TWI870627B - Display element sealing material, organic EL element sealing material and display element sealing sheet - Google Patents

Abstract

The display device sealing material of the present invention contains: a resin component, an oxycyclobutane compound, and a curing agent. The resin component contains: an epoxidized polybutadiene resin, an epoxy resin containing a biphenyl skeleton, and an adhesive resin.

Description

Display element sealing material, organic EL element sealing material and display element sealing sheet

The present invention relates to a display element sealing material, an organic EL element sealing material and a display element sealing sheet.

Known image display devices with display elements include liquid crystal displays and organic electroluminescent (hereinafter referred to as "organic EL") displays. Such image display devices use a sealing member to seal the display element. This can prevent the display element from being degraded by moisture in the atmosphere.

The sealing member is formed by, for example, burying the display element in the sealing resin composition and then hardening the sealing resin composition. In order to give the sealing member the performance required for various uses, various examinations are conducted on the composition of the sealing resin composition.

For example, there is a proposal for a curable resin composition for sealing an organic EL display element, which contains a phenoxy resin, an oxyalkylene-type alicyclic epoxy compound, and a curing agent (see, for example, Patent Document 1).

Furthermore, there is a proposal for an epoxy resin composition containing a low molecular weight epoxy resin having a molecular weight of 200 to 2,000, a high molecular weight epoxy resin having a molecular weight of 20,000 to 100,000, and a latent curing agent (see, for example, Patent Document 2).

After the display element is buried, the sealing resin composition is hardened by heating to seal the display element. [Prior art document] [Patent document]

[Patent Document 1] International Publication No. 2015/129670 [Patent Document 2] International Publication No. 2006/104078

(Invent the problem you want to solve)

However, the sealing member of the cured product of the curable resin composition for sealing the organic EL display element described in Patent Document 1 has a high dielectric constant. For example, when used in a touch panel of an organic EL display, noise caused by the sealing member may cause erroneous operation of the touch panel.

Furthermore, when sealing the display element, if the epoxy resin composition described in Patent Document 2 is heated, the epoxy resin composition may flow before hardening and may deviate from the desired position and then harden.

The present invention is to improve the initial curing property and form a display element sealing material, an organic EL element sealing material and a display element sealing sheet that can form a sealing member with a lower dielectric constant while suppressing positional deviation relative to the display element. (Technical means to solve the problem)

The present invention [1] is a display element sealing material, which contains: a resin component, an oxycyclobutane compound, and a hardener; and the resin component contains: an epoxidized polybutadiene resin, a biphenyl skeleton-containing epoxy resin, and an adhesive resin.

The present invention [2] is a display device sealing material as described in the above [1], wherein the content ratio of the above epoxidized polybutadiene resin is more than 20 parts by mass and less than 35 parts by mass relative to 100 parts by mass of the total of the above resin component and the above cyclohexane compound.

The present invention [3] is a display device sealing material as described in [1] or [2] above, wherein the content ratio of the above-mentioned biphenyl skeleton-containing epoxy resin is more than 20 parts by mass relative to 100 parts by mass of the total of the above-mentioned resin component and the above-mentioned cyclohexane compound.

The present invention [4] is a display device sealing material as described in any one of the above [1] to [3], wherein the content ratio of the above cyclohexane compound is more than 5 parts by mass and less than 20 parts by mass relative to 100 parts by mass of the total of the resin component and the above cyclohexane compound.

The present invention [5] is a display device sealing material as described in any one of the above [1] to [4], wherein the adhesive resin contains a cycloaliphatic hydrocarbon resin and/or a terpene phenol resin.

The present invention [6] is an organic EL element sealing material, which is formed by the display element sealing material described in any one of the above [1] to [5].

The present invention [7] is a display element sealing sheet having a sealing layer formed by the display element sealing material described in any one of the above [1] to [5]. (Compared with the effect of the prior art)

The display element sealing material, organic EL element sealing material and display element sealing sheet of the present invention contain: epoxidized polybutadiene resin, biphenyl skeleton-containing epoxy resin, adhesive resin and cyclobutane compound. Therefore, the initial curing property can be improved, and a sealing member with a lower dielectric constant can be formed while suppressing positional deviation relative to the display element.

<Display element sealing material> The display element sealing material of the present invention (hereinafter referred to as "sealing material") is a sealing resin composition (display element sealing resin composition) used to seal the display element of the image display device described below, and is a curable resin composition that forms the sealing member described below by curing. The sealing material contains: a resin component, an oxycyclobutane compound, and a curing agent.

(1) Resin component The resin component contains essential components of epoxidized polybutadiene resin, biphenyl skeleton-containing epoxy resin, and adhesive resin.

(1-1) Epoxy polybutadiene resin Epoxy polybutadiene resin is a multifunctional epoxy resin having a polybutadiene skeleton and a plurality of epoxy groups. In addition, the multifunctional epoxy resin also includes a difunctional epoxy resin (hereinafter the same).

The polybutadiene skeleton is a molecular chain (main chain) composed of a polymer of 1,3-butadiene. The polybutadiene skeleton contains the molecular structure of 1,2-polybutadiene and has side chains branching from the above molecular chain.

Epoxy groups are located on the side chains of the polybutadiene backbone. Epoxy groups are introduced by oxidizing the vinyl groups of 1,2-polybutadiene contained in the polybutadiene backbone.

Epoxidized polybutadiene resin is compatible with adhesive resin. The solubility parameter (hereinafter referred to as "SP value") of epoxidized polybutadiene resin is, for example, 9.0 (cal/cm ³ ) ^1/2 or more and 10.0 (cal/cm ³ ) ^1/2 or less. The SP value can be calculated using the calculation software CHEOPS (version 4.0) of Million Zillion Software (hereinafter the same). In addition, the calculation method used by the calculation software is described in Chapter XII of Computational Materials Science of Polymers (AAAskadskii, Cambridge Intl Science Pub (2005/12/30)).

The number average molecular weight (Mn) of the epoxidized polybutadiene resin is, for example, 3,000 or more, preferably 5,000 or more, and, for example, 10,000 or less, preferably 8,000 or less. The number average molecular weight (Mn) can be obtained by gel permeation chromatography (GPC) using polystyrene as a standard substance (the same applies hereinafter).

The epoxy equivalent of the epoxidized polybutadiene resin is, for example, 100 g/eq. or more, preferably 150 g/eq. or more, and, for example, 300 g/eq. or less, preferably 250 g/eq. or less. The epoxy equivalent can be measured according to JIS K7236:2001 (the same applies hereinafter).

Such epoxidized polybutadiene resins may be used alone or in combination of two or more.

The content ratio of the epoxidized polybutadiene resin is, for example, 5 parts by mass or more, preferably 10 parts by mass or more, more preferably more than 20 parts by mass, particularly preferably 22 parts by mass or more, and for example, 60 parts by mass or less, preferably 50 parts by mass or less, more preferably 40 parts by mass or less, particularly preferably less than 35 parts by mass, further preferably less than 30 parts by mass, further particularly preferably 28 parts by mass or less, based on 100 parts by mass of the total of the resin component and the cyclohexane oxide compound.

If the content ratio of the epoxidized polybutadiene resin is within the above range, the dielectric constant of the sealing member described below can be surely reduced while the initial curability of the sealing material can be surely improved.

(1-2) Biphenyl skeleton-containing epoxy resin The biphenyl skeleton-containing epoxy resin is, for example, a multifunctional epoxy resin having a plurality of biphenyl skeletons and a plurality of epoxy groups. The biphenyl skeleton-containing epoxy resin is preferably a difunctional epoxy resin having: a molecular chain containing a plurality of biphenyl skeletons and epoxy groups bonded to both ends of the molecular chain.

The biphenyl skeleton-containing epoxy resin is more preferably represented by the following formula (1):

Formula (1) [Chemical 1] [In formula (1), I, II and III are constituent units, I and III are terminal units, and II is a repeating unit. ^R1 is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.]

The biphenyl skeleton-containing epoxy resin represented by the above formula (1) is a copolymer of a dihydroxybiphenyl derivative and epichlorohydrin, and has a molecular chain containing a plurality of biphenyl skeletons and glycidyl ether units bonded to both ends of the molecular chain.

The alkyl group represented by ^R1 in the above formula (1) includes, for example, a linear alkyl group having 1 to 6 carbon atoms and a branched alkyl group having 3 to 6 carbon atoms. Examples of the linear alkyl group having 1 to 6 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, and hexyl. Examples of the branched alkyl group having 3 to 6 carbon atoms include isopropyl, isobutyl, and t-butyl.

In the above formula (1), R ¹ is preferably a hydrogen atom or a methyl group. In addition, a plurality of R ¹ in formula (1) may be the same or different from each other.

In the above formula (1), among the plurality of R ¹ , R ¹ bonded to the 3-position and 5-position of the benzene ring is preferably a methyl group. Also, among the plurality of R ¹ , R ¹ bonded to the 2-position and 6-position of the benzene ring is preferably a hydrogen atom.

Furthermore, the biphenyl skeleton-containing epoxy resin represented by the above formula (1) may contain other constituent units in addition to the constituent units I to III. Other constituent units may include, for example, polyol units derived from divalent or higher polyols, bisphenol units derived from bisphenols, and the like.

The weight average molecular weight (Mw) of the biphenyl skeleton-containing epoxy resin is, for example, 200 or more, preferably 250 or more, and, for example, 100,000 or less, preferably 90,000 or less. The weight average molecular weight (Mw) can be obtained by gel permeation chromatography (GPC) using polystyrene as a standard substance (the same applies hereinafter).

The epoxy equivalent of the biphenyl skeleton-containing epoxy resin is, for example, 500 g/eq. or more, preferably 1,000 g/eq. or more, and, for example, 20,000 g/eq. or less, preferably 16,000 g/eq. or less.

Such biphenyl skeleton-containing epoxy resins may be used alone or in combination of two or more.

The content ratio of the biphenyl skeleton-containing epoxy resin is, for example, 5 parts by mass or more, preferably 15 parts by mass or more, more preferably more than 20 parts by mass, particularly preferably 22 parts by mass or more, and for example, 50 parts by mass or less, preferably 40 parts by mass or less, more preferably 30 parts by mass or less, relative to 100 parts by mass of the total of the resin component and the cyclohexane compound.

If the content ratio of the biphenyl skeleton-containing epoxy resin is within the above range, the dielectric constant of the sealing member described below can be reduced while the initial curability of the sealing material can be improved.

(1-3) Adhesive resin By including an adhesive resin in the sealing material, the sealing material can be given adhesiveness while maintaining the dielectric constant of the sealing member described later. The adhesive resin contains a ring skeleton (aliphatic ring and/or aromatic ring) but does not contain an epoxy group.

Examples of adhesive resins include petroleum resins, terpene resins, phenol resins, and rosin resins.

The petroleum-based resin may be, for example, the petroleum resin described in paragraphs [0056] and [0057] of International Publication No. 2020/031941.

The terpene resin may be, for example, the terpene resin described in paragraph [0058] of International Publication No. 2020/031941.

The phenolic resin may be, for example, the phenolic resin described in paragraph [0059] of International Publication No. 2020/031941.

The rosin resin may be, for example, the rosin resin described in paragraph [0060] of International Publication No. 2020/031941.

Preferred adhesive resins include petroleum resins and terpene resins.

Examples of the petroleum-based resin include alicyclic hydrocarbon resins, and more preferably ester-modified hydrocarbon resins.

Ester modified hydrocarbon resin is produced by introducing ester groups into petroleum hydrocarbon resin. The main raw material of petroleum hydrocarbon resin is dicyclopentadiene extracted from C5 fraction obtained by cracking light oil. The petroleum hydrocarbon resin is preferably a monomer of dicyclopentadiene.

The ester-modified hydrocarbon resin has an aliphatic ring derived from dicyclopentadiene and an ester-containing atomic group. The ester-containing atomic group can be, for example, a vinyl acetate unit derived from vinyl acetate.

The weight average molecular weight (Mw) of the ester-modified hydrocarbon resin is, for example, 500 or more, and for example, less than 10,000, and preferably 4,000 or less.

The saponification value of the ester-modified hydrocarbon resin is, for example, 100 mgKOH/g or more and 200 mgKOH/g or less. The saponification value can be measured by the method described in JIS K0070.

The terpene resin may preferably be, for example, a terpene phenol resin.

Terpene phenol resin is a copolymer (reactant) of a terpene compound and a phenol compound. The terpene phenol resin is prepared by reacting a terpene compound and a phenol compound in the presence of an acidic catalyst at 20°C to 150°C for 1 to 20 hours. The acidic catalyst may be, for example, hydrochloric acid, sulfuric acid, and cation exchange resin.

The main skeleton of terpene compounds is a hydrocarbon with isoprene (C ₅ H ₈ ) as a constituent unit. Examples of terpene compounds include α-pinene, β-pinene, dipentene, limonene, α-phenanthrene, β-phenanthrene, α-terpinene, β-terpinene, γ-terpinene, terpinenediene, myrcene, alloocimene, 1,8-cineole, 1,4-cineole, α-terpineol, β-terpineol, γ-terpineol, 4-terpineol, camphene, tricyclene, Olefin-1, Olefin-2, Olefin-3, Olefin-8, Terpene compounds such as dienes, Δ2-carene, Δ3-carene, caryophyllene, and longifolene may be used alone or in combination of two or more.

Examples of the phenolic compound include phenol, cresol, xylenol, propylphenol, nonylphenol, hydroquinone, resorcinol, methoxyphenol, bromophenol, bisphenol A, and bisphenol F. The phenolic compound may be used alone or in combination of two or more. Among the phenolic compounds, phenol is preferred.

The weight average molecular weight (Mw) range of the terpene phenol resin is the same as the weight average molecular weight (Mw) range of the above-mentioned ester-modified hydrocarbon resin.

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

The adhesive resin preferably contains alicyclic hydrocarbon resins and/or terpene phenol resins, and more preferably is formed from alicyclic hydrocarbon resins and/or terpene phenol resins.

More specifically, the adhesive resin preferably contains an alicyclic hydrocarbon resin and a terpene phenol resin from the viewpoint of lowering the dielectric constant of the sealing member described below. Furthermore, the adhesive resin is preferably formed of an alicyclic hydrocarbon resin from the viewpoint of improving the initial curability of the sealing material.

The SP value of the binder resin is, for example, 8.8 (cal/cm ³ ) ^1/2 or more, preferably 9.0 (cal/cm ³ ) ^1/2 or more, and for example, 11.5 (cal/cm ³ ) ^1/2 or less, preferably 10.0 (cal/cm ³ ) ^1/2 or less, more preferably 9.5 (cal/cm ³ ) ^1/2 or less, and particularly preferably 9.2 (cal/cm ³ ) ^1/2 or less.

If the SP value of the adhesive resin is within the above range, the transparency of the sealing material described below can be improved.

The content ratio of the adhesive resin is, for example, 5 parts by mass or more, preferably 10 parts by mass or more, more preferably 20 parts by mass or more, and for example, 50 parts by mass or less, preferably 40 parts by mass or less, more preferably 30 parts by mass or less, based on 100 parts by mass of the total of the resin component and the oxycyclobutane compound.

(1-4) Optional resin component Furthermore, the resin component is a bisphenol skeleton-containing epoxy resin which may further contain an optional component.

The bisphenol skeleton-containing epoxy resin is a multifunctional epoxy resin having a plurality of bisphenol skeletons and a plurality of epoxy groups. The bisphenol skeleton-containing epoxy resin is preferably a difunctional epoxy resin having a molecular chain containing a plurality of bisphenol skeletons and glycidyl ether units bonded to both ends of the molecular chain.

The bisphenol skeleton-containing epoxy resin is, for example, a copolymer of bisphenol and epichlorohydrin.

The bisphenol may be, for example, bisphenol A and bisphenol F, preferably bisphenol F.

The weight average molecular weight (Mw) of the bisphenol skeleton-containing epoxy resin is, for example, 800 or more, preferably 900 or more, and less than 10,000, preferably 8,000 or less.

The epoxy equivalent of the bisphenol skeleton-containing epoxy resin is, for example, 100 g/eq. or more, preferably 150 g/eq. or more, and, for example, 2,000 g/eq. or less, preferably 1,500 g/eq. or less.

The SP value of the bisphenol skeleton-containing epoxy resin is, for example, 11.5 (cal/cm ³ ) ^1/2 or more and 13.0 (cal/cm ³ ) ^1/2 or less.

The content ratio of the bisphenol skeleton-containing epoxy resin is, for example, 5 parts by mass or more, preferably 10 parts by mass or more, and for example, 40 parts by mass or less, preferably 30 parts by mass or less, based on 100 parts by mass of the total of the resin component and the oxycyclobutane compound.

In addition, the resin component may contain other resin components other than the above-mentioned specific resin components (epoxy polybutadiene resin, biphenyl skeleton-containing epoxy resin, adhesive resin, and bisphenol skeleton-containing epoxy resin) within a range that does not hinder the effect of the present invention.

Other resin components include, for example, epoxy resins containing alicyclic skeletons, styrene oligomers, polyolefins, polychloroprene, polyamide, polyamide imide, polyurethane, polyether, polyester, and polysilicone resins. These other resin components can be used alone or in combination of two or more. The content of the other resin components in the resin components is, for example, 10% by mass or less, preferably 5% by mass or less.

Furthermore, the resin component preferably does not contain other resin components and is composed of: an epoxidized polybutadiene resin, an epoxy resin containing a biphenyl skeleton, an adhesive resin, and, if necessary, an epoxy resin containing a bisphenol skeleton.

(2) Oxycyclobutane compounds The cationically polymerizable group contained in the oxycyclobutane compounds is an oxycyclobutane group.

The oxycyclobutane compound may be, for example, the oxycyclobutane compound described in paragraphs [0037] to [0053] of International Publication No. 2020/031941.

Among the cyclohexane compounds, the cyclohexane compounds represented by the following formula (2) are preferred. [In formula (2), Y represents an oxygen atom, a sulfur atom or a single bond. ^R2 represents a hydrogen atom, a fluorine atom, an alkyl group having 1 to 6 carbon atoms, a fluoroalkyl group having 1 to 6 carbon atoms, an allyl group, an aryl group having 6 to 18 carbon atoms, a furyl group or an ethynyl group. ^R3 represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an aralkyl group having 7 to 18 carbon atoms, an alkylcarbonyl group having 2 to 6 carbon atoms, an alkoxycarbonyl group having 2 to 6 carbon atoms, an N-alkylaminoformyl group having 2 to 6 carbon atoms, a (meth)acryl group, or an atomic group of an oxygen-containing heterocyclobutane group represented by the following formula (3). m represents an integer greater than 1 and less than 5.] In addition, the (meth)acryl group may be, for example, an acryl group and a methacryl group.

In the above formula (2), Y is preferably an oxygen atom or a sulfur atom, and more preferably an oxygen atom.

In the above formula (2), R ² is preferably a hydrogen atom, a fluorine atom, an alkyl group having 1 to 6 carbon atoms, a fluoroalkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 18 carbon atoms, a furyl group, and an ethynyl group, and more preferably an alkyl group having 1 to 6 carbon atoms.

In the above formula (2), R ³ is preferably an oxygen-containing heterocyclobutane radical such as that represented by the following formula (3).

[Chemistry 3]

[In formula (3), ^R2 represents the same functional group as ^R2 in the above formula (2). m represents an integer of 1 or more and 5 or less.]

In the above formula (2) and formula (3), m is preferably 1.

Examples of such cyclohexane compounds include 3-ethyl-3-hydroxymethylcyclohexane, 3-(methyl)allyloxymethyl-3-ethylcyclohexane, (3-ethyl-3-cyclohexanebutylmethoxy)methylbenzene, 4-fluoro-[1-(3-ethyl-3-cyclohexanebutylmethoxy)methyl]benzene, 4-methoxy-[1-(3-ethyl-3-cyclohexanebutylmethoxy)methyl]benzene, [1-(3-ethyl-3-cyclohexanebutylmethoxy)ethyl]phenyl ether, isobutoxymethyl (3-ethyl-3-cyclohexanebutylmethoxy)ethyl]benzene, 2-ethylhexyl (3-ethyl-3-oxocyclobutanyl methyl) ether, ethyl diethylene glycol (3-ethyl-3-oxocyclobutanyl methyl) ether, dicyclopentadiene (3-ethyl-3-oxocyclobutanyl methyl) ether, 3-methacryloyloxymethyl-3-ethyloxocyclobutane, and 3-ethyl-3-[(2-ethylhexyloxy)methyl]oxocyclobutane.

Such oxycyclobutane compounds may be used alone or in combination of two or more.

The molecular weight of the oxycyclobutane compound is, for example, 180 or more, preferably 190 or more, more preferably 200 or more, and for example, 400 or less.

The oxygen atom content of the oxycyclobutane compound is, for example, 15 mass % or more, and, for example, 30 mass % or less, preferably 25 mass % or less, and more preferably 20 mass % or less. The oxygen atom content can be calculated by the following formula (4).

Oxygen atom content (mass %) = total mass of oxygen atoms in one molecule / molecular weight × 100... (4)

When the oxygen atom content of the oxycyclobutane compound is within the above range, the dielectric constant of the sealing member described below can be stably reduced.

The content ratio of the cyclohexylbutane compound is, for example, 1 part by mass or more, preferably 3 parts by mass or more, more preferably more than 5 parts by mass, particularly preferably 8 parts by mass or more, and for example, 30 parts by mass or less, preferably less than 20 parts by mass, more preferably less than 15 parts by mass, particularly preferably 12 parts by mass or less, based on 100 parts by mass of the total of the resin component and the cyclohexylbutane compound.

If the content ratio of the cyclohexane compound is within the above range, the initial curability of the sealing member described below can be improved more reliably, and the dielectric constant of the sealing member described below can be reduced more reliably.

(3) Hardener The hardener polymerizes the resin component to harden the sealant. The hardener is not particularly limited as long as it can harden the sealant. Examples of hardeners include amine hardeners, imidazole hardeners, acid anhydride hardeners, thermal cationic hardeners, and photo-cationic hardeners.

Among the curing agents, preferred ones include: thermal cationic curing agents and light cationic curing agents.

The heat cationic curing agent and the light cationic curing agent are compounds that can initiate polymerization of the above-mentioned epoxidized polybutadiene resin, the above-mentioned biphenyl skeleton-containing epoxy resin, and, if necessary, the above-mentioned bisphenol skeleton-containing epoxy resin, respectively, and there are no particular limitations on the rest.

The thermal cationic curing agent is a thermal acid generator that generates acid (cations) when heated. The thermal cationic curing agent is preferably a compound that can start polymerization at a heat-resistant temperature of 120°C or below for display devices.

The thermal cationic curing agent may be a known thermal cationic polymerization initiator. Examples of the thermal cationic polymerization initiator include cobalt salts, phosphonium salts, quaternary ammonium salts, diazonium salts, and iodonium salts that form conjugated anions with the following. Examples of the conjugated anions include AsF ₆ ^- , SbF ₆ ^- , PF ₆ ^- , BF ₄ ^- , B(C ₆ F ₅ ) ₄ ^- , and CF ₃ SO ₃ ^- .

The photo-cationic hardener is a photo-acid generator that generates acid (cations) when irradiated with light. The photo-cationic hardener can use a known photo-cationic polymerization initiator. Examples of the photo-cationic hardener include CPI-210S (manufactured by SAN-APRO) and IK-1 (manufactured by SAN-APRO).

Such hardeners can be used alone or in combination of two or more.

Among the hardeners, a heat cationic hardener is particularly preferred, and a quaternary ammonium salt is more preferred. That is, the hardener particularly preferably contains at least a heat cationic hardener, and may further contain a photo cationic hardener, or may not contain a photo cationic hardener.

The content ratio of the hardener is, for example, 0.3 parts by mass or more, preferably 0.5 parts by mass or more, and for example, 10 parts by mass or less, preferably 5 parts by mass or less, based on 100 parts by mass of the total of the resin component and the cyclohexane compound.

(4) Other additives The sealing material may also contain other additives such as silane coupling agents as needed.

Examples of the silane coupling agent include epoxy-containing silane coupling agents, amino-containing silane coupling agents, and methyl-containing acryl silane coupling agents. The silane coupling agents may be used alone or in combination of two or more.

Among the silane coupling agents, preferred are silane coupling agents containing an epoxy group, for example.

Examples of the epoxy group-containing silane coupling agent include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and more preferably γ-glycidoxypropyltrimethoxysilane.

The content ratio of the silane coupling agent is, for example, 0.05 parts by mass or more, preferably 0.1 parts by mass or more, and for example, 30 parts by mass or less, preferably 5 parts by mass or less, based on 100 parts by mass of the total of the resin component and the cyclohexane compound.

Furthermore, the sealing material may further contain other additives in appropriate proportions as needed, such as: leveling agents, fillers, polymerization initiation aids, anti-aging agents, wettability improvers, surfactants, plasticizers, ultraviolet absorbers, preservatives, antibacterial agents, colorants (dyes, pigments), etc.

<Effects> The above-mentioned sealing material contains: epoxidized polybutadiene resin, biphenyl skeleton-containing epoxy resin, adhesive resin, and cyclobutane compound. Therefore, it can improve the initial curing property and form a sealing component with a lower dielectric constant while suppressing the position shift relative to the display element.

<Display element sealing sheet> The above-mentioned sealing material can be directly circulated alone and is a product that can be used in the industry. From the perspective of disposal, it is preferably circulated in the form of a display element sealing sheet.

1 , a sealing sheet 1 of an embodiment of a display device sealing sheet of the present invention will be described.

As shown in FIG1 , the sealing sheet 1 includes: a sealing layer 2 made of the above-mentioned sealing material, a base film 3, and a release film 4. In addition, the sealing sheet 1 is a component for manufacturing an image display device. The sealing sheet 1 does not contain a display element and a substrate on which the display element is mounted, and is specifically composed of a sealing layer 2, a base film 3, and a release film 4. The sealing sheet 1 is a device that is distributed separately as a component and can be used in the industry.

In order to prevent foreign matter from being attached to the sealing layer 2, when the sealing sheet 1 is stored, it is preferred to protect the sealing layer 2 with the base film 3 and the release film 4. In addition, the base film 3 and the release film 4 are peeled off when the sealing sheet 1 is used.

The sealing layer 2 is a dried product of the sealing material and has a film shape (flat plate shape). Specifically, the sealing layer 2 has a predetermined thickness and has a flat front surface and a flat back surface extending in a predetermined direction perpendicular to the thickness direction.

The sealing layer 2 does not react with the above-mentioned resin components (epoxy polybutadiene resin, biphenyl skeleton-containing epoxy resin, bisphenol skeleton-containing epoxy resin), and the sealing layer 2 contains the epoxy components in an uncured state.

The thickness of the sealing layer 2 is, for example, not less than 1 μm, preferably not less than 5 μm, and, for example, not more than 100 μm, preferably not more than 30 μm.

The bottom film 3 is releasably adhered to the back of the sealing layer 2 to support and protect the sealing layer 2 until the sealing sheet 1 is used in the formation of the sealing member described later. That is, the bottom film 3 is laminated on the back of the sealing layer 2 in a manner covering the back of the sealing layer 2 when the sealing sheet 1 is shipped, transported, and stored. The bottom film 3 is a flexible film that can be bent into a slightly U-shaped shape and peeled off from the back of the sealing layer 2 just before the sealing sheet 1 is used.

The base film 3 has a flat plate shape, specifically has a predetermined thickness, and has a flat surface and a flat back surface extending in a predetermined direction perpendicular to the thickness direction. The adhesive surface (surface) of the base film 3 may also be subjected to a peeling treatment as needed.

The material of the base film 3 may be, for example, a resin material. The resin material may be, for example, polyester and polyolefin. The polyester may be, for example, polyethylene terephthalate (PET). The polyolefin may be, for example, polyethylene and polypropylene. Among the resin components, polyethylene terephthalate is preferred.

The base film 3 is preferably a film with waterproof or gas barrier properties, and more preferably a film made of polyethylene terephthalate. The thickness of the base film 3 is appropriately selected according to the film material, and can be set to about 25 μm to 150 μm from the perspective of tracking the sealed material such as the display element.

The release film 4 is releasably adhered to the surface of the sealing layer 2 to protect the sealing layer 2 until the sealing sheet 1 is used to form a sealing member. That is, the release film 4 is laminated on the surface of the sealing layer 2 in a manner covering the surface of the sealing layer 2 during shipment, transportation, and storage of the sealing sheet 1. The release film 4 is a flexible film that can be bent into a substantially U-shape and peeled off from the surface of the sealing layer 2 just before the sealing sheet 1 is used.

The release film 4 is in the shape of a flat plate, specifically, has a predetermined thickness, and has a flat surface and a flat back surface extending in a predetermined direction orthogonal to the thickness direction. In addition, the adhesive surface (back surface) of the release film 4 can also be subjected to a peeling treatment as needed. The material of the release film 4 can be, for example, the same resin material as the base film 3. The thickness of the release film 4 is appropriately selected according to the film material, and can be set to, for example, 25μm~150μm from the viewpoint of having tracking properties for the sealed material such as the display element.

<Manufacturing method of display element sealing sheet> Next, the manufacturing method of the sealing sheet 1 is described.

When manufacturing the sealing sheet 1 , for example, the above-mentioned sealing material is prepared and applied on the surface of the base film 3 by a known method.

The sealing material is prepared by mixing the above-mentioned resin component, cyclohexane compound, hardener and additive according to the above-mentioned proportion. In addition, when manufacturing the sealing sheet 1, the sealing material is preferably diluted with an organic solvent to prepare a varnish of the sealing material.

The organic solvent is not particularly limited as long as it can evenly disperse or dissolve the resin component and the hardener. Examples of the organic solvent include aromatic hydrocarbons, ketones, ethers, esters, and nitrogen-containing compounds.

The organic solvents may be used alone or in combination of two or more.

Among the organic solvents, ketones are preferred. Examples of ketones include acetone, methyl ethyl ketone, and methyl isobutyl ketone, and methyl ethyl ketone is preferred. When the organic solvent contains ketones, the resin component can be uniformly dissolved.

The solid content concentration of the sealing material varnish is, for example, 30 mass % or more, preferably 40 mass % or more, and, for example, 70 mass % or less, preferably 60 mass % or less.

The components can be mixed by, for example, dispersing them in a ball mill, stirring them in a flask, or kneading them using a three-roll mill.

Furthermore, the sealing material may be applied by, for example, screen printing, a dispenser, and a coating roller.

Next, the sealing material is dried and the organic solvent is volatilized as necessary to form a coating film.

The heating temperature is a temperature at which the sealing material is dried without hardening. The heating temperature is, for example, 20°C or higher, preferably 90°C or higher, and, for example, 120°C or lower, preferably less than 100°C. The heating time is, for example, 1 minute or longer, preferably 2 minutes or longer, and, for example, 30 minutes or lower, preferably 15 minutes or lower.

The coating is thereby dried to prepare the sealing layer 2 formed of the sealing material. Next, the release film 4 is attached to the surface of the sealing layer 2.

The sealing sheet 1 is prepared according to the above contents.

<Manufacturing of image display device> This sealing sheet 1 is suitable for sealing the display element of the image display device. The display element can be, for example, an organic EL element. Referring to FIG. 2 , an organic EL display with a touch sensor (hereinafter referred to as "organic EL display 10") in one embodiment of the image display device is described. In this embodiment, the sealing material is an organic EL element sealing material, and the sealing sheet 1 is an organic EL element sealing sheet. In other words, the organic EL element sealing material is composed of the above-mentioned sealing material, and the organic EL element sealing sheet is composed of the sealing sheet 1.

In addition, in this embodiment, the image display device is exemplified as an organic EL display with a touch sensor, but the image display device is not particularly limited. The image display device may be, for example, a liquid crystal display (including a liquid crystal display with a touch sensor) and an organic EL display (including an organic EL display with a touch sensor).

The organic EL display 10 includes a device mounting unit 11 , a sealing member 14 , and a cover glass or a barrier film 15 .

The device mounting unit 11 includes a substrate 13, an organic EL device 12 which is an example of a display device, a barrier layer 16, and electrodes (not shown).

The substrate 13 supports the organic EL element 12. The substrate 13 is preferably flexible.

The organic EL element 12 is a well-known organic EL element, and is mounted on a substrate 13. Although not shown, the organic EL element 12 includes a cathode reflective electrode, an organic EL layer, and an anode transparent electrode.

The barrier layer 16 covers the organic EL element 12 and prevents moisture in the atmosphere from coming into contact with the organic EL element 12. The barrier layer 16 includes a first inorganic barrier layer 17, a planarization layer 19, and a second inorganic barrier layer 18.

The first inorganic barrier layer 17 is disposed on the upper surface and the side surface of the organic EL element 12 in a manner of surrounding the organic EL element 12. The material of the first inorganic barrier layer 17 may be, for example, metal oxide and metal nitride. The metal oxide may be, for example, aluminum oxide, silicon oxide, and copper oxide. The metal nitride may be, for example, aluminum nitride and silicon nitride.

The material of the first inorganic barrier layer 17 may be used alone or in combination of two or more. The material of the first inorganic barrier layer 17 is preferably metal nitride, more preferably silicon nitride.

The planarization layer 19 is disposed on the first inorganic barrier layer 17. The material of the planarization layer 19 may be, for example, a known resin material.

The second inorganic barrier layer 18 is disposed on the upper surface and the side surface of the planarization layer 19 so as to surround the planarization layer 19. The material of the second inorganic barrier layer 18 may be the same as that of the first inorganic barrier layer 17, for example.

The electrode not shown in the figure is a sensor constituting the organic EL display with a touch sensor. The electrode not shown in the figure is located between the substrate 13 and the sealing member 14. For example, the electrode not shown in the figure can be located in the substrate 13 or on the organic EL element 12.

The sealing member 14 is a cured product of the sealing layer 2 (sealing material), and seals the organic EL element 12 covered by the barrier layer 16. The sealing member 14 is formed by the sealing layer 2 from which the base film 3 and the release film 4 are peeled off.

Specifically, the sealing layer 2 after peeling off the base film 3 and the release film 4 is attached to the substrate 13 in a manner of burying the organic EL element 12 covered by the barrier layer 16, and then a cover glass or barrier film 15 is attached on the sealing layer 2.

Then, the sealing layer 2 is heated to harden. The heating temperature of the sealing layer 2 is, for example, 90° C. or higher, preferably 100° C. or higher, and, for example, 130° C. or lower, preferably 120° C. or lower. At this time, the sealing layer 2 is quickly hardened, and the sealing member 14 is not displaced relative to the organic EL element 12 and the substrate 13, and is formed at a desired position.

Therefore, the sealing member 14 can be formed at a desired position by simply performing thermal curing on the sealing layer 2 without performing preliminary fixing by UV irradiation, for example. As a result, the manufacturing efficiency of the image display device can be improved.

The dielectric constant of the sealing member 14 is, for example, greater than 3.00, preferably greater than 3.10, and, for example, less than 3.50, preferably less than 3.40, and more preferably less than 3.20. In addition, the dielectric constant can be measured according to the method described in the embodiment described below.

If the dielectric constant of the sealing member 14 is above the lower limit, the degree of freedom in material selection can be improved. If the dielectric constant of the sealing member 14 is below the upper limit, erroneous operation of an organic EL display with a touch sensor can be suppressed.

The haze of the sealing member 14 is, for example, 0.1% or more and 15.0% or less, preferably 10.0% or less, more preferably 5.0% or less, particularly preferably 1.0% or less, and even more preferably 0.5% or less. The haze can be measured by the method described in the embodiments described below.

If the haze of the sealing member 14 is below the above upper limit, the visibility of the display (including a display with a touch sensor) can be improved.

The cover glass or barrier film 15 is disposed on the upper surface of the sealing member 14. Although not shown, the cover glass or barrier film 15 includes: a glass plate and an electrode, and the electrode is disposed under the glass plate to constitute a sensor of the organic EL display with a touch sensor.

This organic EL display 10 has an in-cell embedded structure in which the organic EL element 12 is arranged between two electrodes constituting a sensor, or an on-cell embedded structure in which one of the two electrodes constituting a sensor is arranged on the organic EL element 12. ＜Variation Example＞

In the variation, the same components and steps as those in the first embodiment are denoted by the same element reference symbols and detailed descriptions are omitted.

As shown in FIG1 , the sealing sheet 1 includes: a sealing layer 2, a base film 3 and a release film 4, but the display device sealing sheet is not limited thereto. The display device sealing sheet may not include the base film 3 and/or the release film 4 under the premise of including the sealing layer 2. That is, the display device sealing sheet may only include the sealing layer 2, or may include: the sealing layer 2, and any one of the base film 3 or the release film 4.

As shown in FIG. 2 , the organic EL display 10 includes a barrier layer 16 , but the present invention is not limited thereto. The organic EL display 10 may not include the barrier layer 16 .

Furthermore, the organic EL display 10 includes: an in-cell embedded structure in which the organic EL element 12 is arranged between two electrodes constituting a sensor, or an on-cell embedded structure in which one of the two electrodes constituting the sensor is arranged on the organic EL element 12, but it is not limited thereto.

For example, as shown in FIG3 , the organic EL display 20 may also have an external structure in which two electrodes constituting the sensor are arranged above the sealing member 14. The organic EL display 20 includes the device mounting unit 11, the sealing member 14, and the sensor unit 25.

The sensor unit 25 is disposed on the sealing member 14. The sensor unit 25 has an electrode constituting a sensor of the organic EL display with a touch sensor. In addition, the substrate 13 of the organic EL display 20 does not have an electrode.

The above-mentioned variations can also achieve the same effects as the above-mentioned implementation forms. The above-mentioned implementation forms and variations can be appropriately combined. [Implementation Examples]

The following examples are provided to further illustrate the present invention, but the present invention is not limited thereto. The specific numerical values of the blending ratio (content ratio), physical property values, parameters, etc. used in the following description may also be replaced by the upper limit values (defined as "below" or "less than") or lower limit values (defined as "above" or "exceeding") of the corresponding blending ratio (content ratio), physical property values, parameters, etc. described in the above "Implementation Method". In addition, "parts" and "%" refer to "quality standards" unless otherwise specified.

[Example 1] Epoxy polybutadiene resin (trade name: EPOLEAD PB3600, manufactured by Daicel, number average molecular weight: 5,900, SP value 9.3, epoxy equivalent: 200 g/eq.), methyl ethyl ketone solution of biphenyl skeleton epoxy resin (trade name: jER-YX6954B35, solid content concentration 35% by mass, epoxy equivalent: 3,000~16,000 g/eq., manufactured by Mitsubishi Chemical Corporation), alicyclic hydrocarbon resin (adhesive resin, SP value 9.0, trade name: Quintone1500, manufactured by ZEON Corporation of Japan), terpene phenol resin (adhesive resin, SP value 9.3, trade name: YS POLYSTAR K125, YASUHARA CHEMICAL), bisphenol skeleton-containing epoxy resin (trade name: jER-4005P, manufactured by Mitsubishi Chemical, epoxy equivalent: 1070g/eq.), oxycyclobutane compound (trade name: OXT-221, manufactured by Toagosei Co., Ltd.), thermal cationic initiator (trade name: CXC-1612, manufactured by King Industries), silane coupling agent (trade name: KBM-403, manufactured by Shin-Etsu Silicone Co., Ltd.), and methyl ethyl ketone (organic solvent) were mixed according to the formula shown in Table 1 to prepare a varnish for the sealing material.

[Example 2] The varnish of the sealing material was prepared in the same manner as in Example 1. In Example 2, the terpene phenol resin (trade name: YS POLYSTAR K125) was not added, and the amount of alicyclic hydrocarbon resin (trade name: Quintone 1500) added was changed to the value shown in Table 1.

[Examples 3 to 5] The varnish of the sealing material is prepared in the same manner as in Example 2. In Examples 3 to 5, the amount of the methyl ethyl ketone solution of the biphenyl skeleton epoxy resin (trade name: jER-YX6954B35) added is changed to the value shown in Table 1, and the amount of the cyclohexane compound (trade name: OXT-221) added is changed to the value shown in Table 1.

[Example 6] The varnish of the sealing material is prepared in the same manner as in Example 2. In Example 6, the alicyclic hydrocarbon resin (trade name: Quintone 1500) is replaced with a terpene phenol resin (trade name: YS POLYSTAR G125).

[Example 7] The varnish of the sealing material is prepared in the same manner as in Example 1. In Example 7, the terpene phenol resin (trade name: YS POLYSTAR K125) is replaced with a terpene phenol resin (trade name: YS POLYSTAR G125, SP value 9.1, manufactured by YASUHARA CHEMICAL Co., Ltd.).

[Example 8] The varnish of the sealing material was prepared in the same manner as in Example 1. In Example 8, the terpene phenol resin (trade name: YS POLYSTAR K125) was replaced with a terpene phenol resin (adhesive resin, trade name: YS POLYSTAR T130, SP value 8.8, manufactured by YASUHARA CHEMICAL Co., Ltd.).

[Comparative Example 1] The varnish of the sealing material was prepared in the same manner as in Example 2. In Comparative Example 1, the methyl ethyl ketone solution of the biphenyl skeleton-containing epoxy resin (trade name: jER-YX6954B35) was replaced with a bisphenol skeleton-containing epoxy resin (trade name: jER-4275, manufactured by Mitsubishi Chemical Corporation, containing a bisphenol A skeleton and a bisphenol F skeleton, epoxy equivalent: 8,400~9,200 g/eq.).

[Comparative Example 2] The varnish of the sealing material was prepared in the same manner as in Example 2. In Comparative Example 2, the alicyclic hydrocarbon resin (trade name: Quintone 1500) was not added, and the amount of the bisphenol skeleton-containing epoxy resin (trade name: jER-4005P) added was changed to the value shown in Table 1.

[Comparative Example 3] The varnish of the sealing material was prepared in the same manner as in Example 2. In Comparative Example 3, the cyclohexane compound (trade name: OXT-221) was not added, and the amount of the epoxy resin containing a bisphenol skeleton (trade name: jER-4005P) added was changed to the value shown in Table 1.

[Comparative Example 4] The varnish of the sealing material was prepared in the same manner as in Example 2. In Comparative Example 4, the epoxy polybutadiene resin (trade name: EPOLEAD PB3600) was not added, and the amount of the bisphenol skeleton-containing epoxy resin (trade name: jER-4005P) added was changed to the value shown in Table 1, and the amount of the oxycyclobutane compound (trade name: OXT-221) added was changed to the value shown in Table 1.

[Comparative Example 5] The varnish of the sealing material was prepared in the same manner as in Comparative Example 4. In Comparative Example 5, the cyclohexane compound (trade name: OXT-221) was replaced with an epoxy resin containing an alicyclic skeleton (oxyethylene olefin type epoxy resin, trade name: CELLOXIDE 2021P, 3,4-epoxyhexylmethyl (3,4-epoxy)cyclohexanecarboxylate, molecular weight: 252.3, epoxy equivalent: 128~145 g/eq., manufactured by Daicel).

[Comparative Example 6] The varnish of the sealing material was prepared in the same manner as in Comparative Example 4. In Comparative Example 6, the cyclohexane compound (trade name: OXT-221) was replaced with an epoxy resin containing an aliphatic ring skeleton (trade name: jER-YX8000, epoxy resin containing a hydrogenated bisphenol A skeleton, manufactured by Mitsubishi Chemical Corporation, epoxy equivalent: 205 g/eq.).

[Comparative Example 7] The varnish of the sealing material was prepared in the same manner as in Comparative Example 5. In Comparative Example 7, the alicyclic hydrocarbon resin (trade name: Quintone 1500) was not added, and the amount of the bisphenol skeleton-containing epoxy resin (trade name: jER-4005P) added was changed to the value shown in Table 1.

<Evaluation> ・Dielectric constant The sealing varnish of each embodiment and each comparative example was applied on a PET film [a release-treated PET film (trade name: PUREX A53, manufactured by Teijin DuPont Films, thickness: 38 μm, base film)] using a coating machine, and then dried at 90°C for 3 minutes in a nitrogen-purified oven to form a sealing layer with a thickness of 15 μm.

Next, a PET film [a release-treated PET film (trade name: PUREX A31, manufactured by Teijin DuPont Films, thickness: 38 μm, release film)] was laminated onto the seal layer at 80°C using a hot lamination press.

A sealing sheet having a base film, a sealing layer and a release film was prepared as described above. This operation was repeated to prepare two sealing sheets according to each embodiment and comparative example. Then, after peeling off the release film from the sealing layer of the two sealing sheets of the same embodiment or comparative example, the two sealing layers were bonded to each other in the thickness direction, and the thickness was set to 30 μm.

Next, the two sealing layers that were bonded to each other were torn off the bottom film on one side, and after curing at 100°C for 1 hour, the bottom film on the other side was torn off from the cured sealing layer to obtain the sample for measurement. The 100kHz dielectric constant of the obtained sample was measured using an LCR meter HP4284A (manufactured by Agilent Technologies) using the automatic balanced bridge method. The results are shown in Table 1.

・Haze The sealing sheets of each embodiment and each comparative example were prepared in the same manner as in the above-mentioned dielectric constant evaluation. Then, after tearing off the release film from the sealing layer, the sealing layer was cured at 100°C for 1 hour. Then, the base film was torn off from the cured sealing layer to obtain a sample for measurement. The haze of the obtained sample was measured using a haze meter NDH2000 manufactured by Nippon Denshoku Industries. The results are shown in Table 1.

・Initial curing (position shift evaluation) 1) Measurement of heat generation and heating start temperature of the sealing layer in the uncured state The sealing sheets of each embodiment and each comparative example were prepared in the same manner as the above-mentioned dielectric constant evaluation. Then, the sealing sheet was cut into approximately 50 mm squares to obtain a test piece. The test piece was prepared by tearing off the release film from the sealing layer and then tearing off the sealing layer from the base film with tweezers. Then, 10 mg of the sealing layer was collected and filled in the aluminum tank for DSC measurement to prepare the test sample for measurement.

Then, the exothermic onset temperature and heat generation of the sealing layer in the uncured state were determined by DSC at a heating rate of 5°C/min and a temperature range of 20°C to 300°C.

2) Epoxy reaction rate (%) after 3 minutes at a curing temperature of 110°C Prepare the DSC test sample in the same way as above. Put the test sample into an oven preset at 110°C and take it out after 3 minutes.

Then, the heat generation of the sealing layer in the curing state is determined by DSC at a temperature increase rate of 5°C/min and a temperature range of 20°C to 300°C. Then, the epoxy reaction rate (%) at a curing temperature of 110°C is calculated from the measured heat generation using the following formula.

Epoxy reaction rate (%) = (heat generated by the sealing layer in the uncured state – heat generated by the sealing layer in the cured state) / heat generated by the sealing layer in the uncured state) × 100

The results are shown in Table 1. In addition, if the epoxy reaction rate is higher, the viscosity of the sealing layer in the initial curing state is higher, so the positional deviation relative to the display element can be suppressed.

[Table 1] Table 1 No. Embodiment 1 Embodiment 2 Embodiment 3 Embodiment 4 Embodiment 5 Embodiment 6 Embodiment 7 Embodiment 8 Comparison Example 1 Comparison Example 2 Comparison Example 3 Comparison Example 4 Comparison Example 5 Comparison Example 6 Comparative Example 7 Prescription [Quantity] Essential resin components Epoxy polybutadiene resin PB3600 30 30 30 25 20 30 30 30 30 30 30 - - - - MEK solution containing biphenyl skeleton epoxy resin solid content concentration 35% jER XY6954 B35 71.4 71.4 57.1 57.1 57.1 71.4 71.4 71.4 - 71.4 71.4 71.4 71.4 71.4 71.4 Solid content 25 25 20 20 20 25 25 25 - 25 25 25 25 25 25 Resin Alicyclic hydrocarbon resins Quintone 1500 10 25 25 25 25 - 10 10 25 - 25 25 25 25 - Terpene phenolic resin K125 15 - - - - 25 - - - - - - - - - G125 - - - - - - 15 - - - - - - - - T130 - - - - - - - 15 - - - - - - - Any resin composition Oxyethylene Oxide Epoxy Resin CELLOXIDE 2021P - - - - - - - - - - - - 30 - 30 Hydrogenated bisphenol A epoxy resin YX8000 - - - - - - - - - - - - - 30 - Bisphenol F solid epoxy resin jER4005P 10 10 20 20 20 10 10 10 10 35 20 20 20 20 45 Bisphenol mixed solid epoxy resin jER4275 - - - - - - - - 25 - - - - - - Oxycyclobutane compounds OXT-221 10 10 5 10 15 10 10 10 10 10 - 30 - - - Thermal cationic hardener CXC-1612 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 Silane coupling agent KBM-403 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Organic solvents MEK 58.6 58.6 67.9 67.9 67.9 58.6 58.6 58.6 105.0 58.6 58.6 58.6 58.6 58.6 58.6 Solid content of sealing material % 50 50 50 50 50 50 50 50 50 50 50 50 50 50 50 Reviews Dielectric constant 100KHz 3.19 3.26 3.32 3.28 3.35 3.18 3.21 3.29 3.58 3.62 3.26 3.32 3.65 3.72 3.81 Fog % 0.22 0.48 0.44 0.40 0.35 4.71 3.10 9.33 1.50 0.41 0.26 0.20 0.41 0.50 0.22 Initial hardening @DSC Epoxy reaction rate% 70.8 71.4 68.9 70.1 73.6 70.5 71.2 68.3 70.5 71.3 59.2 55.4 71.3 65.5 70.4

In addition, the details of the codes in each table are as follows. PB3600: Epoxy polybutadiene resin, trade name EPOLEAD PB3600, manufactured by Daicel; jER-YX6954B35: Methyl ethyl ketone solution of biphenyl skeleton epoxy resin, manufactured by Mitsubishi Chemical Corporation; Quintone1500: Adhesive resin, alicyclic hydrocarbon resin, SP value 9.0, manufactured by ZEON Corporation of Japan; K125: Adhesive resin, terpene phenol resin, SP value 9.3, trade name YS POLYSTAR K125, manufactured by YASUHARA CHEMICAL; G125: Adhesive resin, terpene phenol resin, SP value 9.1, trade name YS POLYSTAR G125, manufactured by YASUHARA CHEMICAL; T130: Adhesive resin, terpene phenol resin, SP value 8.8, trade name YS POLYSTAR T130, manufactured by YASUHARA CHEMICAL; OXT-221: Oxycyclobutane compound, manufactured by Toagosei Co., Ltd.; CXC-1612: Thermal cationic initiator, manufactured by King Industries; KBM-403: Silane coupling agent, manufactured by Shin-Etsu Silicon Co., Ltd.; jER-4275: Epoxy resin containing bisphenol skeleton, manufactured by Mitsubishi Chemical Corporation; CELLOXIDE 2021P: Epoxy resin containing alicyclic skeleton, oxyethylene olefin type epoxy resin, manufactured by Daicel; jER-YX8000: Epoxy resin containing aliphatic ring skeleton, epoxy resin containing hydrogenated bisphenol A skeleton, manufactured by Mitsubishi Chemical Corporation.

In addition, the above invention only provides an exemplary implementation form of the present invention, which is only for illustration and not for limiting interpretation. All variations of the present invention that can be easily thought of by those familiar with this technology are included in the scope of the patent application described below. (Industrial applicability)

The display element sealing material, organic EL element sealing material and display element sealing sheet of the present invention are suitable for sealing of display elements (organic EL elements), for example.

1: Sealing sheet 2: Sealing layer 3: Base film 4: Release film 10: Organic EL display 11: Component mounting unit 12: Organic EL component 13: Substrate 14: Sealing member 15: Cover glass or barrier film 16: Barrier layer 17: First inorganic barrier layer 18: Second inorganic barrier layer 19: Planarization layer

FIG1 is a side sectional view of a sealing sheet of an embodiment of the display element sealing sheet of the present invention; FIG2 is a side sectional view of an organic EL display with a touch sensor in an embodiment of an image display device having a sealing member formed by the sealing layer shown in FIG1 (having an in-cell embedded structure or an on-cell embedded structure); and FIG3 is a side sectional view of an organic EL display with a touch sensor in another embodiment of the image display device (having an external structure).

1: Sealing sheet

2: Sealing layer

3: Base film

4: Release film

Claims (7)

A display element sealing material, comprising: a resin component, an oxycyclobutane compound, and a hardener; wherein, the resin component comprises: an epoxidized polybutadiene resin, an epoxy resin containing a biphenyl skeleton, and an adhesive resin. The display device sealing material of claim 1, wherein the content ratio of the above-mentioned epoxidized polybutadiene resin is more than 20 parts by mass and less than 35 parts by mass relative to 100 parts by mass of the total of the above-mentioned resin component and the above-mentioned cyclohexane oxide compound. The display device sealing material of claim 1, wherein the content ratio of the biphenyl skeleton-containing epoxy resin exceeds 20 parts by mass relative to 100 parts by mass of the total of the resin component and the cyclohexane compound. The display device sealing material of claim 1, wherein the content ratio of the above-mentioned cyclohexane compound is more than 5 parts by mass and less than 20 parts by mass relative to 100 parts by mass of the total of the above-mentioned resin component and the above-mentioned cyclohexane compound. The display element sealing material of claim 1, wherein the adhesive resin contains alicyclic hydrocarbon resin and/or terpene phenol resin. An organic EL element sealing material is formed by the display element sealing material of claim 1. A display element sealing sheet has a sealing layer formed by the display element sealing material of claim 1.