JP2002164165A - Organic electroluminescent element and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic electroluminescent element that can sufficiently and stably suppress the expansion of a dark spot with the lapse of the time and its manufacturing method. SOLUTION: The organic electroluminescent element comprises a first electrode that is formed on the substrate, a film layer that is formed on the first electrode and contains a light emitting layer made of at least an organic compound, a second electrode that is formed on the film layer, and a sealing plate that is pasted to the substrate by an adhesive. The above adhesive contains epoxy resin and polyaminoamide.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic electroluminescent device that can be used in fields such as display devices, flat panel displays, backlights, and interiors, and a method for manufacturing the same.

[0002]

2. Description of the Related Art An organic electroluminescent device emits light when holes injected from an anode and electrons injected from a cathode are recombined in an organic light emitting layer sandwiched between both electrodes.
A typical structure is a transparent first electrode (anode), hole transport layer, organic light emitting layer, and second electrode (cathode) on a glass substrate.
The light emission generated by the driving is extracted to the outside through the first electrode and the glass substrate. Such an organic electroluminescent element can be thin, emit high-intensity light under low-voltage driving, and emit multicolor light by selecting an organic light-emitting material. Applications to light-emitting devices and displays are being studied. .

One of the problems in the organic electroluminescent device is that the area of a non-light-emitting portion called a dark spot increases with time. It is known that the cause of such characteristic deterioration is moisture.
That is, moisture enters the organic thin film layer due to a defect of the second electrode or the like, and inactivates the element.

[0004] In order to prevent such dark spots from expanding, it is necessary to keep the organic electroluminescent device in a low humidity atmosphere. Usually, the organic electroluminescent device is sealed for the purpose of protecting the device from an external environment such as moisture. Stop means have been used. This means includes a method of bonding an element and a sealing plate via an adhesive (Japanese Patent Application Laid-Open No. 1-313892), and a method of forming a protective film having a moisture shielding property such as an oxide or a fluoride on a thin film layer. There is a wide variety of methods, such as a method of forming the same (JP-A-4-212284) and a method of enclosing a desiccant in a sealing element (JP-A-6-176867). As the adhesive, a method using a moisture-resistant photocurable resin (JP-A-5-182759), a method of heating and melting a low-melting glass with a laser beam (JP-A-10-74583), a cation-curing type ultraviolet curing Method using an epoxy resin (Japanese Unexamined Patent Publication No.
233283) has been published.

[0005]

However, in the prior art, the penetration of water into the inside of the device due to a decrease in the moisture shielding capability of the adhesive, the deterioration of the device due to heat or ultraviolet rays added to cure the resin, and the moisture shielding capability are mainly caused by the decrease in the moisture shielding capability of the adhesive. However, the inorganic protective film having the above has many problems such as easy damage to the element at the time of film formation, and the enlargement of the dark spot cannot be sufficiently suppressed.

An object of the present invention is to solve such a problem and to provide an organic electroluminescent device capable of sufficiently and stably suppressing the temporal expansion of a dark spot, and a method of manufacturing the same.

[0007]

That is, the present invention provides a first electrode formed on a substrate, a thin film layer formed on the first electrode, the light emitting layer comprising at least an organic compound, and a thin film layer formed on the first electrode. An organic electroluminescent device including the formed second electrode and a sealing plate bonded to a substrate with an adhesive, wherein the adhesive includes an epoxy resin and an aliphatic polyaminoamide. It is a light emitting element.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below, but the present invention is not limited to a method for manufacturing an organic electroluminescent device having the exemplified form and structure. Therefore,
Single light emitting element, segment type, simple matrix type, active matrix type and other light emitting element types, colors,
The present invention can be applied to an organic electroluminescent device having an arbitrary structure irrespective of the number of emission colors such as monochrome.

The components of the organic electroluminescent device according to the present invention include, for example, a substrate 1 and a sealing plate 2 in the device shown in FIG.
1, all the members in contact with the sealing internal space 23, such as the bonding means 22, are included. Depending on the element configuration, a wiring, a connector, a lead electrode, a protective film covering the element surface, and the like may be included, and the constituent members are not particularly limited.

In the present invention, a resin that maintains stable adhesive strength at room temperature or higher is used as the adhesive. The resin may be cured by heat treatment, ultraviolet irradiation, or the like, but a two-liquid mixed type epoxy resin that does not require such treatment is preferred. A two-component epoxy resin is a very suitable adhesive as an adhesive for sealing an organic electroluminescent element because it does not generate moisture during a curing reaction and has a high adhesive strength to a metal or a glass substrate. The epoxy resin of the main ingredient is bisphenol A type, bisphenol F type, bisphenol S
Types, phenol novolak type, polyphenol type, polyhydroxybenzene type, vinyl polymer type, aromatic carboxylic acid type, cyclohexene type, etc., among which there are various types, especially bisphenol A type, bisphenol F type,
It is desirable to include a phenol novolak type epoxy resin. It is not necessary to use the epoxy main agent alone, and it is possible to combine a plurality of epoxy resins for the purpose of adjusting physical properties such as viscosity.

From the viewpoint of improving the heat resistance of the cured resin, it is desirable that the epoxy resin contains a large number of epoxy groups. Specifically, it is desirable that the average number of epoxy groups contained in the epoxy resin in one molecule is larger than two. For example, a phenol novolak type epoxy resin is a preferred example.

The curing agent may be an aliphatic amine, an aromatic amine,
Secondary and tertiary amines, amines such as modified heterocyclic diamines, phthalic anhydride, acid anhydrides such as maleic anhydride,
Although there are various types such as a polysulfide resin having a mercaptan group, the present invention is characterized by using an aliphatic polyaminoamide-based curing agent.

In the present invention, the term "polyaminoamide-based curing agent" refers to an amide-based curing agent having a molecular weight that extends from an oligomer having an active amino group in a molecule synthesized from a polyamine and a polycarboxylic acid to a polymer region. The aliphatic in the present invention, methane, ethylene,
A chain aliphatic having no cyclic structure, such as an acetylene-based or hydrocarbon derivative, and a cyclic aliphatic having a ring such as cyclohexane, imide, or lactone but having a relationship with the parent compound and a ring that is easily opened are also included. .

In addition to the aliphatic polyaminoamide, the curing agent according to the present invention may be any of aliphatic amines, aromatic amines, secondary and tertiary amines in order to improve physical properties such as mechanical strength and heat resistance of the cured product. Amines, phenol compounds, amines such as modified heterocyclic diamines, acid anhydrides such as phthalic anhydride and maleic anhydride, and polysulfide resins having a mercaptan group may be contained. In the present invention, the sealing adhesive for an organic electroluminescent device may be one or more selected from the group consisting of tertiary amines, phenolic compounds, and organic acid salts of tertiary amines for the purpose of shortening the curing time. Can be included as a curing accelerator. The amount of the curing accelerator is desirably the minimum necessary in consideration of the heat resistance and chemical resistance of the cured resin. Specifically, the amount is preferably 10% or less, more preferably 5% by weight of the cured resin. % Or less, more preferably 3% or less.

Since the polyaminoamide-based curing agent has both a hydrophobic group and a hydrophilic group, it has high wettability to non-adhesives and good adhesion. For this reason, when a polyaminoamide-based curing agent is used for the sealing adhesive, the adhesiveness between the sealing plate or the substrate and the adhesive is increased, which effectively prevents moisture from entering the sealing space from the outside. Can be suppressed. Further, since it has a hydrophobic group, it has excellent moisture shielding properties as compared with ordinary amine-based cured products and the like, and can effectively suppress the diffusion of moisture in the resin. Further, since curing with an epoxy resin (base material) is possible at room temperature, there is no possibility of thermal damage to an organic thin film layer or the like when the resin is cured. The amine value of the curing agent is preferably large in order to improve the heat resistance of the cured resin, and is preferably at least 370 or more, more preferably 400 or more as measured by JIS K7237.

Further, in the present invention, the resin adhesion is improved.
To bond the substrate and the sealing plate when the resin cures
Means to apply pressure in the direction
It is effective in the adhesion between the plate or sealing plate and the resin.
You. By applying pressure, minute recesses on the surface of the adherend
The resin penetrates into the convex portions, and the adhesion is improved. Additional pressure
Regarding the force, resin viscosity, curing temperature, material of the adherend
There is an optimum value depending on various conditions.
Can not be determined, but at least 0.01 kg / cm ^TwoMore than
Large enough. As a method of applying pressure
Is a method of placing a weight on the element.
The method of using the bonding device and the gas filling the processing chamber for sealing
Any method such as applying hydrostatic pressure to media such as
It does not matter how.

The state of the interface between the substrate or the sealing plate and the resin is very important. In many cases, a stress is generated at the bonding interface when the resin is cured, and the bonding stress causes the separation of the bonding interface. There is. Therefore, a process for improving the adhesion at the bonding interface becomes important.

In addition to the above-mentioned method of applying pressure, as a method for improving the resin adhesion, it is effective to apply a primer treatment to the substrate and the sealing plate. The primer treatment means that the surface of the substrate or the sealing plate is preliminarily treated with an adhesive in order to increase the affinity of the interface between the resin and the substrate and between the resin and the sealing plate.

Preferred examples of the primer include those obtained by diluting a silane coupling agent with a solvent. As the solvent, alcohols, toluene, xylene, ethyl acetate, methyl ethyl ketone, acetone and the like can be used, and when diluting the silane coupling agent, 1 to
What was diluted about 20% can be used as a suitable thing. As for the primer treatment method, it is only necessary to apply the primer on the substrate or the sealing plate surface and dry it,
If the substrate and the sealing plate are cleaned with a solvent or the like before applying the primer, the adhesion is further improved.

The silane coupling agent preferably has at least two or more types of functional groups in order to have an affinity for the resin and the adherend. Particularly when the resin contains an epoxy resin, it is preferable that at least one of the functional groups has an epoxy group.When the substrate or the sealing plate is an inorganic compound such as glass or metal, an alkoxy group such as a methoxy group or an ethoxy group is preferably used. It is preferable to have.

In order to further reduce the water permeability and the water absorption of the resin, a filler can be mixed into the adhesive resin. The filler is a fine particle made of an inorganic material such as silica, and the size, shape, and mixing ratio of the particle are not particularly limited, and are optimized as needed.

The curing condition of the sealing resin is not limited to the curing at room temperature, but it is needless to say that the temperature condition can be selected as needed within a range that does not deteriorate the organic electroluminescent element. In order to further improve the adhesion between the resin and the sealing plate, the sealing plate may be washed with an appropriate solvent,
A method of performing a V treatment to clean the surface of the sealing plate is effective.

The sealing method in the present invention is not particularly limited as long as the substrate and the sealing plate are bonded together. Therefore, the sealed internal space can be filled with a low-humidity liquid or gas. Examples of the former include inert liquids such as silicone oil, grease, and fluorocarbon oil. Examples of the latter include rare gases such as helium and argon, and inert gases such as nitrogen and carbon dioxide. Further, the inside of the sealed space can be kept at a vacuum.

The above method of filling the sealing space with a low-humidity gas can be easily achieved by bonding the substrate and the sealing plate in a low-humidity atmosphere. In order to obtain a sufficient sealing effect, the dew point in a low humidity atmosphere is preferably -30 ° C or lower, -60 ° C or lower, and more preferably -1 ° C or lower.
It is more preferable that the temperature is not higher than 00 ° C.

As the sealing plate, a plate or film formed of a material having low moisture permeability such as glass, resin, or a metal such as aluminum or stainless steel can be used. These may be a single type or a composite type obtained by depositing a metal such as aluminum on a resin film such as polyethylene.

In the present invention, the shape of the sealing plate 21 is not particularly limited, and the sealing plate 21 may be sealed with the substrate by forming a recess 24 as shown in FIG. 2 or a leg 25 as shown in FIG. The position to be bonded to the stop plate can be defined. By doing so, it is also possible to secure a volume for filling the sealing internal space 23 with gas or oil or for providing a moisture absorbent. Similar effects can be obtained by increasing the thickness of the bonding means. Furthermore, if the sealing method of the present invention is used, a getter film having a moisture absorbing effect or the like, or a black film or a light absorbing film having an anti-reflection effect is formed on the surface of the sealing plate in advance as necessary. You can also. Examples of the hygroscopic agent include silica gel, zeolite, activated carbon, calcium oxide, germanium oxide, barium oxide, magnesium oxide, phosphorus pentoxide, calcium chloride, and the like.As the getter film, aluminum, magnesium, barium, a metal-deposited film of titanium, or the like. Examples can be given.

The bonding position between the substrate and the sealing plate is not particularly limited, and the bonding means may be positioned so as to cover the entire device. However, from the viewpoint of light emission stability, the bonding means is in contact with the light emitting region. It is preferable that they are not located. Furthermore, from the viewpoint of power supply, it is preferable that each of the first electrode and the second electrode is sealed so as to be exposed to the outside. Further, it is also possible to take out the electrode through a through hole provided in the substrate.

The material of the substrate is not particularly limited as long as it has optical transparency, mechanical strength, heat resistance and the like suitable for functioning as a display or a light emitting element. Although plastic plates and films such as polymethyl methacrylate, polycarbonate and amorphous polyolefin can be used, it is most preferable to use a glass plate. As the glass material, non-alkali glass, soda lime glass coated with a barrier coat such as a silicon oxide film, or the like can be used. Since the thickness only needs to be sufficient to maintain the mechanical strength, 0.5 mm or more is sufficient. In addition, an antireflection function can be added to the first electrode or the substrate by using a known technique.

The thin film layers included in the organic electroluminescent device include 1) a hole transport layer / a light emitting layer, 2) a hole transport layer / a light emitting layer / an electron transport layer, 3) a light emitting layer / an electron transport layer, and 4) And e) a light-emitting layer in which the above-mentioned combined substances are mixed in a single layer. That is, if a light-emitting layer made of an organic compound is present as an element configuration, a light-emitting material alone or a light-emitting material and a hole-transport material or an electron-transport, as described in 4), in addition to the multi-layer structure of 1) to 3) above. Only one light-emitting layer containing a material may be provided.

The hole transporting layer is formed of a hole transporting substance alone or a hole transporting substance and a polymer binder.
As the hole transporting substance, N, N'-diphenyl-N,
N'-di (3-methylphenyl) -1,1'-diphenyl-4,4'-diamine (TPD) and N, N'-diphenyl-N, N'-dinaphthyl-1,1'-diphenyl-
Triphenylamines represented by 4,4'-diamine (NPD), N-isopropylcarbazole, biscarbazole derivatives, pyrazoline derivatives, stilbene compounds, hydrazone compounds, oxadiazole derivatives and phthalocyanine derivatives Heterocyclic compounds, in the polymer system, polycarbonate and polystyrene derivatives having the monomer in the side chain, polyvinyl carbazole, polysilane, polyphenylene vinylene and the like are preferable,
There is no particular limitation.

The material of the light emitting layer formed by patterning on the first electrode is anthracene, pyrene, and 8-hydroxyquinoline aluminum, for example, bisstyrylanthracene derivative, tetraphenylbutadiene derivative, coumarin derivative, Oxadiazole derivatives,
A distyrylbenzene derivative, a pyrrolopyridine derivative, a perinone derivative, a cyclopentadiene derivative, a thiadiazolopyridine derivative, and a polymer system include polyphenylenevinylene derivatives, polyparaphenylene derivatives, and polythiophene derivatives. As the dopant to be added to the light emitting layer, rubrene, quinacridone derivative, phenoxazone 660, DCM1, perinone, perylene, coumarin 540, diazaindacene derivative, and the like can be used as they are.

As the electron transporting substance, it is necessary to efficiently transport electrons from the cathode between the electrodes to which an electric field is applied, and it is desirable to have a high electron injection efficiency and to efficiently transport the injected electrons. . For this purpose, it is required that the material has a high electron affinity, a high electron mobility, a high stability, and a small amount of impurities serving as traps during production and use. As materials satisfying such conditions, 8-hydroxyquinoline aluminum (Alq ₃ ), hydroxybenzoquinoline beryllium, 2- (4-biphenyl) -5- (4-t-butylphenyl) -1,3,4-oxadiene Azole (t-Bu
Oxadiazole derivatives such as PBD) and 1,3 oxadiazole dimer derivatives having improved thin film stability
-Bis (4-t-butylphenyl-1,3,4-oxadizolyl) biphenylene (OXD-1), 1,3-bis (4-t-butylphenyl-1,3,4-oxadizolyl) phenylene (OXD- 7), triazole derivatives, phenanthroline derivatives and the like.

The above materials used for the hole transporting layer, the light emitting layer and the electron transporting layer can be used alone to form each layer. As the polymer binder, polyvinyl chloride, polycarbonate, polystyrene, poly (N- (Vinyl carbazole), polymethyl methacrylate, polybutyl methacrylate, polyester, polysulfone, polyphenylene ether, polybutadiene, hydrocarbon resins, ketone resins, phenoxy resins, polyurethane resins, and other solvent-soluble resins, phenol resins, xylene resins, petroleum resins,
Urea resin, melamine resin, unsaturated polyester resin,
It is also possible to use the resin dispersed in a curable resin such as an alkyd resin, an epoxy resin, and a silicone resin.

The method of forming the organic layers such as the hole transport layer, the light emitting layer, and the electron transport layer includes resistance heating evaporation, electron beam evaporation, and sputtering. Although not particularly limited, an evaporation method such as resistance heating evaporation or electron beam evaporation is usually preferable in terms of characteristics. Although the thickness of the layer depends on the resistance value of the organic layer and cannot be limited, it is empirically selected from the range of 10 to 1000 nm.

The cathode serving as the second electrode is not particularly limited as long as it can efficiently inject electrons into the light emitting layer of the device. Therefore, it is possible to use a low work function metal such as an alkali metal, but considering the stability of the electrode, platinum, gold,
Preferable examples include metals such as silver, copper, iron, tin, aluminum, magnesium and indium, and alloys of these metals with low work function metals. In addition, a stable electrode can be obtained while maintaining high electrode injection efficiency by doping the organic layer with a small amount of a low work function metal in advance and then forming a film of a relatively stable metal as a cathode. These electrodes are also manufactured by resistance heating evaporation,
Dry processes such as electron beam evaporation, sputtering, and ion plating are preferred.

[0036]

The present invention will be described below with reference to examples and comparative examples, but the present invention is not limited to these examples.

Example 1 An ITO substrate having a 130 nm thick ITO transparent electrode film formed on a 1.1 mm thick non-alkali glass surface by sputtering was prepared. After patterning this ITO film using the photolithography method, 46 mm × 38
mm, and a 12 mm wide I
A substrate was fabricated by patterning so that a TO film (first electrode) was present.

After washing the substrate, it was set in a vapor deposition machine and evacuated to a vacuum of 2 × 10 ⁻⁴ Pa. With the shadow mask for the light emitting layer having an opening of 15 mm square arranged, copper phthalocyanine 10 nm, N, N'-diphenyl-N, N'-
Dinaphthyl-1,1′-diphenyl-4,4′-diamine (α-NPD) 50 nm and tris (8-quinolinolato) aluminum (Alq ₃ ) 50 nm were deposited. After that, the thin film layer was exposed to lithium vapor to dope (0.5 nm in equivalent film thickness). Next, the mask was replaced with a second electrode shadow mask having four 5 × 12 mm openings, and aluminum was vapor-deposited to a thickness of 120 nm at a degree of vacuum of 3 × 10 ⁻⁴ Pa to pattern the second electrode. Thus, an organic electroluminescent device having four green light emitting regions on the substrate was manufactured.

The device was taken out of the evaporator, kept in a reduced pressure atmosphere by a rotary pump for 20 minutes, and then transferred to an argon atmosphere having a dew point of -90 ° C. Under the dry atmosphere, a phenol novolak-type epoxy resin ("Epicoat 152", manufactured by Japan Epoxy Resin Co., Ltd.) as a main agent, a polyaminoamide-based curing agent ("XNH3101",・ Specialty Chemicals Co., Ltd.) was mixed in an appropriate amount and thoroughly stirred. The mixed resin was applied as an adhesive to a position surrounding the light emitting portion on the substrate, and a sealing plate made of non-alkali glass was bonded and sealed.

After the adhesive was cured at room temperature for 24 hours, the obtained device was allowed to stand in an atmosphere of 80 ° C. and 80% RH.
The above light emitting region was maintained for up to 200 hours.

Comparative Example 1 A sealing element was produced in the same manner as in Example 1 except that a heterocyclic amine-based curing agent (B001, manufactured by Yuka Shell Epoxy Co., Ltd.) was used as the curing agent. The obtained device was heated at 80 ° C. for 8 hours.
When left in an atmosphere of 0% RH for 40 hours, only 30% or less of the light emitting region was maintained among the light emitting regions observed immediately after sealing.

Comparative Example 2 A sealing element was produced in the same manner as in Example 1 except that a heterocyclic amine-based curing agent (LX2S, manufactured by Yuka Shell Epoxy Co., Ltd.) was used as the curing agent. The obtained device was heated at 80 ° C. for 8 hours.
When left in an atmosphere of 0% RH for 40 hours, only 30% or less of the light emitting region was maintained among the light emitting regions observed immediately after sealing.

Comparative Example 3 A sealing element was produced in the same manner as in Example 1 except that a heterocyclic amine-based curing agent (RX2, manufactured by Yuka Shell Epoxy Co., Ltd.) was used as the curing agent. The obtained device was heated at 80 ° C and 80 ° C.
When left in an atmosphere of% RH for 40 hours, only 30% or less of the light emitting region was maintained among the light emitting regions observed immediately after sealing.

Comparative Example 4 A sealing element was produced in the same manner as in Example 1 except that a heterocyclic amine-based curing agent (P002, manufactured by Yuka Shell Epoxy Co., Ltd.) was used as the curing agent. The obtained device was heated at 80 ° C. for 8 hours.
When left in an atmosphere of 0% RH for 40 hours, only 30% or less of the light emitting region was maintained among the light emitting regions observed immediately after sealing.

Comparative Example 5 A sealing element was produced in the same manner as in Example 1, except that a mercaptan-based curing agent (TMTP, manufactured by Yodo Chemical Co., Ltd.) was used as the curing agent. When the obtained device was left under an atmosphere of 80 ° C. and 80% RH for 40 hours, only a light emitting region of 30% or less was maintained among light emitting regions observed immediately after sealing.

Comparative Example 6 A sealing element was produced in the same manner as in Example 1 except that a mercaptan-based curing agent (PETP, manufactured by Yodo Chemical Co., Ltd.) was used as the curing agent. When the obtained device was left in an atmosphere of 80 ° C. and 80% RH for 40 hours, only 40% or less of the light emitting region observed from immediately after sealing was maintained.

Example 2 A sealing element was manufactured in the same manner as in Example 1 except that the interface between the substrate and the resin and the interface between the sealing plate and the resin were treated with a primer. In the primer treatment, a silane coupling agent ("KBE903", manufactured by Shin-Etsu Chemical Co., Ltd.) diluted to 2 wt% with ethanol is applied and dried in advance on the substrate and the sealing plate where the resin is applied, and then the resin is applied. Was applied, and the substrate and the sealing plate were bonded and sealed.

Even after the obtained device was left in an atmosphere of 80 ° C. and 80% RH for 300 hours, 99% or more of the light emitting regions observed immediately after sealing were maintained.

Example 3 The sealing was carried out in the same manner as in Example 1 except that a pressure of 0.2 kg / cm ² was applied in the direction of bonding the substrate and the sealing plate when the sealing adhesive hardened. A stop element was produced.
The obtained device was placed in an atmosphere at 80 ° C. and 80% RH for 400 hours.
Even after standing for a period of time, 99% or more of the light emitting regions observed in the light emitting region observed immediately after sealing were maintained.

Example 4 As a curing accelerator, 2,4,6-tris (dimethylaminomethyl) phenol ("EH-30", manufactured by Cognis Japan Co., Ltd.) was added in an amount of 1% based on the total weight of the resin. A sealing element was produced in the same manner as in Example 1 except that the curing time was changed to 3 hours. When the obtained device was left in an atmosphere of 80 ° C. and 80% RH, 99% or more of the light emitting regions observed immediately after sealing were maintained for 200 hours.

Example 5 The same procedure as in Example 1 was carried out except that a polyaminoamide ("Virsamide" 150, Cognis Japan Co., Ltd., amine value = 380) composed of a dimer acid-modified resin was used as a curing agent for the sealing resin. Thus, an element was manufactured. 8
When the device was left in an atmosphere of 0 ° C. and 80% RH, 99% or more of the light emitting regions observed immediately after sealing were maintained for up to 200 hours.

Example 6 A polyaminoamide composed of a dimer acid-modified resin as a curing agent for a sealing resin ("VERSAMID" JP1460, Inc.)
A device was produced in the same manner as in Example 1 except that Cognis Japan Co., Ltd., amine value = 580) was used. When the obtained device was left in an atmosphere of 80 ° C. and 80% RH,
Of the light emitting regions observed immediately after sealing, 99% or more of the light emitting regions were maintained for up to 250 hours.

Example 7 The same procedure as in Example 1 was carried out except that a polyaminoamide ("Virsamide" 125, manufactured by Cognis Japan Co., Ltd., amine value = 350) composed of a dimer acid-modified resin was used as a curing agent for the sealing resin. Thus, an element was manufactured. 8
When the device was left for 100 hours in an atmosphere of 0 ° C. and 80% RH, 70% or less of the light-emitting region observed immediately after sealing was maintained.

Example 8 A device was produced in the same manner as in Example 1 except that a bisphenol A type epoxy resin ("Epicoat" 825, Japan Epoxy Resin Co., Ltd.) was used as the main component of the sealing resin. When the obtained device was left in an atmosphere of 80 ° C. and 80% RH, of the light emitting region observed immediately after sealing,
A light emission region of 99% or more was maintained for up to 180 hours.

Example 9 A device was produced in the same manner as in Example 1 except that a bisphenol F type epoxy resin ("Epicoat" 806L, Japan Epoxy Resin Co., Ltd.) was used as the main component of the sealing resin. When the obtained device was left in an atmosphere of 80 ° C. and 80% RH, 99% or more of the light emitting regions observed immediately after sealing were maintained for 180 hours.

Example 10 N, N, N ', N'-tetraglycidyl m-xylenediamine ("TETRAD-
X ", Mitsubishi Gas Chemical Co., Ltd., average number of epoxy groups in one molecule = 4) and phenol novolak type epoxy resin (" Epicoat "152, manufactured by Japan Epoxy Resin Co., Ltd., average number of epoxy groups in one molecule = 2.1) And a sealing element was produced in the same manner as in Example 1 except that a main agent (average number of epoxy groups in one molecule = 3) obtained by mixing the same in an equimolar manner was used. Even after the obtained device was left under an atmosphere of 80 ° C. and 80% RH for 250 hours, 9
The light emission region of 9% or more was maintained.

[0057]

According to the organic electroluminescent device of the present invention, since the encapsulating resin contains an epoxy resin and polyaminoamide, it is possible to suppress the temporal expansion of dark spots with good reproducibility.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an example of an organic electroluminescent device manufactured according to the present invention.

FIG. 2 is a cross-sectional view showing another example of the organic electroluminescent device manufactured by the present invention.

FIG. 3 is a cross-sectional view showing another example of the organic electroluminescent device manufactured by the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 1st electrode 3 Drive source 5 Hole transport layer 6 Light emitting layer 8 2nd electrode 21 Sealing plate 22 Adhesive resin 23 Sealing internal space 24 Depression 25 Leg

Continued on the front page F term (reference) 3K007 AB11 AB18 BB01 BB03 BB04 CA01 CB01 DA01 DB03 EA01 EB00 FA02

Claims (8)

[Claims] A first electrode formed on the substrate, a thin film layer formed on the first electrode, the light emitting layer including at least an organic compound, and a second electrode formed on the thin film layer; An organic electroluminescent device including a sealing plate bonded to a substrate with an agent, wherein the adhesive includes an epoxy resin and an aliphatic polyaminoamide. 2. The organic electroluminescent device according to claim 1, wherein said adhesive further comprises a curing accelerator. 3. The organic electroluminescent device according to claim 1, wherein the epoxy resin contains at least one skeleton of bisphenol A type, bisphenol F type, and phenol novolak type. 4. The organic electroluminescent device according to claim 1, wherein said adhesive contains an epoxy resin having an average number of epoxy groups in one molecule of more than 2. 5. The organic electroluminescent device according to claim 1, wherein the amine value of the aliphatic polyaminoamide resin is larger than 370. 6. The epoxy resin composition according to claim 2, wherein the curing accelerator is at least one compound selected from the group consisting of tertiary amines, phenolic compounds and organic acid salts of tertiary amines. . 7. The method for manufacturing an organic electroluminescent device according to claim 1, wherein, when the adhesive is cured, a pressure of 0.01 kg / cm ² or more is applied in a direction of bonding the substrate and the sealing plate. A method for manufacturing an organic electroluminescent device, comprising: 8. The method for manufacturing an organic electroluminescent device according to claim 1, wherein a surface of the substrate or the sealing plate in contact with the adhesive is subjected to a primer treatment, and then an adhesive is applied to the substrate and the sealing plate. A method for manufacturing an organic electroluminescent device, comprising laminating.