TWI770057B - Adhesive composition, sealing sheet and sealing body - Google Patents

Abstract

The present invention relates to an adhesive composition, a sealing sheet having an adhesive layer formed using the adhesive composition, and a sealing body using the sealing sheet to seal an object to be sealed, wherein the adhesive composition contains (A) component: modified polyolefin-based resin, and (B) component: adhesive composition of polyfunctional epoxy compound, characterized in that when the storage elastic modulus is measured with respect to the solid content, storage at 23° C. The elastic modulus is 0.1~600MPa, and the storage elastic modulus at 80℃ is below 0.1MPa. According to the present invention, it is possible to provide an adhesive composition that is easy to form into a sheet and has excellent conformability to irregularities, a sealing sheet having an adhesive layer that is formed using the adhesive composition and has excellent conformability to concavities and convexities, and the use of the aforementioned adhesive composition. The sealing sheet is a sealing body that is sealed by the sealing material.

Description

Adhesive composition, sealing sheet and sealing body

The present invention relates to an adhesive composition that is easily formed into a sheet shape and has excellent conformability to irregularities, a sealing sheet having an adhesive layer excellent to conformability to concavities and convexities formed using the adhesive composition, and a sealant using the above-mentioned sealant A sealed body formed by sealing the sheet with a sealant.

In recent years, organic EL elements have been attracting attention as being capable of high-intensity light emission by low-voltage DC driving.

However, the organic EL element has a problem that light emission characteristics such as light emission luminance, light emission efficiency, light emission uniformity, etc. tend to decrease with the passage of time.

As a cause of the problem of the decrease in light emission characteristics, it is considered that oxygen, moisture, and the like penetrate into the interior of the organic EL element, thereby deteriorating the electrodes and the organic layer. Therefore, conventionally, the organic EL element is sealed using a sealing material to prevent the penetration of oxygen and moisture.

Moreover, when sealing an organic EL element using a sealing material, since it is necessary to fill the micro gap and unevenness|corrugation of an organic EL element, development of the sealing material which has a low viscosity has been performed previously.

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

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

[Prior Art Literature]

[Patent Literature]

[Patent Document 1] WO 2012/014499

Since the composition described in Patent Document 1 has a low viscosity, it has excellent conformability to irregularities. However, since this composition has fluidity before the hardening reaction, it is necessary to use a special coating apparatus such as a dispenser when using this composition to coat an organic EL element.

Therefore, an adhesive composition which is easy to be in a sheet shape and has excellent conformability to irregularities, and a sealing sheet having an adhesive layer which is excellent in conformability to irregularities are required.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide an adhesive composition which is easy to be molded into a sheet shape and has excellent unevenness followability, and an adhesive with excellent unevenness followability formed using the adhesive composition A sealing sheet of a layer, and a sealing body obtained by sealing a to-be-sealed object using the sealing sheet.

In order to solve the above-mentioned problems, the inventors of the present invention, as a result of intensive research, found that the adhesive composition containing a modified polyolefin-based resin and a polyfunctional epoxy compound, when the storage elastic modulus of the solid content of the adhesive composition was measured at 23° C. An 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 easily formed into a sheet and has excellent unevenness followability, thereby completing the present invention.

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

(1) An adhesive composition comprising the following components (A) and (B), characterized in that: when the storage elastic modulus is measured for the solid content of the adhesive composition, it is The storage elastic modulus is 0.1~600MPa, and the storage elastic modulus at 80°C is 0.1MPa or less, (A) component: modified polyolefin resin, (B) component: multifunctional epoxy compound.

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

(3) The adhesive composition as described in (1) whose content of the said (B) component is 25-200 mass parts with respect to 100 mass parts of said (A) components.

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

(5) The adhesive composition as described in (4) whose content of the said (C) component is 1-200 mass parts with respect to 100 mass parts of said (A) components.

(6) The adhesive composition as described in (1) which further contains the following (D)component: (D)component: imidazole type hardening catalyst.

(7) The adhesive composition as described in (6) whose content of the said (D) component is 1-10 mass parts with respect to 100 mass parts of said (A) components.

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

(9) The adhesive composition as described in (8) whose content of the said (E) component is 0.01-10 mass parts with respect to 100 mass parts of said (A) components.

(10) A sealing sheet comprising two peeling films and an adhesive layer sandwiched by the peeling films, wherein the adhesive layer is as described in any one of (1) to (9) The adhesive composition is formed.

(11) 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 as described in (1) It is formed by the adhesive composition described in any one of (9).

(12) The sealing sheet according to (11), wherein the gas barrier film is a metal foil, a resin-made film, or a thin-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 formed by sealing a to-be-sealed object using the sealing sheet as described in (10) or (11).

(15) The sealing body according to (14), wherein the sealing 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 is easy to form into a sheet and has excellent conformability to irregularities, a sealing sheet having an adhesive layer that is formed using the adhesive composition and has excellent conformability to concavities and convexities, and the use of the aforementioned adhesive composition. The sealing sheet is a sealing body that is sealed by the sealing material.

Hereinafter, the present invention will be described in detail by dividing it into 1) adhesive composition, 2) sealing sheet, and 3) sealing body.

1) Adhesive composition

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

(A) Component: Modified polyolefin-based 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 the modified polyolefin-based resin. Moreover, by using the adhesive composition containing a modified polyolefin resin, a thin adhesive layer can be formed efficiently.

Modified polyolefin resins are polyolefin resins into which functional groups are introduced.

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

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

As another monomer which can be copolymerized with an olefin type monomer, vinyl acetate, (meth)acrylate, styrene, etc. are mentioned. Here, (meth)acrylic acid means acrylic acid or methacrylic acid (the same applies hereinafter).

Examples of polyolefin resins include very low density polyethylene (VLDPE), low density polyethylene (LDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), linear low density polyethylene, polyethylene 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 are not limited by these.

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 that can contribute to the crosslinking reaction described later.

The functional group includes a carboxyl group, a carboxylic acid anhydride group, a carboxylate ester group, a hydroxyl group, an epoxy group, an amide group, an ammonium group, a nitrile group, an amino group, an amide imide group, an isocyanate group, an acetyl group, a sulfur group Alcohol group, ether group, thioether group, sulfonic acid group, phosphoric acid group, nitro group, urethane group, halogen atom and the like. Among them, carboxyl group, carboxylic acid anhydride group, carboxylate group, hydroxyl group, ammonium group, amine group, imide group and isocyanate group are preferred, carboxylic acid anhydride group and alkoxysilyl group are preferred, and Carboxylic acid anhydride groups are particularly preferred.

The compound which has a functional group may have 2 or more types of functional groups in a molecule|numerator.

Examples of the modified polyolefin-based resin include acid-modified polyolefin-based resins and silane-modified polyolefin-based resins. In particular, an acid-modified polyolefin-based resin is preferable from the viewpoint that the present invention can obtain more excellent effects.

The acid-modified polyolefin-based resin refers to one obtained by graft-modifying a polyolefin resin with an acid. For example, a polyolefin resin is made to react with an unsaturated carboxylic acid, and what introduce|transduces a carboxyl group (graft modification) is mentioned. In addition, in the present specification, the term "unsaturated carboxylic acid" includes the concept of carboxylic acid anhydride, and the term "carboxyl group" includes the concept of carboxylic acid anhydride group.

Examples of the unsaturated carboxylic acid to be reacted with the polyolefin resin 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, norbornedicarboxylic anhydride, tetrahydrophthalic anhydride, etc.

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

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

The amount of the unsaturated carboxylic acid to be reacted with the polyolefin resin is preferably 0.1 to 5 parts by mass, preferably 0.2 to 3 parts by mass, and more preferably 0.2 to 1.0 parts by mass relative to 100 parts by mass of the polyolefin resin. The adhesive composition containing the acid-modified polyolefin-based resin thus obtained has relatively excellent adhesive strength.

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

The silane-modified polyolefin resin refers to a polyolefin resin obtained by graft-modifying a polyolefin resin with an unsaturated silane compound. The silane-modified polyolefin resin has a structure in which an unsaturated silane compound is graft-copolymerized to the main chain of the polyolefin resin. The silane-modified polyolefin-based resin is not particularly limited. For example, a silane-modified polyethylene resin and a silane-modified ethylene-vinyl acetate copolymer are mentioned. In particular, 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 to be reacted with the above-mentioned polyolefin resin, a vinyl silane compound is preferable. Examples of the vinylsilane compound include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripropoxysilane, vinyltriisopropoxysilane, vinyltributoxysilane, vinyl Tripentyloxysilane, vinyltriphenoxysilane, vinyltribenzyloxysilane, vinyltrimethylenedioxysilane, vinyltriphenylethyldioxysilane, vinylpropionyloxy Silane, vinyltriacetoxysilane, vinyltricarboxysilane, etc. These can be used alone or in combination of two or more.

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

The amount of the unsaturated silane compound to be reacted with the polyolefin resin is preferably 0.1 to 10 parts by mass, particularly preferably 0.3 to 7 parts by mass, and further preferably 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 to be reacted with the polyolefin resin is within the above range, the obtained adhesive composition containing the silane-modified polyolefin-based resin will have relatively excellent adhesive strength.

In the present invention, a commercial item can be used as the silane-modified polyolefin-based resin. As a commercial item, for example, LINKLON (registered trademark) (manufactured by Mitsubishi Chemical Corporation) etc. can be mentioned, and especially LINKLON of low density polyethylene type, LINKLON of linear low density polyethylene type, ultra low density polyethylene type can be suitably used. Ethylene-based LINKLON, and ethylene-vinyl acetate copolymer-based LINKLON.

Modified polyolefin-based resins 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, but is preferably 10,000 to 2,000,000, and more preferably 20,000 to 1,500,000, from the viewpoint of obtaining superior effects of the present invention.

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

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

(B) component: polyfunctional epoxy compound

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

Since the adhesive composition of the present invention contains a polyfunctional epoxy compound, the storage elastic modulus before hardening is lower. In addition, the cured product of the adhesive composition containing the polyfunctional epoxy compound has excellent water vapor barrier properties.

The polyfunctional epoxy compound refers to a compound having at least two or more epoxy groups in the molecule.

Examples of epoxy compounds having two or more 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, novolak epoxy resin (such as phenol novolak epoxy resin, methyl alcohol Phenol‧Novolak Epoxy Resin, Brominated Phenol‧Novolak Epoxy Resin), Hydrogenated Bisphenol A Diglycidyl Ether, Hydrogenated Bisphenol F Diglycidyl Ether, Hydrogenated Bisphenol S Diepoxy propyl ether, neopentylerythritol polyglycidyl ether, 1,6-hexanediol diglycidyl ether, diglycidyl hexahydrophthalate, neopentyl glycol diglycidyl ether ether, trimethylolpropane polyglycidyl ether, 2,2-bis(3-epoxypropyl-4-glycidoxyphenyl)propane, dimethyloltricyclodecane diepoxide propyl ether, etc.

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 liquid polyfunctional epoxy compound (B1) at 25° C. as the component (B). The component (B) has the effect of reducing the storage elastic modulus of the adhesive composition when the temperature of the adhesive composition is high (hereinafter referred to as "the effect of reducing the storage elastic modulus"). By using the adhesive composition of this invention, the adhesive layer which has the outstanding uneven|corrugated followability can be formed efficiently.

The lower limit of the weight average molecular weight of the polyfunctional epoxy compound (B1) that 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 adhesive composition whose weight average molecular weight of the polyfunctional epoxy compound (B1) is 700 or more, a sealing material with low outgassing properties can be formed. The weight-average molecular weight of the polyfunctional epoxy compound is an adhesive composition of 3,700 or less, which has excellent fluidity and can sufficiently fill the unevenness of the surface of the object to be sealed and the unevenness of the thickness of the object to be sealed.

The epoxy equivalent of the liquid polyfunctional epoxy compound (B1) at 25°C is preferably 100 g/eq or more and 500 g/eq or less, and preferably 150 g/eq or more and 300 g/eq or less. By using the adhesive composition whose epoxy equivalent of the polyfunctional epoxy compound (B1) is 100 g/eq or more and 500 g/eq or less, a sealing material with low outgassing properties can be formed.

The adhesive composition of this invention may contain the polyfunctional epoxy compound (B2) which is solid at 25 degreeC as (B) component.

Unlike the polyfunctional epoxy compound of the (B1) component, the polyfunctional epoxy compound of the component (B2) is considered to have almost no effect of lowering the storage elastic modulus. On the other hand, when the adhesive composition contains the component (B2), the performance of maintaining the sheet shape of the adhesive layer is improved.

As a result of such a tendency, when the component (B2) is used in combination with the component (B1), the effect of reducing the storage elastic modulus of the component (B1) can be further enhanced. By the presence of the (B2) component, the content of the (B) component in the adhesive composition can be increased while the adhesive layer maintains the performance of the sheet shape. Therefore, in the adhesive composition, the ratio of the continuous phase region of the component (B) in the phase-separated structure formed by the component (A) and the component (B) increases. When the temperature of the adhesive layer formed of such an adhesive composition is raised, the region of the continuous phase of the component (B) is softened, so that a high storage elastic modulus lowering effect can be exhibited.

Therefore, it is preferable that the adhesive composition of this invention contains (B2) component, and it is preferable to contain both of (B1) component and (B2) component.

The lower limit of the weight average molecular weight of the polyfunctional epoxy compound (B2) which is a 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, more preferably 7,000. By using the adhesive composition whose weight average molecular weight of the polyfunctional epoxy compound (B2) is 3,800 or more, the adhesive layer can more easily maintain the sheet shape.

The epoxy equivalent of the solid polyfunctional epoxy compound (B2) 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 the adhesive composition whose epoxy equivalent of the polyfunctional epoxy compound (B2) is 600 g/eq or more and 6,000 g/eq or less, the adhesive layer system can more easily maintain the sheet shape.

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

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

When the amount of the component (B1) increases according to the component (B2), when the adhesive composition is formed into a sheet shape, it tends to be easy to maintain a constant shape.

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

Components other than (A) component and (B) component include the following (C) component, (D) component, and (E) component, (C) component: adhesion imparting agent having a softening point of 80°C or higher , (D) Component: imidazole-based hardening catalyst, (E) Component: a silane coupling agent.

(C) Component: Adhesion imparting agent having a softening point of 80°C or higher

As mentioned above, the adhesive composition containing (A) component and (B) component has a low storage elastic modulus before hardening, and has excellent unevenness|corrugation followability. However, such an adhesive composition is not easy to maintain a constant shape, and it may be difficult to shape into a sheet. 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; terpene-based resins such as polyterpene resins, aromatic modified terpene resins and their hydrogenated products, and terpene phenol resins. Resins; Coumarone-indene resins; aliphatic petroleum resins, aromatic petroleum resins and their hydrides, petroleum resins such as aliphatic/aromatic copolymer petroleum resins; low molecular weight polymers of styrene or substituted styrene ; α -methylstyrene homopolymeric resin, α -methylstyrene/styrene copolymer resin, styrene monomer/aliphatic monomer copolymer resin, styrene monomer/α -Styrenic resins such as methylstyrene/aliphatic monomer copolymerization resins, styrene monomer homopolymerization resins, styrene monomer/aromatic monomer copolymerization resins, and the like. Among these, styrene-based resins are preferred, and styrene-based monomer/aliphatic-based monomer copolymerization-based resins are preferred.

These tackifiers 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 temperature can be obtained. Moreover, the workability|operativity at the time of shaping|molding the 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 (C) component of 80° C. or higher, the content thereof is 1 to 200 parts by mass, preferably 1 to 200 parts by mass relative to 100 parts by mass of the aforementioned (A) component. 10 to 150 parts by mass. When there are too few adhesion-imparting agents whose softening point is 80 degreeC or more, it may become difficult to shape|mold the adhesive composition into a sheet shape. On the other hand, if there are too many adhesion-imparting agents having a softening point of 80° C. or higher, the adhesive layer may become brittle.

(D) Component: imidazole-based hardening catalyst

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

Examples of imidazole-based curing catalysts include 2-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-ethyl-4-methylimidazole, and 2-benzene yl-4-methylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, etc. Among these, 2-ethyl-4-methylimidazole is preferable.

These imidazole-based hardening 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, 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 the hardened product of the adhesive composition within this range, and has excellent adhesiveness even at high temperature.

(E) Component: Silane coupling agent

A silane coupling agent is an organosilicon compound having both a functional group that reacts with an organic material and a functional group (hydrolyzable group) that reacts with an inorganic material in the molecule.

As the silane coupling agent, a known silane coupling agent can be used, and especially an organosilicon compound having at least one alkoxysilyl group in the molecule is preferable.

Examples of the silane coupling agent include polymerizable unsaturated group-containing silicon compounds such as vinyltrimethoxysilane, vinyltriethoxysilane, and methylacryloxypropyltrimethoxysilane; 3-epoxy Propoxypropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane and other silicon compounds with epoxy structure; 3-aminopropyltrimethoxysilane, N-( 2-Aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane and other amine-containing silicon compounds; 3-chloro Propyltrimethoxysilane; 3-Isocyanatopropyltriethoxysilane, etc.

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

By using the adhesive composition containing a silane coupling agent, it is easy to obtain a cured product with better adhesive strength under normal temperature (15°C to 30°C) and high temperature (40°C to 100°C) environments.

When the adhesive composition of the present invention contains a silane coupling agent, the content thereof is 0.01 to 10 parts by mass relative to 100 parts by mass of the aforementioned (A) component, from the viewpoint of obtaining a cured product having more excellent adhesive strength. parts are preferably, 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 aromatic hydrocarbon-based solvents such as benzene and toluene; ester-based solvents such as ethyl acetate and butyl acetate; and ketone-based solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; Aliphatic hydrocarbon-based solvents such as n-pentane, n-hexane, and n-heptane; alicyclic hydrocarbon-based solvents such as cyclopentane, cyclohexane, and methylcyclohexane; and the like.

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 this invention may contain other components in the range which does not inhibit the effect of this invention.

As other components, an ultraviolet absorber is mentioned. Additives for antistatic agents, light stabilizers, antioxidants, resin stabilizers, fillers, pigments, extenders, softeners, etc.

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

When the adhesive composition of this invention contains these additives, the content can be suitably determined according to the objective.

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

When the storage elastic modulus of the adhesive composition of the present invention is measured with respect to its solid content, the storage elastic modulus at 23° C. is 0.1-600 MPa, preferably 0.2-500 MPa, and more preferably 0.2-100 MPa.

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

In the present specification, the term "solid content" refers to a solid content obtained by removing volatile components such as a solvent from the adhesive composition.

When the storage elastic modulus of the adhesive composition of the present invention is measured with respect to 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 having a storage elastic modulus of 0.1 MPa or less at 80°C has excellent conformability to irregularities.

In addition, the lower limit of the storage elastic modulus at 80°C is preferably 1 kPa, more preferably 5 kPa. The adhesive composition whose storage elastic modulus at 80°C is 1 kPa or more has relatively excellent handleability.

The storage elastic modulus of the solid content of the adhesive composition of the present invention can be obtained by applying the adhesive composition of the present invention and drying the sheet-like adhesive as a test piece, for example, as described in the examples. measured by the method.

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

Specifically, by adding (B) component, the storage elastic modulus at 23 degreeC and 80 degreeC tends to fall. On the other hand, when the (B) component is added excessively, it becomes difficult to form into a sheet-like system. In this case, when an appropriate amount of the component (C) is added, the storage elastic modulus at 80° C. can be lowered while the formability is improved.

The adhesive composition of the present invention is easy to form into a sheet and has excellent conformability to irregularities. Therefore, the adhesive composition of this invention can be used suitably 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), sealing sheet ( α ): a sealing sheet composed of two peeling films and an adhesive layer sandwiched by these peeling films , which is characterized in that: the adhesive layer is formed by 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. A sealing sheet composed of an adhesive layer sandwiched by a film is characterized in that the above-mentioned adhesive layer is formed by using the adhesive composition composition of the present invention.

In addition, these sealing sheets show the state before use, and when the sealing sheet of this invention is used, a peeling film is normally peeled and removed.

[Sealing sheet ( α )]

The release film constituting the sealing sheet ( α ) functions as a support in the manufacturing process of the sealing sheet ( α ), and functions as a protective sheet for the adhesive layer until the sealing sheet ( α ) is used .

As a release film, a conventionally known thing can be utilized. For example, on the base material for a release film, there is a release layer obtained by performing a release treatment with a release agent.

Examples of the base material for the release film include paper base materials such as cellophane, coated paper, and high-quality paper; laminated paper obtained by laminating thermoplastic resins such as polyethylene to these paper base materials; Plastic films of ethylene phthalate resin, polybutylene terephthalate resin, polyethylene naphthalate resin, polypropylene resin, polyethylene resin, etc.

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

The two peeling films of the sealing sheet ( α ) may be the same or different from each other, and 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 off the peeling films can be performed more efficiently initially.

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.

In this way, although the adhesive layer is very thin, since the adhesive layer is formed using the adhesive composition of the present invention, it has excellent conformability to irregularities and can sufficiently fill the irregularities of the adherend.

The adhesive layer of the sealing sheet ( α ) is preferably one with thermosetting properties. The adhesive layer with thermosetting property has excellent adhesive strength after hardening.

The conditions for thermosetting 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 1 to 6 hours.

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

The water vapor transmission rate of the adhesive layer after curing 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, the sealing sheet ( α ) can be produced using a conventional casting method. More specifically, an adhesive layer with a release film can be produced by applying the adhesive composition of the present invention to the release treated surface of the release film by using a conventional method, and drying the obtained coating film to produce an adhesive layer with a release film. A sealing sheet ( α ) was obtained by overlapping another release film on the adhesive layer.

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

The drying conditions at the time of drying the coating film are not particularly limited. For example, the drying temperature is 80~150°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 ), respectively.

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

The water vapor transmission rate of the gas barrier film in an environment with a temperature of 40°C and a relative humidity of 90% (hereinafter, abbreviated as "90%RH") is preferably 0.1g/m ² /day or less, preferably 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 40°C and 90% RH, which can effectively prevent oxygen, moisture, etc. from penetrating into the organic EL formed on the transparent substrate. The inside of the element or the like causes deterioration of the electrode and the organic layer.

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

As a gas-barrier film, a metal foil, a thin film glass, a resin-made film, etc. are mentioned. Among them, a resin-made film is preferable, and a gas-barrier film having a base material and a gas-barrier layer is preferable.

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 alloys.

The composition and composition of the thin-film glass are not particularly limited, but alkali-free borosilicate glass is preferable in terms of obtaining relatively stable flexibility.

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

Moreover, as a thin-film glass, it is preferable that the thickness is about 10-200 micrometers and has flexibility.

Examples of the resin component constituting the base material of the gas barrier film include Polyimide, polyamide, polyamide imide, polyphenyl ether, polyether ketone, polyether ether ketone, polyolefin, polyester, polycarbonate, polysiloxane, polyether pipette, polyphenylene Sulfur (polyphenylene sulfide), polyarylate (polyarylate), acrylic resin, cycloolefin polymer, aromatic polymer, polyurethane polymer, etc.

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

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

Among them, since the thickness is thin and a 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 reforming treatment is preferable.

Although it does not specifically limit as an inorganic film, For example, an inorganic vapor deposition film is mentioned.

As an inorganic vapor-deposited film, the vapor-deposited film of an inorganic compound and a metal is mentioned.

Examples of the raw material for the vapor deposition film of the inorganic compound 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 nitrides; Inorganic oxide carbides; Inorganic nitride carbides;

As a metal vapor deposition film raw material, aluminum, magnesium, zinc, tin, etc. are mentioned.

As an inorganic film formation method, a vacuum vapor deposition method, an EB vapor deposition method, and a sputtering method are mentioned. Ion plating method, bonding method, plasma vapor deposition method (CVD method), etc.

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

In the gas barrier layer obtained by ion implanting a layer containing a polymer compound (hereinafter referred to as "polymer layer"), polyorganosiloxane is used as the polymer compound. , Silicon-containing polymer compounds such as polysilazane compounds, polyimide, polyimide, polyimide, polyphenyl ether, polyether ketone, polyether ether ketone, polyolefin, polyester , Polycarbonate, Polycarbonate, Polyethercarbonate, Polyphenylene Sulfide, Polyarylate, Acrylic Resin, Cycloolefin Polymer, Aromatic Polymer, etc. 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 preferable, and a polysilazane-based compound is preferable.

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

Compounds of the indicated repeating units are preferred. In addition, the number average molecular weight of the polysilazane-based compound to be used is not particularly limited, but is preferably 100 to 50,000.

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

The polysilazane-based compound can be used alone or in combination of two or more. In the present invention, a polysilazane-modified product can also be used as a polysilazane-based compound. Moreover, in this invention, as a polysilazane type-compound, what is marketed as a glass coating material etc. can also be used as it is.

The said polymer layer may contain other components in the range which does not inhibit the objective of this invention other than the above-mentioned polymer compound. Examples of other components include curing agents, other polymers, anti-aging agents, light stabilizers, flame retardants, and the like.

Since a gas barrier layer having excellent gas barrier properties can be obtained, the content of the polymer compound in the polymer layer is preferably 50 mass % or more, more preferably 70 mass % or more.

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

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

As a method of forming the polymer layer, for example, a solution for forming a layer containing at least one type of polymer compound, other components as necessary, and a solvent, etc., is prepared using a spin coater, a knife coater, or a gravure coater. A method in which the coating film is formed by coating with a conventional device such as a cloth machine, and drying the obtained coating film appropriately.

Examples of the modification treatment of the polymer layer include ion implantation treatment, plasma treatment, radiation irradiation treatment, heat treatment, and the like. It is preferable to change the bond structure of the polymer layer. These processes can be performed individually by 1 type, and can also be performed in combination of 2 or more types. The ion implantation treatment is a method of modifying the polymer layer in order to implant ions into the polymer layer, as will be described later.

Plasma treatment is a method of modifying the polymer layer by exposing the polymer layer to plasma. For example, the plasma treatment can be performed in accordance with the method described in Japanese Patent Laid-Open No. 2012-106421.

The radiation irradiation treatment is a method of modifying the polymer layer by irradiating the polymer layer with radiation. The radiation is preferably a short wavelength with a high effect of changing the bond structure of the polymer layer, and ultraviolet rays, especially vacuum ultraviolet rays, are preferably used. For example, the vacuum ultraviolet light modification treatment can be performed in accordance with the method described in Japanese Patent Laid-Open No. 2013-226757.

Among these, since the surface of the polymer layer is not roughened and can be efficiently modified to the inside thereof, and a gas barrier layer having relatively excellent gas barrier properties can be formed, the ion implantation treatment is used as the good

Examples of ions implanted 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, sulfur, and the like; methane, ethylene Ions of alkane-based gases such as alkane; ions of alkene-based gases such as ethylene and propylene; ions of alkane-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 naphthenic-based gases such as cyclopropane; ions of cycloolefin-based gases such as cyclopentene; ions of metals; ions of organosilicon compounds, etc.

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

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

The method of implanting ions is not particularly limited. For example, a method of irradiating ions (ion beam) accelerated by an electric field, a method of implanting ions in plasma (ion of plasma generating gas), etc., are mentioned, because the gas barrier layer can be easily obtained , the latter method of implanting plasma ions is better. Plasma ion implantation, for example, can be performed by generating a plasma in an environment containing a plasma generating gas and applying a negative high voltage pulse to a layer in which the ions are implanted, and ions (cations) in the plasma. ) into the surface portion of the ion-implanted layer.

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

Moreover, the sealing sheet (β) can also be produced by peeling off one peeling film after producing the sealing sheet ( α ), and sticking the exposed adhesive layer and the gas barrier film. In this case, when the sealing sheet ( α ) is two peeling films having different peeling strengths, it is preferable to peel off the peeling film with the smaller peeling strength from the viewpoint of workability.

As described above, the sealing sheet adhesive layer system of the present invention has excellent conformability to irregularities. Therefore, even if the adhesive layer is thin, the unevenness of the surface of the object to be sealed and the unevenness caused by the thickness of the object to be sealed can be sufficiently filled. For example, when the unevenness on the surface of the object to be sealed and the unevenness caused by the thickness of the object to be sealed are 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 , the system can easily fill it.

3) Sealing body

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

The sealing body of the present invention includes, for example, a transparent substrate, an element (object to be sealed) formed on the transparent substrate, and a sealing material for sealing the element. The sealing material includes 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 with high visible light transmittance. In addition, it is preferable to use a material having high barrier properties against moisture and gas to be infiltrated from the outside of the element, and having excellent solvent resistance and weather resistance. Specifically, transparent inorganic materials such as quartz and glass; polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polystyrene, polyethylene, polypropylene, polyphenylene sulfide , polyvinylidene fluoride, cellulose acetate, brominated phenoxy, polyarylamide (ARAMID), polyimide, polystyrene, polyarylester, polysiloxane, polyolefin, etc. The 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 separating the inside and outside of the element.

As a to-be-sealed object, an organic EL element, an organic EL display element, a liquid crystal display element, a solar cell element, etc. are mentioned.

The manufacturing method of the sealing body of this invention is not specifically limited. For example, after stacking the sealing sheet adhesive layer of the present invention 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 this invention can be manufactured by hardening this adhesive bond layer.

The adhesion conditions at the time of adhering the sealing sheet adhesive layer and the object to be sealed are not particularly limited. The adhesion temperature is, for example, 23 to 100°C, preferably 40 to 80°C. The adhesion treatment may be carried out under pressure.

As hardening conditions when hardening the adhesive layer, the conditions described above can be used.

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

Therefore, in the sealing body of the present invention, the performance of the to-be-sealed object 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 by the following examples at all.

The parts and % in each example are the quality standards unless notified in advance. In addition, the weight average molecular weight (Mw) of a modified polyolefin resin and a polyfunctional epoxy compound is the value measured using the following method.

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

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

(measurement conditions)

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

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

‧Column temperature: 40℃

‧Developing 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 was measured using a gel permeation chromatography (GPC) apparatus (manufactured by TOSOH Co., Ltd., product name "HLC-8320") and converted into plural numbers under the following conditions Among the peaks observed, the weight average molecular weight of standard polystyrene corresponds to the retention time of the peak with the largest area.

(measurement conditions)

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

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

‧Column temperature: 40℃

‧Developing solvent: tetrahydrofuran

‧Flow rate: 0.60mL/min

[Example 1]

100 parts of acid-modified polyolefin-based resin ( α -olefin polymer, manufactured by Mitsui Chemicals Co., Ltd., trade name: UNISTOLEH-200, weight average molecular weight: 52,000), polyfunctional epoxy compound (1) (hydrogenated bisphenol A Glycidyl ether, manufactured by Kyōeisha Chemical Co., Ltd., trade name: Epolite 4000, liquid at 25°C, epoxy equivalent 215-245 g/eq, weight average molecular weight: 800) 100 parts, adhesion-imparting agent (styrene-based monolayer) Body aliphatic monomer copolymer, softening point 95°C, manufactured by Mitsui Chemicals Co., Ltd., trade name: FTR6100) 50 parts, and imidazole-based hardening catalyst (manufactured by Shikoku Chemical Co., Ltd., trade name: CUREZOLE 2E4MZ, 2-ethyl -4-methylimidazole) 1 part was melt|dissolved in methyl ethyl ketone, and the adhesive composition 1 of 30% of solid content concentration was prepared.

The adhesive composition 1 was applied to the peeling-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. , and the sealing sheet 1 was obtained by pasting the peeling-treated surface of another release film (manufactured by LINTEC, trade name: SP-PET381031).

[Example 2]

Example 1, except that a polyfunctional epoxy compound (2) (manufactured by ADEKA, trade name: ADEKARESIN, EP-4080E, liquid at 25° C., epoxy equivalent 215 g/eq, weight average molecular weight: 800) was used as a polyfunctional Except the epoxy compound, it carried out similarly to Example 1, and obtained the sealing sheet 2.

[Example 3]

In Example 1, except that 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 Except the compound, it carried out similarly to Example 1, and obtained the sealing sheet 3.

[Example 4]

In Example 1, except that 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 Except for the compound, the sealing sheet 4 was obtained in the same manner as in Example 1.

[Example 5]

The sealing sheet 5 was obtained in the same manner as in Example 1, except that the compounding amount described in Table 1 was changed.

[Example 6]

Acid-modified polyolefin resin (acid-modified α -olefin polymer, manufactured by Mitsui Chemicals, trade name: UNISTOLEH-200, weight average molecular weight: 52,000) 100 parts, polyfunctional epoxy compound (3) 100 parts, Polyfunctional epoxy 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 , 1 part of imidazole-based hardening catalyst (manufactured by Shikoku Chemical Co., Ltd., trade name: CUREZOLE 2E4MZ, 2-ethyl-4-methylimidazole), and 0.1 silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KBM4803) 1 part was dissolved in methyl ethyl ketone to prepare adhesive composition 2 with a solid content concentration of 25%.

The adhesive composition 2 was applied to the peeling-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. , and the sealing sheet 6 was obtained by bonding the peeling-treated surface of another release film (manufactured by LINTEC, trade name: SP-PET381031).

[Comparative Example 1]

The sealing sheet 7 was produced using only a modified polyolefin-based resin ( α -olefin polymer, manufactured by Mitsui Chemicals, trade name: UNISTOLEH-200, number average molecular weight: 47,000).

[Comparative Example 2]

The sealing sheet 8 was obtained in the same manner as in Example 1 except that the compounding amount described in Table 1 was changed.

The following tests were performed about 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 layers obtained in Examples or Comparative Examples were stacked, and heated at 60° C. using a thermal bonding machine to obtain a layered body having a thickness of 1 mm. Using this laminated body as a sample, the storage elastic modulus of the adhesive layer before hardening was measured by the measuring apparatus (Physica MCR301) made by Anton Paar in the frequency range of 1 Hz and the temperature range of 23-150 degreeC. The storage elastic moduli at 23°C and 80°C are shown in Table 1.

[Evaluation of embedment of unevenness]

The PET-attached adhesive layer was obtained by overlapping the sealing sheet adhesive layer obtained in Examples or Comparative Examples with a polyethylene terephthalate film having a thickness of 25 μm.

On the other hand, a small piece (pseudo device) of polyethylene terephthalate having a thickness of 10 μm was placed on a glass substrate. The PET-attached adhesive layer was overlaid on the glass substrate so that the dummy element on the glass substrate was completely covered, and was sealed at 80°C using a thermal bonding machine. Pressure-treated for 20 minutes, and then hardened at 100°C for 2 hours.

This product was observed with an optical microscope to investigate whether or not the unevenness was lifted, and the unevenness embedding property was evaluated according to the following criteria.

○: No floating.

╳: There is floating.

The evaluation results are shown in the first table.

The following situations are known from Table 1.

The sealing sheet systems of Examples 1 to 6 had excellent embedment of concavities and convexities.

On the other hand, the sealing sheets of Comparative Examples 1 and 2 had large storage elastic modulus at 80° C. and poor embedment of concavo-convex.

Claims (14)

An adhesive composition comprising the following (A) components and (B) components, characterized in that: with respect to 100 parts by mass of the aforementioned (A) components, the content of the aforementioned (B) components is: 50~150 parts by mass, when the storage elastic modulus is measured for the solid content of the adhesive composition, the storage elastic modulus at 23°C is 0.1~600MPa, and the storage elastic modulus at 80°C is 0.1MPa or less, (A ) component: modified polyolefin-based resin, (B) component: a polyfunctional epoxy compound selected from the group consisting of bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, and bisphenol S bicyclic Oxypropyl ether, brominated bisphenol A diglycidyl ether, brominated bisphenol F diglycidyl ether, brominated bisphenol S diglycidyl ether, novolac epoxy resin, hydrogenated bisphenol Phenol A Diglycidyl Ether, Hydrogenated Bisphenol F Diglycidyl Ether, Hydrogenated Bisphenol S Diglycidyl Ether, Neotaerythritol Polyglycidyl Ether, 1,6-Hexanediol Di Glycidol, Diglycidyl Hexahydrophthalate, Neopentyl Glycol Diglycidyl Ether, Trimethylolpropane Polyglycidyl Ether, 2,2-Bis(3-Cyclic One or more of the group consisting of oxypropyl-4-glycidoxyphenyl) propane and dimethylol tricyclodecane diglycidyl ether. The adhesive composition according to claim 1, wherein the component (A) is an acid-modified polyolefin resin. The adhesive composition described in claim 1 of the scope of the application further contains the following (C) component: (C) Component: an adhesion-imparting agent having a softening point of 80°C or higher. The adhesive composition according to claim 3, 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 described in claim 1 further contains the following (D) component: (D) component: imidazole-based hardening catalyst. The adhesive composition according to claim 5, wherein the content of the component (D) is 0.1 to 10 parts by mass relative to 100 parts by mass of the component (A). The adhesive composition as described in claim 1 further contains the following (E) component: (E) component: a silane coupling agent. The adhesive composition according to claim 7, 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, which is a sealing sheet composed of two peeling films and an adhesive layer sandwiched by the peeling films. adhesive composition. A sealing sheet is a sealing sheet composed of a peeling film, a gas barrier film, and an adhesive layer sandwiched by the peeling film and the gas barrier film. The adhesive composition described in any one of the 8 items is formed. The sealing sheet according to claim 10, wherein the gas barrier film is a metal foil, a resin-made film, or a thin-film glass. The sealing sheet according to claim 9 or 10, wherein the thickness of the adhesive layer is 5-25 μm. A sealing body is formed by using the sealing sheet as described in item 9 or 10 of the patent application scope to seal a to-be-sealed object. The sealing body according to claim 13, wherein the sealing object is an organic EL element, an organic EL display element, a liquid crystal display element, or a solar cell element.