JP4941295B2 - Organic EL element sealing film and organic EL element sealing structure - Google Patents

Description

  The present invention relates to a sealing film for an organic EL element that emits light with high brightness when an electric field is applied, and more specifically, covers the entire surface of an organic EL element formed on a substrate in order to protect the organic EL element from moisture and the like. The present invention relates to a film-shaped sealing material to be formed and an organic EL element sealing structure using the sealing material.

An organic EL element is a polycrystalline semiconductor device, and can be used for a backlight of a liquid crystal because it can obtain high luminance light emission at a low voltage, and is expected to be a thin flat display device.
However, the organic EL element is extremely sensitive to moisture, the interface between the metal electrode and the organic EL element layer peels off due to the influence of moisture, the resistance of the metal increases due to oxidation, and the organic matter itself of the organic EL element is altered by moisture. For this reason, there is a drawback that light emission stops or luminance decreases.
In order to solve such a problem, the organic EL element is integrated with a sealing base material such as glass by using a thermosetting epoxy resin, and is shielded from external factors such as water (Japanese Patent Application Laid-Open (JP-A) No. 2002-216950). However, this method always has the disadvantages that it is difficult to cope with thinning because it is necessary to bond glass substrates, and that it is difficult to cope with enlargement and film formation.

In addition, a film provided with a gas barrier function by directly forming an inorganic film such as silicon oxide on a transparent substrate (base film) (Japanese Patent Laid-Open No. 2001-283645), and an adhesive function provided to such a gas barrier film Sealing with a film adhesive has also been proposed (Japanese Patent Laid-Open No. 2004-139777). However, for reasons such as a thin gas barrier layer and insufficient adhesion between the transparent substrate and the inorganic film, it has been difficult to reduce the gas permeability to a level necessary for maintaining the quality of the organic EL element.
Further, sealing with an inorganic film single layer has been proposed, but there are problems such as adhesion of the inorganic film single layer and generation of pinholes. Furthermore, a sealing method for forming a laminated structure of an inorganic layer / organic layer on an organic EL element by a vapor deposition process has also been proposed, but the process is complicated due to the vapor deposition process, and the implementation facility is large and a simple method. I can't.

Further, gas barrier films having an organic / inorganic multilayer structure have also been proposed, but all are proposals as a base film, and the organic layer is made of acrylic (JP 2004-244606 A, JP 10-119170 A). Gazette) or polyparaxylylene (Japanese Patent Laid-Open No. 2003-109748), which is not sufficient in terms of adhesive strength to organic EL elements and reliability.
As described above, many sealing methods using an adhesive or an inorganic film have been proposed, but sufficient in terms of sealing performance, cost, etc. when considering thinning, upsizing, and filming of an organic EL element. It cannot be said that it is a proper sealing means. Furthermore, since the organic EL element is weak against moisture, the manufacturing site needs to keep the humidity in an extremely low environment, but in order to carry out a plurality of processes for forming an organic film or an inorganic film on the entire surface as in the conventional case. However, environmental management must be performed in all processes such as coating, drying, and curing, resulting in a problem that the manufacturing apparatus and equipment are complicated.
JP 2002-216950 A JP 2001-283645 A JP 2004-139777 A Japanese Patent Laid-Open No. 2004-244606 JP 10-119170 A JP 2003-109748 A

  The present invention solves the above-mentioned problems of the prior art, can be sealed without adversely affecting the organic EL element by a simple process, and enables the organic EL display to be thinned, enlarged and made into a film. It aims at providing the film-form sealing material for organic EL element sealing.

In order to solve the above problems, in the present invention, in order to seal the entire surface of the organic EL element formed on the substrate, the epoxy resin layer 1, the inorganic film layer, and the epoxy resin layer 2 are sequentially formed on the base film. A laminated organic EL element sealing film is provided.
The organic EL element sealing film of the present invention is a film formed in a separate process from the organic EL element, unlike the conventional sealing film that has already been cross-linked and has no re-fusion property, The film of the present invention has a structure of organic layer-inorganic layer-organic layer.
For this reason, the sealing film of the present invention can be sealed by a simple process in which a separately manufactured organic EL element is thermocompression bonded and adhered to the surface irregularities of the organic EL element by melting and crosslinking. That is, according to the present invention, the above-described problems are solved, and the organic EL display can be made thinner, larger and made into a film.
Furthermore, by using the sealing film of the present invention, the formation of the sealing layer on the entire surface of the organic EL element can be performed without strict humidity control, and the manufacture of the device including the organic EL element is facilitated.

Therefore, the present invention is an organic EL element sealing film having an epoxy resin layer 1, an inorganic film layer, and an epoxy resin layer 2 sequentially laminated on a base film, the epoxy resin layer 1, The epoxy resin composition forming the epoxy resin layer 2 includes a low molecular weight epoxy resin having a molecular weight of 200 to 2,000 and a high molecular weight epoxy resin having a molecular weight of 20,000 to 100,000, and the low molecular weight epoxy. Provided is the organic EL element sealing film in which a resin and a high molecular weight epoxy resin can be cured.
Furthermore, the present invention is a low molecular weight epoxy resin having a molecular weight of 200 to 2,000, wherein the low molecular weight epoxy resin has at least two glycidyl groups in one molecule, and the high molecular weight epoxy resin is in one molecule. The organic EL element sealing film, which is a high molecular weight epoxy resin having at least two glycidyl groups and having a molecular weight of 20,000 to 100,000.

Furthermore, in the present invention, the epoxy resin composition for forming the epoxy resin layer 1 and / or the epoxy resin layer 2 further comprises a latent imidazole compound having a melting point or decomposition temperature of 80 ° C. or higher, and a silane coupling agent. The organic electroluminescent element sealing film containing is provided.
Furthermore, this invention provides the sealing structure of the organic EL element by which the whole surface of the organic EL element formed on the glass or film substrate is sealed with the said organic EL element sealing film.
The organic EL element sealing structure is formed on a glass or plastic film substrate after an organic EL element layer comprising a transparent electrode, a hole transport layer, an organic EL element layer and a back electrode is formed thereon. The sealing film of the present invention is bonded together, and the epoxy resin layers 1 and 2 are further heat-cured. Even if the base film of the organic EL device sealing film of the present invention is used as a release film and peeled before or after thermosetting, the sealing performance is not particularly affected. Further, after the release film is peeled off before thermosetting, it can be sealed with another glass substrate or metal substrate while being heated.

By using a film for sealing an organic EL element having a laminated structure of the base film / epoxy resin layer 1 / inorganic film layer / epoxy resin layer 2, the organic EL element is sealed in a simple manner with a high gas barrier property. And the progress of the deterioration of the organic EL element can be significantly suppressed. Moreover, the organic EL element sealing film of the present invention can be applied to flexible organic EL by forming epoxy resins on both the upper and lower sides of the inorganic film.
In addition, by using a peelable film as the base film, it is possible to peel the release film and bond it to another film (thin plate) substrate before curing the epoxy resin layer. It becomes. Furthermore, it is possible to correspond to a top emission structure by making the base film transparent.
In addition, by forming the epoxy resin layer 1 or 2 with a thermosetting composition mainly composed of a high molecular weight epoxy resin, a low molecular weight epoxy resin, an imidazole epoxy curing agent, and a silane coupling agent, generation of dark spots By suppressing growth reliably and maintaining high transmittance, an organic EL element sealing structure that can maintain stable light emission characteristics over a long period of time can be provided. Next, the present invention will be described in further detail.

  The sealing structure of the organic EL element in the present invention is manufactured as follows. First, a transparent electrode is formed to a thickness of about 0.1 μm on a glass or film substrate. The transparent electrode can be formed by a method such as vacuum deposition or sputtering. However, film formation by vacuum deposition may cause crystal grains to grow and reduce the smoothness of the film surface, and when applied to a thin film EL, it needs to be taken care of because it causes a dielectric breakdown film and uneven light emission. . On the other hand, film formation by sputtering has good surface smoothness, and favorable results are obtained when a thin film device is laminated thereon. Subsequently, a hole transport layer and an organic EL element layer are sequentially formed on the transparent electrode in a thickness of 0.01 μm to 0.10 μm, preferably 0.03 μm to 0.07 μm, particularly preferably 0.05 μm. Film. Further, a back electrode is formed to a thickness of 0.1 to 0.3 μm on the organic EL element layer.

The film for sealing an organic EL element of the present invention is bonded to the upper part of the glass or film substrate on which these elements have been formed with a roll laminator or the like.
At this time, in the organic EL element sealing film of the present invention, the thickness of the base film is preferably about 25 to 200 μm. The inorganic film layer has a thickness of 1 μm to 15 μm, preferably 5 μm to 15 μm, particularly preferably 5 μm to 10 μm in order to ensure the gas barrier function. If an inorganic film of about 5 μm is formed directly on the organic EL element substrate or sealing film, cracks may occur due to stress, but by forming an epoxy resin layer on both the upper and lower sides, it becomes a cushioning material. Generation of cracks can be suppressed. The thickness of each of the epoxy resin layers 1 and 2 is 5-30 μm, particularly 5-20 μm, considering transfer workability and the like. The organic EL element sealing film preferably has a total thickness of 36 μm to 250 μm.

The organic EL element sealing film of the present invention is pressure-bonded onto the organic EL element produced in a separate process using a pressure bonding apparatus such as a vacuum laminator or a roll laminator. At that time, by heating appropriately, for example, at 50 to 100 ° C., the epoxy resin layer softens and develops fluidity, easily deforms due to pressure stress, and closely adheres to the surface shape of the organic EL element. can do.
Then, by continuously or heating the heating temperature, the low molecular weight epoxy resin group and the glycidyl group of the high molecular weight epoxy resin cause a three-dimensional crosslinking reaction in the epoxy resin layer, and the resin is cured. To do. Once the epoxy resin has been three-dimensionally cross-linked, it has no heat melting property and exhibits a strong adhesive force. Although it does not restrict | limit in particular, It is preferable to heat-process at 80-150 degreeC, Preferably it is 80-120 degreeC.
The melting temperature (flowing temperature expression temperature) and the curing temperature (crosslinking reaction temperature) of the epoxy resin composition can be adjusted by the composition of the epoxy resin composition. That is, the melting temperature can be adjusted depending on the molecular weight and addition amount of the high molecular weight epoxy resin used, the molecular weight and structure of the low molecular weight epoxy, and the addition amount, and the kind and amount of filler such as silica powder. For example, it can be adjusted so that it does not have fluidity at room temperature of 25 ° C. and exhibits fluidity at 50 ° C. to 100 ° C.
The expression of the fluidity means that the epoxy resin composition forming the epoxy resin layers 1 and 2 has a viscosity that does not flow drastically, and the resin composition enters the uneven space of the organic EL element due to stress. It means that some degree of flexibility occurs.

The curing temperature can be adjusted mainly by the type and addition amount of the curing agent in the composition. In the present invention, it is preferable to use a latent curing agent.
The “latent curing agent” used in the present specification is stable over a long period of time when kept at room temperature when blended in the epoxy resin composition, but rapidly cures under predetermined conditions such as heating. Means hardener to start. By using the latent curing agent, a one-component heat-curable epoxy resin composition can be obtained.
Such latent curing agents include dicyandiamide, diaminodiphenylsulfone, polyhydric phenol, imidazole, and the like, and imidazole compounds that initiate a curing reaction at a relatively low temperature are particularly preferable.
In the present invention, the epoxy resin layers 1 and 2 can be cured by heating, and are not particularly limited as long as the latent imidazole compound is solid at room temperature and has a melting point or decomposition temperature of 80 ° C. or higher. It can be used as a latent curing agent.

  Examples of the imidazole compound include 2-methylimidazole, 2-heptadecylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecyl. Imidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6- [2'-methylimidazolyl- (1 ')]-ethyl-s-triazine, 2,4-diamino -6- [2'-undecylimidazolyl- (1 ')]-ethyl-s-triazine, 2,4-diamino-6- [2'-ethyl-4'-methylimidazolyl- (1')]-ethyl -S-triazine, 2,4-diamino-6- [2'-methylimidazolyl- (1 ')]-ethyl- -Triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-methylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole 2-methylimidazoline, 2-phenylimidazoline, 2,3-dihydro-1H-pyrrolo [1,2-a] benzimidazole, and the like. These imidazole compounds can be used alone or in combination.

Examples of commercially available imidazole compounds include Amicure PN-23, PN-R (Ajinomoto Co., Inc.), Adeka Hardener EH-4346S (Asahi Denka Kogyo Co., Ltd.), NovaCure HX-3721. And NOVACURE HX-3921HP (manufactured by Asahi Kasei Corporation).
In addition, a release film such as a polyethylene terephthalate film can be used as the base film, and the release film may be peeled off before or after the epoxy resin layers 1 and 2 are thermally cured. There is no effect on the sealing performance. Further, the release film is removed before thermosetting, and a glass substrate is further bonded on the sealing film of the present invention, or a metal substrate is bonded for the purpose of heat dissipation, and then the epoxy resin layer is cured by heat treatment. It can also be made.
Further, in order to carry out the bonding step in the air, the organic EL sealing substrate of the present invention is formed on the organic EL element substrate after forming a minimum inorganic film having a thickness of, for example, about 100 to 200 nm. It can also be sealed with.

The cured product of the epoxy resin composition forming the epoxy resin layer 1 and / or 2 of the present invention has a moisture permeability of 500 mg / m ² × 24 in an atmosphere having a moisture permeability of 60 μC and a humidity of 95% at a thickness of 150 μm. The transmittance of light of 405 nm is 90% or more with respect to a 20 μm-thick cured product layer, and has an adhesive strength of 1.0 MPa or more in a peel adhesion test between glasses. Is preferred. Further, the epoxy resin composition is preferably cured at a relatively low temperature of 120 ° C. or lower.

  The epoxy resin composition for forming the epoxy resin layer 1 and the epoxy resin layer 2 of the present invention is a polymerizable composition containing a compound having a polymerizable glycidyl group in the molecule, and the composition as a whole is at room temperature ( At 25 ° C.). Such a composition is preferably prepared by mixing a low molecular weight epoxy resin having a molecular weight of 200 to 2,000 and a high molecular weight epoxy resin having a molecular weight of 20,000 to 100,000. Furthermore, a filler such as silica powder may be added to an epoxy resin that is liquid at room temperature, or a high molecular polymer that is compatible with the epoxy resin may be dissolved so as to be apparently solid at room temperature.

  The high molecular weight epoxy resin having a molecular weight of 20,000 to 100,000 used when forming the epoxy resin layer 1 and / or 2 of the present invention is solid at room temperature, preferably at least in one molecule. It has two or more glycidyl groups. Specific examples include epoxy resins such as solid bisphenol A type epoxy resin, solid bisphenol F type epoxy resin, and phenoxy resin. Among these, a phenoxy resin having film strength is preferable when the epoxy resin layers 1 and 2 are laminated and formed in an unreacted state. Examples of commercially available high molecular weight epoxy resins include Epicoat 1256 (manufactured by Japan Epoxy Resin), PKHH (INCHEM), and YP-70 (manufactured by Toto Kasei).

  With the high molecular weight epoxy resin alone, it is difficult to form the epoxy resin layers 1 and 2 on the base film, or fluidity is obtained when the epoxy resin layers 1 and 2 formed on the film base are heated and melted. In order to adjust the curing characteristics when the epoxy resin layer is cured by heating, a low molecular weight epoxy resin is added. In the present invention, a compound having a molecular weight of less than 2,000, particularly a molecular weight of 200 to 2,000 and having one or more glycidyl groups in the molecule is preferred. Specific examples include epoxy resins such as bisphenol A type epoxy resins, bisphenol F type epoxy resins, hydrogenated bisphenol type epoxy resins, and phenol novolac type resins. Among these resins, those having a low chlorine ion content, particularly those having hydrolyzable chlorine of 500 ppm or less are preferred. Moreover, when the specific example on the market of the said low molecular-weight epoxy resin is given, Epiklon EXA-835LV (made by Dainippon Ink Industries) and Epicoat 152 (made by Japan Epoxy Resin Co., Ltd.) with few chlorine ion concentration can be used preferably. .

  The mixing ratio of the high molecular weight epoxy resin and the low molecular weight epoxy resin may be 40 to 150 parts by weight, particularly 50 to 100 parts by weight, based on 100 parts by weight of the low molecular weight epoxy resin. preferable. When the high molecular weight epoxy resin is less than 40 parts by weight, a film cannot be formed when formed into a sheet, whereas when it exceeds 150 parts by weight, the sheet film becomes hard and brittle, workability is deteriorated, and the crosslinking density Becomes low and it becomes difficult to maintain reliability.

  The addition amount of the curing agent component is 0.5 to 20 parts by weight, particularly 1.5 to 10 parts by weight with respect to 100 parts by weight of the total amount of the epoxy resin compound in consideration of storage stability, curability, and transmittance. It is preferable to add. When the curing agent is added in an amount of less than 0.5 parts by weight, the epoxy resin compound cannot be sufficiently cured. On the other hand, when it exceeds 20 parts by weight, coloring of the cured product becomes intense, and the film-like property of the present invention is further increased. The stability after forming becomes worse.

  In order to improve the adhesiveness after curing of the epoxy resin layers 1 and 2 of the present invention, it is effective to use a silane coupling agent in combination. Examples of the silane coupling agent include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3,4-epoxycyclohexyl). ) Ethyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N- (2-aminoethyl) 3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) 3-aminopropylmethyltrimethoxysilane 3-aminopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, vinyltrimethoxysilane, N- (2- (vinylbenzylamino) ethyl) 3-aminopropyltrimethoxysilane hydrochloride, and 3-methacryloxypropyl Trimethoxysila And the like. These silane coupling agents can be used alone or in admixture of two or more. Among these silane coupling agents, 3-glycidoxypropyltrimethoxysilane (KBM-403: manufactured by Shin-Etsu Chemical Co., Ltd.) is preferable because of its good compatibility with the epoxy resin composition and excellent stability.

The addition amount of the silane coupling agent is preferably 0.1 to 10 parts by weight, particularly 0.3 to 2 parts by weight, based on 100 parts by weight of the total amount of the epoxy resin composition. If the amount of the silane coupling agent is less than 0.1 parts by weight, the effect cannot be exhibited. On the other hand, if the amount exceeds 10 parts by weight, an adverse effect may occur in terms of outgassing.
As long as the object of the present invention can be achieved, the epoxy resin composition used for forming the epoxy resin layers 1 and 2 of the present invention further includes other components such as a storage stabilizer, a plasticizer, and a tack adjuster. It can also be added.

  An inorganic film layer is formed between the epoxy resin layers 1 and 2 of the present invention. The inorganic film layer is formed of at least one inorganic compound selected from the group consisting of silicon oxide, aluminum oxide, magnesium oxide, zinc oxide, tin oxide, indium tin oxide (ITO), and silicon nitride. As the method for forming the inorganic film layer, sputtering, CVD, vapor deposition, or the like can be used. However, since the inorganic film is formed on the uncured epoxy resin layer 1 in the present invention, the inorganic film can be formed at a low temperature and in a short time, and the gas barrier performance is ensured. Therefore, it is necessary to obtain a sufficient film thickness of 1 μm or more. Therefore, in the present invention, an inorganic film containing silicon oxide formed by low-temperature CVD is preferable.

Next, the manufacturing process of the organic EL element sealing film of the present invention will be described. First, a solution prepared by dissolving and mixing a solid epoxy resin composition in an organic solvent such as methyl ethyl ketone and toluene at room temperature to form the epoxy resin layer 1 or 2 is prepared. A curing agent and, if necessary, an additive and the like are added to the solution. Next, it is applied on the base film so as to have a constant thickness by a coating machine such as a roll coater, and then the organic solvent is volatilized to form a solid sheet, film, or tape in the normal temperature range (about 25 ° C.). Form.
Next, an inorganic film layer is formed on the epoxy resin layer 1 formed on the base film by an appropriate forming method, for example, low temperature CVD (FIG. 2). The low temperature CVD is preferably performed at a temperature of 80 ° C. or lower.

On the other hand, an epoxy resin layer 2 is formed on a base film (transparent film, release film) in the same manner as described above (FIG. 2). This epoxy resin layer 2 may be comprised from the composition similar to the epoxy resin layer 1, and may use the epoxy resin composition from which a composition differs as needed. Since the epoxy resin layers 1 and 2 are formed so that one of the layers covers the entire surface of the organic EL element layer, it is necessary to consider that the organic EL element layer is not affected.
Thereafter, the two films are bonded together with a roll laminator or the like so that the inorganic film layer is sandwiched between the epoxy resin layers 1 and 2. An organic EL element sealing film is formed through such steps (FIG. 2). The film for encapsulating an organic EL device of the present invention can be stored for a long time at a low temperature by forming the epoxy resin layers 1 and 2 in a solid state in a normal temperature range, but in order to keep the moisture content below a certain level. It is preferable to store with a desiccant such as silica gel.
Next, based on an Example, this invention is demonstrated in detail. The scope of the present invention is not limited by these examples.

Epoxy resin compositions for forming the epoxy resin layers 1 and 2 were prepared at the blending ratios shown in Table 1. The contents of each component shown in Table 1 are as follows (low molecular weight epoxy resin)
* Epicoat 152: Phenol novolac type epoxy resin Molecular weight: about 530 (made by Japan Epoxy Resin Co., Ltd.)
* Epicoat 1001: Solid bisphenol A type epoxy resin Molecular weight: about 900 (made by Japan Epoxy Resin Co., Ltd.)
(High molecular weight epoxy resin)
* PKHH: Phenoxy resin Molecular weight: approx. 52,000 (manufactured by INCEM)
* Epicoat 1256: Phenoxy resin Molecular weight: approx. 50,000 (manufactured by Japan Epoxy Resin)
(Epoxy curing agent)
* 2 PZ-CNS-PW: ground product of 1-cyanoethyl-2-phenylimidazolium trimellitate Melting point 105 to 111 ° C. (manufactured by Shikoku Kasei Kogyo Co., Ltd.)
* C11Z-CNS: 1-cyanoethyl-2-undecylimidazolium trimellitate Melting point: 123-129 ° C. (manufactured by Shikoku Chemicals)
* 2E4MZ: 2-ethyl-4-methylimidazole Melting point: about 41 ° C. (manufactured by Shikoku Chemicals)
(Silane coupling agent)
* KBM403: Silane coupling agent (Shin-Etsu Chemical Co., Ltd.)

Example 1
On a transparent PET (polyethylene terephthalate thickness 75 μm) substrate, the composition 1 of Table 1 (16X-082E-7B (manufactured by ThreeBond Co., Ltd .: trade name) was uniformly applied to a thickness of 20 μm and dried at 40 ° C. The sheet-like board | substrate A in which the resin layer 1 was formed was created, then, the composition 1 was applied on the release film by the same method as described above, and dried at 40 ° C. to form the epoxy resin layer 2 A sheet-like film B was prepared.
Next, an inorganic film was further deposited on the surface of the epoxy resin layer of the sheet-like substrate A. As the inorganic film, a silicon oxide film of 5 μm was applied using SMARTWEB manufactured by Applied Films.

Thereafter, the inorganic film layer of the sheet-like substrate A and the epoxy resin layer of the sheet-like film B were combined and bonded at 60 ° C. using a roll laminator. 60 ° C. is a temperature at which the epoxy resin layers 1 and 2 exhibit fluidity and do not undergo polymerization and curing, and the epoxy resin layer 1, the inorganic film layer, and the epoxy resin layer 2 are uniformly laminated.
In such a procedure, a sealing film having a five-layer structure of sheet-like substrate (PET film) / epoxy resin layer 1 / inorganic film layer (SiOx) / epoxy resin layer 2 / release film was formed.
In another process, a transparent electrode, a hole transport layer, an organic EL layer, and a back electrode were formed on a glass substrate to form an organic EL element. The sealing film prepared in Example 1 was bonded to the organic EL element. The said bonding process peeled the release film of the film for sealing, installed so that the epoxy resin layer 2 and the organic EL element might face, and crimped | bonded by 90 degreeC with the roll laminator. Then, it heated at 110 degreeC for 1 hour, and the epoxy resin layers 1 and 2 were bridge | crosslinked and hardened. Thereby, the organic EL element sealing structure (organic EL light-emitting body) sealed with the sealing film could be obtained.

A sealing film was prepared using the epoxy resin compositions 2 to 7 in Table 1 in the same procedure, and was similarly bonded to the organic EL element. However, it processed at the crimping | compression-bonding temperature and heating temperature which were described in Table 1, respectively.
The obtained organic EL light-emitting body was continuously lit in a high-temperature and high-humidity environment (60 ° C. × 90% RH), and the light emission state after 100 hours and after 1000 hours was observed. The light emission state is obtained by measuring the average value of the width of the dark area from the end of the light emission area. The results are shown in the lower part of Table 1. The unit is μm.

(Comparative Example 1)
Silicon oxide, which is an inorganic film, was directly deposited on the sheet-like substrate (PET) using SMARTWEB manufactured by Applied Films as in Example 1. Moreover, it carried out similarly to Example 1, and created the sheet-like film which applied the composition 1 on the release film and formed the epoxy resin layer. Subsequently, both were bonded in the same manner to form a sealing film of sheet-like substrate (PET) / inorganic film layer (SiOx) / epoxy resin layer (composition 1) / release film. Using the sealing film, an organic EL light emitter was prepared in the same manner as in Example 1, and a continuous lighting experiment was similarly performed under high temperature and high humidity. Similarly, the average width of the dark area from the edge of the light emitting area The value was measured.

(Comparative Example 2)
The composition 1 of the table | surface was uniformly apply | coated to 20 micrometers in thickness on a sheet-like board | substrate (PET), and it was made to dry at 40 degreeC, and the sheet-like board | substrate A in which the epoxy resin layer 1 was formed was created. On the other hand, the composition 1 was applied onto the release film in the same manner as described above, and dried at 40 ° C. to prepare a sheet-like film B on which the epoxy resin layer 2 was formed. The epoxy resin layers of the sheet substrate A and the sheet film B were faced to each other and bonded at 60 ° C. using a roll laminator. In this way, a sealing film having a four-layer structure of sheet-like substrate (PET film) / epoxy resin layer 1 / epoxy resin layer 2 / release film was formed. However, since the epoxy resin layer 1 and the epoxy resin layer 2 are almost integrated, they cannot be substantially distinguished. Using the sealing film, an organic EL light emitter was prepared in the same manner as in Example 1, and a continuous lighting experiment was similarly performed under high temperature and high humidity. Similarly, the average width of the dark area from the edge of the light emitting area The value was measured.
The result of Comparative Example 1 was 250 μm after 100 hours and 1500 μm after 1000 hours, and the result of Comparative Example 2 was 350 μm after 100 hours and 2,000 μm after 1000 hours. Therefore, it was shown from Comparative Example 1 that when the epoxy resin layer 1 is provided only on one side of the inorganic film layer and the epoxy resin layer 2 is missing, the organic EL element is not sufficiently sealed. Moreover, it was shown by Comparative Example 2 that the organic EL element is not sufficiently sealed when the inorganic film layer is missing.

  As described above, the organic EL element film of the present invention has a sufficient gas barrier property while being sealed with a thin film, and can be sealed with a simple process. The thin film is preferably 250 μm or less.

  The film for sealing an organic EL element of the present invention is not limited to sealing an organic EL element, but can be applied to sealing applications for the purpose of improving moisture resistance, weather resistance, and impact resistance of organic semiconductors and other electronic components.

1 is a cross-sectional view of an organic EL element film of Example 1. FIG. It is explanatory drawing which shows the manufacturing process of the film for organic EL elements.

Explanation of symbols

1 Base film 2 Epoxy resin layer 1
3 Inorganic film layer 4 Epoxy resin layer 2
5 Release film 6 Pressure roller

Claims (8)

An organic EL element sealing film having an epoxy resin layer 1, an inorganic film layer, and an epoxy resin layer 2 sequentially laminated on a base film, wherein the epoxy resin layer 1 and / or the epoxy resin layer 2 are The epoxy resin composition to be formed includes a low molecular weight epoxy resin having a molecular weight of 200 to 2,000, a high molecular weight epoxy resin having a molecular weight of 20,000 to 100,000, and a latent curing agent having a melting point or decomposition temperature of 80 ° C. or higher. The organic EL element sealing film, wherein the low molecular weight epoxy resin and the high molecular weight epoxy resin are in an uncured state and can be cured. The epoxy resin layer is formed by applying a solution obtained by dissolving an epoxy resin composition in an organic solvent onto the base film so as to have a constant thickness, and then volatilizing the organic solvent. 1. The organic EL element sealing film according to 1. The film for organic electroluminescent element sealing of Claim 1 or 2 in which the said epoxy resin layer 1 and / or the epoxy resin layer 2 contain an imidazole compound and a silane coupling agent as a latent hardening | curing agent .   The said epoxy resin layer 1 and / or the epoxy resin layer 2 are solid in normal temperature range, and express fluidity | liquidity by heating to 50-100 degreeC. Organic EL element sealing film.   The organic EL element sealing film according to claim 1, wherein the inorganic film is a film of silicon nitride, silicon oxide, or silicon nitride oxide.   The organic EL element by which the whole surface of the organic EL element formed on the glass or film substrate is sealed with the film for organic EL element sealing of any one of Claims 1-5.   The film for sealing an organic EL element according to any one of claims 1 to 5 is softened by heating to exhibit fluidity, and is deformed by a pressure stress to adhere to the surface shape of the organic EL element. The method of pressure-bonding the organic EL element sealing film to the organic EL element.   Furthermore, the heating temperature is raised to 80 to 150 ° C., and the heat treatment is performed, so that the glycidyl group of the low molecular weight epoxy resin and the high molecular weight epoxy resin contained in the epoxy resin layer of the organic EL element sealing film is three-dimensional. The method of crimping | bonding the film for organic electroluminescent element sealing of Claim 7 to an organic EL element including making a crosslinking reaction raise and hardening this epoxy resin layer.

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