TW202122486A - Light-diffusing heat-curing sheet - Google Patents

Abstract

A light-diffusing heat-curing sheet comprising a heat-curing resin composition which comprises a heat-curing resin and surface-modified silica particles, the surface-modified silica particles having an average primary-particle diameter of 0.1-1.5 [mu]m.

Description

Light diffusion thermosetting sheet

The present invention relates to a light-diffusing thermosetting sheet.

In the past, it has been known to seal with a sealing material in order to suppress the deterioration of optical elements included in an image display device due to moisture in the atmosphere or the like.

As such a sealing material, for example, an image display device sealing material containing a biphenyl skeleton-containing epoxy resin and an alicyclic skeleton-containing epoxy resin has been proposed (for example, refer to Patent Document 1).

Moreover, this kind of image display device sealing material seals the optical element by embedding the optical element and then curing it. [Prior Art Literature] [Patent Literature]

Patent Document 1: International Publication No. 2018/235824

[The problem to be solved by the invention] However, it has been studied to use the image display device sealing material described in Patent Document 1 for various applications, and it is desirable to provide the image display device sealing material described in Patent Document 1 with performance corresponding to each application.

For example, the image display device sealing material described in Patent Document 1 is used in general building window glass, vehicle window glass, signboards, lighting fixtures, display lamps, etc., lighting covers, liquid crystal backlight diffusers, display panels In the case of the light source, it is required to diffuse the light emitted from the light source and transmit the same brightness and reduce the linear transmitted light so that the image of the light source such as a lamp cannot be seen.

The present invention provides a light-diffusing thermosetting sheet which can increase the haze value, has a good appearance, and can impart excellent light diffusibility to various products. [Means to solve the problem]

The present invention [1] includes a light diffusing thermosetting sheet containing a thermosetting resin composition containing a thermosetting resin and surface-modified silica particles, and the surface-modifying silica The average primary particle size of the silicon particles is 0.1 μm or more and 1.5 μm or less, and the surface-modified silica particles are silica particles that have been surface-modified with a silane coupling agent.

The present invention [2] includes the light-diffusing thermosetting sheet as described in [1], wherein the thermosetting resin contains epoxy resin.

The present invention [3] includes the light-diffusing thermosetting sheet according to [1] or [2], wherein the silica particles are non-porous.

The present invention [4] includes the light-diffusing thermosetting sheet according to any one of [1] to [3], wherein the surface modification dioxide is based on 100 parts by mass of the thermosetting resin The content ratio of silicon particles is 5 parts by mass or more and 50 parts by mass or less.

The present invention [5] includes the light-diffusing thermosetting sheet according to any one of [1] to [4], wherein the thermosetting resin composition is formed into a sheet with a thickness of 15 μm In the case of thermosetting, the haze value of the thermosetting resin composition is 35% or more, and the total light transmittance is 80% or more.

The present invention [6] includes the light-diffusing thermosetting sheet according to any one of [1] to [4], wherein the thermosetting resin composition further includes pigment particles, The average primary particle size is 100 nm or less. [Effects of the invention]

According to the light-diffusing thermosetting sheet of the present invention, the thermosetting resin composition includes a thermosetting resin and surface-modified silica particles. Therefore, the cured material of the thermosetting resin composition can achieve a haze value. Improve, and at the same time can achieve an improved appearance. As a result, it is possible to impart excellent light diffusibility to various products including a cured product of a thermosetting resin composition.

＜Light-diffusing thermosetting sheet＞ The light-diffusing thermosetting sealing sheet (hereinafter also referred to as the sealing sheet) as the first embodiment of the light-diffusing thermosetting sheet of the present invention contains a thermosetting resin composition. The thermosetting resin composition contains thermosetting resin and surface-modified silica particles.

＜Thermosetting resin＞ As a thermosetting resin, epoxy resin etc. are mentioned, for example. In other words, the thermosetting resin includes, for example, epoxy resin, and is preferably composed of epoxy resin.

Examples of epoxy resins include bisphenol type epoxy resins (for example, bisphenol A type, bisphenol F type, bisphenol E type, bisphenol S type, bisphenol AD type, mixed types of these, etc.), Diphenyl ether type epoxy resin, novolak type epoxy resin (for example, phenol novolak type, cresol novolak type, biphenol novolak type, bisphenol novolak type, naphthol novolak type, triphenol novolak type , Dicyclopentadiene novolac type, etc.), biphenyl type epoxy resin, naphthyl type epoxy resin, triphenol alkane type epoxy resin (such as triphenol methane type, triphenol ethane type, triphenol propane type) Etc.), epoxy resin containing alicyclic skeleton, etc.

The epoxy resin can be used alone or in combination of two or more kinds.

Among epoxy resins, bisphenol-type epoxy resins, biphenyl-type epoxy resins, and epoxy resins containing alicyclic skeletons are preferred, and bisphenol-type epoxy resins and biphenyl-type epoxy resins are more preferred. Combination of oxy resin and epoxy resin containing alicyclic skeleton.

In other words, the epoxy resin preferably includes at least one selected from the group consisting of a bisphenol type epoxy resin, a biphenyl type epoxy resin, and an alicyclic skeleton-containing epoxy resin, and more preferably includes a bisphenol type epoxy resin. The epoxy resin, the biphenyl type epoxy resin, and the epoxy resin containing an alicyclic skeleton are more preferably composed of a bisphenol type epoxy resin, a biphenyl type epoxy resin, and an epoxy resin containing an alicyclic skeleton.

When the epoxy resin contains a bisphenol-type epoxy resin, a biphenyl-type epoxy resin, and an epoxy resin containing an alicyclic skeleton, the total light transmittance of the sealing member described later can be reliably improved.

The bisphenol epoxy resin may be a normal temperature solid or a normal temperature liquid, but it is preferably a normal temperature solid. In addition, the so-called "normal temperature solid" means a solid state that is not fluid at normal temperature (23°C), and the so-called "normal temperature liquid" means a fluid state of liquid at normal temperature (23°C) (below the same).

In other words, the bisphenol-type epoxy resin is preferably a bisphenol-type epoxy resin containing a normal temperature solid, and more preferably is composed of a normal-temperature solid bisphenol-type epoxy resin. When the bisphenol-type epoxy resin contains a room-temperature solid bisphenol-type epoxy resin, the sheet formability of the thermosetting resin composition can be improved, and the moisture permeability of the sealing member described later can be reduced.

Among such bisphenol type epoxy resins, bisphenol F type epoxy resins are preferable, and bisphenol F type epoxy resins which are solid at room temperature are more preferable.

The weight average molecular weight (Mw) of the bisphenol-type epoxy resin is not particularly limited. For example, it is 100 or more, preferably 1,000 or more, more preferably 5,000 or more, further preferably 10,000 or more, particularly preferably 20,000 or more, and particularly preferably 30,000 or more, and for example, 100,000 or less, preferably 90,000 or less. The weight average molecular weight (Mw) can be determined by gel permeation chromatography (GPC) using polystyrene as a standard substance (the same applies below).

If the weight average molecular weight of the bisphenol-type epoxy resin is greater than or equal to the above lower limit, the barrier properties and bending resistance of the cured product of the thermosetting resin composition can be improved.

The epoxy equivalent of the bisphenol-type epoxy resin is, for example, 100 g/eq. or more, preferably 500 g/eq. or more, more preferably 2,000 g/eq. or more, and still more preferably 4,000 g/eq. or more. It is preferably 7,000 g/eq. or more, for example, 20,000 g/eq. or less, and more preferably 16,000 g/eq. or less. The epoxy equivalent can be measured in accordance with Japanese Industrial Standards (JIS) K7236:2001 (the same applies below).

In the thermosetting resin, the content of the bisphenol epoxy resin is, for example, 0% by mass or more, preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 20% by mass or more, and for example 100% by mass or less, preferably 70% by mass or less, more preferably 50% by mass or less.

The biphenyl type epoxy resin may be a normal temperature solid or a normal temperature liquid, but it is preferably a normal temperature solid.

In other words, the biphenyl type epoxy resin is preferably a biphenyl type epoxy resin containing a room temperature solid, and more preferably a biphenyl type epoxy resin containing a room temperature solid. When the biphenyl type epoxy resin contains a normal temperature solid biphenyl type epoxy resin, the sheet formability of the thermosetting resin composition can be reliably improved, and the moisture permeability of the sealing member described later can be reliably achieved. reduce.

The weight average molecular weight (Mw) of the biphenyl type epoxy resin is not particularly limited. For example, it is 100 or more, preferably 1,000 or more, more preferably 5,000 or more, still more preferably 10,000 or more, particularly preferably 20,000 or more, and particularly preferably 30,000 or more, and for example, 100,000 or less, preferably 90,000 or less.

When the weight average molecular weight of the biphenyl type epoxy resin is equal to or greater than the above lower limit, the barrier properties and bending resistance of the cured product of the thermosetting resin composition can be improved.

The epoxy equivalent of the biphenyl type epoxy resin is, for example, 100 g/eq. or more, preferably 500 g/eq. or more, more preferably 2,000 g/eq. or more, and still more preferably 4,000 g/eq. or more. It is preferably 7,000 g/eq. or more, for example, 20,000 g/eq. or less, and more preferably 16,000 g/eq. or less.

In the thermosetting resin, the content of the biphenyl type epoxy resin is, for example, 0 mass% or more, preferably 5 mass% or more, more preferably 10 mass% or more, and still more preferably 20 mass% or more, and for example 100% by mass or less, preferably 70% by mass or less, and more preferably 50% by mass or less.

The epoxy resin containing an alicyclic skeleton is an epoxy resin having at least an epoxy group and an aliphatic ring (alicyclic skeleton).

The epoxy resin containing an alicyclic skeleton may be a solid at room temperature or a liquid at room temperature, but it is preferably a liquid at room temperature.

In other words, the alicyclic skeleton-containing epoxy resin is preferably composed of an alicyclic skeleton-containing epoxy resin that is liquid at room temperature, and more preferably is composed of an alicyclic skeleton-containing epoxy resin that is liquid at room temperature. When the alicyclic skeleton-containing epoxy resin includes a normal temperature liquid alicyclic skeleton-containing epoxy resin, the transparency of the sealing member described later can be further improved, and the moisture permeability of the sealing member can be more reliably achieved. reduce.

Examples of epoxy resins containing an alicyclic skeleton include alicyclic epoxy compounds having an oxidized cycloalkene structure, and dicyclopentadiene type epoxy resins (hereinafter referred to as dicyclopentadiene (DCPD) type). Epoxy resin), hydrogenated epoxy resin, etc.

As an alicyclic epoxy compound having an oxidized cycloolefin structure, for example, an epoxy compound having an epoxy cyclohexane structure represented by the following formula (1) (hereinafter referred to as epoxy cyclohexane (epoxy cyclohexane) , ECH) structure of epoxy compound), or its modifications, etc. Formula 1)

[化1]

[In formula (1), X represents a single bond or a linking group (a divalent group having one or more atoms). Substituents such as alkyl groups may be bonded to the carbon atoms constituting the cyclohexane ring, or may not be bonded to the carbon atoms constituting the cyclohexane ring] As the linking group represented by X in the formula (1), for example, a divalent hydrocarbon group, a carbonyl group, an ether group, a thioether group, an ester group, a carbonate group, an amide group, and those connected base.

Examples of the divalent hydrocarbon group include linear or branched alkylene groups having 1 to 18 carbon atoms (for example, methylene, methylmethylene, dimethylmethylene, ethylene, and propylene). Group, trimethylene, etc.), cycloalkylene (for example, 1,2-cyclopentylene, 1,3-cyclopentylene, 1,2-cyclohexylene, 1,3-cyclohexylene, 1, 4-cyclohexylene, etc.), cycloalkylene (e.g. cyclopentylene, cyclohexylene, etc.), etc.

Among the linking groups represented by X in the formula (1), from the viewpoint of the adhesiveness of the sealing member described later, a linking group containing an oxygen atom is preferable, and a carbonyl group and an ether group are more preferable. , An ester group, a carbonate group, and more preferably an ester group.

Examples of the ECH structure-containing epoxy compound represented by the formula (1) include: (3,3',4,4'-diepoxy)bicyclohexyl, bis(3,4-epoxycyclohexyl) Methyl) ether, 1,2-bis(3,4-epoxycyclohexane-1-yl)ethane, 1,2-epoxy-1,2-bis(3,4-epoxycyclohexane -1-yl)ethane, 2,2-bis(3,4-epoxycyclohexane-1-yl)propane, 3,4-epoxycyclohexylmethyl (3,4-epoxy)cyclohexane Alkyl carboxylate, ε-caprolactone is modified 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexane carboxylate, etc.

The ECH structure-containing epoxy compound represented by the formula (1) may also be a commercially available product. Examples of commercially available products include Celloxide 8000, Celloxide 2021P, and Celloxide 2081 manufactured by Daicel.

Dicyclopentadiene type epoxy resin (hereinafter referred to as DCPD type epoxy resin) is represented by the following formula (2).

[化2]

[In formula (2), substituents such as alkyl groups may be bonded to the carbon atoms constituting the aliphatic ring derived from dicyclopentadiene, or may not be bonded to the carbon atoms constituting the aliphatic ring derived from dicyclopentadiene carbon atom] The DCPD type epoxy resin represented by the above formula (2) may also be a commercially available product. As a commercial product of the DCPD type epoxy resin represented by the above formula (2), for example, EP-4088S (epoxy equivalent 170 g/eq.) manufactured by ADEKA (ADEKA), and ADEKA ( ADEKA) EP-4088L (epoxy equivalent 165 g/eq.), etc. manufactured by the company.

The hydrogenated epoxy resin is an epoxy resin obtained by hydrogenating an epoxy resin having an aromatic ring in the epoxy resin. Specifically, a hydrogenated bisphenol type epoxy resin and a hydrogenated biphenyl type epoxy resin may be mentioned. Etc. Preferably, hydrogenated bisphenol type epoxy resin is mentioned.

As hydrogenated bisphenol type epoxy resin, hydrogenated bisphenol F type epoxy resin, hydrogenated bisphenol A type epoxy resin, etc. are mentioned specifically,.

Commercially available hydrogenated bisphenol epoxy resins can also be used.

As a commercially available product of the hydrogenated bisphenol F type epoxy resin, for example, YL-6753 manufactured by Mitsubishi Chemical Corporation and the like can be cited. As commercially available products of hydrogenated bisphenol A epoxy resins, for example, YX-8000 and YX-8034 manufactured by Mitsubishi Chemical Corporation, EXA-7015 manufactured by DIC Corporation, ST-3000 manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., Rikaresin HBE-100 manufactured by Nippon Chemical Co., Ltd., EX-252 manufactured by Nagase ChemteX, etc.

Such an alicyclic skeleton-containing epoxy resin may be used alone or in combination of two or more kinds.

Among the epoxy resins containing an alicyclic skeleton, hydrogenated epoxy resins and epoxy compounds containing an ECH structure are preferably cited.

In other words, the epoxy resin containing an alicyclic skeleton preferably contains a hydrogenated epoxy resin and/or an epoxy compound containing an ECH structure, and more preferably contains a hydrogenated epoxy resin or an epoxy compound containing an ECH structure. It is composed of hydrogenated epoxy resin or epoxy compound containing ECH structure.

Among the hydrogenated epoxy resins, preferably, hydrogenated bisphenol A type epoxy resins can be cited. Among the epoxy compounds containing an ECH structure, 3,4-epoxycyclohexylmethyl (3,4-epoxy)cyclohexane carboxylate is preferably mentioned.

The weight average molecular weight of such an alicyclic skeleton-containing epoxy resin is, for example, 100 or more, preferably 180 or more, and for example, 1,000 or less, preferably 790 or less, and more preferably 500 or less.

The epoxy equivalent in the alicyclic skeleton-containing epoxy resin is, for example, 90 g/eq. or more, preferably 100 g/eq. or more, and for example, 300 g/eq. or less, preferably 200 g/eq. the following.

In the thermosetting resin, the content of the alicyclic skeleton-containing epoxy resin is, for example, 0% by mass or more, preferably 10% by mass or more, more preferably 20% by mass or more, and for example, 100% by mass or less. It is preferably 50% by mass or less, more preferably 40% by mass or less, and still more preferably 35% by mass or less.

The content ratio of the thermosetting resin in the thermosetting resin composition is, for example, 60% by mass or more, preferably 70% by mass or more, and for example, 95% by mass or less, preferably 92% by mass or less, more preferably 90% by mass. Less than mass%.

＜Surface modified silica particles＞ Surface-modified silica particles are silica particles that have been surface-modified with a silane coupling agent.

The silica particles preferably have a spherical shape. It is more preferable that the silica particles have a high sphericity. The silicon dioxide particles can be prepared, for example, by a dry method (combustion method or arc method).

The silica particles may be porous or non-porous. Porous silica particles have higher hygroscopicity and gas adsorption than non-porous silica particles. Therefore, porous silica particles and non-porous silica particles are used separately according to the purpose of the sealing sheet.

For example, when the sealing sheet is used as a sealing sheet for image display elements such as organic EL, the silicon dioxide particles are preferably non-porous from the viewpoint of releasing the components adsorbed on the silicon dioxide particles.

Furthermore, as the definition of silica particles mentioned here, the specific surface area of porous silica particles is 300 m ² /g or more, and the specific surface area of non-porous silica particles is 30 m ² /g or less .

As the silane coupling agent, for example, an epoxy group-containing silane coupling agent (for example, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, β-(3) ,4-Epoxycyclohexyl) ethyl trimethoxy silane, etc.), amino-containing silane coupling agent (such as N-2-(aminoethyl)-3-aminopropyl methyl dimethoxy silane , N-2-(aminoethyl)-3-aminopropylmethyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyltriethoxysilane, 3-aminopropyl trimethoxysilane, etc.), silane coupling agents containing methacrylic acid groups (such as γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxy Group propyl trimethoxysilane, etc.) and so on.

The silane coupling agent can be used alone or in combination of two or more.

Among the silane coupling agents, preferably, an epoxy group-containing silane coupling agent can be cited.

In order to prepare such surface-modified silica particles, the surface of the silica particles is treated with the silane coupling agent.

As a surface treatment method using a silane coupling agent, for example, the following method can be cited: after adding a silane coupling agent to water and hydrolyzing, adding a catalyst such as alcohol and acetic acid, dissolving it in water to prepare an aqueous solution, The silicon dioxide particles are immersed in the aqueous solution and surface treatment is performed. In addition, as a surface treatment method using a silane coupling agent, for example, the following method can also be cited: the powder to be processed containing silica particles is placed in a processing container, the powder to be processed is stirred, and the powder is vaporized at the same time. Silane coupling agent reaction.

The average primary particle size of the surface-modified silica particles is 0.1 μm or more, preferably 0.2 μm or more, more preferably 0.4 μm or more, and 1.5 μm or less, preferably 1.3 μm or less. The average primary particle size can be measured with a laser diffraction/scattering particle size distribution measuring device (HORIBA LA-750, etc.) (the same applies below). In addition, the average primary particle size in this disclosure is a particle size corresponding to 50% of the cumulative volume from the small diameter side.

If the average primary particle size of the surface-modified silica particles is greater than or equal to the lower limit, the sealing member described later can be given a haze value within the range of the present invention. If the average primary particle size of the surface-modified silica particles is less than or equal to the above upper limit, the sedimentation of the surface-modified silica particles in the varnish of the thermosetting resin composition described later can be suppressed.

The surface-modified silica particles can also use commercially available products. Examples of commercially available products of surface-modified silica particles include SE1050-SEO, SC-2050MB, and 10SE-CM1 manufactured by Admatechs.

The content ratio of the surface-modified silica particles relative to 100 parts by mass of the thermosetting 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, It is preferably 40 parts by mass or less, and more preferably 35 parts by mass or less.

The content of the surface-modified silica particles in the thermosetting resin composition is, for example, 3% by mass or more, preferably 4% by mass or more, more preferably 8% by mass or more, and for example, 40% by mass or less, preferably It is 30% by mass or less, more preferably 25% by mass or less.

If the content ratio of the surface-modified silica particles is greater than or equal to the above lower limit, the haze value of the sealing member described later can be reliably improved, and the light diffusibility of the sealing member can be improved. If the content ratio of the surface-modified silica particles is less than or equal to the above upper limit, the total light transmittance of the sealing member described later can be reliably improved.

＜Thermal hardener＞ The thermosetting resin composition preferably further contains a thermosetting agent.

As the thermosetting agent, for example, a thermal cationic curing agent, a thermal anionic curing agent, etc., which initiate a curing reaction of a thermosetting resin by heat, can be cited.

The thermal cationic hardener is a thermal acid generator that generates acid (cation) by heating.

As the thermal cationic curing agent, a known thermal cationic polymerization initiator can be used. As the thermal cationic polymerization initiator include, for example: In _{^{AsF 6 -, SbF 6 -,}} PF 6 -, BF 4 -, B (C 6 F 5) 4 -, CF 3 SO 3 - anion as the counter sulfonium Salt, phosphonium salt, quaternary ammonium salt, diazonium salt, enonium salt, etc.

The thermal anionic hardener is a compound that is a basic compound that is dissolved by heat or a basic compound that is formed by a bond deviated by heat.

Examples of the thermionic curing agent include imidazole compounds that are solid at room temperature, amine-epoxy adduct compounds (reaction products of amine compounds and epoxy compounds), and amine-isocyanate compounds (combination of amine compounds and isocyanate compounds). Reaction product) and so on.

The thermosetting agent can be used alone or in combination of two or more kinds.

Among the thermal hardeners, preferably, a thermal cationic hardener is used, and more preferably, a quaternary ammonium salt is used.

The content ratio of the thermosetting agent relative to 100 parts by mass of the thermosetting resin 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.

The content of the thermosetting agent in the thermosetting resin composition is, for example, 1% by mass or more, preferably 2% by mass or more, and, for example, 10% by mass or less, preferably 5% by mass or less.

＜Pigment＞ In addition, it is sometimes desirable to impart a desired color to the sealing member according to the use of the sealing member described later. In this case, the thermosetting resin composition preferably contains pigment particles.

When the thermosetting resin composition contains surface-modified silica particles and pigment particles, a desired color can be imparted to the sealing member described later, and the haze value and total light transmittance can be adjusted in a well-balanced manner.

The pigment particles are solvent-dispersible pigments that are dispersible in a solvent, and have a particulate shape.

The average primary particle diameter of the pigment particles is, for example, 10 nm or more, preferably 30 nm or more, and for example, 100 nm or less, preferably 70 nm or less.

When the average primary particle diameter of the pigment particles is greater than or equal to the above lower limit, the content ratio of the pigment particles described later can be reduced. When the average primary particle size of the pigment particles is equal to or less than the upper limit, transparency can be ensured in the sealing member described later.

Examples of the pigment particles include inorganic pigment particles, and more specifically, black pigment particles such as carbon black, oxide-based pigments, and hydroxide-based pigments. The pigment particles can be used alone or in combination of two or more kinds.

Among the pigment particles, preferably, inorganic pigment particles are used, more preferably, black pigment particles are used, and even more preferably, carbon black is used.

Relative to 100 parts by mass of the thermosetting resin, the content of the pigment particles is, for example, 0.01 parts by mass or more, preferably 0.1 parts by mass or more, and for example, 10 parts by mass or less, preferably 5 parts by mass or less, and more preferably 2 parts by mass. Parts by mass or less.

The content of the pigment particles in the thermosetting resin composition is, for example, 0.1% by mass or more, preferably 0.2% by mass or more, and, for example, 15% by mass or less, preferably 10% by mass or less, more preferably 5% by mass the following.

If the content ratio of the pigment particles is greater than or equal to the above lower limit, a desired color can be imparted to the sealing member described later. If the content ratio of the pigment particles is less than or equal to the above upper limit, a desired color can be imparted to the sealing member described later, and at the same time, the total light transmittance can be sufficiently ensured.

＜Other ingredients＞ The thermosetting resin composition may contain components other than the above in an appropriate ratio as necessary. Other components include thermoplastic resins, coupling agents, leveling agents, polymerization initiators, anti-aging agents, wettability modifiers, surfactants, plasticizers, ultraviolet absorbers, preservatives, antibacterial agents, etc. .

＜Light-diffusing thermosetting sheet＞ Next, the sealing sheet 1 which is an embodiment of the light diffusing thermosetting sheet of the present invention will be described with reference to FIG. 1.

As shown in FIG. 1, the sealing sheet 1 includes a sealing layer 2, a base film 3, and a release film 4 including the thermosetting resin composition.

In order to prevent foreign matter from adhering to the sealing layer 2 or the like, it is preferable to protect the sealing layer 2 by the base film 3 and the release film 4 when the sealing sheet 1 is stored. In addition, when the sealing sheet 1 is used, the base film 3 and the release film 4 are peeled off.

The sealing layer 2 is a dried product of the thermosetting resin composition, and has a sheet shape (flat plate shape). Specifically, the sealing layer 2 has a predetermined thickness, extends in a predetermined direction orthogonal to the thickness direction, and has a flat surface and a flat back surface.

In the sealing layer 2, the thermosetting resin does not react (curing), and these thermosetting resins are contained in the sealing layer 2 in an uncured state.

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, preferably 30 μm or less.

In addition, when the sealing layer 2 with a thickness of 15 μm is cured (that is, when the thermosetting resin composition is formed into a sheet with a thickness of 15 μm and thermally cured), the cured product of the sealing layer 2 is misted The degree value is, for example, 30% or more, preferably 35% or more, more preferably 40% or more, particularly preferably 50% or more, particularly preferably 80% or more, and for example, 100% or less, preferably 95% or less. In addition, the haze value can be measured according to the method described in the below-mentioned Examples.

When the haze value of the cured product of the sealing layer 2 is greater than or equal to the lower limit, the sealing layer can be thickened without significantly increasing the haze value. When the haze value of the cured product of the sealing layer 2 is less than the upper limit, the sealing layer can be thinned without significantly lowering the haze value.

In addition, in the case of curing the sealing layer 2 having a thickness of 15 μm, the total light transmittance of the cured product of the sealing layer 2 is, for example, 10% or more, preferably 20% or more, more preferably 50% or more, and more preferably It is 70% or more, particularly preferably 80% or more, particularly preferably 85% or more, most preferably 90% or more, and for example, 100% or less, preferably 98% or less. In addition, the total light transmittance can be measured according to the method described in the below-mentioned Examples.

When the total light transmittance of the cured product of the sealing layer 2 is greater than or equal to the lower limit, the extraction loss of the light source can be reduced. When the total light transmittance of the cured product of the sealing layer 2 is less than the upper limit, the extraction loss of the light source can be eliminated.

In addition, when the haze value of the cured product of the sealing layer 2 is greater than or equal to the lower limit and the total light transmittance is greater than the lower limit, the light diffusibility of the cured product of the sealing layer 2 can be reliably improved.

In the period until the sealing sheet 1 is used for the formation of a sealing member, the base film 3 is detachably adhered to the back surface of the sealing layer 2 in order to support and protect the sealing layer 2. That is, the base film 3 is a flexible film: when the sealing sheet 1 is shipped, transported, and stored, the base film 3 is laminated on the back of the sealing layer 2 so as to cover the back of the sealing layer 2, and the sealing sheet 1 is immediately used for sealing. Before the sheet 1, it can be peeled off from the back surface of the sealing layer 2 in a manner of being bent into a substantially U-shape.

The base film 3 has a flat plate shape, specifically, has a predetermined thickness, extends in a predetermined direction orthogonal to the thickness direction, and has a flat surface and a flat back surface. If necessary, the adhesion surface (surface) of the base film 3 is peeled off.

As a material of the base film 3, resin materials, such as polyester (for example, polyethylene terephthalate (PET) etc.), polyolefin (for example, polyethylene, polypropylene, etc.), are mentioned, for example.

In the base film 3, preferably, a film having moisture barrier properties or gas barrier properties is exemplified, and more preferably, a film containing polyethylene terephthalate is exemplified. The thickness of the base film 3 is also appropriately selected according to the material of the film, but in terms of traceability to a sealed material such as a display element, it can be set to 25 μm or more and 150 μm or less, for example.

In the period until the sealing sheet 1 is used for the formation of the sealing member, the release film 4 is adhered to the surface of the sealing layer 2 in a peelable manner in order to protect the sealing layer 2. That is, the release film 4 is a flexible film in which 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, transported, and stored. Before the sealing sheet 1 is used, it can be peeled off from the surface of the sealing layer 2 in a manner of being bent into a substantially U-shape.

The release film 4 has a flat plate shape, specifically, has a predetermined thickness, extends in a predetermined direction orthogonal to the thickness direction, and has a flat surface and a flat back surface. In addition, if necessary, the adhesion surface (back surface) of the release film 4 is peeled off. As a material of the release film 4, the same resin material as the base film 3 is mentioned, for example. The thickness of the release film 4 is also appropriately selected according to the material of the film, but in terms of traceability to a material to be sealed such as a display element, it can be set to 25 μm or more and 150 μm or less, for example.

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

In order to manufacture the sealing sheet 1, first, the thermosetting resin composition is prepared.

The thermosetting resin composition is prepared by mixing the thermosetting resin and the surface-modified silica particles with the thermosetting agent, the pigment particles, and the other components as necessary. In addition, in the production of the sealing sheet 1, the thermosetting resin composition is preferably diluted with an organic solvent to prepare a varnish of the thermosetting resin composition.

The organic solvent is not particularly limited as long as it can uniformly disperse or dissolve the thermosetting resin and surface-modified silica particles. As an organic solvent, for example, aromatic hydrocarbons (for example, benzene, toluene, xylene, etc.), ketones (for example, acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.), ethers (for example, dibutyl ketone, etc.), Base ether, tetrahydrofuran, dioxane, ethylene glycol monoalkyl ether, ethylene glycol dialkyl ether, 1-methoxy-2-propanol, etc.), esters (such as ethyl acetate, butyl acetate, 2-methoxymethyl ethyl acetate, etc.), nitrogen-containing compounds (such as N-methylpyrrolidone, dimethylimidazolidone, dimethylformaldehyde, etc.). The organic solvent can be used alone or in combination of two or more.

Among the organic solvents, ketones are preferred, and methyl ethyl ketone is more preferred.

With respect to 100 parts by mass of the thermosetting resin composition, the addition ratio of the organic solvent is, for example, 50 parts by mass or more, preferably 80 parts by mass or more, and for example, 200 parts by mass or less, preferably 150 parts by mass or less.

In addition, as a method of mixing the above-mentioned components (thermosetting resin, surface-modified silica particles, thermosetting agent, pigment particles, other components, and organic solvent), for example, dispersion mixing using a ball mill, and filling into a flask can be mentioned. Mixing, mixing with three rolls, etc.

In addition, the components may be mixed together, or a part of the components may be dispersed or dissolved in the organic solvent in advance, and the dispersion or solution may be mixed with the remaining components. For example, after uniformly dispersing the surface-modified silica particles in an organic solvent by ultrasonic waves or the like in advance, the dispersion may be mixed with the remaining components (thermosetting resin, etc.). In addition, after the pigment particles are uniformly dispersed in an organic solvent (preferably esters) in advance, the dispersion may be mixed with the remaining components (thermosetting resin, etc.).

Then, the thermosetting resin composition is applied to the surface of the base film 3 by a known method.

As a coating method of a thermosetting resin composition, screen printing, a dispenser, a coating roller, etc. are mentioned, for example.

Then, the thermosetting resin composition is dried, and if necessary, the organic solvent is volatilized to form a coating film.

The heating temperature is a temperature at which the thermosetting resin is dried without being hardened, and is, for example, 20°C or higher, preferably 90°C or higher, and for example, 120°C or lower, and 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 thermosetting resin composition is prepared. Then, the release film 4 is attached to the surface of the sealing layer 2.

By the above, the sealing sheet 1 is manufactured.

Such a sealing sheet 1 can be applied to applications requiring light diffusivity, such as image display devices, lighting covers, window panes, and the like. When the sealing sheet 1 is applied to various applications, a material to be sealed (such as a light source, etc.) is embedded in the sealing layer 2, and then the sealing layer 2 is heated to, for example, 80°C or higher and 120°C or lower, 0.5 hours or longer, and 3 Less than hours, and harden it.

＜Manufacturing of image display devices＞ The sealing sheet 1 is suitable for sealing the light source (display element, optical element) of an image display device, for example. An organic EL display with a touch sensor (hereinafter referred to as an organic EL display 10) as an embodiment of an image display device will be described with reference to FIG. 2.

Furthermore, in this embodiment, as the image display device, an organic EL display with a touch sensor can be cited, but the image display device is not particularly limited. Examples of image display devices include liquid crystal displays (including liquid crystal displays with touch sensors), organic EL displays (including organic EL displays with touch sensors), and miniature light emitting diodes (light emitting diodes). diode, LED) display, etc.

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, a barrier layer 16, and an electrode (not shown).

The substrate 13 supports the organic EL element 12. The substrate 13 preferably has flexibility.

The organic EL element 12 is a well-known organic EL element, and is mounted on the 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 contacting 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 arranged on the upper surface and side surfaces of the organic EL element 12 so as to surround the organic EL element 12. Examples of the material of the first inorganic barrier layer 17 include metal oxides (for example, aluminum oxide, silicon oxide, copper oxide, etc.), metal nitrides (for example, aluminum nitride, silicon nitride, etc.), and the like. The material of the first inorganic barrier layer 17 may be used alone or in combination of two or more kinds. Among the materials of the first inorganic barrier layer 17, metal nitrides are preferable, and silicon nitride is more preferable.

The planarization layer 19 is disposed on the upper surface of the first inorganic barrier layer 17. As a material of the planarization layer 19, a well-known resin material can be mentioned.

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

Electrodes (not shown) constitute a sensor of an organic EL display with a touch sensor. The electrode (not shown) is located between the substrate 13 and the sealing member 14. For example, the electrode (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 sheet), and seals the organic EL element 12 covered by 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 from which the base film 3 and the release film 4 have been peeled off is attached to the substrate 13 so as to embed the organic EL element 12 covered by the barrier layer 16, and then attached to the upper surface of the sealing layer 2. Cover glass or barrier film 15 and then harden sealing layer 2. Thereby, the sealing member 14 is formed.

The moisture permeability of the sealing member 14 is, for example, 20 g/m ² ·24 h or more, and for example, is less than 45 g/m ² ·24 h. In addition, the moisture permeability can be measured according to the method described in the below-mentioned Examples.

If the moisture permeability of the sealing member 14 is equal to or less than the upper limit, the deterioration of the optical element sealed by the sealing member 14 can be suppressed.

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 barrier film 15 includes a glass plate and electrodes that are provided on the lower surface of the glass plate and constitute a sensor of an organic EL display with a touch sensor.

Such an organic EL display 10 has a built-in structure in which the organic EL element 12 is arranged between two electrodes constituting the sensor, or one of the two electrodes constituting the sensor is arranged in the organic EL element Built-in structure on 12.

<Effects> In the light diffusing thermosetting sheet, the thermosetting resin composition contains a thermosetting resin. Therefore, the thermosetting resin composition can be sealed by embedding the material to be sealed (for example, a light source, etc.) and then curing.

However, when a large amount of fillers are added to thermosetting resins such as epoxy resins, it is generally possible to increase the haze value and improve the light diffusibility, but the total light transmittance tends to decrease. Therefore, it is difficult to balance the improvement of the haze value and the excellent total light transmittance.

In addition, fillers generally tend to aggregate in organic solvents, and have poor dispersibility with thermosetting resins such as epoxy resins. Therefore, when a varnish of a thermosetting resin composition containing a large amount of filler is applied, the surface of the coating film may become rough due to the aggregated filler, or the filler concentration may be uneven.

In contrast, in the light-diffusing thermosetting sheet, the thermosetting resin composition includes surface-modified silica particles. Therefore, in the cured product of the thermosetting resin composition, the haze value can be improved while ensuring excellent total light transmittance. As a result, the cured product of the thermosetting resin composition can have a sufficient haze value and an excellent total light transmittance, and can ensure excellent light diffusibility.

In addition, in the surface-modified silica particles, since the surface of the silica particles is modified with a silane coupling agent, the adhesion of the surface-modified silica particles to the thermosetting resin can be improved. In the long-term storage of the composition (especially the varnish of the thermosetting resin composition), the sedimentation of the surface-modified silica particles can be suppressed, and the storage characteristics of the thermosetting resin composition can be improved. The reason for this is considered to be that the presence of the silane coupling agent on the surface of the silica particles prevents the aggregation of the surface-modified silica particles with each other.

In addition, it is sometimes desirable to impart a desired color and light diffusibility to the sealing member according to the use of the sealing member. In this case, the thermosetting resin composition preferably contains pigment particles in addition to the surface-modified silica particles. When the thermosetting resin composition contains surface-modified silica particles and pigment particles, it can impart the desired color to the sealing member. At the same time, the haze value and total light transmittance in the sealing member can be adjusted in a well-balanced manner. Ensure light diffusivity.

<Modifications> In the modified example, the same reference numerals are attached to the same members and steps as in the above-mentioned embodiment, and detailed descriptions thereof 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 sealing sheet is not limited to this. If the sealing sheet includes the sealing layer 2, the base film 3 and/or the release film 4 may not be included. That is, the sealing sheet may include only the sealing layer 2, and may also include any of the sealing layer 2, the base film 3, and the release film 4.

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

In addition, the organic EL display 10 has a built-in structure in which the organic EL element 12 is arranged between two electrodes constituting the sensor, or an externally embedded structure in which one of the two electrodes is arranged on the organic EL element 12 The structure is not limited to this.

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

The sensor unit 25 is arranged on the sealing member 14. The sensor unit 25 includes electrodes constituting a sensor of the organic EL display with a touch sensor. Furthermore, in the organic EL display 20, the substrate 13 does not include electrodes.

In addition, in FIGS. 2 and 3, the sealing member 14 seals the organic EL element 12 covered by the barrier layer 16, but the sealing member 14 may be provided in other positions.

In addition, in the above-mentioned embodiment, the sealing sheet 1 is thermally cured when or after contact with the material to be sealed, and seals the material to be sealed, but the light-diffusing thermosetting sheet of the present invention is not limited to the sealing material. For example, after heat-curing the light-diffusing thermosetting sheet in advance, other adhesives and/or other pressure sensitive adhesives can be used to bond the cured product of the light-diffusing thermosetting sheet to impart light diffusion. Sexual objects.

Regarding each of the above-mentioned modification examples, the same effects as those of the above-mentioned embodiment are exhibited. The above-mentioned embodiments and modifications can be combined as appropriate. [Example]

Examples and comparative examples are shown below and the present invention will be further specifically described, but the present invention is not limited to these. The specific values of the blending ratio (content ratio), physical property values, and parameters used in the following descriptions can be replaced with the corresponding blending ratios (content ratio), physical property values, parameters, etc., described in the "embodiment" described above. The upper limit (defined as "below" or "less than full") or lower limit (defined as "above" or "exceeding"). Furthermore, as long as there is no special mention, "parts" and "%" are quality standards.

＜Raw materials＞ The raw materials used in the examples and comparative examples are as follows.

Epoxy resin A with alicyclic skeleton: 3,4-epoxycyclohexylmethyl (3,4-epoxy)cyclohexane carboxylate, molecular weight 252.3, epoxy equivalent 128 g/eq.～145 g/ eq., trade name Celloxide 2021P (CEL2021P), manufactured by Daicel, Epoxy resin B containing alicyclic skeleton: hydrogenated bisphenol A epoxy resin, weight average molecular weight 352, epoxy equivalent 205 g/eq., trade name YX8000, manufactured by Mitsubishi Chemical Corporation, Epoxy resin C containing alicyclic skeleton: DCPD type epoxy resin, weight average molecular weight 340, epoxy equivalent 165 g/eq., trade name EP-4088L, manufactured by ADEKA, Bisphenol F type liquid epoxy resin A: Normal temperature liquid bisphenol F type epoxy resin, weight average molecular weight 398, epoxy equivalent 165 g/eq., trade name YL983U, manufactured by Mitsubishi Chemical Corporation, Bisphenol F type solid epoxy resin B: Normal temperature solid bisphenol F type epoxy resin, weight average molecular weight 7582, epoxy equivalent 10,000 g/eq., trade name jER4005P, manufactured by Mitsubishi Chemical Corporation, Bisphenol mixed type solid epoxy resin C: room temperature solid bisphenol A/bisphenol F type solid epoxy resin, weight average molecular weight 58,287, epoxy equivalent 8,400 g/eq., trade name jER4275, manufactured by Mitsubishi Chemical Corporation, Biphenyl type epoxy resin A: Biphenyl type epoxy resin of room temperature solid, weight average molecular weight 36,691, epoxy equivalent 10,000 g/eq., trade name XY-6954B35, manufactured by Mitsubishi Chemical Corporation, Methyl ethyl ketone (MEK) solution of biphenyl type epoxy resin A: Dissolve biphenyl type epoxy resin A in MEK for preparation. The concentration of biphenyl type epoxy resin A is 35% by mass, Non-porous surface modified spherical silica particles A: average primary particle size 0.3 μm, epoxy-containing silane coupling agent treatment, trade name SE1050-SEO, manufactured by Admatechs, Non-porous surface modified spherical silica particles B: average primary particle size 0.5 μm, epoxy-containing silane coupling agent treatment, trade name SC-2050MB, manufactured by Admatechs, slurry product (containing 30% by mass MEK), Non-porous surface modified spherical silica particles C: average primary particle size 1.3 μm, epoxy-containing silane coupling agent treatment, trade name 10SE-CM1, manufactured by Admatechs, slurry product (containing 25% by mass MEK), MEK dispersion of non-porous surface-modified spherical silica particles A: Prepare the non-porous surface-modified spherical silica particles A by ultrasonic dispersion in MEK for 30 minutes. The concentration of non-porous surface modified spherical silica particles is 60% by mass, Porous spherical silica particles D: average primary particle size 1.0 μm, no surface modification, trade name hipresica FQ, manufactured by Ube-exsymo, MEK dispersion of porous spherical silica particles D: Prepare porous spherical silica particles D by ultrasonic dispersion in MEK for 30 minutes. The concentration of porous spherical silica particles is 60% by mass, Silicone resin powder spherical particles A: Average primary particle size of 2.0 μm, trade name KMP-590, manufactured by Shin-Etsu Silicone Co., Ltd. MEK dispersion of silicone resin powder spherical particles A: Prepare the silicone resin powder spherical particles A by ultrasonic dispersion in MEK for 30 minutes. The concentration of spherical particles of silicone resin powder is 60% by mass, Silicone rubber composite powder spherical particles B: Average primary particle size 2.0 μm, trade name KMP-605, manufactured by Shin-Etsu Silicone Co., Ltd. MEK dispersion of silicone rubber composite powder spherical particles B: Prepare the silicone rubber composite powder spherical particles B by ultrasonic dispersion in MEK for 30 minutes. The concentration of spherical particles of silicone rubber composite powder is 60% by mass, Pigment particle dispersion: a solvent-based carbon prepared by dispersing pigment particles (carbon black, average primary particle size 50 nm) in a mixed solvent of 2-methoxymethyl ethyl acetate/ethyl acetate/butyl acetate Black dispersion liquid, pigment concentration 12% by mass, trade name TSBK-105, manufactured by Dacheng Chemical Co., Ltd., Thermal cationic hardener: trade name CXC-1612, manufactured by King Industries, Thermionic hardener: 2-ethyl-4-methylimidazole, trade name 2E4MZ, manufactured by Shikoku Chemical Industry Co., Ltd., Coupling agent: trade name KBM-403, manufactured by Shin-Etsu Chemical Industry Co., Ltd., Organic solvent: methyl ethyl ketone (MEK) <Example 1> Mix the MEK solution of epoxy resin B containing alicyclic skeleton, bisphenol F type solid epoxy resin B, biphenyl type epoxy resin A, and non-porous surface modified spherical silica particles with the formula shown in Table 1. A. Thermal cationic hardener, coupling agent and organic solvent to prepare varnish of thermosetting resin composition.

Then, the varnish was applied to the PET film (PET film subjected to mold release treatment) (trade name: Purex A53, manufactured by Teijin Dupont Film) with a coater, thickness: 38 μm, base film), and then dried in a nitrogen purge oven at 90°C for 3 minutes to form a sealing layer with a thickness of 15 μm.

Then, the PET film (PET film subjected to demolding treatment) (trade name: Purex A31, manufactured by Teijin Dupont Film), thickness: 38 μm, stripping Mold film) is bonded to the sealing layer at 80°C.

By the above, a sealing sheet including a sealing layer, a base film, and a release film is prepared.

<Example 2 to Example 10, Comparative Example 1 to Comparative Example 6> Except for changing the formula of each raw material to the formula shown in Table 1 and Table 2, the varnish and sealing sheet of the thermosetting resin composition were prepared in the same manner as in Example 1.

<Example 11> Mix the alicyclic skeleton-containing epoxy resin B, the bisphenol F type solid epoxy resin B, the MEK solution of the biphenyl type epoxy resin A, the dispersion of pigment particles, and the non-porous surface modification with the formula shown in Table 3. Spherical silicon dioxide particles B, thermal cationic hardener and coupling agent are used to prepare a varnish of thermosetting resin composition.

Then, with a coater, the varnish was applied to a PET film (PET film subjected to mold release treatment) (trade name: Purex (Purex) A53, Teijin Dupont Film (Teijin Dupont Film) company, thickness: 38 μm, base film), and then dried in a nitrogen purge oven at 90 °C for 3 minutes to form a sealing layer.

Then, the PET film (PET film subjected to demolding treatment) (trade name: Purex A31, manufactured by Teijin Dupont Film), thickness: 38 μm, stripping Mold film) is bonded to the sealing layer at 80°C.

By the above, a sealing sheet including a sealing layer, a base film, and a release film is prepared.

<Example 12 to Example 18, Comparative Example 7 and Comparative Example 8> Except that the formulation of each raw material was changed to the formulation shown in Table 3, the varnish of the thermosetting resin composition and the sealing sheet were prepared in the same manner as in Example 11.

＜Evaluation＞ [Particle sinkability] Put 30 g of the varnish prepared in each embodiment and each comparative example shown in Table 1 and Table 2 into a 50 ml threaded tube (35 mm in diameter) and let it stand for 24 hours at room temperature (23°C). Visually confirm the presence or absence of sedimentation. Then, the particle sedimentation properties were evaluated using the following criteria. The results are shown in Table 1 and Table 2. No sediment: ○ There are sediments: × [90°Peel Strength] Prepare aluminum-PET composite film (aluminum surface)/resin/alkali glass spring balance (for 1 kg weighing). After peeling the release film of the sealing sheet of each Example and each comparative example shown in Table 1 and Table 2 from the sealing layer, the sealing layer was attached to the aluminum surface of an aluminum-PET composite film. Then, the sealing layer was cured at 100°C for 1 hour (in Example 9, Example 10, and Comparative Example 3, it was cured at 100°C for 2 hours). Then, the 90-degree peel strength of the cured product of the aluminum surface and the sealing layer was measured. In Example 1 to Example 10 and Comparative Example 1 to Comparative Example 6, the 90-degree peel strength was used as the adhesive strength. The results are shown in Table 1 and Table 2.

[Water permeability] After peeling the release film of the sealing sheet of each example and each comparative example shown in Table 1 and Table 2 from the sealing layer, the sealing layer was cured at 100°C for 1 hour (Example 9, Example 10 and Comparative In Example 3, it was cured at 100°C for 2 hours). Then, the base film was peeled off from the sealing layer after curing to obtain a measurement sample. According to JIS Z0208, the moisture permeability (moisture permeability) of the obtained sample was measured under the conditions of 60°C and 90%RH. Then, it is converted into a value when the thickness of the sample is 100 μm based on the film thickness of the sample used in the measurement. The results are shown in Table 1 and Table 2.

[Haze value, total light transmittance (TT)] After peeling the release film of the sealing sheet of each example and each comparative example shown in Table 1 to Table 3 from the sealing layer, the sealing layer was cured at 100°C for 1 hour (Example 9, Example 10 and Comparative In Example 3, it was cured at 100°C for 2 hours). Then, the base film was peeled off from the sealing layer after curing to obtain a measurement sample. The haze meter NDH2000 manufactured by Nippon Denshoku Kogyo Co., Ltd. was used to measure the haze value and total light transmittance of the obtained sample. The results are shown in Tables 1 to 3. In particular, it was confirmed that the haze value of 80% or more and the total light transmittance of 90% or more are compatible to exhibit excellent light diffusibility. In addition, it was confirmed that by adding pigment particles to the thermosetting resin composition, the cured product of the sealing layer can be given the desired color, and at the same time, the haze value and total light can be adjusted in a well-balanced manner in the cured product of the sealing layer Transmittance.

[Appearance of the sealing layer] After peeling the release film of the sealing sheet of each example and each comparative example shown in Table 1 to Table 3 from the sealing layer, the sealing layer was cured at 100°C for 1 hour (Example 9, Example 10 and Comparative In Example 3, it was cured at 100°C for 2 hours). By visually observing the cured sealing layer, those with a smooth surface were evaluated as ○, and those with a rough surface were evaluated as ×. The results are shown in Tables 1 to 3.

[L*value (blackness)] After peeling the release film of the sealing sheet of each Example and each comparative example shown in Table 3 from the sealing layer, the sealing layer was hardened at 100 degreeC for 1 hour.

Then, the base film was peeled off from the sealing layer after curing to obtain a measurement sample. The L* value (blackness) of the obtained sample was measured using a colorimeter CR-200 manufactured by KONICA MINOLTA. The results are shown in Table 3.

[Table 1] No. Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Example 10 Formula [mass part] CEL2021P Epoxy resin A with alicyclic skeleton - - - - - - 30 30 - - YX8000 Epoxy resin B with alicyclic skeleton 30 30 30 30 30 30 - - - - YL983U Bisphenol F type liquid epoxy resin A - - - - - - - - 30 30 jER4005P Bisphenol F type solid epoxy resin B 50 50 50 50 50 50 50 50 50 50 XY-6954B35 MEK solution of biphenyl type epoxy resin A (solid content 35%) 57.1 (Solid content 20) 57.1 (Solid content 20) 57.1 (Solid content 20) 57.1 (Solid content 20) 57.1 (Solid content 20) 57.1 (Solid content 20) 57.1 (Solid content 20) 57.1 (Solid content 20) - - jER4275 Bisphenol mixed solid epoxy resin C - - - - - - - - 20 20 SE1050-SEO Non-porous surface modified spherical silica particles A 0.3 μmMEK dispersion (silica particle concentration 60%) 50 (solid content 30) - - - - - - - - - SC-2050MB Non-porous surface modification spherical silica particles B 0.5 μm slurry (silica particle concentration 70%) - 7.1 (Solid content 5) 14.3 (Solid content 10) 42.9 (Solid content 30) - - 14.3 (Solid content 10) 42.9 (Solid content 30) 14.3 (Solid content 10) 42.9 (Solid content 30) 10SE-CM1 Non-porous surface modified spherical silica particles C 1.3 μm slurry (silica particle concentration 75%) - - - - 13.3 (Solid content 10) 37.5 (Solid content 30) - - - - CXC-1612 Thermal cationic hardener 4 4 4 4 4 4 4 4 - - 2E4MZ Thermal anionic hardener - - - - - - - - 1 1 KBM-403 Coupling agent 1 1 1 1 1 1 1 1 1 1 MEK Organic solvent 78 71 74 85 75 90 74 85 108 119 Evaluation Particle sedimentation 24 hours later 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 90 degree peel strength gf/15 mm width 590 780 740 600 650 650 550 700 600 680 Water permeability 60℃90%RH g/m ² ･1 day twenty four 31 26 25 30 28 30 27 29 27 Haze value % 61.7 40.5 51.5 83.2 60.8 89.6 42.3 82.6 67.8 87.6 TT (total light transmittance) % 88.9 92.1 91.2 90.1 92.8 92.2 91.1 90.2 89.2 81.6 Slice appearance Visually 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇

[Table 2] No. Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4 Comparative example 5 Comparative example 6 Formula [mass part] CEL2021P Epoxy resin A with alicyclic skeleton - 30 - - - - YX8000 Epoxy resin B with alicyclic skeleton 30 - - 30 30 30 YL983U Bisphenol F type liquid epoxy resin A - - 30 - - - jER4005P Bisphenol F type solid epoxy resin B 50 50 50 50 50 50 XY-6954B35 MEK solution of biphenyl type epoxy resin A (solid content 35%) 57.1 (Solid content 20) 57.1 (Solid content 20) - 57.1 (Solid content 20) 57.1 (Solid content 20) 57.1 (Solid content 20) jER4275 Bisphenol mixed solid epoxy resin C - - 20 - - - Hipresica FQ Porous spherical silica particles D 1.0 μmMEK dispersion (silica particle concentration 60%) - - - 50 (solid content 30) - - KMP-590 Silicone resin powder spherical particles A 2.0 μmMEK dispersion (silica particle concentration 60%) - - - - 50 (solid content 30) - KMP-605 Silicone rubber composite powder spherical particles B 2.0 μmMEK dispersion (silica particle concentration 60%) - - - - - 50 (solid content 30) CXC-1612 Thermal cationic hardener 4 4 - 4 4 4 2E4MZ Thermal anionic hardener - - 1 - - - KBM-403 Coupling agent 1 1 1 1 1 1 MEK Organic solvent 68 68 102 78 78 78 Evaluation Particle sedimentation 24 hours later - - - X X X 90 degree peel strength gf/15 mm width 610 690 620 500 440 440 Water permeability 60℃ 90%RH g/m ² ･1 day 32 35 31 42 61 55 Haze value % 0.2 0.3 0.2 98.2 93.2 93.6 TT (total light transmittance) % 95.3 94.3 96.8 85.3 73.7 66.2 Slice appearance Visually 〇 〇 〇 X X X

[table 3] No. Example 11 Example 12 Example 13 Example 14 Example 15 Example 16 Example 17 Example 18 Comparative example 7 Comparative example 8 Formula [mass part] CEL2021P Epoxy resin A with alicyclic skeleton - - - - - 30 - - - - YX8000 Epoxy resin B with alicyclic skeleton 30 30 30 30 30 - - 30 30 30 EP-4088L Epoxy resin C with alicyclic skeleton - - - - - - 30 - - - jER4005P Bisphenol F type solid epoxy resin B 50 50 50 50 50 50 50 50 50 50 XY-6954B35 MEK solution of biphenyl type epoxy resin A (solid content 35%) 57.1 (Solid content 20) 57.1 (Solid content 20) 57.1 (Solid content 20) 57.1 (Solid content 20) 57.1 (Solid content 20) 57.1 (Solid content 20) 57.1 (Solid content 20) 57.1 (Solid content 20) 57.1 (Solid content 20) 57.1 (Solid content 20) TSBK-105 Dispersion liquid of pigment particles (carbon black) (pigment concentration 12% by mass) 8.3 (Solid content 1.0) 25 (Solid content 3.0) 0.83 (Solid content 0.1) 2.5 (Solid content 0.3) 4.2 (Solid content 0.5) 8.3 (Solid content 1.0) 8.3 (Solid content 1.0) - 8.3 (Solid content 1.0) 25 (Solid content 3.0) SC-2050MB Non-porous surface modification spherical silica particles B 0.5 μm slurry (silica particle concentration 70%) 42.9 (Solid content 30) 42.9 (Solid content 30) 42.9 (Solid content 30) 42.9 (Solid content 30) 42.9 (Solid content 30) 42.9 (Solid content 30) 42.9 (Solid content 30) 42.9 (Solid content 30) - - CXC-1612 Thermal cationic hardener 4 4 4 4 4 4 4 4 4 4 KBM-403 Coupling agent 1 1 1 1 1 1 1 1 1 1 Evaluation Coating film thickness μm 16 15 13 14 14 15 15 14 15 16 Haze value % 89.3 88.7 87.6 88.1 88.3 85.3 87.5 87.9 0.5 0.6 TT (total light transmittance) % 56.7 25.2 84.7 74.6 71.6 55.8 53.8 91.8 54.3 17.9 L*value (blackness) - 61.1 33.9 87.5 77.2 74.2 59.3 57.1 93.5 62.7 29.4 Slice appearance Visually 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇

In addition, the said invention is provided as an exemplary embodiment of this invention, It is only an illustration, and it should not be interpreted restrictively. Modifications of the present invention that are clarified by those skilled in the art are included in the scope of the invention application described below. [Industrial availability]

The light-diffusing thermosetting sheet of the present invention can be applied to, for example, window glass for general buildings; window glass for vehicles; glazing materials; protective covers for signs, lighting fixtures, display lamps, etc.; image display devices ( Organic EL displays, liquid crystal displays, micro LED displays, etc.).

1: Sealing sheet 2: Sealing layer 3: Basement membrane 4: Release film 10, 20: organic EL display 11: Component mounting unit 12: Organic EL element 13: substrate 14: Sealing member 15: Cover glass or barrier film 16: barrier layer 17: The first inorganic barrier layer 18: The second inorganic barrier layer 19: Planarization layer 25: sensor unit

Fig. 1 is a side cross-sectional view of a sealing sheet as an embodiment of the light-diffusing thermosetting sheet of the present invention. FIG. 2 is an embodiment of an image display device including a sealing member formed of the sealing layer shown in FIG. 1 (an aspect having an in-cell structure or an on-cell structure ) Side cross-sectional view of an organic electroluminescence (EL) display with a touch sensor. 3 is a side cross-sectional view of an organic EL display with a touch sensor as another embodiment of an image display device (an aspect with an out-cell structure).

1: Sealing sheet

2: Sealing layer

3: Basement membrane

4: Release film

Claims (6)

A light-diffusing thermosetting sheet, which is characterized by containing a thermosetting resin composition containing a thermosetting resin and surface-modified silica particles, The average primary particle size of the surface-modified silica particles is 0.1 μm or more and 1.5 μm or less, and the surface-modified silica particles are silica particles that have been surface-modified with a silane coupling agent. The light-diffusing thermosetting sheet according to claim 1, wherein the thermosetting resin contains epoxy resin. The light-diffusing thermosetting sheet according to claim 1, wherein the silicon dioxide particles are non-porous. The light-diffusing thermosetting sheet according to claim 1, wherein the content ratio of the surface-modified silica particles is 5 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the thermosetting resin. The light-diffusing thermosetting sheet according to claim 1, wherein when the thermosetting resin composition is formed into a sheet with a thickness of 15 μm and thermosetting is performed, the thermosetting resin composition The haze value is more than 35%, and the total light transmittance is more than 80%. The light-diffusing thermosetting sheet according to claim 1, wherein the thermosetting resin composition further contains pigment particles, The average primary particle diameter of the pigment particles is 100 nm or less.

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