Sealing composition and sealing sheet

Abstract

To provide a sealing composition that can form a sealing layer with excellent water vapor barrier properties and high-temperature adhesion. [Solution] (A) an olefin polymer having an acid anhydride group and / or a carboxyl group, (B) calcium oxide, and (C) a BET specific surface area of ​​50 m² 2 A sealing composition comprising silica in an amount of 1 / g or more, wherein the content of component (B) relative to the total nonvolatile content of the sealing composition is 48% by mass or more, and the amount of component (C) is 1 to 12 parts by mass per 100 parts by mass of component (B).

Description

[Technical Field] 【0001】 The present invention relates to a sealing composition and a sealing sheet useful for protecting electronic devices and the like from moisture. [Background technology] 【0002】 To protect moisture-sensitive electronic devices such as organic light-emitting diodes (OLEDs) and perovskite solar cells (PSCs) from moisture, encapsulation compositions containing moisture adsorbents such as calcium oxide have been developed. For example, Patent Documents 1 and 2 disclose encapsulation compositions containing calcium oxide. [Prior art documents] [Patent Documents] 【0003】 [Patent Document 1] Special Publication No. 2021-508348 [Patent Document 2] Special Publication No. 2020-533463 [Overview of the project] [Problems that the invention aims to solve] 【0004】 A sealing layer with excellent water vapor barrier properties can be formed from a sealing composition containing a large amount of calcium oxide. However, sealing layers containing a large amount of calcium oxide exhibit reduced adhesion in high-temperature environments (hereinafter sometimes abbreviated as "high-temperature adhesion"). 【0005】 The present invention has been made in view of the above circumstances, and its object is to provide a sealing composition that can form a sealing layer with excellent water vapor intrusion barrier properties and high-temperature adhesion. [Means for solving the problem] 【0006】 The present invention, which can achieve the above objectives, is as follows: [1] The following components (A) to (C): (A) An olefin polymer having an acid anhydride group and / or a carboxy group, (B) Calcium oxide, and (C) silica having a BET specific surface area of 50 m 2 / g or more, A sealing composition containing the same, The content of the component (B) with respect to the total non-volatile content of the sealing composition is 48% by mass or more, and The amount of the component (C) with respect to 100 parts by mass of the component (B) is 1 part by mass to 12 parts by mass, a sealing composition. [2] The sealing composition according to [1] above, wherein the average primary particle diameter of the component (C) is 50 nm or less. [3] The sealing composition according to [1] or [2] above, wherein the silica of the component (C) is fumed silica. [4] The sealing composition according to any one of [1] to [3] above, wherein the median diameter of the component (B) is 0.03 μm to 20 μm. [5] The sealing composition according to any one of [1] to [4] above, wherein the content of the component (B) with respect to the total non-volatile content of the sealing composition is 80% by mass or less. [6] The following component (D): (D) An olefin polymer having an epoxy group The sealing composition according to any one of [1] to [5] above, further containing the same. [7] The following component (E): (E) A liquid olefin polymer having none of an acid anhydride group, a carboxy group, and an epoxy group The sealing composition according to any one of [1] to [6] above, further containing the same. [8] The following component (F): (F) A tackifier The sealing composition according to any one of [1] to [7] above, further containing the same. [9] A sealing sheet having a laminated structure including a support and a sealing layer formed from the sealing composition according to any one of [1] to [8] above.

[10] The sealing sheet according to [9] above, wherein the tanδ of the sealing layer at 120 °C is less than 1.10. An electronic device including a sealing layer formed from the sealing composition according to any one of [1] to [8] above. 【Advantages of the Invention】 【0007】 According to the sealing composition of the present invention, a sealing layer excellent in water vapor intrusion barrier properties and high-temperature adhesiveness can be formed. 【Embodiments for Carrying Out the Invention】 【0008】 <Sealing Composition> The sealing composition of the present invention contains the following components (A) to (C) as essential components: (A) An olefin polymer having an acid anhydride group and / or a carboxy group, (B) Calcium oxide, and (C) Silica having a BET specific surface area of 50 m 2 / g or more. 【0009】 In this specification, the "olefin polymer" means a polymer in which the structural unit derived from an olefin (hereinafter sometimes abbreviated as "olefin unit") is the main structural unit (that is, the amount of the olefin unit is the largest among all the structural units). In the following, the "structural unit derived from butene" or the like, which is an olefin unit, may be abbreviated as "butene unit" or the like. 【0010】 The olefin polymer may be an olefin resin (for example, a propylene-butene copolymer) or an olefin rubber (for example, butyl rubber, that is, an isobutylene-isoprene copolymer). In this specification, the "olefin resin" means an olefin polymer that cannot form a rubber elastomer by crosslinking, and the "olefin rubber" means an olefin polymer that can form a rubber elastomer by crosslinking. 【0011】 Preferred olefins are monoolefins having one olefinic carbon-carbon double bond and / or diolefins having two olefinic carbon-carbon double bonds. Examples of monoolefins include α-olefins such as ethylene, propylene, 1-butene, isobutylene, 1-pentene, 1-hexene, 1-heptene, and 1-octene. Examples of diolefins include 1,3-butadiene, isoprene, 1,3-pentadiene, and 2,3-dimethylbutadiene. 【0012】 Olefin polymers may be homopolymers or copolymers. Copolymers may be random copolymers or block copolymers. Furthermore, olefin polymers may be copolymers of olefins and monomers other than olefins. Examples of olefin copolymers include ethylene-non-conjugated diene copolymers, ethylene-propylene copolymers, ethylene-propylene-non-conjugated diene copolymers, ethylene-butene copolymers, ethylene-propylene-butene copolymers, propylene-butene copolymers, propylene-butene-non-conjugated diene copolymers, isobutylene-isoprene copolymers, styrene-isobutylene copolymers, styrene-isobutylene copolymers, styrene-butylene-butadiene copolymers, styrene-ethylene-butylene copolymers, hydrogenated styrene-isoprene copolymers, hydrogenated styrene-butadiene copolymers, and hydrogenated styrene-isoprene-butadiene copolymers. 【0013】 The following describes each component in detail. Unless otherwise specified in this specification, each component may be used individually or in combination of two or more. 【0014】 <(A) component> Component (A) is an olefin polymer having an acid anhydride group (i.e., a carbonyloxycarbonyl group (-CO-O-CO-)) and / or a carboxyl group. Examples of acid anhydride groups include groups derived from succinic anhydride, maleic anhydride, and glutaric anhydride. By using component (A), a sealing layer that is resistant to deformation and can maintain its shape can be obtained. Without using component (A), it becomes difficult to form a sealing layer. Furthermore, component (A) can effectively disperse calcium oxide (component (B)) in the sealing composition by forming a crosslinked structure through coordination of the acid anhydride group and / or carboxyl group to calcium oxide. 【0015】 (A) When an olefin polymer having an acid anhydride group is used as component, the concentration of the acid anhydride group in the polymer is preferably 0.05 mmol / g to 10 mmol / g, and more preferably 0.10 mmol / g to 5 mmol / g. The concentration of the acid anhydride group is obtained from the acid value, which is defined as the number of mg of potassium hydroxide required to neutralize the acid present in 1 g of polymer, in accordance with JIS K 2501. 【0016】 (A) When an olefin polymer having a carboxyl group is used as component, the concentration of the carboxyl group in the polymer is preferably 0.05 mmol / g to 20 mmol / g, and more preferably 0.10 mmol / g to 10 mmol / g. The concentration of the carboxyl group is obtained from the acid value, which is defined as the number of mg of potassium hydroxide required to neutralize the acid present in 1 g of polymer, in accordance with JIS K 2501. 【0017】 (A) When an olefin polymer having an acid anhydride group and a carboxyl group is used as component, the sum of the concentrations of the acid anhydride group and the carboxyl group in the polymer is preferably 0.05 mmol / g to 20 mmol / g, and more preferably 0.10 mmol / g to 10 mmol / g. 【0018】 Component (A) can be produced, for example, by (i) graft modification of an olefin polymer under radical reaction conditions with an unsaturated compound having an acid anhydride group and / or a carboxyl group (e.g., maleic anhydride), or by (ii) copolymerizing an unsaturated compound having an acid anhydride group and / or a carboxyl group with an α-olefin. 【0019】 The number-average molecular weight of the olefin polymer having acid anhydride groups and / or carboxyl groups is not particularly limited, but from the viewpoint of preventing repulsion of the varnish of the sealing composition during coating and improving the mechanical strength of the sealing layer, this number-average molecular weight is preferably 800 or more, more preferably 850 or more, even more preferably 900 or more, and particularly preferably 950 or more. On the other hand, from the viewpoint of the coatability of the varnish of the sealing composition, this number-average molecular weight is preferably 1,000,000 or less, more preferably 750,000 or less, even more preferably 500,000 or less, even more preferably 400,000 or less, even more preferably 300,000 or less, particularly preferably 200,000 or less, and most preferably 150,000 or less. The number-average molecular weight in this invention is measured by gel permeation chromatography (GPC) (polystyrene equivalent). Specifically, the number-average molecular weight can be calculated using the GPC method by measuring with a Shimadzu LC-9A / RID-6A as the measuring instrument, a Showa Denko Shodex K-800P / K-804L / K-804L as the column, and toluene or the like as the mobile phase, at a column temperature of 40°C, and then using a calibration curve for standard polystyrene. 【0020】 In the present invention, the olefin polymer having an acid anhydride group and / or a carboxyl group is preferably amorphous from the viewpoint of suppressing a decrease in fluidity due to the thickening of the varnish. Here, amorphous means that the olefin polymer does not have a clear melting point, and for example, when the melting point of the olefin polymer is measured by DSC (differential scanning calorimetry), a polymer in which no clear peak is observed can be used. 【0021】 Next, specific examples of olefin polymers having acid anhydride groups and / or carboxyl groups will be described. Specific examples of polyisobutylene resins or polybutene resins include "HV-300M" (acid value: 65 mg KOH / g, acid anhydride group concentration: 1.16 mmol / g, number average molecular weight: 2,100) and "HV-100M" (acid value: 82 mg KOH / g, acid anhydride group concentration: 1.46 mmol / g, number average molecular weight: 1,218) from Toho Chemical Industry Co., Ltd., and "DOVERMULSE H1000" (acid value: 54 mg KOH, acid anhydride group concentration: 0.96 mmol / g, number average molecular weight: 1,204) from DOVER. 【0022】 Specific examples of styrene-isobutylene copolymers include "T-YP757B" (maleic anhydride-modified styrene-isobutylene-styrene block copolymer, acid anhydride group concentration: 0.46 mmol / g, number average molecular weight: 100,000) manufactured by Seikoh PMC, "T-YP766" (glycidyl methacrylate-modified styrene-isobutylene-styrene block copolymer, epoxy group concentration: 0.64 mmol / g, number average molecular weight: 100,000) manufactured by Seikoh PMC, and "T-YP8920" (maleic anhydride-modified styrene-isobutylene-styrene copolymer, acid anhydride group concentration: 0.46 mmol / g, number average molecular weight: 35,800) manufactured by Seikoh PMC. 【0023】 Specific examples of polyethylene-based or polypropylene-based resins include "Yumex 1010" manufactured by Sanyo Chemical Industries, Ltd. (acid anhydride group concentration: 0.98 mmol / g, number average molecular weight: 30,000) and "MG-441P" manufactured by Riken Vitamin Co., Ltd. (acid anhydride group concentration: 0.73 mmol / g). 【0024】 Specific examples of propylene-butene copolymers include "T-YP279" (maleic anhydride-modified propylene-butene random copolymer, acid anhydride group concentration: 0.46 mmol / g, number average molecular weight: 35,000) and "T-YP312" (maleic anhydride-modified propylene-butene random copolymer, acid anhydride group concentration: 0.46 mmol / g, number average molecular weight: 60,900) from Seikoh PMC. Specific examples of ethylene-propylene copolymers include "Lucant A-5260" (acid anhydride group concentration: 0.44 mmol / g, number average molecular weight: 5,400) from Mitsui Chemicals. 【0025】 A specific example of isobutylene-isoprene copolymer (butyl rubber) is "ER661" manufactured by Seikoh PMC Co., Ltd. (maleic anhydride-butyl methacrylate random copolymer modified butyl rubber, butyl methacrylate unit concentration: 0.32 mmol / g, acid anhydride group concentration: 0.46 mmol / g, number average molecular weight: 40,000). 【0026】 (A) component is, Preferably, it is an olefin polymer having an acid anhydride group. More preferably, at least one selected from the group consisting of polybutene having an acid anhydride group and ethylene-propylene copolymer having an acid anhydride group, More preferably, at least one selected from the group consisting of liquid polybutene having acid anhydride groups and liquid ethylene-propylene copolymer having acid anhydride groups. Particularly preferred is a liquid polybutene having an acid anhydride group. 【0027】 In this invention, "liquid polymer" (e.g., "liquid olefin polymer") means that the viscosity at 25°C is 5,000 Pa·s or less. Furthermore, in this invention, "viscosity at 25°C" means the viscosity calculated by multiplying the kinematic viscosity at 25°C, measured by a dynamic viscoelasticity measuring device, by the density. Examples of dynamic viscoelasticity measuring devices include the rheometer manufactured by TA Instruments Corporation (product name: DISCOVERY HR-2). 【0028】 There is no particular limit to the lower limit of the content of component (A) relative to the total nonvolatile content of the sealing composition. However, from the viewpoint of the coating properties and moldability of the sealing composition, and the handling properties (tack suppression) of the sealing layer, the content is preferably 1% by mass or more, more preferably 2% by mass or more, and even more preferably 5% by mass or more. There is no particular limit to the upper limit of the content. However, from the viewpoint of the coating properties and moldability of the sealing composition, and the handling properties (tack suppression) of the sealing layer, the content is preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less. In one embodiment of the present invention, the content is preferably 1% by mass to 40% by mass, more preferably 2% by mass to 30% by mass, and even more preferably 5% by mass to 20% by mass. 【0029】 <(B) component> Component (B) is calcium oxide. By using component (B), the sealing layer can be given excellent water vapor intrusion barrier properties. 【0030】 (B) Median diameter of component (D 50The median diameter of component (B) is preferably 0.03 μm or larger, more preferably 0.05 μm or larger, and even more preferably 0.1 μm or larger, from the viewpoint of the dispersibility of component (B) in the sealing composition. The median diameter is preferably 20 μm or smaller, more preferably 15 μm or smaller, and even more preferably 12 μm or smaller, in order to prevent component (B) from damaging electronic devices. In one embodiment of the present invention, the median diameter of component (B) is preferably 0.03 μm to 20 μm, more preferably 0.05 μm to 15 μm, and even more preferably 0.1 μm to 12 μm. The median diameter of component (B) can be measured and calculated by a laser diffraction-scattering method based on Mie scattering theory. Specifically, the median diameter can be calculated by creating a volume-based particle size distribution of component (B) using a laser diffraction particle size distribution analyzer. A sample of component (B) dispersed in ethanol by ultrasound is preferably used as the measurement sample. For laser diffraction scattering particle size distribution analyzers, devices such as the LA-500 manufactured by Horiba, Ltd. can be used. 【0031】 The content of component (B) relative to the total nonvolatile content of the sealing composition must be 48% by mass or more from the viewpoint of the water vapor intrusion barrier properties of the sealing layer. The content is preferably 50% by mass or more from the viewpoint of the water vapor intrusion barrier properties of the sealing layer. The content is preferably 80% by mass or less, more preferably 75% by mass or less, and even more preferably 70% by mass or less from the viewpoint of the adhesion of the sealing layer. In one embodiment of the present invention, the content is preferably 48% by mass to 80% by mass, more preferably 50% by mass to 75% by mass, and even more preferably 50% by mass to 70% by mass. 【0032】 <(C) component> (C) Component has a BET specific surface area of ​​50 m². 2It is silica of / g or more. The silica as the component (C) is preferably fumed silica. By using the component (C), excellent high-temperature adhesiveness can be imparted to the sealing layer. As this presumed mechanism, it is considered that by using the component (C), the aggregation of the component (B) (calcium oxide) is suppressed, and as a result, excellent high-temperature adhesiveness is imparted to the sealing layer. However, the present invention is not limited to this presumed mechanism. 【0033】 (C) component (especially fumed silica) has a BET specific surface area of 50 m 2 / g or more, preferably 75 m 2 / g or more, more preferably 100 m 2 / g or more. From the viewpoint of the high-temperature adhesiveness of the sealing layer, the BET specific surface area is preferably 400 m 2 / g or less, more preferably 350 m 2 / g or less, still more preferably 300 m 2 / g or less. In one embodiment of the present invention, the BET specific surface area is preferably 50 m 2 / g to 400 m 2 / g, more preferably 75 m 2 / g to 350 m 2 / g, still more preferably 100 m 2 / g to 300 m<​​​​​​​​In this invention, the average primary particle diameter of component (C) is a value obtained by analyzing images of component (C) using a transmission electron microscope and calculating the average by number of particles. Specifically, 50 images of component (C) are taken with a transmission electron microscope (for example, Hitachi High-Tech Corporation's HT7800 (product name)) with different fields of view. 2500 particles of component (C) are randomly selected from the captured images, their primary particle diameters are analyzed, and the value obtained by calculating the average by number of particles is defined as the average primary particle diameter of component (C). 【0036】 The amount of component (C) relative to 100 parts by mass of component (B) is 1 to 12 parts by mass. The amount must be 1 part by mass or more from the viewpoint of high-temperature adhesion. The amount must be 12 parts by mass or less from the viewpoint of room-temperature adhesion. The amount is preferably 1.2 parts by mass or more from the viewpoint of high-temperature adhesion. The amount is preferably 11 parts by mass or less from the viewpoint of room-temperature adhesion. In one embodiment of the present invention, the amount is preferably 1.2 parts by mass to 11 parts by mass. 【0037】 <(D) component> The sealing composition of the present invention comprises the following component (D): (D) Olefin polymer having epoxy groups It may further contain the following: The epoxy groups of component (D) form a crosslinked structure through reaction with the acid anhydride groups and / or carboxyl groups of component (A), thereby improving the water vapor intrusion barrier properties of the resulting sealing layer. 【0038】 The concentration of epoxy groups in component (D) is preferably 0.05 mmol / g to 10 mmol / g, and more preferably 0.10 mmol / g to 5 mmol / g. The epoxy group concentration is determined from the epoxy equivalent obtained according to JIS K 7236-1995. 【0039】 The number-average molecular weight of component (D) is preferably 1,000 to 1,000,000, more preferably 2,000 to 500,000, and even more preferably 2,000 to 200,000, in order to improve the coatability of the varnish of the sealing composition, as well as the sealing performance and mechanical strength of the sealing layer. 【0040】 Component (D) can be obtained, for example, by (i) graft-modifying an olefin polymer with an epoxy-containing unsaturated compound (e.g., glycidyl (meth)acrylate, 4-hydroxybutyl acrylate glycidyl ether, allyl glycidyl ether) under radical reaction conditions, or by (ii) copolymerizing an epoxy-containing unsaturated compound with an α-olefin. 【0041】 Specific examples of component (D) include "ER829" (glycidyl methacrylate-modified propylene-butene random copolymer, epoxy group concentration: 0.64 mmol / g, number average molecular weight: 400,000) manufactured by Seikoh PMC, "T-YP276" (glycidyl methacrylate-modified propylene-butene random copolymer, epoxy group concentration: 0.64 mmol / g, number average molecular weight: 57,000) manufactured by Seikoh PMC, "ER850" (glycidyl methacrylate-modified isobutylene-isoprene random copolymer, epoxy group concentration: 0.654 mmol / g, number average molecular weight: 99,200) manufactured by Seikoh PMC, and "ER866" (glycidyl methacrylate-modified butyl rubber (i.e., glycidyl methacrylate-modified isobutylene-isoprene copolymer), epoxy group concentration: 1.63 mmol / g, number average molecular weight: 113,000) manufactured by Seikoh PMC. 【0042】 (D) component is, Preferably, it is at least one selected from the group consisting of ethylene-glycidyl methacrylate copolymer, ethylene-glycidyl methacrylate-vinyl acetate copolymer, ethylene-glycidyl methacrylate-methyl acrylate copolymer, propylene-butene copolymer having an epoxy group, butyl rubber having an epoxy group, and ethylene-methyl methacrylate copolymer having an epoxy group. More preferably, at least one selected from the group consisting of propylene-butene copolymer having epoxy groups, butyl rubber having epoxy groups, and ethylene-methyl methacrylate copolymer having epoxy groups. More preferably, at least one selected from the group consisting of propylene-butene copolymer having epoxy groups and butyl rubber having epoxy groups, Particularly preferred is butyl rubber having epoxy groups. 【0043】 (D) When using butyl rubber having epoxy groups (i.e., isobutylene-isoprene copolymer having epoxy groups) as component, from the viewpoint of preventing yellowing of the sealing layer, the amount of isoprene units in the copolymer is preferably 0.1% to 20% by mass, more preferably 0.3% to 15% by mass, and even more preferably 0.5% to 10% by mass, based on the total of isobutylene units and isoprene units. The amount of isoprene units is based on isobutylene units and isoprene units excluding the modified portion (for example, the portion derived from glycidyl (meth)acrylate for introducing epoxy groups). 【0044】 When component (D) is used, its content is preferably 1% by mass or more, more preferably 2% by mass or more, and even more preferably 4% by mass or more, relative to the total nonvolatile content of the sealing composition, from the viewpoint of sealing performance and mechanical strength of the sealing layer. When component (D) is used, its content is preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less, relative to the total nonvolatile content of the sealing composition, from the viewpoint of sealing performance and mechanical strength of the sealing layer. When component (D) is used, its content in one embodiment of the present invention is preferably 1% to 40% by mass, more preferably 2% to 30% by mass, and even more preferably 4% to 20% by mass, relative to the total nonvolatile content of the sealing composition. 【0045】 <(E) component> The sealing composition of the present invention comprises the following component (E): (E) Liquid olefin polymers that do not have acid anhydride groups, carboxyl groups, or epoxy groups. It may further contain the following. By using component (E), the dispersibility of component (B) (calcium oxide) in the sealing composition and the adhesion of the sealing layer can be improved. In this invention, liquid olefin polymers having acid anhydride groups and / or carboxyl groups are classified as component (A), and liquid olefin polymers having epoxy groups are classified as component (D). 【0046】 The viscosity of component (E) at 25°C is preferably 5 Pa·s to 5,000 Pa·s, more preferably 10 Pa·s to 4,000 Pa·s, and even more preferably 20 Pa·s to 3,000 Pa·s, from the viewpoint of adhesion and flexibility of the sealing layer. 【0047】 The number-average molecular weight of component (E) is preferably 100 to 50,000, more preferably 200 to 30,000, and even more preferably 300 to 20,000, from the viewpoint of the coatability of the varnish of the sealing composition. 【0048】 (E) Component can be a commercially available product. Such commercially available products include, for example, ENEOS's "HV-100" (liquid polybutene), ENEOS's "HV-300" (liquid polybutene), ENEOS's "HV-1900" (liquid polybutene), ENEOS's "HV-50" (liquid polybutene), ENEOS's "HV-35" (liquid polybutene), Kothari's "950MW" (liquid polybutene), Kothari's "2400MW" (liquid olefin polymer), INEOS's "H-1900" (liquid polybutene), INEOS's " H-6000 (liquid polybutene), INEOS's H-18000 (liquid polybutene), NOF Corporation's 200N (liquid polybutene), Nippon Soda Co., Ltd.'s BI-2000 (liquid hydrogenated polybutadiene), Nippon Soda Co., Ltd.'s BI-3000 (liquid hydrogenated polybutadiene), Nippon Soda Co., Ltd.'s GI-3000 (liquid hydrogenated polybutadiene), Mitsui Chemicals' Lucant LX100 (liquid olefin polymer), Mitsui Chemicals' Lucant LX400 (liquid olefin polymer), Idemitsu Showa Shell Co., Ltd.'s Poly bd R-45HT (butadiene-based liquid rubber), Idemitsu Showa Shell Co., Ltd.'s Poly bd R-15HT (butadiene-based liquid rubber), Idemitsu Showa Shell Co., Ltd.'s Poly "ip" (liquid polyisoprene), Nippon Soda Co., Ltd. "B-1000" (liquid polybutadiene), Nippon Soda Co., Ltd. "B-3000" (liquid polybutadiene), Nippon Soda Co., Ltd. "G-3000" (liquid polybutadiene), Kuraray Co., Ltd. "LIR-30" (liquid polyisoprene), Kuraray Co., Ltd. "LIR-390" (liquid polyisoprene), Kuraray Co., Ltd. "LIR-290" (liquid polyisoprene), Kuraray Co., Ltd. "LBR-302" (liquid polybutadiene), Kuraray Co., Ltd. "LBR-305" (liquid polybutadiene), Kuraray Co., Ltd. "LBR-361" (liquid polybutadiene), Kuraray Co., Ltd. "L-SBR-820" (liquid styrene-butadiene random copolymer), Cray Valley Co., Ltd. "Ricon 154" (liquid butadiene), Cray Examples include "Ricon 184" (liquid styrene-butadiene random copolymer) manufactured by VALLEY. 【0049】 Component (E) is preferably at least one selected from the group consisting of liquid polybutene and liquid hydrogenated polybutadiene, and more preferably liquid polybutene. 【0050】 When component (E) is used, its content is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, relative to the total nonvolatile content of the sealing composition, from the viewpoint of adhesion and flexibility of the sealing layer. When component (E) is used, its content is preferably 35% by mass or less, more preferably 30% by mass or less, and even more preferably 25% by mass or less, relative to the total nonvolatile content of the sealing composition, from the viewpoint of handlingability (tack suppression) of the sealing layer. When component (E) is used, its content in one embodiment of the present invention is preferably 1% to 35% by mass, more preferably 5% to 30% by mass, and even more preferably 10% to 25% by mass, relative to the total nonvolatile content of the sealing composition. 【0051】 <(F) component> The sealing composition of the present invention comprises the following component (F): (F) Tackifier It may further contain (F). By using component (F), the adhesion of the sealing layer can be improved. 【0052】 Examples of tackifiers include terpene resins, modified terpene resins, coumarone resins, indene resins, petroleum resins, and saturated hydrocarbon resins. Examples of modified terpene resins include hydrogenated terpene resins, terpene-phenol copolymer resins, and aromatically modified terpene resins. Examples of petroleum resins include aliphatic petroleum resins, alicyclic petroleum resins (e.g., dicyclopentadiene petroleum resins), aromatic petroleum resins, aliphatic-aromatic copolymer petroleum resins, and their hydrides (e.g., hydrogenated alicyclic petroleum resins). 【0053】 Examples of commercially available tackifiers include the following: Terpene resins include, for example, YS Resin PX and YS Resin PXN (both manufactured by Yasuhara Chemical Co., Ltd.). Aromatic modified terpene resins include, for example, YS Resin TO and TR series (both manufactured by Yasuhara Chemical Co., Ltd.). Hydrogenated terpene resins include, for example, Clearon P, Clearon M, and Clearon K series (all manufactured by Yasuhara Chemical Co., Ltd.). Terpene phenol copolymer resins include, for example, YS Polystar 2000, Polystar U, Polystar T, Polystar S, and Mighty Ace G (all manufactured by Yasuhara Chemical Co., Ltd.). Alicyclic petroleum resins include, for example, Quintone 1325 and Quintone 1345 (both manufactured by Nippon Zeon Co., Ltd.). Aromatic petroleum resins include, for example, ENDEX 155 (manufactured by Eastman). Examples of aliphatic aromatic copolymer petroleum resins include Quintone D100 (manufactured by Zeon Corporation). Examples of hydrogenated alicyclic petroleum resins include T-REZ OP501, T-REZ PR803, T-REZ HA085, T-REZ HA103, T-REZ HA105, T-REZ HA125 (all manufactured by ENEOS Corporation), Escorez 5300 series, 5600 series (all manufactured by ExxonMobil Corporation). Examples of saturated hydrocarbon resins include Alcon P100, Alcon P125, Alcon P140, TFS13-030 (all manufactured by Arakawa Chemical Industries, Ltd.). 【0054】 The softening point of the tackifier is preferably 50°C to 200°C, more preferably 90°C to 180°C, and even more preferably 100°C to 150°C, so that the sheet softens during the lamination process of the sealing sheet and has the desired heat resistance. The softening point is measured by the ring-and-ball method in accordance with JIS K2207. 【0055】 From the viewpoint of the adhesiveness of the sealing composition, component (F) (tackifier) ​​is preferably a petroleum resin, more preferably at least one selected from the group consisting of alicyclic petroleum resins and hydrogenated alicyclic petroleum resins, and even more preferably a hydrogenated dicyclopentadiene petroleum resin. 【0056】 When component (F) is used, its content is preferably 3% by mass or more, more preferably 5% by mass or more, and even more preferably 8% by mass or more, relative to the total nonvolatile content of the sealing composition, from the viewpoint of adhesion of the sealing layer. When component (F) is used, its content is preferably 45% by mass or less, more preferably 35% by mass or less, and even more preferably 25% by mass or less, relative to the total nonvolatile content of the sealing composition, from the viewpoint of handlingability of the sealing layer (tack suppression). When component (F) is used, its content in one embodiment of the present invention is preferably 3% to 45% by mass, more preferably 5% to 35% by mass, and even more preferably 8% to 25% by mass, relative to the total nonvolatile content of the sealing composition. 【0057】 <Other ingredients> The sealing composition of the present invention may contain components other than those described above (hereinafter sometimes abbreviated as "other components"), as long as they do not impair the effects of the present invention. Examples of other components include olefin polymers other than components (A), (D), and (E), curing accelerators, hygroscopic fillers other than calcium oxide, antioxidants, plasticizers, etc. Any one of the other components may be used, or two or more may be used in combination. 【0058】 In this specification, "olefin polymers other than components (A), (D), and (E)" (hereinafter sometimes abbreviated as "other polymers") means non-liquid olefin polymers that do not have any acid anhydride groups, carboxyl groups, or epoxy groups, and have a viscosity at 25°C that exceeds 5,000 Pa·s. Examples of commercially available other polymers include "7311F" (hydrogenated styrene-isoprene-butadiene copolymer) manufactured by Kuraray Co., Ltd. 【0059】 When other polymers are used, their content is preferably 0.3% to 30% by mass, more preferably 0.5% to 25% by mass, and even more preferably 1% to 20% by mass, relative to the total nonvolatile content of the sealing composition, from the viewpoint of the water vapor intrusion barrier properties and mechanical strength of the sealing layer. 【0060】 In the present invention, a curing accelerator may be used to promote the crosslinking reaction between component (A) (an olefin polymer having an acid anhydride group and / or a carboxyl group) and component (D) (an olefin polymer having an epoxy group). Examples of curing accelerators include imidazole compounds, tertiary and quaternary amine compounds, dimethylurea compounds, and organophosphine compounds. 【0061】 Examples of imidazole compounds include 1H-imidazole, 2-methylimidazole, 2-phenyl-4-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 2-undecylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-undecylimidazole, 2-phenyl-4,5-bis(hydroxymethyl)imidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 2-phenylimidazole, 2-dodecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole. Specific examples of imidazole compounds include Cureazole 2MZ, 2P4MZ, 2E4MZ, 2E4MZ-CN, C11Z, C11Z-CN, C11Z-CNS, C11Z-A, 2PHZ, 1B2MZ, 1B2PZ, 2PZ, C17Z, 1.2DMZ, 2P4MHZ-PW, 2MZ-A, and 2MA-OK (all manufactured by Shikoku Chemicals Co., Ltd.). 【0062】 Examples of tertiary and quaternary amine compounds include quaternary ammonium salts such as tetramethylammonium bromide, tetrabutylammonium bromide, and triethylmethylammonium 2-ethylhexanoate; diazabicyclo compounds such as DBU (1,8-diazabicyclo[5.4.0]undecene-7), DBN (1,5-diazabicyclo[4.3.0]nonene-5), DBU-phenol salt, DBU-octylate, DBU-p-toluenesulfonate, DBU-formate, and DBU-phenol novolac resin salt; and benzyldimethylamine, 2-(dimethylaminomethyl)phenol, and 2,4,6-tris(dimethylaminomethyl)phenol (TAP). Among these, TAP is preferred. 【0063】 Examples of dimethylurea compounds include aromatic dimethylureas such as DCMU (3-(3,4-dichlorophenyl)-1,1-dimethylurea) and U-CAT3512T (manufactured by Sunapro Co., Ltd.), and aliphatic dimethylureas such as U-CAT3503N (manufactured by Sunapro Co., Ltd.). 【0064】 Examples of organic phosphine compounds include triphenylphosphine, tetraphenylphosphonium tetra-p-tolylborate, tetraphenylphosphonium tetraphenylborate, tri-tert-butylphosphonium tetraphenylborate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, butyltriphenylphosphonium thiocyanate, and triphenylphosphinetriphenylborane. Specific examples of organic phosphine compounds include TPP, TPP-MK, TPP-K, TTBuP-K, TPP-SCN, and TPP-S (all manufactured by Hokko Chemical Industry Co., Ltd.). 【0065】 When a curing accelerator is used, its content is preferably 0.001% to 5% by mass, more preferably 0.001% to 2.5% by mass, and even more preferably 0.001% to 1% by mass, relative to the total nonvolatile content of the sealing composition, in order to promote the crosslinking reaction. 【0066】 Examples of hygroscopic fillers other than calcium oxide include semi-calcined hydrotalcite, calcined hydrotalcite, magnesium oxide, and molecular sieves. 【0067】 Examples of antioxidants include BASF's "Irganox 1010" (a hindered phenol antioxidant). 【0068】 Examples of plasticizers include mineral oils such as paraffinic process oils, naphthenic process oils, liquid paraffin, and petrolatum, as well as vegetable oils such as castor oil, cottonseed oil, rapeseed oil, soybean oil, palm oil, coconut oil, and olive oil. 【0069】 <Sealing sheet> The present invention also provides a sealing sheet having a laminated structure comprising a support and a sealing layer formed from the sealing composition of the present invention. 【0070】 The sealing layer can be formed by methods known to those skilled in the art. For example, it can be formed by preparing a varnish of the sealing composition by dissolving or dispersing the above-mentioned components in an organic solvent, and then applying and drying the varnish on a support. The non-volatile content of the varnish is preferably 20% to 80% by mass, more preferably 30% to 70% by mass. 【0071】 Examples of organic solvents include ketones such as acetone, methyl ethyl ketone (MEK), and cyclohexanone; acetic acid esters such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, and carbitol acetate; cellosolves such as cellosolve; carbitols such as butyl carbitol; aromatic hydrocarbons such as toluene and xylene; dimethylformamide, dimethylacetamide, and N-methylpyrrolidone. Only one organic solvent may be used, or two or more may be used in combination. 【0072】 Drying varnish is most easily done by heating. Heating may be carried out under normal pressure or under reduced pressure. The heating temperature and heating time may vary depending on the components and organic solvents used. The heating temperature and heating time can be appropriately set by those skilled in the art depending on the components and organic solvents used. 【0073】 The thickness of the sealing layer is preferably 1 μm to 200 μm, and more preferably 2 μm to 180 μm, from the viewpoint of sealing performance and other factors. 【0074】 Examples of support materials include polyolefins such as polyethylene, polypropylene, and polyvinyl chloride; cycloolefin polymers; polyesters such as polyethylene terephthalate (hereinafter sometimes abbreviated as "PET") and polyethylene naphthalate; polycarbonate; and plastic films such as polyimide. The surface of the support material that is joined to the sealing layer may be treated with a release agent. Examples of release agents include silicone resin-based release agents, alkyd resin-based release agents, and fluororesin-based release agents. 【0075】 The thickness of the support is preferably 10 μm to 150 μm, and more preferably 20 μm to 100 μm, from the viewpoint of handling the sealing sheet and other factors. 【0076】 A support having a barrier layer (for example, a plastic film having a barrier layer) is preferred as the support. By using a support with low moisture permeability, moisture absorption of the sealing layer can be prevented during storage of the sealing sheet. Examples of the barrier layer include inorganic films such as silica vapor-deposited films, silicon nitride films, and silicon oxide films. The barrier layer may consist of multiple layers of multiple inorganic films (for example, silica vapor-deposited films). The barrier layer may also consist of organic and inorganic materials, or it may be a composite multilayer of an organic layer and an inorganic film. 【0077】 Examples of supports having a barrier layer include those with a water vapor transmission rate (WVTR) of 0.0005 g / m³. 2A high-barrier plastic film with a water vapor transmission rate (g / m³) of 24hr or less can be used. 2 " / 24hr)" refers to the following conditions for temperature and humidity, over an area of ​​1 m² 2 This refers to the amount of water vapor (g) that passes through the film in 24 hours. Examples of high-barrier plastic films include those manufactured by laminating inorganic films such as silicon dioxide (silica), aluminum oxide, magnesium oxide, silicon nitride, silicon oxide nitride, SiCN, amorphous silicon, etc., on the surface of a plastic film in single or multiple layers using chemical vapor deposition (e.g., chemical vapor deposition using heat, plasma, ultraviolet light, vacuum heat, vacuum plasma, or vacuum ultraviolet light) or physical vapor deposition (e.g., vacuum deposition, sputtering, ion plating, laser deposition, molecular beam epitaxy) (see, for example, Japanese Patent Publication No. 2016-185705, Japanese Patent No. 5719106, Japanese Patent No. 5712509, Japanese Patent No. 5292358, etc.). To prevent cracking of the inorganic film, it is preferable to alternately laminate the inorganic film and a transparent planarization layer (e.g., a transparent plastic layer). 【0078】 Furthermore, as a support having a barrier layer, for example, if the WVTR is 0.01 (g / m²) 2 / 24hr) or more 1(g / m 2 A medium-barrier plastic film with a barrier function of less than 24 hours can be used. 【0079】 Examples of medium-barrier plastic films include, A method of depositing an inorganic film containing inorganic materials such as silicon dioxide (silica), aluminum oxide, magnesium oxide, silicon nitride, silicon oxide nitride, SiCN, amorphous silicon, etc., as a barrier layer onto a substrate, or A method of applying a coating liquid consisting of a metal oxide and an organic resin having barrier properties to a substrate, and drying it to form a barrier layer. Examples include those manufactured by the following methods (see, for example, Japanese Patent Publication No. 2013-108103, Japanese Patent Publication No. 4028353, etc.). 【0080】 Water vapor transmission can be measured using a MOCON PERMATRAN series water vapor transmission rate analyzer (compliant with ISO 15106-2 and JIS K7129B). Specifically, the film is measured over 50 cm. 2 After cutting the material and setting it in a jig using silicone grease, the temperature is adjusted to 40°C and the humidity to 90%RH using ultrapure water, and the water vapor transmission rate is measured until it reaches a steady state. 【0081】 Commercially available products may be used as the support having a barrier layer. Examples of commercially available medium-barrier plastic films include "Clarista CI" from Kuraray, "Tech Barrier HX," "Tech Barrier LX," and "Tech Barrier L" from Mitsubishi Plastics, Inc., "IB-PET-PXB" from Dai Nippon Printing Co., Ltd., and the "GL, GX series" from Toppan Printing Co., Ltd. Examples of commercially available high-barrier plastic films include "X-BARRIER" from Mitsubishi Plastics, Inc. 【0082】 It is preferable to protect the sealing layer provided on the support with a protective film. Laminating the protective film onto the sealing layer can be done using known equipment. Examples of equipment used for laminating the protective film include a roll laminator, a press, and a vacuum pressure laminator. 【0083】 Examples of protective films include the aforementioned plastic films. It is preferable that the surface of the protective film that adheres to the sealing layer is treated with a release agent. Examples of release agents include silicone resin-based release agents, alkyd resin-based release agents, and fluororesin-based release agents. 【0084】 The thickness of the protective film is preferably 10 μm to 150 μm, and more preferably 20 μm to 100 μm, from the viewpoint of ease of handling of the sealing sheet. 【0085】 As a protective film, it is preferable to use a protective film having a barrier layer to suppress the absorption of moisture by the sealing layer after drying. Examples of protective films having a barrier layer include the aforementioned plastic film having a barrier layer. From the viewpoint of cost and other factors, it is preferable to use the aforementioned medium-barrier plastic film as the plastic film having a barrier layer used for the protective film. 【0086】 The tanδ (loss coefficient) of the sealing layer in the sealing sheet of the present invention at 120°C is preferably less than 1.10, more preferably less than 1.09, and even more preferably less than 1.08, in order to exhibit cohesive force (hereinafter sometimes abbreviated as "high-temperature cohesive force") in the high-temperature environment of the sealing layer and improve its high-temperature adhesion. The tanδ of the sealing layer at 120°C can be calculated by the method described in the Examples section below. 【0087】 <Application> The encapsulating composition and encapsulating sheet of the present invention can be used to protect moisture-sensitive electronic devices such as organic EL devices, organic light-emitting diodes (OLEDs), solar cells (e.g., organic thin-film solar cells (OPVs), perovskite solar cells (PSCs), dye-sensitized solar cells (DSSCs)), and organic transistors (OTFTs) from moisture. Accordingly, the present invention provides an electronic device comprising an encapsulating layer formed from the encapsulating composition of the present invention. [Examples] 【0088】 The present invention will be described in more detail below with reference to examples, but the present invention is not limited by the following examples, and it is possible to implement it with appropriate modifications within the scope that is consistent with the spirit of the above and below, and all such modifications are included in the technical scope of the present invention. In addition, unless otherwise specified, "parts" and "%" in the amounts of components and copolymer units mean "parts by mass" and "mass%", respectively. 【0089】 <Ingredients> The components used in the examples and comparative examples are shown below. 【0090】 (A) Component: Olefin polymer having acid anhydride groups and / or carboxyl groups • "HV-300M" (manufactured by Toho Chemical Industry Co., Ltd.): Maleic anhydride-modified liquid polybutene, acid anhydride group concentration 1.16 mmol / g, number average molecular weight: 2,100 • "Lucant A-5260" (manufactured by Mitsui Chemicals, Inc.): Liquid ethylene-propylene copolymer containing acid anhydride groups, acid anhydride group concentration: 0.44 mmol / g, number average molecular weight: 5,400 【0091】 (B) Ingredients: Calcium oxide • "QC2-F1" (manufactured by Inoue Lime Industry Co., Ltd.): Calcium oxide, median diameter (D 50 ): 2.6 μm • "VESTA-PP" (manufactured by Inoue Lime Industry Co., Ltd.): Calcium oxide, median diameter (D) 50 ): 11.1 μm 【0092】 (C) Component: BET specific surface area is 50m² 2 Silica that is 1 / g or more • "AEROSIL R976S" (manufactured by Nippon Aerosil Co., Ltd.): Fumed silica, BET specific surface area: 240 m² 2 / g, average primary particle size: 7nm • "AEROSIL R805" (manufactured by Nippon Aerosil Co., Ltd.): Fumed silica, BET specific surface area: 150 m² 2 / g, average primary particle size: 12nm • "AEROSIL RY200" (manufactured by Nippon Aerosil Co., Ltd.): Fumed silica, BET specific surface area: 100 m² 2 / g, average primary particle size: 12nm 【0093】 (C') component: BET specific surface area is 50m² 2 Silica less than / g • "SO-C6" (manufactured by Admatex): Silica, BET specific surface area: 2.0 m² 2 / g, median diameter (D 50 ): 2.0 μm 【0094】 (D) Component: Olefin polymer having epoxy groups • "ER866" (manufactured by Seikoh PMC, glycidyl methacrylate-modified butyl rubber (hereinafter sometimes referred to as "GMA-modified IIR"), epoxy group concentration: 1.63 mmol / g, number average molecular weight: 113,000, isobutene units / isoprene units: 98.9% / 1.1%) 【0095】 (E) Liquid olefin polymers that do not have acid anhydride groups, carboxyl groups, or epoxy groups. • "HV-1900" (manufactured by ENEOS Corporation, liquid polybutene, number average molecular weight: 2,900) 【0096】 Other polymers (i.e., olefin polymers other than components (A), (D), and (E)) • "7311F" (manufactured by Kuraray Co., Ltd.): Hydrogenated styrene-isoprene-butadiene copolymer, number average molecular weight: 100,000, styrene units / olefin units (isoprene units and butadiene units): 12% / 88% 【0097】 (F) Tackifier • "T-REZ HA125" (manufactured by ENEOS): Hydrogenated dicyclopentadiene petroleum resin, softening point: 125℃ 【0098】 Curing accelerator • "2,4,6-tris(dimethylaminomethyl)phenol" (hereinafter referred to as "TAP") (manufactured by Kayaku Nurion Co., Ltd.) 【0099】 <Examples 1-9 and Comparative Examples 1-7> Varnishes with the mixing ratios shown in Tables 1-1 to 1-4 below were prepared using the following procedure, and sealing sheets were made using the obtained varnishes. The amount (parts) of each component listed in Tables 1-1 to 1-4 below indicates the amount of non-volatile content of each component in the varnish. 【0100】 <Example 1> A mixture was obtained by dispersing maleic anhydride-modified liquid polybutene (HV-300M, Toho Chemical Industry Co., Ltd.), liquid polybutene (HV-1900, ENEOS Corporation), calcium oxide (QC2-F1, Inoue Lime Industry Co., Ltd.), and fumed silica (AEROSIL R976S, Nippon Aerosil Co., Ltd.) in a toluene solution (non-volatile content: 60%) of a tackifier (T-REZ HA125, ENEOS Corporation) using a high-speed rotary mixer. To the obtained mixture, GMA-modified IIR (ER866, Seikoh PMC Co., Ltd.), a curing accelerator (TAP, Kayaku Nurion Co., Ltd.), and toluene were added, and the resulting mixture was uniformly dispersed in a high-speed rotary mixer to obtain a varnish for sealing composition. The obtained varnish was uniformly applied using a die coater to the release-treated surface of a polyethylene terephthalate (PET) film (Toyo Cloth Co., Ltd. "SP3000", PET film thickness: 38 μm) that had been treated with a silicone-based release agent. The film was then heated at 150°C for 3 minutes to obtain a sealing sheet having a sealing layer with a thickness of 50 μm. 【0101】 <Example 2> Except for changing the amount of fumed silica (AEROSIL R976S, manufactured by Nippon Aerosil Co., Ltd.) used from 4 parts to 6 parts, a sealing sheet having a sealing varnish of the sealing composition and a sealing layer with a thickness of 50 μm was prepared using the same method as in Example 1. 【0102】 <Example 3> Except for changing the amount of fumed silica (AEROSIL R976S, manufactured by Nippon Aerosil Co., Ltd.) used from 4 parts to 12 parts, a sealing sheet having a sealing varnish of the sealing composition and a sealing layer with a thickness of 50 μm was prepared using the same method as in Example 1. 【0103】 <Example 4> Except for changing the amount of fumed silica (AEROSIL R976S, manufactured by Nippon Aerosil Co., Ltd.) used from 4 parts to 18 parts, a sealing sheet having a sealing varnish of the sealing composition and a sealing layer with a thickness of 50 μm was prepared in the same manner as in Example 1. 【0104】 <Example 5> Except for changing the amount of fumed silica (AEROSIL R976S, manufactured by Nippon Aerosil Co., Ltd.) used from 4 parts to 24 parts, a sealing sheet having a sealing varnish of the sealing composition and a sealing layer with a thickness of 50 μm was prepared using the same method as in Example 1. 【0105】 <Example 6> Except for changing calcium oxide (Inoue Lime Industry Co., Ltd. "QC2-F1") to calcium oxide (Inoue Lime Industry Co., Ltd. "VESTA-PP"), a varnish for the sealing composition and a sealing sheet having a sealing layer with a thickness of 50 μm were prepared in the same manner as in Example 5. 【0106】 <Example 7> Except for replacing fumed silica ("AEROSIL R976S" manufactured by Nippon Aerosil Co., Ltd.) with fumed silica ("AEROSIL R805" manufactured by Nippon Aerosil Co., Ltd.), a sealing sheet having a sealing layer with a thickness of 50 μm was prepared using the same method as in Example 5. 【0107】 <Example 8> Except for replacing fumed silica ("AEROSIL R976S" manufactured by Nippon Aerosil Co., Ltd.) with fumed silica ("AEROSIL RY200" manufactured by Nippon Aerosil Co., Ltd.), a sealing sheet having a sealing layer with a thickness of 50 μm was prepared using the same method as in Example 4. 【0108】 <Example 9> The amount of maleic anhydride-modified liquid polybutene (HV-300M, manufactured by Toho Chemical Industry Co., Ltd.) was replaced with 18.8 parts of liquid ethylene-propylene copolymer having an acid anhydride group (Lucant A-5260, manufactured by Mitsui Chemicals, Inc.). The amount of calcium oxide (QC2-F1 manufactured by Inoue Lime Industry Co., Ltd.) used was changed from 295 parts to 55.5 parts, and The liquid polybutene (ENEOS Corporation's "HV-1900") in 62 parts and the GMA-modified IIR (Seikoh PMC Corporation's "ER866") in 32 parts were replaced with hydrogenated styrene-ethylene-ethylene-propylene copolymer (Kuraray Corporation's "7311F" in 2 parts). Except for the differences described above, a sealing sheet having a sealing varnish and a sealing layer with a thickness of 50 μm was prepared using the same method as in Example 2. 【0109】 <Comparative Example 1> Except for not using fumed silica (AEROSIL R976S manufactured by Nippon Aerosil Co., Ltd.), a sealing sheet having a sealing composition varnish and a sealing layer with a thickness of 50 μm was prepared using the same method as in Example 1. 【0110】 <Comparative Example 2> Except for changing the amount of fumed silica (AEROSIL R976S, manufactured by Nippon Aerosil Co., Ltd.) used from 4 parts to 48 parts, a sealing sheet having a sealing varnish of the sealing composition and a sealing layer with a thickness of 50 μm was prepared using the same method as in Example 1. 【0111】 <Comparative Example 3> Except for changing from fumed silica ("AEROSIL R976S" manufactured by Nippon Aerosil Co., Ltd.) to silica ("SO-C6" manufactured by Admatex Co., Ltd.), a sealing sheet having a sealing varnish for the sealing composition and a sealing layer with a thickness of 50 μm was prepared using the same method as in Example 3. 【0112】 <Comparative Example 4> Except for changing the amount of calcium oxide (QC2-F1, manufactured by Inoue Lime Industry Co., Ltd.) used from 295 parts to 115 parts, a sealing sheet having a sealing layer with a thickness of 50 μm was prepared using the same method as in Example 5. 【0113】 <Comparative Example 5> Except for not using fumed silica (AEROSIL R976S manufactured by Nippon Aerosil Co., Ltd.), a sealing sheet having a sealing composition varnish and a sealing layer with a thickness of 50 μm was prepared using the same method as in Example 6. 【0114】 <Comparative Example 6> Except for not using calcium oxide (QC2-F1 manufactured by Inoue Lime Industry Co., Ltd.), a sealing sheet having a sealing layer with a thickness of 50 μm was prepared using the same method as in Example 5. 【0115】 <Comparative Example 7> Except for not using fumed silica (AEROSIL R976S manufactured by Nippon Aerosil Co., Ltd.), a sealing sheet having a sealing composition varnish and a sealing layer with a thickness of 50 μm was prepared using the same method as in Example 9. 【0116】 [Table 1-1] 【0117】 [Table 1-2] 【0118】 [Table 1-3] 【0119】 [Table 1-4] 【0120】 <Method for evaluating high-temperature adhesion> The sealing layer of the sealing sheet (50 mm in length, 20 mm in width) prepared in each example and comparative example was laminated to the aluminum foil side of a composite film "PET-Tsuki AL1N30" (aluminum foil thickness 30 μm, polyethylene terephthalate film thickness 25 μm, manufactured by Tokai Toyo Aluminum Sales Co., Ltd.), which comprises aluminum foil and polyethylene terephthalate film, using a batch-type vacuum laminator (V-130, manufactured by Nichigo Morton Co., Ltd.). Lamination was performed under conditions of 80°C, 30 seconds, and 0.3 MPa. The support of the sealing sheet was then peeled off, and a glass plate (76 mm in length, 26 mm in width, 1.2 mm in thickness, microslide glass) was further laminated onto the exposed sealing layer under the same conditions as above. The adhesive strength (kgf / cm) of the obtained laminate was measured when peeled off at a tensile speed of 50 mm / min in a 90-degree direction relative to the length direction of the aluminum foil under a 120°C environment, and the high-temperature adhesion was evaluated according to the following criteria. The results are shown in Tables 2-1 to 2-4 below. In addition, in the "Adhesion Strength of Examples / Adhesion Strength of Comparative Examples" column of Tables 2-1 and 2-2 below, the following are listed: "Adhesion strength at 120°C for Examples 1-5, 7, or 8 / Adhesion strength at 120°C for Comparative Example 1", "Adhesion strength at 120°C for Example 6 / Adhesion strength at 120°C for Comparative Example 5", and "Adhesion strength at 120°C for Example 9 / Adhesion strength at 120°C for Comparative Example 7". (Standards for high-temperature adhesion) ○: Adhesion strength at 120℃ is 0.03 kgf / cm or higher. ×: Adhesion strength at 120℃ is less than 0.03 kgf / cm. 【0121】 <Method for evaluating high-temperature cohesive force> A sealing layer was obtained by peeling the support from each sealing sheet prepared in the examples and comparative examples. By laminating these sealing layers, a laminate with a thickness of 800 μm was obtained. The obtained laminate was punched out with a 10 mm belt punch to prepare a sample. The storage modulus G' and loss modulus G'' of the sample at 120°C were measured using a rheometer manufactured by TA Instruments (product name: DISCOVERY HR-2), and the tanδ (loss coefficient) of the sealing layer at 120°C (hereinafter referred to as "tanδ at 120°C") was calculated using the following formula. The measurement conditions for tanδ at 120°C were as follows. tanδ at 120℃ = Loss modulus of elasticity at 120°C G'' / Storage modulus of elasticity at 120°C G' Plate diameter: 8mm Measurement start temperature: 25℃ Measurement end temperature: 150℃ Heating rate: 6°C / min Frequency: 1Hz Strain: 0.1% 【0122】 The tanδ value at 120°C represents the ratio of viscosity to elasticity in the sealing layer; a smaller tanδ value at 120°C indicates greater elasticity in the sealing layer. The high-temperature cohesive force of the sealing layer was evaluated according to the following criteria. The results are shown in Tables 2-1 to 2-4 below. (Criteria for high-temperature cohesive force) ○: Tanδ at 120℃ is less than 1.10 ×: tanδ at 120℃ is 1.10 or higher. 【0123】 <Method for evaluating water vapor barrier properties> As a support, a composite film comprising aluminum foil and polyethylene terephthalate film (Tokai Toyo Aluminum Sales Co., Ltd.'s "PET-Tsuki AL1N30", with an aluminum foil thickness of 30 μm and a PET film thickness of 25 μm) was prepared (water vapor transmission rate of the composite film: 0.001 (g / m³) 2 / 24hr) or less). 【0124】 A test sheet having a laminated structure of "support (composite film) / sealing layer" was obtained in the same manner as in each example and comparative example, except that the aforementioned composite film was used as the support. The sealing layer was formed on the aluminum foil of the composite film. 【0125】 A 50mm x 50mm square glass plate made of alkali-free glass was prepared. This glass plate was washed with boiled isopropyl alcohol for 5 minutes and dried at 150°C for more than 30 minutes. 【0126】 Calcium was deposited onto one side of the dried glass plate using a mask that covered the peripheral area 0mm to 2mm from the edge of the glass plate. As a result, a 200nm thick calcium film (purity: 99.8%) was formed on the central portion of one side of the glass plate, excluding the peripheral area 0mm to 2mm from the edge. 【0127】 In a nitrogen atmosphere, the sealing layer of the test sheet described above and the calcium film side of the glass plate were bonded together using a thermal laminator (Fujiplas Corporation's "Lamipacker DAiSY A4 (LPD2325)") to obtain a laminate. This laminate was used as an evaluation sample. 【0128】 Generally, when calcium comes into contact with water, it becomes transparent as calcium oxide. Furthermore, in the aforementioned evaluation sample, the glass plate and aluminum foil have sufficiently high water vapor penetration barrier properties, so moisture usually moves in the in-plane direction (perpendicular to the thickness direction) through the edges of the sealing layer and reaches the calcium film. When moisture reaches the calcium film, it gradually oxidizes from the edges and becomes transparent, so a shrinkage of the calcium film is observed. Therefore, moisture penetration into the evaluation sample can be evaluated by measuring the sealing distance (mm) from the edge of the evaluation sample to the calcium film. Thus, the evaluation sample containing the calcium film can be used as a model for electronic devices. 【0129】 First, the initial sealing distance X2 (mm) from the edge of the evaluation sample to the edge of the calcium film was measured using an image dimension measuring instrument (Keyence IM-8020). 【0130】 Next, the evaluation sample was placed in a constant temperature and humidity chamber set to 85°C and 85% RH. The evaluation sample was removed from the chamber when the sealing distance X1 (mm) between the edge of the evaluation sample and the edge of the calcium film increased by 0.1 mm compared to the initial sealing distance X2. The time from when the evaluation sample was placed in the chamber to when it was removed was defined as the decrease start time t (hours). This decrease start time t is calculated from the time T when the evaluation sample was placed in the chamber. P1 Therefore, at the point T when the sealing distance X1 (mm) between the end of the evaluation sample stored in the constant temperature and humidity chamber and the end of the calcium membrane becomes "X2 + 0.1 mm" P2 This corresponds to the time until [a certain point]. 【0131】 The sealing distance X1 and the decrease start time t were applied to Fick's diffusion equation in equation (1) to calculate the constant K as a water vapor infiltration barrier parameter. 【0132】 【number】 【0133】 Using the obtained constant K, the ability of the sealing layer to suppress moisture intrusion (water vapor intrusion barrier property) was evaluated according to the following criteria. A smaller value of constant K indicates higher water vapor intrusion barrier property. The results are shown in Tables 2-1 to 2-4 below. Below, "hr" means "time," and "cm / hr^0.5" in Tables 2-1 to 2-4 means "cm / hr 0.5 This means "[...]." Furthermore, in the test sheet of Comparative Example 6, the edges of the calcium film, which had shrunk due to moisture intrusion, were rough, making it impossible to measure the sealing distance and thus calculate the constant K. Therefore, its water vapor intrusion barrier property was evaluated as ×. (Criteria for water vapor intrusion barrier property) ○: Constant K is 0.1 cm / hr0.5 less than ×: Constant K is 0.1 cm / hr 0.5 That's all. 【0134】 [Table 2-1] 【0135】 [Table 2-2] 【0136】 [Table 2-3] 【0137】 [Table 2-4] [Industrial applicability] 【0138】 The sealing composition and sealing sheet of the present invention are useful for protecting electronic devices and the like from moisture.

Claims

[Claim 1] The following components (A) to (C): (A) Olefin polymer having an acid anhydride group and / or a carboxyl group, (B) Calcium oxide, and (C) BET specific surface area is 50 m ２ Silica that is 1 / g or more A sealing composition comprising, The content of component (B) relative to the total nonvolatile content of the sealing composition is 48% by mass or more, and A sealing composition in which the amount of component (C) is 1 to 12 parts by mass per 100 parts by mass of component (B). [Claim 2] The encapsulation composition according to claim 1, wherein the average primary particle diameter of component (C) is 50 nm or less. [Claim 3] The sealing composition according to claim 1, wherein the silica of component (C) is fumed silica. [Claim 4] The sealing composition according to claim 1, wherein the median diameter of component (B) is 0.03 μm to 20 μm. [Claim 5] The sealing composition according to claim 1, wherein the content of component (B) relative to the total nonvolatile content of the sealing composition is 80% by mass or less. [Claim 6] The following component (D): (D) Olefin polymer having epoxy groups The sealing composition according to claim 1, further comprising: [Claim 7] The following (E) component: (E) Liquid olefin polymers that do not have acid anhydride groups, carboxyl groups, or epoxy groups. The sealing composition according to claim 1, further comprising: [Claim 8] The following (F) components: (F) Tackifier The sealing composition according to claim 1, further comprising: [Claim 9] A sealing sheet having a laminated structure comprising a support and a sealing layer formed from the sealing composition described in any one of claims 1 to 8. [Claim 10] The sealing sheet according to claim 9, wherein the tanδ of the sealing layer at 120°C is less than 1.

10. [Claim 11] An electronic device comprising a sealing layer formed from the sealing composition according to any one of claims 1 to 8.

Images