CN116003958A - Sealing material composition and sealing material - Google Patents

Abstract

The present invention provides a sealing material composition excellent in water vapor barrier properties under high temperature and high humidity. A sealing material composition according to an embodiment of the present invention contains an epoxy resin, a flake-shaped inorganic compound, and a photoinitiator, and the flake-shaped inorganic compound has an average particle diameter of 0.5 μm or more as measured by a dynamic light scattering method And less than 5 μm, the average value of major diameter/thickness is 1.3 to 50, and the sealing material composition basically does not contain a solvent whose main purpose is to dissolve the photoinitiator.

Description

Sealing material composition and sealing material

technical field

The present invention relates to a sealing material composition and a sealing material.

Background technique

In recent years, devices using organic thin films, such as photosensors, organic memory elements, display elements, organic transistors, organic thin-film solar cells, organic semiconductor elements, and communication elements, have attracted attention. However, electronic devices, particularly devices using organic thin films, have a problem of reduced lifetime due to intrusion of water or the like. This is because organic elements deteriorate due to moisture or the like, resulting in a decrease in device functionality. Therefore, there is a need for a sealing material having water vapor barrier properties. Here, the term "water vapor barrier property" refers to the property of suppressing intrusion of moisture from the outside.

As an example of a technique for imparting water vapor barrier properties to a sealing material, the technique described in Patent Document 1 can be cited. Patent Document 1 discloses a sealing material composition for an organic device obtained by dispersing a flaky inorganic compound in a matrix polymer in a bulk form.

prior art literature

patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2013-28722

Contents of the invention

The problem to be solved by the invention

However, in the prior art as described above, there is room for improvement in the water vapor barrier property under high temperature and high humidity. One aspect of the present invention aims to realize a sealing material composition excellent in water vapor barrier properties under high temperature and high humidity.

means of solving problems

In order to solve the above-mentioned problems, the inventors of the present invention have repeatedly carried out in-depth research, and found that: by using epoxy resin, a sheet-like inorganic compound of a specific shape, and a photoinitiator, and basically not containing substances whose main purpose is to dissolve the photoinitiator, Solvent, and a sealing material composition capable of realizing excellent water vapor barrier properties under high temperature and high humidity, and completed the present invention. One aspect of the present invention includes the following configurations.

<1> A sealing material composition comprising an epoxy resin, a flake-shaped inorganic compound, and a photoinitiator, wherein the flake-shaped inorganic compound has an average particle diameter of 0.5 μm or more and less than 0.5 μm as measured by a dynamic light scattering method. 5 μm, the average value of major diameter/thickness is 1.3 to 50, and the sealing material composition does not substantially contain a solvent whose main purpose is to dissolve the photoinitiator.

<2> The sealing material composition according to <1>, wherein the content of the flaky inorganic compound is 20% by weight to 45% by weight.

<3> The sealing material composition according to <1> or <2>, wherein the epoxy resin is an epoxy resin containing a phenol skeleton.

<4> The sealing material composition according to any one of <1> to <3>, wherein the photoinitiator contains PF ₆ ⁻ , SbF ₆ ⁻ , (Rf) _n PF _6-n ⁻ or B(C ₆ F ₅ ) ₄ is a sulfonium salt or iodonium salt as a counter anion, the Rf is a perfluoroalkyl group, and the n is a real number from 1 to 6.

<5> The sealing material composition according to any one of <1> to <4>, further comprising a silane coupling agent having an epoxy group.

<6> A sealing material obtained by curing the sealing material composition according to any one of <1> to <5>.

The effect of the invention

According to one aspect of the present invention, it is possible to provide a sealing material composition excellent in water vapor barrier properties under high temperature and high humidity.

Detailed ways

Next, an embodiment of the present invention will be described, but the present invention is not limited thereto. In addition, unless otherwise stated in this specification, "A to B" showing a numerical range means "A or more and B or less".

[1. Sealing material composition]

The sealing material composition according to one embodiment of the present invention contains an epoxy resin, a flaky inorganic compound, and a photoinitiator, and the flaky inorganic compound has an average particle diameter of 0.5 μm or more as measured by a dynamic light scattering method And less than 5 μm, the average value of major diameter/thickness is 1.3 to 50, and the sealing material composition basically does not contain a solvent whose main purpose is to dissolve the photoinitiator. Thereby, a sealing material composition excellent in water vapor barrier property under high temperature and high humidity can be provided. In particular, as shown in the examples described below, it is surprising that the sealing material composition can obtain water vapor barrier properties under high temperature and high humidity conditions of 85° C./85% RH. The water vapor barrier property can be evaluated by the water vapor transmission rate measured by the method described in the examples. It can also be said that water vapor transmission rate means moisture permeability.

When light is irradiated to the sealing material composition, the photoinitiator is decomposed to generate acid. The acid is added to the epoxy groups in the epoxy resin. A cured product obtained by addition polymerization can be obtained by subjecting another epoxy group to an electrophilic addition reaction with this epoxy group. The obtained cured product has low free volume due to π-π stacking of epoxy resin and excellent water vapor barrier properties. Furthermore, the water vapor barrier property can be further improved by using the flaky inorganic compound. In addition, since the sealing material composition substantially does not contain a solvent whose main purpose is to dissolve the photoinitiator, it is possible to prevent the solvent from entering between the π-π stacks of the epoxy resin to increase the free volume. It is presumed that in this way, excellent water vapor barrier properties under high temperature and high humidity can be realized. Accordingly, as a sealing material obtained by curing the sealing material composition, increase in free volume can be suppressed, and as a result, water vapor permeation can be suppressed even under high temperature and high humidity.

In this specification, a "sealing material composition" means a composition for obtaining a sealing material. As described below, the sealing material can be obtained by curing the sealing material composition. The sealing material composition may be an uncured composition. The sealing material composition can also be said to be a photocurable resin composition. In this specification, the so-called "solvent whose main purpose is to dissolve the photoinitiator" refers to those liquids (including additives) that are not added for the purpose of improving adhesion, improving compatibility, and improving defoaming properties.

In this specification, "substantially no solvent" means that the content of the solvent whose main purpose is to dissolve the photoinitiator in the sealing material composition is 0.5% by weight or less. The fact that the content of the solvent whose main purpose is to dissolve the photoinitiator in the sealing material composition is 0.5% by weight or less can be confirmed by outgassing detection using GC/MS or the like. The content of the solvent whose main purpose is to dissolve the photoinitiator in the sealing material composition is more preferably 0.2% by weight or less.

<1-1. Epoxy resin>

The sealing material composition contains an epoxy resin as a base polymer. Epoxy resins can also be said to be cationic polymerizable compounds. Addition polymerization of the epoxy resin occurs by an acid generated from a photoinitiator described below, and as a result, a three-dimensional network structure is formed. Water vapor permeation can be suppressed by the π-π stacking property of the three-dimensional network structure. The sealing material composition may contain only the epoxy resin as a matrix polymer, or may contain a matrix polymer other than the epoxy resin as described below in addition to the epoxy resin.

Examples of epoxy resins include bisphenol F epoxy resins, bisphenol A epoxy resins, bisphenol E epoxy resins, phenol novolac epoxy resins, alicyclic epoxy resins, and glycidyl epoxy resins. Amine type epoxy resin, hydrogenated bisphenol A type epoxy resin, etc. In addition, modified epoxy resins can also be used. Examples of the modified epoxy resin include acrylic-modified epoxy resins, polybutadiene-based modified epoxy resins, graft-modified epoxy resins, silylated polyepoxy resins, and the like.

Among them, the epoxy resin is preferably an epoxy resin containing a phenol skeleton. Examples of the epoxy resin containing a phenol skeleton include bisphenol F-type epoxy resins, bisphenol A-type epoxy resins, bisphenol E-type epoxy resins, phenol novolak-type epoxy resins, and the like. Epoxy resins can also be used with cure accelerators.

＜1-2. Flaky inorganic compound＞

The sealing material composition contains a flaky inorganic compound as a filler. Clay, mica, talc, silicate compounds, etc. are mentioned as a flaky inorganic compound.

In one embodiment of the present invention, the flaky inorganic compound has an average particle diameter of 0.5 μm or more and less than 5 μm as measured by a dynamic light scattering method, and an average value of major axis/thickness of 1.3 to 50. The ratio of the long diameter to the thickness (long diameter/thickness) represents the aspect ratio. By using a flaky inorganic compound with a high aspect ratio, the water permeation path becomes long, and water vapor permeation can be suppressed. That is, the flaky inorganic compound exhibits a function of diverting moisture when it has penetrated into the sealing material.

When the average particle diameter of the flaky inorganic compound measured by the dynamic light scattering method is 0.5 μm or more, the particles are less likely to be secondary aggregated. When this average particle diameter is less than 5 micrometers, it becomes easy to become a piled state. The average particle diameter can be measured by the dynamic light scattering method, for example, using DLS-6000 manufactured by Otsuka Electronics. The average particle diameter is preferably 1 μm or more and less than 5 μm, more preferably 1.5 μm to 4.8 μm, still more preferably 2 μm to 4.5 μm.

When the average value of the ratio of the major axis to the thickness (major axis/thickness) of the flake-shaped inorganic compound is 1.3 or more, it is easy to disperse in the sealing material in a state where the directions are aligned. When the average value of major diameter/thickness is 50 or less, workability is excellent. The average value of major diameter/thickness is preferably 1.5 to 25, more preferably 2 to 20.

Hereinafter, an example of a sealing material obtained by applying the sealing material composition on a base material or sandwiching the sealing material composition between two base materials and then curing it will be described. . In this sealing material, most of the sheet-like inorganic compound dispersed in the matrix polymer can be oriented parallel to the substrate. In addition, the flaky inorganic compound may be dispersed in a stacked state (in a layered manner). When the proportion of the flaky inorganic compound oriented parallel to the substrate becomes larger, the gap between the flaky inorganic compound and the flaky inorganic compound becomes smaller or decreases. Also, the accumulation state will become clear. Thereby, the function which fully detours moisture etc. can be exhibited.

The sheet-like inorganic compound oriented parallel to the base material exhibits a peak attributable to the (00c) plane (c is a natural number) from the diffraction angle θ in the X-ray diffraction pattern of the sealing material. Here, let the sum of the diffraction intensities of all peaks attributable to the (00c) plane be Ip. Furthermore, the sum of the diffraction intensities of all peaks attributable to the (abc) plane (both a and b are not 0), that is, all peaks due to the flaky inorganic compound not oriented parallel to the substrate, is set to Inp. In this case, as long as the ratio of the two is 0≤α≤0.1 (non-parallel orientation ratio α=Inp/Ip), the function of diverting moisture and the like when it is about to permeate through the sealing material can be fully exhibited. c is a natural number, a positive (plus) integer, excluding 0 (zero), usually 1-20, preferably 1-12. The value of α being 0 means that all the flaky inorganic compounds are oriented parallel to the substrate (Inp=0).

The content of the flaky inorganic compound in 100% by weight of the sealing material composition is preferably 20% by weight to 45% by weight, more preferably 25% by weight to 40% by weight. When the content of the flaky inorganic compound is at least 20% by weight, the water detour function can be sufficiently exhibited. Furthermore, if the content of the flaky inorganic compound is 45% by weight or less, the relative ratio of the matrix polymer can be sufficiently ensured, so that the properties that the matrix polymer should exhibit, such as substrate adhesion, can be fully exhibited.

<1-3, Photoinitiator>

The sealing material composition contains a photoinitiator as a cationic polymerization initiator. In one embodiment of the present invention, the photoinitiator is, for example, a powdery solid, and does not contain a solvent whose main purpose is to dissolve the photoinitiator. Although a small amount (about 0 to 10% by weight) of the solvent used in the photoinitiator production process may remain in the photoinitiator, even in this case, the fact that the photoinitiator is solid does not change. In addition, the shape of the photoinitiator may not be powdery, but may be granular, massive, or the like.

When the example of a preferable photoinitiator is classified according to a cation, a sulfonium salt type initiator, an iodonium salt type initiator, etc. are mentioned. When examples of preferable photoinitiators are classified by anion, antimony-based initiators, borate-based initiators, phosphorus-based initiators, and the like are mentioned. The photoinitiator is preferably a sulfonium salt or an iodonium salt containing PF ₆ ^- , SbF ₆ ^- , (Rf) _n PF _6-n ^- or B(C ₆ F ₅ ) ₄ as a counter anion. Here, the Rf is a perfluoroalkyl group, and the n is a real number of 1 to 6. Examples of the cation contained in the photoinitiator include triarylsulfonium, diaryliodonium, and the like.

The content of the photoinitiator in 100% by weight of the sealing material composition is preferably 0.5% to 10% by weight, more preferably 1% to 5% by weight. If the content of the photoinitiator is more than 0.5% by weight, the matrix polymer can be fully crosslinked. In addition, if the content of the photoinitiator is 10% by weight or less, since the relative ratio of the matrix polymer can be sufficiently ensured, the properties that the matrix polymer should exhibit, such as substrate adhesion, can be fully exhibited. The solvent for dissolving the photoinitiator (a solvent whose main purpose is to dissolve the photoinitiator) is not particularly limited as long as it is an organic solvent that does not contain a highly reactive functional group and can dissolve the photoinitiator. Examples of the organic solvent include ketone-based solvents, ester-based solvents, ether-based solvents, and hydrocarbon-based solvents. Acetone, methyl ethyl ketone, etc. are mentioned as a ketone solvent, and propylene carbonate, ethyl acetate, etc. are mentioned as an ester solvent.

＜1-4, other ingredients＞

The sealing material composition may contain other components besides the epoxy resin, the flake inorganic compound, and the photoinitiator. Examples of other components include base polymers other than epoxy resins, and additives (coupling agents, compatibilizers, antifoaming agents, etc.). The content of other components in 100% by weight of the sealing material composition may be 0 to 15% by weight, or 0 to 10% by weight.

Examples of matrix polymers other than epoxy resins include polyurethane resins, polycarbonate resins, polyacrylate resins, modified olefin resins, polyester resins, and the like.

The sealing material composition may contain a coupling agent. Thereby, the adhesiveness with a base material can be improved. Examples of coupling agents include: γ-aminopropyltriethoxysilane, N-β(aminoethyl)γ-aminopropyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane Base silane, vinyl trimethoxy silane, methacryl triethoxy silane, mercapto trimethoxy silane, epoxy modified silane, carbamate modified silane, amine titanate coupling agent, sub Phosphate-based titanate coupling agents, pyrophosphate-based titanate coupling agents, carboxylic acid-based titanate coupling agents, and the like. Among them, epoxy-modified silanes, that is, silane coupling agents having epoxy groups are preferred. Examples of silane coupling agents having epoxy groups include: 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane , 3-Glycidoxypropyltrimethoxysilane, 3-Glycidoxypropylmethyldiethoxysilane, 3-Glycidoxypropyltriethoxysilane, etc.

Examples of compatibilizers include: aliphatic diene polymer-based compatibilizers, polyolefin-based compatibilizers, alicyclic diene-based compatibilizers, vinylidene-based compatibilizers, mixed vinyl acetate and propylene Compatibilizer made of alcohol, etc.

Examples of the antifoaming agent include acrylic antifoaming agents, low-viscosity silicone-based antifoaming agents, alcohol-based antifoaming agents, fatty acid ester-based antifoaming agents, polyether-based antifoaming agents, and the like.

<1-5. Method for producing sealing material composition>

For example, by compounding a sheet-like inorganic compound, a photoinitiator, and other components as needed in a base polymer, and mixing them using a bead mill, a homomixer, a ball mill, a three-roll machine, a kneader, etc., it is possible to The sealing material composition was obtained. It is preferable to mix using a ball mill, a three-roll mill, a kneader, etc., whereby the flaky inorganic compound can be more easily and uniformly dispersed. In addition, when the photoinitiator is difficult to mix, the photoinitiator may be dissolved in a liquid component among the components other than the above-mentioned photoinitiator to mix the above-mentioned various materials.

<1-6. Properties of sealing material composition>

The sealing material composition is preferably a thixotropic liquid at 25°C. The viscosity at 25° C. at a shear rate of 2 (1/s) is preferably 100 Pa·s or more. In addition, the viscosity at a shear rate of 2 (1/s) is preferably 500 Pa·s or less, more preferably 200 Pa·s or less. The thixotropic ratio calculated from the ratio of the viscosity at a shear rate of 2 (1/s) to the viscosity at a shear rate of 10 (1/s) is preferably 1.5 to 6, more preferably 1.5 to 3.

〔2. Sealing material〕

The sealing material according to one embodiment of the present invention is obtained by curing the sealing material composition. It can also be said that the sealing material is a cured product obtained from the sealing material composition. Specifically, the sealing material is obtained by subjecting the sealing material composition to a crosslinking reaction. The crosslinking reaction may be a photocuring reaction. The cumulative light amount used for photocuring may be, for example, 1 J/cm ² to 20 J/cm ² . In addition, after photocuring, heat treatment is performed under the condition of, for example, 80° C. to 100° C.×1 hour, thereby completing the crosslinking reaction.

The sealing material is used, for example, to seal electronic devices such as organic devices. Since the sealing material exhibits excellent water vapor barrier properties even under high temperature and high humidity, it can suppress deterioration of organic devices. In this specification, an organic device refers to a device having an organic thin film. Examples of organic devices include organic electroluminescent devices, photosensors, organic memory elements, display elements, organic transistors, organic thin-film solar cells, organic semiconductor elements, communication elements, and the like. More specific examples of organic devices include PM-OLED, AM-OLED, and the like. For example, the sealing material can be used as an end face sealing material of an organic device. The sealing material may also be sandwiched between two substrates included in the organic device.

As the sealing material, the water vapor transmission rate at 85°C/85%RH measured by the method described in the examples is preferably 60 g/m ² ·day or less, more preferably 55 g/m ² ·day or less, More preferably, it is 50 g/m ² ·day or less.

As the sealing material, the glass transition temperature measured by the method described in the examples is preferably 125°C or higher, more preferably 130°C or higher, and still more preferably 135°C or higher. From the viewpoint of heat resistance, the sealing material preferably has a glass transition temperature of 125° C. or higher.

The present invention is not limited to the above-mentioned embodiments, and various changes can be made within the scope shown in the claims. Embodiments obtained by appropriately combining technical means disclosed in different embodiments are also included in the present invention. within the technical scope of the invention.

【Example】

Next, an embodiment of the present invention will be described.

〔Evaluation method〕

<Measurement of water vapor transmission rate (WVTR) of cured product>

The sealant composition of the example or the comparative example was coated on a Teflon (registered trademark) sheet using a YD-3 doctor blade manufactured by Yoshimitsu Seiki Co., Ltd. (Yoshimitsu Seiki Co., Ltd.) to a film thickness of 100 μm. Next, using a thermostat equipped with a metal halide lamp manufactured by Ushio Electric Co., Ltd., it was treated at 80° C. for 1 hour at an integrated UV amount of 6 J/cm ² . Then, it was peeled off from the Teflon (registered trademark) sheet to obtain a cured film. The obtained cured film was cut into a predetermined size, set on a moisture-permeable cup manufactured by Yasuda Seiki Co., Ltd. containing calcium chloride, and fixed with a special jig with screws. The water vapor transmission rate was calculated from the change in weight of the cup before it was left to stand and after it was left to stand at 85° C./85% RH for 24 hours.

<Measurement of glass transition temperature (Tg) of cured product>

A cured film having a thickness of 100 μm was prepared using the sealing material composition of the example or the comparative example in the same procedure as described in the above water vapor transmission rate measurement. The obtained cured film was placed on a tension measuring jig of a rheometer manufactured by TA Instruments, and the temperature was raised to 0 to 200°C at a frequency of 1 Hz, a strain of 0.2% by weight, and a heating rate of 10°C/min. , for viscoelasticity measurements. From the obtained data, the ratio of the storage modulus to the loss modulus, that is, the maximum point of Tan δ was calculated, and this temperature was taken as the glass transition temperature.

<Average particle diameter and major diameter/thickness average of flake inorganic compound>

The average particle diameter of the flaky inorganic compound was measured by a dynamic light scattering method using DLS-6000 manufactured by Otsuka Electronics. In addition, the average value of the major axis/thickness of the flake-shaped inorganic compound was measured using an electron microscope JST-IT 100 manufactured by JEOL Ltd. The result is as follows.

"FG-15" manufactured by Nippon Talc Co., Ltd.: the average particle diameter is 1.5 μm, and the average value of major axis/thickness is 20.

"P-8" manufactured by Nippon Talc Co., Ltd.: the average particle diameter is 2.8 μm, and the average value of major axis/thickness is 30.

"P-4" manufactured by Nippon Talc Co., Ltd.: the average particle diameter is 4.5 μm, and the average value of major axis/thickness is 30.

"P-2" manufactured by Nippon Talc Co., Ltd.: the average particle diameter is 7.0 μm, and the average value of major axis/thickness is 30.

[Example 1]

2% by weight of triarylsulfonium salt type antimony photoinitiator ("CPI-110A" manufactured by San-Apro company, powder (solvent-free)) was added to 65% by weight of bisphenol F type epoxy resin ( "jER 806" manufactured by Mitsubishi Chemical Corporation) and stirred at 80°C to dissolve it. Next, 25% by weight of talc ("FG-15" manufactured by Nippon Talc Co., Ltd.) as a flake inorganic compound and 8% by weight of silane-coupling ("KBM-403" manufactured by Shin-Etsu Chemical Co., Ltd.), and kneaded and dispersed by a three-roll machine. Then, pressure filtration was performed to prepare a sealing material composition.

[Example 2]

2% by weight of triarylsulfonium salt type antimony photoinitiator ("CPI-110A" manufactured by San-Apro company, powder (solvent-free)) was added to 73% by weight of bisphenol F type epoxy resin ( "jER 806" manufactured by Mitsubishi Chemical Corporation) and stirred at 80°C to dissolve it. Next, 25% by weight of talc ("P-8" manufactured by Nippon Talc Co., Ltd.) as a flake inorganic compound was added to the bisphenol F-type epoxy resin in which the photoinitiator was dissolved, and kneaded and dispersed by a three-roll machine. . Then, pressure filtration was performed to prepare a sealing material composition.

[Example 3]

2% by weight of triarylsulfonium salt type antimony photoinitiator ("CPI-110A" manufactured by San-Apro company, powder (solvent-free)) was added to 40% by weight of bisphenol F type epoxy resin ( "jER 806" manufactured by Mitsubishi Chemical Corporation) and 20% by weight of phenol novolac type epoxy resin ("N-740" manufactured by DIC Corporation), and stirred at 80°C to dissolve it. Next, 30% by weight of talc ("P-4" manufactured by Nippon Talc Co., Ltd.) and 8% by weight of a silane coupling agent (Shin-Etsu Chemical Co., Ltd.) as an additive were added to the epoxy resin in which the photoinitiator was dissolved. "KBM-403" manufactured by Industrial Co., Ltd.), and kneaded and dispersed by a three-roll machine. Then, pressure filtration was performed to prepare a sealing material composition.

[Example 4]

Add 4% by weight of a triarylsulfonium salt-type borate-based photoinitiator ("CPI-310B" manufactured by San-Apro, powder (solvent-free)) to 51% by weight of bisphenol F-type epoxy Resin (“jER806” manufactured by Mitsubishi Chemical Corporation) was stirred and dissolved at 80°C. Next, 40% by weight of talc ("P-8" manufactured by Nippon Talc Co., Ltd.) and 5% by weight of silane coupling agent (Shin-Etsu Chemical Co., Ltd.) as an additive were added to the epoxy resin in which the photoinitiator was dissolved. "KBM-403" manufactured by Industrial Co., Ltd.), and kneaded and dispersed by a three-roll machine. Then, pressure filtration was performed to prepare a sealing material composition.

[Example 5]

4% by weight of triarylsulfonium salt type antimony photoinitiator ("CPI-110A" manufactured by San-Apro company, powder (solvent-free)) was added to 59% by weight of bisphenol F type epoxy resin ( "jER 806" manufactured by Mitsubishi Chemical Corporation) and 2% by weight of a silane coupling agent ("KBM-403" manufactured by Shin-Etsu Chemical Co., Ltd.) as an additive, and stirred at 80°C to dissolve it. Next, 35% by weight of talc ("FG-15" manufactured by Nippon Talc Co., Ltd.) was added as a flake-shaped inorganic compound to the epoxy resin in which the photoinitiator was dissolved, and kneaded and dispersed by a three-roll mill. Then, pressure filtration was performed to prepare a sealing material composition.

[Comparative Example 1]

63% by weight of bisphenol F-type epoxy resin ("jER 806" manufactured by Mitsubishi Chemical Co., Ltd.), 25% by weight of talc ("FG-15" manufactured by Nippon Talc Co., Ltd.) , 8% by weight of a silane coupling agent ("KBM-403" manufactured by Shin-Etsu Chemical Co., Ltd.) and 4% by weight of a triarylsulfonium salt type liquid antimony photoinitiator ("SP-170 ", containing 50% by weight of solvent) for mixing and dispersing. Then, pressure filtration was performed to prepare a sealing material composition. In addition, the above-mentioned liquid antimony-based photoinitiator is obtained by dissolving a solid photoinitiator in a solvent equal to the weight of the photoinitiator.

[Comparative Example 2]

63% by weight of bisphenol F-type epoxy resin ("jER 806" manufactured by Mitsubishi Chemical Co., Ltd.), 25% by weight of talc ("FG-15" manufactured by Nippon Talc Co., Ltd.) , 8% by weight of a silane coupling agent ("KBM-403" manufactured by Shin-Etsu Chemical Co., Ltd.) as an additive, and a liquid photoinitiator were kneaded and dispersed. A salt-type antimony-based photoinitiator (“CPI-110A” manufactured by San-Apro, powder (solvent-free)) was dissolved in a 2% by weight propylene carbonate solvent (manufactured by Tokyo Chemical Industry Co., Ltd.). Then, pressure filtration was performed to prepare a sealing material composition. In Comparative Example 2, the ratio of the propylene carbonate solvent to the total amount of the propylene carbonate solvent and the photoinitiator was 50% by weight.

[Comparative Example 3]

65% by weight of bisphenol F-type epoxy resin ("jER 806" manufactured by Mitsubishi Chemical Corporation) and 25% by weight of talc ("P-2" manufactured by Nippon Talc Co., Ltd.) , 8% by weight of a silane coupling agent ("KBM-403" manufactured by Shin-Etsu Chemical Co., Ltd.) and 2% by weight of a triarylsulfonium salt type antimony photoinitiator ("CPI- 110A", powder (solvent-free)) for mixing and dispersing. Then, pressure filtration was performed to prepare a sealing material composition.

〔Evaluation results〕

Table 1 shows the evaluation results of Examples and Comparative Examples.

Table 1

First, Example 1 and Comparative Examples 1 and 2 having the same composition except for the photoinitiator were compared. According to Table 1, it can be seen that Example 1 using a solvent-free photoinitiator and Comparative Example 1 using a photoinitiator containing 50% by weight of a solvent, and using a solvent to dissolve a powdery photoinitiator to form a liquid Compared with Comparative Example 2 of the photoinitiator (solvent content in the liquid photoinitiator: 50% by weight), the water vapor transmission rate is lowered, so the water vapor barrier property under high temperature and high humidity is improved. Moreover, compared with Comparative Examples 1 and 2, the glass transition temperature of Example 1 was raised. The same tendency was also found in the comparison between Examples 4 and 5 and Comparative Examples 1 and 2. It can be considered that: compared with Example 1, Example 2 did not add a silane coupling agent, and Example 3 added a phenol novolak type epoxy resin, so the glass transition temperature was further increased, and the water vapor transmission rate was further reduced. In addition, in Comparative Example 3, it is considered that the water vapor transmission rate is increased compared with Example 1 because the average particle diameter of the inorganic compound used is 5.0 μm or more.

【Industrial availability】

One aspect of the present invention is applicable to sealing materials requiring water vapor barrier properties under high temperature and high humidity.

Claims (6)

1. A sealing material composition comprising an epoxy resin, a sheet-like inorganic compound and a photoinitiator,

regarding the sheet-like inorganic compound, an average particle diameter measured by a dynamic light scattering method is 0.5 μm or more and less than 5 μm, an average value of a long diameter/thickness is 1.3 to 50,

the sealant composition is substantially free of solvents that primarily serve the purpose of dissolving the photoinitiator.

2. The sealing material composition according to claim 1, wherein the content of the sheet-like inorganic compound is 20 to 45% by weight.

3. The sealing material composition according to claim 1 or 2, wherein the epoxy resin is an epoxy resin containing a phenol skeleton.

4. The sealing material composition according to claim 1 or 2, wherein the photoinitiator is a composition containing PF ₆ ^－ 、SbF ₆ ^－ 、(Rf) _n PF _6-n ^－ Or B (C) ₆ F ₅ ) ₄ A sulfonium salt or iodonium salt as a counter anion, said Rf being a perfluoroalkyl group, said n being a real number from 1 to 6.

5. The sealing material composition according to claim 1 or 2, further comprising a silane coupling agent having an epoxy group.

6. A sealing material obtained by curing the sealing material composition according to any one of claims 1 to 5.