JP2011222385A - Organic electroluminescent element manufacturing method and organic electroluminescent element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic electroluminescent element manufacturing method, with which adhesion of foreign matter is reduced, an influence on an application property in an application process is prevented, and occurrence of dark sports is suppressed, and an organic electroluminescent element obtained using the organic electroluminescent element manufacturing method.SOLUTION: An organic electroluminescent element manufacturing method includes: forming a transparent conductive film on a flexible base material; and then forming at least one organic compound layer which includes a light-emitting layer, and a counter electrode layer on the transparent conductive film. In the manufacturing method, after the transparent conductive film is formed on the flexible base material and a surface of the transparent conductive film is cleaned using an organic solvent for cleaning, the at least one organic compound layer is formed on the transparent conductive film using an application solution containing an organic solvent for application having a vapor pressure that is equal to or higher than a vapor pressure of the organic solvent for cleaning.

Description

  The present invention relates to a method for producing an organic electroluminescent element and an organic electroluminescent element obtained thereby.

  An organic electroluminescence element (hereinafter also referred to as an organic EL element) is an element that performs an electrical operation using an organic substance. In recent years, an organic electroluminescence element is expected to exhibit features such as energy saving, low cost, and flexibility. It attracts attention as an alternative technology to inorganic semiconductors mainly composed of silicon.

  An organic EL element is an element that emits light by controlling a current through an electrode through a very thin film of organic matter, controls the current or voltage, or generates electricity or charges by irradiating light. It is. Among them, the organic electroluminescence panel can be obtained in fields such as display use and illumination use, in particular, a thin surface light source.

  In the manufacturing process of such an organic EL element, even if a minute dust (foreign matter) of several μm or less is mixed, it causes a problem. For example, dust adheres to the substrate on which the electrode is formed. Even if an organic compound thin film on the order of several nanometers is formed thereon, a uniform thin film cannot be formed, which causes a leakage current.

  In order to solve the problem of foreign matter adhesion as described above, many cleaning methods have been proposed. As a typical cleaning method, for example, an ultrasonic cleaning method in which a substrate is immersed in a cleaning liquid tank filled with a cleaning liquid, an ultrasonic vibrator is vibrated, and cleaning is performed with ultrasonic energy propagating through the cleaning liquid ( For example, refer to Patent Document 1), or a cleaning method performed using a flowing water method (for example, refer to Patent Document 2), or a cleaning method for cleaning using a high-pressure cleaning nozzle that ejects high-pressure liquid (for example, refer to Patent Document 3). Etc.) are disclosed. However, all of the proposed methods have a drawback that moisture is difficult to escape with a flexible substrate because water is used as a cleaning medium.

  In the case of organic EL elements, the lifetime of the elements is significantly reduced due to the influence of moisture, oxygen, etc., and if the dehydration treatment is insufficient, damage to the organic EL elements will increase. Therefore, it is necessary to carry out heat treatment for a long period of time, resulting in a production method with poor production efficiency.

  Therefore, as a method for removing moisture, a method has been proposed in which a substrate is exposed to an organic solvent vapor under reduced pressure to replace moisture and dehydrate (see, for example, Patent Documents 4 and 5). Usually, it took a long time to dry the flexible substrate, and it was not possible to sufficiently dehydrate it. In addition, commercially available alternative chlorofluorocarbons (for example, HFC (hydrofluorocarbon), PFC (perfluorocarbon), hydrochlorofluorocarbon (HCFC)) are highly volatile and can remove moisture, but prevent global warming. From the point of view, it may be subject to reduction and may become unusable in the future. Accordingly, there is a demand for the development of a dehydration method that is both environmentally friendly and has both a cleaning effect and moisture volatility.

JP 2002-93765 A JP-A-10-309548 Japanese Patent Laid-Open No. 9-171986 JP 2009-181770 A Japanese Patent Publication No. 7-89547

  The present invention has been made in view of the above problems, and its purpose is that there is little adhesion of foreign matter due to poor cleaning, less applicability in the coating process of the organic electroluminescence element, and there is no moisture or residual solvent. An object of the present invention is to provide a method for producing an organic electroluminescence device in which the generation of dark spots due to influence is suppressed and an organic electroluminescence device obtained thereby.

  The above object of the present invention is achieved by the following configurations.

  1. Manufacture of an organic electroluminescence device manufactured by forming a transparent conductive film on a flexible substrate and then forming at least one organic compound layer including a light emitting layer and a counter electrode layer on the transparent conductive film In the method, the transparent conductive film is formed on a flexible substrate, the surface of the transparent conductive film is cleaned with a cleaning organic solvent, and then the vapor pressure of the cleaning organic solvent is set on the transparent conductive film. A method for producing an organic electroluminescence device, comprising producing at least one layer of the organic compound layer using a coating solution containing a coating organic solvent having a vapor pressure equal to or higher than that.

  2. 2. The organic electroluminescence device according to 1 above, wherein the surface of the transparent conductive film is washed with the cleaning organic solvent, and then the transparent conductive film is heated and dried at a temperature of 50 ° C. or more and 150 ° C. or less. Manufacturing method.

  3. 3. The method for producing an organic electroluminescent element according to 1 or 2, wherein the cleaning organic solvent has a vapor pressure of 2.5 kPa or more and 25 kPa or less.

  4). 4. The method for producing an organic electroluminescent element according to any one of 1 to 3, wherein a vapor pressure of the organic solvent for coating is 2.5 kPa or more and 25 kPa or less.

  5. The cleaning organic solvent is at least one selected from alcohols, fatty acid esters, ketones, aromatic hydrocarbons, halogenated hydrocarbons, aliphatic hydrocarbons, amines, nitriles and ethers. 5. The method for producing an organic electroluminescent element according to any one of 1 to 4, wherein the organic electroluminescent element is provided.

  6). The organic solvent for coating is at least one selected from alcohols, fatty acid esters, ketones, aromatic hydrocarbons, halogenated hydrocarbons, aliphatic hydrocarbons, amines, nitriles and ethers. 6. The method for producing an organic electroluminescent element according to any one of 1 to 5, wherein the organic electroluminescent element is provided.

  7). All the layers of the said organic compound layer are formed with the coating liquid containing the said organic solvent for application | coating, The manufacturing method of the organic electroluminescent element of any one of said 1-6 characterized by the above-mentioned.

  8). 8. The organic electroluminescence device according to any one of 1 to 7 above, wherein at least one of the organic compound layers is formed of a coating solution containing 70% by mass or more of the coating organic solvent. Method.

  9. 9. An organic electroluminescence device manufactured by the method for manufacturing an organic electroluminescence device according to any one of 1 to 8 above.

  According to the present invention, there is little adhesion of foreign matter due to poor cleaning, little influence on the coating property in the coating process of the organic electroluminescence element, and the generation of dark spots due to the influence of moisture and residual solvent is suppressed. And an organic electroluminescence device obtained thereby.

It is a schematic diagram which shows the fundamental structure of the whole organic EL element of this invention. It is a block diagram which shows an example of the manufacture order of the organic EL element of this invention. It is a schematic diagram which shows an example of the manufacturing process of the organic EL element of this invention. It is a figure which shows the measurement points AE in the brightness nonuniformity tolerance evaluation of an Example.

  Hereinafter, embodiments for carrying out the present invention will be described in detail.

  As a result of intensive studies in view of the above problems, the present inventor has formed a transparent conductive film on a flexible substrate, and then, on the transparent conductive film, at least one organic compound layer including a light emitting layer and In the method of manufacturing an organic electroluminescence element manufactured by forming a counter electrode layer, after forming the transparent conductive film on a flexible substrate and cleaning the surface of the transparent conductive film with an organic solvent for cleaning, On the transparent conductive film, at least one layer of the organic compound layer is formed by using a coating solution containing a coating organic solvent having a vapor pressure equal to or higher than the vapor pressure of the cleaning organic solvent. The organic electroluminescence device manufacturing method characterized by the above has less adhesion of foreign matters due to poor cleaning, has less influence on the coating property in the coating process of the organic electroluminescence device, and is less affected by the influence of moisture and residual solvent. Found that it is possible to generate the click spot to achieve a method for manufacturing an organic electroluminescent device is suppressed, it is completed the invention.

  That is, in the method for producing an organic electroluminescent element of the present invention, an organic solvent for coating having the same or higher vapor pressure than the organic solvent for cleaning used for cleaning is used for the coating liquid for forming at least one organic compound layer. This makes it possible to reduce the residual solvent that permeates the substrate during cleaning, and further significantly reduces the occurrence of dark spots due to dust adhesion and moisture without affecting the coating properties. However, in the cleaning organic solvent according to the present invention, water does not correspond to the cleaning organic solvent.

  In addition, the vapor pressure (kPa) of the organic solvent in the present invention means a literature value at 20 ° C. (for example, described in the new edition, Solvent Pocketbook, edited by Organic Synthetic Chemistry Association, Ohm Co., etc.). The higher the value, the easier it is to volatilize. Further, the organic solvent for cleaning or coating may be one kind or a mixed solvent of plural kinds, and the cleaning liquid or coating liquid contains 30% by mass or more of the organic solvent of each total mass. It is defined that it should be done. Preferably, it contains 50% by mass or more of organic solvent, and more preferably contains 70% by mass or more of organic solvent. In particular, in the present invention, the ratio of the coating organic solvent contained in the coating solution for forming the organic compound layer is preferably 70% by mass or more.

  In the present invention, the vapor pressure in a system in which two or more organic solvents are mixed is defined as a value obtained by multiplying each volume ratio by the vapor pressure.

  The organic solvent for washing or the organic solvent for coating according to the present invention is not particularly limited, but in particular alcohols, fatty acid esters, ketones, aromatic hydrocarbons, halogenated hydrocarbons, aliphatic hydrocarbons. It is preferably at least one selected from the group consisting of amines, amines, nitriles and ethers. Specifically, for example, methanol (13.0 kPa), ethanol (6.0 kPa), isopropyl alcohol (4.4 kPa), n Alcohols such as -propanol (2.0 kPa), n-butanol (0.6 kPa), 2-butanol (1.7 kPa), t-butyl alcohol (0.6 kPa), acetone (24.7 kPa), methyl ethyl ketone (9 .6 kPa), ketones such as cyclohexanone (0.5 kPa), ethyl acetate (10.0 kPa) a), fatty acid esters such as butyl acetate (1.0 kPa) and isopropyl acetate (5.8 kPa), halogenated hydrocarbons such as dichlorobenzene (0.1 kPa), toluene (2.9 kPa), xylene (0. 8 kPa), mesitylene (0.2 kPa), aromatic hydrocarbons such as styrene (0.6 kPa), cyclohexane (12.7 kPa), aliphatic hydrocarbons such as decalin (1.3 kPa), dimethylformamide (3.5 kPa) ), Amines such as propionitrile (5.2 kPa), diethyl ether (5.9 kPa), isopropyl ether (21.1 kPa), methyl propyl ether (5.1 kPa), dioxane (3.6 kPa) , Ethers such as tetrahydrofuran (19.3 kPa), and the like. Among these, an organic solvent having a higher vapor pressure than water (2.3 kPa) that does not correspond to the cleaning organic solvent according to the present invention is preferable. In addition, the numerical value in a parenthesis is a value of a vapor pressure (20 degreeC).

  The organic EL device manufacturing method of the present invention is characterized in that the vapor pressure of the coating organic solvent is equal to or higher than the vapor pressure of the cleaning organic solvent. The vapor pressure difference (vapor pressure of coating organic solvent-vapor pressure of cleaning organic solvent) is preferably 0 kPa or more and 35 kPa or less, more preferably 0 kPa or more and 15 kPa or less.

  Moreover, in the manufacturing method of the organic EL element of this invention, it is preferable that the vapor pressure of the organic solvent for washing | cleaning or the organic solvent for application | coating is 2.5 kPa or more and 25 kPa or less, respectively.

  In the method for producing an organic EL element of the present invention, after forming a transparent conductive film on a flexible substrate, the surface of the transparent conductive film is cleaned using a cleaning organic solvent. .

  The cleaning time of the surface of the transparent conductive film using the organic solvent for cleaning is immediately after forming the transparent conductive film on the flexible base material, even if it is continuously cleaned online, or like roll-to-roll, Once the roll is wound, it may be washed off-line again.

  Any method may be used for cleaning the flexible substrate on which the transparent conductive film is formed. However, in the present invention, the ultrasonic cleaning tank containing the cleaning organic solvent according to the present invention is flexible. A method using wet cleaning such as immersing and cleaning the substrate and further combining a dry cleaning method such as plasma cleaning is preferable. Although it does not specifically limit as temperature of the washing | cleaning liquid containing the organic solvent for washing | cleaning which concerns on this invention at the time of washing | cleaning, It is preferable that it is the range of 10-40 degreeC, and it is still more preferable that it is the range of 15-30 degreeC.

  In the method for producing an organic EL device of the present invention, the surface of the transparent conductive film is washed with a washing organic solvent as described above, and then the residual amount of the organic solvent in the flexible substrate is reduced. From the viewpoint of securing the stability of the organic EL device including the organic compound layer to be formed, the surface of the transparent conductive film is washed with an organic solvent for washing before forming the organic compound layer, and then 50 ° C. or higher and 150 ° C. or lower. The transparent conductive film is preferably heat-dried at a temperature of

  The heating temperature during the heat drying treatment of the transparent conductive film according to the present invention may be any temperature that can accelerate the removal of the residual solvent, and is generally equal to or higher than the boiling point of the cleaning organic solvent used for cleaning. However, in the present invention, if a small amount of moisture or organic solvent remains, the performance of the organic EL element may be deteriorated. On the other hand, since it is necessary to avoid deterioration of the flexible base material and a polyester base material is preferably used in the present invention, the upper limit is preferably 150 ° C. or lower.

  Moreover, it is preferable that the time of the heat treatment at 50 ° C. or more and 150 ° C. or less is preferably 1 to 120 minutes, more preferably 5 to 60 minutes, and further preferably 10 to 30 minutes. By setting the heat treatment time to 1 minute or longer, the remaining solvent can be sufficiently removed, and by setting the heat treatment time to 120 minutes or less, the deterioration of the flexible base material on which the transparent conductive film is formed due to heating is suppressed. Can do.

  As a heating method, a heater heating method (for example, an infrared heater, a halogen heater, a panel heater or the like is placed on or under a flexible base material on which a transparent conductive film is formed and heated by radiant heat) may be used. (For example, hot air or the like is blown and heated in a zone adjusted to a predetermined temperature). In the present invention, the zone heating method is preferable from the viewpoint of uniformity. In the case of the zone heating method, for example, a thermostatic bath can be used. The thermostat may be of any form as long as it is a device capable of performing heat treatment of a flexible base material on which a transparent conductive film is formed at a set temperature. For example, the thermostat is set with a hot air set at a predetermined temperature. The entire inside of the bath may be heated, or warm air may be blown to the flexible base material on which the transparent conductive film is formed, or the inside of the thermostatic bath is set to a desired temperature using a heater. May be. The attachment position of such a heating device such as a heater may be attached to any position inside the thermostatic bath as long as the flexible base material on which the transparent conductive film is formed can be uniformly heated. Regarding the temperature distribution inside the thermostatic chamber, the temperature may be increased from the entrance toward the exit, the temperature may be decreased, or the temperature increase and decrease may be repeated. Moreover, a preheating part may be provided before heating, and a cooling part may be provided after heating.

  In the method for producing an organic electroluminescence device of the present invention, at least one layer of the organic compound layer is formed using a coating liquid containing a coating organic solvent having a vapor pressure equal to or higher than the vapor pressure of the cleaning organic solvent. It is characterized by manufacturing.

  Moreover, it is preferable that all the layers of the organic compound layer constituting the organic EL device according to the present invention are formed with a coating liquid containing a coating organic solvent having a vapor pressure defined in the present invention. Furthermore, it is preferable that at least one of the organic compound layers is formed of a coating solution containing 70% by mass or more of the coating organic solvent according to the present invention.

  In the method for producing an organic EL device of the present invention, it is not necessary that the coating liquid used for forming all the organic compound layers contains a coating organic solvent having a vapor pressure equivalent to or higher than the cleaning organic solvent, If at least one layer satisfies the conditions defined in the present invention, the residual solvent in the flexible substrate can be sufficiently reduced. That is, for example, after the flexible base material on which the transparent conductive film is formed is washed with a washing liquid containing a washing organic solvent, the organic compound layer provided as the first layer contains the coating organic solvent defined in the present invention. It may be a method of forming with a coating solution, or a method of forming an organic compound layer formed in the second layer with a coating solution containing an organic solvent for coating as defined in the present invention. In addition, the detail of each organic compound layer which comprises the organic EL element which concerns on this invention is mentioned later.

  The coating temperature of the organic compound layer according to the present invention is not particularly limited, but is in the range of 5 to 45 ° C., preferably 10 to 35 ° C. in view of coating properties.

  Examples of the method for forming the organic compound layer according to the present invention include a vapor deposition method and a wet process such as a spin coating method, a casting method, an ink jet method, and a printing method. Film formation by a printing method or the like is preferable. Further, a different film forming method may be applied to each organic compound layer to be formed.

  In addition, as after the cleaning, each organic compound layer may be formed on the flexible base material on which the transparent conductive film is formed, and then heat treatment may be performed. The heating conditions are preferably 50 ° C. or higher and 150 ° C. or lower from the viewpoint of suppressing the heat resistance of the flexible substrate and the deterioration of the formed organic compound layer.

<< Constituent layers of organic EL elements >>
An example of the fundamental structure of the organic EL element which concerns on this invention is shown.

(I) Anode / hole injection layer / light emitting layer / electron injection layer / cathode (ii) Anode / hole injection layer / hole transport layer / light emitting layer / electron injection layer / cathode (iii) Anode / hole injection layer / Hole Transport Layer / Light-Emitting Layer / Electron Transport Layer / Electron Injection Layer / Cathode FIG. 1 is a schematic diagram showing the overall basic configuration of the organic EL device of the present invention.

  In FIG. 1A, an organic EL element 1 has an organic electronic structure (also referred to as a light emitting element) 3 composed of a plurality of organic layers and electrodes on a substrate 2, and the light emitting element 3 is It has the structure sealed with the sealing material 5 through the adhesive agent 4.

  FIG. 1B shows an example of the configuration of an organic electronics structure (also referred to as a light-emitting element) 3, and an anode 7 (ITO electrode) as a transparent conductive film on an inorganic film 6 provided on a substrate. And a hole injection layer 8, a hole transport layer 9, a light emitting layer 10, an electron injection layer 11 and a cathode 12 (aluminum electrode 12) are sequentially stacked thereon to form the light emitting element 3. The

  Next, details of components of each layer constituting the organic EL element according to the present invention will be described.

<< Injection layer: hole injection layer, electron injection layer >>
The injection layer is provided as necessary, and there are an electron injection layer and a hole injection layer, and as described above, between the anode and the light emitting layer, or between the anode and the hole transport layer, and between the cathode and the light emitting layer, or You may exist between a cathode and an electron carrying layer.

  The injection layer referred to in the present invention is a layer provided between the electrode and the organic layer in order to lower the driving voltage and improve the light emission luminance. “The organic EL element and the forefront of its industrialization (November 30, 1998, NT. 2) Chapter 2 “Electrode Materials” (pages 123 to 166) of the second edition of “S. Co., Ltd.”, and includes a hole injection layer and an electron injection layer.

  The details of the hole injection layer are described in JP-A Nos. 9-45479, 9-260062, and 8-288069. Examples of the hole injection layer include triazole derivatives, Polymers including oxadiazole derivatives, imidazole derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, etc. There are aniline-based copolymers, polyarylalkane derivatives, or conductive polymers, preferably polythiophene derivatives, polyaniline derivatives, polypyrrole derivatives, and more preferably polythiophene derivatives.

  The details of the electron injection layer are described in JP-A-6-325871, JP-A-9-17574, JP-A-10-74586, and the like, and specifically, strontium, aluminum, and the like are representative. Examples thereof include a metal buffer layer, an alkali metal compound buffer layer typified by lithium fluoride, an alkaline earth metal compound buffer layer typified by magnesium fluoride, and an oxide buffer layer typified by aluminum oxide. The buffer layer (injection layer) is desirably a very thin film, and although depending on the material, the film thickness is about 0.1 nm to 5 μm, preferably 0.1 to 100 nm, more preferably 0.5 to 10 nm, Most preferably, it is 0.5-4 nm.

《Hole transport layer》
As the hole transport material, the constituent material of the hole injection layer described above can be used. In addition, porphyrin compounds, aromatic tertiary amine compounds, and styrylamine compounds, particularly aromatic tertiary amines. It is preferable to use a 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 two more described in US Pat. No. 5,061,569 Having a condensed aromatic ring of, for example, 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPD), JP-A-4-30 4,4 ', 4 "-tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine in which three triphenylamine units described in Japanese Patent No. 688 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-4-297076, JP-A-2000-196140, JP-A-2001-102175, J. Pat. Appl. Phys. , 95, 5773 (2004), JP-A-11-251067, J. MoI. Huang et. al. It is also possible to use a hole transport material that has a so-called p-type semiconducting property as described in the literature (Applied Physics Letters 80 (2002), p. 139), JP 2003-519432 A. it can.

  Although there is no restriction | limiting in particular about the film thickness of a positive hole transport layer, Usually, 5 nm-about 5 micrometers, Preferably it is 5-200 nm. The hole transport layer may have a single layer structure composed of one or more of the above materials.

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

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

Also, metal complexes of 8-quinolinol derivatives such as tris (8-quinolinol) aluminum (Alq) ₃ , tris (5,7-dichloro-8-quinolinol) aluminum, tris (5,7-dibromo-8-quinolinol) Aluminum, tris (2-methyl-8-quinolinol) aluminum, tris (5-methyl-8-quinolinol) aluminum, bis (8-quinolinol) zinc (Znq), etc., and the central metals of these metal complexes are In, Mg Metal complexes replaced with Cu, Ca, Sn, Ga, or Pb can also be used as electron transport materials. In addition, metal-free or metal phthalocyanine, or those having terminal ends substituted with an alkyl group or a sulfonic acid group can be preferably used as the electron transporting material. In addition, the distyrylpyrazine derivative exemplified as the material of the light emitting layer can also be used as an electron transport material, and an inorganic semiconductor such as n-type-Si, n-type-SiC, etc. as in the case of the hole injection layer and the hole transport layer. Can also be used as an electron transporting material.

  Although there is no restriction | limiting in particular about the film thickness of an electron carrying layer, Usually, 5 nm-about 5 micrometers, Preferably it is 5-200 nm. The electron transport layer may have a single layer structure composed of one or more of the above materials.

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

<Light emitting layer>
The light-emitting layer is a layer that emits light by recombination of electrons and holes injected from the electrode, the electron transport layer, or the hole transport layer, and the light-emitting portion is the light-emitting layer even in the light-emitting layer. It may be an interface with an adjacent layer.

  The light emitting layer is not particularly limited in its configuration as long as the light emitting material contained satisfies the above requirements. Moreover, there may be a plurality of layers having the same emission spectrum and emission maximum wavelength. It is preferable to have a non-light emitting intermediate layer between each light emitting layer.

  The total thickness of the light emitting layers in the present invention is preferably in the range of 1 to 100 nm, and more preferably 50 nm or less because a lower driving voltage can be obtained. In addition, the sum total of the film thickness of the light emitting layer as used in this invention is a film thickness also including the said intermediate | middle layer, when a nonluminous intermediate | middle layer exists between light emitting layers.

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

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

  In the present invention, the structure of the light-emitting layer preferably contains a host compound and a light-emitting material (also referred to as a light-emitting dopant compound) and emits light from the light-emitting material.

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

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

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

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

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

  Next, the light emitting material will be described.

  As the light-emitting material applicable to the present invention, a fluorescent compound or a phosphorescent light-emitting material (also referred to as a phosphorescent compound or a phosphorescent compound) can be used, and a phosphorescent light-emitting material is preferable.

  In the present invention, a phosphorescent material is a compound in which light emission from an excited triplet is observed. Specifically, it is a compound that emits phosphorescence at room temperature (25 ° C.), and the phosphorescence quantum yield is 0 at 25 ° C. A preferred phosphorescence quantum yield is 0.1 or more, although it is defined as 0.01 or more compounds.

  The phosphorescence quantum yield can be measured by the method described in Spectroscopic II, page 398 (1992 edition, Maruzen) of the Fourth Edition Experimental Chemistry Course 7. The phosphorescence quantum yield in a solution can be measured using various solvents. However, when a phosphorescent material is used in the present invention, the phosphorescence quantum yield (0.01 or more) is achieved in any solvent. Just do it.

  There are two types of light emission principles of phosphorescent materials. One is the recombination of carriers on the host compound to which carriers are transported, generating an excited state of the host compound, and this energy is transferred to the phosphorescent material. Energy transfer type to obtain light emission from the phosphorescent light emitting material, and another one is that the phosphorescent light emitting material becomes a carrier trap, and recombination of carriers occurs on the phosphorescent light emitting material, and light emission from the phosphorescent light emitting material is obtained. Although it is a trap type, in any case, the excited state energy of the phosphorescent material is required to be lower than the excited state energy of the host compound.

  The phosphorescent light-emitting material can be appropriately selected from known materials used for the light-emitting layer of the organic EL element, and is preferably a complex compound containing a group 8-10 metal in the periodic table of elements. More preferably, an iridium compound, an osmium compound, a platinum compound (platinum complex compound), or a rare earth complex, and most preferably an iridium compound.

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

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

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

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

《Middle layer》
In the present invention, a non-light emitting intermediate layer may be provided between the light emitting layers.

  The non-light emitting intermediate layer is a layer provided between the light emitting layers in the case of having a plurality of light emitting layers.

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

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

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

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

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

  Hereinafter, although the preferable specific example of the compound used for the positive hole transport material of the organic EL element which concerns on this invention, a light emission host, an electron transport material, etc. is given, this invention is not limited to these.

  (Hole transport material)

  In addition, n described in each said exemplary compound represents a polymerization degree, and represents the integer from which the weight average molecular weight becomes the range of 50,000-200,000. If the weight average molecular weight is less than this range, there is a concern of mixing with other layers during film formation due to the high solubility in the solvent. Even if a film can be formed, the light emission efficiency does not increase at a low molecular weight. When the weight average molecular weight is larger than this range, problems arise due to difficulty in synthesis and purification. Since the molecular weight distribution increases and the residual amount of impurities also increases, the light emission efficiency, voltage, and life of the organic EL element deteriorate. These polymer compounds are disclosed in Makromol. Chem. , Pages 193, 909 (1992) and the like.

  (Light emitting host)

  (Electron transport material)

  These compounds are disclosed in JP 2007-288035 A, Chem. Mater. , 2008, 20, 5951, Experimental Chemistry Course 5th Edition (Edited by the Chemical Society of Japan), etc.

"anode"
As the anode in the organic EL element, an electrode material made of a metal, an alloy, an electrically conductive compound, or a mixture thereof having a high work function (4 eV or more) is preferably used. Specific examples of such electrode 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 having a desired shape may be formed by a photolithography method, or when pattern accuracy is not so high (about 100 μm or more) A pattern may be formed through a mask having a desired shape at the time of vapor deposition or sputtering of the electrode material. Or when using the substance which can be apply | coated like an organic electroconductivity compound, wet film-forming methods, such as a printing system and a coating system, can also be used. When light emission is extracted from the anode, it is desirable that the transmittance be 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 in the range of 10 to 1000 nm, preferably in the range of 10 to 200 nm.

"cathode"
On the other hand, as the cathode, a material having a low work function (4 eV or less) metal (referred to as an electron injecting metal), an alloy, an electrically conductive compound, and a mixture thereof as an electrode material is used. Specific examples of such electrode materials include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide (Al ₂ O ₃ ) Mixtures, indium, lithium / aluminum mixtures, rare earth metals and the like. Among these, from the point of durability against electron injection and oxidation, etc., a mixture of an electron injecting metal and a second metal which is a stable metal having a larger work function than this, for example, a magnesium / silver mixture, Magnesium / aluminum mixtures, magnesium / indium mixtures, aluminum / aluminum oxide (Al ₂ O ₃ ) mixtures, lithium / aluminum mixtures, aluminum and the like are preferred. The cathode can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering. The sheet resistance as the cathode is preferably several hundred Ω / □ or less, and the film thickness is usually selected in the range of 10 nm to 5 μm, preferably 50 to 200 nm. In order to transmit the emitted light, 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 said metal with a film thickness of 1-20 nm on a cathode, a transparent or semi-transparent cathode can be produced by producing the electroconductive transparent material quoted by description of the anode on it, By applying this, an element in which both the anode and the cathode are transmissive can be manufactured.

<Supporting substrate>
As a support substrate (hereinafter also referred to as a substrate, substrate, substrate, support, etc.) that can be used in the organic EL device according to the present invention, there is no particular limitation on the type of glass, plastic, etc., and transparent Or opaque. When taking out light from the support base material side, it is preferable that the support base material is transparent. Examples of the transparent support substrate preferably used include glass, quartz, and a transparent resin film. Since the effect of the film reinforcing functional layer appears greatly with a flexible base material rather than a rigid base material, a particularly preferable support base material is a resin film that can give flexibility to the organic EL element.

  Examples of the flexible substrate include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyethylene, polypropylene, cellophane, cellulose diacetate, cellulose triacetate, cellulose acetate butyrate, and cellulose acetate propionate ( CAP), cellulose esters such as cellulose acetate phthalate (TAC), cellulose nitrate or derivatives thereof, polyvinylidene chloride, polyvinyl alcohol, polyethylene vinyl alcohol, syndiotactic polystyrene, polycarbonate, norbornene resin, polymethylpentene, polyether Ketone, polyimide, polyethersulfone (PES), polyphenylene sulfide, polysulfones, Cycloolefin resins such as polyetherimide, polyetherketoneimide, polyamide, fluororesin, nylon, polymethylmethacrylate, acrylic or polyarylate, Arton (trade name, manufactured by JSR) or Appel (trade name, manufactured by Mitsui Chemicals) Can be mentioned.

On the surface of the flexible substrate, an inorganic film, an organic film, or a hybrid film of both may be formed as a barrier film, and the water vapor transmission rate (measured by a method according to JIS K 7129-1992) 25 ± 0.5 ° C., relative humidity (90 ± 2)% RH) is preferably 0.01 g / (m ² · 24 h) or less of a barrier film, and further conforms to JIS K 7126-1987. The oxygen permeability measured by the method is 10 ⁻³ cm ³ / (m ² · 24 h · atm) or less and the water vapor permeability is 10 ⁻³ g / (m ² · 24 h) or less. The water vapor permeability is preferably 10 ⁻⁵ g / (m ² · 24 h) or less.

  As a material for forming the barrier film, any material may be used as long as it has a function of suppressing entry of elements that cause deterioration of elements such as moisture and oxygen. For example, silicon oxide, silicon dioxide, silicon nitride, or the like can be used. Furthermore, in order to improve the brittleness of the barrier 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, sputtering method, reactive sputtering method, molecular beam epitaxy method, cluster ion beam method, ion plating method, plasma polymerization method, atmospheric pressure plasma weight 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 opaque support substrate include metal plates such as aluminum and stainless steel, films, opaque resin substrates, ceramic substrates, and the like.

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

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

<Sealing>
As a sealing means used for this invention, the method of adhere | attaching a sealing member, an electrode, and a support base material with an adhesive agent can be mentioned, for example.

  The sealing member may be disposed so as to cover the display area of the organic EL element, and may be intaglio or flat. Further, transparency and electrical insulation are not particularly limited.

  Specific examples include a glass plate, a polymer plate / film, and a metal plate / film. Examples of the glass plate include soda-lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, and quartz. Examples of the polymer plate include polycarbonate, acrylic, polyethylene terephthalate, polyether sulfide, and polysulfone. Examples of the metal plate include those made of one or more metals or alloys selected from the group consisting of stainless steel, iron, copper, aluminum, magnesium, nickel, zinc, chromium, titanium, molybdenum, silicon, germanium, and tantalum.

In the present invention, a polymer film and a metal film can be preferably used because the element can be thinned. Furthermore, the polymer film has an oxygen permeability measured by a method according to JIS K 7126-1987 of 1 × 10 ⁻³ cm ³ / (m ² · 24 h · atm) or less, and conforms to JIS K 7129-1992. The water vapor permeability (25 ± 0.5 ° C., relative humidity (90 ± 2)% RH) measured by the above method is preferably 1 × 10 ⁻³ g / (m ² · 24 h) or less.

  For processing the sealing member into a concave shape, sandblasting, chemical etching, or the like is used.

  Specific examples of the adhesive include photocuring and thermosetting adhesives having reactive vinyl groups such as acrylic acid oligomers and methacrylic acid oligomers, and moisture curing adhesives such as 2-cyanoacrylates. be able to. Moreover, heat | fever and chemical curing types (two-component mixing), such as an epoxy type, can be mentioned. Moreover, hot-melt type polyamide, polyester, and polyolefin can be mentioned. Moreover, a cationic curing type ultraviolet curing epoxy resin adhesive can be mentioned.

  In addition, since an organic EL element may deteriorate by heat processing, what can be adhesive-hardened in the temperature range from room temperature to 80 degreeC is preferable. A desiccant may be dispersed in the adhesive.

  Application | coating of the adhesive agent to a sealing part may use commercially available dispenser, and may print like screen printing.

  It is also preferable to coat the electrode and the organic layer on the outside of the electrode facing the support substrate with the organic layer interposed therebetween, and form an inorganic or organic layer in contact with the support substrate to form a sealing film. Can be. In this case, the material for forming the film may be any material that has a function of suppressing intrusion of elements that cause deterioration of elements such as moisture and oxygen. For example, silicon oxide, silicon dioxide, silicon nitride, or the like may be used. it can. Further, 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.

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

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

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

《Light extraction》
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 can extract only about 15% to 20% of the light generated in the light emitting layer. It is generally said. This is because light incident on the interface (interface between the transparent base material 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 base material This is because the light undergoes total reflection between them and the light is guided through the transparent electrode or the light emitting layer, and as a result, the light escapes in the direction of the side surface of the device.

  As a technique for improving the light extraction efficiency, for example, a method of forming irregularities on the surface of the transparent substrate to prevent total reflection at the interface between the transparent substrate and the air (US Pat. No. 4,774,435). ), A method for improving the efficiency by imparting a light collecting property to the substrate (Japanese Patent Laid-Open No. 63-314795), a method for forming a reflective surface on the side surface of the 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 the base material and the light emitter (Japanese Patent Laid-Open No. 62-172691), and more than the base material between the base material and the light emitter. A method of introducing a flat layer having a low refractive index (Japanese Patent Laid-Open No. 2001-202827), and forming a diffraction grating between any one of the base material, the transparent electrode layer and the light emitting layer (including between the base material and the outside). Method (Japanese Patent Laid-Open No. 11-283951).

  In the present invention, these methods can be used in combination with the organic EL device according to the present invention, or a method of introducing a flat layer having a lower refractive index than the base material between the base material and the light emitter, or A method of forming a diffraction grating between any of the base material, the transparent electrode layer and the light emitting layer (including between the base material 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 uses the property that the diffraction grating can change the direction of light to a specific direction different from refraction by so-called Bragg diffraction such as first-order diffraction and second-order diffraction. Of these, light that cannot be emitted 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). It is intended to be taken 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. Therefore, the light extraction efficiency does not increase so much. However, by making the refractive index distribution a two-dimensional distribution, light traveling in all directions is diffracted, and light extraction efficiency is increased.

  As described above, the position where the diffraction grating is introduced may be in any one of the layers or in the medium (in the transparent base material or in the transparent electrode), but is preferably in the vicinity of the organic light emitting layer where light is generated. At this time, the period of the diffraction grating is preferably about 1/2 to 3 times the wavelength of light in the medium.

  The arrangement of the diffraction grating is preferably two-dimensionally repeated such as a square lattice, a triangular lattice, or a honeycomb lattice.

《Condensing sheet》
The organic EL device of the present invention can be processed on the light extraction side of the substrate, for example, by providing a microlens array-like structure, or combined with a so-called condensing sheet, for example, in a specific direction, for example, the device light emitting surface. On the other hand, the brightness | luminance in a specific direction can be raised by condensing in a front direction.

  As an example of the microlens array, quadrangular pyramids having a side of 30 μm and an apex angle of 90 degrees are 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 Co., Ltd. can be used. As the shape of the prism sheet, for example, the base material may be formed by forming a △ -shaped stripe having a vertex angle of 90 degrees and a pitch of 50 μm, or the vertex angle is rounded and the pitch is changed randomly. Other shapes may be used.

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

<< Method for producing organic EL element >>
A manufacturing flow of the organic EL element of the present invention will be described with reference to FIGS.

  FIG. 2 is a block diagram showing an example of the production order of the organic EL element of the present invention. As an example of the configuration of the organic EL element of the present invention, an inorganic film is formed on a flexible transparent substrate, The flow for producing an organic EL device having an anode (transparent conductive film) / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode is shown.

  Specifically, first, after forming an inorganic film having a gas barrier property on a flexible transparent substrate using a chemical vapor deposition method or the like, a thin film made of a desired anode forming material, for example, ITO or the like is 1 μm or less, preferably After forming it by methods, such as vapor deposition and sputtering, so that it may become a film thickness of 10-200 nm, patterning is performed and an anode is formed. Next, the formed anode is subjected to a washing step with an organic solvent specified in the present invention, and then a drying process for removing the applied organic solvent is performed.

  Next, a hole injection layer constituting the light-emitting element is formed on the anode subjected to the cleaning treatment and the drying treatment by a wet coating method and dried. Similarly, after applying / drying the hole transport layer, applying / drying the light-emitting layer, and applying / drying the electron transport layer, heat treatment is performed to completely remove the residual solvent related to the wet application. . At this time, in the formation of the organic compound layer using the wet coating method, the coating liquid used to form at least one organic compound layer is a coating organic having a vapor pressure equal to or higher than the vapor pressure of the cleaning organic solvent. It contains a solvent.

  Next, an electron injection layer is formed on the electron transport layer by a chemical vapor deposition method. Next, a cathode material, for example, a thin film made of aluminum is formed on the electron injection layer by a method such as chemical vapor deposition or sputtering so as to have a thickness of 1 μm or less, preferably in the range of 50 nm to 200 nm. Is provided.

  Next, an organic EL element is manufactured by laminating a sealing material so as to have the configuration shown in FIG.

  In addition, it is also possible to reverse the production order and produce the cathode, the electron injection layer, the electron transport layer, the light emitting layer, the hole transport layer, the hole injection layer, and the anode in this order. When a DC voltage is applied to the multicolor display device thus obtained, light emission can be observed by applying a voltage of about 2 to 40 V with the positive polarity of the anode and the negative polarity of the cathode. An alternating voltage may be applied. The alternating current waveform to be applied may be arbitrary.

  FIG. 3 is a schematic diagram showing an example of the manufacturing process of the organic EL element of the present invention.

1. Formation process of inorganic film and anode on flexible substrate (not shown)
For the flexible substrate A, first, as described above, formation of an inorganic film (gas barrier film), formation of a transparent conductive film (transparent electrode, ITO, etc.), and patterning are performed.

2. Anode cleaning process, drying process (not shown)
Next, in the present invention, the surface of the formed transparent conductive film is washed with a washing organic solvent, and then dried.

3. Hole transport layer coating process The hole transport layer coating process is possible when applying with the edge position controller (EPC) 101 that adjusts the lateral position of the flexible transparent substrate A supplied from the substrate feeding device B. A backup roll 102 for holding the flexible transparent substrate A, a coating device 103 for coating the flexible transparent substrate A held by the backup roll 102, and a coating liquid supply line 104 for supplying the coating liquid to the coating device. Consists of.

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

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

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

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

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

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

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

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

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

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

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

  In the organic EL element of the present invention, patterning may be performed by a metal mask, an ink jet printing method, or the like as needed during film formation. In the case of patterning, only the electrode may be patterned, the electrode and the light emitting layer may be patterned, or the entire layer of the element may be patterned. In the fabrication of the element, a conventionally known method is used. Can do.

<Application>
The organic EL element of the present invention can be used as a display device, a display, and various light emission sources. Examples of light sources include home lighting, interior lighting, clock and liquid crystal backlights, billboard advertisements, traffic lights, light sources for optical storage media, light sources for electrophotographic copying machines, light sources for optical communication processors, and light sources for optical sensors. Furthermore, it can be used in a wide range of applications such as general household appliances that require a display device, but it can be used effectively as a backlight for a liquid crystal display device combined with a color filter, and as a light source for illumination. it can.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, although the display of "part" or "%" is used in an Example, unless otherwise indicated, "part by mass" or "mass%" is represented.

Example 1
<< Production of organic EL element >>
[Production of Organic EL Element 101]
(Preparation of gas barrier flexible base material)
As a flexible substrate, an atmospheric pressure plasma discharge having a structure described in Japanese Patent Application Laid-Open No. 2004-68143 is formed on the entire surface of a polyethylene naphthalate film having a thickness of 100 μm (a film made by Teijin DuPont, hereinafter abbreviated as PEN). Using a processing apparatus, a gas barrier film (thickness 500 nm) composed of SiO _{2 is} continuously formed on a flexible substrate, and the oxygen permeability is 0.001 cm ³ / (m ² · 24 h · atm). A gas barrier flexible base material having a water vapor permeability of 0.001 g / (m ² · 24 h) or less was prepared below.

(Formation of the first electrode)
An ITO film (indium tin oxide) having a thickness of 120 nm is formed as a transparent conductive film on the gas barrier flexible substrate prepared above by sputtering, and patterned by photolithography to form a first electrode. did. In addition, the 1st electrode was formed so that a light emission area might become a pattern of 50 mm square.

(Cleaning process)
The flexible base material on which the first electrode is formed is immersed in water at 30 ° C. (vapor pressure: 2.3 kPa / 20 ° C.) as a cleaning solution, and then subjected to ultrasonic cleaning treatment (MULTI SOFT (5) (Manufactured by ALEX Co., Ltd.), washing conditions: output 300 W, treatment at 40 kHz for 2 minutes, treatment at 180 kHz for 3 minutes).

(Formation of hole transport layer)
Polyethylenedioxythiophene / polystyrene sulfonate (PEDOT / PSS, Baytron P AI 4083 manufactured by Bayer) and isopropyl alcohol (abbreviated as IPA in Table 1, vapor pressure 4.4 kPa / 20 ° C.) as a coating solution for the hole transport layer. ) And diluted to a concentration of 70% by mass.

  The dried coating film for the hole transport layer is formed on the flexible substrate that has been washed by the die coater installed in the first coating chamber kept in an environment of 30 ° C. Coating was performed so that the thickness was 50 nm, and a hole transport layer was provided. After coating, the solvent isopropyl alcohol was removed by a heated air stream. The air flow was 100 mm in height from the slit nozzle type ejection port toward the film forming surface, the ejection wind speed was 1 m / s, and the ejection wind speed width variation was 5%. The drying temperature was 80 ° C., and the residence time in the drying furnace was 10 minutes. The drying furnace was of a type that can be changed into several zones as appropriate according to the material of the organic layer, and the temperature condition can be changed and the wind speed can be changed.

(Formation of light emitting layer)
Next, on the hole transport layer, the film thickness after drying is 100 nm by a die coater installed in the second coating chamber maintained in the same environment as that used for forming the hole transport layer. The light emitting layer was formed using the light emitting layer coating solution. The light emitting layer coating solution used is a low molecular weight polyvinyl carbazole (PVK) having a molecular weight of 10,000 or less as a light emitting host compound, and a low molecular weight Ir (ppy) ₃ having a molecular weight of 10,000 or less as a dopant compound. It melt | dissolved in toluene (vapor pressure: 2.9 kPa / 20 degreeC), and prepared so that the total mass might be 10 mass%, and obtained the coating liquid for light emitting layers. The surface tension of the light emitting layer was 0.032 N / m, and a good coating film was obtained. Then, it dried for 5 minutes at 25 degreeC by the method similar to a positive hole transport layer using a drying furnace.

(Formation of electron transport layer)
Next, electron transport is performed on the light emitting layer by a die coater installed in a third coating chamber maintained in the same environment as that used for forming the hole transport layer so that the film thickness after drying becomes 40 nm. An electron transport layer was formed using the layer coating solution. As the electron transport layer coating solution, the following electron transport agent ET-A was dissolved in toluene (vapor pressure: 2.9 kPa / 20 ° C.) to prepare and use a 0.75 mass% solution. Then, it dried for 5 minutes at 25 degreeC using the drying furnace similar to a positive hole transport layer. Subsequently, it heated at 98 degreeC for 30 minute (s). After the heat treatment, the flexible substrate was cooled to the same temperature as the room temperature and wound up in a roll shape. In the coating process under normal pressure, an atmosphere having a moisture concentration of 1 ppm to 200 ppm and an oxygen concentration of 30 ppm or less in a nitrogen atmosphere was maintained.

(Formation of electron injection layer)
Subsequently, an electron injection layer was formed on the formed electron transport layer. First, the flexible base material formed up to the electron transport layer was put into a decompression chamber and decompressed to 5 × 10 ⁻⁴ Pa. In advance, cesium fluoride prepared in a tantalum vapor deposition boat was heated in a vacuum chamber to form an electron injection layer having a thickness of 3 nm.

(Formation of second electrode)
Next, a second electrode was formed on the formed electron injection layer and extraction electrode. In a vacuum of 5 × 10 ⁻⁴ Pa, aluminum prepared in advance in a tungsten vapor deposition boat is heated to form a mask pattern so that the light emission area is 50 mm square, and a second electrode having a thickness of 100 nm. Were stacked to prepare an organic EL element 101.

(Sealing of organic EL elements)
An aluminum foil with a thickness of 100 μm was prepared as a barrier layer, and a thermosetting liquid adhesive (epoxy resin) was applied with a thickness of 30 μm on one surface of the aluminum foil to obtain a sealing member. A dry laminating method is performed by laminating the adhesive surface of the sealing member and the organic layer surface of the organic EL element so that the end portions of the first electrode and the second electrode of the organic EL element 101 produced can be exposed to the outside. Was adhered and sealed.

[Production of Organic EL Elements 102 to 105]
In the production of the organic EL element 101, the organic solvent for washing used in the washing treatment of the flexible substrate on which the first electrode was formed was changed to the organic solvent shown in Table 1 in the same manner. EL elements 102 to 105 were produced.

<< Evaluation of organic EL elements >>
[Confirmation of white light emission]
A DC constant current of 50 mA (20 A / m ² ) was passed through each element using a DC voltage / current source R6243 manufactured by ADC, and a spectral radiance meter CS1000 manufactured by Konica Minolta Sensing Co., Ltd. was used. As a result of measuring the front luminance at a viewing angle of 2 degrees, white light emission with a color temperature of 3500K could be confirmed.

[Evaluation of luminance unevenness resistance]
Each produced organic EL element was conveyed to the luminance distribution measurement chamber in a state where it was not in contact with the atmosphere. The luminance distribution measurement chamber was maintained in a nitrogen atmosphere with a residual oxygen concentration of 1 ppm or less. Here, by applying a current of 25 A / m ^{2 at} a voltage of 6 V to the organic EL element to emit light, using a luminance meter (CS1000A) manufactured by Konica Minolta Sensing Co., Ltd., measurement points A to E shown in FIG. The light emission luminance (cd / m ² ) at 5 points was measured.

  Next, among the measurement points A to E, the minimum light emission luminance and the maximum light emission luminance were obtained, the light emission luminance uniformity rate (%) was measured according to the following formula, and the luminance unevenness resistance was evaluated according to the following evaluation rank.

Emission luminance uniformity rate = [minimum emission luminance (cd / m ² ) / maximum emission luminance (cd / m ² )] × 100 (%)
A: Emission luminance uniformity ratio is 80% or more. O: Emission luminance uniformity ratio is 70% or more and less than 80%. Δ: Emission luminance uniformity ratio is 60% or more and less than 70%. Luminance uniformity rate is less than 60% [Evaluation of initial dark spot resistance]
Using a source measure unit 2400 type manufactured by Toyo Technica Co., Ltd., a DC voltage of 5 V was applied to the organic EL element to emit light. At this time, the number of dark spots generated when light was emitted at 100 cd / m ² was measured using a 100-fold magnifier, and the initial dark spot resistance was evaluated according to the following evaluation rank.

A: Generation of dark spots is not recognized at all O: The number of dark spots generated is 1 / mm ² Δ: The number of generated dark spots is 2 to 4 / mm ² ×: Dark spots Is 5 or more / mm ² [Evaluation of preservability]
Each organic EL element was allowed to stand for 1000 hours in an environment at a temperature of 60 ° C. and a relative humidity of 80%. After that, a DC voltage of 5 V was applied to the organic EL element to emit light, and a microscope (MS-804 manufactured by Moritex Co., Ltd., lens MP) was used. -ZW25-200) is used to measure the light emitting area after the forced deterioration treatment, image analysis is performed using Win Roof (manufactured by Mitani Corp.), and the non-light emitting area relative to the initial light emitting area before the forced deterioration processing is performed. The ratio was measured, and storage stability was evaluated according to the following criteria.

Evaluation rank of life ◎: Non-light emitting area ratio after forced deterioration treatment is less than 0.1% ○: Non-light emitting area ratio after forced deterioration processing is 0.1% or more and less than 1.0% Δ: The non-light emitting area ratio after the forced deterioration treatment is 1.0% or more and less than 2.0%. ×: The non-light emitting area ratio after the forced deterioration treatment is 2.0% or more. The results are shown in Table 1.

  As is clear from the results shown in Table 1, the organic EL device produced by performing the cleaning treatment of the flexible substrate and the formation of the organic compound layer under the conditions specified in the present invention was poorly cleaned relative to the comparative example. It can be seen that the generation of dark spots due to foreign matters and residual solvent due to the above is suppressed, the coating property is good, and the luminance unevenness resistance and storage stability are excellent.

Example 2
<< Production of organic EL element >>
[Production of Organic EL Elements 201-205]
In the production of the organic EL element 105 described in Example 1, the organic solvent used for the hole transport layer forming coating solution is changed to toluene, and the organic solvent used for the light emitting layer forming coating solution is set forth in Table 2. Organic EL elements 201 to 205 were produced in the same manner except that the organic solvent was changed.

<< Evaluation of organic EL elements >>
The produced organic EL elements 201 to 205 were evaluated for luminance unevenness resistance, initial dark spot resistance and storage stability in the same manner as in the method described in Example 1, and the obtained results are shown in Table 2.

  As is clear from the results shown in Table 2, at least one organic compound layer (light-emitting layer) is formed using an organic solvent having a higher vapor pressure than the cleaning organic solvent used in the cleaning step. By doing this, it can be seen that the generation of dark spots due to foreign matters, residual solvents, etc. due to poor cleaning is suppressed, coating properties are good, luminance unevenness resistance, and excellent storage stability can be obtained.

Example 3
<< Production of organic EL element >>
[Production of organic EL elements 301 to 303]
In the production of the organic EL element 201 described in Example 2, the flexible substrate on which the first electrode was formed was washed with isopropyl alcohol and then heated as described in Table 3 before forming the organic compound layer. Organic EL elements 301 to 303 were produced in the same manner except that the heat treatment was performed at the temperature and the heating time.

<< Evaluation of organic EL elements >>
For the organic EL elements 301 to 303 produced above and the organic EL element 201 produced in Example 2, the luminance unevenness resistance, initial dark spot resistance and storage stability are evaluated in the same manner as in the method described in Example 1. The obtained results are shown in Table 3.

  As is apparent from the results shown in Table 3, the effect of the residual solvent can be reduced and the initial dark spot resistance can be further improved by performing the heat treatment after the cleaning step and before forming the organic compound layer. I understand.

Example 4
<< Preparation of mixed solvent >>
Isopropyl alcohol and water are mixed at a mass ratio shown in Table 4, and solvent A (vapor pressure: 3.8 kPa), solvent B (vapor pressure: 3.4 kPa), solvent C (vapor pressure) having different vapor pressures are mixed. : 2.9 kPa).

<< Production of organic EL element >>
[Production of Organic EL Element 401]
In the production of the organic EL element 104 described in Example 1, the organic EL element 401 was similarly obtained except that isopropyl acetate was used in place of toluene as the coating organic solvent used for the preparation of the light emitting layer forming coating solution. Was made.

[Preparation of organic EL elements 402 to 404]
In the production of the organic EL element 401, as the organic solvent for coating used for preparing the coating liquid for forming the hole transport layer, the solvents A to C prepared as shown in Table 5 were used instead of isopropyl alcohol, respectively. Organic EL elements 402 to 404 were produced in the same manner except that.

<< Evaluation of organic EL elements >>
The produced organic EL elements 401 to 404 were evaluated in terms of luminance unevenness resistance, initial dark spot resistance and storage stability in the same manner as in the method described in Example 1. Table 5 shows the obtained results.

  As is clear from the results shown in Table 5, the coating liquid composition of the hole transport layer, which is one of the organic compound layers, is a coating containing 70% by mass or more of a coating organic solvent having a higher vapor pressure than the cleaning organic solvent. The organic EL elements 401 and 402 produced using the liquid have improved initial dark spot resistance compared to the organic EL elements 403 and 404 produced using the coating liquid having a coating organic solvent ratio of less than 70% by mass. And it was able to confirm that it was a more preferable aspect.

DESCRIPTION OF SYMBOLS 1 Organic EL element 2 Base material 3 Organic electronics structure (light emitting element)
4 Adhesive 5 Sealing Material 6 Inorganic Film 7 Anode 8 Hole Injection Layer 9 Hole Transport Layer 10 Light-Emitting Layer 11 Electron Injection Layer 12 Cathode (Aluminum Electrode)
101, 301, 501, 701 EPC
102, 302, 502 Backup roll 103, 303, 503 Coating device 104, 304, 504 Coating liquid supply line 201, 401, 601, 703 Dry air supply port 202, 402, 602, 704 Dry air exhaust port 203, 403, 603 Transport rolls 702, 705 Suction roll A Flexible transparent base material B Base material feeding device C Base material take-up device

Claims (9)

  Manufacture of an organic electroluminescence device manufactured by forming a transparent conductive film on a flexible substrate and then forming at least one organic compound layer including a light emitting layer and a counter electrode layer on the transparent conductive film In the method, the transparent conductive film is formed on a flexible substrate, the surface of the transparent conductive film is cleaned with a cleaning organic solvent, and then the vapor pressure of the cleaning organic solvent is set on the transparent conductive film. A method for producing an organic electroluminescence device, comprising producing at least one layer of the organic compound layer using a coating solution containing a coating organic solvent having a vapor pressure equal to or higher than that.   2. The organic electroluminescence according to claim 1, wherein after the surface of the transparent conductive film is washed with the cleaning organic solvent, the transparent conductive film is heated and dried at a temperature of 50 ° C. or more and 150 ° C. or less. Device manufacturing method.   The method for producing an organic electroluminescent element according to claim 1, wherein the cleaning organic solvent has a vapor pressure of 2.5 kPa or more and 25 kPa or less.   4. The method of manufacturing an organic electroluminescent element according to claim 1, wherein a vapor pressure of the coating organic solvent is 2.5 kPa or more and 25 kPa or less. 5.   The cleaning organic solvent is at least one selected from alcohols, fatty acid esters, ketones, aromatic hydrocarbons, halogenated hydrocarbons, aliphatic hydrocarbons, amines, nitriles and ethers. It exists, The manufacturing method of the organic electroluminescent element of any one of Claim 1 to 4 characterized by the above-mentioned.   The organic solvent for coating is at least one selected from alcohols, fatty acid esters, ketones, aromatic hydrocarbons, halogenated hydrocarbons, aliphatic hydrocarbons, amines, nitriles and ethers. It exists, The manufacturing method of the organic electroluminescent element of any one of Claim 1 to 5 characterized by the above-mentioned.   All the layers of the said organic compound layer are formed with the coating liquid containing the said organic solvent for application | coating, The manufacturing method of the organic electroluminescent element of any one of Claim 1 to 6 characterized by the above-mentioned.   8. The organic electroluminescent element according to claim 1, wherein at least one of the organic compound layers is formed of a coating solution containing 70% by mass or more of the organic solvent for coating. Production method.   An organic electroluminescent element manufactured by the method for manufacturing an organic electroluminescent element according to claim 1.

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