WO2006104078A1

WO2006104078A1 - Organic el element sealing film and organic el element sealing structure

Info

Publication number: WO2006104078A1
Application number: PCT/JP2006/306099
Authority: WO
Inventors: Kenichi Horie
Original assignee: Three Bond Co., Ltd.
Priority date: 2005-03-29
Filing date: 2006-03-27
Publication date: 2006-10-05
Also published as: JP4941295B2; JPWO2006104078A1; TWI407611B; TW200711195A

Abstract

An organic EL element sealing film is provided for performing sealing by a simple process and permitting an organic EL display to be thin, large and made into a film, without affecting the organic EL element. The entire surface of the organic EL element formed on a substrate is sealed by using the organic EL element sealing film, which includes an epoxy resin layer (1), an inorganic film layer and an epoxy resin layer (2) which are successively laminated on a base film.

Description

Specification

Organic EL element sealing film and organic EL element sealing structure

Technical field

The present invention relates to a film for sealing an organic EL element that emits light with high brightness by application of an electric field, and more specifically, 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-like sealing material formed on the entire surface of the film, and an organic EL element sealing structure using the sealing material.

Background art

An organic EL element is a polycrystalline semiconductor device that can be used for a backlight of a liquid crystal because it can emit light with high luminance at a low voltage, and is expected to be a thin flat display device. However, the organic EL element has a very weak moisture interface, the interface between the metal electrode and the organic EL element layer is peeled off due to the influence of moisture, the metal becomes highly resistive due to oxidation, and the organic substance itself of the organic EL element is moisture. As a result, the light emission stops or the brightness decreases.

In order to solve these problems, organic EL elements are integrated with a sealing substrate such as glass by using a thermosetting epoxy resin to isolate them from external factors such as water. No. 2002-216950) was developed. This method has the drawbacks that it is difficult to deal with thin films because it requires the pasting of glass substrates, and that it is difficult to deal with the increase in size and film.

[0003] Further, a film provided with a gas barrier function by directly forming an inorganic film such as silicon oxide on a transparent substrate (substrate film) (Japanese Patent Laid-Open No. 2001-283645), and such a gas barrier film Sealing with a film adhesive having an adhesive function has also been proposed (Japanese Patent Laid-Open No. 2004-139977). However, because the gas barrier layer is thin and the adhesion between the transparent substrate and the inorganic film is insufficient, it has been difficult to reduce the gas permeability to the level necessary to maintain the quality of the organic EL device.

Further, sealing with a single inorganic film layer has been proposed, but there are problems such as adhesion of the single inorganic film layer and generation of pinholes. Furthermore, a laminated structure of inorganic / organic layers is deposited In addition, a sealing method for forming on an organic EL element has been proposed, and the process is complicated because of the use of a vapor deposition process.

[0004] Further, gas barrier films having an organic / inorganic multilayer structure have also been proposed, all of which are proposals as substrate films, and the organic layer is made of acrylic (Japanese Patent Laid-Open No. 2004-244606, Kaihei 10-119170) 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. However, the sealing performance, cost, etc. when considering thinning, upsizing, and filming of an organic EL element are reduced. Therefore, it cannot be a sufficient sealing means. Furthermore, since organic EL devices are sensitive to moisture, the manufacturing site must maintain an extremely low humidity environment, but in order to carry out multiple steps of forming an organic film or inorganic film on the entire surface as in the past. However, there is a problem that environmental management must be performed in all processes such as coating, drying, and curing, and the manufacturing equipment and facilities become complicated.

Patent Document 1: JP 2002-216950 A

Patent Document 2: Japanese Patent Laid-Open No. 2001-283645

Patent Document 3: Japanese Patent Application Laid-Open No. 2004-139977

Patent Document 4: Japanese Patent Application Laid-Open No. 2004-244606

Patent Document 5: JP-A-10-119170

Patent Document 6: Japanese Unexamined Patent Publication No. 2003-109748

Disclosure of the invention

Problems to be solved by the invention

[0005] 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 the organic EL display is made thin, large, and film. The purpose is to provide a film-like encapsulant for encapsulating organic EL elements.

Means for solving the problem

[0006] 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 are formed on the base film. Provided is an organic EL device sealing film in which resin layers 2 are sequentially laminated.

The film for sealing an organic EL element of the present invention is a film formed in a separate process from an organic EL element, unlike a conventional sealing film that has already been cross-linked and does not have re-fusing properties, but is heated. The film of the present invention has a structure of an organic layer, an inorganic layer, and an 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-mentioned 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, it is possible to form a sealing layer on the entire surface of the organic EL element without strict humidity control, and to easily manufacture a device including the organic EL element.

Accordingly, the present invention is a film for sealing an organic EL element 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 The epoxy resin composition forming the layer 1 and / or 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. Also provided is the organic EL device sealing film, wherein the low molecular weight epoxy resin and the 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 having at least two glycidyl groups in one molecule, and the high molecular weight epoxy resin is in one molecule. The organic EL device sealing film is a high molecular weight epoxy resin having a molecular weight of 20,000-100,000 and having at least two glycidinole groups.

[0008] Further, the present invention provides the latent imidazole compound, wherein the epoxy resin composition forming the epoxy resin layer 1 and Z or the epoxy resin layer 2 further has a melting point or decomposition temperature of 80 ° C or higher. And a film for sealing the organic EL device, comprising a silane coupling agent.

Furthermore, in the present invention, the entire surface of the organic EL element formed on the glass or film substrate is An organic EL element sealing structure sealed with the organic EL element sealing film is provided.

The organic EL device sealing structure is formed on a glass or plastic film substrate after forming an organic EL device layer comprising a transparent electrode, a hole transport layer, an organic EL device layer and a back electrode. In addition, the sealing film of the present invention is bonded together, and the epoxy resin layers 1 and 2 are further thermally 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.

The invention's effect

[0009] 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 gas barrier property can be easily applied to the organic EL element. High sealing can be performed, and the progress of deterioration of the organic EL element can be greatly suppressed. In addition, the film for sealing an organic EL device of the present invention can be applied to a flexible organic EL by forming an epoxy resin on both upper and lower sides of the inorganic film.

In addition, by using a peelable film as the base film, it is possible to peel off the release film and bond it to another film (thin plate) substrate before curing the epoxy resin layer. It becomes. Furthermore, by making the base film transparent, it is possible to correspond to a top emission structure.

In addition, dark spots are generated by forming epoxy resin layers 1 and 2 with a thermosetting composition mainly composed of high molecular weight epoxy resin, low molecular weight epoxy resin, imidazole epoxy curing agent and silane coupling agent. · An organic EL element sealing structure that can maintain stable light emission characteristics over a long period of time by suppressing growth and maintaining high transmittance can be provided. Next, the present invention will be described in further detail.

BEST MODE FOR CARRYING OUT THE INVENTION

[0010] The sealing structure of the organic EL element in the present invention is manufactured as follows. First, a transparent electrode is formed on a glass or film substrate with a thickness of about 0.1 lxm. Formation of the transparent electrode The film can be formed by a method such as vacuum deposition and sputtering. However, the film formation by vacuum deposition may cause crystal grains to grow and reduce the smoothness of the film surface. When applied to a thin film EL, the dielectric breakdown film causes non-uniform light emission. Need attention. On the other hand, the film formation by the 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 formed on the transparent electrode at a thickness of 0.01 μm to 0.10 μm, preferably 0.03 μm to 0.07 μm. ί Preferably deposited sequentially with a thickness of 0.05 zm. In addition, a back electrode is formed on the organic EL element layer with a thickness of 0.:! To 0.3 zm.

[0011] The organic EL device sealing film of the present invention is bonded to the upper part of the glass or film substrate on which these devices have been formed, using 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 zm. In order to ensure the gas barrier function, the inorganic film layer is set to 1 111 to 15/1 111, preferably 5 / im to 15 μΐη, particularly preferably 5 μ μη to 10 μm. If an organic film of about 5 μm is formed directly on the organic EL element substrate or sealing film, cracks may occur due to stress. However, by forming an epoxy resin layer on both the upper and lower sides. It becomes a buffer material and can suppress the occurrence of cracks. In addition, the thickness of each of the epoxy resin layers 1 and 2 is 5 to 30 / im, particularly 5 to 20 μΐη, considering transfer workability and the like. The organic EL element sealing film preferably has a total thickness of 36 μm to 250 μm.

[0012] The organic EL element sealing film of the present invention is pressure-bonded onto an 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 to an appropriate temperature, for example, 50 to 100 ° C., the epoxy resin layer softens and develops fluidity, easily deforms due to pressure stress, and matches the surface shape of the organic EL element. The ability to adhere is S.

Thereafter, the heat treatment is performed continuously or by raising the heating temperature, whereby the low molecular weight epoxy resin group and the glycidyl group of the high molecular weight epoxy resin cause a three-dimensional cross-linking reaction in the epoxy resin layer. Hardens. Once three-dimensionally cross-linked epoxy resin is no longer meltable and exhibits strong adhesive strength. Although not particularly limited 80-: 150 ° C, preferably 80-: 120 ° C.

The melting temperature (flowing 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 according to 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, the addition amount, and the type and amount of filler such as silica powder. it can. For example, it can be adjusted so that it does not have fluidity at 25 ° C at room temperature 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 does not have a viscosity that flows out 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.

[0013] The curing temperature can be adjusted mainly by the type and 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 for a long period of time when it is kept at room temperature when it is blended in the epoxy resin composition, but it rapidly cures under predetermined conditions such as heating. Means a curing agent that begins. 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 are particularly limited as long as they are latent imidazole compounds that can be cured by heating, are solid at room temperature, and have a melting point or decomposition temperature of 80 ° C or higher. It can be used as a latent curing agent.

[0014] Examples of the imidazole compound include 2_methylimidazole, 2_heptadecylimidazole, 2_phenylimidazole, 2_phenylimidazole, 4-methylimidazole, and 1-cyanoethyl-2-phenylimidazole. , 1-cyanethyl-2-undecylimidazolium trimellitite, 1-cyanethyl-2-methylimidazolium trimellitite, 2, 4-diamino-6_ [2, monomethylimidazolyl _ (1,) ] _Ethyl _ s-triazine, 2, 4-diamino 1 6_ [2, 1-decylimidazolyl _ (1,)] _Ethyl _ s-triazine, 2, 4-dia Minnow 6— [2, -Ethyru 4'-Methylimidazolyl (1 ')]-Ethyru s Triazine, 2,4-Diamino 1 6- [2'-Methylimidazolyl 1 (1')]-Ethyl s Triazine isocyanuric acid Adduct, 2-phenylimidazol isocyanuric acid adduct, 2-methylimidazol isocyanuric acid adduct, 2_phenyl 4,5-dihydroxymethylimidazole, 2-phenyl-1-methyl_5-hydroxymethyl Examples include imidazole, 2-methylimidazoline, 2-phenylimidazoline, 2,3-dihydro-1H-pyro-mouth [1, 2 _a] benzimidazole. These imidazole compounds can be used alone or in combination.

[0015] Examples of the commercially available imidazole compounds include Amicure PN_23, PN-R (Ajinomoto Co., Inc.), Ade force Hardener EH-4346S (Asahi Denka Kogyo Co., Ltd.), Nova Cure HX_ 3721, Novaki Yua HX-3921HP (manufactured by Asahi Kasei Corporation) and the like.

In addition, a release film such as a polyethylene terephthalate film can be used as the base film, and the release film is peeled off and removed before or after the epoxy resin layers 1 and 2 are thermally cured. However, the sealing performance is not affected. Further, the release film is removed before thermosetting, and a glass substrate is further bonded onto 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 formed by heat treatment. It can also be cured.

In addition, in order to perform the bonding process in the air, a minimum inorganic film having a thickness of, for example, about 100 to 200 nm is formed on the organic EL element substrate, and then the organic EL sealing of the present invention is performed. It can also be sealed with a film.

[0016] 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 S at a thickness of 150 zm of the cured product layer in an atmosphere of 95% humidity at 60 ° C. 500mgZm ² X 24 hours or less, and the light transmittance of 405ηm is 90% or more for the 20 μm thickness of the cured product layer. It is preferable to have the above adhesive strength. Furthermore, 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 glycidinole group in the molecule. The composition as a whole must be solid at room temperature (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. In addition, a filler such as silica powder is added to an epoxy resin that is liquid at room temperature, or a high molecular polymer that is compatible with epoxy resin is dissolved so that it becomes an apparent solid at room temperature. May be.

[0018] The high molecular weight epoxy resin having a molecular weight of 20,000-100,000 used for forming the epoxy resin layer 1 and Z or 2 of the present invention is solid at room temperature, preferably 1 minute. It has at least two or more glycidinole groups in the child. 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 a film strength when the epoxy resin layers 1 and 2 are laminated in an unreacted state is preferable. 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).

[0019] With the high molecular weight epoxy resin alone, it is difficult to form the epoxy resin layers 1 and 2 on the substrate film, or when the epoxy resin layers 1 and 2 formed on the film substrate are heated and melted. In order to obtain fluidity or 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 preferred examples include epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, hydrogenated bisphenol type epoxy resin, and phenol novolac type resin. Among these resins, those having a low chlorine ion content, particularly those having hydrolyzable chlorine of 500 ppm or less are preferred. As specific examples of commercially available low molecular weight epoxy resins, Epiclone EXA_ 835LV (produced by Dainippon Ink Industries, Ltd.) with low chloride ion concentration and Nephepicoat 152 (produced by Japan Epoxy Resin Co., Ltd.) can be preferably used. .

[0020] The mixing ratio of the high molecular weight epoxy resin and the low molecular weight epoxy resin is such that the high molecular weight epoxy resin is 40 to 150 parts by weight with respect to 100 parts by weight of the low molecular weight epoxy resin. In particular, it is preferable to add 50 to 100 parts by weight. If the high molecular weight epoxy resin is less than 40 parts by weight, a film cannot be formed when formed into a sheet, whereas if it exceeds 150 parts by weight, the film of the sheet becomes hard and brittle, workability is deteriorated, and crosslinking is performed. Density is low and reliability is difficult to maintain.

[0021] The amount of the curing agent component added is 0.5 to 20 parts by weight, particularly 1.5 to 5 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 10 parts by weight. If the curing agent is added in an amount of less than 0.5 parts by weight, the epoxy resin compound cannot be sufficiently cured, while if it exceeds 20 parts by weight, the cured product becomes highly colored, and further, Stability after forming into a film is deteriorated.

[0022] For the purpose of improving 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 epoxycyclohexane Hexyl) ethyltrimethoxysilane, N-phenyl-1-yaminopropyltrimethoxysilane, N— (2 aminoethyl) 3 aminopropylmethyldimethoxysilane, N— (2 aminoethyl) 3 aminopropylmethyltrimethoxysilane , 3 aminopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, butyltrimethoxysilane, N- (2 (bibenzylbenzylamino) ethyl) 3-aminopropyltrimethoxysilane hydrochloride, and 3 alone or Two or more types can be mixed and used. 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.

[0023] The addition amount of the silane coupling agent is preferably 0.1 to 10 parts by weight, more preferably 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 exerted. On the other hand, if the amount exceeds 10 parts by weight, there may be an adverse effect in terms of gas.

The epoxy resin composition used for forming the epoxy resin layers 1 and 2 of the present invention has other components such as a storage stabilizer, a plasticizer, and the like as long as the object of the present invention can be achieved. A tack adjuster or the like can also be added.

[0024] 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. Is done. As a method for forming the inorganic film layer, sputtering, CVD, vapor deposition, or the like can be used. However, in the present invention, since the inorganic film is formed on the epoxy resin layer 1 in an uncured state, the inorganic film can be formed at a low temperature in a short time, and the gas barrier performance is ensured. In order to achieve this, it is necessary to obtain a sufficient film thickness of at least m. Therefore, in the present invention, an inorganic film containing silicon oxide formed by low-temperature CVD is preferable.

Next, a process for producing the organic EL element sealing film of the present invention will be described. First, a solution obtained by dissolving and mixing a solid epoxy resin composition in an organic solvent such as methyl ketone and toluene at room temperature for forming the epoxy resin layer 1 or 2 is prepared. The solution includes a curing agent and, if necessary, an additive. 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 at room temperature (about 25 ° C). Form into form. Next, an inorganic film layer is formed on the epoxy resin layer 1 formed on the substrate 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). The epoxy resin layer 2 may be composed of the same composition as the epoxy resin layer 1, or an epoxy resin composition having a different composition may be used as necessary. Since the epoxy resin layers 1 and 2 are formed so that either of them 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. Through this process, an organic EL element sealing film is formed (Figure 2). Film for sealing organic EL element of the present invention Can be stored for a long time at low temperatures by forming the epoxy resin layers 1 and 2 in a solid state at room temperature, but it can be stored with a desiccant such as silica gel in order to keep the moisture content below a certain level. preferable.

Next, based on an Example, this invention is demonstrated in detail. The scope of the invention is not limited by these examples.

Example

[0027] 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: Phenolic novolac epoxy resin Molecular weight: approx. 530 (manufactured by Japan Epoxy Resin)

* Epicoat 1001: Solid bisphenol A type epoxy resin Molecular weight: approx. 900 (made by Japan Epoxy Resin Co., Ltd.)

(High molecular weight epoxy resin)

* PKHH: Phenoxy resin Molecular weight: approx. 52,000 (Made by INCEM)

* Epicoat 1256: Phenoxy resin Molecular weight: approx. 50,000 (manufactured by Japan Epoxy Resin)

(Epoxy curing agent)

* 2PZ— CNS— PW: 1—Cyanethyl 1-2-Phenolimidazolium trimellitite pulverized product Melting point: 105 to 111 ° C (manufactured by Shikoku Chemicals)

* C11Z_CNS: 1—Cyanethyl _ 2—Undecyl imidazolium trimellitate Melting point 123 ~: 129 ° C (manufactured by Shikoku Chemicals)

* 2E4MZ: 2_ethyl _4—methylimidazole Melting point approx. 41 ° C (manufactured by Shikoku Chemicals) (silane coupling agent)

* KBM403: Silane coupling agent (Shin-Etsu Chemical Co., Ltd.)

[0028] [Table 1] table 1

** Comparative ingredients

[0029] (Example 1)

On a transparent PET (polyethylene terephthalate thickness 75 μΐη) substrate, uniformly apply the composition 1 (1 6X-082E-7B (manufactured by ThreeBond Co., Ltd .: product name) shown in Table 1 to a thickness of 20 μm, 40 ° C Was dried to produce a sheet-like substrate A on which the epoxy resin layer 1 was formed, and then the composition 1 was coated on the release film by the same method as described above and dried at 40 ° C. Then, a sheet-like film B on which the epoxy resin layer 2 was formed was prepared.

Next, an inorganic film was further deposited on the surface of the epoxy resin layer of the sheet-like substrate A. The inorganic film was a 5 μm thick silicon oxide film using SMARTWEB manufactured by Applied Films.

[0030] 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. The temperature at 60 ° C. was a temperature at which the epoxy resin layers 1 and 2 exhibited fluidity and did not cure by polymerization. The epoxy resin layer 1, the inorganic film layer, and the epoxy resin layer 2 were uniformly laminated.

In a separate process, a sheet-like substrate (PET film) / epoxy resin layer 1 / inorganic film layer (Si Ox) / epoxy resin layer 2 / release film was formed in this way. 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. Sealing made in Example 1 on the organic EL element The film for the application was bonded. In the laminating step, the release film of the sealing film was peeled off, and the epoxy resin layer 2 and the organic EL element were placed so as to face each other, and pressure-bonded at 90 ° C. with a roll laminator. Thereafter, the epoxy resin layers 1 and 2 were crosslinked and cured by heating at 110 ° C. for 1 hour. As a result, an organic EL element sealing structure (organic EL light emitting body) sealed with the sealing film could be obtained.

[0031] A sealing film was prepared using the epoxy resin compositions 2 to 7 shown in Table 1 by the same procedure, and bonded to the organic EL device in the same manner. However, each was processed at the crimping temperature and heating temperature shown in Table 1.

The obtained organic EL phosphor 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 edge of the light emission area. The results are shown in the lower part of Table 1. The unit is μm.

[0032] (Comparative Example 1)

Silicon oxide, which is an inorganic film, was directly deposited on the sheet substrate (PET) in the same manner as in Example 1 using SMARTWEB manufactured by Applied Films. Further, in the same manner as in Example 1, a sheet-like film was prepared by coating composition 1 on a release film to form an epoxy resin layer. Subsequently, both were bonded in the same manner to form a sheet-like substrate (PET) / inorganic film layer (SiOx) / epoxy resin layer (composition 1) / release film sealing film. Using the sealing film, an organic EL light emitter was prepared in the same manner as in Example 1. Similarly, a continuous lighting experiment was performed under high temperature and high humidity. The average width was measured.

[0033] (Comparative Example 2)

The composition 1 shown in the table was uniformly applied to a sheet-like substrate (PET) to a thickness of 20 zm and dried at 40 ° C. to prepare a sheet-like substrate A on which an epoxy resin layer 1 was formed. On the other hand, composition 1 was applied onto the release film in the same manner as described above, and dried at 40 ° C. to prepare sheet-like film B in which epoxy resin layer 2 was formed. Use the roll laminator 60 with the epoxy resin layers of sheet substrate A and sheet film B facing each other. Bonded with C. In this way, sheet-like substrate (PET film) Z epoxy resin layer 1 / epoxy resin layer 2Z A sealing film having a four-layer structure of a release film was formed. However, since the epoxy resin layer 1 and the epoxy resin layer 2 are almost integrated, they could not be substantially distinguished. Using this sealing film, an organic EL luminescent material was prepared in the same manner as in Example 1, and a continuous lighting experiment was conducted in the same way under high temperature and high humidity. Similarly, the width of the dark area from the edge of the luminescent area The average value of was measured.

The result of Comparative Example 1 is 250 μm after 100 hours and 1500 μm after 1000 hours, and the result of Comparative Example 2 is 350 xm after 100 hours and 2,000 zm after 1000 hours. there were. Therefore, Comparative Example 1 shows 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 cannot be sufficiently sealed. In addition, Comparative Example 2 showed that the organic EL element was not sufficiently sealed when the inorganic film layer was missing.

[0034] 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 μΐη or less.

Industrial applicability

[0035] The organic EL device sealing film of the present invention is not limited to organic EL device sealing, but is used for sealing purposes for the purpose of improving moisture resistance, weather resistance, and impact resistance of organic semiconductors and other electronic components. Yes.

Brief Description of Drawings

FIG. 1 is a cross-sectional view of a film for an organic EL device of Example 1.

FIG. 2 is an explanatory view showing a production process of a film for organic EL elements.

Explanation of symbols

[0037] 1 Substrate film

2 Epoxy resin layer 1

3 Inorganic membrane layer

4 Epoxy resin layer 2

5 Release film

6 Crimp roller

Claims

The scope of the claims

[1] 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 An epoxy resin composition strength S for 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 The film for sealing an organic EL element, wherein the epoxy resin and the high molecular weight epoxy resin can be cured.

[2] The low molecular weight epoxy resin is a low molecular weight epoxy resin having a molecular weight of 200 to 2,000 having at least two glycidinole groups in one molecule, and the high molecular weight epoxy resin is at least 2 in one molecule. 2. The organic EL device sealing film according to claim 1, which is a high molecular weight epoxy resin having one glycidyl group and having a molecular weight of 20,000 to 100,000.

[3] The epoxy resin composition forming the epoxy resin layer 1 and / or the epoxy resin layer 2, the latent imidazole compound having a melting point or decomposition temperature of 80 ° C. or higher, and silane The film for sealing an organic EL device according to claim 1, which contains a coupling agent.

[4] The organic EL device according to claim 1, wherein the epoxy resin layer 1 and / or the epoxy resin layer 2 is solid in a normal temperature range and exhibits fluidity when heated to 50 to 100 ° C. Sealing film.

[5] The film for sealing an organic EL element according to claim 1, wherein the epoxy resin layer 1 and / or the epoxy resin layer 2 is cured in a temperature range of 80 to 150 ° C.

[6] 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.

[7] The organic EL element formed on the glass or film substrate is entirely sealed with the organic EL element sealing film according to any one of claims:! EL element sealing structure.