JP5093049B2 - ORGANIC ELECTRONIC ELECTRONIC DEVICE, METHOD FOR MANUFACTURING THE SAME - Google Patents

Description

  The present invention relates to a method and apparatus for manufacturing an organic electronics element, and an organic electronics element manufactured by them.

  More specifically, the present invention relates to a manufacturing method and a manufacturing apparatus for manufacturing an organic electronics element used as a surface light source, a display, a solar cell, etc., and particularly manufactures an organic electronics element provided on a flexible substrate such as a plastic film. The present invention relates to a manufacturing method for manufacturing, a manufacturing apparatus for carrying out the method, and an organic electronic device manufactured by the manufacturing method.

  In recent years, development of various organic electronics elements such as organic electroluminescence elements (hereinafter referred to as “organic EL elements”), organic photoelectric conversion elements, organic photoconductors for electrophotography, organic transistors and the like has been studied.

  Organic electronics elements are elements that perform electrical operations using organic substances, and are expected to exhibit features such as energy saving, low cost, and flexibility, and are attracting attention as a technology that can replace conventional inorganic semiconductors based on silicon. ing.

  These organic electronic elements are elements that emit light, generate power, charge, or control current and voltage by passing a current through an extremely thin film of an organic substance through an electrode.

  An organic EL element, which is one of the organic electronics elements, is an element that emits light when a current is supplied between electrodes, with a light emitting layer made of an organic compound thin film sandwiched between electrodes. Therefore, when a thin-film organic EL element is used as a light source, it is easy to reduce the size and weight, and the light emitting response speed is higher than that of a fluorescent lamp, and the amount of light immediately after lighting is relatively stable.

  Here, when the organic EL element is used as a light source for a liquid crystal display device or an illumination device for various displays, the emission color is preferably white. However, the organic EL element is very sensitive to a substance represented by moisture, oxygen, and the like that interfere with an electrochemical process from formation of excitons in the light emitting layer to light emission. If these substances are present as impurities or diffuse from the outside, the light emission efficiency and drive life are remarkably shortened, and practical illumination and display performance cannot be obtained.

  In addition, water, oxygen, etc. may change the electrical and chemical characteristics of the electrode surface and the interior, thereby obstructing the movement of electrons and holes. As a result, the practical characteristics are greatly deteriorated. Therefore, as disclosed in Patent Document 1, the organic EL element is encapsulated with a desiccant and enclosed in a structure sealed with glass or a metal can, or as disclosed in Patent Document 2, moisture or oxygen It has been studied to secure performance against a gas component such as a base material or a sealing material having barrier performance.

  By the way, in the manufacture of organic EL elements, in order to avoid the influence of moisture and oxygen on the light emitting element (organic EL structure) and to maintain high quality and high reliability, the influence of outside air called sealing is completely eliminated. An operation for forming a protective film for shut-out is performed.

  As a sealing technique for organic EL elements, for example, a thin film such as nitride or nitride oxide is coated on a light emitting element (organic EL structure) by an electron beam method, a sputtering method, a plasma CVD method, an ion plating method, or the like. A sealing technique using a facing target type sputtering apparatus (see, for example, Patent Document 3) or a sheet-like sealing material attached to a light emitting element portion including a light emitting layer for sealing. (For example, refer to Patent Document 4).

  For example, as a technique for preventing deterioration due to oxygen and moisture, a technique of sealing a light emitting layer formed on a substrate of an organic EL element with a sealing material is generally used, but a conventional adhesive is used. In the sealing, the desired sealing performance was not sufficiently obtained due to moisture permeation from the adhesive part.

  On the other hand, recently, an organic EL element using a flexible base material such as a resin film has also appeared due to expansion of the use of the organic EL element, etc., and by using such a flexible base material, a roll -Manufacture of the organic EL element of a two-roll system (it is also called "Roll to Roll system") has come to be performed (for example, refer patent document 5). Here, the roll-to-roll organic EL element manufacturing method refers to forming a light-emitting element (organic EL structure) on a base material rolled out in a roll shape, The manufacturing method which winds up the formed base material on a roll again and produces an organic EL element is called. Manufacturing by the roll-to-roll method has an advantage that production efficiency can be improved because continuous production is possible.

  When sealing is performed by roll-to-roll, the line length becomes long. Therefore, it is effective to temporarily perform temporary bonding on the roll-to-roll, cut to a desired size, and then cure them together. However, if cutting is performed in a temporarily bonded state, delamination occurs between the base material (substrate) and the sealing material, and oxygen and moisture permeation from the peeled portion proceeds, and the desired sealing performance cannot be obtained. There is a problem.

  In addition, since the formation of light emitting elements by vapor deposition or the like is performed in an environment close to vacuum, in the roll-to-roll method, the substrate is unwound from the roll in an environment close to vacuum to form the light emitting elements. After being carried out, it is wound around a roll again, and the wound roll is housed in a container filled with an inert gas to prevent deterioration of the light emitting element due to moisture or oxygen, and is put into a sealing process in another line. Have been taken.

  However, putting the wound roll into a sealing process in another line makes the process complicated, and the container filled with an inert gas for carrying the roll formed a light emitting element (organic EL structure). It is difficult to maintain the environment, and the light-emitting element (organic EL structure) of the housed base material is affected by moisture and oxygen remaining in the container, which may affect the product quality degradation and life. It was.

  On the other hand, an organic photoelectric conversion element, which is one of organic electronics elements, is an element that generates electricity when irradiated with light in a configuration in which a power generation layer made of a thin film of an organic compound is sandwiched between electrodes. Therefore, if a thin-film organic photoelectric conversion element is used as a solar cell, it is easy to reduce the size and weight, and the output is relatively stable even in low-light and high-temperature environments compared to existing inorganic semiconductor solar cells. The solar cell can be obtained.

Similarly to the organic EL element, the organic photoelectric conversion element also forms a carrier trap in the power generation layer due to the influence of moisture, oxygen, and the like, thereby inhibiting the collection of carriers generated by charge separation. As a result, not only the power generation efficiency is lowered, but also the life of the element is affected. Therefore, in the organic photoelectric conversion element as well, as disclosed in Patent Document 6, performance can be secured by using a sealing material having barrier performance against gas components such as moisture and oxygen. Although being studied, there is a problem common to the case of the organic EL element described above.
JP 2007-18497A JP 2007-83644 A JP 2002-332567 A JP 2005-4063 A International Publication No. 01/005194 Pamphlet JP 2004-165512 A

  The present invention has been made in view of the above-described problems and situations, and a solution to the problem is a basis for cutting an organic electronics element provided on a flexible substrate into a unit (element-like). To provide an organic electronic element manufacturing method, a manufacturing apparatus, and an organic electronic element manufactured by the manufacturing method, which can suppress delamination that occurs between a material and a sealing material and obtain desired sealing performance It is.

  The above-mentioned problem according to the present invention is solved by the following means.

1. A method for producing an organic electronic device comprising at least a flexible substrate, a pair of opposed electrodes, an organic layer sandwiched between them (hereinafter referred to as “organic functional device”), and a sealing material. And after the step of forming the organic functional element on the base material, (i) a sealing step of adhering a sealing material on the base material with a thermosetting adhesive so as to cover the organic functional element; And (ii) a cutting step of curing the cut end portion of the thermosetting adhesive by performing hot melt cutting after the sealing material is bonded and before the thermosetting adhesive is cured. A method for producing an organic electronics element, comprising:

  2. 2. The method of manufacturing an organic electronics element as described in 1 above, wherein a hot blade is used as the means for hot melt cutting.

  3. The heating blade includes a heater and detection means for detecting a blade edge temperature, and controls thermal energy supplied to the heater according to the temperature detected by the detection means. Manufacturing method of organic electronics element.

  4). 4. The method of manufacturing an organic electronic element according to 2 or 3, wherein a blade edge temperature of the hot blade is equal to or higher than a heat curing temperature of the thermosetting adhesive.

  5). 4. The method of manufacturing an organic electronics element according to any one of 1 to 3, wherein the organic electronics element is an organic electroluminescence element.

  6). It is an organic electronics element manufacturing apparatus for implementing the manufacturing method of the organic electronics element as described in any one of said 1-5, Comprising: After the process of forming an organic functional element on a flexible base material (I) a sealing means for bonding a roll-shaped sealing material on the base material with a thermosetting adhesive so as to cover the organic functional element; and (ii) the heat after the sealing material is bonded. An organic electronics element manufacturing apparatus, comprising: a cutting unit that performs hot-melt cutting before the curable adhesive is cured.

  The above-described means of the present invention suppresses delamination that occurs between the base material and the sealing material when the organic electronic element provided on the flexible base material is cut for each unit (element-like). It is possible to provide an organic electronic device manufactured by an organic electronic device manufacturing method, a manufacturing apparatus, a manufacturing method, and the like that can obtain desired sealing performance.

  In other words, the means of the present invention enables cutting with the sealing material in a temporarily bonded state, and therefore the production line of the organic electronics element can be shortened. Since it is possible to cut while melting the adhesive, it is possible to suppress delamination and to provide an organic electronics element having a desired sealing performance. Moreover, since the cutting waste generated from the substrate or the like adheres to the melted adhesive, scattering of the cutting waste is suppressed, and process contamination and waste adhesion to the product are reduced. Furthermore, it is possible to cure the cut end portion before the main curing, and handling after cutting is advantageous.

  In addition, the organic electronic element manufacturing method of the present invention can provide an organic electronic element that has improved gas barrier properties and is excellent in performance such as the light emission efficiency half life of the light emitting element.

  The method for producing an organic electronic device of the present invention includes at least a flexible substrate, a pair of electrodes facing each other, an organic layer sandwiched between them (hereinafter referred to as “organic functional device”), and a sealing material. A method for producing an organic electronics element comprising: (i) applying a sealing material on the base material so as to cover the organic functional element after the step of forming the organic functional element on the base material; A sealing step of bonding with a curable adhesive; and (ii) a cutting step of performing hot-melt cutting after the sealing material is bonded and before the thermosetting adhesive is cured. To do. This feature is a technical feature common to the inventions according to claims 1 to 7. In the present application, the “organic functional element” is an element composed of at least a pair of electrodes and an organic layer sandwiched between them, and has a basic function of developing electronic and electrical functions such as light emission and photoelectric conversion. It refers to a component element.

  As an embodiment of the present invention, it is preferable to use a hot blade as the means for hot melt cutting. In this case, it is preferable that the thermal blade includes a heater and a detection unit that detects the blade edge temperature, and controls the thermal energy supplied to the heater in accordance with the temperature detected by the detection unit. Moreover, it is preferable that the blade edge | tip temperature of the said thermal blade is more than the thermosetting temperature of the said thermosetting adhesive.

  In particular, the method for producing an organic electronic device of the present invention can be suitably used as a method for producing an organic electroluminescence device.

  As is clear from the above, the organic electronic device manufacturing apparatus for carrying out the organic electronic device manufacturing method of the present invention includes (i) the organic device after the step of forming the organic functional device on the substrate. (Function) A sealing means for adhering a roll-shaped sealing material on the base material with a thermosetting adhesive so as to cover the element, and (ii) the thermosetting adhesive after the sealing material is bonded. It is preferable that it is a manufacturing apparatus of the aspect provided with the cutting means which performs a hot-melt cutting before hardening | curing.

  The organic electronic device manufactured by the method for manufacturing an organic electronic device of the present invention has improved gas barrier properties and is excellent in performance such as the light emission efficiency half life.

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

(Outline of manufacturing method of organic electronics element)
The method for producing an organic electronic device of the present invention comprises at least a flexible substrate, an organic layer sandwiched between a pair of opposing electrodes (hereinafter referred to as “organic functional device”), and a sealing material. It is a manufacturing method of the organic electronics element which comprises the following process after the process of forming an organic functional element on the said base material.
(I) A sealing step of adhering a sealing material on the base material with a thermosetting adhesive so as to cover the organic functional element (ii) After the sealing material is bonded, the thermosetting adhesive is cured. Cutting process in which heat cutting is performed before cutting In the manufacturing method of the present invention, before the above steps (i) and (ii), a substrate cleaning step, an organic functional element on the substrate It is preferable that it is an aspect provided with the process etc. of forming.

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

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

  <Step of forming an organic functional element>: A step of forming a light emitting element composed of an electrode, various organic functional layers, and the like on a substrate by a known technique such as a vapor deposition method, an ink jet method, a printing method, or a coating method. FIG. 1 shows a basic configuration of the organic EL element. FIG. 1A is a schematic diagram showing the overall configuration of the organic EL element. FIG. 1B is a schematic diagram showing a configuration of a light emitting element portion of the organic EL element. Details of each element constituting the organic EL element will be described later.

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

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

  <Cutting step>: A cutting step in which after the sealing material is bonded, the thermosetting adhesive is cut before the thermosetting adhesive is cured.

  As an embodiment of the present invention, it is preferable to use a hot blade as the means for hot melt cutting. In this case, it is preferable that the thermal blade includes a heater and a detection unit that detects the blade edge temperature, and controls the thermal energy supplied to the heater in accordance with the temperature detected by the detection unit. Moreover, it is preferable that the blade edge | tip temperature of the said thermal blade is more than the thermosetting temperature of the said thermosetting adhesive.

  FIG. 2 is a schematic diagram illustrating an example of a hot blade. In addition, a cylindrical heater is put in the hole 4 in FIG. 2 and a hot blade is heated, and the organic EL element provided on the roll-shaped flexible substrate is heated and melted at a predetermined position (location) for each unit. Cutting is performed to obtain an organic EL element having a predetermined size.

  3 and 4 show a concept of a sealing process in which a roll-shaped sealing material is bonded on a base material with a thermosetting adhesive, and a cutting process in which hot-melt cutting is performed before the thermosetting adhesive is cured. FIG.

  In the present invention, it is possible to cut the sealing material in a temporarily bonded state by the above means, and therefore it is possible to shorten the production line of the organic EL element. Further, since it is possible to cut while melting the adhesive, it is possible to suppress delamination and to provide a desired sealing performance. Moreover, since the cutting waste generated from the substrate or the like adheres to the melted adhesive, scattering of the cutting waste is suppressed, and process contamination and waste adhesion to the product are reduced. Furthermore, it is possible to cure the cut end portion before the main curing, and handling after cutting is advantageous.

  FIG. 5 shows a basic configuration form of the organic EL element and the sealing material. FIG. 5A is a schematic view showing a conventional type, and FIG. 5B is a schematic view showing a form according to the present invention.

  In the conventional type configuration, since the aluminum can is used as the sealing material, the thickness of the entire substrate is increased. Generally used UV curable adhesives have insufficient moisture permeation and oxygen permeation and require a hygroscopic material. Since the substrate is made of glass, there are disadvantages such as processing in sheet units and inferior productivity.

  In the configuration according to the present invention, for example, a resin film (PEN) is used as a base material, and it is excellent in moisture permeation and oxygen permeation. In addition, by using a thermosetting adhesive and using an aluminum foil as the sealing material, it is possible to process in a roll shape, and there are advantages such as not only excellent productivity but also thinning of the entire substrate.

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

(Base material: Substrate)
As a base material (hereinafter also referred to as a substrate, a base, a base, a support substrate, a support, etc.) according to the present invention, a flexible base material capable of imparting flexibility (flexibility) to an organic EL element. For example, it is necessary to use a resin film. However, a metal, glass, quartz or the like can be partially used as a substrate depending on the purpose.

  Examples of the resin film include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyethylene, polypropylene, cellophane, cellulose diacetate, cellulose triacetate, cellulose acetate butyrate, cellulose acetate propionate (CAP), Cellulose esters such as cellulose acetate phthalate and cellulose nitrate or derivatives thereof, polyvinylidene chloride, polyvinyl alcohol, polyethylene vinyl alcohol, syndiotactic polystyrene, polycarbonate, norbornene resin, polymethylpentene, polyether ketone, polyimide, polyether Sulfone (PES), polyphenylene sulfide, polysulfones, polyether Examples include cycloolefin resins such as luimide, polyether ketone imide, polyamide, fluororesin, nylon, polymethyl methacrylate, acrylic or polyarylate, Arton (trade name, manufactured by JSR) or Apel (trade name, manufactured by Mitsui Chemicals). It is done.

On the surface of the resin film, an inorganic film, an organic film, or a hybrid film of both may be formed. Is preferably a barrier film of 0.01 g / m ² · day · atm or less, and further has an oxygen permeability (20 ° C., 100% RH) of 10 measured by a method according to JIS K 7126-1992. ⁻³ g / m ² / day or less and a water vapor transmission rate of 10 ⁻³ g / m ² / day or less are preferable, and both the water vapor transmission rate and the oxygen transmission rate are 10 ^−5. More preferably, it is g / m ² / day or less.

  As a material for forming the barrier film, any material may be used as long as it has a function of suppressing entry of elements that cause deterioration of elements such as moisture and oxygen. For example, silicon oxide, silicon dioxide, silicon nitride, or the like can be used. Furthermore, in order to improve the brittleness of the film, it is more preferable to have a laminated structure of these inorganic layers and organic material layers. Although there is no restriction | limiting in particular about the lamination | stacking order of an inorganic layer and an organic layer, It is preferable to laminate | stack both alternately several times.

  The method for forming the barrier film is not particularly limited. For example, vacuum deposition, sputtering, reactive sputtering, molecular beam epitaxy, cluster ion beam, ion plating, plasma polymerization, atmospheric pressure plasma polymerization A plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, or the like can be used, but an atmospheric pressure plasma polymerization method as described in JP-A-2004-68143 is particularly preferable.

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

"anode"
As the anode in the organic EL element, an electrode material made of a metal, an alloy, an electrically conductive compound, or a mixture thereof having a high work function (4 eV or more) is preferably used. Specific examples of such an electrode material include metals such as Au, and conductive light transmissive materials such as CuI, indium tin oxide (ITO), SnO ₂ , and ZnO. Alternatively, a material such as IDIXO (In ₂ O ₃ —ZnO) that can form an amorphous light-transmitting conductive film may be used. For the anode, these electrode materials may be formed into a thin film by a method such as vapor deposition or sputtering, and a pattern having a desired shape may be formed by a photolithography method. ), A pattern may be formed through a mask having a desired shape when the electrode material is deposited or sputtered. Or when using the substance which can be apply | coated like an organic electroconductivity compound, wet film forming methods, such as a printing system and a coating system, can also be used. The sheet resistance as the anode is preferably several hundred Ω / □ or less. Further, although the film thickness depends on the material, it is usually selected in the range of 10 to 1000 nm, preferably 10 to 200 nm.

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

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

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

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

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

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

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

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

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

  For the production of the light emitting layer, a light emitting material or a host compound, which will be described later, is formed by forming a film by a known thinning method such as a vacuum deposition method, a spin coating method, a casting method, an LB method, an ink jet method, or the like. it can.

  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). )But it is good.

  As the known host compound, a compound that has a hole transporting ability and an electron transporting ability, prevents the emission of light from being increased in wavelength, and has 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 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 according to the present invention, a fluorescent compound or a phosphorescent material (also referred to as a phosphorescent compound or a phosphorescent compound) is used.

  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 phosphorescent quantum yield can be measured by the method described in Spectroscopic II, page 398 (1992 edition, Maruzen) of Experimental Chemistry Course 4 of the 4th edition. 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 of the phosphorescent material. In principle, the carrier recombination occurs on the host compound to which the carrier is transported to generate 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, or a platinum compound (platinum complex compound), or a rare earth complex, and most preferably an iridium compound.

  Specific examples of the compound used as the phosphorescent material are shown below, but the present invention is not limited to these. These compounds are described, for example, in Inorg. Chem. 40, 1704-1711, and the like.

  A fluorescent substance can also be used for the organic electroluminescent element according to the present invention. Representative examples of fluorescent emitters (fluorescent dopants) include coumarin dyes, pyran dyes, cyanine dyes, croconium dyes, squalium dyes, oxobenzanthracene dyes, fluorescein dyes, rhodamine dyes, 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, it is also preferable to provide a non-light emitting intermediate layer (also referred to as an undoped region) between the light emitting layers.

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

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

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

  The non-light-emitting intermediate layer may contain a non-light-emitting layer, a compound common to each light-emitting layer (for example, a host compound), and each common host material (where a common host material is used) In the case where the physicochemical characteristics such as phosphorescence emission energy and glass transition point are the same, or the molecular structure of the host compound is the same, etc.) The 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 the host compound contained in each light-emitting layer in the undoped light-emitting layer, device fabrication, which is a major problem in conventional organic EL device fabrication, is achieved. Complexity can also be eliminated.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

As a method for thinning the organic compound thin film, there are a vapor deposition method and a wet process (spin coating method, casting method, ink jet method, printing method) as described above, but it is easy to obtain a uniform film and a pinhole. From the point of being difficult to form, a vacuum deposition method, a spin coating method, an ink jet method, and a printing method are particularly preferable. Further, different film forming methods may be applied for each layer. When employing a vapor deposition method for film formation, the vapor deposition conditions vary depending on the type of compound used, but generally a boat heating temperature of 50 to 450 ° C., a degree of vacuum of 10 ⁻⁶ to 10 ⁻² Pa, and a vapor deposition rate of 0.01 to It is desirable to select appropriately within the range of 50 nm / second, substrate temperature −50 to 300 ° C., film thickness 0.1 nm to 5 μm, preferably 5 to 200 nm.

  After these layers are formed, a thin film made of a cathode material is formed thereon by a method such as vapor deposition or sputtering so as to have a thickness of 1 μm or less, preferably in the range of 50 to 200 nm, and a cathode is provided. Thus, a desired organic EL element can be obtained. The organic EL element is preferably produced from the hole injection layer to the cathode consistently by a single evacuation, but may be taken out halfway and subjected to different film forming methods. At that time, it is necessary to consider that the work is performed in a dry inert gas atmosphere.

  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 liquid crystal 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.

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

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

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

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

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

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

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

  It is desirable that the diffraction grating to be introduced has a two-dimensional periodic refractive index. This is because light emitted from the light-emitting layer is randomly generated in all directions, so in a general one-dimensional diffraction grating having a periodic refractive index distribution only in a certain direction, only light traveling in a specific direction is diffracted. The light extraction efficiency does not increase so much. However, by making the refractive index distribution a two-dimensional distribution, light traveling in all directions is diffracted, and light extraction efficiency is increased.

  The position where the diffraction grating is introduced may be in any one of the layers or in the medium (in the transparent substrate or the transparent electrode) as described above, but is preferably in the vicinity of the organic light emitting layer where light is generated.

  At this time, the period of the diffraction grating is preferably about 1/2 to 3 times the wavelength of light in the medium. The arrangement of the diffraction grating is preferably two-dimensionally repeated, such as a square lattice, a triangular lattice, or a honeycomb lattice.

  The light emitting device according to the present invention is processed on the light extraction side of the support substrate so as to provide, for example, a structure on a microlens array, or is combined with a so-called condensing sheet, for example, with respect to a specific direction, for example, the device light emitting surface. By condensing in the front direction, the luminance in a specific direction can be increased.

  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 to 100 μm. If it becomes smaller than this, the effect of diffraction will generate | occur | produce and color, and if too large, thickness will become thick and is not preferable.

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

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

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

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

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

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

(Encapsulant)
The sealing material according to the present invention seals an organic EL element and protects the element from a severe external environment such as temperature change, humidity, oxygen, and impact.

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

  In particular, a metal foil laminated with a resin film (polymer film) cannot be used as a gas barrier film on the light extraction side, but it is a low-cost and low moisture-permeable sealing material and is intended for light extraction. If not (transparency is not required), it is preferable as a sealing material.

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

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

  The thickness of the metal foil is preferably 6 to 50 μm from the viewpoints of barrier properties (moisture permeability, oxygen permeability) and cost.

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

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

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

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

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

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

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

  Moreover, as the sealing material (film), a ceramic film is formed on the metal foil on the opposite side of the resin film (polymer film) of the film in which one side of the metal foil is coated with the resin film (polymer film). It is also preferable to use it.

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

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

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

  In addition, since an organic EL element may deteriorate by heat processing, what can be adhesive-hardened from room temperature to 100 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 it like screen printing.

  In addition, it is also preferable to coat the electrode and the organic layer on the outside of the electrode facing the support substrate with the organic layer interposed therebetween, and form an inorganic or organic layer in contact with the support substrate to form a sealing film. it can. In this case, the material for forming the film may be any material that has a function of suppressing intrusion of elements that cause deterioration of elements such as moisture and oxygen. For example, silicon oxide, silicon dioxide, silicon nitride, or the like may be used. it can. Furthermore, in order to improve the brittleness of the film, it is preferable to 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 method, sputtering method, reactive sputtering method, molecular beam epitaxy method, cluster ion beam method, ion plating method, plasma polymerization method, atmospheric pressure plasma A polymerization method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, or the like can be used.

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

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

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

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

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

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

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

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

(Organic EL device manufacturing equipment)
An example of an organic EL element manufacturing apparatus and a manufacturing method (process) using the same according to the present invention will be described with reference to FIG.

  FIG. 6 is a schematic diagram of a manufacturing apparatus and a manufacturing process for producing an organic EL element having a multilayer structure using a band-shaped substrate. In the description of the manufacturing apparatus shown in the figure, as an example of an organic EL element, a gas barrier layer, a first electrode, a hole transport layer, a light emitting layer, an electron injection layer, a second electrode, The case of the organic EL element for illumination (surface emitting) formed in the order of the sealing layers is performed. In this figure, since the gas barrier layer and the first electrode already formed on the belt-like flexible substrate are used, the first electrode forming step is omitted.

  The manufacturing process includes a strip-shaped substrate supplying step 3 ′, a hole transport layer forming step 4 ′ for forming a hole transport layer, a light emitting layer forming step 5 ′ for forming a light emitting layer, and a first recovery step 6. ', An electron injection layer forming step 7' for forming an electron injection layer, a second electrode forming step 8 'for forming a second electrode, a sealing layer forming step 9' for forming a sealing layer, And a recovery step 10 '. In the manufacturing process shown in this figure, the supply step 3 'to the light emitting layer formation step 5' are continuously performed under atmospheric pressure conditions, and after winding up under atmospheric pressure conditions, the electron injection layer formation step 7 'is performed. -The case where the sealing layer forming step 9 'is continuously performed under reduced pressure conditions is shown. The second recovery step 10 'may be arranged under either atmospheric pressure conditions or reduced pressure conditions.

The supply process 3 ′ includes a feeding process 301 ′ and a surface treatment process 302 ′. In the feeding step 301 ′, a gas barrier film used to form at least one organic EL element and at least one anode layer including the first electrode are already formed in this order in a band-shaped substrate 301′b (band-shaped substrate 301′b). The base material A) is wound around a winding core and supplied in a roll state. 301'a shows the former winding roll of strip | belt-shaped base material 301'b. The surface treatment process 302 'includes a cleaning surface modification apparatus 302'a and a first antistatic means 302'b. The cleaning surface modification processing apparatus 302'a cleans and modifies the surface of the first electrode (not shown) of the belt-like substrate A sent from the feeding step 301 'before applying the hole transport layer forming coating solution. Therefore, for example, it is preferable to use a low-pressure mercury lamp, an excimer lamp, a plasma cleaning apparatus, or the like. As conditions for the cleaning surface modification treatment using a low-pressure mercury lamp, for example, a cleaning surface modification treatment is performed by irradiating a low-pressure mercury lamp with a wavelength of 184.2 nm at an irradiation intensity of 5 to ²⁰ mW / cm ² and a distance of 5 to 15 mm. Conditions are mentioned. For example, atmospheric pressure plasma is preferably used as the condition for the cleaning surface modification treatment by the plasma cleaning apparatus. Examples of the cleaning conditions include conditions in which a gas containing oxygen of 1 to 5% by volume is used for argon gas, and the cleaning surface modification treatment is performed at a frequency of 100 KHz to 150 MHz, a voltage of 10 V to 10 KV, and an irradiation distance of 5 to 20 mm.

The first antistatic means 302'b has a non-contact type static elimination preventing device 302'b1 and a contact type static elimination preventing device 302'b2. Examples of the non-contact type static elimination preventing device 302′b1 include a non-contact type ionizer, and the type of ionizer is not particularly limited, and the ion generation method may be either an AC method or a DC method. An AC type, a double DC type, a pulsed AC type, and a soft X-ray type can be used, but the AC type is particularly preferable from the viewpoint of precise static elimination. Air or N ₂ is used as the injection gas required when using the AC type, but it is preferable to use N ₂ with sufficiently high purity. From the viewpoint of in-line operation, the blower type or the gun type is selected.

  The contact type static elimination preventing device 302′b2 is performed using a static elimination roll or a conductive brush connected to the ground. The static elimination roll as the static eliminator is grounded and removes the surface charge by rotatingly contacting the neutralized surface. Such static elimination rolls include rolls made of elastic plastic or rubber mixed with conductive materials such as carbon black, metal powder, and metal fibers in addition to rolls made of metal such as aluminum, copper, nickel, and stainless steel. used. In particular, an elastic material is preferable in order to improve contact with the belt-like flexible continuous sheet. Examples of the conductive brush connected to the earth include a neutralizing bar or a neutralizing yarn structure having a brush member made of conductive fibers arranged in a line or a linear metal brush. The neutralization bar is not particularly limited, but a corona discharge type is preferably used. For example, SJ-B manufactured by Keyence Corporation is used. The neutralizing yarn is not particularly limited, but usually a flexible yarn can be preferably used.

  The non-contact type antistatic device 302′b1 is used on the first electrode surface side of the belt-like flexible substrate A, and the contact-type antistatic device 302′b2 is used on the back surface side of the belt-like flexible substrate A. Is preferred. The first antistatic means removes the charge of the base material and prevents the adhesion of the dust and the dielectric breakdown, thereby improving the yield of the elements.

  The hole transport layer forming step 4 ′ is a backup roll 401 ′ that holds the belt-shaped substrate A, and a hole transport layer-forming coating solution is applied to the belt-shaped substrate A held by the backup roll 401 ′ as an external extraction electrode. And removing the solvent from the coating film a ′ for forming the hole transport layer formed on the first electrode (not shown) on the belt-like substrate A and removing the solvent. It has a drying device 403 ′ having a drying air supply port 403′a, an exhaust port 403′b, and a transporting roll 403′c for forming b ′. Note that the drying device 403 includes a portion that allows heat treatment.

  Reference numeral 404 ′ denotes a second charge removal processing means for removing charge from the formed hole transport layer b ′. The second static elimination processing unit 404 ′ includes the same non-contact type static elimination prevention device 404′a and the contact type static elimination prevention device 404′b2 as the first static elimination processing unit 302′b.

  The light emitting layer forming step 5 'includes a first coating step 5'a, a first drying step 5'b, a second coating step 5'c, a second drying step 5'd, and a third coating step 5'e. And a third drying step 5'f. The first application step 5'a includes an electrostatic nozzle ejection device 5'a1, a holding base 5a2, and a first accumulator portion 5'a3 as first droplet ejection means. In the first application process 5'a, the application by the electrostatic nozzle discharge device 5'a1 is such that the liquid droplets discharged from the electrostatic nozzle discharge device 5'a1 land on the hole transport layer at regular intervals and emit light discontinuously. A layer forming coating film c ′ (discontinuous second organic functional layer forming coating film) is formed.

  The first accumulator unit 5′a3 moves the roll 5′a31 in the vertical direction (in the direction of the arrow in the drawing), so that the transport speed between the hole transport layer forming step 4 ′ and the first coating step 5′a is increased. The roll 5'a31 can be added according to the speed difference.

  The first drying step 5'b includes a drying device 5'b1 having a drying air supply port 5'b11, an exhaust port 5'b12, and a transport roll 5'b13, and formation of the formed discontinuous light emitting layer. And 3rd static elimination process means 5'b2 which neutralizes static electricity coating film c '. The third static elimination processing means 5'b2 has the same non-contact type static elimination prevention device 5'b21 and contact type static elimination prevention device 5'b22 as the first static elimination processing means 302'b. Note that the drying device 5'b1 has a portion that allows heat treatment inside. The discontinuous light emitting layer forming coating c ′ (discontinuous second organic functional layer forming coating) is removed by the drying device 5′b1 and the discontinuous light emitting layer d ′ (discontinuous second organic) is removed. Functional layer).

  The second coating step 5'c includes an electrostatic nozzle ejection device 5'c1, a mounting table 5'c2, and a second accumulator unit 5'c3 as second droplet ejection means. In the application by the electrostatic nozzle discharge device 5'c1 in the second application step 5'c, the liquid droplets discharged from the electrostatic nozzle discharge device 5'c1 are discontinuous formed in the first application step 5'a. Landing on an uncoated portion of the light emitting layer d ′ (discontinuous second organic functional layer) forms a continuous light emitting layer forming coating film e ′ (continuous second organic functional layer forming coating film).

  The second accumulator unit 5′c3 moves the roll 5′c31 in the vertical direction (in the direction of the arrow in the drawing), so that the conveyance speed of the first application step 5′a and the second application step 5′c is increased. The roll 5'c31 can be added according to the speed difference. The second drying step 5'd includes a drying device 5'd1 having a drying air supply port 5'd11, an exhaust port 5'd12, and a transporting roll 5'd13, and the formed continuous light emitting layer f '. And 4th static elimination process means 5'd2 which performs static elimination of this. The fourth static elimination processing means 5'd2 has the same non-contact type static elimination prevention device 5'd21 and contact type static elimination prevention device 5'd22 as the first static elimination processing means 302'b. Incidentally, the drying device 5'd1 has a portion that enables heat treatment inside.

  The third application step 5'e includes an electrostatic nozzle ejection device 5'e1, a mounting table 5'e2, and a third accumulator portion 5'e3 as third droplet ejection means. The third accumulator unit 5′e3 moves the roll 5′e31 in the vertical direction (in the direction of the arrow in the drawing), so that the conveyance speed between the second application step 5′c and the third application step 5′e is increased. The roll 5'e31 can be added according to the speed difference. In the third coating step 5'e, the electrostatic nozzle discharge device 5'e1 is applied to form droplets discharged from the electrostatic nozzle discharge device 5'e1 using the same solvent as the light emitting layer forming coating solution. Landing on the continuous light emitting layer f ′ forms a solvent coating g ′. The electrostatic nozzle ejection device 5'a1, the electrostatic nozzle ejection device 5'c1 and the electrostatic nozzle ejection device 5'e1 are arranged in a frame (not shown) so that the belt-like substrate can be moved in the width direction. ) Is preferable.

  The third drying step 5'f includes a drying device 5'f1 having a drying air supply port 5'f11, an exhaust port 5'f12, and a conveying roll 5'f13, and a continuous light emitting layer h 'formed. 4th static elimination process means 5'f2 which performs static elimination of this. The fourth static elimination processing means 5'f2 has the same non-contact type static elimination prevention device 5'f21 and contact type static elimination prevention device 5'f22 as the first static elimination processing means 302'b. The drying device 5'f1 has a portion that allows heat treatment inside.

  Since the solvent coating g ′ is the same solvent as the solvent used for the light emitting layer forming coating solution, the continuous light emitting layer f ′ (continuous second organic functional layer) is removed before being removed by the drying device 5′f1. Is dissolved to uniformize the continuous light emitting layer f ′ (continuous second organic functional layer) and level the surface, thereby forming a uniform continuous light emitting layer h ′. In addition, it is preferable to arrange | position 3rd application | coating process 5'e and 3rd drying process 5'f for the further uniformization of a continuous light emitting layer, and it may arrange | position suitably as needed. It is possible.

  The first recovery step 6 'includes a fourth accumulator portion 6'a and a winding device (not shown). The belt-like base material (referred to as belt-like base material B) on which the continuous light emitting layer h ′ is formed is wound around a winding core and collected by the roll-shaped belt-like base material B 601 ′. The fourth accumulator section 6'a and the roll 6'a1 move in the vertical direction (in the direction of the arrow in the figure), so that the conveying speed of the third coating step 5'e and the winding speed of the first recovery step 6 'are obtained. The roll 6'a1 can be added according to the speed difference.

  The electron injection layer forming step 7 ′ includes a supply unit 701 ′ and an electron injection layer formation unit 702 ′. In the supply unit 701 ′, the roll-shaped strip base material B 601 ′ produced in the previous process is fed out and supplied to the electron injection layer forming unit 702 ′. In the electron injection layer forming part 702 ′, the electron injection layer i ′ is formed on the continuous light emitting layer h ′. 702'a represents a vapor deposition apparatus, and 702'b represents an evaporation source container. The strip-shaped flexible base material on which the electron injection layer i ′ is formed is subsequently sent to the second electrode forming step 8 ′.

  In the second electrode formation step 8 ′, the second electrode j ′ is formed on the electron injection layer i ′ formed by the electron injection layer formation unit 702 ′ in the second electrode formation unit 801 ′. Reference numeral 801'a denotes a vapor deposition apparatus, and 801'b denotes an evaporation source container.

  The strip-shaped flexible base material on which the second electrode j ′ is formed is subsequently sent to the sealing layer forming step 9 ′. The sealing layer forming step 9 ′ includes a fifth accumulator unit 901 ′, a sealing layer forming device 902 ′, and a fifth antistatic means 903 ′. The fifth antistatic means 903 'has the same non-contact type static elimination preventing apparatus 903'a and the contact type static elimination preventing apparatus 903'b as the first static elimination processing means 302'b. A sealing layer k ′ is formed on the second electrode j ′ by the sealing layer forming device 902 ′ except for the end portion of the second electrode j ′ formed in the second electrode forming step 8, so that the belt-like base material is formed. At least one lighting (surface emitting) organic EL element is produced.

  The collecting step 10 ′ has a winding device (not shown). In the collecting step 10, a strip-shaped flexible base material (referred to as a strip-shaped flexible base material C) on which at least one illumination (surface emitting) organic EL element is formed is encapsulated by a winding device (not shown). It is wound up and collected with the k 'side inside. Reference numeral 10'a denotes a roll-shaped belt-like base material in which the belt-like flexible base material C is wound around a winding core and collected as a roll. The oxygen concentration is 1 in consideration of performance maintenance, dark spots (non-light-emitting portions), and the like. It is preferable to store in an environment of ˜100 ppm and a moisture concentration of 1 to 100 ppm.

  In the first coating process 5'a shown in the figure, coating is performed by the electrostatic nozzle ejection device 5'a1, in the second coating process 5'c, coating by the electrostatic nozzle ejection device 5'c1 and third coating process 5'e. In the application by the electrostatic nozzle ejection device 5'e1, the electrostatic nozzle ejection device 5a1, the electrostatic nozzle ejection device 5c1 and the electrostatic nozzle ejection device 5e1 are moved in the width direction of the belt-like substrate in accordance with the transport speed of the belt-like substrate. The method of doing is mentioned.

  In this figure, the electron injection layer forming step 7 'and the second electrode forming step 8' are shown in the case of the vapor deposition apparatus. However, the electron injection layer and the second electrode are formed by electron injection independent of the vapor deposition method. A method of forming the layer and the second electrode can also be used. Further, instead of the sealing layer shown in this figure, a method of sticking a sealing film may be used.

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

  The step of forming the hole transport layer and the light emitting layer, which are the constituent layers of the organic EL device shown in FIG. It is preferable that the dew point is −20 ° C. or lower and the measured cleanliness is Class 3 to Class 5 and the atmospheric pressure is 10 to 45 ° C. excluding the drying part.

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

  FIG. 7 is a schematic diagram showing an example of a sealing material bonding / cutting process in the embodiment of the invention. In the manufacturing process, the sealing material bonding step 140 includes an adhesive layer forming step 141, a laminating step 142, a curing step 143, and an electrode portion exposing step 144.

  The substrate A on which the light-emitting element (organic EL structure) wound in a roll shape and the protective film are formed is put into an off-line sealing material bonding step 140 and a cutting step 150 to form a sealing material layer. Then, before the thermosetting adhesive is cured using a hot blade, it is heat-melt cut to a predetermined size and formed into an organic EL element.

  In the sealing material bonding step 140, the base material roll on which the organic EL structure and the barrier film are formed is fed out again to adhere the long sealing material to the base material. This is a step of forming the sealing material layer 16 on the surface. By forming the encapsulant layer 16 on the organic EL structure, the organic light emitting layer of the organic EL structure is covered with the encapsulant, and high quality without causing deterioration in quality due to moisture or oxygen in the air. High reliability can be maintained.

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

  The adhesive layer forming step 141 is a step of forming the adhesive layer 15 by applying an adhesive to a selected region of the base material on which the organic EL structure is formed. In the adhesive layer forming step 141, the adhesive layer 15 is formed in a region excluding the anode and cathode lead portions 12a and 14a of the organic EL structure.

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

  The curing step 143 is a step of curing the adhesive, and the electrode portion exposing step 144 is a step of removing the sealing material from the electrode lead portions 12a and 14a of the organic EL structure to expose the lead portion.

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

  In the sealing material bonding step 140, the adhesive layer 15 is selectively applied only to a predetermined range of the base material 11 by screen printing, that is, to a region excluding the anode and cathode lead portions 12a and 14a. It is formed by coating.

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

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

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

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

Example 1
<< Production of Substrate A >>
(Process for forming an electrode layer, a hole injection layer, a hole transport layer, and a light emitting layer on a flexible substrate)
In advance, a polyethylene naphthalate film having a dew point of −65 ° C., an inert gas atmosphere and a pressure of 80 Pa, and subjected to dehydration and deoxygenation treatment to a single-sided 100 μm thick polyethylene naphthalate film is disclosed in JP-A-2007-83644. A gas barrier layer was formed by the method described in the column “Examples”. That is, the roll electrode type discharge treatment apparatus shown in FIG.

  A gas barrier film was formed on one side of a polyethylene naphthalate film by forming an adhesion layer / ceramic layer / protective layer on the resin film substrate in the following order. Regarding the respective film thicknesses, the adhesion layer is 50 nm, the ceramic layer is 30 nm, and the protective layer is 400 nm. The substrate holding temperature during film formation was 120 ° C.

<Ceramic layer>
Discharge gas: N ₂ gas reaction gas 1: 5% of oxygen gas to the total gas
Reaction gas 2: TEOS (tetraethoxysilane) is 0.1% of the total gas
Low frequency side power supply power: 80 kHz at 10 W / cm ² High frequency power supply power: 13.56 MHz at 10 W / cm ²
<Adhesion layer>
Discharge gas: N ₂ gas reactive gas 1: 1% of hydrogen gas with respect to the total gas
Reaction gas 2: 0.5% of TEOS with respect to the total gas
Low frequency side power supply power: 80 kHz at 10 W / cm ² High frequency power supply power: 13.56 MHz at 5 W / cm ²
<Protective layer>
Discharge gas: N ₂ gas reactive gas 1: 1% of hydrogen gas with respect to the total gas
Reaction gas 2: 0.5% of TEOS with respect to the total gas
Low frequency side power supply power: 80 kHz at 10 W / cm ² High frequency power supply power: 13.56 MHz at 5 W / cm ²
Next, on the polyethylene naphthalate film on which the gas barrier layer is formed, using indium tin oxide (ITO) as a target material, and using argon containing 5% by volume of oxygen as a sputtering gas in a vacuum chamber, An ITO film having a thickness of 110 nm was patterned by sputtering as an electrode layer while continuously feeding at 0.5 Pa. As the ITO pattern, the conductive layer pattern shown in FIG. 3 was used. This was wound around a core in a vacuum chamber, returned to normal pressure under a nitrogen stream, and transferred to a coating process under normal pressure without exposure to the atmosphere (air).

  On this base material with a conductive layer, a coating solution for a hole injection layer (deoxygenated) having the liquid composition described below is applied with an extrusion coater installed in the first coating chamber, and dried under an inert gas stream. (30 nm thickness after drying). Subsequently, the hole transport layer coating solution (deoxygenated and dehydrated) is applied in the second coating chamber, irradiated with UV rays to crosslink, insolubilized in the coating solvent after this step, and then dried. (The thickness after drying was 40 nm). Further, in the third coating chamber, a light-emitting layer is applied on the cross-linked hole transport layer (thickness after drying is 50 nm), dried, and a coated original fabric (web) in which three functional layers are laminated W-1) was produced. The coating process under normal pressure was maintained in an atmosphere having a moisture concentration in a nitrogen atmosphere of 1 ppm to 200 ppm and an oxygen concentration of 30 ppm or less.

(Coating solution for hole injection layer)
A solution obtained by diluting polyethylene dioxythiophene / polystyrene sulfonate (PEDOT / PSS, Baytron P AI 4083 manufactured by Bayer) with pure water at 65% and methanol at 5% was used.

(Coating liquid for hole transport layer)
A solution in which 50 mg of the following compound A was contained in 10 ml of toluene was used. After irradiating with ultraviolet light for 90 seconds to carry out photopolymerization and crosslinking, the film was dried under a nitrogen stream while being slowly conveyed through a drying zone at 90 ° C.

(Light emitting layer coating solution)
A solution in which PVK (polyvinylcarbazole) (60 mg) and 1.5 mg of Ir (ppy) ₃ were contained in 6 ml of chlorobenzene was used. After film formation, the film was dried under a nitrogen stream while slowly transporting through a 95 ° C. drying zone to form a light emitting layer having a dry film thickness of 50 nm.

<< Production of Substrate B >>
(Step of forming a surface smooth layer on a film having a layer containing a desiccant)
A desiccant-containing film as a sealing film is a polyethylene 2,6 naphthalate film containing barium oxide in the core layer using the method for producing a laminated substrate described in Example 1 of JP-A-2005-38661. A-1) was prepared and used.

That is, polyethylene-2,6-naphthalate A (containing barium oxide; barium oxide powder (average particle size, 0.5 μm) was mixed and kneaded with polyethylene-2,6-naphthalate chips at 280 ° C. (content 5 mass) ) And polyethylene-2,6-naphthalate chips were each vacuum dried at 170 ° C. for 10 hours, and then kept in a dry nitrogen stream while three units from a hopper installed on the extruder. Each was supplied to an extruder, melt extruded at 290 ° C., passed through a 40 mesh filter, and then joined in layers so that the thickness ratio was 4: 3: 2 in a T-die. It was brought into close contact with the cooling drum while applying an electrostatic force, and cooled and solidified rapidly to obtain a laminated unstretched sheet. At this time, the core layer was polyethylene-2,6-naphthalate A (containing barium oxide), and the surface layer was polyethylene-2,6-naphthalate. This unstretched sheet was guided to a roll-type longitudinal stretching machine, preheated at 90 ° C., and stretched 2.8 times in the longitudinal direction while being heated with an IR heater between low-speed and high-speed rolls. The obtained uniaxially stretched film was supplied to a tenter-type transverse stretching machine and stretched at 130 ° C. so that the transverse stretching ratio was 2.8 times. The obtained biaxially oriented film was heat-fixed at 210 ° C. for 10 seconds. Subsequently, the film was slowly cooled to room temperature over 30 seconds while being subjected to a 5% relaxation treatment in the transverse direction to obtain a biaxially stretched laminated PEN film support having a thickness of 90 μm (desiccant-containing film A-1).
It was 15 nm or less when the surface roughness was measured using the optical interference type surface roughness meter RST / PLUS (made by WYKO).

  The layer structure of A-1 consists of three layers of polyethylene-2,6-naphthalate (PEN) / PEN and barium oxide / PEN, and the overall thickness is 90 μm, and the thickness ratio is 40/30/20.

  This original film roll was stored in an inert gas atmosphere storage with a dew point temperature of −65 degrees (water content of 10 ppm or less).

(Process of forming electrode layer and electron injection layer on desiccant-containing film)
Similarly to the above, on the surface of the desiccant-containing film A-1 whose surface layer polyethylene-2,6-naphthalate (PEN) is 40 μm, a gas barrier layer having the composition described in Examples of JP-A-2007-83644 is formed in the same manner. The film containing a desiccant was coated. Next, a surface smooth layer made of an acrylate ester is formed on the surface (opposite side) where the surface layer polyethylene-2,6-naphthalate (PEN) is 20 microns, cross-linked and cured with ultraviolet rays, and then passed through a decompression chamber. Then, it was introduced into a vacuum transfer chamber, and aluminum was patterned to a thickness of 120 nm by vapor deposition as a counter electrode layer in the first thin film forming chamber. Subsequently, lithium fluoride (electron injection layer) was deposited by 0.3 nm in the second thin film formation chamber.

(Step of applying a sealing resin to the desiccant-containing film with the counter electrode layer / injection layer formed and laminating it with the web with the functional layer formed)
A film in which an electrode layer and an electron injection layer are formed on the desiccant-containing film A-1 is heated in an inert gas stream (in a nitrogen atmosphere, a moisture concentration of 1 ppm to 200 ppm and an oxygen concentration of 30 ppm or less) as an adhesive. A curable epoxy resin (UV resin XNR5516, manufactured by Nagase Chemtech Co., Ltd.) was applied in a predetermined shape using screen printing. Without winding up the sealing film with electrode, it is continuously sent to the bonding / sealing process using the pressure roll shown in FIG. 5, while controlling the bonding position with W-1 at 140 ° C. Then, after bonding (bonding pressure was set to 0.2 MPa) and bonding, in the middle of curing (before the thermosetting adhesive was cured), it was heated to the temperature shown in Table 1 (25 to 140 ° C.). Various organic EL elements were produced by cutting (cutting) each element with a hot blade at a cutting speed (20 to 80 m / min) shown in Table 1.

  About the organic EL element produced by said method, the peeling amount of the sealing material and the luminous efficiency (luminance) half life were measured and evaluated.

<Measurement of amount of peeling of sealing material>
The measurement of the amount of peeling of the sealant was performed according to the following procedure (see FIG. 8). : (I) Cut the cut end face into 10 mm square. (Ii) The cut end face side portion is polished with a microtome. (Iii) The cut end face is magnified 400 times with an electron microscope (SEM) or a laser microscope, and the amount of peeling is measured.

<Measurement of luminous efficiency (luminance) half-life>
Luminous efficiency (luminance) half-life was measured by adjusting the applied voltage so that the initial luminance of each sample element was 500 cd / m ² and then reducing the luminous efficiency (luminance) by 50% from the initial stage. . The half life of various organic EL elements was evaluated by relative values when the light emission efficiency half life of an organic EL element cut and produced at a blade edge temperature of 140 ° C. was set to 1.0.

  The conditions and evaluation results in the above experiments are summarized in Tables 1 to 3 and FIG.

  As is clear from the results shown in Tables 2 and 3, and FIG. 9, it can be seen that the organic EL device according to the present invention has a small amount of peeling and a long half-life of luminous efficiency.

  That is, by means of the present invention, delamination that occurs between the base material and the sealing material when the organic EL element provided on the flexible base material is cut for each unit (element-like) is suppressed. And it turns out that the manufacturing method of an organic EL element from which desired sealing performance is obtained, a manufacturing apparatus, and an organic EL element can be provided.

Example 2
In the production of the web W-1 of the organic EL element, after forming the hole injection layer, the power generation layer having the liquid composition described later is applied in the third coating chamber (the thickness after drying is 150 nm). An organic photoelectric conversion element having a desiccant in the element was produced in the same manner as in the production of the organic EL element except that W-2 was produced.

(Coating liquid for power generation layer)
In 6 ml of chlorobenzene, a regioregular P3HT having a number average molecular weight of 45000 (poly (3-hexylthiophene)) and a fullerene derivative PCBM (6,6-phenyl-C ₆₁ -butyric acid methyl ester) was used at a mass ratio of 1: 1. After forming the film, the film was dried in a nitrogen stream while slowly transporting the drying zone at 140 ° C. to form a power generation layer having a dry film thickness of 150 nm.

The organic photoelectric conversion device having the obtained desiccant in the device was evaluated for short-circuit current density Jsc when the solar simulator (AM1.5G) was continuously irradiated with light of 100 mW / cm ^2. It was clear that it showed high stability over time and had sufficient light resistance. In addition, as with organic electroluminescence elements, it has been clarified that the yield of products, that is, the manufacturing cost can be reduced in an organic photoelectric conversion element in a mass production level process.

(A) is a schematic diagram which shows the fundamental structure of the whole organic EL element, (b) The schematic diagram which shows the structure of the light emitting element part of an organic EL element Schematic diagram showing an example of a hot blade Conceptual diagram of a sealing process for bonding a roll-shaped sealing material on a base material with a thermosetting adhesive and a cutting process for performing hot-melt cutting before the thermosetting adhesive is cured Conceptual diagram of a sealing process for bonding a roll-shaped sealing material on a base material with a thermosetting adhesive and a cutting process for performing hot-melt cutting before the thermosetting adhesive is cured Schematic diagram showing basic configuration of organic EL element and sealing material; (a) Schematic diagram showing conventional type configuration, (b) Schematic diagram showing configuration according to the present invention Schematic diagram of organic EL device manufacturing apparatus and manufacturing process according to the present invention The schematic diagram which shows an example of the sealing material adhesion | attachment / cutting process which concerns on this invention Conceptual diagram showing the method for measuring the amount of peeling of the sealing material Diagram showing the relationship between luminous efficiency and luminous lifetime

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Organic EL element 2 Hot sword 3 Organic functional element (OLED) formation base Pr Manufacturing apparatus and process 3 'Supply process 301' Band-shaped base material 4 'Hole transport layer formation process 5' Light emitting layer formation process 5'a 1st 1 coating process 5'a1 electrostatic nozzle ejection device 5'b first drying process 5'c second coating process 5'c1 electrostatic nozzle ejection device 5'd second drying process 5'e third coating process 5'e1 Electrostatic nozzle discharge device 5'f Third drying step 7 'Electron injection layer forming step 8' Second electrode forming step 9 'Sealing layer forming step 10 Collection step 140 Sealing material adhesion-cutting step 141C Stencil 141D Adhesive sheet 144X 144Y Hot sword 150 Cutting process 151A, 151B Hot sword

Claims (6)

A method for producing an organic electronic device comprising at least a flexible substrate, a pair of opposed electrodes, an organic layer sandwiched between them (hereinafter referred to as “organic functional device”), and a sealing material. And after the step of forming the organic functional element on the base material, (i) a sealing step of adhering a sealing material on the base material with a thermosetting adhesive so as to cover the organic functional element; And (ii) a cutting step of curing the cut end portion of the thermosetting adhesive by performing hot melt cutting after the sealing material is bonded and before the thermosetting adhesive is cured. A method for producing an organic electronics element, comprising: The method for producing an organic electronic element according to claim 1, wherein a hot blade is used as the means for hot melt cutting. The said hot blade is provided with the detection means which detects a heater and blade edge | tip temperature, and controls the thermal energy supplied to the said heater according to the temperature detected by the said detection means. The manufacturing method of the organic electronics element of description. 4. The method of manufacturing an organic electronic element according to claim 2, wherein a blade edge temperature of the hot blade is equal to or higher than a heat curing temperature of the thermosetting adhesive. 5. The said organic electronics element is an organic electroluminescent element, The manufacturing method of the organic electronics element as described in any one of Claim 1 to 3 characterized by the above-mentioned. An organic electronics element manufacturing apparatus for carrying out the organic electronics element manufacturing method according to any one of claims 1 to 5, wherein the organic functional element is formed on a flexible substrate. (I) sealing means for bonding a roll-shaped sealing material on the base material with a thermosetting adhesive so as to cover the organic functional element; and (ii) after bonding the sealing material, An apparatus for manufacturing an organic electronic element, comprising: a cutting unit that performs hot-melt cutting before the thermosetting adhesive is cured.

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