JPWO2013141190A1 - SEALING ELEMENT FOR ORGANIC ELECTROLUMINESCENT ELEMENT, METHOD FOR PRODUCING ORGANIC ELECTROLUMINESCENT ELEMENT - Google Patents

Abstract

An object of the present invention is to provide a sealing element for an organic electroluminescence element, which can simplify the process after bonding, and has excellent adhesion stability under a high-temperature environment after bonding, and the sealing element for the organic electroluminescence element And providing a method for producing an organic electroluminescence device excellent in high-temperature stability and sealing performance. The sealing element for organic electroluminescence elements of the present invention is characterized by having a thermosetting resin layer containing a thermosetting resin and an auxiliary electrode layer in this order on a substrate.

Description

  The present invention relates to a sealing element for an organic electroluminescence element and a method for producing an organic electroluminescence element using the same.

  In recent years, organic electroluminescence elements using organic substances (hereinafter also referred to as organic EL elements) have been promising for use as solid light emitting inexpensive large-area full-color display elements and writing light source arrays. Research and development is ongoing.

  An organic EL element is formed by laminating an organic functional layer containing an organic light-emitting substance with a thickness of only about 0.1 μm between a pair of anode and cathode formed on a flexible film. This is a thin film type all solid state device.

  In such an organic EL element, by applying a relatively low voltage of about 2 to 20 V, electrons are injected from the cathode and holes are injected from the anode into the organic functional layer. When the electrons and holes recombine in the light-emitting layer that constitutes the organic functional layer, excitons formed as energy levels return from the excited state to the ground state, thereby emitting energy as light. Is a technique expected as a next-generation flat display device and lighting device.

  In recent years, organic EL devices that use phosphorescence have been found to be capable of realizing a luminous efficiency that is approximately four times that of organic EL devices that use fluorescence. As a result, research on the layer structure and electrode structure of light-emitting elements has been widely conducted all over the world. In particular, as part of measures to prevent global warming, application to lighting fixtures, which account for a high proportion of human energy consumption, has begun to be studied, and in order to commercialize white light-emitting panels that can replace conventional lighting fixtures. Researches on organic EL elements applied to the field have been actively conducted.

  In recent years, for white light emitting panels for lighting, organic light-emitting devices have become popular in the market in response to rapid improvements in luminous efficiency, long life, and low product prices in the field of competing LEDs. Therefore, further improvement in light emission efficiency, improvement in device lifetime, and cost reduction are required. In particular, in order to realize cost reduction, it is an important factor how to simplify each manufacturing process such as a method for forming an organic functional layer, a method for forming an electrode, a sealing method, and a mounting process. .

  As one means for simplifying the manufacturing process, a bonding method has been studied. For example, a method for producing an organic EL element by bonding a first substrate in which a part of an organic EL element is formed on a substrate and a second substrate in which the remaining part is formed is disclosed ( For example, see Patent Document 1.) In this method, after bonding a 1st board | substrate and a 2nd board | substrate, in order to join the bonding interface in a molecular level, it is necessary to perform a post-process.

  Moreover, the method of bonding an electrode and its auxiliary electrode is shown (for example, refer patent document 2). According to the method disclosed in Patent Document 2, it is assumed that an auxiliary electrode is formed on a hot-melt resin, so that poor adhesion at the time of bonding is unlikely to occur. Further, since electrodes having high conductivity are bonded to each other, there is an advantage that electrical bonding is sufficient if a part of the electrodes is in contact. However, since hot-melt resin is used, it has a problem that heat resistance is low. On the other hand, if the heat-resistant temperature of the hot melt resin is raised, the organic EL element is damaged at the time of bonding. Moreover, in general hot melt resin, it is easy to permeate | transmit a water | moisture content and the sealing process will be needed after bonding.

JP 2009-289716 A JP 2006-318776 A

  This invention is made | formed in view of the said problem, The solution subject is applicable to the method of manufacturing an organic electroluminescent element by the bonding method, the process after bonding can be simplified, and after bonding The sealing element for organic electroluminescent elements excellent in the adhesion stability and sealing performance in the high temperature environment of this, and the manufacturing method of the organic electroluminescent element using this sealing element for organic electroluminescent elements are provided.

As a result of intensive studies in view of the above problems, the inventor has a thermosetting resin layer containing a thermosetting resin and an auxiliary electrode layer in this order on the first substrate. 1) A thermosetting resin layer containing a thermosetting resin and an auxiliary electrode forming layer are formed in this order on a first substrate, and the curing temperature T of the thermosetting resin _A sealing element for an organic electroluminescence element formed by converting the auxiliary electrode forming layer into an auxiliary electrode layer by heat treatment at a temperature (conversion temperature T ₂ ) of less than ₁ (° C.), and 2) on the second substrate An organic electroluminescence element substrate having a first electrode, an organic functional layer, and a second electrode layer in this order; 3) an auxiliary electrode layer of the organic electroluminescence element sealing element; and the organic electroluminescence element substrate After the second electrode layer is laminated in contact, and characterized in that by heating at a curing temperature above T ₁ of the temperature of thermosetting resin, prepared by curing the thermosetting resin layer The organic electroluminescence device can be simplified by the method for producing an organic electroluminescence device, and the sealing element for organic electroluminescence device having excellent adhesion stability in a high-temperature environment after pasting, and the organic electroluminescence device It has been found that a method for producing an organic electroluminescent element excellent in productivity can be realized by using a sealing element for manufacturing, and the present invention has been achieved.

  That is, the said subject of this invention is solved by the following means.

  1. A sealing element for an organic electroluminescence element, comprising a thermosetting resin layer containing a thermosetting resin and an auxiliary electrode layer in this order on a substrate.

2. 2. The sealing element for an organic electroluminescence element according to claim 1, wherein the thermosetting resin has a water increase start time _Ttr measured by the following water permeability test method of 300 hours or more. .

Moisture permeability test method: Using a measuring container with the upper part open, wall thickness of 1 cm, side length of 10 cm and height of 10 cm, the upper side of the measuring container is 1 cm thick. A thermosetting resin is applied to all with a thickness of 30 μm. Next, a glass plate having an area larger than the cross-sectional area (10 cm × 10 cm) of the measurement container is bonded to the thermosetting resin provided above the measurement container, and the curing temperature T ₁ (° C.) of the thermosetting resin. After being cured and bonded at a higher temperature, the measurement container is placed in an environment of 60 ° C. and 90% relative humidity, passes through the thermosetting resin layer of the measurement container, and flows into the measurement container. The amount of moisture to be measured is measured, and the time when the moisture amount becomes a value of 10 or more in the SN ratio with respect to the background noise value is obtained, and this is set as the moisture increase start time T _tr .

  3. 3. The sealing element for an organic electroluminescence element according to item 1 or 2, wherein the thermosetting resin is an epoxy resin.

4). The auxiliary electrode layer is formed by subjecting the auxiliary electrode forming layer to a heat treatment at a conversion temperature T ₂ (° C.), and has a specific resistance value of 1.0 × 10 ⁻⁵ Ω · m or less. The sealing element for organic electroluminescent elements according to any one of items 1 to 3.

5. The conversion temperature T _{2 (°} C.), the organic electroluminescence device for sealing element according to item 4, characterized in that is less than the curing temperature T ₁ of the said thermosetting resin _(° C.).

  6). The organic electroluminescent element sealing according to any one of claims 1 to 5, wherein the auxiliary electrode layer is electrically connected to a part of the surface of the first substrate. Stop element.

7). It is a manufacturing method of the organic electroluminescent element using the sealing element for organic electroluminescent elements according to any one of items 1 to 6,
1) A sealing element for an organic electroluminescence element in which a thermosetting resin layer containing a thermosetting resin and an auxiliary electrode layer are formed in this order on a first substrate;
2) An organic electroluminescence element substrate having a first electrode, an organic functional layer, and a second electrode layer in this order on the second substrate,
3) After bonding together so that the auxiliary electrode layer of the sealing element for organic electroluminescence elements and the second electrode layer of the organic electroluminescence element substrate are in contact with each other, the curing temperature T ₁ or higher of the thermosetting resin A method for producing an organic electroluminescent element, wherein the thermosetting resin layer is cured by heating at a temperature of 5%.

8). It is a manufacturing method of the organic electroluminescent element using the sealing element for organic electroluminescent elements according to any one of items 1 to 6,
1) A thermosetting resin layer containing a thermosetting resin and an auxiliary electrode forming layer are formed on the first substrate in this order, and the temperature (conversion temperature) of the thermosetting resin is lower than the curing temperature T ₁ (° C.). A sealing element for an organic electroluminescence element formed by performing a heat treatment at T ₂ ) and converting the auxiliary electrode forming layer into an auxiliary electrode layer;
2) An organic electroluminescence element substrate having a first electrode, an organic functional layer, and a second electrode layer in this order on the second substrate,
3) After bonding together so that the auxiliary electrode layer of the sealing element for organic electroluminescence elements and the second electrode layer of the organic electroluminescence element substrate are in contact with each other, the curing temperature T ₁ or higher of the thermosetting resin A method for producing an organic electroluminescent element, wherein the thermosetting resin layer is cured by heating at a temperature of 5%.

  By the above-mentioned means of the present invention, the process after pasting can be simplified, and the sealing element for organic electroluminescence device excellent in adhesion stability and sealing performance under a high-temperature environment after pasting, and the organic electroluminescence The manufacturing method of the organic electroluminescent element using the sealing element for elements can be provided.

  It is presumed that the above problem can be solved by the configuration defined in the present invention for the following reason.

  In the form of an organic EL element formed by pasting an organic EL element substrate using a sealing element for an organic EL element in which an auxiliary electrode is formed on a hot-melt resin layer, which is a conventional method, particularly in a high temperature environment. When stored below, often the softening point of the hot melt resin used is exceeded, and as a result, the hot melt resin used exhibits fluidity. In the above configuration, since the auxiliary electrode constituting the organic EL element sealing element and the cathode constituting the organic EL element substrate are only in physical contact with each other, they flow into the hot melt resin. If the property is manifested, it results in peeling between the organic EL element sealing element and the organic EL element substrate. In addition, since fluidity comes out in the resin under a high temperature environment, there is a problem that water vapor easily passes through the resin.

  In order to cope with the above problem, when a hot melt resin having a high softening point is used, it is necessary to heat and pressure bond under high temperature conditions at the time of bonding, so that the organic EL element is exposed to a high temperature environment, and organic Damage to the performance of the EL element is increased.

  With respect to the above problem, in the configuration defined in the present invention, since a thermosetting resin is used as a resin component used for sealing, fluidity does not develop during high-temperature storage, and as a result, peeling occurs. Can be drastically prevented. In addition, since the thermosetting resin applied to the present invention is three-dimensionally thermally cross-linked, the resin density can be kept high even in a high temperature environment, and the permeation of water vapor into the resin can be suppressed. is there.

The schematic top view which shows an example of the method of manufacturing an organic EL element by the bonding method using the sealing element for organic EL elements Schematic sectional view showing an example of the arrangement of the organic EL element sealing element before bonding and the organic EL element substrate Schematic sectional view showing an example of a sealed organic EL element prepared by bonding and heating an organic EL element sealing element and an organic EL element substrate Schematic showing an example of a measuring device used for moisture permeability measurement of thermosetting resin The graph which shows an example of the increase curve of the moisture content measured with the moisture permeability measuring device Sectional drawing which shows an example of schematic structure of the organic electroluminescent element which concerns on this invention

  The sealing element for an organic electroluminescence element of the present invention has a thermosetting resin layer containing a thermosetting resin and an auxiliary electrode layer in this order on a first substrate, and is organic by a bonding method. It can be applied to a method for producing an electroluminescence element, the process after pasting can be simplified, and sealing for organic electroluminescence element excellent in adhesion stability and sealing performance under a high temperature environment after pasting The element can be realized. This feature is a technical feature common to the inventions according to claims 1 to 8.

As an embodiment of the present invention, the thermosetting resin has a water increase start time T _tr measured by the water permeability test method of 300 hours from the viewpoint of further manifesting the effect of the present invention. The above is preferable. The thermosetting resin is preferably an epoxy resin. The auxiliary electrode layer is preferably formed by subjecting the auxiliary electrode forming layer to a heat treatment at a conversion temperature T ₂ (° C.) and a specific resistance value of 1.0 × 10 ⁻⁵ Ω · m or less. The conversion temperature T ₂ (° C.) is preferably less than the curing temperature T ₁ (° C.) of the thermosetting resin. Moreover, it is a preferable aspect that the auxiliary electrode layer is electrically connected to a part of the surface of the first substrate.

Further, as a method for producing an organic electroluminescent element using the sealing element for organic electroluminescent elements of the present invention, 1) a thermosetting resin layer containing a thermosetting resin and an auxiliary electrode layer on a first substrate; A thermosetting resin layer containing a thermosetting resin and an auxiliary electrode forming layer are formed in this order on a sealing element for an organic electroluminescence element formed in this order, or a first substrate, and the thermosetting resin A sealing element for an organic electroluminescence device formed by converting the auxiliary electrode forming layer into an auxiliary electrode layer by performing a heat treatment at a temperature lower than the curing temperature T ₁ (° C.) (conversion temperature T ₂ ); An organic electroluminescence element substrate having a first electrode, an organic functional layer, and a second electrode layer in this order on two substrates; 3) the sealing element for the organic electroluminescence element An auxiliary electrode layer, after the the second electrode layer of the organic electroluminescent device substrate were bonded into contact and heated at a curing temperature above T ₁ of the temperature of thermosetting resin, the thermosetting resin The layer is cured to produce an organic electroluminescence device.

  Hereinafter, the present invention, its components, and modes and modes for carrying out the present invention will be described in detail. In addition, "-" shown below is used in the meaning which includes the numerical value described before and behind that as a lower limit and an upper limit.

<< Method for Manufacturing Organic Electroluminescent Element >>
Hereinafter, the manufacturing method which manufactures an organic electroluminescent element by the bonding method using the sealing element for organic electroluminescent elements of this invention is demonstrated using a figure.

  FIG. 1: is a schematic top view which shows an example of the method of manufacturing an organic EL element by the bonding method using the sealing element for organic EL elements of this invention.

  FIG. 1A is a schematic top view showing the configuration of an organic EL element substrate 1 which is one of the components of the organic EL element according to the present invention, and FIG. It is a schematic top view which shows the structure of the sealing element 6, (C) of FIG. 1 is an organic EL element produced by bonding and heating the organic EL element substrate 1 and the organic EL element sealing element 6. 10 is a schematic top view of FIG.

  An organic EL element substrate 1 shown in FIG. 1A has a pattern of, for example, tin-doped indium oxide (Indium Tin Oxide, abbreviated as ITO) as a first electrode (anode) 3 on a second substrate 2. The organic functional layer 5 including the light emitting layer is formed on the first electrode (anode) 3. Next, a second electrode (cathode) 4, for example, an aluminum thin film is formed on a part of the organic functional layer 5.

The organic EL element sealing element 6 shown in FIG. 1B is provided with a thermosetting resin layer 8 on the entire surface of the first substrate 7, and a part of the auxiliary element is formed on the thermosetting resin layer 8. The electrode forming layer 9 or the auxiliary electrode layer 9A is formed in a pattern. When the auxiliary electrode is formed by vapor deposition or the like, the auxiliary electrode layer 9A is formed directly without going through the auxiliary electrode forming layer 9. On the other hand, when the auxiliary electrode forming layer 9 is formed of metal particles or the like, the organic EL element sealing element 6 is heated to a temperature lower than the curing temperature T ₁ (° C.) of the thermosetting resin (conversion temperature T ₂ ). in is subjected to heat treatment H _1, to convert the auxiliary electrode layer 9 to the auxiliary electrode layer 9A. The conversion temperature T ₂ in the present invention refers to a temperature at which the auxiliary electrode layer 9 is converted to the auxiliary electrode layer 9A.

Next, as shown in FIG. 1, the second electrode (cathode) 4 of the organic EL element substrate 1 and the auxiliary electrode layer 9A of the organic EL element sealing element 6 are bonded L (Lamination), and then heat treatment H ₂ is applied to produce a sealed organic EL element 10. 11 shown in FIG. 1C shows an electrode bonding portion between the second electrode (cathode) 4 of the organic EL element substrate 1 and the auxiliary electrode layer 9A of the organic EL element sealing element 6.

  FIG. 2 is a schematic cross-sectional view showing the arrangement of an organic EL element sealing element and an organic EL element substrate before bonding.

As shown in FIG. 2, after the second electrode (cathode) 4 of the organic EL element substrate 1 and the auxiliary electrode layer 9 </ b> A of the organic EL element sealing element 6 are disposed at opposing positions, the bonding L and heating H ₂ to perform the effect of the resin.

FIG. 3 is a schematic cross-sectional view of a sealed organic EL element 10 produced by bonding L and heating H ₂ the organic EL element sealing element 6 and the organic EL element substrate 1.

As shown in FIG. 3, after bonding L the second electrode (cathode) 4 surface of the organic EL element substrate 1 and the auxiliary electrode layer 9 </ b> A surface of the organic EL element sealing element 6, the thermosetting resin layer. Heated H ₂ at a temperature equal to or higher than the curing temperature T ₁ of the thermosetting resin constituting 8 to form a sealing structure while melting and curing the thermosetting resin layer 8, thereby sealing the organic The EL element 10 is produced.

<< Sealing element for organic electroluminescence element >>
Subsequently, the sealing element for organic electroluminescent elements of this invention is demonstrated in detail.

As shown in FIGS. 1 to 3, the organic EL element sealing element 6 of the present invention (hereinafter also referred to as the sealing element of the present invention) has a thermosetting resin layer 8 on the first substrate 7, and The auxiliary electrode forming layer 9 (after the heat treatment H ₁ is the auxiliary electrode layer 9A) is provided in this order. As shown in FIGS. 1 to 3, the organic EL element sealing element 6 of the present invention is used by being bonded to a separately prepared organic EL element substrate 1. Although the sealing element for organic EL elements of the present invention can be suitably used mainly for bottom emission type organic EL elements, it is not limited thereto.

  1 to 3, the auxiliary electrode layer 9A (9) is shown as an example of a single layer configuration, but in the present invention, the auxiliary electrode layer 9A (9) is configured as a single layer, If necessary, it may be composed of two or more auxiliary electrode layers. For example, as an example of the auxiliary electrode layer 9A (9) having a two-layer structure, the thermosetting resin layer 8 is formed on the first substrate 7, and the first auxiliary electrode layer 9A ′ (9) is formed thereon. A configuration in which a reflective electrode layer is formed as ′) and a transparent electrode layer is formed as the second auxiliary electrode layer 9A ″ (9 ″) on the reflective electrode layer can be exemplified.

(First substrate)
Specific examples of the first substrate 7 include a glass plate, a polymer plate / film hybrid material, and a metal plate / film hybrid material. Examples of the glass plate include soda lime glass, barium and strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, and quartz. Examples of the polymer plate include resin plates made of polycarbonate, acrylic, polyethylene terephthalate, polyether sulfide, polysulfone, and the like. The metal plate is made of one or more metals or alloys selected from the group consisting of stainless steel, iron, copper, aluminum, magnesium, nickel, zinc, chromium, titanium, molybdenum, silicon, germanium and tantalum, and composites thereof. Things.

  When a resin film is used as the first substrate 7, a laminated barrier film in which a gas barrier layer formed of aluminum, aluminum oxide, silicon oxide, silicon nitride or the like is laminated on the surface for the purpose of imparting barrier properties. Can be used. These gas barrier layers are formed on both sides or one side of the first substrate by, for example, sputtering method, vapor deposition method, atmospheric pressure plasma film forming method, coating method (excimer method) or the like before forming the sealing element. Alternatively, after the organic EL element is finally formed, a gas barrier layer may be formed on the surface of the first substrate by the same method.

The first substrate according to the present invention has an oxygen permeability of 1 × 10 ⁻³ ml / (m ² · 24 h · atm) or less, a water vapor permeability (25 ± 0.5 ° C., relative humidity (90 ± 2)% RH. ) Having a characteristic of 1 × 10 ⁻³ g / (m ² · 24 h) or less is preferable.

  Moreover, as the 1st board | substrate 7 applied to this invention, the laminated film structure which laminated metal foil, such as aluminum, may be sufficient. As a method for laminating the polymer film on one side of the metal foil, a generally used laminating machine can be used. As the adhesive, for example, polyurethane, polyester, epoxy, acrylic, and the like can be used. You may use a hardening | curing agent together as needed. A dry lamination method, a hot melt lamination method, an extrusion lamination method, a coextrusion lamination method, and the like can be used, but the dry lamination method is preferable.

  In addition, when a metal foil is formed by sputtering or vapor deposition, and a fluid electrode material such as a conductive paste is produced, the metal foil is formed by using a polymer film as a base material. May be. As another method, for example, a part of the insulating substrate can be hollowed out and the part can be replaced with a conductive material such as metal.

(Thermosetting resin layer)
The thermosetting resin applicable to the formation of the thermosetting resin layer according to the present invention is not particularly limited. For example, phenol resin (PF), epoxy resin (EP), melamine resin (MF), urea resin (UF), unsaturated polyester resin (UP), alkyd resin, polyurethane resin (PUR), thermosetting polyimide (PI), and the like. Among these exemplified thermosetting resins, epoxy resins can be suitably used in the present invention.

  As a material constituting the thermosetting resin layer according to the present invention, for example, in addition to a thermoplastic resin (for example, epoxy resin), a curing agent, a curing accelerator, other additives, and the like can be used. For details, for example, a material as described in JP-A-2009-269984 can be cited, but the material is not limited thereto. Moreover, generally, it can adjust to a desired hardening rate in the temperature range of 80-200 degreeC by adjusting suitably the ratio of an epoxy resin, a hardening | curing agent, and a hardening accelerator.

  In addition, the thermosetting resin layer according to the present invention can contain a hygroscopic agent. By containing a hygroscopic agent, a labyrinth effect of moisture permeation (moisture permeation delay) and a hygroscopic effect can be imparted to the thermoplastic resin layer.

  Examples of the hygroscopic agent applicable to the present invention include metal oxides (for example, sodium oxide, potassium oxide, calcium oxide, barium oxide, magnesium oxide, aluminum oxide, etc.), 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 ( (For example, barium perchlorate, magnesium perchlorate, etc.) and the like. Among them, sulfates, metal halides and anhydrous salts of perchloric acids are preferably used. Further, fine particles in which these are supported on silica can also be used.

  As will be described later, it is preferable that the thermosetting resin applied to the present invention has a low water permeability. Thus, the thermosetting resin layer also serves as a sealing effect of the organic EL element. Can do.

  The thermosetting resin layer according to the present invention can be formed by mixing a thermosetting resin, a curing agent, a curing accelerator and the like in a desired ratio, and then dissolving and applying the mixture.

The curing temperature T ₁ of the thermosetting resin according to the present invention is not particularly limited, but is preferably 150 ° C. or lower, and more preferably 120 ° C. or lower. Further, as will be described later, when the auxiliary electrode forming layer 9 is provided on the thermosetting resin and the auxiliary electrode forming layer 9 is converted into the conductive auxiliary electrode layer 9A by heating, the conversion temperature is changed. The curing temperature T ₁ of the thermosetting resin is preferably higher than T ₂ (heat treatment temperature T ₂ ), and the conversion temperature T ₂ is preferably 100 ° C. or higher. In this case, even if the thermosetting resin is heated at the conversion temperature T ₂ for 30 minutes, the curing rate of the thermosetting resin is preferably 5.0% or less. Moreover, once the pre-baking at a high temperature is performed, the curing temperature T ₁ is lowered. If a conversion temperature T ₂ <curing temperature T ₁ <pre-baking temperature is used, the thermosetting resin is hardly cured, The auxiliary electrode forming layer 9 can be converted into the auxiliary electrode layer 9A. However, this is not the case when the auxiliary electrode forming layer 9 is converted to the auxiliary electrode layer 9A by ultraviolet irradiation.

  The thickness of the thermosetting resin layer may be thicker than the thickness of the organic EL element layer, but a thickness in the range of 10 to 100 μm is preferable, and a thickness in the range of 20 to 50 μm is more preferable. Is preferred.

(Auxiliary electrode formation layer and auxiliary electrode layer)
Next, the auxiliary electrode forming layer 9 that can be used in the present invention and the auxiliary electrode layer 9A formed by heating and converting the auxiliary electrode forming layer 9 will be described.

In the present invention, the method for forming the auxiliary electrode forming layer 9 or the auxiliary electrode layer 9A is not particularly limited, whether it is a vapor deposition method or a wet coating method. For example, after the thermosetting resin is applied on the first substrate 7 to form the thermosetting resin layer 8, a conductor serving as an auxiliary electrode is vapor-deposited thereon to form the auxiliary electrode layer 9A. Alternatively, a material that changes into a conductor for forming the auxiliary electrode layer by heat treatment or the like may be formed by wet coating and provided as the auxiliary electrode forming layer 9. The conductor here is defined as a material having a specific resistance value of 1.0 × 10 ⁻⁵ Ω · m or less.

Any material having a specific resistance value of 1.0 × 10 ⁻⁵ Ω · m or less may be used as a material for film formation by vapor deposition, but preferably 5.0 × 10 ⁻⁶ Ω · m or less. More preferably, it is a material having a specific resistance value of 1.0 × 10 ⁻⁶ Ω · m or less.

  In order to bond the first substrate 7 / thermosetting resin layer 8 / auxiliary electrode layer 9A onto the cathode (second electrode) of the organic EL element substrate, a material usually used as a cathode in the organic EL element is used. The use of the auxiliary electrode layer is preferable because the same kind of material is bonded to each other, so that the affinity is improved. However, the bonding of different materials may be performed, and the combination is not particularly limited.

Usually, materials used as the cathode of the organic EL element are metals (referred to as electron-injecting metals), alloys, electrically conductive compounds, and mixtures thereof having a small work function (4 eV or less). It can be used as a material for forming the auxiliary electrode layer 9A. Specific examples of the electrode forming material 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 ) mixture, indium, lithium / aluminum mixture, rare earth metal and the like can be mentioned, and can be formed by vapor deposition or the like.

  Moreover, as a material of the auxiliary electrode forming layer 9 that can be formed by coating, for example, Ag paste or Ag nanoparticles can be used. For example, materials described in JP 2010-265543 A can be used. This is a method of obtaining conductivity by sintering by heating, but it is converted into a conductive auxiliary electrode layer 9A by ultraviolet rays, for example, a silver paste provided by Tanaka Kikinzoku Kogyo Co., Ltd. Materials can also be used.

  The auxiliary electrode layer can be applied in a certain pattern, and when bonded, a part of the auxiliary electrode layer can be in contact with the cathode, and a part of the auxiliary electrode layer electrically separated from the cathode can be in contact with the anode.

  Although there is no restriction | limiting in the thickness of the auxiliary electrode formation layer 9, The range of the thickness of 50 nm-1 micrometer can be used conveniently. The auxiliary electrode layer 9A may be composed of two or more layers as described above.

(Moisture content of the sealing element)
The moisture content of the sealing element for an organic electroluminescent element of the present invention is preferably 300 ppm or less, more preferably in the range of 0.01 to 200 ppm, and in the range of 0.01 to 100 ppm. Is most preferred.

  The moisture content in the present invention may be measured by any moisture content measuring method. For example, a capacitance method moisture meter (Karl Fischer), an infrared moisture meter, a microwave transmission moisture meter, a heat dry weight Method, GC / MS, IR, DSC (differential scanning calorimeter), TDS (temperature programmed desorption analysis), and the like. In addition, for example, using a precision moisture meter AVM-3000 (manufactured by Omnitech Co., Ltd.), moisture can be measured from a pressure increase caused by evaporation of moisture, and applied to measurement of moisture content of a film or a solid film. be able to.

  In the present invention, the moisture content of the sealing element can be adjusted by, for example, storing in a nitrogen atmosphere having a dew point temperature of −80 ° C. or lower and an oxygen concentration of 0.8 ppm, and changing the storage time. Also, the moisture content can be adjusted by changing the treatment time and drying in a vacuum state of 100 Pa or less.

  The first substrate and the thermosetting resin layer on which the auxiliary electrode forming layer according to the present invention is provided are not necessarily provided on the entire surface, and a part thereof may be replaced with a conductor. By providing the auxiliary electrode forming layer thereon, the auxiliary electrode forming layer and the conductor can be electrically connected. With such a configuration, it is possible to simplify the process for supplying power from the outside of the substrate. In addition, by attaching a substrate with a hole in part to the release film, patterning and coating the region other than the hole with a thermosetting resin layer, and providing an auxiliary electrode forming layer thereon, It can also be connected.

  In the present invention, after the auxiliary electrode forming layer is formed, the auxiliary electrode forming layer may be converted into a conductor to form an auxiliary electrode layer, and then a protective film may be attached and stored. By doing so, the long-term storage and carrying convenience of the sealing element of the present invention is improved. In this case, it is preferable to remove the protective film components and the oxides of the auxiliary electrode which are slightly left in the auxiliary electrode forming layer by performing dry etching before peeling off the protective film and bonding to the organic EL element.

(Method for producing sealing element)
In the present invention, the sealing element of the present invention can be produced according to the following method.

In the first method, a thermosetting resin layer containing a thermosetting resin and an auxiliary electrode layer are formed on the first substrate in this order to produce a sealing element for an organic electroluminescence element. . In the second method, a thermosetting resin layer containing a thermosetting resin and an auxiliary electrode forming layer are formed in this order on the first substrate, and the thermosetting resin has a curing temperature T ₁ (° C.) lower than that. This is a method for producing a sealing element for an organic electroluminescence element by performing a heat treatment at a temperature (inversion temperature T ₂ ) to convert the auxiliary electrode forming layer into an auxiliary electrode layer.

As the first substrate, for example, a polyethylene terephthalate (hereinafter abbreviated as PET) film having a thickness of 50 μm laminated with an aluminum foil (30 μm thickness) is used. Aluminum surface of the first substrate, using a dispenser, the curing temperature is uniformly coated with thermosetting resin for sealing a T ₁ (adhesive) to form a thermosetting resin layer, on which Then, silver nanoparticles are applied to form an auxiliary electrode forming layer. Thereafter, the auxiliary electrode forming layer is heated at a conversion temperature T ₂ at which the auxiliary electrode forming layer is converted into the auxiliary electrode layer, and the silver nanoparticles are converted into an auxiliary electrode layer which is a conductor having a specific resistance of 1.0 × 10 ⁻⁶ Ω · m or less. Convert.

  Next, the auxiliary electrode layer constituting the sealing element of the present invention and the organic EL element (second substrate / first electrode (anode) / organic functional layer / second electrode (cathode)) prepared in advance After aligning the two electrodes, they are tightly bonded and bonded (adhered) within a range of 0.1 to 3 MPa as a pressure condition and 80 to 180 ° C. as a temperature condition, and tightly sealed (solid sealed) To do.

  Depending on the type or amount of the thermosetting resin to be used, or the area to be applied, the heating and pressure-bonding times are different. In the range, the thermosetting time may be selected in the range of 5 seconds to 10 minutes.

  Further, as a heating and pressure bonding method, a method using a pressure heating roller with a built-in heating mechanism is one of preferred embodiments from the viewpoint that pressure bonding (temporary adhesion) and heating can be performed simultaneously and internal voids can be eliminated simultaneously.

  In addition, as a method for forming the thermosetting resin layer, a dispenser is used according to the thermosetting resin material to be used, and a coating method such as roller coating, spin coating, screen printing, spray coating, or the like is used. Can do.

  By using the sealing element of the present invention, it is possible to reduce the film thickness of the cathode of the organic EL element and to achieve an improvement in production speed. The reduced thickness of the cathode can be compensated by the auxiliary electrode layer constituting the sealing element of the present invention.

  Normally, in the case of bottom emission type organic EL elements, when aluminum is used as the cathode in order to increase the reflectance of the cathode, the film thickness is required to be 50 nm or more, preferably 80 nm or more. By using the stop element, the film thickness of the cathode of the organic EL element may be in the range of 10 to 50 nm.

  Since the cathode of the organic EL element is often formed by a vapor deposition method, the thickness of the cathode is greatly related to the film formation time, that is, the production speed or production efficiency, and the reduction of the cathode film thickness leads to the improvement of the production efficiency. Moreover, a protective film can be affixed on it by forming a cathode with a thin film, and in the case of the organic EL element produced by roll-to-roll, the storage after winding can be performed now. Then, when sealing by bonding, the component of the protective film slightly adhered to the cathode and the oxide of the cathode can be removed by dry etching.

  In addition, by using the method defined in the present invention, heating and press-bonding at a temperature equal to or higher than the curing temperature of the thermosetting resin are performed by pasting a combination of the thermosetting resin layer and the auxiliary electrode layer. And since it hardens | cures in the state which the thermosetting resin crimped | bonded, the bonding defect can be prevented. Moreover, since the thermosetting resin is used, even if what was bonded is preserve | saved in a high temperature environment, peeling in a bonding location does not arise and it can use stably. When a thermoplastic resin or a hot melt resin is used instead of the thermosetting resin, the bonded portion is peeled off during high-temperature storage, so that stability against environmental changes is poor.

  In addition, since the thermosetting resin used in the present invention has low moisture permeability, an additional sealing step is unnecessary or an additional sealing step can be performed after atmospheric storage for a certain period of time. It is easy to improve the performance and perform sealing only in another place.

(Water permeability of thermosetting resin)
The thermoplastic resin according to the present invention preferably has a water increase start time T _tr measured by the following water permeability test method of 300 hours or more.

The moisture permeability test method defined in the present invention uses a measuring container having an open top, a wall thickness of 1 cm, a side length of 10 cm, and a height of 10 cm. A thermosetting resin is applied in a thickness of 30 μm to all of the upper side of the 1 cm wall. Next, a glass plate having an area larger than the cross-sectional area (10 cm × 10 cm) of the measurement container is bonded to the thermosetting resin provided above the measurement container, and the curing temperature T ₁ (° C.) of the thermosetting resin. After being cured and bonded at a higher temperature, the measurement container is placed in an environment of 60 ° C. and 90% relative humidity, passes through the thermosetting resin layer of the measurement container, and flows into the measurement container. The amount of water to be measured is measured, and the time when the amount of water becomes a value of 10 or more with respect to the background noise value is obtained, and this is set as the water increase start time T _tr defined in the present invention.

  The moisture permeability test method used in the present invention will be specifically described with reference to the drawings.

  FIG. 4 is a schematic diagram illustrating an example of a measuring device used for measuring moisture permeability of a thermosetting resin.

  The principle of the thermosetting resin moisture permeability measuring apparatus applied in the present invention is based on the gas barrier property evaluation technique introduced in the 13th regular meeting S3-3 of the organic EL debate. In addition, the detection method can be substituted by a method such as a mocon method, a change in mass of the moisture absorbent, or a corrosion test of Ca.

In FIG. 4, the moisture permeability measuring apparatus 12 applicable to the present invention uses a stainless steel container having a barrier property with an upper wall thickness of 1 cm and a side length of 10 cm as the measurement container 15. . The upper side of the measurement container 15 is designed to be horizontal. The thermosetting resin 14 is uniformly applied to all the upper sides (one side is 10 cm × width 1 cm) of the measurement container 15 under the condition of a thickness of 30 μm, and then from the upper part (10 cm × 10 cm) of the measurement container 15. The glass plate 13 having a large area is covered above the measuring device 15. Here, the measuring device 15 and the glass plate 13 are made of a water-impermeable material that can ignore moisture permeability. Further, as a method for improving the adhesion of the thermosetting resin 14 to the stainless steel measurement container 15 (increasing the surface energy), the surface of the measurement container 15 may be subjected to an oxidation treatment. Thereafter, the thermosetting resin 14 is cured under a temperature condition higher than the curing temperature T _{1 of the} thermosetting resin 14, and the space between the measurement container 15 and the glass plate 13 is sealed with the thermosetting resin 14. At this time, from the viewpoint of accurate moisture measurement, the residual solvent in the measurement container 15 is heated firmly so as to be sufficiently volatilized.

Next, in order to remove residual moisture in the measurement container 15, evacuation of the measurement container 15 is performed. The water content in the measurement container is detected by the mass spectrometer 18 via the liquid nitrogen trap 17 and evacuated until the background level of the water vapor in the measurement container 15 becomes 1 × 10 ⁻⁶ Pa or less. I do. When the condition is reached, the external environment of the measurement container 15 is set to 60 ° C. and 90% RH. Reference numeral 16 denotes a valve for controlling the flow of gas in the measurement container 15.

  Next, the time when the environmental condition is 60 ° C. and 90% RH is set as the measurement start time, and how the moisture content inside the measurement container 15 changes with the passage of time is measured by the mass moisture meter 18 every 10 hours. . As a result of the measurement, a moisture content measurement curve is obtained as shown in FIG.

  FIG. 5 is a graph showing an example of an increase curve of the moisture amount measured by the moisture permeability measuring device 12.

Here, the curve is obtained by smoothly connecting the measurement points. Although no increase in water content is observed after the start of measurement, the water content is 10 or more in terms of SN ratio (water content / background noise) with respect to background noise when T _{tr has} elapsed after the start of measurement. Increase is observed. At first, even if moisture enters the thermosetting resin 14 from the outside, the thermosetting resin has a thickness of 30 μm and a width of 1 cm. It is considered that time is required for diffusion of moisture therein, and moisture does not escape into the measurement container 15 due to the action of a moisture trap or the like by the moisture absorbent contained in the thermosetting resin. However, as time elapses, the diffusion of moisture proceeds, and the moisture trapping effect of the thermosetting resin 14 decreases, so that moisture diffuses to the interface between the measurement container 15 and the thermosetting resin 14. Come on. Then, moisture is released from the thermosetting resin 14 into the measurement container 15, and the measured value by the moisture mass meter 18 increases. Here, T _tr is the time when the signal of the moisture amount reaches 10 or more (point of SN ≧ 10 described in FIG. 5) in the SN ratio with respect to the background noise.

Further, the water increase start time T _tr conforming to the water permeability test method defined in the present invention described above can also be obtained using a commercially available water permeability measuring device. For example, TI Corporation “Super Detect SKT Series Model No. WV-6S”, which is a moisture permeability measuring device for energy device sealing material (sales company: MORESCO, Inc.) manufactured by the company.

In the thermosetting resin according to the present invention, by selecting a thermosetting resin that forms a three-dimensional network structure after thermosetting and containing a moisture absorbent, the T _tr defined in the present invention is 300 hours or more. can do.

<< Structure of organic electroluminescence element >>
Next, a specific configuration of the organic electroluminescence element according to the present invention will be described.

  FIG. 6 is a cross-sectional view showing an example of a schematic configuration of the organic electroluminescence element 100 according to the present invention.

  As shown in FIG. 6, an organic electroluminescence element 100 (hereinafter also referred to as an organic EL element 100) according to the present invention has a flexible support substrate 101. An anode 102 is formed on the flexible support substrate 101, an organic functional layer 120 is formed on the anode 102, and a cathode 108 is formed on the organic functional layer 120.

  The organic functional layer 120 refers to each layer provided between the anode 102 and the cathode 108. Specifically, the organic functional layer 120 includes a hole injection layer 103, a hole transport layer 104, a light emitting layer 105, an electron transport layer 106, and an electron injection layer 107, in addition to the hole block layer and the electron block layer. Layers and the like may be included.

  Note that these layer structures of the organic EL element 100 as shown in FIG. 6 merely show preferred specific examples, and the present invention is not limited to these. For example, the organic EL element 100 of the present invention may have the following layer structures (i) to (viii).

(I) Flexible support substrate / anode / light emitting layer / electron transport layer / cathode (ii) Flexible support substrate / anode / hole transport layer / light emitting layer / electron transport layer / cathode (iii) Flexible support Substrate / anode / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode (iv) Flexible support substrate / anode / hole transport layer / light emitting layer / hole block layer / electron transport layer / Cathode buffer layer / cathode (v) Flexible support substrate / anode / anode buffer layer / hole transport layer / light emitting layer / hole block layer / electron transport layer / cathode buffer layer / cathode (vi) Glass support / anode / Hole injection layer / light emitting layer / electron injection layer / cathode (vii) Glass support / anode / hole injection layer / hole transport layer / light emission layer / electron injection layer / cathode (viii) Glass support / anode / Hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode [Organic device constituting the organic EL element] Layer]
Subsequently, the detail of the organic functional layer which comprises the organic EL element which concerns on this invention is demonstrated.

(1: Injection layer)
In the organic EL device according to the present invention, the injection layer can be provided as necessary. As the injection layer, there are an electron injection layer and a hole injection layer. As described above, the injection layer may exist 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.

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

  Details of the hole injection layer are described in, for example, JP-A-9-45479, JP-A-9-260062, and JP-A-8-288069, and can be applied to the formation of a hole injection layer. Examples of such hole injection materials include triazole derivatives, oxadiazole derivatives, imidazole derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, Examples thereof include polymers containing hydrazone derivatives, stilbene derivatives, silazane derivatives, aniline copolymers, polyarylalkane derivatives, or conductive polymers, preferably polythiophene derivatives, polyaniline derivatives, polypyrrole derivatives, In is preferably a polythiophene derivative.

  The electron injection layer may or may not be provided in the present invention. For example, JP-A-6-325871, JP-A-9-17574, and JP-A-10-74586 disclose details thereof. Specifically, a metal buffer layer typified by strontium or aluminum, an alkali metal compound buffer layer typified by lithium fluoride, an alkaline earth metal compound buffer layer typified by magnesium fluoride, Examples thereof include an oxide buffer layer typified by aluminum oxide. In the present invention, the buffer layer (electron injection layer) is desirably a very thin film, and potassium fluoride and sodium fluoride are preferable. The film thickness is in the range of 0.1 nm to 5 μm, preferably in the range of 0.1 to 100 nm, more preferably in the range of 0.5 to 10 nm, and most preferably 0.5 to 4 nm. Is within the range.

(2: Hole transport layer)
In the present invention, as the hole transport material constituting the hole transport layer, the same compounds as those applied in the hole injection layer can be used, but in addition, a porphyrin compound, an aromatic tertiary amine It is preferable to use a 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 (hereinafter abbreviated as 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-tolylaminophenyl) -4-phenylcyclohexane, bis (4-dimethylamino-2-methylphenyl) phenylmethane, bis (4-di-p-tolylaminophenyl) phenylmethane, N, N′-dipheni -N, N'-di (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 further US Pat. No. 5,061,569 Having two condensed aromatic rings in the molecule, for example, 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (hereinafter referred to as NP) Abbreviation.), 4,4 ′, 4 ″ -tris [N- (3-methylphenyl)-, in which three triphenylamine units described in JP-A-4-308688 are linked in a starburst type. N-phenylamino] triphenylamine (hereinafter abbreviated as MTDATA).

  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. In the present invention, since the light emitting layer is applied on the upper layer of the hole transport layer, these polymer materials can be suitably used.

  JP-A-4-297076, JP-A-2000-196140, JP-A-2001-102175, J. Pat. Appl. Phys. , 95, 5773 (2004), JP-A-11-251067, J. MoI. Huang et. al. It is also possible to use a hole transport material that has a so-called p-type semiconducting property as described in the literature (Applied Physics Letters 80 (2002), p. 139), JP 2003-519432 A. it can.

  In the present invention, the hole transport layer can be formed by coating and drying using a wet coating method (for example, a spin coating method, a casting method, a printing method including an inkjet method, or the like). In addition, as another hole transport layer forming method, the hole transport material is formed by forming a thin film by a known method such as a vacuum deposition method or a Langmuir-Blodgett method (LB method). be able to.

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

  Hereinafter, although the preferable compound example (exemplary compound (1)-(60)) of the positive hole transport material applicable to the positive hole transport layer of the organic EL element which concerns on this invention is given, this invention is not limited to these.

  In addition, n described in the above exemplary compounds represents the degree of polymerization, and represents an integer having a weight average molecular weight in the range of 50,000 to 200,000. The weight average molecular weight is more preferably in the range of 60,000 to 100,000. When it is desired to make the polymer into primary particles, it is preferable to use the higher molecular weight side than the above molecular weight range, and more preferably in the range of 200,000 to 1,000,000.

  These polymer compounds are described in, for example, Makromol. Chem. , Pages 193, 909 (1992) and the like.

(3: Electron transport layer)
The electron transport layer which is one of the organic functional layers according to the present invention 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 may be formed of a single layer or a plurality of layers. For example, it can be used as a hole block layer / electron transport layer combination.

  Conventionally, when a single-layer electron transport layer or a plurality of electron transport layers are used, 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, As long as it has a function of transmitting electrons injected from the cathode to the light-emitting layer, a material having an arbitrary function can be selected and used as a material, for example, , Fluorene derivatives, carbazole derivatives, azacarbazole derivatives, oxadiazole derivatives, triazole derivatives, silole derivatives, pyridine derivatives, pyrimidine derivatives, 8-quinolinol derivatives, and the like.

  In addition, metal-free or metal phthalocyanine, or a compound whose terminal is substituted with an alkyl group or a sulfonic acid group can also be preferably used as the electron transport material.

  Among these, carbazole derivatives, azacarbazole derivatives, pyridine derivatives and the like are preferable in the present invention, and among them, an azacarbazole derivative is more preferable.

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

  In the present invention, semiconductor nanoparticles may be used. For example, oxides such as zinc oxide, yttrium oxide, and titanium oxide can be used.

  In the present invention, in addition to semiconductor nanoparticles, an electron transport material having high n property doped with impurities as a guest material 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, the electron transport layer preferably further contains an alkali metal salt of an organic acid. The type of organic acid is not particularly limited, but formate, acetate, propionic acid, butyrate, valerate, capronate, enanthate, caprylate, oxalate, malonate, succinate Acid salt, benzoate, phthalate, isophthalate, terephthalate, salicylate, pyruvate, lactate, malate, adipate, mesylate, tosylate, benzenesulfonate Preferably, formate, acetate, propionate, butyrate, valerate, caprate, enanthate, caprylate, oxalate, malonate, succinate, benzoate, More preferred are alkali metal salts of aliphatic carboxylic acids such as formate, acetate, propionate, butyrate, etc., and the aliphatic carboxylic acid preferably has 4 or less carbon atoms. Most preferred is acetate.

  The kind of alkali metal of the alkali metal salt of the organic acid is not particularly limited, and examples thereof include Na, K, and Cs, preferably K, Cs, and more preferably Cs. Examples of the alkali metal salt of an organic acid include a combination of the above organic acid and alkali metal, and preferably, formic acid Li, formic acid K, formic acid Na, formic acid Cs, acetic acid Li, acetic acid K, Na acetate, Cs acetate, propionic acid Li, Na propionate, propionate K, propionate Cs, oxalate Li, oxalate Na, oxalate K, oxalate Cs, malonic acid Li, malonate Na, malonic acid K, malonic acid Cs, succinic acid Li, Succinic acid Na, succinic acid K, succinic acid Cs, benzoic acid Li, benzoic acid Na, benzoic acid K, benzoic acid Cs, more preferably Li acetate, K acetate, Na acetate, Cs acetate, most preferably Cs acetate .

  The content of these doping materials is preferably in the range of 1.5 to 35% by mass, more preferably in the range of 3.0 to 25% by mass, and most preferably 5. It is in the range of 0 to 15% by mass.

(4: Light emitting layer)
Hereinafter, the light emitting layer which is one of the organic functional layers constituting the organic EL element will be described in detail.

  The light emitting layer constituting the organic EL element is a layer that emits light by recombination of electrons and holes injected from the electrode or the electron transport layer and the hole transport layer, and the light emitting portion is within the layer of the light emitting layer. Even the interface between the light emitting layer and the adjacent layer may be used.

  In the present invention, the thickness of the light emitting layer is preferably in the range of 10 to 500 nm, and more preferably in the range of 10 to 100 nm.

  In the present invention, the light emitting layer is formed by a wet coating method (for example, spin coating method) using a solution containing each constituent material of the light emitting layer as shown below, for example, a light emitting material (dopant compound) or a host compound. , A printing method including a casting method, an ink jet method, and the like) and coating and drying. As another method for forming a light emitting layer, the above light emitting layer material can be formed as a thin film by a known method such as a vacuum deposition method or a Langmuir-Blodgett method (LB method).

  The light emitting layer is mainly composed of a dopant compound and a host compound.

<4.1: Host compound>
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 preferred is a compound having a phosphorescence quantum yield of less than 0.01.

  As a host compound, by using a plurality of kinds of known host compounds and a light emitting material described later, it becomes possible to mix different light emission, thereby obtaining an arbitrary emission color.

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

  Specific examples of known host compounds include compounds described in the following 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.

  The host compound used in the present invention is preferably a carbazole derivative. Furthermore, in this invention, it is preferable to use the compound shown by following General formula (1) as a host compound.

  In the above general formula (1), X represents NR ′, oxygen atom, sulfur atom, CR′R ″ or SiR′R ″. R ′ and R ″ each represent a hydrogen atom or a substituent. Ar represents an aromatic ring. N represents an integer of 0 to 8.

  In X of the general formula (1), examples of the substituent represented by R ′ and R ″ include an alkyl group (for example, methyl group, ethyl group, propyl group, isopropyl group, t-butyl group, pentyl group). Hexyl group, octyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, etc.), cycloalkyl group (for example, cyclopentyl group, cyclohexyl group, etc.), alkenyl group (for example, vinyl group, allyl group, etc.), alkynyl group (For example, ethynyl group, propargyl group, etc.), aromatic hydrocarbon ring group (also called aromatic carbocyclic group, aryl group, etc.), for example, phenyl group, p-chlorophenyl group, mesityl group, tolyl group, xylyl group, naphthyl group Group, anthryl group, azulenyl group, acenaphthenyl group, fluorenyl group, phenanthryl group, indenyl group, pyreth Group, biphenylyl group, etc.), aromatic heterocyclic group (for example, pyridyl group, pyrimidinyl group, furyl group, pyrrolyl group, imidazolyl group, benzoimidazolyl group, pyrazolyl group, pyrazinyl group, triazolyl group (for example, 1,2,4) -Triazol-1-yl group, 1,2,3-triazol-1-yl group, etc.), oxazolyl group, benzoxazolyl group, thiazolyl group, isoxazolyl group, isothiazolyl group, flazanyl group, thienyl group, quinolyl group, Benzofuryl group, dibenzofuryl group, benzothienyl group, dibenzothienyl group, indolyl group, carbazolyl group, carbolinyl group, diazacarbazolyl group (one of the carbon atoms constituting the carboline ring of the carbolinyl group is replaced by a nitrogen atom) ), Quinoxalinyl group, pyridazinyl , Triazinyl group, quinazolinyl group, phthalazinyl group, etc.), heterocyclic group (eg, pyrrolidyl group, imidazolidyl group, morpholyl group, oxazolidyl group, etc.), alkoxy group (eg, methoxy group, ethoxy group, propyloxy group, pentyloxy group) Hexyloxy group, octyloxy group, dodecyloxy group, etc.), cycloalkoxy group (eg, cyclopentyloxy group, cyclohexyloxy group, etc.), aryloxy group (eg, phenoxy group, naphthyloxy group, etc.), alkylthio group (eg, , Methylthio group, ethylthio group, propylthio group, pentylthio group, hexylthio group, octylthio group, dodecylthio group, etc.), cycloalkylthio group (for example, cyclopentylthio group, cyclohexylthio group, etc.), arylthio group (for example, phenyl group) Ruthio group, naphthylthio group, etc.), alkoxycarbonyl group (eg, methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, octyloxycarbonyl group, dodecyloxycarbonyl group, etc.), aryloxycarbonyl group (eg, phenyloxy) Carbonyl group, naphthyloxycarbonyl group, etc.), sulfamoyl group (for example, aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group, butylaminosulfonyl group, hexylaminosulfonyl group, cyclohexylaminosulfonyl group, octylaminosulfonyl group, dodecyl) Aminosulfonyl group, phenylaminosulfonyl group, naphthylaminosulfonyl group, 2-pyridylaminosulfonyl group, etc.), acyl group (for example, acetyl group, ethyl group) Carbonyl group, propylcarbonyl group, pentylcarbonyl group, cyclohexylcarbonyl group, octylcarbonyl group, 2-ethylhexylcarbonyl group, dodecylcarbonyl group, phenylcarbonyl group, naphthylcarbonyl group, pyridylcarbonyl group, etc.), acyloxy group (for example, acetyloxy) Group, ethylcarbonyloxy group, butylcarbonyloxy group, octylcarbonyloxy group, dodecylcarbonyloxy group, phenylcarbonyloxy group, etc.), amide group (for example, methylcarbonylamino group, ethylcarbonylamino group, dimethylcarbonylamino group, propyl) Carbonylamino group, pentylcarbonylamino group, cyclohexylcarbonylamino group, 2-ethylhexylcarbonylamino group, octylcarbonylamino , Dodecylcarbonylamino group, phenylcarbonylamino group, naphthylcarbonylamino group, etc.), carbamoyl group (for example, aminocarbonyl group, methylaminocarbonyl group, dimethylaminocarbonyl group, propylaminocarbonyl group, pentylaminocarbonyl group, cyclohexylaminocarbonyl) Group, octylaminocarbonyl group, 2-ethylhexylaminocarbonyl group, dodecylaminocarbonyl group, phenylaminocarbonyl group, naphthylaminocarbonyl group, 2-pyridylaminocarbonyl group, etc., ureido group (for example, methylureido group, ethylureido group, Pentylureido group, cyclohexylureido group, octylureido group, dosylureido group, phenylureido group, naphthylureido group, 2-pyridylaminourei Group), sulfinyl group (for example, methylsulfinyl group, ethylsulfinyl group, butylsulfinyl group, cyclohexylsulfinyl group, 2-ethylhexylsulfinyl group, dodecylsulfinyl group, phenylsulfinyl group, naphthylsulfinyl group, 2-pyridylsulfinyl group, etc.) ), Alkylsulfonyl group (for example, methylsulfonyl group, ethylsulfonyl group, butylsulfonyl group, cyclohexylsulfonyl group, 2-ethylhexylsulfonyl group, dodecylsulfonyl group, etc.), arylsulfonyl group or heteroarylsulfonyl group (for example, phenylsulfonyl group) , Naphthylsulfonyl group, 2-pyridylsulfonyl group, etc.), amino group (for example, amino group, ethylamino group, dimethylamino group, butylamino group, cyclopente) Ruamino group, 2-ethylhexylamino group, dodecylamino group, anilino group, naphthylamino group, 2-pyridylamino group, etc.), halogen atom (eg, fluorine atom, chlorine atom, bromine atom etc.), fluorinated hydrocarbon group (eg. , Fluoromethyl group, trifluoromethyl group, pentafluoroethyl group, pentafluorophenyl group, etc.), cyano group, nitro group, hydroxy group, mercapto group, silyl group (for example, trimethylsilyl group, triisopropylsilyl group, triphenylsilyl group) Group, phenyldiethylsilyl group, etc.). These substituents may be further substituted with the above substituents. A plurality of these substituents may be bonded to each other to form a ring.

  Among these, X is preferably NR ′ or an oxygen atom. R ′ may be an aromatic hydrocarbon group (also referred to as aromatic carbocyclic group, aryl group, etc., for example, phenyl group, p-chlorophenyl group, mesityl group, tolyl group, xylyl group, naphthyl group, anthryl group, An azulenyl group, an acenaphthenyl group, a fluorenyl group, a phenanthryl group, an indenyl group, a pyrenyl group, a biphenylyl group, or an aromatic heterocyclic group (for example, a furyl group, a thienyl group, a pyridyl group, a pyridazinyl group, a pyrimidinyl group, a pyrazinyl group, Triazinyl group, imidazolyl group, pyrazolyl group, thiazolyl group, quinazolinyl group, phthalazinyl group and the like are particularly preferable.

  The above aromatic hydrocarbon group and aromatic heterocyclic group may each have a substituent represented by R ′ and R ″ described in X of the general formula (1).

  In the general formula (1), examples of the aromatic ring represented by Ar include an aromatic hydrocarbon ring and an aromatic heterocyclic ring. The aromatic ring may be a single ring or a condensed ring, may be unsubstituted, or may have a substituent represented by R ′ and R ″ in X of the general formula (1). Good.

  In the general formula (1), examples of the aromatic hydrocarbon ring represented by Ar include a benzene ring, biphenyl ring, naphthalene ring, azulene ring, anthracene ring, phenanthrene ring, pyrene ring, chrysene ring, naphthacene ring, and triphenylene. Ring, o-terphenyl ring, m-terphenyl ring, p-terphenyl ring, acenaphthene ring, coronene ring, fluorene ring, fluoranthrene ring, naphthacene ring, pentacene ring, perylene ring, pentaphen ring, picene ring, pyrene Ring, pyranthrene ring, anthraanthrene ring and the like. These rings may further have a substituent represented by R ′ and R ″ in X represented by the general formula (1).

  In the general formula (1), examples of the aromatic heterocycle represented by Ar include a furan ring, a dibenzofuran ring, a thiophene ring, an oxazole ring, a pyrrole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, and a triazine ring. , Benzimidazole ring, oxadiazole ring, triazole ring, imidazole ring, pyrazole ring, thiazole ring, indazole ring, indazole ring, benzimidazole ring, benzothiazole ring, benzoxazole ring, quinoxaline ring, quinazoline ring, cinnoline ring, quinoline Ring, isoquinoline ring, phthalazine ring, naphthyridine ring, carbazole ring, carboline ring, diazacarbazole ring (represents a ring in which one of the carbon atoms of the hydrocarbon ring constituting the carboline ring is further substituted with a nitrogen atom), etc. Is mentioned.

  These rings may have a substituent represented by R ′ and R ″ in the general formula (1).

  Among the above, in the general formula (1), the aromatic ring represented by Ar is preferably a carbazole ring, a carboline ring, a dibenzofuran ring, or a benzene ring, and more preferably a carbazole ring, A carboline ring and a benzene ring, more preferably a benzene ring having a substituent, and particularly preferably a benzene ring having a carbazolyl group.

  In the general formula (1), the aromatic ring represented by Ar is preferably a condensed ring having 3 or more rings, and the aromatic hydrocarbon condensed ring in which 3 or more rings are condensed includes Specifically, naphthacene ring, anthracene ring, tetracene ring, pentacene ring, hexacene ring, phenanthrene ring, pyrene ring, benzopyrene ring, benzoazulene ring, chrysene ring, benzochrysene ring, acenaphthene ring, acenaphthylene ring, triphenylene ring, coronene ring, Benzocoronene ring, hexabenzocoronene ring, fluorene ring, benzofluorene ring, fluoranthene ring, perylene ring, naphthoperylene ring, pentabenzoperylene ring, benzoperylene ring, pentaphen ring, picene ring, pyrantrene ring, coronene ring, naphthocolonene ring, ovalen ring Anthracanthrene ring And the like. In addition, these rings may further have the above substituent.

  Specific examples of the aromatic heterocycle condensed with three or more rings include an acridine ring, a benzoquinoline ring, a carbazole ring, a carboline ring, a phenazine ring, a phenanthridine ring, a phenanthroline ring, a carboline ring, a cyclazine ring, Kindin ring, tepenidine ring, quinindrin ring, triphenodithiazine ring, triphenodioxazine ring, phenanthrazine ring, anthrazine ring, perimidine ring, diazacarbazole ring (any one of the carbon atoms constituting the carboline ring is a nitrogen atom Phenanthroline ring, dibenzofuran ring, dibenzothiophene ring, naphthofuran ring, naphthothiophene ring, benzodifuran ring, benzodithiophene ring, naphthodifuran ring, naphthodithiophene ring, anthrafuran ring, anthradifuran ring, A Tiger thiophene ring, anthradithiophene ring, thianthrene ring, phenoxathiin ring, such as thio fan Tren ring (naphthaldehyde thiophene ring), and the like. In addition, these rings may further have a substituent.

  In the general formula (1), n represents an integer of 0 to 8, preferably 0 to 2, particularly 1 or 2 when X is an oxygen atom or a sulfur atom. preferable.

  In the present invention, a host compound having both a dibenzofuran ring and a carbazole ring is particularly preferable.

  Specific examples (a-1 to a-40) of the host compound represented by the general formula (1) are shown below, but are not limited thereto.

<4.2: Light emitting material (light emitting dopant)>
As the light-emitting material (light-emitting dopant) according to the present invention, a fluorescent compound or a phosphorescent light-emitting material (also referred to as a phosphorescent compound or a phosphorescent compound) can be used, and a phosphorescent material is preferable.

  In the present invention, a phosphorescent material is a compound in which light emission from the lowest triplet energy level in an excited state is observed. Specifically, it is a compound that emits phosphorescence at room temperature (25 ° C.). Although the rate is defined as a compound of 0.01 or more at 25 ° C., the preferred phosphorescence quantum yield is 0.1 or more.

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

  There are two types of light-emitting principles of phosphorescent materials. One is the recombination of carriers on the host compound to which carriers are transported to generate an excited state of the host compound, and this energy is transferred to the phosphorescent 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 carrier recombination occurs on the phosphorescent light emitting material and light emission from the phosphorescent light emitting material is obtained. In any case, the condition is that the excited state energy of the phosphorescent material is lower than the excited state energy of the host compound.

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

  In the present invention, it is preferable to use a phosphorescent dopant represented by the following general formula (2) as the phosphorescent compound.

In the general formula (2), R ₁ represents a substituent. Z represents a nonmetallic atom group necessary for forming a 5- to 7-membered ring. n1 represents the integer of 0-5. B _{1 to} B ₅ each represent a carbon atom, a nitrogen atom, an oxygen atom, or a sulfur atom, and at least one represents a nitrogen atom. M ₁ represents a group 8 to group 10 metal in the periodic table. X ₁ and X ₂ each represent a carbon atom, a nitrogen atom or an oxygen atom, and L ₁ represents an atomic group which forms a bidentate ligand together with X ₁ and X ₂ . m1 represents an integer of 1, 2, or 3, m2 represents an integer of 0, 1, or 2, and m1 + m2 is 2 or 3.

  The phosphorescent compound represented by the general formula (2) has an energy level of the highest occupied molecular orbital (HOMO) in the range of −5.15 to −3.50 eV, and the lowest orbital ( The energy level of Lowest Unoccupied Molecular Orbital (LUMO) is preferably in the range of −1.25 to +1.00 eV, more preferably the energy level of HOMO is in the range of −4.80 to −3.50 eV. The LUMO energy level is in the range of −0.80 to +1.00 eV.

In the phosphorescent compound represented by the general formula (2), examples of the substituent represented by R ₁ include an alkyl group (for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, a tert-butyl group, a pentyl group). Group, hexyl group, octyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group etc.), cycloalkyl group (eg cyclopentyl group, cyclohexyl group etc.), alkenyl group (eg vinyl group, allyl group etc.), alkynyl Group (for example, ethynyl group, propargyl group, etc.), aromatic hydrocarbon ring group (also called aromatic carbocyclic group, aryl group, etc.), for example, phenyl group, p-chlorophenyl group, mesityl group, tolyl group, xylyl group, Naphthyl, anthryl, azulenyl, acenaphthenyl, fluorenyl, phenanthryl, inde Nyl group, pyrenyl group, biphenylyl group, etc.), aromatic heterocyclic group (for example, pyridyl group, pyrimidinyl group, furyl group, pyrrolyl group, imidazolyl group, benzimidazolyl group, pyrazolyl group, pyrazinyl group, triazolyl group (for example, 1, 2,4-triazol-1-yl group, 1,2,3-triazol-1-yl group, etc.), oxazolyl group, benzoxazolyl group, thiazolyl group, isoxazolyl group, isothiazolyl group, furazanyl group, thienyl group, A quinolyl group, a benzofuryl group, a dibenzofuryl group, a benzothienyl group, a dibenzothienyl group, an indolyl group, a carbazolyl group, a carbolinyl group, a diazacarbazolyl group (one of the carbon atoms constituting the carboline ring of the carbolinyl group is a nitrogen atom) ), Quinoxalinyl group, Ridazinyl group, triazinyl group, quinazolinyl group, phthalazinyl group, etc.), heterocyclic group (eg, pyrrolidyl group, imidazolidyl group, morpholyl group, oxazolidyl group, etc.), alkoxy group (eg, methoxy group, ethoxy group, propyloxy group, pentyl) Oxy group, hexyloxy group, octyloxy group, dodecyloxy group, etc.), cycloalkoxy group (eg, cyclopentyloxy group, cyclohexyloxy group, etc.), aryloxy group (eg, phenoxy group, naphthyloxy group, etc.), alkylthio group (Eg, methylthio group, ethylthio group, propylthio group, pentylthio group, hexylthio group, octylthio group, dodecylthio group, etc.), cycloalkylthio group (eg, cyclopentylthio group, cyclohexylthio group, etc.), arylthio group ( For example, phenylthio group, naphthylthio group, etc.), alkoxycarbonyl group (eg, methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, octyloxycarbonyl group, dodecyloxycarbonyl group, etc.), aryloxycarbonyl group (eg, Phenyloxycarbonyl group, naphthyloxycarbonyl group, etc.), sulfamoyl group (for example, aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group, butylaminosulfonyl group, hexylaminosulfonyl group, cyclohexylaminosulfonyl group, octylaminosulfonyl group) , Dodecylaminosulfonyl group, phenylaminosulfonyl group, naphthylaminosulfonyl group, 2-pyridylaminosulfonyl group, etc.), acyl group (for example, aceto Til group, ethylcarbonyl group, propylcarbonyl group, pentylcarbonyl group, cyclohexylcarbonyl group, octylcarbonyl group, 2-ethylhexylcarbonyl group, dodecylcarbonyl group, phenylcarbonyl group, naphthylcarbonyl group, pyridylcarbonyl group, etc.), acyloxy group ( For example, acetyloxy group, ethylcarbonyloxy group, butylcarbonyloxy group, octylcarbonyloxy group, dodecylcarbonyloxy group, phenylcarbonyloxy group, etc.), amide group (for example, methylcarbonylamino group, ethylcarbonylamino group, dimethylcarbonyl) Amino group, propylcarbonylamino group, pentylcarbonylamino group, cyclohexylcarbonylamino group, 2-ethylhexylcarbonylamino group, octylcal Nylamino group, dodecylcarbonylamino group, phenylcarbonylamino group, naphthylcarbonylamino group, etc.), carbamoyl group (for example, aminocarbonyl group, methylaminocarbonyl group, dimethylaminocarbonyl group, propylaminocarbonyl group, pentylaminocarbonyl group, cyclohexyl) Aminocarbonyl group, octylaminocarbonyl group, 2-ethylhexylaminocarbonyl group, dodecylaminocarbonyl group, phenylaminocarbonyl group, naphthylaminocarbonyl group, 2-pyridylaminocarbonyl group, etc.), ureido group (for example, methylureido group, ethylureido) Group, pentylureido group, cyclohexylureido group, octylureido group, dodecylureido group, phenylureido group, naphthylureido group, 2-pyri Sulfinyl group (eg, methylsulfinyl group, ethylsulfinyl group, butylsulfinyl group, cyclohexylsulfinyl group, 2-ethylhexylsulfinyl group, dodecylsulfinyl group, phenylsulfinyl group, naphthylsulfinyl group, 2-pyridylsulfinyl group) Group), alkylsulfonyl group (for example, methylsulfonyl group, ethylsulfonyl group, butylsulfonyl group, cyclohexylsulfonyl group, 2-ethylhexylsulfonyl group, dodecylsulfonyl group, etc.), arylsulfonyl group or heteroarylsulfonyl group (for example, phenyl) Sulfonyl group, naphthylsulfonyl group, 2-pyridylsulfonyl group, etc.), amino group (for example, amino group, ethylamino group, dimethylamino group, butylamino) Group, cyclopentylamino group, 2-ethylhexylamino group, dodecylamino group, anilino group, naphthylamino group, 2-pyridylamino group, etc., cyano group, nitro group, hydroxy group, mercapto group, silyl group (for example, trimethylsilyl group, Triisopropylsilyl group, triphenylsilyl group, phenyldiethylsilyl group, etc.). Of these substituents, preferred are an alkyl group and an aryl group.

  Z represents a nonmetallic atom group necessary for forming a 5- to 7-membered ring. Examples of the 5- to 7-membered ring formed by Z include a benzene ring, naphthalene ring, pyridine ring, pyrimidine ring, pyrrole ring, thiophene ring, pyrazole ring, imidazole ring, oxazole ring, and thiazole ring. Of these, a benzene ring is preferred.

B ₁ .about.B ₅ represents a carbon atom, a nitrogen atom, an oxygen atom or a sulfur atom, at least one nitrogen atom. The aromatic nitrogen-containing heterocycle formed by these five atoms is preferably a monocycle. Examples include pyrrole ring, pyrazole ring, imidazole ring, triazole ring, tetrazole ring, oxazole ring, isoxazole ring, thiazole ring, isothiazole ring, oxadiazole ring, and thiadiazole ring. Among these, a pyrazole ring and an imidazole ring are preferable, and an imidazole ring in which B ₂ and B ₅ are nitrogen atoms is particularly preferable. These rings may be further substituted with the above substituents. Preferred as the substituent are an alkyl group and an aryl group, and more preferably an aryl group.

L ₁ represents an atomic group that forms a bidentate ligand together with X ₁ and X ₂ . Specific examples of the bidentate ligand represented by X ₁ -L ₁ -X ₂ include, for example, substituted or unsubstituted phenylpyridine, phenylpyrazole, phenylimidazole, phenyltriazole, phenyltetrazole, pyrazabol, picolinic acid And acetylacetone. These groups may be further substituted with the above substituents.

m1 represents an integer of 1, 2 or 3, m2 represents an integer of 0, 1 or 2, and m1 + m2 is 2 or 3. Especially, the case where m2 is 0 is preferable. The metal represented by M _1, but the transition metal elements of Groups 8-10 of the periodic table is used, inter alia iridium, platinum are preferred, more preferably iridium.

  Hereinafter, specific compounds (D-1 to D-132) of the phosphorescent compound represented by the general formula (2) are exemplified, but the present invention is not limited thereto.

〔anode〕
As the anode constituting the organic EL device, an electrode material made of a metal, an alloy, an electrically conductive compound or a mixture thereof having a high work function (4 eV or more) is preferably used. Specific examples of such electrode substances include metals such as Au, and conductive transparent materials such as CuI, tin-doped indium oxide (ITO), SnO ₂ , and ZnO. Alternatively, an amorphous material such as IDIXO (In ₂ O ₃ —ZnO) capable of forming a transparent conductive film may be used. For the anode, these electrode materials may be formed into a thin film by a method such as vapor deposition or sputtering, and a desired shape pattern may be formed by a photolithography method, or when pattern accuracy is not so high (about 100 μm or more) A pattern may be formed through a mask having a desired shape at the time of vapor deposition or sputtering of the electrode material. Or when using the substance which can be apply | coated like an organic electroconductivity compound, wet film-forming methods, such as a printing system and a coating system, can also be used. When light emission is extracted from the anode, it is desirable that the transmittance be greater than 10%, and the sheet resistance as the anode is preferably several hundred Ω / □ or less. Further, although the film thickness depends on the material, it is usually in the range of 10 to 1000 nm, preferably in the range of 10 to 200 nm.

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

  Moreover, after producing the metal with a film thickness of 1 to 20 nm on the cathode, a transparent or semitransparent cathode can be produced by forming the conductive transparent material mentioned in the explanation of the anode on the cathode, By applying this, an organic EL element in which both the anode and the cathode are transmissive can be produced.

[Support substrate]
The support substrate (hereinafter also referred to as a substrate, substrate, substrate, support, etc.) that can be used in the organic EL device according to the present invention is not particularly limited in type, such as glass and plastic, and is transparent. Or opaque. When extracting light from the support substrate side, the support substrate is preferably transparent. Examples of the transparent support substrate preferably used include glass, quartz, and a transparent resin film. Since the effect of suppressing high-temperature storage stability and chromaticity variation appears greatly in a flexible substrate rather than a rigid substrate, as a particularly preferable support substrate, flexibility that can impart flexibility to an organic EL element It is a resin film provided with.

  Examples of the resin film include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyethylenes, or polypropylenes, cellophane, cellulose diacetate, cellulose triacetate (TAC), cellulose acetate butyrate, and cellulose acetate. Cellulose esters such as propionate (CAP), cellulose acetate phthalate, cellulose nitrate or derivatives thereof, polyvinylidene chloride, polyvinyl alcohol, polyethylene vinyl alcohol, syndiotactic polystyrene, polycarbonate, norbornene resin, polymethylpentene, poly Ether ketone, polyimide, polyether sulfone (PES), polyphenylene sulfide, police Cycloolefins such as phons, polyether imides, polyether ketone imides, polyamides, fluororesins, nylons, polymethyl methacrylates, acrylics or polyarylates, Arton (trade name, manufactured by JSR) or Apel (trade name, manufactured by Mitsui Chemicals) Based resins and the like.

On the surface of the resin film, a film composed of an inorganic material or an organic material, or a hybrid film of the both may be formed, and the water vapor transmission rate (25 ± 0.00%) measured by a method according to JIS K 7129-1992. It is preferably a barrier film having a relative humidity (90 ± 2)% RH) of 0.01 g / (m ² · 24 h) or less, and further measured by a method based on JIS K 7126-1987. It is a high barrier film having an oxygen permeability of 1 × 10 ⁻³ cm ³ / (m ² · 24 h · atm) or less and a water vapor permeability of 1 × 10 ⁻³ g / (m ² · 24 h) or less. Preferably, the water vapor permeability is 1 × 10 ⁻⁵ g / (m ² · 24 h) or less.

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

  The method for forming the barrier film is not particularly limited. For example, the vacuum deposition method, sputtering method, reactive sputtering method, molecular beam epitaxy method, cluster ion beam method, ion plating method, plasma polymerization method, atmospheric pressure plasma A polymerization method, 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.

  Examples of the opaque support substrate include metal plates such as aluminum and stainless steel, films, opaque resin substrates, and ceramic substrates.

  In the organic EL device according to the present invention, the external extraction efficiency at room temperature for light emission is preferably 1.0% or more, more preferably 5.0% or more. The external extraction efficiency here can be expressed by the following equation.

  External extraction quantum efficiency (%) = number of photons emitted to the outside of the organic EL element / number of electrons sent to the organic EL element × 100.

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

  In the present invention, a light extraction member can be provided between the flexible support substrate and the anode or at any location on the light emission side from the flexible support substrate.

  Examples of the light extraction member include a prism sheet, a lens sheet, and a diffusion sheet. Further, a diffraction grating or a diffusion structure introduced into an interface or any medium that causes total reflection can be used.

  In general, in an organic electroluminescence element that emits light from a substrate, a part of the light emitted from the light emitting layer causes total reflection at the interface between the substrate and air, causing a problem of loss of light. In order to solve this problem, prismatic or lens-like processing is applied to the surface of the substrate, or prism sheets, lens sheets, and diffusion sheets are attached to the surface of the substrate, thereby suppressing total reflection and light extraction efficiency. To improve.

  In order to increase the light extraction efficiency, a method of introducing a diffraction grating or a method of introducing a diffusion structure in an interface or any medium that causes total reflection is known.

<< Method for Manufacturing Organic EL Element >>
As an example of the method for producing an organic EL device of the present invention, a method for producing an organic EL device substrate comprising anode / hole injection layer / hole transport layer / light emitting layer / n-type electron transport layer / cathode will be described.

  First, a desired electrode material, for example, a thin film made of an anode material is formed on a suitable substrate by a thin film forming method such as vapor deposition or sputtering so as to have a film thickness of 1 μm or less, preferably 10 to 200 nm, An anode is produced.

  Next, an organic functional layer (organic compound thin film) of a hole injection layer, a hole transport layer, a light emitting layer, and an electron transport layer, which is an organic EL element material, is formed thereon.

  The step of forming the organic functional layer mainly includes a step of applying and laminating the coating liquid constituting the organic functional layer on the anode of the support substrate and a step of drying the coating liquid after coating and lamination. Composed. The step of applying and drying may be performed in the air, but the step of drying is preferably performed in an inert gas atmosphere such as nitrogen, and the step of applying is also preferably performed in an inert gas atmosphere. . Here, the inert gas atmosphere preferably contains 100 ppm or less of water or oxygen, more preferably 10 ppm or less, and even more preferably 1 ppm or less.

  As a method for forming a coating film according to the present invention, a wet process (for example, spin coating method, casting method, die coating method, blade coating method, roller coating method, ink jet method, printing method, spray coating method, curtain coating method, LB method) (Langmuir Brodgett method, etc.) can be used.In the present invention, among wet processes, spin coating method, casting method, die coating method, blade coating method, roller coating method can be used. In addition, film formation by a coating method such as an ink jet method is preferable, and in addition, it can also be formed using a vapor deposition method.

  Examples of the liquid medium for dissolving or dispersing the organic EL material according to the present invention include ketones such as methyl ethyl ketone and cyclohexanone, fatty acid esters such as ethyl acetate, halogenated hydrocarbons such as dichlorobenzene, toluene, xylene, and mesitylene. Aromatic hydrocarbons such as cyclohexylbenzene, aliphatic hydrocarbons such as cyclohexane, decalin, and dodecane, and organic solvents such as dimethylformamide (DMF) and dimethylsulfoxide (DMSO) can be used. Moreover, as a dispersion method, it can disperse | distribute by addition to the poor solvent in dispersion methods, such as an ultrasonic wave, high shear force dispersion | distribution, and media dispersion | distribution.

  Moreover, it is preferable that the liquid preparation process which melt | dissolves or disperse | distributes the organic EL material which concerns on this invention is in inert gas atmosphere, and the process by which a solution is not exposed to an application atmosphere until it applies on a base material by the above-mentioned wet process. It is preferable that

  The coating, laminating and drying processes of these layers may be single wafer manufacturing or continuous online manufacturing. In addition, the atmosphere when applying each layer may be common, but from the viewpoint of eliminating the influence of the solvent that volatilizes, the coating booth of each layer is separated by a partition, and the atmosphere is circulated independently. It is preferable. Further, the drying process may be performed while being conveyed on the line, but from the viewpoint of productivity, it may be deposited or rolled in a non-contact manner in a roll form.

  After these layers are dried, a thin film made of a cathode material is formed thereon by a method such as vapor deposition or sputtering so as to have a film thickness of 1 μm or less, preferably in the range of 10 nm to 50 nm. By providing, a desired organic EL element substrate can be obtained.

<Application>
The organic EL element according to the present invention can be used as a display device, a display, and various light sources.

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

  In the organic EL device according to the present invention, patterning may be performed by a metal mask, an inkjet printing method, or the like at the time of film formation, if necessary. In the case of patterning, only the electrode may be patterned, the electrode and the light emitting layer may be patterned, or the entire layer of the element may be patterned. In the fabrication of the element, a conventionally known method is used. Can do.

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

<Preparation of sealing resin>
(Preparation of hot melt resin)
As comparative examples, the following three types of hot melt resins were prepared.

Hot melt resin 1: Hot melt resin (softening point 80 ° C.) mainly composed of ethylene methacrylic acid copolymer
Hot melt resin 2: Hot melt resin (softening point 83 ° C.) mainly composed of ethylene methacrylic acid copolymer
Hot melt resin 3: Hot melt resin mainly composed of ethylene vinyl acetate copolymer (softening point 85 ° C)
(Preparation of thermosetting resin)
<Preparation of thermosetting resin 1>
The following components (A) to (D) were mixed under the condition that the curing rate was 50% when heat-treated at 120 ° C. for 20 minutes to prepare a thermosetting resin 1 as an epoxy adhesive.

(A) Bisphenol A
(B) Diglycidyl ether (DGEBA)
(C) Dicyandiamide (DICY) Epoxy adduct curing accelerator (D) Calcium oxide (1.0% by volume)
<Preparation of thermosetting resin 2>
In the preparation of the thermosetting resin 1, a thermosetting resin 2 was prepared in the same manner except that the calcium oxide in the item (D) was changed to the same amount of barium oxide.

<Preparation of thermosetting resin 3>
A thermosetting resin 3 was prepared in the same manner as in the preparation of the thermosetting resin 1 except that the amount of calcium oxide added in the item (D) was changed to 2.0% by volume.

(Measurement of water permeability of each sealing resin)
About each prepared hot-melt resin and each thermosetting resin, according to the following method, the water permeability test was done and the water _| moisture-content increase start time _Ttr was calculated _| required.

  The moisture permeability of each sealing resin was measured using the measuring apparatus shown in FIG.

As a moisture permeability measuring device, a square stainless steel measuring container 15 having an upper wall thickness of 1 cm and a side length of 10 cm was used. After subjecting the upper side of the measurement container 15 to corona discharge treatment by a corona discharge device and surface-treating, the hot melt resin or thermosetting resin prepared above is applied to the upper side of the measurement container 15 with a film thickness of 30 μm, Next, the upper part of the measurement container 15 was covered with a glass plate 13 having a larger area than the upper part of the measurement container 15. Then, after press-bonding for 5 minutes at a temperature (120 ° C.) higher than the softening point of each sealing resin, a pressure of 0.2 MPa was applied, followed by heating at 120 ° C. for 30 minutes. Next, the measurement container was evacuated in an environment of 60 ° C. and 90% RH, and the moisture content in the measurement container was detected with a mass spectrometer through a liquid nitrogen trap. At this time, evacuation was performed until the background level of water vapor in the measurement container was 1 × 10 ⁻⁶ Pa or less. Thereafter, the environment around the measurement container was set to 60 ° C. and 90% RH. The moisture content inside the measurement container is measured every 10 hours, the moisture content increase curve shown in FIG. 5 is created, and the time when the SN ratio is 10 or more is measured with respect to the background noise value. This was determined as T _tr . The obtained results are shown in Table 1.

<Production of sealing element>
[Preparation of sealing element 1]
As shown in FIG. 1, an Alpet in which an aluminum foil (30 μm thickness) was laminated on a 50 μm thick PET film (polyethylene terephthalate film) via an adhesive layer was used as the first substrate. On the aluminum foil surface of Alpet, the hot melt resin 1 was uniformly applied as a sealing resin with a thickness of 30 μm using a dispenser. Next, the first substrate was transferred to a vacuum chamber, and an aluminum thin film was deposited as an auxiliary electrode layer 9A with a thickness of 200 nm in a pattern as shown in FIG.

(Production of sealing elements 2 to 6)
In the production of the sealing element 1, sealing elements 2 to 6 were produced in the same manner except that the hot melt resin 1 was changed to the respective sealing resins shown in Table 2.

(Preparation of sealing element 7)
In the production of the sealing element 4, the sealing element 7 was produced in the same manner except that the formation of the auxiliary electrode layer was changed to the method for forming the auxiliary electrode layer using the coated silver ultrafine particles described below.

<Formation of auxiliary electrode layer>
According to the method described in Example 1 of paragraph No. (0072) of JP 2010-265543 A, an auxiliary electrode layer 7A composed of coated silver ultrafine particles was formed.

  2.04 g (20.0 mmol) of N, N-dimethyl-1,3-diaminopropane (Tokyo Kasei, special grade), 1.94 g (15.0 mmol) of n-octylamine (Kao, purity 98%), 0.93 g (5.0 mmol) of n-dodecylamine (Kanto Chemical Co., Ltd.) was mixed, and this mixed solution was mixed with silver oxalate [silver nitrate (Kanto Chemical Co., Ltd.) and ammonium oxalate monohydrate or oxalic acid dihydrate. 6.08 g (20.0 mmol) of a hydrate (synthesized from Kanto Chemical Co., Ltd.) was added and stirred for 3 minutes to prepare an oxalate ion / alkylamine / alkyldiamine / silver complex compound. This was heated and stirred at 95 ° C. for 25 minutes, and the reaction accompanied by foaming of carbon dioxide was completed and changed to a suspension exhibiting a blue gloss. To this, 10 ml of methanol (Kanto Chemical Co., Ltd., first grade) was added, and the precipitate obtained by centrifugation was naturally dried to give 4.62 g of a solid product of blue glossy coated silver ultrafine particles (silver reference yield 97.0%). )

  The coated silver ultrafine particles obtained above were dispersed in n-butanol to prepare a coated silver ultrafine particle dispersion. Next, the above-mentioned coated silver ultrafine particle dispersion is applied on the thermosetting resin layer in which the thermosetting resin 1 is formed with a thickness of 30 μm on the Alpet under the condition that the solid content film thickness is 200 nm. An electrode forming layer 7 was provided. Next, the auxiliary electrode forming layer 7 was heated and baked at 100 ° C. for 20 minutes to convert into the auxiliary electrode layer 7A, and the sealing element 7 was produced.

(Measurement of resistance value)
The resistance value of each auxiliary electrode layer constituting each of the produced sealing elements was measured.

As a representative example of the level of providing an aluminum thin film by vapor deposition as an auxiliary electrode layer on a thermosetting resin, on a thermosetting resin layer provided with a thermosetting resin 1 having a thickness of 30 μm on an alpet. As a result of measuring the electrical resistance value of the sealing element 4 on which aluminum was deposited with a thickness of 200 nm using K-705RS (four-probe method) manufactured by Kyowa Riken Co., Ltd., 2.0 × 10 ⁻⁷ Ω · m It was specific resistance.

Moreover, as a result of measuring the electrical resistance value of the sealing element 7 in which the auxiliary electrode layer was formed using the coated silver ultrafine particles using K-705RS (four probe method) manufactured by Kyowa Riken Co., Ltd., 5.0 × 10 ⁻⁶ Ω · m.

  The details of the sealing elements 1 to 7 produced as described above are shown in Table 1.

<< Preparation of organic EL element substrate >>
[Preparation of organic EL element substrate 1]
(1: Formation of anode layer)
An ITO thin film having a thickness of 120 nm is formed on the prepared non-alkali glass plate by a sputtering method and patterned by a photolithography method. An anode (first electrode 3) having a pattern as shown in FIG. The pattern was formed so that the light emission area was 50 mm square.

(2: Formation of hole injection layer)
The ITO substrate after patterning was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and UV ozone cleaning was performed for 5 minutes. On this substrate, using a solution obtained by diluting poly (3,4-ethylenedioxythiophene) -polystyrene sulfonate (PEDOT / PSS, Bayer, Baytron P Al 4083) to 70% with pure water, 3000 rpm, 30 A film was formed by spin coating under the condition of seconds. Film formation was performed in an air atmosphere. Then, it dried at 200 degreeC for 1 hour, and formed the positive hole injection layer with a film thickness of 30 nm.

(3: Formation of hole transport layer)
The substrate on which the hole injection layer is formed is transferred to a nitrogen gas atmosphere, and a solution in which the exemplified compound (60) (Mw = 80,000) is dissolved in chlorobenzene at a concentration of 0.5% as a hole transport material is used. After forming a film by spin coating under conditions of 1500 rpm and 30 seconds, the film was dried at 130 ° C. for 30 minutes to form a hole transport layer having a film thickness of 30 nm.

(4: Formation of light emitting layer)
Subsequently, the substrate formed up to the hole transport layer was attached to a vacuum deposition apparatus without being exposed to the atmosphere. After depressurizing the vacuum chamber to 4 × 10 ⁻⁵ Pa, Exemplified Compound a-1 as a host compound, Exemplified Compound D-66, Exemplified Compound D-67, and Exemplified Compound D-80 were added as phosphorescent dopants, respectively. Four molybdenum boats were heated to 0.1 nm / second (Exemplary Compound a-1), 0.018 nm / second (Exemplary Compound D-66), 0.005 nm / second (Exemplary Compound D-67), respectively. Four-element co-evaporation was performed at a rate of 0.002 nm / second (Exemplary Compound D-80) to form a light emitting layer having a total thickness of 60 nm.

(5: Formation of electron transport layer)
Subsequently, a molybdenum boat containing Alq ₃ which is an electron transport material having the structure shown below is heated and deposited on the light emitting layer at a deposition rate of 0.1 nm / second, and an electron having a layer thickness (film thickness) of 30 nm. A transport layer was formed.

(6: Formation of electron injection layer and cathode)
Subsequently, the substrate formed up to the electron transport layer is attached to a vacuum deposition apparatus, a molybdenum boat containing lithium fluoride is heated, and deposited on the electron transport layer at a deposition rate of 0.02 nm / second. A 5 nm electron injection layer was formed. Subsequently, aluminum was deposited on the electron injection layer to form a cathode (second electrode 4 shown in FIG. 1) having a film thickness of 100 nm, and the organic EL element substrate 1 was produced.

[Preparation of organic EL element substrate 2]
In the production of the organic EL element substrate 1, an organic EL element substrate 2 was produced in the same manner except that the film thickness of the cathode (second electrode 4 shown in FIG. 1) was changed to 50 nm.

[Preparation of organic EL element substrate 3]
In the production of the organic EL element substrate 1, the organic EL element substrate 3 was produced in the same manner except that the film thickness of the cathode (second electrode 4 shown in FIG. 1) was changed to 30 nm.

<< Production of organic EL element >>
The produced sealing element and the organic EL element substrate were bonded in the combinations shown in Table 2 to produce organic EL elements 1 to 9.

[Production of Organic EL Element 1: Comparative Example]
The organic EL element element 1 and the sealing element 1 (hot melt resin 1) produced above are combined, and as shown in FIGS. 2 and 3, the second electrode (4) of the organic EL element element 1 and the sealing element After placing and aligning with one auxiliary electrode layer (9A) facing each other, the two are pressure-bonded at 0.2 MPa, adhered and bonded at a temperature of 110 ° C., and this state is maintained for 3 minutes. Then, close sealing (solid sealing) was performed to obtain a bonded organic EL element (10) 1 as shown in FIG.

[Production of Organic EL Elements 2 and 3: Comparative Example]
In the production of the organic EL element 1, the organic EL elements 2 and 3 were similarly manufactured except that the sealing elements 2 and 3 using the same hot-melt resin were used instead of the sealing element 1, respectively. Was made.

[Preparation of Organic EL Element 4: Present Invention]
The produced organic EL element element 1 and the sealing element 4 (thermosetting resin 1) are combined, and the second electrode (4) of the organic EL element element 1 is sealed as shown in FIGS. After arranging and aligning the auxiliary electrode layer (9A) of the element 4 so as to face each other, the two are pressure-bonded at a pressure of 0.2 MPa, closely adhered and bonded at a temperature of 120 ° C., and this state is maintained for 3 minutes. Maintained and sealed tightly (solid sealed). Next, a heat treatment was performed at 110 ° C. for 20 minutes without applying pressure to cure the thermosetting resin, thereby producing an organic EL element 4 having the configuration shown in FIG.

[Production of Organic EL Elements 5 and 6: Present Invention]
In the production of the organic EL element 4, in place of the sealing element 4, the organic EL element 5 and the organic EL element 5 were similarly obtained except that the sealing elements 5 and 6 using the same thermosetting resin were respectively solid-sealed. 6 was produced.

[Preparation of Organic EL Element 7: Present Invention]
In the production of the organic EL element 4, an organic EL element 7 was produced in the same manner except that the organic EL element substrate 2 was used for solid sealing instead of the organic EL element element 1.

[Preparation of Organic EL Element 8: Present Invention]
In the production of the organic EL element 4, an organic EL element 8 was produced in the same manner except that the organic EL element substrate 3 was used for solid sealing instead of the organic EL element element 1.

[Preparation of Organic EL Element 9: Present Invention]
In the production of the organic EL element 8, an organic EL element 9 was produced in the same manner except that the sealing element 7 was used instead of the sealing element 7 and solid sealing was performed.

<< Evaluation of organic EL elements >>
[Evaluation of high-temperature storage stability]
The bonded organic EL elements 1 to 9 prepared above were suspended in the air in an environment of 85 ° C. and 20% RH and stored for 24 hours, and then the following evaluation was performed.

(Evaluation of adhesion)
The state of the organic EL element after storage for 24 hours in the above environment was visually observed, and the adhesion was evaluated according to the following criteria.

○: No peeling occurred between the sealing element and the organic EL element substrate. Δ: Slight peeling occurred at the end of the sealing element and the organic EL element substrate. The organic EL element substrate is clearly separated (emission evaluation)
A voltage was applied to the organic EL element after storage for 24 hours, the state of light emission was visually observed, and the light emitting property was evaluated according to the following criteria.

○: Normal light emission Δ: Almost normal light emission ×: Non-light emitting portion is generated due to peeling between the sealing element and the organic EL element substrate [Evaluation of sealing performance]
Each organic EL element was stored in an environment of 60 ° C. and 90% RH for 300 hours. Subsequently, the change in the light emission state before and after the high temperature and high humidity treatment was visually observed, and the sealing performance was evaluated according to the following criteria.

○: Almost no change in emission area before and after high-temperature and high-humidity treatment △: Some decrease in emission area is observed after high-temperature and high-humidity treatment ×: Decrease in emission area after high-temperature and high-humidity treatment Table 2 shows the results obtained as described above.

  As is clear from the results shown in Table 2, the organic EL device of the present invention is more stable than the comparative example even when stored for a long period of time under high temperature storage conditions (adhesion) and high temperature and high humidity. It can be seen that the stopping performance is excellent.

  The sealing element for organic electroluminescence elements of the present invention can simplify the process after bonding, has excellent adhesion stability under a high temperature environment after bonding, has high temperature stability and sealing performance. An excellent organic electroluminescence element can be provided, and the organic electroluminescence element is suitably used as various light sources for flat illumination, optical fiber light source, liquid crystal display backlight, liquid crystal projector backlight, display device, etc. it can.

1 organic EL element substrate 2 second substrate 3 first electrode (anode)
4 Second electrode (cathode)
5, 120 Organic functional layer 6 Sealing element for organic EL element 7 First substrate 8 Thermosetting resin layer 9 Auxiliary electrode forming layer 9A Auxiliary electrode layer 10, 100 Organic EL element 11 Electrode bonding part 12 Water permeability measuring device 13 Glass plate 14 Thermosetting resin 15 Chamber 16 Valve 17 Liquid nitrogen trap 18 Mass spectrometer L Lamination
DESCRIPTION OF SYMBOLS 101 Flexible support substrate 102 Anode 103 Hole injection layer 104 Hole transport layer 105 Light emitting layer 106 Electron transport layer 107 Electron injection layer 108 Cathode

Claims (8)

  A sealing element for an organic electroluminescence element, comprising a thermosetting resin layer containing a thermosetting resin and an auxiliary electrode layer in this order on a substrate. 2. The sealing element for an organic electroluminescence element according to claim 1, wherein the thermosetting resin has a water increase start time T _tr measured by the following water permeability test method of 300 hours or more. .
Moisture permeability test method: Using a measuring container with the upper part open, wall thickness of 1 cm, side length of 10 cm and height of 10 cm, the upper side of the measuring container is 1 cm thick. A thermosetting resin is applied to all with a thickness of 30 μm. Next, a glass plate having an area larger than the cross-sectional area (10 cm × 10 cm) of the measurement container is bonded to the thermosetting resin provided above the measurement container, and the curing temperature T ₁ (° C.) of the thermosetting resin. After being cured and bonded at a higher temperature, the measurement container is placed in an environment of 60 ° C. and 90% relative humidity, passes through the thermosetting resin layer of the measurement container, and flows into the measurement container. The amount of moisture to be measured is measured, and the time when the moisture amount becomes a value of 10 or more in the SN ratio with respect to the background noise value is obtained, and this is set as the moisture increase start time T _tr .   The sealing element for an organic electroluminescence element according to claim 1, wherein the thermosetting resin is an epoxy resin. The auxiliary electrode layer is formed by subjecting the auxiliary electrode forming layer to a heat treatment at a conversion temperature T ₂ (° C.), and has a specific resistance value of 1.0 × 10 ⁻⁵ Ω · m or less. The sealing element for organic electroluminescent elements as described in any one of Claim 1- Claim 3. The conversion temperature T _{2 (°} C.), the organic electroluminescence device for sealing element according to claim 4, characterized in that is less than the curing temperature T ₁ of the said thermosetting resin _(° C.).   6. The organic electroluminescent element seal according to claim 1, wherein the auxiliary electrode layer is electrically connected to a part of the surface of the first substrate. 7. Stop element. It is a manufacturing method of the organic electroluminescent element using the sealing element for organic electroluminescent elements according to any one of claims 1 to 6,
1) A sealing element for an organic electroluminescence element in which a thermosetting resin layer containing a thermosetting resin and an auxiliary electrode layer are formed in this order on a first substrate;
2) An organic electroluminescence element substrate having a first electrode, an organic functional layer, and a second electrode layer in this order on the second substrate,
3) After bonding together so that the auxiliary electrode layer of the sealing element for organic electroluminescence elements and the second electrode layer of the organic electroluminescence element substrate are in contact with each other, the curing temperature T ₁ or higher of the thermosetting resin A method for producing an organic electroluminescent element, wherein the thermosetting resin layer is cured by heating at a temperature of 5%. It is a manufacturing method of the organic electroluminescent element using the sealing element for organic electroluminescent elements according to any one of claims 1 to 6,
1) A thermosetting resin layer containing a thermosetting resin and an auxiliary electrode forming layer are formed on the first substrate in this order, and the temperature (conversion temperature) of the thermosetting resin is lower than the curing temperature T ₁ (° C.). A sealing element for an organic electroluminescence element formed by performing a heat treatment at T ₂ ) and converting the auxiliary electrode forming layer into an auxiliary electrode layer;
2) An organic electroluminescence element substrate having a first electrode, an organic functional layer, and a second electrode layer in this order on the second substrate,
3) After bonding together so that the auxiliary electrode layer of the sealing element for organic electroluminescence elements and the second electrode layer of the organic electroluminescence element substrate are in contact with each other, the curing temperature T ₁ or higher of the thermosetting resin A method for producing an organic electroluminescent element, wherein the thermosetting resin layer is cured by heating at a temperature of 5%.

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