JP2005213316A - Resin composition for sealing organic electroluminescent element and organic electroluminescent element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic electroluminescent element capable of sufficiently and stably suppressing expansion of a non-electroluminescent region with the passing of time, and to provide its production method. <P>SOLUTION: The resin composition for sealing the organic electroluminescent element comprises (A) an epoxy resin, (B) a thermoset type curing agent and (C) a silane coupling agent as essential components, where crosslinking and curing is carried out by mixing (A), (B) and (C). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a resin composition for sealing an organic electroluminescent element and an organic light emitting element that can be used in fields such as a display element, a flat panel display, a backlight, and an interior.

  The organic electroluminescence device emits light by recombining holes injected from an anode and electrons injected from a cathode in an organic light emitting layer sandwiched between both electrodes. A typical structure is a transparent first electrode (anode), a hole transport layer, an organic light emitting layer, and a second electrode (cathode) laminated on a glass substrate. It is taken out through the electrode and the glass substrate. Such organic electroluminescence elements are thin, can emit high-intensity light emission under low-voltage driving, and multicolor light emission by selecting an organic light-emitting material, and are actively studied for application to light-emitting devices and displays. .

  As one of the problems in the organic electroluminescence device, a problem has been pointed out that a part of the light emitting region becomes non-light emitting and the area of the non light emitting region increases with time. Moisture is known as one of the causes that cause such characteristic deterioration. That is, moisture permeates into the element such as the organic light emitting layer from a defect of the second electrode, and inactivates the element.

  In order to prevent such expansion of the non-light-emitting region, it is effective to keep the organic electroluminescent device in a low humidity atmosphere, and a sealing means is used for the purpose of protecting the device from an external environment such as moisture. Has been. For example, a method of bonding an element and a sealing plate through an adhesive (for example, refer to Patent Document 1) or a method of forming a protective film having moisture shielding properties such as an oxide or fluoride on a cathode layer ( For example, see Patent Document 2). In addition, as a sealing resin composition, a method using a moisture-resistant photocurable resin (see, for example, Patent Document 3), a method using a photocurable resin having two or more epoxy groups in the molecule (high crosslinking density). (For example, refer to Patent Document 4), a method of heating and melting a low-melting glass with a laser beam (for example, refer to Patent Document 5), and a method using a cationic curable ultraviolet curable epoxy resin (for example, refer to Patent Document 6). A method using an epoxy resin having a heat resistant temperature of 80 ° C. or higher (for example, see Patent Document 7) is known.

In addition, the state of the adhesive interface between the sealing resin composition and the substrate or between the sealing resin composition and the sealing plate is very important, and various techniques have been studied to improve the interfacial adhesion. . For example, a method of containing a silane coupling agent in an ultraviolet curable resin (one liquid type) (for example, see Patent Document 8), a method of applying a primer treatment to a substrate or a sealing plate (for example, see Patent Document 9), etc. It has been known.
JP-A-1-338992 (Claims 1 and 2) JP-A-4-212284 (Claim 1) JP-A-5-182759 (Claim 1) JP 2001-85155 A (Claim 1) Japanese Patent Laid-Open No. 10-74583 (Claims 1 and 2) JP-A-10-233283 (Claim 1) JP 2000-243557 A (Claim 1) JP 2001-139933 A (Claim 1) JP 2002-164165 A (Claim 8)

  However, in the prior art, for example, it is difficult to form a defect-free film on the entire substrate by the method of forming a protective film, and in the method using a light (ultraviolet) curable resin, a separate light irradiation device is prepared to cure the resin. There was a need. Furthermore, when a silane coupling agent is contained in the ultraviolet curable resin, a silane coupling agent that is reactive with the resin component cannot be contained from the viewpoint of the storage stability of the resin. In addition, when a silane coupling agent is used as a primer, in addition to the step of applying a resin composition for sealing an organic electroluminescent element, it is necessary to separately perform a primer application step on the substrate and the sealing plate, resulting in a problem of excessive processes. there were. Further, in the primer application process, it is difficult to control the process atmosphere (cleaning), and there is a possibility that the substrate surface is contaminated.

  An object of the present invention is to solve such problems and to provide an organic electroluminescent device capable of sufficiently and stably suppressing the time-dependent expansion of a non-light emitting region and a method for manufacturing the same.

  In order to solve this problem, the present invention has the following configuration. That is, (A) an epoxy resin, (B) a thermosetting curing agent, and (C) a silane coupling agent are essential components, and crosslinking is performed by mixing (A), (B), and (C). It is a resin composition for sealing an organic electroluminescent element, which is cured.

  According to the present invention, even if an organic electroluminescent element is used for a long period of time, generation or expansion of a non-light emitting region can be prevented.

  Hereinafter, the present invention will be described in detail. However, the present invention is not limited to the organic electroluminescent element sealing resin composition having the exemplified form and structure and the organic electroluminescent element using the same. Therefore, it can be applied to organic electroluminescent elements of any structure regardless of the type of light emitting elements such as single light emitting elements, segment type, simple matrix type, active matrix type, and the number of colors of light emission such as color and monochrome. It is.

  The organic electroluminescent element sealing resin composition in the present invention comprises (A) an epoxy resin, (B) a thermosetting curing agent, and (C) a silane coupling agent as essential components, (B) and (C) are mixed and hardened by crosslinking. Details of these essential components will be described below.

  As the epoxy resin (A) in the present invention, bisphenol A type, bisphenol F type, phenol novolac type, naphthalene type, dicyclopentadiene type, polyphenol type, polyhydroxybenzene type, vinyl polymer type, aromatic carboxylic acid type, cyclohexene Any type such as a mold can be used.

  The (B) thermosetting curing agent in the present invention includes amine resins such as aliphatic amines, aromatic amines, secondary and tertiary amines, modified heterocyclic diamines, phthalic anhydride, maleic anhydride, and the like. An acid anhydride, a polysulfide resin having a mercaptan group, a phenolic curing agent having two or more hydroxyl groups in one molecule, and the like can be used. The thermosetting curing agent in the present invention refers to a curing agent that undergoes crosslinking and curing at a temperature of 0 ° C. or higher after mixing and stirring with an epoxy resin. The upper limit of the curing temperature is desirably 100 ° C. or less because of restrictions for preventing the organic electroluminescent element from being thermally damaged. Among the curing agents exemplified above, an amine resin is the most suitable curing agent because crosslinking curing proceeds rapidly at a temperature relatively close to room temperature and it is not necessary to add a catalyst for curing.

  The (C) silane coupling agent in this invention has a role which improves the interfacial adhesiveness of a board | substrate or a sealing board, and the resin composition for organic electroluminescent element sealing. By improving the interfacial adhesiveness, the penetration of moisture into the inside of the sealing space is suppressed, and the sealing characteristics are improved.

  The silane coupling agent has at least one alkoxy group per molecule. A trace amount of alcohol is generated when the silane coupling agent reacts due to this alkoxy group. Since alcohol may damage the organic thin film layer of the organic electroluminescent device, it is preferable to add the silane coupling agent to the minimum necessary amount. Specifically, it is desirable that it is 0.01 wt% or more and 5 wt% or less, more preferably 0.1 wt% or more and 2 wt% or less of the total weight of the sealing resin composition. When alcohol is generated in the sealed space, the generated alcohol can be captured by disposing a material (getter) reactive with alcohol such as aluminum in the space. At this time, hydrogen gas is generated inside the sealed space, and the internal pressure of the sealed space becomes a positive pressure, which has an effect of suppressing moisture intrusion from the outside of the sealed space.

  In the present invention, the (C) silane coupling agent is a primer treatment step that is a conventional silane coupling agent treatment step by previously mixing with (A) an epoxy resin or (B) a thermosetting curing agent. Can be omitted. In the conventional one-pack type sealing resin composition, a silane coupling agent reactive with an epoxy resin cannot be added from the viewpoint of storage stability. However, in the present invention, since (A) the epoxy resin and (B) the curing agent can be stored separately, by mixing the silane coupling agent with the thermosetting curing agent in advance, the epoxy resin is reactive with the epoxy resin. Some silane coupling agents can be used. Thereby, it became possible to obtain a sealing resin having stronger interfacial adhesion than before.

  In the present invention, (C) as a silane coupling agent, vinyltrimethoxysilane having a vinyl group, vinyltriethoxysilane, vinyltris (βmethoxyethoxy) silane, and β- (3,4 epoxycyclohexyl) ethyl having an epoxy group. Trimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-methacryloxypropylmethyldimethoxysilane having methacryloxy group, γ- Any of methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane having a mercapto group, etc. It may be used, in particular (A) is highly reactive with epoxy groups, and it has a amino group. Specific examples of the silane coupling agent having an amino group include N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N -(6 aminohexyl) aminopropyltrimethoxysilane, N- (2-aminoethyl) -11-aminoundecyltrimethoxysilane, N-3-[(amino (polypropylenoxy)] aminopropyltrimethoxysilane, 3 -Aminopropyldimethylethoxysilane, 3-aminopropylmethyldiethoxysilane, aminopropylsilanetriol, 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, and thermal properties of the cured product From the viewpoint of not deteriorating It is desirable that the coupling agent. Examples of the aromatic silane coupling agent having an amino group include (aminoethyl aminomethyl) phenethyl trimethoxy silane, aminophenyl trimethoxy silane.

  The crosslinking curing in the present invention means that chemical bonding occurs between the compounds by mixing (A), (B), and (C), resulting in an increase in molecular weight, an increase in mechanical strength, and solvent resistance. This refers to a phenomenon in which improvement in the quality occurs. As a measure of the development of cross-linking and curing, it can be easily determined by measuring the glass transition temperature before and after mixing each compound. Specifically, if the glass transition temperature after mixing each compound is 60 ° C. or higher, it can be said that cross-linking curing has occurred.

  The environment in which the sealing resin composition is applied to the substrate or the sealing plate is preferably a dry atmosphere. Specifically, the dew point temperature is preferably −60 ° C. or lower, more preferably −80 ° C. or lower. In an environment where the dew point temperature exceeds −60 ° C., the non-light emitting region of the organic electroluminescent element is enlarged due to the influence of moisture inside the sealed space. Further, it is desirable to reduce the moisture absorbed by the encapsulating resin composition as much as possible. Specifically, it is preferably 1 wt% or less, more preferably 0.1 wt% or less of the total resin amount. When moisture exceeding 1 wt% is contained, the adhesion between the substrate or the sealing plate and the resin interface is lowered.

  The organic electroluminescent element sealing resin composition used in the present invention may contain other components other than the essential components as long as the object of the present invention is not impaired. For example, organic or inorganic spherical or linear particles, acid anhydrides such as phthalic anhydride and maleic anhydride, and synthetic resins such as curing accelerators such as polysulfide resins having a mercaptan group can be used.

  Next, the details of the organic electroluminescent device in the present invention will be described.

  For example, as shown in FIG. 1, the organic electroluminescent device of the present invention has a display region around a first electrode 2, an organic thin film layer comprising a hole transport layer 5 and a light emitting layer 6, and a second electrode 8 sequentially laminated. A method of disposing the organic electroluminescent element sealing resin composition 22 at a position surrounding the display area, as shown in FIG. 2, a method of disposing the organic electroluminescent element sealing resin composition 22 at a position covering the display area, As shown in FIG. 3, any arrangement such as a method of covering the display area with the protective film 26 and then covering the display area with the organic electroluminescent element sealing resin composition 22 can be used. As a method for arranging the resin composition for sealing an organic electroluminescent device, a dispenser or screen printing method is used if a linear arrangement is performed, and a spin coating method or a slit die coating method is used if a planar arrangement is performed. A suitable example is a screen printing method.

  The sealing plate 21 may be made of glass, resin, or a material having a low water permeability such as aluminum or stainless steel formed into a plate shape or a film shape. These may be a single system or a composite system in which a metal such as aluminum is deposited on a resin film such as polyethylene. From the viewpoint of interfacial adhesiveness, it is desirable to use the same material for the substrate and the sealing plate, since the influence of thermal stress at the time of heat addition can be reduced.

  In the present invention, the shape of the sealing plate 21 is not particularly limited, and the substrate and the sealing plate are formed by forming the recess 24 as shown in FIG. 4 or the leg portion 25 as shown in FIG. It is also possible to define the bonding position. By doing so, it is possible to fill the sealed internal space 23 with gas or oil or to secure a volume for providing a hygroscopic agent. The same effect can be obtained by increasing the thickness of the sealing resin composition by adding a spacer to the resin. Furthermore, the light-emitting element of the present invention may be obtained by forming a getter film having a hygroscopic effect on the surface of the sealing plate in advance, or by forming a black film or a light absorbing film having an antireflection effect, if necessary. it can. Examples of the hygroscopic agent include silica gel, zeolite, activated carbon, calcium oxide, germanium oxide, barium oxide, magnesium oxide, phosphorus pentoxide, and calcium chloride. Examples of the getter film include metal vapor deposition films such as aluminum, magnesium, barium, and titanium. be able to.

  The first electrode and the second electrode used in the organic electroluminescence device of the present invention have a role of supplying a sufficient current for light emission of the device, and at least one of them is transparent for taking out light. Is desirable. Usually, the first electrode formed on the substrate is a transparent electrode, and this is the anode.

  Preferred transparent electrode materials include tin oxide, zinc oxide, indium oxide, ITO and the like. For the purpose of patterning, it is preferable to use ITO excellent in workability.

  When patterning the first electrode, a photolithography method involving wet etching can be used. The pattern shape of the first electrode is not particularly limited, and an optimal pattern may be selected depending on the application. In the present invention, a plurality of striped electrodes arranged with a certain interval can be cited as a preferable example.

  In order to reduce the surface resistance of the transparent electrode or to suppress the voltage drop, ITO may contain a small amount of metal such as silver or gold, and tin, gold, silver, zinc, indium, aluminum, chromium It is also possible to use nickel as a guide electrode for ITO. In particular, chromium is a suitable metal because it can function as both a black matrix and a guide electrode. From the viewpoint of power consumption of the element, it is desirable that ITO has a low resistance. For example, an ITO substrate of 300Ω / □ or less (a transparent substrate on which an ITO thin film is formed) functions as an element electrode, but at present, it is possible to supply an ITO substrate of about 10Ω / □. □ The following low-resistance products can be used. The thickness of ITO is related to the resistance value and cannot be defined unconditionally, but is usually 50 to 300 nm. The ITO film forming method is not particularly limited, such as an electron beam method, a sputtering method, a chemical reaction method, or a coating method.

  If the transparent electrode has a visible light transmittance of 30% or more, there is no major obstacle to its use, but ideally it is preferably close to 100%. Basically, it is preferable to have the same degree of transmittance in the entire visible light range, but if it is desired to change the emission color, it is also possible to positively impart light absorption. In such a case, it is technically easy to change the color using a color filter or an interference filter.

  The organic thin film layer which the electroluminescent element of this invention comprises is comprised from a light emitting layer and another functional layer. The light emitting layer is a functional layer that emits light. Other functional layers include an electron transport layer for injecting electrons into the light emitting layer or transporting electrons (hereinafter, a material used for the layer is referred to as an electron transport material), a hole being injected into the light emitting layer, or a positive layer. And a hole transport layer for transporting holes (a material used for the layer is hereinafter referred to as a hole transport material).

  As the hole transporting material, N, N′-diphenyl-N, N′-di (3-methylphenyl) -1,1′-diphenyl-4,4′-diamine (TPD), N, N′— Triphenylamines represented by diphenyl-N, N′-dinaphthyl-1,1′-diphenyl-4,4′-diamine (NPD), N-isopropylcarbazole, biscarbazole derivatives, pyrazoline derivatives, stilbene compounds , Hydrazone compounds, heterocyclic compounds typified by oxadiazole derivatives and phthalocyanine derivatives, and polymer systems are preferably polycarbonates or polystyrene derivatives having the above-mentioned monomers in the side chain, polyvinylcarbazole, polysilane, polyphenylene vinylene, etc. It is not limited.

  In addition to anthracene, pyrene, and 8-hydroxyquinoline aluminum, the material of the light emitting layer includes, for example, bisstyryl anthracene derivatives, tetraphenylbutadiene derivatives, coumarin derivatives, oxadiazole derivatives, distyrylbenzene derivatives, pyrrolopyridine derivatives, In the case of perinone derivatives, cyclopentadiene derivatives, thiadiazolopyridine derivatives, and polymer systems, polyphenylene vinylene derivatives, polyparaphenylene derivatives, polythiophene derivatives, and the like can be used. Further, as the dopant added to the light emitting layer, rubrene, quinacridone derivatives, phenoxazone 660, DCM1, perinone, perylene, coumarin 540, diazaindacene derivatives and the like can be used as they are.

  The electron transport material in the present invention needs to efficiently transport electrons from the cathode between electrodes to which an electric field is applied, and has high electron injection efficiency, and preferably transports the injected electrons efficiently. For this purpose, a substance having a high electron affinity, a high electron mobility, excellent stability, and a trapping impurity that is unlikely to occur during manufacture and use is preferable. Specifically, quinolinol derivative metal complexes represented by 8-hydroxyquinoline aluminum, tropolone metal complexes, flavonol metal complexes, perylene derivatives, perinone derivatives, naphthalene derivatives, coumarin derivatives, oxadiazole derivatives, aldazine derivatives, bisstyryl derivatives, pyrazines Examples include derivatives, oligopyridine derivatives such as bipyridine and terpyridine, phenanthroline derivatives, quinoline derivatives, and aromatic phosphorus oxide compounds. These electron transport materials are used alone, but may be laminated or mixed with different electron transport materials.

  The materials used for the hole transport layer, the light emitting layer, and the electron transport layer can form each layer alone. Polyvinyl chloride, polycarbonate, polystyrene, poly (N-vinylcarbazole) are used as the polymer binder. , Polymethyl methacrylate, polybutyl methacrylate, polyester, polysulfone, polyphenylene ether, polybutadiene, hydrocarbon resin, ketone resin, phenoxy resin, polyurethane resin and other solvent-soluble resins, phenol resin, xylene resin, petroleum resin, urea resin, melamine It can also be used by being dispersed in a curable resin such as a resin, an unsaturated polyester resin, an alkyd resin, an epoxy resin, or a silicone resin.

  Examples of the method for forming the organic thin film layer such as the hole transport layer, the light emitting layer, and the electron transport layer include resistance heating vapor deposition, electron beam vapor deposition, and sputtering. Although not particularly limited, usually, vapor deposition methods such as resistance heating vapor deposition and electron beam vapor deposition are preferable in terms of characteristics. The thickness of the layer cannot be limited because it depends on the resistance value of the organic thin film layer, but is usually selected from 10 to 1000 nm.

  The cathode serving as the second electrode is not particularly limited as long as it can efficiently inject electrons into the electron transport layer or the light emitting layer provided in the element of the present invention. Therefore, it is possible to use low work function metals such as alkali metals, but considering the stability of the electrodes, metals such as platinum, gold, silver, copper, iron, tin, aluminum, magnesium, and indium, or these metals A preferable example is an alloy of a low work function metal and the like. In addition, a stable electrode can be obtained while maintaining high electrode injection efficiency by previously doping a small amount of low work function metal into the organic thin film layer and then forming a film using a relatively stable metal as a cathode. These electrodes are preferably produced by a dry process such as resistance heating vapor deposition, electron beam vapor deposition, sputtering, or ion plating.

  When the organic electroluminescent element in the present invention is sealed with the resin composition for sealing an organic electroluminescent element, the substrate is used when the organic electroluminescent element sealing resin composition is cured in order to improve resin adhesion. A means for applying pressure in the direction in which the sealing plate and the sealing plate are attached can be used, which is effective in adhesion between the substrate or the sealing plate and the organic electroluminescent element sealing resin composition. By applying pressure, the resin composition for sealing an organic electroluminescent element enters a minute uneven portion on the surface of the adherend, thereby improving adhesion. The applied pressure has an optimum value depending on various conditions such as the resin viscosity, the curing temperature, and the material of the adherend, and thus cannot be defined unconditionally, but it is sufficient that the pressure is at least 1 kPa or more. As a method of applying pressure, any method such as a method of placing a weight on the element or a method of applying a hydrostatic pressure to a medium such as a gas or a liquid that fills the processing chamber for sealing may be used.

  The curing conditions for the resin composition for sealing an organic electroluminescent element are not limited to curing at room temperature, and it is a matter of course that the temperature conditions can be selected as long as the organic electroluminescent element is not degraded. . Further, in order to improve the adhesion between the organic electroluminescent element sealing resin composition and the sealing plate, the sealing plate is washed with an appropriate solvent or subjected to UV treatment to obtain a surface of the sealing plate. It is effective to use a method to clean the surface.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated, this invention is not limited by these examples.

Example 1
An ITO substrate in which an ITO transparent electrode film having a thickness of 130 nm was formed on a non-alkali glass surface having a thickness of 1.1 mm by a sputtering vapor deposition method was prepared. After patterning this ITO film using a photolithographic method, it was cut into a size of 46 mm × 38 mm, and patterned so that an ITO film (first electrode) having a width of 12 mm was present in the center of the substrate to produce a substrate. .

The substrate was washed with alkali and UV ozone, set in a vapor deposition machine, and evacuated to a vacuum of 2 × 10 ⁻⁴ Pa. With a shadow mask for the light emitting layer having an opening of 15 mm square disposed, copper phthalocyanine 10 nm, N, N′-diphenyl-N, N′-dinaphthyl-1,1 ′ in terms of a film thickness monitor display value by a crystal resonator -Diphenyl-4,4'-diamine (α-NPD) 50 nm and tris (8-quinolinolato) aluminum (Alq ₃ ) 50 nm were deposited. Then, the organic thin film layer was exposed to lithium vapor for doping (film thickness conversion amount 0.5 nm). Next, the shadow mask for the second electrode having four openings of 5 × 12 mm was replaced, and aluminum was deposited to a thickness of 120 nm at a vacuum degree of 3 × 10 ⁻⁴ Pa, thereby patterning the second electrode. In this manner, an organic electroluminescent element having four green light emitting regions on the substrate was produced. The organic electroluminescent element was taken out from the vapor deposition machine, held for 20 minutes under a reduced pressure atmosphere by a rotary pump, and then transferred to a glove box having an argon atmosphere with a dew point of −80 ° C. Sealing was performed in the dry atmosphere by the following procedure.

  (A) Bisphenol A type epoxy resin ("Epicoat 825", manufactured by Japan Epoxy Resin Co., Ltd.) as an epoxy resin, (B) Diethylenetriamine (manufactured by Tokyo Chemical Industry Co., Ltd.) as a curing agent, (C) Silane cup As the ring agent, γ-glycidoxypropyltrimethoxysilane (“KBM403”, manufactured by Shin-Etsu Chemical Co., Ltd.) was prepared. At room temperature, the (C) silane coupling agent was added to the (B) curing agent so as to be 0.5 wt% of the total weight of the resin after curing, and the mixture was stirred for 3 hours using a rotary shaker until uniform. The curing agent after mixing and (A) the epoxy resin were weighed so as to be 13: 100, and then mixed and stirred at room temperature using a spatula for 5 minutes.

  The mixed sealing resin composition is applied around the light emitting layer 6 of the organic electroluminescent element so as to have the configuration shown in FIG. 1, and a non-alkali glass plate having a thickness of 0.7 mm is used as the sealing plate 21. Pasted together. The width of the cured resin composition (horizontal direction with respect to the substrate surface) was set to 2 mm. The sealing resin composition was crosslinked and cured at 25 ° C. for 20 hours in a state where a load of 10 kPa was applied in the bonding direction to the organic electroluminescent element after bonding.

  The obtained organic electroluminescence device was subjected to a storage test in an atmosphere at a temperature of 60 ° C. and a relative humidity of 90% RH. As a result, 99% (area ratio) or more of the light emitting region observed at the start of the storage test was maintained for up to 150 hours.

Example 2
In Example 1, the same evaluation was performed except that (C) the silane coupling agent was changed to γ-aminopropyltriethoxysilane having an amino group (“KBE903”, manufactured by Shin-Etsu Chemical Co., Ltd.). .

  The obtained organic electroluminescence device was subjected to a storage test in an atmosphere at a temperature of 60 ° C. and a relative humidity of 90% RH. As a result, 99% (area ratio) or more of the light emitting region observed at the start of the storage test was maintained for up to 300 hours.

Example 3
In Example 1, it is the same except that (C) the silane coupling agent is changed to aminophenyltrimethoxysilane (“SIA0599.2”, manufactured by Gelest Co., Ltd.) which has an amino group and is aromatic. Was evaluated.

  The obtained organic electroluminescence device was subjected to a storage test in an atmosphere at a temperature of 60 ° C. and a relative humidity of 90% RH. As a result, 99% (area ratio) or more of the light-emitting region observed at the start of the storage test was maintained for up to 500 hours.

Example 4
In Example 3, the same evaluation was performed except that the amount of (C) the silane coupling agent added was 0.005 wt%.

  The obtained organic electroluminescence device was subjected to a storage test in an atmosphere at a temperature of 60 ° C. and a relative humidity of 90% RH. As a result, 99% (area ratio) or more of the light emitting region observed at the start of the storage test was maintained for up to 150 hours.

Example 5
In Example 3, the same evaluation was performed except that the amount of (C) the silane coupling agent added was 0.1 wt%.

  The obtained organic electroluminescence device was subjected to a storage test in an atmosphere at a temperature of 60 ° C. and a relative humidity of 90% RH. As a result, 99% (area ratio) or more of the light emitting region observed at the start of the storage test was maintained for up to 300 hours.

Example 6
In Example 3, the same evaluation was performed except that the amount of (C) the silane coupling agent added was 1 wt%.

  The obtained organic electroluminescence device was subjected to a storage test in an atmosphere at a temperature of 60 ° C. and a relative humidity of 90% RH. As a result, 99% (area ratio) or more of the light-emitting region observed at the start of the storage test was maintained for up to 500 hours.

Example 7
In Example 3, the same evaluation was performed except that the amount of (C) the silane coupling agent added was 7 wt%.

  The obtained organic electroluminescence device was subjected to a storage test in an atmosphere at a temperature of 60 ° C. and a relative humidity of 90% RH. As a result, 99% (area ratio) or more of the light emitting region observed at the start of the storage test was maintained for up to 300 hours. However, due to the influence of alcohol generated inside the sealed space due to the addition of the silane coupling agent, the light emitting surface showed a non-uniform luminance distribution.

Example 8
In Example 3, the same evaluation was performed except that (C) a silane coupling agent was mixed in advance with (B) the curing agent and the evaluation was performed after storage for 1 month. Storage was performed in a desiccator controlled to a relative humidity of 20% or less. The storage temperature was 25 ° C.

The obtained organic electroluminescence device was subjected to a storage test in an atmosphere at a temperature of 60 ° C. and a relative humidity of 90% RH. As a result, among the light emitting regions observed at the start of the storage test, a light emitting region of 99% (area ratio) or more was maintained for up to 500 hours, and the storage stability of the sealing resin composition was confirmed. (Maintenance of initial characteristics)
Comparative Example 1
(C) The same evaluation as in Example 1 was performed except that no silane coupling agent was added.

  The obtained organic electroluminescence device was subjected to a storage test in an atmosphere at a temperature of 60 ° C. and a relative humidity of 90% RH. As a result, the light-emitting region observed at the start of the test became non-light-emitting to 10% (area ratio) or less within 100 hours.

Comparative Example 2
As a resin composition for sealing an organic electroluminescent element, an ultraviolet curable resin (“XNR5516”, manufactured by Nagase ChemteX Corporation) is used, and (C) γ-aminopropyltriethoxysilane having an amino group as a silane coupling agent. ("KBE903", manufactured by Shin-Etsu Chemical Co., Ltd.) was added at 0.5 wt%. When evaluation was performed after storage for 1 month in the same manner as in Example 8, the sealing resin composition was thickened and could not be applied to the substrate. (Insufficient storage stability)
The results of Examples 1-8 and Comparative Examples 1-2 are summarized in Table 1.

Sectional drawing which shows an example of the organic electroluminescent element of this invention. Sectional drawing which shows another example of the organic electroluminescent element of this invention. Sectional drawing which shows another example of the organic electroluminescent element of this invention. Sectional drawing which shows another example of the organic electroluminescent element of this invention. Sectional drawing which shows another example of the organic electroluminescent element of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Board | substrate 2 1st electrode 3 Drive source 5 Hole transport layer 6 Light emitting layer 8 Second electrode 21 Sealing plate 22 Organic electroluminescent element sealing resin composition 23 Internal space 24 Recessed part 25 Leg part 26 Protective film

Claims (6)

(A) An epoxy resin, (B) a thermosetting curing agent, and (C) a silane coupling agent are essential components, and the above (A), (B), and (C) are mixed and cured by crosslinking. What is claimed is: 1. A resin composition for sealing an organic electroluminescent element, comprising: The content of the (C) silane coupling agent is 0.01 wt% or more and 5 wt% or less of the total weight of the encapsulating resin composition. Resin composition. The resin composition for sealing an organic electroluminescent element according to claim 1, wherein the (C) silane coupling agent has an amino group. The resin composition for sealing an organic electroluminescent element according to claim 1, wherein the (C) silane coupling agent is an aromatic silane coupling agent. The resin composition for sealing an organic electroluminescent element according to claim 1, wherein the (B) curing agent is an amine resin. 6. An organic electroluminescent device, which is sealed with the resin composition for sealing an organic electroluminescent device according to claim 1.

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