JP5574037B2 - Roll-to-roll organic electronics device manufacturing equipment - Google Patents

Description

  The present invention relates to a roll-to-roll organic electronic device manufacturing apparatus. More specifically, the present invention relates to an apparatus for manufacturing an organic electronics element used as a surface light source, a display, a solar cell, or the like, and more particularly, to an apparatus for manufacturing an organic electronics element provided on a flexible substrate such as a plastic film.

  Conventionally, in the formation of an organic layer of an organic electronics element (also referred to as an organic compound layer, a hole injection layer, a hole transport layer, a light emitting layer, a hole blocking layer, an electron transport layer, a hole transport layer, and the like) Various methods such as vapor deposition, sputtering, CVD, PVD, and solvent coating can be used. Among these methods, the manufacturing process can be simplified, the manufacturing cost can be reduced, the workability can be improved, From the viewpoint of application to a flexible large-area element such as a light or an illumination light source, it is known that a wet film forming method such as a coating method is advantageous. For example, Japanese Patent Application Laid-Open No. 2002-170676 describes a method of forming an organic layer on a single glass sheet by spin coating. Japanese Patent Application Laid-Open No. 2003-142260 describes a method of sequentially forming an organic layer on a sheet of film by an inkjet method. Since each of these methods uses a single-wafer film as a film, producing a large-area full-color display element has a drawback that the apparatus is large and the cost is high.

  For this reason, roll-to-roll, which is an inexpensive manufacturing method for organic electroluminescence elements (hereinafter also referred to as organic EL elements) that are expected to be used as solid-state light-emitting large-area full-color display elements and writing light source arrays. A roll manufacturing method has been studied. For example, as a method for producing an organic EL display in which a plastic film is used as a light-transmitting substrate and a cathode, at least one light emitting layer made of an organic material and an anode layer are provided on the plastic film, polystyrene, polymethyl methacrylate A light emitting layer is formed by a coating method using a coating solution in which a low molecular weight light emitting pigment is dispersed or dissolved in a polymer material such as polyvinyl carbazole, or a coating solution in which a polymer material such as a polyphenylene vinylene derivative or a polyalkylfluorene derivative is dissolved. A method of manufacturing is known (see, for example, Patent Document 1).

  On the other hand, organic EL materials include low molecular weight materials and high molecular weight materials. Low molecular weight materials can be purified by sublimation, are easy to purify, can use high-purity organic EL materials, and are extremely excellent in terms of luminous efficiency and lifetime (also referred to as luminous lifetime). However, high-purity polymer materials are difficult to purify and have the demerits that the light emission efficiency and lifetime are deteriorated. Recently, wet film forming methods using low-molecular materials have been studied.

  An important problem in the wet film formation method is removal of the residual solvent after coating. The reason for this is that when the solvent remains in the organic layer, the generation of dark spots, the lifetime, and the light emission efficiency deteriorate, which is one of the factors inferior to the performance of the device manufactured by the vapor deposition process. In general, there are two methods for removing residual solvent: vacuum drying and heat drying, but vacuum drying is one of the merits of wet film formation, so it cannot be manufactured in the atmosphere. There is a problem that it becomes difficult and productivity is inferior. Therefore, the heat drying method is preferable in terms of productivity.

  In order to efficiently perform the heat drying method, it is common to heat to a temperature equal to or higher than the boiling point of the solvent used in the wet film formation, but it is necessary to avoid deterioration of the substrate and the formed organic layer. The temperature has an upper limit and is selected by the system.

  However, in roll-to-roll wet film formation, when heating at 100 ° C. or higher is performed to remove the residual solvent, the luminous efficiency is improved even though the residual solvent can be removed without deterioration of the substrate and the organic layer. The phenomenon that the life is deteriorated has been found, and improvement has been demanded.

JP 2003-77669 A

  The present invention has been made in view of the above problems, and an object thereof is to provide a manufacturing apparatus for manufacturing an organic electronic device having excellent performance stability by roll-to-roll wet coating excellent in productivity. It is in. In particular, it is to provide an organic electroluminescence device manufacturing apparatus with high luminous efficiency and long life.

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

  1. A base material supply device having a roll for feeding out the wound flexible transparent base material, and a base material winding device having a roll for taking up the flexible transparent base material fed from the base material supply device. In an apparatus for manufacturing a roll-to-roll organic electronic device, a transfer tension is applied to the flexible transparent substrate and the flexible transparent substrate is transferred, and at least one organic layer is formed on the transferred transparent transparent substrate. The coating liquid is applied to the conveyed flexible transparent base material to form the organic layer, and the flexible transparent base material on which the organic layer is formed is heated at less than 100 ° C. A heating device, another heating device that heats the flexible transparent substrate on which the organic layer is formed at 100 ° C. or higher, and a tension adjusting device that changes a transport tension applied to the flexible transparent substrate. The tension adjusting device is provided with a front A roll-to-roll organic electronic element that reduces the transport tension applied to a flexible transparent substrate heated by another heating device to be less than the transport tension applied to the flexible transparent substrate heated by the one heating device. manufacturing device.

  2. 2. The roll-to-roll organic electronic device manufacturing apparatus according to claim 1, wherein the tension adjusting device includes one tension cut roll that reduces a transport tension applied to the flexible transparent substrate.

  3. 3. The roll-to-roll organic electronics element according to 2 above, wherein the tension adjusting device includes another tension cut roll that increases a transport tension applied to the flexible transparent base material reduced by the one tension cut roll. manufacturing device.

  According to the present invention, there is provided an organic electronics device manufacturing apparatus with excellent performance stability by roll-to-roll wet coating with excellent productivity. It is possible to provide an organic electronic device manufacturing apparatus capable of manufacturing an electroluminescent device.

(A) is a schematic diagram which shows the fundamental structure of the whole organic EL element, (b) The schematic diagram which shows the structure of the light emitting element part of an organic EL element Conceptual diagram of a sealing step for bonding a sealing substrate with a thermosetting adhesive on a flexible transparent substrate and a step showing a cutting position Conceptual diagram of a sealing process and a cutting process for bonding a sealing base material with a thermosetting adhesive on a flexible transparent base material Schematic diagram showing basic configuration of organic EL element and sealing substrate Schematic showing the manufacturing process of the organic EL device according to the present invention The schematic diagram which shows the manufacturing apparatus of the organic EL element which concerns on this invention Schematic diagram showing an example of the sealing substrate bonding / cutting process according to the present invention

  The inventors of the present invention have studied in detail the influence of heat treatment mainly for removing the residual solvent in the manufacturing process of the organic EL element which is one of the organic electronics elements performed by the wet film forming method.

  Here, as the solvent used for the production of the organic EL device, a solvent having high solubility and which does not re-dissolve the formed lower layer is preferable. For example, ketones such as methyl ethyl ketone and cyclohexano, and fatty acid esters such as ethyl acetate And halogenated hydrocarbons such as dichlorobenzene, aromatic hydrocarbons such as toluene, xylene, mesitylene and cyclohexylbenzene, aliphatic hydrocarbons such as cyclohexane, decalin and dodecane, and organic solvents such as DMF and DMSO. .

  As a result, in the method of manufacturing an organic EL element having a patterned transparent electrode and at least one organic layer formed by roll-to-roll wet coating on a flexible transparent substrate, the roll If the transport tension of the process of heating to 100 ° C. or higher in the two-roll wet coating and drying process is larger than the transport tension of the process of less than 100 ° C., the light emission efficiency decreases and the service life deteriorates. It has been found that when the transport tension of the process of heating to 100 ° C. or higher in the process is made smaller than the transport tension of the process of less than 100 ° C., an organic EL element with high luminous efficiency and a long lifetime can be obtained.

  As described above, in the roll-to-roll wet film formation method, heating at 100 ° C. or higher is unavoidable to remove residual solvent and moisture, but the flexible transparent substrate is heat-treated at a high temperature of 100 ° C. or higher (removal of residual solvent). ) When the transport tension is large, the flexible transparent substrate softens / deforms, and the internal stress increases, and the organic EL structure (the electrode obtained by removing the flexible transparent substrate from the organic EL element) The portion having the organic layer is damaged. As a result, it is presumed that the light emitting efficiency is lowered and the lifetime is deteriorated in the device. Although this damage cannot be evaluated by a dimensional change of a normal base material, it is estimated that a minute strain is generated between an organic layer and an inorganic layer such as a CHC layer.

  On the other hand, if the conveyance tension when heat-treating the flexible transparent substrate at a high temperature of 100 ° C. or higher is reduced, the flexible transparent substrate is less softened and deformed, and the organic EL structure is not easily damaged. It seems that problems such as a decrease in luminous efficiency and inferior life are solved. If the transport tension is reduced in all processes of the wet film formation method, softening and deformation of the flexible transparent substrate will be reduced, but the tension during web running will be insufficient, causing problems such as meandering and derailment, and stable production will be achieved. Since it can not be performed, the feasible manufacturing method divides the drying step into a step of heating at 100 ° C. or higher and a step of heating at a temperature lower than 100 ° C., and the conveyance tension of the step of heating at 100 ° C. or higher is less than 100 ° C. This is smaller than the conveyance tension in the heating step.

  The method for producing an organic electronic device of the present invention can be suitably used particularly as a method for producing an organic EL device.

  The organic EL device produced by the method for producing an organic electronic device of the present invention is excellent in performance such as luminous efficiency and half life of the light emitting device.

  Hereinafter, the present invention, its constituent elements, and the best mode and mode for carrying out the present invention will be described in detail.

<< Outline of Manufacturing Method of Organic Electronics Element >>
The method for producing an organic electronics element of the present invention comprises organic electronics having at least one organic layer formed by roll-to-roll wet coating on a flexible transparent substrate having a patterned transparent electrode. In the element manufacturing method, the roll-to-roll wet coating and drying process is characterized in that the transport tension in the process of heating to 100 ° C. or higher is lower than the transport tension in the process of heating to less than 100 ° C. .

(Roll-to-roll manufacturing)
The roll-to-roll manufacturing has the advantage that production efficiency is improved because continuous production is possible. The roll-to-roll method uses a strip-shaped base material wound around a roll, feeds out the strip-shaped base material, and conveys the organic electronic structure (base material, sealing from the organic electronics element to the base material). A method in which an electrode excluding a base material, a portion having an organic layer) is provided, and a strip-shaped base material having a plurality of organic electronics structures is wound around a roll again, and a strip-shaped base material having a plurality of organic electronics structures is rolled. A method is also included in which, after being rolled up, it is unwound and further processed while being conveyed. In general, a method of continuously processing a product using a band-shaped substrate wound around a roll is also included. This may be superior in terms of manufacturing cost (yield, production space).

(Transport tension)
The heat treatment is performed while applying a tension while transporting the film, and the tension at the time of transport is referred to as transport tension in the present invention. The conveyance tension is preferably about 0.98 to 196 N / m. When the transport tension is less than 0.98 N / m, problems such as meandering and derailment occur during traveling, and sufficient transport cannot be performed. When the conveyance tension exceeds 196 N / m, the flexible transparent substrate is deformed, the internal stress is increased, and the organic EL structure in contact with the substrate is damaged.

  In the process of less than 100 ° C., the base material is less likely to be softened and deformed than in the process of heat treatment (removal of residual solvent) at a high temperature of 100 ° C. or higher, and the organic EL structure in contact with the substrate is less likely to be damaged. In order to prevent meandering, derailment, and the like, the transport tension in the process of less than 100 ° C. is preferably about 100 to 196 N / m, more preferably 150 N / m or more.

  On the other hand, when the transport tension in the process of 100 ° C. or higher is lower than the transport tension in the process of less than 100 ° C., the effect of improving the life and efficiency can be obtained. Further, when the transport tension in the process of 100 ° C. or higher is 0.98 to 98 N / m, a remarkable improvement effect is obtained, and more preferably 50 N / m or less.

  The difference between the transport tension in the process of less than 100 ° C. and the transport tension in the process of 100 ° C. or more is preferably 20 to 180 N / m, more preferably 100 to 180 N / m, and still more preferably 150 N / m or more.

  In order to change the conveyance tension in the process of less than 100 ° C. and the conveyance tension in the process of 100 ° C. or more, it is preferable to provide a tension cut roll.

  In general, a tension adjusting mechanism is generally a nip method between a metal roll and a rubber roll, and is often used in gravure printing or the like. Other methods include a method using a suction roll, a wire suction roll, and a grooved roll.

  However, since the nip method sandwiches the base material with a constant pressure, the effect is certain from the viewpoint of tension cut, but the roll touches the organic layer application surface, so even a small amount of foreign dust can be caught on the surface. This causes undesirable scratches and is not preferable.

  The suction roll is used to cut a tension by preventing a slippage between the roll and the film by perforating numerous fine holes on the surface and sucking the film from the holes to adsorb the film to the suction roll. Unlike the nip method, the roll touches only one side of the film, which is preferable. However, since the film is physically drawn into the hole, the film has numerous fine dimples, but it can be handled depending on the material and thickness of the film. There is also a method called a wire suction roll having a roll structure.

  When lowering the transport tension in the heat treatment step of 100 ° C. or higher, a non-contact flotation heating method (air floating) can be preferably used as the transport method in the heat treatment step in addition to the normal roll transport method.

  The conveyance tension can be measured by attaching a load cell type sensor to both sides of the conveyance roll.

  Hereinafter, as a typical example of a method for manufacturing an organic electronics element, steps in a method for manufacturing an organic EL element that is one of the organic electronics elements will be described with reference to the drawings as appropriate.

<Washing process>: A process of cleaning the substrate by a process that combines wet cleaning, such as rolling out the substrate wound in a roll and immersing it in an ultrasonic cleaning tank, and dry cleaning such as plasma cleaning. It is.

<Step of forming an organic EL structure>: An organic EL structure (light emitting element portion, organic material) comprising electrodes, various organic layers, and the like on a substrate by a known technique such as a vapor deposition method, an ink jet method, a printing method, or a coating method. This is a step of forming an electrode excluding a substrate and a sealing substrate from the EL element, and a portion having an organic layer. In the present invention, in this step, when an organic EL structure is formed on a flexible transparent substrate having a transparent electrode, the conveyance tension in the step of heating to 100 ° C. or higher is the conveyance tension in the step of less than 100 ° C. Make it smaller than the tension.

  FIG. 1 shows a basic configuration of the organic EL element. FIG. 1A is a schematic diagram showing the overall configuration of the organic EL element. The organic EL element 20 includes an organic EL structure (light emitting element portion) 30 and a sealing substrate 50 on a substrate (flexible transparent substrate) 40. FIG.1 (b) is a schematic diagram which shows the structure of the organic electroluminescent structure of an organic electroluminescent element. The organic EL structure 20 includes an aluminum electrode 31, an electron injection layer 32, a light emitting layer 33, a hole transport layer 34, a hole injection layer 35, an ITO electrode 36, and an inorganic film 37. Details of each element constituting the organic EL element will be described later.

<Substrate supply step>: A step of feeding and supplying a roll-shaped substrate provided with the light emitting element.

<Sealing process>: It is a sealing process in which a roll-shaped sealing base material is adhered to the base material with a thermosetting adhesive so as to cover the light emitting element. Details of the sealing substrate and the thermosetting adhesive will be described later.

  In this invention, in this process, a flexible sealing base material is bonded and bonded only on the center part except the electrode extraction part of the organic EL structure on the organic EL structure.

<Cutting step>: A cutting step in which the sealing substrate is cut after bonding.

  FIG. 2 is a conceptual diagram of a process showing a cutting position where cutting is performed after the sealing substrate 50 is bonded to the organic EL structure 30 on the substrate 40 with a thermosetting adhesive. Reference numeral 38 denotes an electrode lead portion. FIG. 3 is a conceptual diagram of a sealing process and a cutting process in which the sealing base material 50 is bonded to the base material 39 on which the organic EL structure 30 has been formed.

  In the present invention, the above-described means makes the organic EL structure less susceptible to damage, and solves problems such as reduction in light emission efficiency and deterioration in life.

  In FIG. 4, the basic structural form of an organic EL element and a sealing base material is shown. 51 is a thermosetting adhesive.

[Basic structure of organic EL element]
Preferred specific examples of the basic layer structure of the organic EL element are shown below.
(I) substrate / anode / light-emitting layer / electron transport layer / cathode (ii) substrate / anode / hole transport layer / light-emitting layer / electron transport layer / cathode (iii) substrate / anode / hole transport layer / light-emitting layer / Hole blocking layer / electron transport layer / cathode (iv) substrate / anode / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode buffer layer / cathode (v) substrate / anode / anode buffer layer / Hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode buffer layer / cathode Here, the light emitting layer preferably contains at least two kinds of light emitting materials having different emission colors. A light emitting layer unit composed of a plurality of light emitting layers may be formed. The hole transport layer also includes a hole injection layer and an electron blocking layer.

(Base material: Substrate)
As a flexible transparent base material (hereinafter also referred to as a substrate, a substrate, a base, a support substrate, a support, etc.) according to the present invention, it is possible to impart flexibility (flexibility) to an organic EL element. A flexible substrate such as a resin film is used. However, metal, glass, quartz, or the like can be partially used as the base material depending on the purpose.

  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 and cellulose nitrate or derivatives thereof, polyvinylidene chloride, polyvinyl alcohol, polyethylene vinyl alcohol, syndiotactic polystyrene, polycarbonate, norbornene resin, polymethylpentene, polyether ketone, polyimide, polyether Sulfone (PES), polyphenylene sulfide, polysulfones, polyether Examples include cycloolefin resins such as luimide, polyether ketone imide, polyamide, fluororesin, nylon, polymethyl methacrylate, acrylic or polyarylate, Arton (trade name, manufactured by JSR) or Apel (trade name, manufactured by Mitsui Chemicals). It is done.

  Among these, polyesters such as polyethylene terephthalate and polyethylene naphthalate are preferable in terms of transparency, durability, and cost.

An inorganic film, an organic film, or a hybrid film of both may be formed on the surface of the resin film, and the water vapor permeability (40 ° C., 90% RH) measured by a method in accordance with JISK 7129-1992. The barrier film is preferably 0.01 g / m ² · day · atm or less, and further has an oxygen permeability (20 ° C., 100% RH) of 10 ⁻³ measured by a method according to JISK 7126-1992. g ^/ m 2 ^/ day or less, preferably water vapor permeability is ¹⁰ -3 ^g / m 2 / day or less of the high barrier film, wherein the water vapor transmission rate, also oxygen permeability any ¹⁰ -5 g / It is more preferable that it is m ² / day or less.

  As a material for forming the barrier film, any material may be used as long as it has a function of suppressing entry of elements that cause deterioration of elements such as moisture and oxygen. For example, silicon oxide, silicon dioxide, silicon nitride, or the like can be used. Furthermore, 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, vacuum deposition, sputtering, reactive sputtering, molecular beam epitaxy, cluster ion beam, ion plating, plasma polymerization, atmospheric pressure plasma polymerization A plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, or the like can be used, but an atmospheric pressure plasma polymerization method as described in JP-A-2004-68143 is particularly preferable.

(Clear hard coat layer)
The clear hard coat layer (CHC layer) will be described. When heating is performed in the organic electronics device manufacturing process, oligomer components that are present in a trace amount in the base film are deposited, resulting in a decrease in light transmittance or contamination of the process, which adversely affects the performance of the organic electronics device. Therefore, it is preferable that a CHC layer is coated on both surfaces of the flexible transparent substrate.

  An actinic radiation curable resin layer is preferably used as the clear hard coat layer. The actinic radiation curable resin layer refers to a layer mainly composed of a resin that cures through a crosslinking reaction or the like by irradiation with actinic rays such as ultraviolet rays or electron beams. As the actinic radiation curable resin, a component containing a monomer having an ethylenically unsaturated double bond is preferably used, and a hard coat layer is formed by curing by irradiation with actinic radiation such as ultraviolet rays or electron beams. Typical examples of the actinic radiation curable resin include an ultraviolet curable resin and an electron beam curable resin, and a resin curable by ultraviolet irradiation is preferable.

  As the ultraviolet curable resin, for example, an ultraviolet curable urethane acrylate resin, an ultraviolet curable polyester acrylate resin, an ultraviolet curable epoxy acrylate resin, an ultraviolet curable polyol acrylate resin, or an ultraviolet curable epoxy resin is preferable. Used.

  The UV curable acrylic urethane resin generally includes 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate (hereinafter referred to as acrylate) in addition to a product obtained by reacting a polyester polyol with an isocyanate monomer or a prepolymer. It can be easily obtained by reacting an acrylate monomer having a hydroxyl group such as 2-hydroxypropyl acrylate. For example, those described in JP-A-59-151110 can be used. For example, a mixture of 100 parts of Unidic 17-806 (manufactured by DIC Corporation) and 1 part of Coronate L (manufactured by Nippon Polyurethane Corporation) is preferably used.

  Examples of UV curable polyester acrylate resins include those which are easily formed when 2-hydroxyethyl acrylate and 2-hydroxy acrylate monomers are generally reacted with polyester polyols. JP-A-59-151112 Can be used.

  Specific examples of the ultraviolet curable epoxy acrylate resin include an epoxy acrylate as an oligomer, a reactive diluent and a photoreaction initiator added to the oligomer, and a reaction. Those described in US Pat. No. 105738 can be used.

  Specific examples of UV curable polyol acrylate resins include trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, alkyl-modified dipentaerythritol pentaacrylate, etc. Can be mentioned.

  Specific examples of the photoreaction initiator of these ultraviolet curable resins include benzoin and its derivatives, acetophenone, benzophenone, hydroxybenzophenone, Michler's ketone, α-amyloxime ester, thioxanthone, and derivatives thereof. You may use with a photosensitizer. The photoinitiator can also be used as a photosensitizer. In addition, when using an epoxy acrylate photoinitiator, a sensitizer such as n-butylamine, triethylamine, or tri-n-butylphosphine can be used. The photoreaction initiator or photosensitizer used in the ultraviolet curable resin composition is 0.1 to 15 parts by weight, preferably 1 to 10 parts by weight, based on 100 parts by weight of the composition.

  Examples of the resin monomer include general monomers such as methyl acrylate, ethyl acrylate, butyl acrylate, benzyl acrylate, cyclohexyl acrylate, vinyl acetate, and styrene as monomers having one unsaturated double bond. In addition, monomers having two or more unsaturated double bonds include ethylene glycol diacrylate, propylene glycol diacrylate, divinylbenzene, 1,4-cyclohexane diacrylate, 1,4-cyclohexyldimethyl adiacrylate, and the above-mentioned trimethylolpropane. Examples thereof include triacrylate and pentaerythritol tetraacryl ester.

  Commercially available UV curable resins that can be used in the present invention include ADEKA OPTMER KR / BY series: KR-400, KR-410, KR-550, KR-566, KR-567, BY-320B (Co., Ltd.) Manufactured by ADEKA); KEIHARD A-101-KK, A-101-WS, C-302, C-401-N, C-501, M-101, M-102, T-102, D-102, NS- 101, FT-102Q8, MAG-1-P20, AG-106, M-101-C (manufactured by Guangei Chemical Co., Ltd.); Seika Beam PHC2210 (S), PHCX-9 (K-3), PHC2213, DP-10 , DP-20, DP-30, P1000, P1100, P1200, P1300, P1400, P1500, P1600, SCR900 (Daiichi Seikagaku Corporation) ); KRM7033, KRM7039, KRM7130, KRM7131, UVECRYL29201, UVECRYL29202 (manufactured by Daicel UCB); RC-5015, RC-5016, RC-5020, RC-5031, RC-5100, RC-5102, RC- 5120, RC-5122, RC-5152, RC-5171, RC-5180, RC-5181 (manufactured by DIC Corporation); 340 clear (manufactured by China Paint Co., Ltd.); Sunrad H-601, RC-750, RC-700, RC-600, RC-500, RC-611, RC-612 (manufactured by Sanyo Chemical Industries); SP -1509, SP-1507 (manufactured by Showa Polymer Co., Ltd.); RCC-15C (manufactured by Grace Japan Co., Ltd.), Aronix M-6100, M-8030, M-8060 (manufactured by Toagosei Co., Ltd.), etc. Can be selected as appropriate.

  Examples of specific compounds include trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, alkyl-modified dipentaerythritol pentaacrylate, and the like. .

  These actinic ray curable resin layers can be coated by a known method such as a gravure coater, a dip coater, a reverse coater, a wire bar coater, a die coater, or an ink jet method.

As a light source for curing an ultraviolet curable resin by a photocuring reaction to form a cured film layer, any light source that generates ultraviolet rays can be used without limitation. For example, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, or the like can be used. Irradiation conditions vary depending on each lamp, but the irradiation amount of active rays is preferably 5 to 150 mJ / cm ² , particularly preferably 20 to 100 mJ / cm ² .

  Moreover, when irradiating actinic radiation, it is preferable to carry out while applying tension | tensile_strength in the conveyance direction of a film, More preferably, it is performing applying tension | tensile_strength also in the width direction. The tension to be applied is preferably 30 to 300 N / m.

  Examples of the organic solvent for the UV curable resin layer composition coating solution include hydrocarbons (toluene, xylene), alcohols (methanol, ethanol, isopropanol, butanol, cyclohexanol), ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone). ), Esters (methyl acetate, ethyl acetate, methyl lactate), glycol ethers, and other organic solvents, or a mixture thereof can be used. Propylene glycol monoalkyl ether (1 to 4 carbon atoms of the alkyl group) or propylene glycol monoalkyl ether acetate ester (1 to 4 carbon atoms of the alkyl group) is 5% by mass or more, more preferably 5 to 80%. It is preferable to use the organic solvent containing at least mass%.

  In addition, it is particularly preferable to add a silicone compound to the ultraviolet curable resin layer composition coating solution. For example, polyether-modified silicone oil is preferably added. The number average molecular weight of the polyether-modified silicone oil is, for example, 1,000 to 100,000, preferably 2,000 to 50,000. When the number average molecular weight is less than 1,000, the coating film is dried. On the contrary, when the number average molecular weight exceeds 100,000, it tends to be difficult to bleed out on the surface of the coating film.

  Examples of commercially available silicone compounds include DKQ8-779 (trade name, manufactured by Dow Corning), SF3771, SF8410, SF8411, SF8419, SF8421, SF8428, SH200, SH510, SH1107, SH3749, SH3771, BX16-034, SH3746, SH3749, SH8400, SH3771M, SH3772M, SH3773M, SH3775M, BY-16-837, BY-16-839, BY-16-869, BY-16-870, BY-16-004, BY-16-891, BY-16 872, BY-16-874, BY22-008M, BY22-012M, FS-1265 (trade name, manufactured by Toray Dow Corning Silicone), KF-101, KF-100T, KF351, KF 52, KF353, KF354, KF355, KF615, KF618, KF945, KF6004, Silicone X-22-945, X22-160AS (above, Shin-Etsu Chemical Co., Ltd. trade name), XF3940, XF3949 (above, Toshiba Silicone trade name) ), Disparon LS-009 (manufactured by Enomoto Kasei Co., Ltd.), Granol 410 (manufactured by Kyoeisha Yushi Chemical Co., Ltd.), TSF4440, TSF4441, TSF4445, TSF4446, TSF4452, TSF4460 (manufactured by GE Toshiba Silicone), BYK-306, BYK- 330, BYK-307, BYK-341, BYK-344, BYK-361 (manufactured by BYK-Japan) L series (for example, L7001, L-7006, L-7604, L-9000) manufactured by Nippon Unicar Co., Ltd. Y Leeds, FZ series (FZ-2203, FZ-2206, FZ-2207) and the like, it is preferably used.

  These components enhance the applicability to the substrate and the lower layer. When added to the outermost surface layer of the laminate, it not only improves the water repellency, oil repellency and antifouling properties of the coating film, but also exhibits an effect on the scratch resistance of the surface. These components are preferably added in a range of 0.01 to 3% by mass with respect to the solid component in the coating solution.

  As a method for applying the ultraviolet curable resin composition coating solution, the above-described methods can be used. The coating amount is suitably 0.1 to 30 μm, preferably 0.5 to 15 μm, as the wet film thickness. The dry film thickness is 0.1 to 20 μm, preferably 1 to 20 μm. Especially preferably, it is 8-20 micrometers.

  The pencil hardness is preferably a hard coat layer of 2H to 8H. Especially preferably, it is 3H-6H. The pencil hardness is determined by JIS-K-5400 using a test pencil specified by JIS-S-6006 after conditioning the prepared hard coat film sample at a temperature of 25 ° C. and a relative humidity of 60% for 2 hours. According to the specified pencil hardness evaluation method, scratching is repeated 10 times with a pencil of each hardness under a load of 1 kg, and the hardness of the hardest pencil with no scratches is recognized.

The ultraviolet curable resin composition is preferably irradiated with ultraviolet rays during or after coating and drying. The irradiation time for obtaining the irradiation dose of the active ray of 5 to 150 mJ / cm ² is from 0.1 seconds to 5 seconds. Minutes are good, and 0.1 to 10 seconds is more preferable from the viewpoint of curing efficiency or work efficiency of the ultraviolet curable resin. Moreover, it is preferable that the illuminance of these active ray irradiation parts is 50-150 mW / m < ² >.

(electrode)
The organic element according to the present invention has at least a first electrode and a second electrode. Usually, one is an anode and the other is a cathode. The preferred anode and cathode configurations are described below.

<anode>
As the anode in the organic EL element, an electrode material made of a metal, an alloy, an electrically conductive compound, or a mixture thereof having a high work function (4 eV or more) is preferably used. Specific examples of such electrode substances include metals such as Au, and conductive light-transmitting materials such as CuI, indium tin oxide (ITO), SnO ₂ , and ZnO. Alternatively, a material such as IDIXO (In ₂ O ₃ —ZnO) that can form an amorphous light-transmitting 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. 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.

<cathode>
On the other hand, as the cathode, a material having a low work function (4 eV or less) metal (referred to as an electron injecting metal), an alloy, an electrically conductive compound, and a mixture thereof as an electrode material is used. Specific examples of such electrode materials include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide (Al ₂ O ₃ ) Mixtures, indium, lithium / aluminum mixtures, rare earth metals and the like.

Among these, from the point of durability against electron injection and oxidation, etc., a mixture of an electron injecting metal and a second metal which is a stable metal having a larger work function than this, for example, a magnesium / silver mixture, Magnesium / aluminum mixtures, magnesium / indium mixtures, aluminum / aluminum oxide (Al ₂ O ₃ ) mixtures, lithium / aluminum mixtures, aluminum and the like are preferred. The cathode can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering. The sheet resistance as the cathode is preferably several hundred Ω / □ or less, and the film thickness is usually selected in the range of 10 nm to 5 μm, preferably 50 to 200 nm.

  In order to transmit the emitted light, either the anode or the cathode of the organic EL element is configured to be light transmissive.

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

  The light emitting layer according to the present invention is not particularly limited in its configuration as long as the contained light emitting material satisfies the above requirements.

  Moreover, there may be a plurality of layers having the same emission spectrum and emission maximum wavelength.

  It is preferable to have a non-light emitting intermediate layer between each light emitting layer.

  The total thickness of the light emitting layers in the present invention is preferably in the range of 1 to 100 nm, and more preferably 30 nm or less because a lower driving voltage can be obtained. In addition, the sum total of the film thickness of the light emitting layer as used in the field of this invention is a film thickness also including the said intermediate | middle layer, when a nonluminous intermediate | middle layer exists between light emitting layers.

  The thickness of each light emitting layer is preferably adjusted to a range of 1 to 50 nm, and more preferably adjusted to a range of 1 to 20 nm. There is no particular limitation on the relationship between the film thicknesses of the blue, green and red light emitting layers.

  For the production of the light-emitting layer, a light-emitting material (also referred to as a light-emitting dopant) or a light-emitting host compound (also referred to as a host compound), which will be described later, is used, for example, a vacuum deposition method, a spin coating method, a casting method, an LB method, an inkjet method, or the like. The film can be formed by the thinning method.

  In the present invention, a plurality of light emitting dopants may be mixed in each light emitting layer, and a phosphorescent light emitting dopant and a fluorescent light emitting dopant may be mixed and used in the same light emitting layer.

  In the present invention, the light emitting layer preferably contains a light emitting host compound and a light emitting dopant and emits light from light emitting dopan.

<Luminescent host compound>
As the light emitting host compound contained in the light emitting layer of the organic EL device according to the present invention, a compound having a phosphorescence quantum yield of phosphorescence emission at room temperature (25 ° C.) of less than 0.1 is preferable. More preferably, the phosphorescence quantum yield is less than 0.01. Moreover, it is preferable that the volume ratio in the layer is 50% or more among the compounds contained in a light emitting layer.

  As the host compound, known host compounds may be used alone or in combination of two or more. By using a plurality of types of host compounds, it is possible to adjust the movement of charges, and the organic EL element can be made highly efficient. Moreover, it becomes possible to mix different light emission by using multiple types of luminescent material mentioned later, and can thereby obtain arbitrary luminescent colors.

  The host compound used in the present invention may be a conventionally known low molecular compound or a high molecular compound having a repeating unit, and a low molecular compound having a polymerizable group such as a vinyl group or an epoxy group (polymerizable light emitting host). But it is good.

  As the luminescent host compound used in the organic electronic device of the present invention, it is preferable to use a low molecular compound. Here, the low molecular weight compound represents a compound having a molecular weight of 10,000 or less, preferably a compound having a molecular weight in the range of 100 to 10,000, and more preferably a compound in the range of 100 to 2000.

  As the known host compound, a compound having a hole transporting ability and an electron transporting ability, preventing an increase in the wavelength of light emission, and having a high Tg (glass transition point) is preferable. Here, the glass transition point (Tg) is a value obtained by a method based on JIS-K-7121 using DSC (Differential Scanning Colorimetry).

  Specific examples of known host compounds include compounds described in the following documents. For example, Japanese Patent Application Laid-Open Nos. 2001-257076, 2002-308855, 2001-313179, 2002-319491, 2001-357777, 2002-334786, 2002-8860 Gazette, 2002-334787 gazette, 2002-15871 gazette, 2002-334788 gazette, 2002-43056 gazette, 2002-334789 gazette, 2002-75645 gazette, 2002-338579 gazette. No. 2002-105445, No. 2002-343568, No. 2002-141173, No. 2002-352957, No. 2002-203683, No. 2002-363227, No. 2002-231453. No. 2003-3165, No. 2002-234888, No. 2003-27048, No. 2002-255934, No. 2002-286061, No. 2002-280183, No. 2002-299060. 2002-302516, 2002-305083, 2002-305084, 2002-308837, and the like.

(Luminescent dopant)
Next, the light emitting dopant will be described.

  As the light-emitting dopant according to the present invention, a fluorescent compound (also referred to as a fluorescent compound) or a phosphorescent material (also referred to as a phosphorescent light-emitting material, a phosphorescent compound, a phosphorescent compound, or the like) can be used. From the viewpoint of obtaining an organic EL device with higher luminous efficiency, the above-mentioned host compound is used as a light-emitting dopant (simply referred to as a light-emitting material) used in the light-emitting layer or light-emitting unit of the organic EL device of the present invention. It is preferable to contain a phosphorescence dopant simultaneously with containing.

  The phosphorescent dopant according to the present invention will be described.

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

  The phosphorescence quantum yield can be measured by the method described in Spectroscopic II, page 398 (1992 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, when using a phosphorescent dopant in the present invention, the above phosphorescence quantum yield (0.01 or more) is achieved in any solvent. Just do it.

  There are two types of light emission of phosphorescent dopants in principle. One is the recombination of carriers on the host compound to which carriers are transported to generate an excited state of the host compound, and this energy is transferred to the phosphorescent dopant. Energy transfer type to obtain light emission from the phosphorescent dopant, another is that the phosphorescent dopant becomes a carrier trap, carrier recombination occurs on the phosphorescent dopant, and light emission from the phosphorescent dopant is obtained Although it is a carrier trap type, in any case, it is a condition that the excited state energy of the phosphorescent dopant is lower than the excited state energy of the host compound.

  The phosphorescent dopant can be appropriately selected from known ones used in the light emitting layer of the organic EL device, but 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, a platinum compound (platinum complex compound), or a rare earth complex, and most preferably an iridium compound.

  As the dopant compound used in the organic electronic device of the present invention, it is preferable to use a low molecular compound. Here, the low molecular weight compound represents a compound having a molecular weight of 10,000 or less, preferably a compound having a molecular weight in the range of 100 to 10,000, and more preferably a compound in the range of 100 to 2000.

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

  A fluorescent substance can also be used for the organic EL element according to the present invention. Typical examples of fluorescent emitters (fluorescent dopants) include coumarin dyes, pyran dyes, cyanine dyes, croconium dyes, squalium dyes, oxobenzanthracene dyes, fluorescein dyes, rhodamine dyes, and pyrylium dyes. Examples thereof include dyes, perylene dyes, stilbene dyes, polythiophene dyes, and rare earth complex phosphors.

  Conventionally known dopants can also be used in the present invention. For example, International Publication No. 00/70655 pamphlet, JP-A Nos. 2002-280178, 2001-181616, 2002-280179, 2001 181617, 2002-280180, 2001-247859, 2002-299060, 2001-313178, 2002-302671, 2001-345183, 2002. No. 324679, International Publication No. 02/15645, JP 2002-332291 A, 2002-50484, 2002-332292, 2002-83684, JP 2002-540572, JP 2 No. 02-117978, No. 2002-338588, No. 2002-170684, No. 2002-352960, Pamphlet of International Publication No. 01/93642, JP 2002-50483, No. 2002-1000047. No. 2002-173684, No. 2002-359082, No. 2002-17584, No. 2002-363552, No. 2002-184582, No. 2003-7469, No. 2002-525808. JP-A 2003-7471, JP-T 2002-525833, JP-A 2003-31366, JP-A 2002-226495, JP-A 2002-234894, JP-A 2002-2335076, JP-A 2002-24175 Gazette, 2001-319779, 2001-319780, 2002-62824, 2002-1000047, 2002-203679, 2002-343572, 2002-203678. There are publications and the like.

  In the present invention, at least one light emitting layer may contain two or more kinds of light emitting materials, and the concentration ratio of the light emitting materials in the light emitting layer may vary in the thickness direction of the light emitting layer.

(Middle layer)
In the present invention, it is also preferable to provide a non-light emitting intermediate layer (also referred to as an undoped region) between the light emitting layers.

  Here, the “non-light emitting intermediate layer” is a layer provided between the light emitting layers when having a plurality of light emitting layers.

  The film thickness of the non-light emitting intermediate layer is preferably in the range of 1 to 20 nm, and further in the range of 3 to 10 nm suppresses interaction such as energy transfer between adjacent light emitting layers, and the current of the device This is preferable because a large load is not applied to the voltage characteristics.

  The material used for the non-light emitting intermediate layer may be the same as or different from the host compound of the light emitting layer, but may be the same as the host material of at least one of the adjacent light emitting layers. preferable.

  The non-light-emitting intermediate layer may contain a non-light-emitting layer, a compound common to each light-emitting layer (for example, a host compound), and each common host material (where a common host material is used) In the case where the physicochemical characteristics such as phosphorescence emission energy and glass transition point are the same, or the molecular structure of the host compound is the same, etc.) The injection barrier is reduced, and it is possible to obtain an effect that the injection balance of holes and electrons can be easily maintained even when the voltage (current) is changed. Furthermore, by using a host material having the same physical characteristics or the same molecular structure as that of the host compound contained in each light emitting layer in the undoped light emitting layer, device fabrication, which is a major problem in conventional organic EL device fabrication, is achieved. Complexity can also be eliminated.

  When the organic EL device is used in the present invention, since the host material is responsible for carrier transport, a material having carrier transport capability is preferable. Carrier mobility is used as a physical property representing carrier transport ability, but the carrier mobility of an organic material generally depends on the electric field strength. Since a material having a high electric field strength dependency easily breaks the balance between injection and transport of holes and electrons, it is preferable to use a material having a low electric field strength dependency of mobility for the intermediate layer material and the host material.

  On the other hand, in order to optimally adjust the injection balance of holes and electrons, it is also preferable that the non-light emitting intermediate layer functions as a blocking layer described later, that is, a hole blocking layer and an electron blocking layer. It is done.

(Injection layer: electron injection layer, hole injection layer)
The injection layer is provided as necessary, and there are an electron injection layer and a hole injection layer, and as described above, it exists between the anode and the light emitting layer or the hole transport layer and between the cathode and the light emitting layer or the electron transport layer. May be.

  An injection layer is a layer provided between an electrode and an organic layer in order to reduce drive voltage and improve light emission luminance. “Organic EL element and its forefront of industrialization (issued by NTT Corporation on November 30, 1998) 2), Chapter 2, “Electrode Materials” (pages 123 to 166) in detail, and includes a hole injection layer (anode buffer layer) and an electron injection layer (cathode buffer layer).

  The details of the anode buffer layer (hole injection layer) are described in JP-A-9-45479, JP-A-9-260062, JP-A-8-288069 and the like. As a specific example, copper phthalocyanine is used. Examples thereof include a phthalocyanine buffer layer represented by an oxide, an oxide buffer layer represented by vanadium oxide, an amorphous carbon buffer layer, and a polymer buffer layer using a conductive polymer such as polyaniline (emeraldine) or polythiophene.

  The details of the cathode buffer layer (electron injection layer) are described in JP-A-6-325871, JP-A-9-17574, JP-A-10-74586, and the like. Specifically, strontium, aluminum, etc. Metal buffer layer typified by lithium, alkali metal compound buffer layer typified by lithium fluoride, alkaline earth metal compound buffer layer typified by magnesium fluoride, oxide buffer layer typified by aluminum oxide, etc. . The buffer layer (injection layer) is preferably a very thin film, and the film thickness is preferably in the range of 0.1 nm to 5 μm although it depends on the material.

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

  In a broad sense, the hole blocking layer has a function of an electron transport layer and is composed of a hole blocking material having a function of transporting electrons and having a remarkably small ability to transport holes, while transporting electrons. By blocking holes, the recombination probability of electrons and holes can be improved. Moreover, the structure of the electron carrying layer mentioned later can be used as a hole-blocking layer concerning this invention as needed. The hole blocking layer is preferably provided adjacent to the light emitting layer.

  On the other hand, the electron blocking layer, in a broad sense, has a function of a hole transport layer, and is made of a material having a function of transporting holes while having a remarkably small ability to transport electrons, while transporting holes. By blocking electrons, the probability of recombination of electrons and holes can be improved. Moreover, the structure of the positive hole transport layer mentioned later can be used as an electron blocking layer as needed. The film thickness of the hole blocking layer and the electron transport layer according to the present invention is preferably 3 to 100 nm, and more preferably 5 to 30 nm.

(Hole transport layer)
The hole transport layer is made of a hole transport material having a function of transporting holes, and in a broad sense, a hole injection layer and an electron blocking layer are also included in the hole transport layer. The hole transport layer can be provided as a single layer or a plurality of layers.

  The hole transport material has any one of hole injection or transport and electron barrier properties, and may be either organic or inorganic. For example, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, Examples thereof include stilbene derivatives, silazane derivatives, aniline copolymers, and conductive polymer oligomers, particularly thiophene oligomers.

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

  Representative examples of aromatic tertiary amine compounds and styrylamine compounds include N, N, N ', N'-tetraphenyl-4,4'-diaminophenyl; N, N'-diphenyl-N, N'- Bis (3-methylphenyl)-[1,1′-biphenyl] -4,4′-diamine (TPD); 2,2-bis (4-di-p-tolylaminophenyl) propane; 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane; N, N, N ′, N′-tetra-p-tolyl-4,4′-diaminobiphenyl; 1,1-bis (4-di-p-tolyl) Aminophenyl) -4-phenylcyclohexane; bis (4-dimethylamino-2-methylphenyl) phenylmethane; bis (4-di-p-tolylaminophenyl) phenylmethane; N, N'-diphenyl-N, N ' − (4-methoxyphenyl) -4,4'-diaminobiphenyl; N, N, N ', N'-tetraphenyl-4,4'-diaminodiphenyl ether; 4,4'-bis (diphenylamino) quadriphenyl; N, N, N-tri (p-tolyl) amine; 4- (di-p-tolylamino) -4 '-[4- (di-p-tolylamino) styryl] stilbene; 4-N, N-diphenylamino- (2-diphenylvinyl) benzene; 3-methoxy-4'-N, N-diphenylaminostilbenzene; N-phenylcarbazole, as well as two of those described in US Pat. No. 5,061,569 Having a condensed aromatic ring in the molecule, for example, 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPD), JP-A-4-308 4,4 ', 4 "-tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine in which three triphenylamine units described in Japanese Patent No. 88 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.

  The hole transport layer can be formed by thinning the hole transport material by a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an ink jet method, or an LB method. it can. Although there is no restriction | limiting in particular about the film thickness of a positive hole transport layer, Usually, 5 nm-about 5 micrometers, Preferably it is 5-200 nm. The hole transport layer may have a single layer structure composed of one or more of the above materials.

  Alternatively, a hole transport layer having a high p property doped with impurities can be used. Examples thereof include JP-A-4-297076, JP-A-2000-196140, 2001-102175, J.A. Appl. Phys. 95, 5773 (2004), and the like.

  In the present invention, it is preferable to use a hole transport layer having such a high p property because a device with lower power consumption can be produced.

(Electron transport layer)
The electron transport layer is made of a material having a function of transporting electrons, and in a broad sense, an electron injection layer and a hole blocking layer are also included in the electron transport layer. The electron transport layer can be provided as a single layer or a plurality of layers.

  Conventionally, in the case of a single electron transport layer and a plurality of layers, an electron transport material (also serving as a hole blocking material) used for an electron transport layer adjacent to the light emitting layer on the cathode side is injected from the cathode. As long as it has a function of transferring electrons to the light-emitting layer, any material can be selected and used from among conventionally known compounds. For example, nitro-substituted fluorene derivatives, diphenylquinone derivatives Thiopyrandioxide derivatives, carbodiimides, fluorenylidenemethane derivatives, anthraquinodimethane and anthrone derivatives, oxadiazole derivatives and the like. Furthermore, in the above oxadiazole derivative, a thiadiazole derivative in which the oxygen atom of the oxadiazole ring is substituted with a sulfur atom, and a quinoxaline derivative having a quinoxaline ring known as an electron withdrawing group can also be used as an electron transport material. Furthermore, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used.

In addition, metal complexes of 8-quinolinol derivatives such as tris (8-quinolinol) aluminum (Alq ₃ ), 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), etc., 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 electron transport materials. 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. Further, the distyrylpyrazine derivatives exemplified as the material of the light emitting layer can also be used as the electron transport material, and inorganic semiconductors such as n-type-Si and n-type-SiC can be used as well as the hole injection layer and the hole transport layer. It can be used as an electron transport material.

  The electron transport layer can be formed by thinning the electron transport material by a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an ink jet method, or an LB method. Although there is no restriction | limiting in particular about the film thickness of an electron carrying layer, Usually, 5 nm-about 5 micrometers, Preferably it is 5-200 nm. The electron transport layer may have a single layer structure composed of one or more of the above materials.

  Further, an electron transport layer having a high n property doped with impurities can also be used. Examples thereof include JP-A-4-297076, JP-A-10-270172, JP-A-2000-196140, 2001-102175, J.A. Appl. Phys. 95, 5773 (2004), and the like.

  In the present invention, it is preferable to use an electron transport layer having such a high n property because an element with lower power consumption can be manufactured.

[Method for producing organic EL element]
As an example of the method for producing an organic EL device according to the present invention, a method for producing an organic EL device comprising an anode / hole injection layer / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode will be described. .

  First, a desired electrode material, for example, a thin film made of an anode material is formed on a suitable support substrate by a method such as vapor deposition or sputtering so as to have a film thickness of 1 μm or less, preferably 10 to 200 nm, thereby producing an anode. To do. Next, an organic compound thin film of a hole injection layer, a hole transport layer, a light emitting layer, a hole blocking layer, and an electron transport layer, which are organic EL element materials, is formed thereon.

  As a method for thinning the organic compound thin film, there are a vapor deposition method, a wet process (spin coating method, casting method, ink jet method, printing method) and the like as described above. The method and the printing method are particularly preferable. Further, a different film forming method may be applied for each layer.

  After these layers are applied by a wet process, heat treatment is preferably performed in order to remove residual solvent.

  The heating method may be a heater heating method (infrared heater, halogen heater, panel heater, etc. are placed on or under the film and heated by radiant heat), or zone heating method (heating in a zone where hot air is blown and adjusted to a predetermined temperature) ) In the present invention, the zone heating method is preferable from the viewpoint of uniformity. In the case of the zone heating method, for example, a thermostatic bath can be used. The thermostat may be in any form as long as it can heat-treat the coating film at a set temperature, for example, the entire thermostat may be heated with warm air set at a predetermined temperature. Alternatively, warm air may be blown onto the film, or the inside of the thermostatic chamber may be set to a desired temperature using a heater. The attachment position of such a heating device such as a heater may be attached to any position inside the thermostatic bath as long as the coating film can be uniformly heated. Regarding the temperature distribution inside the thermostatic chamber, the temperature may be increased from the entrance toward the exit, the temperature may be decreased, or the temperature increase and decrease may be repeated. Moreover, a preheating part may be provided before heating, and a cooling part may be provided after heating.

  The heating temperature only needs to be a temperature at which the residual solvent can be removed, and is generally higher than the boiling point of the solvent used for coating. preferable. However, since it is necessary to avoid deterioration of the substrate and the organic layer formed by coating, the temperature has an upper limit and is selected depending on the system. In this invention, since a polyester-type base material is used preferably, 200 degrees C or less is preferable.

  The heat treatment time is preferably 1 to 120 minutes, more preferably 5 to 60 minutes, and further preferably 10 to 30 minutes. By setting the heat treatment time to 1 minute or longer, the residual solvent can be sufficiently removed, and by setting the heat treatment time to 120 minutes or shorter, deterioration of the organic layer due to heating can be suppressed.

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

  The organic EL device can be produced in the order of the cathode, the electron injection layer, the electron transport layer, the light emitting layer, the hole transport layer, the hole injection layer, and the anode by reversing the production order. When a DC voltage is applied to the organic EL device thus obtained, light emission can be observed by applying a voltage of about 2 to 40 V with the positive polarity of the anode and the negative polarity of the cathode. An alternating voltage may be applied. The alternating current waveform to be applied may be arbitrary.

  An organic EL element generally emits light within a layer having a refractive index higher than that of air (refractive index of about 1.6 to 2.1) and can extract only about 15 to 20% of light generated in the light emitting layer. It has been said. This is because light incident on the interface (interface between the transparent substrate and air) at an angle θ greater than the critical angle causes total reflection and cannot be extracted outside the device, or between the transparent electrode or light emitting layer and the transparent substrate. This is because the light is totally reflected between the light and the light is guided through the transparent electrode or the light emitting layer, and as a result, the light escapes in the direction of the element side surface.

  As a method for improving the light extraction efficiency, for example, a method of forming irregularities on the surface of the transparent substrate to prevent total reflection at the interface between the transparent substrate and the air (for example, US Pat. No. 4,774,435). ), A method of improving the efficiency by giving the substrate a light condensing property (for example, JP-A-63-314795), a method of forming a reflective surface on the side surface of the element (for example, JP-A-1-220394) Gazette), a method of forming an antireflection film by introducing a flat layer having an intermediate refractive index between the substrate and the light emitter (for example, Japanese Patent Application Laid-Open No. 62-172691), and a substrate between the substrate and the light emitter. A method of introducing a flat layer having a lower refractive index than that (for example, Japanese Patent Application Laid-Open No. 2001-202827), 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). Method of forming There is 1-283751 JP), and the like.

  In the present invention, these methods can be used in combination with the light emitting device according to the present invention. However, a method of introducing a flat layer having a lower refractive index than the substrate between the substrate and the light emitter, or a substrate, transparent A method of forming a diffraction grating between any layers of the electrode layer and the light emitting layer (including between the substrate and the outside) can be suitably used. In the present invention, by combining these means, it is possible to obtain an element having higher luminance or durability.

  When a medium with a low refractive index is formed between the transparent electrode and the transparent substrate with a thickness longer than the wavelength of light, the light extracted from the transparent electrode has a higher extraction efficiency to the outside as the refractive index of the medium is lower. .

  Examples of the low refractive index layer include aerogel, porous silica, magnesium fluoride, and a fluorine-based polymer. Since the refractive index of the transparent substrate is generally about 1.5 to 1.7, the low refractive index layer preferably has a refractive index of about 1.5 or less. Furthermore, it is preferable that it is 1.35 or less.

  Further, the thickness of the low refractive index medium is preferably at least twice the wavelength in the medium. This is because the effect of the low refractive index layer is diminished when the thickness of the low refractive index medium becomes about the wavelength of light and the electromagnetic wave that has exuded by evanescent enters the substrate.

  The method of introducing a diffraction grating into an interface or any medium that causes total reflection is characterized by a high effect of improving light extraction efficiency. This method uses the property that the diffraction grating can change the direction of light to a specific direction different from refraction by so-called Bragg diffraction, such as first-order diffraction and second-order diffraction. Among them, light that cannot be emitted due to total reflection between layers, etc. is diffracted by introducing a diffraction grating into any layer or medium (in a transparent substrate or transparent electrode), and the light is emitted outside. I want to take it out.

  It is desirable that the diffraction grating to be introduced 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.

  The light emitting device according to the present invention is processed on the light extraction side of the support substrate so as to provide, for example, a structure on the microlens array, or is combined with a so-called light collecting sheet, for example, in a specific direction, for example, the device light emitting surface On the other hand, the brightness | luminance in a specific direction can be raised by condensing in a front direction.

  As an example of the microlens array, quadrangular pyramids having a side of 30 μm and an apex angle of 90 degrees are arranged two-dimensionally on the light extraction side of the substrate. One side is preferably 10 to 100 μm. If it becomes smaller than this, the effect of diffraction will generate | occur | produce and color, and if too large, thickness will become thick and is not preferable.

  As the condensing sheet, for example, a sheet that is put into practical use in an LED backlight of a liquid crystal display device can be used. As such a sheet, for example, a brightness enhancement film (BEF) manufactured by Sumitomo 3M Limited can be used. As the shape of the prism sheet, for example, the base material may be formed by forming a △ -shaped stripe having a vertex angle of 90 degrees and a pitch of 50 μm, or the vertex angle is rounded and the pitch is changed randomly. Other shapes may be used.

  Moreover, in order to control the light emission angle from a light emitting element, you may use together a light diffusing plate and a film with a condensing sheet. For example, a diffusion film (light-up) manufactured by Kimoto Co., Ltd. can be used.

  When a light-emitting panel is configured by arranging a plurality of light-emitting elements according to the present invention so that a part of the light-emitting area of the light-emitting element as viewed from the direction perpendicular to the light emitting surface overlaps each other, Agents and adhesives can be used.

  The pressure-sensitive adhesive in the present invention is widely used in the industrial field, among pressure-sensitive adhesives, adhesives, or agents or materials used in designations such as pressure-sensitive adhesives, adhesives, etc. It means something that is not accompanied.

  Although the kind of adhesive and adhesive is not specifically limited, It is preferable to use the adhesive and adhesive excellent in light transmittance. As the adhesive, a curable adhesive that forms a high molecular weight body or a crosslinked structure by various chemical reactions after being applied and bonded is suitably used. Specific examples of pressure-sensitive adhesives and adhesives that can be used in the present invention include, for example, urethane-based, epoxy-based, aqueous polymer-isocyanate-based, acrylic-based curable adhesives and pressure-sensitive adhesives, and moisture-cured urethane adhesives. And anaerobic pressure-sensitive adhesives such as polyether methacrylate type, ester type methacrylate type and oxidized type polyether methacrylate, cyanoacrylate type instantaneous adhesive, acrylate and peroxide type two liquid type instantaneous adhesive, and the like.

  The method for forming the pressure-sensitive adhesive layer and the adhesive layer on the element laminate is not particularly limited, and a general method such as a gravure coater, a micro gravure coater, a comma coater, a bar coater, a spray coating, an ink jet method, or the like. Is mentioned.

(Sealing substrate)
The sealing substrate according to the present invention is for sealing an organic EL element and protecting the element from a severe external environment such as temperature change, humidity, oxygen, and impact.

  As the sealing substrate, various known gas barrier films on which a barrier film is formed can be used. For example, a known gas barrier film used for packaging materials, for example, a film in which silicon oxide or aluminum oxide is vapor-deposited on a resin (plastic) film, a dense ceramic layer, and a flexible impact relaxation polymer layer are alternately arranged. A gas barrier film or the like having a configuration laminated on can be used as a sealing substrate.

  In particular, a metal foil laminated with a resin film (polymer film) cannot be used as a gas barrier film on the light extraction side, but it is a sealing base material that is low in cost and has low moisture permeability, and can extract light. When it is not intended (transparency is not required), it is preferable as a sealing substrate.

  In the present invention, “metal foil” means a metal foil formed by rolling or the like, unlike a metal thin film formed by sputtering or vapor deposition, or a conductive film formed from a fluid electrode material such as a conductive paste. Or a film.

  As metal foil, there is no limitation in particular in the kind of metal, for example, copper (Cu) foil, aluminum (Al) foil, gold (Au) foil, brass foil, nickel (Ni) foil, titanium (Ti) foil, copper alloy Examples thereof include foil, stainless steel foil, tin (Sn) foil, and high nickel alloy foil. Among these various metal foils, a particularly preferred metal foil is an Al foil.

  The thickness of the metal foil is preferably 5 nm to 50 μm from the viewpoint of barrier properties (moisture permeability, oxygen permeability) and cost.

  As a resin film in a metal foil laminated with a resin film (polymer film), various materials described in the new development of functional packaging materials (Toray Research Center, Inc.) can be used. Resin, polypropylene resin, polyethylene terephthalate resin, polyamide resin, ethylene-vinyl alcohol copolymer resin, ethylene-vinyl acetate copolymer resin, acrylonitrile-butadiene copolymer resin, cellophane resin, vinylon resin, chloride Examples thereof include vinylidene resins. Resins such as polypropylene resins and nylon resins may be stretched and further coated with a vinylidene chloride resin. In addition, a polyethylene resin having a low density or a high density can be used.

  Among the above polymer materials, nylon (Ny), nylon (KNy) coated with vinylidene chloride (PVDC), unstretched polypropylene (CPP), stretched polypropylene (OPP), polypropylene coated with PVDC (KOP), polyethylene Use terephthalate (PET), cellophane coated with PVDC (KPT), polyethylene-vinyl alcohol copolymer (Eval), low density polyethylene (LDPE), high density polyethylene (HDPE), linear low density polyethylene (LLDPE) Is preferred. As these thermoplastic films, a multilayer film formed by coextrusion with a different film, a multilayer film laminated by changing the stretching angle, and the like can be used as needed. Furthermore, it is naturally possible to combine the density and molecular weight distribution of the film used to obtain the required physical properties of the packaging material.

  The thickness of the resin film (polymer film) cannot be generally defined, but is preferably 3 to 400 μm, more preferably 10 to 200 μm, and still more preferably 10 to 50 μm.

  As a method of coating (laminating) a polymer film on one side of a metal foil, a generally used laminating machine can be used.

  A dry lamination method, a hot melt lamination method and an extrusion lamination method can also be used, but the dry lamination method is preferred.

  As the adhesive, polyurethane-based, polyester-based, epoxy-based, acrylic-based adhesives, and the like can be used. You may use a hardening | curing agent together as needed.

  A film in which one side of a metal foil is coated with a resin film (polymer film) is commercially available for packaging materials. For example, a dry laminate film having a configuration of adhesive layer / aluminum film 9 μm / polyethylene terephthalate (PET) 38 μm can be obtained, and the cathode side of the organic EL element can be sealed using this.

  Also, as the sealing substrate (film), a ceramic film is formed on the metal foil on the opposite side of the resin film (polymer film) of the film coated with a resin film (polymer film) on one side of the metal foil. It is also preferable to use them.

  As will be described later, as a method for sealing the two films, for example, a method of laminating a commonly used impulse sealer heat-fusible resin film (layer), fusing with an impulse sealer, and sealing is preferable. .

In the present invention, the gas barrier properties of the sealing substrate (film) are preferably those having an oxygen permeability of 10 ⁻³ g / m ² / day or less and a water vapor permeability of 10 ⁻³ g / m ² / day or less. . Moreover, it is more preferable that both the water vapor permeability and the oxygen permeability are 10 ⁻⁵ g / m ² / day or less.

(adhesive)
Examples of the adhesive for adhering the sealing substrate include a thermosetting adhesive having a reactive vinyl group such as an acrylic acid oligomer or a methacrylic acid oligomer. As commercial products, ThreeBond 1152, 1153 and the like can be used.

  In addition, since an organic EL element may be deteriorated by heat treatment, a thermosetting adhesive that cures in about 1 hour at a temperature equal to or higher than the Tg of the sealing substrate and lower than the Tg of the flexible transparent substrate. Is preferred. For example, when polyethylene naphthalate (Tg, 155 ° C.) is used as the flexible transparent substrate and polyethylene terephthalate (Tg, 110 ° C.) is used as the sealing substrate, an epoxy thermosetting adhesive with a curing condition of 120 ° C. for 1 hour is used. Agents.

  In addition, it is also preferable to coat the electrode and the organic layer on the outside of the electrode facing the support substrate with the organic layer interposed therebetween, and form an inorganic or organic layer in contact with the support substrate to form a sealing film. it can. In this case, the material for forming the film may be any material that has a function of suppressing intrusion of elements that cause deterioration of elements such as moisture and oxygen. For example, silicon oxide, silicon dioxide, silicon nitride, or the like may be used. it can. Furthermore, in order to improve the brittleness of the film, it is preferable to provide a laminated structure of these inorganic layers and layers made of organic materials. The method for forming these films is not particularly limited. For example, vacuum deposition method, sputtering method, reactive sputtering method, molecular beam epitaxy method, cluster ion beam method, ion plating method, plasma polymerization method, atmospheric pressure plasma A polymerization method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, or the like can be used.

  In the gap between the sealing substrate and the display area of the organic EL element, an inert gas such as nitrogen or argon, or an inert liquid such as fluorinated hydrocarbon or silicone oil can be injected in the gas phase and liquid phase. preferable. A vacuum can also be used. Moreover, a hygroscopic compound can also be enclosed inside.

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

[Encapsulation of organic EL elements]
In the present invention, a transparent conductive film is formed on a substrate, and various functional layers constituting the organic EL element are formed on the produced resin substrate for an organic EL element, and then purged with an inert gas. Thus, the organic EL element can be sealed by covering the cathode surface with the sealing substrate.

As the inert gas, a rare gas such as He and Ar is preferably used in addition to N ₂ , but a rare gas in which He and Ar are mixed is also preferable, and the ratio of the inert gas in the gas is 90 to 99.99. It is preferably 9% by volume. Preservability is improved by sealing in an environment purged with an inert gas.

  In sealing an organic EL element using a metal foil laminated with the resin film (polymer film), a ceramic film is formed on the metal foil instead of the laminated resin film surface. The ceramic film surface is preferably bonded to the cathode of the organic EL element.

  As an adhesion method, the dry laminating method is excellent in terms of workability. This method generally uses a curable adhesive layer of about 1.0 to 2.5 μm. Preferably, the amount of adhesive is preferably adjusted to 3 to 5 μm in terms of dry film thickness.

  In addition, the method (hot melt laminating method) which melts a hot melt adhesive and coats an adhesive layer on a substrate, or a resin (LDPE, EVA, PP, etc.) melted at a high temperature is coated on the substrate by a die. A method (extrusion laminating method) or the like may also be used.

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

[Organic EL device manufacturing equipment]
FIG. 5 is a schematic view showing a manufacturing process of the organic EL device according to the present invention.

  An example of the organic EL element manufacturing apparatus according to the present invention will be described with reference to FIG.

1. Hole transport layer coating process The formation of a gas barrier layer on a flexible transparent substrate and the patterning of a transparent electrode (ITO) are shown in FIG. This formation step is omitted because the product is used.

Moreover, you may have the surface treatment process by a washing | cleaning surface modification processing apparatus and an antistatic means before going into a positive hole transport layer application | coating process. The cleaning surface reforming apparatus cleans and modifies the surface of the electrode (not shown) of the flexible transparent substrate sent from the feeding process before applying the hole transport layer coating solution. It is preferable to use a lamp, an excimer lamp, a plasma cleaning apparatus or 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 condition 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 antistatic means has a non-contact type static elimination prevention device and a contact type static elimination prevention device. Examples of the non-contact type static elimination preventing device include a non-contact type ionizer, and the type of ionizer is not particularly limited, and the ion generation method may be either an AC method or a DC method. An AC type, a double DC type, a pulsed AC type, and a soft X-ray type can be used, but the AC type is particularly preferable from the viewpoint of precise static elimination. Air or N ₂ is used as the injection gas required when using the AC type, but it is preferable to use N ₂ with sufficiently high purity. Moreover, from a viewpoint performed in-line, it is selected from a blower type or a gun type.

  As the contact type static elimination preventing device, a static elimination roll or a grounded conductive brush is used. The static elimination roll as the static eliminator is grounded and removes the surface charge by rotatingly contacting the neutralized surface. As such static elimination rolls, in addition to metal rolls such as aluminum, copper, nickel and stainless steel, elastic plastic or rubber rolls mixed with conductive materials such as carbon black, metal powder and metal fibers are used. Is done. In particular, an elastic material is preferable in order to improve contact with the belt-like flexible continuous sheet. Examples of the conductive brush connected to the earth include a neutralizing bar or a neutralizing yarn structure having a brush member made of conductive fibers arranged linearly or a linear metal brush. The neutralization bar is not particularly limited, but a corona discharge type is preferably used. For example, SJ-B manufactured by Keyence Corporation is used. The static elimination yarn is not particularly limited, but usually a flexible yarn can be preferably used.

  The non-contact type antistatic device is preferably used on the electrode surface side of a flexible flexible transparent substrate, and the contact type antistatic device is preferably used on the back side of the flexible flexible transparent substrate. . The first antistatic means removes the charge of the base material and prevents the adhesion of the dust and the dielectric breakdown, thereby improving the yield of the elements.

  The hole transport layer coating step includes an edge position controller (EPC) 101 that adjusts the width position of the plastic transparent substrate A supplied from the substrate feeding device B, and a backup that holds the plastic transparent substrate A when coating. It comprises a roll 102, a coating device 103 for coating the plastic transparent substrate A held by the backup roll 102, and a coating liquid supply line 104 for supplying the coating liquid to the coating device.

  The process from the hole transport layer formation process to the electron transport layer drying process is continuously performed under atmospheric pressure conditions, and after winding up under atmospheric pressure conditions, the process from the electron injection layer formation process to the sealing layer formation process is continued. It is preferable to carry out under reduced pressure conditions. Moreover, it is preferable to provide an accumulator for adjusting the difference in conveyance speed in the coating process of each layer and a non-contact type static elimination preventing device for static elimination.

2. Hole Transport Layer Drying Process The hole transport layer drying process includes a transport roll 203 that stably transports the plastic transparent substrate A in the process, a drying air supply port 201 necessary for drying, and an exhaust port 202.

3. Light-Emitting Layer Coating Device The light-emitting layer coating process includes an edge position controller (EPC) 301 that adjusts the width position of the plastic transparent substrate A, a backup roll 302 that holds the plastic transparent substrate A when coating, and a backup roll 302. A coating device 303 for coating the plastic transparent base material A held on the coating device, and a coating solution supply line 304 for supplying a light emitting layer coating solution to the coating device.

4). Light-Emitting Layer Drying Process The light-emitting layer drying process includes a transport roll 403 that stably transports the plastic transparent substrate A in the process, a drying air supply port 401 necessary for drying, and an exhaust port 402.

5. Electron Transport Layer Coating Step The electron transport layer coating step includes an edge position controller (EPC) 501 that adjusts the width position of the plastic transparent substrate A, a backup roll 502 that holds the plastic transparent substrate A when coating, and a backup. It comprises a coating device 503 for coating the plastic transparent substrate A held by the roll 502 and a coating liquid supply line 504 for supplying the coating liquid to the coating device.

6). Electron Transport Layer Drying Process The electron transport layer drying process includes a transport roll 603 that stably transports the plastic transparent substrate A in the process, a drying air supply port 601 necessary for drying, and an exhaust port 602.

7). Heat treatment (heat treatment) process The heat treatment process includes an edge position controller (EPC) 701 for adjusting the width position of the transparent plastic substrate A, a suction roll 702 having a tension cut function for reducing the transport tension, and heat treatment. It comprises a necessary dry air supply port 703, an exhaust port 704, a suction roll 705 having a tension cut function for increasing the transport tension, and a winding device C.

8). Electron injection layer forming process (not shown)
The electron injection layer forming step includes a supply unit and an electron injection layer formation unit. In the supply unit, the flexible transparent substrate produced in the previous step is fed out and supplied to the electron injection layer forming unit. In the electron injection layer forming part, an electron injection layer is formed on the electron transport layer. The flexible transparent substrate on which the electron injection layer is formed is subsequently sent to the electrode forming step.

9. Electrode formation process (not shown)
In the electrode forming step, an electrode is formed on the electron transport layer formed by the electron transport layer forming portion at the electrode forming portion.

10. Details of the sealing layer forming step will be described later.

  The flexible flexible transparent substrate on which the electrode is formed is subsequently sent to the sealing layer forming step. The sealing layer forming step includes an accumulator unit, a sealing layer forming device, and an antistatic means. The antistatic means has the same non-contact type static elimination preventing device and contact type static elimination preventing apparatus as the static elimination processing means. A sealing layer is formed on the electrode by the sealing layer forming apparatus except for the end portion of the electrode formed in the electrode forming step, so that at least one for illumination (surface emission) is formed on the flexible transparent substrate. An organic EL element is produced.

  In the collection step, a flexible flexible transparent base material (referred to as flexible flexible transparent base material C) on which at least one lighting (surface emitting) organic EL element is formed is taken up by a winding device (not flexible). As shown in the figure, the film is wound and collected with the sealing layer side inward. A roll-shaped flexible transparent substrate in which a flexible flexible transparent substrate C is wound around a winding core and collected as a roll is formed in consideration of maintaining performance, dark spots (non-light-emitting portions), and the like. It is preferable to store in an environment having a concentration of 1 to 100 ppm and a water concentration of 1 to 100 ppm.

  In the above description, the case where the electron injection layer forming step and the electrode forming step are vapor deposition apparatuses has been shown. However, as the method for forming the electron injection layer and the electrode, a formation method not based on the vapor deposition method can be used. Moreover, the system which sticks a sealing film instead of the sealing layer shown to this figure may be sufficient.

The hole transport layer coating solution and the light emitting layer coating solution used in the production process shown in FIG. 6 have at least one organic compound material and at least one solvent. In consideration of the above, it is preferable that the surface tension is 15 × 10 ^{−3 to} 55 × 10 ⁻³ N / m.

  The step of forming the hole transport layer and the light emitting layer, which are the constituent layers of the organic EL element shown in FIG. 6, considers the maintenance of the performance of the hole transport layer and the light emitting layer, the prevention of failure defects due to foreign matter adhesion, etc. It is preferable that the dew point is −20 ° C. or lower and the measured cleanliness is Class 3 to Class 5 and the atmospheric pressure is 10 to 45 ° C. excluding the drying part.

<Sealing substrate bonding process and cutting process>
The sealing substrate bonding step and the cutting step will be described in detail with reference to FIG.

  FIG. 7 is a schematic diagram illustrating an example of a sealing substrate bonding / cutting process. In the manufacturing process, the sealing substrate bonding step 140 includes an adhesive layer forming step 141, a laminating step 142, and a curing step 143.

  The light-emitting element (organic EL structure) wound in a roll shape and the base material on which the protective film is formed are put into an off-line sealing base material bonding step 140 and a cutting step 150, and the sealing base material layer is formed. After being formed and the thermosetting adhesive is cured, it is cut into a predetermined size and formed into an organic EL element.

  The sealing substrate adhesion step 140 is a method of extending an organic EL structure and a roll of a substrate on which a barrier film is formed, and then extending the substrate again to bond a long sealing substrate to the substrate to form an organic EL structure. This is a step of forming the sealing substrate layer 16 on the body. By forming the sealing substrate layer 16 on the organic EL structure, the organic light-emitting layer of the organic EL structure is covered with the sealing substrate, and high quality without causing deterioration of quality due to moisture or oxygen in the air. Quality and high reliability can be maintained.

  The sealing substrate adhesion process 140 is an atmospheric pressure environment of approximately tens of thousands to hundreds of thousands of Pa. Here, a barrier film by sputtering has already been formed on the organic EL structure, and there is no need for a vacuum environment in which moisture and oxygen are reduced.

  The adhesive layer forming step 141 is a step of forming the adhesive layer 15 by applying an adhesive to a selected region of the base material on which the organic EL structure is formed. In the adhesive layer forming step 141, the adhesive layer 15 is formed in a region excluding the anode and cathode lead portions of the organic EL structure.

  The laminating step 142 is a step of forming the sealing base material layer 16 on the organic EL structure by pressing the sealing film 16A as a sealing base material onto the base material 11 with a roller through the adhesive layer.

  The curing step 143 is a step for curing the adhesive.

  Further, the cutting step 150 is a step of cutting a flexible transparent substrate on which the sealing substrate is bonded and the sealing substrate layer 16 is formed at a predetermined position to obtain a sheet organic EL element.

  In the sealing substrate bonding step 140, the adhesive layer 15 is selectively applied only to a predetermined range of the substrate 11, that is, a region excluding the anode and cathode lead portions by screen printing. Is formed.

  The screen printing method is a printing method in which ink is spread on a plate (stencil) with a squeegee (scalar), rubbed, and the ink is attached to the medium through a screen mesh stretched on the opening of the plate. In this printing method, ink can be selectively attached only to a position range facing the opening of the plate. In the present embodiment, the ink in the screen printing method is used as an adhesive, the medium is used as a base on which the organic EL structure is formed, and the adhesive is selectively attached only to a predetermined range of the base. The adhesive layer is selectively formed only in a predetermined range of the material. In the following description, the plate is referred to as a stencil, the portion of the stencil that transmits the adhesive is referred to as an opening portion, and the portion that transmits the adhesive is referred to as a mask portion.

  The adhesive layer forming step 141 has a squeegee 141B that reciprocates in the direction of the arrow shown by a moving means (not shown), and the squeegee 141B spreads and rubs the adhesive 141A on the surface of the stencil 141C at the tip. The stencil 141C has an opening having a screen through which the adhesive can pass and a mask portion through which the adhesive cannot pass. The stencil 141C is spread and rubbed on the stencil 141C by the squeegee 141B. The agent 141 </ b> A passes through the screen of the opening and is applied to a region facing the opening of the base material 11. On the other hand, since the adhesive cannot pass through the mask portion, the adhesive is not applied to the region facing the mask portion.

  According to the present invention, in particular, in a method for manufacturing an organic EL element in which a light emitting element (organic EL structure) is formed on a flexible substrate by a roll-to-roll method, the substrate is washed and decontaminated, and the light emitting element ( It is possible to provide a method for manufacturing an organic EL element, in which the formation of the organic EL structure) and the formation of the protective film on the light emitting element (organic EL structure) can be performed in-line. In the manufacturing method according to the present invention, the formation of the light emitting element (organic EL structure) on the substrate and the formation of the protective film are performed in-line, so that the influence on the light emitting element (organic EL structure) due to moisture and oxygen can be avoided. High-quality and highly reliable organic EL elements can be manufactured. In addition, it is possible to carry out processes performed in different conditions of vacuum environment or atmospheric pressure environment in a roll-to-roll method, and the process is simplified compared to a manufacturing method in which each process is performed off-line. , Work efficiency can be improved and process stop time can be shortened.

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

Example 1
<< Production of Organic EL Element 1 >>
[Step of forming gas barrier layer and electrode layer on flexible substrate]
A polyethylene terephthalate film having a thickness of 100 μm that has been stored in advance under a dew point of −65 ° C. under an inert gas atmosphere at a pressure of 80 Pa and subjected to dehydration and deoxygenation treatment (Teijin-DuPont film, hereinafter abbreviated as PET) A gas barrier layer was formed on one surface of a film provided with an acrylic clear hard coat layer having a thickness of 5 μm on both sides by the method described in Examples of JP-A-2007-83644. That is, the roll electrode type discharge treatment apparatus shown in FIG.

  On the said base material, it formed in order of adhesion layer / ceramic layer / adhesion layer / ceramic layer on the conditions shown below, and the gas barrier layer was obtained on the single side | surface of PET film. Each film thickness is 200 nm for the adhesion layer and 25 nm for the ceramic layer. The substrate holding temperature during film formation was 140 ° C.

<Ceramic layer>
Discharge gas: N ₂ gas reaction gas 1: 5% of oxygen gas to the total gas
Reaction gas 2: TEOS (tetraethoxysilane) is 0.1% of the total gas
Low frequency side power supply: 80 kHz, 10 W / cm ²
High frequency side power supply power: 13.56 MHz at 10 W / cm ²
<Adhesion layer>
Discharge gas: N ₂ gas reactive gas 1: 1% of hydrogen gas with respect to the total gas
Reaction gas 2: 0.5% of TEOS with respect to the total gas
Low frequency side power supply: 80 kHz, 10 W / cm ²
High frequency side power supply power: 13.56 MHz at 5 W / cm ²
Next, on the PET film on which the gas barrier layer is formed, using indium tin oxide (ITO) as a target material, and using argon containing 5% by volume of oxygen as a sputtering gas in the vacuum chamber, the gas pressure is set to 0. An ITO film having a thickness of 110 nm was patterned by sputtering as an electrode layer while continuously feeding at 5 Pa. This was wound around a core in a vacuum chamber, returned to normal pressure under a nitrogen stream, and transferred to a coating process under normal pressure without exposure to the atmosphere (air).

[Step of forming hole transport layer, light emitting layer, electron transport layer]
The continuous wet film forming method as the coating film forming process includes die coating method, screen printing method, flexographic printing method, ink jet method, wire bar method, cap coating method, spray coating method, casting method, roll coating method, bar coating method. Method, gravure coating method and the like can be used. These film forming methods can be appropriately selected according to the material of the organic layer. In this example, a coating film was formed using a die coating method.

  The conveyed flexible substrate is closely conveyed onto a backup roll, and a die coater for forming a coating film is provided on the backup roll with a certain gap from the flexible substrate. Note that a cleaning device may be appropriately attached to the backup roll.

  The coating solution is fed to the die coater by controlling the amount of the solution prepared in the tank via a precision pump such as a gear pump. The supplied coating solution is filled into the manifold through a filtration filter, and the chamber is kept at a constant pressure, and is uniformly coated on the substrate in the width direction from the coating head through the slit to form a film. The thickness of the coating layer is appropriately adjusted depending on the substrate conveyance speed, the amount of liquid fed, and the solution concentration. In addition, when performing simultaneous multilayer coating, an extrusion coating machine and a slide coating machine that can be supplied simultaneously are preferably used.

  The conveyance speed unevenness during coating film formation is preferably 0.2% or more and 10% or less with respect to the average speed of the coating. More preferably, it is 0.2% or more and 3% or less. Thereby, the thickness accuracy in the longitudinal direction of the element is maintained, and the light emission characteristics are made uniform.

(Formation of hole transport layer)
A solution obtained by diluting polyethylenedioxythiophene / polystyrene sulfonate (PEDOT / PSS, Baytron P AI 4083 manufactured by Bayer) at 70% with pure water as a coating solution for the hole transport layer was placed in the first coating chamber. Film formation was performed by a die coater so that the film thickness after drying was 50 nm, and a hole transport layer was provided. After coating, the solvent was removed by a heated air stream. The air flow was 100 mm in height from the slit nozzle type ejection port toward the film forming surface, the ejection wind speed was 1 m / s, and the ejection wind speed width variation was 5%.

  The drying temperature was 80 ° C., and the residence time in the drying furnace was 10 minutes. It is possible to change the temperature condition, change the wind speed, etc. by appropriately setting the drying furnace to several zones according to the material of the organic layer.

(Formation of light emitting layer)
Then, the light emitting layer was provided on the positive hole transport layer so that the film thickness after drying might be set to 100 nm with the die coater installed in the 2nd coating chamber. As a light emitting layer coating solution, a low molecular weight polyvinyl carbazole (PVK) having a molecular weight of 10,000 or less as a light emitting host compound, a low molecular weight Ir (ppy) ₃ having a molecular weight of 10,000 or less as a dopant compound, 5 mass% of 1,2-dichloroethane. A 10% by mass solution was prepared by dissolving in the solution. The surface tension of the light emitting layer was 0.032 N / m, and a good coating film was obtained. Then, it dried for 5 minutes at 25 degreeC using the drying furnace similar to a positive hole transport layer.

(Formation of electron transport layer)
Next, an electron transport layer was provided on the light emitting layer by a die coater installed in the third coating chamber so that the film thickness after drying was 40 nm. As a coating solution for an electron transport layer, the following electron transport agent ET-A was dissolved in 2,2,3,3-tetrafluoro-1-propanol to prepare a 0.75 mass% solution. Then, it dried for 5 minutes at 25 degreeC using the drying furnace similar to a positive hole transport layer. Subsequently, it heated at 98 degreeC for 30 minute (s). After the heat treatment, the substrate was cooled to the same temperature as the room temperature, and then wound into a roll. In the coating process under normal pressure, an atmosphere having a moisture concentration of 1 ppm to 200 ppm and an oxygen concentration of 30 ppm or less in a nitrogen atmosphere was maintained.

  The temperatures during the coating and drying steps of the hole transport layer, the light emitting layer, and the electron transport layer were all less than 100 ° C., and the transport tension was all 196 N / m (20 kgf / m). The transport tension was measured by attaching a load cell type sensor to both sides of the transport roll. As the sensor, a C2G1-25K type manufactured by Minebea Co., Ltd. was used. The measurement range is a specification capable of measuring 0 to 250 N / m. The value obtained by calibrating by strictly converting the tension value from the roll weight and the holding angle of the film conveyance was taken as the tension value.

(Heating process)
The substrate provided up to the electron transport layer was heated at 130 ° C. for 30 minutes at a transport tension of 210 N / m to remove the residual solvent.

[Step of forming electron injection layer and electrode layer]
The substrate provided up to the electron transport layer was introduced into the vacuum transfer chamber via the decompression chamber without being exposed to the atmosphere, and lithium fluoride (electron injection layer) was deposited in a thickness of 0.3 nm in the first thin film formation chamber. . Subsequently, aluminum was deposited and patterned to a thickness of 120 nm as a counter electrode layer in the second thin film formation chamber.

[Sealing process]
The electron injection layer and the electrode layer are formed. The film is in an inert gas stream (in a nitrogen atmosphere, the water concentration is 1 ppm to 200 ppm and the oxygen concentration is 30 ppm or less), and a thermosetting epoxy resin (Nagase Chemtech ( Co., Ltd. UV resin XNR5516) was applied in a predetermined shape using screen printing, and continuously sent to a bonding / sealing process using a pressure roll, and bonded to a 40 μm aluminum foil at 140 ° C. ( After bonding, the bonding pressure was 0.2 MPa, and each element was cut (cut) to produce an organic EL element sample 1.

<< Preparation of organic EL elements 2-8 >>
In the production of the organic EL element 1, the organic EL element was similarly prepared except that the kind of the flexible transparent substrate, the application of the electron transport layer, and the temperature and the transport tension in the heating process after drying were changed as shown in Table 1. 2-8 were produced. The temperatures during the drying process of the hole transport layer, the light emitting layer, and the electron transport layer were all less than 100 ° C., and the transport tension was all 196 N / m (20 kgf / m).

<< Evaluation of organic EL elements >>
About the produced organic EL element, luminous efficiency and half life were evaluated by the following method.

(Luminescence efficiency)
Using the DC voltage / current source / monitor R6243 manufactured by ADC Co., Ltd., the organic EL element is driven, and the luminance is measured using the spectral radiance meter CS1000 manufactured by Konica Minolta Sensing Co., Ltd. A certain current efficiency (cd / A) was determined. The luminous efficiency is expressed as a relative value when the current efficiency of the organic EL element 1 is 100.

(Half life)
The half-life was measured by adjusting the applied voltage so that the initial luminance of the element of each sample was 4000 cd / m ² and then reducing the luminous efficiency (luminance) by 50% from the initial stage. The half life is expressed as a relative value when the half life of the organic EL element sample 1 is 1.0.

  The evaluation results are shown in Table 1.

  As is clear from Table 1, it can be seen that the organic EL elements 2 to 8 according to the present invention have higher luminous efficiency and longer half-life than the organic EL element 1 of the comparative example. In particular, it can be seen that the organic EL elements 4 to 6 and 8 according to the present invention in which the transport tension in the heating step after application and drying of the electron transport layer is 50 N / m or less have a long half-life.

Example 2
In the production of the organic EL elements 4 and 6 of Example 1, after forming the hole injection layer, the following power generation layer coating solution was less than 100 ° C. on the hole injection layer so that the film thickness after drying was 150 nm. Organic photoelectric conversion elements 4 and 6 were produced in the same manner as in the production of the organic EL elements 4 and 6 except that the organic EL elements 4 and 6 were provided except that the coating was applied and dried at 150 ° C. to provide a power generation layer. As a power generation layer coating solution, 6 ml of chlorobenzene, regioregular P3HT (poly-3-hexylthiophene) having a number average molecular weight of 45,000 and fullerene derivative PCBM (6,6-phenyl-C ₆₁ -butyric acid methyl ester) are in a mass ratio. Was 1: 1, and a solution dissolved so as to be 3% by mass was used.

About the obtained organic photoelectric conversion elements 4 and 6, when short-circuit current density Jsc when irradiating the light of a solar simulator (AM1.5G) with the intensity | strength of 100 mW / cm < ² > was evaluated, the organic photoelectric conversion element 4 and All of 6 showed high stability over a long period of time and were found to have sufficient light resistance. In the manufacturing method of the present invention, it has been clarified that the yield of products, that is, the manufacturing cost can be reduced in an organic photoelectric conversion element as well as an organic EL element in a mass production level process.

A plastic transparent base material B base material feeding device C base material take-up device 10 recovery step 20 organic EL element 30 organic EL structure 40 base material (plastic transparent base material)
50 Sealing substrate 101, 301, 501, 701 EPC
102, 302, 502 Backup roll 103, 303, 503 Coating device 104, 304, 504 Coating liquid supply line 140 Sealing substrate adhesion-cutting process 141C Stencil 150 Cutting process 151A, 151B, 151C Cutting blades 201, 401, 601, 703 Dry air supply ports 202, 402, 602, 704 Dry air exhaust ports 203, 403, 603 Transport rolls 702, 705 Suction rolls

Claims (3)

A base material supply device having a roll for feeding out the wound flexible transparent base material, and a base material winding device having a roll for taking up the flexible transparent base material fed from the base material supply device. In an apparatus for manufacturing a roll-to-roll organic electronic device, a transfer tension is applied to the flexible transparent substrate and the flexible transparent substrate is transferred, and at least one organic layer is formed on the transferred transparent transparent substrate. ,
A coating apparatus that coats the flexible transparent substrate to be conveyed and forms the organic layer; and
One heating device for heating the flexible transparent substrate on which the organic layer is formed at less than 100 ° C .;
Another heating device for heating the flexible transparent substrate on which the organic layer is formed at 100 ° C. or higher;
A tension adjusting device that changes the transport tension applied to the flexible transparent substrate,
The tension adjusting device is a roll-to-roller that reduces the conveyance tension applied to the flexible transparent substrate heated by the other heating device to be less than the conveyance tension applied to the flexible transparent substrate heated by the one heating device. Roll type organic electronics device manufacturing equipment. The apparatus for manufacturing a roll-to-roll organic electronics element according to claim 1, wherein the tension adjusting device includes one tension cut roll that reduces a conveyance tension applied to the flexible transparent substrate. The roll-to-roll organic electronics element according to claim 2, wherein the tension adjusting device includes another tension cut roll that increases a transport tension applied to the flexible transparent base material reduced by the one tension cut roll. Manufacturing equipment.

Images