JP5575353B2 - Method for manufacturing organic electroluminescence device - Google Patents

Description

  The present invention relates to a method for manufacturing an organic electroluminescence element. More specifically, the present invention relates to a method for manufacturing an organic electroluminescence element, in which an organic electroluminescence element having a multilayer structure is manufactured by a roll-to-roll method using a strip-like flexible support.

In recent years, organic EL elements using organic substances have been promising for use as solid light-emitting inexpensive, large-area full-color display elements and writing light source arrays, and active research and development have been promoted. The organic EL element includes a first electrode formed on the substrate (anode or cathode), and an organic EL layer having an organic functional layer including a light emitting layer laminated thereon was laminated to the light-emitting layer It is a thin film type element having a second electrode (cathode or anode). When a voltage is applied to such an organic EL element, electrons are injected from the cathode and holes are injected from the anode into the organic EL layer. It is known that light is obtained by releasing energy as light when the electrons and holes recombine in the light emitting layer and the energy level returns from the conduction band to the valence band.

As described above, since the organic EL element is a thin film type element, when an organic EL panel in which one or a plurality of organic EL elements are formed on a substrate is used as a surface light source such as a backlight, A device provided with a light source can be easily made thin. In addition, when a display device is configured using an organic EL panel in which a predetermined number of organic EL elements as pixels are formed on a base material as a display panel, the liquid crystal display device has high visibility and no viewing angle dependency. There are advantages that cannot be obtained.

On the other hand, when forming the organic EL layer of the organic EL element, as described in JP-A-9-102393 and JP-A-2002-170676, vapor deposition, sputtering, CVD, PVD, solvent Various methods, such as coating methods using a glass, can be used. Among these methods, manufacturing processes are simplified, manufacturing costs are reduced, workability is improved, flexible large-area elements such as backlights and illumination light sources, etc. It is known that a wet film-forming method such as a coating method is advantageous from the viewpoint of application to a film. For example, Japanese Patent Application Laid-Open No. 2002-170676 describes a method of forming an organic functional layer on a single glass substrate by spin coating. Japanese Patent Application Laid-Open No. 2003-142260 describes a method of sequentially forming an organic functional layer on a single-wafer substrate by an ink jet method. These schemes is limited to raise the production efficiency due to the use of any single wafer substrate as a base material. After forming the various layers constituting the organic EL element on a substrate using a production efficiency can be mentioned property is high roll-shaped substrate from these situations, the production of organic EL element according to the winding roll form A method (roll-to-roll method) is being studied.

For example, a method is known in which a long film in a roll shape is supplied and a light emitting layer is formed on the film while being conveyed by a wet coating method, and then wound into a winding roll shape (for example, a patent) See reference 1.) As a method of manufacturing an organic EL display in which a plastic film is used as a translucent substrate and a cathode, one or a plurality of light emitting layers made of an organic material, and an anode layer are provided on the plastic film, There is known a method in which the patterning of one or a plurality of light-emitting layers and the patterning of the cathode are produced by a roll-to-roll method using a vapor deposition method under vacuum (see, for example, Patent Document 2).

Although the method of manufacturing an organic EL element by the roll-to-roll method described in Patent Document 1 and Patent Document 2 is an excellent method for increasing production efficiency, it has the following drawbacks. The key to practical use and performance improvement of the organic EL element is improved in luminous efficiency, if the light emitting efficiency is Takamare high brightness, so that low power consumption, long life is realized at the same time. In order to increase luminous efficiency, electrons and holes injected from the electrode are efficiently injected into the light emitting layer to form excitons (excitons), and excitons are recombined efficiently in the light emitting layer. It is known that a multilayer structure in which a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, and the like are provided above and below a light emitting layer is being promoted. Further, studies on multilayering are underway from the viewpoint of luminance stability of the light emitting layer and production of white elements. For such multi-layering, the roll-to-roll method described in Patent Document 1 and Patent Document 2 continuously forms the anode layer, the light emitting layer, and the cathode layer, so that the process becomes long and takes an installation place. For this reason, it is difficult to handle multiple layers.

Under these circumstances, it is desired to develop a method for manufacturing an organic EL element that has high productivity, high quality, and multi-layer compatibility without lengthening the manufacturing process.
Japanese Patent Laid-Open No. 10-77467 International Publication No. 01/5194 Pamphlet

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a method for manufacturing an organic EL element that has high productivity, high quality, and can be multilayered without lengthening the manufacturing process. It is.

  The above object of the present invention has been achieved by the following constitution.

1. At least a first electrode (anode layer), a first organic functional layer, a second organic functional layer, a second electrode (cathode layer), and a sealing layer are sequentially laminated on the belt-shaped flexible substrate. One organic electroluminescent element is formed by adding at least a strip-shaped flexible base material supplying step, a first electrode (anode layer) forming step, a first organic functional layer forming step, a second organic functional layer forming step, and a second electrode and (cathode layer) formation process, in the manufacturing method of the organic electroluminescence element produced using the production process and a sealing layer forming process, after the previous SL first electrode (anode layer) formation step, the second After the organic functional layer forming step and after the second electrode (cathode layer) forming step, the base material on which each layer is laminated is wound up and collected in a roll shape, stored in an inert gas atmosphere , and the inert material. The oxygen concentration in the gas atmosphere is 1-1000 a pm, a manufacturing method of an organic electroluminescence element water concentration of the inert gas atmosphere, characterized in 1~1000ppm der Rukoto.

  Without prolonging the manufacturing process, it is possible to provide a method of manufacturing an organic EL element that is highly productive, has high quality, and can handle multiple layers, thereby enabling stable production.

  Embodiments of the present invention will be described with reference to FIGS. 1 and 2, but the present invention is not limited thereto.

  FIG. 1 is a schematic cross-sectional view showing an example of the layer structure of an organic EL element having a multilayer structure.

  In the figure, 1 indicates an organic EL element. The organic EL element 1 includes an anode (first electrode) 102, a hole transport layer (hole injection layer) 103, a light emitting layer 104, an electron injection layer 105, and a cathode (second electrode) on a substrate 101. ) 106, an adhesive layer 107, and a flexible sealing member 108 in this order. In this figure, the hole transport layer (hole injection layer) 103 is a first organic functional layer, and the light emitting layer 104 is a second organic functional layer.

In the organic EL element shown in this figure, a hole injection layer (not shown) may be provided between the anode 102 and the hole transport layer 103. Further, an electron transport layer (not shown) may be provided between the cathode 106, the organic functional layer (light emitting layer) 104, and the electron injection layer 105. In the organic EL element 1, a gas barrier film (not shown) may be provided between the anode 102 and the substrate 101.

  The layer structure of the organic EL element shown in this figure is an example, but the following structure can be given as a layer structure of an organic EL element having another typical multilayer structure.

(1) Base material / anode / light emitting layer / electron transport layer / cathode / sealing layer (2) Base material / anode / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode / sealing layer (3) substrate / anode / hole transport layer (hole injection layer) / light emitting layer / hole blocking layer / electron transport layer / cathode buffer layer (electron injection layer) / cathode / sealing layer (4) substrate / Anode / anode buffer layer (hole injection layer) / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode buffer layer (electron injection layer) / cathode / sealing layer (5) substrate / Anode / hole transport layer / blue light emitting layer / orange light emitting layer / electron transport layer / cathode / sealing layer (6) substrate / anode / hole transport layer / blue light emitting layer / green light emitting layer / red light emitting layer / blue Light emitting layer / cathode / sealing layer (7) Base material / anode / hole transport layer / blue light emitting layer / green light emitting layer / red light emitting layer / blue light emitting layer / green light emitting layer / cathode / sealing layer (8) group Material / Anode / hole transport layer / blue light emitting layer / green light emitting layer / red light emitting layer / blue light emitting layer / green light emitting layer / red light emitting layer / cathode / sealing layer The present invention is an organic having a multilayer structure shown in the figure. The present invention relates to a method for manufacturing an organic EL element including an EL element and manufacturing an organic EL element having a multilayer structure shown in the above (1) to (5) by a roll-to-roll method.

  FIG. 2 is a schematic diagram showing an example of a manufacturing process for manufacturing the organic EL element having the multilayer structure shown in FIG. 1 by a roll-to-roll method.

  In the figure, reference numeral 2 denotes a manufacturing process of the organic EL element. The manufacturing process 2 includes a strip-shaped flexible support supplying process 3, a first organic functional layer forming process 4, a second organic functional layer forming process 5, an electron injection layer forming process 6, and a second electrode forming process 7. And a sealing layer forming step 8.

  The strip-shaped flexible support supply process 3 includes a feeding process 301 and a cleaning process 302. In the feeding process 301, the first electrode (anode layer) is already formed, wound around the winding core, and fed out from the roll-shaped flexible support 301b as a strip-shaped flexible support 301a. In addition, the roll-shaped strip | belt-shaped flexible support body 301b uses what was stored in the inert gas atmosphere. By storing in an inert gas atmosphere, oxidation of the first electrode due to oxygen can be prevented, and the performance of the first electrode is maintained. When the moisture content of the support exceeds 0.2%, the organic layer formed on the first electrode is agglomerated and crystallized to deteriorate the device, resulting in degradation of light emission performance (luminance, efficiency, lifetime, etc.) In consideration of generation of dark spots (sites that do not emit light) due to oxidation of the organic layer by oxygen, the oxygen concentration in the inert gas atmosphere is preferably 1 to 1000 ppm, and the water concentration is 1 to 1000 ppm. It is preferable that Until processing is performed in the first organic functional layer forming process 4 which is the next process, the storage period in the inert gas atmosphere is within 3 months in consideration of the performance of the first electrode (anode layer), the process inventory, etc. preferable. A barrier layer may be provided under the first electrode formed on the roll-shaped flexible support 301b.

In the cleaning step 302, the first electrode (anode layer) (not shown) of the strip-shaped flexible support 301a sent from the strip-shaped flexible support supply step 3 before applying the organic functional layer forming coating solution. A cleaning surface modification treatment step 302a for cleaning and modifying the surface and a first static elimination treatment step 302b are provided. The cleaning surface modification process 302a is provided with a low-pressure mercury lamp, an excimer lamp, a plasma cleaning apparatus, and the like. As conditions for the cleaning surface modification treatment using a low-pressure mercury lamp, for example, a cleaning surface modification treatment is performed by irradiating a low-pressure mercury lamp with a wavelength of 184.2 nm at an irradiation intensity of 5 to ²⁰ mW / cm ² and a distance of 5 to 15 mm. Conditions are mentioned. For example, atmospheric pressure plasma is preferably used as the condition for the cleaning surface modification treatment by the plasma cleaning apparatus. Examples of the cleaning conditions include conditions in which a gas containing oxygen of 1 to 5% by volume is used for argon gas, and the cleaning surface modification treatment is performed at a frequency of 100 KHz to 150 MHz, a voltage of 10 V to 10 KV, and an irradiation distance of 5 to 20 mm.

  The first charge removal treatment step 302b is provided with charge removal treatment means such as a light irradiation method and a corona discharge method, and can be appropriately selected from these as required. The light irradiation type generates weak ions, and the corona discharge type generates air ions by corona discharge. The air ions are attracted to the charged object to compensate for the opposite polarity charge and neutralize static electricity. A static eliminator using corona discharge or a static eliminator using soft X-rays can be used. The first static elimination processing means removes the charging of the belt-like flexible support 301a, thereby preventing the adhesion of dust and dielectric breakdown, thereby improving the device yield.

  The first organic functional layer forming step 4 includes a first application step 401, a first drying step 402, and a second charge removal treatment step 403. In the first application step 401, a backup roll 401a holding the strip-shaped flexible support 301a and a coating liquid for forming the first organic functional layer are applied to the strip-shaped flexible support 301a held by the backup roll 401a. 1 wet coater 401b. In the drawing, the first organic functional layer indicates a hole transport layer, and the first organic functional layer forming coating solution indicates a hole transport layer forming coating solution.

  The first drying step 402 is a first organic functional layer forming coating (hole transporting layer forming coating) formed on the first electrode (anode layer) (not shown) on the strip-shaped flexible support 301a. ) It has a first drying device 402a for removing the solvent a. It is preferable that the 1st drying apparatus 402a has the heat processing part 402b.

  The second charge removal processing step 403 includes second charge removal processing means for removing charge from the formed first organic functional layer b, and is the same charge removal treatment means as the first charge removal processing means.

  The second organic functional layer formation step 5 includes a second coating step 501, a second drying step 502, a second charge removal treatment step 503, and a first recovery step 504. The second coating step 501 is formed on the backup roll 501a holding the strip-shaped flexible support 301a formed up to the first organic functional layer b, and on the strip-shaped flexible support 301a held by the backup roll 501a. And a second wet coater 501b that coats the second organic functional layer forming coating solution on the first organic functional layer b. In addition, in this figure, the 2nd organic functional layer shows a light emitting layer, and the coating liquid for 2nd organic functional layer formation shows the coating liquid for light emitting layer formation.

  The 2nd drying process 502 has the 2nd drying apparatus 502a which removes the solvent of the coating film for 2nd organic functional layer formation (coating film for light emitting layer formation) c formed on the 1st organic functional layer b. Yes. It is preferable that the 2nd drying apparatus 502a has the heat processing part 502b.

  The second charge removal processing step 503 has second charge removal processing means for removing charge from the formed second organic functional layer (light emitting layer) d, and is the same charge removal treatment means as the first charge removal treatment means.

  The first recovery step 504 includes a winding device (not shown), winds a strip-shaped flexible support 301a on which a second organic functional layer (light emitting layer) d is formed around a winding core, and allows a roll-shaped strip It collect | recovers as the flexible support body 301c. The recovered roll-shaped strip-like flexible support 301c is stored in an inert gas atmosphere. By storing in an inert gas atmosphere, it becomes possible to prevent oxidation of the first electrode (anode layer) and the organic layer by oxygen, and the performance of the first electrode (anode layer) and the organic layer is maintained. The Considering the degradation of light emitting performance (brightness, efficiency, lifetime, etc.) due to the aggregation and crystallization of the organic layer due to moisture and oxygen, the occurrence of dark spots (sites that do not emit light) due to oxidation of the organic layer, etc. The oxygen concentration in the active gas atmosphere is preferably 1-1000 ppm, and the moisture concentration is preferably 1-1000 ppm. The period of storage in the inert gas atmosphere is 3 months in consideration of the first electrode (anode layer), the performance of the organic layer, the inventory of the process, etc. Is preferred.

  Application and drying in the first organic functional layer forming step 4 and the second organic functional layer forming step 5 can both be performed at atmospheric pressure. This figure shows the case of two steps of the first organic functional layer forming step 4 and the second organic functional layer forming step 5 as the organic functional layer forming step, but it can be increased as necessary. It has become. For example, when the light emitting layer is multilayered (for example, blue light emitting layer / orange light emitting layer), the same process as the second organic functional layer forming process 5 shown in FIG. ing.

The electron injection layer forming step 6 includes a material supplying step 601 and an electron injection layer forming device 602. In the supply step 601, the roll-shaped strip-shaped flexible support body 301c collected on the first recovery step (on the strip-shaped flexible support body, the first electrode, the first organic functional layer (hole transport layer), the second organic functional layer (light emitting layer) and is formed) is supplied. In the electron injection layer forming apparatus 602, a first electrode unwound from a supply step 601, the first organic functional layer (hole transport layer), the second organic function layer strip (the light-emitting layer) and is formed An electron injection layer e is formed on the second organic functional layer (light emitting layer) d of the flexible support. Reference numeral 602a denotes a vapor deposition apparatus, and 602b denotes an evaporation source container.

The second electrode formation step 7 includes a second electrode formation device 701 and a second recovery step 702. In the second electrode forming apparatus 701, the second electrode f is formed on the electron injection layer e formed in the electron injection layer forming step 6. Reference numeral 701a denotes a vapor deposition apparatus, and 701b denotes an evaporation source container. After the second electrode f is formed, it is wound around the winding core in the second recovery step 702 and recovered as a roll-like strip-shaped flexible support 301d. The recovered roll-like strip-like flexible support 301d is stored in an inert gas atmosphere. By storing in an inert gas atmosphere, the layers formed performance prevents affected by oxygen is maintained. Moisture and oxygen cause aggregation and crystallization of the organic layer to cause deterioration of the device and degradation of light emission performance (brightness, efficiency, lifetime, etc.), oxidation of the first electrode (anode layer), second electrode, electron injection layer, and organic layer Therefore, considering the generation of dark spots (sites that do not emit light), the oxygen concentration in the inert gas atmosphere is preferably 1-1000 ppm, and the moisture concentration is preferably 1-1000 ppm. The period of storage in an inert gas atmosphere is preferably within 3 months in consideration of the performance maintenance of each formed layer, the inventory of the process, and the like until the next sealing layer forming process 8 is processed.

  The electron injection layer forming step 6 and the second electrode forming step 7 are all under reduced pressure conditions. In this figure, the case where the electron injection layer and the second electrode use a vapor deposition apparatus is shown. However, the method for forming the electron injection layer and the second electrode is not particularly limited. For example, a sputtering method, a reactive sputtering method, A molecular beam epitaxy method, a cluster ion beam method, an ion plating method, a plasma polymerization method, an atmospheric pressure plasma polymerization method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, or the like can be used.

  The sealing layer forming step 8 includes a material supply step 801, a sticking step 802, and a third recovery step 803, and the steps from the supply step 801 to the third recovery step 803 are continuous under atmospheric pressure conditions. It is supposed to be done. In the supply step 801, the roll-shaped strip-shaped flexible support 301d recovered in the second recovery step is supplied.

  The adhering step 802 includes a coating device 802a for applying an adhesive on the second electrode formed on the belt-like flexible support drawn from the supplying step 801, a sealing film supply unit 802b, It has a pressure-bonding roll 802c and a curing processing unit 802d. Reference numeral 802e denotes a roll-shaped sealing film wound around the winding core.

  The strip-shaped flexible support body 301a fed out from the supply step 801 is an end portion that forms the first electrode and the second electrode external extraction electrode formed on the strip-shaped flexible support body 301a by the coating apparatus 802a. The adhesive is continuously applied around the first electrode and the second electrode. Thereafter, the sealing film is continuously bonded and passed through the pressure roll 802c, whereby the sealing film is continuously bonded onto the cathode layer via an adhesive. After the sealing film 802e1 is pasted through an adhesive, a curing process for pasting the sealing film is performed. An organic EL element protected by the sealing film 802e1 is produced at the stage where the curing process of the adhesive is completed, and is collected as a rolled-up organic EL element 803a on a winding core in a third recovery step 803. After the collection, the sheet-like organic EL device can be used by cutting as necessary. Since the collected roll-shaped organic EL element 803a is bonded to the sealing film, it is not affected by the outside air and can be stored in the air.

  In the present invention, the inert gas refers to nitrogen, carbon dioxide, helium, neon, argon, krypton, xenon, and radon.

As shown in this figure, a first electrode (anode layer), a first organic functional layer, a first organic functional layer, a second electrode (cathode layer), and a sealing layer are sequentially formed on a roll-shaped flexible substrate. The laminated organic EL elements are continuously laminated and manufactured up to the sealing layer, without the first electrode (anode layer) forming step, the second organic functional layer forming step, and the second electrode (cathode layer) forming step. after each step is completed, and collected as a roll, a material obtained by collecting the following effects were obtained by following the manufacturing method stored in an inert gas atmosphere until use.
1) corresponds to high luminous efficiency corresponding multilayer organic EL element is enabled without increasing the manufacturing steps.
2) Semi-finished organic EL elements can be kept in stock, making production management easier.
3) It became possible to hold the organic EL element of the final product as a roll, and it became possible to provide a sheet-like organic EL element having a size that meets the market requirements.

  Hereinafter, the substrate, gas barrier layer, first electrode, hole transport layer, light emitting layer, electron transport layer, second electrode, sealing layer and the like constituting the organic EL device according to the present invention will be described.

  A transparent resin film is mentioned as a strip | belt-shaped flexible base material with which the gas barrier layer concerning this invention and the 1st electrode were already formed. Examples of the resin film include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyethylene, polypropylene, cellophane, cellulose diacetate, cellulose triacetate, cellulose acetate butyrate, cellulose acetate propionate (CAP), Cellulose esters such as cellulose acetate phthalate (TAC), cellulose nitrate or derivatives thereof, polyvinylidene chloride, polyvinyl alcohol, polyethylene vinyl alcohol, syndiotactic polystyrene, polycarbonate, norbornene resin, polymethylpentene, polyether ketone, polyimide , Polyethersulfone (PES), polyphenylene sulfide, polysulfones, Cycloolefin resins such as polyether imide, polyether ketone imide, polyamide, fluororesin, nylon, polymethyl methacrylate, acrylic or polyarylate, Arton (trade name, manufactured by JSR) or Appel (trade name, manufactured by Mitsui Chemicals) Is mentioned.

  Although the thickness of a strip | belt-shaped flexible base material is not specifically limited, Considering handleability, a conveyance property, etc., the range of 0.05-1 mm is preferable. The width of the strip-shaped flexible substrate is not particularly limited, and can be appropriately selected according to the screen size of the electroluminescent display device to be used.

  The band-shaped flexible base material may contain an additive or the like. For example, when an electromagnetic wave shielding transparent plate is attached to the front surface of the plasma display panel, the near infrared ray generated from the front surface of the panel is absorbed. In order to improve the visibility of the display, it may be colored with a colorant such as a dye or a pigment.

It is preferable that a gas barrier film is formed on the surface of the resin film used as the strip-shaped flexible substrate, if necessary. Examples of the gas barrier film include an inorganic film, an organic film, or a hybrid film of both. As a characteristic of the gas barrier film, the water vapor permeability is preferably 0.01 g / m ² · day · atm or less. Furthermore, a high barrier film having an oxygen permeability of 10 ⁻³ ml / m ² / day or less and a water vapor permeability of 10 ⁻⁵ g / m ² / day or less is preferable.

  As a material for forming the gas barrier film, any material may be used as long as it has a function of suppressing intrusion of elements that cause deterioration of elements such as moisture and oxygen. For example, silicon oxide, silicon dioxide, silicon nitride, or the like can be used. Further, in order to improve the brittleness of the film, it is more preferable to have a laminated structure of these inorganic layers and layers made of organic materials. Although there is no restriction | limiting in particular about the lamination | stacking order of an inorganic layer and an organic layer, It is preferable to laminate | stack both alternately several times. The method for forming the barrier film is not particularly limited. For example, the vacuum deposition method, the sputtering method, the reactive sputtering method, the molecular beam epitaxy method, the cluster ion beam method, the ion plating method, the plasma polymerization method, the atmospheric pressure plasma weighting. A combination method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, and the like can be used, but an atmospheric pressure plasma polymerization method as described in JP-A-2004-68143 is particularly preferable.

As the first electrode, 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 metals such as Au, and conductive transparent materials such as CuI, indium tin oxide (ITO), SnO ₂ , and ZnO. Alternatively, an amorphous material such as IDIXO (In ₂ O ₃ .ZnO) capable of forming a transparent conductive film may be used. For the anode, these electrode materials may be formed into a thin film by a method such as vapor deposition or sputtering, and a pattern having a desired shape may be formed by a photolithography method, or when the pattern accuracy is not required (about 100 μm or more) ), A pattern may be formed through a mask having a desired shape when the electrode material is deposited or sputtered. Or when using the substance which can be apply | coated like an organic electroconductivity compound, wet film-forming methods, such as a printing system and a coating system, can also be used. When light emission is extracted from the anode, the 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, it is usually selected in the range of 10 to 1000 nm, preferably 10 to 200 nm.

  A hole injection layer (anode buffer layer) may be present between the first electrode and the light emitting layer or the hole transport layer. The hole injection layer is a layer provided between the electrode and the organic layer in order to lower the driving voltage and improve the luminance of light emission. “The organic EL element and the forefront of industrialization (November 30, 1998, NTS) The details are described in the second volume, Chapter 2, “Electrode Materials” (pages 123 to 166) of “The Company”. The details of the anode buffer layer (hole injection layer) are described in JP-A-9-45479, JP-A-9-260062, JP-A-8-288069 and the like. As a specific example, copper phthalocyanine is used. Examples thereof include a phthalocyanine buffer layer represented by an oxide, an oxide buffer layer represented by vanadium oxide, an amorphous carbon buffer layer, and a polymer buffer layer using a conductive polymer such as polyaniline (emeraldine) or polythiophene.

  The hole transport layer is made of a hole transport material having a function of transporting holes, and in a broad sense, a hole injection layer and an electron blocking layer are also included in the hole transport layer. The hole transport layer can be provided as a single layer or a plurality of layers. The hole transport material has any one of hole injection or transport and electron barrier properties, and may be either organic or inorganic. For example, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, Examples include stilbene derivatives, silazane derivatives, aniline copolymers, and conductive polymer oligomers, particularly thiophene oligomers.

  The above-mentioned materials can be used as the hole transport material, but it is preferable to use a porphyrin compound, an aromatic tertiary amine compound and a styrylamine compound, particularly an aromatic tertiary amine compound. Representative examples of aromatic tertiary amine compounds and styrylamine compounds include N, N, N ', N'-tetraphenyl-4,4'-diaminophenyl; N, N'-diphenyl-N, N'- Bis (3-methylphenyl)-[1,1′-biphenyl] -4,4′-diamine (TPD); 2,2-bis (4-di-p-tolylaminophenyl) propane; 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane; N, N, N ′, N′-tetra-p-tolyl-4,4′-diaminobiphenyl; 1,1-bis (4-di-p-tolyl) Aminophenyl) -4-phenylcyclohexane; bis (4-dimethylamino-2-methylphenyl) phenylmethane; bis (4-di-p-tolylaminophenyl) phenylmethane; N, N'-diphenyl-N, N ' − (4-methoxyphenyl) -4,4'-diaminobiphenyl; N, N, N ', N'-tetraphenyl-4,4'-diaminodiphenyl ether; 4,4'-bis (diphenylamino) quadriphenyl; N, N, N-tri (p-tolyl) amine; 4- (di-p-tolylamino) -4 '-[4- (di-p-tolylamino) styryl] stilbene; 4-N, N-diphenylamino- (2-diphenylvinyl) benzene; 3-methoxy-4′-N, N-diphenylaminostilbenzene; N-phenylcarbazole, and also two of those described in US Pat. No. 5,061,569. Having a condensed aromatic ring in the molecule, for example, 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPD), JP-A-4-3086 4,4 ', 4 "-tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine in which three triphenylamine units described in Japanese Patent No. 8 are linked in a starburst type ( MTDATA) and the like.

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

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

  Although there is no restriction | limiting in particular about the film thickness of a positive hole transport layer, Usually, 5 nm-about 5 micrometers, Preferably it is 5-200 nm. This hole transport layer may have a single layer structure composed of one or more of the above materials. A hole transport layer having a high p property doped with impurities can also be used. Examples thereof include JP-A-4-297076, JP-A-2000-196140, JP-A-2001-102175, J.A. Appl. Phys. 95, 5773 (2004), and the like. It is preferable to use such a hole transport layer having a high p property because an organic EL element with lower power consumption can be produced.

  The material used for the light emitting layer according to the present invention is not particularly limited. For example, Toray Research Center, Inc. The latest trend of flat panel displays The current state of EL displays and the latest technological trends Various materials as described on pages 228 to 332 Can be mentioned. The light emitting layer according to the present invention preferably contains a known host compound and a known phosphorescent compound (also referred to as a phosphorescent compound) in order to increase the light emission efficiency of the light emitting layer. The host compound is a compound contained in the light-emitting layer, the mass ratio in the layer is 20% or more, and the phosphorescence quantum yield of phosphorescence emission is 0.1 at room temperature (25 ° C.). Is defined as less than a compound. The phosphorescence quantum yield is preferably less than 0.01. A plurality of host compounds may be used in combination. By using a plurality of types of host compounds, it is possible to adjust the movement of charges, and the organic EL element can be made highly efficient. In addition, by using a plurality of phosphorescent compounds, it is possible to mix different light emission, thereby obtaining an arbitrary emission color. White light emission is possible by adjusting the kind of phosphorescent compound and the amount of doping, and can also be applied to illumination and backlight.

  As these host compounds, compounds having a hole transporting ability and an electron transporting ability, preventing emission light from being increased in wavelength, and having a high Tg (glass transition temperature) are preferable. Known host compounds include, for example, JP-A Nos. 2001-257076, 2002-308855, 2001-313179, 2002-319491, 2001-357777, and 2002-334786. Gazette, 2002-8860, 2002-334787, 2002-15871, 2002-334788, 2002-43056, 2002-334789, 2002-75645 2002-338579, 2002-105445, 2002-343568, 2002-141173, 2002-352957, 2002-203683, 2002-363227 2002-231453, 2003-3165, 2002-234888, 2003-27048, 2002-255934, 2002-260861, 2002-280183, Examples thereof include compounds described in 2002-299060, 2002-302516, 2002-305083, 2002-305084, 2002-308837 and the like.

In the case of having a plurality of light-emitting layers, it is preferable that 50% by mass or more of the host compound in each layer is the same compound because it is easy to obtain a uniform film property over the entire organic functional layer. It is more preferable that the phosphorescence emission energy is 2.9 eV or more because it is advantageous in efficiently suppressing energy transfer from the dopant and obtaining high luminance. Phosphorescence emission energy means the peak energy of the 0-0 band of the phosphorescence emission measured by measuring the photoluminescence of a deposited film of 100 nm using a host compound as a base material .

  The host compound has a phosphorescence emission energy of 2.9 eV or more and a Tg of 90 ° C. or more in consideration of deterioration of the organic EL device over time (decrease in luminance and film properties), market needs as a light source, and the like. Preferably there is. That is, in order to satisfy both luminance and durability, it is preferable that phosphorescence emission energy is 2.9 eV or more and Tg is 90 ° C. or more. Tg is more preferably 100 ° C. or higher.

  A phosphorescent compound (phosphorescent compound) is a compound in which light emission from an excited triplet is observed, is a compound that emits phosphorescence at room temperature (25 ° C.), and has a phosphorescence quantum yield of 25. The compound is 0.01 or more at ° C. When used in combination with the host compound described above, an organic EL device with higher luminous efficiency can be obtained.

  The phosphorescent compound according to the present invention preferably has a phosphorescence quantum yield of 0.1 or more. The phosphorescent quantum yield can be measured by the method described in Spectroscopic II, page 398 (1992 version, Maruzen) of Experimental Chemistry Course 4 of the 4th edition. Although the phosphorescence quantum yield in a solution can be measured using various solvents, the phosphorescence quantum yield used in the present invention only needs to achieve the phosphorescence quantum yield in any solvent.

  There are two types of light emission of the phosphorescent compound in principle. One is the recombination of the carriers on the host compound to which carriers are transported, and an excited state of the host compound is generated, and this energy is converted into the phosphorescent compound. The energy transfer type, in which light emission from the phosphorescent compound is obtained by moving to the phosphorescent compound, and the other is that the phosphorescent compound becomes a carrier trap, resulting in recombination of the carriers on the phosphorescent compound and from the phosphorescent compound. Although it is a carrier trap type in which light emission can be obtained, in any case, it is a condition that the excited state energy of the phosphorescent compound is lower than the excited state energy of the host compound.

  The phosphorescent compound can be appropriately selected from known compounds used for the light emitting layer of the organic EL device. The phosphorescent compound is preferably a complex compound containing a group 8-10 metal in the periodic table of elements, more preferably an iridium compound, an osmium compound, or a platinum compound (platinum complex compound), rare earth Of these, iridium compounds are the most preferred.

The organic EL device according to the present invention and the color emitted by the compound are shown in FIG. 4.16 on page 108 of “New Color Science Handbook” (Edited by the Japan Color Society, University of Tokyo Press, 1985). -1000 (manufactured by Konica Minolta Sensing Co., Ltd.) is determined by the color when the result of fitting to the CIE chromaticity coordinates. Further, the white element means that the chromaticity in the CIE 1931 color system at 1000 cd / m ² is X = 0.33 ± 0.07, Y = 0. It is in the region of 33 ± 0.07.

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

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

  The light emitting layer formed by drying is a layer that emits light by recombination of electrons and holes injected from the electrode or electron injection layer and hole transport layer, and the light emitting part is within the layer of the light emitting layer. Even the interface between the light emitting layer and the adjacent layer may be used.

  The electron injection layer is made of a material having a function of transporting electrons and is included in the electron transport layer in a broad sense. The electron injection layer is a layer provided between the electrode and the organic layer for lowering the driving voltage and improving the luminance of the light emission. “Organic EL element and its forefront of industrialization (NST 30, November 30, 1998) Issue) ”, Chapter 2, Chapter 2,“ Electrode Materials ”(pages 123-166). The details of the electron injection layer (cathode buffer layer) are also described in JP-A-6-325871, JP-A-9-17574, JP-A-10-74586, and the like. Specifically, strontium, aluminum, etc. Metal buffer layer typified by lithium, alkali metal compound buffer layer typified by lithium fluoride, alkaline earth metal compound buffer layer typified by magnesium fluoride, oxide buffer layer typified by aluminum oxide, etc. . The buffer layer (injection layer) is preferably a very thin film, and the film thickness is preferably in the range of 0.1 nm to 5 μm although it depends on the material.

  In addition, as an electron transport material (also serving as a hole blocking material) used for the electron transport layer adjacent to the light emitting layer side, it is sufficient if it has a function of transmitting electrons injected from the cathode to the light emitting layer. As a material, any one of conventionally known compounds can be selected and used. For example, nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, carbodiimides, fluorenylidenemethane derivatives, anthraquinodisides. Examples include methane and anthrone derivatives, oxadiazole derivatives and the like. Furthermore, in the above oxadiazole derivatives, thiadiazole derivatives in which the oxygen atom of the oxadiazole ring is substituted with a sulfur atom, and quinoxaline derivatives having a quinoxaline ring known as an electron-withdrawing group can also be used as the electron transport material. Furthermore, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used.

  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 sulfonic acid group can be preferably used as the electron transporting material. Distyrylpyrazine derivatives can also be used as electron transport materials, and inorganic semiconductors such as n-type-Si and n-type-SiC are also used as electron transport materials in the same manner as the hole injection layer and hole transport layer. I can do it. Although there is no restriction | limiting in particular about the film thickness of an electron carrying layer, Usually, 5 nm-about 5 micrometers, Preferably it is 5-200 nm. The electron transport layer may have a single layer structure composed of one or more of the above materials.

  An electron transport layer having a high n property doped with impurities can also be used. Examples thereof include JP-A-4-297076, JP-A-10-270172, JP-A-2000-196140, JP-A-2001-102175, J. Pat. Appl. Phys. 95, 5773 (2004), and the like. It is preferable to use such an electron transport layer having a high n property because an element with lower power consumption can be manufactured. The electron transport layer can also be formed by thinning the electron transport material by a known method such as wet coating or vacuum deposition.

The organic EL device according to the present invention is preferably used in combination with the following method in order to efficiently extract light generated in the light emitting layer. The organic EL element emits light inside a layer having a refractive index higher than that of air (refractive index is about 1.7 to 2.1), and only about 15% to 20% of the light generated in the light emitting layer can be extracted. It is generally said that there is no. This is because the light incident on the interface (the interface between the transparent substrate and air) at the critical angle or more angle θ is and can not be extracted outside the device undergoes total reflection, the transparent electrode or the light emitting layer and the transparent base This is because light undergoes total reflection with the material, and the light is guided through the transparent electrode or the light emitting layer, and as a result, the light escapes in the side surface direction of the element.

As a technique for improving the light extraction efficiency, for example, a method of forming irregularities on the surface of the transparent substrate to prevent total reflection at the interface between the transparent substrate and the air (US Pat. No. 4,774,435). A method for improving efficiency by imparting a light collecting property to a substrate (Japanese Patent Laid-Open No. 63-134795). A method of forming a reflective surface on the side surface of an element (Japanese Patent Laid-Open No. 1-220394). A method of forming an antireflection film by introducing a flat layer having an intermediate refractive index between a substrate and a light emitter (Japanese Patent Laid-Open No. 62-172691). A method of introducing a flat layer having a lower refractive index than the base material between the base material and the light emitter (Japanese Patent Laid-Open No. 2001-202827). There is a method of forming a diffraction grating between any one of the substrate , the transparent electrode layer, and the light emitting layer (including between the substrate and the outside) (Japanese Patent Laid-Open No. 11-283951).

In the present invention, these methods can be used in combination with an organic EL element. However, a method of introducing a flat layer having a lower refractive index than the base material between the base material and the light emitter, or a base material, transparent A method of forming a diffraction grating between any one of the electrode layer and the light emitting layer (including between the substrate and the outside) can be suitably used, and by combining these means, it is further excellent in high luminance or durability. Can be obtained.

When a medium with a low refractive index is formed between the transparent electrode and the transparent substrate with a thickness longer than the wavelength of the light, the light extracted from the transparent electrode has a higher extraction efficiency to the outside as the refractive index of the medium is lower. Become. Examples of the low refractive index layer include aerogel, porous silica, magnesium fluoride, and a fluorine-based polymer. Since the refractive index of the transparent substrate is generally about 1.5 to 1.7, the low refractive index layer preferably has a refractive index of about 1.5 or less. Further, it is preferably 1.35 or less. The thickness of the low refractive index medium is preferably at least twice the wavelength in the medium. This thickness of the low refractive index medium is that electromagnetic waves oozed via evanescent turned about the wavelength of light becomes a film thickness enter into the substrate, effects of the low refractive index layer fades. The method of introducing a diffraction grating into an interface or any medium that causes total reflection is characterized by a high effect of improving light extraction efficiency. This method is generated from the light emitting layer by utilizing the property that the diffraction grating can change the direction of light to a specific direction different from refraction by so-called Bragg diffraction such as first-order diffraction and second-order diffraction. Of the light, the light that cannot go out due to total reflection between layers, etc. is diffracted by introducing a diffraction grating in any layer or medium (inside transparent substrate or transparent electrode) And trying to extract light outside. The introduced diffraction grating desirably has a two-dimensional periodic refractive index. This is because light emitted from the light-emitting layer is randomly generated in all directions, so in a general one-dimensional diffraction grating having a periodic refractive index distribution only in a certain direction, only light traveling in a specific direction is diffracted. The light extraction efficiency does not increase so much. However, by making the refractive index distribution a two-dimensional distribution, light traveling in all directions is diffracted, and light extraction efficiency is increased.

As described above, the position where the diffraction grating is introduced may be in any one of the layers or in the medium (in the transparent substrate or the transparent electrode), but is preferably in the vicinity of the organic light emitting layer where light is generated. At this time, the period of the diffraction grating is preferably about 1/2 to 3 times the wavelength of light in the medium. The arrangement of the diffraction grating is preferably two-dimensionally repeated, such as a square lattice, a triangular lattice, or a honeycomb lattice.

Furthermore, the organic EL device according to the present invention can be processed so as to provide, for example, a structure on the microlens array on the light extraction side of the substrate in order to efficiently extract the light generated in the light emitting layer, or so-called By combining with a condensing sheet, the brightness in a specific direction can be increased by condensing light in a specific direction, for example, the front direction with respect to the element light emitting surface. As an example of the microlens array, quadrangular pyramids having a side of 30 μm and an apex angle of 90 degrees are two-dimensionally arranged on the light extraction side of the substrate . One side is preferably 10 μm to 100 μm. If it becomes smaller than this, the effect of diffraction will generate | occur | produce and color, and if too large, thickness will become thick and is not preferable.

  As the condensing sheet, for example, a sheet that is put into practical use in an LED backlight of a liquid crystal display device can be used. As such a sheet, for example, a brightness enhancement film (BEF) manufactured by Sumitomo 3M Limited can be used. As the shape of the prism sheet, for example, a substrate may be formed with a Δ-shaped stripe having an apex angle of 90 degrees and a pitch of 50 μm, or the apex angle is rounded and the pitch is changed randomly. Other shapes may be used. Moreover, in order to control the light emission angle from a light emitting element, you may use a light-diffusion plate and a film together with a condensing sheet. For example, a diffusion film (light-up) manufactured by Kimoto Co., Ltd. can be used.

As the second electrode, a material having a work function (4 eV or less) metal (referred to as an electron injecting metal), an alloy, an electrically conductive compound, and a mixture thereof as an electrode material is used. Specific examples of such electrode materials include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide (Al ₂ O ₃ ) Mixtures, indium, lithium / aluminum mixtures, rare earth metals and the like. Among these, from the point of durability against electron injection and oxidation, etc., a mixture of an electron injecting metal and a second metal which is a stable metal having a larger work function than this, for example, a magnesium / silver mixture, Suitable are a magnesium / aluminum mixture, a magnesium / indium mixture, an aluminum / aluminum oxide (Al ₂ O ₃ ) mixture, a lithium / aluminum mixture, aluminum and the like. The cathode can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering. The sheet resistance as the cathode is preferably several hundred Ω / □ or less, and the film thickness is usually selected in the range of 10 nm to 5 μm, preferably 50 to 200 nm. In order to transmit the emitted light, if either one of the first electrode (anode) or the second electrode (cathode) of the organic EL element is transparent or translucent, the emission luminance is advantageously improved.

  Moreover, after producing the metal with a thickness of 1 to 20 nm on the second electrode, the conductive transparent material mentioned in the description of the first electrode is produced thereon, so that a transparent or translucent second electrode ( A cathode) can be manufactured, and by applying this, an element in which both the first electrode (anode) and the second electrode (cathode) are transmissive can be manufactured.

The sealing layer according to the present invention may be provided by depositing SiOx, or as a flexible sealing member, a deposition method or a coating method on a support made of a flexible resin film such as polyethylene terephthalate or nylon. It is possible to use a flexible sealing member using a metal foil as a material for forming a barrier layer or a barrier layer. Examples of the barrier layer include metals such as In, Sn, Pb, Au, Cu, Ag, Al, Ti, and Ni, MgO, SiO, SiO ₂ , Al ₂ O ₃ , GeO, NiO, CaO, BaO, and Fe ₂ O _3. , Y ₂ O ₃ , TiO _{2, and} other metal oxide vapor deposited materials. Moreover, as a material of the metal foil, for example, a metal material such as aluminum, copper, or nickel, or an alloy material such as stainless steel or an aluminum alloy can be used, but aluminum is preferable in terms of workability and cost. The film thickness is about 1 to 100 μm, preferably about 10 to 50 μm. In order to facilitate handling during production, a film such as polyethylene terephthalate or nylon may be laminated in advance. When a resin film is used for the flexible sealing member, it is preferable to have a thermoplastic adhesive resin layer on the side in contact with the liquid sealing agent.

The water vapor permeability of the flexible sealing member used in the present invention is preferably 0.01 g / m ² · day or less, and the oxygen permeability is 0.01 ml / m ² · day · atm or less. Preferably there is. The moisture permeability is a value measured mainly by the MOCON method by a method based on the JIS K7129B method (1992), and the oxygen permeability is a value measured mainly by the MOCON method by a method based on the JIS K7126B method (1987). is there. The Young's modulus of the flexible sealing member is 1 × 10 ⁻³ GPa in consideration of adhesion between the flexible sealing member, the first pressure-bonding member, and the second pressure-bonding member and prevention of spreading of the sealing agent. It is 80 GPa and the thickness is preferably 10 μm to 500 μm.

  Hereinafter, although an example is given and the concrete effect of the present invention is shown, the mode of the present invention is not limited to this.

Example 1
(Preparation of strip-shaped flexible support)
A PET having a thickness of 1.1 mm, a width of 100 mm, and a length of 500 m on which a first electrode (anode layer) using ITO (indium tin oxide) was formed was prepared.

(Production of organic EL element)
Using the manufacturing process shown in Figure 2, it is coercive tube under the conditions shown in Table 1, using a band-shaped flexible support having prepare, on the first electrode (anode layer), the first organic function layers (positive a hole transport layer), the second organic function layer (light emitting layer), an electron transport layer, after the second electrode (cathode layer) and the sequential product layer, the flexible sealing member laminated with a roll An organic EL element was fabricated and sample No. 101-116. Each sample No. In producing 101 to 116, the storage condition of the first recovery step is that the oxygen concentration in the inert gas (argon) is 100 ppm and the moisture concentration is 100 ppm in an inert gas (argon) atmosphere for 3 days. The storage conditions in the recovery process were three days in an inert gas (argon) atmosphere having an oxygen concentration of 100 ppm and a water concentration of 100 ppm in the inert gas (argon).

  An organic EL device was prepared under the same conditions except that the roll-shaped flexible support on which the first electrode (anode layer) was formed was stored at 70% humidity and 30 ° C. for 4 days. 117. Further, all the storage in the first recovery step and the second recovery step is performed in the air, and the organic EL elements are manufactured under the same conditions except that the storage days are the same. 118.

<Formation of hole transport layer and light emitting layer>
After forming the hole transport layer-forming coating film on the first electrode layer of the belt-like flexible support prepared in the first organic functional layer forming step shown in FIG. After removing the charge and cooling to the same temperature as the room temperature, a light emitting layer forming coating film is subsequently formed on the hole transport layer formed in the second organic functional layer forming step, and heat treatment is performed to form the light emitting layer. Then, after performing static elimination treatment and cooling to the same temperature as room temperature, it was collected in the form of a winding roll on the core and stored. The cleanliness was measured in accordance with JISB 9920, and was measured in class 5.

  The hole transport layer was formed by applying the following hole transport layer forming coating solution by a wet coating method using an extrusion coater, followed by drying and post-heating treatment. The light emitting layer was formed by applying the following light emitting layer forming coating solution using an extrusion coater, followed by drying and post-heating treatment.

Before applying the coating liquid for forming the hole transport layer, the surface of the belt-like flexible support is subjected to a cleaning surface modification treatment using a low-pressure mercury lamp with a wavelength of 184.9 nm at an irradiation intensity of 15 mW / cm ² and a distance of 10 mm. Carried out. The charge removal treatment was performed using a static eliminator with weak X-rays.

  The coating liquid for forming the hole transport layer was applied so that the thickness after drying was 50 nm. The light emitting layer forming coating solution was applied so that the thickness after drying was 100 nm.

(Application conditions)
The coating temperature for the hole transport layer forming coating solution and the light emitting layer forming coating solution was 25 ° C., and the ambient temperature was 25 ° C. under atmospheric pressure conditions except for the drying device and the heat treatment device.

(Drying and heat treatment conditions)
After applying the hole transport layer forming coating solution, the height of the drying part from the slit nozzle type discharge port to the film forming surface is 100 mm, discharge air velocity is 1 m / s, width air velocity distribution is 5%, and temperature is 100 ° C. After removing the solvent, the back surface heat transfer type heat treatment was subsequently performed at a temperature of 200 ° C. with a heat treatment apparatus to form a hole transport layer.

  After applying the light emitting layer forming coating solution, the drying unit removes the solvent from the slit nozzle type discharge port toward the film forming surface at a height of 100 mm and at a temperature of 60 ° C., and then at the heat treatment unit at a temperature of 220 ° C. Heat treatment was performed to form a light emitting layer.

(Preparation of coating solution for hole transport layer formation)
A solution prepared by diluting polyethylene dioxythiophene / polystyrene sulfonate (PEDOT / PSS, Baytron P AI 4083 manufactured by Bayer) with pure water at 65% and methanol at 5% was prepared as a coating solution for forming a hole transport layer.

(Preparation of light emitting layer forming coating solution)
Preparation of coating solution for forming blue light emitting layer Coating material for forming organic functional layer by dissolving 5% by mass of dopant material Fir (pic) 3 in 1,2-dichloroethane in polyvinylcarbazole (PVK) as a host material. Prepared as.

(Formation of electron transport layer)
In the electron transport layer forming step shown in FIG. 2, a band-shaped flexible support formed up to the light emitting layer is used, and the electron transport layer forming material is formed in the region where the hole transport layer including the light emitting layer is formed. LiF was vapor-deposited with an electron transport layer forming vapor deposition apparatus under a vacuum of 5 × 10 ⁻⁴ Pa using LiF.

(Formation of second electrode)
As a second electrode forming material, a belt-like flexible support having the electron transport layer formed in the second electrode formation step shown in FIG. 2 is used, and the second electrode formation material is formed on the electron transport layer in a direction perpendicular to the first electrode. Al was vapor-deposited with a second electrode forming vapor deposition apparatus under a vacuum of 5 × 10 ⁻⁴ Pa using Al.

(Formation of sealing layer)
In the sealing layer forming step shown in FIG. 2, an ultraviolet curable liquid sealing agent (manufactured by ThreeBond 3124C, manufactured by Three Bond Co., Ltd.) is used as the sealing agent, and the end portions for forming the external extraction electrodes of the first electrode and the second electrode are formed. Except for this, a liquid sealant was applied around the first electrode and the second electrode. The sealing agent was applied so as to have a thickness of 300 μm and a width of 500 μm. Thereafter, a flexible sealing member (resin base material thickness: 100 μm, barrier layer thickness: 300 nm) having a two-layer structure using PEN as the resin base material and silica as the barrier layer is bonded to the sealing layer. Formed.

(Evaluation)
Each prepared sample No. Tables 1 to 118 are cut to form a sheet, and light emission unevenness was tested by the test method shown below. The results of evaluation according to the evaluation rank shown below are shown in Table 1.

Method for testing light emission unevenness Using a KEITHLEY source measure unit type 2400, a direct current voltage was applied to the organic EL element to emit light. With respect to the light-emitting element that emitted light at 200 cd, light emission unevenness was observed with a 50 × microscope.

Evaluation rank of light emission unevenness ◎: 90% or more emit light uniformly ○: 80% or more emit light uniformly △: 70% or more emit light uniformly ×: 50% or more, less than 70% Only uniformly emits light XX: Less than 50% emits uniformly

  Sample No. No. 101 showed a good result of uneven light emission, but there were some problems in maintaining the oxygen concentration. Sample No. No. 109 showed a good result of uneven light emission, but there were some problems in maintaining the moisture concentration. The effectiveness of the present invention was confirmed.

Example 2
(Preparation of strip-shaped flexible support)
A PET having a thickness of 1.1 mm, a width of 100 mm, and a length of 500 m on which a first electrode (anode layer) using the same ITO (indium tin oxide) as in Example 1 was formed was prepared.

(Production of organic EL element)
Using the manufacturing process shown in FIG. 2 and using a strip-like flexible support prepared under the following conditions, a first organic functional layer (hole transport layer) on the first electrode (anode layer), 2 in the process of sequentially laminating an organic functional layer (light emitting layer), an electron transport layer, a second electrode (cathode layer), and a sealing layer to produce an organic EL device (first recovery step shown in FIG. After the storage conditions of the roll-shaped strip-like flexible base material formed up to the light-emitting layer collected in the form of a roll in the state where the light-emitting layer is formed are changed as shown in Table 2, the electron transport layer is formed. The organic EL element is manufactured through the process, the second electrode (cathode layer) forming process, and the sealing layer forming process, and is recovered as a roll-shaped organic EL element in the third recovery process shown in FIG. 201-216. Each sample No. In producing 201 to 216, the storage conditions of the second recovery step were three days in an inert gas (argon) atmosphere having an oxygen concentration of 100 ppm and a water concentration of 100 ppm in the inert gas (argon). The band-like flexible support on which the first electrode (anode layer) using ITO (indium tin oxide) is formed is an inert gas (argon) having an oxygen concentration of 100 ppm and a moisture concentration of 100 ppm in the inert gas (argon). Stored in atmosphere for 10 days.

  The organic EL elements were produced under the same conditions except that the storage in the first recovery step was performed in air and the storage days were the same. 217. In addition, except that the storage in the first recovery step and the second recovery step was performed in the air and the storage days were the same, the organic EL elements were manufactured under the same conditions. 218.

<Formation of hole transport layer and light emitting layer>
The same material as in Example 1 was used, and the hole transport layer and the light emitting layer were formed under the same conditions.

(Formation of electron transport layer)
The same material as in Example 1 was used, and an electron transport layer was formed under the same conditions.

(Formation of second electrode)
The same material as in Example 1 was used, and the second electrode was formed under the same conditions.

(Evaluation)
Each prepared sample No. 201 to 218 are cut into sheets, and the light emission unevenness is tested by the same test method as in Example 1. Table 2 shows the results of evaluation according to the same evaluation rank as in Example 1.

  Sample No. No. 201 shows a favorable result of uneven emission, but there are some problems in maintaining the oxygen concentration. Sample No. No. 209 showed a good result of uneven light emission, but there were some problems in maintaining the moisture concentration. The effectiveness of the present invention was confirmed.

Example 3
(Preparation of strip-shaped flexible support)
A PET having a thickness of 1.1 mm, a width of 100 mm, and a length of 500 m on which a first electrode (anode layer) using the same ITO (indium tin oxide) as in Example 1 was formed was prepared.

(Production of organic EL element)
Using the manufacturing process shown in FIG. 2 and using a strip-like flexible support prepared under the following conditions, a first organic functional layer (hole transport layer) on the first electrode (anode layer), 2 in the process of sequentially stacking an organic functional layer (light emitting layer), an electron transport layer, a second electrode (cathode layer), and a sealing layer to produce an organic EL device (second recovery step shown in FIG. (Recovered in the state where the second electrode is formed) The storage conditions of the roll-shaped strip-shaped flexible base material formed up to the second electrode recovered in the form of a roll are changed and stored as shown in Table 3, and then sealed. An organic EL element is manufactured through a layer forming process, and is recovered as a roll-shaped organic EL element in the third recovery process shown in FIG. 301 to 316. Each sample No. In producing 301 to 316, the storage conditions of the first recovery step were 3 days in an inert gas (argon) atmosphere having an oxygen concentration of 100 ppm and a water concentration of 100 ppm in the inert gas (argon). The band-like flexible support on which the first electrode (anode layer) using ITO (indium tin oxide) is formed is an inert gas (argon) having an oxygen concentration of 100 ppm and a moisture concentration of 100 ppm in the inert gas (argon). Stored in atmosphere for 10 days.

  The organic EL elements were produced under the same conditions except that the second recovery process was stored in air and the storage days were the same. 317. The organic EL elements were manufactured under the same conditions except that the first recovery process and the second recovery process were stored in air and the storage days were the same. 318. Storage of the strip-shaped flexible support on which the first electrode (anode layer) using ITO (indium tin oxide) is formed, the first recovery step, and the second recovery step are performed in the air, and the storage days are the same. An organic EL element was produced under the same conditions except that the comparative sample No. 319.

<Formation of hole transport layer and light emitting layer>
The same material as in Example 1 was used, and the hole transport layer and the light emitting layer were formed under the same conditions.

(Formation of electron transport layer)
The same material as in Example 1 was used, and an electron transport layer was formed under the same conditions.

(Formation of second electrode)
The same material as in Example 1 was used, and the second electrode was formed under the same conditions.

(Evaluation)
Each prepared sample No. Tables 3 to 319 are cut into sheets, and the light emission unevenness is tested by the same test method as in Example 1. Table 3 shows the results of evaluation according to the same evaluation rank as in Example 1.

  Sample No. Although the light emission unevenness 301 showed a good result, there are some problems in maintaining the oxygen concentration. Sample No. 309 shows a favorable result of uneven light emission, but there are some problems in maintaining the moisture concentration. The effectiveness of the present invention was confirmed.

It is a schematic sectional drawing which shows an example of the layer structure of the organic EL element which has a multilayer structure. It is a schematic diagram which shows an example of the manufacturing process which manufactures the organic EL element which has a multilayered structure shown in FIG. 1 by a roll-to-roll system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Organic EL element 101 Base material 102 Anode (1st electrode)
103 Hole transport layer (hole injection layer)
104 Light emitting layer 105 Electron injection layer 106 Cathode (second electrode)
2 Manufacturing Process 3 Band-shaped Flexible Support Supply Process 301b to 301d Roll-shaped Flexible Support 4 First Organic Functional Layer Formation Process 5 Second Organic Functional Layer Formation Process 504 First Recovery Process 6 Electron Injection Layer Formation Process 6
7 Second Electrode Formation Step 702 Second Recovery Step 8 Sealing Layer Formation Step 803 Third Recovery Step 803a Rolled Organic EL Element

Claims (1)

At least a first electrode (anode layer), a first organic functional layer, a second organic functional layer, a second electrode (cathode layer), and a sealing layer are sequentially laminated on the belt-shaped flexible substrate. One organic electroluminescent element is formed by adding at least a strip-shaped flexible base material supplying step, a first electrode (anode layer) forming step, a first organic functional layer forming step, a second organic functional layer forming step, and a second In the manufacturing method of an organic electroluminescence element manufactured using a manufacturing process having an electrode (cathode layer) forming process and a sealing layer forming process,
After pre-Symbol first electrode (anode layer) formation step, after the after and the second electrode of the second organic functional layer forming step (cathode layer) formation step, the substrate obtained by laminating each layer in a roll Rewind and collect, store in inert gas atmosphere ,
The oxygen concentration of the inert gas atmosphere is 1-1000 ppm;
Method of manufacturing an organic electroluminescence element water concentration of the inert gas atmosphere, characterized in 1~1000ppm der Rukoto.

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