JPH11214152A - Organic el element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic EL element which can suppress deterioration over aging as much as possible, can maintain the initial performance for a long time, and has a long service life. SOLUTION: This organic EL element has a substrate 1, an organic EL structural body 2 accumulated on the substrate 1, a sealing plate 3 arranged on the organic EL structural body 2 across a predetermined clearance, and adhesive for sealing 5 which fixes the sealing plate 3 on the substrate 1 and seals the organic EL structural body 2. The adhesive for sealing 5 is photo- curing adhesive, and 25 μg/g or less of propylene carbonate, 15 μg/g or less of propylene glycol, and 20 μg/g or less of toluene are generated by in terms of benzene among gases generated by heating conditions of 85 deg.C for 60 minutes after light hardening.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic EL device using an organic compound, and more particularly, to an adhesive for fixing a sealing plate for protecting an organic EL structure laminated on a substrate. Regarding improvement.

[0002]

2. Description of the Related Art In recent years, organic EL devices have been actively studied. This involves depositing a hole transporting material such as triphenyldiamine (TPD) on a hole injecting electrode to form a thin film, further laminating a fluorescent substance such as an aluminum quinolinol complex (Alq ₃ ) as a light emitting layer, and further forming a work function such as Mg. It is an element that has a basic structure in which a small metal electrode (electron injection electrode) is formed, and is attracting attention because it can obtain an extremely high luminance of several hundreds to several 10,000 cd / m ² at a voltage of about 10 V.

Incidentally, the organic EL element has a problem that it is extremely weak to moisture. For example, due to the effect of moisture,
There is a problem in that separation occurs between the light emitting layer and the electrode layer, or a constituent material is altered, a non-light emitting region called a dark spot is generated, or light emission cannot be maintained. .

[0004] As one method for solving this problem,
For example, JP-A-5-36475 and JP-A-5-8995
No. 9, No. 7-169567, etc., an airtight case covering the organic EL laminated structure portion,
2. Description of the Related Art There is known a technique in which a sealing layer or the like is tightly fixed on a substrate to shut off the outside.

However, even if such a sealing layer or the like is provided, the light emission luminance is reduced with the elapse of the driving time, dark spots are generated, or these spots are enlarged, and the element is deteriorated. There was a problem that it could not be used.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a long-life organic EL device capable of minimizing deterioration over time and maintaining its initial performance for a long period of time.

[0007]

Means for Solving the Problems The present inventors have proposed an organic EL device.
As a result of various studies on the factors that cause deterioration of the device, it was found that one of the causes is that gas generated from the sealing adhesive reacts with each structural film of the organic EL device, thereby deteriorating the device. I arrived.

That is, the above object is achieved by the following constitution. (1) A substrate, an organic EL structure laminated on the substrate, a sealing plate arranged with a predetermined gap on the organic EL structure, and fixing the sealing plate on the substrate. Together with a sealing adhesive for sealing the organic EL structure,
The sealing adhesive is a photo-curing adhesive, and among the gas generated under heating conditions of 85 ° C. and 60 minutes after photo-curing, propylene carbonate: 25 μg / g or less in terms of benzene, propylene glycol : 15 μg / g or less, toluene: 20 μg / g or less. (2) The organic EL device according to (1), wherein the gas contains iodobenzene in an amount of 1 μg / g or more. (3) The organic EL device according to (1) or (2), wherein the adhesive is a cationic polymerization epoxy UV-curable adhesive. (4) A substrate, an organic EL structure laminated on the substrate, a sealing plate arranged at a predetermined gap on the organic EL structure, and fixing the sealing plate on the substrate. Together with a sealing adhesive for sealing the organic EL structure,
The sealing adhesive is a light-curing adhesive, and may be a low-molecular-weight linear aliphatic carbon which may be substituted among gases generated under heating conditions of 85 ° C. and 60 minutes after light curing. The total of hydrogen, an optionally substituted aromatic hydrocarbon, an optionally substituted alicyclic hydrocarbon, an optionally substituted heterocyclic compound and siloxane is 2 in terms of benzene.
Propylene carbonate: 25 μg / g in terms of benzene.
Hereinafter, an organic EL device in which propylene glycol is 15 μg / g or less and toluene is 20 μg / g or less. (5) The organic EL device according to (4), wherein the gas contains iodobenzene in an amount of 1 μg / g or more. (6) The organic EL device according to (4) or (5), wherein the adhesive is a cationic polymerization epoxy UV-curable adhesive.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An organic EL device according to the present invention comprises a substrate, an organic EL structure laminated on the substrate, and a sealing plate disposed on the organic EL structure with a predetermined gap. And fixing the sealing plate on a substrate and the organic EL.
A sealing adhesive for hermetically sealing the structure, wherein the sealing adhesive is a photocurable adhesive,
Of the gas generated under heating conditions of 60 minutes, propylene carbonate: 25 μg / g or less in terms of benzene;
Propylene glycol: 15 μg / g or less, toluene:
It is 20 μg / g or less.

[0010] In addition, a low-molecular-weight linear aliphatic hydrocarbon which may be substituted, an aromatic hydrocarbon which may be substituted, an alicyclic hydrocarbon which may be substituted, The total of the optionally substituted heterocyclic compound and siloxane is preferably 200 μg / g or less in terms of benzene.

As described above, by suppressing the amount of gas generated from the sealing adhesive to a predetermined value or less, it is possible to prevent the organic EL structure from being attacked by gas and deteriorated.

The gas generated from the sealing adhesive includes:
It is roughly classified into gas generated before curing and gas generated after curing. In the present invention, the ratio of the gas mainly contributing to the deterioration of the organic EL element is high.
The gas generated after curing is a problem. The gas generated after curing varies depending on the type of resin or catalyst used, and is not particularly limited.For example, propylene carbonate, acetone, acrolein, has a low molecular substituent such as dichloromethane. May be substituted linear aliphatic hydrocarbons, benzene, iodobenzene, benzaldehyde, acetophenone, methylphenyl sulfide, aromatic hydrocarbons which may have a substituent such as benzoyl chloride, a substituent such as cyclohexanone. Examples include alicyclic hydrocarbons which may be possessed, heterocyclic compounds which may have a substituent such as γ-butyrolactone, and siloxanes such as cyclic dimethylsiloxane.
It is considered that these gases are mainly generated by a polymerization reaction and are derived from a catalyst or the like.

The amount of gas to be measured is determined as a measured amount per unit gram of the sample. In this case, various gases are converted to benzene in an amount of not more than 25 μg / g, preferably 10 μg, of propylene carbonate per unit gram of the sample.
/ G or less, propylene glycol is 15 μg / g or less,
Preferably, an adhesive having a concentration of 8 μg / g or less, toluene: 20 μg / g or less, and preferably 10 μg / g or less is used. These lower limits are preferably lower than the detection limit. Preferably, these gases are adhesives containing iodobenzene of 1 μg / g or more, more preferably 5 to 70 μg / g. If propylene carbonate, propylene glycol and toluene exceed the above range, they react with the respective structural films of the organic EL device, erode or inhibit their functions, and cause deterioration of the device such as dark spots. Or degrade the light emission characteristics. In addition, iodobenzene is considered to be derived from the reaction initiator. Further, among the generated gases, propylene carbonate, propylene glycol,
If the amount of toluene and iodobenzene in terms of benzene is within the above range, the amount may exceed the total amount.
In particular, there is no problem if the total amount is exceeded by adding the amount of iodobenzene generated.

More preferably, among the above-mentioned gas components, a low-molecular-weight linear aliphatic hydrocarbon which may be substituted, an aromatic hydrocarbon which may be substituted, and a fat which may be substituted. The total amount of the cyclic hydrocarbon, the optionally substituted heterocyclic compound and the siloxane is preferably not more than 200 μg / g, more preferably not more than 150 μg / g, especially not more than 100 μg / g in terms of benzene. The lower limit is not particularly limited and may be 0 μg / g, but is usually about 50 μg / g. Here, the benzene conversion amount is a benzene conversion value in the quantitative analysis, for example, a value obtained by converting a benzene used as a standard sample into a calibration curve in the quantitative analysis.

The method for qualitatively and quantitatively determining the generated gas is not particularly limited, and the qualitative and qualitative methods of ordinary gas can be used.
A quantitative method may be used, and examples thereof include gas chromatography and the like, and particularly preferred is head space, gas chromatogram, and mass spectrometry. In addition, in order to perform acceleration evaluation of the generated gas, in the present invention, the amount of gas generated when the gas is held at 85 ° C. for 60 minutes is measured.

The sealing adhesive used in the present invention is a photo-curing adhesive and is not particularly limited as long as the amount of each gas generated is within the above range. Adhesives using resins such as acrylates, urethane acrylates, epoxy acrylates, melamine acrylates, acrylic resin acrylates, resins such as urethane polyesters, cationic adhesives using resins such as epoxy, vinyl ether, thiol / ene addition And the like. Among them, a cationic adhesive which is not inhibited by oxygen and in which the polymerization reaction proceeds even after light irradiation is preferable.

As the cationic adhesive, a cationic curing type ultraviolet curing epoxy resin adhesive is preferable.
The glass transition temperature of each organic layer constituting material of the organic EL structure portion is usually 140 ° C. or lower, particularly about 80 to 100 ° C. Therefore, when a normal thermosetting adhesive is used, the curing temperature is about 140 to 180 ° C., and the organic EL structure is softened during the curing, and the characteristics are deteriorated. There's a problem. On the other hand, in the case of an ultraviolet-curable adhesive, such a problem as softening of the organic EL structure does not occur, but an ultraviolet-curable adhesive generally used at present is of an acrylic type. In addition, there is a problem that the acrylic monomer in the component volatilizes, which adversely affects each constituent material of the organic EL structure and deteriorates its characteristics. Therefore, in the present invention, it is preferable to use the above-mentioned cationically-curable ultraviolet-curable epoxy resin adhesive, which does not have the above-described problems or is an extremely small amount of adhesive.

In some cases, an ultraviolet-curable epoxy resin adhesive is commercially available as an ultraviolet-curable epoxy resin adhesive. In this case, a radical-curable acrylic resin is used. In many cases, the epoxy resin of the heat-curable type is mixed or denatured, and the problem of volatilization of the acrylic monomer of the acrylic resin and the problem of the curing temperature of the thermosetting epoxy resin have not been solved. It is not preferable as an adhesive used for the organic EL display of the present invention.

The cationically curable UV-curable epoxy resin adhesive includes a Lewis acid salt type curing agent which releases a Lewis acid catalyst by photolysis by irradiation with light such as ultraviolet rays as a main curing agent, and is generated by light irradiation. This type of adhesive is a type in which an epoxy resin, which is a main component, is polymerized by a cationic polymerization type reaction mechanism by using a Lewis acid as a catalyst and cured.

The epoxy resin which is the main component of the adhesive includes an epoxidized olefin resin, an alicyclic epoxy resin and a novolak epoxy resin. Further, as the curing agent, Lewis acid salt of aromatic diazonium,
Examples thereof include Lewis acid salts of diallyliodonium, Lewis acid salts of triallylsulfonium, Lewis acid salts of triallyl selenium, and the like. Of these, Lewis acid salts of diallyliodonium are preferred.

The amount of the adhesive to be applied depends on the size of the laminated organic EL structure and the type and structure of the display constituted by the organic EL elements.
10 ^{−2 to} 2 × 10 ⁻⁴ g / cm ² , especially 9 × 10 ⁻³ to 2 × 1
It is preferably about 0 ^-4 g / cm ² . In addition, the thickness of the adhesive layer is usually a thickness at which a predetermined gap can be secured at the height of the arrangement position of the sealing plate, that is, the thickness of the stacked organic EL structure, and is not particularly limited. Is usually 5 × 10 ⁵ to 1 × 10 ³ nm, especially 2 × 10 ⁴ to 2 × 10
It is about ³ nm.

Next, the method for evaluating the sealing adhesive used in the present invention will be described more specifically. In the present invention,
This is to prevent the gas generated from the adhesive from affecting the organic EL structure, and the method for evaluating the adhesive should be the same as or similar to that used when actually used for an organic EL display. Is preferred.

Therefore, for example, a substrate and a glass plate corresponding to a sealing plate are prepared, a predetermined amount of an uncured adhesive is applied to one of them, and a predetermined pressure is applied while the two glass plates are rubbed together. Press to form a thin layer of adhesive between the glass plates.
At this time, a spacer of a predetermined size is interposed so as to secure the thickness of the organic EL structure and a predetermined gap. Thereafter, the adhesive is cured using a curing lamp such as a metal halide lamp. After curing, the glass plates are peeled from each other to expose the adhesive, a predetermined amount of the adhesive on the glass substrate is taken out, accurately weighed, placed in an analysis vial, etc., and used as a sample for measurement. The generated gas may be analyzed.

Next, the organic EL device of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic sectional view showing an example of the configuration of the organic EL device of the present invention. In the figure, an organic EL device according to the present invention comprises an organic EL structure 2 on a substrate 1, a sealing plate 3 arranged on the organic EL structure 2 so as to have a predetermined gap, An organic EL is fixed to a granular or fiber-shaped spacer 4 which is arranged at a connection portion of the plate 3 and maintains the sealing plate 3 at a predetermined distance from the substrate 1, and the sealing plate.
It has a sealing adhesive 5 for sealing the structure. As shown in the illustrated example, the distance from the upper end of the organic EL element structure to the lower end surface of the sealing plate is a distance having a predetermined gap a at the height c of the organic EL structure.

Next, the organic EL structure constituting the organic EL device of the present invention will be described. The organic EL structure of the present invention has a hole injection electrode, an electron injection electrode, and one or more organic layers provided between these electrodes on a substrate.
The organic layer may have at least one hole transport layer and at least one light emitting layer, an electron injection electrode thereon, and a protective electrode as the uppermost layer. Note that the hole transport layer can be omitted. The electron injection electrode is made of a metal, a compound or an alloy having a small work function, which is preferably formed by vapor deposition, sputtering, or the like, preferably by sputtering.

The hole injecting electrode usually has a structure in which light emitted from the substrate side is taken out. Therefore, a transparent electrode is preferable, and ITO (tin-doped indium oxide), IZO
(Zinc-doped indium oxide), ZnO, SnO ₂ , I
Examples include n ₂ O ₃ , and preferably ITO (tin-doped indium oxide) and IZO (zinc-doped indium oxide). The mixing ratio of SnO ₂ with respect to In ₂ O ₃ is preferably 1 to 20 wt%, more preferably 5~12wt%. The mixing ratio of ZnO to In ₂ O ₃ is 1-2.
It is preferably 0 wt%, more preferably 5 to 12 wt%, or particularly preferably 12 to 32 wt%. In addition, Sn, Ti, P
b and the like may be contained in the form of an oxide in an amount of 1 wt% or less in terms of oxide.

The hole injection electrode can be formed by a vapor deposition method or the like, but is preferably formed by a sputtering method. When a sputtering method is used for forming the ITO or IZO electrode, a target in which Sn ₂ or ZnO is doped into In ₂ O ₃ is preferably used. IT by sputtering method
When the O-transparent electrode is formed, the change in emission luminance with time is less than that of the film formed by vapor deposition. The sputtering method is D
C sputtering is preferred, and the input power is preferably in the range of 0.1 to 10 W / cm ² , particularly 0.2 to 5 W / cm ² . Further, the film formation rate is preferably in the range of 2 to 100 nm / min, particularly preferably in the range of 5 to 50 nm / min.

The sputtering gas is not particularly limited, and an inert gas such as Ar, He, Ne, Kr, Xe, or a mixed gas thereof may be used. As the pressure at the time of sputtering such a sputtering gas,
Usually, it may be about 0.1 to 20 Pa.

The thickness of the hole injecting electrode may be at least a certain value for sufficiently injecting holes.
0 nm, preferably in the range of 10 to 300 nm.

As a constituent material of the electron injection electrode to be formed, a material having a low work function for effectively injecting electrons is preferable. For example, K, Li, Na, Mg, La, Ce, C
a, Sr, Ba, Al, Ag, In, Sn, Zn, Z
r, Cs, Er, Eu, Ga, Hf, Nd, Rb, S
Metal element simple substance such as c, Sm, Ta, Y, Yb, or BaO, BaS, CaO, HfC, LaB ₆ , Mg
O, MoC, NbC, PbS, SrO, TaC, Th
C, ThO ₂ , ThS, TiC, TiN, UC, UN,
It is preferable to use compounds such as UO ₂ , W ₂ C, Y ₂ O ₃ , ZrC, ZrN, and ZrO ₂ . Alternatively, in order to improve stability, it is preferable to use a two-component or three-component alloy system containing a metal element. As an alloy system, for example, AgMg (A
g: 1 to 20 at%), Al.Ca (Ca: 0.01 to 2)
0 at%, particularly 5 to 20 at%), Al.In (In: 1 to 1)
10 at%), Al.Li (Li: 0.1 to less than 20 at%, especially 0.3 to 14 at%), Al.R [R is Y, Sc
Aluminum alloys such as
n.Mg (Mg: 50 to 80 at%) and the like are preferable. Among these, in particular, Al alone or Al.Li (Li: 0.4
~ 6.5 (but not including 6.5) at%) or (L
i: 6.5 to 14 at%) or (Li: 0.01 to 12)
at%), Al.R (R: 0.1 to 25, especially 0.5 to 2)
Aluminum alloys such as 0 at%) are preferable because they do not easily generate compressive stress. Therefore, such a metal or alloy constituting an electron injection electrode is usually used as a sputter target. These work functions are 4.5 eV or less, and metals and alloys having a work function of 4.0 eV or less are particularly preferable.

By using a sputtering method for forming the electron injection electrode, the formed electron injection electrode film has relatively higher kinetic energy in the sputtered atoms and atomic groups than in the case of vapor deposition. Therefore, the surface migration effect works and the adhesion at the organic layer interface is improved. In addition, by performing pre-sputtering, a surface oxide layer can be removed in a vacuum, or moisture and oxygen adsorbed at the organic layer interface can be removed by reverse sputtering, so that a clean electrode-organic layer interface and electrodes can be formed. As a result, high-quality and stable organic EL
Display is possible. As the target, an alloy having the above composition range or a metal alone may be used, and in addition to these, a target of an additional component may be used. Further, even when a mixture of materials having greatly different vapor pressures is used as a target, there is little deviation in composition between a film to be formed and the target, and there is no limitation on a material to be used due to vapor pressure or the like as in a vapor deposition method. Also,
Compared with the vapor deposition method, there is no need to supply a material for a long time, the film thickness and the film quality are excellent in uniformity, and it is advantageous in terms of productivity.

Since the electron injection electrode formed by the sputtering method is a dense film, the penetration of moisture into the film is very small, the chemical stability is high, and the organic EL has a long life as compared with a coarse vapor deposition film. An element is obtained.

The pressure of the sputtering gas at the time of sputtering is preferably in the range of 0.1 to 5 Pa. By adjusting the pressure of the sputtering gas within this range, the Li gas in the above range can be obtained.
A high concentration of AlLi alloy can be easily obtained. Also,
By changing the pressure of the sputtering gas within the above range during the film formation, an electron injection electrode having the above-mentioned Li concentration gradient can be easily obtained.

The sputtering gas may be an inert gas used in a normal sputtering apparatus, or a reactive gas such as N ₂ , H ₂ , O ₂ , C ₂ H ₄ , NH _{3 in the case} of reactive sputtering. Can be used.

As a sputtering method, a high-frequency sputtering method using an RF power source or the like is also possible, but a DC sputtering method is used in order to easily control a film forming rate and to reduce damage to the organic EL structure. Is preferred. The power of the DC sputtering apparatus is preferably 0.1 to 10 W
/ Cm ² , especially in the range of 0.5 to ⁷ W / cm ² . The deposition rate is 5 to 100 nm / min, especially 10 to 50 nm / mi.
The range of n is preferred.

The thickness of the electron injecting electrode thin film may be a certain thickness or more for sufficiently injecting electrons, and may be 1 nm or more, preferably 3 nm or more. The upper limit is not particularly limited, but the thickness may be generally about 3 to 500 nm.

The organic EL device (display) of the present invention
A protective electrode may be provided on the electron injection electrode, that is, on the side opposite to the organic layer. By providing the protective electrode, the electron injection electrode is protected from the outside air, moisture, and the like, the deterioration of the constituent thin film is prevented, the electron injection efficiency is stabilized, and the element life is dramatically improved. The protection electrode has a very low resistance, and also has a function as a wiring electrode when the resistance of the electron injection electrode is high. This protective electrode contains one or more of Al, Al and a transition metal (except for Ti), Ti and titanium nitride (TiN), and when these are used alone, each of the protective electrodes contains Al: 90 to 100 at%, Ti: 90 to 100 at%
%, TiN: preferably about 90 to 100 mol%. When two or more kinds are used, the mixing ratio is arbitrary, but in the case of mixing Al and Ti, the content of Ti is 1
0 at% or less is preferable. Further, a layer containing these alone may be laminated. In particular, when Al, Al and transition metals are used as wiring electrodes described later, good effects are obtained, and TiN has high corrosion resistance and a large effect as a sealing film. TiN may deviate by about 10% from its stoichiometric composition. Furthermore, alloys of Al and transition metals are particularly suitable for transition metals, especially Sc, Nb, Zr, Hf, Nd, Td.
a, Cu, Si, Cr, Mo, Mn, Ni, Pd, Pt
And W, etc., preferably in a total of 10 at% or less, especially 5 at% or less, especially 2 at% or less. The lower the content of the transition metal, the lower the thin film resistance when functioning as a wiring material.

The thickness of the protective electrode may be a certain thickness or more, preferably 50 nm or more, more preferably 100 nm or more, particularly 100 nm, in order to secure electron injection efficiency and prevent entry of moisture, oxygen or an organic solvent. A range of ~ 1000 nm is preferred. If the protective electrode layer is too thin, the effect of the present invention cannot be obtained, and the step coverage of the protective electrode layer will be low, and the connection with the terminal electrode will not be sufficient. On the other hand, if the thickness of the protective electrode layer is too large, the stress of the protective electrode layer increases, and the dark spot growth rate increases. The thickness when functioning as a wiring electrode is
Since the thickness of the electron injection electrode is small, the film resistance is high. To compensate for this, the thickness is usually about 100 to 500 nm, and when it functions as another wiring electrode, it is about 100 to 300 nm.

The total thickness of the electron injecting electrode and the protective electrode is not particularly limited, but is usually 100 to 100.
It may be about 0 nm.

After forming the electrode, in addition to the protective electrode, S
inorganic materials iO _X such as Teflon, a protective film may be formed using an organic material such as fluorocarbon polymers containing chlorine. The protective film may be transparent or opaque, and the thickness of the protective film is about 50 to 1200 nm. The protective film may be formed by a general sputtering method, a vapor deposition method, a PECVD method or the like in addition to the reactive sputtering method described above.

Then, a sealing plate is disposed on the organic EL structure in order to prevent oxidation of the organic layers and electrodes of the organic EL structure. The sealing plate adheres and seals a sealing plate such as a glass plate using the above-mentioned sealing adhesive in order to prevent invasion of moisture or the like. Besides a glass plate, a metal plate, a plastic plate or the like can be used.

In order to secure the thickness of the organic EL structure and a predetermined gap, a spacer of a predetermined size may be used when fixing the sealing plate with an adhesive. Such a spacer may be any as long as it corresponds to the thickness of the adhesive as described above, and its size is preferably a circle-equivalent diameter of 1,000 to 20,000 nm, particularly 1 to 20,000 nm.
Those having a thickness of about 500 to 8000 nm are preferred. In addition, as the material thereof, glass, a resin such as divinylbenzene and the like can be preferably mentioned. Granular or fibrous spacers may be present in the adhesive layer between 0.01 and 30
wt%, preferably about 0.1 to 5 wt%.

The interior of the organic EL element (display) sealed with an adhesive is preferably made of He, N ₂ , Ar
And the like. Further, the water content of the inert gas in the hermetic space is desirably 100 ppm or less, preferably 10 ppm or less, particularly preferably 1 ppm or less. Although there is no particular lower limit for this water content,
Usually, it is about 0.1 ppm.

Next, the EL device (display) of the present invention
The organic layer provided in the above will be described. The light emitting layer has a hole (hole) and electron injection function, their transport function,
It has a function of generating excitons by recombination of holes and electrons. It is preferable to use a relatively electronically neutral compound for the light emitting layer.

The hole injecting / transporting layer has a function of facilitating the injection of holes from the hole injecting electrode, a function of stably transporting holes, and a function of hindering electrons. It has a function of facilitating electron injection, a function of stably transporting electrons, and a function of hindering holes. These layers increase and confine holes and electrons injected into the light-emitting layer, and form a recombination region. To optimize luminous efficiency.

The thickness of the light emitting layer, the thickness of the hole injecting and transporting layer, and the thickness of the electron injecting and transporting layer are not particularly limited, and vary depending on the forming method.
The thickness is preferably from 0 to 300 nm.

The thickness of the hole injecting and transporting layer and the thickness of the electron injecting and transporting layer depend on the design of the recombination / light emitting region, but may be about the same as the thickness of the light emitting layer or about 1/10 to 10 times. When the injection layer and the transport layer for holes or electrons are separated from each other, it is preferable that the injection layer has a thickness of 1 nm or more and the transport layer has a thickness of 1 nm or more. At this time, the upper limit of the thickness of the injection layer and the transport layer is usually about 500 nm for the injection layer and 50 nm for the transport layer.
It is about 0 nm. Such a film thickness is the same when two injection / transport layers are provided.

The light emitting layer of the organic EL device (display) of the present invention contains a fluorescent substance which is a compound having a light emitting function. As such a fluorescent substance, for example,
Examples include compounds as disclosed in JP-A-63-264892, such as at least one selected from compounds such as quinacridone, rubrene, and styryl dyes. Also, quinoline derivatives such as metal complex dyes having 8-quinolinol or its derivatives as ligands, such as tris (8-quinolinolato) aluminum, tetraphenylbutadiene, anthracene, perylene, coronene, 12-
And phthaloperinone derivatives. Further, JP-A-8-12600 (Japanese Patent Application No. 6-110569)
Phenylanthracene derivatives described in JP-A-8-12
No. 969 (Japanese Patent Application No. 6-114456) can be used.

Further, it is preferable to use in combination with a host substance capable of emitting light by itself, and it is preferable to use it as a dopant. In such a case, the content of the compound in the light emitting layer is 0.01 to 10% by weight, and more preferably 0.1 to 10% by weight.
It is preferably 1 to 5% by weight. When used in combination with a host substance, the emission wavelength characteristics of the host substance can be changed, light emission shifted to a longer wavelength becomes possible, and the luminous efficiency and stability of the device are improved.

As the host substance, a quinolinolato complex is preferable, and an aluminum complex having 8-quinolinol or a derivative thereof as a ligand is preferable. Such an aluminum complex is disclosed in JP-A-63-26469.
No. 2, JP-A-3-255190, JP-A-5-7073
3, JP-A-5-258859, JP-A-6-2158
No. 74 and the like.

Specifically, first, tris (8-quinolinolato) aluminum, bis (8-quinolinolato) magnesium, bis (benzo {f} -8-quinolinolato) zinc, bis (2-methyl-8-quinolinolato) aluminum Oxide, tris (8-quinolinolato) indium,
Tris (5-methyl-8-quinolinolato) aluminum, 8-quinolinolatolithium, tris (5-chloro-
8-quinolinolato) gallium, bis (5-chloro-8-
Quinolinolato) calcium, 5,7-dichloro-8-quinolinolatoaluminum, tris (5,7-dibromo-
8-hydroxyquinolinolato) aluminum, poly [zinc (II) -bis (8-hydroxy-5-quinolinyl) methane], and the like.

In addition to 8-quinolinol or its derivative, an aluminum complex having another ligand may be used, such as bis (2-methyl-
8-quinolinolato) (phenolato) aluminum (III)
, Bis (2-methyl-8-quinolinolato) (ortho-
Cresolato) aluminum (III), bis (2-methyl-
8-quinolinolato) (meth-cresolate) aluminum
(III), bis (2-methyl-8-quinolinolato) (para-cresolato) aluminum (III), bis (2-methyl-8-quinolinolato) (ortho-phenylphenolate)
Aluminum (III), bis (2-methyl-8-quinolinolato) (meth-phenylphenolato) aluminum (II
I), bis (2-methyl-8-quinolinolato) (para-
Phenylphenolato) aluminum (III), bis (2-
Methyl-8-quinolinolato) (2,3-dimethylphenolato) aluminum (III), bis (2-methyl-8-quinolinolato) (2,6-dimethylphenolato) aluminum (III), bis (2-methyl- 8-quinolinolato)
(3,4-dimethylphenolato) aluminum (III),
Bis (2-methyl-8-quinolinolato) (3,5-dimethylphenolato) aluminum (III), bis (2-methyl-8-quinolinolato) (3,5-di-tert-butylphenolato) aluminum (III) ), Bis (2-methyl-8)
-Quinolinolato) (2,6-diphenylphenolato) aluminum (III), bis (2-methyl-8-quinolinolato) (2,4,6-triphenylphenolato) aluminum (III), bis (2-methyl- 8-quinolinolato)
(2,3,6-trimethylphenolato) aluminum (I
II), bis (2-methyl-8-quinolinolato) (2,
3,5,6-tetramethylphenolato) aluminum (I
II), bis (2-methyl-8-quinolinolato) (1-naphthrat) aluminum (III), bis (2-methyl-8
-Quinolinolato) (2-naphthrat) aluminum (II
I), bis (2,4-dimethyl-8-quinolinolato)
(Ortho-phenylphenolato) aluminum (III),
Bis (2,4-dimethyl-8-quinolinolato) (para-
Phenylphenolato) aluminum (III), bis (2,
4-dimethyl-8-quinolinolato) (meta-phenylphenolato) aluminum (III), bis (2,4-dimethyl-8-quinolinolato) (3,5-dimethylphenolato) aluminum (III), bis (2 4-dimethyl-8
-Quinolinolato) (3,5-di-tert-butylphenolato) aluminum (III), bis (2-methyl-4-ethyl-8-quinolinolato) (para-cresolato) aluminum (III), bis (2-methyl) -4-methoxy-8-quinolinolato) (para-phenylphenolato) aluminum (III), bis (2-methyl-5-cyano-8-quinolinolato) (ortho-cresolato) aluminum (III),
Bis (2-methyl-6-trifluoromethyl-8-quinolinolato) (2-naphthrat) aluminum (III);

In addition, bis (2-methyl-8-quinolinolato) aluminum (III) -μ-oxo-bis (2-
Methyl-8-quinolinolato) aluminum (III), bis (2,4-dimethyl-8-quinolinolato) aluminum
(III) -μ-oxo-bis (2,4-dimethyl-8-quinolinolato) aluminum (III), bis (4-ethyl-
2-methyl-8-quinolinolato) aluminum (III)-
μ-oxo-bis (4-ethyl-2-methyl-8-quinolinolato) aluminum (III), bis (2-methyl-4
-Methoxyquinolinolato) aluminum (III) -μ-oxo-bis (2-methyl-4-methoxyquinolinolato)
Aluminum (III), bis (5-cyano-2-methyl-
8-quinolinolato) aluminum (III) -μ-oxo-
Bis (5-cyano-2-methyl-8-quinolinolato) aluminum (III), bis (2-methyl-5-trifluoromethyl-8-quinolinolato) aluminum (III) -μ
-Oxo-bis (2-methyl-5-trifluoromethyl-8-quinolinolato) aluminum (III) and the like.

Other host materials are disclosed in
Phenylanthracene derivative described in JP-A-12600 (Japanese Patent Application No. 6-110569) and JP-A-8-1296
No. 9 (Japanese Patent Application No. 6-114456) is also preferable.

The light emitting layer may also serve as the electron injection / transport layer. In such a case, it is preferable to use tris (8-quinolinolato) aluminum or the like. These fluorescent substances may be deposited.

Further, if necessary, the light emitting layer is preferably a mixed layer of at least one or more hole injecting / transporting compounds and at least one or more electron injecting / transporting compounds. It is preferable to include them. The content of the compound in such a mixed layer is
It is preferably 0.01 to 20% by weight, more preferably 0.1 to 15% by weight.

In the mixed layer, a carrier hopping conduction path is formed, so that each carrier moves in a material having a polarity predominant, injection of a carrier having the opposite polarity hardly occurs, and organic compounds are hardly damaged. There is an advantage that the device life is extended, but by including the above-mentioned dopant in such a mixed layer, the emission wavelength characteristic of the mixed layer itself can be changed, and the emission wavelength can be shifted to a longer wavelength. In addition, the emission intensity can be increased and the stability of the element can be improved.

The hole injecting / transporting compound and the electron injecting / transporting compound used in the mixed layer may be selected from the compounds for the hole injecting / transporting layer and the compounds for the electron injecting / transporting layer described below, respectively. Among them, compounds for the hole injection transport layer include amine derivatives having strong fluorescence,
For example, it is preferable to use a triphenyldiamine derivative which is a hole transport material, a styrylamine derivative, or an amine derivative having an aromatic condensed ring.

As the compound capable of injecting and transporting electrons, it is preferable to use a quinoline derivative, furthermore a metal complex having 8-quinolinol or a derivative thereof as a ligand, particularly tris (8-quinolinolato) aluminum (Alq ₃ ). It is also preferable to use the above-mentioned phenylanthracene derivatives and tetraarylethene derivatives.

As the compound for the hole injecting and transporting layer, an amine derivative having strong fluorescence, for example, a triphenyldiamine derivative which is the above-described hole transporting material, a styrylamine derivative, or an amine derivative having an aromatic condensed ring is used. Is preferred.

The mixing ratio in this case is determined by considering the respective carrier mobilities and carrier concentrations. In general, the weight ratio of the compound of the hole injecting / transporting compound / the compound having the electron injecting / transporting function is used. But 1 / 99-99 /
1, further from 10/90 to 90/10, especially 20/8
It is preferable to set it to about 0 to 80/20.

Further, the thickness of the mixed layer is preferably less than the thickness of the organic compound layer from the thickness corresponding to one molecular layer, more preferably 1 to 85 nm.
Further, the thickness is preferably 5 to 60 nm, particularly preferably 5 to 50 nm.

As a method for forming a mixed layer, co-evaporation in which evaporation is performed from different evaporation sources is preferable. However, when the vapor pressures (evaporation temperatures) are approximately the same or very close, they are mixed in advance in the same evaporation board. Alternatively, it can be deposited. In the mixed layer, it is preferable that the compounds are uniformly mixed, but in some cases, the compounds may exist in an island shape. The light-emitting layer is generally formed to a predetermined thickness by vapor-depositing an organic fluorescent substance or by dispersing and coating the resin in a resin binder.

The hole injecting and transporting layer is described in, for example, JP-A-63-295695 and JP-A-2-19169.
4, JP-A-3-792, JP-A-5-234
681, JP-A-5-239455, JP-A-5-299174, JP-A-7-126225, JP-A-7-126226, JP-A-8-100
Various organic compounds described in JP-A-172, EP0650955A1, and the like can be used. For example, a tetraarylbendicine compound (triaryldiamine or triphenyldiamine: TPD), an aromatic tertiary amine, a hydrazone derivative, a carbazole derivative, a triazole derivative, an imidazole derivative, an oxadiazole derivative having an amino group, polythiophene, etc. . Two or more of these compounds may be used in combination, and when they are used in combination, they may be stacked as separate layers or mixed.

When the hole injecting and transporting layer is divided into a hole injecting layer and a hole transporting layer, a preferable combination can be selected from the compounds for the hole injecting and transporting layer. At this time, it is preferable to stack the layers of the compound having the smaller ionization potential in order from the hole injection electrode (ITO or the like) side. It is preferable to use a compound having good thin film properties on the surface of the hole injection electrode. Such a stacking order is the same when two or more hole injection transport layers are provided. With such a stacking order, the driving voltage is reduced, and the occurrence of current leakage and the occurrence and growth of dark spots can be prevented. In the case of forming an element, a thin film of about 1 to 10 nm can be made uniform and pinhole-free because of the use of vapor deposition, so that the hole injection layer has a small ionization potential and has absorption in the visible part. Even when such a compound is used, it is possible to prevent a change in the color tone of the emission color or a decrease in efficiency due to reabsorption.
The hole injecting and transporting layer can be formed by vapor deposition of the above compound in the same manner as the light emitting layer and the like.

The electron injecting and transporting layer, which is provided as necessary, includes quinoline such as an organometallic complex having 8-quinolinol or a derivative thereof such as tris (8-quinolinolato) aluminum (Alq ₃ ) as a ligand. Derivatives, oxadiazole derivatives, perylene derivatives, pyridine derivatives, pyrimidine derivatives, quinoxaline derivatives, diphenylquinone derivatives, nitro-substituted fluorene derivatives, and the like can be used. The electron injection / transport layer may also serve as the light emitting layer. In such a case, it is preferable to use tris (8-quinolinolato) aluminum or the like. The electron injecting and transporting layer may be formed by vapor deposition or the like, similarly to the light emitting layer.

When the electron injecting and transporting layer is divided into an electron injecting layer and an electron transporting layer, a preferable combination can be selected from the compounds for the electron injecting and transporting layer. At this time, it is preferable to stack the compounds in descending order of the electron affinity value from the electron injection electrode side. This stacking order is the same when two or more electron injection / transport layers are provided.

The emission color may be controlled by using a color filter film, a color conversion film containing a fluorescent substance, or a dielectric reflection film on the substrate.

As the color filter film, a color filter used in a liquid crystal display or the like may be used.
The characteristics of the color filter may be adjusted in accordance with the light emitted from the organic EL to optimize the extraction efficiency and the color purity.

When a color filter capable of cutting off short-wavelength external light that is absorbed by the EL element material or the fluorescence conversion layer is used, the light resistance of the element and the contrast of display are improved.

Further, an optical thin film such as a dielectric multilayer film may be used instead of the color filter.

The fluorescence conversion filter film absorbs EL light and emits light from the phosphor in the fluorescence conversion film, thereby performing color conversion of the emission color. It is formed from a fluorescent material and a light absorbing material.

As the fluorescent material, basically, a material having a high fluorescence quantum yield may be used, and it is desirable that the fluorescent material has strong absorption in the EL emission wavelength region. Actually, laser dyes are suitable, and rhodamine compounds, perylene compounds, cyanine compounds, phthalocyanine compounds (including subphthalo, etc.) naphthaloimide compounds, condensed ring hydrocarbon compounds, condensed heterocyclic compounds, A styryl compound, a coumarin compound, or the like may be used.

Basically, a material that does not extinguish the fluorescence may be selected as the binder, and a material that can be finely patterned by photolithography, printing, or the like is preferable.
Further, a material that does not suffer damage during the formation of ITO or IZO is preferable.

The light absorbing material is used when the light absorption of the fluorescent material is insufficient, but may be omitted when unnecessary. As the light absorbing material, a material that does not quench the fluorescence of the fluorescent material may be selected.

For forming the hole injection transport layer, the light emitting layer and the electron injection transport layer, it is preferable to use a vacuum deposition method since a uniform thin film can be formed. When a vacuum deposition method is used, a homogeneous thin film having an amorphous state or a crystal grain size of 0.2, preferably 0.1 μm or less can be obtained. If the crystal grain size exceeds 0.2 μm, uneven light emission will occur.
The drive voltage of the device must be increased, and the charge injection efficiency is significantly reduced.

The conditions for vacuum deposition are not particularly limited.
The degree of vacuum is 0 ^-4 Pa or less, and the deposition rate is 0.01 to 1 nm /
It is preferable to set it to about sec. Further, it is preferable to form each layer continuously in a vacuum. If they are formed continuously in a vacuum, impurities can be prevented from adsorbing at the interface between the layers, so that high characteristics can be obtained. Further, the driving voltage of the element can be reduced, and the growth and generation of dark spots can be suppressed.

In the case where a plurality of compounds are contained in one layer when a vacuum evaporation method is used for forming each of these layers, it is preferable to co-deposit each boat containing the compounds by individually controlling the temperature.

The organic EL display of the present invention usually comprises
Although used as a DC drive type EL element, AC drive or pulse drive can be used. The applied voltage is usually about 2 to 30 V, especially about 2 to 20 V.

EXAMPLES Next, the present invention will be described more specifically with reference to experimental examples and examples. <Experimental example 1> On a Corning 7059 glass substrate,
A commercially available Three Bond 30Y296D was used as an ultraviolet-curable epoxy resin adhesive, and 100 mg of this was applied in an uncured state. Further, another 7059 glass manufactured by Corning was overlaid as a sealing plate, and a pressure of 3 kg / cm ² was applied to the substrates while sliding the substrates together to form a thin layer of adhesive between the glass substrate and the sealing plate. At this time, a 7 μm spacer was dispersed in the adhesive in an amount of 1 wt% so that the adhesive had a thickness of 7 μm. Next, the adhesive surface was irradiated with UV light through a glass substrate using a metal halide lamp so that the integrated light amount became 6000 mJ, thereby curing the adhesive. After curing, the sealing plate was peeled off from the glass substrate to expose the adhesive surface, and the adhesive was scraped off from about 50 mg as a guide. After the collected sample was accurately weighed, it was placed in a vial for analysis, placed in a thermostat as a head space, and a tube for introducing the sample gas into the gas chromatograph was connected to the mouth of the bottle.

The sample was analyzed by headspace gas chromatography / mass spectrometry (HS-GC-MS method).
The analyzer is a Hewlett-Packard 5970B
Was used. As measurement conditions, a thermostat in a head space was kept at 85 ° C. for 60 minutes, and generated gas was analyzed.
At this time, the loop temperature from the vial bottle to the sample inlet of the gas chromatograph was set to 150 ° C. HP-WAX: 0.2 mm × 25 m was used for the column of the gas chromatograph, and the temperature of the column was adjusted to 40 to 230 ° C. (10 ° C./min). Helium gas: 1 as carrier gas
Using 3 psi (0.5 ml / min), the injection temperature at the sample inlet was 250 ° C., and the sample split ratio was:
As 50, 2% was introduced. As mass spectrometry conditions, mass monitor: M / Z = 35 to 550,
The temperature of the detector was 280 ° C.

A qualitative analysis was carried out from the TIC retention time and the mass spectrum, and a quantitative analysis was carried out based on the calibration curve conversion of benzene as a standard sample. Table 1 shows the obtained results.

[0084]

[Table 1]

As is clear from Table 1, the adhesive sample of the present invention has a small amount of gas generation after UV curing of 118 μg / g in total in terms of benzene.

<Experimental Example 2> In Experimental example 1, an adhesive using a metallocene compound as a reaction initiator was prepared as an adhesive for a comparative sample, and the other samples were analyzed in the same manner as in Experimental example 1. As a result, the comparative adhesive sample
The total amount of gas generated after V curing is 21
This was an extremely large value of 7 μg / g.

Example 1 An organic EL device was manufactured using the sample of the present invention used in Experimental Example 1.

On a glass substrate, an ITO transparent electrode (hole injecting electrode) was formed and patterned so as to constitute pixels of 64 dots × 7 lines (280 × 280 μm per pixel) with a film thickness of 85 nm. Next, the substrate on which the patterned hole injection electrode was formed was subjected to ultrasonic cleaning using a neutral detergent, acetone and ethanol, pulled up from boiling ethanol, and dried. Then, the surface is UV / O ₃
After cleaning, fix it on the substrate holder of the vacuum evaporation device,
The pressure in the tank was reduced to 1 × 10 ⁻⁴ Pa or less. 4,4 ', 4 "
-Tris (-N- (3-methylphenyl) -N-phenylamino) triphenylamine (m-MTDATA) was deposited at a deposition rate of 0.2 nm / sec. To a thickness of 40 nm to form a hole injection layer, N, N 'while maintaining the reduced pressure
-Diphenyl-N, N'-m-tolyl-4,4'-diamino-1,1'-biphenyl (TPD) was deposited at a deposition rate of 0.2 nm / sec. To a thickness of 35 nm and transported by holes. Layers. Further, while maintaining the reduced pressure, tris (8-quinolinolato) aluminum (hereinafter, Alq ₃ ) was vapor-deposited at a vapor deposition rate of 0.2 nm / sec. To a thickness of 50 nm to form an electron injection transport / light-emitting layer. Then, while maintaining the reduced pressure, MgA
g by co-evaporation (binary evaporation) at an evaporation speed ratio of Mg: Ag = 1:
A film was formed to a thickness of 200 nm at 10 to form an electron injection electrode. Further, while maintaining the reduced pressure, the EL element substrate was transferred to a sputtering apparatus, and an Al protective electrode was formed to a thickness of 200 nm by a DC sputtering method using an Al target at a sputtering pressure of 0.3 Pa. At this time, the sputtering gas is A
r, the input power was 500 W, the size of the target was 4 inches in diameter, and the distance between the substrate and the target was 90 mm.
Finally, using the adhesive of the present invention and a spacer having a diameter of 7 μm, the glass material used in the experimental example was bonded as a sealing plate.
Sealed.

The obtained organic EL device was driven at a constant current density of 10 mA / cm ² by applying a DC voltage in the air atmosphere, and it was confirmed that no dark spot was observed in the initial state. Then, after storing for 100 hours and 500 hours under accelerated conditions of a temperature of 60 ° C. and a humidity of 95%,
The device was driven under the same conditions, and the occurrence of dark spots was evaluated.

In the sample of the present invention, no dark spots having a diameter of 50 μm or less were found in 64 × 7 = 448 pixels after storage for 100 hours.
1 to 5 dark spots of 0 μm or less were confirmed.

Comparative Example 1 An organic EL device was obtained in the same manner as in Example 1, except that the adhesive was changed to a comparative sample used in Experimental Example 2. The obtained organic EL device was evaluated in the same manner as in Example 1.
After storage for a time, no dark spots with a diameter of 50 μm or less were found, and after storage for 500 hours, 10 to 15 dark spots with a diameter of 100 μm or less were confirmed.

Example 2 In the same manner as in Experimental Example 1, samples 1 to 5 commercially available as an ultraviolet-curable epoxy resin adhesive were evaluated and quantitatively analyzed. Table 2 shows the obtained results.

[0093]

[Table 2]

As is clear from Table 2, the adhesive sample of the present invention has a gas generation amount after UV curing of propylene carbonate: 30 μg / g or less in terms of benzene.
Propylene glycol: 20 μg / g or less, toluene:
It is less than 20 μg / g.

On a glass substrate, an ITO transparent electrode (hole injection electrode) was formed and patterned so as to form a pixel of 85 dots in thickness and 64 dots × 7 lines (280 × 280 μm per pixel). Next, the substrate on which the patterned hole injection electrode was formed was subjected to ultrasonic cleaning using a neutral detergent, acetone and ethanol, pulled up from boiling ethanol, and dried. Then, the surface is UV / O ₃
After cleaning, fix it on the substrate holder of the vacuum evaporation device,
The pressure in the tank was reduced to 1 × 10 ⁻⁴ Pa or less. 4,4 ', 4 "
-Tris (-N- (3-methylphenyl) -N-phenylamino) triphenylamine (m-MTDATA) was deposited at a deposition rate of 0.2 nm / sec. To a thickness of 40 nm to form a hole injection layer, N, N 'while maintaining the reduced pressure
-Diphenyl-N, N'-m-tolyl-4,4'-diamino-1,1'-biphenyl (TPD) was deposited at a deposition rate of 0.2 nm / sec. To a thickness of 35 nm and transported by holes. Layers. Further, while maintaining the reduced pressure, tris (8-quinolinolato) aluminum (hereinafter, Alq ₃ ) was deposited at a deposition rate of 0.2 nm / sec. To a thickness of 50 nm to form an electron injection transport / light emitting layer. Then, while maintaining the reduced pressure, MgA
g by co-evaporation (binary evaporation) at an evaporation speed ratio of Mg: Ag = 1:
A film was formed to a thickness of 200 nm at 10 to form an electron injection electrode. Further, while maintaining the reduced pressure, the EL element substrate was transferred to a sputtering apparatus, and an Al protective electrode was formed to a thickness of 200 nm by a DC sputtering method using an Al target at a sputtering pressure of 0.3 Pa. At this time, the sputtering gas is A
r, the input power was 500 W, the size of the target was 4 inches in diameter, and the distance between the substrate and the target was 90 mm.
Finally, the same glass material as above was used as a sealing plate by using the adhesive of each of the above samples 1 to 5 and a spacer having a diameter of 7 μm, followed by sealing.

The obtained organic EL display was heated at 85 ° C. for 1 hour in an initial state by applying a DC voltage in an air atmosphere and driving at a constant current density of 10 mA / cm ² . The generation of the dark spot and the size of the dark spot of the sample not subjected to the heat treatment were evaluated. Then
After storage under accelerated conditions of a temperature of 60 ° C. and a humidity of 95% for 300 hours, the samples were driven under the same conditions and subjected to a heat treatment at 85 ° C. for 1 hour, and the occurrence of dark spots in a sample not subjected to the heat treatment and its dark spots. The size was evaluated. Table 2 shows the results. In addition, the dark spot was selected with the largest diameter for four light emitting surfaces per element, and was evaluated by averaging the four elements.

[0097]

[Table 3]

As is clear from Table 3, the sample of the present invention had no dark spots in the initial state, and the diameter of the dark spots generated was small when heat treatment was not performed after the storage test. You can see that there is. In addition,
A diameter of the dark spot of 100 μm or less is within the allowable range.

In the heat-treated sample, although the diameter of the dark spot after the storage test was large, it was confirmed that the initial luminance was improved and the half-life of the luminance was also increased. For this reason, it is desirable to determine whether or not to perform heat treatment in consideration of overall characteristics.

[0100]

As described above, according to the present invention, it is possible to provide a long-life organic EL device capable of minimizing deterioration over time and maintaining initial performance for a long time.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing a specific configuration example of an organic EL device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Organic EL structure 3 Sealing plate 4 Spacer 5 Sealing adhesive

Continuation of the front page (72) Inventor Junichi Shimamura 1-13-1 Nihonbashi, Chuo-ku, Tokyo TDK Corporation (72) Inventor Osamu Onitsuka 1-13-1 Nihonbashi, Chuo-ku, Tokyo TDK Corporation (72) Inventor Akira Ebisawa 1-13-1 Nihonbashi, Chuo-ku, Tokyo Inside TDK Corporation

Claims (6)

[Claims] 1. A substrate, and organic E laminated on the substrate.
An L structure; a sealing plate disposed at a predetermined gap on the organic EL structure; and a sealing adhesive for fixing the sealing plate on a substrate and sealing the organic EL structure. The sealing adhesive is a photo-curing adhesive, and among the gas generated under heating conditions of 85 ° C. and 60 minutes after photo-curing, propylene carbonate: 25 μg / g or less, propylene glycol: 15 μg / g or less, toluene: 20 μg / g or less. 2. The gas contains 1 μg of iodobenzene /
2. The organic EL device according to claim 1, which contains at least g. 3. The adhesive is a cationic polymerization epoxy UV.
3. The organic EL device according to claim 1, which is a curable adhesive. 4. A substrate, and organic E laminated on the substrate.
An L structure; a sealing plate disposed at a predetermined gap on the organic EL structure; and a sealing adhesive for fixing the sealing plate on a substrate and sealing the organic EL structure. The sealing adhesive is a photo-curable adhesive, and is a gas generated by heating at 85 ° C. for 60 minutes after photo-curing, which is a low-molecular-weight straight-chain which may be replaced. Chain aliphatic hydrocarbons,
The total of the optionally substituted aromatic hydrocarbon, the optionally substituted alicyclic hydrocarbon, the optionally substituted heterocyclic compound and the siloxane is not more than 200 μg / g in terms of benzene; The organic EL element in which, in terms of benzene, propylene carbonate: 25 μg / g or less, propylene glycol: 15 μg / g or less, and toluene: 20 μg / g or less in terms of benzene. 5. The gas comprises 1 μg / iodobenzene /
5. The organic EL device according to claim 4, wherein the organic EL device contains at least g. 6. The adhesive is a cationic polymerization epoxy UV.
6. The organic EL device according to claim 4, which is a curable adhesive.