JP5035394B2 - Organic electroluminescence element and display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic electroluminescence element which allows light emission of blue to bluish purple color of high luminance and furthermore has a long lifetime. <P>SOLUTION: The organic electroluminescence element and a display contain a compound expressed in general formula (6). <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an organic electroluminescence (hereinafter also abbreviated as organic EL) element and a display device.

  Conventionally, inorganic electroluminescent elements have been used as planar light sources, but an alternating high voltage is required to drive the light emitting elements.

  The recently developed organic electroluminescence device has a structure in which a thin film containing a fluorescent organic compound is sandwiched between a cathode and an anode, and excitons (excitons) by injecting electrons and holes into the thin film and recombining them. Is a device that emits light using the emission of light (fluorescence / phosphorescence) when this exciton is deactivated, but can emit light at a low voltage of several V to several tens of V, and is self-emitting. Since it is a type, it has a wide viewing angle dependency, has high visibility, and is a thin-film type complete solid-state device, so it is attracting attention from the viewpoints of space saving and portability.

  Various organic EL elements have been reported so far, but those that exhibit blue to blue-violet light emission still satisfy sufficient performance in terms of various performances such as light emission luminance and light emission lifetime. There are no examples. For example, although it has been reported that an organic electroluminescence device containing p-quarterphenyl emits light at 420 nm (for example, see Patent Document 1), the light emission luminance is not low enough.

  Moreover, although the compound which took in the benzimidazole in the molecule | numerator is examined (for example, refer patent document 2, 3), the light-emission brightness | luminance was not enough.

  A fluorescent material made of a pyrazoline compound is disclosed (for example, see Patent Document 4), but it is insufficient from the viewpoint of thermal stability to be used as a material for an organic EL device.

  N, N'-diphenyl-N, N'-bis (3-methylphenyl) [1,1'-biphenyl] -4,4'-diamine (TPD) is known to emit EL at 420 nm. However, for example, when a red color is attempted to be produced by the color conversion filter, the color purity is poor.

  From these viewpoints, as a light emitting material of an organic electroluminescence element that emits blue to blue-violet light, an element that emits light with higher luminance is required, and further improvement in energy conversion efficiency and emission quantum efficiency is expected. Yes.

  On the other hand, when a display device using an organic EL element or an organic EL element is used for portable purposes, those using glass as a substrate are not flexible (flexible) and can be broken by an unexpected impact such as dropping. There was sex.

  In addition, moisture in the atmosphere enters the organic EL element and forms a dark spot (black spot) on the light emitting surface, causing deterioration of the light emitting characteristics of the organic EL element.

Japanese Patent Laid-Open No. 3-152897 Japanese Patent Laid-Open No. 10-92578 Japanese Patent Laid-Open No. 10-106749 Japanese Patent Laid-Open No. 6-184531 JP-A-8-286033

  The first object of the present invention is to provide an organic EL device that enables light emission of high brightness blue to blue-violet, and the second object is to provide a long-life organic electroluminescence device. is there. A third object is to provide a display device using the organic EL element. The fourth object is to provide a flexible organic EL element. A fifth object is to provide an organic EL element that maintains stable light emission characteristics even in the atmosphere.

  The above object of the present invention can be achieved by the following configuration.

  1. The organic electroluminescent element characterized by containing the compound represented by following General formula (6).

Wherein, Ar ₈ and Ar ₉ each represent an aromatic heterocyclic group optionally having a may have a substituent aromatic hydrocarbon ring group or a substituent, Ar ₁₀ is, naphthyl group, methylnaphthyl group, binaphthyl group, a trifluoromethyl naphthyl group or anthryl _{group, a 1, a 2, a} 3 and _{a 4} represent each N or _{C (R 9), a 1} , a 2 , A ₃ and A ₄ represent N, at least one of A ₁ , A ₂ , A ₃ and A ₄ represents C (R ₉ ), and one or more R ₉ is Each represents a hydrogen atom or a substituent selected from an alkyl group, a halogen atom and an alkoxy group. ]
2. 2. The organic electroluminescence device according to 1 above, wherein at least one of Ar ₈ and Ar ₉ in the general formula (6) is represented by the following general formula (7).

Wherein, _{Ar 11} represents a naphthyl group, methylnaphthyl group, binaphthyl group, a trifluoromethyl naphthyl group or anthryl _{group, A 5, A 6, A} 7 and _{A 8} are each N or C _{(R 10)} the _stands, at least one of a _5, a 6, _{a 7} and _{a 8} represent _N, at least one of a _5, a 6, _{a 7} and _{a 8} represent C _{(R 10),} one One or a plurality of R ₁₀ each represents a hydrogen atom or a substituent selected from an alkyl group, a halogen atom and an alkoxy group. ]
3. The organic electroluminescent element characterized by containing the compound represented by following General formula (8).

_Wherein, Ar 12, _{Ar 13} and _{Ar 14} represents a naphthyl group, methylnaphthyl group, binaphthyl group, a trifluoromethyl naphthyl group or anthryl _{group, A 9, A 10, A} 11, A 12, A 13, at least one of _{a 14, a 15, a 16} , a 17, a 18, a 19 and _{a 20} represent each N or _{C (R 11), a 9} , a 10, a 11 and _{a 12} Represents N, at least one of A ₉ , A ₁₀ , A ₁₁ and A ₁₂ represents C (R ₁₁ ), and at least one of A ₁₃ , A ₁₄ , A ₁₅ and A ₁₆ represents N , A ₁₃ , A ₁₄ , A ₁₅ and A ₁₆ represent C (R ₁₂ ), and at least one of A ₁₇ , A ₁₈ , A ₁₉ and A ₂₀ represents N , A ₁₇ , A _18, A At least one of ₉ and _{A 20} represents C _{(R 13),} one or more of _{R 11, R 12} and _{R 13} are substituted each hydrogen atom, or an alkyl group, selected from a halogen atom and an alkoxy group Represents a group. ]
4). 4. The organic electroluminescent device according to 3 above, wherein at least one of Ar ₁₂ , Ar ₁₃ and Ar ₁₄ in the general formula (8) is a naphthyl group represented by the following general formula (4).

[Wherein, one or a plurality of R ₆ each represents a substituent selected from an alkyl group, a cycloalkyl group, an aryl group, a halogen atom, an alkoxy group, an aryloxy group and a heterocyclic group; Represents an integer. ]
5. 4. The organic electroluminescence device as described in 3 above, wherein at least one of Ar ₁₂ , Ar ₁₃ and Ar ₁₄ in the general formula (8) is a binaphthyl group represented by the following general formula (5).

[Wherein, one or a plurality of R ₇ and R ₈ each represents a substituent selected from an alkyl group, a cycloalkyl group, an aryl group, a halogen atom, an alkoxy group, an aryloxy group, and a heterocyclic group; N8 represents an integer of 0 to 7, and n8 represents an integer of 0 to 7. ]
6). 6. The organic electroluminescence device according to any one of 1 to 5, which has a color conversion unit.

  7). 6. A display device, wherein the organic electroluminescence elements according to any one of 1 to 5 are juxtaposed on the same substrate.

  8). 6. The organic electroluminescence device as described in any one of 1 to 5 above, which has a base made of a plastic film.

  9. 9. The organic electroluminescence device according to 8, wherein a sealing member that covers the organic electroluminescence device is provided and sealed together with the base.

  According to the present invention, it is possible to provide an organic EL device that can emit blue-blue-violet light with high luminance, and it is possible to provide a long-life organic electroluminescence device.

It is a chart figure showing the NMR spectrum of exemplary compound 21 of the present invention. It is a chart showing the absorption, fluorescence, and excitation spectrum of the exemplary compound 21 of the present invention. It is the schematic diagram which showed an example of the display apparatus comprised from an organic electroluminescent element. It is a schematic diagram of a display part. It is a schematic diagram of a pixel. It is sectional drawing which looked at the organic electroluminescent element which has a color conversion layer from the thickness direction. It is a schematic diagram of the display apparatus by a passive matrix system. It is the schematic diagram which looked at the bent organic EL element from the long side direction. It is sectional drawing of the sealed organic EL element.

  The present invention will be described in more detail. The color emitted by the organic compound in the present specification is obtained by measuring the result of measurement with a spectral radiance meter CS-1000 (manufactured by Minolta), 108 of “New Color Science Handbook” (edited by the Japan Color Society, University of Tokyo Press, 1985). It is determined by the color when applied to the CIE chromaticity coordinates described in FIG. 4.16 on the page.

  Further, the “cathode buffer layer” in the present invention is a layer provided between the cathode and the organic layer in order to lower the driving voltage and improve the luminous efficiency. JP-A-6-325871, 9-17574, 10 The details are described in No.-74586, specifically, a metal buffer layer represented by strontium or aluminum, an alkali metal compound buffer layer represented by lithium fluoride, and represented by magnesium fluoride. Examples thereof include an alkaline earth metal compound buffer layer and an oxide buffer layer typified by aluminum oxide.

  Hereinafter, the compounds represented by the general formulas (4) to (8) of the present invention will be described in detail.

In general formulas (4) and (5), n6 and n8 each represent an integer of 0 to 7, and n7 represents an integer of 0 to 6. One or a plurality of R ₆ , R ₇ and R ₈ each represents a substituent selected from an alkyl group, a cycloalkyl group, an aryl group, a halogen, an alkoxy group, an aryloxy group and a heterocyclic group, a methyl group, A trifluoromethyl group and a naphthyl group are particularly preferable.

In the general formula (6), Ar ₈ , Ar ₉ and Ar ₁₀ each represent an aromatic hydrocarbon ring group which may have a substituent or an aromatic heterocyclic group which may have a substituent. To express. Ar ₈ and Ar ₉ are preferably substituted with an aryl group at the 3-position, for example, phenyl, pyridyl, pyrazyl, pyrimidyl, triazyl and the like. Ar ₁₀ preferably includes naphthyl, binaphthyl, quinolyl, isoquinolyl, benzoxazolyl, benzoimidazolyl group and the like.

In the general formula (7), Ar ₁₁ represents an aromatic hydrocarbon ring group which may have a substituent or an aromatic heterocyclic group which may have a substituent, preferably naphthyl, binaphthyl, quinolyl. , Isoquinolyl, benzoxazolyl, benzimidazolyl group and the like.

In the general formula (8), Ar ₁₂ , Ar ₁₃ and Ar ₁₄ each represents an aromatic hydrocarbon ring group which may have a substituent or an aromatic heterocyclic group which may have a substituent. A ₉ , A ₁₀ , A ₁₁ , A ₁₂ , A ₁₃ , A ₁₄ , A ₁₅ , A ₁₆ , A ₁₇ , A ₁₈ , A ₁₉ and A ₂₀ are each represented by -N = or = C (R ₁₁ ) - _represents, a _9, a _10, at least one of _{a 11} and _{a 12} represent -N _=, at least one of _{a 9,} a 10, a ₁₁ and _{a 12} is = C _{(R 11)} - _represents, a _13, a _14, at least one of _{a 15} and _{a 16} represent -N _=, at least one of a _13, a _{14, a 15} and _{a 16} is = C _{(R 12)} - _represents, if less of the _{a 17,} a 18, a ₁₉ and _{a 20} One represents -N _=, and at least one of = C _{(R 13)} of the _{A 17,} A 18, A ₁₉ and _{A 20} - represents one or more of _{R 11, R 12} and _{R 13} And each represents a substituent selected from a hydrogen atom, an alkyl group, a halogen atom, and an alkoxy group.

  Specific examples of the compounds represented by the general formulas (4) to (8) of the present invention are shown below, but the present invention is not limited to these.

  In the present invention, the organic compound thin film layer (hereinafter also referred to as an organic layer) of the organic EL element may be a single layer or a multilayer stack. For example, in the case of a multilayer configuration, a layer other than an organic substance (for example, fluoride) A lithium layer, an inorganic metal salt layer, or a layer containing them) may be disposed at an arbitrary position.

  The organic EL device of the present invention basically has a structure in which at least one light emitting layer is held between a pair of electrodes, and a hole transport layer or an electron transport layer is interposed as required.

In particular,
1: anode / light emitting layer / cathode 2: anode / hole transport layer / light emitting layer / cathode 3: anode / light emitting layer / electron transport layer / cathode 4: anode / hole transport layer / light emitting layer / electron transport layer / cathode 5: Anode / hole injection layer / light emitting layer / cathode buffer layer / cathode 6: Anode / hole injection layer / light emitting layer / electron injection layer / cathode buffer layer / cathode.

  The substrate preferably used for the organic EL device of the present invention is not particularly limited in its kind such as glass and plastic, and is not particularly limited as long as it is transparent. Examples of the substrate preferably used in the electroluminescence device of the present invention include glass, quartz, and a light transmissive plastic film. In particular, in the case of portable use, a light-transmitting plastic film having flexibility (flexibility) may be used in order to avoid breakage due to impact such as dropping.

  Examples of the light transmissive plastic film include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), polyetherimide, polyetheretherketone, polyphenylene sulfide, polyarylate, polyimide, polycarbonate (PC ), Cellulose triacetate (TAC), cellulose acetate propionate (CAP) and the like.

  The light-emitting layer 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 an interface between adjacent layers.

  The material used for the light emitting layer (hereinafter referred to as the light emitting material) is preferably an organic compound or complex that emits fluorescence or phosphorescence, and is appropriately selected from known materials used for the light emitting layer of the organic EL device. Can be used. Such a light-emitting material is mainly an organic compound, and has a desired color tone, for example, Macromol. Synth. 125, pages 17 to 25, and the like.

  The light emitting material may have the hole transport function and the electron transport function in addition to the light emitting performance, and most of the hole transport material and the electron transport material can be used as the light emitting material.

  The light-emitting material may be a polymer material such as p-polyphenylene vinylene or polyfluorene, and a polymer material in which the light-emitting material is introduced into a polymer chain or the light-emitting material is a polymer main chain is used. May be.

  In addition, a dopant (guest material) may be used in combination with the light emitting layer, and an arbitrary one can be selected from known materials used as a dopant for an EL element. Specific examples of the dopant include quinacridone, DCM, coumarin derivatives, rhodamine, rubrene, decacyclene, pyrazoline derivatives, squarylium derivatives, europium complexes and the like.

  This light emitting layer can be formed by forming the above compound by a known thinning method such as a vacuum deposition method, a spin coating method, a casting method, or an LB method. Although the film thickness as a light emitting layer does not have a restriction | limiting in particular, Usually, it selects in the range of 5 nm-5 micrometers. This light emitting layer may have a single layer structure composed of one or two or more of these light emitting materials, or may have a laminated structure composed of a plurality of layers having the same composition or different compositions.

  Further, as described in JP-A-57-51781, this light emitting layer is prepared by dissolving the above light emitting material in a solvent together with a binder such as a resin, and then using a spin coating method or the like. It can be formed as a thin film. There is no restriction | limiting in particular about the film thickness of the light emitting layer formed in this way, Although it can select suitably according to a condition, Usually, it is the range of 5 nm-5 micrometers.

  The buffer layer is a layer provided between the electrode and the organic layer in order to lower the driving voltage and improve the luminous efficiency. “The organic EL element and its forefront of industrialization (November 30, 1998, NTS Corporation) Issue) ”, Chapter 2,“ Electrode Materials ”(pages 123 to 166) in detail, specifically, an anode buffer layer and a cathode buffer layer.

  Details of the anode buffer layer are described in JP-A Nos. 9-45479, 9-260062, and 8-288069. Specific examples thereof include a phthalocyanine buffer layer typified by copper phthalocyanine and a vanadium oxide representative. And an oxide buffer layer, an amorphous carbon buffer layer, a polymer buffer layer using a conductive polymer such as polyaniline (emeraldine) and polythiophene, and the like.

  Details of the cathode buffer layer are described in JP-A-6-325871, JP-A-9-17574, JP-A-10-74586, and the like. Specifically, a metal buffer layer represented by strontium, aluminum, etc. Examples thereof include an alkali metal compound buffer layer typified by lithium, an alkaline earth metal compound buffer layer typified by magnesium fluoride, and an oxide buffer layer typified by aluminum oxide.

  The buffer layer is preferably a very thin film, and depending on the material, the film thickness is preferably in the range of 0.1 to 100 nm.

  Further, in addition to the above basic constituent layers, layers having other functions may be laminated as required. For example, JP-A-11-204258, JP-A-11-204359, and “Organic EL devices and their industrialization It may have a functional layer such as a hole blocking layer described on page 237 of the front line (issued on November 30, 1998 by NTS).

As an anode in this 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 an electrode substance include conductive transparent materials such as metals such as Au, CuI, indium tin oxide (ITO), SnO ₂ , and ZnO.

  For the anode, a thin film may be formed by a method such as vapor deposition or sputtering of these electrode materials, and a pattern having a desired shape may be formed by a photolithography method, or when pattern accuracy is not so high (100 μm or more) The degree) may form a pattern through a mask having a desired shape at the time of vapor deposition or sputtering of the electrode material. When light emission is extracted from the anode, the visible light transmittance is desirably 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 used, it is usually in the range of 10 nm to 1 μm, preferably 10 to 200 nm.

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, a mixture of an electron injecting metal and a second metal which is a stable metal having a larger work function value than this from the viewpoint of durability against electron injecting and oxidation, for example, a magnesium / silver mixture, A magnesium / aluminum mixture, a magnesium / indium mixture, an aluminum / aluminum oxide (Al ₂ O ₃ ) mixture, a lithium / aluminum mixture, and the like are suitable.

  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 1 μm, preferably 50 to 200 nm. In the present invention, when a cathode buffer layer is provided between the organic compound layer and the cathode, the metal used for the cathode does not necessarily have a low work function, and a metal having a relatively high work function such as aluminum is used. It is also possible to use a non-metallic conductive material such as ITO.

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

  Next, the hole transport layer provided as necessary has a function of transmitting holes injected from the anode to the light emitting layer, and the hole transport layer is interposed between the anode and the light emitting layer. Many electrons are injected into the light emitting layer at a lower electric field, and moreover, electrons injected from the cathode or the electron transport layer into the light emitting layer are blocked by an electron barrier present at the interface between the light emitting layer and the hole transport layer. It is accumulated at the interface in the light emitting layer, resulting in an element with excellent light emitting performance, such as improved luminous efficiency.

  The material for the hole transport layer (hereinafter referred to as the hole transport material) is not particularly limited as long as it has the above-mentioned preferable properties, and conventionally used as a charge transport material for holes in photoconductive materials. Can be selected and used from the known ones used for the hole transport layer of EL devices.

  The hole transport material has either hole injection or electron barrier properties, and may be either organic or inorganic. Examples of the hole transport material include 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, stilbene derivatives, silazane derivatives, aniline copolymers, conductive polymer oligomers, particularly thiophene oligomers, and the like.

  As the hole transporting material, those described above can be used. For example, 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 the aromatic tertiary amine compound and styrylamine compound 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; Bis (4-di-p-tolylaminophenyl) cyclohexane; N, N, N ′, N′-tetra-p-tolyl-4,4′-diaminobiphenyl; 1,1-bis (4-di-p- Tolylaminophenyl) -4-phenylcyclohexane; bis (4-dimethylamino-2-methylphenyl) phenylmethane; bis (4-di-p-tolylaminophenyl) phenylmethane; N, N′-diphenyl-N, N -Di (4-methoxyphenyl) -4,4'-diaminobiphenyl; N, N, N ', N'-tetraphenyl-4,4'-diaminodiphenyl ether; 4,4'-bis (diphenylamino) quadri N; N, N-tri (p-tolyl) amine; 4- (di-p-tolylamino) -4 '-[4- (di-p-tolylamino) styryl] stilbene; 4-N, N-diphenyl Amino- (2-diphenylvinyl) benzene; 3-methoxy-4'-N, N-diphenylaminostilbenzene; N-phenylcarbazole, as well as 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-4-30868 4,4 ′, 4 ″ -tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine (MTDATA), etc., in which three triphenylamine units described in No. 1 are linked in a starburst type Is mentioned.

  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 transport material. 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, or an LB method. Although there is no restriction | limiting in particular about the film thickness of a positive hole transport layer, Usually, it is about 5 nm-5 micrometers.

  The hole transport layer may have a single-layer structure composed of one or more of the above materials, or a multilayer structure composed of a plurality of layers having the same composition or different compositions. Furthermore, the electron transport layer used as necessary only needs to have a function of transmitting electrons injected from the cathode to the light emitting layer. As the material thereof, any one of conventionally known compounds can be used. It can be selected and used.

  Examples of materials used for the electron transport layer (hereinafter referred to as electron transport materials) include, for example, heterocyclic tetracarboxylic acid anhydrides such as nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, and naphthalene perylene. , Carbodiimide, fluorenylidenemethane derivatives, anthraquinodimethane and anthrone derivatives, oxadiazole derivatives and the like. In addition, a series of electron transport compounds described in JP-A-59-194393 is disclosed as a material for forming a light emitting layer in the publication, but as a result of studies by the present inventors, as an electron transport material. It turns out that it can be used. Further, in the above oxadiazole derivatives, thiadiazole derivatives in which the oxygen atom of the oxadiazole ring is substituted with a sulfur atom, quinoxaline derivatives having a quinoxaline ring known as an electron-withdrawing group, and phenanthroline derivatives are also used as electron transport materials. Can be used.

  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.

  Also, 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 sulfo group can be preferably used as the electron transporting material. Further, the distyrylpyrazine derivatives exemplified as the material of the light emitting layer can also be used as an electron transport material, and similarly to the hole transport layer, inorganic semiconductors such as n-type-Si and n-type-SiC can be used as an electron transport material. Can be used as

  This electron transport layer can be formed by forming the above compound by a known thinning method such as a vacuum deposition method, a spin coating method, a casting method, or an LB method. Although the film thickness as an electron carrying layer does not have a restriction | limiting in particular, Usually, it selects in 5 nm-5 micrometers. The electron transport layer may have a single-layer structure composed of one or two or more of these electron transport materials, or a multilayer structure composed of a plurality of layers having the same composition or different compositions.

  Next, an example suitable for producing an organic EL element will be described.

  As an example, a method for producing an EL device composed of the anode / hole transport layer / light emitting layer / electron transport layer / cathode will be described. First, a desired electrode material such as an anode material is formed on a suitable substrate. A thin film is formed by a method such as vapor deposition or sputtering so as to have a film thickness of 1 μm or less, preferably in the range of 10 to 200 nm, to produce an anode. Next, a thin film made of materials of a hole transport layer, a light emitting layer, and an electron transport layer, which are element materials, is formed thereon.

  The compounds represented by the general formulas (1) to (11) of the present invention are contained in any layer of a hole blocking layer, a hole transporting layer, a light emitting layer, an electron transporting layer, a cathode buffer layer, and an anode buffer layer. It is also possible to form a layer alone or in combination with other compounds.

As described above, the method of thinning the organic thin film layer includes a spin coating method, a casting method, a vapor deposition method, etc., but from the viewpoint that a uniform film is easily obtained and pinholes are not easily generated. Vacuum deposition or spin coating is particularly preferred. Further, a different film forming method may be applied for each layer. When a vapor deposition method is adopted for film formation, the vapor deposition conditions vary depending on the type of compound used, the target crystal structure of the molecular deposition film, the association structure, etc., but generally the boat heating temperature is 50 to 450 ° C., the degree of vacuum It is desirable to select appropriately within the range of 10 ⁻⁶ to 10 ⁻³ Pa, a deposition rate of 0.01 to 50 nm / second, a substrate temperature of −50 to 300 ° C., and a film thickness of 5 nm to 5 μm.

  After the formation of these layers, a thin film made of a cathode material is formed thereon by a method such as vapor deposition or sputtering so as to have a film thickness of 1 μm or less, preferably in the range of 50 to 200 nm, and a cathode is provided. Thus, a desired EL element can be obtained. The organic EL device is preferably produced from the hole transport layer to the cathode consistently by a single evacuation, but it may be taken out in the middle and subjected to a different film forming method. Therefore, it is necessary to consider that the work is performed in a dry inert gas atmosphere.

  In addition, it is possible to reverse the production order and produce the cathode, the electron transport layer, the light emitting layer, the hole transport layer, and the anode in this order. When a DC voltage is applied to the EL element thus obtained, light emission can be observed by applying a voltage of about 5 to 40 V with the anode as + and the cathode as-polarity. 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.

  Next, in the present invention, an organic EL element having a color conversion unit will be described. The color conversion unit absorbs light emitted from the light emitting layer of the organic EL element, converts the wavelength, and contains a fluorescent dye that emits fluorescence of different wavelengths. Thus, the organic EL element can display not only the color of light emitted from the light emitting layer but also other colors converted by the color conversion layer.

  The color conversion unit is preferably a color conversion layer. The fluorescent dye may be an organic phosphor or an inorganic phosphor, and can be selected depending on the wavelength to be converted.

  Organic phosphors include coumarin dyes, pyran dyes, cyanine dyes, croconium dyes, squalium dyes, oxobenzanthracene dyes, fluorescein dyes, rhodamine dyes, pyrylium dyes, perylene dyes, stilbene dyes Examples thereof include dyes and polythiophene dyes.

  The inorganic phosphor is preferably a fine particle having a particle size of 3 μm or less, and the production method is preferably an ultrafine particle phosphor close to synthesized monodisperse via a liquid phase method.

  Examples of the inorganic phosphor include an inorganic phosphor composed of a crystal matrix and an activator, or a rare earth complex phosphor.

The composition of the inorganic phosphor is not particularly limited, but metal oxides such as Y ₂ O ₂ S, Zn ₂ SiO ₄ , Ca ₅ (PO ₄ ) ₃ Cl, etc., which are crystal bases, and ZnS, SrS, CaS. And sulfides such as Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and other rare earth metal ions, Ag, Al, Mn, In, Cu A combination of metal ions such as Sb as activator or coactivator is preferable.

The crystal matrix will be described in more detail. As the crystal matrix, a metal oxide is preferable. For example, (X) ₃ Al ₁₆ O ₂₇ , (X) ₄ Al ₁₄ O ₂₅ , (X) ₃ Al ₂ Si ₂ O ₁₀ , ( X) ₄ Si ₂ O ₈ , (X) ₂ Si ₂ O ₆ , (X) ₂ P ₂ O ₇ , (X) ₂ P ₂ O ₅ , (X) ₅ (PO ₄ ) ₃ Cl, (X) ₂ Si ₃ O ₈ [wherein X represents an alkaline earth metal. In addition, the alkaline earth metal represented by X may be a single component or a mixture of two or more kinds, and the mixing ratio may be arbitrary.] Aluminum oxide, silicon oxide substituted with alkaline earth metal Phosphoric acid, halophosphoric acid and the like are listed as typical crystal bases.

  Other preferable crystal matrixes include oxides and sulfides of zinc, oxides of rare earth metals such as yttrium, gadolinium, and lanthanum, and oxides in which part of oxygen in the oxides is changed to sulfur atoms (sulfides), and Examples include rare earth metal sulfides and oxides or sulfides thereof containing any metal element.

  Preferred examples of the crystal matrix are listed below.

Mg ₄ GeO _5.5 F, Mg ₄ GeO ₆ , ZnS, Y ₂ O ₂ S, Y ₃ Al ₅ O ₁₂ , Y ₂ SiO ₁₀ , Zn ₂ SiO ₄ , Y ₂ O ₃ , BaMgAl ₁₀ O ₁₇ , BaAl ₁₂ O ₁₉ , (Ba, Sr, Mg) O.aAl ₂ O ₃ , (Y, Gd) BO ₃ , (Zn, Cd) S, SrGa ₂ S ₄ , SrS, GaS, SnO ₂ , Ca ₁₀ (PO ₄ ) ₆ (F, Cl) ₂ , (Ba, Sr) (Mg, Mn) Al ₁₀ O ₁₇ , (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ Cl ₂ , (La, Ce) PO ₄ , CeMgAl _{11 O 19, GdMgB 5 O 10,} Sr 2 P 2 O 7, Sr 4 Al 14 O 25, Y 2 SO 4, Gd 2 O 2 S, Gd 2 O 3, YVO 4, Y (P, V) O 4 or the like It is.

  The above crystal matrix and activator or coactivator may be partially replaced with elements of the same family, and there is no particular limitation on the element composition, so long as it absorbs light in the blue-violet region and emits visible light. Good.

  In the present invention, preferred as the activator and coactivator of the inorganic phosphor are the ions of lanthanoid elements represented by La, Eu, Tb, Ce, Yb, Pr, etc., Ag, Mn, Cu, In, Al The ion amount of the metal is preferably 0.001 to 100 mol%, more preferably 0.01 to 50 mol% with respect to the base material.

  The activator and coactivator are doped into the crystal by replacing some of the ions constituting the crystal matrix with ions such as the above lanthanoids.

Strictly speaking, the actual composition of the phosphor crystal has the following composition formula, but since the amount of the activator often does not affect the intrinsic fluorescence properties, the following is especially true: Unless stated, the following numerical values of x and y are not described. For example, Sr _4-x Al ₁₄ O ₂₅ : Eu ²⁺ _x is expressed as Sr ₄ Al ₁₄ O ₂₅ : Eu ²⁺ in the present invention.

The composition formulas of typical inorganic phosphors (inorganic phosphors composed of a crystal matrix and an activator) are described below, but the present invention is not limited to these. _{(Ba z Mg 1-z)} 3-x-y Al 16 O 27: Eu 2+ x, Mn 2+ y, Sr 4- x Al 14 O 25: Eu 2+ x, (Sr 1-z Ba z) 1-x Al ₂ Si ₂ O ₈ : Eu ²⁺ _x , Ba ²⁻ _x SiO ₄ : Eu ²⁺ _x , Sr ²⁻ _x SiO ₄ : Eu ²⁺ _x , Mg ²⁻ _x SiO ₄ : Eu ²⁺ _x , (BaSr) _1-x SiO ₄ : Eu ²⁺ _x , Y _2−x−y SiO ₅ : Ce ³⁺ _x , Tb ³⁺ _y , Sr ²⁻ _x P ₂ O ₅ : Eu ²⁺ _x , Sr ²⁻ _x P ₂ O ₇ : Eu ²⁺ _x , _{(Ba y Ca z Mg 1-} y-z) 5-x (PO 4) 3 Cl: Eu 2+ x, Sr 2- x Si 3 O 8 -2SrCl 2: Eu 2+ x [x, y and z are each 1 The following arbitrary numbers are represented. ]
The inorganic phosphors preferably used in the present invention are shown below, but the present invention is not limited to these compounds.
[Blue light emitting inorganic phosphor]
(BL-1) Sr ₂ P ₂ O ₇ : Sn ⁴⁺
(BL-2) Sr ₄ Al ₁₄ O ₂₅ : Eu ²⁺
(BL-3) BaMgAl ₁₀ O ₁₇ : Eu ²⁺
(BL-4) SrGa ₂ S ₄ : Ce ³⁺
(BL-5) CaGa ₂ S ₄ : Ce ³⁺
(BL-6) (Ba, Sr) (Mg, Mn) Al ₁₀ O ₁₇ : Eu ²⁺
(BL-7) (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu ²⁺
(BL-8) BaAl ₂ SiO ₈ : Eu ²⁺
(BL-9) Sr ₂ P ₂ O ₇ : Eu ²⁺
_{(BL-10) Sr 5 (} PO 4) 3 Cl: Eu 2+
(BL-11) (Sr, Ca, Ba) ₅ (PO ₄ ) ₃ Cl: Eu ²⁺
_{(BL-12) BaMg 2 Al} 16 O 27: Eu 2+
(BL-13) (Ba, Ca) ₅ (PO ₄ ) ₃ Cl: Eu ²⁺
(BL-14) Ba ₃ MgSi ₂ O ₈ : Eu ²⁺
(BL-15) Sr ₃ MgSi ₂ O ₈ : Eu ²⁺
[Green light emitting inorganic phosphor]
(GL-1) (BaMg) Al ₁₆ O ₂₇ : Eu ²⁺ , Mn ²⁺
(GL-2) Sr ₄ Al ₁₄ O ₂₅ : Eu ²⁺
_{(GL-3) (SrBa)} A l2 Si 2 O 8: Eu 2+
(GL-4) (BaMg) ₂ SiO ₄ : Eu ^{2+
_{(GL-5) Y 2 SiO}} 5: Ce 3+, Tb 3+
_{(GL-6) Sr 2 P} 2 O 7 -Sr 2 B 2 O 5: Eu 2+
(GL-7) (BaCaMg) ₅ (PO ₄ ) ₃ Cl: Eu ²⁺
_{(GL-8) Sr 2 Si} 3 O 8 -2SrCl 2: Eu 2+
_{(GL-9) Zr 2 SiO} 4, MgAl 11 O 19: Ce 3+, Tb 3+
(GL-10) Ba ₂ SiO ₄ : Eu ²⁺
(GL-11) Sr ₂ SiO ₄ : Eu ²⁺
_{(GL-12) (BaSr)} SiO 4: Eu 2+
[Red light-emitting inorganic phosphor]
(RL-1) Y ₂ O ₂ S: Eu ³⁺
(RL-2) YAlO ₃ : Eu ³⁺
(RL-3) Ca ₂ Y ₂ (SiO ₄ ) ₆ : Eu ³⁺
(RL-4) LiY ₉ (SiO ₄ ) ₆ O ₂ : Eu ³⁺
(RL-5) YVO ₄ : Eu ³⁺
(RL-6) CaS: Eu ³⁺
(RL-7) Gd ₂ O ₃ : Eu ³⁺
(RL-8) Gd ₂ O ₂ S: Eu ³⁺
(RL-9) Y (P, V) O ₄ : Eu ³⁺
(RL-10) Mg ₄ GeO _5.5 F: Mn ⁴⁺
(RL-11) Mg ₄ GeO ₆ : Mn ⁴⁺
(RL-12) K ₅ Eu _2.5 (WO ₄ ) _6.25
(RL-13) Na ₅ Eu _2.5 (WO ₄ ) _6.25
(RL-14) K ₅ Eu _2.5 (MoO ₄ ) _6.25
(RL-15) Na ₅ Eu _2.5 (MoO ₄ ) _6.25
The inorganic phosphor may be subjected to a surface modification treatment as required, and as a method thereof, a chemical treatment such as a silane coupling agent or a physical treatment by adding submicron order fine particles or the like. And those obtained by using them in combination.

  Examples of rare earth complex phosphors include those having Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, etc. as rare earth metals. The ligand may be either aromatic or non-aromatic, and preferably a compound represented by the following general formula (B).

Formula _{(B) Xa- (L x)} - (L y) n - (L z) -Ya
In the formula, L _x , L _y , and L _z each independently represent an atom having two or more bonds, n represents 0 or 1, and Xa has an atom that can be coordinated to the adjacent position of L _x. represents a substituent, Ya represents a substituent having a coordinating an atom at the adjacent position to L _z. Further, any part of Xa and L _x may be condensed with each other to form a ring, and any part of Ya and L _z may be condensed with each other to form a ring, and L _x and L _z May be condensed with each other to form a ring, and at least one aromatic hydrocarbon ring or aromatic heterocyclic ring is present in the molecule. _{However, Xa- (L x) - (} L y) n - (L z) -Ya is beta-diketone derivative and beta-keto ester derivative, beta-ketoamide derivative or an oxygen atom of the ketone sulfur atom or -N (R ₂₀₁ )-, a crown ether, an azacrown ether, a thiacrown ether, or a crown ether in which any number of oxygen atoms in the crown ether are replaced by sulfur atoms or -N (R ₂₀₁ )- There may be no aromatic hydrocarbon ring or aromatic heterocycle. In —N (R ₂₀₁ ) —, R ₂₀₁ represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group.

  In the general formula (B), the coordinateable atoms represented by Xa and Ya are specifically an oxygen atom, a nitrogen atom, a sulfur atom, a selenium atom, and a tellurium atom, particularly an oxygen atom, a nitrogen atom, A sulfur atom is preferred.

In the general formula (B), the atom having two or more bonds represented by L _x , L _y , and L _z is not particularly limited, but typically, a carbon atom, an oxygen atom, a nitrogen atom, A silicon atom, a titanium atom, etc. are mentioned, A carbon atom is preferable.

  Specific examples of the rare earth complex-based phosphor having the organic ligand represented by the general formula (B) are shown below, but the present invention is not limited thereto.

  The place where the color conversion part is provided is not particularly limited as long as it can absorb light emitted from the organic EL part having the optical microresonance structure, but it is between the transparent electrode and the transparent substrate or the transparent substrate. It is preferably provided on the side opposite to the transparent electrode (the front side where light emission is extracted).

The color conversion part may be in any form such as film formation by vapor deposition or sputtering of the phosphor, or a coating film in which an appropriate resin is dispersed as a binder. The film thickness is suitably about 100 nm to 5 mm. Here, when an appropriate resin is used as a binder to form a coating film dispersed therein, the phosphor dispersion concentration does not cause fluorescence concentration quenching and sufficiently absorbs light emitted from the organic EL portion. Any range that can be used is acceptable. Depending on the type of phosphor, about 10 ⁻⁷ to 10 ⁻³ mol is suitable for 1 g of the resin used. In the case of an inorganic phosphor, since concentration quenching hardly causes a problem, about 0.1 to 10 g can be used with respect to 1 g of resin.

  Examples of the sealing means used in the present invention include a method of adhering a sealing member, an electrode, and a translucent substrate with an adhesive. The sealing member may be disposed so as to cover the display area of the organic EL element, and may be concave or flat. Further, transparency and electrical insulation are not particularly limited. Specifically, a glass plate, a polymer plate, a metal plate, etc. are mentioned. 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. The sealing member is processed into a concave shape by sandblasting, chemical etching, or the like.

  Specific examples of the adhesive include photocuring and thermosetting adhesives having a reactive vinyl group of acrylic acid oligomers and methacrylic acid oligomers, and moisture curing adhesives such as 2-cyanoacrylate. be able to. Moreover, the heat | fever and chemical curing types (two-component mixing), such as an epoxy type, can be mentioned. Moreover, hot-melt type polyamide, polyester, and polyolefin can be mentioned. Moreover, a cationic curing type ultraviolet curing epoxy resin adhesive can be mentioned. In addition, since an organic EL element may deteriorate by heat processing, what can be 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 it like screen printing.

  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 is injected in the gas phase and the liquid phase. Is preferred. A vacuum can also be used. Moreover, a hygroscopic compound can also be enclosed inside.

  Examples of the hygroscopic compound include metal oxides (eg, sodium oxide, potassium oxide, calcium oxide, barium oxide, magnesium oxide, aluminum oxide), sulfates (eg, sodium sulfate, calcium sulfate, magnesium sulfate, cobalt sulfate, etc.). Metal halides (eg, calcium chloride, magnesium chloride, cesium fluoride, tantalum fluoride, cerium bromide, magnesium bromide, barium iodide, magnesium iodide, etc.), perchloric acids (eg, barium perchlorate, In particular, anhydrous salts are preferably used in sulfates, metal halides and perchloric acids.

  Furthermore, the organic EL device of the present invention may have a color conversion layer or a color conversion filter containing a fluorescent substance or the like inside or outside the device, and also have a hue improving filter such as a color filter. May be.

  The organic EL device of the present invention may be used as a kind of lamp for illumination or exposure light source, or may be used as a display device for reproducing still images and moving images. In particular, 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.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, the aspect of this invention is not limited to this.

Example 1
Exemplified compound 21 of the present invention was synthesized according to the method shown below. A synthesis scheme is shown below.

  While stirring 1.58 g of 3-bromoaniline, 21.6 g of 1,3-dibromobenzene, 1.46 g of copper powder and 5.57 g of potassium carbonate, the mixture was heated at 200 degrees for 22 hours. Tetrahydrofuran, ethyl acetate and water were added to the reaction solution, and the mixture was filtered using Celite. After removing the aqueous layer, the remaining organic layer was washed with saturated brine, dried over magnesium sulfate, and then concentrated. After column purification, 1.00 g of tris (3-bromophenyl) amine (Compound A) was obtained by recrystallization from ethanol. By reacting 1.00 g of Compound A with 2.50 g of binaphthylboronic acid in the presence of 1.81 g of potassium carbonate and 360 mg of palladium catalyst in a two-layer solvent of 30 ml of dioxane and 5 ml of water, 930 mg of exemplified compound 21 was obtained. NMR and mass spectrum confirmed the target product.

Mass data of Exemplified Compound 21; MS (FAB) m / z 1003 (M + H)
FIG. 1 shows a chart of NMR (400 MHz, CDCl ₃ ) of Exemplary Compound 21.

  Further, FIG. 2 shows a chart of absorption, fluorescence, and excitation spectrum of the exemplified compound 21 measured in tetrahydrofuran. The fluorescence quantum yield was 0.10.

Example 2
Exemplified compound 51 of the present invention was synthesized according to the method shown below. A synthesis scheme is shown below.

  α-Naphtylamine 1.43 g, α-iodonaphthalene 15.2 g, copper powder 1.40 g and potassium carbonate 3.04 g were heated at 200 ° C. for 25 hours with stirring. Tetrahydrofuran, ethyl acetate, and water were added to the reaction solution, followed by filtration using celite. The aqueous layer was removed, and the remaining organic layer was washed with saturated brine, dried over magnesium sulfate, concentrated, and column purified. By recrystallization from ethyl acetate, 400 mg of trinaphthylamine (B) was obtained. Next, 1.0 g of (B) was added to 20 ml of methylene chloride, 0.39 ml of bromine was added dropwise thereto at 0 degree, and the mixture was stirred for 1 hour, concentrated and purified to obtain 1.42 g of tris (4-bromo-α -Naphthyl) amine (C) was obtained. (C) 670 mg of Exemplified Compound 51 was obtained by reacting 1.42 g with 1.28 g quinolylboronic acid in the presence of potassium carbonate and a palladium catalyst in a two-layer solvent composed of 60 ml of tetrahydrofuran and 5 ml of water. The product was confirmed by NMR (nuclear magnetic resonance spectrum) and mass spectrum.

Example 3
(Production of organic EL element)
<Comparison Organic EL Element: Production of OLED-01>
After patterning on a substrate (NA-45 manufactured by NH Techno Glass Co., Ltd.) with a 150 nm ITO (indium tin oxide) film on glass as the anode, the transparent support substrate provided with this ITO transparent electrode was replaced with i-propyl. Ultrasonic cleaning with alcohol, drying with dry nitrogen gas, and UV ozone cleaning were performed for 5 minutes. This transparent support substrate was fixed to a substrate holder of a commercially available vacuum evaporation apparatus, while 200 mg of compound H-1 was placed in a molybdenum resistance heating boat, and Tris (8-hydroxyquinolyl) was placed in another molybdenum resistance heating boat. 200 mg of natto aluminum (Alq3) was added and attached to a vacuum deposition apparatus.

Next, after reducing the vacuum chamber to 4 × 10 ⁻⁴ Pa, the heating boat containing the compound E-1 was energized, heated to 220 ° C., and transparent at a deposition rate of 0.1 to 0.3 nm / sec. It vapor-deposited on the support substrate and provided the positive hole transport layer with a film thickness of 60 nm. Further, the heating boat containing Alq3 is energized and heated to 220 ° C., and deposited on the hole transport layer at a deposition rate of 0.1 to 0.3 nm / sec to provide a light emitting layer having a thickness of 40 nm. It was. In addition, the substrate temperature at the time of vapor deposition was room temperature.

Next, the vacuum chamber is opened, and a stainless steel rectangular perforated mask is placed on the light emitting layer. Meanwhile, 3 g of magnesium is placed in a resistance heating boat made of molybdenum, and 0.5 g of silver is placed in a tungsten vapor deposition basket. The vacuum chamber was again depressurized to 2 × 10 ⁻⁴ Pa, and then magnesium was deposited at a deposition rate of 1.5 to 2.0 nm / sec by energizing a boat containing magnesium. The organic EL element OLED-01 for comparison shown in Table 1 was produced by heating and depositing silver at a deposition rate of 0.1 nm / sec to obtain a counter electrode made of the mixture of magnesium and silver.

<Comparison of the organic EL device: OLED-02~OLED-04 and the organic EL element of the present invention: OLED- 10 ~OLED- 14 Preparation of>
In the produced organic EL element OLED-01, in place of the compound shown in Table 1 instead of the compound H-1 which is the hole transport material used in the hole transport layer of the first layer, Organic EL elements OLED-02 to OLED-19 were produced.

(Evaluation as a hole transport material for organic EL devices)
Using the ITO electrode of each of the organic EL devices produced above as the anode and the counter electrode made of magnesium and silver as the cathode, continuous lighting is performed by applying a 15 V DC voltage in a dry nitrogen gas atmosphere at a temperature of 23 degrees, and light emission at the start of lighting The luminance (cd / m ² ) and the time for half the luminance were measured. The light emission luminance at the start of lighting is expressed as a relative value when the light emission luminance of the sample OLED-01 is 100, and the time when the luminance is halved is expressed as a relative value when the time when the luminance of the sample OLED-01 is halved is 100. did.

  The results obtained as described above are shown in Table 1.

As is clear from Table 1, all of the samples (OLED- 10 to OLED- 14 ) using the compound of the present invention as the hole transport material of the organic EL device have high emission luminance and light emission as the organic EL device. It can be seen that the lifetime is long.

Example 4
(Comparison of the organic EL device: OLED-20~OLED-22 and the organic EL element of the present invention: OLED- 28 ~OLED- 32 Preparation of)
In the organic EL element OLED-01 produced in Example 3, the hole transport material used in the first hole transport layer is copper phthalocyanine, the film thickness is changed to 10 nm, and the second light emitting layer is used. Organic EL elements OLED-20 to OLED-38 were produced in the same manner except that Alq3, which is the light emitting material used, was changed to the compound shown in Table 2 and the film thickness was changed to 60 nm.

(Evaluation of organic EL elements as light emitting materials)
With the ITO electrode of the produced organic EL element as the anode and the counter electrode made of magnesium and silver as the cathode, continuous lighting is performed by applying a 15 V DC voltage in a dry nitrogen gas atmosphere at a temperature of 23 degrees, and the light emission luminance at the start of lighting ( cd / m ² ) and the time to halve the brightness. The light emission luminance is expressed as a relative value when the light emission luminance of the OLED-20 is 100, and the time when the luminance is halved is expressed as a relative value when the time when the luminance of the sample OLED-20 is halved is 100. The results are shown in Table 2.

As is apparent from Table 2, the samples OLED- 28 to OLED- 32 using the compound of the present invention for the light emitting layer of the organic EL device all have a light emission color of blue-violet to blue, high light emission luminance, and organic EL. It can be seen that the light emission lifetime as an element is also long.

Example 5
Production of comparative organic EL elements (OLED-101, OLED-102) and organic EL elements of the present invention ( OLED- 111 to OLED-118, OLED-125, OLED-126, OLED-129 and OLED-130 ) In the same manner as in Example 3, m-MTDATA was deposited to a thickness of 30 nm on a transparent support substrate provided with an ITO transparent electrode to form a hole transport layer. On top of this, E-1 was deposited to 40 nm to form a light emitting layer. Subsequently, BC was deposited thereon to a thickness of 30 nm to form an electron transport layer. Subsequently, 100 nm of aluminum was vapor-deposited thereon to form a counter electrode, thereby producing a comparative organic EL element OLED-101.

  Further, a comparative organic EL element OLED-102 was produced in the same manner as OLED-101 except that lithium fluoride was deposited to a thickness of 0.5 nm between the electron transport layer and the aluminum layer to form a cathode buffer layer. .

Furthermore, the organic EL elements OLED- 111 to OLED- of the present invention were the same as OLED-101 except that the hole transport layer, the light emitting layer, the electron transport layer, and the cathode buffer layer were configured as shown in Table 3. 118, OLED-125, OLED-126, OLED-129 and OLED-130 were produced.

These elements were continuously lit by applying a 10 V DC voltage in a dry nitrogen gas atmosphere at a temperature of 23 ° C. using the ITO electrode as an anode and the counter electrode made of aluminum as a cathode, and the emission luminance (cd / m ² ) at the start of lighting and The time for halving the luminance was measured. The light emission luminance is expressed as a relative value when the light emission luminance of the OLED-101 is 100, and the time when the luminance is reduced by half is expressed as a relative value where the time when the luminance of the sample OLED-101 is reduced by half is 100. The results are shown in Table 3.

From the results in Table 3, the following is clear.
1) It is effective to use the compound of the present invention even in an organic three-layer structure. 2) When the cathode buffer layer is laminated, the compound of the present invention is more effective than the conventional compound obtained by laminating lithium fluoride. 4) It is more effective when the compound of the present invention is used in combination with the hole transport layer and the light emitting layer. 4) It is more effective when the compound of the present invention is used in combination with the hole transport layer and the light emitting layer and further a cathode buffer layer is laminated. 5) An organic EL device having excellent emission luminance and life and emitting blue to blue-violet light has been achieved.

Example 6
<Preparation of color conversion filter using inorganic phosphor>
15 g of ethanol and 0.22 g of γ-glycidoxypropyltriethoxysilane were added to 0.16 g of aerosil having an average particle diameter of 5 nm, and the mixture was stirred at room temperature for 1 hour. This mixture and 20 g of (RL-12) were transferred to a mortar and thoroughly mixed, and then heated in an oven at 70 ° C. for 2 hours and further in an oven at 120 ° C. for 2 hours to obtain surface-modified (RL-12). It was.

  Similarly, surface modification of (GL-10) and (BL-3) was also performed.

  30 g of butyral (BX-1) dissolved in a mixed solution (300 g) of toluene / ethanol = 1/1 was added to 10 g of the above surface-modified (RL-12), and the mixture was stirred and then wet film thickness was added. It was coated on glass at 200 μm. The obtained coated glass was heated and dried in an oven at 100 ° C. for 4 hours to produce a red color conversion filter (F-1) as a color conversion part of the present invention.

  Also, a green color conversion filter (F-2) coated with (GL-10) and a blue color conversion filter (F-3) coated with (BL-3) were produced in the same manner.

<Preparation of an organic EL element having a color conversion filter as a color conversion unit>
Subsequently, a blue color conversion filter (F-3) as a color conversion part was attached in a stripe shape to the lower side of the base of the OLED-130 of Example 5. The organic EL device of this example has the following configuration.

Color conversion part / substrate / transparent electrode (ITO) / organic compound thin film / LiF thin film / metal electrode When a voltage of 10 V was applied to these elements, blue light emission was obtained. The maximum emission wavelength of the emission spectrum was 448 nm and (0.15, 0.06) on the CIE chromaticity coordinates.

  Furthermore, the organic EL element which replaced the blue conversion filter (F-3) of the said color conversion part with the green conversion filter (F-2) or the red conversion filter (F-1) was produced. As a result, from the organic EL element provided with the green conversion filter (F-2), green light having a maximum emission wavelength of 532 nm and CIE chromaticity coordinates (0.24, 0.63) is converted into a red conversion filter (F− From the organic EL element provided with 1), red light having a maximum emission wavelength of 615 nm and CIE chromaticity coordinates (0.63, 0.33) was obtained.

  In addition, an organic EL device having the same color conversion filter was produced for the OLED-132 of Example 5, and the emission spectrum of the maximum emission wavelength and CIE chromaticity coordinates almost the same as those of the blue, green, and red was obtained. .

  Moreover, the organic EL element of the following layer structures which changed the position of the following color conversion parts to the upper side of a transparent base | substrate was produced about each of OLED-130 and OLED-132.

Transparent substrate / color conversion part / transparent electrode (ITO) / organic compound thin film / LiF thin film / metal electrode Also in this case, the emission spectrum of the maximum emission wavelength and CIE chromaticity coordinates almost the same as the above blue, green and red are obtained. The emission luminance was improved over the elements (above) in which the color conversion part was on the lower side of the transparent substrate in all of blue, green and red.

Example 7
An example of the display device of the present invention composed of the organic EL element of the present invention produced in Example 6 will be described below based on the drawings.

  FIG. 3 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 L having a plurality of pixels, a control unit M that performs image scanning of the display unit L based on image information, and the like.

  The control unit M is electrically connected to the display unit L, sends a scanning signal and an image data signal to each of the plurality of pixels 3 based on image information from the outside, and the pixel 3 for each scanning line is image data by the scanning signal. In accordance with the signal, light is sequentially emitted and image scanning is performed to display image information on the display unit L.

  FIG. 4 is a schematic diagram of the display unit L.

  The display unit L 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 base. The main members of the display unit L 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 lines 5 and the plurality of data lines 6 in the wiring portion are each made of a conductive material, and the scanning lines 5 and the data lines 6 are orthogonal to each other in a grid pattern and are connected to the pixels 3 at orthogonal positions (details not shown). ).

  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 that emit light on the same substrate.

  Next, the light emission process of the pixel 3 will be described.

  FIG. 5 is a schematic diagram of the pixel 3.

  The pixel 3 includes an organic EL element 10, a switching transistor 11, a driving transistor 12, a capacitor 13, and the like.

  In the figure, an image data signal is applied from the control unit to the drain of the switching transistor 11 via the data line 6. When a scanning signal is applied from the control unit 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, 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 a scanning signal is next applied by sequential scanning, the drive 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 organic EL element 10 emits light by providing a switching transistor 11 and a drive transistor 12 as active elements for each of the organic EL elements 10 of the plurality of pixels 3. Emitting light. 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 on / off of a predetermined light emission amount by a binary image data signal. But it ’s okay.

  The potential of the capacitor 13 may be held continuously until the next scanning signal is applied, or may be discharged immediately before the next scanning signal is applied.

  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. 6 is a cross-sectional view of only the portion of the organic EL element 10 of the pixel 3 extracted from the thickness direction.

  FIG. 6A and FIG. 6B show aspects in which the arrangement of the color conversion units is different. 6A, the organic EL element 10 is an aspect in which the organic EL portion Y is laminated on the upper side of the transparent substrate 10e and the color conversion portion X is laminated on the lower side. In FIG. In this embodiment, the color conversion part X and the organic EL part Y are laminated in this order on the upper side of the transparent substrate 10e.

  In the figure, reference numeral 10a is a metal electrode, 10b is a cathode buffer layer, 10c is an organic compound thin film including a light emitting layer, 10d is a transparent electrode, 10e is a transparent substrate, and 10f is a color conversion layer.

  When current is supplied to the cathode buffer layer 10b and the organic compound thin film 10c through the metal electrode 10a and the transparent electrode 10d, light is emitted according to the amount of current. The emitted light at this time is extracted in the lower direction in the figure. And when absorbed by the color conversion layer 10f through the transparent substrate 10e, and the color conversion layer has a red conversion ability, it has a red conversion ability, and when it has a green conversion ability, it has a green conversion ability. The light emission in the blue region can be extracted in the direction indicated by the white arrow in the figure.

  FIG. 7 is a schematic view of a passive matrix display.

  In the figure, 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.

Example 8
Silicon oxide was formed by reactive sputtering using Si as a sputtering target on one side of a PES (polyethersulfone) film (Sumitomo Bakelite Co., Ltd. Sumitrite FS-1300) having a size of 25 mm × 75 mm and a thickness of 0.1 mm. A moisture-proof inorganic oxide film made of (SiOx) and having a thickness of 600 angstroms was formed. In the reactive sputtering at this time, a PES film is attached to a sputtering apparatus, and the inside of the vacuum chamber is depressurized to 1 × 10 ⁻³ Pa or less, and Ar gas (purity 99.99%) and O ₂ gas (purity 99.99%). 99%) was introduced into the vacuum chamber until the vacuum pressure reached 1.0 × 10 ⁻¹ Pa, and then the conditions were a target applied voltage of 400 V and a substrate temperature of 80 ° C.

Next, Si ₃ N ₄ is used as a sputtering target on the moisture-proof inorganic oxide film, and sputtering is performed in a mixed gas atmosphere of Ar gas (purity 99.99%) and O ₂ gas (purity 99.99%). A moisture-proof inorganic oxynitride film having a thickness of 200 Å made of a silicon oxynitride film (SiO _1.5 N _0.6 ) was formed.

Further, the moisture-proof inorganic oxynitride formed above by a DC magnetron sputtering method using a sintered body made of a mixture of indium oxide and zinc oxide (In atomic ratio In / (In + Zn) = 0.80) as a sputtering target. On the physical film, an amorphous oxide film having a thickness of 250 nm containing indium element and zinc element as main cation elements was formed. In this case, DC magnetron sputtering is performed by mounting a PES film on a DC magnetron sputtering apparatus and reducing the pressure in the vacuum chamber to 1 × 10 ⁻³ Pa or less, and Ar gas (purity 99.99%) and O ₂ gas (purity). 99.99%) was introduced into the vacuum chamber until the vacuum pressure reached 1.0 × 10 ⁻¹ Pa, and then the target applied voltage was 420 V and the substrate temperature was 60 ° C. After patterning this transparent conductive film, it was ultrasonically cleaned with i-propyl alcohol, dried with dry nitrogen gas, and subjected to UV ozone cleaning for 5 minutes.

  On the PES film provided with this transparent conductive film, m-MTDATA was deposited in a thickness of 30 nm in the same manner as in Example 5 to form a hole transport layer. The exemplified compound 9 was deposited thereon by 40 nm to form a light emitting layer.

  Subsequently, BC was deposited thereon to a thickness of 30 nm to form an electron transport layer. Further, lithium fluoride was deposited to a thickness of 0.5 nm to form a cathode buffer layer, and then aluminum was deposited to a thickness of 100 nm to form a counter electrode, thereby fabricating the organic EL element OLED-201 of the present invention. Further, OLED-202 to OLED-211 were produced using the compounds shown in Table 4 instead of the exemplified compound 9. Table 4 shows the luminescent color when a transparent electrode of the produced organic EL element is used as an anode and a counter electrode made of aluminum is used as a cathode and a DC voltage of 10 V is applied in a dry nitrogen gas atmosphere at a temperature of 23 degrees.

  FIG. 8 is a schematic view of the bent organic EL element as seen from the long side direction.

  A force was applied to each of the short sides of OLED-201 to OLED-211 and bent as shown in FIG. 8, but none of the substrate (film) was broken, and light was emitted in a bent state.

  From this result, the organic EL element which has flexibility (flexibility) was able to be provided.

Example 9
A concave glass sealing can is used as the sealing member 20, and barium oxide is attached to the bottom thereof as a moisture absorbent 21 with an adhesive. In a dry box under a nitrogen stream, a convex portion around the sealing member is provided. A photo-curing adhesive (Luxtrac LCR0629B manufactured by Toagosei Co., Ltd.) is applied as the sealing agent 22, and a sealing member is applied so as to cover the display area of the organic EL element OLED-103 of Example 5, and light irradiation is performed to seal The sealing organic EL element OLED-301 shown in FIG. 9 was produced by bonding the convex portion of the stopper member to the surface of the transparent substrate 10e and the surfaces of the anode and cathode extraction electrodes. In FIG. 9, OLED-301 emits light downward.

  An enlarged photograph of 50 times was taken immediately after enclosing the light emitting part of this OLED-301. Next, this organic EL device was stored for 500 hours at a temperature of 85 ° C., and then an enlarged photograph was taken of the light emitting portion in the same manner as immediately after the encapsulation. When these enlarged photographs were compared and observed, the growth of dark spots was hardly observed.

  Moreover, when the organic EL element which performed the same sealing also about the organic EL element OLED-104 to OLED-132 of Example 5 and produced the same storage test as the above, any sealed organic In the EL device, dark spot growth was hardly observed.

  From this result, it was possible to provide an organic EL element that maintains stable light emission characteristics even in the atmosphere.

A 9H peak B 24H peak C 18H peak D CHCl ₃ derived peak E THF derived peak F C ₆ H ₅ CH ₃ derived peak G THF derived peak H H ₂ O derived peak IC ₆ H ₆ derived peak 1 display 3 pixels 5 scanning Line 6 Data line 7 Power line 10 Organic EL element 10a Metal electrode 10b Cathode buffer layer 10c Organic compound thin film 10d Transparent electrode 10e Transparent substrate 10f Color conversion layer 11 Switching transistor 12 Drive transistor 13 Capacitor 15 Organic EL element 16a Tangential line 16b Tangential line 20 Sealing Stop member 21 Hygroscopic agent 22 Sealant L Display part M Control part X Color conversion part Y Organic EL part

Claims (9)

The organic electroluminescent element characterized by containing the compound represented by following General formula (6).

Wherein, Ar ₈ and Ar ₉ each represent an aromatic heterocyclic group optionally having a may have a substituent aromatic hydrocarbon ring group or a substituent, Ar ₁₀ is, naphthyl group, methylnaphthyl group, binaphthyl group, a trifluoromethyl naphthyl group or anthryl _{group, a 1, a 2, a} 3 and _{a 4} represent each N or _{C (R 9), a 1} , a 2 , A ₃ and A ₄ represent N, at least one of A ₁ , A ₂ , A ₃ and A ₄ represents C (R ₉ ), and one or more R ₉ is Each represents a hydrogen atom or a substituent selected from an alkyl group, a halogen atom and an alkoxy group. ] The organic electroluminescence device according to claim 1, wherein at least one of Ar ₈ and Ar ₉ in the general formula (6) is represented by the following general formula (7).

Wherein, _{Ar 11} represents a naphthyl group, methylnaphthyl group, binaphthyl group, a trifluoromethyl naphthyl group or anthryl _{group, A 5, A 6, A} 7 and _{A 8} are each N or C _{(R 10)} the _stands, at least one of a _5, a 6, _{a 7} and _{a 8} represent _N, at least one of a _5, a 6, _{a 7} and _{a 8} represent C _{(R 10),} one One or a plurality of R ₁₀ each represents a hydrogen atom or a substituent selected from an alkyl group, a halogen atom and an alkoxy group. ] The organic electroluminescent element characterized by containing the compound represented by following General formula (8).

_Wherein, Ar 12, _{Ar 13} and _{Ar 14} represents a naphthyl group, methylnaphthyl group, binaphthyl group, a trifluoromethyl naphthyl group or anthryl _{group, A 9, A 10, A} 11, A 12, A 13, at least one of _{a 14, a 15, a 16} , a 17, a 18, a 19 and _{a 20} represent each N or _{C (R 11), a 9} , a 10, a 11 and _{a 12} Represents N, at least one of A ₉ , A ₁₀ , A ₁₁ and A ₁₂ represents C (R ₁₁ ), and at least one of A ₁₃ , A ₁₄ , A ₁₅ and A ₁₆ represents N , A ₁₃ , A ₁₄ , A ₁₅ and A ₁₆ represent C (R ₁₂ ), and at least one of A ₁₇ , A ₁₈ , A ₁₉ and A ₂₀ represents N , A ₁₇ , A _18, A At least one of ₉ and _{A 20} represents C _{(R 13),} one or more of _{R 11, R 12} and _{R 13} are substituted each hydrogen atom, or an alkyl group, selected from a halogen atom and an alkoxy group Represents a group. ] At least one organic electroluminescent device according to claim 3, wherein the naphthyl group represented by the following general formula (4) of _Ar 12, _{Ar 13} and _{Ar 14} in the general formula (8).

[Wherein, one or a plurality of R ₆ each represents a substituent selected from an alkyl group, a cycloalkyl group, an aryl group, a halogen atom, an alkoxy group, an aryloxy group and a heterocyclic group; Represents an integer. ] 4. The organic electroluminescence device according to claim 3, wherein at least one of Ar ₁₂ , Ar _13, and Ar ₁₄ in the general formula (8) is a binaphthyl group represented by the following general formula (5).

[Wherein, one or a plurality of R ₇ and R ₈ each represents a substituent selected from an alkyl group, a cycloalkyl group, an aryl group, a halogen atom, an alkoxy group, an aryloxy group, and a heterocyclic group; N8 represents an integer of 0 to 7, and n8 represents an integer of 0 to 7. ]   The organic electroluminescence device according to claim 1, further comprising a color conversion unit.   6. A display device, wherein the organic electroluminescence elements according to claim 1 are juxtaposed on the same substrate.   6. The organic electroluminescence element according to claim 1, further comprising a base made of a plastic film.   The organic electroluminescence element according to claim 8, wherein a sealing member that covers the organic electroluminescence element is provided in cooperation with the base and is sealed.

Images