TW201827544A - Adhesive composition, sealing sheet, and sealed body - Google Patents

Abstract

Provided is an adhesive composition containing a component (A) being a modified polyolefin resin and a component (B) being a polyfunctional epoxy compound, said adhesive composition being characterized by having no more than 20 mg of outgas per 1 cm3 solid content, when the outgas content of the solid content is measured at 120 DEG C for 20 minutes. Also provided are: a sealing sheet having an adhesive layer formed using this adhesive composition; and a sealed body comprising an object-to-be-sealed that has been sealed by this sealing sheet. As a result of the present invention, provided are: an adhesive composition that is readily molded into a sheet shape and has low outgas properties; a sealing sheet having an adhesive layer formed using this adhesive composition and having low outgas properties; and a sealed body comprising an object-to-be-sealed that has been sealed using the sealing sheet.

Description

 Adhesive composition, sealing sheet and sealing body  

The present invention relates to an adhesive composition which is easily formed into a sheet shape and has low venting properties, a sealing sheet having an adhesive layer having a low venting property formed using the adhesive composition, and a sealing sheet using the sealing sheet described above. A sealed body sealed by a seal.

In recent years, organic EL devices have attracted attention as high-luminance light emission by low-voltage direct current driving.

However, the organic EL element has a problem that the light-emitting characteristics such as the light-emitting luminance, the light-emitting efficiency, and the light-emitting uniformity are liable to be lowered at the same time.

In the light of the problem that the light-emitting property is low, it is considered that oxygen, moisture, or the like intrudes into the interior of the organic EL element to deteriorate the electrode and the organic layer. Therefore, conventionally, the organic EL element is sealed by using a sealing material to prevent intrusion of oxygen and moisture.

In addition, when the organic EL element is sealed by using a sealing material, the organic EL element is deteriorated when the exhaust gas is generated from the sealing material. Therefore, a sealing material having a low exhaust property has been developed.

For example, Patent Document 1 describes a composition for sealing comprising a specific cationic curable compound, a photocationic polymerization initiator, and an azole compound.

Patent Document 1 also discloses that the cured product of the composition for sealing has low exhaust gas and moisture resistance.

Prior technical literature

Patent literature

[Patent Document 1] WO 2015/111525

Patent Document 1 also discloses a sealing composition capable of obtaining low venting properties by using an azole compound as a curing retardation agent.

However, according to the study by the inventors of the present invention, it has been found that the cause of the exhaust gas in the sealing material is not only the hardening retarder, but also a sealing material having a lower exhausting property, which must be further studied.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an adhesive composition which is easily formed into a sheet shape and has low venting properties, and an adhesive layer having low venting properties formed using the adhesive composition. A sealing sheet and a sealing body obtained by sealing the sealed article using the sealing sheet.

In order to solve the problem, the inventors of the present invention have found that an adhesive composition containing a modified polyolefin resin and a polyfunctional epoxy compound is suitable as a material for forming a low-venting sealing material. The invention has been made.

As described above, according to the present invention, the adhesive composition of the following (1) to (9), the sealing sheet of (10) to (13), and the sealing body of (14) and (15) are provided.

(1) An adhesive composition comprising the following (A) component and (B) component adhesive composition, wherein the solid component is measured at 120 ° C for 20 minutes. In the case of a gas amount, the solid content per unit volume of 1 cm ³ is 20 mg or less, (A) component: modified polyolefin resin, and (B) component: polyfunctional epoxy compound.

(2) The adhesive composition according to (1), wherein the component (A) is an acid-modified polyolefin resin.

(3) The adhesive composition according to (1), wherein the content of the component (B) is from 25 to 200 parts by mass based on 100 parts by mass of the component (A).

(4) The adhesive composition according to (1), further comprising the following component (C): component (C): an adhesion-imparting agent having a softening point of 80 ° C or higher.

(5) The adhesive composition according to (4), wherein the content of the component (C) is from 1 to 200 parts by mass based on 100 parts by mass of the component (A).

(6) The adhesive composition according to (1), further comprising the following component (D): component (D): an imidazole-based curing catalyst.

(7) The adhesive composition according to (6), wherein the content of the component (D) is 0.1 to 10 parts by mass based on 100 parts by mass of the component (A).

(8) The adhesive composition according to (1), which further comprises the following component (E): component (E): a decane coupling agent.

(9) The adhesive composition according to (8), wherein the content of the component (E) is 0.01 to 10 parts by mass based on 100 parts by mass of the component (A).

(10) A sealing sheet comprising two release films and a pressure-sensitive adhesive layer held by the release film, wherein the adhesive layer is any one of the items (1) to (9). The adhesive composition is formed.

(11) A sealing sheet comprising a release film, a gas barrier film, and a pressure-sensitive adhesive layer sandwiched between the release film and the gas barrier film, wherein the adhesive layer is used as (1) The adhesive composition according to any one of (9), wherein the adhesive composition is formed.

(12) The sealing sheet according to (11), wherein the gas barrier film is a metal foil, a resin film, or a film glass.

(13) The sealing sheet according to (10) or (11), wherein the thickness of the adhesive layer is 5 to 25 μm.

(14) A sealing body obtained by sealing a sealing material using the sealing sheet according to any one of (10) to (13).

(15) The sealing body according to (14), wherein the sealed object is an organic EL element, an organic EL display element, a liquid crystal display element, or a solar cell element.

According to the present invention, it is possible to provide an adhesive composition which is easily formed into a sheet shape and has low venting properties, a sealing sheet having an adhesive layer having a low venting property formed using the adhesive composition, and a sealing sheet using the same A sealed body sealed with a seal.

Hereinafter, the present invention will be described in detail as 1) an adhesive composition, 2) a sealing sheet, and 3) a sealing body.

In the present specification, the term "low venting property" refers to the amount of exhaust gas discharged even when the solid component of the adhesive composition (or the adhesive layer formed of the adhesive composition) is placed in a high temperature environment. Less of the characteristics of the adhesive composition or adhesive layer.

1) Adhesive composition

The adhesive composition of the present invention is an adhesive composition containing the component (A) and the component (B), which is characterized in that the solid content is measured at a temperature of 120 ° C for 20 minutes. The solid content per unit volume of 1 cm ³ is 20 mg or less, (A) component: modified polyolefin resin, and component (B): polyfunctional epoxy compound.

The modified polyolefin resin is a polyolefin resin into which a functional group is introduced.

The polyolefin resin is a polymer containing a repeating unit derived from an olefin-based monomer. The polyolefin resin may be a homopolymer composed of only one repeating unit derived from an olefin-based monomer, or may be a copolymer composed of two or more repeating units derived from an olefin-based monomer, or may be A copolymer composed of a repeating unit derived from an olefin monomer and a repeating unit derived from another monomer (other monomer other than the olefin monomer) copolymerizable with the olefin monomer.

The olefin-based monomer is preferably an α -olefin having 2 to 8 carbon atoms, more preferably ethylene, propylene, 1-butene, isobutylene or 1-hexene, and more preferably ethylene or propylene.

Examples of other monomers copolymerizable with the olefin-based monomer include vinyl acetate, (meth) acrylate, and styrene. Here, the term "(meth)acrylic acid" means acrylic acid or methacrylic acid (the same applies hereinafter).

Examples of the polyolefin resin include ultra low density polyethylene (VLDPE), low density polyethylene (LDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), linear low density polyethylene, and poly. Propylene (PP), ethylene-propylene copolymer, olefin-based elastomer (TPO), ethylene-vinyl acetate copolymer (EVA), ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylate copolymer Etc., but not limited by this.

The modified polyolefin resin can be obtained by subjecting a polyolefin resin as a precursor to a modification treatment using a modifier.

The modifier used in the modification treatment of the polyolefin resin is a compound having a functional group in the molecule, that is, a group capable of contributing to a crosslinking reaction to be described later.

Examples of the functional group include a carboxyl group, a carboxylic anhydride group, a carboxylate group, a hydroxyl group, an epoxy group, a decylamino group, an ammonium group, a nitrile group, an amine group, an oximine group, an isocyanate group, an ethyl sulfonate group, and a sulfur group. An alcohol group, an ether group, a thioether group, a sulfonic acid group, a phosphoric acid group, a nitro group, a carbamate group, a halogen atom or the like. Among these, a carboxyl group, a carboxylic anhydride group, a carboxylate group, a hydroxyl group, an ammonium group, an amine group, an oxime imide group, and an isocyanate group are preferred, and a carboxylic anhydride group or an alkoxyalkyl group is preferred. The carboxylic anhydride group is particularly preferred.

The compound having a functional group may have two or more functional groups in the molecule.

Examples of the modified polyolefin-based resin include an acid-modified polyolefin resin and a decane-modified polyolefin resin. In particular, from the viewpoint of obtaining more excellent effects of the present invention, an acid-modified polyolefin resin is preferred.

The acid-modified polyolefin-based resin is obtained by graft-modifying a polyolefin resin with an acid. For example, a resin obtained by reacting a polyolefin resin with an unsaturated carboxylic acid and introducing a carboxyl group (graft modification) can be mentioned. Further, in the present specification, the unsaturated carboxylic acid is a concept including a carboxylic anhydride, and the carboxyl group contains a carboxylic acid anhydride group.

Examples of the unsaturated carboxylic acid which reacts the polyolefin resin include maleic acid, fumaric acid, itaconic acid, citraconic acid, glutaconic acid, tetrahydrophthalic acid, aconitic acid, Maleic anhydride, itaconic anhydride, glutaconic anhydride, citraconic anhydride, aconitic anhydride, norbornene dicarboxylic anhydride, tetrahydrophthalic anhydride, and the like.

These can be used alone or in combination of two or more. Among these, since an adhesive composition having a relatively excellent adhesive strength can be obtained, maleic anhydride is preferred.

The amount of the unsaturated carboxylic acid to be reacted with the polyolefin resin is preferably 0.1 to 5 parts by mass, more preferably 0.2 to 3 parts by mass, even more preferably 0.2 to 1.0 part by mass, per 100 parts by mass of the polyolefin resin. The adhesive composition containing the acid-modified polyolefin resin obtained as described above has excellent adhesion strength.

In the present invention, a commercially available product can also be used as the acid-modified polyolefin resin. As a commercial item, for example, ADMER (registered trademark) (manufactured by Mitsui Chemicals, Inc.), UNISTOLE (registered trademark) (manufactured by Mitsui Chemicals, Inc.), BondyRam (manufactured by Polyram Co., Ltd.), and orevac (registered trademark) (manufactured by ARKEMA Co., Ltd.) Modic (registered trademark) (manufactured by Mitsubishi Chemical Corporation).

The decane-modified polyolefin-based resin is obtained by graft-modifying a polyolefin resin with an unsaturated decane compound. The decane-modified polyolefin resin has a structure in which an unsaturated decane compound is graft-copolymerized with a polyolefin resin of a main chain. The decane-modified polyolefin resin is not particularly limited. A decane-modified polyethylene resin and a decane-modified ethylene-vinyl acetate copolymer are exemplified. In particular, a decane-modified polyethylene resin such as decane-modified low-density polyethylene, decane-modified ultra-low-density polyethylene, or decane-modified linear low-density polyethylene is preferred.

As the unsaturated decane compound which reacts the above polyolefin resin, a vinyl decane compound is preferred. Examples of the vinyl decane compound include vinyl trimethoxy decane, vinyl triethoxy decane, vinyl tripropoxy decane, vinyl triisopropoxy decane, vinyl tributoxy decane, and ethylene. Tripentyloxydecane, vinyltriphenoxydecane, vinyltribenzyloxydecane, vinyltrimethylenedioxydecane,vinyltriethylethoxirane,vinylpropoxyloxy Decane, vinyl triethoxydecane, vinyl tricarboxydecane, and the like. These can be used alone or in combination of two or more.

The conditions for the unsaturated decane compound to be bonded to the polyolefin resin of the main chain may be a conventional method of conventional graft polymerization.

The amount of the unsaturated decane compound to be reacted with the polyolefin resin is preferably 0.1 to 10 parts by mass, more preferably 0.3 to 7 parts by mass, and further preferably 0.5 to 5 parts by mass per 100 parts by mass of the polyolefin resin. good. When the amount of the unsaturated decane compound to be reacted with the polyolefin resin is in the above range, the obtained adhesive composition containing a decane-modified polyolefin resin has a particularly excellent adhesive strength.

In the present invention, a commercially available product can be used as the decane-modified polyolefin resin. For example, LINKLON (registered trademark) (manufactured by Mitsubishi Chemical Corporation), etc., and LINKLON, which is a low-density polyethylene-based LINKLON, linear low-density polyethylene-based LINKLON, ultra-low-density poly, can be suitably used. LINKLON of ethylene type and LINKLON of ethylene-vinyl acetate copolymer type.

The modified polyolefin resin can be used alone or in combination of two or more.

The number average molecular weight (Mn) of the modified polyolefin resin is not particularly limited, and from the viewpoint of obtaining a superior effect of the present invention, it is preferably 10,000 to 2,000,000, more preferably 20,000 to 1,500,000.

The number average molecular weight (Mn) of the modified polyolefin-based resin can be determined by gel permeation chromatography using tetrahydrofuran as a solvent to obtain a standard polystyrene equivalent value.

The content of the modified polyolefin resin is not particularly limited, and from the viewpoint that the present invention can obtain a superior effect, the total amount of the modified polyolefin resin and the following component (B) is an adhesive combination. The solid content of the material is preferably 30% by mass or more, and more preferably 50% by mass or more.

(B) Component: Polyfunctional epoxy compound

The adhesive composition of the present invention contains a polyfunctional epoxy compound as the component (B).

Since the adhesive composition of the present invention contains a polyfunctional epoxy compound, the cured product thereof has excellent hardenability water vapor barrier properties.

The polyfunctional epoxy compound means a compound having at least two epoxy groups in the molecule.

Examples of the epoxy compound having two epoxy groups include bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, and brominated bisphenol A. Diepoxypropyl ether, brominated bisphenol F diglycidyl ether, brominated bisphenol S diglycidyl ether, novolak type epoxy resin (eg phenol ‧ novolak type epoxy resin, cresol ‧ Novolak type epoxy resin, brominated phenol ‧ novolak type epoxy resin), hydrogenated bisphenol A diglycidyl ether, hydrogenated bisphenol F diglycidyl ether, hydrogenated bisphenol S diepoxy Ether, neopentyl alcohol polyepoxypropyl ether, 1,6-hexanediol diepoxypropyl ether, hexahydrophthalate diglycidyl ester, neopentyl glycol diepoxypropyl ether , trimethylolpropane polyepoxypropyl ether, 2,2-bis(3-epoxypropyl-4-glycidoxypropyl)propane, dimethylol tricyclodecane diepoxypropane Ether and the like.

These polyfunctional epoxy compounds can be used alone or in combination of two or more.

The lower limit of the weight average molecular weight of the polyfunctional epoxy compound is preferably 1,000, preferably 1,200. The upper limit of the weight average molecular weight of the polyfunctional epoxy compound is preferably 5,000, preferably 4,500. By using an adhesive composition having a weight average molecular weight of 1,000 or more of the polyfunctional epoxy compound, it is possible to form a sealing material having a low exhaust property. The adhesive composition having a weight average molecular weight of 5,000 or less of the polyfunctional epoxy compound has excellent fluidity, and can sufficiently fill the unevenness due to the unevenness of the surface of the sealed object and the thickness of the sealed object (having excellent unevenness followability) ).

The epoxy equivalent of the polyfunctional epoxy compound (B1) is preferably 100 g/eq or more and 500 g/eq or less, and more preferably 150 g/eq or more and 300 g/eq or less. By using an adhesive composition having an epoxy equivalent of 100 g/eq or more and 500 g/eq or less of the polyfunctional epoxy compound, a sealing material having a low venting property can be formed.

The content of the polyfunctional epoxy compound in the adhesive composition of the present invention is preferably from 25 to 200 parts by mass, preferably from 50 to 150 parts by mass, per 100 parts by mass of the component (A). The cured product of the adhesive composition having a content of the polyfunctional epoxy compound within this range has more excellent water vapor barrier properties.

The adhesive composition of the present invention may contain components other than the components (A) and (B).

Examples of the components other than the component (A) and the component (B) include the following components (C), (D), and (E), and component (C): an adhesive-imparting agent having a softening point of 80 ° C or higher. (D) component: imidazole-based hardening catalyst, (E) component: decane coupling agent.

(C) component: an adhesion-imparting agent having a softening point of 80 ° C or more

The adhesive composition containing the component (B) has a low storage elastic modulus before curing and has excellent unevenness followability. However, such an adhesive composition is not easy to maintain a certain shape and is difficult to form into a sheet shape. At this time, the moldability can be improved by containing the component (C).

Examples of the adhesion-imparting agent include a rosin-based resin such as a polymerized rosin, a polymerized rosin ester, and a rosin derivative; a terpene-based resin such as a polyterpene resin, an aromatic-modified terpene resin, a hydrogenated product thereof, or a terpene phenol resin; Resin; coumarone ‧ oxime resin; petroleum resin such as aliphatic petroleum resin, aromatic petroleum resin and its hydride, aliphatic/aromatic copolymer petroleum resin; low molecular weight polymer of styrene or substituted styrene Α -methylstyrene homopolymer resin, α -methylstyrene/styrene copolymer resin, styrene monomer/aliphatic monomer copolymer resin, styrene monomer/α a styrene resin such as a methyl styrene/aliphatic monomer copolymerization resin, a styrene monomer homopolymer resin, or a styrene monomer/aromatic monomer copolymer resin. Among these, a styrene resin is preferred, and a styrene monomer/aliphatic monomer copolymerized resin is preferred.

These adhesion-imparting agents can be used alone or in combination of two or more.

The softening point of the adhesion-imparting agent is 80 ° C or more. The softening point of the adhesive-imparting agent is 80 ° C or more, and an adhesive composition having excellent adhesiveness can be obtained at a high temperature. Moreover, workability at the time of shaping|molding an adhesive composition into a sheet shape improves.

When the adhesive composition of the present invention contains an adhesion-imparting agent having a softening point of 80 ° C or higher, the content thereof is preferably from 1 to 200 parts by mass, preferably from 10 to 150, per 100 parts by mass of the component (A). Parts by mass. When the amount of the adhesion-imparting agent having a softening point of 80 ° C or more is too small, it may become difficult to form the adhesive composition into a sheet form. On the other hand, the adhesion-imparting agent having a softening point of 80 ° C or more is too much, and the adhesive layer may become brittle.

(D) component: imidazole-based hardening catalyst

The imidazole-based curing catalyst is a compound having an imidazole skeleton and has a catalytic action in the hardening reaction of the adhesive composition.

Examples of the imidazole-based curing catalyst include 2-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-ethyl-4-methylimidazole, and 2-benzene. Base-4-methylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, and the like. Among these, 2-ethyl-4-methylimidazole is preferred.

These imidazole-based curing catalysts can be used alone or in combination of two or more.

By using an adhesive composition containing an imidazole-based curing catalyst, it is easy to obtain a cured product having excellent adhesion even at a high temperature.

When the adhesive composition of the present invention contains an imidazole-based curing catalyst, the content thereof is preferably 0.1 to 10 parts by mass, more preferably 0.2 to 5 parts by mass, per 100 parts by mass of the component (A). The content of the imidazole-based curing catalyst is a cured product of the adhesive composition in this range, and has excellent adhesion even at a high temperature.

(E) component: decane coupling agent

The decane coupling agent is an organic hydrazine compound having a functional group reactively bonded to an organic material and a functional group (hydrolyzable group) reactively bonded to the inorganic material in the molecule.

As the decane coupling agent, a conventional decane coupling agent can be used, and in particular, an organic fluorene compound having at least one alkoxyalkyl group in the molecule is preferred.

Examples of the decane coupling agent include a polymerizable unsaturated group-containing hydrazine compound such as vinyl trimethoxy decane, vinyl triethoxy decane or methyl propyl methoxy propyl trimethoxy decane; An anthracene compound having an epoxy structure such as propoxypropyltrimethoxydecane or 2-(3,4-epoxycyclohexyl)ethyltrimethoxydecane; 3-aminopropyltrimethoxydecane, N-( An amine group-containing hydrazine compound such as 2-aminoethyl)-3-aminopropyltrimethoxydecane or N-(2-aminoethyl)-3-aminopropylmethyldimethoxydecane; 3-chloro Propyltrimethoxydecane; 3-isocyanatepropyltriethoxydecane, and the like.

These decane coupling agents can be used alone or in combination of two or more.

By using an adhesive composition containing a decane coupling agent, it is easy to obtain a cured product having more excellent adhesion strength in a normal temperature (15 ° C to 30 ° C) and a high temperature (40 ° C to 100 ° C) environment.

When the adhesive composition of the present invention contains a decane coupling agent, the content is 0.01 to 10 by mass from 100 parts by mass of the component (A) from the viewpoint of obtaining a cured product having more excellent adhesive strength. Preferably, it is preferably 0.02 to 5 parts by mass.

The adhesive composition of the present invention may also contain a solvent.

Examples of the solvent include an aromatic hydrocarbon solvent such as benzene or toluene; an ester solvent such as ethyl acetate or butyl acetate; and a ketone solvent such as acetone, methyl ethyl ketone or methyl isobutyl ketone; An aliphatic hydrocarbon solvent such as n-pentane, n-hexane or n-heptane; a ring-type hydrocarbon solvent such as cyclopentane, cyclohexane or methylcyclohexane.

These solvents can be used alone or in combination of two or more.

The content of the solvent can be appropriately determined in consideration of coatability and the like.

The adhesive composition of the present invention may contain other components insofar as it does not impair the effects of the present invention.

As another component, a ultraviolet absorber is mentioned. Additives such as antistatic agents, light stabilizers, antioxidants, resin stabilizers, fillers, pigments, extenders, softeners, and the like.

These can be used alone or in combination of two or more.

When the adhesive composition of the present invention contains these additives, the content thereof can be appropriately determined in accordance with the purpose.

The adhesive composition of the present invention can be prepared by appropriately mixing and stirring a predetermined component in accordance with a usual method.

In the adhesive composition of the present invention, when the amount of exhaust gas is measured under conditions of 120 ° C for 20 minutes for the solid content, the amount of exhaust of the solid component per 1 cm ³ is 20 mg or less, preferably 18 mg or less, and 15 mg. The following is preferred, and it is particularly preferably 10 mg or less, and most preferably 8 mg or less. The lower limit is not particularly specified, and is usually 0.1 mg or more. In the present specification, the solid component refers to a solid portion obtained by removing a volatile substance such as a solvent from the adhesive composition.

Further, by using a polyfunctional epoxy compound having a weight average molecular weight of 1,000 to 5,000, it is possible to more easily form a low-exhaust adhesive layer.

The amount of exhaust of the solid component of the adhesive composition can be, for example, a flaky adhesive which can be obtained by applying the adhesive composition of the present invention to a base film (or a release film) and drying it. The film was used as a test piece, and was measured in accordance with the method described in the examples.

The adhesive composition having a small amount of exhaust gas can be efficiently obtained by using a polyfunctional epoxy compound having a relatively high molecular weight.

The adhesive composition of the present invention is easily formed into a sheet shape and has low venting properties. Therefore, the adhesive composition of the present invention can be suitably used in forming the sealing material.

2) Sealing sheet

The sealing sheet of the present invention is a sealing sheet ( α ) or a sealing sheet ( β ), and a sealing sheet ( α ): a sealing sheet composed of two release films and an adhesive layer held by the release films. The adhesive layer is formed using the adhesive composition of the present invention, and the sealing sheet ( β ) is composed of a release film, a gas barrier film, and the release film and the gas barrier property. A sealing sheet comprising a film-holding adhesive layer, wherein the pressure-sensitive adhesive layer is formed using the pressure-sensitive adhesive composition of the present invention.

Moreover, these sealing sheets are the things in the state before use, and when using the sealing sheet of this invention, normally, a peeling film is peeled and removed.

[sealing sheet ( α )]

The release film constituting the sealing sheet ( α ) functions as a support while the sealing step ( α ) is produced, and functions as a protective sheet for the adhesive layer until the sealing sheet ( α ) is used. .

As the release film, it is possible to use a conventional one. For example, on the substrate for a release film, there is a release layer obtained by performing a release treatment using a release agent.

Examples of the substrate for a release film include a paper base material such as cellophane, coated paper, and upper paper; and a laminated paper obtained by laminating a thermoplastic resin such as polyethylene on the paper base; A plastic film such as ethylene phthalate resin, polybutylene terephthalate resin, polyethylene naphthalate resin, polypropylene resin, or polyethylene resin.

Examples of the release agent include a rubber-based elastomer such as an anthrone-based resin, an olefin-based resin, an isoprene-based resin, and a butadiene-based resin, a long-chain alkyl-based resin, an alkyd-based resin, and a fluorine-based resin. Wait.

The two release films of the sealing sheet ( α ) may be the same or different from each other, and the two release films are preferably different in peeling force. By making the peeling force of the two peeling films different, the step of peeling off the peeling film can be performed more efficiently first.

The thickness of the adhesive layer of the sealing sheet ( α ) is not particularly limited, and is preferably 5 to 25 μm, more preferably 10 to 20 μm.

Since the adhesive layer is formed to be very thin, the adhesive layer is formed by using the adhesive composition of the present invention. Therefore, the adhesive layer has excellent unevenness and can sufficiently fill the unevenness of the adherend.

The adhesive layer of the sealing sheet ( α ) is preferably one having thermal curability. The thermosetting adhesive layer has a very excellent adhesive strength after hardening.

The conditions when the adhesive layer is thermally cured are not particularly limited.

The heating temperature is usually 80 to 200 ° C, preferably 90 to 150 ° C.

The heating time is usually from 30 minutes to 12 hours, preferably from 1 to 6 hours.

The adhesive strength of the hardened adhesive layer at 23 ° C is usually 1 to 100 N / 25 mm, preferably 10 to 50 N / 25 mm, and the adhesive strength at 85 ° C is usually 1 to 100 N / 25 mm, preferably 1 to 100 N / 25 mm. It is 5~50N/25mm.

The peeling strength described above was measured in accordance with the method described in the examples.

The water vapor transmission rate of the adhesive layer after the hardening treatment is usually 0.1 to 200 g/m ² /day, preferably 1 to 150 g/m ² /day.

The method for producing the sealing sheet ( α ) is not particularly limited. For example, a sealing sheet ( α ) can be produced by a conventional casting method. More specifically, the adhesive composition of the present invention can be applied to the release-treated surface of the release film by a conventional method, and the obtained coating film can be dried to produce an adhesive layer with a release film, and secondly, by A separate release film was laminated on the adhesive layer to obtain a sealing sheet ( α ).

Examples of the method of applying the pressure-sensitive adhesive composition include a spin coating method, a spray coating method, a bar coating method, a knife coating method, a roll coating method, a blade coating method, a die coating method, and a gravure method. Coating method, etc.

The drying conditions at the time of drying the coating film are not particularly limited. For example, the drying temperature is 80 to 150 ° C, and the drying time is 30 seconds to 5 minutes.

[sealing sheet ( β )]

The release film and the adhesive layer constituting the sealing sheet ( β ) are the same as those disclosed as the release film and the adhesive layer constituting the sealing sheet ( α ).

The gas barrier film constituting the sealing sheet ( β ) is not particularly limited as long as it has moisture barrier properties.

The gas barrier film is preferably a water vapor transmission rate of 0.1 g/m ² /day or less at a temperature of 40 ° C and a relative humidity of 90% (hereinafter, abbreviated as "90% RH"), and is 0.05. Preferably, g/m ² /day or less is more preferably 0.005 g/m ² /day or less.

When the gas barrier film has a water vapor transmission rate of 0.1 g/m ² /day or less in an environment of a temperature of 40 ° C and 90% RH, it is possible to effectively suppress the infiltration of oxygen, moisture, or the like into the organic EL formed on the transparent substrate. The inside of the element such as the element causes the electrode and the organic layer to deteriorate.

The transmittance of water vapor or the like of the gas barrier film can be measured using a conventional gas permeability measuring device.

Examples of the gas barrier film include a metal foil, a resin film, and a film glass. Among these, a resin film is preferable, and a gas barrier film having a substrate and a gas barrier layer is preferable.

Examples of the metal of the metal foil include metal materials such as copper, nickel, and aluminum; alloy materials such as stainless steel and aluminum alloy.

The composition and the composition of the film glass are not particularly limited, and in the case of obtaining a stable flexibility, an alkali-free borosilicate glass is preferred.

In the film glass, the film glass can be used as a monomer, and a metal foil such as an aluminum foil or a resin film can be laminated or bonded to the film glass.

Further, as the film glass, it is preferable to have flexibility having a thickness of about 10 to 200 μm.

Examples of the resin component of the substrate constituting the gas barrier film include polyimide, polyamine, polyamidamine, polyphenyl ether, polyether ketone, polyether ether ketone, and polyolefin. Polyester, polycarbonate, polyfluorene, polyether oxime, polyphenylene sulfide, polyarylate, acrylic resin, cycloolefin polymer, aromatic polymer, polyurethane polymer, etc. .

The thickness of the substrate is not particularly limited, and is preferably 0.5 to 500 μm, more preferably 1 to 200 μm, still more preferably 5 to 100 μm from the viewpoint of ease of handling.

The gas barrier layer is not particularly limited as long as it can impart a desired gas barrier property, and the gas barrier layer may be a layer obtained by modifying a layer of an inorganic film or a polymer compound. Wait. Among these, since the thickness is thin and the layer having excellent gas barrier properties can be efficiently formed, the gas barrier layer is a gas barrier layer composed of an inorganic film and a layer containing a polymer compound. A gas barrier layer obtained by performing a upgrading treatment is preferred.

The inorganic film is not particularly limited, and examples thereof include an inorganic deposited film.

As an inorganic vapor deposition film, the vapor deposition film of an inorganic compound and metal is mentioned.

Examples of the vapor deposition film material of the inorganic compound include inorganic oxides such as cerium oxide, aluminum oxide, magnesium oxide, zinc oxide, indium oxide, and tin oxide; and inorganic nitrides such as tantalum nitride, aluminum nitride, and titanium nitride. Inorganic carbide; inorganic sulfide; inorganic oxynitride such as lanthanum oxynitride; inorganic oxidized carbide; inorganic carbide carbide; inorganic oxynitride carbide.

Examples of the material for vapor deposition of the metal include aluminum, magnesium, zinc, and tin.

Examples of the method for forming the inorganic film include a vacuum deposition method, an EB vapor deposition method, and a sputtering method. Ion spray method, paste method, plasma vapor phase growth method (CVD method), and the like.

The thickness of the inorganic film can be appropriately selected in accordance with the type and composition of the inorganic material. It is preferably 1 to 500 nm, preferably 2 to 300 nm.

A gas barrier layer obtained by ion-implanting a layer containing a polymer compound (hereinafter referred to as a "polymer layer"), and examples of the polymer compound to be used include polyorganosiloxane. A ruthenium containing a polyazane-based compound or the like contains a polymer compound, a polyimine, a polyamine, a polyamidamine, a polyphenyl ether, a polyether ketone, a polyether ether ketone, a polyolefin, and a polyester. Polycarbonate, polyfluorene, polyether oxime, polyphenylene sulfide, polyarylate, acrylic resin, cycloolefin polymer, aromatic polymer, and the like. These polymer compounds can be used alone or in combination of two or more.

Among these, from the viewpoint of being able to form a gas barrier layer having excellent gas barrier properties, it is preferable to use a fluorene-containing polymer compound, and a polyazane-based compound is preferable.

The polyazane-based compound is a polymer compound having a repeating unit containing a -Si-N- bond (azepine bond) in the molecule. Specifically, it has the formula (1)

The compound of the repeating unit represented is preferred. Further, the number average molecular weight of the polyazane-based compound to be used is not particularly limited, and is preferably from 100 to 50,000.

In the above formula (1), n represents an arbitrary natural number. R _X, R _y, R _z are each independently based and represent a hydrogen atom, an unsubstituted or substituted alkyl group, the unsubstituted or the substituted cycloalkyl, unsubstituted or substituted alkenyl group, the unsubstituted or A non-hydrolyzable group such as an aryl group having a substituent or an alkyl decyl group. Among these, R _X , R _y , and R _z are preferably a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a phenyl group, and particularly preferably a hydrogen atom. The polyazane compound having a repeating unit represented by the above formula (1) may be an inorganic decazane in which R _X , R _y and R _z are all hydrogen atoms, and may be R _X , R _y or R. At least one of _z is not an organic decazane of a hydrogen atom.

The polyazane-based compound can be used alone or in combination of two or more. In the present invention, a polyazane-modified product can also be used as a polyazane-based compound. Further, in the present invention, as the polyazane-based compound, a commercially available product such as a glass coating material can be used as it is.

The polymer layer may contain other components in addition to the above-described polymer compound insofar as it does not inhibit the object of the present invention. Examples of other components include a curing agent, other polymers, an antioxidant, a photostabilizer, and a flame retardant.

The gas barrier layer having a superior gas barrier property can be obtained, and the polymer compound content in the polymer layer is preferably 50% by mass or more, and more preferably 70% by mass or more.

The thickness of the polymer layer is not particularly limited, and is preferably 50 to 300 nm, more preferably 50 to 200 nm.

In the present invention, even if the thickness of the polymer layer is in the nanometer grade, a sealing sheet having sufficient gas barrier properties can be obtained.

The method of forming a polymer layer is, for example, a solution for forming a layer containing at least one kind of a polymer compound, other components as needed, and a solvent, and the like, using a spin coater, a knife coater, and a gravure coat. A method in which a conventional device such as a cloth machine is applied and the obtained coating film is appropriately dried to form a film.

Examples of the modification treatment of the polymer layer include ion implantation treatment, plasma treatment, radiation irradiation treatment, and heat treatment. It is preferred to treat the bond structure of the polymer layer. These processes can be performed in a single type or in combination of two or more types.

The ion implantation treatment is a method of modifying ions into a polymer layer and modifying the polymer layer as described later.

The plasma treatment is a method in which a polymer layer is exposed to a plasma to reform a polymer layer. For example, the plasma treatment can be carried out in accordance with the method described in JP-A-2012-106421.

The radiation irradiation treatment is a method of irradiating a polymer layer with radiation to modify a polymer layer. The radiation is preferably a short wavelength having a high effect of changing the bond structure of the polymer layer, and it is preferable to use ultraviolet rays, particularly vacuum ultraviolet light. For example, the vacuum ultraviolet light modification treatment can be carried out in accordance with the method described in JP-A-2013-226757.

Among these, since the surface of the polymer layer is not roughened and can be efficiently reformed to the inside thereof, and a gas barrier layer having excellent gas barrier properties can be formed, the ion implantation treatment is performed. Good

Examples of the ions to be injected into the polymer layer include ions of rare gases such as argon, helium, neon, krypton, and xenon; ions such as fluorocarbon, hydrogen, nitrogen, oxygen, carbon dioxide, chlorine, fluorine, and sulfur; methane and B; An ion such as an alkane-based gas; an ion of an olefinic gas such as ethylene or propylene; an ion of an alkadiene-based gas such as pentadiene or butadiene; an ion of an acetylene-based gas such as acetylene; benzene or toluene; An ion of an aromatic hydrocarbon-based gas; an ion of a naphthenic gas such as cyclopropane; an ion of a cycloolefin-based gas such as cyclopentene; an ion of a metal; an ion of an organic ruthenium compound.

These plasmas can be used alone or in combination of two or more.

Among these, since it is possible to easily obtain an ion value and obtain a gas barrier layer having particularly excellent gas barrier properties, it is preferable to use ions of a rare gas such as argon, helium, neon, krypton or xenon.

The method of implanting ions is not particularly limited. For example, a method of irradiating ions (ion beams) accelerated by an electric field, a method of injecting ions in plasma (ions of plasma generating gas), and the like; and a gas barrier layer can be easily obtained. The latter method of implanting plasma ions is preferred. Plasma ion implantation, for example, is capable of performing ions (cations) in a plasma by generating a plasma in an environment containing a plasma generating gas and applying a negative high voltage pulse to a layer implanted with ions. ) is injected into the surface portion of the layer in which the ions are implanted.

The method for producing the sealing sheet ( β ) is not particularly limited. For example, by the previously described method of manufacturing a sealing sheet ([alpha]) will replace a release film serves as a gas barrier film manufactured sealing sheet (β).

Further, after the sealing sheet ( α ) is produced, one of the release films can be peeled off, and the exposed adhesive layer and the gas barrier film can be attached to each other to produce a sealing sheet ( β ). In this case, when the sealing sheet ( α ) is a two-part release film having a different peeling force, it is preferable to peel off the release film having the smaller peeling force from the viewpoint of workability.

As described above, the sealing sheet adhesive layer of the present invention has low exhaustibility. Therefore, when the organic EL element is sealed, deterioration thereof can be suppressed.

3) Sealing body

The sealing body of the present invention is obtained by sealing a sealed article using the sealing sheet of the present invention.

The sealing body of the present invention includes, for example, a transparent substrate, an element (sealed material) formed on the transparent substrate, and a sealing material for sealing the element. The sealing material may be a sealing sheet adhesive of the present invention. Floor.

The transparent substrate is not particularly limited, and various substrate materials can be used. It is particularly preferable to use a substrate material having a high transmittance of visible light. Further, it is preferable to prevent a material having high barrier property between moisture and gas to be immersed from the outside of the element and having excellent solvent resistance and weather resistance. Specific examples thereof include transparent inorganic materials such as quartz and glass; polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polystyrene, polyethylene, polypropylene, and polyphenylene sulfide. , polyvinylidene fluoride, cellulose acetate, phenoxy bromide, polyarylamine (ARAMID), polyimide, polystyrene, polyaryl ester, polyfluorene, polyolefin, etc. Transparent plastic, and the aforementioned gas barrier film.

The thickness of the transparent substrate is not particularly limited, and can be appropriately selected in consideration of the transmittance of light and the performance of isolating the inside and outside of the element.

Examples of the object to be sealed include an organic EL element, an organic EL display element, a liquid crystal display element, and a solar cell element.

The method for producing the sealed body of the present invention is not particularly limited. For example, after the sealing sheet adhesive layer of the present invention is superposed on the object to be sealed, the sealing sheet adhesive layer and the object to be sealed are adhered by heating.

Next, the sealing body of the present invention can be produced by curing the adhesive layer.

The adhesive condition when the sealing sheet adhesive layer is adhered to the sealed object is not particularly limited. The adhesion temperature is, for example, 23 to 100 ° C, preferably 40 to 80 ° C. This adhesive treatment can also be carried out while pressing.

As the curing conditions at the time of curing the adhesive layer, the conditions described above can be utilized.

The sealing system of the present invention is obtained by sealing a sealed article using the sealing sheet of the present invention.

Therefore, in the sealing body of the present invention, it is possible to maintain the performance of the sealed object for a long period of time.

[Examples]

Hereinafter, the present invention will be described in more detail by way of examples. However, the present invention is not limited at all by the following examples.

The parts and % in each case are the quality standards as long as they are not notified in advance. Moreover, the weight average molecular weight (Mw) of the modified polyolefin resin and the polyfunctional epoxy compound is a value measured by the following method.

<Weight Average Molecular Weight (Mw) of Modified Polyolefin-Based Resin>

The weight average molecular weight (Mw) of the modified polyolefin resin was measured and used under the following conditions using a gel permeation chromatography (GPC) apparatus (manufactured by TOSOH Co., Ltd., product name "HLC-8320"). Converted to the value of the weight average molecular weight of standard polystyrene

(measurement conditions)

‧Measurement sample: modified polyolefin resin with a concentration of 1% by mass of tetrahydrofuran solution

‧ Pipe column: Two "TSK gel Super HM-H" and one "TSK gel Super H2000" (all of which are manufactured by TOSOH Co., Ltd.) are connected in order.

‧column temperature: 40 ° C

‧Expanding solvent: tetrahydrofuran

‧Flow rate: 0.60mL/min

<Weight average molecular weight (Mw) of polyfunctional epoxy compound>

The weight average molecular weight (Mw) of the polyfunctional epoxy compound is measured by a gel permeation chromatography (GPC) apparatus (product name "HLC-8320", manufactured by TOSOH Co., Ltd.), and is measured under the following conditions and converted into plural numbers. Among the observed peaks, the corresponding area is the weight average molecular weight of the standard polystyrene of the peak hold time of the largest one.

(measurement conditions)

‧Measurement sample: a polyfunctional epoxy compound concentration of 1% by mass in tetrahydrofuran solution

‧Pipe: Two pieces of "TSK gel Super HM-H" and "TSK gel Super H2000" (one of which is manufactured by TOSOH Co., Ltd.)

‧column temperature: 40 ° C

‧Expanding solvent: tetrahydrofuran

‧Flow rate: 0.60mL/min

[Example 1]

100 parts of an acid-modified polyolefin resin ( α -olefin polymer, manufactured by Mitsui Chemicals Co., Ltd., trade name: UNISTOLEH-200, weight average molecular weight: 52,000), polyfunctional epoxy compound (1) (bisphenol A bicyclic ring) Oxypropyl propyl ether, manufactured by Mitsubishi Chemical Corporation, trade name: YL980, epoxy equivalent 180-190 g/eq, molecular weight: 2,400) 100 parts, adhesion-imparting agent (styrene-based monomer aliphatic monomer copolymer, softening point) 50 parts at 95 ° C, manufactured by Mitsui Chemicals Co., Ltd., trade name: FTR6100), and 1 part of imidazole-based hardening catalyst (manufactured by Shikoku Kasei Co., Ltd., trade name: CUREZOLE 2E4MZ, 2-ethyl-4-methylimidazole) Methyl ethyl ketone was used to prepare an adhesive composition 1 having a solid concentration of 30%.

The adhesive composition 1 was applied onto a release-treated surface of a release film (manufactured by LINTEC Co., Ltd., trade name: SP-PET382150), and the obtained coating film was dried at 100 ° C for 2 minutes to form an adhesive layer having a thickness of 12 μm. The release sheet of the other release film (manufactured by LINTEC Co., Ltd., trade name: SP-PET381031) was bonded thereto to obtain a sealing sheet 1.

[Embodiment 2]

In Example 1, except that a polyfunctional epoxy compound (2) (hydrogenated bisphenol A diglycidyl ether, manufactured by Mitsubishi Chemical Corporation, trade name: YX8000, epoxy equivalent: 205 g/eq, weight average molecular weight: 1,400) was used. The sealing sheet 2 was obtained in the same manner as in Example 1 except for the polyfunctional epoxy compound.

[Example 3]

In Example 1, except that a polyfunctional epoxy compound (3) (hydrogenated bisphenol A diglycidyl ether, manufactured by Mitsubishi Chemical Corporation, trade name: YX8034, epoxy equivalent: 270 g/eq, weight average molecular weight: 3,200) was used. The sealing sheet 3 was obtained in the same manner as in Example 1 except for the polyfunctional epoxy compound.

[Example 4]

In Example 1, except that a polyfunctional epoxy compound (4) (hydrogenated bisphenol A diglycidyl ether, manufactured by Mitsubishi Chemical Corporation, trade name: YX8040, epoxy equivalent of 1100 g/eq, weight average molecular weight of 4,200) was used as The sealing sheet 4 was obtained in the same manner as in Example 1 except for the functional epoxy compound.

[Comparative Example 1]

In Example 1, except that a polyfunctional epoxy compound (5) (hydrogenated bisphenol A diglycidyl ether, manufactured by Kyoeisha Chemical Co., Ltd., trade name: Epolite 4000, epoxy equivalent: 215 to 245 g/eq, weight average molecular weight) was used. In the same manner as in Example 1, except that the polyfunctional epoxy compound was used, the sealing sheet 5 was obtained.

[Comparative Example 2]

In Example 1, except that a polyfunctional epoxy compound (6) (hydrogenated bisphenol A diglycidyl ether, ADEKA company, trade name: ADEKARESIN, EP-4080E, epoxy equivalent 215 g/eq, molecular weight: 800) was used. The sealing sheet 6 was obtained in the same manner as in Example 1 except that the polyfunctional epoxy compound was used.

The following tests were carried out on the sealing sheets 1 to 6 obtained in Examples 1 to 4 and Comparative Examples 1 and 2.

[Low exhaustivity evaluation test]

One piece of the release film of the sealing sheet obtained in the example or the comparative example was peeled off, and the sealing sheet was placed on the glass plate so that the exposed adhesive layer faced the glass plate, and the heat bonding machine was used at 60. Adhesion at °C.

Next, the remaining material obtained by peeling off the peeling film was used as a measurement sample, and exhaust gas was generated at 120 ° C for 20 minutes, and the amount of production was quantified.

The amount of exhaust gas generated is determined by using a gas chromatograph mass spectrometer (manufactured by Shimadzu Corporation, GCMS-QP2010) and using a column of 5%-diphenyl-95% dimethylpolyoxane (HP- 5ms). At this time, a calibration curve was prepared using toluene.

[Evaluation test of organic EL elements]

An organic EL device was produced by the following method using a glass substrate on which an indium tin oxide (ITO) film (thickness: 100 nm, sheet resistance: 50 Ω/□) was formed as an anode.

N,N'-bis(naphthalen-1-yl)-N,N'-bis(phenyl)-benzidine (manufactured by Luminescence Technology Co., Ltd.) was vapor-deposited on the above glass substrate at a rate of 0.1 to 0.2 nm/min. On the ITO film, a hole transport layer having a thickness of 50 nm was formed, and second, aluminum tris(8-hydroxy-quinolinate) (manufactured by Luminescence Technology Co., Ltd.) was vapor-deposited at a speed of 0.1 to 0.2 nm/min. On the transport layer, a light-emitting layer having a thickness of 50 nm was formed. Lithium fluoride (LiF) (manufactured by High Purity Chemical Research Co., Ltd.) was deposited on the light-emitting layer at a rate of 0.1 nm/min to form an electron injecting layer having a thickness of 4 nm, and secondly, aluminum (Al) (high purity) The chemical research institute company was deposited on the electron injecting layer at a rate of 0.1 nm/min to form a cathode having a thickness of 100 nm to obtain an organic EL device. Further, the degree of vacuum at the time of vapor deposition was all 1 × 10 ^-4 Pa or less.

Each of the release films of the sealing sheets 1 to 6 obtained in the examples and the comparative examples was peeled off, and the exposed adhesive layer was superposed on the metal foil film, and the adhesive layer was adhered at 40 ° C using a heat bonding machine. . Next, another peeling film was peeled off, and the exposed adhesive layer was superimposed so as to cover the organic EL element formed on the glass substrate, and the adhesive layer was adhered at 40 ° C using a heat bonding machine. Next, the adhesive layer was heated at 100 ° C for 2 hours to obtain an electronic device in which bottom emission of the organic EL element was sealed.

After the electronic device was allowed to stand in an environment of 85 ° C and a relative humidity of 85% for 240 hours, the organic EL device was started and the area of the dark spot (non-light-emitting portion) was measured.

The expansion ratio of the dark spot area of the electronic device before being placed in an environment of 85° C. and a relative humidity of 85% was calculated and evaluated based on the following criteria.

<benchmark>

○: The expansion rate of dark spots is less than 150%

╳: The expansion rate of dark spots is 150% or more

The evaluation results are shown in the first table.

The following situation is known from the first table.

The sealing sheets of Examples 1 to 4 have low exhaust properties, and are excellent in evaluation tests for organic EL elements.

On the other hand, in the sealing sheets of Comparative Examples 1 and 2, a large amount of exhaust gas was generated, and the evaluation test of the organic EL element was inferior.

Claims (15)

An adhesive composition comprising the following (A) component and (B) component, wherein when the exhaust gas amount is measured at 120 ° C for 20 minutes for the solid content thereof The solid content per unit volume of 1 cm ³ is 20 mg or less, (A) component: modified polyolefin resin, and component (B): polyfunctional epoxy compound.  The adhesive composition according to claim 1, wherein the component (A) is an acid-modified polyolefin resin.    The adhesive composition according to claim 1, wherein the content of the component (B) is from 25 to 200 parts by mass based on 100 parts by mass of the component (A).    The adhesive composition according to claim 1, further comprising the following component (C): component (C): an adhesion-imparting agent having a softening point of 80 ° C or higher.    The adhesive composition according to claim 4, wherein the content of the component (C) is from 1 to 200 parts by mass based on 100 parts by mass of the component (A).    The adhesive composition according to claim 1, further comprising the following component (D): component (D): an imidazole-based curing catalyst.    The adhesive composition according to claim 6, wherein the content of the component (D) is 0.1 to 10 parts by mass based on 100 parts by mass of the component (A).    The adhesive composition according to claim 1, further comprising the following component (E): component (E): a decane coupling agent.    The adhesive composition according to claim 8, wherein the content of the component (E) is 0.01 to 10 parts by mass based on 100 parts by mass of the component (A).    A sealing sheet comprising two release films and a pressure-sensitive adhesive layer held by the release film, wherein the adhesive layer is used according to any one of claims 1 to 9. It is formed by an adhesive composition.    A sealing sheet comprising a release film, a gas barrier film, and an adhesive layer sandwiched between the release film and the gas barrier film, wherein the adhesive layer is used as in Patent Application No. 1 to The adhesive composition according to any one of the items 9, wherein the adhesive composition is formed.    The sealing sheet according to claim 11, wherein the gas barrier film is a metal foil, a resin film, or a film glass.    The sealing sheet according to claim 10 or 11, wherein the thickness of the adhesive layer is 5 to 25 μm.    A sealing body which is sealed by a sealing member as described in any one of claims 10 to 13.    The sealing body according to claim 14, wherein the sealed object is an organic EL element, an organic EL display element, a liquid crystal display element, or a solar cell element.