JP2015191800A - Element-sealing transparent resin composition for organic electronic devices, element-sealing resin sheet for organic electronic devices, organic electroluminescent element, and image display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: an element-sealing transparent resin composition for organic electronic devices, which enables the overall sealing without forming a hollow part between an organic EL element and a sealed substrate, which can be also used for top emission type devices and which is superior in long-term reliability and the convenience of handling; an element-sealing resin sheet for organic electronic devices; an organic electroluminescent element; and an image display.SOLUTION: An element-sealing resin composition for organic electronic devices according to the present invention comprises at least, a resin (A) having an isobutylene skeleton, and a filler (B) of which the content is 20 wt.% or less to the total weight thereof. In the element-sealing resin composition, the filler (B) includes no metal atom.

Description

  The present invention relates to a transparent resin composition for sealing an element for an organic electronic device, a resin sheet for sealing an element for an organic electronic device, an organic electroluminescence element, and an image display device used when sealing an element for an organic electronic device. .

  In recent years, research on various organic electronic devices such as organic electroluminescence (hereinafter also referred to as “organic EL”) displays, organic EL lighting, and organic semiconductors and organic solar cells has been actively conducted. It is expected as a next-generation display that replaces Liquid Crystal Display (LCD) and a next-generation illumination that replaces Light Emitting Diode (LED) illumination. Furthermore, since all components of the organic EL element can be formed from a solid material, there is a possibility that the organic EL element may be used as a flexible display or illumination. The organic EL element basically has a configuration in which an anode layer, a light emitting layer, and a cathode layer are sequentially formed on a substrate made of glass or the like, and self-emits when energized between the anode layer and the cathode layer. Since light can be extracted from either of the cathode layers, there are a top emission method and a bottom emission method as light emission methods of organic EL devices.

  However, in the organic EL device, when moisture, impurities, etc. exist around the device, a non-light emitting portion called a dark spot is generated and grows. When the diameter of the dark spot grows to several tens of μm, the non-light emitting portion is visually confirmed. It becomes possible to lead to deterioration of visibility.

  Therefore, in order to shield the organic EL element from moisture, impurities, etc., a transparent sealing substrate (sometimes a sealing can) made of glass or the like is provided, and the organic EL element is interposed between the organic EL element and the sealing substrate. An organic EL device in which a dehydrating agent is disposed in a generated space is disclosed (for example, see Patent Document 1). However, since a hollow portion exists between the organic EL element and the sealing substrate, a flexible organic device is disclosed. It is difficult to apply to EL devices.

  In order to obtain a flexible organic EL device, a method of sealing an organic EL element with a film-like or sheet-like adhesive intermediate film has been disclosed (Patent Document 2). This adhesive intermediate film is made of ethylene vinyl acetate. Since it is composed only of a resin such as a copolymer or nitrile rubber, the adhesive interlayer is easily stretched, and the handleability during sealing work is very poor.

  Moreover, although the sealing method of the organic EL element which contained the desiccant in order to improve water vapor | steam barrier property is also disclosed (for example, refer patent document 3), the metal oxide etc. are used for the desiccant, As the desiccant absorbs water and reacts, the volume changes, or the color tone changes after the reaction, so the top emission type organic EL device in which the sealing layer must transmit the light emitted from the light emitting element, Not applicable.

JP 2005-166265 A Japanese Patent Laid-Open No. 06-203594 Japanese Patent No. 4106953

  Therefore, the present invention can seal the entire surface without generating a hollow portion between the organic EL element and the sealing substrate, is excellent in handleability, can be used for a top emission type, and has long-term reliability. It aims at providing the transparent resin composition for element sealing for organic electronic devices excellent also in the property, the resin sheet for element sealing for organic electronic devices, an organic electroluminescent element, and an image display apparatus.

  In order to solve the above problems, a resin composition for sealing an element for an organic electronic device according to the present invention contains at least a resin (A) having an isobutylene skeleton and a filler (B), and contains a filler (B). The amount is 20% by weight or less of the whole, and the filler (B) does not contain a metal atom.

  Moreover, it is preferable that the total light transmittance of the said resin composition is 75% or more as for the said resin composition for element sealing for organic electronic devices.

  Moreover, it is preferable that the said filler (B) is a silica filler as for the said resin composition for element sealing for organic electronic devices.

  Moreover, it is preferable that the said resin composition for element sealing for organic electronic devices further contains the petroleum resin hydrogenated as tackifying resin (C).

  The resin composition for sealing an element for an organic electronic device preferably has a total light transmittance of 80% or more of the resin composition.

  Moreover, in order to solve the said subject, the resin sheet for element sealing for organic electronic devices by this invention is the sealing layer formed with the transparent resin composition for element sealing for organic electronic devices in any one of the said It is characterized by having at least.

  Moreover, in order to solve the said subject, the organic electroluminescent element by this invention is sealed with the transparent resin composition for element sealing for organic electronic devices in any one of the said.

  Moreover, the image display apparatus by this invention has the said organic electroluminescent element, It is characterized by the above-mentioned.

  The resin composition for sealing an element for an organic electronic device and the resin sheet for sealing an element for an organic electronic device according to the present invention use an organic EL element by using a resin having an isobutylene skeleton, which is a skeleton having a high gas barrier property, and a filler. Since the entire surface can be sealed without generating a hollow portion between the sealing substrate and the sealing substrate, it is possible to suppress the characteristics of the resin that are very easily stretched, and the handleability is excellent. Furthermore, the gas barrier property can be further enhanced by the maze effect. Moreover, the transparency which can be applied also to a top emission type | mold is obtained by using the filler whose content of a filler is 20% or less and does not have a metal atom. Here, the maze effect refers to a state in which, since the filler is dispersed, water vapor is inhibited by the filler and hardly passes.

  Further, the image display device according to the present invention can block the organic EL element from moisture by the element sealing resin composition for organic electronic devices, thereby suppressing the occurrence of dark spots and improving the image visibility. be able to.

It is sectional drawing which shows typically the structure of the resin sheet for element sealing for organic electronic devices which concerns on embodiment of this invention. It is sectional drawing which shows typically the structure of the image display apparatus using the resin sheet for element sealing for organic electronic devices which concerns on embodiment of this invention. It is explanatory drawing for demonstrating typically the usage example of the resin sheet for element sealing for organic electronic devices which concerns on embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail.

  In the element sealing resin sheet 1 for an organic electronic device according to the embodiment of the present invention, at least one sealing layer 3 is formed on at least one side of the base sheet 2. FIG. 1: is a schematic sectional drawing which shows the preferable embodiment of the resin sheet 1 for element sealing for organic electronic devices of this invention. As shown in FIG. 1, the element sealing resin sheet 1 for an organic electronic device has a base sheet 2, and a sealing layer 3 is formed on the base sheet 2. The element sealing resin sheet 1 for an organic electronic device further includes a release film 4 on the sealing layer 3 for protecting the sealing layer 3.

  Hereinafter, each component of the resin sheet 1 for element sealing for organic electronic devices of this embodiment is demonstrated in detail.

(Base sheet 2, release film 4)
The base material sheet 2 temporarily attaches the resin composition for the purpose of improving the handleability when the oil composition constituting the sealing layer 3 is formed into a film. The release film 4 is used for the purpose of protecting the sealing layer 3.

  The base sheet 2 and the release film 4 are not particularly limited. For example, a polyethylene film, a polypropylene film, a polybutene film, a polybutadiene film, a polymethylpentene film, a polypinyl chloride film, a vinyl chloride copolymer film, a polyethylene terephthalate film, Polyethylene naphthalate film, polybutylene terephthalate film, polyurethane film, ethylene / vinyl acetate copolymer film, ionomer resin film, ethylene / (meth) acrylic acid copolymer film, ethylene / (meth) acrylic acid ester copolymer film , Polystyrene film, polycarbonate film, polyimide film, fluororesin film and the like. These crosslinked films are also used. Furthermore, these laminated films may be sufficient. In particular, it is preferable to use polyethylene terephthalate from the viewpoints of cost, handleability, and the like.

  As an example of the peeling force at the time of peeling the sealing layer 3 from the base material sheet 2 and the release film 4, peeling is performed by a 180 ° peeling method at a linear speed of 300 mm / min, measured according to JISZ0237. The force is preferably 0.3 N / 20 mm or less, more preferably 0.2 N / 20 mm. Although there is no restriction | limiting in particular in the minimum of peeling force, 0.005 N / 20mm or more is practical. Moreover, when temporarily attaching a peeling film to both surfaces, in order to improve handleability, it is preferable to use a thing with different peeling force.

  The film thickness of the base material sheet 2 and the release film 4 is usually about 5 to 300 μm, preferably about 10 to 200 μm, and particularly preferably about 20 to 100 μm.

(Sealing layer 3)
The transparent resin composition for sealing an element for an organic electronic device of the present invention constituting the sealing layer 3 contains a resin (A) having an isobutylene skeleton, which is a skeleton having a high gas barrier property, and a filler (B). And content of a filler (B) is 20% or less, and a filler (B) does not have a metal atom.

[Resin (A)]
The resin (A) having an isobutylene skeleton is not particularly limited, and examples thereof include various rubbers such as butyl rubber and polyisobutylene, and rubbers obtained by adding polar groups (hydroxyl groups and halogen groups) to these various rubbers. Butyl rubber and polyisobutylene are preferred from the viewpoint of low water permeability, adhesiveness and flexibility. The butyl rubber is commercially available from, for example, JSR Corporation and Lanxess Corporation, and polyisobutylene is available from BASF Corporation.

[Filler (B)]
The filler (B) is added for the purpose of improving the handleability. As the filler (B), a filler that does not contain a metal atom is applied in terms of transparency and reaction activity. Of these, silica and boron nitride are preferably used.

  Content of the said filler (B) is 20 weight% or less of the whole. When there is more content of a filler (B) than 20 weight%, it does not have transparency or adhesiveness worsens. Further, when the resin composition is made into a film, the brittleness increases and the film does not become a film.

  The filler (B) may be surface-treated with a silane coupling agent or the like for the purpose of improving dispersibility.

[Tackifying resin (C)]
The tackifier resin (C) is used for the purpose of imparting an appropriate viscosity and adhesiveness. Examples of the tackifier resin (B) include rosin, rosin derivatives (hydrogenated rosin, disproportionated rosin, polymerized rosin, rosin ester (such as esterified rosin such as alcohol, glycerin and pentaerythritol)), and terpene resin (α-pinene). , Β-pinene), terpene phenol resin, aromatic modified terpene resin, hydrogenated terpene resin, C5 petroleum resin, C9 petroleum resin, petroleum resin obtained by copolymerizing C5 petroleum resin and C9 petroleum resin, DCPD petroleum resin, hydride of C5 petroleum resin, hydride of C9 petroleum resin, hydride of petroleum resin obtained by copolymerizing C5 petroleum resin and C9 petroleum resin, hydride of DCPD petroleum resin , Coumarone-indene resin, styrene resin, phenol resin, xylene resin and the like.

  Among them, one or more selected from the group consisting of hydrides of each petroleum resin, hydrogenated rosin-based resins, and hydrogenated terpene-based resins are preferable because they have good compatibility with the polymer containing the isoprene skeleton. Used for. Among these, hydrides of C5 petroleum resins, hydrides of C9 petroleum resins, and hydrides of petroleum resins obtained by copolymerizing C5 petroleum resins and C9 petroleum resins have good water vapor barrier performance. Therefore, it is preferably used.

  The softening point of the petroleum resin hydride is preferably 60 to 150 ° C. When the temperature is lower than 60 ° C., the cohesive strength of the composition is lowered, so that the retention characteristics at high temperature are lowered. When it exceeds 150 degreeC, since the fluidity | liquidity of a composition will fall, sealing performance will fall.

  The petroleum resin hydride is commercially available from, for example, Arakawa Chemical Co., Ltd., Idemitsu Kosan Co., Ltd., and the like.

[Other additives]
[Plasticizer]
Moreover, the transparent resin composition for element sealing for organic electronic devices may contain a plasticizer, as long as the characteristic is not impaired. The flowability can be changed by introducing a plasticizer. Examples of the plasticizer include waxes, paraffins, esters such as phthalic acid esters and adipic acid esters, polybutenes and polyisobutylenes.

[Silane coupling agent]
Moreover, the transparent resin composition for element sealing for organic electronic devices may contain a silane coupling agent. By using a silane coupling agent, the amount of chemical bonding to the adherend is increased and the adhesive strength is improved.

  Specific examples of the silane coupling agent include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 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, 3-methacryloxypropyltri Methoxysilane And the like of the silane coupling agent. Two or more kinds of these silane coupling agents may be mixed. 0.05-10 mass parts is preferable with respect to 100 mass parts of resin compositions, and, as for content of a silane coupling agent, 0.1-1 mass part is more preferable.

  In the present invention, as long as the object of the present invention can be achieved, other components such as a storage stabilizer, an antioxidant, a tack adjuster, a resin stabilizer and the like can be added. Care must be taken because the visibility of the image display device may deteriorate due to moisture and impurities therein.

  In addition, the transparent resin composition for sealing an element for an organic electronic device preferably has a light transmittance of 75% or more, more preferably 80% or more with respect to light having a wavelength of 550 nm at a thickness of 0.1 mm. . This is because if the light transmittance at 550 nm is less than 80%, the visibility decreases. The light transmittance can be selected by selecting the resin and changing the blending amount of the filler.

  The light transmittance can be obtained by measuring the amount of transmitted light using a spectrophotometer (Hitachi High-Technologies spectrophotometer U-4100 type solid sample measuring system).

  The transparent resin composition for sealing an organic EL element may contain a solvent when obtaining the film-shaped sealing layer 3. Examples of such a solvent include organic solvents such as methyl ethyl ketone, toluene, ethanol, and isopropanol, and methyl ethyl ketone and toluene are particularly preferable. Each material contained in the resin composition is added to such a solvent, mixed and dispersed, and the obtained resin solution is applied to the release surface of the base sheet 2 by a roll knife coater, gravure coater, die coater, reverse coater, etc. Generally, it can be applied directly or by transfer according to a known method and dried to obtain a sealing layer.

  Moreover, as a method of obtaining the film-shaped sealing layer 3 without using an organic solvent, the transparent resin composition for sealing an organic EL element is melted at a high temperature and extruded by a generally known method such as a hot melt coater. Thereafter, the sealing layer 3 can be obtained by cooling.

  If the thickness of the sealing layer 3 is too thin, the sealing effect may not be obtained when the surface has irregularities, and there is a risk of allowing moisture or impurities to enter from the outside. There is a risk of affecting the moldability and workability of the sealing layer 3. In this respect, 3 to 100 μm is preferable, and 5 to 50 μm is more preferable.

  Moreover, it is further more preferable that surface roughness Ra of the bonding target which the sealing layer 3 and the said sealing layer 3 contact is 2 micrometers or less. When the surface roughness exceeds 2 μm, the possibility that the sealing layer 3 cannot follow the surface of the object to be bonded increases even if the followability of the transparent resin composition for sealing an organic EL element itself is high. End up. For this reason, if the surface roughness is in an appropriate range, the sealing layer 3 and the object to be bonded are in close contact with each other, and thus visibility is improved. The surface roughness of the object to be bonded can be changed by polishing or surface treatment, and the surface roughness of the sealing layer 3 can be changed by changing the surface roughness of the cooling roll or forming the release film 4 when forming the film. It can be changed by changing the surface roughness.

  The resin sheet 1 for sealing an element for an organic electronic device may have two or more sealing layers 3 or may have a layer other than the sealing layer 3.

<How to use>
Next, the usage method of the element sealing resin sheet 1 for organic electronic devices is demonstrated.

  The resin sheet 1 for sealing an element for an organic electronic device of the present invention is used for sealing an element for an organic electronic device such as the organic EL element 6. More specifically, it is disposed between an element for an organic electronic device such as the organic EL element 6 provided on the element substrate 5 (see FIGS. 2 and 3) and the sealing substrate 8 (see FIGS. 2 and 3). The organic electronic device element is hermetically sealed with the element substrate 5 and the sealing substrate 8 to obtain various organic electronic devices having a solid adhesive sealing structure. Examples of organic electronic devices include organic EL displays, organic EL lighting, organic semiconductors, and organic solar cells.

  Hereinafter, an organic EL display (image display device) will be described as an example of the organic electronic device. In the organic EL display 10, as shown in FIG. 2, the organic EL element 6 provided on the element substrate 5 is sealed by the sealing substrate 8 via the organic EL element sealing transparent resin layer 7. In the housing 9.

  For example, as shown in FIG. 2, the organic EL element 6 includes an anode 61 formed by patterning a conductive material on an element substrate 5 made of a glass substrate or the like, and an organic compound material laminated on the upper surface of the anode 61. And a cathode 63 formed by patterning a transparent conductive material laminated on the upper surface of the organic layer 62. Part of the anode 61 and the cathode 63 is drawn to the end of the element substrate 5 and connected to a drive circuit (not shown). The organic layer 62 is formed by laminating a hole injection layer, a hole transport layer, a light emitting layer, and an electron transport layer in order from the anode 61 side. The light emitting layer is composed of a blue light emitting layer, a green light emitting layer, and a red light emitting layer. Become. In addition, the light emitting layer may have a non-light emitting intermediate | middle layer between each light emitting layer of blue, green, and red.

  The sealing substrate 8 may be any material that does not significantly impair the visibility of the display content of the organic EL display 10. For example, glass, resin, or the like can be used.

  The organic EL element sealing transparent resin layer 7 is formed using the above-described element sealing resin sheet 1 for organic electronic devices, and can be formed by the following steps. First, as shown in FIG. 3A, the release film 4 of the element sealing resin sheet 1 for organic electronic devices is peeled off, and as shown in FIG. 3B, the sealing layer 3 is sealed substrate. 8 rolls. Next, as shown in FIG. 3C, the base material sheet 2 of the resin sheet 1 for sealing an element for an organic electronic device bonded to the sealing substrate 8 is peeled off. 3D, the sealing layer 3 of the organic electronic device element sealing resin sheet 1 bonded to the sealing substrate 8 is laminated to the organic EL element 6 on the cathode 63 side. The sealing layer 3 of the element sealing resin sheet 1 for organic electronic devices constitutes the organic EL element sealing transparent resin layer 7 in the organic EL display 10.

  It is preferable that the said bonding and lamination are performed at the temperature of 100 degrees C or less. If it exceeds 100 ° C., the constituent material of the organic EL element 6 may be deteriorated, and the light emission characteristics may be deteriorated.

  In addition, in the formation process of the above-mentioned transparent resin layer 7 for organic EL element sealing, the resin sheet 1 for organic electronic device element sealing was roll-bonded to the sealing substrate 8 first, but organic EL element The organic EL element with the sealing layer 3 may be produced by pasting to 6. In this case, after the base material sheet 2 of the resin sheet 1 for sealing an element for an organic electronic device is peeled off, the sealing layer 3 is laminated on the sealing substrate 8.

  EXAMPLES Hereinafter, although the structure of this invention is demonstrated in detail based on an Example, this invention is not limited to these.

(raw materials)
<Resin (A)>
A1: Butyl rubber (JSR BUTYL 065, manufactured by JSR Corporation)
A2: Polyisobutylene (BASF, B80)

<Acrylic resin>
D: Acrylic resin (Toa Gosei Co., Ltd. S-1511X)

<Filler (B)>
B1: Silica filler (manufactured by Denki Kagaku Kogyo Co., Ltd., FB-3SDC particle size (d90) 6.7 μm)
B2: Boron nitride (manufactured by Showa Denko KK, UHP-S1 particle size (d90) 3 μm)
B3: Silica filler (manufactured by Denki Kagaku Kogyo Co., Ltd., FB-20D particle size (d90) 46.0 μm)
B4: CaO (particle size 1-5 mm before crushing) was pulverized with a valverizer pulverizer (MST Co., Ltd.), and the particle size was adjusted through a mesh (average particle size 25.3 μm)
B5: MgO (manufactured by Tateho Chemical Co., Ltd., KMAO-F # 330 or less)
B6: Zeolite (manufactured by Tosoh Corporation, Zeorum A-3 # 100 or less)

<Tackifying resin (C)>
C1: C9 hydrogenated petroleum resin (Arakawa Chemical Industries, Alcon P100)
C2: C9 hydrogenated petroleum resin (Arakawa Chemical Industries, Ltd., Alcon M100)

(Example 1)
Toluene which is 20 parts by mass of silica filler (FB-3SDC particle size (d90) 6.7 μm) as filler (B) with respect to 80 parts by mass of butyl rubber (manufactured by JSR Corporation, JSR BUTYL065) as polymer (A) The resin composition A was obtained by adding the mixture so that the solid content was 30% and stirring. The resin composition A is applied to a 25 μm thick axially stretched polyethylene terephthalate film (A31, manufactured by Teijin DuPont Films, Ltd.) as a base sheet with a bar coater, and heated and dried at 130 ° C. for 3 minutes to obtain a thickness of 20 μm. The sealing layer was obtained. A 50 μm release polyester film (Toyobo Co., Ltd., Toyobo Ester film E7006) as a release film was further laminated on the release surface to the sealing layer thus obtained, and the organic electronic device according to Example 1 having a uniform thickness An element sealing resin sheet was prepared. Using the adjusted resin sheet for sealing an element for an organic electronic device, transmittance measurement, adhesive force measurement, dark spot evaluation, and handleability at that time were evaluated. The results are shown in Table 1.

(Examples 2 to 13)
Except having made the resin composition into the composition shown in Table 1, it carried out similarly to Example 1, and produced the resin sheet for element sealing for organic electronic devices which concerns on Examples 2-13. Using the adjusted resin sheet for sealing an element for an organic electronic device, transmittance measurement, adhesive force measurement, dark spot evaluation, and handleability at that time were evaluated. The results are shown in Table 1.

(Comparative Examples 1-10)
Except having made the resin composition into the compounding composition shown in Table 2, it carried out similarly to Example 1, and produced the resin sheet for element sealing for organic electronic devices which concerns on Comparative Examples 1-10. Using the adjusted resin sheet for sealing an element for an organic electronic device, transmittance measurement, adhesive force measurement, dark spot evaluation, and handleability at that time were evaluated. The results are shown in Table 2.

(Evaluation method)
Evaluation was performed according to the following evaluation method.

<Light transmittance>
The light transmittance of the resin composition for sealing an element for an organic electronic device was determined by a transmission mode using a spectrophotometer (spectrometer “V-670” manufactured by JASCO Corporation). Specifically, a sample prepared by bonding a sealing layer to a thickness of 0.1 mm at 80 ° C. was prepared, and a wavelength range of 220 nm to 2200 nm was measured at 25 ° C. with a data interval of 1 nm, a UV / VIS bandwidth of 5 nm, Scanning speed was 1000 nm / min, and the light transmittance was obtained by averaging the transmittance for every 1 nm obtained by measurement in the wavelength region of 400 nm to 800 nm. Baseline / dark correction was performed during the measurement. The light source was switched at 340 nm and the diffraction grating was switched at 850 nm, and the filter was exchanged by a step method.

<Dark spot>
An organic EL device having an anode on an element substrate made of insulating transparent glass, an organic layer on the upper surface, and a cathode on the upper surface was prepared. Next, the 25 μm release-treated polyester film of the prepared resin sheet for sealing an element for an organic electronic device was peeled and placed on the upper surface of the cathode of the organic EL element. Thereafter, the 50 μm release polyester film of the organic EL element sealing transparent resin sheet is peeled off, and an insulating transparent glass is disposed on the upper surface of the sealing layer of the organic electronic device element sealing resin sheet as a sealing substrate. Then, pressurization was performed for 1 minute at a pressure of 0.6 MPa at 80 ° C. under reduced pressure to prepare a model of an organic EL display.

  Next, the above model was treated at 80 ° C. and 85% RH for 1000 hours, and then cooled to room temperature (25 ° C.). Then, the organic EL element was activated, and dark spots (non-light emitting portions) were observed. When the area of the dark spot was less than 5% of the whole, “◯” was given as being excellent in suppressing the occurrence of the dark spot, and when it was 5% or more, “X” was given as being inferior in suppressing the occurrence of the dark spot.

<Handability>
When preparing a sample for observing dark spots, the release-treated polyester film of the element sealing resin sheet for organic electronic devices prepared with the A4 plate was peeled at 1500 mm / min in the direction of 180 degrees, and the adhesive layer was stretched. If the film was left attached to the release-treated polyester film or cracked or cracked in the adhesive layer, the product was extended as a defective product. Those that were not treated were evaluated as “△” as acceptable products, and those that were handled without problems were evaluated as “Good”.

<Adhesive strength>
What peeled 25 micrometer peeling process polyester film of the resin sheet for element sealing for organic electronic devices which adjusted, and bonded 38 micrometer easy adhesion processing polyester film (Teijin DuPont Films company make, G2-C) at 80 degreeC. A test piece was obtained. With respect to the obtained test piece, the adherend was made of glass in accordance with JIS R3202, the bonding temperature was set to 80 ° C., and the adhesive strength was measured by a 180 ° peeling method in accordance with JIS Z0237.

  Examples 1 to 13 contain at least a resin (A) containing an isobutylene skeleton and a filler (B), the filler (B) content is 20% by weight or less, and the filler (B) However, since no metal atom was contained, good results were obtained in all the characteristics of light transmittance, dark spot, handleability, and adhesive strength.

  On the other hand, in Comparative Example 1, since the content of the filler (B) is more than 20% by weight of the whole, the light transmittance is low, the handleability is deteriorated, and the dark spot evaluation cannot be performed. Since Comparative Example 2 did not contain the filler (B), the pressure-sensitive adhesive layer was very easy to stretch, the handleability was poor, and the gas barrier property was also deteriorated, so dark spots were generated. In Comparative Examples 3, 4, and 5, since the filler (B) contains metal atoms, the transmittance was deteriorated, the light-emitting element was damaged due to volume expansion after water absorption, and dark spots were generated. In Comparative Example 6, since the content of the filler (B) was more than 20% by weight of the whole, the film became brittle, the handleability was poor, and the dark spot evaluation could not be performed. In Comparative Examples 7 and 8, since the resin (A) is an acrylic resin that does not have an isobutylene skeleton, the water content of the entire resin is large and the gas barrier property is low, so dark spots are generated. Comparative Example 9 is an acrylic resin in which the resin (A) does not have an isobutylene skeleton, and since the added filler contains metal atoms and further contains 20% by weight or more, the water content of the entire resin is large, and the gas barrier The properties were low, dark spots were generated, the light transmittance was low, the film was fragile and the handleability was poor. Since Comparative Example 10 did not contain the filler (B), the gas barrier properties were also deteriorated and dark spots were generated.

1: Resin sheet 2 for sealing elements for organic electronic devices 2: Base sheet 3: Sealing layer 4: Release film 5: Element substrate 6: Organic EL element 10: Organic EL display 61: Anode 62: Organic layer 63: Cathode 7: Transparent resin layer for sealing organic EL element 8: Sealing substrate 9: Housing

Claims (8)

  It contains at least a resin (A) having an isobutylene skeleton and a filler (B), the filler (B) content is 20% by weight or less, and the filler (B) does not contain a metal atom. A transparent resin composition for sealing an element for an organic electronic device.   2. The resin composition for sealing an element for an organic electronic device according to claim 1, wherein the total light transmittance of the resin composition is 75% or more.   The resin composition for sealing an element for an organic electronic device according to claim 1, wherein the filler (B) is a silica filler.   Furthermore, the hydrogenated petroleum resin is included as tackifying resin (C), The element sealing resin composition for organic electronic devices as described in any one of Claims 1-3 characterized by the above-mentioned.   5. The resin composition for sealing an element for an organic electronic device according to claim 1, wherein the resin composition has a total light transmittance of 80% or more.   It has at least the sealing layer formed with the transparent resin composition for element sealing for organic electronic devices as described in any one of Claims 1-5, The element sealing for organic electronic devices characterized by the above-mentioned. Resin sheet.   The organic electroluminescent element sealed with the transparent resin composition for element sealing for organic electronic devices as described in any one of Claims 1-6.   An image display device comprising the organic electroluminescence element according to claim 7.

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