KR101234895B1 - Thermosetting composition for organic EL device sealing - Google Patents

Abstract

The present invention provides a thermosetting composition for encapsulating an organic EL device that can be sealed without adversely affecting the organic EL device, thereby reliably suppressing the occurrence and growth of dark spots to maintain high transmittance and maintain stable light emission characteristics over a long period of time. to provide. Specifically, the present invention provides (A) 100 parts by weight of a low molecular weight epoxy resin having at least two or more glycidyl groups in one molecule and a molecular weight of 200 to 2000, and (B) a bisphenol A or bisphenol F epoxy skeleton. 0.5-20 weight of the latent imidazole compound which has (C) nitrile group with respect to 40-150 weight part of high molecular weight epoxy resins which have a molecular weight of 20000-100000, and 100 weight part of (A) component and (B) component in total. Part and (D) 0.1-10 weight part of silane coupling agents were made to seal the organic electroluminescent element with the composition which has a main component.

Organic EL device, thermosetting type, imidazole

Description

Thermosetting composition for organic EL device sealing

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermosetting composition used for sealing an organic EL device that emits high luminance by application of an electric field, and more particularly, an organic EL formed on a substrate in order to protect the organic EL device from moisture and the like. The present invention relates to a thermosetting composition coated on the entire surface of a device.

An organic EL element is a polycrystalline semiconductor device, is used in backlights of liquid crystals and the like for obtaining high luminance light emission at low voltage, and is expected to be a thin flat display device. However, the organic EL device is extremely weak in moisture, the interface between the metal electric field and the organic EL layer may be peeled off due to the influence of moisture, the metal may be oxidized and become highly resistant, and the organic material itself may be deteriorated by moisture. There is a drawback that the light may not be emitted and the brightness may be lowered.

In order to solve such a problem, a method of molding an organic EL element with an acrylic resin (Japanese Patent Laid-Open No. 3-37991), a method of enclosing P205 in an airtight case of an organic EL element and blocking it from external air (Japan Japanese Patent Application Laid-Open No. H3-261091), a method of airtight using a glass plate after providing a protective film of metal oxide or the like on an organic EL device (Japanese Laid-Open Patent Publication No. H4-212284), and an organic EL device To provide a plasma polymerized film and a photocurable resin layer (Japanese Patent Laid-Open Publication No. Hei 5-36475), and a method of storing an organic EL element in an inert liquid made of fluorocarbon (Japanese Patent Laid-Open Publication No. Hei 4-363890) G), a method of adhering a glass plate coated with polyvinyl alcohol with an epoxy resin on a protective film such as an inorganic oxide provided on an organic EL element (JP-A-5-89959), and organic EL Such as those in the method for encapsulating liquid paraffin or a silicone oil (Japanese Unexamined Patent Publication No. 5-129080 gazette) have been proposed. In recent years, a method has been proposed in which a moisture absorbent is added to the encapsulating resin and laminated on the organic EL device to hold the organic EL device from the influence of moisture.

However, none of the conventional methods for encapsulating the organic EL layer is satisfactory, and for example, only by encapsulating the element in an airtight structure together with a moisture absorbent, it is possible to suppress the occurrence and growth of dark spots. In addition, the method of preserving in carbon fluoride or silicon oil is not only complicated by the encapsulation process by going through the process of encapsulating the liquid, but also prevents the increase of the dark spot completely. There is also a problem of invading the interface and encouraging peeling of the cathode. Even when a moisture absorbent was added to the resin, the resin itself expanded due to moisture absorption and peeling could occur. In addition, in order to eliminate the adverse effects of moisture on the organic EL device, it is also proposed to separately install a moisture barrier by adding a moisture absorbent made of a metal oxide such as barium oxide or calcium oxide to the photocurable epoxy layer separately from the encapsulation layer. (Japanese Patent Laid-Open No. 2001-237064).

Furthermore, as described in Japanese Patent Laid-Open No. 5-182759, an organic EL element is formed on a glass substrate using an ultraviolet curable resin, and a resin composition is laminated so as to cover the entire organic EL element, and a non-permeable glass. Adhering to the substrate has been developed. However, the resin composition described in this invention does not have the problem of deterioration of the organic EL element by the organic solvent and ultraviolet rays contained in the said resin, the problem of peeling of the negative electrode in the organic layer by the stress stress at the time of hardening, or an ultraviolet-ray. There was a problem that uncured in some places, inferior in practicality. In the case of using an epoxy resin, there is less chemical influence on the device compared with an acrylic resin, but there is a problem in the moisture permeability of the cured product after curing. In order to improve this, a moisture absorbent made of a metal oxide such as barium oxide or calcium oxide is incorporated. In this case, since the metal oxide blended in the resin expands with water, there is a problem of destroying the organic EL element itself in some cases. In addition, when the epoxy resin is cured with an amine curing agent, the organic EL element may be corroded from the pinhole of the protective film under the influence of the amine gas generated at the time of curing, and the transmittance may decrease because the cured product is easily colored. there was.

On the other hand, Japanese Patent Laid-Open No. 11-274377 discloses a paste composition composed of a thermoplastic resin, an epoxy resin, a coupling agent, silicon dioxide powder, and an organic solvent, and describes the use of IC or LSI chips for direct encapsulation. have. However, this invention focuses on the stress relaxation property (elasticity) of hardened | cured material, and although it mentions that it is excellent in moisture resistance, it does not consider at all about the water content contained in the system of a paste composition. Furthermore, when the two-component curable epoxy resin was used, there was a problem in the workability due to the trouble of mixing and mixing, the accompanying equipment, and the pot life.

In addition, Japanese Patent Application Laid-open No. Hei 9-176413 discloses a method of preparing a transparent film using maleic anhydride copolymer polymer as a curing agent. However, it cannot be bonded because it contains styrene. In Japanese Patent Laid-Open Nos. 9-235357 and 10-135255, imidazole is used in combination with an acid anhydride-based curing agent as a curing accelerator. However, also about these, hardening temperature is high and damage of organic electroluminescent element is large, and cannot be used. Furthermore, Japanese Patent Laid-Open No. 2003-277628 uses 2,4-diamino-6- [2'-methylimidazole- (1 ')]-ethyl-S-triazineisocyanuric acid adduct. Moreover, the compounding for the purpose of imparting flame retardance by the inert gas which arises at the time of hardening is disclosed. In this compounding system, a transparent cured product cannot be obtained and cannot be used as an organic EL panel. In addition, the use of phenoxy resins and bisphenol-type epoxy resins is disclosed in International Publication No. WO02 / 006399 and Japanese Patent Laid-Open No. 2004-315688. In this system, however, the visible light transmittance of the cured product is lowered and the coloring is strong, which makes it practical. none.

Japanese Patent Laid-Open No. 2004-59718 or Japanese Patent Laid-Open No. 2004-210901 discloses an adhesive film or a thermosetting resin using imidazole as a curing agent or a curing accelerator. Together, these have a high curing temperature at the time of curing and a great damage to the organic EL device. Moreover, although Japanese Unexamined-Japanese-Patent No. 2004-115650 discloses the compounding which used the liquid imidazole compound, in this compounding system, thermal stability cannot be ensured in the case of the coating formed into a sheet form. Furthermore, although Japanese Patent Application Laid-Open No. 2004-292594 discloses a combination of an epoxy resin, a phenoxy resin, and a curing agent, there is no mention of a flow start temperature, a water content, and an outgas generation amount in this compounding system. Not suitable for encapsulant.

In addition, in the case of the sealing method using the above-mentioned liquid resin, the generation of bubbles is a big problem in the step of bonding the organic EL element and the sealing glass. It is very difficult to bond the bubbles to the front of the display unit without bubbles, which causes bubbles to deteriorate the lifetime of the device. In addition, when multi-sided acquisition is carried out from a glass, when a liquid resin is used, the non-bonded part requires masking and deteriorates workability.

Patent Document 1: Japanese Patent Application Laid-open No. Hei 5-182759

Patent Document 2: Japanese Patent Application Laid-Open No. 2001-237064

Patent Document 3: Japanese Patent Application Laid-Open No. 11-274377

Patent Document 4: Japanese Patent Application Laid-Open No. 3-261091

Patent Document 5: Japanese Patent Application Laid-Open No. 4-212284

Patent Document 6: Japanese Patent Application Laid-Open No. 5-36475

Patent Document 7: Japanese Patent Application Laid-Open No. 4-363890

Patent Document 8: Japanese Patent Application Laid-Open No. 5-89959

Patent Document 9: Japanese Patent Application Laid-Open No. 5-129080

Patent Document 10: Japanese Patent Application Laid-Open No. 9-176413

Patent Document 11: Japanese Patent Application Laid-Open No. 9-235357

Patent Document 12: Japanese Patent Application Laid-open No. Hei 10-135255

Patent Document 13: JP 2003-277628 A

Patent Document 14: Japanese Patent Application Laid-Open No. 2004-59718

Patent Document 15: Japanese Patent Application Laid-Open No. 2004-210901

Patent Document 16: Japanese Patent Application Laid-Open No. 10-273644

Patent Document 17: Japanese Patent Application Laid-Open No. 2004-59778

Patent Document 18: Japanese Patent Publication No. 2003-82064

The deterioration due to the dark spot of the organic EL element as described above is not sufficiently improved and the light emitting characteristics are unstable, which is a serious defect as a light source such as a backlight of a facsimile machine, a copier and a liquid crystal display, and also as a display element such as a flat panel and a display. Not desirable The present invention solves the problems of the prior art, and by sealing the organic EL device without adversely affecting the occurrence and growth of dark spots reliably to maintain a high transmittance, it is possible to maintain stable light emission characteristics for a long time It is an object to provide a thermosetting composition for sealing an organic EL device.

In order to solve the above problems, in the present invention, (A) 100 parts by weight of a low molecular weight epoxy resin having at least two or more glycidyl groups and a molecular weight of 200 to 2000, and (B) bisphenol A or bisphenol F type The latent imidazole compound 0.5 which has an epoxy skeleton and has a (C) nitrile group with respect to 40-150 weight part of high molecular weight epoxy resins with a molecular weight of 20000-100000, and 100 weight part of (A) component and (B) component in total. An organic EL device comprising, as a main component, ˜20 parts by weight and (D) 0.1-10 parts by weight of a silane coupling agent, wherein the composition exhibits non-flowability at 25 ° C. and exhibits fluidity in a range of 50 ° C. to 100 ° C. when heated. The sealing thermosetting composition was used to seal between the organic EL element formed on the glass or film substrate and the sealing glass or film substrate.

Specifically, an organic EL layer composed of a transparent electrode, a hole transport layer crystal, an organic EL layer, and a back electrode is formed on a glass or film substrate, and the thermosetting composition of the present invention is thermally transferred thereon, It was bonded and sealed by heating with a water impermeable glass or film. Or you may heat-transfer to a water-impermeable glass or a film, and may bond and seal while heating to the glass or the film in which the organic electroluminescent layer was formed. Moreover, it is preferable that the thermosetting composition which has said (A)-(D) as a main component is 100 ppm or less in water content, and 1000 ppm or less in outgas amount at the time of hardening.

The above-mentioned thermosetting resin composition containing (A) to (D) as a main component is used as an encapsulant of an organic EL element, and it is possible to reliably suppress the occurrence and growth of dark spots and to maintain a high transmittance to ensure stable light emission characteristics for a long time. It is possible to provide an organic EL panel capable of maintaining a.

Specifically, the thermosetting resin of the present invention is used for encapsulation of an organic EL element layer formed on a glass or a film, or for filling sealing adhesion of an interval between an organic EL element layer formed on a glass or a film and a water impermeable glass or film substrate layer. By adhering and sealing the whole surface of an organic electroluminescent element layer using, it is possible to significantly suppress the progress of deterioration of an organic electroluminescent element. Moreover, compared with the sealing by the sheet-like adhesive which does not produce reactivity, or the sheet-like thermoplastic resin, heat resistance and moisture resistance are improved. Moreover, compared with the sealing by the ultraviolet curable resin composition, since the uncured and the large hardening shrinkage of the location which ultraviolet rays do not reach are few, the obtained organic electroluminescent element exhibits the stable performance.

In more detail, the sealing structure of the organic electroluminescent element in this invention is manufactured as follows. First, a transparent electrode is formed to a thickness of about 0.1 탆 on a glass or film substrate. In film formation of a transparent electrode, there exist a method by vacuum deposition, sputter | spatter, etc. However, film formation by vacuum deposition may decrease crystallinity of the film surface due to growth of crystal grains, and when applied to the thin film EL, care should be taken because it causes an insulation breakdown film or a non-uniform emission of light. On the other hand, the film formation by sputtering has good surface smoothness, and a preferable result is obtained when laminating | stacking a thin film device on it. Subsequently, a hole transport layer and an organic EL layer are sequentially formed on the transparent electrode with a thickness of 0.05 占 퐉. Further, a back electrode is formed on the organic EL layer to a thickness of 0.1 to 0.3 mu m.

The thermosetting composition of the present invention is transferred to a roll laminate or the like on the glass or film substrate having finished film formation of these devices. At this time, the thermosetting composition of the present invention is continuously developed in advance on a gas film (release film) and formed in a sheet form, so that the thermosetting composition formed in this sheet form is transferred to a roll laminate. In addition, when using the method by an electric transfer, when the layer thickness of the thermosetting composition continuously developed on the film may be 10-30 micrometers, transfer can be performed smoothly. Subsequently, a non-permeable glass or film substrate is superimposed from above the transferred thermosetting composition. This is heat-compression-bonded using a vacuum laminator device, and the upper and lower boards are pre-fixed. Thereafter, the thermosetting resin is completely cured at a temperature of heating (120 ° C. or less). In addition, when heat-hardening, it is preferable to carry out at 120 degrees C or less, in order not to damage an organic EL element. It is also possible to transfer the thermosetting composition of the present invention to a non-permeable glass or film substrate and to polymerize the organic EL element substrate. For the purpose of improving the reliability of the organic EL device, it is also possible to polymerize the organic EL device substrate and the non-permeable glass or film in a state where the device is protected by the inorganic film in advance with the thermosetting composition of the present invention. The inorganic film referred to here includes silicon oxide, silicon nitride, silicon oxynitride, and the like.

In addition, in consideration of workability, the thermosetting composition preferably has a shelf life of 7 days or more at room temperature.

If the thermosetting composition of the present invention is formed as described above, storage layer, and a moisture permeability in the thickness of the cured layer 150㎛ 1000mg / m ² x 24 hours or less at 60 ℃ and 95% humidity environment, the cured The light transmittance of 405 nm is 90% or more with respect to the layer of 20 micrometers in thickness, Furthermore, it is preferable to have the adhesive force of 1.0 MPa or more in the peeling adhesion test between glass, and to harden at comparatively low temperature (120 degrees C or less).

을 흡수하기도 하며, 2장의 프레이트 (글라스 또는 필름)사이를 접착하는 것이 어렵게 된다. 또한, 본 발명에 있어서의 열경화형 조성물의 경화물 층의 두께는 상기의 것이 바람직하지만, 405nm의 광투과율을 90% 확복할 수 있는 범위에 있어서 막두께를 증가시켜도 좋다 (200㎛ 이상).Especially in this invention, it is suitable to make thickness of the hardened | cured material layer of a thermosetting composition into 1-100 micrometers, More preferably, it is good to set it as 10-30 micrometers. In the case of less than 1 mu m,

It also absorbs and makes it difficult to bond between two plates (glass or film). In addition, although the thickness of the hardened | cured material layer of the thermosetting composition in this invention is the said thing, you may increase a film thickness in the range which can expand 90% of light transmittances of 405 nm (200 micrometers or more).

In the thermosetting resin composition of the present invention, the compound having a glycidyl group in the molecule (A) is specifically a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a hydrogenated bisphenol type epoxy resin or a phenol novolak type resin. Although epoxy resins, such as these, are preferable, Among these, it is preferable that the thing with small chlorine ion content, specifically, the hydrolyzable chlorine is 500 ppm or less. Preferable specific examples of the component (A) include epicron EXA-835LV (manufactured by Japan Ink Industry Co., Ltd.) or epicoat 152 (manufactured by Japan Epoxy Resin) having a low chlorine ion concentration.

The high molecular weight epoxy resin (B) which has a bisphenol A type or bisphenol F type epoxy skeleton used in the present invention and has a molecular weight of 2000 to 70000 is specifically a solid bisphenol A type epoxy resin, a solid bisphenol F type epoxy resin, or phenoxy. Epoxy resins, such as resin, are preferable. Among these, the phenoxy resin which has a film strength is preferable when forming a thermosetting composition in a sheet form. In addition, these high molecular weight epoxy resins often do not contain glycidyl groups (epoxy groups) remaining in the system, and are often excellent in physical properties of the cured product.

As a specific example of the said (B) component, Epicoat 1256 (made by Japan Epoxy Resin) or PKHH (made by INCHEM) can be used preferably. It is preferable to add 40-150 weight part with respect to 100 weight part of (A) component, and, as for the addition amount of (B) component, More preferably, 50 weight part-100 weight part are preferable. If it is less than 40 parts by weight, it cannot impart non-flowability (cannot form a film when formed into a sheet), and if it exceeds 150 parts by weight, the film becomes rigid and brittle when formed into a sheet, for example. This gets worse. In addition, the crosslinking density becomes low and reliability cannot be guaranteed.

Specific examples of the latent imidazole compound having a (C) nitrile group used in the present invention include 1-cyanoethyl-2-phenylimidazole and 1-cyanoethyl-2-undecylimizazolium trimerate. And imidazole compounds such as 1-cyanoethyl-2-phenylimidazolium trimellitate are preferable, and commercially available products include C11Z-CNS or 2PZ-CNS-PW (manufactured by Tetra Chrysanthemum Co., Ltd.).

The component (C) functions as a curing agent (in the case of having an epoxy group in the component (B)) of the components (A) and (B), and the amount of the component (C) is arbitrarily determined in consideration of the epoxy equivalent, storage property, curability and transmittance. Although it is possible, it is usually preferable to add 0.5-20 weight part with respect to a total of 100 weight part of (A) component and (B) component, and 1.5-10 weight part is more preferable. When it adds less than 0.5 weight part, (A) and (B) component cannot fully harden, and when it exceeds 20 weight part, coloring will become severe and stability as a composition will worsen.

Specific examples of the (D) silane coupling agent that can be used in the present invention include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2 -(3,4-epoxycyclohexyl) ethyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N- (2-aminoethyl) 3-aminopropylmethyltrimethoxysilane, 3-amino Propyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, vinyltrimethoxysilane, N- (2- (vinylbenzylamino) ethyl) 3-aminopropyltrimethoxysilane hydrochloride, 3-methacryloxypropyl Silane coupling agents such as trimethoxysilane and the like. These silane coupling agents may mix two or more types. Among them, 3-glycidoxypropyltrimethoxysilane (KBM-403: manufactured by Shinwol Chemical Co., Ltd.) is preferable because of its good compatibility with component (A) or component (B) and excellent stability. It is preferable that the addition amount of (D) component is 0.1-10 weight part with respect to a total of 100 weight part of (A) and (B) component. More preferably, it is 0.3-2 weight part. If it is less than 0.1 weight part, the effect cannot be ensured, and when it exceeds 10 weight part, there exists a weak influence in the point of outgas.

In the thermosetting composition of the present invention, after dissolving each of the components (A) to (D) in an organic solvent such as methyl ethyl ketone or toluene, the solution is formed on a gas film (release film) so as to have a constant thickness in a coating machine. It is preferable to apply | coat and apply | coat to an organic solvent, and to shape | mold in the sheet form (film form, tape form) which is a solid form in normal temperature area | region (about 25 degreeC). Thus, if previously formed in a sheet form, thermal transfer can be made easy with respect to the surface of organic electroluminescent element. Furthermore, you may apply | coat and form the thermosetting composition of this invention directly to the gas phase, the impermeable sealing glass in which organic electroluminescent element was formed, or the sealing film which has gas batter barrier property. Thus, when formed into a solid phase in the normal temperature region, long-term storage at a low temperature is possible, but it is preferable to store it with a desiccant such as silica gel because the moisture content is kept below a certain level.

로 원활하게 충진하여 기포를 배제하기 때문이다. 유동온도가 50℃ 미만인 경우에는 열전사의 경우 또는 열경화에 의한 봉지의 경우에 열경화형 조성물의 유동성이 너무 커져서 늘어짐이 생기기 쉬우며, 경화물의 막 두께의 관리가 곤란하게 되고, 경화 전의 보관안정성이 손상되는 경우가 있다. 한편, 100℃를 초과하는 경우에는 열전사의 작업성이 나빠지기 때문에 기포를 함유하기 쉽게 되기도 하며, 필요 이상으로 가열하여야 하기 때문에 유기 EL 소자에 영향을 줄 가능성이 있다.Moreover, it is preferable that the thermosetting composition of this invention expresses fluidity in the range of 50-100 degreeC. In the case of encapsulating an organic EL device, the thermosetting composition obtained by heating and fluidizing the

This is because bubbles are smoothly filled to eliminate bubbles. When the flow temperature is less than 50 ° C., in the case of thermal transfer or encapsulation by thermosetting, the fluidity of the thermosetting composition becomes too large to cause sagging, making it difficult to manage the film thickness of the cured product, and the storage stability before curing. It may be damaged. On the other hand, when it exceeds 100 degreeC, since workability of thermal transfer will worsen, it may become easy to contain a bubble, and since it needs to heat more than necessary, there exists a possibility to affect organic electroluminescent element.

In the present invention, other components such as a preservative stabilizer, a plasticizer, a talc adjusting agent, and the like may be added as long as the object of the present invention can be further achieved. However, attention is required to moisture or impurities in these additive components. .

In the following Examples, the present invention will be described in detail, but the present invention is not limited to the following Examples.

As shown in Table 1 and Table 2, each composition was prepared and various evaluation tests were performed, and the results are shown in Table 1 and Table 2. In addition, each component used is as follows. In addition, the compounding ratio is based on weight unless there is particular notice.

(A) Component

Epicron EXA-835LV: Bisphenol A and F mixed epoxy resin Low chlorine molecular weight 300 to 350 (manufactured by Japan Ink Chemical Co., Ltd.)

Epicoat 152: phenol novolac-type epoxy resin molecular weight approximately 530 (product made in Japan epoxy resin)

Epicode 1001: solid bisphenol epoxy resin, molecular weight approx. 900 (manufactured by Japan Epoxy Resin)

Component (B)

PKHH: Phenoxy resin molecular weight 52000 (product of INCHEM company)

YP-70: Phenoxy Resin Molecular Weight 45000 ~ 55000 (by Dodo Chemical)

Epicoat 1256: phenoxy resin molecular weight approximately 50000 (product of Japan epoxy resin)

(C) Component

C11Z-CNS: 1-cyanoethyl-2-undecyl imidazolium trimellitate melting point 123 ~ 129 ° C (product of Chrysanthemum Chemical Industries, Ltd.)

2PZ-CNS-PW: Crushed product melting point of 1-cyanoethyl-2-phenylimizazolium trimellitate 105 ~ 111 ° C (product of Chrysanthemum Chemical Industries, Ltd.)

(Other curing agents)

2MAOK-PW: Crushed product at 2,4-diamino-6- [2'-methylimidazole- (1 ')]-ethyl-s-triazine isocyanuric acid admixture decomposition temperature 260 ° C

2E4MZ: 2-ethyl-4-methylimidazole melting point about 41 ° C (product of Chrysanthemum Chemical Industries, Ltd.)

Amicua PN-23: amine epoxyadact solid dispersion latent curing agent (manufactured by Ajinomodo Co., Ltd.)

FujiQA FXE-1000: Urea Adact Solid Dispersion Latent Hardener (manufactured by Butatom Co., Ltd.)

(D) Component

KBM403: Silane Coupling Agent (Shinwol Chemical Co., Ltd.)

The numerical values shown in Examples 1-8 in Table 1 are by weight unless there is particular notice.

In addition, specific preparation means are as follows.

(1) Crushed product of 1-cyanoethyl-2-phenylimidazolium trimellitate (2PZ-CNS-PW), and / or 1-cyanoethyl-2 in epoxy resin (835LV, Epicoat 152) -A master bag having uniformly dispersed undecyl imidazolium trimellitate (C11Z-CNS) was prepared.

(2) The phenoxy resin (PKHH, Epicoat 1256) was stirred at room temperature in methyl ethyl ketone and dissolved.

The said (1), (2) and silane coupling agent (KBM403) were mix | blended in predetermined amount, and it stirred at room temperature, and obtained each composition. Subsequently, each composition was coated on a PET film subjected to the release treatment using a coating machine so as to have a thickness of about 20 μm, and laminated on each release film to obtain a solid sheet-like sample in the normal temperature region (about 25 ° C.).

Moreover, each thermosetting composition was prepared in the compounding ratio shown in Table 2 similarly to an Example about Comparative Examples 1-9. Specifically,

(1) 2MA-OK-PW, 2PZ-CNS-PW, 2E4MZ, PN-23, and FXE1000 were added to the epoxy resin (835LV, Epicoat 152), respectively, and two rolls were placed in a ceramic three-roller. The masterbatch mixed uniformly was prepared.

(2) The phenoxy resin (YP-70, Epicoat 1256) was stirred at room temperature with methyl ethyl ketone and dissolved. Electricity (1), (2), and a silane coupling agent (KBM403) were mix | blended in predetermined amount, and each composition was obtained by normal temperature stirring. Each composition was then about 20 thick on a release treated PET film. It coated using the coating machine so that it might become micrometer, and it laminated | stacked on each release film, and obtained the solid sheet-like sample in the normal temperature area | region (about 25 degreeC).

Various evaluation tests are as follows.

(Evaluation test 1): measurement of the flow start temperature

Each sample formed in the sheet form was peeled off from the release paper, and five sheets were degassed so that the thickness might be about 100 micrometers (using a vacuum laminator). This was heated to 25-150 degreeC using a rheometer, and the flow start temperature at that time was measured (used apparatus: DAR-100 viscoelasticity measurement by Reologica).

(Evaluation Result 2): Moisture Content Measurement

About 0.1g of each sample formed in the sheet form was weighed, it heated at 150 degreeC using the Kahl Fischer moisture meter, and the moisture content which generate | occur | produced at that time was measured (solid vaporization method).

 (Evaluation test 3): Out gas measurement

About 5 mg of each sample formed in the sheet form was measured, and the amount of outgassing when it heats at 120 degreeC x 15 minutes by the dynamic space method using the double shot pyroiser and glass chromatography / mass spectrometry (GC-MS) was measured. The total outgas generated was quantified n-decane as a standard.

(Evaluation test 4): visible light transmittance measurement

The glass substrate for panels was cut | disconnected 25 mm x 50 mm, each sample formed in the sheet form was transferred, and it hardened | cured at the hardening conditions of 100 degreeC x 3 hours. The transmittance | permeability of each sample piece was measured with the glass spectrophotometer.

(Evaluation test 5): Dark spot evaluation

The transparent electrode by sputtering was formed into a film of 0.1 micrometer on the glass substrate. Subsequently, a hole transport layer and an organic EL layer were sequentially formed on the transparent electrode with a thickness of 0.05 µm. Further, a film having a thickness of 0.2 μm of a back electrode was formed on the organic EL layer. After the film formation of these elements was finished, each sample formed in the sheet form on the glass substrate 1 was transferred using a roll laminator. The non-permeable glass substrate was piled up on this transferred glass substrate 1, and it was heat-compression-bonded using the vacuum laminator. Then, each sample was completely hardened by the heat dryer on 100 degreeC x 3 hours conditions. Thus, the panel was created and the growth of the dark spot was observed in the environment of 60 degreeC x 90% by continuous lighting. (Circle) and the case where a dark spot is seen by (triangle | delta) and the case where a dark spot is clearly seen are represented by x when there is no dark spot generate | occur | produced after 1000 hours of passage more than diameter of 100 micrometers.

In addition, as a comprehensive determination, (circle), the thing which can be used as a sealing agent of organic electroluminescent element without problems, (triangle | delta), and the thing which cannot be used were represented by x.

 [Table 1]

  [Table 2]

"-" In the table indicates unmeasured.

In the case of Examples 1-8, the outstanding result was obtained in all the evaluations. On the other hand, in the comparative example 1, the flow start temperature was low and it became 50 degrees C or less. Moreover, in the case of the coating formed in a sheet form, uniform film formation was difficult. Moreover, also in evaluation of a dark spot, the low molecular weight component did not bring a favorable result by much influence. In Comparative Example 2, there were many high molecular weight components, the flow initiation temperature was not a problem, but the membrane became stiff and brittle, and also the workability was deteriorated. Moreover, the dry state of ethyl methyl ketone at the time of sheet formation worsened, and the outgas generation amount increased.

 In the comparative example 3, the compounding quantity of the hardening | curing agent component was large, the moisture content exceeded 0.50 weight%, and visible light transmittance became 90% or less under the influence of a hardening | curing agent.

In Comparative Example 4, curing was insufficient, and the amount of outgas generated during curing exceeded 1000 ppm even more. In addition, since the curing was insufficient, sufficient reliability could not be secured, and good results could not be obtained in the dark spot evaluation.

In Comparative Example 5, 2E4MZ having a melting point of 50 ° C. or lower (about 41 ° C.) was used for the curing agent. Therefore, hardening reaction started at the time of coating formed into a sheet form, and became unpreservable and impractical. In addition, since the state of semi-curing, the fluidity starting temperature could not be measured clearly.

In Comparative Examples 6 and 7, the curing agent was evaluated using curing agents other than imidazole. As a result, the visible light transmittance of all became 80% or less, and in the case of coating, the reaction started and became impractical.

In Comparative Example 8, no coupling agent was added. As a result, reliability could not be secured and good results could not be obtained from the evaluation of dark spots. In Comparative Example 9, a large amount of coupling agent was added. As a result, there were many liquid components, and the flow start temperature became 50 degrees C or less. In addition, the stickiness of the sheet-like adhesive surface became severe, workability was also reduced.

The thermosetting composition of the present invention can be applied to sealing applications for the purpose of improving the moisture resistance, weather resistance, and impact resistance of other electronic components without limiting the organic EL device encapsulation.

Claims (6)

(A) 100 parts by weight of a low molecular weight epoxy resin having at least two or more glycidyl groups in one molecule and a molecular weight of 200 to 2000, and (B) a bisphenol A or bisphenol F type epoxy skeleton having a molecular weight of 20000 to 100000 40-20 weight part of phosphorus high molecular weight epoxy resin, 0.5-20 weight part of latent imidazole compounds which have (C) nitrile group with respect to a total of 100 weight part of (A) component and (B) component, (D) A composition comprising 0.1 to 10 parts by weight of a silane coupling agent as a main component, wherein the composition exhibits non-fluidity at 25 ° C. and exhibits fluidity in a range of 50 to 100 ° C. when heated, wherein the composition is a thermosetting composition for sealing an organic EL device. The thermosetting composition for sealing an organic EL device according to claim 1, wherein the thermosetting composition is previously formed in a sheet form. The thermosetting composition for sealing an organic EL device according to claim 2, wherein the flow initiation temperature of the thermosetting composition formed in the sheet form is 50 to 100 ° C. The thermosetting composition for sealing an organic EL device according to claim 1, wherein the amount of outgas generated during curing of the thermosetting composition is 1000 ppm or less. The thermosetting composition for sealing an organic EL device according to claim 1, wherein a moisture content of the thermosetting composition is 100 ppm or less. The thermosetting composition for sealing an organic EL device according to claim 1, wherein a transmittance of 405 nm in the cured product of the thermosetting composition is 90% or more.