Sealing sheet and adhesive composition layer

Abstract

The present invention provides a sealing sheet capable of forming a sealing layer with excellent flex resistance, moisture barrier property, and adhesiveness at high temperatures. The sealing sheet has a laminated structure including a support and an adhesive composition layer, and the adhesive composition layer contains (A) a crosslinked polymer having an isobutene-isoprene copolymer chain, (B) a liquid polyolefin resin and / or a liquid rubber, and (C) a hygroscopic inorganic filler.

Description

Technical Field

[0001] The present invention relates to a sealing sheet and an adhesive composition layer useful for sealing electronic devices. Background Art

[0002] With the increasing development of foldable devices, there is a demand for a sealing sheet that can form a sealing layer with excellent resistance to the generation of voids, cracks, etc. (i.e., excellent bend resistance) after multiple bendings. As such a sealing sheet, for example, Patent Document 1 discloses a sealing sheet having a layer of a composition containing a polyolefin resin and / or a polyolefin rubber, an inorganic filler, and a metal complex obtained by bonding a bidentate ligand having two coordinating atoms both being oxygen atoms and a monodentate ligand having a coordinating atom being an oxygen atom to a central metal.

[0003] In addition, elements using organic substances such as OLED elements and OPV elements commonly used in foldable devices are extremely water-sensitive. In order to protect such elements, there is a demand for a sealing sheet that can form a sealing layer with excellent moisture barrier properties. As such a sealing sheet, for example, Patent Document 2 discloses a sealing sheet having a resin composition layer containing a polyolefin resin and a metal hydroxide selected from hydrotalcite and semi-calcined hydrotalcite.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: International Publication No. 2019 / 189723

[0007] Patent Document 2: International Publication No. 2017 / 057708. Summary of the Invention

[0008] Problems to be Solved by the Invention

[0009] As described above, there is a demand for a sealing sheet that can form a sealing layer with excellent bend resistance and moisture barrier properties. In addition, there is a demand for a sealing sheet that can form a sealing layer with excellent adhesiveness at high temperatures. The present invention has been made in view of such circumstances, and an object thereof is to provide a sealing sheet that can form a sealing layer with excellent bend resistance, moisture barrier properties, and adhesiveness at high temperatures.

[0010] Means for Solving the Problems

[0011] The present invention that can achieve the above object is as follows.

[0012] [1] A sealing sheet having a laminated structure including a support and an adhesive composition layer,

[0013] The adhesive composition layer contains:

[0014] (A) A crosslinked polymer having an isobutene-isoprene copolymer chain,

[0015] (B) A liquid polyolefin resin and / or a liquid rubber, and

[0016] (C) A hygroscopic inorganic filler.

[0017] [2] The sealing sheet according to [1] above, wherein the content of the hygroscopic inorganic filler is 30% by mass or more based on 100% by mass of the non-volatile components of the adhesive composition layer.

[0018] [3] The sealing sheet according to [1] or [2] above, wherein the content of the hygroscopic inorganic filler is 80% by mass or less based on 100% by mass of the non-volatile components of the adhesive composition layer.

[0019] [4] The sealing sheet according to any one of [1] to [3] above, wherein the crosslinked polymer having an isobutene-isoprene copolymer chain is at least one selected from the reaction product of an isobutene-isoprene copolymer having an epoxy group and an olefin-based polymer having a carboxyl group and / or an acid anhydride group, and the reaction product of an isobutene-isoprene copolymer having a carboxyl group and / or an acid anhydride group and an olefin-based polymer having an epoxy group.

[0020] [5] The sealing sheet according to any one of [1] to [4] above, which is used for sealing an electronic device.

[0021] [6] An adhesive composition layer, comprising:

[0022] (A) A crosslinked polymer having an isobutene-isoprene copolymer chain,

[0023] (B) A liquid polyolefin resin and / or a liquid rubber, and

[0024] (C) A hygroscopic inorganic filler.

[0025] [7] The adhesive composition layer according to [6] above, wherein the content of the hygroscopic inorganic filler is 30% by mass or more based on 100% by mass of the non-volatile components of the adhesive composition layer.

[0026] [8] The adhesive composition layer according to [6] or [7] above, wherein the content of the hygroscopic inorganic filler is 80% by mass or less based on 100% by mass of the non-volatile components of the adhesive composition layer.

[0027] [9] The adhesive composition layer according to any one of the foregoing [6] to [8], wherein the crosslinked polymer having an isobutene-isoprene copolymer chain is at least one selected from the reaction product of an isobutene-isoprene copolymer having an epoxy group and an olefin polymer having a carboxyl group and / or an acid anhydride group, and the reaction product of an isobutene-isoprene copolymer having a carboxyl group and / or an acid anhydride group and an olefin polymer having an epoxy group.

[0028] Advantages of the Invention

[0029] By using the sealing sheet of the present invention, a sealing layer excellent in bending resistance, moisture barrier property, and adhesiveness at high temperature can be formed. Detailed Description of the Invention

[0030] The present invention provides a sealing sheet having a laminated structure including a support and an adhesive composition layer. In addition, the present invention also provides the adhesive composition layer itself that can be used as a sealing layer.

[0031] One of the features of the adhesive composition layer of the present invention is that it contains a crosslinked polymer having an isobutene-isoprene copolymer (i.e., butyl rubber) chain (hereinafter sometimes referred to as "(A) component"). One type of (A) component can be used alone, or two or more types can be used in combination. By using the (A) component, good bending resistance can be achieved.

[0032] The (A) component can be formed by reacting an isobutene-isoprene copolymer having a reactive functional group (hereinafter sometimes referred to as "first reactive functional group") (i.e., butyl rubber having a first reactive functional group) with an olefin polymer having a reactive functional group capable of reacting with the first reactive functional group (hereinafter sometimes referred to as "second reactive functional group"). Here, the "olefin polymer" means a polymer in which the structural unit derived from an olefin (hereinafter sometimes simply referred to as "olefin unit") is the main structural unit (i.e., the amount of the olefin unit is the largest among all the structural units). It should be noted that hereinafter, the "structural unit derived from butene" and the like as the olefin unit may be simply referred to as "butene unit" and the like.

[0033] As the olefin, a monoolefin having one ethylenic carbon-carbon double bond and / or a diolefin having two ethylenic carbon-carbon double bonds is preferred. Examples of the monoolefin include α-olefins such as ethylene, propylene, 1-butene, isobutene (isobutylene), 1-pentene, 1-hexene, 1-heptene, and 1-octene. Examples of the diolefin include 1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethylbutadiene, and the like.

[0034] The olefin-based polymer can be a homopolymer or a copolymer. The copolymer can be a random copolymer or a block copolymer. In addition, the olefin-based polymer can be a copolymer of an olefin and a monomer other than an olefin. Examples of the olefin-based copolymer include, for example, ethylene-non-conjugated diene copolymer, ethylene-propylene copolymer, ethylene-propylene-non-conjugated diene copolymer, ethylene-butene copolymer, propylene-butene copolymer, propylene-butene-non-conjugated diene copolymer, styrene-isobutene copolymer, styrene-isobutene-styrene copolymer, and the like.

[0035] The olefin-based polymer having a second reactive functional group is preferably a butene-based polymer having a second reactive functional group. Here, the "butene-based polymer" refers to a polymer in which the butene unit is the main structural unit (that is, the amount of the butene unit is the largest among all the structural units). Examples of the butene include, for example, 1-butene, isobutene, and the like. Examples of the butene-based polymer include, for example, polybutene, isobutene-isoprene copolymer, and the like. Polybutene can be a homopolymer (for example, 1-butene homopolymer, isobutene homopolymer) or a copolymer (for example, a copolymer of 1-butene and isobutene).

[0036] In order to form the component (A), either only one kind of the isobutene-isoprene copolymer having a first reactive functional group and the olefin-based polymer having a second reactive functional group can be used, or two or more kinds can be used in combination.

[0037] Examples of the combination of the first reactive functional group and the second reactive functional group include, for example, the combination of an epoxy group and a carboxyl group and / or an acid anhydride group (that is, carbonyloxycarbonyl (-CO-O-CO-)), the combination of a carboxyl group and / or an acid anhydride group and an epoxy group, the combination of an epoxy group and an amino group, the combination of an amino group and an epoxy group, the combination of a hydroxyl group and an isocyanate group (that is, isocyanato group), the combination of an isocyanate group and a hydroxyl group, and the like. Among these, from the viewpoint of moisture barrier property, the combination of an epoxy group and a carboxyl group and / or an acid anhydride group, and the combination of a carboxyl group and / or an acid anhydride group and an epoxy group are preferred, and the combination of an epoxy group and an acid anhydride group and the combination of an acid anhydride group and an epoxy group are more preferred. It should be noted that in the above combination, the former reactive functional group represents the first reactive functional group, and the latter reactive functional group represents the second reactive functional group.

[0038] In one aspect of the present invention, the component (A) is preferably at least one selected from the reaction products of an isobutene-isoprene copolymer having an epoxy group and an olefin-based polymer having a carboxyl group and / or an acid anhydride group, and the reaction products of an isobutene-isoprene copolymer having a carboxyl group and / or an acid anhydride group and an olefin-based polymer having an epoxy group. In the above aspect, the olefin-based polymer is preferably a butene-based polymer, more preferably polybutene or isobutene-isoprene copolymer. In the above aspect, the carboxyl group and / or the acid anhydride group is preferably an acid anhydride group.

[0039] In one embodiment of the present invention, component (A) is preferably a reaction product of an isobutene-isoprene copolymer having an epoxy group and a polybutene having a carboxyl group and / or an acid anhydride group. In the above embodiment, the carboxyl group and / or the acid anhydride group is preferably an acid anhydride group.

[0040] In one embodiment of the present invention, component (A) is preferably a reaction product of an isobutene-isoprene copolymer having an epoxy group and an isobutene-isoprene copolymer having a carboxyl group and / or an acid anhydride group. In the above embodiment, the carboxyl group and / or the acid anhydride group is preferably an acid anhydride group.

[0041] The amount of the isobutene-isoprene copolymer having a reactive functional group (e.g., an epoxy group, a carboxyl group, and / or an acid anhydride group) relative to the total amount of the polymers used to form component (A) (e.g., the total amount of the isobutene-isoprene copolymer having a first reactive functional group and the olefin-based polymer having a second reactive functional group) is preferably 15 to 100% by mass, more preferably 20 to 100% by mass, and still more preferably 30 to 100% by mass. It should be noted that when using an isobutene-isoprene copolymer having a first reactive functional group and an isobutene-isoprene copolymer having a second reactive functional group to form component (A), the "amount of the isobutene-isoprene copolymer having a reactive functional group" means the "total amount of the isobutene-isoprene copolymer having a first reactive functional group and the isobutene-isoprene copolymer having a second reactive functional group".

[0042] The number average molecular weight of the isobutene-isoprene copolymer having a reactive functional group (e.g., an epoxy group, a carboxyl group, and / or an acid anhydride group) used to form component (A) is preferably 5,000 to 500,000, more preferably 10,000 to 400,000, and still more preferably 20,000 to 300,000. It should be noted that the number average molecular weight in the present invention is measured by gel permeation chromatography (GPC) method (polystyrene conversion). Specifically, the number average molecular weight based on the GPC method can be measured by using "LC-9A / RID-6A" manufactured by Shimadzu Corporation as the measuring device, using "Shodex K-800P / K-804L / K-804L" manufactured by Showa Denko K.K. as the column, using toluene or the like as the mobile phase, measuring at a column temperature of 40°C, and calculating using the standard curve of standard polystyrene.

[0043] The number average molecular weight of the olefin-based polymer (excluding isobutene-isoprene copolymer) having a second reactive functional group (e.g., an epoxy group, a carboxyl group, and / or an acid anhydride group) used to form component (A) is preferably 500 to 500,000, more preferably 1,000 to 300,000, and still more preferably 1,500 to 200,000.

[0044] From the viewpoint of flex resistance, the amount of isoprene units in the isobutene-isoprene copolymer having reactive functional groups (such as epoxy groups, carboxyl groups, and / or acid anhydride groups) used to form the component (A) is preferably 0.1 to 20% by mass, more preferably 0.3 to 10% by mass, and still more preferably 0.5 to 15% by mass, respectively, based on the total of isobutene units and isoprene units. It should be noted that the amount of the aforementioned isoprene units is based on isobutene units and isoprene units other than the modified part (such as the part derived from maleic anhydride used for introducing acid anhydride groups).

[0045] The concentration of epoxy groups in the olefin polymer having epoxy groups (such as isobutene-isoprene copolymer having epoxy groups, polybutene having epoxy groups) used to form the component (A) is preferably 0.01 to 10 mmol / g, more preferably 0.05 to 5 mmol / g. The epoxy group concentration is determined from the epoxy equivalent based on JIS K 7236-1995.

[0046] The concentration of carboxyl groups in the olefin polymer having carboxyl groups (such as isobutene-isoprene copolymer having carboxyl groups, polybutene having carboxyl groups) used to form the component (A) is preferably 0.01 to 10 mmol / g, more preferably 0.05 to 5 mmol / g. The concentration of carboxyl groups is obtained from the value of the acid value defined as the number of mg of potassium hydroxide required to neutralize the acid present in 1 g of the resin, as described in JIS K 2501.

[0047] The concentration of acid anhydride groups in the olefin polymer having acid anhydride groups (such as isobutene-isoprene copolymer having acid anhydride groups, polybutene having acid anhydride groups) used to form the component (A) is preferably 0.01 to 10 mmol / g, more preferably 0.05 to 5 mmol / g. The concentration of acid anhydride groups is obtained from the value of the acid value defined as the number of mg of potassium hydroxide required to neutralize the acid present in 1 g of the resin, as described in JIS K 2501.

[0048] The total of the concentration of carboxyl groups and the concentration of acid anhydride groups in the olefin polymer having carboxyl groups and acid anhydride groups (such as isobutene-isoprene copolymer having carboxyl groups and acid anhydride groups, polybutene having carboxyl groups and acid anhydride groups) used to form the component (A) is preferably 0.01 to 10 mmol / g, more preferably 0.05 to 5 mmol / g.

[0049] The amounts of the isobutene-isoprene copolymer having an epoxy group and the olefin polymer having a carboxyl group (e.g., isobutene-isoprene copolymer having a carboxyl group, polybutene having a carboxyl group) are not particularly limited as long as they can form the component (A) as a crosslinked polymer. The ratio of the amount (mol) of the epoxy group to the amount (mol) of the carboxyl group (i.e., amount (mol) of epoxy group: amount (mol) of carboxyl group) is preferably 100:10 to 100:500, more preferably 100:25 to 100:475, and further preferably 100:40 to 100:450.

[0050] The amounts of the isobutene-isoprene copolymer having an epoxy group and the olefin polymer having an acid anhydride group (e.g., isobutene-isoprene copolymer having an acid anhydride group, polybutene having an acid anhydride group) are not particularly limited as long as they can form the component (A) as a crosslinked polymer. The ratio of the amount (mol) of the epoxy group to the amount (mol) of the acid anhydride group (i.e., amount (mol) of epoxy group: amount (mol) of acid anhydride group) is preferably 100:10 to 100:500, more preferably 100:25 to 100:475, and further preferably 100:40 to 100:450.

[0051] The amounts of the isobutene-isoprene copolymer having an epoxy group and the olefin polymer having a carboxyl group and an acid anhydride group (e.g., isobutene-isoprene copolymer having a carboxyl group and an acid anhydride group, polybutene having a carboxyl group and an acid anhydride group) are not particularly limited as long as they can form the component (A) as a crosslinked polymer. The ratio of the "amount (mol) of the epoxy group" to the "total of the amount (mol) of the carboxyl group and the amount (mol) of the acid anhydride group" (i.e., amount (mol) of epoxy group: (amount (mol) of carboxyl group + amount (mol) of acid anhydride group)) is preferably 100:10 to 100:500, more preferably 100:25 to 100:475, and further preferably 100:40 to 100:450.

[0052] The olefin polymer having an epoxy group (e.g., isobutene-isoprene copolymer having an epoxy group, polybutene having an epoxy group) can be obtained by graft-modifying the olefin polymer under free radical reaction conditions using an unsaturated compound having an epoxy group (e.g., glycidyl (meth)acrylate, glycidyl 4-hydroxybutyl acrylate, allyl glycidyl ether).

[0053] As the olefin polymer having an epoxy group, a polymer available from manufacturers such as Starlight PMC Co., Ltd. can be used, for example. As the isobutene-isoprene copolymer having an epoxy group, “ER866” (glycidyl methacrylate-modified butyl rubber) and “ER850” (glycidyl methacrylate-modified butyl rubber) manufactured by Starlight PMC Co., Ltd. can be cited, for example. As the olefin polymer having an epoxy group (excluding isobutene-isoprene copolymer), “T-YP341” (glycidyl methacrylate-modified propylene-butene random copolymer), “T-YP276” (glycidyl methacrylate-modified propylene-butene random copolymer), “T-YP313” (glycidyl methacrylate-modified propylene-butene random copolymer) manufactured by Starlight PMC Co., Ltd. can be cited, for example.

[0054] The olefin polymer having a carboxyl group and / or an acid anhydride group (e.g., isobutene-isoprene copolymer having a carboxyl group and / or an acid anhydride group, polybutene having a carboxyl group and / or an acid anhydride group) can be obtained by graft-modifying the olefin polymer under radical reaction conditions using an unsaturated compound having a carboxyl group and / or an acid anhydride group (e.g., maleic anhydride).

[0055] As the olefin polymer having a carboxyl group and / or an acid anhydride group, a polymer available from manufacturers such as Starlight PMC Co., Ltd. can be used, for example. As the isobutene-isoprene copolymer having a carboxyl group and / or an acid anhydride group, “ER661” (maleic anhydride-modified butyl rubber) and “ER641” (maleic anhydride-modified butyl rubber) manufactured by Starlight PMC Co., Ltd. can be cited, for example. As the olefin polymer having a carboxyl group and / or an acid anhydride group (excluding isobutene-isoprene copolymer), “HV-300M” (maleic anhydride-modified polybutene) manufactured by Toho Chemical Industry Co., Ltd., “T-YP279” (maleic anhydride-modified propylene-butene random copolymer), “T-YP312” (maleic anhydride-modified propylene-butene random copolymer) manufactured by Starlight PMC Co., Ltd., “Lucant A-5260” (maleic anhydride-modified ethylene-α-olefin random copolymer) and “Lucant A-5320” (maleic anhydride-modified ethylene-α-olefin random copolymer) manufactured by Mitsui Chemicals, Inc. can be cited, for example.

[0056] Regarding the content of the component (A) in the adhesive composition layer, from the viewpoint of bending resistance, it is preferably 5% by mass or more, more preferably 10% by mass or more, and still more preferably 15% by mass or more. From the viewpoint of moisture barrier properties, it is preferably 50% by mass or less, more preferably 45% by mass or less, and still more preferably 40% by mass or less. It should be noted that the aforementioned content is a value relative to 100% by mass of the non-volatile components of the adhesive composition layer.

[0057] One of the features of the adhesive composition layer of the present invention is that it contains a liquid polyolefin resin and / or a liquid rubber (hereinafter referred to as the "component (B)"). In the present invention, "liquid" means that the viscosity at 25°C is 5,000 Pa·s or less. In addition, in the present invention, the "viscosity at 25°C" is the viscosity calculated by multiplying the kinematic viscosity at 25°C measured by a dynamic viscoelasticity measuring device by the density. As the dynamic viscoelasticity measuring device, for example, a rheometer (trade name: DISCOVERY HR-2) manufactured by TA Instruments can be cited.

[0058] Regarding the component (B) of the present invention, the "liquid polyolefin resin" means an olefin polymer having a viscosity at 25°C of 5,000 Pa·s or less and that cannot form a rubber elastomer by crosslinking, and the "liquid rubber" means a substance having a viscosity at 25°C of 5,000 Pa·s or less and that can form a rubber elastomer by crosslinking. For example, liquid polyisoprene can form a rubber elastomer by crosslinking, and thus is classified as a liquid rubber.

[0059] The viscosities of the liquid polyolefin resin and the liquid rubber at 25°C are each preferably 5 to 5,000 Pa·s, more preferably 10 to 4,000 Pa·s, and still more preferably 20 to 3,000 Pa·s.

[0060] The component (B) can be used alone or in combination of two or more. By using the component (B), good adhesiveness (especially adhesiveness at high temperatures) can be achieved. In addition, the adhesive composition layer of the present invention contains a hygroscopic inorganic filler, but when a large amount of the hygroscopic inorganic filler is used, the adhesiveness of the adhesive composition layer will decrease. From this point of view, by using the component (B), good adhesiveness can be achieved even when a large amount of the hygroscopic inorganic filler is used.

[0061] The number average molecular weight of the liquid polyolefin resin is preferably 500 to 15,000, more preferably 750 to 12,500, and still more preferably 1,000 to 10,000. In addition, the number average molecular weight of the liquid rubber is 500 to 15,000, more preferably 750 to 12,500, and still more preferably 1,000 to 10,000.

[0062] The liquid polyolefin resin and / or the liquid rubber is preferably liquid polybutene. The liquid polybutene may be a homopolymer (e.g., 1-butene homopolymer, isobutene homopolymer) or a copolymer (e.g., copolymer of 1-butene and isobutene).

[0063] The liquid polyolefin resin and / or the liquid rubber may be a commercially available product. Examples of commercially available products of the liquid polyolefin resin include "HV-300" (liquid polybutene) manufactured by ENEOS Corporation, "HV-1900" (liquid polybutene) manufactured by ENEOS Corporation, "HV-50" (liquid polybutene) manufactured by ENEOS Corporation, "HV-35" (liquid polybutene) manufactured by ENEOS Corporation, "950MW" (liquid polybutene) manufactured by Kothari Corporation, "2400MW" manufactured by Kothari Corporation, "H-1900" (liquid polybutene) manufactured by INEOS Corporation, "H-6000" (liquid polybutene) manufactured by INEOS Corporation, "H-18000" (liquid polybutene) manufactured by INEOS Corporation, "200N" (liquid polybutene) manufactured by NOF Corporation, "BI-2000" (hydrogenated polybutadiene) manufactured by Nippon Soda Co., Ltd., "BI-3000" (hydrogenated polybutadiene) manufactured by Nippon Soda Co., Ltd., "GI-3000" (hydrogenated polybutadiene) manufactured by Nippon Soda Co., Ltd., "Lucant LX100" (liquid olefin polymer) manufactured by Mitsui Chemicals, Inc., "Lucant LX400" (liquid olefin polymer) manufactured by Mitsui Chemicals, Inc., and the like.

[0064] Examples of commercially available liquid rubbers include "Poly bd R-45HT" (butadiene-based liquid rubber), "Poly bd R-15HT" (butadiene-based liquid rubber), "Poly ip" (liquid polyisoprene), all manufactured by Idemitsu Showa Shell Co., Ltd.; "B-1000" (liquid polybutadiene), "B-3000" (liquid polybutadiene), "G-3000" (liquid polybutadiene), all manufactured by Nippon Soda Co., Ltd.; "LIR-30" (liquid polyisoprene), "LIR-390" (liquid polyisoprene), "LIR-290" (liquid polyisoprene), "LBR-302" (liquid polybutadiene), "LBR-305" (liquid polybutadiene), "LBR-361" (liquid polybutadiene), "L-SBR-820" (liquid styrene-butadiene random copolymer), all manufactured by Kuraray Co., Ltd.; "Ricon154" (liquid butadiene), "RICON184" (liquid styrene-butadiene random copolymer), all manufactured by CRAY VALLEY Co., Ltd.

[0065] Regarding the content of component (B) in the adhesive composition layer (when both a liquid polyolefin resin and a liquid rubber are used, it is the total of these contents), from the viewpoint of adhesiveness, it is preferably 5% by mass or more, more preferably 7.5% by mass or more, and further preferably 10% by mass or more. From the viewpoint of adhesiveness at high temperatures, it is preferably 50% by mass or less, more preferably 40% by mass or less, and further preferably 30% by mass or less. It should be noted that the aforementioned content is a value relative to 100% by mass of the non-volatile components of the adhesive composition layer.

[0066] One of the features of the adhesive composition layer of the present invention is that it contains a hygroscopic inorganic filler (hereinafter referred to as "(C) component"). The (C) component can be used alone or in combination of two or more. By using the (C) component, good moisture barrier properties can be achieved.

[0067] Examples of the (C) component include uncalcined hydrotalcite, semi-calcined hydrotalcite, calcined hydrotalcite, calcium oxide, magnesium oxide, calcined dolomite (a mixture containing calcium oxide and magnesium oxide), calcium hydride, strontium oxide, alumina, barium oxide, molecular sieve, silica, etc. The (C) component is preferably at least one selected from semi-calcined hydrotalcite, calcium oxide, and calcium hydride, and more preferably at least one selected from semi-calcined hydrotalcite and calcium oxide.

[0068] Hydrotalcite can be classified into uncalcined hydrotalcite, semi-calcined hydrotalcite, and calcined hydrotalcite.

[0069] Uncalcined hydrotalcite is a metal hydroxide with a layered crystal structure represented by, for example, natural hydrotalcite (Mg6Al2(OH) 16 CO3・4H2O). For example, it contains layers [Mg 1-X Al X (OH)2] X＋ and an intermediate layer [(CO3) X / 2 ・mH2O] X- . Uncalcined hydrotalcite is a concept that includes hydrotalcite-like compounds such as synthetic hydrotalcite. As hydrotalcite-like compounds, compounds represented by the following formula (I) and the following formula (II) can be cited.

[0070] [M 2＋ 1-x M 3＋ x (OH)2] x＋ ・[(A n- ) x / n ・mH2O] x- (I)

[0071] (In the formula, M 2＋ represents divalent metal ions such as Mg 2＋ , Zn 2＋ , etc., M 3＋ represents trivalent metal ions such as Al 3＋ , Fe 3＋ , etc., A n- represents n-valent anions such as CO3 2- , Cl - , NO3 - , etc., 0 < x < 1, 0 ≤ m < 1, and n is a positive number.)

[0072] In formula (I), M 2＋ is preferably Mg 2＋ , M 3＋ is preferably Al 3＋ , and A n- is preferably CO3 2- .

[0073] M 2＋ x Al2(OH) 2x＋6-nz (A n- ) z ・mH2O (II)

[0074] (In the formula, M 2＋ represents Mg 2＋ , Zn 2＋divalent metal ions such as A n- represents CO3 2- , Cl - , NO3 - and other n-valent anions, x is a positive number of 2 or more, z is a positive number of 2 or less, m is a positive number, and n is a positive number.)

[0075] In formula (II), M 2＋ is preferably Mg 2＋ , A n- is preferably CO3 2- .

[0076] Semi-calcined hydrotalcite refers to a metal hydroxide with a layered crystal structure obtained by calcining uncalcined hydrotalcite, in which the amount of interlayer water is reduced or disappeared. "Interlayer water", when explained by the composition formula, refers to "H2O" recorded in the composition formula of the above-mentioned uncalcined natural hydrotalcite and hydrotalcite-like compounds.

[0077] On the other hand, calcined hydrotalcite refers to a metal oxide with an amorphous structure obtained by calcining uncalcined hydrotalcite or semi-calcined hydrotalcite, in which not only the interlayer water disappears but also the hydroxyl groups disappear due to condensation dehydration.

[0078] Uncalcined hydrotalcite, semi-calcined hydrotalcite and calcined hydrotalcite can be distinguished by the saturated water absorption rate. The saturated water absorption rate of semi-calcined hydrotalcite is 1% by mass or more and less than 20% by mass. On the other hand, the saturated water absorption rate of uncalcined hydrotalcite is less than 1% by mass, and the saturated water absorption rate of calcined hydrotalcite is 20% by mass or more.

[0079] "Saturated water absorption rate" means: weighing 1.5 g of the test sample (such as semi-calcined hydrotalcite) with a balance and measuring the initial mass, and then leaving it static in a small environmental test chamber (SH-222 manufactured by Espec Corporation) set at atmospheric pressure, 60 °C, and 90% RH (relative humidity) for 200 hours. The mass increase rate relative to the initial mass can be obtained by the following formula (i): saturated water absorption rate (% by mass) = 100 × (mass after moisture absorption - initial mass) / initial mass (i).

[0080] The saturated water absorption rate of semi-calcined hydrotalcite is preferably 3% by mass or more and less than 20% by mass, more preferably 5% by mass or more and less than 20% by mass.

[0081] In addition, the uncalcined hydrotalcite, semi-calcined hydrotalcite, and calcined hydrotalcite can be distinguished by the thermogravimetric reduction rate measured by thermogravimetric analysis. The thermogravimetric reduction rate of the semi-calcined hydrotalcite at 280°C is less than 15% by mass, and its thermogravimetric reduction rate at 380°C is 12% by mass or more. On the other hand, the thermogravimetric reduction rate of the uncalcined hydrotalcite at 280°C is 15% by mass or more, and the thermogravimetric reduction rate of the calcined hydrotalcite at 380°C is less than 12% by mass.

[0082] Thermogravimetric analysis can be carried out under the following conditions: Using TG / DTA EXSTAR6300 manufactured by Hitachi High-Tech Science Corporation, weigh 5 mg of hydrotalcite into an aluminum sample pan, and under the condition of being open without a lid and in an atmosphere with a nitrogen flow rate of 200 mL / minute, heat from 30°C to 550°C at a heating rate of 10°C / minute. The thermogravimetric reduction rate can be obtained by the following formula (ii): Thermogravimetric reduction rate (% by mass) = 100×(mass before heating - mass at the specified temperature) / mass before heating (ii).

[0083] In addition, the uncalcined hydrotalcite, semi-calcined hydrotalcite, and calcined hydrotalcite can be distinguished by the peaks and relative intensity ratios measured by powder X-ray diffraction. The semi-calcined hydrotalcite shows peaks split into two or peaks with shoulders formed by the synthesis of two peaks around 2θ of 8 - 18° according to powder X-ray diffraction, and the relative intensity ratio (low-angle side diffraction intensity / high-angle side diffraction intensity) of the diffraction intensity of the peak or shoulder appearing on the low-angle side (= low-angle side diffraction intensity) to the diffraction intensity of the peak or shoulder appearing on the high-angle side (= high-angle side diffraction intensity) is 0.001 - 1,000. On the other hand, the uncalcined hydrotalcite has only one peak around 8 - 18° or the relative intensity ratio of the diffraction intensity of the peak or shoulder appearing on the low-angle side to the diffraction intensity of the peak or shoulder appearing on the high-angle side is outside the above range. The calcined hydrotalcite does not have characteristic peaks in the region of 8° - 18°, but has characteristic peaks at 43°. Powder X-ray diffraction measurement is carried out using a powder X-ray diffractometer (Empyrean manufactured by PANalytical) under the conditions of a copper target CuKα (1.5405 Å), voltage: 45 V, current: 40 mA, sampling amplitude: 0.0260°, scanning speed: 0.0657° / s, and measurement diffraction angle range (2θ): 5.0131 - 79.9711°. Peak search can be carried out using the peak search function of the software attached to the diffractometer under the conditions of "minimum significant difference degree: 0.50, minimum peak chip: 0.01°, maximum peak chip: 1.00°, peak baseline amplitude: 2.00°, method: minimum of second derivative".

[0084] The BET specific surface area of the semi-calcined hydrotalcite is preferably 1 - 250 m 2 / g, more preferably 5 to 200 m 2 / g. These BET specific surface areas can be calculated by the BET method using a specific surface area measuring device (Macsorb HM Model 1210, manufactured by Mountech Co., Ltd.) to adsorb nitrogen onto the surface of the sample and using the BET multi-point method.

[0085] The particle size of the semi-calcined hydrotalcite is preferably 1 to 1,000 nm, more preferably 10 to 800 nm. These particle sizes are the median particle sizes of the particle size distribution when making the particle size distribution based on volume by laser diffraction scattering particle size distribution measurement (JIS Z 8825).

[0086] The semi-calcined hydrotalcite can be a substance obtained by surface treatment with a surface treatment agent. As the surface treatment agent used in the surface treatment, for example, higher fatty acids, alkylsilanes, silane coupling agents, etc. can be used. Among them, higher fatty acids and alkylsilanes are suitable. One or more than two kinds of surface treatment agents can be used.

[0087] The semi-calcined hydrotalcite can be a commercially available product. As its commercially available products, for example, "DHT-4C", "DHT-4A-2", etc. manufactured by Kyowa Chemical Industry Co., Ltd. can be cited.

[0088] Calcium oxide can be a commercially available product. As its commercially available products, for example, "QC-X" manufactured by Inoue Lime Industry Co., Ltd.; "Moistop #10" manufactured by Sankyo Flour Milling Co., Ltd.; "HAL-G", "HAL-J", "HAL-F" manufactured by Yoshizawa Lime Industry Co., Ltd.; "CaO Nano Powder" manufactured by Filgen Co., Ltd., etc. can be cited.

[0089] The particle size of calcium oxide and the particle size of the mixture containing calcium oxide are preferably 0.03 to 10 μm, more preferably 0.05 to 5 μm, and further preferably 0.1 to 3 μm, respectively. These particle sizes are the median particle sizes of the particle size distribution when making the particle size distribution based on volume by laser diffraction scattering particle size distribution measurement (JIS Z8825).

[0090] Regarding the content of the component (C) in the adhesive composition layer, from the viewpoint of moisture barrier properties, it is preferably 30% by mass or more, more preferably 35% by mass or more, and further preferably 40% by mass or more. From the viewpoints of adhesiveness and flexibility, it is preferably 80% by mass or less, more preferably 75% by mass or less, and further preferably 70% by mass or less. It should be noted that the aforementioned content is a value relative to 100% by mass of the non-volatile components of the adhesive composition layer.

[0091] The adhesive composition layer may contain components other than the components (A) to (C) (hereinafter sometimes referred to as "other components") within a range that does not impair the effects of the present invention. Examples of the other components include tackifiers, curing accelerators, antioxidants, plasticizers, metal complexes obtained by bonding a bidentate ligand having two oxygen atoms as coordination atoms and a monodentate ligand having an oxygen atom as a coordination atom to a central metal, and the like. Each of them may be used alone or in combination of two or more.

[0092] The tackifier is a component that imparts adhesiveness to the adhesive composition layer. In the present invention, the tackifier is not particularly limited, and known substances can be used.

[0093] From the viewpoint of heat resistance and the like of the adhesive composition layer, the softening point of the tackifier is preferably 50 to 200 °C, more preferably 90 to 180 °C, and further preferably 100 to 150 °C. It should be noted that the softening point is measured by the ring and ball method in accordance with JIS K2207.

[0094] Commercially available products can be used as the tackifier. Examples of the commercially available products include "Alcon P-90", "Alcon P-100", "Alcon P-115", "Alcon P-125", "Alcon P-140", "Alcon M-90", "Alcon M-100", "Alcon M-115", "Alcon M-135" (all are hydrogenated petroleum resins containing a cyclohexane ring) manufactured by Arakawa Chemical Industries, Ltd.

[0095] From the viewpoints of adhesiveness and sealing performance of the adhesive composition layer, the content of the tackifier is preferably 0 to 30% by mass, more preferably 0 to 25% by mass, and further preferably 0 to 22.5% by mass based on 100% by mass of the non-volatile components of the adhesive composition layer.

[0096] Examples of the curing accelerator include imidazole compounds, tertiary amine and quaternary amine compounds, dimethylurea compounds, organic phosphine compounds, and the like.

[0097] Examples of the imidazole compound 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, 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 the imidazole compound include Cuazele 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 Chemical Industries, Ltd.).

[0098] The tertiary amine / quaternary amine compound is not particularly limited, and examples thereof include quaternary ammonium salts such as tetramethylammonium bromide and tetrabutylammonium bromide; diazabicyclic compounds such as DBU (1,8-diazabicyclo[5.4.0]undecene-7), DBN (1,5-diazabicyclo[4.3.0]nonene-5), DBU-phenolate, DBU-octanoate, DBU-p-toluenesulfonate, DBU-formate, and DBU-phenol novolac resin salt; tertiary amines such as benzyldimethylamine, 2-(dimethylaminomethyl)phenol, and 2,4,6-tris(dimethylaminomethyl)phenol (TAP) or salts thereof; and dimethyl urea compounds such as aromatic dimethyl urea and aliphatic dimethyl urea.

[0099] Examples of the dimethyl urea compound include DCMU (3-(3,4-dichlorophenyl)-1,1-dimethylurea), aromatic dimethyl ureas such as U-CAT3512T (manufactured by Sanapro Co., Ltd.), and aliphatic dimethyl ureas such as U-CAT3503N (manufactured by Sanapro Co., Ltd.). Among them, aromatic dimethyl ureas are preferably used from the viewpoint of curability.

[0100] Examples of the organic phosphine compound include triphenylphosphine, tetraphenylphosphonium tetra-p-tolyl borate, tetraphenylphosphonium tetraphenyl borate, tri-tert-butylphosphonium tetraphenyl borate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, butyltriphenylphosphonium thiocyanate, triphenylphosphine triphenylborane, etc. Specific examples of the organic phosphine compound include TPP, TPP-MK, TPP-K, TTBuP-K, TPP-SCN, TPP-S (all manufactured by Hokko Chemical Industry Co., Ltd.), etc.

[0101] When using a curing accelerator, in order to promote the formation of component (A) (i.e., a crosslinked polymer having an isobutene-isoprene copolymer chain), etc., its content is preferably 0.0001 to 0.1% by mass, more preferably 0.0002 to 0.075% by mass, and still more preferably 0.0002 to 0.05% by mass based on 100% by mass of the nonvolatile components of the adhesive composition layer.

[0102] In the present invention, the antioxidant is not particularly limited, and known substances can be used. When using an antioxidant, its content is preferably 0.01 to 0.5% by mass, more preferably 0.05 to 0.4% by mass, and still more preferably 0.1 to 0.3% by mass based on 100% by mass of the nonvolatile components of the adhesive composition layer.

[0103] Examples of the plasticizer include mineral oils such as paraffinic process oils, naphthenic process oils, liquid paraffin, and petrolatum; and vegetable oils such as castor oil, cottonseed oil, rapeseed oil, soybean oil, palm oil, coconut oil, and olive oil.

[0104] In order to improve the adhesiveness and bending resistance of the adhesive composition layer, a metal complex obtained by bonding a bidentate ligand having two coordination atoms both being oxygen atoms (hereinafter sometimes referred to as "oxygen-bidentate ligand") and a monodentate ligand having a coordination atom being an oxygen atom (hereinafter sometimes referred to as "oxygen-monodentate ligand") to a central metal can also be used.

[0105] The aforementioned metal complex is preferably a metal complex represented by the following formula (1) (hereinafter referred to as "metal complex (1)").

[0106] [Chemical formula 1]

[0107]

[0108] In formula (1),

[0109] M is the central metal of the metal complex, representing a metal of the 2nd to 6th periods of the periodic table,

[0110] R1 and R3 each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, an aralkyl group, an alkoxy group, an alkenyloxy group, an aryloxy group, or an aralkyloxy group,

[0111] R2 represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, an aralkyl group, an alkoxy group, an alkenyloxy group, an aryloxy group, an aralkyloxy group, an alkoxycarbonyl group, or an alkenyloxycarbonyl group,

[0112] X represents an oxygen-monodentate ligand,

[0113] The solid line between the oxygen atom (O) in [ ] and M represents a covalent bond, and the dashed line between the oxygen atom (O) in [ ] and M represents a coordination bond, and

[0114] m represents an integer of 3 or 4, n represents an integer of 1 to 3, and m > n.

[0115] In formula (1), M is preferably a metal of the 3rd to 5th periods, more preferably Al, Ti, Mn, Fe, Co, Ni, Cu, Zn, Ge, Zr, In, or Sn, and still more preferably Al, Ti, or Zr.

[0116] In this specification, examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0117] In this specification, the alkyl group can be either linear or branched. The number of carbon atoms of the alkyl group is preferably 1 to 20, more preferably 1 to 10, and particularly preferably 1 to 6. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, a 1-ethylpropyl group, a hexyl group, an isohexyl group, a 1,1-dimethylbutyl group, a 2,2-dimethylbutyl group, a 3,3-dimethylbutyl group, a 2-ethylbutyl group, etc. The alkyl group may optionally have a substituent. Examples of the substituent include a halogen atom, a hydroxyl group, an amino group optionally having a substituent, etc.

[0118] In this specification, the alkenyl group can be either linear or branched. The number of carbon atoms of the alkenyl group is preferably 2 to 20. Examples of the alkenyl group include an ethenyl group (i.e., a vinyl group), a 1-propenyl group, a 2-propenyl group, a 2-methyl-1-propenyl group, a 1-butenyl group, a 2-butenyl group, a 3-butenyl group, a 3-methyl-2-butenyl group, a 1-pentenyl group, a 2-pentenyl group, a 3-pentenyl group, a 4-pentenyl group, a 4-methyl-3-pentenyl group, a 1-hexenyl group, a 3-hexenyl group, a 5-hexenyl group, an octadecenyl group (e.g., a 9-octadecenyl group), etc. Examples of the substituent optionally possessed by the alkenyl group include a halogen atom, a hydroxyl group, an amino group optionally having a substituent, etc.

[0119] In this specification, the alkynyl group can be either linear or branched. The number of carbon atoms of the alkynyl group is preferably 2 to 10, more preferably 2 to 6. Examples of the alkynyl group include an ethynyl group, a 1-propynyl group, a 2-propynyl group, a 1-butynyl group, a 2-butynyl group, a 3-butynyl group, a 1-pentynyl group, a 2-pentynyl group, a 3-pentynyl group, a 4-pentynyl group, a 1-hexynyl group, a 2-hexynyl group, a 3-hexynyl group, a 4-hexynyl group, a 5-hexynyl group, a 4-methyl-2-pentynyl group, etc. Examples of the substituent optionally possessed by the alkynyl group include a halogen atom, a hydroxyl group, an amino group optionally having a substituent, etc.

[0120] In this specification, the number of carbon atoms of the aryl group is preferably 6 to 18, more preferably 6 to 14. Examples of the aryl group include phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl, 9-anthryl, etc. The aryl group may optionally have a substituent. Examples of the substituent include a halogen atom, a hydroxyl group, an alkyl group optionally having a substituent, an alkenyl group optionally having a substituent, an alkynyl group optionally having a substituent, an amino group optionally having a substituent, etc.

[0121] In this specification, the number of carbon atoms of the aralkyl group is preferably 7 to 16. Examples of the aralkyl group include benzyl, phenethyl, naphthylmethyl, phenylpropyl, etc. The aralkyl group may optionally have a substituent. Examples of the substituent include a halogen atom, a hydroxyl group, an amino group optionally having a substituent, etc.

[0122] In this specification, examples of the amino group optionally having a substituent include an amino group, a monoalkylamino group or a dialkylamino group (such as methylamino, dimethylamino, ethylamino, diethylamino, propylamino, dibutylamino), a monocycloalkylamino group or a dicycloalkylamino group (such as cyclopropylamino, cyclohexylamino), a monoarylamino group or a diarylamino group (such as phenylamino), a monoaralkylamino group or a diarylamino group (such as benzylamino, dibenzylamino), a heterocyclic amino group (such as pyridylamino), etc.

[0123] In this specification, the description of the alkyl group in the alkoxy group (i.e., alkoxy) is the same as the description of the above alkyl group. The alkoxy group may optionally have a substituent. Examples of the substituent include a halogen atom, a hydroxyl group, an amino group optionally having a substituent, etc.

[0124] In this specification, the description of the alkenyl group in the alkenyloxy group is the same as the description of the above alkenyl group. The alkenyloxy group may optionally have a substituent. Examples of the substituent include a halogen atom, a hydroxyl group, an amino group optionally having a substituent, etc.

[0125] In this specification, the description of the aryl group in the aryloxy group is the same as the description of the above aryl group. The aryloxy group may optionally have a substituent. Examples of the substituent include a halogen atom, a hydroxyl group, an alkyl group optionally having a substituent, an alkenyl group optionally having a substituent, an alkynyl group optionally having a substituent, an amino group optionally having a substituent, etc.

[0126] In this specification, the description of the aralkyl group in the aralkyloxy group is the same as the description of the above aralkyl group. The aralkyloxy group may optionally have a substituent. Examples of the substituent include a halogen atom, a hydroxyl group, an amino group optionally having a substituent, etc.

[0127] In this specification, the description of the alkyl group in the alkoxycarbonyl group (i.e., alkoxycarbonyl) is the same as the description of the above alkyl group. The alkoxycarbonyl group may optionally have a substituent. Examples of such a substituent include a halogen atom, a hydroxyl group, an amino group optionally having a substituent, and the like.

[0128] In this specification, the description of the alkenyl group in the alkenyloxycarbonyl group is the same as the description of the above alkenyl group. The alkenyloxycarbonyl group may optionally have a substituent. Examples of such a substituent include a halogen atom, a hydroxyl group, an amino group optionally having a substituent, and the like.

[0129] The oxygen-monodentate ligand represented by X in formula (1) is usually the conjugate base of a Bronsted acid, and examples thereof include RO - (R: organic group), RCOO - (R: organic group), and the like.

[0130] RO - In, the organic group R can be either an aliphatic group or an aromatic group. In addition, the aliphatic group can be either a saturated aliphatic group or an unsaturated aliphatic group. The number of carbon atoms of the organic group R is preferably 1 to 20, more preferably 1 to 10, and particularly preferably 1 to 6. Examples of RO - include, for example, methoxide anion, ethoxide anion, propoxide anion, isopropoxide anion, butoxide anion, isobutoxide anion, sec-butoxide anion, tert-butoxide anion, pentoxide anion, hexoxide anion, and the like.

[0131] RCOO - In, the organic group R can be either an aliphatic group or an aromatic group. In addition, the aliphatic group can be either a saturated aliphatic group or an unsaturated aliphatic group. The number of carbon atoms of the organic group R is preferably 1 to 20, more preferably 1 to 10, and particularly preferably 1 to 6. Examples of RCOO - include, for example, anions corresponding to carboxylic acids such as acetic acid, propionic acid, benzoic acid, and the like.

[0132] The content within [ ] in formula (1) represents an oxygen-bidentate ligand. Specific examples of the oxygen-bidentate ligand include acetylacetone, 3-methyl-2,4-pentanedione, acetylacetaldehyde, 2,4-hexanedione, 2,4-heptanedione, 5-methyl-2,4-hexanedione, 5,5-dimethyl-2,4-hexanedione, benzoylacetone, benzoylacetophenone, salicylaldehyde, 1,1,1-trifluoroacetylacetone, 1,1,1,5,5,5-hexafluoroacetylacetone, 3-methoxy-2,4-pentanedione, 3-cyano-2,4-pentanedione, 3-nitro-2,4-pentanedione, 3-chloro-2,4-pentanedione, acetoacetic acid, methyl acetoacetate, ethyl acetoacetate, propyl acetoacetate, salicylic acid, methyl salicylate, malonic acid, dimethyl malonate, diethyl malonate, etc. In the state of coordinating to the central metal, the oxygen-bidentate ligand exhibits a structure obtained by removing one or more protons therefrom.

[0133] As the metal complex (1) with the central metal M being Al, for example, octadecenyloxyacetic acid diisopropoxyaluminum, ethylacetoacetic acid diisopropoxyaluminum, ethylacetoacetic acid dibutylaluminum, propylacetoacetic acid diisopropoxyaluminum, n-butylacetoacetic acid diisopropoxyaluminum, etc. can be cited.

[0134] As the metal complex (1) with the central metal M being Ti, for example, allyl acetoacetate triisopropoxytitanium, (bis-2,4-pentanedionato) dibutoxytitanium, bis(tetramethylheptanedionato) diisopropoxytitanium, bis(ethylacetoacetate) diisopropoxytitanium, methylphenoxytitanium, titanium oxide bis(pentanedionate), etc. can be cited.

[0135] As the metal complex (1) with the central metal M being Zr, for example, allyl acetoacetate triisopropoxyzirconium, (bis-2,4-pentanedionato) dibutoxyzirconium, (bis-2,4-pentanedionato) diisopropoxyzirconium, bis(tetramethylheptanedionato) diisopropoxyzirconium, bis(ethylacetoacetate) diisopropoxyzirconium, (acetoacetate)(bisethylacetoacetate) butoxyzirconium, monoacetylacetone tributoxyzirconium, etc. can be cited.

[0136] When using a metal complex (especially the metal complex (1)) obtained by bonding an oxygen-bidentate ligand and an oxygen-monodentate ligand to the central metal, its content is preferably 0.05 to 5.0% by mass, more preferably 0.1 to 4.0% by mass, and further preferably 0.15 to 3.0% by mass based on 100% by mass of the non-volatile components of the adhesive composition layer.

[0137] The sealing sheet of the present invention has a laminated structure including a support and an adhesive composition layer. In the present invention, a protective sheet can be used. That is, the sealing sheet of the present invention can have a laminated structure including a support, an adhesive composition layer, and a protective sheet in this order. Other layers (such as a release layer) can be present between the support and the adhesive composition layer, and between the adhesive composition layer and the protective sheet.

[0138] Examples of the support and the protective sheet include polyolefins such as polyethylene, polypropylene, and polyvinyl chloride; cycloolefin polymers; polyesters such as polyethylene terephthalate (hereinafter sometimes referred to as "PET") and polyethylene naphthalate; polycarbonate; plastic films such as polyimide. The support and the protective sheet can both be single-layer films or laminated films.

[0139] As the support and the protective sheet, for example, a low moisture permeability film having a barrier layer or a laminated film of a low moisture permeability film having a barrier layer and other films can be used. Examples of the barrier layer include inorganic films such as a silicon dioxide vapor deposition film, a silicon nitride film, and a silicon oxide film. The barrier layer can be composed of multiple layers of inorganic films (such as a silicon dioxide vapor deposition film). In addition, the barrier layer can be composed of an organic substance and an inorganic substance, or can be a composite multilayer of an organic layer and an inorganic film.

[0140] In the protective sheet, it is preferable that the surface in contact with the adhesive composition layer is subjected to a release treatment. On the other hand, the support may or may not be subjected to a release treatment. Examples of the release treatment include a release treatment based on a release agent such as a silicone resin-based release agent, an alkyd resin-based release agent, and a fluororesin-based release agent.

[0141] The thicknesses of the support and the protective sheet are not particularly limited. From the viewpoint of the processability of the sealing sheet and the like, they are preferably 10 to 150 μm, more preferably 20 to 100 μm, respectively. It should be noted that when the support and the protective sheet are laminated films, the aforementioned thickness is the thickness of the laminated film. On the other hand, from the viewpoint of sealing performance and the like, the thickness of the adhesive composition layer is preferably 5 to 200 μm, more preferably 5 to 150 μm, and further preferably 5 to 100 μm.

[0142] The sealing sheet and the adhesive composition layer of the present invention can be manufactured as follows: For example, (1) dissolving or dispersing the above components in an organic solvent to prepare a varnish of the adhesive composition; (2) coating the obtained varnish on the support to form a coating film; (3) removing the organic solvent by heating the obtained coating film and reacting the raw materials of component (A) (for example, an isobutene-isoprene copolymer having an epoxy group and an olefin-based polymer having a carboxyl group and / or an acid anhydride group).

[0143] Examples of the organic solvents that can be used for preparing varnishes include, for example, ketones such as acetone, methyl ethyl ketone, and cyclohexanone; acetates 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; amides such as dimethylformamide, dimethylacetamide, and N-methylpyrrolidone amides. The organic solvent can be used alone or in combination of two or more. As the organic solvent, commercially available products can be used. Examples of such commercially available products include "Swazol" manufactured by Maruzen Petrochemical Co., Ltd. and "Ipzol" manufactured by Idemitsu Kosan Co., Ltd. The varnish can be applied by a known method (for example, a method using a die coater), and the coating method is not particularly limited.

[0144] The heating temperature of the coating film is preferably 50 to 200 °C, more preferably 80 to 150 °C, and the time is preferably 1 to 60 minutes, more preferably 10 to 30 minutes. The heating of the coating film can be carried out under normal pressure or under reduced pressure.

[0145] The sealing sheet of the present invention can be used for sealing electronic devices. Examples of electronic devices include, for example, organic EL devices, solar cells, and sensor devices. The electronic device is more preferably an electronic device that is not resistant to moisture, such as an organic EL device or a solar cell. In addition, the sealing sheet of the present invention can be used for sealing a conductive substrate or the like.

[0146] Recently, as next-generation devices, foldable devices that can be freely bent have attracted much attention. In foldable devices, electronic devices that are not resistant to moisture, such as organic EL devices and solar cells, are mainly used. Since soft and thin glass substrates and plastic substrates are used in foldable devices, for the sealing sheet, in addition to requiring adhesiveness, it is also required that no voids are generated during bending. The sealing sheet of the present invention can also be used for sealing foldable devices. Examples

[0147] Hereinafter, examples are listed to more specifically illustrate the present invention. However, the present invention is not limited to the following examples, and can also be implemented with appropriate modifications within the scope that can conform to the above / below gist, and they are all included in the technical scope of the present invention. It should be noted that "parts" and "%" in the component amount and the copolymer unit amount respectively refer to "parts by mass" and "mass%" unless otherwise specified.

[0148] <Component>

[0149] The components used in the examples and comparative examples are shown below.

[0150] (1)Raw materials of the crosslinked polymer ((A) component) having an isobutene-isoprene copolymer chain

[0151] "ER866" (manufactured by Starlight PMC Co., glycidyl methacrylate modified butyl rubber (glycidyl methacrylate modified isobutylene-isoprene copolymer), epoxy group concentration: 1.63 mmol / g, number average molecular weight: 113,000, isobutylene unit / isoprene unit: 98.9% / 1.1%)

[0152] "ER661" (manufactured by Starlight PMC Co., maleic anhydride modified butyl rubber (maleic anhydride modified isobutylene-isoprene copolymer), anhydride group concentration: 0.77 mmol / g, number average molecular weight: 40,000, isobutylene unit / isoprene unit: 98.9% / 1.1%)

[0153] "HV-300M" (manufactured by Toho Chemical Industry Co., maleic anhydride modified liquid polybutene, anhydride group concentration: 0.77 mmol / g, number average molecular weight: 2,100)

[0154] (2) Liquid polyolefin resin and / or liquid rubber ((B) component)

[0155] "HV-1900" (manufactured by ENEOS Co., liquid polybutene, number average molecular weight: 2,900, viscosity at 25°C: 460 Pa・s)

[0156] (3) Hygroscopic inorganic filler ((C) component)

[0157] Semi-calcined hydrotalcite (manufactured by Kyowa Chemical Industry Co., "DHT-4C", particle size (median particle size): 400 nm, BET specific surface area: 15 m 2 / g)

[0158] Calcium oxide (manufactured by Yoshizawa Lime Industry Co., particle size (median particle size): 2.1 μm)

[0159] (4) Tackifier

[0160] "Alcon P-125" (manufactured by Arakawa Chemical Industry Co., hydrogenated petroleum resin containing cyclohexane ring, softening point: 125°C)

[0161] (5) Other polymers

[0162] "BUTYL065" (manufactured by JSR Co., butyl rubber (isobutylene-isoprene copolymer)), Mooney viscosity (125°C): 32)

[0163] "ER829" (manufactured by Starlight PMC Co., glycidyl methacrylate modified propylene-butene random copolymer, propylene unit / butene unit: 71% / 29%, epoxy group concentration: 0.67 mmol / g, number average molecular weight: 180,000)

[0164] “ER645” (manufactured by Starlight PMC Co., Ltd.): maleic anhydride-modified propylene-butene random copolymer, propylene unit / butene unit: 71% / 29%, acid anhydride group concentration: 2.01 mmol / g, number average molecular weight: 58,000)

[0165] (6) Metal complex

[0166] “Puranact Al-M” (manufactured by Ajinomoto Fine-Techno Co., Inc., diisopropoxyaluminum (octadecenyloxyacetoacetate))

[0167] (7) Antioxidant

[0168] “Irganox1010” (manufactured by BASF, hindered phenol antioxidant)

[0169] (8) Curing agent accelerator

[0170] 2,4,6-tris(dimethylaminomethyl)phenol (hereinafter abbreviated as “TAP”) (manufactured by KAYAKU Nouryon Co., Ltd.)

[0171] <Example 1>

[0172] The following steps are used to prepare a varnish with the compounding ratio shown in the following table, and a sealing sheet is made using the obtained varnish. It should be noted that the amount (parts) of each component described in the following table represents the amount of the non-volatile component of each component in the varnish. In addition, the following table shows the content (%) of the crosslinked polymer having an isobutene-isoprene copolymer chain ((A) component), the liquid polyolefin resin and / or liquid rubber ((B) component), and the hygroscopic inorganic filler ((C) component) relative to 100% of the non-volatile component of the varnish.

[0173] Specifically, a maleic anhydride-modified liquid polybutene ("HV-300M" manufactured by Toho Chemical Industry Co., Ltd.), polybutene ("HV-1900" manufactured by ENEOS Corporation), semi-calcined hydrotalcite ("DHT-4C" manufactured by Kyowa Chemical Industry Co., Ltd.), and a metal complex ("Purenact Al-M" manufactured by Ajinomoto Fine-Techno Co., Inc.) were dispersed in a swazol solution (non-volatile content: 60%) of a hydrogenated petroleum resin containing a cyclohexane ring (tackifier, "Alcon P-125" manufactured by Arakawa Chemical Industries, Ltd.) using a three-roll mill to obtain a mixture. A toluene solution (non-volatile content: 25%) of glycidyl methacrylate-modified butyl rubber ("ER866" manufactured by Starlight PMC Co., Ltd.), a hindered phenol antioxidant ("Irganox 1010" manufactured by BASF), a curing agent accelerator (TAP, manufactured by Kayaku Nurion Co., Ltd.), and toluene were admixed into the obtained mixture, and the obtained mixture was uniformly dispersed using a high-speed rotary stirrer to obtain a varnish of the adhesive composition. Using a die coater, the obtained varnish was uniformly coated on the release-treated surface of a polyethylene terephthalate (PET) film (thickness of the PET film: 50 μm, "SP4020" manufactured by Toyo Cloth Co., Ltd.) treated with a silicone-based release agent, and heated at 130°C for 30 minutes to obtain a sealing sheet having an adhesive composition layer with a thickness of 20 μm.

[0174] <Example 2>

[0175] Except that the amount of semi-calcined hydrotalcite ("DHT-4C" manufactured by Kyowa Chemical Industry Co., Ltd.) was changed from 140 parts to 220 parts, a varnish of the adhesive composition and a sealing sheet having an adhesive composition layer with a thickness of 20 μm were produced in the same manner as in Example 1.

[0176] <Example 3>

[0177] Except that 140 parts of semi-calcined hydrotalcite ("DHT-4C" manufactured by Kyowa Chemical Industry Co., Ltd.) was changed to 140 parts of calcium oxide (manufactured by Yoshizawa Lime Industry Co., Ltd., median particle size: 2.1 μm), a varnish of the adhesive composition and a sealing sheet having an adhesive composition layer with a thickness of 20 μm were produced in the same manner as in Example 1.

[0178] <Example 4>

[0179] Using a three-roll mill, polybutene (“HV-1900” manufactured by ENEOS), semi-calcined hydrotalcite (“DHT-4C” manufactured by Kyowa Chemical Industry Co., Ltd.), and a metal complex (“Purenact Al-M” manufactured by Ajinomoto Fine-Techno Co., Inc.) were dispersed in a Swazol solution (non-volatile component: 60%) of a hydrogenated petroleum resin containing a cyclohexane ring (tackifier, “Alcon P-125” manufactured by Arakawa Chemical Industries, Ltd.) to obtain a mixture. A toluene solution (non-volatile component: 25%) of glycidyl methacrylate-modified butyl rubber (“ER866” manufactured by Starlight PMC), a toluene solution (non-volatile component: 35%) of maleic anhydride-modified butyl rubber (“ER661” manufactured by Starlight PMC), a hindered phenol antioxidant (Irganox1010, manufactured by BASF), a curing agent accelerator (TAP, manufactured by Kayaku Nurion Co., Ltd.), and toluene were compounded into the obtained mixture, and the obtained mixture was uniformly dispersed with a high-speed rotary stirrer to obtain a varnish of the adhesive composition. Then, in the same manner as in Example 1, a varnish of the adhesive composition and a sealing sheet having an adhesive composition layer with a thickness of 20 μm were produced.

[0180] <Example 5>

[0181] After appropriately adding Swazol to polybutene (“HV-1900” manufactured by ENEOS), maleic anhydride-modified liquid polybutene (“HV-300M” manufactured by Toho Chemical Industry Co., Ltd.), semi-calcined hydrotalcite (“DHT-4C” manufactured by Kyowa Chemical Industry Co., Ltd.), and a metal complex (“Purenact Al-M” manufactured by Ajinomoto Fine-Techno Co., Inc.), the mixture was mixed using a three-roll mill to obtain a mixture. A toluene solution (non-volatile component: 25%) of glycidyl methacrylate-modified butyl rubber (“ER866” manufactured by Starlight PMC), a hindered phenol antioxidant (Irganox1010, manufactured by BASF), a curing agent accelerator (TAP, manufactured by Kayaku Nurion Co., Ltd.), and toluene were compounded into the obtained mixture, and the obtained mixture was uniformly dispersed with a high-speed rotary stirrer to obtain a varnish of the adhesive composition. Then, in the same manner as in Example 1, a varnish of the adhesive composition and a sealing sheet having an adhesive composition layer with a thickness of 20 μm were produced.

[0182] <Comparative Example 1>

[0183] Using a three-roll mill, polybutene (ENEOS Corporation's "HV-1900"), semi-calcined hydrotalcite (Kyowa Chemical Industry Co., Ltd.'s "DHT-4C"), and a metal complex (Ajinomoto Fine-Techno Co., Inc.'s "Purenact Al-M") were dispersed in a swazol solution (non-volatile component: 60%) of a hydrogenated petroleum resin containing a cyclohexane ring (tackifier, "Alcon P-125" manufactured by Arakawa Chemical Industries, Ltd.) to obtain a mixture. A toluene solution (non-volatile component: 15%) of butyl rubber (JSR Corporation's "BUTYL065"), a hindered phenol antioxidant (BASF Corporation's "Irganox1010"), a curing agent accelerator (TAP, manufactured by Kayaku NuRion Co., Ltd.), and toluene were compounded into the obtained mixture, and the obtained mixture was uniformly dispersed using a high-speed rotary stirrer to obtain a varnish of the adhesive composition. Thereafter, in the same manner as in Example 1, a varnish of the adhesive composition and a sealing sheet having an adhesive composition layer with a thickness of 20 μm were produced.

[0184] <Comparative Example 2>

[0185] Except that the toluene solution (non-volatile component: 15%) of butyl rubber (JSR Corporation's "BUTYL065") was changed to a toluene solution of glycidyl methacrylate-modified propylene-butene random copolymer (Starlight PMC Corporation's "ER829") and an ipzole solution (non-volatile component: 20%) of maleic anhydride-modified propylene-butene random copolymer (Starlight PMC Corporation's "ER645"), a varnish of the adhesive composition and a sealing sheet having an adhesive composition layer with a thickness of 20 μm were produced in the same manner as in Comparative Example 1.

[0186] <Comparative Example 3>

[0187] Disperse semi-calcined hydrotalcite (“DHT-4C” manufactured by Kyowa Chemical Industry Co., Ltd.) and a metal complex (“Purenact Al-M” manufactured by Ajinomoto Fine-Techno Co., Ltd.) into a Swazol solution (non-volatile content: 60%) of a hydrogenated petroleum resin containing a cyclohexane ring (tackifier, “Alcon P-125” manufactured by Arakawa Chemical Industries, Ltd.) using a three-roll mill to obtain a mixture. Mix a toluene solution (non-volatile content: 25%) of glycidyl methacrylate-modified butyl rubber (“ER866” manufactured by Starlight PMC Co., Ltd.), a toluene solution (non-volatile content: 35%) of maleic anhydride-modified butyl rubber (“ER661” manufactured by Starlight PMC Co., Ltd.), a hindered phenol antioxidant (“Irganox1010” manufactured by BASF), a curing agent accelerator (TAP, manufactured by Kayaku Nurion Co., Ltd.), and toluene into the obtained mixture, and uniformly disperse the obtained mixture using a high-speed rotary stirrer. After obtaining a varnish of the adhesive composition, uniformly coat the obtained varnish onto the same support as in Example 1 using a die coater in the same manner as in Example 1, and heat at 130 °C for 30 minutes to obtain a sealing sheet having an adhesive composition layer with a thickness of 20 μm.

[0188] <Comparative Example 4>

[0189] Mix a toluene solution (non-volatile content: 25%) of glycidyl methacrylate-modified butyl rubber (“ER866” manufactured by Starlight PMC Co., Ltd.), maleic anhydride-modified liquid polybutene (“HV-300M” manufactured by Toho Chemical Industry Co., Ltd.), liquid polybutene (“HV-1900” manufactured by ENEOS Corporation), a metal complex (“Purenact Al-M” manufactured by Ajinomoto Fine-Techno Co., Ltd.), a Swazol solution (non-volatile content: 60%) of a hydrogenated petroleum resin containing a cyclohexane ring (tackifier, “Alcon P-125” manufactured by Arakawa Chemical Industries, Ltd.), a hindered phenol antioxidant (“Irganox1010” manufactured by BASF), a curing agent accelerator (TAP, manufactured by Kayaku Nurion Co., Ltd.), and toluene into the obtained mixture, and uniformly disperse the obtained mixture using a high-speed rotary stirrer. After obtaining a varnish of the adhesive composition, perform the same operation as in Example 1, uniformly coat it onto the same support as in Example 1 using a die coater, and heat at 130 °C for 30 minutes to obtain a sealing sheet having an adhesive composition layer with a thickness of 50 μm.

[0190] <Evaluation method for adhesiveness>

[0191] The sealing sheets produced in the examples and comparative examples were cut into a length of 50 mm and a width of 20 mm. Next, using an intermittent vacuum laminator (manufactured by Nichigo-Morton Co., Ltd., Morton-724), a composite film having an aluminum foil and a polyethylene terephthalate (PET) film ("PET Tsuki AL1N30" sold by Tokai Toho Aluminum Co., Ltd., thickness of aluminum foil: 30 μm, thickness of PET film: 25 μm) was laminated on the adhesive composition layer of the sealing sheet. Lamination was carried out under the conditions of a temperature of 80 °C, a time of 30 seconds, and a pressure of 0.3 MPa. And, the support (PET film) was peeled off from the obtained sheet, and a polyimide film ("Upilex-S" manufactured by Ube Industries, Ltd., thickness: 50 μm) was laminated on the exposed adhesive composition layer under the same conditions as above, to obtain a laminate having a laminated structure of "composite film / adhesive composition layer / polyimide film". For the obtained laminate, the stretching speed was set to 300 mm / minute in the direction 180 degrees with respect to the length direction of the aluminum foil, and the adhesive strength (room temperature adhesive strength) when peeling the "composite film / adhesive composition layer" from the polyimide film at room temperature was measured. In addition, the adhesive strength (high temperature adhesive strength) when peeling the laminate produced in the same manner as above in an environment of 60 °C was measured.

[0192] Regarding the adhesiveness of the adhesive composition at high temperature, evaluation was carried out according to the following criteria.

[0193] (Adhesiveness at high temperature)

[0194] ◎: High temperature adhesive strength is 400 gf / cm or more

[0195] 〇: High temperature adhesive strength is 200 gf / cm or more and less than 400 gf / cm

[0196] △: High temperature adhesive strength is 100 gf / cm or more and less than 200 gf / cm

[0197] ×: High temperature adhesive strength is less than 100 gf / cm.

[0198] <Evaluation method of moisture barrier property>

[0199] As a support film, a composite film having an aluminum foil and a polyethylene terephthalate (PET) film ("PET Tsuki AL1N30" sold by Tokai Toho Aluminum Co., Ltd., thickness of aluminum foil: 30 μm, thickness of PET film: 25 μm) was prepared. Except that this composite film was used as a support, the same operations as in each example and each comparative example were carried out to obtain a test piece having a laminated structure of "support (composite film) / adhesive composition layer". It should be noted that the adhesive composition layer was formed on the aluminum foil of the composite film.

[0200] Prepare a glass plate with a size of 50 mm × 50 mm square formed of non-alkali glass. Clean the glass plate with boiling isopropyl alcohol for 5 minutes and dry it at 150 °C for 30 minutes or more.

[0201] Using a mask that covers the edge region at a distance of 0 mm to 2 mm from the end of the aforementioned glass plate, calcium is vapor-deposited on one side of the dried glass plate. Thus, a calcium film (purity: 99.8%) with a thickness of 200 nm is formed in the central portion of one side of the glass plate except for the edge region at a distance of 0 mm to 2 mm from the end of the aforementioned glass plate.

[0202] In a nitrogen atmosphere, using a hot press (Lami Packer DAiSY A4 (LPD2325) manufactured by Fujipura Co., Ltd.), the adhesive composition layer of the above test piece is bonded to the surface of the aforementioned glass plate on the side of the calcium film to obtain a laminate. This laminate is used as an evaluation sample.

[0203] Generally speaking, if calcium comes into contact with water and forms calcium oxide, it becomes transparent. In addition, in the aforementioned evaluation sample, the glass plate and the aluminum foil have a sufficiently high water vapor intrusion barrier property. Therefore, moisture usually moves in the in-plane direction (the direction perpendicular to the thickness direction) through the end portion of the adhesive composition layer and reaches the calcium film. If moisture reaches the calcium film, the calcium film is oxidized sequentially from the end portion and becomes transparent. Therefore, a reduction in the calcium film is observed. Therefore, the intrusion of moisture into the evaluation sample can be evaluated by measuring the sealing distance (mm) from the end of the evaluation sample to the calcium film. Therefore, an evaluation sample containing a calcium film can be used as a model of an electronic device.

[0204] First, use a microscope ("Measuring Microscope MF-U" manufactured by Mitutoyo Corporation) to measure the sealing distance X1 (mm) from the end of the evaluation sample to the end of the calcium film.

[0205] Next, place the evaluation sample in a thermo-hygrostat set to a temperature of 60 °C and a humidity of 90% RH. After 100 hours from the start of storage, take out the evaluation sample from the thermo-hygrostat and measure the sealing distance X2 (mm) to the end of the calcium film.

[0206] Using the aforementioned sealing distances X1 and X2, calculate D (that is, the difference between X2 and X1) from the following formula: D (mm) = X2 (mm) - X1 (mm), and evaluate the water vapor intrusion barrier property according to the following criteria.

[0207] (Criteria for water vapor intrusion barrier property)

[0208] ○: D is less than 2.0 mm

[0209] ×: D is 2.0 mm or more.

[0210] <Evaluation method of flex resistance>

[0211] Cut the sealing sheets produced in the examples and comparative examples into a length of 110 mm and a width of 20 mm. Then, using an intermittent vacuum laminator (manufactured by Nichigo-Morton Co., Ltd., Morton-724), laminate them onto a polyimide film ("Upilex-S" manufactured by Ube Industries, Ltd., thickness: 25 μm). The lamination is carried out under the conditions of a temperature of 80°C, a time of 30 seconds, and a pressure of 0.3 MPa. Moreover, peel the support (PET film) from the obtained sheet, and laminate the same polyimide film ("Upilex-S" manufactured by Ube Industries, Ltd., thickness: 25 μm) on the exposed adhesive composition layer under the same conditions as above to obtain a laminate having a laminated structure of "polyimide film / adhesive composition layer / polyimide film". Place the obtained laminate in a clam-shell type bending test apparatus "CL40R type-E02" (manufactured by Yuasa System Machine Co., Ltd.), and bend the laminate 50,000 times under the conditions of a temperature of 60°C, a humidity of 90%RH, a curvature radius of 2.5 mm, and a speed of 60 rpm. Use a digital microscope "VHX-5000" manufactured by Keyence Corporation (magnification: 20 times) to observe the peripheral portion of the bent part in the bent laminate, and investigate whether voids are generated. Evaluate the flex resistance according to the following criteria.

[0212] (Criteria for flex resistance)

[0213] ○: After bending 50,000 times, the occurrence of voids is present.

[0214] ×: After bending 50,000 times, the occurrence of voids does not occur.

[0215]

[0216] As shown in Table 1, the sealing sheets of Examples 1 to 5 in which the adhesive composition layer contains a crosslinked polymer having an isobutene-isoprene copolymer chain ((A) component), a liquid polyolefin resin and / or a liquid rubber ((B) component), and a hygroscopic inorganic filler ((C) component) exhibit excellent adhesiveness, moisture barrier property, and flex resistance at high temperatures.

[0217] On the other hand, the flex resistance of the sealing sheet of Comparative Example 1 in which the adhesive composition layer does not contain the (A) component and the sealing sheet of Comparative Example 2 in which the adhesive composition layer contains a crosslinked polymer not having an isobutene-isoprene copolymer chain in place of the (A) component is poor.

[0218] In addition, the sealing sheet of Comparative Example 3 in which the adhesive composition layer does not contain the component (B) has poor adhesiveness. It should be noted that the normal temperature adhesive strength and high temperature adhesive strength of the sealing sheet of Comparative Example 3 are zero. Therefore, the moisture barrier property and the bending resistance were not measured.

[0219] In addition, the sealing sheet of Comparative Example 3 in which the adhesive composition layer does not contain the component (C) has poor moisture barrier property.

[0220] Industrial applicability

[0221] The sealing sheet of the present invention is useful for sealing electronic devices (such as organic EL devices, solar cells, sensor devices, etc.), conductive substrates, and the like.

[0222] This application is based on Japanese Patent Application No. 2020-125486 filed in Japan, and the content thereof is incorporated herein by reference in its entirety.

Claims

1. A sealing sheet having a laminated structure including a support and an adhesive composition layer, The adhesive composition layer contains: (A) A crosslinked polymer having an isobutene-isoprene copolymer chain, (B) A liquid polyolefin resin and / or a liquid rubber, and (C) A hygroscopic inorganic filler, and The crosslinked polymer having an isobutene-isoprene copolymer chain is at least one selected from the reaction products of an isobutene-isoprene copolymer having an epoxy group and a butene-based polymer having a carboxyl group and / or an acid anhydride group, and the reaction products of an isobutene-isoprene copolymer having a carboxyl group and / or an acid anhydride group and a butene-based polymer having an epoxy group.

2. The sheet for sealing according to claim 1, wherein, The content of the hygroscopic inorganic filler is 30% by mass or more based on 100% by mass of the non-volatile components of the adhesive composition layer.

3. The sheet for sealing according to claim 1, wherein, The content of the hygroscopic inorganic filler is 40% by mass or more based on 100% by mass of the non-volatile components of the adhesive composition layer.

4. The sealing sheet according to any one of claims 1 to 3, wherein, The content of the hygroscopic inorganic filler is 80% by mass or less based on 100% by mass of the non-volatile components of the adhesive composition layer.

5. The sheet for sealing according to any one of claims 1 to 3, wherein, The content of the hygroscopic inorganic filler is 70% by mass or less based on 100% by mass of the non-volatile components of the adhesive composition layer.

6. The sealing sheet according to any one of claims 1 to 3, which is used for sealing an electronic device.

7. An adhesive composition layer, which contains: (A) A crosslinked polymer having an isobutene-isoprene copolymer chain, (B) A liquid polyolefin resin and / or a liquid rubber, and (C) A hygroscopic inorganic filler, and The crosslinked polymer having an isobutene-isoprene copolymer chain is at least one selected from the reaction products of an isobutene-isoprene copolymer having an epoxy group and a butene-based polymer having a carboxyl group and / or an acid anhydride group, and the reaction products of an isobutene-isoprene copolymer having a carboxyl group and / or an acid anhydride group and a butene-based polymer having an epoxy group.

8. The adhesive composition layer according to claim 7, wherein, The content of the hygroscopic inorganic filler is 30% by mass or more based on 100% by mass of the non-volatile components of the adhesive composition layer.

9. The adhesive composition layer according to claim 7, wherein, The content of the hygroscopic inorganic filler is 40% by mass or more based on 100% by mass of the non-volatile components of the adhesive composition layer.

10. The adhesive composition layer according to any one of claims 7 to 9, wherein, The content of the hygroscopic inorganic filler is 80% by mass or less based on 100% by mass of the non-volatile components of the adhesive composition layer.

11. The adhesive composition layer according to any one of claims 7 to 9, wherein, The content of the hygroscopic inorganic filler is 70% by mass or less based on 100% by mass of the non-volatile components of the adhesive composition layer.

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