TW201823404A - 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 a storage elastic modulus of 0.1-600 MPa at 23 DEG C and a storage elastic modulus of no more than 0.1 MPa at 80 DEG C, when the storage elastic modulus is measured for the solid content of the adhesive composition. 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 excellent conformability to unevenness; a sealing sheet formed using this adhesive composition and having an adhesive layer having excellent conformability to unevenness; 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 can be easily formed into a thin sheet and has excellent unevenness followability, a sealing sheet having an adhesive layer having excellent unevenness followability formed by using the adhesive composition, and the aforementioned seal The sheet is a sealing body formed by sealing the object to be sealed.

In recent years, organic EL elements have attracted attention as those capable of emitting light with high luminance by low-voltage DC driving.

However, the organic EL element has a problem that light emission characteristics such as light emission brightness, light emission efficiency, light emission uniformity, and the like are easily deteriorated as time passes.

It is considered that the problem that the light emitting characteristics are deteriorated is that oxygen, moisture, and the like penetrate into the inside of the organic EL element and cause deterioration of the electrode and the organic layer. Therefore, conventionally, an organic EL element is sealed using a sealing material to prevent the intrusion of oxygen and moisture.

Moreover, when sealing an organic EL element using a sealing material, it is necessary to fill the minute gaps and irregularities of the organic EL element. Therefore, a sealing material having a low viscosity has been developed previously.

For example, Patent Document 1 describes a composition which is a resin composition containing a specific epoxy resin, a specific epoxy resin hardener, a specific epoxy resin hardener, and a specific amount of a filler, and is measured using an E-type viscometer. Its viscosity at 25 ℃ and 2.5rpm is 0.5 ~ 50Pa‧s.

Patent Document 1 also describes that by using a liquid epoxy resin and a liquid epoxy hardener and adjusting the content of the filler, a resin composition that can provide a cured product with low viscosity and high moisture resistance can be obtained.

[Prior technical literature]

[Patent Literature]

[Patent Document 1] WO 2012/014499

Since the composition described in Patent Document 1 has a low viscosity, it has excellent unevenness followability. However, since the composition is fluid before the curing reaction is performed, a special coating device such as a dispenser must be used when the organic EL element is used with the composition.

Therefore, there is a need for a sealing sheet having an adhesive composition that is easily formed into a sheet shape and has excellent unevenness followability, and an adhesive layer having excellent unevenness followability.

The present invention has been made in view of the above-mentioned circumstances, and an object thereof is to provide an adhesive composition that is easily formed into a sheet shape and has excellent unevenness followability, and an adhesive having excellent unevenness followability formed using the adhesive composition Layer sealing sheet, and a sealing body obtained by sealing the object to be sealed using the sealing sheet.

In order to solve the above problems, the present inventors and others have conducted intensive research and found that an adhesive composition containing a modified polyolefin-based resin and a polyfunctional epoxy compound is stored at 23 ° C. when the storage elastic modulus is measured for its solid content The adhesive composition having an elastic modulus of 0.1 to 600 MPa and a storage elastic modulus of 0.1 MPa or less at 80 ° C is easy to form a sheet and has excellent unevenness followability, and completed the present invention.

Thus, according to the present invention, the following adhesive compositions (1) to (9) are provided, the sealing sheets (10) to (13), and the sealing bodies (14) and (15).

(1) An adhesive composition, which is an adhesive composition containing the following components (A) and (B), characterized in that when the storage elastic modulus of the solid component is measured, it is at 23 ° C. The storage elastic modulus is 0.1 to 600 MPa, and the storage elastic modulus at 80 ° C is 0.1 MPa or less. (A) component: modified polyolefin resin, (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 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): (C) component: 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 1 to 200 parts by mass based on 100 parts by mass of the component (A).

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

(7) The adhesive composition according to (6), wherein the content of the component (D) is 1 to 10 parts by mass based on 100 parts by mass of the component (A).

(8) The adhesive composition according to (1), further comprising the following component (E): (E) component: a silane 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 is a sealing sheet composed of two peeling films and an adhesive layer held by the peeling films, and the aforementioned adhesive layer uses any one of items (1) to (9) The adhesive composition is formed.

(11) A sealing sheet is a sealing sheet composed of a release film, a gas barrier film, and an adhesive layer held between the release film and the gas barrier film, and the adhesive layer is used as described in (1) It is formed by the adhesive composition as described in any one of (9).

(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 the object to be sealed using the sealing sheet according to (10) or (11).

(15) The sealed 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 that can be easily formed into a thin sheet and has excellent unevenness followability, a sealing sheet having an adhesive layer with excellent unevenness followability formed using the adhesive composition, and the use of the aforementioned. A sealing body in which a sealing sheet seals an object to be sealed.

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

1) Adhesive composition

The adhesive composition of the present invention is an adhesive composition containing the component (A) and the component (B), and is characterized in that when the storage elastic modulus is measured with respect to its solid content, the storage elastic modulus is 23 ° C. It is 0.1 to 600 MPa, and the storage elastic modulus at 80 ° C is 0.1 MPa or less. (A) component: a modified polyolefin resin, and (B) component: a polyfunctional epoxy compound.

(A) Component: Modified polyolefin resin

The adhesive composition of this invention contains a modified polyolefin resin as (A) component.

The adhesive composition of the present invention has excellent adhesive strength by containing a modified polyolefin resin. Furthermore, by using an adhesive composition containing a modified polyolefin resin, a thin adhesive layer can be formed efficiently.

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 a copolymer composed of two or more repeating units derived from an olefin-based monomer. A copolymer composed of a repeating unit derived from an olefin-based monomer and a repeating unit derived from another monomer (a monomer other than the olefin-based monomer) that can be copolymerized with the olefin-based 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 that can be copolymerized with the olefin-based monomer include vinyl acetate, (meth) acrylate, and styrene. Here, (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 polyethylene. Propylene (PP), ethylene-propylene copolymer, olefin-based elastomer (TPO), ethylene-vinyl acetate copolymer (EVA), ethylene- (meth) acrylic copolymer, ethylene- (meth) acrylate copolymer Etc., but not limited by them.

The modified polyolefin resin is obtained by modifying the polyolefin resin as a precursor by 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 that can contribute to a crosslinking reaction described later.

Examples of the functional group include a carboxyl group, a carboxylic acid anhydride group, a carboxylic acid ester group, a hydroxyl group, an epoxy group, a fluorenylamino group, an ammonium group, a nitrile group, an amine group, a fluorenimine group, an isocyanate group, an acetamyl group, and a sulfur group. Alcohol group, ether group, thioether group, sulfonic acid group, phosphate group, nitro group, urethane group, halogen atom and the like. Among them, a carboxyl group, a carboxylic acid anhydride group, a carboxylic acid ester group, a hydroxy group, an ammonium group, an amine group, a fluorenimine group, and an isocyanate group are preferable, and a carboxylic acid anhydride group and an alkoxysilyl group are more preferable. Carboxylic acid anhydride groups are particularly preferred.

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

Examples of the modified polyolefin-based resin include an acid-modified polyolefin-based resin and a silane-modified polyolefin-based resin. In particular, from the viewpoint that a more excellent effect can be obtained by the present invention, an acid-modified polyolefin resin is preferred.

The term "acid-modified polyolefin resin" refers to a polymer obtained by graft-modifying a polyolefin resin with an acid. Examples thereof include those obtained by reacting a polyolefin resin with an unsaturated carboxylic acid and introducing a carboxyl group (graft modification). In the present specification, the term "unsaturated carboxylic acid" refers to a concept including a carboxylic anhydride, and the term "carboxy group" refers to a concept including a carboxylic anhydride group.

Examples of unsaturated carboxylic acids that react with polyolefin resins include maleic acid, fumaric acid, itaconic acid, citraconic acid, glutaric acid, tetrahydrophthalic acid, aconitic acid, Maleic anhydride, itaconic anhydride, glutaric anhydride, citraconic anhydride, aconitic anhydride, norbornene dicarboxylic anhydride, tetrahydrophthalic anhydride, and the like.

These can be used individually by 1 type or in combination of 2 or more types.

Among these, maleic anhydride is preferred because an adhesive composition having excellent adhesive strength can be obtained.

The amount of the unsaturated carboxylic acid that reacts the polyolefin resin with respect to 100 parts by mass of the polyolefin resin is preferably 0.1 to 5 parts by mass, more preferably 0.2 to 3 parts by mass, and still more preferably 0.2 to 1.0 part by mass. The adhesive composition containing the acid-modified polyolefin resin obtained in this way has excellent adhesive strength.

In the present invention, a commercially available product can also be used as the acid-modified polyolefin resin. Examples of commercially available products include ADMER (registered trademark) (manufactured by Mitsui Chemicals), UNISOLE (registered trademark) (manufactured by Mitsui Chemicals), BondyRam (manufactured by Polyram), ororevac (registered trademark) (manufactured by ARKEMA) , Modic (registered trademark) (manufactured by Mitsubishi Chemical Corporation), etc.

The silane-modified polyolefin resin refers to a polymer obtained by graft-modifying a polyolefin resin with an unsaturated silane compound. The silane-modified polyolefin resin has a structure obtained by graft-copolymerizing a polyolefin resin of a main chain with an unsaturated silane compound. The silane-modified polyolefin resin is not particularly limited. Examples thereof include a silane-modified polyethylene resin and a silane-modified ethylene-vinyl acetate copolymer. Particularly, silane-modified polyethylene resins such as silane-modified low-density polyethylene, silane-modified ultra-low-density polyethylene, and silane-modified linear low-density polyethylene are preferred.

As the unsaturated silane compound for reacting the polyolefin resin, a vinyl silane compound is preferred. Examples of the vinylsilane compound include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripropoxysilane, vinyltriisopropoxysilane, vinyltributoxysilane, and ethylene. Tripentyloxysilane, vinyltriphenoxysilane, vinyltribenzyloxysilane, vinyltrimethylenedioxysilane, vinyltriethylenedioxysilane, vinylpropyloxy Silane, vinyltriethoxysilane, vinyltricarboxysilane, etc. These can be used individually by 1 type or in combination of 2 or more types.

The conditions for attaching an unsaturated silane compound to a polyolefin resin in the main chain may be a method commonly used in conventional graft polymerization.

The amount of the unsaturated silane compound that reacts the polyolefin resin is preferably 0.1 to 10 parts by mass, more preferably 0.3 to 7 parts by mass, and further 0.5 to 5 parts by mass relative to 100 parts by mass of the polyolefin resin. good. When the amount of the unsaturated silane compound that reacts the polyolefin resin is within the above range, the obtained silane-modified polyolefin resin-containing adhesive composition has a relatively excellent adhesive strength.

In the present invention, a commercially available product can be used as the silane-modified polyolefin-based resin. Examples of commercially available products include LINKLON (registered trademark) (manufactured by Mitsubishi Chemical Corporation) and the like. In particular, low-density polyethylene-based LINKLON, linear low-density polyethylene-based LINKLON, and ultra-low density polymer Ethylene-based LINKLON and ethylene-vinyl acetate copolymer-based LINKLON.

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-based resin is not particularly limited, and from the viewpoint that the present invention can obtain a superior effect, it is preferably 10,000 to 2,000,000, and more preferably 20,000 to 1,500,000.

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

The content of the modified polyolefin-based resin is not particularly limited. From the viewpoint that the present invention can obtain a relatively excellent effect, the total amount of the modified polyolefin-based resin and the following (B) component is a combination of adhesives. The solid content of the product is used as a reference, preferably 30% by mass or more, and more preferably 50% by mass or more.

(B) Ingredient: Multifunctional epoxy compound

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

Since the adhesive composition of the present invention contains a polyfunctional epoxy compound, the storage elastic modulus before curing is lower. Moreover, the hardened | cured material system of the adhesive composition containing a polyfunctional epoxy compound has the outstanding water vapor barrier property.

The so-called polyfunctional epoxy compound refers to 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. Diglycidyl ether, brominated bisphenol F diglycidyl ether, brominated bisphenol S diglycidyl ether, novolac epoxy resin (e.g. phenol, novolac epoxy resin, cresol ‧Novolac epoxy resin, brominated phenol‧Novolac epoxy resin), hydrogenated bisphenol A diglycidyl ether, hydrogenated bisphenol F diglycidyl ether, hydrogenated bisphenol S diglycidyl Ether, neopentaerythritol polyglycidyl ether, 1,6-hexanediol diglycidyl ether, hexahydrophthalic acid diglycidyl ester, neopentyl glycol diglycidyl ether , Trimethylolpropane polyglycidyl ether, 2,2-bis (3-glycidyl-4-glycidoxypropyl) propane, dimethylol tricyclodecane dipropylene oxide Ether.

These polyfunctional epoxy compounds can be used individually by 1 type or in combination of 2 or more types.

The adhesive composition of the present invention preferably contains a polyfunctional epoxy compound (B1) which is a liquid at 25 ° C as a component (B). (B) The component has an effect of reducing the storage elastic modulus of the adhesive composition when the adhesive composition is heated to a high temperature (hereinafter, it may be referred to as a "storage elastic modulus reduction effect"). By using the adhesive composition of the present invention, an adhesive layer having excellent unevenness followability can be efficiently formed.

The lower limit of the weight average molecular weight of the polyfunctional epoxy compound (B1) which is liquid at 25 ° C is preferably 500, more preferably 700. The upper limit of the molecular weight of the polyfunctional epoxy compound is preferably 3,700, more preferably 3,400. By using the pressure-sensitive adhesive composition having a weight-average molecular weight of 700 or more of the polyfunctional epoxy compound (B1), it is possible to form a sealing material having a low outgassing property. An adhesive composition having a weight-average molecular weight of 3,700 or less for a polyfunctional epoxidized compound has excellent fluidity and can sufficiently fill unevenness caused by unevenness on the surface of the sealed object and the thickness of the sealed object.

The epoxy equivalent of the polyfunctional epoxy compound (B1) which is liquid at 25 ° C 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 (B1), it is possible to form a sealing material having a low outgassing property.

The adhesive composition of the present invention may further contain, as a component (B), a polyfunctional epoxy compound (B2) which is solid at 25 ° C.

The polyfunctional epoxy compound of the component (B2) is different from the polyfunctional epoxy compound of the component (B1), and it is considered that there is almost no effect of reducing the storage elastic modulus. On the other hand, when the adhesive composition contains the component (B2), the performance of the adhesive layer to maintain the sheet shape is improved.

As a result of this tendency, when the (B2) component is used in combination with the (B1) component, the storage elastic modulus reduction effect possessed by the (B1) component can be further improved. The presence of the component (B2) can increase the content of the component (B) in the adhesive composition while maintaining the performance of the sheet shape of the adhesive layer. Therefore, in the adhesive composition, the phase separation structure formed by the component (A) and the component (B) increases the proportion of the continuous phase region of the component (B). When the adhesive layer formed from such an adhesive composition is heated, the region of the continuous phase of the component (B) is softened, so that a high storage elastic modulus reduction effect can be exhibited.

Therefore, the adhesive composition of the present invention preferably contains the component (B2), and more preferably contains both the component (B1) and the component (B2).

The lower limit of the weight average molecular weight of the polyfunctional epoxy compound (B2) which is solid at 25 ° C is preferably 3,800, more preferably 4,000. The upper limit of the molecular weight of the polyfunctional epoxy compound (B2) is preferably 8,000, and more preferably 7,000. By using an adhesive composition having a weight-average molecular weight of 3,800 or more of the polyfunctional epoxy compound (B2), it is easier for the adhesive layer system to maintain the sheet shape.

The epoxy equivalent of the polyfunctional epoxy compound (B2) which is solid at 25 ° C is preferably 600 g / eq or more and 6,000 g / eq or less, more preferably 700 g / eq or more and 5,500 g / eq or less. By using an adhesive composition having an epoxy equivalent of 600 g / eq or more and 6,000 g / eq or less of the polyfunctional epoxy compound (B2), it is easier for the adhesive layer system to maintain the sheet shape.

The content of the (B) component, that is, the polyfunctional epoxy compound in the adhesive composition of the present invention is preferably 25 to 200 parts by mass, and more preferably 50 to 200 parts by mass relative to 100 parts by mass of the aforementioned (A) component. 150 parts by mass. The hardened | cured material of the adhesive composition whose content of a polyfunctional epoxy compound exists in this range has more excellent water-vapor-barrier property.

When the adhesive composition of the present invention contains both (B1) component and (B2) component, the content ratio (mass ratio) of (B1) component and (B2) component is based on [(B1) component: (B2) component )] = 100: 1 ~ 1: 1 is better, 10: 1 ~ 2: 1 is better.

When the amount of the component (B2) to the component (B1) increases, there is a tendency that when the adhesive composition is formed into a sheet shape, a certain shape is easily maintained.

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

As components other than (A) component and (B) component, the following (C) component, (D) component, and (E) component are mentioned, and (C) component: the adhesion imparting agent whose softening point is 80 degreeC or more (D) component: imidazole-based hardening catalyst, (E) component: silane coupling agent.

(C) component: Adhesion imparting agent with a softening point of 80 ° C or higher

As described above, the adhesive composition containing the component (A) and the component (B) has a low storage elastic modulus of the cured surface and has excellent unevenness followability. However, such an adhesive composition system is difficult to maintain a certain shape and may be difficult to form into a sheet shape. In this case, the moldability can be improved by containing the (C) component.

Examples of the adhesion-imparting agent include rosin-based resins such as polymerized rosin, polymerized rosin esters, and rosin derivatives; polyterpene resins, aromatic-modified terpene resins and their hydrides, and terpene-based resins such as terpene phenol resin Resin; Coumarone · Indene resin; Petroleum resins such as aliphatic petroleum resins, aromatic petroleum resins and their hydrides, aliphatic / aromatic copolymer petroleum resins; styrene or low molecular weight polymers substituted for 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 methylstyrene / aliphatic monomer copolymerization resin, a styrene monomer homopolymerization resin, a styrene monomer / aromatic monomer copolymerization resin, and the like. Among these, a styrene-based resin is preferable, and a styrene-based monomer / aliphatic monomer copolymerization-based resin is more preferable.

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 higher. When the softening point of the adhesion-imparting agent is 80 ° C. or higher, an adhesive composition having excellent adhesion at high temperatures can be obtained. In addition, workability is improved when the adhesive composition is formed into a sheet shape.

When the adhesive composition of the present invention contains an adhesion-imparting agent having a softening point of (C) component of 80 ° C. or higher, the content thereof is 1 to 200 parts by mass based on 100 parts by mass of the component (A), and more preferably 10 ~ 150 parts by mass. When the adhesion-imparting agent having a softening point of 80 ° C. or higher is too small, it may become difficult to form the adhesive composition into a sheet shape. 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 hardening catalyst

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

Examples of the imidazole-based hardening catalyst include 2-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-ethyl-4-methylimidazole, 2-benzene Methyl-4-methylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5-dimethylolimidazole, and the like. Among these, 2-ethyl-4-methylimidazole is preferable.

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

When the adhesive composition of the present invention contains an imidazole-based hardening catalyst, its content is preferably 0.1 to 10 parts by mass, and more preferably 0.2 to 5 parts by mass, relative to 100 parts by mass of the component (A). The content of the imidazole-based hardening catalyst is a hardened product of the adhesive composition within this range, and it has excellent adhesion even at high temperatures.

(E) Ingredient: Silane coupling agent

Silane coupling agents are organic silicon compounds that have both a functional group reactively bonded to an organic material and a functional group (hydrolyzable group) reactively bonded to an inorganic material in the molecule.

As the silane coupling agent, a conventional silane coupling agent can be used, and an organic silicon compound having at least one alkoxysilyl group in the molecule is particularly preferable.

Examples of the silane coupling agent include a polymerizable unsaturated group-containing silicon compound such as vinyltrimethoxysilane, vinyltriethoxysilane, and methylpropoxypropyltrimethoxysilane; 3-epoxy Silicon compounds with epoxy structure, such as propoxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane; 3-aminopropyltrimethoxysilane, N- ( Amine-containing silicon compounds such as 2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane; 3-chloro Propyltrimethoxysilane; 3-isocyanatepropyltriethoxysilane and the like.

These silane coupling agents can be used individually by 1 type or in combination of 2 or more types.

By using the adhesive composition containing a silane coupling agent, it is easy to obtain a hardened | cured material which has more excellent adhesive strength in normal temperature (15 degreeC-30 degreeC) and high temperature (40 degreeC-100 degreeC) environment.

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

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

Examples of the solvent include aromatic hydrocarbon solvents such as benzene and toluene; ester solvents such as ethyl acetate and butyl acetate; ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; Aliphatic hydrocarbon solvents such as n-pentane, n-hexane, and n-heptane; cyclic hydrocarbon solvents such as cyclopentane, cyclohexane, methylcyclohexane, and the like.

These solvents can be used individually by 1 type or in combination of 2 or more types.

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

The adhesive composition of this invention is a range which does not inhibit the effect of this invention, and may contain other components.

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

These can be used individually by 1 type or in combination of 2 or more types.

When the adhesive composition of the present invention contains such additives, its content can be appropriately determined depending on the purpose.

The adhesive composition of the present invention can be prepared by appropriately mixing and stirring predetermined components according to a commonly used method.

When measuring the storage elastic modulus of the adhesive composition of the present invention, the storage elastic modulus at 23 ° C is 0.1 to 600 MPa, preferably 0.2 to 500 MPa, and more preferably 0.2 to 100 MPa.

An adhesive composition having a storage elastic modulus of 0.1 MPa or less at 23 ° C is difficult to form into a sheet shape. On the other hand, an adhesive layer formed by using an adhesive composition having a storage elastic modulus of more than 600 MPa at 23 ° C tends to become brittle and has poor sealing properties.

In this specification, a solid content means the solid part after removing the volatile component, such as a solvent, from an adhesive composition.

When the storage elastic modulus of the adhesive composition of the present invention is measured for its solid content, the upper limit of the storage elastic modulus at 80 ° C is 0.1 MPa, preferably 0.05 MPa. The adhesive composition system having a storage elastic modulus at 80 ° C of 0.1 MPa or less has excellent unevenness followability.

The lower limit of the storage elastic modulus at 80 ° C is preferably 1 kPa, and more preferably 5 kPa. The adhesive composition having a storage elastic modulus of 1 kPa or higher at 80 ° C has superior operability.

The storage elastic modulus of the solid content of the adhesive composition of the present invention is, for example, a sheet-like adhesive obtained by applying and drying the adhesive composition of the present invention as a test piece, as described in Examples. Method.

The adhesive composition having the above-mentioned characteristics can be obtained efficiently by optimizing the amount of the (B) component and the amount of the (C) component used as necessary.

Specifically, by adding the component (B), the storage elastic modulus tends to decrease at 23 ° C and 80 ° C. On the other hand, when the component (B) is added in excess, it becomes difficult to form a sheet-like system. At this time, when an appropriate amount of the component (C) is added, the moldability is improved and the storage elastic modulus at 80 ° C can be reduced.

The adhesive composition of the present invention is easily formed into a thin sheet and has excellent unevenness followability. Therefore, the adhesive composition of the present invention can be suitably used when forming a sealing material.

2) sealing sheet

The sealing sheet of the present invention is the following sealing sheet ( α ) or sealing sheet (β), and the sealing sheet ( α ): a sealing sheet composed of two release films and an adhesive layer held by the release films It is characterized in that the adhesive layer is formed by using the adhesive composition of the present invention, and the sealing sheet (β): is made of a release film, a gas barrier film, and is formed by the release film and the gas barrier property. The sealing sheet composed of an adhesive layer held by a film is characterized in that the aforementioned adhesive layer is formed by using the adhesive composition composition of the present invention.

In addition, these sealing sheets are a state before use, and when using the sealing sheet of this invention, a peeling film is usually peeled and removed.

[Sealing sheet ( α )]

During the release film sealing sheet ([alpha]), the Department of the sealing sheet ([alpha]) production step function as a support of the same time, a sealing sheet ([alpha]) in until the Department as adhesive layer function protection sheet of .

As the release film, a conventionally known thing can be used. For example, it is a thing which has a peeling layer which performed the peeling process using a peeling agent on the base material for peeling films.

Examples of the base material for a release film include paper base materials such as cellophane, coated paper, and fine paper; bonding papers obtained by bonding a thermoplastic resin such as polyethylene to these paper base materials; Plastic films such as polyethylene terephthalate resin, polybutylene terephthalate resin, polyethylene naphthalate resin, polypropylene resin, polyethylene resin, etc.

Examples of the release agent include silicone-based resins, olefin-based resins, isoprene-based resins, butadiene-based resins, rubber-based elastomers, long-chain resins, alkyd resins, and fluorine-based resins. Wait.

The two peeling films of the sealing sheet ( α ) may be the same as or different from each other. It is preferable that the two peeling films have different peeling forces. By making the peeling force of the two peeling films different, the step of peeling the peeling film can be performed more efficiently at first.

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

As described above, although the adhesive layer is very thin, since the adhesive layer is formed using the adhesive composition of the present invention, it has excellent unevenness followability and can sufficiently fill the unevenness of the adherend.

The adhesive layer of the sealing sheet ( α ) is preferably one having thermosetting properties. The thermosetting adhesive layer has very good adhesive strength after curing.

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

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 manufacturing method of the sealing sheet ( α ) is not particularly limited. For example, a sealing sheet ( α ) can be produced using a conventional casting method. More specifically, the adhesive composition of the present invention can be coated with the release-treated surface of a release film by using a known method, and the obtained coating film can be dried to produce an adhesive layer with a release film. Next, by The other peeling film was laminated | stacked on the adhesive layer, and the sealing sheet (( alpha )) was obtained.

Examples of the method for applying the adhesive composition include a spin coating method, a spray coating method, a bar coating method, a blade coating method, a roll coating method, a blade coating method, a die coating method, and a gravure plate. Coating method, etc.

The drying conditions when the coating film is dried are not particularly limited. For example, the drying temperature is 80 ~ 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) may be 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 has a water vapor transmission rate under an environment of a temperature of 40 ° C and a relative humidity of 90% (hereinafter, abbreviated as "90% RH"), preferably 0.1 g / m ² / day or less, and 0.05 g / m ² / day or less is preferable, and 0.005 g / m ² / day or less is more preferable.

The gas barrier film has a water vapor transmission rate of 0.1 g / m ² / day or less under an environment of a temperature of 40 ° C and 90% RH, which can effectively prevent oxygen, moisture, and the like from entering the organic EL formed on the transparent substrate. The inside of the element such as the element causes deterioration of the electrode and the organic layer.

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

Examples of the gas barrier film include metal foil, thin-film glass, and resin-made thin films. Among these, a resin film is preferred, and a gas barrier film having a substrate and a gas barrier layer is more preferred.

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

The composition and composition of the thin-film glass are not particularly limited, and alkali-free borosilicate glass is preferred in order to obtain relatively stable flexibility.

The thin-film glass may be formed by using the thin-film glass as a single body or by laminating or bonding a metal foil such as an aluminum foil and a resin film to the thin-film glass.

The thin film glass is preferably one having a thickness of about 10 to 200 μm and having flexibility.

Examples of the resin component of the base material constituting the gas barrier film include polyimide, polyimide, polyimide, polyphenylene ether, polyetherketone, polyetheretherketone, polyolefin, Polyester, polycarbonate, polyfluorene, polyetherfluorene, polyphenylene sulfide, polyarylate, acrylic resin, cycloolefin polymer, aromatic polymer, polyurethane polymer, etc. .

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

The gas barrier layer is not particularly limited as long as it can provide the required gas barrier properties. Examples of the gas barrier layer include layers obtained by modifying the inorganic film and a layer containing a polymer compound. Wait.

Among these, because the thickness is thin and a layer having excellent gas barrier properties can be formed efficiently, the gas barrier layer is a layer formed of a gas barrier layer composed of an inorganic film and a layer containing a polymer compound. A gas barrier layer obtained by performing a modification treatment is preferred.

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

Examples of the inorganic vapor-deposited film include vapor-deposited films of inorganic compounds and metals.

Examples of raw materials for the vapor deposition film of inorganic compounds include inorganic oxides such as silicon oxide, aluminum oxide, magnesium oxide, zinc oxide, indium oxide, and tin oxide; and inorganic nitrides such as silicon nitride, aluminum nitride, and titanium nitride. Inorganic carbides; inorganic sulfides; inorganic oxide nitrides such as silicon oxide nitride; inorganic oxide carbides; inorganic nitride carbides; inorganic oxide nitride carbides, etc.

Examples of the raw material of the metal deposited film include aluminum, magnesium, zinc, and tin.

Examples of the inorganic film formation method include a vacuum deposition method, an EB deposition method, and a sputtering method. Ion spraying, pasting, plasma vapor growth (CVD), etc.

The thickness of the inorganic film can be appropriately selected according to the type and configuration of the inorganic material. It is preferably 1 to 500 nm, and more preferably 2 to 300 nm.

For a gas barrier layer obtained by ion implantation of a layer containing a polymer compound (hereinafter referred to as a "polymer layer"), as the polymer compound used, polyorganosiloxane And silicon containing polysilazane-based compounds, including polymer compounds, polyimide, polyamidide, polyimide, polyphenylene ether, polyetherketone, polyetheretherketone, polyolefin, polyester , Polycarbonate, polyfluorene, polyetherfluorene, polyphenylene sulfide, polyaromatic esters, acrylic resins, cycloolefin polymers, aromatic polymers, 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, a silicon-containing polymer compound is preferred, and a polysilazane-based compound is preferred.

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

The compound represented by the repeating unit is preferred. The number average molecular weight of the polysilazane-based compound used is not particularly limited, but is preferably 100 to 50,000.

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

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

The polymer layer system may contain other components in addition to the above-mentioned polymer compound, as long as the object of the present invention is not hindered. Examples of the other components include hardeners, other polymers, antioxidants, light stabilizers, and flame retardants.

Because a gas barrier layer having excellent gas barrier properties can be obtained, 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, but is preferably 50 to 300 nm, and more preferably 50 to 200 nm.

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

Examples of the method for forming a polymer layer include a solution for forming a layer containing at least one polymer compound, other components as needed, and a solvent, using a spin coater, a knife coater, or a gravure coating. Coating is performed by a known device such as a cloth spreader, and the resulting coating film is appropriately dried to form a method.

Examples of the modification treatment of the polymer layer include an ion implantation treatment, a plasma treatment, a radiation irradiation treatment, and a heat treatment. The treatment for changing the bond structure of the polymer layer is preferred. These processes can be performed individually by 1 type, and can also be performed by combining 2 or more types. The ion implantation process is a method of modifying a polymer layer in order to implant ions into a polymer layer as described later.

Plasma treatment is a method in which the polymer layer is modified by exposing the polymer layer to the plasma. For example, plasma processing can be performed according to the method described in Japanese Patent Application Laid-Open No. 2012-106421.

The radiation irradiation treatment is a method of irradiating a polymer layer with radiation to modify the polymer layer. The radiation is preferably a short wavelength that has a high effect of changing the bond structure of the polymer layer, and it is preferable to use ultraviolet light, particularly vacuum ultraviolet light. For example, vacuum ultraviolet light modification treatment can be performed in accordance with the method described in Japanese Patent Application Laid-Open No. 2013-226757.

Among these, because the surface of the polymer layer is not rough and can be efficiently modified to the inside thereof, and a gas barrier layer having excellent gas barrier properties can be formed, the ion implantation process is used as Good

Examples of the ions injected into the polymer layer include ions of rare gases such as argon, helium, neon, krypton, and xenon; ions of fluorocarbon, hydrogen, nitrogen, oxygen, carbon dioxide, chlorine, fluorine, and sulfur; methane, and ethyl Ions of alkane-based gases such as alkane; Ions of olefin-based gases such as ethylene and propylene; Ions of alkadiene-based gases such as pentadiene and butadiene; Ions of acetylene-based gases such as acetylene; Benzene, toluene, etc. Ions of aromatic hydrocarbon-based gases; Ions of cycloalkane-based gases such as cyclopropane; Ions of cycloolefin-based gases such as cyclopentene; Ions of metals; Ions of organic silicon compounds.

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

Among these, ions can be easily implanted and a gas barrier layer having particularly excellent gas barrier properties can be obtained, and ions of rare gases such as argon, helium, neon, krypton, and xenon are preferred.

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 implanting ions in a plasma (plasma-generated gas ions); etc .; because a gas barrier layer can be easily obtained The latter method of implanting plasma ions is better. Plasma ion implantation can be performed, for example, by generating a plasma in an environment containing a plasma-generating gas and applying a negative high-voltage pulse to a layer of implanted ions to ionize the ions in the plasma (cations ) Is implanted into the surface portion of the layer of implanted ions.

The method for producing the sealing sheet (β) is not particularly limited. For example, the sealing sheet (β) can be produced by replacing the one sheet of the release film with a gas barrier film by the method for manufacturing the sealing sheet ( α ) described above.

In addition, after the sealing sheet ( α ) is manufactured, one of the release films is peeled off and the exposed adhesive layer and the gas barrier film are attached to produce a sealing sheet (β). In this case, when the sealing sheet ( α ) is two peeling films having different peeling forces, it is preferable to peel the peeling film having the smaller peeling force from the viewpoint of operability.

As described above, the sealing sheet adhesive layer system of the present invention has excellent convexoconvex followability. Therefore, even if the adhesive layer is thin, it is possible to sufficiently fill the unevenness caused by the unevenness on the surface of the sealed object and the thickness of the sealed object. For example, when the unevenness caused by the unevenness on the surface of the sealed object and the thickness of the sealed object is 10 μm, even if the thickness of the adhesive layer is more than 1 time (more than 10 μm) and less than 2 times (20 μm or less), the sealing sheet of the present invention , Department can easily fill it.

3) Sealing body

The sealing body of the present invention is obtained by sealing an object to be sealed using the sealing sheet of the present invention.

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

The transparent substrate system 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. In addition, it is preferable to use a material that has high barrier properties against moisture and gas to be immersed from the outside of the device and has excellent solvent resistance and weather resistance. Specific examples include transparent inorganic materials such as quartz and glass; polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polystyrene, polyethylene, polypropylene, and polyphenylene sulfide , Polyvinylidene fluoride, cellulose acetate, brominated phenoxy, polyaramide (ARAMID), polyimide, polystyrene, polyaromatic 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 light transmittance and the ability to isolate the inside and the outside of the device.

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 manufacturing method of the sealing body of this invention is not specifically limited. For example, after the sealing sheet adhesive layer of the present invention is superimposed on an 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 manufactured by curing the adhesive layer.

There are no particular restrictions on the adhesion conditions when the sealing sheet adhesive layer is adhered to the object to be sealed. The adhesion temperature is, for example, 23 to 100 ° C, preferably 40 to 80 ° C. This adhesion treatment may be performed under pressure.

As the curing conditions when the adhesive layer is cured, the conditions described above can be used.

The sealing system of the present invention is obtained by sealing the object to be sealed using the sealing sheet of the present invention.

Therefore, in the sealing body of the present invention, the performance of the object to be sealed can be maintained for a long period of time.

[Example]

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

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

<Weight average molecular weight (Mw) of modified polyolefin resin>

The weight average molecular weight (Mw) of the modified polyolefin resin is measured and used under the following conditions using a gel permeation chromatography (GPC) device (manufactured by TOSOH Corporation, product name "HLC-8320"). The value converted into the weight average molecular weight of standard polystyrene.

(Measurement conditions)

‧Measurement sample: Tetrahydrofuran solution containing 1% by mass of modified polyolefin resin

‧Tube: Two TSK gel Super HM-H and one TSK gel Super H2000 (one of them are made by TOSOH Corporation) in order.

‧Column temperature: 40 ℃

‧Developing solvent: tetrahydrofuran

‧Flow rate: 0.60mL / min

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

The weight-average molecular weight (Mw) of the polyfunctional epoxy compound is measured using a gel permeation chromatography (GPC) device (manufactured by TOSOH Corporation, product name "HLC-8320") and converted to a plural number under the following conditions. Among the observed peaks, the weight average molecular weight of standard polystyrene corresponding to the retention time of the peak with the largest area.

(Measurement conditions)

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

‧Pillar string: Two "TSK gel Super HM-H" and one "TSK gel Super H2000" (either of them are made by TOSOH Corporation) are connected in sequence.

‧Column temperature: 40 ℃

‧Developing solvent: tetrahydrofuran

‧Flow rate: 0.60mL / min

[Example 1]

100 parts of an acid-modified polyolefin resin ( α -olefin polymer, manufactured by Mitsui Chemicals, trade name: UNISTOLEH-200, weight average molecular weight: 52,000), a polyfunctional epoxy compound (1) (hydrogenated bisphenol A Glycidyl ether, manufactured by Kyoeisha Chemical Co., Ltd., trade name: Epolite4000, liquid at 25 ° C, epoxy equivalent 215 to 245 g / eq, weight average molecular weight: 800, 100 parts, adhesion imparting agent (styrene-based monomer Body-aliphatic monomer copolymer, softening point 95 ° C, 50 parts by Mitsui Chemicals Co., Ltd., trade name: FTR6100), and imidazole-based hardening catalyst (manufactured by Shikoku Chemical Co., Ltd., trade name: CUREZOLE 2E4MZ, 2-ethyl 4-methylimidazole) was dissolved in methyl ethyl ketone to prepare an adhesive composition 1 having a solid content concentration of 30%.

This adhesive composition 1 was coated on a release-treated surface of a release film (manufactured by LINTEC, 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 sealing sheet 1 was obtained by bonding the peeled surface of another peeling film (manufactured by LINTEC Corporation, trade name: SP-PET381031) thereon.

[Example 2]

Example 1 except that a polyfunctional epoxy compound (2) (made by ADEKA Corporation, trade names: ADEKARESIN, EP-4080E, liquid at 25 ° C, epoxy equivalent 215 g / eq, weight average molecular weight: 800) was used as the polyfunctional A sealing sheet 2 was obtained in the same manner as in Example 1 except for the epoxy compound.

[Example 3]

In Example 1, a polyfunctional epoxy compound (3) (manufactured by Mitsubishi Chemical Corporation, trade name: YX8000, liquid at 25 ° C, epoxy equivalent 205 g / eq, weight average molecular weight: 1,400) was used as the polyfunctional epoxy compound. A sealing sheet 3 was obtained in the same manner as in Example 1 except for the compound.

[Example 4]

In Example 1, a polyfunctional epoxy compound (4) (manufactured by Mitsubishi Chemical Corporation, trade name: YX8034, liquid at 25 ° C, epoxy equivalent 270 g / eq, weight average molecular weight: 3,200) was used as the polyfunctional epoxy. A sealing sheet 4 was obtained in the same manner as in Example 1 except for the compound.

[Example 5]

A sealing sheet 5 was obtained in the same manner as in Example 1 except that the blending amount described in the first table was changed.

[Example 6]

100 parts of an acid-modified polyolefin resin ( α -olefin polymer, manufactured by Mitsui Chemicals, trade name: UNISOLEH-200, weight average molecular weight: 52,000), 100 parts of a polyfunctional epoxy compound (3), and a polyfunctional ring Oxygen compound (5) (hydrogenated bisphenol A epoxy resin, manufactured by Mitsubishi Chemical Corporation, trade name: YX8040, solid at 25 ° C, epoxy equivalent: 1100 g / eq, weight average molecular weight: 4,200), 25 parts, imidazole 1 part of hardening catalyst (manufactured by Shikoku Kasei Co., Ltd., trade name: CUREZOLE 2E4MZ, 2-ethyl-4-methylimidazole), and 0.1 part of a silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KBM4803) were dissolved in Methyl ethyl ketone to prepare an adhesive composition 2 having a solid content concentration of 25%.

This adhesive composition 2 was coated on a release-treated surface of a release film (manufactured by LINTEC, 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 sealing sheet 6 was obtained by bonding the peeled surface of another peeling film (manufactured by LINTEC, trade name: SP-PET381031) thereon.

[Comparative Example 1]

Only the modified polyolefin-based resin ( α -olefin polymer, manufactured by Mitsui Chemicals, trade name: UNISTOLEH-200, number average molecular weight: 47,000) was used to produce the sealing sheet 7.

[Comparative Example 2]

A sealing sheet 8 was obtained in the same manner as in Example 1 except that the blending amount described in the first table was changed.

The following tests were performed on the sealing sheets 1 to 8 obtained in Examples 1 to 6 and Comparative Examples 1 and 2.

[Determination of storage elastic modulus]

The sealing sheet adhesive layer obtained in the Example or the comparative example was superimposed, and it laminated | stacked by the heat bonding machine and heated at 60 degreeC, and obtained the thickness 1mm. Using this laminated body as a sample, the storage elastic modulus of the adhesive layer before curing was measured at a frequency of 1 Hz and a temperature range of 23 to 150 ° C. using a measuring device (Physica MCR301) made by Anton Paar. Table 1 shows the storage elastic modulus at 23 ° C and 80 ° C.

[Evaluation of Buriedness]

The sealing sheet adhesive layer obtained in the Example or the comparative example was superimposed on a polyethylene terephthalate film having a thickness of 25 μm to obtain a PET-attached adhesive layer.

On the other hand, a small piece (pseudo device) of polyethylene terephthalate having a thickness of 10 μm was left to stand on a glass substrate. With the dummy element on the glass substrate completely covered, the adhesive layer with PET was overlaid on the glass substrate and sealed at 80 ° C using a heat bonder. Secondly, in an environment of 80 ° C and 0.5 MPa, the application was performed. It was press-treated for 20 minutes and hardened under the conditions of 100 ° C and 2 hours.

This object was observed with an optical microscope, and it was investigated whether or not the unevenness was raised, and the unevenness embedding property was evaluated in accordance with the following criteria.

○: No floating.

╳: There is floating.

The evaluation results are shown in Table 1.

The following table is known from Table 1.

The sealing sheets of Examples 1 to 6 have excellent unevenness embedding properties.

On the other hand, the sealing sheets of Comparative Examples 1 and 2 had a large storage elastic modulus at 80 ° C. and poor unevenness embedding properties.

Claims (15)

    An adhesive composition is an adhesive composition containing the following components (A) and (B), which is characterized in that when the storage elastic modulus of the solid component is measured, the storage elastic modulus is stored at 23 ° C. The number is 0.1 to 600 MPa, and the storage elastic modulus at 80 ° C is 0.1 MPa or less. (A) component: a modified polyolefin resin, and (B) component: a polyfunctional epoxy compound.         The adhesive composition according to item 1 of the scope of patent application, wherein the component (A) is an acid-modified polyolefin resin.         The adhesive composition according to item 1 of the scope of patent application, wherein the content of the component (B) is 25 to 200 parts by mass relative to 100 parts by mass of the component (A).         The adhesive composition according to item 1 of the scope of patent application, further comprising the following component (C): (C) component: an adhesion-imparting agent having a softening point of 80 ° C or higher.         The adhesive composition according to item 4 of the scope of patent application, wherein the content of the component (C) is 1 to 200 parts by mass relative to 100 parts by mass of the component (A).         The adhesive composition according to item 1 of the scope of patent application, further comprising the following (D) component: (D) component: an imidazole curing catalyst.         The adhesive composition according to item 6 of the scope of patent application, 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 item 1 of the scope of patent application, further comprising the following (E) component: (E) component: a silane coupling agent.         The adhesive composition according to item 8 of the scope of patent application, wherein the content of the component (E) is 0.01 to 10 parts by mass relative to 100 parts by mass of the component (A).         A sealing sheet is a sealing sheet composed of two peeling films and an adhesive layer held by the peeling films. The aforementioned adhesive layer is used as described in any one of claims 1 to 9 of the scope of patent application. Formed with an adhesive composition.         A sealing sheet is a sealing sheet composed of a release film, a gas barrier film, and an adhesive layer held between the release film and the gas barrier film. The aforementioned adhesive layer is used as described in the first to It is formed from the adhesive composition as described in any one of 9 items.         The sealing sheet according to item 11 of the application, wherein the gas barrier film is a metal foil, a resin film, or a film glass.         The sealing sheet according to item 10 or 11 of the scope of patent application, wherein the thickness of the adhesive layer is 5 to 25 μm.         The utility model relates to a sealing body, which is formed by sealing the object to be sealed by using the sealing sheet according to item 10 or 11 of the scope of patent application.         The sealing body according to item 14 of the scope of application for a patent, wherein the object to be sealed is an organic EL element, an organic EL display element, a liquid crystal display element, or a solar cell element.