JP2006128325A - Organic el element, organic el display device and organic el illuminator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic El element being capable of sufficiently improving the lifetime of the element by inhibiting the deterioration of the element and suppressing the lowering of a brightness, by preventing the deterioration of material itself constituting an organic layer when the organic EL element is driven and having an excellent durability, and to provide a display device having the organic EL element and an illuminator. <P>SOLUTION: The organic electroluminescence element has the organic layer requiring a light-emitting layer between a pair of electrodes. In the organic electroluminescence element, at least one layer constituting the organic layer contains a compound having 2,2,6,6-tetramethylpiperidine and/or 2,2,6,6-tetramethylpiperazine skeletons. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to an organic EL (electroluminescence) element, an organic EL display device, and an organic EL lighting device. More specifically, the present invention relates to an organic EL element, an organic EL display device, and an organic EL lighting device that are configured by electroluminescent elements and are suitable for display devices, lighting devices, and the like.

An electroluminescent element (hereinafter also referred to as “EL element” or “EL device”) is a self-luminous light emitting element when holes injected from an anode and electrons injected from a cathode are recombined in a light emitting layer. It is expected to be widely applied as a display element for various information terminals and lighting devices due to its high visibility and impact resistance. Such EL elements are roughly classified into inorganic EL and organic EL depending on the fluorescent compound constituting the light emitting layer. Currently, those using inorganic phosphors are the mainstream and widely used. However, since an AC voltage of 200 V or more is required for driving, the manufacturing cost is high and the luminance is not sufficient.

On the other hand, research on organic EL devices using organic compounds started with a single crystal such as anthracene, but the thickness is about 1 mm and a driving voltage of 100 V or higher is required. Various techniques for realizing driving voltage and thinning have been studied, and attempts have been made to reduce the thickness by vapor deposition. However, since the drive voltage is still as high as 30 V, the carrier density of electrons and holes in the film is low, and the excitation probability due to carrier recombination is low, sufficient brightness is not obtained in such a method. In addition, when manufacturing a low molecular weight organic EL element using a low molecular weight material as an organic material constituting the light emitting layer, vapor deposition is performed in a high vacuum, and the operation is complicated and the manufacturing cost is high. From the viewpoint of production, it is not always preferable. In particular, when used in a lighting device or the like, since elements must be formed in a large area, it is difficult in terms of cost and technology to manufacture in this way by vapor deposition.

On the other hand, as a polymer type organic EL device, a light emitting device having a polymer single layer structure and a light emitting device having a laminated structure, which are expected to improve productivity, have been studied. As the polymer single layer type EL element, for example, a conductive polymer such as polyphenylene vinylene is used, or an electron transporting material and a fluorescent dye are mixed in hole transporting polyvinyl carbazole (PVCz). However, characteristics such as driving voltage, luminance, luminous efficiency, and stability have not yet reached the stacked EL element. However, in recent years, a two-layer stacked EL device in which poly (3,4) ethylenedioxythiophene / polystyrene sulfonate (PEDOT-PSS) is stacked on a conventional polymer single layer structure has been proposed. In such a two-layer stacked type, it has become possible to improve driving voltage, luminance, luminous efficiency, stability, etc., compared with a single-layer type EL element, but it is still not sufficient, and in particular, has a short lifetime. Improvement is demanded in that respect.

As described above, the problem of the lifetime is greatly involved as a major problem until the organic EL element reaches a practical use level. One of the reasons why the lifetime of the organic EL element is not sufficient is that many organic materials are weak against moisture and oxygen, and in particular, the probability that the organic molecules are deteriorated in the excited state is higher than the ground state. The organic EL element emits light when holes injected from the anode and electrons injected from the cathode are recombined in the light emitting layer, but the energy is changed when the excited state changes to the ground state. This is because it is considered that deterioration is likely to occur due to the generation of equivalent light emission. For this reason, a sealing technique for blocking organic molecules from the external environment has been studied, and attempts have been made to extend the lifetime by incorporating a desiccant into the device, but this is not sufficient.

An organic light-emitting element in which a singlet oxygen quencher is contained in a light-emitting layer is disclosed with respect to a conventional technique for improving the lifetime of an organic EL element (for example, see Patent Document 1). In this organic light emitting device, a fluorescent coumarin dye, a styryl dye or the like is used as a light emitting agent contained in the light emitting layer. In the organic electroluminescence device in which the light emitting material and the hole transport material are contained in the same organic layer or in different organic layers, at least one of the organic layers containing the hole transport material is an antioxidant. And those containing at least one light stabilizer (for example, see Patent Document 2). In this organic electroluminescence device, when the light emitting material and the hole transport material are contained in the same organic layer, for example, at least one of the light emitting material, the antioxidant and the light stabilizer, and the hole An element structure including a light emitting layer including a transport material is disclosed. As the light emitting material contained in the light emitting layer, polyarylene vinylene and its derivatives are used.
However, in these elements, in order to reach the practical use level, which is the greatest problem of organic EL, the deterioration of the organic layer in the organic EL element, particularly the material constituting the light emitting layer among them, is suppressed. There was room for improvement to improve durability.
Japanese Patent No. 3228984 (pages 1, 2, 6) Japanese Patent Laid-Open No. 10-255981 (pages 1, 2, 3)

The present invention has been made in view of the above-described situation, and when driving an organic EL element, the deterioration of the element itself is prevented by preventing the deterioration of the material constituting the organic layer, thereby suppressing a decrease in luminance. It is an object of the present invention to provide an organic EL element with excellent durability that can sufficiently improve the life of the element, and a display device and an illumination device including the organic EL element.

The inventors of the present invention have made various studies on improving the lifetime of the organic EL device. In the electroluminescence device, when light is emitted under a constant current condition, the driving voltage gradually increases with time, and the emission luminance is increased. Although this will gradually decrease, the cause of this includes, for example, deterioration of the charge transport layer and deterioration of the light emitting layer, corrosion of the electrode, etc., but the organic material constituting the organic layer in the electroluminescent element, In particular, attention has been paid to the problem of deterioration of the light emitting element material itself constituting the light emitting layer. Then, a 2,2,6,6-tetramethylpiperidine and / or 2,2,6,6-tetramethylpiperazine skeleton is formed on the organic layer such as the charge transport layer and the light emitting layer constituting the laminated structure of the organic EL element. By including the compound having an anti-oxidant and / or a light stabilizer and a polymer compound having a fluorene skeleton, the deterioration of the element is suppressed at the time of driving the element, thereby reducing the luminance. The inventors have found that the problems can be sufficiently suppressed, and have conceived that the above problems can be solved brilliantly, and have reached the present invention.

That is, the present invention is an organic electroluminescence device having an organic layer in which a light emitting layer is essential between a pair of electrodes, wherein at least one layer constituting the organic layer is 2,2,6,6-tetramethylpiperidine. And / or an organic electroluminescence device containing a compound having a 2,2,6,6-tetramethylpiperazine skeleton. Thereby, a luminance fall can be suppressed by suppressing deterioration of organic material itself which comprises the organic layer in an organic EL element, and it can be excellent in durability.

The light emitting layer is preferably composed of a π-conjugated polymer material, and the π-conjugated polymer material preferably contains a polymer compound having a fluorene skeleton. Moreover, as a preferable form of the organic electroluminescence device, the light emitting layer contains a 2,2,6,6-tetramethylpiperidine and / or a compound having a 2,2,6,6-tetramethylpiperazine skeleton. is there.

The effect of suppressing the decrease in luminance exhibited by the organic EL device of the present invention is sufficiently exhibited when a π-conjugated polymer material is used for the light emitting layer, and above all, when a polymer compound having a fluorene skeleton is used. In addition, a polymer having a fluorene skeleton in particular by a combination of a 2,2,6,6-tetramethylpiperidine and / or a compound having a 2,2,6,6-tetramethylpiperazine skeleton and a π-conjugated polymer material The effect of the present invention is more effectively exhibited by the combination with the compound.

Further, the light emitting layer is a compound having 2,2,6,6-tetramethylpiperidine and / or 2,2,6,6-tetramethylpiperazine skeleton with respect to 100% by mass of the polymer compound having fluorene skeleton. It is preferable to contain 0.01-0.1 mass%. In such a concentration range, the above-mentioned compound effectively acts on the suppression of luminance reduction.

The present invention is also an organic electroluminescence device having an organic layer in which a light-emitting layer is essential between a pair of electrodes, wherein at least one layer constituting the organic layer includes an antioxidant and / or a light stabilizer and a fluorene skeleton. It is also an organic electroluminescent element containing the high molecular compound which has this.
In this way, by combining an antioxidant and / or a light stabilizer and a polymer compound having a fluorene skeleton in the organic layer, it is possible to sufficiently suppress a decrease in luminance and exhibit excellent durability. Become. Even in such a form, the antioxidant and / or light stabilizer is preferably a hindered amine compound. More preferred are compounds having a 2,2,6,6-tetramethylpiperidine and / or 2,2,6,6-tetramethylpiperazine skeleton.
Moreover, as a preferable form of the said organic electroluminescent element, a light emitting layer is a form containing the high molecular compound which has antioxidant and / or a light stabilizer, and a fluorene skeleton. As a result, element deterioration during element driving caused by deterioration of the light emitting element material itself constituting the light emitting layer is effectively suppressed.

As a configuration of the organic EL element, an organic layer is formed on a substrate at least between an anode, a cathode, and an anode and a cathode, and the organic layer has a laminated structure in which a light emitting layer is essential. The organic layer is preferably configured by further laminating a charge transport layer. In this case, the charge transport layer is laminated between one or both of the anode and the light emitting layer and between the cathode and the light emitting layer. When the organic layer contains a 2,2,6,6-tetramethylpiperidine and / or a compound having a 2,2,6,6-tetramethylpiperazine skeleton, either or both of the light emitting layer and the charge transport layer Although it will contain a compound, it is preferable to make it contain at least in a light emitting layer. In addition, when the organic layer contains a combination of an antioxidant and / or a light stabilizer and a polymer compound having a fluorene skeleton, either or both of the light-emitting layer and the charge transport layer may contain an antioxidant and / or light. A stabilizer and a polymer compound having a fluorene skeleton are contained, but it is preferably contained at least in the light emitting layer.

When an antioxidant and / or a light stabilizer is used in the organic layer in the organic EL element, the reactive material is used to oxidize the organic material constituting the organic layer. Inhibitors and / or light stabilizers can also be incorporated. In this case, a reactive antioxidant and / or a reactive light stabilizer is incorporated into the low molecular material or polymer material constituting the organic layer, particularly the low molecular material or polymer material constituting the light emitting layer. As described above, an embodiment in which a reactive antioxidant and / or a reactive light stabilizer is incorporated in an organic material constituting an organic layer in an organic EL element is also one aspect of the present invention. Even in such a form, a form using a 2,2,6,6-tetramethylpiperidine and / or a compound having a 2,2,6,6-tetramethylpiperazine skeleton as a reactive light stabilizer, or a reactive oxidation A form using an inhibitor and / or a reactive light stabilizer and a polymer compound having a fluorene skeleton is preferred.

The organic EL element has an excellent basic performance as an organic EL element by preventing deterioration of the organic material constituting the organic layer in the electroluminescent element, in particular, deterioration of the light emitting element material itself constituting the light emitting layer. And is suitably applied to display elements, lighting devices, and the like. That is, an organic electroluminescence display device including the organic electroluminescence element of the present invention and an organic electroluminescence lighting device including the organic electroluminescence element of the present invention are also one aspect of the present invention.

By adopting the element structure of the present invention, in the display device, by using three kinds of organic EL elements of blue, red, and green light emission, full color display is possible, and active or passive driving is excellent in visibility and long time. A long-life image display device can be provided.
Moreover, in order to manufacture an organic EL element using a low molecular material, since the deposition is performed in a high vacuum, the operation is complicated and the cost is high, which is not always preferable from the viewpoint of manufacturing. In particular, when used for illumination or the like, the element must be formed in a large area, and thus it must be said that it must be difficult to manufacture by vapor deposition in terms of cost and technology. On the other hand, when the organic EL device of the present invention is used, 2,2,6,6-tetramethylpiperidine and / or 2,2,6,6 are used as the organic material constituting the organic layer, particularly the light emitting device material constituting the light emitting layer. By using a compound having a 6-tetramethylpiperazine skeleton, or using a combination of an antioxidant and / or light stabilizer and a polymer compound having a fluorene skeleton, simple and efficient long-life illumination A device can be provided.
In addition, as a structure of the organic EL element of this invention, a display apparatus, and an illuminating device, what is necessary is the thing provided with the component which these apparatuses have normally and which has the above-mentioned characteristic, It is limited especially in other structures. It is not a thing.

According to the organic EL element of the present invention, when the organic EL element is driven, the deterioration of the element is suppressed by preventing the deterioration of the organic material constituting the organic layer, particularly the light emitting element material itself constituting the light emitting layer. In addition, it is possible to provide a display device, a lighting device, or the like that can sufficiently improve the element life by suppressing a decrease in luminance and has excellent durability. For example, if the organic EL element of the present invention is applied to a display device, it is possible to provide an image display device with excellent visibility and a long lifetime, and if applied to a lighting device, the lifetime is improved and it is manufactured. It is possible to provide a device that has advantageous effects from the viewpoint of the above.

In the following, the best mode for carrying out the present invention will be described in more detail with reference to the drawings and examples, but the present invention is not limited only to these embodiments.

In the organic EL device of the present embodiment, the organic layer between the pair of electrodes may be any layer as long as the light emitting layer is essential, and may be a single layer or a multilayer structure. It is not limited. Such an organic layer is preferably configured by further laminating a charge transport layer, which makes it possible to cause the organic EL element to emit light more efficiently. Further, a charge injection layer can be further laminated. In addition, the order in the case of laminating | stacking these organic layers is not specifically limited.
In the present embodiment, an organic layer containing a compound having a 2,2,6,6-tetramethylpiperidine and / or 2,2,6,6-tetramethylpiperazine skeleton, an antioxidant and / or a light stabilizer. As for, it may be one layer or may be contained in two or more layers. A preferred form is to contain them in at least one of the light emitting layers.

With respect to the substrate configuration of the organic EL element of the present embodiment, preferred embodiments will be exemplified below.
(i) Anode / hole transport layer / light emitting layer / cathode
(ii) Anode / hole injection layer / hole transport layer / light emitting layer / cathode
(iii) Anode / light emitting layer / electron transport layer / cathode
(iv) Anode / light emitting layer / electron transport layer / electron injection layer / cathode
(v) Anode / hole transport layer / light emitting layer / electron transport layer / cathode
(vi) Anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / cathode
(vii) Anode / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode
(viii) Anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode These organic EL devices have a structure in which the layers are laminated in the order shown above on the substrate. is there. In the present embodiment, the display device may be provided with a polarizing plate, and each layer is sealed with a sealing film and a sealing substrate in order to block the influence of moisture and oxygen. Also good.

In the organic EL element, the film forming method of each layer is not particularly limited, and for example, a film forming method usually used in an organic EL element can be used. Specifically, when the organic layer is not patterned as a method for forming the organic layer, a dry process such as a vacuum deposition method; a spin coating method, a blade coating method, a dip coating method, a nozzle coating method, a printing method, etc. However, the present invention is not particularly limited to these. When the organic layer needs to be patterned, for example, a mask vapor deposition method (for example, see JP-A-8-227276) or a transfer method (for example, see JP-A-10-208881). It is possible to use a wet process such as an ink jet method (Japanese Patent Laid-Open No. 10-12377), a printing method, a discharge coating method, or a spray coating method, but the present invention is not particularly limited thereto. Absent.
The environment for forming the organic layer is not particularly limited, but particularly when the organic layer is formed by a wet process, it should be performed in an inert gas in consideration of moisture absorption of the film and material alteration. Is preferred. In addition, after the organic layer is formed, it is preferable to perform heat drying for the purpose of removing the residual solvent. The environment for drying is not particularly limited. For example, it is preferably performed in an inert gas from the viewpoint of preventing alteration such as oxidation of the used organic material. More preferably, it is performed under reduced pressure. Thereby, it becomes possible to remove a residual solvent more effectively.

In the organic EL element, the electrode forming method is not particularly limited. For example, a dry process such as a vapor deposition method, an EB method, an MBE method, or a sputtering method; a wet process such as a spin coating method, a printing method, or an ink jet method is used. Is possible.
(1) Substrate, (2) Electrode, (3) Light emitting layer, (4) Charge injection layer, (5) Charge transport layer, (6) Polarizing plate, (7) The structure of the sealing film and the sealing substrate will be described, and examples and comparative examples will be shown.

1. Substrate As the substrate that can be used in the present embodiment, an insulating substrate is usually used. For example, a substrate made of an inorganic material such as glass or quartz, a plastic material such as polyethylene terephthalate, or a material such as ceramics such as alumina; A substrate in which a metal substrate such as aluminum or iron is coated with an insulator such as SiO ₂ or an organic insulating material; a substrate in which the surface of a metal substrate such as aluminum is subjected to insulation treatment by a method such as anodic oxidation, etc. It is not limited to these.
As a substrate configuration, a switching element such as a thin film transistor may be formed on the substrate. In order to form a thin film transistor using a polysilicon TFT formed by a low temperature process, it is preferable to use a substrate that does not melt at a temperature of 500 ° C. or less and does not cause distortion. In order to form a thin film transistor using a polysilicon TFT formed by a high temperature process, it is preferable to use a substrate that does not melt at a temperature of 1000 ° C. or less and does not cause distortion.

2. Electrode As an electrode of the present embodiment, an electrode material that can be usually used for an organic EL element may be used, but it is not particularly limited. As an anode, a metal having a high work function (Au, Pt, Ni, etc.) is used for the purpose of efficiently injecting holes into the organic layer, or a transparent electrode (ITO, IDIXO) for the purpose of extracting emitted light to the outside. , SnO ₂ or the like) is preferably used. As a cathode, an electrode (Ca / Al, Ce / Al, Cs / Al, Ba / Al, etc.) laminated with a low work function metal and a stable metal for the purpose of efficiently injecting electrons into the organic layer, work A material containing at least a metal having a low function (Ca: Al alloy, Mg: Ag alloy, Li: Al alloy, etc.), a combination of a thin insulating layer and a metal electrode (LiF / Al, LiF / Ca / Al, BaF) ₂ / Ba / Al, etc.), or for the purpose of extracting emitted light to the outside, a transparent electrode containing a metal having a low work function (ITO: Cs, IDIXO: Cs, SnO ₂ : Cs, etc.), transparent electrode and a laminate of the low work function metal (Ba / ITO, Ca / IDIXO , Ba / SnO 2 , etc.) are preferable. Among these, it is preferable to use a Ba / Al cathode in which Al is laminated on Ba. These materials can use a dry process such as an evaporation method, an EB method, an MBE method, a sputtering method, or a wet process such as a spin coating method, a printing method, or an ink jet method, but this is also particularly limited. It is not something.

3. Light-emitting layer The light-emitting layer (organic light-emitting layer) of the present embodiment can be formed by forming a film using a light-emitting material, and may be a single layer or a multilayer structure. It is not particularly limited.
The organic light emitting layer may be formed by depositing one kind of light emitting material by a dry process or by forming a plurality of light emitting materials by a dry process. In addition, a light emission assisting agent, a hole transport material, an additive (donor, acceptor, etc.), a light emitting dopant, and the like may be contained.
The organic light emitting layer may be formed by a wet process from a light emitting layer forming coating solution. The coating solution for forming the light emitting layer is a solution containing at least a light emitting material, and may contain one kind or many kinds of light emitting materials, in addition to a binding resin, in addition to a leveling agent, a light emission assisting agent, A hole injecting and transporting material, an additive (donor, acceptor, etc.), a luminescent dopant, and the like may be contained.

As a method of adding an antioxidant and / or a light stabilizer such as a compound having 2,2,6,6-tetramethylpiperidine and / or a 2,2,6,6-tetramethylpiperazine skeleton to the light emitting layer, , Depending on the method of forming the light emitting layer. For example, when using a 2,2,6,6-tetramethylpiperidine and / or a compound having a 2,2,6,6-tetramethylpiperazine skeleton as an example, when forming a light emitting layer by a wet process, The compound can be dissolved in a light emitting layer forming coating solution, and the coating solution can be formed using a process such as a spin coating method, a printing method, or an ink jet method. Further, by irradiating the coated light-emitting layer with a laser, a compound having 2,2,6,6-tetramethylpiperidine and / or 2,2,6,6-tetramethylpiperazine skeleton is contained in the light-emitting layer. It is possible to use a method (for example, see JP-A-6-297457).
The same applies to the case where an organic layer other than the light emitting layer contains an antioxidant and / or a light stabilizer such as the above compound, and also contains an antioxidant and / or a light stabilizer other than the above compound. In the case of making it, it can be performed similarly.

The light-emitting material is not particularly limited as long as it is a light-emitting material that can be normally used for an organic EL element, but is preferably selected in consideration of compatibility with an electrode material used for a cathode. Examples of the low-molecular light-emitting material include aromatic dimethylidene compounds such as 4,4′-bis (2,2′-diphenylvinyl) -biphenyl (DPVBi), 5-methyl-2- [2- [4- (5 Oxadiazole compounds such as -methyl-2-benzoxazolyl) phenyl] vinyl] benzoxazole, 3- (4-biphenylyl) -4-phenyl-5-t-butylphenyl-1,2,4-triazole (TAZ) and other triazole derivatives, 1,4-bis (2-methylstyryl) benzene and other styrylbenzene compounds, thiopyrazine dioxide derivatives, benzoquinone derivatives, naphthoquinone derivatives, anthraquinone derivatives, diphenoquinone derivatives, fluorenone derivatives, etc. Fluorescent organic material, azomethine zinc complex, (8-hydroxyquinolinato) aluminum Fluorescent organometallic compounds such as mu complex (Alq3) and the like, and examples of the polymer light emitting material include poly (2-decyloxy-1,4-phenylene) DO-PPP, poly [2,5-bis- [2- (N, N, N-triethylammonium) ethoxy] -1,4-phenyl-alt-1,4-phenylene] dibromide (PPP-NEt3 +), poly [2- (2'-ethylhexyloxy)- 5-methoxy-1,4-phenylenevinylene] (MEH-PPV), poly [5-methoxy- (2-propanoxysulfonide) -1,4-phenylenevinylene] (MPS-PPV), poly [2, 5-bis- (hexyloxy) -1,4-phenylene- (1-cyanovinylene)] (CN-PPV), poly (9,9-dioctylfluorene) (PDAF), police Examples of the precursor of the polymer light emitting material include a PPV precursor, a PNV precursor, and a PPP precursor.

Among the above light-emitting materials, it is preferable to use a π-conjugated polymer material, and such a polymer material contains a polymer compound having a fluorene skeleton represented by polyfluorene or a derivative thereof. It is particularly preferred. In the present embodiment, light represented by a polymer compound having a fluorene skeleton and a compound having a 2,2,6,6-tetramethylpiperidine and / or 2,2,6,6-tetramethylpiperazine skeleton, etc. By combining with the stabilizer, the synergistic effect can sufficiently suppress the decrease in luminance, and the device life can be greatly improved. The light emitting layer contains a 2,2,6,6-tetramethylpiperidine and / or a compound having a 2,2,6,6-tetramethylpiperazine skeleton and a polymer compound having a fluorene skeleton. Is a particularly preferred form.

As the light emitting material, a compound having a hindered amine skeleton represented by 2,2,6,6-tetramethylpiperidine and / or 2,2,6,6-tetramethylpiperazine skeleton is used in the compound. Can do. In this case, the light emitting layer may further contain an antioxidant and / or a light stabilizer such as a hindered amine compound, and may or may not contain a light emitting material. The hindered amine skeleton in the inside can exhibit the effects of the present invention.

As the light emitting layer, as described above, an antioxidant and / or a light stabilizer such as 2,2,6,6-tetramethylpiperidine and / or a compound having a 2,2,6,6-tetramethylpiperazine skeleton. It is preferable to contain. As such an antioxidant and / or light stabilizer, those usually used can be used, for example, phenol compounds, aromatic amine compounds, organic sulfur compounds, organophosphorus compounds, hindered amine compounds. Compounds and the like. Phenol compounds and hindered amine compounds are particularly preferable. More preferred are hindered amine compounds such as 2,2,6,6-tetramethylpiperidine and / or compounds having a 2,2,6,6-tetramethylpiperazine skeleton.

Among these antioxidants and light stabilizers, reactive oxidation such as double bonds can be incorporated into low-molecular compounds and high-molecular compounds that constitute the organic layer. Inhibitors and / or light stabilizers can be used.

Examples of the phenol compound include 2,6-di-tert-butylphenol, 2,4-di-tert-butylphenol, 2-tert-butyl-4-methoxyphenol, 2-tert-butyl-4,6- Di-methylphenol, 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,4,6-tri-tert-butylphenol, 2,6 -Di-tert-butyl-4-hydroxymethylphenol, 2,6-di-tert-butyl-2-dimethylamino-p-cresol, 2,5-di-tert-butylhydroquinone, 2,5-di-tert Amyl hydroquinone, n-octadecyl-3- (3 ′, 5′-di-tert-butyl-4′-hydroxyphenyl) propyl Pionate, 2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-tert-butylanilino) -1,3,5-triazine, phenol substituted with 1-phenylethyl group 1-phenylethyl group and a phenol substituted with a methyl group, 2-tert-butyl-6- (3′-tert-butyl-5′-methyl-2′-hydroxybenzyl) -4-methylphenyl acrylate, 2 , 2'-methylene-bis- (4-methyl-6-tert-butylphenol), 2,2'-methylene-bis- (4-ethyl-6-tert-butylphenol), 2,2'-methylene-bis- (6-cyclohexyl-4-methylphenol), 2,2′-methylene-bis- [6- (1-methylcyclohexyl) -p-cresol], 2, '-Ethylidene-bis- (2,4-di-tert-butylphenol), 2,2'-butylidene-bis- (2-tert-butyl-4-methylphenol), 4,4'-methylene-bis- ( 2,6-di-tert-butylphenol), 4,4'-butylidene-bis- (3-methyl-6-tert-butylphenol), 1,6-hexanediol-bis- [3- (3,5-di -Tert-butyl-4-hydroxyphenyl) -propionate], tri-ethylene glycol-bis- [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) -propionate], N, N'-bis -[3- (3,5-di-tert-butyl-4-hydroxyphenyl) -propionyl] -hydrazine, N, N'-bis- [3- (3,5-di-t ert-butyl-4-hydroxyphenyl) -propionyl] -hexamethylenediamine, 2,2′-thio-bis- (4-methyl-6-tert-butylphenol), 4,4′-thio-bis- (3- Methyl-6-tert-butylphenol), 2,2′-thio-diethylene-bis- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) -propionate], bis [2-tert-butyl -4-methyl-6- (3-tert-butyl-5-methyl-2-hydroxybenzyl) -phenyl] -terephthalate, 1,1,3-tris- (2-methyl-4-hydroxy-5-tert- Butylphenyl) -butane, 1,3,5-trimethyl-2,4,6-tris- (3,5-di-tert-butyl-4-hydroxybenzyl) -benzene Zen, tris (3,5-di-tert-butyl-4-hydroxybenzyl) -isocyanurate, tris [2- (3,5-di-tert-butyl-4-hydroxyhydro-cinnamoyloxy) ethyl] isocyanurate, Tris (4-tert-butyl-2,6-di-methyl-3-hydroxybenzyl) -isocyanurate, tetrakis- [methylene-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] -Methane, calcium bis- [ethyl- (3,5-di-tert-butyl-4-hydroxybenzyl) -phosphate], propyl-3,4,5-tri-hydroxybenzene carbonate, octyl-3,4 , 5-Tri-hydroxybenzene carbonate, dodecyl-3,4,5-tri-hydroxyben Carbonate, 2,2′-methylene-bis- (4-m-ethyl-6-tert-butylphenol), 4,4′-methylene-bis- (2,6-di-tert-butylphenol), 1,1 -Bis- (4-hydroxy-phenyl) -cyclohexane, 1,1,3-tris- (2-methyl-4-hydroxy-5-tert-butylphenyl) -butane, 1,3,5-trimethyl-2, 4,6-Tris- (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, 3,9-bis [1,1, -di-methyl-2- [β- (3-tert-butyl) One type or two or more types such as -4-hydroxy-5-methylphenyl) propionyloxy] ethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane can be used.

Examples of the aromatic amine compound include 4,4′-dioctyl-diphenylamine, diphenylamine substituted with an alkyl group, N, N′-diphenyl-p-phenylenediamine, and N, N′-diaryl-p-phenylene. Diamine, 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline, N-phenyl-N′-isopropyl-p-phenylenediamine, N-phenyl-N′-1,3-dimethylbutyl-p -Phenylenediamine, 2,2,4-trimethyl-1,2-dihydroquinoline polymer, aldol-1-naphthylamine, N-phenyl-2-naphthylamine, N, N'-di-2-naphthyl-p-phenylenediamine 1 type, or 2 or more types, such as these, can be used.

Examples of the organic sulfur compound include dilauryl-3,3′-thiodipropionate, ditridecyl-3,3′-thiodipropionate, dimyristyl-3,3′-thiodipropionate, and distearyl-3. , 3′-methyl-3,3′-thiodipropionate, bis [2-methyl-4- [3-n-alkylthiopropionyloxy] -5-tert-butylphenyl] sulfide, pentaerythrityl-tetrakis- 1 type (s) or 2 or more types, such as (3-lauryl thiopropionate), 2-mercaptobenzimidazole, 2-mercapto-5-methylbenzimidazole, can be used.

Examples of the organic phosphorus compound include tris (isodecyl) phosphite, tris (tridecyl) phosphite, phenyl diisooctyl phosphite, phenyl diisodecyl phosphite, phenyl di (tridecyl) phosphite, diphenyl isooctyl phosphite, and diphenyl. Isodecyl phosphite, diphenyl tridecyl phosphite, phosphorous acid [1,1′-biphenyl-4,4′-diylbistetrakis [2,4-bis- (1,1-dimethylethyl) phenyl]] ester, Triphenyl phosphite, tris (nonylphenyl) phosphite, 4,4′-isopropylidene-diphenol alkyl phosphite, tris (2,4-di-tert-butylphenyl) -phosphite, tris (biphenyl) phosphite The Thearylpentaerythritol diphosphite, di (2,4-di-tert-butylphenyl) pentaerythritol diphosphite, di (nonylphenyl) pentaerythritol diphosphite, phenyl-bisphenol-pentaerythritol diphosphite, tetratri Decyl-4,4′-butylidenebis (3-methyl-6-tert-butylphenol) -diphosphite, hexatridecyl-1,1,3-tris- (2-methyl-4-hydroxy-5-tert-butylphenyl) Butane triphosphite, 3,5-di-tert-butyl-4-hydroxybenzyl phosphate-di-ethyl ester, 9,10-dihydro-9-oxa-10-phosphophenanthracene-10-oxide, sodium bis (4-tert One or two types such as butylphenyl) phosphate, sodium-2,2′-methylene-bis (4,6-di-tert-butylphenyl) phosphate, 1,3-bis (diphenoxyphosphonoxy) -benzene The above can be used.

Examples of the hindered amine compound include phenyl-4-piperidyl carbonate, bis- [2,2,6,6-tetramethyl-4-piperidyl] sebacate, and bis- [N-methyl-2,2,6,6]. -Tetramethyl-4-piperidyl] sebacate, bis- (1,2,2,6,6-pentamethyl-4-piperidyl) -2- (3,5-di-tert-butyl-4-hydroxybenzyl) -2 N-butyl malonate, poly [[6- (1,1,3,3-tetramethylbutyl) imino-1,3,5-triazine-2,4-diyl] [(2,2,6,6 -Tetramethyl-4-piperidyl) imino] hexamethylene [(2,2,6,6-tetramethyl-4-piperidyl) iminol]], tetrakis (2,2,6,6-tetra-methyl-4-piperi L) -1,2,3,4-butane-tetracarboxylate, 1,1 ′-(1,2-ethanediyl) bis (3,3,5,5-tetra-methylpiperazinone), 4-hydroxy -2,2,6,6-tetramethyl-1-piperidineethanol and dimethyl succinate polymer, (2,2,6,6-tetramethyl-4-piperidyl / tridecyl) -1,2,3,4 -Butanetetracarboxylate, (1,2,2,6,6-pentamethyl-4-piperidyl / tridecyl) -1,2,3,4-butanetetracarboxylate, [2,2,6,6-tetramethyl -4-piperidyl / β, β, β ′, β′-tetramethyl-3,9- [2,4,8,10-tetraoxaspiro (5,5) undecane] diethyl] -1,2,3 4-butanetetracarboxylate [1,2,2,6,6-pentamethyl-4-piperidyl / β, β, β ′, β′-tetramethyl-3,9- [2,4,8,10-tetraoxaspiro (5, 5) One or more of undecane] diethyl] -1,2,3,4-butanetetracarboxylate and the like can be used.

Among the hindered amine compounds, it is particularly preferable to use a compound having a 2,2,6,6-tetramethylpiperidine and / or a 2,2,6,6-tetramethylpiperazine skeleton, and for an organic layer such as a light emitting layer. By containing such a compound, the deterioration of the organic layer can be more sufficiently suppressed, and the device life can be greatly improved. Such a compound may be a low-molecular compound or a high-molecular compound. Among the above compounds, the following general formula (1);

Those having a structural unit derived from a compound represented by are particularly preferably used.

When the light emitting layer contains an antioxidant and / or a light stabilizer and a π-conjugated polymer material, the mass ratio is not particularly limited, and the kind of the antioxidant and / or the light stabilizer (for example, Low molecular weight type or high molecular weight type), a combination of an antioxidant and / or a light stabilizer and a π-conjugated polymer material, or the like. For example, a π-conjugated polymer material using a 2,2,6,6-tetramethylpiperidine and / or a compound having a 2,2,6,6-tetramethylpiperazine skeleton as an antioxidant and / or light stabilizer When a polymer compound having a fluorene skeleton is used as 2,4,6,6-tetramethylpiperidine and / or 2,2,6,6-, based on 100% by mass of the polymer compound having a fluorene skeleton. The compound having a tetramethylpiperazine skeleton is preferably 0.001 to 1% by mass. If the amount is less than 0.001% by mass, the effect of the present invention for suppressing a decrease in luminance may not be sufficiently exhibited. If the amount exceeds 1% by mass, the driving voltage becomes too high and the durability is sufficient. There is a risk of not being able to. A more preferable lower limit is 0.01% by mass, and an upper limit is 0.1% by mass.

Examples of the binding resin include polycarbonate and polyester.
The solvent may be any solvent that can dissolve or disperse the light emitting material, and examples thereof include pure water, methanol, ethanol, THF, chloroform, toluene, xylene, and trimethylbenzene. When an ink jet method or the like is used as the film forming method, it is preferable to contain a high boiling point solvent having a high boiling point of 150 ° C. or higher.
The film thickness of the light emitting layer is usually 5 mm to 1 μm, preferably 10 nm to 200 nm. If the thickness of the light emitting layer is less than 10 nm, pinholes may occur. If it exceeds 200 nm, the resistance of the element increases and a high driving voltage may be required.

4). Charge Injection Layer The charge injection layer that can be used in the present embodiment can be formed by forming a film using a charge injection material that can be generally used for an organic EL element, and may be a single layer. The multilayer structure may be used and is not particularly limited. Examples of the charge injection layer include a hole injection layer and an electron injection layer. In such a charge injection layer, at least a charge injection material can be formed by a dry process.
Alternatively, the film may be formed by a wet process from the charge injection layer forming coating solution. The coating solution for forming a charge injection layer is a solution containing at least a charge injection material, and may contain one or more types of injection materials. In addition, a binding resin, a leveling agent, an additive ( Donors, acceptors, etc.) may be contained.

As the hole injection material for forming the hole injection layer, hole injection materials for organic EL and organic photoconductors can be used. However, the hole injection material is not particularly limited, and examples thereof include copper phthalocyanine. (CuPc) and other metal phthalocyanines and phthalocyanines, 4,4 ', 4'-tris (3-methylphenylphenylamino) triphenylamine (m-MTDATA), N, N'-(3-methylphenyl)- Low molecular weight materials such as 1,1'-biphenyl-4,4'-diamine (TPD), polyaniline (PANI), 3,4-polyethylenedioxythiophene / polystyrene sulfonate (PEDOT-PSS), polypyrrole, polypara P represented by phenylene vinylene (PPV) and derivatives thereof, polysilane and derivatives, polysiloxane and derivatives, etc. Conductive polymers.

As the electron injection material for forming the electron injection layer, an electron injection material for organic EL or organic photoconductor can be used, but is not particularly limited thereto. For example, as a low molecular compound, An azole derivative represented by 3- (4-biphenyl) -4-phenyl-5- (4-t-butylphenyl) 1,2,4-triazole, 1,3-bis {[4- (4-diphenylamino] )] Oxadiazole derivatives typified by phenyl-1,3,4-oxadiazol-2-yl} benzene and the like, and high electron affinity materials such as polythiophene are used as polymer electron injection materials. A functional polymer.

Examples of the binding resin include polycarbonate and polyester.
The solvent may be any solvent that can dissolve or disperse the hole injection material, and examples thereof include pure water, methanol, ethanol, THF, chloroform, xylene, and trimethylbenzene.
The film thickness of the charge injection layer is usually 5 to 1 μm, preferably 10 to 200 nm. If the thickness of the charge injection layer is less than 10 nm, pinholes may occur. If it exceeds 200 nm, the resistance of the device increases and a high drive voltage may be required.

5. Charge Transport Layer The charge transport layer that can be used in this embodiment can be formed by forming a film using a charge transport material that can be usually used in an organic EL device, and may be a single layer. The multilayer structure may be used and is not particularly limited. Examples of the charge transport layer include a hole transport layer and an electron transport layer. In such a charge transport layer, at least a charge transport material can be formed by a dry process.
Alternatively, the film may be formed by a wet process from the charge transport layer forming coating solution. The coating solution for forming a charge transport layer is a solution containing at least a charge transport material, may contain one kind or many kinds of transport materials, other polymer materials or binding resins, Leveling agents, additives (donors, acceptors, etc.) and the like may be contained.

Examples of the hole transport material forming the hole transport layer include 4,4′-bis (N-3-methylphenyl-N-phenylamino) biphenyl, 1,3,5-tris (N, N— And diphenylamino) benzene and derivatives thereof.
Examples of the electron transport material forming the electron transport layer include azole derivatives typified by 3- (4-biphenyl) -4-phenyl-5- (4-t-butylphenyl) 1,2,4-triazole. Oxadiazole derivatives represented by 1,3-bis {[4- (4-diphenylamino)] phenyl-1,3,4-oxadiazol-2-yl} benzene.
Examples of the polymer material include polycarbazole, poly (N-vinylcarbazole), polyaniline and derivatives thereof, polythiophene and derivatives thereof, poly (p-phenylene vinylene) and derivatives thereof, and poly (2,5-thienylene vinylene. ) And derivatives thereof, polycarbonate, polysiloxane, polymethyl acrylate, polymethyl methacrylate, polystyrene, vinyl polymers such as polyvinyl chloride, polyethersulfone, and the like.

6). Polarizing plate A polarizing plate that can be used in the present embodiment is preferably a combination of a commonly used linear deflection plate and a 1 / 4λ plate. Thereby, the contrast can be improved.

7). Sealing film, sealing substrate The sealing film or the sealing substrate that can be used in the present embodiment is not particularly limited, and materials and methods used for sealing are usually used in organic EL elements. For example, a method of sealing an inert gas such as nitrogen gas or argon gas with glass, metal or the like, and a method of mixing a hygroscopic agent such as barium oxide in the inert gas, etc. Can do. Alternatively, a sealing film may be formed by directly spin-coating or bonding a resin on the counter electrode. As a result, it is possible to prevent external oxygen and moisture from being mixed into the element, which is effective in improving the life.

An organic EL display device (organic EL display panel) can be formed by the organic EL element of the present embodiment. As a driving method of the organic EL display panel, a normal driving method of the organic EL display panel can be used, but is not particularly limited. For example, passive matrix driving or active matrix driving may be used.
Moreover, various illuminating devices as a light emission source can be formed from the organic EL element of this embodiment.
Examples of light emission sources include 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 sensors Examples include a light source.
Thus, the organic EL element of the present embodiment is suitable as a display device such as various information terminals and as various illumination devices.

Example 1
As shown in FIG. 1, PEDOT is used as a hole injection material on a glass substrate (commercial product, manufactured by Asahi Glass Co., Ltd.) having a pattern of ITO (2) having a thickness of 15 nm on a glass (1) having a length and width of 25 mm and a width of 2 mm. A hole injection layer forming coating solution containing / PSS is spin-coated at 3000 rpm for 50 seconds to form a 50 nm-thick hole injection layer (3), and then heated in high-purity nitrogen at 200 ° C. for 10 minutes. Drying was performed. Here, as the hole injection layer forming coating solution, a solution in which PEDOT / PSS was dissolved in pure water at a solid content of 0.1% by mass was used.
After the hole injection layer (3) is formed, 2,2,6,6-tetramethylpiperidine (ADK STAB LA-7RD, luminescent material) with respect to a 1.0 mass% solution of the luminescent material polyfluorene derivative, A xylene solution containing 0.1% by mass of Asahi Denki Kagaku Kogyo Co., Ltd. was prepared, and this solution was spin-coated at 2000 rpm for 50 seconds to form a light-emitting layer (4) having a film thickness of 70 nm. Baked for 10 minutes.
Next, 10 nm of LiF (5) was deposited at a deposition rate of 0.1 nm / sec on the light emitting layer under a pressure condition of 10 ⁻⁵ Pa, and 20 nm of Ca (6) was deposited at a deposition rate of 0.1 nm / sec, On top of that, Al (7) was deposited to a thickness of 100 nm at a deposition rate of 20 nm / sec to form a cathode, and the device shown in FIG. 1 was fabricated.
Next, in order to eliminate the influence of oxygen and air on the element, sealing was performed using a UV curable resin, avoiding the pixel portion, using sealing glass (commercially available, manufactured by Asahi Glass Co., Ltd.) having a length and width of 20 mm. At that time, the pixel portion was covered with aluminum foil or the like so as not to be deteriorated by UV during resin curing.

(Example 2)
A device was fabricated using the same method as in Example 1, except that a xylene solution in which 0.01% by mass of 2,2,6,6-tetramethylpiperidine was added to the light emitting material was used.

(Comparative Example 1)
As shown in FIG. 1, PEDOT is used as a hole injection material on a glass substrate (commercial product, manufactured by Asahi Glass Co., Ltd.) having a pattern of ITO (2) having a thickness of 15 nm on a glass (1) having a length and width of 25 mm and a width of 2 mm. A hole injection layer forming coating solution containing / PSS is spin-coated at 3000 rpm for 50 seconds to form a 50 nm-thick hole injection layer (3), and then heated in high-purity nitrogen at 200 ° C. for 10 minutes. Drying was performed. Here, as the hole injection layer forming coating solution, a solution in which PEDOT / PSS was dissolved in pure water at a solid content of 0.1% by mass was used.
After forming the hole injection layer (3), a 1.0 mass% solution of the light emitting material polyfluorene derivative was spin-coated at 2000 rpm for 50 seconds to form a light emitting layer (4) having a film thickness of 70 nm, and then 60 ° C. For 10 minutes.
Next, 10 nm of LiF (5) was deposited at a deposition rate of 0.1 nm / sec on the light emitting layer under a pressure condition of 10 ⁻⁵ Pa, and 20 nm of Ca (6) was deposited at a deposition rate of 0.1 nm / sec, On top of that, Al (7) was deposited to a thickness of 100 nm at a deposition rate of 20 nm / sec to form a cathode, and the device shown in FIG. 1 was fabricated.
Next, in order to eliminate the influence of oxygen and air on the element, sealing was performed using a UV curable resin, avoiding the pixel portion, using sealing glass (commercially available, manufactured by Asahi Glass Co., Ltd.) having a length and width of 20 mm. At that time, the pixel portion was covered with aluminum foil or the like so as not to be deteriorated by UV during resin curing.

The luminance half life (au) of the organic EL devices produced in Examples 1 and 2 and Comparative Example 1 was measured. Table 1 shows the results when the luminance half-life of the element of Comparative Example 1 is 1.

As shown in Table 1, with respect to Examples 1 and 2 in which 2,2,6,6-tetramethylpiperidine was added to the light emitting material, both of the elements of Comparative Example 1 using the light emitting material alone were 1. The lifetime is increased by about 5 to 2.5 times, and it has been found that the lifetime of the element is improved by this method.
From Examples 1 and 2, the more preferable lower limit of the most optimal concentration range is 0.01% by mass, and the upper limit is 0.1% by mass.

(Example 3)
As shown in FIG. 2, PEDOT is used as a hole injection material on a glass substrate (commercial product, manufactured by Asahi Glass Co., Ltd.) having a pattern of ITO (2) having a thickness of 15 nm formed on a glass (1) having a length and width of 25 mm and a width of 2 mm. A hole injection layer forming coating solution containing / PSS is spin-coated at 3000 rpm for 50 seconds to form a 50 nm-thick hole injection layer (3), and then heated in high-purity nitrogen at 200 ° C. for 10 minutes. Drying was performed. Here, as the hole injection layer forming coating solution, a solution in which PEDOT / PSS was dissolved in pure water at a solid content of 0.1% by mass was used.
After forming the hole injection layer (3), the following general formula (2) for the luminescent material with respect to the 1.0 mass% solution of the luminescent material polyfluorene derivative;

A xylene solution to which 0.1% by mass of a compound represented by the formula (ADK STAB LA-57 (hereinafter also referred to as “LA-57”), manufactured by Asahi Denki Kagaku Kogyo Co., Ltd.) was added was prepared. Spin coating was performed for 2 seconds to form a light emitting layer (4) having a film thickness of 70 nm, followed by baking at 60 ° C. for 10 minutes.
Next, Ba (8) was deposited to 1 nm at a deposition rate of 0.05 nm / sec on the light emitting layer under a pressure condition of 10 ⁻⁵ Pa, and 100 nm of Al (9) was deposited thereon at a deposition rate of 20 nm / sec. A cathode was formed to produce the device shown in FIG.
Next, in order to eliminate the influence of oxygen and air on the element, sealing was performed using a UV curable resin, avoiding the pixel portion, using sealing glass (commercially available, manufactured by Asahi Glass Co., Ltd.) having a length and width of 20 mm. At that time, the pixel portion was covered with aluminum foil or the like so as not to be deteriorated by UV during resin curing.

Example 4
Instead of the compound represented by the general formula (2), the following general formula (3);

Except that a xylene solution in which 0.1% by mass of the compound represented by the formula (ADK STAB LA-60 (hereinafter also referred to as “LA-60”), manufactured by Asahi Denki Kagaku Kogyo Co., Ltd.) is added to the luminescent material is used. A device was fabricated using the same method as in Example 3.

(Comparative Example 2)
As shown in FIG. 2, PEDOT is used as a hole injection material on a glass substrate (commercial product, manufactured by Asahi Glass Co., Ltd.) having a pattern of ITO (2) having a thickness of 15 nm formed on a glass (1) having a length and width of 25 mm and a width of 2 mm. A hole injection layer forming coating solution containing / PSS is spin-coated at 3000 rpm for 50 seconds to form a 50 nm-thick hole injection layer (3), and then heated in high-purity nitrogen at 200 ° C. for 10 minutes. Drying was performed. Here, as the hole injection layer forming coating solution, a solution in which PEDOT / PSS was dissolved in pure water at a solid content of 0.1% by mass was used.
After forming the hole injection layer (3), a 1.0% by mass solution of the light emitting material polyfluorene derivative was spin-coated at 2000 rpm for 50 seconds to form a light emitting layer (4) having a film thickness of 70 nm, and then 60 ° C. For 10 minutes.
Next, Ba (8) was deposited to 1 nm at a deposition rate of 0.05 nm / sec on the light emitting layer under a pressure condition of 10 ⁻⁵ Pa, and 100 nm of Al (9) was deposited thereon at a deposition rate of 20 nm / sec. A cathode was formed to produce the device shown in FIG.
Next, in order to eliminate the influence of oxygen and air on the element, sealing glass (commercial product, manufactured by Asahi Glass Co., Ltd.) having a length and width of 20 mm was used, and sealing was performed using a UV curable resin, avoiding the pixel portion. At that time, the pixel portion was covered with aluminum foil or the like so as not to be deteriorated by UV during resin curing.

The luminance half-life (au) of the organic EL devices produced in Examples 3 and 4 and Comparative Example 2 was measured. Table 2 shows the results when the luminance half-life of the element of Comparative Example 2 is 1.

As shown in Table 2, when LA-57 was added to the luminescent material (Example 3), the luminance half-life was 1.5 times longer than that of the element of Comparative Example 2 using the luminescent material alone, In the case where LA-60 was added (Example 4), the lifetime was improved by 2.5 times.

It is the schematic which shows the board | substrate structure of the organic EL element produced in Example 1, 2 and the comparative example 1. FIG. It is the schematic which shows the board | substrate structure of the organic EL element produced in Example 3, 4 and the comparative example 2. FIG.

Explanation of symbols

1: Glass 2: ITO
3: Hole injection layer 4: Light emitting layer 5: LiF (cathode)
6: Ca (cathode)
7: Al (cathode)
8: Ba (cathode)
9: Al (cathode)

Claims (11)

An organic electroluminescence device having an organic layer that requires a light emitting layer between a pair of electrodes,
At least one layer constituting the organic layer contains 2,2,6,6-tetramethylpiperidine and / or a compound having a 2,2,6,6-tetramethylpiperazine skeleton. element. The organic light-emitting device according to claim 1, wherein the light emitting layer is composed of a π-conjugated polymer material. The organic electroluminescent element according to claim 2, wherein the π-conjugated polymer material contains a polymer compound having a fluorene skeleton. 2. The organic electroluminescence device according to claim 1, wherein the light emitting layer contains a compound having a 2,2,6,6-tetramethylpiperidine and / or a 2,2,6,6-tetramethylpiperazine skeleton. The organic electroluminescent element as described in any one of -3. The light emitting layer contains 0% of a compound having a 2,2,6,6-tetramethylpiperidine and / or 2,2,6,6-tetramethylpiperazine skeleton with respect to 100% by mass of the polymer compound having a fluorene skeleton. The organic electroluminescence device according to claim 4, wherein the organic electroluminescence device is contained in an amount of 0.01 to 0.1% by mass. An organic electroluminescence device having an organic layer that requires a light emitting layer between a pair of electrodes,
At least one layer constituting the organic layer contains an antioxidant and / or a light stabilizer and a polymer compound having a fluorene skeleton, and an organic electroluminescence device. The organic electroluminescence device according to claim 6, wherein the organic electroluminescence device comprises a light emitting layer containing an antioxidant and a polymer compound having a fluorene skeleton. 8. The organic electroluminescence device according to claim 6, wherein the antioxidant and / or the light stabilizer is a hindered amine compound. The organic electroluminescence device according to claim 1, wherein the organic layer is configured by further laminating a charge transport layer. An organic electroluminescence display device comprising the organic electroluminescence element according to claim 1. An organic electroluminescent lighting device comprising the organic electroluminescent element according to claim 1.

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