TW202221097A - Display element sealing material, organic EL element sealing material, and display element sealing sheet - Google Patents

Abstract

This display element sealing material contains a resin component, an oxetane compound and a curing agent. The resin component contains an epoxidized polybutadiene resin, a biphenyl skeleton-containing epoxy resin, and a tackifying 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 including display elements include liquid crystal displays and organic electroluminescence (hereinafter referred to as "organic EL") displays. In such an image display device, the display element is sealed with a sealing member. Thereby, deterioration of the display element due to moisture or the like in the atmosphere can be suppressed.

The sealing member is formed by, for example, burying the display element in the sealing resin composition and then curing the sealing resin composition. Here, in order to provide the sealing member with the performance required in accordance with various applications, various examinations have been carried out on the composition of the sealing resin composition.

For example, a curable resin composition for sealing an organic EL display element containing a phenoxy resin, an oxidized cycloolefin type alicyclic epoxy compound, and a curing agent is proposed (for example, refer to Patent Document 1).

Furthermore, 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 has been proposed (for example, refer to Patent Document 2).

These sealing resin compositions seal the display element by heating and curing after burying the display element. [Prior Art Literature] [Patent Literature]

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

(The problem that the invention intends to solve)

However, since the sealing member of the cured product of the curable resin composition for sealing an organic EL display element described in Patent Document 1 has a high dielectric constant, for example, it is used in a touch panel of an organic EL display. noise, causing the touch panel to malfunction.

Furthermore, when the epoxy resin composition described in Patent Document 2 is heated when the display element is sealed, the epoxy resin composition may flow before hardening and may be shifted to a desired position and hardened.

The present invention is a display element sealing material, an organic EL element sealing material, and a display element sealing sheet which can form a sealing member with a low dielectric constant while improving initial sclerosis and suppressing positional displacement with respect to the display element. (Technical means to solve problems)

The present invention [1] is a display element sealing material comprising: a resin component, an oxetane compound, and a curing agent; and the resin component contains: an epoxidized polybutadiene resin, a biphenyl skeleton-containing epoxy resin resin, and tackifying resin.

The present invention [2] is the display element sealing material according to the above [1], wherein the content ratio of the epoxidized polybutadiene resin is based on 100 mass of the sum of the resin component and the oxetane compound parts, more than 20 parts by mass and less than 35 parts by mass.

The present invention [3] is the display element sealing material according to the above [1] or [2], wherein the content ratio of the biphenyl skeleton-containing epoxy resin is based on the resin component and the oxetane compound. A total of 100 parts by mass is more than 20 parts by mass.

The present invention [4] is the display element sealing material according to any one of the above [1] to [3], wherein the content ratio of the above-mentioned oxetane compound is relative to the above-mentioned resin component and the above-mentioned oxetane The total of 100 parts by mass of butane compounds is more than 5 parts by mass and less than 20 parts by mass.

The present invention [5] is the display element sealing material according to any one of the above [1] to [4], wherein the tackifying resin contains an alicyclic hydrocarbon resin and/or a terpene phenol resin.

The present invention [6] is an organic EL element sealing material formed from the display element sealing material according to any one of the above [1] to [5].

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

The display element sealing material, the organic EL element sealing material, and the display element sealing sheet of the present invention contain an epoxidized polybutadiene resin, a biphenyl skeleton-containing epoxy resin, a tackifying resin, and an oxetane compound. Therefore, the initial sclerosis can be improved, and the sealing member with a low dielectric constant can be formed while suppressing the positional displacement with respect to the display element.

<Display element sealing material> The display element sealing material (hereinafter referred to as "sealing material") of the present invention is a sealing resin composition (display element sealing resin composition) for sealing a display element included in an image display device to be described later, and is formed by curing to be described later. Curable resin composition of sealing member. The sealing material contains a resin component, an oxetane compound, and a curing agent.

(1) Resin component The resin component contains the necessary components of epoxidized polybutadiene resin, epoxy resin containing biphenyl skeleton, and tackifying resin.

(1-1) Epoxidized polybutadiene resin The epoxidized polybutadiene resin is a polyfunctional epoxy resin having a polybutadiene skeleton and a plurality of epoxy groups. In addition, the polyfunctional epoxy resin also includes a bifunctional epoxy resin (the same applies hereinafter).

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 a side chain branched from the above-mentioned molecular chain.

The epoxy groups are located on the side chains of the polybutadiene backbone. The epoxy group is introduced by oxidizing the vinyl group of 1,2-polybutadiene contained in the polybutadiene skeleton.

Epoxidized polybutadiene resin is compatible with tackifying resin. The solubility parameter (hereinafter referred to as "SP value") of the 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 (the same applies hereinafter). 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 a 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 can 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, relative to 100 parts by mass of the total of the resin component and the oxetane compound, Especially preferred is 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 preferred less than 35 parts by mass, and still more preferably less than 30 parts by mass , and more preferably 28 parts by mass or less.

When the content ratio of the epoxidized polybutadiene resin is within the above-mentioned range, the lowering of the dielectric constant of the sealing member described later can be reliably achieved while the improvement of the initial curability of the sealing material is reliably achieved.

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

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

[式(1)中，I、II及III係構成單元，I及III分別係表示末端單元，II係表示重複單元。R ¹係表示氫原子或碳數1~6烷基。] Formula (1) [Chemical 1]

[In formula (1), I, II and III are structural units, I and III are terminal units, respectively, and II is a repeating unit. R ¹ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. ]

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

Examples of the alkyl group represented by R ¹ in the above formula (1) include straight-chain alkyl groups having 1 to 6 carbon atoms and branched alkyl groups having 3 to 6 carbon atoms. Examples of linear alkyl groups having 1 to 6 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group. Examples of branched alkyl groups having 3 to 6 carbon atoms include isopropyl group, isobutyl group, and tertiary butyl group.

Among R ¹ in the above formula (1), a hydrogen atom and a methyl group are preferable. In addition, a plurality of R ¹ series in the 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 the 5-position of the benzene ring is preferably a methyl group. In addition, among the plurality of R ^1s , R ¹ bonded to the 2-position and the 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 structural units in addition to the structural units I to III. As other structural unit systems, a polyol unit derived from a dihydric or higher polyol, a bisphenol unit derived from a bisphenol, etc. are mentioned, for example.

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 a 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 can 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, relative to the total of 100 parts by mass of the resin component and the oxetane compound, Particularly preferred is 22 parts by mass or more, and, for example, is 50 parts by mass or less, preferably 40 parts by mass or less, and more preferably 30 parts by mass or less.

When the content ratio of the biphenyl skeleton-containing epoxy resin is within the above-mentioned range, the lowering of the dielectric constant of the sealing member described later can be surely achieved while the improvement of the initial curability of the sealing material is surely achieved.

(1-3) Tackifying resin By including the tackifying resin in the sealing material, it is possible to impart tackiness to the sealing material while maintaining the dielectric constant of the sealing member described later. The tackifying resin contains a ring skeleton (aliphatic ring and/or aromatic ring), but does not contain an epoxy group.

Examples of tackifying resins include petroleum-based resins, terpene resins, phenol resins, and rosin resins.

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

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

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

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

Among the tackifying resins, preferable ones include, for example, petroleum-based resins and terpene resins.

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

In the ester-modified hydrocarbon resin, an ester group is introduced into a petroleum-based hydrocarbon resin. The petroleum-based hydrocarbon resin is based on dicyclopentadiene extracted from the C5 fraction obtained by cracking light oil as the main raw material. The petroleum-based hydrocarbon resin is preferably a monomer of dicyclopentadiene, for example.

The ester-modified hydrocarbon resin has an aliphatic ring derived from dicyclopentadiene and an ester group-containing atomic group. The ester group-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, 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. In addition, the saponification value can be measured according to the method described in JIS K0070.

Preferred terpene resins may be, for example, terpene phenol resins.

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

烯-1、對

烯-2、對

烯-3、對

烯-8、對

二烯類、Δ2-烯(carene)、Δ3-烯、石竹烯(caryophyllene)、及長葉烯(longifolene)萜烯化合物係可單獨使用或併用2種以上。 The main skeleton of the terpene compound is a hydrocarbon having isoprene (C ₅ H ₈ ) as a structural unit. Examples of terpene compounds include α-pinene, β-pinene, dipentene, limonene, α-phenanthrene, β-phenanthrene, α-terpinene, β-terpinene, γ-terpinene, Terpinene, myrcene, alloocimene, 1,8-eucalyptol, 1,4-eucalyptol, alpha-terpineol, beta-terpineol, gamma-terpineol , 4-terpineol sabinene, camphene, tricyclene, para

ene-1, right

ene-2, right

ene-3, right

ene-8, right

Dienes, Δ2-ene (carene), Δ3-ene, caryophyllene (caryophyllene), and longifolene (longifolene) terpene compounds can 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 compounds can be used alone or in combination of two or more. Among the phenolic compounds, phenols are preferred.

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

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

The tackifying resin preferably contains an alicyclic hydrocarbon resin and/or a terpene phenol resin, and more preferably consists of an alicyclic hydrocarbon resin and/or a terpene phenol resin.

More specifically, the tackifying resin preferably contains an alicyclic hydrocarbon resin and a terpene phenol resin from the viewpoint of reducing the dielectric constant of the sealing member described later. In addition, it is preferable that the tackifying resin is formed of an alicyclic hydrocarbon resin from the viewpoint of improving the initial curability of the sealing material.

The SP value of the tackifying 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, It is 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.

When the SP value of the tackifying resin is within the above range, the transparency of the sealing material to be described later can be improved.

The content ratio of the tackifying 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 relative to the total of 100 parts by mass of the resin component and the oxetane compound Parts by mass or less, preferably 40 parts by mass or less, more preferably 30 parts by mass or less.

(1-4) Optional resin components In addition, the resin component is a bisphenol skeleton-containing epoxy resin which may further contain an arbitrary component.

The bisphenol skeleton-containing epoxy resin is a polyfunctional epoxy resin having a plurality of bisphenol skeletons and a plurality of epoxy groups. The epoxy resin containing a bisphenol skeleton is preferably a bifunctional 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 epoxy resin containing a bisphenol skeleton is, for example, a copolymer of bisphenol and epichlorohydrin.

Examples of bisphenols include 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 1500 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, relative to 100 parts by mass of the total of the resin component and the oxetane compound. It is preferably 30 parts by mass or less.

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

Examples of other resin components include epoxy resins containing alicyclic skeletons, styrene-based oligomers, polyolefins, polychloroprene, polyamides, polyamideimides, polyurethanes, Polyether, polyester, and polysiloxane. These other resin components may be used alone or in combination of two or more. Among the resin components, the content ratio of other resin components is, for example, 10% by mass or less, or preferably 5% by mass or less.

Furthermore, the resin component is particularly preferably one that does not contain other resin components, and is composed of epoxidized polybutadiene resin, biphenyl skeleton-containing epoxy resin, tackifying resin, and optionally bisphenol skeleton-containing epoxy resin.

(2) Oxetane compounds The cationically polymerizable group contained in the oxetane compound is an oxetanyl group.

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

[式(2)中，Y係表示氧原子、硫原子或單鍵。R ²係表示氫原子、氟原子、碳數1~6之烷基、碳數1~6之氟烷基、烯丙基、碳數6~18之芳基、呋喃基(furyl group)或乙炔基。R ³係表示氫原子、碳數1~10之烷基、碳數2~6之烯基、碳數7~18之芳烷基、碳數2~6之烷羰基、碳數2~6之烷氧羰基、碳數2~6之N-烷胺甲醯基、(甲基)丙烯醯基、或下述式(3)所示之含氧雜環丁烷基之原子團。m係表示1以上且5以下的整數。] 另外，(甲基)丙烯醯基係可例如：丙烯醯基及甲基丙烯醯基。 Among the oxetane compounds, the oxetane compounds represented by the following formula (2) are preferably used. [hua 2]

[In formula (2), Y represents an oxygen atom, a sulfur atom or a single bond. R ² 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 acetylene base. R ³ 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 alkanecarbonyl group having 2 to 6 carbon atoms, and an alkenyl group having 2 to 6 carbon atoms. An alkoxycarbonyl group, an N-alkylaminocarbamoyl group having 2 to 6 carbon atoms, a (meth)acryloyl group, or an oxetanyl-containing atomic group represented by the following formula (3). m represents an integer of 1 or more and 5 or less. ] In addition, the (meth)acryloyl group may be, for example, an acryl group and a methacryloyl group.

Among Y in the above formula (2), preferable ones are, for example, oxygen atoms and sulfur atoms, and more preferable ones are oxygen atoms.

In the R ² of the above-mentioned formula (2), the preferred system can be, for example, 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, Furanyl and ethynyl are preferably alkyl groups having 1 to 6 carbon atoms.

In the above-mentioned formula (2), R ³ is preferably an oxetanyl-containing atomic group represented by the following formula (3).

[hua 3]

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

Preferably, m in the above formula (2) and formula (3) represents 1.

Examples of such oxetane compounds include 3-ethyl-3-hydroxymethyloxetane, 3-(methyl)allyloxymethyl-3-ethyloxetane Alkane, (3-ethyl-3-oxetanylmethoxy)methylbenzene, 4-fluoro-[1-(3-ethyl-3-oxetanylmethoxy)methyl yl]benzene, 4-methoxy-[1-(3-ethyl-3-oxetanylmethoxy)methyl]benzene, [1-(3-ethyl-3-oxetane Butyl methoxy) ethyl] phenyl ether, isobutoxy methyl (3-ethyl-3-oxetanyl methyl) ether, iso(3-ethyl-3-ethyl) - oxetanyl methyl) ether, isoxetanyl (3-ethyl-3-oxetanyl methyl) ether, 2-ethylhexyl (3-ethyl-3-oxane Butyl methyl) ether, ethyl diethylene glycol (3-ethyl-3-oxetanyl methyl) ether, dicyclopentadiene (3-ethyl-3-oxetane) Alkylmethyl)ether, 3-methacryloyloxymethyl-3-ethyloxetane, and 3-ethyl-3-[(2-ethylhexyloxy)methyl]oxy Heterobutane.

Such an oxetane compound can be used individually or in combination of 2 or more types.

The molecular weight of the oxetane 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 oxetane compound is, for example, 15% by mass or more, and also, for example, 30% by mass or less, preferably 25% by mass or less, and more preferably 20% by mass or less. In addition, the oxygen atom content rate can be calculated from the following formula (4).

Oxygen atom content (mass %) = total mass of oxygen atoms in 1 molecule/molecular weight × 100・・・(4)

When the oxygen atom content of the oxetane compound is within the above-mentioned range, the lowering of the dielectric constant of the sealing member described later can be stably achieved.

The content ratio of the oxetane 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, more preferably more than 5 parts by mass, relative to 100 parts by mass of the total of the resin component and the oxetane compound. It is preferably 8 parts by mass or more, and, for example, is 30 parts by mass or less, more preferably less than 20 parts by mass, more preferably less than 15 parts by mass, and particularly preferably 12 parts by mass or less.

When the content ratio of the oxetane compound is within the above-mentioned range, the improvement of the initial sclerosis of the sealing member described later can be achieved more reliably, and the reduction of the dielectric constant of the sealing member described later can be achieved more reliably.

(3) Hardener The hardener is to polymerize the resin component to harden the sealing material. The hardener is not particularly limited as long as the sealing material can be hardened. Examples of the curing agent include amine-based curing agents, imidazole-based curing agents, acid anhydride-based curing agents, thermal cationic curing agents, and photocationic curing agents.

Among the hardeners, preferable ones include, for example, thermal cationic hardeners and photocationic hardeners.

A thermal cationic hardener and a photocationic hardener are compounds that can initiate polymerization of the above-mentioned epoxidized polybutadiene resin, the above-mentioned biphenyl skeleton-containing epoxy resin, and optionally the above-mentioned bisphenol skeleton-containing epoxy resin, respectively. Under the premise of the other, there are no special restrictions.

The thermal cationic curing agent is a thermal acid generator that generates an acid (cation) by heating. The thermal cationic curing agent is preferably a compound capable of starting polymerization at a heat resistance temperature of 120° C. or lower for the display element.

As the thermal cationic hardener, a known thermal cationic polymerization initiator can be used. Examples of the thermal cationic polymerization initiators include perium salts, phosphonium salts, quaternary ammonium salts, diazonium salts, and iodonium salts that form conjugated anions with the following. Examples of the conjugated anion system include AsF ₆ ⁻ , SbF ₆ ⁻ , PF ₆ ⁻ , BF ₄ ⁻ , B(C ₆ F ₅ ) ₄ ⁻ , and CF ₃ SO ₃ ⁻ .

A photocationic curing agent is a photoacid generator that generates an acid (cation) by light irradiation. As the photocationic curing agent, a known photocationic polymerization initiator can be used. As the photocationic curing agent, for example, CPI-210S (manufactured by SAN-APRO) and IK-1 (manufactured by SAN-APRO) can be used.

Such a curing agent can be used alone or in combination of two or more.

Among the hardeners, particularly preferable ones are thermal cationic hardeners, and more preferable ones are quaternary ammonium salts. That is, a hardening|curing agent is especially preferable to contain a thermal cationic hardener at least, and may contain a photocationic hardener further, and may not contain a photocationic 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, relative to 100 parts by mass of the total of the resin component and the oxetane compound copies or less.

(4) Other additives The sealing material is a silane coupling agent containing other additives as needed.

As a silane coupling agent, an epoxy group containing silane coupling agent, an amine group containing silane coupling agent, and a methyl group containing acryl silane coupling agent are mentioned, for example. The silane coupling agents may be used alone or in combination of two or more.

Among the silane coupling agents, for example, epoxy group-containing silane coupling agents are preferable.

Examples of epoxy-containing silane coupling agents include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, and β-(3,4- Epoxycyclohexyl)ethyltrimethoxysilane, 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, relative to 100 parts by mass of the total of the resin component and the oxetane compound parts by mass or less.

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

<Action effect> The said sealing material contains an epoxidized polybutadiene resin, a biphenyl skeleton-containing epoxy resin, a tackifying resin, and an oxetane compound. Therefore, the initial sclerosis can be improved, and the sealing member with a low dielectric constant can be formed while suppressing the positional displacement with respect to the display element.

<Display element sealing sheet> The above-mentioned sealing material can be distributed as it is, and an industrially usable product is preferably distributed as a display element sealing sheet from the viewpoint of disposability.

1, the sealing sheet 1 which concerns on one Embodiment of the display element sealing sheet of this invention is demonstrated.

As shown in FIG. 1 , the sealing sheet 1 includes a sealing layer 2 composed of the above-described sealing material, a base film 3 , and a release film 4 . In addition, the sealing sheet 1 is a component for producing an image display device. The sealing sheet 1 does not include the display element and the substrate on which the display element is mounted, but is specifically composed of the sealing layer 2 , the base film 3 , and the release film 4 . The sealing sheet 1 is an industrially applicable device, which is distributed independently according to the parts.

In order to prevent foreign matter and the like from adhering to the sealing layer 2 , when the sealing sheet 1 is stored, it is preferable 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 only when the sealing sheet 1 is used.

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

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

The thickness of the sealing layer 2 is, for example, 1 μm or more, preferably 5 μm or more, and, for example, 100 μm or less, or preferably 30 μm or less.

The base film 3 is releasably attached to the back surface of the sealing layer 2 in order to support and protect the sealing layer 2 until the sealing sheet 1 is used for the formation of the sealing member described later. That is, the base film 3 is laminated on the back surface of the sealing layer 2 so as to cover the back surface of the sealing layer 2 when the sealing sheet 1 is shipped, conveyed, and stored. The base film 3 is a flexible film that can be peeled off from the back surface of the sealing layer 2 by being bent in a U-shape 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 orthogonal to the thickness direction. The sticking surface (surface) of the base film 3 may also be subjected to peeling treatment if necessary.

The material of the base film 3 can be, for example, a resin material. The resin material can be, for example, polyester, and polyolefin. The polyester can be, for example, polyethylene terephthalate (PET). Examples of polyolefins include polyethylene, and polypropylene. Among the resin components, for example, polyethylene terephthalate is preferable.

Among the base film 3, a film having water repellency or gas barrier properties, for example, is preferable, and a film made of polyethylene terephthalate is more preferable. The thickness of the base film 3 is appropriately selected according to the material of the film, and can be set to, for example, about 25 μm to 150 μm from the viewpoint of having traceability to a material to be sealed such as a display element.

The release film 4 is releasably adhered to the surface of the sealing layer 2 in order to protect the sealing layer 2 during the period until the sealing sheet 1 is used for the formation of the sealing member. That is, the release film 4 is laminated on the surface of the sealing layer 2 so as to cover the surface of the sealing layer 2 when the sealing sheet 1 is shipped, conveyed, and stored. The release film 4 is a flexible film that can be bent and peeled off from the surface of the sealing layer 2 in a slightly U-shape just before the sealing sheet 1 is used.

The release film 4 has a flat plate shape, specifically a predetermined thickness, and has a flat surface and a flat back surface extending in a predetermined direction orthogonal to the thickness direction. again. The sticking surface (back surface) of the release film 4 may also be subjected to peeling treatment if necessary. 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 material of the film, and can be set to, for example, about 25 μm to 150 μm from the viewpoint of having traceability to a material to be sealed such as a display element.

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

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

A sealing material is prepared by mixing the said resin component, an oxetane compound, a hardening|curing agent, and an additive in the said ratio. Moreover, when manufacturing the sealing sheet 1, it is preferable that the sealing material is a varnish prepared as a sealing material by dilution with an organic solvent.

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

An organic solvent system can be used individually or in combination of 2 or more types.

Among the organic solvents, preferred ones may be, for example, ketones. Examples of the 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.

Each component can be mixed by, for example, dispersing with a ball mill, stirring by placing in a flask, or kneading with three rolls.

In addition, the coating method of a sealing material can be, for example, screen printing, a dispenser, and a coating roll.

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

The heating temperature is the temperature at which the sealing material is dried without being hardened. 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 more, preferably 2 minutes or more, and, for example, 30 minutes or less, preferably 15 minutes or less.

Thereby, the coating film is dried, and the sealing layer 2 formed of the sealing material is prepared. Next, the release film 4 is attached to the surface of the sealing layer 2 .

The sealing sheet 1 was produced according to the above.

<Manufacture of video display devices> Such a sealing sheet 1 is quite suitable for sealing of display elements of an image display device. The display element can be, for example, an organic EL element. 2 , an organic EL display with a touch sensor (hereinafter referred to as “organic EL display 10 ”) according to an embodiment of the image display device will be 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-described 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 an organic EL display with a touch sensor, but the image display device is not particularly limited. The image display device can 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 an element mounting unit 11 , a sealing member 14 , and a cover glass or barrier film 15 .

The element mounting unit 11 includes a substrate 13 , an organic EL element 12 which is an example of a display element, 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 known organic EL element, and is mounted on the substrate 13 . Although not shown, the organic EL element 12 includes a cathodic 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 contacting the organic EL element 12 . The barrier rib layer 16 includes a first inorganic barrier rib layer 17 , a planarization layer 19 , and a second inorganic barrier rib layer 18 .

The first inorganic barrier layer 17 is disposed on the upper surface and the side surface of the organic EL element 12 so as to surround the organic EL element 12 . The material of the first inorganic barrier layer 17 can be, for example, metal oxides and metal nitrides. Metal oxides can be, for example, aluminum oxide, silicon oxide, and copper oxide. Metal nitrides can 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. Among the materials of the first inorganic barrier rib layer 17, metal nitrides, and more preferably silicon nitrides can be preferably used.

The planarization layer 19 is arranged on the upper surface of the first inorganic barrier layer 17 . The material of the planarization layer 19 can 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 planarizing layer 19 so as to surround the planarizing layer 19 . The material of the second inorganic barrier rib layer 18 can be, for example, the same material as that of the first inorganic barrier rib layer 17 .

The electrodes not shown constitute the sensor of the organic EL display with touch sensor. Electrodes not shown are located between the substrate 13 and the sealing member 14 . For example, electrodes not shown may 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 with the barrier layer 16 . The sealing member 14 is formed of the sealing layer 2 from which the base film 3 and the release film 4 have been peeled off.

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

Then, the sealing layer 2 is heated and hardened. 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, or preferably 120° C. or lower. At this time, the sealing layer 2 is rapidly hardened, and the sealing member 14 is formed at a desired position without positional displacement relative to the organic EL element 12 and the substrate 13 .

Therefore, the sealing member 14 can be formed at a desired position only by thermally hardening 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, 3.00 or more, preferably 3.10 or more, and, for example, 3.50 or less, preferably 3.40 or less, and more preferably 3.20 or less. In addition, the dielectric constant can be measured according to the method described in the later-mentioned Example.

If the dielectric constant of the sealing member 14 is greater than or equal to the above lower limit, the degree of freedom of material selection can be improved. If the dielectric constant of the sealing member 14 is below the above-mentioned upper limit, the occurrence of erroneous operation can be suppressed for an organic EL display having a touch sensor or the like.

The haze of the sealing member 14 is, for example, 0.1% or more and, for example, 15.0% or less, preferably 10.0% or less, more preferably 5.0% or less, particularly preferably 1.0% or less, and still more preferably 0.5% or less. The haze can be measured according to the method described in the following examples.

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

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

Such an organic EL display 10 has an in-cell structure in which the organic EL element 12 is disposed between two electrodes constituting the sensor, or one of the two electrodes constituting the sensor is disposed in the organic EL On-cell in-cell construction on element 12. <Variation example>

In the modified example, the same components and steps as those of the above-described first embodiment are given the same reference numerals and detailed descriptions are omitted.

As shown in FIG. 1 , the sealing sheet 1 includes a sealing layer 2 , a base film 3 and a release film 4 , but the display element sealing sheet is not limited to this. The display element sealing sheet may not be provided with the base film 3 and/or the release film 4 under the premise of being provided with the sealing layer 2 . That is, the display element sealing sheet may be composed of only the sealing layer 2 , or may include any one of the sealing layer 2 , the base film 3 , or the release film 4 .

As shown in FIG. 2, the organic EL display 10 includes the barrier layer 16, but is not limited to this. The organic EL display 10 may not include the barrier layer 16 .

Furthermore, the organic EL display 10 includes an in-cell in-cell structure in which the organic EL element 12 is disposed between two electrodes constituting a sensor, or one of the two electrodes constituting the sensor is disposed in the organic EL The on-cell embedded structure on the element 12 is not limited to this.

For example, as shown in FIG. 3 , the organic EL display 20 may have a hanging structure in which the two electrodes constituting the sensor are arranged above the sealing member 14 . The organic EL display 20 includes the above-described element mounting unit 11 , the above-described sealing member 14 , and a sensor unit 25 .

The sensor unit 25 is disposed on the sealing member 14 . The sensor unit 25 includes electrodes constituting a sensor of the organic EL display with a touch sensor. In addition, the substrate 13 of the organic EL display 20 is not provided with electrodes.

Each of the above-mentioned modifications can also achieve the same functions and effects as those of the above-mentioned embodiment. The above-described embodiments and modifications can be appropriately combined. [Example]

The following exemplary embodiments are used to further illustrate the present invention, but the present invention is not limited to these. The specific numerical values such as the blending ratio (content ratio), physical property value, parameter, etc. used are described below, and may be replaced by the upper limit of the corresponding blending ratio (content ratio), physical property value, parameter, etc. described in the above-mentioned "Embodiment". Value (defined as "below", "less than" value), or lower limit (defined as "above", "over" value). In addition, "part" and "%" refer to "quality standard" unless otherwise specified.

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

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

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

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

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

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

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

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

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

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

[Comparative Example 5] In the same manner as in Comparative Example 4, a varnish of a sealing material was prepared. In Comparative Example 5, an oxetane compound (trade name: OXT-221) was changed to an epoxy resin containing an alicyclic skeleton (cycloolefin oxide type epoxy resin, trade name: CELLOXIDE 2021P, 3,4-ring Oxycyclohexylmethyl(3,4-epoxy)cyclohexanecarboxylate, molecular weight: 252.3, epoxy equivalent: 128 to 145 g/eq., manufactured by Daicel).

[Comparative Example 6] In the same manner as in Comparative Example 4, a varnish of a sealing material was prepared. In Comparative Example 6, the oxetane compound (trade name: OXT-221) was changed to an epoxy resin containing an alicyclic skeleton (trade name: jER-YX8000, an epoxy resin containing a hydrogenated bisphenol A skeleton, Mitsubishi The chemical company make, epoxy equivalent: 205g/eq.).

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

＜Evaluation＞ ・Dielectric constant The sealing material varnishes of each example and each comparative example were coated on a PET film [release-treated PET film (trade name: PUREX A53, manufactured by Teijin DuPont Film Co., Ltd., thickness: 38 μm, base film) using a coater. )], and dried in a nitrogen forced clean oven at 90° C. for 3 minutes to form a sealing layer with a thickness of 15 μm.

Next, a PET film [release-treated PET film (trade name: PUREX A31, manufactured by Teijin DuPont Film Co., Ltd., thickness: 38 μm, release film)] was attached to the sealing layer by thermal lamination at 80°C.

According to the above preparation, a sealing sheet having a base film, a sealing layer and a release film is obtained. This operation was repeated, and two sealing sheets were prepared according to each Example and Comparative Example. Then, after peeling off the release film from the sealing layer with respect to the two sealing sheets of the same Example or Comparative Example, the two sealing layers were bonded to each other in the thickness direction, and the thickness of these was set to 30 μm.

Next, tear off the single-sided base film from the two mutually adhered sealing layers, and after curing at 100° C. for 1 hour, tear off the other single-sided base film from the cured sealing layer to obtain a measurement sample. The 100 kHz dielectric constant of the obtained sample was measured by an automatic balance bridge method using an LCR meter HP4284A (manufactured by Agilent Technologies). The results are shown in Table 1.

・Haze The sealing sheets of each Example and each Comparative Example were prepared in the same manner as in the evaluation of the above-mentioned dielectric constant. Then, after peeling the release film from the sealing layer, the sealing layer was cured at 100° C. for 1 hour. Next, the base film was torn from the hardened 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 Kogyo Co., Ltd. The results are shown in Table 1.

・Initial sclerosis (evaluation of positional displacement) 1) Measurement of calorific value of the sealing layer in the unhardened state and measurement of the starting temperature of the calorific value The sealing sheets of each Example and each Comparative Example were prepared in the same manner as in the evaluation of the above-mentioned dielectric constant. Then, the sheet for sealing was cut out into a square of about 50 mm to obtain a test piece. After the test piece is torn off the release film from the sealing layer, the sealing layer is then peeled off from the base film with tweezers. Next, 10 mg of the sealing layer was collected and packed in an aluminum tank for DSC measurement to prepare a measurement test sample.

Then, the exothermic onset temperature (exothermic onset temperature) and the calorific value of the sealing layer in the uncured state were specified by DSC according to the temperature increase rate of 5°C/min and the measurement temperature range: 20°C to 300°C.

2) Epoxy reaction rate (%) after 3 minutes at a curing temperature of 110°C A test sample for DSC measurement was prepared in the same manner as described above. The test sample was put into the oven preset at 110°C, and taken out after 3 minutes.

Then, the calorific value of the sealing layer in the hardened state was specified by DSC according to the temperature increase rate of 5°C/min and the measurement temperature range: 20°C to 300°C. Then, from the measured calorific value, the epoxy reaction rate (%) at a curing temperature of 110° C. was obtained from the formula shown below.

Epoxy reaction rate (%)=(heat value of the sealing layer in the unhardened state – heat generation value of the sealing layer in the hardened state)/heat value of the sealing layer in the unhardened state)×100

The results are shown in Table 1. In addition, when the epoxy reaction rate is high, the viscosity of the sealing layer in the initial hardening state is high, so that the occurrence of positional displacement with respect to the display element can be suppressed.

[Table 1] Table 1 No. Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 Prescription [mass parts] Necessary Resin Components Epoxidized Polybutadiene Resin PB3600 30 30 30 25 20 30 30 30 30 30 30 - - - - The solid content of MEK solution containing biphenyl skeleton epoxy resin is 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 Adhesive resin Alicyclic hydrocarbon resin Quintone 1500 10 25 25 25 25 - 10 10 25 - 25 25 25 25 - Terpene phenol resin K125 15 - - - - 25 - - - - - - - - - G125 - - - - - - 15 - - - - - - - - T130 - - - - - - - 15 - - - - - - - Arbitrary resin composition Oxidized cycloolefin type epoxy resin CELLOXIDE 2021P - - - - - - - - - - - - 30 - 30 Hydrogenated bisphenol A epoxy resin jER YX8000 - - - - - - - - - - - - - 30 - Bisphenol F type solid epoxy resin jER4005P 10 10 20 20 20 10 10 10 10 35 20 20 20 20 45 Bisphenol Hybrid Solid Epoxy Resin jER4275 - - - - - - - - 25 - - - - - - oxetane compound 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 sealant % 50 50 50 50 50 50 50 50 50 50 50 50 50 50 50 Evaluation 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 haze % 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: epoxidized polybutadiene resin, trade name EPOLEAD PB3600, manufactured by Daicel; jER-YX6954B35: methyl ethyl ketone solution containing biphenyl skeleton epoxy resin, manufactured by Mitsubishi Chemical Corporation; Quintone1500: Tackifying resin, alicyclic hydrocarbon resin, SP value 9.0, made by ZEON Corporation of Japan; K125: tackifying resin, terpene phenol resin, SP value 9.3, trade name YS POLYSTAR K125, manufactured by YASUHARA CHEMICAL; G125: tackifying resin, terpene phenol resin, SP value 9.1, trade name YS POLYSTAR G125, manufactured by YASUHARA CHEMICAL; T130: Tackifying resin, terpene phenol resin, SP value 8.8, trade name YS POLYSTAR T130, manufactured by YASUHARA CHEMICAL; OXT-221: Oxetane compound, manufactured by Toagosei Corporation; CXC-1612: Thermal cationic initiator, manufactured by King Industries; KBM-403: Silane coupling agent, manufactured by Shin-Etsu Silico Co., Ltd.; jER-4275: epoxy resin containing bisphenol skeleton, manufactured by Mitsubishi Chemical Corporation; CELLOXIDE 2021P: epoxy resin containing alicyclic skeleton, cycloolefin oxide epoxy resin, manufactured by Daicel; jER-YX8000: epoxy resin containing alicyclic skeleton, epoxy resin containing hydrogenated bisphenol A skeleton, manufactured by Mitsubishi Chemical Corporation.

In addition, the above-mentioned invention provides only the embodiment exemplified in the present invention, and it is only exemplification, and is not intended to limit interpretation. Variations of the present invention that can be easily conceived by those skilled in the art are included in the scope of the patent application described later. (Industrial Availability)

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

1: sealing sheet 2: sealing layer 3: Bottom film 4: release film 10: Organic EL Display 11: Component mounting unit 12: Organic EL elements 13: Substrate 14: Sealing member 15: Cover glass or barrier film 16: Barrier layer 17: The first inorganic barrier layer 18: Second inorganic barrier layer 19: Flattening layer

1 is a side sectional view of a sealing sheet of an embodiment of a sealing sheet for a display element of the present invention; FIG. 2 is an embodiment of an image display device having a sealing member formed by the sealing layer shown in FIG. 1 (a form with an in-cell embedded structure or an on-cell embedded structure), which has a touch sense. A side sectional view of the organic EL display of the detector; and FIG. 3 is a side sectional view of an organic EL display with a touch sensor according to another embodiment of the image display device (a form with an on-board structure).

1: sealing sheet

2: sealing layer

3: Bottom film

4: release film

Claims (7)

A display element sealing material comprising: a resin component, an oxetane compound, and a curing agent; wherein, The above resin component contains: Epoxidized polybutadiene resin, epoxy resin containing biphenyl skeleton, and Adhesive resin. The display element sealing material according to claim 1, wherein the content ratio of the epoxidized polybutadiene resin exceeds 20 parts by mass and does not exceed 100 parts by mass of the total of the resin component and the oxetane compound. Full 35 parts by mass. The display element sealing material of Claim 1 whose content rate of the said biphenyl skeleton-containing epoxy resin exceeds 20 mass parts with respect to the sum total of 100 mass parts of the said resin component and the said oxetane compound. The display element sealing material according to claim 1, wherein the content ratio of the oxetane compound exceeds 5 parts by mass and does not exceed 100 parts by mass of the total of the resin component and the oxetane compound. Full 20 parts by mass. The display element sealing material of Claim 1 whose said tackifying resin contains an alicyclic hydrocarbon resin and/or a terpene phenol resin. An organic EL element sealing material formed from the display element sealing material of claim 1. A display element sealing sheet having a sealing layer formed of the display element sealing material of claim 1.

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