WO2019240261A1

WO2019240261A1 - Adhesive sheet for device sealing, and method for manufacturing device seal

Info

Publication number: WO2019240261A1
Application number: PCT/JP2019/023655
Authority: WO
Inventors: 健太西嶋; 樹長谷川
Original assignee: リンテック株式会社
Priority date: 2018-06-15
Filing date: 2019-06-14
Publication date: 2019-12-19
Also published as: JP7303188B2; KR20210021454A; TW202000843A; TWI811382B; JPWO2019240261A1; CN112368353B; CN112292435A; TWI813697B; JPWO2019240260A1; KR20210021455A; CN112368353A; CN112292435B; WO2019240260A1; KR102710152B1; JP7239579B2; TW202000832A

Abstract

The present invention is: an adhesive sheet for device sealing, having a first release film and a second release film, and an adhesive layer sandwiched by the first release film and the second release film, the adhesive sheet for device sealing satisfying all of a condition relating to a component included in the adhesive layer, a condition relating to the storage modulus of the adhesive layer, and a condition relating to the release force of the release films; and a method for manufacturing a device seal using the adhesive sheet for device sealing. When this adhesive sheet for device sealing is used, the release films can be released without tearing of the adhesive layer.

Description

Device sealing adhesive sheet and method for manufacturing device sealing body

This invention manufactures a device sealing body using the adhesive sheet for device sealing which has two peeling films, and the adhesive bond layer clamped by these peeling films, and this adhesive sheet for device sealing. Regarding the method.

In recent years, organic EL elements have attracted attention as light-emitting elements that can emit light with high luminance by low-voltage direct current drive.
However, the organic EL element has a problem that light emission characteristics such as light emission luminance, light emission efficiency, and light emission uniformity are likely to deteriorate with time.
As a cause of the problem of the deterioration of the light emission characteristics, it has been considered that oxygen, moisture and the like enter the inside of the organic EL element to deteriorate the electrode and the organic layer. For this reason, it has been proposed to form a sealing material using a pressure-sensitive adhesive layer or an adhesive layer having excellent moisture barrier properties and solve this problem.

For example, Patent Document 1 describes a sheet-like sealing material containing a specific epoxy resin, a specific alicyclic epoxy compound, a thermal cationic polymerization initiator, a photocationic polymerization initiator, and a specific sensitizer. ing.
The sealing material formed using the sheet-like sealing material described in Patent Document 1 has low oxygen permeability and moisture permeability, and has good sealing performance.

JP-A-2018-95679

However, it has been found that when a sealing material is formed using an adhesive layer as in Patent Document 1, a new problem may occur.
That is, the adhesive layer is usually manufactured and stored in a state of being sandwiched between two release films, and the release film is peeled and removed when used, but the first release film is not peeled cleanly and bonded. The agent layer sometimes ruptured.

The present invention has been made for the purpose of solving this problem, and has two release films and an adhesive layer sandwiched between these release films, without tearing the adhesive layer. It aims at providing the device sealing adhesive sheet which can peel a peeling film, and the method of manufacturing a device sealing body using this device sealing adhesive sheet.

In order to solve the above-mentioned problems, the inventors of the present invention provide a device sealing adhesive sheet having two release films and an adhesive layer containing a compound having a cyclic ether group sandwiched between these release films. We studied diligently.
As a result, a device that can peel the release film without tearing the adhesive layer by satisfying both the requirements for the storage elastic modulus at 23 ° C. of the adhesive layer and the requirements for the peel force of the two release films. It discovered that the adhesive sheet for sealing was obtained, and came to complete this invention.

Thus, according to the present invention, there are provided device sealing adhesive sheets [1] to [9] below and a method for producing a device sealing body [10].

[1] A device sealing adhesive sheet having a first release film and a second release film, and an adhesive layer sandwiched between the first release film and the second release film, the following requirements (I) A device sealing adhesive sheet that satisfies all of the requirements (III).
Requirement (I): The adhesive layer is a layer containing one or more compounds having a cyclic ether group.
Requirement (II): The storage elastic modulus of the adhesive layer at 23 ° C. is 5.0 × 10 ⁵ Pa or more and 3.0 × 10 ⁷ Pa or less.
Requirement (III): The value of the peeling force between the first release film and the adhesive layer is represented by x (mN / 50 mm), and the value of the peeling force between the second release film and the adhesive layer is When expressed as y (mN / 50 mm), the device sealing adhesive sheet satisfies the following formula (1).

[2] The device sealing adhesive sheet according to [1], wherein at least one of the compounds having a cyclic ether group is a liquid compound at 25 ° C.
[3] The device sealing adhesive sheet according to [2], wherein the content of the compound having a cyclic ether group that is liquid at 25 ° C. is 53% by mass or more based on the entire adhesive layer.
[4] The device sealing adhesive sheet according to any one of [1] to [3], wherein the adhesive layer further contains a thermal cationic polymerization initiator.
[5] The adhesive sheet for device sealing according to [4], wherein at least one of the compounds having a cyclic ether group is a compound having a glycidyl ether group.
[6] The adhesive sheet for device sealing according to any one of [1] to [5], wherein the adhesive layer further contains a binder resin.
[7] The device sealing adhesive sheet according to [6], wherein the binder resin is a resin having a glass transition temperature of 90 ° C. or higher.
[8] The device sealing adhesive according to any one of [1] to [7], wherein a layer obtained by curing the adhesive layer has a storage elastic modulus at 90 ° C. of 1 × 10 ⁸ Pa or more. Sheet.
[9] The device sealing adhesive sheet according to any one of [1] to [8], wherein a peel force value x between the first release film and the adhesive layer is 30 to 200 mN / 50 mm.
[10] A step of peeling the second release film from the device sealing adhesive sheet according to any one of [1] to [9], and the exposed adhesive layer is sealed in a temperature environment of 20 to 30 ° C. A method for producing a device sealing body, comprising a step of attaching to an object or a substrate.

According to the present invention, the device sealing adhesive has two release films and an adhesive layer sandwiched between these release films, and can release the release film without tearing the adhesive layer. A sheet and a method for producing a device sealing body using the device sealing adhesive sheet are provided.

The device sealing adhesive sheet of the present invention is a device sealing adhesive sheet having a first release film and a second release film, and an adhesive layer sandwiched between the first release film and the second release film. Thus, the above-mentioned requirement (I), requirement (II), and requirement (III) are all satisfied.

In the present invention, the “first release film” refers to one having a high peel strength among the two release films, and the “second release film” refers to a one having a low peel strength among the two release films. Say.
The “adhesive layer” is a layer obtained by forming a curable adhesive into a coating film, and is a layer having curability, tackiness, and adhesiveness. That is, the “adhesive layer” is an uncured layer.
In the present specification, the “layer obtained by curing the adhesive layer” may be referred to as “adhesive cured product layer”. This adhesive hardened | cured material layer is utilized as a sealing material.
In the present invention, “curing” means that the cohesive force and storage elastic modulus of the layer are increased by the reaction of the cyclic ether group contained in the adhesive layer.

[Adhesive layer]
(Compound having a cyclic ether group)
The adhesive layer contains one or more compounds having a cyclic ether group (hereinafter sometimes referred to as “cyclic ether compound (A)”).
By curing the adhesive layer containing the cyclic ether compound (A), a sealing material having high adhesive strength and excellent water vapor barrier properties can be formed.

The cyclic ether compound (A) refers to a compound having at least one, preferably two or more cyclic ether groups in the molecule. In the present invention, the phenoxy resin described later is not included in the cyclic ether compound (A).

The molecular weight of the cyclic ether compound (A) is usually 100 to 5,000, preferably 200 to 3,000.
The cyclic ether equivalent of the cyclic ether compound (A) is preferably 50 to 1000 g / eq, more preferably 100 to 800 g / eq.
By curing the adhesive layer containing the cyclic ether compound (A) having a cyclic ether equivalent weight in the above range, a sealing material having higher adhesive strength and superior moisture barrier properties can be formed more efficiently.
The cyclic ether equivalent in the present invention means a value obtained by dividing the molecular weight by the number of cyclic ether groups.

Examples of the cyclic ether group include an oxirane group (epoxy group), an oxetane group (oxetanyl group), a tetrahydrofuryl group, and a tetrahydropyranyl group. Among these, from the viewpoint that a sealing material with higher adhesive strength can be formed, the cyclic ether group is preferably an oxirane group or an oxetane group, and more preferably an oxirane group.
For the same reason, the cyclic ether compound (A) preferably has two or more oxirane groups or oxetane groups in the molecule, and more preferably has two or more oxirane groups in the molecule.

As a compound which has an oxirane group in a molecule | numerator, an aliphatic epoxy compound (except an alicyclic epoxy compound), an aromatic epoxy compound, an alicyclic epoxy compound etc. are mentioned, for example.
Examples of aliphatic epoxy compounds include monofunctional epoxy compounds such as glycidyl ethers of aliphatic alcohols and glycidyl esters of alkylcarboxylic acids;
And polyfunctional epoxy compounds such as polyglycidyl etherified products of aliphatic polyhydric alcohols or alkylene oxide adducts thereof, and polyglycidyl esters of aliphatic long-chain polybasic acids.

Typical examples of these aliphatic epoxy compounds include alkenyl glycidyl ethers such as allyl glycidyl ether; alkyl glycidyl ethers such as butyl glycidyl ether, 2-ethylhexyl glycidyl ether, and C12-13 mixed alkyl glycidyl ether; 1,4- Butanediol diglycidyl ether, neopentyl glycol diglycidyl ether, triglycidyl ether of glycerin, triglycidyl ether of trimethylolpropane, tetraglycidyl ether of sorbitol, hexaglycidyl ether of dipentaerythritol, diglycidyl ether of polyethylene glycol, polypropylene glycol Diglycidyl ether, dicyclopentadiene dimethanol diglycidyl ether, etc. Glycidyl ether of alcohol; polyglycidyl etherified product of polyether polyol obtained by adding one or two or more alkylene oxides to an aliphatic polyhydric alcohol such as propylene glycol, trimethylolpropane and glycerin; aliphatic long chain Diglycidyl esters of dibasic acids; monoglycidyl ethers of higher aliphatic alcohols, glycidyl esters of higher fatty acids, epoxidized soybean oil, octyl epoxy stearate, butyl epoxy stearate, epoxidized polybutadiene, and the like.

Moreover, a commercial item can also be used as an aliphatic epoxy compound. Commercially available products include Denacol EX-121, Denacol EX-171, Denacol EX-192, Denacol EX-211, Denacol EX-212, Denacol EX-313, Denacol EX-314, Denacol EX-321, Denacol EX-411, Denacol EX-421, Denacol EX-512, Denacol EX-521, Denacol EX-611, Denacol EX-612, Denacol EX-614, Denacol EX-622, Denacol EX-810, Denacol EX-811, Denacol EX-850, Denacol EX-851, Denacol EX-821, Denacol EX-830, Denacol EX-832, Denacol EX-841, Denacol EX-861, Denacol EX-911, Denacol EX-941, Call EX-920, Denacol EX-931 (manufactured by Nagase ChemteX Corporation);
Epolite M-1230, Epolite 40E, Epolite 100E, Epolite 200E, Epolite 400E, Epolite 70P, Epolite 200P, Epolite 400P, Epolite 1500NP, Epolite 1600, Epolite 80MF, Epolite 100MF (above, Kyoeisha Chemical Co., Ltd.);
Adekaglycilol ED-503, Adekaglycilol ED-503G, Adekaglycilol ED-506, Adekaglycilol ED-523T (manufactured by ADEKA, Inc.);

Examples of aromatic epoxy compounds include phenols having at least one aromatic ring, such as phenol, cresol, and butylphenol, or mono / polyglycidyl etherified products of alkylene oxide adducts thereof; epoxy compounds having aromatic heterocycles, etc. Is mentioned.
Representative compounds of these aromatic epoxy compounds include bisphenol A, bisphenol F, or glycidyl etherified compounds or epoxy novolac resins obtained by further adding alkylene oxide to these compounds;
Mono / polyglycidyl etherified products of aromatic compounds having two or more phenolic hydroxyl groups such as resorcinol, hydroquinone, catechol;
Glycidyl etherified products of aromatic compounds having two or more alcoholic hydroxyl groups such as phenyldimethanol, phenyldiethanol and phenyldibutanol;
Glycidyl ester of polybasic aromatic compound having two or more carboxylic acids such as phthalic acid, terephthalic acid, trimellitic acid, glycidyl ester of benzoic acid, epoxide of styrene oxide or divinylbenzene;
And epoxy compounds having a triazine skeleton such as 2,4,6-tri (glycidyloxy) -1,3,5-triazine.

Moreover, a commercial item can also be used as an aromatic epoxy compound. Commercially available products include Denacol EX-146, Denacol EX-147, Denacol EX-201, Denacol EX-203, Denacol EX-711, Denacol EX-721, Oncoat EX-1020, Oncoat EX-1030, Oncoat EX -1040, on-coat EX-1050, on-coat EX-1051, on-coat EX-1010, on-coat EX-1011, on-coat 1012 (above, manufactured by Nagase ChemteX);
Ogsol PG-100, Ogsol EG-200, Ogsol EG-210, Ogsol EG-250 (above, manufactured by Osaka Gas Chemical Company);
HP4032, HP4032D, HP4700 (above, manufactured by DIC);
ESN-475V (above, manufactured by Nippon Steel Chemical &Materials);
JER (former Epicoat) YX8800 (above, manufactured by Mitsubishi Chemical Corporation);
Marproof G-0105SA, Marproof G-0130SP (above, manufactured by NOF Corporation);
Epicron N-665, Epicron HP-7200 (above, manufactured by DIC);
EOCN-1020, EOCN-102S, EOCN-103S, EOCN-104S, XD-1000, NC-3000, EPPN-501H, EPPN-501HY, EPPN-502H, NC-7000L (above, Nippon Kayaku Co., Ltd.);
Adeka Resin EP-4000, Adeka Resin EP-4005, Adeka Resin EP-4100, Adeka Resin EP-4901 (above, manufactured by ADEKA);
TECHMORE VG-3101L (above, manufactured by Printec);
TEPIC-FL, TEPIC-PAS, TEPIC-UC (manufactured by Nissan Chemical Co., Ltd.);

As the alicyclic epoxy compound, a polyglycidyl etherified product of a polyhydric alcohol having at least one alicyclic structure, or cyclohexene oxide or cyclopentene obtained by epoxidizing a cyclohexene or cyclopentene ring-containing compound with an oxidizing agent. An oxide containing compound is mentioned.
Typical examples of these alicyclic epoxy compounds include hydrogenated bisphenol A diglycidyl ether, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, and 3,4-epoxy-1-methylcyclohexyl. -3,4-epoxy-1-methylhexanecarboxylate, 6-methyl-3,4-epoxycyclohexylmethyl-6-methyl-3,4-epoxycyclohexanecarboxylate, 3,4-epoxy-3-methylcyclohexylmethyl -3,4-epoxy-3-methylcyclohexanecarboxylate, 3,4-epoxy-5-methylcyclohexylmethyl-3,4-epoxy-5-methylcyclohexanecarboxylate, bis (3,4-epoxycyclohexylmethyl) adip 3,4-epoxy-6-methylcyclohexanecarboxylate, methylenebis (3,4-epoxycyclohexane), propane-2,2-diyl-bis (3,4-epoxycyclohexane), 2,2-bis (3 4-epoxycyclohexyl) propane, dicyclopentadiene diepoxide, ethylenebis (3,4-epoxycyclohexanecarboxylate), dioctyl epoxyhexahydrophthalate, di-2-ethylhexyl epoxyhexahydrophthalate, 1-epoxyethyl-3 , 4-epoxycyclohexane, 1,2-epoxy-2-epoxyethylcyclohexane, α-pinene oxide, limonene dioxide and the like.

Moreover, a commercial item can also be used as an alicyclic epoxy compound. Commercially available products include Celoxide 2021P, Celoxide 2081, Celoxide 2000, Celoxide 3000 (above, manufactured by Daicel Corporation); Epolite 4000 (produced by Kyoeisha Chemical Co., Ltd.); YX8000, YX8034 (above, manufactured by Mitsubishi Chemical Corporation); Adeka Resin EP-4088S, Adeka Resin EP-4088L, Adeka Resin EP-4080E (manufactured by ADEKA);

In addition, examples of the compound having an oxirane group in the molecule include an epoxy compound having both an alicyclic structure and an aromatic ring in one molecule. An example of such a compound is Epicron HP-7200 (manufactured by DIC).

Among these, from the viewpoint of reducing the dielectric constant of the cured adhesive layer, the oxirane group-containing compound is preferably an alicyclic epoxy resin.
Moreover, when using a thermal cationic polymerization initiator as a curing catalyst described later, the compound having an oxirane group is preferably a compound having a glycidyl ether group. Glycidyl ether groups undergo a relatively mild cationic polymerization reaction. Therefore, when the manufacturing process of the adhesive layer includes a process of heating the composition containing the components constituting the adhesive layer (for example, a process of heating to 90 ° C. or higher), the polymerization reaction of the glycidyl ether group is difficult to proceed. It is easy to keep the storage elastic modulus of the adhesive layer at 23 ° C. low. The content of the compound having a glycidyl ether group is preferably 70% by mass or more, and preferably 90% by mass or more with respect to the entire compound having a cyclic ether group.

Examples of the compound having an oxetane group in the molecule include 3,7-bis (3-oxetanyl) -5-oxa-nonane, 1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene, 1, 2-bis [(3-ethyl-3-oxetanylmethoxy) methyl] ethane, 1,3-bis [(3-ethyl-3-oxetanylmethoxy) methyl] propane, ethylene glycol bis (3-ethyl-3-oxetanylmethyl) ) Ether, triethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, tetraethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, 1,4-bis (3-ethyl-3-oxetanylmethoxy) Bifunctional fats such as butane and 1,6-bis (3-ethyl-3-oxetanylmethoxy) hexane Group oxetane compounds, 3-ethyl-3-[(phenoxy) methyl] oxetane, 3-ethyl-3- (hexyloxymethyl) oxetane, 3-ethyl-3- (2-ethylhexyloxymethyl) oxetane, 3-ethyl And monofunctional oxetane compounds such as -3- (hydroxymethyl) oxetane and 3-ethyl-3- (chloromethyl) oxetane.

A commercial item can also be used as a compound which has an oxetane group in a molecule | numerator. Commercially available products include 2-hydroxyethyl vinyl ether, diethylene glycol monovinyl ether, 4-hydroxybutyl vinyl ether (manufactured by Maruzen Petrochemical Co., Ltd.);
Aron Oxetane OXT-121, OXT-221, EXOH, POX, OXA, OXT-101, OXT-211, OXT-212 (above, manufactured by Toagosei Co., Ltd.);
Etanacol OXBP, OXTP (manufactured by Ube Industries, Ltd.) and the like can be mentioned.

These cyclic ether compounds (A) can be used singly or in combination of two or more.

The content of the cyclic ether compound (A) in the adhesive layer (when two or more cyclic ether compounds (A) are included, the total amount thereof) is preferably 45 to 90 mass with respect to the entire adhesive layer. %, More preferably 50 to 85% by mass, still more preferably 60 to 80% by mass.
By making content of a cyclic ether compound (A) into the said range, it becomes easy to obtain an adhesive cured material layer with a high storage elastic modulus in 90 degreeC.

At least one of the cyclic ether compounds (A) in the adhesive layer is preferably a compound that is liquid at 25 ° C. (cyclic ether compound (AL) that is liquid at 25 ° C.). Here, the liquid is one of the aggregated states of substances and has a substantially constant volume but does not have a specific shape.
By using a cyclic ether compound (AL) that is liquid at 25 ° C., it is possible to prevent the storage elastic modulus of the adhesive layer at 23 ° C. from becoming too high. For this reason, it becomes easy to obtain an adhesive layer having sufficient adhesive strength near room temperature (meaning 20 to 30 ° C., hereinafter the same).

From the viewpoint of adjusting the storage elastic modulus at 23 ° C. of the adhesive layer, the cyclic ether equivalent of the cyclic ether compound (AL) which is liquid at 25 ° C. is preferably 150 to 1000 g / eq, more preferably 240 to 900 g / eq. is there.

The content of the cyclic ether compound (AL) that is liquid at 25 ° C. in the adhesive layer (the total amount when containing two or more compounds) is preferably 53% by mass with respect to the entire adhesive layer. The above is more preferably 53 to 80% by mass, and still more preferably 54 to 65% by mass. When the content of the cyclic ether compound (AL) that is liquid at 25 ° C. is 53% by mass or more with respect to the entire adhesive layer, an adhesive layer having sufficient adhesive strength near room temperature is easily obtained. In addition, it becomes easy to obtain a cured adhesive layer having a high storage elastic modulus at 90 ° C. Moreover, it becomes easy to raise the storage elastic modulus in 23 degreeC of an adhesive bond layer because content of the cyclic ether compound (AL) which is liquid at 25 degreeC is 80 mass% or less with respect to the whole adhesive bond layer.

(Binder resin)
The adhesive layer may contain a binder resin (B). The adhesive layer containing the binder resin is excellent in shape retention and handling properties.

The weight average molecular weight (Mw) of the binder resin (B) is not particularly limited, but is preferably more than 10,000, more preferably more excellent in compatibility with the cyclic ether compound (A) and further in shape retention. Is 10,000 to 150,000, more preferably 10,000 to 100,000.
The weight average molecular weight (Mw) of the binder resin can be obtained as a standard polystyrene equivalent value by performing gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent.

When the adhesive layer contains the binder resin (B), the content of the binder resin (the total amount when containing two or more binder resins) is preferably 5 to 50 with respect to the entire adhesive layer. % By mass, more preferably 10 to 45% by mass.
When the content of the binder resin (B) is within the above range, an adhesive layer having excellent shape retention and sufficient adhesive force can be easily obtained.

As will be described later, when the storage elastic modulus at 90 ° C. of the cured adhesive layer is 1 × 10 ⁸ Pa or higher, the binder resin (B) is a resin having a glass transition temperature of 90 ° C. or higher. It is preferable because the storage elastic modulus at 90 ° C. of the cured product layer tends to increase. Examples of the resin having a glass transition temperature of 90 ° C. or higher include some phenoxy resins, polyimide resins, polyamideimide resins, polyvinyl butyral resins, and polycarbonate resins. Examples of the resin having a glass transition temperature of less than 90 ° C. include acrylic resins, urethane resins, and olefin resins.
These resins can be used alone or in combination of two or more.

The binder resin (B) is preferably at least one selected from the group consisting of phenoxy resins and modified olefin resins. From the viewpoint of increasing the storage elastic modulus at 90 ° C. of the cured adhesive layer, a phenoxy resin is used. A resin is preferred.

The phenoxy resin generally corresponds to a high molecular weight epoxy resin and has a degree of polymerization of about 100 or more.

The phenoxy resin used in the present invention preferably has a weight average molecular weight (Mw) of 10,000 to 150,000, and more preferably 10,000 to 100,000. The weight average molecular weight (Mw) of the phenoxy resin can be obtained as a standard polystyrene equivalent value by performing gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent.
A phenoxy resin corresponding to such a high molecular weight epoxy resin is excellent in heat distortion resistance.
The epoxy equivalent of the phenoxy resin used in the present invention is preferably 5,000 or more, more preferably 7,000 or more. The value of epoxy equivalent can be measured according to JIS K7236.

Examples of the phenoxy resin used in the present invention include bisphenol A type, bisphenol F type, bisphenol S type phenoxy resin, copolymer type phenoxy resin of bisphenol A type and bisphenol F type, distilled products thereof, naphthalene type phenoxy resin, novolak type phenoxy. Examples thereof include resins, biphenyl type phenoxy resins, cyclopentadiene type phenoxy resins, and the like.
These phenoxy resins can be used singly or in combination of two or more.

The phenoxy resin can be obtained by a method in which a bifunctional phenol and epihalohydrin are reacted to a high molecular weight, or a bifunctional epoxy resin and a bifunctional phenol are obtained by a polyaddition reaction.
For example, it can be obtained by reacting a bifunctional phenol with epihalohydrin in the presence of an alkali metal hydroxide in an inert solvent at a temperature of 40 to 120 ° C. In addition, an amide solvent, an ether solvent, a boiling point of 120 ° C. or higher in the presence of a catalyst such as an alkali metal compound, an organic phosphorus compound, or a cyclic amine compound, and a bifunctional epoxy resin and a bifunctional phenol. It can also be obtained by polyaddition reaction by heating to 50 to 200 ° C. in an organic solvent such as a ketone solvent, a lactone solvent, an alcohol solvent or the like at a reaction solid concentration of 50% by weight or less.

The bifunctional phenols are not particularly limited as long as they are compounds having two phenolic hydroxyl groups. For example, monocyclic bifunctional phenols such as hydroquinone, 2-bromohydroquinone, resorcinol, and catechol; bisphenols such as bisphenol A, bisphenol F, bisphenol AD, and bisphenol S; dihydroxybiphenyls such as 4,4′-dihydroxybiphenyl; Dihydroxyphenyl ethers such as bis (4-hydroxyphenyl) ether; and the aromatic ring of these phenol skeletons in a linear alkyl group, branched alkyl group, aryl group, methylol group, allyl group, cyclic aliphatic group, halogen ( Tetrabromobisphenol A etc.), nitro group etc. introduced; straight chain alkyl group, branched alkyl group, allyl group, allyl group with substituent on the carbon atom at the center of these bisphenol skeletons, cycloaliphatic Group, alkoxy Polycyclic bifunctional phenols obtained by introducing carbonyl group or the like; and the like.

Epihalohydrins include epichlorohydrin, epibromohydrin, epiiodohydrin, and the like.

In the present invention, a commercially available product can also be used as the phenoxy resin. For example, trade names: YX7200 (glass transition temperature: 150 ° C.), YX6954 (bisphenolacetophenone skeleton-containing phenoxy resin, glass transition temperature: 130 ° C.), YL7553, YL6794, YL7213, YL7290, YL7482, YX8100 (bisphenol) S skeleton-containing phenoxy resin), trade names manufactured by Tohto Kasei Co., Ltd .: FX280, FX293, FX293S (fluorene skeleton-containing phenoxy resin), trade names manufactured by Mitsubishi Chemical Corporation: jER1256, jER4250 (glass transition temperature: less than 85 ° C.), jER4275 (Glass transition temperature: 75 ° C.), trade names: YP-50 (glass transition temperature: 84 ° C.), YP-50S (both bisphenol A skeleton-containing phenoxy resin), YP 70 (a bisphenol A skeleton / bisphenol F skeleton copolymer type phenoxy resin, a glass transition temperature below 85 ℃), ZX-1356-2 (glass transition temperature: 72 ° C.), and the like. In addition, the glass transition temperature was shown about what has known the glass transition temperature.

The modified olefin resin is an olefin resin having a functional group introduced, which is obtained by subjecting an olefin resin as a precursor to a modification treatment using a modifier.

Olefin resin means a polymer containing repeating units derived from olefin monomers. The olefin resin may be a polymer composed only of a repeating unit derived from an olefin monomer, or a monomer copolymerizable with an olefin monomer and a repeating unit derived from an olefin monomer. The polymer which consists of a repeating unit derived from may be sufficient.

The olefin monomer is preferably an α-olefin having 2 to 8 carbon atoms, more preferably ethylene, propylene, 1-butene, isobutylene, or 1-hexene, and even more preferably ethylene or propylene. These olefinic monomers can be used alone or in combination of two or more.
Examples of the monomer copolymerizable with the olefin monomer include vinyl acetate, (meth) acrylic acid ester, and styrene. Here, “(meth) acrylic acid” means acrylic acid or methacrylic acid (the same applies hereinafter).
The monomers copolymerizable with these olefinic monomers can be used singly or in combination of two or more.

Examples of olefin resins include very low density polyethylene (VLDPE), low density polyethylene (LDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), linear low density polyethylene, polypropylene (PP), and ethylene-propylene. Examples include copolymers, olefin elastomers (TPO), ethylene-vinyl acetate copolymers (EVA), ethylene- (meth) acrylic acid copolymers, ethylene- (meth) acrylic acid ester copolymers, and the like.

The modifier used for the modification treatment of the olefin resin is a compound having a functional group in the molecule.
Functional groups include carboxyl groups, carboxylic anhydride groups, carboxylic ester groups, hydroxyl groups, epoxy groups, amide groups, ammonium groups, nitrile groups, amino groups, imide groups, isocyanate groups, acetyl groups, thiol groups, ether groups. Thioether group, sulfone group, phosphone group, nitro group, urethane group, alkoxysilyl group, silanol group, halogen atom and the like. The compound having a functional group may have two or more kinds of functional groups in the molecule.

As the modified olefin resin, an acid-modified olefin resin is preferable.
The acid-modified olefin resin is a resin obtained by graft-modifying an olefin resin with an acid or an acid anhydride. For example, an olefin resin is reacted with an unsaturated carboxylic acid or an unsaturated carboxylic acid anhydride (hereinafter sometimes referred to as “unsaturated carboxylic acid”) to introduce a carboxyl group or a carboxylic acid anhydride group (graft). Modified).

Examples of the unsaturated carboxylic acid to be reacted with the olefin resin include unsaturated carboxylic acids such as maleic acid, fumaric acid, itaconic acid, citraconic acid, glutaconic acid, tetrahydrophthalic acid and aconitic acid; maleic anhydride, itaconic anhydride, And unsaturated carboxylic acid anhydrides such as glutaconic anhydride, citraconic anhydride, aconitic anhydride, norbornene dicarboxylic acid anhydride, and tetrahydrophthalic acid anhydride.
These can be used alone or in combination of two or more. Among these, maleic anhydride is preferable because a sealing material with higher adhesive strength is easily obtained.

The amount of the unsaturated carboxylic acid or the like to be reacted with the olefin resin is preferably 0.1 to 5 parts by mass, more preferably 0.2 to 3 parts by mass, and still more preferably 0 with respect to 100 parts by mass of the olefin resin. 2 to 1 part by mass. By curing the adhesive layer containing the acid-modified olefin resin thus obtained, a sealing material with higher adhesive strength can be formed.

The method for introducing the unsaturated carboxylic acid unit or the unsaturated carboxylic acid anhydride unit into the olefin resin is not particularly limited. For example, in the presence of a radical generator such as organic peroxides or azonitriles, a method in which an olefin resin and an unsaturated carboxylic acid are heated and melted to a temperature equal to or higher than the melting point of the olefin resin, or an olefin After dissolving resin and unsaturated carboxylic acid in organic solvent, graft copolymerization with unsaturated carboxylic acid or the like on olefin resin by heating and stirring in the presence of radical generator. A method is mentioned.

A commercially available product can also be used as the acid-modified olefin resin. Examples of commercially available products include Admer (registered trademark) (manufactured by Mitsui Chemicals), Unistor (registered trademark) (manufactured by Mitsui Chemicals), BondyRam (manufactured by Polyram), orevac (registered trademark) (manufactured by ARKEMA), Modic (registered trademark) (manufactured by Mitsubishi Chemical Corporation) and the like.

The weight average molecular weight (Mw) of the modified olefin resin is preferably 10,000 to 150,000, more preferably 30,000 to 100,000.
The weight average molecular weight (Mw) of the modified olefin resin can be obtained as a standard polystyrene equivalent value by performing gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent.

(Curing catalyst)
The adhesive layer may contain a curing catalyst. The curing catalyst is used for promoting the reaction of the cyclic ether group in the cyclic ether compound (A).
Examples of the curing catalyst include an anionic polymerization initiator and a cationic polymerization initiator.
From the viewpoint of allowing the curing reaction to proceed in a short time and improving the storage stability of the adhesive layer, a cationic polymerization initiator is preferred.

Anionic polymerization initiators include 2-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-ethyl-4-methylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl Examples include imidazole-based curing catalysts such as -4-methyl-5-hydroxymethylimidazole and 2-phenyl-4,5-dihydroxymethylimidazole.

Examples of the cationic polymerization initiator include a thermal cationic polymerization initiator and a photo cationic polymerization initiator, and can be used when it is difficult to irradiate the adhesive layer with light on the manufacturing process of the device sealing body. From the viewpoint of versatility of thermosetting equipment, a thermal cationic polymerization initiator is preferred.

The thermal cationic polymerization initiator is a compound capable of generating a cationic species that initiates polymerization upon heating.
Examples of the thermal cationic polymerization initiator include sulfonium salts, quaternary ammonium salts, phosphonium salts, diazonium salts, iodonium salts and the like. Among these, a sulfonium salt is preferable from the viewpoints of easy availability and easy to obtain a sealing material superior in adhesiveness and transparency.

Examples of the sulfonium salt include triphenylsulfonium tetrafluoroborate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium hexafluoroarsenate, tris (4-methoxyphenyl) sulfonium hexafluoroarsinate, diphenyl (4-phenylthiophenyl) sulfonium. Hexafluoroalcinate and the like can be mentioned.

Moreover, a commercial item can also be used as a sulfonium salt. Commercially available products include Adeka Opton SP-150, Adeka Opton SP-170, Adeka Opton CP-66, Adeka Opton CP-77 (manufactured by ADEKA), Sun-Aid SI-60L, Sun-Aid SI-80L, Sun-Aid SI-100L (and more, three Shin Chemical Co., Ltd.), CYRACURE UVI-6974, CYRACURE UVI-6990 (above, Union Carbide), UVI-508, UVI-509 (above, made by General Electric), FC-508, FC-509 ( The above includes Minnesota Mining and Manufacturing Co., Ltd.), CD-1010, CD-1011 (manufactured by Thurstomer Co., Ltd.), CI series products (Nihon Soda Co., Ltd.)

Examples of quaternary ammonium salts include tetrabutylammonium tetrafluoroborate, tetrabutylammonium hexafluorophosphate, tetrabutylammonium hydrogen sulfate, tetraethylammonium tetrafluoroborate, tetraethylammonium p-toluenesulfonate, N, N-dimethyl-N— Benzylanilinium hexafluoroantimonate, N, N-dimethyl-N-benzylanilinium tetrafluoroborate, N, N-dimethyl-N-benzylpyridinium hexafluoroantimonate, N, N-diethyl-N-benzyltrifluoromethanesulfonate N, N-dimethyl-N- (4-methoxybenzyl) pyridinium hexafluoroantimonate, N, N-diethyl-N- ( - etc. methoxybenzyl) preparative Luigi hexafluoroantimonate and the like specifically. Examples of the phosphonium salt include ethyltriphenylphosphonium hexafluoroantimonate and tetrabutylphosphonium hexafluoroantimonate.

Examples of the diazonium salt include AMERICURE (manufactured by American Can), ULTRASET (manufactured by ADEKA), and the like.

Examples of the iodonium salt include diphenyliodonium hexafluoroarsenate, bis (4-chlorophenyl) iodonium hexafluoroarsenate, bis (4-bromophenyl) iodonium hexafluoroarsinate, phenyl (4-methoxyphenyl) iodonium hexafluoroarsenate, etc. Is mentioned. In addition, commercially available products include UV-9310C (manufactured by Toshiba Silicone), Photoinitiator 2074 (manufactured by Rhone-Poulenc), UVE series products (manufactured by General Electric), and FC series products (Minnesota Mining and Manufacturing). Etc.) can also be used.

The photocationic polymerization initiator is a compound capable of generating a cationic species that initiates polymerization upon irradiation with light.
Examples of the photocationic polymerization initiator include aromatic sulfonium salts, aromatic iodonium salts, aromatic diazonium salts, and thioxanthonium salts.

An aromatic sulfonium salt is a salt having aromatic sulfonium as a cation moiety. The anion moiety includes anions such as BF ₄ ⁻ , PF ₆ ⁻ and SbF ₆ ^— .
Examples of aromatic sulfonium salts include triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, diphenyl-4- (phenylthio) phenylsulfonium hexafluorophosphate, diphenyl-4- (phenylthio) phenylsulfonium hexafluoroantimonate, and the like. Can be mentioned.

An aromatic iodonium salt is a salt having aromatic iodonium as a cation moiety. As an anion part, the thing similar to the anion part of an aromatic sulfonium salt is mentioned.
Aromatic iodonium salts include diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroantimonate, diphenyliodonium tetrafluoroborate, diphenyliodonium tetrakis (pentafluorophenyl) borate, bis (dodecylphenyl) iodonium hexafluorophosphate, 4-methylphenyl -4- (1-methylethyl) phenyliodonium hexafluorophosphate and the like.

An aromatic diazonium salt is a salt having aromatic diazonium as a cation moiety. As an anion part, the thing similar to the anion part of an aromatic sulfonium salt is mentioned.
Examples of the aromatic diazonium salt include phenyldiazonium hexafluorophosphate, phenyldiazonium hexafluoroantimonate, phenyldiazonium tetrafluoroborate, and phenyldiazonium tetrakis (pentafluorophenyl) borate.

A thioxanthonium salt is a salt having thioxanthonium as a cation moiety. As an anion part, the thing similar to the anion part of an aromatic sulfonium salt is mentioned.
Examples of the thioxanthonium salt include S-biphenyl-2-isopropylthioxanthonium hexafluorophosphate.

The adhesive layer may contain one type of curing catalyst or two or more types.
When the adhesive layer contains a curing catalyst, the content of the curing catalyst (the total amount of these when two or more curing catalysts are included) is not particularly limited, but relative to 100 parts by mass of the cyclic ether compound (A) The amount is preferably 0.1 to 15 parts by mass, more preferably 1 to 10 parts by mass.

(Silane coupling agent)
The adhesive layer may contain a silane coupling agent. By curing the adhesive layer containing the silane coupling agent, it is possible to form a sealing material that is superior in wet heat durability.

A known silane coupling agent can be used as the silane coupling agent. Of these, organosilicon compounds having at least one alkoxysilyl group in the molecule are preferred.
Silane coupling agents include 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltri Silane coupling agents having a (meth) acryloyl group, such as methoxysilane and 8-methacryloxyoctyltrimethoxysilane;
Silane coupling agents having a vinyl group such as vinyltrimethoxysilane, vinyltriethoxysilane, dimethoxymethylvinylsilane, diethoxymethylvinylsilane, trichlorovinylsilane, vinyltris (2-methoxyethoxy) silane, 6-octenyltrimethoxysilane;
2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, 8-glycid Silane coupling agents having an epoxy group such as xyloctyltrimethoxysilane;
Silane coupling agents having a styryl group such as p-styryltrimethoxysilane and p-styryltriethoxysilane;
N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltriethoxysilane 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1,3-dimethylbutylidene) propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N A silane coupling agent having an amino group such as hydrochloride of (vinylbenzyl) -2-aminoethyl-3-aminopropyltrimethoxysilane;
Silane coupling agents having a ureido group such as 3-ureidopropyltrimethoxysilane and 3-ureidopropyltriethoxysilane;
Silane coupling agents having a halogen atom such as 3-chloropropyltrimethoxysilane and 3-chloropropyltriethoxysilane;
Silane coupling agents having a mercapto group such as 3-mercaptopropylmethyldimethoxysilane and 3-mercaptopropyltrimethoxysilane;
Silane coupling agents having sulfide groups such as bis (trimethoxysilylpropyl) tetrasulfide and bis (triethoxysilylpropyl) tetrasulfide;
Silane coupling agents having an isocyanate group such as 3-isocyanatopropyltrimethoxysilane and 3-isocyanatopropyltriethoxysilane;
Silane coupling agents having an allyl group such as allyltrichlorosilane, allyltriethoxysilane, and allyltrimethoxysilane;
Silane coupling agents having a hydroxyl group such as 3-hydroxypropyltrimethoxysilane and 3-hydroxypropyltriethoxysilane;
Among these, 8-methacryloxyoctyltrimethoxysilane, 6-octenyltrimethoxysilane, and 8-glycidoxyoctyl are used from the viewpoint of improving the adhesiveness of the adhesive layer to the surface of the device to be sealed. A long-chain spacer type silane coupling agent having an alkyl group having 4 to 8 carbon atoms between an alkoxysilyl group and an organic group, such as trimethoxysilane, is preferable.
These silane coupling agents can be used alone or in combination of two or more.

When the adhesive layer contains a silane coupling agent, the content of the silane coupling agent (when two or more silane coupling agents are included, the total amount thereof) is preferably 0. The content is from 01 to 5% by mass, more preferably from 0.05 to 1% by mass.
Further, the content of the silane coupling agent is preferably 0.01 to 10 parts by mass, more preferably 0.02 to 5 parts by mass with respect to 100 parts by mass of the component (A).
When the content of the silane coupling agent is within the above range, it becomes easier to obtain a sealing agent having excellent wet heat durability.

(Other ingredients)
The adhesive layer may contain other components as long as the effects of the present invention are not hindered.
Examples of other components include additives such as ultraviolet absorbers, antistatic agents, light stabilizers, antioxidants, resin stabilizers, fillers, pigments, extenders, softeners, and tackifiers.
These can be used alone or in combination of two or more.
When the adhesive layer contains these additives, the content can be appropriately determined according to the purpose.

(Adhesive layer)
The shape and size of the adhesive layer are not particularly limited. Further, it may be a strip shape or a long shape. In this specification, “long shape” means a shape having a length of 5 times or more with respect to the width, preferably 10 times or more, and specifically wound in a roll shape. It refers to the shape of a film having a length that can be taken and stored or transported. Although the upper limit of the ratio of the length with respect to the width of a film is not specifically limited, For example, it can be 100,000 times or less.

The thickness of the adhesive layer is usually 1 to 50 μm, preferably 1 to 25 μm, more preferably 5 to 25 μm. An adhesive layer having a thickness in the above range is suitably used as a forming material for a sealing material.
The thickness of the adhesive layer can be measured according to JIS K 7130 (1999) using a known thickness meter.

The adhesive layer may have a single layer structure, or may have a multilayer structure (a structure in which a plurality of adhesive layers are laminated).
The adhesive layer may have a uniform component or a non-uniform component (for example, in the above-mentioned adhesive layer having a multilayer structure, the two components are mixed at the interface of the two adhesive layers). Or an apparently single layer structure).

The storage elastic modulus of the adhesive layer at 23 ° C. is 5.0 × 10 ⁵ Pa or more, preferably 7.0 × 10 ⁵ Pa or more. When the storage elastic modulus at 23 ° C. of the adhesive layer is 5.0 × 10 ⁵ Pa or more, the release film can be peeled without tearing the adhesive layer.
An adhesive layer having a storage elastic modulus at 23 ° C. of 5.0 × 10 ⁵ Pa or more is easily obtained by using, for example, a cyclic ether compound (A) having a large cyclic ether equivalent. Moreover, the storage elastic modulus in 23 degreeC of an adhesive bond layer can be reduced by reducing content in the adhesive bond layer of liquid cyclic ether compound (AL) at 25 degreeC. Further, by using a relatively rigid resin such as a phenoxy resin, storage at 23 ° C. is possible even when the content of the cyclic ether compound (AL) that is liquid at 25 ° C. in the adhesive layer is large. An adhesive layer having an elastic modulus of 5.0 × 10 ⁵ Pa or more is easily obtained.

The storage elastic modulus at 23 ° C. of the adhesive layer is 3.0 × 10 ⁷ Pa or less, preferably 2.0 × 10 ⁷ Pa or less, and more preferably 1.5 × 10 ⁷ Pa or less. Since the adhesive layer having a storage elastic modulus at 23 ° C. of 3.0 × 10 ⁷ Pa or less has a sufficient adhesive force at room temperature, the adhesive layer has excellent adhesiveness to an object to be sealed at room temperature.
An adhesive layer having a storage elastic modulus at 23 ° C. of 3.0 × 10 ⁷ Pa or less is easily obtained by increasing the amount of the cyclic ether compound (AL) that is liquid at 25 ° C., for example. Further, as described above, when the adhesive layer contains a thermal cationic polymerization initiator, the cyclic ether compound (A) is a compound having a glycidyl ether group, so that the adhesive layer is stored at 23 ° C. The elastic modulus is lowered, and it becomes easy to set it to 3.0 × 10 ⁷ Pa or less.

The storage elastic modulus of the adhesive layer can be measured using a known dynamic viscoelasticity measuring device.
Specifically, it can be measured by the method described in the examples.

The adhesive layer has curability. That is, by performing a predetermined curing treatment on the adhesive layer, the cyclic ether group in the cyclic ether compound (A) reacts, and the adhesive layer is cured to become an adhesive cured product layer.
Examples of the curing treatment include heat treatment and light irradiation treatment. These can be appropriately determined according to the properties of the adhesive layer.

The storage elastic modulus at 90 ° C. of the cured adhesive layer is preferably 1 × 10 ⁸ Pa or more, more preferably 1 × 10 ⁹ to 1 × 10 ¹¹ Pa. A cured adhesive layer having a storage elastic modulus at 90 ° C. of 1 × 10 ⁸ Pa or more is more suitable as a sealing material because it has excellent sealing properties. Moreover, in the process implemented for manufacture of a device sealing body after formation of an adhesive cured material layer, destruction and peeling of the adhesive cured material layer are easily prevented.

The storage elastic modulus of the cured adhesive layer can be measured using a known dynamic viscoelasticity measuring device.
Specifically, it can be measured by the method described in the examples.

The cured adhesive layer has excellent adhesive strength. The adhesive strength of the cured adhesive layer is usually 1 to 20 N / 25 mm, preferably 2.5 to 15 N / 25 mm when a 180 ° peel test is performed under conditions of a temperature of 23 ° C. and a relative humidity of 50%. . This 180 ° peel test can be performed, for example, under the conditions of a temperature of 23 ° C. and a relative humidity of 50% according to the method for measuring adhesive strength described in JIS Z0237: 2009.

When the adhesive sheet for device sealing of the present invention is used for sealing a display or the like, the cured adhesive layer is preferably excellent in colorless transparency. The total light transmittance of the cured adhesive layer having a thickness of 20 μm is preferably 85% or more, more preferably 90% or more. There is no particular upper limit on the total light transmittance, but it is usually 95% or less.
The total light transmittance can be measured according to JIS K7361-1: 1997.

The water vapor transmission rate of the cured adhesive layer is usually 0.1 to 200 g · m ⁻² · day ⁻¹ , preferably 1 to 150 g · m ⁻² · day ⁻¹ .
The water vapor transmission rate can be measured using a known gas transmission rate measuring device.

[Peeling film]
The adhesive sheet for device sealing of this invention has a 1st peeling film and a 2nd peeling film.
When using the device sealing adhesive sheet of the present invention, the release film is usually peeled off. At this time, since the second release film has a lower peeling force, the second release film is peeled off before the first release film.
In the following description, the “first release film” and the “second release film” are not distinguished and may be simply described as “release film”.

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

As the release film, a conventionally known film can be used. For example, what has a peeling layer on the base material for peeling films is mentioned. The release layer can be formed using a known release agent.

As the substrate for the release film, paper substrates such as glassine paper, coated paper, and high-quality paper; laminated paper obtained by laminating a thermoplastic resin such as polyethylene on these paper substrates; polyethylene terephthalate resin, polybutylene terephthalate resin, Examples thereof include plastic films such as polyethylene naphthalate resin, polypropylene resin, and polyethylene resin.
Examples of the release agent include rubber elastomers such as silicone resins, olefin resins, isoprene resins, and butadiene resins, long chain alkyl resins, alkyd resins, and fluorine resins.
The thickness of the release film is not particularly limited, but is usually about 20 to 250 μm.

[Adhesive sheet for device sealing]
The adhesive sheet for device sealing of this invention has the said 1st peeling film and 2nd peeling film, and the said adhesive bond layer pinched | interposed into these peeling films.
Examples of the device sealing adhesive sheet of the present invention include those having a three-layer structure of first release film / adhesive layer / second release film.

The method for producing the device sealing adhesive sheet of the present invention is not particularly limited. For example, the adhesive sheet for device sealing can be manufactured using the casting method.

When manufacturing the adhesive sheet for device sealing by the casting method, it can manufacture by the following method, for example.
Two release films having a release layer (a release film (A) and a release film (B)) and a coating solution containing components constituting the adhesive layer are prepared. Using a known method, the coating liquid is applied to the release layer surface of the release film (A), and the resulting coating film is dried to form an adhesive layer. Subsequently, an adhesive sheet for device sealing can be obtained by stacking the release film (B) on the adhesive layer so that the release layer surface of the release film (B) is in contact with the adhesive layer.

When adjusting the coating liquid by diluting the components constituting the adhesive layer, the solvent used for preparing the coating liquid includes aromatic hydrocarbon solvents such as benzene and toluene; esters such as ethyl acetate and butyl acetate Solvents; ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; aliphatic hydrocarbon solvents such as n-pentane, n-hexane, and n-heptane; alicyclic hydrocarbons such as cyclopentane, cyclohexane, and methylcyclohexane System solvents; 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 coating properties and the like.

Examples of the method for applying the coating liquid include spin coating, spray coating, bar coating, knife coating, roll coating, blade coating, die coating, and gravure coating.

Examples of the method for evaporating the solvent in the coating film and drying the coating film include conventionally known drying methods such as hot air drying, hot roll drying, and infrared irradiation.
The conditions for drying the coating film are, for example, 80 to 150 ° C. for 30 seconds to 5 minutes, and more preferably 90 to 120 ° C. for 1 minute to 4 minutes. By drying the coating film at 90 ° C. or more, it is easy to dry the coating film even with a drying time of 5 minutes or less, and the productivity is excellent.

The device sealing adhesive sheet of the present invention satisfies the following formula (1).

In the formula, x is a peel force between the first release film and the adhesive layer (hereinafter, sometimes referred to as “first peel force”. This unit is “mN / 50 mm”), and y. Is the peel force between the second peelable film and the adhesive layer (hereinafter sometimes referred to as “second peel force”. This unit is “mN / 50 mm”).

When the value of xy is 20 or more, the release film can be peeled without tearing the adhesive layer. The value of xy is preferably 25 to 500, more preferably 30 to 300.

The first peeling force is usually 30 to 200 mN / 50 mm, preferably 40 to 150 mN / 50 mm. If the first peeling force is in such a range, the second release film is peeled off and the adhesive layer is bonded to the adherend, and then the adhesive layer is peeled off from the adherend when the first release film is peeled off. The first release film can be easily removed without causing peeling.
The second peeling force is usually 5 to 50 mN / 50 mm, preferably 10 mN / 50 mm or more and less than 30 mN / 50 mm.
The first peeling force and the second peeling force can be measured according to the methods described in the examples.

The device sealing adhesive sheet satisfying the formula (1) and the device sealing adhesive sheet in which the first peeling force and the second peeling force are within the above ranges are, for example, 2 based on the tendency shown below. By appropriately selecting a single release film, it can be produced efficiently.

Generally, when the release film is thick, the release force tends to increase.
Moreover, in the manufacturing method of the above-mentioned adhesive sheet for device sealing, the peeling force between the release film (A) to which the coating liquid is applied and the adhesive layer is the release film ( Even if it uses the same peeling film compared with the peeling force between B) and an adhesive bond layer, there exists a tendency for peeling force to become high. Therefore, in such a manufacturing method, in order to increase the difference between the first peeling force and the second peeling force, it is preferable to manufacture using the first peeling film as the peeling film (A).
Moreover, about a peeling film (B), when it heats, when it overlaps with an adhesive bond layer, there exists a tendency for the peeling force between adhesive bond layers to become higher than when working at room temperature. Therefore, when using a 2nd peeling film as a peeling film (B), in order to enlarge the difference of a 1st peeling force and a 2nd peeling force, a peeling film (B) and an adhesive bond layer are piled up at room temperature. Is preferred.

When a release film having a release layer formed from a silicone resin is selected as the two release films, the following tendencies exist. Typical examples of the silicone-based resin include, for example, a first organopolysiloxane having at least two alkenyl groups (for example, vinyl groups) in one molecule and a second organopolysiloxane having at least two hydrosilyl groups in one molecule. And an addition reaction type silicone resin obtained from the organopolysiloxane (corresponding to a crosslinking agent). In this case, the rigidity of the skeleton of the addition reaction type silicone resin affects the hardness of the release agent layer and the release force of the release film. Moreover, when adding a silicone resin to an addition reaction type silicone resin, surface polarity can be adjusted with the compounding quantity of a silicone resin, and peeling force can be adjusted.

The method for producing a device sealing body using the device sealing adhesive sheet of the present invention is not particularly limited. For example, by performing the following steps (a1) to (a5) and steps (b1) to (b5), an object to be sealed (device) can be sealed and a device sealing body can be manufactured.

Step (a1): The second release film of the device sealing adhesive sheet is peeled and removed.
Step (a2): The adhesive layer exposed by performing step (a1) is attached to an object to be sealed (device).
Step (a3): The first release film is peeled off from the one obtained in step (a2).
Step (a4): The adhesive layer exposed by performing step (a3) is attached to a substrate (glass plate, gas barrier film, etc.).
Step (a5): The adhesive layer included in the step (a4) is cured by a predetermined means to form a cured adhesive layer.

Step (b1): The second release film of the device sealing adhesive sheet is peeled and removed.
Step (b2): The adhesive layer exposed by performing step (b1) is attached to a substrate (glass plate, gas barrier film, etc.).
Step (b3): The first release film is peeled off from the one obtained in step (b2).
Step (b4): The adhesive layer exposed by performing step (b3) is attached to an object to be sealed (device).
Step (b5): The adhesive layer included in the step (b4) is cured by a predetermined means to form a cured adhesive layer.

In the method for producing the above device-sealed body, in the step (a2) or the step (b2), the adhesive layer is attached to the object to be sealed or the substrate from the viewpoints of workability and productivity. It is preferable to carry out under an environment. Similarly, the step (b4) is also preferably performed in a room temperature environment.

In the device sealing adhesive sheet of the present invention, the release film can be peeled without tearing the adhesive layer.
Furthermore, the adhesive cured material layer formed using the adhesive layer constituting the device sealing adhesive sheet of the present invention is excellent in adhesive strength and water vapor barrier property. For this reason, the adhesive sheet for device sealing of this invention is used suitably as a forming material of the sealing material in a device sealing body.

The device sealing body is not particularly limited. Examples of the device sealing body include organic EL devices such as organic EL displays and organic EL lighting; liquid crystal displays; electronic paper; solar cells such as inorganic solar cells and organic thin film solar cells. When the cured adhesive layer obtained from the adhesive layer constituting the adhesive sheet for device sealing of the present invention is transparent, the adhesive sheet for device sealing of the present invention is an organic EL display, organic EL lighting, etc. The organic EL device; a liquid crystal display; and a material for forming a sealing material in an optical device such as electronic paper.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples.
Unless otherwise indicated, the part and% in each example are based on mass.

[Method for measuring storage modulus]
(1) Storage elastic modulus of adhesive layer It was obtained by laminating an adhesive layer of an adhesive sheet for device sealing obtained in Examples or Comparative Examples using a laminator until the thickness became 1 mm or more at 23 ° C. The storage modulus was measured using the laminate as a measurement sample.
That is, for this measurement sample, using a storage elastic modulus measuring device (product name: Physica MCR301, manufactured by Anton Paar), measurement was performed under the conditions of a frequency of 1 Hz, a strain of 1%, and a heating rate of 3 ° C./min. A storage modulus value of 23 ° C. was obtained.
(2) Storage elastic modulus of adhesive cured product layer The adhesive layer of the device sealing adhesive sheet obtained in the examples or comparative examples was laminated using a laminator until the thickness became 200 μm or more at 23 ° C. The obtained laminate was heated at 100 ° C. for 1 hour to obtain a cured product. Using this cured product as a measurement sample, its storage elastic modulus was measured.
That is, for this measurement sample, a storage elastic modulus measuring apparatus (TA Instruments, trade name: DMAQ800) was used, and the frequency was 11 Hz, the amplitude was 5 μm, and the temperature rising rate was 3 ° C./min. The storage elastic modulus in the temperature range of ˜ + 90 ° C. was measured to obtain a storage elastic modulus value of + 90 ° C.

[Measurement of peel strength of first peelable film and second peelable film]
The device-sealing adhesive sheets produced in Examples and Comparative Examples were cut to obtain test pieces having a width of 50 mm and a length of 150 mm. The test piece was subjected to a 180 ° peel test at a peel rate of 300 mm / min under conditions of a temperature of 23 ° C. and a relative humidity of 50%.
That is, the adhesive layer exposed by peeling off the second release film of the device sealing adhesive sheet was overlaid on an alkali-free glass under conditions of a temperature of 23 ° C. and a relative humidity of 50%, and was crimped by a pressure roll. Then, the peeling force of the 1st peeling film was obtained by performing said peeling test. In addition, in the evaluation of tearing of the adhesive layer at the time of peeling of the second release film described below, for the evaluation of “B”, when the second release film is peeled off, the adhesive layer is partially applied to the second release film. Carefully peeled off manually so that no significant transfer occurred.
On the other hand, for the peel test of the second release film, the above test piece is obtained in a state where the double-sided tape is bonded to the exposed surface of the first release film, and the test piece is attached to the alkali-free glass with the double-sided tape. In addition, a laminate having a layer structure of “alkali-free glass / double-sided tape / first release film / adhesive layer / second release film” was obtained. Then, about this laminated body, the peeling test of the 2nd peeling film was done similarly to the peeling force of the 1st peeling film, and peeling force was obtained.

[Evaluation of tearing of adhesive layer during peeling of second release film]
In the measurement of the peeling force of the second release film, the state of transfer to the adhesive layer to the second release film after the peel test was observed, and the tear of the adhesive layer was evaluated according to the following criteria.
A: There is no transfer of the adhesive layer to the second release film.
B: The adhesive layer was torn and the adhesive layer partially transferred to the second release film.

[Evaluation of adhesiveness of adhesive layer to objects to be sealed]
In the measurement of the peel strength of the first release film, before performing the peel test, the state of the adhesive layer floating from the non-alkali glass is observed. It was set as evaluation B.

[Compounds and release films used in Examples or Comparative Examples]
Cyclic ether compound (AL1): hydrogenated bisphenol A type glycidyl ether epoxy resin (manufactured by Mitsubishi Chemical Corporation, trade name: YX8034, liquid at 25 ° C., epoxy equivalent: 270 g / eq)
Cyclic ether compound (AL2): hydrogenated bisphenol A type glycidyl ether type epoxy resin (manufactured by Mitsubishi Chemical Corporation, trade name: YX8000, liquid at 25 ° C., epoxy equivalent: 205 g / eq)
Binder resin (B1): Phenoxy resin (Mitsubishi Chemical Corporation, trade name: YX7200B35, glass transition temperature: 150 ° C.)
Curing catalyst (C1): Imidazole-based curing catalyst (manufactured by Shikoku Kasei Kogyo Co., Ltd., trade name: Curesol 2E4MZ)
Curing catalyst (C2): Thermal cationic polymerization initiator (manufactured by Sanshin Chemical Co., Ltd., trade name: Sun-Aid SI-B3)
Silane coupling agent (D1): 8-glycidoxyoctyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KBM4803)
-Release film (E1): manufactured by Lintec Corporation, trade name: SP-PET752150
-Release film (E2): manufactured by Lintec Corporation, trade name: SP-PET381130
Release film (E3): manufactured by Lintec Corporation, trade name: SP-PET751130
-Release film (E4): manufactured by Lintec Corporation, trade name: SP-PET 381031

[Example 1]
100 parts by mass of the binder resin (B1), 250 parts by mass of the cyclic ether compound (AL1), 2 parts by mass of the curing catalyst (C1) and 0.2 parts by mass of the silane coupling agent (D1) are dissolved in methyl ethyl ketone. Prepared.
This coating solution is applied onto the release-treated surface of the release film (E1) (first release film), and the resulting coating film is dried at 100 ° C. for 2 minutes to form an adhesive layer having a thickness of 15 μm. did. On this adhesive layer, the release treatment surface of the release film (E2) (second release film) was bonded to obtain an adhesive sheet for device sealing.

[Example 2]
In Example 1, instead of the cyclic ether compound (AL1), 130 parts by mass of the cyclic ether compound (AL2) was used, and instead of the curing catalyst (C1), 3.8 parts by mass of the curing catalyst (C2) was used. Except for this, an adhesive sheet for device sealing was obtained in the same manner as in Example 1.

[Comparative Example 1]
In Example 1, 250 parts by mass of the cyclic ether compound (AL2) was used instead of the cyclic ether compound (AL1), and 2 parts by mass of the curing catalyst (C2) was used instead of the curing catalyst (C1). In the same manner as in Example 1, an adhesive sheet for device sealing was obtained.

[Comparative Example 2]
In Example 1, the release film (E3) (first release film) was used instead of the release film (E1), and the release film (E4) (second release film) was used instead of the release film (E2). Except having used, it carried out similarly to Example 1, and obtained the adhesive sheet for device sealing.

[Comparative Example 3]
In Example 1, in place of the cyclic ether compound (AL1), 100 parts by mass of the cyclic ether compound (AL2) was used, and in place of the curing catalyst (C1), 5 parts by mass of the curing catalyst (C2) was used. In the same manner as in Example 1, an adhesive sheet for device sealing was obtained.

The composition of the adhesive layer of the adhesive sheet for device sealing of Examples 1-2 and Comparative Examples 1-3 and the test results are shown below.

In the device sealing adhesive sheets of Examples 1 and 2, the second release film can be peeled without tearing the adhesive layer. Further, the adhesive layer of the device sealing adhesive sheet has a sufficient adhesive strength at room temperature, and is excellent in sticking ability.
On the other hand, since the storage elastic modulus at 23 ° C. of the adhesive layer of the adhesive sheet for device sealing of Comparative Example 1 is too low, the adhesive layer is torn when the second release film is peeled off.
Moreover, since the adhesive sheet for device sealing of the comparative example 2 has a small difference in peeling force between the two release films, the adhesive layer is torn when the second release film is peeled off.
Moreover, since the adhesive sheet for device sealing of the comparative example 3 has a large storage elastic modulus at 23 ° C. of the adhesive layer, the second release film is peeled even if the difference in peel force between the two release films is small. At that time, the adhesive layer did not tear. However, the adhesive layer does not have sufficient adhesive strength at room temperature, and is inferior in applicability.

Claims

A device sealing adhesive sheet comprising a first release film and a second release film, and an adhesive layer sandwiched between the first release film and the second release film, wherein the following requirements (I) to ( A device sealing adhesive sheet satisfying all of III).
Requirement (I): The adhesive layer is a layer containing one or more compounds having a cyclic ether group.
Requirement (II): The storage elastic modulus of the adhesive layer at 23 ° C. is 5.0 × 10 5 Pa or more and 3.0 × 10 7 Pa or less.
Requirement (III): The value of the peeling force between the first release film and the adhesive layer is represented by x (mN / 50 mm), and the value of the peeling force between the second release film and the adhesive layer is When expressed as y (mN / 50 mm), the device sealing adhesive sheet satisfies the following formula (1).
The adhesive sheet for device sealing according to claim 1, wherein at least one of the compounds having a cyclic ether group is a compound that is liquid at 25 ° C.
The adhesive sheet for device sealing according to claim 2, wherein the content of the compound having a cyclic ether group, which is liquid at 25 ° C, is 53% by mass or more based on the entire adhesive layer.
The device sealing adhesive sheet according to any one of claims 1 to 3, wherein the adhesive layer further contains a thermal cationic polymerization initiator.
The device sealing adhesive sheet according to claim 4, wherein at least one of the compounds having a cyclic ether group is a compound having a glycidyl ether group.
The device sealing adhesive sheet according to any one of claims 1 to 5, wherein the adhesive layer further contains a binder resin.
The adhesive sheet for device sealing according to claim 6, wherein the binder resin is a resin having a glass transition temperature of 90 ° C or higher.
The device sealing adhesive sheet according to any one of claims 1 to 7, wherein a layer obtained by curing the adhesive layer has a storage elastic modulus at 90 ° C of 1 x 10 8 Pa or more.
The adhesive sheet for device sealing according to any one of claims 1 to 8, wherein a peel force value x between the first release film and the adhesive layer is 30 to 200 mN / 50 mm.
A step of peeling the second release film from the device sealing adhesive sheet according to any one of claims 1 to 9, and bonding the exposed adhesive layer to an object to be sealed or a substrate in a temperature environment of 20 to 30 ° C. The method to manufacture a device sealing body including the process to attach.