TW201903104A - Adhesive composition, adhesive sheet and sealing body - Google Patents

Abstract

Provided is an adhesive composition containing: component (A) a modified polyolefin resin and component (B) a polyfunctional epoxy compound which is a liquid at 25 DEG C, and optionally containing component (C) a polyfunctional epoxy compound which is a solid at 25 DEG C. The total quantity of component (B) and component (C) is more than 100 parts by mass with respect to 100 parts by mass of component (A). Also provided are an adhesive sheet having an adhesive layer formed using this adhesive composition, and a sealed body obtained by sealing an object to be sealed with this adhesive sheet. According to the present invention it is possible to provide an adhesive composition which can be formed easily into sheet form, an adhesive sheet having an adhesive layer with outstanding tracking of recesses and protrusions, and which is formed using this adhesive composition, and a sealed body obtained by sealing an object to be sealed with the adhesive sheet.

Description

Adhesive composition, adhesive sheet and sealing body

The present invention relates to an adhesive composition that can be easily formed into a thin sheet; an adhesive sheet having an adhesive layer formed using the adhesive composition and having excellent unevenness tracking; and a sealed body to be sealed by the adhesive sheet. .

In recent years, organic EL devices have attracted much attention because they are light-emitting devices that can emit light with high luminance by using low-voltage DC driving. However, the organic EL element has a problem that light emission characteristics such as light emission brightness, light emission efficiency, and light emission uniformity tend to decrease over time. The problem of the decrease in light emitting characteristics is considered to be that oxygen and moisture penetrate into the organic EL element and cause deterioration of the electrode and the organic layer. Therefore, a sealing material is used to seal the organic EL element to prevent oxygen and moisture. Infiltrate. Since it is necessary to bury the minute gaps and irregularities of the organic EL element when sealing the organic EL element with a sealing material, it has been known to develop a low-viscosity sealing material.

For example, the composition described in Patent Document 1 is a resin composition containing a specific epoxy resin, a specific epoxy resin hardener, a specific microcapsule, and a specific amount of a filler, and measured at 25 ° C and 2.5 with an E-type viscometer. The viscosity of rpm is 0.5 ~ 50Pa‧s. Patent Document 1 also describes that by using a liquid epoxy resin and a liquid epoxy resin hardener and adjusting the filler content, it is possible to achieve both low viscosity and high moisture resistance of the cured product. [Antecedent Literature] [Patent Literature]

[Patent Document 1] WO2012 / 014499 (US2013128435 A1)

(Problems to be solved by the invention)

The composition described in Patent Document 1 has low viscosity and excellent unevenness tracking. However, since the composition is fluid before the curing reaction is performed, it is necessary to use a special coating device such as a dispenser when sealing the organic EL element. Therefore, an adhesive composition that can be easily formed into a sheet shape and can form an adhesive layer with excellent unevenness tracking properties is expected.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an adhesive composition that can be easily formed into a sheet shape, an adhesive sheet having an adhesive layer formed using the adhesive composition and having excellent unevenness tracking properties, and to be sealed. The object is a sealed body which is sealed by the above-mentioned adhesive sheet. (Means for solving problems)

The present inventors conducted intensive research in order to solve the above-mentioned problems, and found that: (i) an adhesive composition containing a modified polyolefin-based resin and one or two or more kinds of polyfunctional epoxy compounds is improved compared to modified products; 100 parts by mass of a polyolefin-based resin, the total amount of the polyfunctional epoxy compound exceeding 100 parts by mass, and at least one of the polyfunctional epoxy compounds being an adhesive composition in a liquid state at 25 ° C, which can be easily molded into Flaky; (ii) The adhesive layer system formed using the adhesive composition is excellent in unevenness tracking, and the present invention has been completed.

The reason is that according to the present invention, the following adhesive compositions (1) to (11), adhesive sheets (12) to (14), and sealing bodies (15) and (16) will be provided. (1) An adhesive composition is an adhesive composition containing the following components (A) and (B), and may also contain the component (C), characterized in that it is 100 masses relative to the component (A) The total amount of the component (B) component and the component (C) exceeds 100 parts by mass. (A) Component: Modified polyolefin resin (B) Component: Polyfunctional epoxy compound (C) which is liquid at 25 ° C Component: Polyfunctional epoxy compound (2) which is solid at 25 ° C 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 total amount of the component (B) and the component (C) exceeds 100 parts by mass and 200 parts by mass or less with respect to 100 parts by mass of the component (A). . (4) The adhesive composition as described in (1) containing the said (C) component. (5) The adhesive composition according to (4), wherein the content ratio (mass ratio) of the component (B) to the component (C) is [(B) component: (C) component] = 100: 1 ~ 1: 1. (6) The adhesive composition according to (1), further comprising the following (D) component: (D) Component: an adhesive with a softening point of 80 ° C or higher (7) As described in (6) The adhesive composition according to the description, wherein the content of the component (D) is 1 to 200 parts by mass based on 100 parts by mass of the component (A). (8) The adhesive composition according to (1), further comprising the following (E) component: (E) Component: imidazole-based hardening catalyst (9) The adhesive combination according to (8) The content of the component (E) is 1 to 10 parts by mass based on 100 parts by mass of the total amount of the component (B) and the component (C). (10) The adhesive composition according to (1), further comprising the following (F) component: (F) component: a silane coupling agent (11) The adhesive composition according to (10), The content of the component (F) is 0.01 to 10 parts by mass based on 100 parts by mass of the component (A). (12) An adhesive sheet, which is an adhesive sheet having an adhesive layer, wherein the adhesive layer is formed using the adhesive composition according to any one of (1) to (11). (13) The adhesive sheet according to (12), wherein the thickness of the adhesive layer is 5 to 25 μm. (14) The adhesive sheet according to (12), further comprising a release film. (15) A sealing body is used for sealing an object to be sealed using the adhesive sheet according to any one of (12) to (14). (16) The sealed body according to (15), 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. [Inventive effect]

According to the present invention, it is possible to provide an adhesive composition that can be easily formed into a sheet, an adhesive sheet adhesive sheet having an adhesive layer formed using the adhesive composition and having excellent unevenness tracking properties, and a sealed object that is sealed by the adhesive sheet. Sealing body.

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

1) Adhesive composition The adhesive composition of the present invention is an adhesive composition containing the following components (A) and (B), and may also contain the component (C), wherein the adhesive composition is 100% of the component (A). The total amount of the component (B) and the component (C) exceeds 100 parts by mass. (A) Component: Modified polyolefin resin (B) Component: Polyfunctional epoxy compound that is liquid at 25 ° C (C) Component: Polyfunctional epoxy compound that is solid at 25 ° C

(A) Component: Modified polyolefin-based resin The adhesive composition of the present invention is a modified polyolefin-based resin containing the component (A). The adhesive composition of the present invention is excellent in adhesive strength by containing a modified polyolefin-based resin. In addition, by using an adhesive composition containing a modified polyolefin resin, a thin adhesive layer can be formed with high efficiency.

The modified polyolefin-based resin is obtained by performing a modification treatment on a precursory polyolefin resin using a modifying agent to obtain a functionalized polyolefin resin.

The "polyolefin resin" refers to a polymer containing a repeating unit derived from an olefin-based monomer. The polyolefin resin may be a polymer composed of only repeating units derived from an olefin-based monomer, or may be a repeating unit derived from an olefin-based monomer and a repeat derived from a monomer capable of copolymerizing with an olefin-based monomer. Unit

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 particularly preferably ethylene or propylene. These olefin-based single systems can be used alone or in combination of two or more. Examples of the single system capable of copolymerizing with an olefin-based monomer include vinyl acetate, (meth) acrylate, and styrene. These monosystems capable of copolymerizing with olefin-based monomers may be used alone or in combination of two or more.

Examples of polyolefin resins include: Ultra 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 copolymer, ethylene- (meth) acrylate copolymer Wait.

The modifier used when the polyolefin resin is modified is a compound having a functional group in the molecule. Functional groups include, for example, carboxyl, carboxylic anhydride, carboxylate, hydroxy, epoxy, amido, ammonium, nitrile, amine, amido, isocyanate, ethyl, and sulfur. Alcohol group, ether group, thioether group, sulfo group, phosphine group, nitro group, amine ester group, halogen atom and the like. Among these, 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 more preferable, and a carboxylic acid anhydride group, an alkoxysilyl group, and a particularly preferable one Carboxylic acid anhydride group. The compound having a functional group may have two or more kinds of functional groups in the molecule.

Examples of the modified polyolefin-based resins include acid-modified polyolefin-based resins and silane-modified polyolefin-based resins. From the viewpoint of obtaining more excellent effects of the present invention, acid-modified polyolefin-based resins are preferred.

The so-called "acid-modified polyolefin resin" refers to a person who graft-modified polyolefin resin with an acid. For example, a polyolefin resin is reacted with an unsaturated carboxylic acid or an unsaturated carboxylic acid anhydride (hereinafter collectively referred to as "unsaturated carboxylic acid"), and a carboxyl group or a carboxylic anhydride group is introduced (graft modification).

Examples of unsaturated carboxylic acids that react with polyolefin resins include maleic acid, fumaric acid, itaconic acid, citraconic acid, glutaric acid, tetrahydrophthalic acid, and aconite. Unsaturated carboxylic acids such as acids; unsaturated carboxylic anhydrides such as maleic anhydride, itaconic anhydride, glutaric anhydride, citraconic anhydride, aconitic anhydride, norbornene dicarboxylic anhydride, and tetrahydrophthalic anhydride. These systems can be used alone or in combination of two or more. Among these, from the viewpoint of easily obtaining an adhesive composition having more excellent adhesive strength, maleic anhydride is preferred.

The amount of unsaturated carboxylic acid or the like reacted with the polyolefin resin is preferably 0.1 to 5 parts by mass, more preferably 0.2 to 3 parts by mass, and 0.2 to 1.0 part by mass based on 100 parts by mass of the polyolefin resin. . The adhesive composition containing the acid-modified polyolefin resin obtained in this way is more excellent in adhesive strength.

As the acid-modified polyolefin resin, a commercially available product may be used. Examples of commercially available products include: ADMER (registered trademark) (manufactured by Mitsui Chemicals), UNISOLE (registered trademark) (manufactured by Mitsui Chemicals), BondyRam (manufactured by Polyram), orevac (registered trademark) (manufactured by ARKEMA), MODIC (registered trademark) (manufactured by Mitsubishi Chemical Corporation), etc.

The so-called "silane-modified polyolefin resin" refers to a graft-modified polyolefin resin using an unsaturated silane compound. The silane-modified polyolefin resin has a structure in which a main chain polyolefin resin is graft-copolymerized with an unsaturated silane compound belonging to a side chain. For example: Silane modified polyethylene resin and silane modified ethylene-vinyl acetate copolymer. Among them, preferred are silane-modified polyethylene resins such as silane-modified low-density polyethylene, silane-modified ultra-low-density polyethylene, and silane-modified linear low-density polyethylene.

The unsaturated silane compound that reacts with the polyolefin resin is preferably an ethylene silane compound, and examples thereof include ethylene trimethoxy silane, ethylene triethoxy silane, ethylene tripropoxy silane, and ethylene triisopropoxy Silane, ethylenetributoxysilane, ethylenetripentyloxysilane, ethylenetriphenoxysilane, ethylenetribenzyloxysilane, ethylenetrimethylenedioxysilane, ethylenetrimethylenedioxysilane, ethylenepropane Ethoxysilane, ethylene triethoxysilane, ethylene tricarboxysilane, etc. These systems can be used alone or in combination of two or more. When the unsaturated silane compound is graft-polymerized to a polyolefin resin belonging to the main chain, the conditions may be a conventional method of 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, more preferably 0.3 to 7 parts by mass, and 0.5 to 5 parts by mass based on 100 parts by mass of the polyolefin resin. When the amount of the unsaturated silane compound to be reacted is within the above range, the adhesive composition containing the obtained silane-modified polyolefin resin becomes more excellent in adhesive strength.

Commercially available silane-modified polyolefin resins can also be used. Commercially available products include, for example, LINKLON (registered trademark) (manufactured by Mitsubishi Chemical Corporation). Particularly preferred are low-density polyethylene-based LINKLON, linear low-density polyethylene-based LINKLON, ultra-low-density polyethylene-based LINKLON, and ethylene-vinyl acetate copolymer-based LINKLON.

The modified polyolefin-based resin may be used singly or in combination of two or more kinds.

The number average molecular weight (Mn) of the modified polyolefin resin is preferably 10,000 to 2,000,000, and more preferably 20,000 to 1,500,000. Tetrahydrofuran (THF) is used as the number-average molecular weight (Mn) -based solvent of the modified polyolefin resin, and gel permeation chromatography (GPC) is performed to obtain a standard polystyrene conversion value.

(B) Component: Polyfunctional epoxy compound which is liquid at 25 ° C The adhesive composition of the present invention contains a polyfunctional epoxy compound which is liquid at 25 ° C as the component (B). The "polyfunctional epoxy compound which is liquid at 25 ° C" refers to a polyfunctional epoxy compound having a certain volume (excluding volatile components) at 25 ° C but having an indefinite shape. The viscosity at 25 ° C of the "polyfunctional epoxy compound in a liquid state at 25 ° C" used in the present invention is usually 0.1 to 100,000 mPa‧s, preferably 0.2 to 50,000 mPa‧s, and more preferably 0.3 to 10,000 mPa‧ s. The component (B) has an effect of reducing the storage elastic modulus of the adhesive composition when the adhesive composition is at a high temperature (hereinafter also referred to as "storage elastic modulus reduction effect"). Therefore, by using the adhesive composition of the present invention, it is possible to form an adhesive layer with excellent unevenness tracking property with high efficiency.

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

(B) The component system may be, for example, bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, hydrogenated bisphenol A epoxy resin, hydrogenated bisphenol F epoxy resin , Hydrogenated bisphenol S-type epoxy resin, etc. (B) The polyfunctional epoxy compound of a component may be used individually by 1 type, or may use 2 or more types together. The molecular weight of the polyfunctional epoxy compound of the component (B) is preferably 700 to 5,000, and more preferably 1,200 to 4,500. By using an adhesive composition containing the component (B) having a molecular weight of 700 or more, a lower outgassing sealing material can be easily obtained. On the other hand, since the adhesive composition containing the component (B) having a molecular weight of 5,000 or less is more excellent in fluidity, by using such an adhesive composition, an adhesive layer having more excellent unevenness tracking can be easily formed. .

The epoxy equivalent of the polyfunctional epoxy compound of the component (B) 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 a polyfunctional epoxy compound (B) component having an epoxy equivalent of 100 g / eq or more and 500 g / eq or less of the adhesive composition, a sealing material with high adhesive strength and excellent hardenability can be formed with high efficiency.

(C) component: polyfunctional epoxy compound which is solid at 25 degreeC The adhesive composition of this invention may contain the polyfunctional epoxy compound of (C) component which is solid at 25 degreeC. The "polyfunctional epoxy compound which is solid at 25 ° C" refers to a polyfunctional epoxy resin having a softening point in a temperature range of 25 ° C or higher. The polyfunctional epoxy compound of the component (C) is different from the polyfunctional epoxy compound of the component (B), and it is considered that there is almost no effect of reducing the storage elastic modulus. Therefore, instead of the component (B), the adhesive composition containing the component (C) is replaced, and the storage elastic modulus is hardly reduced even at a high temperature. However, when the component (C) is used in combination with the component (B), the storage elastic modulus reduction effect of the component (B) can be further improved. The reason is considered that the presence of the component (C) can increase the sea area ratio of the island structure described later. Furthermore, since the component (C) also has the effect of improving the film-forming property of the adhesive composition, the adhesive composition containing the (C) component can be more easily formed into a sheet shape. Therefore, it is more preferable that the adhesive composition of the present invention contains the component (C).

(C) The component system can be exemplified by bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, hydrogenated bisphenol A epoxy resin, and hydrogenated bisphenol F epoxy resin. , Hydrogenated bisphenol S-type epoxy resin, etc. (C) The polyfunctional epoxy compound of a component can be used individually by 1 type or in combination of 2 or more types. The molecular weight of the polyfunctional epoxy compound of the component (C) is preferably 500 to 10,000, and more preferably 1,000 to 5000.

In the adhesive composition of the present invention, the total amount of the (B) component and the (C) component is 100 parts by mass of the (A) component. [The case where the (C) component is not contained in the adhesive composition means (B) The component content (the same applies hereinafter)] is more than 100 parts by mass, preferably more than 100 parts by mass and 200 parts by mass, and more preferably 120 parts by mass and 200 parts by mass. When the total amount of the (B) component and the (C) component exceeds 100 parts by mass with respect to 100 parts by mass of the component (A), it can be efficiently formed. "Island" and an island structure adhesive layer of "sea" composed of a polyfunctional epoxy compound ((B) component and (C) component). Since the adhesive layer of such a sea-island structure has a significantly reduced storage elastic modulus during heating, it has excellent unevenness tracking.

When the adhesive composition of the present invention contains (C) component, the content ratio (mass ratio) of (B) component and (C) component is preferably [(B) component: (C) component] = 100: 1 ~ 1: 1, more preferably 10: 1 ~ 2: 1. As the amount of the component (C) relative to the component (B) increases, the shape of the adhesive composition tends to be easily maintained when the adhesive composition is formed into a sheet shape.

The adhesive composition of this invention may contain components other than said (A) component, (B) component, and (C) component. The component systems other than (A) component, (B) component, and (C) component are the following (D) component, (E) component, and (F) component, for example. (D) Component: Tackifier with a softening point of 80 ° C or higher (E) Component: Imidazole-based hardening catalyst (F) Component: Silane coupling agent

Component (D): Tackifier with a softening point of 80 ° C or higher The adhesive composition containing the component (B) has a low storage elastic modulus before hardening and is excellent in unevenness tracking. However, such an adhesive composition may be difficult to maintain a certain shape and may be difficult to form into a sheet shape. In particular, when the component (C) is not contained, or when the content of the component (C) is small, it tends to be difficult to form a sheet. In this case, by including the component (D), the moldability can be improved.

The component (D) of the tackifier is a tackifier having a softening point of 80 ° C or higher, and the rest is not particularly limited. Examples include: turpentine resins such as polymerized turpentine, polymerized turpentine esters, and turpentine derivatives; polyterpene resins, aromatic modified terpene resins and their hydrides, and terpene resins such as terpene phenol resins; Resins; 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 monomers Polyresin, α-methylstyrene / styrene copolymer resin, styrene monomer / aliphatic monomer copolymer resin, styrene monomer / α-methylstyrene / aliphatic resin A styrenic resin such as a monomer copolymer resin, a styrenic monomer monopolymer resin, a styrenic monomer / aromatic monomer copolymer resin, and the like. Among these, a styrene-based resin is more preferable, and a styrene-based monomer / aliphatic monomer copolymer resin is more preferable. These tackifiers can be used individually by 1 type or in combination of 2 or more types.

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

When the adhesive composition of the present invention contains the component (D), the content is preferably 1 to 200 parts by mass, and more preferably 10 to 150 parts by mass based on 100 parts by mass of the component (A). When the content of the component (D) is too small, the adhesive composition may be difficult to be formed into a sheet. On the other hand, if the content of the component (D) is too large, the adhesive layer may become brittle.

(E) Component: Imidazole-based hardening catalysts Examples of imidazole-based hardening catalysts are 2-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2- Ethyl-4-methylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5-dimethylol Imidazole and so on. Among these, 2-ethyl-4-methylimidazole is preferable. These imidazole-based hardening catalysts can be used alone or in combination of two or more.

By using an adhesive composition containing an imidazole-based hardening catalyst, a hardened material having excellent adhesiveness even at high temperatures can be easily obtained.

When the adhesive composition of the present invention contains the component (E), its content is 100 parts by mass relative to the total amount of the components (B) and (C), and is preferably 1 to 10 parts by mass, and more preferably 2 to 5 parts by mass. The hardened product of the adhesive composition having an imidazole-based hardening catalyst content within this range has excellent adhesion even at high temperatures.

(F) Component: Silane coupling agent A well-known silane coupling agent can be used for a silane coupling agent. Among them, an organic silicon compound having at least one alkoxysilyl group in the molecule is preferred. Examples of the silane coupling agent system include polymerizable unsaturated silicon compounds such as ethylenetrimethoxysilane, ethylenetriethoxysilane, methacryloxypropyltrimethoxysilane, etc .; 3-glycidoxy Silicon compounds with epoxy structure, such as propyltrimethoxysilane, 8-glycidoxyoctyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane; 3 -Aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -8-aminooctyltrimethoxysilane, N -(2-aminoethyl) -3-aminopropylmethyldimethoxysilane and other amine-containing silicon compounds; 3-chloropropyltrimethoxysilane; 3-isocyanatepropyltriethoxysilane , 3-mercaptopropyltrimethoxysilane, 3-trimethoxysilylpropylsuccinic anhydride, and the like. These silane coupling agents can be used singly or in combination of two or more kinds.

By using an adhesive composition containing a silane coupling agent, a hardened product having more excellent adhesive strength under normal temperature and high temperature environments can be easily obtained.

When the adhesive composition of the present invention contains a silane coupling agent, the content thereof is preferably 0.01 to 10 parts by mass, and more preferably 0.02 to 5 parts by mass relative to 100 parts by mass of the component (A).

The adhesive composition of the present invention may contain a solvent. Examples of the solvent system 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; n-pentane, n-hexane, and n-hexane Aliphatic hydrocarbon solvents such as heptane; alicyclic hydrocarbon solvents such as cyclopentane, cyclohexane, and methylcyclohexane. These solvents may be used alone or in combination of two or more. The content of the solvent may be appropriately determined in consideration of coating properties and the like.

The adhesive composition of the present invention may contain other ingredients within a range that does not prevent the effect of the present invention. Examples of the other components include additives such as ultraviolet absorbers, antistatic agents, light stabilizers, antioxidants, resin stabilizers, fillers, pigments, extenders, and softeners. These systems can be used alone or in combination of two or more. When the adhesive composition of the present invention contains such additives, the content can be appropriately determined according to the purpose.

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

When the adhesive composition of the present invention is used to measure the storage elastic modulus of the solid content, the 23 ° C storage elastic modulus is preferably 0.1 to 600 MPa, and more preferably 0.2 to 500 MPa. With a storage elastic modulus of more than 0.1 MPa at 23 ° C, it can be easily formed into a sheet shape. On the other hand, when the storage elastic modulus at 23 ° C is 600 MPa or less, an adhesive layer that is relatively soft and has excellent sealing properties can be formed. In the present specification, the "solid content" refers to a solid portion excluding a volatile substance such as a solvent.

When measuring the storage elastic modulus of the adhesive composition of the present invention with respect to its solid content, the upper limit of the storage elastic modulus at 80 ° C. is preferably 0.1 MPa. The adhesive composition having an elastic modulus at 80 ° C. of 0.1 MPa or less tends to have good unevenness tracking. The lower limit of the storage elastic modulus at 80 ° C is preferably 1 kPa. The adhesive composition system having a storage elastic modulus at 80 ° C. of 1 kPa or more is more excellent in handling properties.

The storage elastic modulus of the solid content of the adhesive composition of the present invention may be, for example, a sheet-shaped adhesive obtained by coating the adhesive composition of the present invention and dried, as a test piece, and then according to the method described in the examples. Determination.

The adhesive composition having the above 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, if the component (B) is excessively added, it may be difficult to form the sheet into a sheet shape. In this case, by adding an appropriate amount of the (C) component, the moldability can be improved, and the storage elastic modulus at 80 ° C can be reduced.

The adhesive composition system of the present invention is easily formed into a sheet shape and has excellent unevenness tracking. Therefore, the adhesive composition of the present invention is suitable for forming a sealing material.

2) Adhesive sheet The adhesive sheet of the present invention is an adhesive sheet having an adhesive layer, and the adhesive layer is formed using the adhesive composition of the present invention.

The thickness of the adhesive layer of the adhesive sheet is not particularly limited, but is preferably 5 to 25 μm, and more preferably 10 to 20 μm. An adhesive layer having a thickness within the above range is suitable as a sealing material.

The adhesive sheet of the present invention may be provided with a release film. The release film functions as a support during the manufacturing process of the adhesive sheet, and functions as a protective sheet for the adhesive layer until the adhesive sheet is used. When using the adhesive sheet of the present invention, the release film is usually removed by peeling.

As the release film, conventionally known materials can be used. For example, a release layer is provided on the base material for a release film, which is subjected to 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-grade paper; laminated paper on which these thermoplastic base materials are laminated with a thermoplastic resin such as polyethylene; Diesel resin, polybutylene terephthalate resin, polyethylene naphthalate resin, polypropylene resin, polyethylene resin and other plastic films. Examples of the release agent include rubber-based elastomers such as silicone resin, olefin-based resin, isoprene-based resin, and butadiene-based resin; long-chain alkyl resin, alkyd resin, and fluorine resin Wait.

When the adhesive sheet is found to have a release film, the number of release films may be one or two, and usually one (a total of two) release films are provided on each side of the adhesive layer. In this case, the two peeling films may be the same or different, but it is preferable that the two peeling films have different peeling forces. Since the peeling force of the two peeling films is different, the adhesive sheet is less prone to problems during use. That is, by setting the peeling force of the two peeling films to be different, the step of tearing the peeling film first can be performed efficiently.

The manufacturing method of an adhesive sheet is not specifically limited. For example, an adhesive sheet can be manufactured using a casting method. When an adhesive sheet is produced by a casting method, the adhesive composition of the present invention is applied to a release-treated surface of a release film by using a known method, and the obtained coating film is dried to produce an adhesive having a release film. Layer, and then by superposing another release film on the adhesive layer, an adhesive sheet can be obtained.

Examples of the method for applying the adhesive composition include a spin coating method, a spray coating method, a bar coating method, a knife coating method, a roll coating method, a doctor blade coating method, a die coating method, and a gravure coating method. The drying conditions when the coating film is dried may be, for example, a drying temperature of 80 to 150 ° C. and a drying time of 30 seconds to 5 minutes.

The adhesive layer of the adhesive sheet of the present invention is thermosetting. The conditions when the adhesive layer is thermally cured are not particularly limited. The heating temperature is usually 80 to 200 ° C, preferably 90 to 150 ° C. The heating time is usually 30 minutes to 12 hours, and preferably 1 to 6 hours.

The 23 ° C tearing adhesive strength of the adhesive layer after hardening treatment is usually 1 ~ 100N / 25mm, preferably 10 ~ 50N / 25mm. The 85 ° C tearing adhesive strength is usually 1 to 100 N / 25 mm, and preferably 5 to 50 N / 25 mm. The peel strength at 23 ° C is tested according to JIS Z0237: 2009 at a temperature of 23 ° C, a relative humidity of 50%, and a temperature of 85 ° C (uncontrolled humidity). Measurable. The water vapor transmission rate of the adhesive layer after hardening treatment is usually 0.1 ~ 200g‧m ^-2 ‧day ^-1 , preferably 1 ~ 150g‧m ^-2 ‧day ^-1 . The water vapor transmission rate can be measured using a known water vapor transmission rate measuring device.

As described above, the adhesive layer of the adhesive sheet of the present invention is excellent in unevenness tracking. Therefore, by using the adhesive sheet of the present invention, the organic EL element and the like can be sealed without gaps.

3) Sealing body The object to be sealed in the sealing system of the present invention is sealed using the adhesive sheet of the present invention. The sealing system of the present invention includes, for example, a substrate, an element (an object to be sealed) formed on the substrate, and a sealing material for sealing the element. The sealing material may be, for example, an adhesive layer derived from the adhesive sheet of the present invention. (Hardened material of the adhesive layer).

The substrate is not particularly limited, and various substrate materials can be used. It is particularly preferable to use a substrate material having a high visible light transmittance. In addition, a material capable of preventing moisture and gas from penetrating from the outside of the element is preferred, and the material is excellent in solvent resistance and weather resistance. Specific examples include transparent inorganic materials such as quartz and glass; polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polystyrene, polyethylene, polypropylene, polyphenylene sulfide, Transparent plastics such as polyvinylidene fluoride, cellulose acetate, brominated phenoxy, aramide, polyimide, polystyrene, polyarylate, polyfluorene, and polyolefin; Sex film and so on. The thickness of the substrate is not particularly limited, and may be appropriately selected after considering light transmittance and blocking performance inside and outside the device.

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

The manufacturing method of the sealing body of this invention is not specifically limited. For example, after the adhesive layer of the adhesive sheet of the present invention is superimposed on an object to be sealed, heating is performed to adhere the adhesive layer of the adhesive sheet to the object to be sealed. Then, by hardening this adhesive layer, the sealing body of this invention can be manufactured.

There are no particular restrictions on the adhesion conditions when the adhesive layer of the adhesive sheet 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 while applying pressure. The hardening conditions at the time of hardening an adhesive layer are the conditions demonstrated previously.

The sealed object of the sealing system of the present invention is sealed by using the adhesive sheet of the present invention. Therefore, the sealing system of the present invention can maintain the performance of the sealed object for a long time. [Example]

Hereinafter, the present invention will be described in more detail with examples. However, the present invention is not limited in any way by the following examples. The "parts" and "%" in each case are the basis of quality without a special statement.

[Example 1] 100 parts of an acid-modified polyolefin resin (acid-modified α-olefin polymer, manufactured by Mitsui Chemicals, trade name: UNISTOLEH-200, number average molecular weight: 47,000), polyfunctional epoxy compound (1) 125 parts (hydrogenated bisphenol A epoxy resin, manufactured by Mitsubishi Chemical Corporation, product name: YX8034, liquid at 25 ° C, epoxy equivalent 270 g / eq), tackifier (styrene monomer aliphatic Based monomer copolymer, softening point 95 ° C, 50 parts by Mitsui Chemicals Corporation, trade name: FTR6100), and imidazole hardening catalyst (manufactured by Shikoku Chemical Co., Ltd., trade names: Curezol 2E4MZ, 2-ethyl-4- 1.25 parts of methyl imidazole) were dissolved in methyl ethyl ketone to prepare an adhesive composition 1 having a solid content concentration of 32%. 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 a 12 μm-thick adhesive film. The adhesive layer 1 was obtained by laminating another peeling treatment surface (made by Lintec Corporation, trade name: SP-PET381031) on the adhesive layer.

[Example 2] Except that in Example 1, the amount of the polyfunctional epoxy compound (1) was changed to 150 parts, and the amount of the imidazole-based curing catalyst was changed to 1.5 parts. Example 1 Similarly, an adhesive sheet 2 was obtained.

[Example 3] 100 parts of an acid-modified polyolefin resin (acid-modified α-olefin polymer, manufactured by Mitsui Chemicals, trade name: UNISTOLEH-200, number average molecular weight: 47,000), polyfunctional epoxy compound (2) (Hydrogenated bisphenol A epoxy resin, manufactured by Mitsubishi Chemical Corporation, trade name: YX8000, liquid at 25 ° C, epoxy equivalent: 205 g / eq), 100 parts, polyfunctional epoxy compound (3) ( Hydrogenated bisphenol A epoxy resin, manufactured by Mitsubishi Chemical Corporation, trade name: YX8040, solid at 25 ° C, epoxy equivalent: 1100g / eq) 25 parts, imidazole-based hardening catalyst (manufactured by Shikoku Chemical Co., Ltd., trade name) : 1 part of Curezol 2E4MZ, 2-ethyl-4-methylimidazole, and 0.1 part of a silane coupling agent (manufactured by Shin-Etsu Chemical Industry Co., Ltd., trade name: KBM4803), dissolved in methyl ethyl ketone to prepare a solid content concentration of 25%胶 胶 组合 物 2。 Adhesive composition 2. This adhesive composition 2 was applied to a release-treated surface of a release film (made by Lintec, trade name: SP-PET382150), and the obtained coating film was dried at 100 ° C for 2 minutes to form an adhesive having a thickness of 12 μm. The adhesive layer 3 was obtained by laminating another peeling treatment surface (manufactured by Lintec Corporation, trade name: SP-PET381031) on the adhesive layer.

[Example 4] An adhesive composition 3 was prepared in the same manner as in Example 3 except that the amount of the polyfunctional epoxy compound (3) was changed to 50 parts in Example 3 and used. An adhesive sheet 4 was obtained.

[Comparative Example 1] Except that in Example 1, the amount of the polyfunctional epoxy compound (1) was changed to 100 parts, and the amount of the imidazole-based curing catalyst was changed to 1.0 part. In Example 1, an adhesive sheet 5 was obtained in the same manner.

For the adhesive sheets 1 to 5 obtained in Examples 1, 2 and Comparative Example 1, the following tests were performed. [Measurement of Storage Elastic Modulus] The adhesive layers of the adhesive sheets obtained in the examples or comparative examples were stacked, and laminated using a heat press at 23 ° C. to obtain a laminated body having a thickness of 1 mm. This laminated body was used as a sample, and 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 storage elastic modulus measuring device (manufactured by Anton Paar, Physica MCR301). The storage elastic modulus at 23 ° C and 80 ° C is shown in Table 1.

[Evaluation of Concavity and Buriedness] The adhesive layer of the adhesive sheet obtained in the example or the comparative example was overlapped with a polyethylene terephthalate film (PET) having a thickness of 25 μm to obtain an adhesive layer with PET. On the other hand, a polyethylene terephthalate chip (simulation device) with a thickness of 10 μm was left to stand on a glass substrate. The above-mentioned adhesive layer with PET is overlapped on the glass substrate in such a manner that the adhesive layer is opposite to the glass substrate and completely covers the simulation device on the glass substrate. Next, these were heated to 60 ° C. using a hot press, and then the adhesive layer was cured under conditions of 100 ° C. and 2 hours. Observation was performed with an optical microscope, and the presence or absence of the unevenness | corrugation was investigated, and the unevenness | corrugation embedding property was evaluated based on the following criteria. ○: No floating. ×: There is floating. The evaluation results are shown in Table 1.

[Table 1]

The following items are known from Table 1. The content of the adhesive sheet-based polyfunctional epoxy compound of Examples 1 to 4 was more than that of the modified polyolefin-based resin. The adhesive sheets of Examples 3 and 4 both contained a polyfunctional epoxy compound that was liquid at 25 ° C and a polyfunctional epoxy compound that was solid at 25 ° C. Compared with the adhesive sheet of Comparative Example 1, these adhesive sheets have a lower storage elastic modulus at 80 ° C. and are more excellent in unevenness embedding.

no

no.

Claims (16)

An adhesive composition is an adhesive composition containing the following (A) component and (B) component, and may also contain the (C) component, and is characterized in that, with respect to 100 parts by mass of the (A) component, ( B) The total amount of component and (C) component exceeds 100 parts by mass; (A) Component: Modified polyolefin resin (B) Component: Polyfunctional epoxy compound (C) component that is liquid at 25 ° C : A polyfunctional epoxy compound that is solid at 25 ° C. For example, the adhesive composition according to item 1 of the patent application range, wherein the component (A) is an acid-modified polyolefin resin. For example, in the adhesive composition of claim 1, the total amount of the component (B) and the component (C) is more than 100 parts by mass and 200 parts by mass relative to 100 parts by mass of the component (A). The adhesive composition according to any one of claims 1 to 3, which contains the component (C). For example, the adhesive composition in the fourth scope of the patent application, wherein the content ratio (mass ratio) of the (B) component and (C) component is [(B) component: (C) component] = 100: 1 ~ 1 :1. For example, the adhesive composition according to item 1 of the patent application scope further contains the following (D) component: (D) Component: an adhesive with a softening point of 80 ° C or higher. For example, in the adhesive composition according to item 6 of the patent application, the content of the component (D) is 1 to 200 parts by mass based on 100 parts by mass of the component (A). For example, the adhesive composition according to item 1 of the patent application scope further includes the following (E) component: (E) component: an imidazole curing catalyst. For example, the adhesive composition according to item 8 of the patent application scope, wherein the content of the component (E) is 1 to 10 parts by mass based on 100 parts by mass of the total amount of the components (B) and (C). For example, the adhesive composition according to item 1 of the patent application scope further contains the following component (F): (F) component: a silane coupling agent. For example, the adhesive composition according to item 10 of the patent application range, wherein the content of the component (F) is 0.01 to 10 parts by mass relative to 100 parts by mass of the component (A). An adhesive sheet is an adhesive sheet having an adhesive layer, wherein the adhesive layer is formed by using an adhesive composition according to any one of claims 1 to 11. For example, the thickness of the adhesive layer is 5 to 25 μm. For example, the adhesive sheet of the scope of application for patent No. 12 is further provided with a release film. The utility model relates to a sealing body, which is used for sealing an object to be sealed using an adhesive sheet according to any one of claims 12 to 14. For example, the sealed body according to item 15 of the patent application scope, 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.