JP5157440B2 - Manufacturing method of organic EL element - Google Patents

Description

  The present invention relates to a method for forming an organic compound layer of an organic EL (electroluminescence) element used as a surface light source or a display panel, a method for producing an organic EL element, and an organic EL element produced by this method.

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

  Thus, since the organic EL element is a thin film type element, when an organic EL panel in which one or a plurality of organic EL elements are formed on a substrate is used as a surface light source such as a backlight, a surface light source. It is possible to easily make a device equipped with In addition, when a display device is configured using an organic EL panel in which a predetermined number of organic EL elements as pixels are formed on a substrate as a display panel, the liquid crystal display device has high visibility and no viewing angle dependency. There are benefits that cannot be obtained.

  On the other hand, when forming an organic compound layer of an organic EL element, as described in JP-A-9-102393 and JP-A-2002-170676, vapor deposition, sputtering, CVD, PVD, solvent Various methods, such as coating methods using a glass, can be used. Among these methods, manufacturing processes are simplified, manufacturing costs are reduced, workability is improved, flexible large-area elements such as backlights and illumination light sources, etc. It is known that a wet film-forming method such as a coating method is advantageous from the viewpoint of application to a film. For example, Japanese Patent Application Laid-Open No. 2002-170676 describes a method of forming an organic compound layer on a single wafer glass substrate by spin coating. Japanese Patent Application Laid-Open No. 2003-142260 describes a method of sequentially forming an organic compound layer on a single wafer substrate by an ink jet method. Since each of these methods uses a single-wafer substrate as a substrate, a large-area full-color display element is manufactured with a large apparatus and a high cost. A method of manufacturing an organic EL element that is expected to be used as a writing light source array has been studied. For example, as a method of manufacturing an organic EL display in which a plastic film is used as a light-transmitting substrate and a cathode, one or a plurality of light emitting layers made of an organic material, and an anode layer are provided on the plastic film, an organic material is used. There is known a method for producing a pattern of one or a plurality of light-emitting layers and a pattern of a cathode by a roll-to-roll method using a vapor deposition method under vacuum (see, for example, Patent Document 1).

  However, the roll-to-roll system described in Patent Document 1 can be mass-produced unlike the conventional single-wafer system, so that an inexpensive organic EL element can be manufactured, but has the following drawbacks.

  1) The use efficiency of an organic compound used to form one or a plurality of light emitting layers made of an organic substance is low, which is one of the causes of high costs.

  2) Since one or a plurality of light emitting layers made of organic substances are formed by vapor deposition, in order to make a display element with a large area, the vapor deposition chamber must be enlarged, and incidental facilities are attached. It must be highly capable and difficult to scale up.

  3) Since one or a plurality of light emitting layers made of an organic material are formed by a vapor deposition method, it takes time to form the light emitting layer and it is difficult to increase productivity.

  4) In particular, in the case of an organic EL element used for illumination purposes, it is difficult to form an organic EL element with a large area without unevenness because the organic EL element must be formed with a large area in the vapor deposition method.

From these circumstances, the productivity is high without increasing the cost, and the method for forming an organic compound layer for forming an organic EL element with a large area without unevenness, the method for producing an organic EL element using the organic compound layer, and the organic EL element Development is desired.
International Publication No. 01/5194 Pamphlet

The present invention has been made in view of the above circumstances, an object thereof is to provide a manufacturing how the productivity is high organic EL element without increasing the cost of high quality.

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

1. On the band-shaped flexible support, a first conductive electrode, and an organic compound layer, and the second electrodes, and a sealing layer or sealing film, an organic EL device having in that order, and the supply unit, and coating the fabric portion and drying section, in the formation method of the organic compound layer to be formed by using a manufacturing apparatus having a recovery unit,
Wherein the supply unit, the belt-shaped flexible support A first electrodes is formed, and supplies a roll state wound around the winding core,
Next, the organic compound layer forming coating solution is applied and dried in the coating unit / drying unit , and the organic compound layer is formed on the strip-shaped flexible support A to form a strip-shaped flexible support B.
In the collection unit, the belt-like flexible support B is wound around a winding core ,
The organic compound layer is coated with the organic compound layer by air-flow drying in which the air velocity distribution in the width direction of the coating film for the organic compound layer is 0.1 to 10% in the drying unit. A method for producing an organic EL device, which is formed by removing a solvent from a film .
2. The coating part / drying part removes the solvent in the organic compound layer under an atmospheric pressure condition by applying an organic compound layer-forming coating solution on the atmospheric pressure condition with a wet coating apparatus. 2. The method of manufacturing an organic EL element according to claim 1, wherein the drying unit that forms the compound layer is one unit, and the manufacturing apparatus includes at least one unit of the coating unit and the drying unit.

3. The band-shaped flexible support A is in claim 1 or 2, characterized in that cleaning the surface modification treatment is performed by washing the surface modification treatment unit prior to applying the organic compound layer forming coating solution The manufacturing method of the organic EL element of description.

4). 4. The method of manufacturing an organic EL element according to claim 3 , wherein the cleaning surface modification processing means is oxygen plasma or UV irradiation.

5. The band-shaped flexible support A is as defined in any one of claims 1 to 4, characterized in that the charge elimination is performed by the charge elimination means prior to applying the organic compound layer forming coating solution Manufacturing method of organic EL element .

6). The band-shaped flexible support A is to claim 1, wherein the variation of the conveying speed at the time of applying an organic compound layer forming coating liquid is from 0.2 to 10% of the average transport speed 6. The method for producing an organic EL element according to any one of 5 above.

7). The coating liquid for forming an organic compound layer has at least one organic compound material and at least one solvent, and has a surface tension of 15 × 10 ^{−3 to} 55 × 10 ⁻³ N / m. The manufacturing method of the organic EL element of any one of Claims 1 thru | or 6 characterized by the above-mentioned.

8). The manufacturing apparatus, a method of manufacturing an organic EL element according to any one of claims 1 to 7, characterized in that it has a heat processing unit after the drying section.

9. Immediately after forming the organic compound layer in the drying unit, the heat treatment unit is -30 to + 30 ° C. with respect to the glass transition temperature of the organic compound layer and does not exceed the decomposition temperature of the organic compound in the organic compound layer the method for manufacturing an organic EL device according to claim 8, wherein in carrying out the heat treatment of the backside heat transfer method.

10. The organic compound layer has a dew point temperature of −20 ° C. or lower, conforms to JISB 9920, has a measured cleanliness of class 5 or lower, and an atmospheric pressure condition of 10 to 45 ° C. excluding a drying section and a heat treatment section. the method for manufacturing an organic EL device according to any one of claims 1 to 9, characterized in that it is formed.

11. The method for manufacturing an organic EL device according to any one of claims 1 to 10 wherein the organic compound layer is characterized by having at least a hole-transporting layer and the organic light emitting layer.

12 The method for manufacturing an organic EL device according to any one of claims 1 to 11, wherein the storing the band-shaped flexible support B under a reduced pressure of ¹⁰ -5 10 Pa.

13. On the band-shaped flexible support, a first conductive electrode, and an organic compound layer, and the second electrodes, and a sealing layer, an organic EL device having in that order, and the supply unit, coating unit and drying In the manufacturing method of an organic EL element manufactured using a manufacturing apparatus having a part, a cathode layer forming part, a sealing layer forming part, and a recovery part,
Wherein the supply unit, the belt-shaped flexible support A first electrodes is formed, and supplies a roll state wound around the winding core,
Next, in the coating part / drying part , a coating solution for forming an organic compound layer is applied and dried to form the organic compound layer on the strip-shaped flexible support A to form a strip-shaped flexible support B.
In the first winding part, the strip-shaped flexible support B is wound into a winding roll around the winding core,
Using the roll-shaped strip-like flexible support B, forming a cathode layer including a second electrode under reduced pressure conditions on the organic compound layer in the cathode layer forming portion,
Subsequently, after forming a sealing layer under reduced pressure on the cathode layer in the sealing layer forming part and forming an organic EL element, it is made into a winding roll shape on the winding core in the recovery step ,
The organic compound layer is coated with the organic compound layer by air-flow drying in which the air velocity distribution in the width direction of the coating film for the organic compound layer is 0.1 to 10% in the drying unit. A method for producing an organic EL device, which is formed by removing a solvent from a film .

14 On the band-shaped flexible support, a first conductive electrode, and an organic compound layer, and the second electrodes, the organic EL device having a sealing film in this order, a supply unit, coating unit and drying unit In the manufacturing method of an organic EL element manufactured using a manufacturing apparatus having a cathode layer forming part, a sealing film sticking part, and a recovery part,
Wherein the supply unit, the belt-shaped flexible support A first electrodes is formed, and supplies a roll state wound around the winding core,
Next, in the coating part / drying part , a coating solution for forming an organic compound layer is applied and dried to form the organic compound layer on the strip-shaped flexible support A to form a strip-shaped flexible support B.
Using the roll-shaped strip-shaped flexible support B, a cathode layer including a second electrode is formed on the organic compound layer under reduced pressure conditions on the cathode layer forming portion to form a strip-shaped flexible support C.
In the second winding part, the belt-like flexible support C is wound into a winding roll around the winding core,
Using the roll-like strip-like flexible support C, the sealing film is applied on the cathode layer under inert gas conditions at the sealing film application part ,
The organic compound layer is coated with the organic compound layer by air-flow drying in which the air velocity distribution in the width direction of the coating film for the organic compound layer is 0.1 to 10% in the drying unit. A method for producing an organic EL device, which is formed by removing a solvent from a film .
15. The coating part / drying part removes the solvent in the organic compound layer under an atmospheric pressure condition by applying an organic compound layer-forming coating solution on the atmospheric pressure condition with a wet coating apparatus. 15. The method of manufacturing an organic EL element according to claim 13, wherein the drying unit forming the compound layer is one unit, and the manufacturing apparatus has at least one unit of the coating unit / drying unit.

  It is possible to provide a method for forming an organic compound layer for forming an organic EL element with high quality and high productivity without increasing costs, a method for producing an organic EL element using the organic compound layer, and an organic EL element. In addition, it has become possible to produce a large-area organic EL device that can be used for surface light sources such as illumination and backlight.

It is a schematic sectional drawing which shows an example of the laminated constitution of an organic EL element. It is a schematic diagram of the process of forming even the organic compound layer which is a structural layer of an organic EL element. It is a schematic diagram which shows an example of the process of producing an organic EL element. It is a schematic diagram which shows another example of the process of producing an organic EL element. FIG. 3 is a schematic flow diagram of forming up to an organic organic compound layer using a step of forming up to an organic organic compound layer shown in FIG. 2. It is a general | schematic flowchart which manufactures an organic EL element using the process of manufacturing the organic EL element shown in FIG. It is a schematic flowchart which manufactures an organic EL element using the process of manufacturing the organic EL element shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a, 1b Organic EL element 101 Base material 102 Anode layer 103, 201c Hole transport layer 104, 201e Organic compound layer (light emitting layer)
105, 201i Electron injection layer (electron transport layer)
106, 201j Cathode layer 107 Sealing layer 108 Adhesive layer 109 Sealing film 2, 3, 7 Manufacturing apparatus 201, 401, 501, 801 Supply unit 201b Band-shaped flexible support A
201h, 201f strip-shaped flexible support B
201k, 201l belt-like flexible support C
201m Sealing film 201o First electrode layer 202 Cleaning surface modification processing unit 203 First coating / drying unit 203b First wet coating machine 203c First drying device 204 First heat processing unit 206 Second coating / drying unit 206b Second Wet coater 207 Second heat treatment unit 209, 6, 404, 503, 9 Collection unit 4 Cathode layer forming unit 402, 802 First cathode layer forming unit 403, 803 Second cathode layer forming unit 404 Second winding unit 5 Sealing film sticking part 502 Sticking part 8 Cathode layer / sealing layer forming part 804 Sealing layer forming part 601 901 Organic EL element

  Embodiments according to the present invention will be described with reference to FIGS. 1 to 7, but the present invention is not limited thereto.

  FIG. 1 is a schematic cross-sectional view showing an example of a layer structure of an organic EL element. FIG. 1A is a schematic cross-sectional view showing a constituent layer of an organic EL element on which a sealing film is formed. FIG. 1B is a schematic cross-sectional view showing a constituent layer of an organic EL element formed by attaching a sealing film via an adhesive.

  The layer structure of the organic EL element shown in FIG. In the figure, 1a represents an organic EL element. The organic EL element 1 a includes an anode layer 102, a hole transport layer 103, an organic compound layer (light emitting layer) 104, an electron injection layer 105, a cathode layer 106, and a sealing layer 107 on a substrate 101. In this order.

  The layer structure of the organic EL element shown in FIG. 1B will be described.

  In the figure, 1b represents an organic EL element. The organic EL element 1b is formed by bonding an anode 102, a hole transport layer (hole injection layer) 103, an organic compound layer (light emitting layer) 104, an electron injection layer 105, a cathode 106 on a base material 101. It has the agent layer 108 and the sealing film 109 in this order. In the organic EL element shown in this figure, a hole injection layer (not shown) may be provided between the anode 102 and the hole transport layer 103. Further, an electron transport layer (not shown) may be provided between the cathode 106, the organic compound layer (light emitting layer) 104, and the electron injection layer 105. In the organic EL element 1a and the organic EL element 1b shown in this figure, a gas barrier film (not shown) may be provided between the anode 102 and the substrate 101.

  The present invention relates to a method for forming the organic compound layer (light emitting layer) 104 and the organic compound layer (hole transporting layer) 103 shown in the figure, the formed organic compound layer (light emitting layer) 104, the organic compound layer (positive). The electron injection layer 105, the cathode 106, and the organic EL element 1 a having the sealing film 107 formed on the hole transport layer 103, and the electron injection layer 105 on the formed organic compound layer (light emitting layer) 104 The present invention relates to a method for producing an organic EL element 1b in which a sealing film 109 is bonded via a cathode 106 and an adhesive layer 108, and an organic EL element produced by these production methods.

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

(1) Base material / anode / light emitting layer / electron transport layer / cathode / sealing layer (2) Base material / anode / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode / sealing layer (3) substrate / anode / hole transport layer (hole injection layer) / light emitting layer / hole blocking layer / electron transport layer / cathode buffer layer (electron injection layer) / cathode / sealing layer (4) substrate / Anode / anode buffer layer (hole injection layer) / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode buffer layer (electron injection layer) / cathode / sealing layer (1) to ( The sealing layer used in 4) includes a sealing film alone, a sealing film via an adhesive layer, or a combination thereof.

  Each layer constituting the organic EL element will be described later.

  FIG. 2 is a schematic view of a process of forming up to the organic compound layer. FIG. 2A is a schematic diagram of a process for forming up to an organic compound layer which is a constituent layer of the organic EL element. FIG. 2B is an enlarged schematic view of a portion indicated by R in FIG. In addition, this figure has shown the case of the manufacturing apparatus which a coating and drying part has 2 units.

  In the figure, reference numeral 2 denotes a manufacturing apparatus for forming up to an organic compound layer which is one of constituent layers of an organic EL element under atmospheric pressure conditions. The manufacturing apparatus 2 includes a strip-shaped flexible support supply unit 201, a belt-shaped flexible support cleaning surface modification processing unit 202, a first application / drying unit 203, a first heat processing unit 204, A second charge removal processing unit, a second application / drying unit 206, a second heat treatment unit 207, a third charge removal processing unit 208, and a recovery unit 209 are provided.

  In the supply unit 201, the strip-shaped flexible support A201a in which the gas barrier film and the anode layer including the first electrode are already formed in this order is wound around the winding core and supplied in a roll state.

The cleaning surface modification processing unit 202 performs cleaning to modify the surface of the anode layer (not shown) of the strip-shaped flexible support A201b sent from the supply unit 201 before applying the organic compound layer forming coating solution. Surface modification processing means 202a and first charge removal processing means 202b are provided. Examples of the cleaning surface modification means 202a include a low-pressure mercury lamp, an excimer lamp, a plasma cleaning apparatus, and the like. As conditions for the cleaning surface modification treatment using a low-pressure mercury lamp, for example, a cleaning surface modification treatment is performed by irradiating a low-pressure mercury lamp with a wavelength of 184.2 nm at an irradiation intensity of 5 to ²⁰ mW / cm ² and a distance of 5 to 15 mm. Conditions are mentioned. For example, atmospheric pressure plasma is preferably used as the condition for the cleaning surface modification treatment by the plasma cleaning apparatus. Examples of the cleaning conditions include conditions in which a gas containing oxygen of 1 to 5% by volume is used for argon gas, and the cleaning surface modification treatment is performed at a frequency of 100 KHz to 150 MHz, a voltage of 10 V to 10 KV, and an irradiation distance of 5 to 20 mm.

  Examples of the first charge removal processing means 202b include a light irradiation method and a corona discharge method, and these can be appropriately selected and used as necessary. The light irradiation type generates weak ions, and the corona discharge type generates air ions by corona discharge. The air ions are attracted to the charged object to compensate for the opposite polarity charge and neutralize static electricity. A static eliminator using corona discharge or a static eliminator using soft X-rays can be used. Since the first charge removal processing means removes the charge of the base material, adhesion of dust and dielectric breakdown are prevented, so that the yield of the elements can be improved.

  The first application / drying unit 203 applies the first organic compound layer forming coating solution to the backup roll 203a holding the strip-shaped flexible support A201b and the strip-shaped flexible support A201b held by the backup roll 203a. And a first drying device 203c for removing the solvent of the first organic compound layer 201c formed on the anode layer (not shown) on the strip-shaped flexible support A201b. Yes.

  Reference numeral 204 denotes a first heat treatment unit. The first heat treatment unit transmits the first organic compound layer 201c from the back side of the apparatus main body 204a and the belt-like flexible support on which the first organic compound layer 201c is formed. And a plurality of heating rollers 204b that are heated by a heat method.

  The first drying device 203c includes a dry air supply header 203c1 having a discharge port 203c3 for discharging dry air, a supply port 203c2 for dry air, an exhaust port 203c4, and a transport roll 203c5.

  Reference numeral 205 denotes a second charge removal processing means for removing charge from the formed first organic compound layer 201c. In addition, in this figure, the coating liquid for 1st organic compound layer formation points out the coating liquid for hole transport layer formation, and the 1st organic compound layer 201c points out a hole transport layer.

  The second coating / drying unit 206 applies a second organic compound layer forming coating solution to a strip-shaped flexible support having a first organic compound layer (hole transport layer) 201c held by a backup roll 206a. And a second wet coater 206b and a second drying device 206c for drying the second organic compound layer 201d formed on the first organic compound layer (hole transport layer) 201c. In the drawing, the second organic compound layer forming coating solution refers to a light emitting layer forming coating solution, and the second organic compound layer 201d refers to a light emitting layer.

  Reference numeral 207 denotes a second heat treatment unit. The second heat treatment unit 207 has the same configuration as the first heat treatment unit 204, and is formed on the first organic compound layer (hole transport layer) 201c. 2 Organic compound layer (light emitting layer) 201d is heated from the back side of the belt-like flexible support by the back side heat transfer method.

  Reference numeral 208 denotes third neutralization processing means for performing neutralization of the formed second organic compound layer (light emitting layer) 201e. The second drying device 206c has the same structure as the first drying device 203c. The first static elimination processing means 202b, the second static elimination processing means 205, and the third static elimination processing means 208 may be the same.

  This figure shows a case where there are two units of the first application / drying unit 203 and the second application / drying unit 204 as the application / drying unit, but it can be increased as necessary. Yes.

  The hole transport layer applied and formed by the first wet coater 203b is made of a hole transport material having a function of transporting holes. In a broad sense, the hole injection layer and the electron blocking layer are also hole transport layers. include. The hole transport layer can be provided as a single layer or a plurality of layers. The hole transport material has any one of hole injection or transport and electron barrier properties, and may be either organic or inorganic. For example, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, Examples include stilbene derivatives, silazane derivatives, aniline copolymers, and conductive polymer oligomers, particularly thiophene oligomers.

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

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

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

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

  In the case where the light emitting layer formed by the second wet coater 206b is a multilayer, it is necessary to dispose units of the coating / drying unit in accordance with the number of layers to be stacked. For example, a white element can be manufactured by forming a light emitting layer in multiple layers. In the present invention, the light emitting layer refers to a blue light emitting layer, a green light emitting layer, and a red light emitting layer. There is no restriction | limiting in particular as a lamination order in the case of laminating | stacking a light emitting layer, You may have a nonluminous intermediate | middle layer between each light emitting layer. In the present invention, it is preferable that at least one blue light emitting layer is provided at a position closest to the anode in all the light emitting layers. Also, when four or more light emitting layers are provided, for example, blue light emitting layer / green light emitting layer / red light emitting layer / blue light emitting layer, blue light emitting layer / green light emitting layer / red light emitting layer / blue light emitting from the order close to the anode. Layered / green light emitting layer, blue light emitting layer / green light emitting layer / red light emitting layer / blue light emitting layer / green light emitting layer / red light emitting layer, etc. It is preferable for improving luminance stability.

  The total thickness of the light emitting layer is not particularly limited, but is usually selected in the range of 2 nm to 5 μm, preferably 2 to 200 nm in consideration of the uniformity of the film and the voltage required for light emission. Furthermore, it is preferable that it exists in the range of 10-20 nm. A film thickness of 20 nm or less is preferable because it has the effect of improving the stability of the emission color with respect to the driving current as well as the voltage surface. The film thickness of each light emitting layer is preferably selected in the range of 2 to 100 nm, and more preferably in the range of 2 to 20 nm. Although there is no restriction | limiting in particular about the film thickness relationship of each light emitting layer of blue, green, and red, It is preferable that the blue light emitting layer (the sum total when there are two or more layers) is the thickest among three light emitting layers.

  The light emitting layer includes at least three layers having different emission spectra, each having an emission maximum wavelength in the range of 430 to 480 nm, 510 to 550 nm, and 600 to 640 nm. If it is three or more layers, there will be no restriction | limiting in particular. When there are more than four layers, there may be a plurality of layers having the same emission spectrum. A layer having an emission maximum wavelength in the range of 430 to 480 nm is referred to as a blue light emitting layer, a layer in the range of 510 to 550 nm is referred to as a green light emitting layer, and a layer in the range of 600 to 640 nm is referred to as a red light emitting layer. Moreover, in the range which maintains the said maximum wavelength, you may mix a several luminescent compound in each light emitting layer. For example, the blue light emitting layer may be used by mixing a blue light emitting compound having a maximum wavelength of 430 to 480 nm and a green light emitting compound having the same wavelength of 510 to 550 nm.

  The material used for the light emitting layer is not particularly limited, and examples thereof include the latest trends of Toray Research Center, Inc. flat panel displays, the current state of EL displays and the latest technological trends, and various materials as described on pages 228-332.

  An organic compound layer (light-emitting layer) formed by applying an organic compound layer-forming coating solution with the second wet coater 206b and drying is an electron injected from an electrode, an electron injection layer, or a hole transport layer. And a layer that emits light by recombination of holes, and the light emitting portion may be in the layer of the light emitting layer or at the interface between the light emitting layer and the adjacent layer.

  As drying conditions for removing the solvent of the coating film for the first organic compound layer (hole transport layer) in the first drying device 203c, in consideration of drying unevenness, rough coating of the coating film surface, etc. Examples include air flow drying with a discharge wind speed of 0.1 to 5 m / s and a wind speed distribution in the width direction of 0.1 to 10%. The drying conditions for removing the solvent of the second organic compound layer (light emitting layer) in the second drying device 206c may be the same as the conditions of the first drying device 203c.

  As heat treatment conditions for the first organic compound layer (hole transport layer) in the first heat treatment unit 204, improvement in smoothness of the first organic compound layer (hole transport layer), removal of residual solvent, organic compound layer (positive) Considering hardening of the hole transport layer), the first organic compound layer (hole transport layer) is configured at −30 to + 30 ° C. with respect to the glass transition temperature of the first organic compound layer (hole transport layer). It is preferable to perform the back surface heat transfer type heat treatment at a temperature not exceeding the decomposition temperature of the organic compound.

  As heat treatment conditions for the second organic compound layer (light emitting layer) in the second heat treatment unit 207, the smoothness of the second organic compound layer (light emitting layer) is improved, the residual solvent is removed, and the second organic compound layer (light emitting layer). In consideration of curing, etc., the decomposition temperature of the organic compound constituting the second organic compound layer (light emitting layer) and −30 to + 30 ° C. with respect to the glass transition temperature of the second organic compound layer (light emitting layer) It is preferable to perform the back surface heat transfer type heat treatment at a temperature not exceeding.

  Variations in the transport speed of the belt-shaped flexible support A when the first organic compound layer (hole transport layer) forming coating solution is applied by the first wet coater 203b and the second wet coater 206b 2 The variation in the transport speed of the strip-shaped flexible support A when applying the coating solution for forming the organic compound layer (light emitting layer) is an average considering the uneven brightness of the coating film due to the uneven coating thickness in the longitudinal direction, etc. It is preferable that it is 0.2 to 10% with respect to the conveyance speed.

The coating liquid for forming the first organic compound layer (hole transport layer) used in the first wet coater 203b and the coating liquid for forming the second organic compound layer (light emitting layer) used in the second wet coater 206b are: , Having at least one organic compound material and at least one solvent, and taking into account repelling during coating, coating unevenness, etc., and surface tension of 15 × 10 ^{−3 to} 55 × 10 ⁻³ N / m It is preferable.

  The step of forming the first organic compound layer (hole transport layer) and the second organic compound layer (light-emitting layer), which are the constituent layers of the organic EL element shown in this figure, includes the first organic compound layer (hole transport layer). ) And the second organic compound layer (light emitting layer), the dew point temperature is −20 ° C. or less, and the measured cleanliness is class 5 or less in consideration of JISB 9920. And it is preferable to form under atmospheric pressure conditions of 10-45 degreeC except a 1st drying part and a 2nd drying part. In the present invention, cleanliness of class 5 or less means class 3 to class 5.

  In the recovery unit 209, the belt-like flexible support B201e on which the second organic compound layer (light emitting layer) 201d is formed is wound around a winding core to produce a roll-like belt-like flexible support B201f. . When winding in a roll shape, it is preferable to wind it through an air-permeable interleaving paper or a spacer tape that provides space on the element surface.

It produced rolled band-shaped flexible support B201f was the performance maintenance of the first organic compound layer (hole transport layer) and the second organic compound layer (light emitting layer), taking into account the non-light emission failure or the like, 10 ^- It is preferable to store under reduced pressure conditions of ^{5 to} 10 Pa. The storage period is preferably 1 hour to 200 hours in consideration of the removal of oxygen and trace moisture caused by the deterioration of the first organic compound layer (hole transport layer) and the second organic compound layer (light emitting layer). In some cases, it may be stored in a heated environment.

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

As the anode, an electrode material made of a metal, an alloy, an electrically conductive compound or a mixture thereof having a high work function (4 eV or more) is preferably used. Specific examples of such electrode materials include metals such as Au, and conductive transparent materials such as CuI, indium tin oxide (ITO), SnO ₂ and ZnO. Alternatively, an amorphous material such as IDIXO (In ₂ O ₃ .ZnO) capable of forming a transparent conductive film may be used. For the anode, these electrode materials may be formed into a thin film by a method such as vapor deposition or sputtering, and a pattern of a desired shape may be formed by photolithography, or if the pattern accuracy is not so high (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 electroconductive compound, wet film forming methods, such as a printing system and a coating system, can also be used. When light emission is taken out from the anode, it is desirable that the transmittance is greater than 10%, and the sheet resistance as the anode is preferably several hundred Ω / □ or less. Further, although the film thickness depends on the material, it is usually selected in the range of 10 to 1000 nm, preferably 10 to 200 nm.

  A hole injection layer (anode buffer layer) may be present between the anode and the organic compound layer (light emitting layer) or the hole transport layer. 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) ) ", Chapter 2, Chapter 2," Electrode Materials "(pp. 123-166).

  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 anode buffer layer (hole injection layer) is desirably 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.

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

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

  Examples of the wet coater that can be used for the first wet coater 203b and the second wet coater 206b include a die coat method, a screen printing method, a flexographic printing method, an ink jet method, a Mayer bar method, a cap coat method, and a spray. It is possible to use a coating machine such as a coating method, a casting method, a roll coating method, a bar coating method, or a gravure coating method. The use of these wet coating machines can be appropriately selected according to the material of the organic compound layer.

  Using the manufacturing apparatus shown in the figure, using a strip-shaped flexible support A on which an anode layer including a first electrode is formed, a first organic compound layer (hole transport layer) on the anode layer, 2 Organic compound layer (light emitting layer) is formed to form a strip-shaped flexible support B, and then the organic compound is formed into a strip-shaped flexible support B in the form of a winding roll using the strip-shaped flexible support B as a winding core. The following effects can be obtained by the layer formation method as compared with the vapor deposition method.

  1) The use efficiency of the organic compound used to form one or a plurality of light emitting layers made of an organic substance is high, and the cost can be reduced.

  2) It is easy to form an organic compound layer having a large area necessary for producing an organic EL element having a large area.

  3) Since the organic compound layer can be formed in a short time, the operation rate can be improved.

  4) It becomes easy to form an organic compound layer having a large area necessary for producing an organic EL element having a large area.

  FIG. 3 is a schematic view showing an example of a process for producing an organic EL element. This figure shows a case of a manufacturing apparatus having two units of application / drying units. The application / drying unit is the same as the application / drying unit shown in FIG.

  In the figure, reference numeral 3 denotes a manufacturing apparatus for producing an organic EL element. The manufacturing apparatus 3 has a coating / drying unit (same as the coating / drying unit 203 shown in FIG. 2) for forming the organic compound layer constituting the organic EL element shown in FIG. 2 under atmospheric pressure conditions, and the formed organic compound Cathode layer forming portion 4 for forming a cathode layer including a second electrode on the layer under reduced pressure conditions, and sealing for adhering a sealing film on the formed cathode layer via an adhesive under atmospheric pressure conditions It has the film sticking part 5 and the collection | recovery part 6. FIG.

  In the manufacturing apparatus 3 for producing the organic EL element shown in the figure, the movement of the object between each application / drying unit 2 to the sealing film adhering step 5 is performed in a roll form, and the recovery unit is also a winding core. It is collected in the roll state wound around. In addition, after sticking a sealing film, you may cut and collect | recover in a sheet form.

  The cathode layer forming unit 4 includes a material supply unit 401, a first cathode layer forming unit 402, a second cathode layer forming unit 403, and a second winding unit 404, and is collected from the supply unit 401. Up to the portion 404 is continuously performed under reduced pressure conditions. In the material supply unit 401, the anode, the hole transport layer, and the organic compound layer (light emitting layer) are formed on the belt-like flexible support manufactured by the manufacturing apparatus 2, and wound around the winding core. The roll-shaped belt-like flexible support B201f thus produced is supplied.

  An electron injection layer 201g is formed by the first cathode layer forming unit 402 on the organic compound layer (light emitting layer) of the strip-shaped flexible support B201f having the organic compound layer (light emitting layer) unwound from the supply unit 401. . Reference numeral 402a denotes a vapor deposition apparatus, and 402b denotes an evaporation source container.

  In the second cathode layer forming unit 403, the cathode layer 201h of the second electrode is formed on the electron injection layer 201g formed in the first cathode layer forming unit 402. Reference numeral 403a denotes a vapor deposition apparatus, and reference numeral 403b denotes an evaporation source container.

  The strip-shaped flexible support C201i in which the cathode layer 201h of the second electrode is formed by the second cathode layer forming unit 403 is wound around the winding core by the collecting unit 404 to become a roll-shaped strip-shaped flexible support C201j.

  In this figure, the case where the first cathode layer forming portion 402 and the second cathode layer forming portion 403 are vapor deposition apparatuses is shown. However, the cathode layer forming method is not particularly limited, and for example, a sputtering method, a reactive sputtering method, A molecular beam epitaxy method, a cluster ion beam method, an ion plating method, a plasma polymerization method, an atmospheric pressure plasma polymerization method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, or the like can be used.

  The sealing film adhering unit 5 includes a material supplying unit 501, an adhering unit 502, and a collecting unit 503, and the process from the supplying unit 501 to the collecting unit 6 is continuously performed under atmospheric pressure conditions. It is supposed to be done. In the supply unit 501, the anode, the hole transport layer, the organic compound layer (light emitting layer), the electron injection layer, and the cathode layer are formed on the belt-like flexible support produced in the cathode layer forming unit 4. The belt-like flexible support body C201i in which the formation is formed is supplied with the roll-like belt-like flexible support body C201j wound around the winding core. In addition, it is preferable to perform the sealing film sticking process 5 in inert gas environment, in order to prevent deterioration of an organic compound layer (light emitting layer).

  The sticking unit 502 includes a coating device 502a that coats an adhesive on the cathode layer of the strip-shaped flexible support C201i fed out from the supply unit 501, a sealing film supply unit 502b, a pressure roll 502c, And a curing processing unit 502d. 502b1 indicates a roll-shaped sealing film wound around a winding core.

  After being unwound from the supply unit 501 and continuously coated with an adhesive on the cathode layer of the strip-shaped flexible support C201i by the coating device 502a, the sealing film is continuously bonded and the pressure roll 502c. The sealing film is continuously stuck on the cathode layer through an adhesive by passing through the adhesive layer. After the sealing film 502b2 is attached via an adhesive, a hardening process for attaching the sealing film is performed. An organic EL element protected by the sealing film 502b2 is produced at the stage where the curing process of the adhesive is completed, and a roll-like shape protected by the sealing film by forming a winding roll around the winding core in the recovery unit 6 The production of the organic EL element 601 is completed. In this case, after sticking the sealing film, it may be cut into a sheet shape without being wound. Other reference numerals are the same as those in FIG.

  The electron injection layer formed by the first cathode layer forming portion 402 is made of a material having a function of transporting electrons and is included in the electron transport layer in a broad sense. The electron injection layer is a layer provided between the electrode and the organic layer for lowering the driving voltage and improving the luminance of the light emission. “Organic EL element and its forefront of industrialization (NST 30, November 30, 1998) Issue) ”, Chapter 2, Chapter 2,“ Electrode Materials ”(pages 123-166). The details of the electron injection layer (cathode buffer layer) are also described in JP-A-6-325871, JP-A-9-17574, JP-A-10-74586, and the like. Specifically, strontium, aluminum, etc. Metal buffer layer typified by lithium, alkali metal compound buffer layer typified by lithium fluoride, alkaline earth metal compound buffer layer typified by magnesium fluoride, oxide buffer layer typified by aluminum oxide, etc. . The buffer layer (injection layer) is preferably a very thin film, and the film thickness is preferably in the range of 0.1 nm to 5 μm although it depends on the material. In addition, as an electron transport material (also serving as a hole blocking material) used for an electron transport layer adjacent to the cathode side, it is sufficient if it has a function of transmitting electrons injected from the cathode to the light emitting layer. Any one of the conventionally known compounds can be selected and used, for example, nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, carbodiimides, fluorenylidenemethane derivatives, anthraquinodimethanes. And anthrone derivatives, oxadiazole derivatives and the like. Furthermore, in the above oxadiazole derivatives, thiadiazole derivatives in which the oxygen atom of the oxadiazole ring is substituted with a sulfur atom, and quinoxaline derivatives having a quinoxaline ring known as an electron-withdrawing group can also be used as the electron transport material. Furthermore, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used.

  Also, metal complexes of 8-quinolinol derivatives such as tris (8-quinolinol) aluminum (Alq), tris (5,7-dichloro-8-quinolinol) aluminum, tris (5,7-dibromo-8-quinolinol) aluminum. Tris (2-methyl-8-quinolinol) aluminum, tris (5-methyl-8-quinolinol) aluminum, bis (8-quinolinol) zinc (Znq), and the like, and the central metals of these metal complexes are In, Mg, Metal complexes replaced with Cu, Ca, Sn, Ga or Pb can also be used as the electron transport material. In addition, metal-free or metal phthalocyanine, or those having terminal ends substituted with an alkyl group or a sulfonic acid group can be preferably used as the electron transporting material. Distyrylpyrazine derivatives can also be used as electron transport materials, and inorganic semiconductors such as n-type-Si and n-type-SiC are also used as electron transport materials in the same manner as the hole injection layer and hole transport layer. I can do it. Although there is no restriction | limiting in particular about the film thickness of an electron carrying layer, Usually, 5 nm-about 5 micrometers, Preferably it is 5-200 nm. The electron transport layer may have a single layer structure composed of one or more of the above materials. An electron transport layer having a high n property doped with impurities can also be used. Examples thereof include JP-A-4-297076, JP-A-10-270172, JP-A-2000-196140, JP-A-2001-102175, J. Pat. Appl. Phys. 95, 5773 (2004), and the like. It is preferable to use such an electron transport layer having high n property because an element with lower power consumption can be manufactured. The electron transport layer can also be formed by thinning the electron transport material by a known method such as wet coating or vacuum deposition. In the present invention, for example, the second application / drying unit 206 and the second heat treatment unit 207 shown in FIG. 3 are arranged after the third static elimination processing unit 208 shown in FIG. 3 to form an electron transport layer. It is also possible to do.

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

  Moreover, after producing the above metal with a film thickness of 1 to 20 nm on the cathode, a transparent or semi-transparent cathode can be produced by producing the conductive transparent material mentioned in the description of the anode thereon. By applying this, an element in which both the anode and the cathode are transmissive can be manufactured.

  As the sealing film to be used, a barrier film and a metal film made of the same material as the gas barrier film can be used. Specific examples of the adhesive include photo-curing and thermosetting adhesives having reactive vinyl groups such as acrylic acid oligomers and methacrylic acid oligomers, moisture-curing adhesives such as 2-cyanoacrylates, and epoxy. Heat- and chemical-curing type (two-component mixed) adhesives, polyamide-based, polyester-based, polyolefin-based hot-melt adhesives, cationic-curing type UV-curable epoxy resin adhesives, etc. I can do it.

  In addition, since an organic compound layer may deteriorate with heat processing, what can be adhesive-hardened from room temperature to 80 degreeC is preferable. A desiccant may be dispersed in the adhesive. For the application of the adhesive to the sealing portion, a die coating or a printing method can be used.

  As shown in this figure, a step of forming a coating film for an organic compound layer by applying a wet coating method at atmospheric pressure, a step of forming an electron injection layer and a cathode layer under reduced pressure conditions on the organic compound layer, It has the process of sticking a sealing film on a cathode layer in atmospheric pressure, and the physical distribution between each process is performed in a roll state, and it shows in FIG. 2 by producing an organic EL element through each of these processes. In addition to the effects of the organic compound layer forming method, the following effects can be obtained.

  1) Optimization in each step is achieved by separating the coating / drying step for forming the organic compound layer, the cathode layer forming step for forming the cathode layer including the second electrode, and the sealing film attaching step. This makes it easier to stabilize the quality and improve productivity.

  2) The use efficiency of the organic compound used to form one or a plurality of light emitting layers made of an organic substance is high, and the cost can be reduced.

  FIG. 4 is a schematic view showing another example of a process for producing an organic EL element. This figure shows a case of a manufacturing apparatus having two units of application / drying units. The application / drying unit is the same as the application / drying unit shown in FIG.

  In the figure, reference numeral 7 denotes a manufacturing apparatus for producing an organic EL element. The manufacturing apparatus 7 includes a coating / drying unit (same as the coating / drying unit 203 shown in FIG. 2) for forming an organic compound layer constituting the organic EL element shown in FIG. 2 under atmospheric pressure conditions, and the formed organic compound On the layer, a cathode layer / sealing layer forming portion 8 for forming a cathode layer including the second electrode and a sealing layer under reduced pressure conditions, and a recovery portion 9 are provided. In the manufacturing apparatus 7 for producing the organic EL element shown in this figure, the movement of the object between each coating / drying unit 2 and the cathode layer / sealing layer forming unit 8 is performed in a roll-like form and collected. The part is also collected in a roll state wound around the winding core.

  The cathode layer / sealing layer forming unit 8 includes a supply unit 801, a first cathode layer forming unit 802, a second cathode layer forming unit 803, a sealing layer forming unit 804, and a recovery unit 9. The material supply unit 801 to the recovery unit 9 are continuously performed under reduced pressure conditions. In the material supply unit 801, the anode, the hole transport layer, and the organic compound layer (light emitting layer) are formed on the belt-like flexible support manufactured by the manufacturing apparatus 2, and wound around the winding core. A rolled belt-like flexible support B201f is supplied.

  An electron injection layer 201i is formed by the first cathode layer forming unit 802 on the organic compound layer (light emitting layer) of the strip-shaped flexible support B201f having the organic compound layer (light emitting layer) unwound from the supply unit 801. . Reference numeral 802a denotes a vapor deposition apparatus, and 802b denotes an evaporation source container.

  In the second cathode layer forming unit 803, the cathode layer 201j is formed on the electron injection layer 201i formed in the first cathode layer forming unit 802. Reference numeral 803a denotes a vapor deposition apparatus, and 803b denotes an evaporation source container. In the sealing layer forming unit 804, a sealing layer is formed on the cathode layer, an organic EL element protected by the sealing layer is produced, and the recovery unit 9 forms a winding roll to form a sealing roll. The production of the roll-shaped organic EL element 901 protected by the stop film is completed. Other reference numerals are the same as those in FIG.

  In the sealing layer forming portion 804 shown in this drawing, it is preferable to take a method of forming a sealing film by a method of forming an inorganic or organic layer outside the cathode layer. In this case, as a material for forming the film, any material may be used as long as it has a function of suppressing intrusion of elements that cause deterioration of the element 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 preferable to have a laminated structure of these inorganic layers and layers made of organic materials. The method for forming these films is not particularly limited. For example, vacuum deposition, sputtering, reactive sputtering, molecular beam epitaxy, cluster-ion beam 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. The electron injection layer and cathode layer formed in the cathode layer / sealing layer forming portion 8 are the same as the electron injection layer and cathode layer formed in the cathode layer forming portion 4 shown in FIG.

  As shown in this figure, a process for forming a coating film for an organic compound layer by applying a wet coating method at atmospheric pressure, and an electron injection layer, a cathode layer, and a sealing layer on the organic compound layer under reduced pressure conditions. In addition to the effect of the organic compound layer forming method shown in FIG. 2 by performing the physical distribution between the processes in a roll state and producing the organic EL element through these processes, the following effects are provided. Is obtained.

  1) Optimization in each step is achieved by separating the coating / drying step for forming the organic compound layer, the cathode layer forming step for forming the cathode layer including the second electrode, and the sealing film attaching step. This makes it easier to stabilize the quality and improve productivity.

  2) The use efficiency of the organic compound used to form one or a plurality of light emitting layers made of an organic substance is high, and the cost can be reduced.

  FIG. 5 is a schematic flow diagram for forming up to the organic organic compound layer using the manufacturing apparatus for forming up to the organic organic compound layer shown in FIG.

  In S1, an anode layer including at least a first electrode is formed around a winding core, and a roll-like strip-like flexible support 201a is prepared in the supply unit. The first electrode layer 201o has already been formed on the belt-like flexible support 201n shown in this figure. The first electrode layer 201o is continuously formed on the barrier layer on the strip-shaped flexible support 201n continuously in the length direction at a constant size and interval. A barrier layer may be provided between the belt-like flexible support 201n and the first electrode layer 201o. In this case, the barrier layer is formed on the entire surface of the belt-like flexible support 201n. The roll-shaped belt-like flexible support 201a is in a state where the first electrode layer 201o is wound inside.

  In S2, a cleaning surface modification process is performed on the belt-like flexible support unwound from the base material supply unit by the cleaning surface modification processing unit.

  In S3, the coating liquid for forming the first organic compound layer (hole transport layer) is applied at atmospheric pressure by the wet coating machine in the first coating unit. At this time, the coating liquid for forming the first organic compound layer (hole transport layer) is applied leaving one end 201o1 of the first electrode layer 201o. After the application, drying is performed by the first drying device of the first drying unit to form the first organic compound layer (hole transport layer) 201c. Subsequently, the first heat treatment apparatus heat-treats the first organic compound layer (hole transport layer). Thereafter, the surface of the hole transport layer formed by the charge removal processing means is discharged.

  In S4, the coating solution for forming the second organic compound layer (light emitting layer) is applied on the formed first organic compound layer (hole transport layer) 201c by the wet coating machine in the second coating unit at atmospheric pressure. Then, drying is performed by the second drying device of the second drying unit to form the second organic compound layer (light emitting layer) 201d. Subsequently, the second heat treatment apparatus heat-treats the second organic compound layer (light emitting layer) 201e. The second organic compound layer (light emitting layer) 201d is applied with the same application width as the first organic compound layer (hole transport layer) 201c. In addition, when there are a plurality of second organic compound layers (light-emitting layers), organic compounds stacked by repeating coating, drying, and heat treatment according to the number of second organic compound layers (light-emitting layers) to be stacked. A layer (light emitting layer) is formed. Thereafter, the surface of the second organic compound layer (light emitting layer) 201e formed by the charge removal processing means is discharged.

In S5, the belt-like flexible support having the second organic compound layer (light-emitting layer) is wound around the core with the second organic compound layer (light-emitting layer) inside, and is rolled into a belt-like flexible support. In the form of 201h, it is stored under reduced pressure conditions of 10 ^{−5 to} 10 Pa while moving to the next step.

  FIG. 6 is a schematic flow diagram for manufacturing an organic EL element using the process for manufacturing the organic EL element shown in FIG. The steps until the organic compound layer (light emitting layer) is formed are the same as S1 to S5 shown in FIG.

  In S′1, a strip-shaped flexible support body having the second organic compound layer (light emitting layer) 201e shown in S5 of FIG. 5 is wound around the winding core to prepare a roll-shaped strip-shaped flexible support body B201f. Is done.

In S′2, an electron injection layer (LiF layer) 201 g having a thickness of 0.5 nm is formed on the second organic compound layer (light emitting layer) 201e on the belt-like flexible support under a reduced pressure condition of 5 × 10 ⁻⁴ Pa. Is formed by vapor deposition. The electron injecting layer is formed in a state where a mask is applied so that one end 201o1 of the first electrode layer 201o is not covered during vapor deposition.

In S′3, an electron injection layer 201i and a second electrode layer (aluminum layer) 201h having a thickness of 100 nm are formed by vapor deposition on the formed electron injection layer 201g under a reduced pressure condition of 5 × 10 ⁻⁴ Pa. . The second electrode layer is formed so that the end opposite to the one end 201o1 of the first electrode layer is wider than the width of the electron injection layer and is on the belt-like flexible support 201n.

  In S′4, a strip-shaped flexible support on which a cathode layer (electron injection layer 201g and second electrode layer 201h) including the second electrode is formed is wound around a core under reduced pressure and rolled into a strip. The flexible support 201j is moved to the next step.

  In S′5, with one end 20101 of the first electrode layer and one end 201h1 of the cathode layer including the second electrode removed, adhesion is performed so as to cover the cathode layer including the second electrode. Agent 201p is applied at atmospheric pressure. As the adhesive, for example, a UV curable epoxy resin (UV resin XNR5570-B1 manufactured by Nagase ChemteX Corporation) was applied by die coating. Subsequently, the sealing film 502b2 supplied from the sealing film supply unit is pasted in accordance with the area of the applied adhesive, and is stuck by a pressure roll, and the UV lamp is irradiated from the cathode side and cured. A band-shaped flexible support (organic EL element protected with a sealing film) on which the organic EL element is formed is produced. The adhesive epoxy resin may be a thermosetting type. In that case, thermocompression bonding is performed by passing between heat rolls at the time of bonding.

  In S'6, the roll protected by the sealing film by forming the belt-like flexible support (organic EL element protected by the sealing film) on which the organic EL element is formed into a winding roll shape around the winding core The organic EL element 601 is finished. Note that, if necessary, the sheet may be cut continuously in accordance with the size of the first electrode layer. In the case of cutting, the adhesive is preferably formed only on the outer periphery of the organic compound layer (light emitting layer) by a dispenser, screen printing or the like.

  FIG. 7 is a schematic flow diagram for manufacturing an organic EL element using the process for manufacturing the organic EL element shown in FIG. The steps until the organic compound layer (light emitting layer) is formed are the same as S1 to S5 shown in FIG.

  In S ″ 1, a strip-shaped flexible support body having the second organic compound layer (light emitting layer) 201e shown in S5 of FIG. 5 is wound around the winding core, and a roll-shaped strip-shaped flexible support body 201f is formed. Prepared.

In S ″ 2, an electron injection layer (LiF layer) having a thickness of 0.5 nm is formed on the second organic compound layer (light emitting layer) 201e on the belt-like flexible support under a reduced pressure of 5 × 10 ⁻⁴ Pa. 201 g is formed by vapor deposition. The electron injecting layer is formed in a state where a mask is applied so that one end 201o1 of the first electrode layer is not covered during vapor deposition.

In S ″ 3, a second electrode layer (aluminum layer) 201h having a thickness of 100 nm is formed on the formed electron injection layer 201g by a vapor deposition method under a reduced pressure condition of 5 × 10 ⁻⁴ Pa. The cathode layer including the second electrode is formed so that one end of the first electrode layer opposite to the end 201o1 is wider than the width of the electron injection layer 201g and is on the belt-like flexible support 201n. It is formed.

  In S ″ 4, one end portion 201o1 of the first electrode layer (anode layer) 201o and one side of the second electrode layer (cathode layer) 201h are formed on the second electrode layer (cathode layer) 201h that is continuously formed. A strip-shaped flexible support body in which an organic EL element is formed by forming a sealing layer 201q under a reduced pressure condition so as to cover the second electrode layer 201j with the end portion 201h1 removed. Produced.

  In S ″ 5, the belt-shaped flexible support (organic EL element protected by the sealing layer) on which the organic EL element was formed was wound around the winding core to be protected by the sealing layer. The production of the roll-shaped organic EL element 901 is completed. Note that, if necessary, the sheet may be cut continuously in accordance with the size of the first electrode layer. In the case of cutting, the adhesive is preferably formed only on the outer periphery of the organic compound layer (light emitting layer) by a dispenser, screen printing or the like.

  Thereafter, it may be continuously cut into a sheet shape in accordance with the size of the first electrode layer, or it may be once wound around the winding core.

  Next, other structural members used for the configuration of the organic EL element according to the present invention will be described. Examples of the layer provided adjacent to the organic compound layer (light emitting layer) include a blocking layer. Examples of the blocking layer include a hole blocking layer and an electron blocking layer. The blocking layer is provided as necessary in addition to the basic constituent layer of the organic compound thin film. For example, it is described in JP-A Nos. 11-204258, 11-204359, and “Organic EL elements and their forefront of industrialization” (issued by NTT, Inc. on November 30, 1998). There is a hole blocking (hole blocking) layer. The hole blocking layer has a function of an electron transport layer in a broad sense, and is made of a hole blocking material that has a function of transporting electrons and has a remarkably small ability to transport holes. By blocking this, the recombination probability of electrons and holes can be improved. Further, the structure of the electron transport layer described later can be used as a hole blocking layer according to the present invention as necessary, and the hole blocking layer is provided adjacent to the organic compound layer (light emitting layer). It is preferable.

  When the organic compound layer (light-emitting layer) has a plurality of light-emitting layers with different emission colors, the light-emitting layer whose emission maximum wavelength is the shortest is preferably closest to the anode among all the light-emitting layers, In such a case, it is preferable to additionally provide a hole blocking layer between the shortest wave layer and the light emitting layer next to the anode next to the anode. Furthermore, it is preferable that 50% by mass or more of the compound contained in the hole blocking layer provided at the position has an ionization potential of 0.3 eV or more higher than the host compound of the shortest wave emitting layer.

  The ionization potential is defined by the energy required to emit electrons at the HOMO (highest occupied molecular orbital) level of the compound to the vacuum level, and can be obtained by the following method, for example. (1) Keywords using Gaussian 98 (Gaussian 98, Revision A.11.4, MJ Frisch, et al, Gaussian, Inc., Pittsburgh PA, 2002.), which is molecular orbital calculation software manufactured by Gaussian, USA. The ionization potential can be obtained as a value obtained by rounding off the second decimal place of the value (eV unit conversion value) calculated by performing structural optimization using B3LYP / 6-31G *. This calculation value is effective because the correlation between the calculation value obtained by this method and the experimental value is high. (2) The ionization potential can also be obtained by a method of directly measuring by photoelectron spectroscopy. For example, a low energy electron spectrometer “Model AC-1” manufactured by Riken Keiki Co., Ltd. or a method known as ultraviolet photoelectron spectroscopy can be suitably used.

  On the other hand, the electron blocking layer has a function of a hole transport layer in a broad sense, and is made of a material that has a function of transporting holes and has an extremely small ability to transport electrons, and transports electrons while transporting holes. By blocking, the 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 nm to 100 nm, and more preferably 5 nm to 30 nm.

  The organic compound layer (light emitting layer) constituting the organic EL device of the present invention has a known host compound and a known phosphorescent compound (phosphorescent) in order to increase the light emission efficiency of the organic compound layer (light emitting layer). It is preferable to contain a luminescent compound.

  The host compound is a compound contained in the light-emitting layer, the mass ratio in the layer is 20% or more, and the phosphorescence quantum yield of phosphorescence emission is 0.1 at room temperature (25 ° C.). Is defined as less than a compound. The phosphorescence quantum yield is preferably less than 0.01. A plurality of host compounds may be used in combination. By using a plurality of types of host compounds, it is possible to adjust the movement of charges, and the organic EL element can be made highly efficient. In addition, by using a plurality of phosphorescent compounds, it is possible to mix different light emission, thereby obtaining an arbitrary emission color. White light emission is possible by adjusting the kind of phosphorescent compound and the amount of doping, and can also be applied to illumination and backlight.

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

  When the organic compound layer (light emitting layer) has a plurality of light emitting layers, it is easy to obtain a uniform film property over the entire organic layer that 50% by mass or more of the host compound in each layer is the same compound. Further, it is more preferable that the phosphorescence emission energy of the host compound is 2.9 eV or more because it is advantageous in efficiently suppressing energy transfer from the dopant and obtaining high luminance. Phosphorescence emission energy means the peak energy of the 0-0 band of phosphorescence emission when the photoluminescence of a deposited film of 100 nm is measured on a substrate with a host compound.

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

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

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

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

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

  In the present invention, the phosphorescence emission maximum wavelength of the phosphorescent compound is not particularly limited, and can be obtained in principle by selecting a central metal, a ligand, a ligand substituent, and the like. The emission wavelength can be changed.

  The light emission color of the organic EL device of the present invention and the compound according to the present invention is shown in FIG. 4.16 on page 108 of “New Color Science Handbook” (edited by the Japan Color Society, University of Tokyo Press, 1985). It is determined by the color when the result measured with the total CS-1000 (manufactured by Konica Minolta Sensing) is applied to the CIE chromaticity coordinates.

The white element referred to in the present invention means that the chromaticity in the CIE1931 color system at 1000 Cd / m ² is X = 0.33 ± 0.07 when the front luminance at 2 ° C. viewing angle is measured by the above method. It is in the region of Y = 0.33 ± 0.07.

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

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

  In the gap between the sealing member (sealing film and sealing film shown in FIG. 1) and the display area of the organic EL element, in the gas phase and the liquid phase, an inert gas such as nitrogen or argon, or fluorocarbon It is preferable to inject an inert liquid such as hydrogen or silicon oil. A vacuum can also be used. Moreover, a hygroscopic compound can also be enclosed inside. Examples of the hygroscopic compound include metal oxides (eg, sodium oxide, potassium oxide, calcium oxide, barium oxide, magnesium oxide, aluminum oxide), sulfates (eg, sodium sulfate, calcium sulfate, magnesium sulfate, cobalt sulfate, etc.). Metal halides (eg, calcium chloride, magnesium chloride, cesium fluoride, tantalum fluoride, cerium bromide, magnesium bromide, barium iodide, magnesium iodide, etc.), perchloric acids (eg, barium perchlorate, In particular, anhydrous salts are preferably used in sulfates, metal halides and perchloric acids.

  The organic EL device of the present invention preferably uses the following method in combination in order to efficiently extract light generated in the light emitting layer. The organic EL element emits light inside a layer having a refractive index higher than that of air (refractive index is about 1.7 to 2.1), and only about 15% to 20% of the light generated in the light emitting layer can be extracted. It is generally said that there is no. This is because the light incident on the interface (interface between the transparent substrate and air) at an angle θ greater than the critical angle causes total reflection and cannot be taken out of the element, or the transparent electrode or light emitting layer and the transparent substrate This is because the light undergoes total reflection between them, and the light is guided through the transparent electrode or the light emitting layer.

  As a method for improving the light extraction efficiency, for example, a method of forming irregularities on the surface of the transparent substrate to prevent total reflection at the interface between the transparent substrate and the air (US Pat. No. 4,774,435). A method for improving efficiency by providing a substrate with a light condensing property (JP-A-63-314795). A method of forming a reflective surface on the side surface of an element (Japanese Patent Laid-Open No. 1-220394). A method of forming an antireflection film by introducing a flat layer having an intermediate refractive index between a substrate and a light emitter (Japanese Patent Laid-Open No. 62-172691). A method of introducing a flat layer having a lower refractive index than the substrate between the substrate and the light emitter (Japanese Patent Laid-Open No. 2001-202827). There is a method of forming a diffraction grating between any one of a substrate, a transparent electrode layer, and a light emitting layer (including between the substrate and the outside) (Japanese Patent Laid-Open No. 11-283951).

  In the present invention, these methods can be used in combination with an organic EL element. However, a method of introducing a flat layer having a lower refractive index than the substrate between the substrate and the light emitter, or a substrate, a transparent electrode layer, A method of forming a diffraction grating between any layers of 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 low refractive index medium is formed between the transparent electrode and the transparent substrate with a thickness longer than the wavelength of light, the light extracted from the transparent electrode has a higher extraction efficiency to the outside as the refractive index of the medium is lower. . Examples of the low refractive index layer include aerogel, porous silica, magnesium fluoride, and a fluorine-based polymer. Since the refractive index of the transparent substrate is generally about 1.5 to 1.7, the low refractive index layer preferably has a refractive index of about 1.5 or less. Further, it is preferably 1.35 or less. The thickness of the low refractive index medium is preferably at least twice the wavelength in the medium. This is because the effect of the low refractive index layer is diminished when the thickness of the low refractive index medium is about the wavelength of light and the electromagnetic wave that has exuded by evanescent enters the substrate. The method of introducing a diffraction grating into an interface or any medium that causes total reflection is characterized by a high effect of improving light extraction efficiency. This method is generated from the light emitting layer by utilizing the property that the diffraction grating can change the direction of light to a specific direction different from refraction by so-called Bragg diffraction such as first-order diffraction and second-order diffraction. Of the light, the light that cannot go out due to total reflection between layers, etc. is diffracted by introducing a diffraction grating into any layer or medium (inside a transparent substrate or transparent electrode) , Trying to extract light out. The introduced diffraction grating desirably has a two-dimensional periodic refractive index. This is because light emitted from the light-emitting layer is randomly generated in all directions, so in a general one-dimensional diffraction grating having a periodic refractive index distribution only in a certain direction, only light traveling in a specific direction is diffracted. The light extraction efficiency does not increase so much. However, by making the refractive index distribution a two-dimensional distribution, light traveling in all directions is diffracted, and light extraction efficiency is increased.

  As described above, the position where the diffraction grating is introduced may be in any of the layers or in the medium (in the transparent substrate or 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 gratings is preferably two-dimensionally repeated, such as a square lattice, a triangular lattice, or a honeycomb lattice.

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

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

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

Example 1
<Preparation of strip-shaped flexible support having gas barrier layer and first electrode layer in this order>
Using a 200 μm thick polyethersulfone (a film manufactured by Sumitomo Bakelite Co., Ltd., hereinafter abbreviated as PES), a gas barrier layer and a first electrode layer are formed by the method described below, and a winding roll is formed on the winding core. A belt-like flexible support having a gas barrier layer and a first electrode layer in this order was prepared.

(Formation of a transparent gas barrier layer)
A transparent gas barrier layer having a thickness of about 90 nm was formed on the prepared PES by an atmospheric pressure plasma discharge treatment method. As a result of measuring the water vapor transmission rate by a method based on JISk-7129B, it was 10 ⁻³ g / m ² / day or less. As a result of measuring the oxygen transmission rate by a method based on JISk-7126B, it was 10 ⁻³ g / m ² / day or less.

(Formation of first electrode layer)
On the barrier layer thus formed, ITO (indium tin oxide) having a thickness of 120 nm was patterned by an evaporation method to form a first electrode layer.

<Formation of organic compound layer (light emitting layer)>
The process shown in FIG. 2 is used, and the following is shown on the first electrode layer of the belt-like flexible support having the gas barrier layer and the first electrode layer in this order on the prepared winding core. After applying and drying the coating liquid for forming the hole transport layer by a wet coating method using an extrusion coating machine, the charge removal treatment is performed, and subsequently, the coating for forming the organic compound layer (light emitting layer) is formed on the pulling hole transport layer. As shown in Table 1, the liquid is applied and dried under the conditions shown below by varying the transport speed when applying the coating liquid for forming an organic compound layer (light emitting layer) by a wet coating method using an extrusion coating machine. After forming the organic compound layer (light emitting layer), it was subjected to charge removal treatment, cooled to the same temperature as the room temperature, and then taken up into a winding roll shape on the winding core. 101-108. The conveyance speed is measured with a laser Doppler velocimeter LV203 manufactured by Mitsubishi Electric Corporation, and the variation in the conveyance speed indicates a value expressed in% of the root mean square with respect to the average speed. The variation in the conveyance speed was changed by changing the conveyance speed.

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

  The coating liquid for forming the hole transport layer was applied so that the thickness after drying was 50 nm. The coating solution for forming the organic compound layer (light emitting layer) was applied so that the thickness after drying was 100 nm. The conveyance speed was 2 m / min.

Preparation of coating solution for forming hole transport layer Polyethylene dioxythiophene / polystyrene sulfonate (PEDOT / PSS, Baytron P AI 4083 manufactured by Bayer) diluted with pure water 65% and methanol 5% to form hole transport layer It was prepared as a coating solution. The surface tension of the coating liquid for forming a hole transport layer was 0.04 Nm (manufactured by Kyowa Interface Chemical Co., Ltd .: surface tension meter CBVP-A3).

Preparation of organic compound layer forming coating solution 5% by mass of dopant material Ir (ppy) 3 in polyvinylcarbazole (PVK) as a host material in 1,2-dichloroethane to form a 10% solution Prepared as. The surface tension of the coating solution for forming an organic compound layer was 0.032 Nm (manufactured by Kyowa Interface Chemical Co., Ltd .: surface tension meter CBVP-A3). The glass transition temperature of the organic compound layer was 225 ° C. In addition, although the material which has green light emission was used for this example, it is possible to produce a white organic EL element by laminating | stacking further using blue, red, and a dopant material.

Drying and Heating Treatment Conditions After applying the hole transport layer forming coating solution, the first drying device and the first heat treatment device shown in FIG. 2 are used. After removing the solvent at a height of 100 mm, a discharge wind speed of 1 m / s, a wide wind speed distribution of 5%, and a temperature of 100 ° C., a backside heat transfer system heat treatment is subsequently performed at a temperature of 200 ° C. in a first heat treatment apparatus. A hole transport layer was formed.

  After applying the organic compound layer (light emitting layer) forming coating solution, the second drying device and the second heat treatment device shown in FIG. 2B are used. In the second drying device, the slit nozzle type discharge port is used. After removing the solvent at a height of 100 mm toward the film forming surface, a discharge wind speed of 1 m / s, a wide wind speed distribution of 5%, and a temperature of 60 ° C., a second heat treatment apparatus is then used for heat treatment at a temperature of 220 ° C. A compound layer (light emitting layer) was formed.

Coating conditions The temperature at the time of application of the coating liquid for forming a hole transport layer was 25 ° C., and the temperature at the time of coating of the coating liquid for forming an organic compound layer was 25 ° C. in an atmospheric environment. The wet coating process was performed with a dew point temperature of −20 ° C. or lower and a cleanliness class 5 or lower (JIS B 9920).

Evaluation The produced sample No. Table 1 shows the results of evaluation of emission luminance unevenness according to the following evaluation ranks attached to 101 to 108.

Method for measuring unevenness of light emission luminance The light emission luminance (cd / m ² ) when a DC voltage of 10 V is applied is manufactured by Konica Minolta Co., Ltd.
It measured using CS-1000 and calculated | required from the formula shown below.

Emission luminance unevenness (%) = (difference between maximum emission luminance−minimum emission luminance) / maximum emission luminance × 100
Evaluation rank of light emission unevenness ○: Light emission unevenness is less than 10% Δ: Light emission unevenness is 10% or more, less than 15% ×: Light emission unevenness is 15% or more

  Sample No. Although the 101 luminance unevenness showed a good result, it is effective to increase the average conveyance speed in order to suppress the variation in the conveyance speed. However, since the conveyance speed increases, the drying apparatus becomes larger than necessary, and the energy efficiency There is a concern that will decrease. The effectiveness of the present invention was confirmed.

Example 2
Sample No. 1 prepared in Example 1 was used. Table 2 shows the drying conditions (discharge air speed, the air speed distribution in the width direction of the organic compound layer (light emitting layer) coating film) after applying the coating liquid for forming the organic compound layer (light emitting layer). The organic compound layer was formed, cooled to room temperature, and wound into a winding roll shape on the winding core. 201-214. The discharge wind speed was measured with a hot air anemometer model 6113 manufactured by Kanomax Co., Ltd., and the wind speed distribution in the width direction was calculated by the following formula.

Wind speed distribution = (maximum wind speed−minimum wind speed) / average wind speed × 100
Evaluation The produced sample No. Table 2 shows the results of evaluations according to the evaluation ranks shown below.

○: No coating surface unevenness or surface roughness △: Slight coating surface unevenness or surface roughness that is not a problem in practice is observed in part ×: Coating surface unevenness or surface roughness is recognized over the entire surface

  The effectiveness of the present invention was confirmed.

Example 3
Sample No. 1 prepared in Example 1 was used. 103, the organic compound layer was formed under the same conditions except that the surface tension of the (light emitting layer) of the coating solution for forming an organic compound layer was changed as shown in Table 3, and then cooled to room temperature and wound. Sample No. was made into a winding roll shape on the core. 301 to 307. The surface tension is a value measured by Kyowa Interface Chemical Co., Ltd .: surface tension meter CBVP-A3.

Evaluation The produced sample No. Table 3 shows the results of the evaluation of the state of the coating film surface by visual observation 301 to 307 according to the evaluation rank shown below.

○: No coating surface unevenness or surface roughness △: Slight coating surface unevenness or surface roughness that is not a problem in practice is observed in part ×: Coating surface unevenness or surface roughness is recognized over the entire surface

  The effectiveness of the present invention was confirmed.

Example 4
Sample No. 1 prepared in Example 1 was used. 103, the coating solution for forming the organic compound layer (light emitting layer) was applied, and the conditions for the heat treatment after drying were changed as shown in Table 4, and all the conditions were the same, and the organic compound layer ( After the light emitting layer is formed, the sample is cooled to room temperature, and a winding roll is formed on the winding core. 401-408.

Evaluation The produced sample No. Table 4 shows the results of evaluating the lifetime of the organic compound layer (light emitting layer) attached to 401 to 408. The lifetime of the organic compound layer (light-emitting layer) is the time required for the luminance to be half of the initial luminance when driven at a constant current of ^2.5 mA / cm ² (half time) as an indicator of the lifetime. The case where no heat treatment was performed was set as 100, and the evaluation was performed based on the relative value. The heat treatment temperature indicates the temperature relative to the glass transition temperature (225 ° C.) of the organic compound layer (light emitting layer).

  The effectiveness of the present invention was confirmed.

Example 5
Sample No. 1 prepared in Example 1 was used. 103 is applied, a hole transport layer forming coating solution and an organic compound layer (light emitting layer) forming coating solution are applied, and the environmental conditions until the hole transport layer and the organic compound layer (light emitting layer) are formed ( All samples were processed under the same conditions except that the dew point temperature and cleanliness were changed as shown in Table 5. After forming the organic compound layer (light emitting layer), the sample was cooled to room temperature and wound into a winding roll around the sample. No. 501-507. The cleanliness indicates a value measured according to JISB 9920, and the cleanliness was changed by changing the filter. In addition, since the coating temperature of the coating solution for forming the hole transport layer and the coating solution for forming the organic compound layer (light emitting layer) was 25 ° C., the temperature was 25 ° C. and the atmospheric pressure condition except for the drying device and the heat treatment device. I went there.

Evaluation The produced sample No. Table 5 shows the results of visually confirming the non-light-emitting failure and the evaluation according to the following evaluation rank.

Method for Confirming Non-Luminous Failure After the prepared sample was stored in a constant temperature room at 80 ° C. for 1 week, it was visually confirmed whether or not there was a portion that did not emit light when driven at a constant current of ^2.5 mA / cm ² . Evaluation rank of non-luminescent failure ○: No non-luminescent failure is confirmed △: Slight non-luminescent failure that does not cause a practical problem is recognized ×: Non-luminescent failure that causes a practical problem is occasionally seen

  Sample No. In the case of 501, depending on the amount of water contained in the sample, the sample No. In the case of 504, it is presumed that a non-light emission failure has occurred due to the adhered foreign matter. The effectiveness of the present invention was confirmed.

Example 6
Sample No. 1 prepared in Example 1 was used. The sample No. 103 was stored under the same conditions except that the conditions for storing 103 were changed as shown in Table 6 and processed. 601-606. The storage period was 5 days.

Evaluation The produced sample No. Table 6 shows the results of measuring the same evaluation items as in Example 4 with the same measurement method as in 601 to 606. The life (relative value) is a relative value when the life is 100 when the storage condition is 10 ⁻⁵ Pa.

  Sample No. Although the life (relative value) 606 shows a good value, it becomes a large-scale facility to maintain a high degree of vacuum with respect to the obtained effect, and there is a concern about maintenance and management of the facility and an increase in cost. The effectiveness of the present invention was confirmed.

Claims (15)

An organic EL element having a first electrode, an organic compound layer, a second electrode, and a sealing layer or a sealing film in this order on a strip-like flexible support, a supply unit, and a coating unit In the method for forming an organic compound layer formed using a manufacturing apparatus having a drying unit and a recovery unit,
Supply the strip-shaped flexible support A on which the first electrode is formed to the supply unit in a roll state wound around a winding core,
Next, the organic compound layer forming coating solution is applied and dried in the coating unit / drying unit, and the organic compound layer is formed on the strip-shaped flexible support A to form a strip-shaped flexible support B.
In the collection unit, the belt-like flexible support B is wound around a winding core,
The organic compound layer is coated with the organic compound layer by air-flow drying in which the air velocity distribution in the width direction of the coating film for the organic compound layer is 0.1 to 10% in the drying unit. A method for producing an organic EL device, which is formed by removing a solvent from a film.   The coating part / drying part removes the solvent in the organic compound layer under an atmospheric pressure condition by applying an organic compound layer-forming coating solution on the atmospheric pressure condition with a wet coating apparatus. 2. The method of manufacturing an organic EL element according to claim 1, wherein the drying unit that forms the compound layer is one unit, and the manufacturing apparatus includes at least one unit of the coating unit and the drying unit.   3. The belt-like flexible support A is subjected to a cleaning surface modification treatment by a washing surface modification treatment means before applying the organic compound layer forming coating solution. The manufacturing method of the organic EL element of description.   4. The method of manufacturing an organic EL element according to claim 3, wherein the cleaning surface modification processing means is oxygen plasma or UV irradiation.   The strip-like flexible support A is subjected to a charge removal process by a charge removal process means before the coating liquid for forming an organic compound layer is applied. Manufacturing method of organic EL element.   The belt-like flexible support A is characterized in that the variation in the conveyance speed when applying the coating solution for forming an organic compound layer is 0.2 to 10% with respect to the average conveyance speed. 6. The method for producing an organic EL element according to any one of 5 above. The coating liquid for forming an organic compound layer has at least one organic compound material and at least one solvent, and has a surface tension of 15 × 10 ^{−3 to} 55 × 10 ⁻³ N / m. The manufacturing method of the organic EL element of any one of Claims 1 thru | or 6 characterized by the above-mentioned.   The said manufacturing apparatus has a heat processing part after a drying part, The manufacturing method of the organic EL element of any one of Claim 1 thru | or 7 characterized by the above-mentioned.   Immediately after forming the organic compound layer in the drying unit, the heat treatment unit is -30 to + 30 ° C. with respect to the glass transition temperature of the organic compound layer and does not exceed the decomposition temperature of the organic compound in the organic compound layer The method for manufacturing an organic EL element according to claim 8, wherein a back-surface heat transfer type heat treatment is performed. The organic compound layer has a dew point temperature of −20 ° C. or lower, conforms to JISB 9920, has a measured cleanliness of class 5 or lower, and an atmospheric pressure condition of 10 to 45 ° C. excluding a drying section and a heat treatment section. It forms, The manufacturing method of the organic EL element of any one of Claim 1 thru | or 9 characterized by the above-mentioned.   The method for producing an organic EL element according to any one of claims 1 to 10, wherein the organic compound layer includes at least a hole transport layer and an organic light emitting layer. The method for producing an organic EL element according to any one of claims 1 to 11, wherein the belt-like flexible support B is stored under a reduced pressure condition of 10 ^-5 to 10 Pa. An organic EL element having a first electrode, an organic compound layer, a second electrode, and a sealing layer in this order on the belt-like flexible support, a supply unit, a coating unit / drying unit, In the method of manufacturing an organic EL element manufactured using a manufacturing apparatus having a cathode layer forming part, a sealing layer forming part, and a recovery part,
Supply the strip-shaped flexible support A on which the first electrode is formed to the supply unit in a roll state wound around a winding core,
Next, in the coating part / drying part, a coating solution for forming an organic compound layer is applied and dried to form the organic compound layer on the strip-shaped flexible support A to form a strip-shaped flexible support B.
In the first winding part, the strip-shaped flexible support B is wound into a winding roll around the winding core,
Using the roll-shaped strip-like flexible support B, forming a cathode layer including a second electrode under reduced pressure conditions on the organic compound layer in the cathode layer forming portion,
Subsequently, after forming a sealing layer under reduced pressure on the cathode layer in the sealing layer forming part and forming an organic EL element, it is made into a winding roll shape on the winding core in the recovery step,
The organic compound layer is coated with the organic compound layer by air-flow drying in which the air velocity distribution in the width direction of the coating film for the organic compound layer is 0.1 to 10% in the drying unit. A method for producing an organic EL device, which is formed by removing a solvent from a film. An organic EL device having a first electrode, an organic compound layer, a second electrode, and a sealing film in this order on a strip-like flexible support, a supply unit, a coating unit / drying unit, In the manufacturing method of an organic EL element manufactured using a manufacturing apparatus having a cathode layer forming part, a sealing film sticking part, and a recovery part,
Supply the strip-shaped flexible support A on which the first electrode is formed to the supply unit in a roll state wound around a winding core,
Next, in the coating part / drying part, a coating solution for forming an organic compound layer is applied and dried to form the organic compound layer on the strip-shaped flexible support A to form a strip-shaped flexible support B.
Using the roll-shaped strip-shaped flexible support B, a cathode layer including a second electrode is formed on the organic compound layer under reduced pressure conditions on the cathode layer forming portion to form a strip-shaped flexible support C.
In the second winding part, the belt-like flexible support C is wound into a winding roll around the winding core,
Using the roll-like strip-like flexible support C, the sealing film is applied on the cathode layer under inert gas conditions at the sealing film application part,
The organic compound layer is coated with the organic compound layer by air-flow drying in which the air velocity distribution in the width direction of the coating film for the organic compound layer is 0.1 to 10% in the drying unit. A method for producing an organic EL device, which is formed by removing a solvent from a film.   The coating part / drying part removes the solvent in the organic compound layer under an atmospheric pressure condition by applying an organic compound layer-forming coating solution on the atmospheric pressure condition with a wet coating apparatus. 15. The method of manufacturing an organic EL element according to claim 13, wherein the drying unit forming the compound layer is one unit, and the manufacturing apparatus has at least one unit of the coating unit / drying unit.