JPH09274990A - Organic electroluminescence element, and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress generation of dark spots in storing or driving an organic electroluminescence element, and maintain stable light emitting characteristics for a long period. SOLUTION: A light emitting element comprises a protective layer 5, a sealing layer 6, and an outer layer shielding material layer 7 formed on an outer surface of an element main body 10 comprising a substrate 1, a positive electrode 2, an organic light emitting layer 3, and a negative electrode 4. The sealing layer 6 is formed of adhesive agent having a 100% tensile stress of JIS K6301 of 50kgf/cm<2> or less, and a water-vapor permeability of JIS Z0208 (condition A) of 20g/m<2> (24 hours, 200μm) or less. Hardening shrinkage distortion or internal stress at the time of hardening of the adhesive agent are thus set so small that peeling of the negative electrode or short-circuiting of the element is not generated, so generation of dark spots can be prevented by sealing the element main body 10. Deterioration of adhesive force or elasticity is not generated even after storage in high-temperature and high-moisture conditions. In addition, aging deterioration of the binding agent by reaction with the protective layer 5 is not generated.

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 and a method for manufacturing the same, and more particularly to a method for sealing a thin film type light emitting device which emits light by applying an electric field to a light emitting layer made of an organic compound. It is about improvement.

[0002]

2. Description of the Related Art Conventionally, as a thin film type electroluminescence (EL) element, Zn which is a II-IV group compound semiconductor of an inorganic material has been used.
Generally, S, CaS, SrS, and the like are doped with Mn or a rare earth element (Eu, Ce, Tb, Sm, or the like) which is a luminescence center. Is required (generally 50 to 1000
Hz). The driving voltage is high (generally about 200 V). It is difficult to make full color. In particular, there is a problem with blue. The cost of the peripheral drive circuit is high. There is a problem that.

However, in recent years, in order to improve the above problems,
Development of EL devices using organic thin films has been started. In particular, in order to increase the luminous efficiency, the type of the electrode is optimized for the purpose of improving the efficiency of carrier injection from the electrode, and the organic hole transport layer composed of an aromatic diamine and the organic layer composed of an aluminum complex of 8-hydroxyquinoline are used. Development of an organic electroluminescent device provided with a light emitting layer (Appl. Ph.
ys. Lett. , 51, p. 913, 1987), the luminous efficiency has been greatly improved as compared with the conventional electroluminescent device using a single crystal such as anthracene, and is approaching practical characteristics.

In addition to the above-described electroluminescent device using a low molecular material, poly (p) is used as a material for an organic light emitting layer.
-Phenylene vinylene) (Nature, 347, 5)
39, 1990 et al.), Poly [2-methoxy-5-
(2-ethylhexyloxy) -1,4-phenylenevinylene] (Appl. Phys. Lett., Vol. 58,
1982, etc.), poly (3-alkylthiophene) (J
pn. J. Appl. Phys., Vol. 30, L1938, etc.) and the development of an electroluminescent device using a polymer material, and a device in which a low molecular light emitting material and an electron transfer material are mixed with a polymer such as polyvinyl carbazole (Applied Physics, Vol. 61) , 10
Page 44, 1992) is also under development.

In these organic electroluminescent devices, a transparent electrode such as indium tin oxide (ITO) is usually used as an anode, and a magnesium alloy, aluminum. Metal electrodes having a low work function such as lithium alloy and calcium are used. These cathode materials are easily oxidized by moisture and oxygen in the atmosphere, and as a result, the cathode is peeled off from the organic layer, and a defect generally called a dark spot (which indicates a portion that does not emit light on the light emitting surface of the device) occurs. . The number and size of dark spots in this organic electroluminescent device are
It increases when the device is stored or driven for a long period of time, which causes instability of the device and shortens its life.

Therefore, in order to improve the stability and the reliability of the organic electroluminescence device, sealing for protecting the device from moisture and oxygen in the atmosphere is indispensable.

Conventionally, as a method for sealing an organic electroluminescence device, a method of molding with an acrylic resin (Japanese Patent Laid-Open No. 3-37)
991), a method of putting P ₂ O ₅ together in an airtight case to shield it from the outside air (JP-A-3-261091), and an airtight case using a glass plate or the like after providing a protective film such as a metal oxide. (Japanese Patent Application Laid-Open No. 4-212284), a method of providing a plasma-polymerized film and a photocurable resin layer (Japanese Patent Application Laid-Open No. 5-36475), and a method of holding in an inert liquid composed of fluorinated carbon (special Kaihei 4-36389
No. 0, etc.), a method of holding a polymer protective film and then holding it in silicone oil (JP-A-5-36475),
A method of adhering a glass plate coated with polyvinyl alcohol on a protective film such as an inorganic oxide with an epoxy resin (JP-A-5-89959) or a method of enclosing it in liquid paraffin or silicone oil (JP-A-5-129080). Gazette), a method using an ultraviolet curable resin (JP-A-5-1)
No. 82759, etc.) has been proposed.

[0008]

However, none of the above-mentioned conventional methods for sealing an organic electroluminescence device is satisfactory, and for example, if the device is sealed in a hermetic structure together with P ₂ O ₅ which is a hygroscopic agent. , The suppression of dark spots is insufficient. In addition, fluorinated carbon (for example,
The product name "Fluorinert") and the method of holding it in silicone oil not only complicate the sealing process due to the step of injecting the liquid, but also cannot completely prevent the increase of dark spots. There is also a problem that it penetrates into the interface between the cathode and the organic layer and promotes peeling of the cathode. The method of adhesive sealing with an ultraviolet curable resin is not practical because it has a problem of deterioration of the element due to a solvent contained in the adhesive or ultraviolet rays, and a problem of peeling of the cathode from the organic layer due to stress strain during curing. Epoxy resin or acrylic resin as an adhesive for sealing entails great damage to the element during curing and is unsuitable for sealing the element.

As described above, the deterioration of the organic electroluminescent device due to the dark spot is not sufficiently improved, and the unstable light emitting property is a serious defect for a light source such as a facsimile, a copying machine, and a backlight of a liquid crystal display. Also, it is not desirable as a display element such as a flat panel display.

The present inventor has solved the above-mentioned conventional problems, and by performing effective sealing without adversely affecting the element, the occurrence of dark spots is surely suppressed, and the dark spot can be maintained for a long period of time. An object of the present invention is to provide an organic electroluminescent device capable of maintaining stable light emitting characteristics.

[0011]

In the organic electroluminescent device of the present invention, at least an anode, an organic light emitting layer and a cathode are laminated on a substrate, and a protective layer and a sealing layer are provided on the outer surface of the laminate in this order from the inside. An organic electroluminescent device having a stop layer and an outside air blocking material layer, wherein the sealing layer has the following (a) and (b):
It is characterized in that the main component is an adhesive that satisfies the condition of.

(A) 100% tensile stress specified by JIS K6301 is 50 kgf / cm ² or less (b) Moisture vapor transmission rate under condition A specified by JIS Z0208 is 20 g / m ² (200 μm) or less in 24 hours. If the adhesive satisfies the conditions of (a) and (b), a sealing layer having a high sealing function can be easily formed without adversely affecting the element, and the occurrence of dark spots can be reliably suppressed. It is possible to maintain stable light emission characteristics for a long period of time.

The effect of the adhesive used for the sealing layer in the present invention is as follows.

To suppress dark spots, the device must first be placed in an airtight structure. At that time, it was found that it was difficult to suppress dark spots when there was a free volume in the closed space. The reason for this is that the adhesion of the cathode formed on the organic light-emitting layer to the organic light-emitting layer is very weak. Therefore, if there is a free volume in the vicinity of the cathode, the cathode is easily heated due to heat generation during driving. It is conceivable that it peels off from. In this respect, it is difficult to avoid dark spots by the method of sealing with an inert gas or an inert liquid. Therefore, it is necessary to completely fill the space sealed with some solid state material, but if an adhesive such as a conventional acrylic resin, epoxy resin, cyanoacrylate resin, or UV curable resin is used, it will occur during curing. Since the curing shrinkage strain and the internal stress concentrate on the interface between the organic electroluminescent element and the adhesive portion, peeling of the cathode becomes more severe, or the element is short-circuited.

On the other hand, as an adhesive for the sealing layer, an adhesive satisfying the above-mentioned conditions (a) and (b), which is different from the conventional sealing layer, is used in the curing shrinkage strain at the time of curing the adhesive. Since the internal stress is small, the element body can be sealed and a dark spot can be prevented without causing peeling of the cathode or short circuit of the element.

Further, according to the present invention, the above (a), (b)
Adhesives satisfying the condition of No. 2 cause peeling of the adhesive portion, which is seen when other adhesives such as epoxy adhesives are used, even after a long time in an environment of 65 ° C.-80% RH. Absent. This is because the adhesive according to the present invention has an advantage that adhesive strength and elasticity do not deteriorate even if the adhesive is left in such an environment for a long time. Further, the adhesive according to the present invention does not cause deterioration over time due to the adhesive reacting with the protective layer even under the high temperature and high humidity conditions. Further, the adhesive according to the present invention does not use a volatile solvent and thus can eliminate the volatilization step.

In the present invention, the adhesive is preferably polyurethane containing hydrocarbon polyol as a main component or polyurethane containing castor oil polyol as a main component, and silica gel, zeolite, calcium chloride, By containing one or more kinds of hygroscopic agents selected from the group consisting of activated carbon, nylon and polyvinyl alcohol, the sealing effect can be further enhanced.

The outside air barrier layer is preferably made of electrically insulating glass or electrically insulating polymer.

The thickness of the cathode is preferably smaller than that of the organic light emitting layer.

Further, the anode is preferably made of indium tin oxide and has a surface roughness of 10 nm or less.

Such an organic electroluminescent device of the present invention is
According to the production method of the present invention, at least an anode, an organic light emitting layer and a cathode are laminated on a substrate, and a protective layer is formed on the outer surface of the laminate, and then the conditions (a) and (b) are satisfied. It can be easily manufactured by forming a sealing layer containing an adhesive as a main component, and then forming an outside air blocking material layer on the outside of the sealing layer.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an organic electroluminescence device of the present invention and a method for manufacturing the same will be described with reference to the drawings.

FIG. 1 is a schematic sectional view showing an embodiment of the organic electroluminescent element of the present invention, FIG. 2 is a schematic sectional view showing an element body of this organic electroluminescent element, and FIGS. It is a typical sectional view showing other examples of a main part. In the figure, 1 is a substrate, 2 is an anode, 3 is an organic light emitting layer, 3a is a hole transport layer,
3b is an electron transport layer, 3c is a hole injection layer, 4 is a cathode, 5 is a protective layer, 6 is a sealing layer, 7 is an outside air blocking layer, 8 is an adhesive portion,
Reference numerals 10, 10A and 10B respectively denote element bodies.

The substrate 1 serves as a support for the organic electroluminescent device, and a quartz or glass plate, a metal plate or metal foil, a plastic film or sheet, or the like is used. Especially,
A glass plate and a transparent synthetic resin plate such as polyester, polymethacrylate, polycarbonate and polysulfone are preferable. However, when using a synthetic resin substrate, it is necessary to pay attention to gas barrier properties. If the gas barrier property of the substrate is too small, the organic electroluminescent element may deteriorate due to the outside air passing through the substrate, which is not preferable. Therefore, a method of providing a dense silicon oxide film or the like on at least one surface of the synthetic resin substrate to secure the gas barrier property is also a preferable method.

The anode 2 formed on the substrate 1 plays a role of injecting holes into the organic light emitting layer 3. This anode 2 is usually made of aluminum, gold, silver, platinum, nickel,
Metals such as palladium and platinum, metal oxides such as indium and / or tin oxides, halides such as copper iodide, carbon black, or high conductivity such as poly (3-methylthiophene), polypyrrole, polyaniline The molecule or the like is preferably formed of indium tin oxide. Usually, the formation of the anode 2 is often performed by a sputtering method, a vacuum evaporation method, or the like. When fine particles of metal such as silver, fine particles of copper iodide, carbon black, fine particles of conductive metal oxide, fine powder of conductive polymer, etc. are used, these are dispersed in a suitable binder resin solution and the substrate 1 The anode 2 can also be formed by applying the composition onto the anode 2. When a conductive polymer is used, a thin film is directly formed on the substrate 1 by electrolytic polymerization, or the substrate 1 is used.
It is also possible to form the anode 2 by applying a conductive polymer on it (Appl. Phys. Lett.,
60, 2711, 1992). The anode 2 can be formed by laminating different materials.

The thickness of the anode 2 depends on whether or not transparency is required. When transparency is required, it is desirable that the visible light transmittance is usually 60% or more, preferably 80% or more. In this case, the thickness is usually 5 to 100.
0 nm, preferably about 10 to 500 nm. When the anode 2 may be opaque, it may be made of the same material as the substrate 1. Further, different conductive materials can be laminated on the anode 2.

The organic light emitting layer 3 formed on the anode 2 is
It is made of a material that efficiently transports and recombines holes injected from the anode 2 and electrons injected from the cathode 4 between the electrodes to which an electric field is applied, and emits light efficiently by the recombination. Usually, in order to improve the luminous efficiency, the organic light emitting layer 3 is divided into a hole transporting layer 3a and an electron transporting layer 3b, as shown in FIG. 3, to be a function separation type (Appl. Phys. Lett., 51, 913.
1987).

In the function-separated device 10A shown in FIG. 3, as the material of the hole transport layer 3a, the efficiency of hole injection from the anode 2 is high, and the injected holes can be efficiently transported. It needs to be a material. For that purpose, it is required that the ionization potential is small, the hole mobility is large, the stability is excellent, and impurities that serve as traps are less likely to be generated during manufacturing or use.

As such a hole transport material, for example, an aromatic diamine compound in which a tertiary aromatic amine unit such as 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane is linked (Japanese Patent Application Laid-Open No. 2000-242242) Sho 59-19439
No. 3), 4,4′-bis [N- (1-naphthyl)-
N-phenylamino] aromatic amines containing two or more tertiary amines represented by biphenyl and having two or more condensed aromatic rings substituted by nitrogen atoms (JP-A-5-234681); Aromatic triamines having a starburst structure in derivatives (US Pat. No. 4,92
Aromatic diamines such as N, N'-diphenyl-N, N'-bis (3-methylphenyl) biphenyl-4,4'-diamine (U.S. Pat. No. 4,764,62)
No. 5), α, α, α ′, α′-tetramethyl-α, α ′
-Bis (4-di-p-tolylaminophenyl) -p-xylene (JP-A-3-269084), a triphenylamine derivative which is sterically asymmetric as a whole molecule (JP-A-4-129271), bienyl In which a plurality of aromatic diamino groups are substituted on a group (JP-A-4-17539)
5), an aromatic diamine in which a tertiary aromatic amine unit is linked by an ethylene group (JP-A-4-264189), and an aromatic diamine having a styryl structure (JP-A-4).
No. 290851), one in which an aromatic tertiary amine unit is linked by a thiophene group (JP-A-4-304466).
No. 3), a starburst type aromatic triamine (JP-A-4-308688), a benzylphenyl compound (JP-A-4-364153), and a fluorene group containing 3
A compound in which a primary amine is linked (JP-A-5-25473), a triamine compound (JP-A-5-239455), and bisdipyridylaminobiphenyl (JP-A-5-3).
20634), N, N, N-triphenylamine derivatives (JP-A-6-1972), and aromatic diamines having a phenoxazine structure (JP-A-7-138562).
Gazette), a diaminophenylphenanthridine derivative (JP-A-7-252474), a hydrazone compound (JP-A-2-311591), a silazane compound (US Pat. No. 4,950,950), a silanamine derivative ( JP-A-6-49079), phosphamine derivatives (JP-A-6-25659), quinacridone compounds and the like. These compounds may be used alone or, if necessary, in combination of two or more.

In addition to the above compounds, the hole transport layer 3
As a material of a, polyvinyl carbazole or polysilane (Appl. Phys. Lett., Vol. 59, 2760)
Page, 1991), Polyphosphazene (Japanese Patent Laid-Open No. 5-3
No. 10949), polyamide (JP-A-5-3109)
No. 49), polyvinyl triphenylamine (Japanese Patent Application Laid-Open No. 7-53953), a polymer having a triphenylamine skeleton (Japanese Patent Application Laid-Open No. 4-133065), and a polymer in which triphenylamine units are linked by a methylene group or the like. (S
Synthetic Metals, 55-57, 41
63, 1993), polyamines containing aromatic amines (J. Polym. Sci., Poly).
m. Chem. Ed. , 21, 969, 1983.
) Can be used.

The hole transport layer 3a is laminated on the anode 2 by forming a film of these hole transport materials by a coating method or a vacuum evaporation method.

In the case of the coating method, one or more hole transporting materials and, if necessary, an additive such as a binder resin or a coatability improving agent which does not become a hole trap are added and dissolved in a solvent. A coating solution is prepared by applying the solution onto the anode 2 by a method such as spin coating and drying to form the organic hole transport layer 3a. In this case, examples of the binder resin include polycarbonate, polyarylate, and polyester. Since a large amount of the binder resin decreases the hole mobility, a small amount is desirable.
It is preferably at most 50% by weight.

On the other hand, in the case of the vacuum vapor deposition method, the hole transport material is placed in a crucible installed in a vacuum container, the interior of the vacuum container is evacuated to about 10 ⁻⁴ Pa by an appropriate vacuum pump, and then the crucible is placed. Is heated to evaporate the hole transporting material, and the hole transporting layer 3a is formed on the anode 2 on the substrate 1 facing the crucible.
To form

When the hole transport layer 3a is formed in this manner, a metal complex and / or metal salt of an aromatic carboxylic acid (JP-A-4-320484), a benzophenone derivative and a thiobenzophenone derivative are further used as acceptors. (Japanese Patent Application Laid-Open No. 5-295361), fullerenes (Japanese Patent Application Laid-Open No. 5-331458) and the like are doped at a concentration of 10 ⁻³ to 10% by weight to generate holes as free carriers, thereby reducing It is possible to enable voltage driving.

The thickness of the hole transport layer 3a is usually 10 to 3
00 nm, preferably 30 to 100 nm. In order to uniformly form such a thin hole transport layer,
Generally, it is preferable to employ a vacuum deposition method.

Further, for the purpose of further improving the hole injection efficiency and improving the adhesion of the entire organic layer to the anode 2,
As shown in FIG. 4, a hole injection layer 3c is also formed between the hole transport layer 3a and the anode 2. As a material used for the hole injection layer 3c, a material having a low ionization potential, high conductivity, and capable of forming a thermally stable thin film on the anode 2 is desirable. A phthalocyanine compound or a porphyrin compound (Japanese Patent Application Laid-Open No. 57-51781, JP-A-63-29569).
By interposing such a hole injection layer 3c, it is possible to obtain the effect of reducing the initial drive voltage of the device and suppressing the voltage rise when the device is continuously driven with a constant current. The conductivity of the hole injection layer 3c can also be improved by doping the acceptor similarly to the hole transport layer 3a.

The thickness of the hole injection layer 3c is usually 2-10.
It is 0 nm, preferably 5 to 50 nm. In order to uniformly form such a thin hole injection layer, it is generally preferable to employ a vacuum evaporation method.

The electron transport layer 3b formed on the hole transport layer 3a is a compound capable of efficiently transporting electrons from the cathode in the direction of the hole transport layer 3a between the electrodes to which an electric field is applied. Composed of.

The electron-transporting compound used in the electron-transporting layer 3b needs to be a compound having a high electron injection efficiency from the cathode 4 and capable of efficiently transporting the injected electrons. For that purpose, it is required that the compound has a high electron affinity, high electron mobility, excellent stability, and hardly generates impurities serving as traps during production or use.

As a material satisfying such a condition, an aromatic compound such as tetraphenyl butadiene (see Japanese Patent Laid-Open No. Sho 5)
7-51781), a metal complex such as an aluminum complex of 8-hydroxyquinoline (JP-A-59-1943).
No. 93), cyclopentadiene derivatives (Japanese Unexamined Patent Publication No.
289675), perinone derivatives (JP-A-2-2)
No. 89676), oxadiazole derivatives (Japanese Patent Application Laid-Open No. 2-216991), and bisstyrylbenzene derivatives (Japanese Patent Application Laid-Open Nos. 1-245087 and 2-222448).
4), perylene derivative (JP-A-2-189890).
JP-A-3-7991), coumarin compounds (JP-A-2-191694 and JP-A-3-792), rare-earth complexes (JP-A-1-256584), and distyrylpyrazine derivatives (JP-A-Heisei 2). 252793)),
p-phenylene compound (JP-A-3-33183), thiadiazolopyridine derivative (JP-A-3-372)
No. 92), pyrrolopyridine derivatives (JP-A-3-37)
293), naphthyridine derivatives (JP-A-3-20
3982) and the like.

Electron transport layer 3b using these compounds
Can generally simultaneously fulfill the role of transporting electrons and the role of providing light emission when holes and electrons recombine.

When the hole transport layer 3a has a light emitting function, the electron transport layer 3b may serve only to transport electrons.

For the purpose of improving the luminous efficiency of the device and changing the luminescent color, for example, a fluorescent dye for laser such as coumarin is doped with an aluminum complex of 8-hydroxyquinoline as a host material (J. Appl. Ph.
ys. 65, 3610, 1989). In the present invention, the above-mentioned organic electron transporting material is used as a host material to dope various fluorescent dyes by 10 ^-3 to 10 mol%. In addition, the light emitting characteristics of the device can be further improved.

The thickness of the electron transport layer 3b is usually 10 to 2
00 nm, preferably 30 to 100 nm.

The electron transport layer can also be formed in the same manner as the hole transport layer, but the vacuum vapor deposition method is usually used.

As the single-layer type organic light emitting layer 3 which does not perform the function separation as shown in FIG.
-Phenylene vinylene) (Nature, 347, 5)
39, 1990 et al.), Poly [2-methoxy-5-
(2-ethylhexyloxy) -1,4-phenylenevinylene] (Appl. Phys. Lett., Vol. 58,
1982, 1991, etc.), poly (3-alkylthiophene) (Jpn. J. Appl. Phys. 30, vol.
L1938, 1991, etc.) or a system in which a light emitting material and an electron transfer material are mixed with a polymer such as polyvinyl carbazole (Applied Physics, vol. 61, p. 1044, 19).
1992).

The cathode 4 plays a role of injecting electrons into the organic light emitting layer 3. As the material used for the cathode 4, the material used for the anode 2 can be used. However, for efficient electron injection, a metal having a low work function is preferable, and tin, magnesium, indium, calcium,
Suitable metals such as aluminum and silver or alloys thereof are preferred. The thickness of the cathode 4 is usually about the same as that of the anode 2.

For the purpose of protecting the cathode made of a low work function metal, the stability of the device can be increased by further laminating a metal layer having a high work function and stable to the atmosphere on the cathode. Metals such as aluminum, silver, nickel, chromium, gold, and platinum are used for the metal layer for this purpose.

2 to 4 show an example of an element body adopted in the present invention, and the present invention is applied to an element body having the following layer constitution other than those shown in the drawings. can do.

Anode / hole transport layer / electron transport layer / interface layer /
Cathode, anode / hole transport layer / electron transport layer / other electron transport layer / cathode, anode / hole transport layer / electron transport layer / other electron transport layer / interface layer / cathode, anode / hole injection layer / Hole transport layer / electron transport layer / interface layer /
Cathode, anode / hole injection layer / hole transport layer / electron transport layer / other electron transport layer / cathode In the above layer structure, the interface layer is for improving the contact between the cathode and the organic layer, and is aromatic. Diamine compounds (JP-A-6-267658), quinacridone compounds (JP-A-6-330031), naphthacene derivatives (JP-A-6-330032), organic silicon compounds (JP-A-6-325871), organic compounds Phosphorus compounds (Japanese Patent Application Laid-Open No. Hei 6-325872) and compounds having an N-phenylcarbazole skeleton (Japanese Patent Application No. Hei 6-199562)
No.), N-vinylcarbazole polymer (Japanese Patent Application No. 6-20)
0942) and the like. The thickness of the interface layer is usually 2 to 100 nm, preferably 5 to 30 n.
m. Instead of providing the interface layer, a region containing 50% by weight or more of the material for the interface layer may be provided near the cathode interface between the organic light emitting layer and the electron transport layer.

The other electron transport layer is further laminated on the electron transport layer in order to further improve the luminous efficiency of the organic electroluminescent device. Is easy to inject electrons from the cathode,
It is required that the ability to transport electrons is further increased. As such an electron transporting material, an oxadiazole derivative (Appl. Phys. Lett., Vol. 55, 1489)
1989, etc.) and a system in which they are dispersed in a resin such as polymethyl methacrylate (PMMA) (Appl. Phys.
s. Lett. 61, 2793, 1992),
Phenanthroline derivatives (JP-A-5-331559), n-type hydrogenated amorphous silicon carbide, n-type zinc sulfide, n-type zinc selenide and the like. The thickness of the other electron transporting layer is usually 5 to 200 nm, preferably 1 to 200 nm.
0-100 nm.

As described above, in order to improve the stability and reliability of the organic electroluminescence device, such a device body is
It is necessary to seal the whole.

In the present invention, the adhesive for the sealing layer satisfies the following conditions (a) and (b), and preferably has a 100% tensile stress of 30 kgf / cm ² defined above.
A two-part curable polyurethane having a moisture permeability of 10 g / m ² or less in 24 hours is used.

(A) 100% tensile stress specified by JIS K6301 is 50 kgf / cm ² or less (b) Moisture vapor transmission rate under condition A specified by JIS Z0208 is 20 g / m ² (200 μm) or less in 24 hours. As a main component, a hydrocarbon-based polyol having good hygroscopicity is used, and an isocyanate compound is NC.
O group / OH group = 0.8 to 1.3, preferably NCO group /
A two-component curing type polyurethane that is mixed and cured at a distribution ratio such that OH groups = 0.9 to 1.1 is preferable.

Polyhydroxypolybutadiene, which is a raw material for the polyol, is a polybutadiene polymer having one or more, preferably 1.8 to 5.0, hydroxy groups in one molecule, and the average molecular weight is usually 500 to 50, 0
00, preferably 1,000 to 20,000. The manufacturing method is not particularly limited, and various known methods can be adopted.

For example, in the polymerization of butadiene, hydrogen peroxide, cyclohexanone peroxide, methyl ethyl ketone peroxide, an azobis compound having a functional group such as β, β'-azobis (β-cyano) -n-
Propanol, δ, δ′-azobis (δ-cyano) -n
-Method of radical polymerization in a solvent such as alcohol, ketone, ester or the like using a radical polymerization initiator containing a hydroxy group such as pentanol, or similar polymerization by a radical polymerization initiator such as aliphatic azodicarboxylic acid or its ester Then, a method of reducing the carboxyl group or the ester portion thereof to obtain polyhydroxypolybutadiene, or the like can be adopted. Alternatively, a method may be used in which anion polymerization is performed using an alkali metal such as sodium or lithium or a complex of an alkali metal and a polycyclic aromatic compound as a catalyst, and then functionalization is performed with alkylene oxide, epichlorohydrin, or the like. Specific examples of the catalyst used for anionic polymerization include lithium naphthalene complex, anthracene complex, lithium complex such as biphenyl complex, 1,4-dialkali metal butane, 1,5-dialkali metal pentane, 1,10-
Dialkali metal decane, 1,4-dialkali metal 1,
Examples include dialkali metal hydrocarbons such as 1,4,4-tetraphenylbutane.

Further, in order to smoothly proceed such anionic polymerization, a hydrocarbon solvent such as hexane, heptane, benzene, toluene, xylene, cyclohexane or the like is used. However, when an alkali metal is used as a catalyst, it is preferable to use the above-mentioned solvent and a Lewis base such as diethyl ether, dipropyl ether, ethylpropyl ether or ethylbutyl ether, which has a relatively low polarity.

Polyhydroxypolybutadiene can be obtained by reacting the living polymer thus obtained with an epoxy compound according to a conventional method and then treating it with a protic acid such as hydrochloric acid, sulfuric acid or acetic acid.

As the epoxy compound used here,
Monoepoxy compounds such as ethylene oxide, propylene oxide, butylene oxide, cyclohexene oxide, styrene oxide, and phenylglycidyl ether; bisphenol-A diglycidyl ether,
Polyepoxy compounds such as vinylcyclohexene diepoxide, butadiene diepoxide, dicyclopentadiene diepoxide, limonene diepoxide, ethylene glycol bisepoxide and the like; haloepoxy compounds such as epichlorohydrin, epifromhydrin and methylepichlorohydrin can be used. More preferred are polyepoxy compounds and haloepoxy compounds.

In the case of the monoepoxy compound, the amount of the epoxy compound used is preferably an equimolar ratio to the polymer, particularly preferably 2 molar ratio or more.

The product obtained by the reaction of the living polymer with the monoepoxy compound has an epoxy compound ring-bonded at both ends of the living polymer, and the hydrogen atom of the ring-opened hydroxy group is substituted with an alkali metal. It is considered that they are bound together in the state of being.

On the other hand, when a polyepoxy compound or a haloepoxy compound is used, the intended use of the polymer,
That is, it is appropriately selected depending on the molecular weight of the polymer and the number of hydroxy groups, but is usually 0.5 with respect to the living polymer.
˜2 molar ratio, preferably 0.6 to 1.7 molar ratio.

After the ring opening of the epoxy by the reaction of this living polymer with a poly or haloepoxy compound, the living polymers are mainly bonded to each other, and several molecules are bonded via the epoxy compound having a hydroxy group substituted with an alkali metal. A polymer is obtained.

Polyhydroxypolybutadiene can also be obtained by a method of reducing a polymer containing oxygen obtained by ozonolysis or other methods from a high molecular weight polybutadiene polymer.

Polyhydroxypolybutadiene is produced by the various methods described above, and the microstructure of the obtained polymer is a polymer having 1,2 bonds and 1,4 bonds in various ratios depending on the production method. Is obtained. For example, the microstructure of polyhydroxypolybutadiene produced by using radical polymerization method is cis-1,4.
5 to 30% bond, 50 to 80 trans-1,4 bond
%, 1,2 bonds are 15 to 30%, and usually a microstructure having many 1,4 bonds. Also in the anionic polymerization method, a polymer having a large number of 1,4 bonds can be obtained by selecting the type of catalyst and solvent used. Polyurethane obtained by curing the hydrogenated product of polyhydroxypolybutadiene having many 1,4 bonds with polyisocyanate has mechanical properties such as tensile strength and elongation as compared with those having many 1,2 bonds. It is excellent in terms of rubber, and its physical properties such as heat deterioration resistance, oxidation resistance, ozone resistance, light resistance and weather resistance are generally better. Therefore, in the present invention, in the microstructure, polyhydroxypolybutadiene having 1,4 bonds more than 1,2 bonds, that is, having 1,4 bonds of 50% or more is preferable.
Particularly, 70% or more is more preferable.

The polyol can be obtained by hydrogenating the double bonds of the main chain and / or the side chains of the polyhydroxypolybutadiene produced in this manner while retaining the hydroxy group by 98% or more with a ruthenium catalyst. .

The ruthenium catalyst is used as a heterogeneous catalyst supported on the metal itself or a carrier, or as a homogeneous catalyst containing a metal as a possible salt. As the carrier, carbon, alumina, silica, silica-alumina,
Diatomaceous earth, barium carbonate, calcium carbonate, etc. are used. In this case, the amount of the above metal supported on the carrier is usually in the range of 0.01 to 50% by weight, preferably 0.2.
１５15% by weight.

Polyhydroxypolybutadiene can be reacted as it is with hydrogen using ruthenium as a catalyst, but a better hydrogenation reaction can be carried out by using a solvent. As this solvent, an aliphatic hydrocarbon, an aromatic hydrocarbon, an alcohol, an ether, or a mixed solvent thereof can be used.

The amount of the ruthenium catalyst used in the hydrogenation varies depending on the type of the catalyst, the hydrogenation type and the like. For example, when the hydrogenation is carried out in a suspension system using a ruthenium catalyst, the ruthenium is added to the polyhydroxypolybutadiene. The ratio is used in the range of 0.01 to 1.00% by weight.

The reaction temperature is preferably 20 ° C to 150 ° C. When the reaction temperature is high, the hydrogenation rate can be increased, but the cleavage of the hydroxy group cannot be ignored, which is not preferable.

The hydrogen used may be used in a normal pressure flow system or at a high pressure, and the hydrogenation reaction may be in any reaction form such as a fixed bed or a suspension system.

Under the above hydrogenation conditions, the main chain and / or side chain double bonds in the polyhydroxypolybutadiene are hydrogenated.

In order to produce polyurethane, it is necessary that the double bonds in the polymer are almost completely hydrogenated, and 98% or more, preferably 99% or more of the double bonds in the polymer before hydrogenation are required. As described above, it is more preferable to use hydrogenated polyhydroxy polybutadiene as a polyol until substantially no double bond remains.

As the polyisocyanate to be reacted with the polyol, any of various ones used in the urethane industry can be used, and examples thereof include tetramethylene diisocyanate, hexamethylene diisocyanate, ethylene diisocyanate, phenylene diisocyanate, tolylene diisocyanate and chlorophenylene. Diisocyanate, diphenylmethane diisocyanate, naphthalene-1,5-diisocyanate, isopropylbenzene-
1,4-diisocyanate and 1,3,6-hexanetriisocyanate are used.

The amount of the isocyanate compound used is preferably about equimolar to the above-mentioned polyol, and the polymerization reaction can be carried out by either one shot method or prepolymer method.

As the reaction accelerator used in the above polycondensation, triethylamine, triethylenediamine,
Tertiary amines such as dimethylaminoethanol and organometallic compounds such as dimethyltin diacetate and dibutyltin dilaurate are preferred.

Another example that satisfies the conditions for the two-part curable polyurethane suitable for the present invention is a polyurethane which contains castor oil-based polyol as a main component and is cured under the same conditions as the above hydrocarbon-based polyol. .

It is also possible to replace a part of the above-mentioned hydrocarbon-based or castor oil-based polyol with another polyester-based or polyether-based polyol. in this case,
The substitution ratio is preferably 0 to 49% of the total polyol.
If it exceeds this range, the non-hygroscopic property, which is a characteristic of hydrocarbons or castor oil-based polyols, may be impaired.

In consideration of workability and safety, the above isocyanate compound is preferably used in the form of a prepolymer which is previously reacted with a part of the polyol.

If necessary, various plasticizers may be used in combination,
The viscosity of the adhesive before curing and the hardness after curing can be adjusted.

In the present invention, in order to further enhance the effect as the sealing layer, one or more kinds of hygroscopic agents such as silica gel, zeolite, calcium chloride, activated carbon, nylon and polyvinyl alcohol are used as the above-mentioned adhesive. It can be mixed with the agent. In this case, the content of the hygroscopic agent is preferably in the range of 10 to 50% by weight.

In the present invention, when the sealing layer 6 is provided, the stress applied to the cathode 4 is relaxed, and the reaction between the chemical component of the adhesive used for the sealing layer 6 and the element body is suppressed. It is necessary to provide the protective layer 5 between the cathode 4 and the sealing layer 6 for the purpose of preventing damage to the element body. The material of the protective layer 5 may be an inorganic material or an organic material as long as it is a material that has electrical insulation properties, a stable film shape, and does not damage the device. Specific examples of the material of the protective layer 5 include metal oxides (JP-A-4-212284, JP-A-4-73886, JP-A-5-335080) and metal fluorides (JP-A-4-212804). 212284), metal sulfides (JP-A-4-212284), metal nitrides (JP-A-4-73886),
Polymer materials (JP-A-4-137483, JP-A-4-13483)
-206386, JP-A-4-233192, JP-A-4-267097, JP-A-4-355.
096), plasma polymerized film (JP-A-5-1018).
No. 86), organic silicon compounds, organic compositions of organic electroluminescent devices, and the like, but are not limited thereto.

In the present invention, the protective layer 5 is provided on the cathode 4 of the organic electroluminescence device body, and after the sealing layer 6 is provided, the outside air blocking material layer 7 for shielding the device body from the outside air.
Is bonded to the substrate 1 by using an appropriate adhesive 8.

The outside air barrier layer 1 is required to have a gas barrier property like the substrate 1. Therefore, an electrically insulating glass plate or an electrically insulating resin plate or film provided with a dense silicon oxide film or the like is usually used.

The adhesive 8 may have any gas barrier property, and examples thereof include an epoxy adhesive, an acrylic adhesive, a polyurethane adhesive, and a modified silicone elastic adhesive.

In the present invention, the thickness of the protective layer 5 is usually 50 nm to 10 μm, preferably 100 nm to 1 μm.
m.

The thickness of the sealing layer 6 is not particularly limited, but is usually 1 μm to 2 mm, and the thickness of the outside air blocking material layer 7 is not particularly limited, but is usually 10 μm to 5 mm.

When applying such a sealing method to actual device fabrication, the device may be short-circuited. This is because, for example, when a void defect in the organic light emitting layer 3 or a defect due to dust during production exists, the cathode 4 near the defect is depressed into the void space by the force from the sealing layer 6, and as a result, the cathode 4 and the anode 2 are short-circuited. However, when the film thickness of the cathode 4 is smaller than the film thickness of the organic light emitting layer 3, the cathode 4 breaks when it is depressed and a short circuit does not occur.
Therefore, the film thickness of the cathode 4 is preferably thinner than that of the organic light emitting layer 3. This short circuit phenomenon is also related to the surface roughness of the anode 2, and if the anode 2 has a ridge-valley undulation, for example, on the slope of the mountain of the anode 2, the organic light emitting layer 3 is perpendicular to the substrate 1. However, when viewed in a direction perpendicular to the slope of the mountain of the anode 2, the film thickness of the organic light emitting layer 3 actually decreases by the inclination of the slope. From this, it is desirable that the surface roughness of the anode 2 is suppressed to about the surface roughness of the substrate 1, and the 10-point average roughness Rz (defined by JIS) is preferably 10 nm or less.

The organic electroluminescent device of the present invention is applicable to a single device, a device having an arrayed structure, and a device having an anode and a cathode arranged in an XY matrix. be able to.

[0090]

EXAMPLES Next, the present invention will be described more specifically by way of examples, but the present invention is not limited to the description of the following examples unless it exceeds the gist.

Example 1 Preparation of Component A 100 g of "Polytail HA" (polyolefin polyol having a number average molecular weight of about 2,000 and a hydroxyl equivalent of 0.907 meq / g) manufactured by Mitsubishi Chemical Corporation, "Adecaquadrol" (Asahi Denka Co., Ltd.) Tetrafunctional polyol, hydroxyl equivalent 13.
7 meq / g) 19.8 g, paraffinic process oil "P-200" (manufactured by Kyodo Oil Co., Ltd.) 110 g, and M
D Chemical Co., Ltd. "UL-22" (tin-based urethane conversion catalyst) 1
Component A was obtained by uniformly mixing 38 mg at 50 ° C. The viscosity of component A was 1800 cps at 25 ° C.

Preparation of Component B 100 g of "Polytel HA" and 116 g of paraffinic process oil "P-200" were uniformly mixed in a separable flask at room temperature. Then, 14.2 g of 2,4-tolylene diisocyanate was added and reacted at 80 ° C. for 6 hours to obtain a component B. The viscosity of component B is 38 at 25 ° C.
00 cps.

Measurement of Physical Properties of Adhesive for Sealing Layer Component A liquid and component B liquid thus prepared were mixed at a weight ratio of 5: 1, vacuum defoamed and then molded at 100 ° C. for 1 hour. Then, a press sheet was obtained.

The mechanical properties of this sheet are measured according to JIS K63.
When measured according to 01, 100% tensile stress 3 kg
The tensile strength was f / cm ² and the tensile strength was 7 kgf / cm ² . Further, the water vapor transmission rate under the condition A defined by JIS Z0208 was 5 g / cm ² in a film having a thickness of 200 μm in 24 hours.

Preparation of Organic Electroluminescent Device First, an organic electroluminescent device body having the structure shown in FIG. 4 was prepared by the following method.

A transparent conductive film of indium tin oxide (ITO) deposited to a thickness of 120 nm on a glass substrate (electron beam film-forming product manufactured by Geomatec; sheet resistance 15)
Ω) was used as the anode substrate. This is a ten-point average roughness Rz (JIS B060) of the ITO surface measured by a stylus-type surface roughness meter (“Taristep” manufactured by Rank Taylor Hobson).
When 1) was measured, it was 7.4 nm. This ITO
The glass substrate was patterned into a 2 mm wide stripe by using a normal photolithography technique and hydrochloric acid etching to form an anode.

The patterned ITO substrate was cleaned in the order of ultrasonic cleaning with acetone, water cleaning with pure water and ultrasonic cleaning with isopropyl alcohol, followed by drying with nitrogen blow, and finally ultraviolet ozone cleaning and vacuum deposition. Installed in the device. After rough exhaust of the apparatus is performed by an oil rotary pump, the degree of vacuum in the apparatus is 2 × 10 ⁻⁶ Torr (about ^2.10 Torr).
It was evacuated using an oil diffusion pump equipped with a liquid nitrogen trap until the pressure became 7 × 10 ⁻⁴ Pa) or less.

Copper phthalocyanine (H1) shown below (having a crystalline form of β type) placed in a molybdenum boat arranged in the above apparatus was heated for vapor deposition. The steam has a degree of vacuum of 1.
The deposition was performed at 1 × 10 ⁻⁶ torr (about 1.5 × 10 ⁻⁴ Pa) for 1 minute to form a hole injection layer 3c having a thickness of 20 nm.

[0099]

Embedded image

Next, the following 4,4'-bis [N- (1 was placed in a ceramic crucible placed in the above apparatus.
-Naphthyl) -N-phenylamino] bisphenol (H2) was laminated on the hole injection layer 3c by heating with a tantalum wire heater around the crucible. At this time, the temperature of the crucible was controlled in the range of 230 to 240 ° C. The hole transport layer 3a having a thickness of 60 nm was formed with a degree of vacuum of 8 × 10 ⁻⁷ Torr (about 1.1 × 10 ⁻⁴ Pa) during the deposition and a deposition time of 1 minute and 50 seconds.

[0101]

Embedded image

Subsequently, the electron transport layer 3 having a light emitting function.
As the material of b, the following aluminum 8-hydroxyquinoline complex: Al (C ₉ H ₆ NO) ₃ (E1) was similarly vapor-deposited on the hole transport layer 3a. The temperature of the crucible at this time was controlled in the range of 310 to 320 ° C.
The degree of vacuum during vapor deposition is 9 × 10 ⁻⁷ Torr (about 1.2 × 10 Torr).
^-4 Pa), a vapor deposition time of 2 minutes and 40 seconds, and a 75 nm-thick electron transport layer 3b was formed.

[0103]

Embedded image

The substrate temperature during vacuum deposition of the hole injection layer 3c, the hole transport layer 3a and the electron transport layer 3b was kept at room temperature.

The substrate on which the hole injecting layer 3c, the hole transporting layer 3a and the electron transporting layer 3b are formed is once taken out from the vacuum vapor deposition apparatus into the atmosphere and 2 m is used as a mask for cathode vapor deposition.
An m-width striped shadow mask is applied to the anode 2 ITO
It is provided in close contact with the stripe so as to be perpendicular to the stripe, and is installed in another vacuum evaporation apparatus, and the degree of vacuum in the apparatus is set to 2 × 10 ⁻⁶ Torr (about 2.7 × 10 ^-Four
Pa). Subsequently, as a cathode 4, an alloy electrode of magnesium and silver was deposited to a thickness of 100 nm by a binary simultaneous deposition method. The vapor deposition was performed using a molybdenum boat at a vacuum degree of 1 × 10 ⁻⁵ Torr (about 1.3 × 10 ⁻³ Pa) and a vapor deposition time of 3 minutes and 10 seconds.
The atomic ratio of magnesium to silver was 10: 1.2. Subsequently, without breaking the vacuum of the apparatus, a cathode 4 was completed by laminating aluminum with a thickness of 100 nm on the magnesium-silver alloy film using a molybdenum boat. The degree of vacuum during aluminum deposition is 2.3 × 10 ^-5 To
rr (about 3.1 × 10 ⁻³ Pa), and the deposition time was 1 minute and 40 seconds. The substrate temperature at the time of vapor deposition of the two-layered cathode of magnesium / silver alloy and aluminum was kept at room temperature.

In this way, an organic electroluminescent element body having a size of 2 mm × 2 mm was obtained. After taking out this element from the vapor deposition apparatus, sealing was performed with the structure shown in FIG.

First, after the above-mentioned device body was installed again in the above-mentioned organic layer vapor deposition apparatus, the compound (E1) was laminated on the cathode 4 to a film thickness of 200 nm in the same manner as in the above-mentioned method to form a protective layer. It was set to 5. The vacuum degree at this time is 1.5 × 10 ^-6 Tor
r (about 2.0 × 10 ⁻⁴ Pa), vapor deposition time is 3 minutes and 50 seconds,
The substrate temperature was room temperature.

Next, the device was taken out of the above apparatus into the atmosphere, put in a nitrogen glove box, and the following work was performed.

That is, the component A liquid and the component B liquid were mixed at a weight ratio of 1: 5, and about 30% by weight of the total weight of silica gel powder (particle size 50 to 300 μm) was added as a filler, followed by protection. Coated on layer 5 with a thickness of about 1 mm. This was cured at room temperature for 1 hour to form a sealing layer 5.

Then, the thickness of the outside air barrier layer 7 is 1.1.
A mm glass plate was attached to the adhesive portion 8 using an epoxy resin (manufactured by Ciba-Geigy, trade name "Araldite") to complete the sealing of the element.

Evaluation of Characteristics of Organic Electroluminescent Device The organic electroluminescent device thus obtained was stored in the atmosphere at room temperature, and a positive DC voltage was applied to the anode 2 and a negative DC voltage was applied to the cathode 4 to emit light. The emission characteristics and the change with time in the generation of dark spots were measured. For the measurement of the dark spot, the light emitting surface of the device was photographed by a CCD camera and then binarized by image analysis for quantification.

FIG. 5 shows the change with time in the emission luminance when a voltage of 5 V was applied to the element. As is clear from FIG.
Even after 0 days storage in the air, the emission brightness is 495c, which is the initial brightness.
It was 432 cd / m ² with respect to d / m ² , showing almost no decrease.
Also, the dark spot is 1% of the total light emitting area even after 30 days.
Was less than.

Example 2 100 g of "Polytail HA" used in Example 1 and 10 g of "SANNIX TP-400" (trifunctional polyol manufactured by Sanyo Kasei Co., Ltd., hydroxyl equivalent 6.93 meq / g) were uniformly mixed at 50 ° C. Then, component A ′ was obtained.

As the component B ', the liquid modified MDI "Is
onate143L ”(manufactured by MD Kasei Co., NCO equivalent 6.
92 meq / g) was used as is.

The component A'solution and the component B'solution were mixed in a weight ratio of 4:
It was mixed in 1, to prepare a press sheet in the same manner as in Example 1 was measured similarly to the properties, 100% tensile stress 28 kgf / cm ^2, tensile strength was 60 kgf / cm ^2, the moisture permeability 7g / M ² .

A device was prepared in the same manner as in Example 1 except that the mixed solution of the above component A ′ liquid and the component B ′ liquid was used as the material for the sealing layer, and the dark spot of the obtained device was obtained. When the generation state was examined, the generation of dark spots was less than 1% of the total light emitting area even after 30 days of storage in the atmosphere.

Comparative Example 1 An element was manufactured in the same manner as in Example 1 except that an epoxy resin (manufactured by Ciba-Geigy, trade name “Araldite”) was used as the material of the sealing layer 6. The epoxy resin did not show rubber-like elasticity. The physical properties of this epoxy resin were measured in the same manner as in Example 1 and found to be 1
The 00% tensile stress was about 180 kgf / cm ² , and the water vapor transmission rate was 16 g / m ² .

FIG. 5 shows the change with time in the emission luminance when a direct current of 8 V was applied to the obtained device. As is clear from FIG. 5, the emission luminance is 2 times the initial luminance after 30 days of storage in the atmosphere.
It was halved to 142 cd / m ^{2 with} respect to 82 cd / m ² .
Also, the dark spot is 25 of the total light emitting area after 30 days.
% Has been reached.

Comparative Example 2 Same as Example 1 except that a material for the sealing layer 6 was a mixture of silica gel powder in silicone oil (trade name “KF-54” manufactured by Shin-Etsu Silicone Co., Ltd.). Then, an element was manufactured.

When the obtained device was stored in the atmosphere, 14 days later, the dark spot showed 50% of the total light emitting area.
Reached.

[0121]

According to the organic electroluminescent device and the method for manufacturing the same of the present invention, by encapsulating with an adhesive having specific physical properties, generation of dark spots during storage or driving in the atmosphere is suppressed. Thus, it is possible to obtain an organic electroluminescent device that exhibits stable emission characteristics over a long period of time.

Therefore, the organic electroluminescent device according to the present invention is a light source (for example, a light source of a copying machine, a performance display or an instrument) which makes the best use of the characteristics of a flat panel display (for OA computer or wall-mounted television, for example) or a surface light emitter. It is expected to be applied to various types of backlight sources, display boards, and marker lights, and its technical value is extremely large.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing one embodiment of the organic electroluminescent device of the present invention.

FIG. 2 is a schematic cross-sectional view showing one embodiment of the element body according to the present invention.

FIG. 3 is a schematic cross-sectional view showing another embodiment of the element body according to the present invention.

FIG. 4 is a schematic cross-sectional view showing another embodiment of the element body according to the present invention.

FIG. 5 is a graph showing changes over time in the emission brightness (initial brightness is 1) of the organic electroluminescent devices of Example 2 and Comparative Example 1 when stored in the atmosphere.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Anode 3 Organic light emitting layer 4 Cathode 3a Hole transport layer 3b Electron transport layer 3c Hole injection layer 5 Protective layer 6 Sealing layer 7 Outside air blocking layer 8 Adhesive part 10, 10A, 10B Element body

Claims (8)

[Claims] 1. An organic material in which at least an anode, an organic light emitting layer and a cathode are laminated on a substrate, and a protective layer, a sealing layer and an outside air blocking material layer are sequentially formed from the inside on the outer surface of the laminate. An organic electroluminescent device, wherein the sealing layer is mainly composed of an adhesive satisfying the following conditions (a) and (b). (A) 100% tensile stress specified by JIS K6301 is 50 kgf / cm ² or less (b) Water vapor permeability under condition A specified by JIS Z0208 is 20 g / m ² (200 μm) or less in 24 hours. 2. The organic electroluminescent device according to claim 1, wherein the adhesive is made of polyurethane containing hydrocarbon polyol as a main component. 3. The organic electroluminescent device according to claim 1, wherein the adhesive is made of polyurethane containing castor oil-based polyol as a main component. 4. The silica gel, zeolite,
4. The organic electroluminescent element according to claim 1, which contains one or more kinds of hygroscopic agents selected from the group consisting of calcium chloride, activated carbon, nylon and polyvinyl alcohol. 5. The organic electroluminescent device according to claim 1, wherein the outside air blocking material layer is made of electrically insulating glass or electrically insulating polymer. 6. The organic electroluminescent device according to claim 1, wherein a film thickness of the cathode is smaller than a film thickness of the organic light emitting layer. 7. The organic electroluminescence device according to claim 1, wherein the anode is made of indium tin oxide and has a surface roughness of 10 nm or less. 8. An adhesive agent, wherein at least an anode, an organic light emitting layer and a cathode are laminated on a substrate, and a protective layer is formed on the outer surface of the laminate, and then the conditions (a) and (b) below are satisfied. 8. An organic electroluminescent element according to claim 1, wherein a sealing layer containing as a main component is formed, and then an outside air blocking material layer is formed outside the sealing layer. Production method. (A) 100% tensile stress specified by JIS K6301 is 50 kgf / cm ² or less (b) Water vapor permeability under condition A specified by JIS Z0208 is 20 g / m ² (200 μm) or less in 24 hours.