt | dissolved 15 mg of Copoly-1 in 3 ml of toluene was formed into a film by the spin coat method on 1000 rpm and 30 second conditions. It heat-dried at 120 degreeC for 1 hour, and provided the 2nd hole transport layer with a film thickness of 20 nm. This was attached to a vacuum deposition apparatus, and the vacuum chamber was depressurized to 4 × 10 ⁻⁴ Pa. Next, co-evaporation was performed at an evaporation rate of OC-15 of 1.0 Å / s and PD-1 of 0.06 Å / s to provide a 40 nm light emitting layer. Furthermore, as an electron transport layer, OC-34 (bis (2-methyl-8-quinolate) -p-phenylphenolate aluminum complex; BAlq) was deposited to 30 nm, lithium fluoride 1 nm as a cathode buffer layer, and aluminum 110 nm as a cathode. Thus, a cathode was formed, and an organic EL element 1-1 was produced.

<< Production of Organic EL Elements 1-2 to 1-20 >>
In the production of the organic EL element 1-1, the organic EL elements 1-2 to 1-20 were exactly the same except that the Poly-1 used for the second hole transport layer was changed to the compounds shown in Table 2 below. Was made.

<< Evaluation of Organic EL Elements 1-1 to 1-20 >>
When evaluating the obtained organic EL elements 1-1 to 1-20, 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.

(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.

(High temperature storage)
The produced organic EL device was measured in the same manner as the above-described external extraction quantum efficiency after storage for a period of time at 23 ° C. [External extraction quantum efficiency after high temperature storage] / [External extraction quantum efficiency] was calculated and used as high temperature storage stability.

  The measurement results of the external extraction quantum efficiency, emission lifetime, and high-temperature storage stability of the organic EL elements 1-1 to 1-20 were evaluated relative to the organic EL element 1-20 as 100.

  From Table 3, it can be seen that the organic EL device of the present invention is excellent in any of external extraction quantum efficiency, light emission lifetime, and high-temperature storage stability.

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

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

  On this hole transport layer, a solution obtained by dissolving 20 mg of co-Poly (Cz-1-Cz-3) and 2 mg of PD-1 in 2 ml of toluene was formed by spin coating at 1500 rpm for 30 seconds. Filmed. Heat-dried at 120 ° C. for 1 hour to provide a light-emitting layer having a thickness of 40 nm.

This was attached to a vacuum deposition apparatus, and the vacuum chamber was depressurized to 4 × 10 ⁻⁴ Pa. Next, as an electron transport layer, OC-34 (bis (2-methyl-8-quinolate) -p-phenylphenolate aluminum complex; BAlq) was deposited to 30 nm, lithium fluoride 1 nm as a cathode buffer layer, and aluminum 110 nm as a cathode. Thus, a cathode was formed, and an organic EL element 2-1 was produced.

<< Production of Organic EL Elements 2-2 to 2-10 >>
In the production of the organic EL element 2-1, the organic EL element 2- was changed in the same manner except that the co-Poly (Cz-1-Cz-3) used in the light emitting layer was changed to the compounds shown in Table 4 below. 2 to 2-10 were produced.

  Measurement of the external extraction quantum efficiency, light emission lifetime, and high-temperature storage stability of the organic EL elements 2-1 to 2-10 was performed in the same manner as described above. The results are shown by relative evaluation when the organic EL element 2-10 is taken as 100.

  From Table 5, it can be seen that the organic EL device of the present invention is excellent in any of external extraction quantum efficiency, light emission lifetime, and high-temperature storage stability.

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

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

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

  The red, green and blue light-emitting organic EL elements are juxtaposed on the same substrate to produce an active matrix type full-color display device having the form shown in FIG. 1, and FIG. 2 shows the display of the produced display device. Only the schematic diagram of part A is shown. That is, a wiring portion including a plurality of scanning lines 5 and data lines 6 on the same substrate, and a plurality of juxtaposed pixels 3 (light emission color is a red region pixel, a green region pixel, a blue region pixel, etc.) The scanning lines 5 and the plurality of data lines 6 in the wiring portion are each made of a conductive material, and the scanning lines 5 and the data lines 6 are orthogonal to each other in a lattice shape and are connected to the pixels 3 at the orthogonal positions ( Details are not shown). The plurality of pixels 3 are driven by an active matrix system provided with an organic EL element corresponding to each emission color, a switching transistor as an active element, and a driving transistor, and a scanning signal is applied from a scanning line 5. Then, an image data signal is received from the data line 6 and light is emitted according to the received image data. Thus, a full color display device was produced by juxtaposing the red, green, and blue pixels appropriately.

  It was confirmed that by driving the full-color display device, a full-color moving image display having a high light emission efficiency and a long light emission life can be obtained.

Example 4
<< Production of white light-emitting lighting device >>
A white light-emitting organic EL element 1-1W was produced in the same manner as in the production of the organic EL element 1-1 in Example 1, except that PD-1 was changed to PD-1, PD-10, and PD-12.

  In the same manner as in Example 1, the obtained organic EL element 1-1W was covered with a glass case to obtain a lighting device. The lighting device has high luminous efficiency and can be used as a thin lighting device that emits white light with a long emission life.

It is the schematic diagram which showed an example of the display apparatus comprised from an organic EL element. It is a schematic diagram of a display part. It is the schematic of an illuminating device. It is sectional drawing of an illuminating device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Display 3 Pixel 5 Scanning line 6 Data line A Display part B Control part 107 Glass substrate with a transparent electrode 106 Organic EL layer 105 Cathode 102 Glass cover 108 Nitrogen gas 109 Water catching agent

Claims (7)

A polymer compound having a repeating unit structure represented by the following general formula ( 2 ) , wherein the polymer compound has a repeating unit structure represented by the following general formula (3) in an amount of 0% by mass to 50% by mass. The organic electroluminescence device material , wherein the polymer compound has a number average molecular weight in the range of 900 to 160,000 .

(In the general formula ( 2 ), R _{1 to} R ₇ represent a hydrogen atom, an alkyl group, an alkoxy group, or an aryl group, and R ₁ and R ₂ , R ₂ and R ₃ , R ₃ and R ₄ are bonded to each other. A 6-membered aromatic ring may be formed, except that R _{1 to} R ₇ are simultaneously hydrogen atoms , wherein R _{8 to} R ₁₂ are hydrogen atoms, alkyl groups, alkoxy groups. R ₈ and R ₉ , R ₉ and R ₁₀ , R ₁₀ and R ₁₁ may be bonded to each other to form a 6-membered aromatic ring, and k and m are macromolecules. The ratio of the repeating unit structure constituting the compound is represented by 50 ≦ k ≦ 100 mass% and 0 ≦ m ≦ 50 mass% .) An organic electroluminescent device having a plurality of organic layers between the opposed electrodes, the organic layer of at least one layer organic electroluminescent element, wherein that you containing an organic electroluminescence device material according to claim 1. At least an organic electroluminescent device according to claim 2 which further is characterized by a hole transport layer der Rukoto of the organic layer. The organic electroluminescence device according to claim 2 , wherein at least one of the organic layers is a light emitting layer. White emission to the organic electroluminescent device according to any one of claims 2-4, characterized in Rukoto. A display device comprising the organic electroluminescence element according to any one of claims 2 to 5. An illuminating device comprising the organic electroluminescence element according to any one of claims 2 to 5 .

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