JPWO2019189618A1 - Manufacturing method of electronic device encapsulant, sheet adhesive, adhesive film for electronic device encapsulation, and electronic device encapsulant - Google Patents

Abstract

The present invention is an electronic device, an electronic device encapsulant including an adhesive cured product layer that seals between a UV-impermeable functional film and the electronic device, and a sheet used for forming the adhesive cured product layer. This is a method for manufacturing a state adhesive, an adhesive film for encapsulating an electronic device having an adhesive layer composed of the functional film and a sheet-like adhesive, and an electronic device encapsulant.

Description

The present invention is an electronic device encapsulant having an adhesive cured product layer that seals between an electronic device and a UV-impermeable functional film and the electronic device, and a sheet used for forming the adhesive cured product layer. The present invention relates to an adhesive, an adhesive film for encapsulating an electronic device having an adhesive layer composed of the functional film and a sheet-like adhesive, and a method for producing an electronic device encapsulant.

Thermosetting adhesives exist as sealing adhesives for sealing electronic devices such as organic EL elements. However, thermosetting adhesives are concerned about heat damage to the device if the device is cured after being sealed. On the other hand, if it is cured before being attached to an electronic device, there is a problem that the initial pressure-sensitive adhesiveness is lost.
On the other hand, if the adhesive is an active energy ray-curable adhesive such as ultraviolet rays, the damage to the electronic device such as the organic EL element is small even when the adhesive is cured after being attached to the electronic device.

Patent Document 1 describes an adhesive for encapsulating an electronic device containing a compound having a cyclic ether group and a photocationic polymerization initiator.

Special Table 2014-534309 (International Publication No. 2013/057256)

Patent Document 1 states that "pressure sensitive adhesives are preferably partially or finally crosslinked only after application to electronic devices" [paragraph (0066)]. The cationic UV curing for such cross-linking was premised on the fact that the sealing adhesive was supported on a material that transmits ultraviolet rays, such as a PET liner or glass.
The present invention is based on the premise that the member to which the sealing adhesive is bonded is a UV-impermeable functional film, and includes an adhesive cured product layer that seals between the functional film and the electronic device. An electronic device encapsulant, a sheet-like adhesive which is a material for forming the adhesive cured product layer, an adhesive film for encapsulating an electronic device having an adhesive layer composed of the functional film and the sheet-like adhesive, and an electron. An object of the present invention is to provide a method for manufacturing a device encapsulant.

The adhesive containing the compound having a cyclic ether group and the photocationic polymerization initiator retains the adhesiveness on the surface of the adhesive even after being irradiated with ultraviolet rays. Therefore, the sheet-shaped adhesive made of such an adhesive can be attached to an electronic device even after being irradiated with ultraviolet rays. Then, in such a sheet-like adhesive, the adhesive layer is cured with time after irradiation with ultraviolet rays, and finally (ultraviolet impermeable functional film) / (adhesive cured product layer) / (electronic device). ), And an electronic device encapsulant having excellent durability can be efficiently obtained.

Thus, according to the present invention, the following electronic device encapsulants [1] to [4], sheet-like adhesives [5], adhesive films for encapsulating electronic devices [6], (7], [8]. , [9] The method for manufacturing the electronic device encapsulant is provided.

[1] The adhesive curing comprises a functional film having a wavelength of 365 nm and a transmittance of ultraviolet rays of 60% or less, an electronic device, and an adhesive cured product layer that seals between the functional film and the electronic device. The material layer is a sealed body of an electronic device, which is a cured product of a sheet-like adhesive containing the following components (A) and (B).
(A) Compound having a cyclic ether group (B) Photocationic polymerization initiator [2] A sheet-like adhesive containing the following components (A) and (B), which seals the electronic device according to claim 1. A sheet-like adhesive used in the manufacture of fasteners.
(A) Compound having a cyclic ether group (B) Photocationic polymerization initiator [3] The sheet-like adhesive has a release film on at least one surface, and is a soda glass measured under the following condition (i). The sheet-like adhesive according to [2], which has an adhesive force to a plate of 3 N / 25 mm or more.
(I) A laminate was prepared by laminating a 23 μm-thick polyethylene terephthalate film on which aluminum was vapor-deposited on the surface opposite to the one to which the release film of the sheet-like adhesive was bonded, and the release film was prepared. The laminate was irradiated with ultraviolet rays having a wavelength of 365 nm from the release film side under the conditions of illuminance: 50 mW / cm ² and light intensity: 200 mJ / cm ² , and 3 minutes later, the laminate The release film was peeled off from the film, the exposed sheet-like adhesive layer was opposed to the soda glass plate, and a 2 kg roll was reciprocated once on the laminate to attach it to the glass, and the film was 50% relative at 23 ° C. After being stored in a humid environment for 24 hours, a 180 ° peeling test is performed.
[4] The sheet-like adhesive according to [2] or [3], further comprising one or more selected from the group consisting of a modified polyolefin resin and a phenoxy resin.

[5] For encapsulating an electronic device, which has an adhesive layer composed of a functional film having an ultraviolet transmittance of 60% or less having a wavelength of 365 nm and a sheet-like adhesive containing the following components (A) and (B). Adhesive film.
(A) Compound having a cyclic ether group (B) Photocationic polymerization initiator [6] The adhesive film for encapsulating an electronic device has a release film on the surface of the adhesive layer on the side where the functional film is not bonded. The adhesive film for sealing an electronic device according to [5], which has an adhesive force to a soda glass plate measured under the following condition (ii) of 3 N / 25 mm or more.
(Ii) With the release film attached to the adhesive film for encapsulating the electronic device, ultraviolet rays having a wavelength of 365 nm are emitted from the release film side under the conditions of illuminance: 50 mW / cm ² and light intensity: 200 mJ / cm ² . After irradiation, 3 minutes later, the release film was peeled off from the electronic device sealing adhesive film, the exposed adhesive layer was opposed to a soda glass plate, and 2 kg was placed on the electronic device sealing adhesive film. The roll is affixed to a soda glass plate by reciprocating once, and after being stored at 23 ° C. in an environment of 50% relative humidity for 24 hours, a 180 ° peeling test is carried out.
[7] The adhesive film for encapsulating an electronic device according to [5] or [6], wherein the sheet-like adhesive further contains one or more selected from the group consisting of a modified polyolefin resin and a phenoxy resin.
[8] (α1) A step of irradiating the adhesive film for encapsulating an electronic contact device according to any one of the above [5] to [7] with ultraviolet rays from the surface side closer to the adhesive layer than the functional film.
(Β1) The step of attaching the adhesive film to an electronic device is provided.
A method for manufacturing a sealed body of an electronic device in which the step (α1) is performed before the step (β1).
[9] (α2) A step of irradiating a sheet-like adhesive containing the following components (A) and (B) with ultraviolet rays, and
(Β2) The sheet-like adhesive is attached to a functional film or an electronic device having a wavelength of 365 nm and an ultraviolet ray transmittance of 60% or less.
A method for manufacturing a sealed body of an electronic device in which the step (α2) is performed before the step (β2).
(A) Compound having a cyclic ether group (B) Photocationic polymerization initiator

According to the present invention, even after irradiation with ultraviolet rays, it is strongly adhered to an ultraviolet-impermeable functional film or an electronic device as an adherend, and peeling does not occur at the time of sticking or after sticking, and The adhesive layer is cured over time, and finally a highly durable device seal can be obtained.

It is a figure which shows an example of the electronic device encapsulation body of this invention. It is a schematic process diagram of the manufacturing method of the electronic device encapsulation body of this invention. It is a schematic process diagram of the manufacturing method of the electronic device encapsulation body of this invention.

Hereinafter, the present invention will be described in detail by dividing it into 2) an electronic device encapsulant, 2) a sheet adhesive, 3) an adhesive film for encapsulating an electronic device, and 4) a method for manufacturing an electronic device encapsulant. Explain to.

1) Electronic device encapsulant The electronic device encapsulant of the present invention is an adhesive that seals between a functional film, an electronic device, and a functional film having an ultraviolet transmittance of 60% or less at a wavelength of 365 nm. The adhesive cured product layer is provided with an agent-cured product layer, and the adhesive cured product layer is a sheet-like adhesive containing the following components (A) and (B) (hereinafter, may be referred to as "sheet-like adhesive of the present invention"). It is characterized by being a cured product.
(A) Compound having a cyclic ether group (B) Photocationic polymerization initiator

An example of the layer structure of the electronic device encapsulant of the present invention is shown in FIG. The electronic device encapsulant 10 shown in FIG. 1 is laminated so that the electronic device 3 and the curing adhesive layer 2 face each other so as to cover the surface of the electronic device 3, and the transmittance of ultraviolet rays having a wavelength of 365 nm is 60%. The functional film 1 below has a layered structure arranged on the outermost surface.

In the electronic device encapsulant of the present invention, examples of the electronic device to be sealed include an organic EL display, an organic EL element such as an organic EL illumination; a liquid crystal element such as a liquid crystal display; an electronic paper; an organic thin-film solar cell. Such as solar cell elements; light emitting diodes and the like.

[Functional film]
The functional film 1 constituting the electronic device encapsulant of the present invention is a film having a wavelength of 365 nm and a transmittance of ultraviolet rays having a transmittance of 60% or less. The transmittance of ultraviolet rays having a wavelength of 365 nm of the functional film is preferably 55% or less, more preferably 50% or less, from the viewpoint that the effect of the present invention can be obtained more remarkably.

The transmittance of ultraviolet rays having a wavelength of 365 nm of the functional film can be measured by the method described in Examples.

The functional film 1 used in the present invention is not particularly limited as long as it has a transmittance of ultraviolet rays having a wavelength of 365 nm of 60% or less and has some function. For example, a conductive layer, a gas barrier film, an antireflection film, a retardation film, a viewing angle improving film, a brightness improving film and the like having a transmittance of ultraviolet rays having a wavelength of 365 nm of 60% or less can be mentioned. Among these, for example, examples of the gas barrier film include a film having a film of a metal or an inorganic compound, and a film having a metal film is preferable. Examples of the metal used include aluminum, zinc, copper and the like, and among these, aluminum is preferable.
The thickness of the functional film used in the present invention is not particularly limited, but is usually 5 to 200 μm, preferably 10 to 100 μm.

When a functional film having a wavelength of 365 nm and a transmittance of 60% or less is provided, even if the sheet-like adhesive is attached to the electronic device and then the ultraviolet rays are irradiated from the functional film side, the ultraviolet rays are in the form of a sheet. The amount that reaches the adhesive is too small to cure the sheet-like adhesive.
As will be described later, the sheet-like adhesive of the present invention is cured by a photocationic polymerization reaction. The photocationic polymerization reaction has a relatively slow reaction rate as compared with a radical polymerization reaction or the like. Therefore, even after the sheet-like adhesive is irradiated with ultraviolet rays, the sheet-like adhesive has sufficient adhesiveness while the curing reaction is in progress, so that the electrons that are the adherends can be used. It adheres strongly to the device and can prevent peeling during or after application. In addition, the adhesive layer is cured over time, and a sealed body of an electronic device having excellent durability can be finally obtained.

[Adhesive cured product layer]
The adhesive cured product layer 2 of the electronic device encapsulant of the present invention is made of a cured product of the sheet-like adhesive of the present invention, and seals the electronic device to seal the electronic device and the functional film. It plays a role of bonding.

[Sheet adhesive]
The sheet-like adhesive of the present invention is a sheet-like material having adhesiveness, and contains the following components (A) and (B).
(A) Compound having a cyclic ether group (B) Photocationic polymerization initiator

The sheet-shaped adhesive refers to an adhesive molded into a sheet shape that exhibits immobility at room temperature (about 25 ° C.). In the present invention, the sheet-shaped adhesive may be a strip-shaped adhesive or a long-shaped (strip-shaped) adhesive.

[Component (A): Compound having a cyclic ether group]
The sheet-shaped adhesive of the present invention contains a compound having a cyclic ether group as the component (A).
By using a compound having a cyclic ether group, a cured product of the sheet-shaped adhesive having excellent curability and water vapor blocking property can be obtained.

Examples of the cyclic ether group include an oxylan group (epoxy group), an oxetane group (oxetanyl group), a tetrahydrofuryl group, a tetrahydropyranyl group and the like.
The compound having a cyclic ether group means a compound having at least one or more cyclic ether groups in the molecule. Among them, a compound having an oxylan group or an oxetane group is preferable, and a compound having two or more oxylan groups or an oxetane group in the molecule is preferable from the viewpoint that a cured product of an adhesive having more excellent adhesive strength can be obtained. Compounds are particularly preferred.

Examples of the compound having an oxylan group in the molecule include an aliphatic epoxy compound (excluding an alicyclic epoxy compound), an aromatic epoxy compound, and an alicyclic epoxy compound.
Examples of the aliphatic epoxy compound include monofunctional epoxy compounds such as glycidyl etherified products of aliphatic alcohols and glycidyl esters of alkylcarboxylic acids;
Examples thereof include polyglycidyl etherified products of aliphatic polyhydric alcohols or alkylene oxide adducts thereof, polyglycidyl esters of aliphatic long-chain polybasic acids, and polyfunctional epoxy compounds such as epoxy compounds having a triazine skeleton.

Representative compounds of these aliphatic epoxy compounds include allyl glycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, C12-13 mixed alkyl glycidyl ether, 1,4-butanediol diglycidyl ether, neopentyl glycol di. Glycidyl ether, triglycidyl ether of glycerin, triglycidyl ether of trimethylolpropane, tetraglycidyl ether of sorbitol, hexaglycidyl ether of dipentaerythritol, diglycidyl ether of polyethylene glycol, diglycidyl ether of polypropylene glycol, dicyclopentadiene dimethanol Polyether polyols obtained by adding one or more alkylene oxides to glycidyl ethers, which are polyhydric alcohols such as diglycidyl ethers, and aliphatic polyhydric alcohols such as propylene glycol, trimethylolpropane, and glycerin. Polyglycidyl etherified, diglycidyl ester of aliphatic long chain dibasic acid;
Monoglycidyl ethers of aliphatic higher alcohols, glycidyl esters of higher fatty acids, epoxidized soybean oil, octyl epoxide stearate, butyl epoxy stearate, epoxidized polybutadiene;
Examples thereof include 2,4,6-tri (glycidyloxy) -1,3,5-triazine.

A commercially available product can also be used as the 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, Denacol EX-920, Denacol EX-931 ( Above, manufactured by Nagase ChemteX);
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 (all manufactured by Kyoeisha Chemical Co., Ltd.);
Adeka Glycyrrol ED-503, Adeka Glycyrrol ED-503G, Adeka Glycyrrol ED-506, Adeka Glycyrrol ED-523T, Adeka Resin EP-4088S, Adeka Resin EP-4088L, Adeka Resin EP-4080E (all manufactured by ADEKA);
Examples thereof include TEPIC-FL, TEPIC-PAS, and TEPIC-UC (all manufactured by Nissan Chemical Industries, Ltd.).

Examples of the aromatic epoxy compound include polyhydric phenols having at least one aromatic ring such as phenol, cresol and butylphenol, and mono / polyglycidyl etherified compounds of alkylene oxide adducts thereof.
Typical 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 compounds of aromatic compounds with two or more phenolic hydroxyl groups such as resorcinol, hydroquinone, catechol;
A glycidyl etherified product of an aromatic compound having two or more alcoholic hydroxyl groups such as phenyldimethanol, phenyldiethanol, and phenyldibutanol;
Examples thereof include glycidyl ester of a polybasic acid aromatic compound having two or more carboxylic acids such as phthalic acid, terephthalic acid and trimellitic acid, glycidyl ester of benzoic acid, and an epoxidized product of styrene oxide or divinylbenzene.

In addition, a commercially available product can also be used as the 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, On-Coat EX-1020, On-Coat EX-1030, On-Coat EX. -1040, On-Coat EX-1050, On-Coat EX-1051, On-Coat EX-1010, On-Coat EX-1011, On-Coat 1012 (all manufactured by Nagase ChemteX Corporation);
Ogsol PG-100, Ogsol EG-200, Ogsol EG-210, Ogsol EG-250 (all manufactured by Osaka Gas Chemical Co., Ltd.);
HP4032, HP4032D, HP4700 (all manufactured by DIC Corporation);
ESN-475V (above, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.);
JER (former Epicoat) YX8800 (manufactured by Mitsubishi Chemical Corporation);
Maproof G-0105SA, Maproof G-0130SP (above, manufactured by NOF CORPORATION);
Epicron N-665, Epicron HP-7200 (all manufactured by DIC Corporation);
EOCN-1020, EOCN-102S, EOCN-103S, EOCN-104S, XD-1000, NC-3000, EPPN-501H, EPPN-501HY, EPPN-502H, NC-7000L (all manufactured by Nippon Kayaku Co., Ltd.);
Adeka Resin EP-4000, Adeka Resin EP-4005, Adeka Resin EP-4100, Adeka Resin EP-4901 (all manufactured by ADEKA Corporation);
TECHMORE VG-3101L (all manufactured by Printec Co., Ltd.) and the like can be mentioned.

Examples of the alicyclic epoxy compound include polyglycidyl etherified compounds of polyhydric alcohols 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. Cyclohexene oxide compounds such as oxide-containing compounds can be mentioned.
Typical compounds of these alicyclic epoxy compounds are 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) adipate , 3,4-Epoxy-6-methylcyclohexanecarboxylate, Methylenebis (3,4-Epoxycyclohexane), Propane-2,2-Diyl-bis (3,4-Epoxycyclohexane), 2,2-Bis (3,3) 4-epoxycyclohexyl) propane, dicyclopentadiene diepoxyside, ethylenebis (3,4-epoxycyclohexanecarboxylate), dioctyl epoxyhexahydrophthalate, di-2-ethylhexyl epoxyhexahydrophthalate, 1-epoxyethyl-3 , 4-Epoxycyclohexane, 1,2-epoxy-2-epoxyethylcyclohexane, α-pinenooxide, limonendioxide and the like.

In addition, a commercially available product can be used as the alicyclic epoxy compound. Examples of commercially available products include YX8000 (manufactured by Mitsubishi Chemical Corporation), Selokiside 2021P, Selokiside 2081, Selokiside 2000, and Selokiside 3000 (manufactured by Daicel).

Compounds 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 aliphatic oxetane compounds such as butane, 1,6-bis (3-ethyl-3-oxetanylmethoxy) hexane, 3-ethyl-3-[(phenoxy) methyl] oxetane, 3-ethyl-3- (hexyloxy) Monofunctional oxetane compounds such as methyl) oxetane, 3-ethyl-3- (2-ethylhexyloxymethyl) oxetane, 3-ethyl-3- (hydroxymethyl) oxetane, 3-ethyl-3- (chloromethyl) oxetane, etc. Can be mentioned.

As the compound having an oxetane group in the molecule, a commercially available product can also be used. Commercially available products include 2-hydroxyethyl vinyl ether, diethylene glycol monovinyl ether, and 4-hydroxybutyl vinyl ether (manufactured by Maruzen Petrochemical Co., Ltd.);
Aron Oxetane OXT-121, OXT-221, EXOH, POX, OXA, OXT-101, OXT-221, OXT-212 (all manufactured by Toagosei Co., Ltd.);
Examples thereof include Etanacol OXBP and OXTP (all manufactured by Ube Industries, Ltd.).

Among these, a compound that is liquid at 25 ° C. is preferable from the viewpoint that an adhesive having excellent sheet processability (film-forming property) and a cured product of the adhesive having excellent adhesive strength can be obtained. Further, it is preferable that the cyclic ether group is an oxylan group. Among the compounds (epoxy compounds) in which the cyclic ether group is an oxylane group, an alicyclic epoxy compound is preferable from the viewpoint of adjusting the characteristics of the cured product of the adhesive and preventing coloring, and from the viewpoint of improving the reactivity of photocationic polymerization. Therefore, a cycloalkene oxide compound is preferable.

Further, a compound having two or more cyclic ether groups in the molecule, such as a polyfunctional epoxy compound and a bifunctional aliphatic oxetane compound, is preferable from the viewpoint of improving the curability of the sheet adhesive.

The molecular weight of the compound having a cyclic ether group is usually 100 to 5,000, preferably 200 to 4,000.
The cyclic ether equivalent of the compound having a cyclic ether group is preferably 100 g / eq or more and 500 g / eq or less, and more preferably 115 g / eq or more and 300 g / eq or less.
When the cyclic ether equivalent of the compound having a cyclic ether group contained in the sheet-shaped adhesive is within the above range, a sealing material having strong adhesive strength and excellent curability can be efficiently obtained.
These compounds having a cyclic ether group can be used alone or in combination of two or more.
The cyclic ether equivalent in the present invention means a value obtained by dividing the molecular weight by the number of cyclic ether groups.

When the sheet-shaped adhesive of the present invention contains a binder resin described later, the content of the compound having a cyclic ether group is preferably 20 to 180 parts by mass, more preferably 40 to 40 parts by mass with respect to 100 parts by mass of the binder resin. It is 140 parts by mass.
By setting the content of the compound having a cyclic ether group in the above range, it becomes easy to obtain a cured product of the adhesive layer having better adhesive strength.

The content of the component (A) in the sheet-shaped adhesive of the present invention is 20 to 80% by mass as a solid content (nonvolatile content, including a liquid one; the same applies hereinafter) with respect to the entire adhesive. Is preferable, 25 to 70% by mass is more preferable, and 30 to 65% by mass is particularly preferable.
When the content of the component (A) of the sheet-shaped adhesive of the present invention is within the above range, it becomes easy to adjust the adhesive strength of the sheet-shaped adhesive after irradiation with ultraviolet rays.

[Component (B): Photocationic polymerization initiator]
The sheet-shaped adhesive of the present invention contains a photocationic polymerization initiator as the component (B). This makes it easy to adjust the adhesive strength of the sheet-shaped adhesive after irradiation with ultraviolet rays.
The photocationic polymerization initiator is a compound that generates a cationic species when irradiated with active energy rays to initiate a curing reaction of a cationically curable compound, and is a cation portion that absorbs active energy rays and a source of acid. It consists of an anion part.

Examples of the photocationic polymerization initiator include sulfonium salt compounds, iodonium salt compounds, phosphonium salt compounds, ammonium salt compounds, antimonate compounds, diazonium salt compounds, selenium salt compounds, and oxonium salt compounds. , Bromine salt compounds and the like. Among these, a sulfonium salt-based compound is preferable, and an aromatic sulfonium salt-based compound having an aromatic group is more preferable from the viewpoint of excellent compatibility with the component (A) and excellent storage stability of the obtained adhesive. ..

Examples of the sulfonium salt-based compound include triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium tetrakis (pentafluorophenyl) borate, and 4,4'-bis [diphenylsulfonio] diphenylsulfide-bishexafluoro. Phosphate, 4,4'-bis [di (β-hydroxyethoxy) phenylsulfonium] diphenylsulfide-bishexafluoroantimonate, 7- [di (p-toluyl) sulfonio] -2-isopropylthioxanthone hexafluorophosphate, 7 -[Di (p-toluyl) Sulfonio] -2-isopropylthioxanthone hexafluoroantimonate, 7- [di (p-toluyl) sulfonio] -2-isopropyltetrakis (pentafluorophenyl) borate, phenylcarbonyl-4'-diphenyl Sulfonio-diphenylsulfide-hexafluorophosphate, phenylcarbonyl-4'-diphenylsulfonio-diphenylsulfide-hexafluoroantimonate, 4-tert-butylphenylcarbonyl-4'-diphenylsulfonio-diphenylsulfide-hexafluorophosphate, 4-tert-Butylphenylcarbonyl-4'-diphenylsulfonio-diphenylsulfide-hexafluoroantimonate, 4-tert-butylphenylcarbonyl-4'-diphenylsulfonio-diphenylsulfide-tetrakis (pentafluorophenyl) borate, thio Phenyldiphenylsulfonium hexafluoroantimonate, thiophenyldiphenylsulfonium hexafluorophosphate, 4- {4- (2-chlorobenzoyl) phenylthio} phenylbis (4-fluorophenyl) sulfonium hexafluoroantimonate, thiophenyldiphenylsulfonium hexafluoroantimo Halogenate of nate, 4,4', 4''-tri (β-hydroxyethoxyphenyl) sulfonium hexafluoroantimonate, 4,4'-bis [diphenylsulfonio] diphenylsulfide-bishexafluoroantimonate, diphenyl [ 4- (Phenylthio) phenyl] Sulfonium Trifluorotris Pentafluoroethyl phosphate, Tris [4- (4-Acetylphenyl sulfanyl) phenyl] Sulfonium Tris [(Trif) Luolomethyl) sulfonyl] metanide and the like.

Examples of iodonium salt compounds include diphenyliodonium tetrakis (pentafluorophenyl) borate, diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroantimonate, di (4-nonylphenyl) iodonium hexafluorophosphate, and (tricumyl) iodonium tetrakis (pentafluoro). Phenyl) Borate and the like can be mentioned.

Examples of the phosphonium salt-based compound include tri-n-butyl (2,5-dihydroxyphenyl) phosphonium bromide and hexadecyltributylphosphonium chloride.

Examples of the ammonium salt compound include benzyltrimethylammonium chloride, phenyltributylammonium chloride, benzyltrimethylammonium bromide and the like.

Examples of antimonate compounds include triphenylsulfonium hexafluoroantimonate, p- (phenylthio) phenyldiphenylsulfonium hexafluoroantimonate, 4-chlorophenyldiphenylsulfonium hexafluoroantimonate, and bis [4- (diphenylsulfonio). Phenyl] Examples thereof include sulfide bishexafluoroantimonate and diallyl iodonium hexafluoroantimonate.

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

In addition, a commercially available product can be used as the photocationic polymerization initiator. Commercially available products include Cyracure UVI-6970, Cyracure UVI-6974, Cyracure UVI-6990, Cyracure UVI-950 (all manufactured by Union Carbide), Irgacure 250, Irgacure 261 and Irgacure 264 (above, Ciba Specialty Chemicals). , SP-150, SP-151, SP-170, Optomer SP-171 (above, ADEKA), CG-24-61 (Ciba Specialty Chemicals), DAICAT II (Daisel), UVAC1590, UVAC1591 (above, manufactured by Daicel Cytec), CI-2064, CI-2339, CI-2624, CI-2481, CI-2734, CI-2855, CI-2823, CI-2758, CIT-1682 (above) , Nippon Soda), PI-2074 (Rhodia), FFC509 (3M), BBI-102, BBI-101, BBI-103, MPI-103, TPS-103, MDS-103, DTS-103 , NAT-103, NDS-103 (all manufactured by Midori Chemical Co., Ltd.), CD-1010, CD-1011, CD-1012 (manufactured by Sartomer), CPI-100P, CPI-101A, CPI-200K, CPI-310B ( As mentioned above, (manufactured by Sun Appro) and the like.

The content of the photocationic polymerization initiator is usually 0.1 to 10 parts by mass, preferably 0.3 to 8 parts by mass, and more preferably 0.5 to 4 parts by mass with respect to 100 parts by mass of the component (A). .5 parts by mass.
By setting the content of the photocationic polymerization initiator within the above range, it becomes easy to adjust the adhesive strength of the sheet-shaped adhesive after irradiation with ultraviolet rays.

The sheet-shaped adhesive of the present invention may contain components other than the components (A) and (B). Examples of the components other than the component (A) and the component (B) include a binder resin, a tackifier, a silane coupling agent, and the like.

[Binder resin]
When the sheet-like adhesive of the present invention contains a binder resin, the composition for forming the sheet-like adhesive is imparted with excellent sheet processability (film-forming property), and the sheet-like adhesive having a desired thickness is adhered. The agent can be formed efficiently.

As the binder resin, one or more selected from the modified polyolefin resin and the phenoxy resin are preferable from the viewpoint of excellent compatibility with the component (A).
When a modified polyolefin resin is used, it is possible to maintain low moisture permeability while incorporating the polyolefin as the main agent into the cured structure. Further, when a phenoxy resin is used, it is possible to maintain a high elastic modulus of the cured product of the sheet-like adhesive, which is preferable because the reliability of the electronic device encapsulant in a high temperature environment is improved.

When the sheet-shaped adhesive of the present invention contains a binder resin, the content thereof is preferably 30 to 80% by mass, more preferably 40 to 70% by mass, based on the entire sheet-shaped adhesive.
By containing the binder resin in such a range, excellent sheet processability (film-forming property) is imparted to the composition for forming the sheet-like adhesive, and the sheet-like adhesive having a desired thickness can be efficiently obtained. Can be formed.

(Modified polyolefin resin)
The modified polyolefin resin is a polyolefin resin into which a functional group has been introduced, which is obtained by subjecting a polyolefin resin as a precursor to a modification treatment using a modifier.

The polyolefin resin refers to a polymer containing a repeating unit derived from an olefin-based monomer. The polyolefin resin may be a polymer consisting of only one type or two or more types of repeating units derived from an olefin-based monomer, or may be a copolymer of a repeating unit derived from an olefin-based monomer and an olefin-based monomer. It may be a polymer composed of repeating units derived from other polymerizable monomers.

As the olefin-based monomer, α-olefin having 2 to 8 carbon atoms is preferable, ethylene, propylene, 1-butene, isobutylene, or 1-hexene is more preferable, and ethylene or propylene is further preferable.
Examples of other monomers copolymerizable with the olefin-based monomer include vinyl acetate, (meth) acrylic acid ester, and styrene. Here, "(meth) acrylic acid" represents acrylic acid or methacrylic acid (the same applies hereinafter).

Examples of the polyolefin resin include ultra-low density polyethylene (VLDPE), low density polyethylene (LDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), linear low density polyethylene (LLDPE), polypropylene (PP), and ethylene. Examples thereof include -propylene copolymer, olefin-based elastomer (TPO), ethylene-vinyl acetate copolymer (EVA), ethylene- (meth) acrylic acid copolymer, and ethylene- (meth) acrylic acid ester copolymer. ..

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

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

The acid-modified polyolefin-based resin refers to a polyolefin resin graft-modified with an acid or an acid anhydride. For example, a polyolefin resin is reacted with an unsaturated carboxylic acid or an unsaturated carboxylic acid anhydride to introduce a carboxyl group or an acid anhydride group (graft modification).

Examples of the unsaturated carboxylic acid to be reacted with the polyolefin resin include maleic acid, fumaric acid, itaconic acid, citraconic acid, glutaconic acid, tetrahydrophthalic acid, aconitic acid and the like. The unsaturated carboxylic acid anhydride includes maleic anhydride. , Itaconic anhydride, glutaconic anhydride, citraconic anhydride, aconitic anhydride, norbornene dicarboxylic acid anhydride, tetrahydrophthalic anhydride and the like.
These can be used alone or in combination of two or more.
Among these, maleic anhydride is preferable because it is easy to obtain a cured product of an adhesive having excellent sheet processability (film-forming property) and a sheet-like adhesive having excellent adhesive strength.

The amount of unsaturated carboxylic acid or unsaturated carboxylic acid anhydride to be reacted with the polyolefin resin is preferably 0.1 to 5 parts by mass, more preferably 0.2 to 3 parts by mass, based on 100 parts by mass of the polyolefin resin. More preferably, it is 0.2 to 1 part by mass. The sheet-like adhesive containing the acid-modified polyolefin-based resin thus obtained tends to obtain an excellent cured product due to the adhesive strength.

As the acid-modified polyolefin resin, a commercially available product can be used. 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 can be mentioned.

The silane-modified polyolefin-based resin refers to a polyolefin resin graft-modified with an unsaturated silane compound. The silane-modified polyolefin-based resin has a structure in which an unsaturated silane compound as a side chain is graft-copolymerized with a polyolefin resin as a main chain. Examples thereof include silane-modified polyethylene resins and silane-modified ethylene-vinyl acetate copolymers, and silane-modified polyethylene resins such as silane-modified low-density polyethylene, silane-modified ultra-low-density polyethylene, and silane-modified linear low-density polyethylene are preferable.

As the unsaturated silane compound to be reacted with the polyolefin resin, a vinylsilane compound is preferable. Examples of vinylsilane compounds include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripropoxysilane, vinyltriisopropoxysilane, vinyltributoxysilane, vinyltripentyroxysilane, vinyltriphenoxysilane, vinyltribenzyloxysilane, and vinyltri. Examples thereof include methylenedioxysilane, vinyltriethylenedioxysilane, vinylpropionyloxysilane, vinyltriacetoxysilane, vinyltricarboxysilane and the like.
These can be used alone or in combination of two or more.
As a condition for graft-polymerizing an unsaturated silane compound on a polyolefin resin as a main chain, a known conventional method of graft polymerization may be adopted.

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 further preferably 0.5 to 0.5 parts by mass with respect to 100 parts by mass of the polyolefin resin. 5 parts by mass. A sheet-like adhesive containing a silane-modified polyolefin-based resin tends to obtain an excellent cured product due to its adhesive strength.

As the silane-modified polyolefin resin, a commercially available product can be used. Examples of commercially available products include Linkron (registered trademark) (manufactured by Mitsubishi Chemical Corporation). Among these, low-density polyethylene-based linklon, linear low-density polyethylene-based linklon, ultra-low-density polyethylene-based linklon, and ethylene-vinyl acetate copolymer-based linklon can be preferably used. ..

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

The weight average molecular weight (Mw) of the modified polyolefin resin is preferably 10,000 to 300,000, more preferably 20,000 to 150,000.
When the weight average molecular weight (Mw) of the modified polyolefin resin is in such a range, it is easy to adjust the characteristics of the composition for forming the sheet-like adhesive while imparting excellent film-forming property.
The weight average molecular weight (Mw) of the modified polyolefin resin can be determined as a standard polystyrene-equivalent value by performing gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent.

(Phenoxy resin)
The phenoxy resin is a polymer whose main chain is a polyaddition structure of an aromatic diol and an aromatic diglycidyl ether.
Examples of the phenoxy resin include bisphenol A type phenoxy resin, bisphenol F type phenoxy resin, bisphenol A-bisphenol F type phenoxy resin, and bisphenol E type phenoxy resin, depending on the type of main chain skeleton.
The phenoxy resin can be obtained by reacting a bisphenol or a biphenol compound with epichlorohydrin such as epichlorohydrin, or by reacting a bisphenol or a biphenol compound with a liquid epoxy resin.

As the phenoxy resin, a commercially available product can be used. As commercially available products, product names: PKHC, PKHH, PKHJ (all manufactured by Tomoe Kagaku Co., Ltd.), product names: Epicoat 4250, Epicoat 1255HX30, Epicoat 5580BPX40 (all manufactured by Nippon Kayaku Co., Ltd.), product names: YP-50, YP50S, YP-55, YP-70 (all manufactured by Toto Kasei Co., Ltd.), trade names: JER 1256, 4250, YX6954BH30, YX7200B35, YL7290BH30 (all manufactured by Mitsubishi Chemical Corporation) and the like can be mentioned.

The weight average molecular weight (Mw) of the phenoxy resin is usually 10,000 to 200,000, preferably 20,000 to 100,000, and more preferably 30,000 to 80,000. If the weight average molecular weight of the phenoxy resin is too small, the supportability of the sheet-like adhesive tends to be weak and the brittleness tends to be strong, and if it is too large, the melt viscosity becomes high and the handleability tends to be poor.
In the present specification, when the phenoxy resin has an epoxy group, the one having a weight average molecular weight (Mw) of 10,000 or less is defined as the compound having the component (A): cyclic ether group, and the weight is defined as the compound. A phenoxy resin having an average molecular weight (Mw) of more than 10,000 is used as a phenoxy resin.
The weight average molecular weight (Mw) of the phenoxy resin can be determined as a standard polystyrene-equivalent value by performing gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent.

[Adhesive imparting agent]
The sheet-shaped adhesive of the present invention may contain a tackifier in addition to the components (A) and (B) and, if desired, a binder resin. By containing the tackifier, it becomes easy to adjust the storage elastic modulus of the sheet-shaped adhesive.

Examples of the tackifier include rosin-based resins such as rosin resin, rosin ester resin, and rosin-modified phenol resin; hydrogenated rosin-based resin obtained by hydrogenating these rosin-based resins;
Terpene resins such as terpene resins, aromatic-modified terpene resins, and terpene phenolic resins; hydrogenated terpene resins obtained by hydrogenating these terpene resins;
α-Methylstyrene monopolymerized resin, α-methylstyrene / styrene copolymer resin, styrene monomer / aliphatic monomer copolymer resin, styrene monomer / α-methylstyrene / aliphatic monomer copolymer Styrene-based resins such as resins, styrene-based monomer monopolymerized resins, styrene-based monomers / aromatic monomer copolymerized resins; hydride-based resins obtained by hydrogenating these styrene-based resins;
C5-based petroleum resin obtained by copolymerizing C5 fractions such as penten, isoprene, piperylene, and 1.3-pentadiene produced by thermal decomposition of petroleum naphtha, and hydride petroleum resin of this C5-based petroleum resin;
Examples thereof include a C9-based petroleum resin obtained by copolymerizing a C9 fraction such as inden and vinyl toluene produced by thermal decomposition of petroleum naphtha, and a hydride petroleum resin obtained from this C9-based petroleum resin. Among these, a styrene-based resin is preferable, and a styrene-based monomer / aliphatic monomer copolymer-based resin is more preferable.
These tackifiers can be used alone or in combination of two or more.

As the tackifier, a commercially available product can be used. Commercially available products include terpene resins such as YS resin P, A series, Clearon (registered trademark) P series (manufactured by Yasuhara Chemical Co., Ltd.), Picolite A, C series (manufactured by PINOVA);
Aliphatic petroleum resins such as Quinton (registered trademark) A, B, R, CX series (manufactured by Zeon Corporation);
Styrene-based resins such as FTR (registered trademark) series (manufactured by Mitsui Chemicals, Inc.);
Archon P, M series (manufactured by Arakawa Chemical Co., Ltd.), ESCOREZ (registered trademark) series (manufactured by ExxonMobil Chemical Co., Ltd.), EASTOTAC (registered trademark) series (manufactured by Eastman Chemical Co., Ltd.), IMARB (registered trademark) series (Idemitsu) Alicyclic petroleum resin such as (manufactured by Kosan Co., Ltd.);
Examples thereof include ester resins such as Foral Series (manufactured by PINOVA), Pencel (registered trademark) A series, ester gum, super ester, and Pine Crystal (registered trademark) (manufactured by Arakawa Chemical Industry Co., Ltd.).

The weight average molecular weight (Mw) of the tackifier is preferably 100 to 10,000, more preferably 500 to 5,000, from the viewpoint of imparting excellent tackiness.
The softening point of the tackifier is preferably 50 to 160 ° C, more preferably 60 to 140 ° C, and even more preferably 70 to 130 ° C from the viewpoint of imparting excellent tackiness.

When the sheet-shaped adhesive of the present invention contains a tackifier, the content thereof is preferably 1 to 200 parts by mass, more preferably 10 to 150 parts by mass with respect to 100 parts by mass of the component (A). is there.

〔Silane coupling agent〕
The sheet-shaped adhesive of the present invention may contain the above-mentioned components (A) and (B), and if desired, a silane coupling agent in addition to the binder resin and the tackifier.
By containing the silane coupling agent, it becomes easy to obtain a cured product of the sheet-like adhesive having superior adhesive strength.
Examples of the silane coupling agent include 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, and 3-acryloxypropyltri. A silane coupling agent having a (meth) acryloyl group such as methoxysilane;
A silane coupling agent having a vinyl group such as vinyltrimethoxysilane, vinyltriethoxysilane, dimethoxymethylvinylsilane, diethoxymethylvinylsilane, trichlorovinylsilane, and vinyltris (2-methoxyethoxy) silane;
Epoxide groups such as 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane Silane coupling agent with;
Silane coupling agent 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 -(Vinylbenzyl) -2-aminoethyl-3-aminopropyl Asilane coupling agent having an amino group such as a hydrochloride of trimethoxysilane;
A silane coupling agent having a ureido group such as 3-ureidopropyltrimethoxysilane and 3-ureidopropyltriethoxysilane;
Silane coupling agent having halogen atoms such as 3-chloropropyltrimethoxysilane and 3-chloropropyltriethoxysilane;
A silane coupling agent having a mercapto group such as 3-mercaptopropylmethyldimethoxysilane and 3-mercaptopropyltrimethoxysilane;
Silane coupling agent having a sulfide group such as bis (trimethoxysilylpropyl) tetrasulfide and bis (triethoxysilylpropyl) tetrasulfide;
Silane coupling agent having an isocyanate group such as 3-isocyanatepropyltrimethoxysilane and 3-isocyanatepropyltriethoxysilane;
A silane coupling agent having an allyl group such as allyltrichlorosilane, allyltriethoxysilane, and allyltrimethoxysilane;
Examples thereof include silane coupling agents having a hydroxyl group such as 3-hydroxypropyltrimethoxysilane and 3-hydroxypropyltriethoxysilane; and the like.
These silane coupling agents can be used alone or in combination of two or more.

When the sheet-shaped adhesive of the present invention contains a silane coupling agent, the content thereof is preferably 0.01 to 5 parts by mass, more preferably 0.02 with respect to 100 parts by mass of the component (A). ~ 3 parts by mass.
By setting the content of the silane coupling agent in the above range, it becomes easier to obtain a cured product of a sheet-like adhesive having better adhesive strength.

Further, the sheet-shaped adhesive of the present invention may further contain components other than the tackifier and the silane coupling agent as long as the effects of the present invention are not impaired.
Examples of the components other than the tackifier and the silane coupling agent include antistatic agents, stabilizers, antioxidants, plasticizers, lubricants, coloring pigments and the like. These contents may be appropriately determined according to the purpose.

As will be described later, the sheet-shaped adhesive of the present invention can be formed by using an adhesive composition prepared by appropriately mixing predetermined components according to a conventional method and stirring them.

(Sheet adhesive)
From the viewpoint of protection from the external environment, the sheet-like adhesive of the present invention preferably has a release film on at least one surface, and may have a release film on both sides.

The sheet-like adhesive of the present invention having a release film on at least one surface represents a state before use, and when the sheet-like adhesive of the present invention is used, the release film is usually peeled off and removed. Will be done. When the sheet-like adhesive has release films on both sides, the release film having a low release force is usually peeled off first.

As the release film, a resin film can usually be used.
The resin components of the resin film include polyimide, polyamide, polyamideimide, polyphenylene ether, polyetherketone, polyetheretherketone, polyolefin, polyester, polycarbonate, polysulfone, polyethersulfone, polyphenylene sulfide, polyallylate, acrylic resin, and cyclo. Examples thereof include olefin-based polymers, aromatic-based polymers, and polyurethane-based polymers. Among these, a polyester resin is preferable, and as the resin film, a polyester film is preferable. As the polyester film, a polyethylene terephthalate film having excellent heat resistance and ease of handling and having a high ultraviolet ray transmittance of about 80% at a wavelength of 365 nm is more preferable.
Examples of the release agent include rubber-based elastomers such as silicone-based resins, olefin-based resins, isoprene-based resins, and butadiene-based resins, long-chain alkyl-based resins, alkyd-based resins, and fluorine-based resins.
The thickness of the release film is preferably 10 to 300 μm, more preferably 10 to 300 μm, from the viewpoint of improving heat resistance and not hindering the sheet-like adhesive when ultraviolet rays are transmitted through the release film. It is 10 to 200 μm, more preferably 15 to 100 μm. From the viewpoint of facilitating the initiation of photocationic polymerization by transmitting the sheet-shaped adhesive of the present invention through the release film and irradiating it with ultraviolet rays having a wavelength of 365 nm, the transmittance of the ultraviolet rays having a wavelength of 365 nm of the release film is determined. It is preferably 65% or more, and preferably 70% or more. When the release film uses a polyethylene terephthalate film as a base material, if the wavelength of ultraviolet rays is less than 330 nm, the transparency is significantly lowered.

The thickness of the sheet-like adhesive is usually 1 to 50 μm, preferably 5 to 30 μm. A sheet-like adhesive having a thickness within the above range is preferably used as a sheet-like encapsulant.
The thickness of the sheet-shaped adhesive can be measured according to JIS K 7130 (1999) using a known thickness meter. The thickness of the sheet-shaped adhesive is the thickness excluding the thickness of the release film.

The sheet-shaped adhesive of the present invention has adhesive strength even after being irradiated with ultraviolet rays, strongly adheres to an electronic device or a functional film, and does not peel off at the time of sticking or after sticking. Is. Therefore, it can be suitably used as a sealing material for an electronic device encapsulant, particularly an electronic device encapsulant having a functional film that is opaque to ultraviolet rays on the surface.

When the sheet-like adhesive of the present invention has a release film on at least one surface, a laminate is prepared by laminating with a 23 μm-thick polyethylene terephthalate film on which aluminum is vapor-deposited on the opposite surface to prepare a release film. The laminated film is irradiated with ultraviolet rays having a wavelength of 365 nm from the release film side under the conditions of illuminance: 50 mW / cm ² and light intensity: 200 mJ / cm ² , and 3 minutes later, the release film is released from the laminate. The exposed sheet-like adhesive layer was opposed to the soda glass plate, and a 2 kg roll was reciprocated once on the laminate to attach it to the soda glass plate. The adhesive strength to the soda glass plate after being stored underneath for 24 hours is preferably 3N / 25mm or more, and more preferably 5N / 25mm or more.
The adhesive strength to glass is measured by the method described in Examples (180 ° peeling test).

(Manufacturing method of sheet adhesive)
The method for producing the sheet-shaped adhesive of the present invention is not particularly limited. For example, it can be manufactured using the casting method.

The method for producing the sheet-shaped adhesive by the casting method is to apply the adhesive composition to the peeled layer surface of the peeling film by using a known method, and dry the obtained coating film. A sheet-like adhesive with a release film is obtained.

The adhesive composition can be prepared by mixing the components (A) and (B) and, if desired, other components by a known method and stirring.
When a solvent is used for preparing the adhesive composition, the viscosity of the adhesive composition can be appropriately adjusted depending on the amount of the solvent used.

Examples of the solvent include aliphatic hydrocarbon solvents such as n-hexane and n-heptane; aromatic hydrocarbon solvents such as toluene and xylene; dichloromethane, ethylene chloride, chloroform, carbon tetrachloride, 1,2-dichloroethane, and mono. Halogenized hydrocarbon solvents such as chlorobenzene;
Alcoholic solvents such as methanol, ethanol, propanol, butanol, propylene glycol monomethyl ether; ketone solvents such as acetone, methyl ethyl ketone, 2-pentanone, isophorone, cyclohexanone; ester solvents such as ethyl acetate and butyl acetate; ethyl cellosolve and the like. Examples thereof include cellosolve-based solvents; ether-based solvents such as 1,3-dioxolane; and the like.
These solvents can be used alone or in combination of two or more.
The content of the solvent can be appropriately determined in consideration of coatability, film thickness and the like.

The release film used for manufacturing the sheet-like adhesive functions as a support in the sheet-like adhesive manufacturing process, and as the above-mentioned sheet-like adhesive release film until the sheet-like adhesive is used. Function.

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 blade coating method, a die coating method, and a gravure coating method.

Examples of the method for drying the coating film of the adhesive composition 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.

[Adhesive film for sealing electronic devices]
The adhesive film for encapsulating an electronic device of the present invention is an adhesive comprising a functional film having a wavelength of 365 nm and an ultraviolet ray transmittance of 60% or less, and a sheet-like adhesive containing the components (A) and (B). It has a layer.
The adhesive film for encapsulating an electronic device of the present invention is used for encapsulating an electronic device via its sheet-like adhesive.
As the "functional film having a wavelength of 365 nm and the transmittance of ultraviolet rays of 60% or less" and the "sheet-like adhesive", the same ones as described above can be used. The adhesive film for encapsulating an electronic device of the present invention can be obtained, for example, by laminating a functional film and a sheet-like adhesive as described later.

The adhesive film for encapsulating an electronic device of the present invention may have at least an adhesive layer composed of the functional film and a sheet-like adhesive, and is composed of only one layer of the adhesive layer. However, it may be a laminate of a plurality of adhesive layers, or may have other layers in addition to the adhesive.
Other layers include a primer layer that improves the adhesiveness at the interface between the adhesive layer and the functional film, a functional coat layer, a protective film, and a functional film provided on a surface of the functional film that does not have an adhesive layer. Examples thereof include an antistatic layer and a stress relaxation layer that can be formed on both sides.
Further, when a plurality of adhesive layers are used for the adhesive film for encapsulating an electronic device of the present invention, each adhesive layer may have the same composition or different compositions. Good.
The adhesive film for encapsulating an electronic device of the present invention preferably has a release film on the surface of the adhesive layer on the side where the functional film is not bonded, and the release film is used for the above-mentioned sheet-like adhesive. The same as the one is preferable.

The thickness of the adhesive film for encapsulating an electronic device of the present invention is usually 6 to 270 μm. The thickness of the adhesive film for encapsulating the electronic device is the thickness excluding the members that are peeled off and removed before use, such as the release film and the protect film.

The adhesive film for encapsulating an electronic device of the present invention has adhesive strength even after being irradiated with ultraviolet rays, strongly adheres to the electronic device, and does not peel off at the time of sticking or after sticking. It can be suitably used as a sealing material for an electronic device encapsulant having a functional film that is opaque to ultraviolet rays on its surface.

When the adhesive film for sealing an electronic device of the present invention has a release film on the surface of the adhesive layer on the side where the functional film is not attached, a state in which the release film is attached to the adhesive film for device encapsulation. Then, from the release film side, ultraviolet rays having a wavelength of 365 nm were irradiated under the conditions of illuminance: 50 mW / cm ² and light intensity: 200 mJ / cm ² , and 3 minutes later, the release film was peeled off from the adhesive film for sealing the electronic device. The exposed adhesive layer is opposed to the soda glass plate, and a 2 kg roll is reciprocated once on the adhesive film for device encapsulation to attach it to the soda glass plate in an environment of 50% relative humidity at 23 ° C. The adhesive strength to the soda glass plate after storage for 24 hours is preferably 3N / 25mm or more, and more preferably 5N / 25mm or more.
The adhesive strength to glass is measured by the method described in Examples (180 ° peeling test).

[Manufacturing method of electronic device encapsulant]
The electronic device encapsulant of the present invention can be produced, for example, as follows.
Hereinafter, description will be made with reference to the drawings.
(Manufacturing method 1)
The electronic device of the present invention comprises (α1) a step of irradiating the adhesive film for encapsulating the electronic device of the present invention with ultraviolet rays from the surface side closer to the adhesive layer than the functional film.
(Β1) The step of attaching the adhesive film to an electronic device is provided.
It can be produced by performing the (α1) step before the (β1) step.

More specifically, it is performed as follows.
First, as shown in FIG. 2A, a sheet-shaped adhesive 2a is prepared.
In this case, the sheet-like adhesive 2a can be stored as an adhesive film with a double-sided release film in which release films are laminated on both the front and back surfaces.
Next, by laminating a functional film 1 having a wavelength of 365 nm and an ultraviolet ray transmittance of 60% or less on one surface side of the obtained sheet-like adhesive 2a, the laminated body 4a shown in FIG. 2 (b) is laminated. To get.
When the sheet-shaped adhesive 2a is an adhesive film with a double-sided release film, the release film on one side is peeled off and bonded to the functional film 1. In this case, a laminate having a layer structure of a functional film 1 / sheet-like adhesive / release film can be obtained.

Next, as shown in FIG. 2C, the sheet-shaped adhesive is irradiated with ultraviolet rays from the side opposite to the surface on which the functional film 1 of the laminated body 4a is laminated, and the sheet-shaped adhesive 2a is photocured. Initiate the reaction. At this time, the photocuring reaction is started in the sheet-shaped adhesive, but the curing reaction is not completed because the reaction rate of the photocationic polymerization is relatively slow, and the sheet-shaped adhesive is sufficient. It has adhesive strength (sheet-like adhesive 2b in FIG. 2C).

When a laminate having a layer structure of a functional film 1 / sheet-like adhesive / release film is used and the release film is ultraviolet-transparent, the release film on the sheet-like adhesive is used. It is preferable to irradiate ultraviolet rays from the release film side without peeling the film from the viewpoint of handleability.
Here, "having ultraviolet transparency" means a property of transmitting 65% or more, preferably 70% or more of ultraviolet rays having a wavelength of 365 nm (the same applies hereinafter).

Specific examples of the ultraviolet source include light sources such as ultra-high pressure mercury lamps, high pressure mercury lamps, low pressure mercury lamps, carbon arc lamps, black light fluorescent lamps, and metal halide lamps. Further, as the wavelength of the ultraviolet rays to be irradiated, a wavelength range of 190 to 380 nm can be used. When the release film of the laminated body having the layer structure of the functional film 1 / sheet adhesive / ultraviolet-transmitting release film is irradiated with ultraviolet rays from the release film side without peeling, the release film is a polyethylene terephthalate film. When it is used as a base material, the transparency of ultraviolet rays of the release film is remarkably lowered in the region where the wavelength of ultraviolet rays is less than 330 nm. Therefore, it is preferable to irradiate ultraviolet rays in the wavelength range of 330 to 380 nm.
The type of ultraviolet rays, the irradiation amount, the irradiation time, and the like can be appropriately determined depending on the constituent components of the sheet-shaped adhesive to be irradiated and the content of each constituent component.
The irradiance is preferably about ^{20 to 1000 mW / cm 2} and the amount of light is about 50 to 1000 mJ / cm 2.
The irradiation time is usually 0.1 to 1000 seconds, preferably about 1 to 500 seconds.

After that, as shown in FIG. 2D, the target electronic device encapsulant 10 can be obtained by laminating the sheet-shaped adhesive 2b in a state where the curing reaction is not completed and the electronic device.
The time from irradiation with ultraviolet rays to bonding to an electronic device is as long as the sheet-like adhesive irradiated with ultraviolet rays has a sufficient adhesive strength in a state where the curing reaction is not completed. All you need is.
The time from irradiation with ultraviolet rays to bonding to the electronic device is not particularly limited, but is usually 1 minute to 5 hours, preferably 5 to 60 minutes.

In the sheet-like adhesive 2b in a state where the curing reaction was not completed, the photocuring reaction proceeded in the sheet-like adhesive even after the electronic devices were bonded, and the sheet-like adhesive was completely cured over time. It is in a state (adhesive cured product layer 2).
As described above, the sheet-shaped adhesive of the present invention has sufficient adhesiveness even after being irradiated with ultraviolet rays as long as the curing reaction is not sufficiently progressing. It adheres strongly to the electronic device that is attached, and can prevent peeling during or after application. In addition, the sheet-like adhesive cures over time, and finally has excellent durability. An electronic device encapsulant can be obtained.

(Manufacturing method 2)
Further, the electronic device encapsulant of the present invention includes (α2) a step of irradiating a sheet-like adhesive containing the following components (A) and (B) with ultraviolet rays.
(Β2) The sheet-like adhesive has a step of attaching it to a functional film or an electronic device.
It can also be produced by performing the (α2) step before the (β2) step.

Specifically, this method is performed as follows.
First, the sheet-shaped adhesive 2a is prepared. The sheet-like adhesive 2a can be stored as an adhesive film with a double-sided release film in which release films are laminated on both the front and back surfaces.
Next, as shown in FIG. 3A, the sheet-shaped adhesive 2a is irradiated with ultraviolet rays to initiate a photocuring reaction of the sheet-shaped adhesive 2a. In this case, it is preferable to irradiate the ultraviolet rays through the release film.

When irradiated with ultraviolet rays, a photocuring reaction starts in the sheet-shaped adhesive, but since the reaction rate of photocationic polymerization is relatively slow, the curing reaction is not completed, and the sheet-shaped adhesive is used. Has sufficient adhesive strength.
The type of ultraviolet rays, the irradiation conditions of ultraviolet rays, and the like are the same as those described in the production method 1.

Next, the functional film 1 or the electronic device 3 is attached to one surface side of the sheet-shaped adhesive 2b to obtain the state shown in FIG. 3 (b).

After that, as shown in FIG. 3C, the surface of the sheet-like adhesive 2b in a state where the curing reaction is not completed, the surface opposite to the surface on which the functional film 1 or the electronic device 3 is bonded, and By superimposing the electronic device 3 or the functional film 1, the desired electronic device encapsulant 10 can be obtained. That is, when the functional film 1 is bonded to one surface side of the sheet-like adhesive 2b, the electronic device 3 is bonded to the surface opposite to the surface to which the functional film 1 is bonded. As a result, the electronic device encapsulant 10 can be obtained. When the electronic device 3 is bonded to one surface side of the sheet-like adhesive 2b, the functional film 1 is bonded to the surface opposite to the surface to which the electronic device 31 is bonded. The electronic device encapsulant 10 can be obtained.

Even after the functional film 1 or the electronic device 3 is bonded to the sheet-like adhesive 2b whose curing reaction is not completed, the photo-curing reaction proceeds in the layer of the sheet-like adhesive, and the sheet-like adhesive over time. The adhesive layer is in a completely cured state (adhesive cured product layer 2).
As described above, in the sheet-like adhesive of the present invention, even after the adhesive layer is irradiated with ultraviolet rays, the adhesive layer has sufficient adhesiveness as long as the curing reaction is not sufficiently progressing. Therefore, it can be strongly adhered to the electronic device as an adherend, and it is possible to prevent peeling at the time of sticking or after sticking, and the adhesive layer is cured over time, and finally. It is possible to obtain an electronic device encapsulant having excellent durability.

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 specified, parts and% in each example are based on mass.

[Transmittance of ultraviolet rays with a wavelength of 365 nm of a functional film]
The transmittance of ultraviolet rays having a wavelength of 365 nm of the functional film was measured using an ultraviolet-visible light transmittance measuring device (UV-3600, manufactured by Shimadzu Corporation).

[Measurement of adhesive strength of adhesive layer after UV irradiation]
A sample was obtained from the adhesive film for encapsulating an electronic device with a release film obtained in Examples and Comparative Examples by cutting to a width of 25 mm without peeling the release film. Under a 50% environment at 23 ° C., ultraviolet rays having a wavelength of 365 nm were irradiated from the release film side with an illuminance of 50 mW / cm ² and an integrated light intensity of 200 mJ / cm ^2. Ultraviolet irradiation was performed using a high-pressure mercury lamp manufactured by Eye Graphics. Further, as the light intensity meter, "UVPF-A1" manufactured by Eye Graphics Co., Ltd. was used.
After 3 minutes, the release film was peeled off, the sheet-like adhesive surface of the exposed adhesive layer was placed on a soda glass plate with a thickness of 1.1 mm, and a 2 kg roll was reciprocated once on the surface of the functional film for pressure bonding. I let you. After the adhesive film for encapsulating an electronic device is pressure-bonded to a soda glass plate, it is allowed to stand under the conditions of a temperature of 23 ° C. and a relative humidity of 50% for 24 hours, and then a 180 ° peeling test is performed at a peeling speed of 300 mm / min. , Adhesive strength was measured.

In the following examples and comparative examples, a compound having a cyclic ether group [(A) component], a photocationic polymerization initiator [(B) component], a binder resin [(C) component], a tackifier, and a silane. The following were used as the coupling agent.

<Compound having a cyclic ether group [Component (A)]>
(1) Compound having a cyclic ether group (A-1)
Hydrogenated bisphenol A type epoxy resin [manufactured by Mitsubishi Chemical Corporation, trade name: YX8000, cyclic ether equivalent: 205 g / eq, liquid at 25 ° C]
(2) Compound having a cyclic ether group (A-2)
3', 4'-Epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate [Manufactured by Daicel Co., Ltd., trade name: seroxide 2021P, cyclic ether equivalent: 128-145 g / eq, liquid at room temperature (23 ° C)]

<Photocationic polymerization initiator [(B) component]>
(1) Photocationic polymerization initiator (B-1)
Triarylsulfonium salt [manufactured by San Apro, trade name: CPI-200K, anion: anion having a hexafluorophosphate skeleton]
(2) Photocationic polymerization initiator (B-2)
Triarylsulfonium salt [manufactured by San Apro, trade name: CPI-100P]

<Binder resin [(C component)]
(1) Binder resin (C-1)
Acid-modified α-olefin polymer [manufactured by Mitsui Chemicals, trade name: Unistor H-200, weight average molecular weight: 52,000]
(2) Binder resin (C-2)
Phenoxy resin (manufactured by Mitsubishi Chemical Corporation, product name: YX7200B35)

[Example 1]
50 parts by mass of compound (A-1) having a cyclic ether group, 20 parts by mass of compound (A-2) having a cyclic ether group, 1 part by mass of photocationic polymerization initiator (B-1), photocationic polymerization initiator ( B-2) was dissolved in 1.5 parts, 100 parts by mass of the acid-modified α-olefin polymer (A), and 0.1 parts by mass of the silane coupling agent in methyl ethyl ketone to prepare an adhesive composition having a solid content concentration of 30%. Prepared.
This adhesive composition (1) is obtained by coating on a peeling-treated surface of a peeling film (manufactured by Lintec Corporation, trade name: SP-PET752150, thickness 75 μm) which is a polyethylene terephthalate film that has been subjected to silicone peeling treatment. The coating film was dried at 100 ° C. for 2 minutes to form an adhesive layer having a thickness of 30 μm.
A polyethylene terephthalate film (manufactured by Mitsubishi Brass Co., Ltd., trade name: metallized film, thickness 23 μm) on which metallic aluminum is vapor-deposited is placed on the adhesive layer as a functional film on the surface side where metallic aluminum is not vapor-deposited. An adhesive film for encapsulating an electronic device was obtained with a release film. The transmittance of this functional film at a wavelength of 365 nm was 0%. The adhesive strength after irradiation with ultraviolet rays was 12 N / 25 mm.

[Example 2]
The electronic device was sealed in the same manner as in Example 1 except that the photocationic polymerization initiator (B-1) was not used and the blending amount of the photocationic polymerization initiator (B-2) was changed to 3.0 parts by mass. An adhesive film for stopping was obtained. The adhesive strength after irradiation with ultraviolet rays was 4N / 25 mm.

[Example 3]
The electronic device was sealed in the same manner as in Example 1 except that the photocationic polymerization initiator (B-1) was not used and the blending amount of the photocationic polymerization initiator (B-2) was changed to 3.5 parts by mass. An adhesive film for stopping was obtained. The adhesive strength after irradiation with ultraviolet rays was 1 N / 25 mm.

[Example 4]
Instead of the raw material (solid content) of the adhesive composition used in Example 1, 120 parts by mass of the compound (A-2) having a cyclic ether group, (2) the photocationic polymerization initiator (B-2) 2. An adhesive composition was prepared using 5 parts by mass, 100 parts by mass of binder resin (C-2), and 0.2 parts by mass of a silane coupling agent (Shinetsu Chemical Industry Co., Ltd., trade name: KBM6803). An adhesive film for encapsulating an electronic device was obtained in the same manner as in Example 1 except for the above. The adhesive strength after irradiation with ultraviolet rays was 6 N / 25 mm.

1 ... Functional film 2a ... Sheet-like adhesive 2b ... Sheet-like adhesive whose curing reaction is not completed 2 ... Adhesive cured product layer 3 ... Electronic device 4a ... Laminated Body 10: Electronic device sealant

Claims (9)

The adhesive cured product layer comprises a functional film having a transmission rate of ultraviolet rays having a wavelength of 365 nm of 60% or less, an electronic device, and an adhesive cured product layer that seals between the functional film and the electronic device. , A sealed body of an electronic device, which is a cured product of a sheet-like adhesive containing the following components (A) and (B).
(A) Compound having a cyclic ether group (B) Photocationic polymerization initiator A sheet-like adhesive containing the following components (A) and (B), which is used for producing an encapsulant for an electronic device according to claim 1.
(A) Compound having a cyclic ether group (B) Photocationic polymerization initiator The sheet-like adhesive according to claim 2, wherein the sheet-like adhesive has a release film on at least one surface and has an adhesive force to a soda glass plate measured under the following condition (i) of 3 N / 25 mm or more. adhesive.
(I) A laminate was prepared by laminating a 23 μm-thick polyethylene terephthalate film on which aluminum was vapor-deposited on the surface opposite to the release film of the sheet-like adhesive to which the release film was attached. The laminate was irradiated with ultraviolet rays having a wavelength of 365 nm from the release film side under the conditions of illuminance: 50 mW / cm ² and light intensity: 200 mJ / cm ² , and 3 minutes later, the laminate The release film was peeled off from the film, the exposed sheet-like adhesive layer was opposed to the soda glass plate, and a 2 kg roll was reciprocated once on the laminate to attach it to the soda glass plate, and the film was attached to the soda glass plate at 23 ° C. After being stored for 24 hours in an environment of% relative humidity, a 180 ° peeling test is performed. The sheet-like adhesive according to claim 2 or 3, further comprising one or more selected from the group consisting of a modified polyolefin resin and a phenoxy resin. An adhesive film for encapsulating an electronic device, comprising a functional film having an ultraviolet transmittance of 60% or less at a wavelength of 365 nm and an adhesive layer composed of a sheet-like adhesive containing the following components (A) and (B).
(A) Compound having a cyclic ether group (B) Photocationic polymerization initiator The adhesive film for encapsulating an electronic device has a release film on the surface of the adhesive layer on the side where the functional film is not bonded, and has an adhesive force to a soda glass plate measured under the following condition (ii). The adhesive film for sealing an electronic device according to claim 5, which is 3N / 25 mm or more.
(Ii) With the release film attached to the adhesive film for encapsulating the electronic device, ultraviolet rays having a wavelength of 365 nm are emitted from the release film side under the conditions of illuminance: 50 mW / cm ² and light intensity: 200 mJ / cm ² . After irradiation, 3 minutes later, the release film was peeled off from the electronic device sealing adhesive film, the exposed adhesive layer was opposed to a soda glass plate, and 2 kg was placed on the electronic device sealing adhesive film. The roll is affixed to a soda glass plate by reciprocating once, and after being stored at 23 ° C. in an environment of 50% relative humidity for 24 hours, a 180 ° peeling test is carried out. The adhesive film for encapsulating an electronic device according to claim 5 or 6, wherein the sheet-like adhesive comprises at least one selected from the group consisting of a modified polyolefin resin and a phenoxy resin. (Α1) A step of irradiating the adhesive film for encapsulating an electronic contact device according to any one of 5 to 7 with ultraviolet rays from the surface side closer to the adhesive layer than the functional film.
(Β1) The step of attaching the adhesive film to an electronic device is provided.
A method for manufacturing a sealed body of an electronic device in which the step (α1) is performed before the step (β1). (Α2) A step of irradiating a sheet-like adhesive containing the following components (A) and (B) with ultraviolet rays, and
(Β2) The sheet-like adhesive is attached to a functional film or an electronic device having a wavelength of 365 nm and an ultraviolet ray transmittance of 60% or less.
A method for manufacturing a sealed body of an electronic device in which the step (α2) is performed before the step (β2).
(A) Compound having a cyclic ether group (B) Photocationic polymerization initiator

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