Encapsulant, encapsulation sheet, electronic device, and perovskite solar cell

Abstract

To provide an encapsulant for an electronic device which can suppress entry of water and can suppress leakage of lead from a lead-containing portion to an outside of an electronic device.SOLUTION: An encapsulant for an electronic device with a lead-containing portion includes an inorganic filler containing one or more kinds selected from a group consisting of semi-baked hydrotalcite and calcined hydrotalcite, and a resin.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to an encapsulant for an electronic device having a lead-containing portion, and an encapsulant sheet, an electronic device, and a perovskite solar cell each using the encapsulant. [Background technology]

[0002] One of the electronic devices that has attracted attention in recent years is the perovskite solar cell. The perovskite solar cell generally includes an electrode and a photoelectric conversion layer containing a perovskite compound. In order to protect the electrode and the photoelectric conversion layer from water, the perovskite solar cell is usually provided with a sealing portion. Various studies have been conducted on such sealing portions (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2018 / 056312 Summary of the Invention [Problem to be solved by the invention]

[0004] The photoelectric conversion layer of a perovskite solar cell may contain lead. If moisture penetrates into this photoelectric conversion layer, lead may flow out of the photoelectric conversion layer and leak out of the solar cell. Such lead leakage may also occur in electronic devices other than perovskite solar cells that include a lead-containing portion such as the photoelectric conversion layer. It is desirable to suppress lead leakage from both environmental and safety perspectives.

[0005] The present invention has been made in view of the above-mentioned problems, and has an object to provide a sealant for electronic devices that can suppress the intrusion of moisture and the leakage of lead from a lead-containing portion to the outside of the electronic device; an encapsulating sheet containing the sealant; and an electronic device and a perovskite solar cell that use the sealant for encapsulation. [Means for solving the problem]

[0006] The present inventors have conducted extensive research to solve the above problems, and as a result, have found that the above problems can be solved by using an appropriate combination of an inorganic filler and a resin, thereby completing the present invention. That is, the present invention includes the following.

[0007] [1] A sealant for an electronic device having a lead-containing part, comprising: the sealant includes an inorganic filler and a resin, The lead adsorption parameter of the sealant is 10 μg / m 2 That's all. The sealant has a water vapor ingress barrier parameter of 0.025 cm / h 0.5 is less than The lead adsorption parameter is the average value of the lead adsorption capacity of the sealant layer per 1 mm when a lead adsorption capacity evaluation test is performed. 2 represents the mass of lead adsorbed per unit area, In the lead adsorption ability evaluation test, the following steps were performed: preparing a first test sheet having a length of 16 cm and a width of 24 cm, the first test sheet including a polyethylene terephthalate film and a layer of the sealant having a thickness of 20 μm formed on the polyethylene terephthalate film; attaching a nylon mesh cloth to the sealant layer side of the first test sheet; cutting the first test sheet with the mesh cloth attached into 1 cm squares; immersing the cut first test sheet in 50 ml of a lead ion-containing aqueous solution having a lead ion concentration of 20 μg / L and adjusted to 20° C. to 25° C., and stirring for 15 minutes; The water vapor barrier property parameter represents a constant K calculated from the following formula (1) when a water vapor barrier property evaluation test is performed: In the water vapor barrier property evaluation test, the following steps were performed: drying a second test sheet comprising a support film comprising an aluminum foil having a thickness of 30 μm and a polyethylene terephthalate film having a thickness of 25 μm, and a layer of the sealant formed on the aluminum foil of the support film; washing a 50 mm square glass plate made of alkali-free glass with boiled isopropyl alcohol for 5 minutes, and drying the glass plate; depositing calcium on one side of the glass plate, excluding an area at a distance of 0 mm to 2 mm from an edge of the glass plate, to form a calcium film having a thickness of 200 nm; and drying the second test sheet in a nitrogen atmosphere. a sealant layer of a glass plate and a surface of the glass plate facing the calcium film to obtain an evaluation sample; measuring a distance X2 [mm] between an end of the evaluation sample and an end of the calcium film; storing the evaluation sample in a thermo-hygrostat chamber at a temperature of 85° C. and a humidity of 85% RH; measuring a time t [hours] from a point in time when the evaluation sample is stored in the thermo-hygrostat chamber to a point in time when the distance X1 [mm] between the end of the evaluation sample stored in the thermo-hygrostat chamber and the end of the calcium film becomes “X2+0.1 mm”; and calculating a constant K based on the following formula (1).

number

[10] A semiconductor device comprising a first electrode, a perovskite layer containing lead atoms, a second electrode, and a sealing part that seals the perovskite layer; The sealing part includes the sealing agent according to any one of [1] to [7]. Effect of the Invention

[0008] According to the present invention, it is possible to provide a sealant for an electronic device that can suppress the intrusion of moisture and the leakage of lead from a lead-containing portion to the outside of the electronic device; an encapsulating sheet including the sealant; and an electronic device and a perovskite solar cell that use the sealant for encapsulation. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view that typically shows an evaluation sample produced in a water vapor barrier property evaluation test. [Diagram 2]FIG. 2 is a plan view that typically shows the evaluation sample as viewed from the glass plate side before it is stored in the thermo-hygrostat. [Diagram 3] FIG. 3 is a plan view that shows a schematic view of the evaluation sample after it has been stored in the thermo-hygrostat, as viewed from the glass plate side. [Figure 4] FIG. 4 is a cross-sectional view that illustrates a schematic example of a perovskite solar cell according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, the present invention will be described in detail with reference to embodiments and examples. However, the present invention is not limited to the embodiments and examples described below, and may be modified and implemented as desired without departing from the scope of the claims and their equivalents.

[0011] [1. Overview of the sealant according to the first embodiment] The sealant according to the first embodiment of the present invention includes an inorganic filler and a resin. The resin usually plays a role of binding and holding the inorganic filler, and may be appropriately referred to as a "binder resin". The sealant according to the present embodiment may further include any component in addition to the inorganic filler and the binder resin. In addition, the sealant according to the present embodiment has a lead adsorption parameter in a specific range. Furthermore, the sealant according to the present embodiment has a water vapor intrusion barrier parameter in a specific range. When used for sealing an electronic device having a lead-containing portion, this sealant can suppress the intrusion of moisture into the lead-containing portion and the leakage of lead from the lead-containing portion to the outside of the electronic device.

[0012] [2. Lead Adsorption Parameter of the Sealant According to the First Embodiment] The lead adsorption parameter of the sealant according to the first embodiment of the present invention is typically 10 μg / m 2 or more, preferably 11 μg / m 2 More preferably, 12 μg / m 2 More preferably, 13 μg / m 2The upper limit of the lead adsorption parameter is preferably as large as possible, for example, 200 μg / m 2 Below, 100μg / m 2 Below, 50μg / m 2 It could be the following, etc.

[0013] The lead adsorption parameter is the amount of lead adsorption that occurs when the following lead adsorption evaluation test is performed on a 1 mm layer of the sealant. 2 represents the mass of lead adsorbed per unit area.

[0014] In the lead adsorption ability evaluation test, the following steps are performed: preparing a first test sheet; attaching a nylon mesh cloth to the sealant layer side of the first test sheet; cutting the first test sheet attached with the mesh cloth into 1 cm squares; immersing the cut first test sheet in 50 ml of a lead ion-containing aqueous solution with a lead ion concentration of 20 μg / L adjusted to 20° C. to 25° C., and stirring for 15 minutes. The first test sheet refers to a sheet having a length of 16 cm and a width of 24 cm, which comprises a polyethylene terephthalate film and a sealant layer with a thickness of 20 μm formed on the polyethylene terephthalate film. The reason for attaching the first test sheet to the mesh cloth in the lead adsorption ability evaluation test is to prevent the first test sheets from sticking to each other in the lead ion-containing aqueous solution. In addition, when the sealant is a thermosetting sealant, the sealant is usually thermally cured at 100° C. for 60 minutes after attaching the mesh cloth, and then cutting the first test sheet.

[0015] Therefore, for example, when the sealant is an adhesive sealant, the lead adsorption ability evaluation test may include the steps of: preparing a first test sheet; attaching a nylon mesh cloth to the sealant layer side of the first test sheet; cutting the first test sheet with the mesh cloth attached into 1 cm squares; and immersing the cut first test sheet in 50 ml of a lead ion-containing aqueous solution with a lead ion concentration of 20 μg / L adjusted to 20°C to 25°C, and stirring for 15 minutes.

[0016] Also, for example, when the sealant is a thermosetting sealant, the lead adsorption ability evaluation test may include the steps of: preparing a first test sheet; attaching a nylon mesh cloth to the sealant layer side of the first test sheet and thermally curing the sealant at 100°C for 60 minutes; cutting the first test sheet with the mesh cloth attached into 1 cm squares; and immersing the cut first test sheet in 50 ml of a lead ion-containing aqueous solution with a lead ion concentration of 20 μg / L adjusted to 20°C to 25°C, and stirring for 15 minutes.

[0017] The mass of lead adsorbed to the sealant layer when the lead adsorption ability evaluation test is performed can be measured using the concentration of lead ions contained in the lead ion-containing aqueous solution. The concentration of lead ions can be measured using a portable scanning lead meter (model name HSA-1000, manufactured by HACH). The specific measurement method can be the method described later in the examples.

[0018] The lead adsorption parameter represents the magnitude of the sealant's ability to adsorb lead. Specifically, the larger the lead adsorption parameter, the greater the sealant's ability to adsorb lead. When a sealant having a lead adsorption parameter within the above range is used to seal a lead-containing portion in an electronic device, it can effectively adsorb lead that leaks out from the lead-containing portion. Thus, it is possible to suppress leakage of lead from the electronic device to the outside. The effect of suppressing lead leakage as described above is beneficial in various situations, such as when storing, transporting, using, and damaging an electronic device.

[0019] The lead adsorption parameter can be adjusted, for example, by the type and amount of inorganic filler.

[0020] [3. Water Vapor Intrusion Barrier Property Parameter of the Sealant According to the First Embodiment] The water vapor ingress barrier parameter of the sealant according to the first embodiment of the present invention is typically 0.025 cm / h 0.5 Less than 0.024cm / h, preferably less than 0.024cm / h 0.5 Less than 0.0230 cm / h, more preferably 0.0230 cm / h 0.5 Less than 0.022 cm / h, more preferably less than 0.022 cm / h 0.5 less than 0.021 cm / h, particularly preferably less than 0.021 cm / h0.5 The lower limit of the water vapor barrier parameter is ideally 0.000 cm / h. 0.5 Above 0.001cm / h 0.5 It may be more than that.

[0021] The water vapor barrier property parameter represents a constant K determined from formula (1) when the following water vapor barrier property evaluation test is performed.

[0022] In the water vapor barrier property evaluation test, the second test sheet is dried; a 50 mm square glass plate made of alkali-free glass is washed with boiled isopropyl alcohol for 5 minutes and dried; calcium is vapor-deposited on the center of one side of the glass plate to form a calcium film having a thickness of 200 nm; the sealant layer of the second test sheet and the surface of the glass plate on the calcium film side are bonded together in a nitrogen atmosphere to obtain an evaluation sample; the sealing distance X2 [mm] of the evaluation sample is measured; the evaluation sample is placed in a constant temperature and humidity chamber at a temperature of 85° C. and a humidity of 85% RH; and at the point T when the evaluation sample is placed in the constant temperature and humidity chamber, P1 From the point T, the sealing distance X1 [mm] of the evaluation sample stored in the temperature and humidity chamber becomes "X2 + 0.1 mm". P2and calculating a constant K based on the following formula (1). In the following description, the time t may be referred to as the "decrease start time t". When the sealant is curable, the sealant layer of the second test sheet is usually attached to the calcium film side of the glass plate, and then the sealant layer is cured to obtain an evaluation sample. The curing conditions may be, for example, the conditions described later in the examples. A specific curing condition may be, for example, 100°C for 60 minutes. In addition, it is preferable to thoroughly dry the second test sheet in the water vapor barrier property evaluation test. A specific drying condition may be at least one of 130°C for 60 minutes and 100°C for 5 minutes. When a water vapor barrier property evaluation test including drying under at least one of the conditions of 130°C for 60 minutes and 100°C for 5 minutes gives a water vapor intrusion barrier property parameter in the above-mentioned range, the sealant can suppress the intrusion of moisture and can suppress the leakage of lead from the lead-containing portion to the outside of the electronic device. In general, when the sealant is an adhesive sealant, drying is performed under the condition of 130°C for 60 minutes. In general, when the sealant is a thermosetting sealant, drying is performed under the condition of 100°C for 5 minutes.

[0023] Therefore, for example, when the sealant is an adhesive sealant, the water vapor barrier property evaluation test includes drying the second test sheet at 130°C for 60 minutes; cleaning a 50 mm square glass plate made of alkali-free glass with boiled isopropyl alcohol for 5 minutes and drying it; depositing calcium on the center of one side of the glass plate to form a calcium film with a thickness of 200 nm; bonding the sealant layer of the second test sheet and the surface of the glass plate on the calcium film side in a nitrogen atmosphere to obtain an evaluation sample; measuring the sealing distance X2 [mm] of the evaluation sample; storing the evaluation sample in a constant temperature and humidity chamber at a temperature of 85°C and a humidity of 85% RH; and measuring the sealing distance T at the time when the evaluation sample was stored in the constant temperature and humidity chamber. P1 From the point T, the sealing distance X1 [mm] of the evaluation sample stored in the temperature and humidity chamber becomes "X2 + 0.1 mm". P2 measuring the decrease start time t [hours] until the start of the decrease; and calculating the constant K based on the following equation (1).

[0024] For example, when the sealant is a thermosetting sealant, the water vapor barrier property evaluation test includes drying the second test sheet at 100°C for 5 minutes; washing a 50 mm square glass plate made of alkali-free glass with boiled isopropyl alcohol for 5 minutes and drying it; depositing calcium on the center of one side of the glass plate to form a calcium film with a thickness of 200 nm; bonding the sealant layer of the second test sheet and the surface of the glass plate on the calcium film side in a nitrogen atmosphere and curing at 100°C for 60 minutes to obtain an evaluation sample; measuring the sealing distance X2 [mm] of the evaluation sample; storing the evaluation sample in a constant temperature and humidity chamber at a temperature of 85°C and a humidity of 85% RH; and measuring the sealing distance T at the time when the evaluation sample was stored in the constant temperature and humidity chamber. P1 From the point T, the sealing distance X1 [mm] of the evaluation sample stored in the temperature and humidity chamber becomes "X2 + 0.1 mm". P2 measuring the decrease start time t [hours] until the start of the decrease; and calculating the constant K based on the following equation (1).

[0025] The second test sheet refers to a sheet comprising a support film comprising an aluminum foil having a thickness of 30 μm and a polyethylene terephthalate film having a thickness of 25 μm, and a layer of a sealant formed on the aluminum foil of the support film. The thickness of the sealant layer may be, for example, 20 μm. The central portion of one side of the glass plate refers to a portion of one side of the glass plate excluding the peripheral area. The peripheral area of ​​one side of the glass plate refers to an area of ​​one side of the glass plate that is 0 mm to 2 mm away from the edge of the glass plate. The sealing distance of the evaluation sample refers to the distance between the edge of the evaluation sample and the edge of the calcium film. The sealing distance usually corresponds to the distance between the edge of the sealant layer and the edge of the calcium film.

[0026]

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[0027] (In formula (1), X1 is the sealing distance [mm] from the end of the evaluation sample to the end of the calcium film after being placed in the thermo-hygrostat; t is the start time [hours] when X1 = X2 + 0.1, X2 is the sealing distance [mm] from the end of the evaluation sample to the end of the calcium film before being placed in the thermo-hygrostat.

[0028] The mechanism of the water vapor barrier property evaluation test and the significance of the constant K as a water vapor barrier property parameter determined by the test will be explained below with reference to the drawings.

[0029] FIG. 1 is a cross-sectional view showing a schematic diagram of an evaluation sample 10 produced in a water vapor barrier property evaluation test. As shown in FIG. 1, the evaluation sample 10 produced in a water vapor barrier property evaluation test includes a square glass plate 100 cleaned with boiled isopropyl alcohol, a calcium film 200 formed on one surface 100U of the glass plate 100, and a second test sheet 300 attached to the surface 100U of the glass plate 100. The calcium film 200 is not formed in a peripheral area 110U of the surface 100U of the glass plate 100, the distance L from the edge 100E of the glass plate 100 being 0 mm to 2 mm. On the other hand, the calcium film 200 is formed in a central portion 120U of the surface 100U of the glass plate 100, excluding the peripheral area 110U. The calcium film 200 is usually formed by deposition using a mask (not shown) that covers the peripheral area 110U, and has a high purity (for example, a purity of 99.8% or more). Furthermore, the second test sheet 300 includes a sealant layer 310 and a support film 320 including a polyethylene terephthalate film 321 and an aluminum foil 322, and the sealant layer 310 is attached to the surface 100U of the glass plate 100. Thus, the calcium film 200 is sealed by the sealant layer 310.

[0030] The glass plate 100 and the support film 320 of the evaluation sample 10 have a sufficiently high moisture blocking ability. Therefore, as shown by arrow A1, moisture around the evaluation sample 10 passes through the end 310E of the sealant layer 310, moves in the in-plane direction (direction perpendicular to the thickness direction) within the sealant layer 310, and can penetrate into the calcium film 200. Therefore, the calcium film 200 of the evaluation sample 10 stored in the thermo-hygrostat can be gradually oxidized from the end 200E toward the center 200C.

[0031] Fig. 2 is a plan view showing a schematic view of evaluation sample 10 from the glass plate 100 side before being stored in a thermo-hygrostat chamber, and Fig. 3 is a plan view showing a schematic view of evaluation sample 10 from the glass plate 100 side after being stored in a thermo-hygrostat chamber. As shown in FIG. 2, in the evaluation sample 10 before being stored in the thermo-hygrostat, oxidation of the calcium film 200 due to the infiltration of moisture does not occur. Therefore, the sealing distance X2 between the end 10E of the evaluation sample 10 and the end 200E of the calcium film 200 can usually maintain the dimension immediately after the formation of the calcium film 200. However, when the evaluation sample 10 is stored in the thermo-hygrostat, moisture can infiltrate into the calcium film 200 through the sealant layer 310 (see FIG. 1), and the calcium in contact with the water can be oxidized to become transparent calcium oxide. Therefore, as shown in FIG. 3, the calcium film 200 can gradually change from the end 200E to the center 200C to a transparent calcium oxide film 210 due to the infiltration of moisture. This change is observed as a shrinkage of the calcium film 200. Therefore, after the evaluation sample 10 is stored in the thermo-hygrostat, the sealing distance X1 between the end 10E of the evaluation sample 10 and the end 200E of the calcium film 200 may gradually increase over time.

[0032] The movement of moisture through the sealant layer 310 generally follows Fick's diffusion law. In the water vapor barrier property evaluation test, the decrease start time t (i.e., the time required for moisture to move the sealing distance X1 in the sealant layer 310 from the time T P1From the point T, the sealing distance X1 [mm] of the evaluation sample 10 stored in the temperature and humidity chamber becomes "X2 + 0.1 mm". P2 The time from the moment the sealing agent reaches the sealing surface to the sealing distance X1 traveled is applied to the Fick diffusion equation represented by equation (1) to derive the constant K as a water vapor barrier property parameter.

[0033] Therefore, the evaluation sample 10 corresponds to a model of an electronic device, and the calcium film 200 corresponds to a lead-containing part to be sealed by a sealant. The water vapor penetration barrier parameter indicates the degree of the ability of the sealant provided in the electronic device to suppress the penetration of moisture in the in-plane direction. Specifically, the smaller the water vapor penetration barrier parameter, the better the sealant's ability to suppress the penetration of moisture. A sealant having a water vapor penetration barrier parameter in the above range can suppress the penetration of moisture into the lead-containing part when used to seal a lead-containing part in an electronic device. Therefore, it can suppress the oxidation of components contained in the lead-containing part and the outflow of lead from the lead-containing part.

[0034] The water vapor infiltration barrier property parameter can be adjusted by, for example, the type and amount of inorganic filler; and the type and amount of binder resin.

[0035] [4. Inorganic filler that may be contained in the sealant according to the first embodiment] The sealant according to the first embodiment of the present invention includes an inorganic filler. A part or all of the inorganic filler can exhibit hygroscopicity and lead adsorption in the sealant as a resin composition containing the inorganic filler and a binder resin. The inorganic filler may be used alone or in combination of two or more types in any ratio. For example, an inorganic filler capable of exhibiting hygroscopicity in the sealant and another inorganic filler capable of exhibiting lead adsorption in the sealant may be used in combination. The present inventors have found for the first time that a lead-adsorbing inorganic filler can exhibit lead adsorption in a sealant as a resin composition containing a binder resin.

[0036] (4.1. Hydrotalcite) Examples of inorganic fillers include hydrotalcite. Hydrotalcite can be classified into uncalcined hydrotalcite, semi-calcined hydrotalcite, and calcined hydrotalcite.

[0037] Uncalcined hydrotalcite is a metal hydroxide having a layered crystal structure, represented by, for example, natural hydrotalcite (Mg6Al2(OH) 16 CO3·4H2O). Uncalcined hydrotalcite consists of, for example, a layer [Mg 1-Xa Al Xa (OH)2] Xa+ and an intermediate layer [(CO3) Xa / 2 ·m a H2O] Xa- where xa represents a number satisfying 0 < xa < 1, and m a represents a positive number. Unless otherwise specified, uncalcined hydrotalcite is a concept encompassing hydrotalcite-like compounds such as synthetic hydrotalcite. Examples of hydrotalcite-like compounds include compounds represented by the following formula (I) or the following formula (II).

[0038] [Mi 2+ 1-xi Mi 3+ xi (OH)2] xi+ ·[(Ai ni- ) xi / ni ·m i H2O] xi- (I) (In formula (I), Mi 2+ represents a divalent metal ion such as Mg 2+ , Zn 2+ , etc., Mi 3+ represents a trivalent metal ion such as Al 3+ , Fe 3+ , etc., Ai ni- represents an ni-valent anion such as CO3 2- , Cl - , NO3 - , etc., xi represents a number satisfying 0 < xi < 1, m i , 0≦m i < 1, ni represents a positive number.)

[0039] In formula (I), Mi 2+ is preferably Mg 2+ Also, Mi 3+ is preferably Al 3+ Furthermore, Ai ni- is preferably CO3 2- Represents.

[0040] Mii 2+ xii Al2(OH) 2xii+6-niizii (Aii nii- ) zii m ii H2O (II) (In the formula (II), Mii 2+ is Mg 2+ , Zn 2+ represents a divalent metal ion such as Aii nii- is CO3 2- , Cl - , NO 3- Represents an anion with a valence of nii, such as xii represents a positive number equal to or greater than 2, zii represents a positive number less than or equal to 2, m ii represents a positive number, nii represents a positive number.)

[0041] In formula (II), Mii 2+ is preferably Mg 2+ Also, Aii nii- is preferably CO3 2- Represents.

[0042] Uncalcined hydrotalcite can exhibit excellent lead adsorption in a sealant. Therefore, for example, when uncalcined hydrotalcite is used in an appropriate combination with an inorganic filler that can exhibit hygroscopicity in a sealant, a sealant having a lead adsorption parameter and a water vapor penetration barrier parameter within the above-mentioned ranges can be obtained.

[0043] The saturated water absorption of uncalcined hydrotalcite is usually less than 1% by mass, and may be less than 0.8% by mass or less than 0.6% by mass. The "saturated water absorption" of hydrotalcite such as uncalcined hydrotalcite refers to the mass increase rate relative to the initial mass when the hydrotalcite is left to stand for 200 hours in an environment of atmospheric pressure, 60°C, and 90% RH (relative humidity). This saturated water absorption can be measured by the following method.

[0044] 1.5 g of hydrotalcite is weighed out on a balance and the initial mass is measured. The weighed hydrotalcite is allowed to stand in a small environmental tester (SH-222 manufactured by ESPEC Corp.) set at atmospheric pressure, 60°C, and 90% RH (relative humidity) for 200 hours to absorb moisture, and the mass after moisture absorption is measured. The saturated water absorption rate is then calculated using the following formula (i). Saturated water absorption rate (mass%) = 100 × (mass after moisture absorption - initial mass) / initial mass (i)

[0045] The thermal weight loss rate of uncalcined hydrotalcite at 280° C. is usually 15% by mass or more, preferably 15.1% by mass or more, and particularly preferably 15.2% by mass or more.

[0046] The thermal weight loss rate of hydrotalcite such as uncalcined hydrotalcite can be measured by thermogravimetric analysis. Thermogravimetric analysis can be performed using a thermal analyzer (TG / DTA EXSTAR6300, Hitachi High-Tech Science Corporation) by weighing 5 mg of hydrotalcite into an aluminum sample pan, leaving it open without a lid, under conditions of a nitrogen flow rate of 200 mL / min and a heating rate of 10°C / min from 30°C to 550°C. The thermal weight loss rate can be calculated from the results of the thermogravimetric analysis using the following formula (ii). Thermal weight loss rate (mass%) = 100 × (mass before heating - mass when reaching a specified temperature) / mass before heating (ii)

[0047] When the powder X-ray diffraction of uncalcined hydrotalcite is measured, it usually has only one peak at 2θ of about 8° to 18°, or the relative intensity ratio between the low-angle diffraction intensity and the high-angle diffraction intensity (low-angle diffraction intensity / high-angle diffraction intensity) is outside the range of 0.001 to 1,000. The low-angle diffraction intensity refers to the diffraction intensity of a peak or shoulder that appears on the low-angle side (the side where 2θ is small). The high-angle diffraction intensity refers to the diffraction intensity of a peak or shoulder that appears on the high-angle side (the side where 2θ is large).

[0048] Powder X-ray diffraction of hydrotalcite such as uncalcined hydrotalcite can be measured using a powder X-ray diffractometer (Empyrean, PANalytical). Powder X-ray diffraction can be measured under the following conditions: anticathode CuKα (1.5405 Å), voltage: 45 V, current: 40 mA, sampling width: 0.0260°, scanning speed: 0.0657° / s, measurement diffraction angle range (2θ): 5.0131 to 79.9711°. Peak search can be performed using the peak search function of the software attached to the diffractometer under the following conditions: "minimum significance: 0.50, minimum peak tip: 0.01°, maximum peak tip: 1.00°, peak base width: 2.00°, method: minimum value of second derivative".

[0049] Examples of uncalcined hydrotalcite include "Almakaiser 1" (average particle size: 620 nm), "Magcera 1" (average particle size: 470 nm), "DHT-4A" (manufactured by Kyowa Chemical Industry Co., Ltd., average particle size: 400 nm), "STABIACE HT-1", "STABIACE HT-7", and "STABIACE HT-P" (Sakai Chemical Industry Co., Ltd.). One type of uncalcined hydrotalcite may be used alone, or two or more types may be used in combination at any ratio.

[0050] Semi-calcined hydrotalcite is a metal hydroxide obtained by calcining uncalcined hydrotalcite and having a layered crystal structure in which the amount of interlayer water is reduced or eliminated. When explained using a composition formula, "interlayer water" refers to "H2O" described in the composition formula of the above-mentioned uncalcined natural hydrotalcite and hydrotalcite-like compound.

[0051] Semi-calcined hydrotalcite can exhibit excellent lead adsorption and moisture absorption in a sealant. Therefore, when semi-calcined hydrotalcite is appropriately used, a sealant having a lead adsorption parameter and a water vapor penetration barrier parameter within the above-mentioned range can be obtained. The inventors were the first to discover that semi-calcined hydrotalcite exhibits lead adsorption.

[0052] Semi-calcined hydrotalcite usually has a different saturated water absorption rate from uncalcined hydrotalcite, so they can be distinguished by the saturated water absorption rate. The saturated water absorption rate of semi-calcined hydrotalcite is usually 1 mass% or more, preferably 3 mass% or more, more preferably 5 mass% or more, and is usually less than 20 mass%. The saturated water absorption rate of semi-calcined hydrotalcite can be measured by the same method as the saturated water absorption rate of uncalcined hydrotalcite.

[0053] Semi-calcined hydrotalcite usually has a different thermal weight loss rate from uncalcined hydrotalcite, so they can be distinguished by the thermal weight loss rate. The thermal weight loss rate of semi-calcined hydrotalcite at 280°C is usually less than 15% by mass, preferably less than 14% by mass, and particularly preferably less than 13% by mass. The thermal weight loss rate of semi-calcined hydrotalcite at 380°C is usually 12% by mass or more, preferably 15% by mass or more, and particularly preferably 16% by mass or more. The thermal weight loss rate of semi-calcined hydrotalcite can be measured by the same method as the thermal weight loss rate of uncalcined hydrotalcite.

[0054] Semi-calcined hydrotalcite usually has different peaks and relative intensity ratios measured by powder X-ray diffraction from uncalcined hydrotalcite, and therefore they can be distinguished by the peaks and relative intensity ratios measured by powder X-ray diffraction. When powder X-ray diffraction of semi-calcined hydrotalcite is measured, it usually shows a peak split into two at 2θ of about 8° to 18°, or a peak having a shoulder due to the synthesis of two peaks, and the relative intensity ratio of the low-angle diffraction intensity to the high-angle diffraction intensity (low-angle diffraction intensity / high-angle diffraction intensity) is 0.001 to 1,000. Powder X-ray diffraction of semi-calcined hydrotalcite can be measured by the same method as powder X-ray diffraction of uncalcined hydrotalcite.

[0055] Examples of semi-calcined hydrotalcite include "DHT-4C" (manufactured by Kyowa Chemical Industry Co., Ltd., average particle size: 400 nm); "DHT-4A-2" (manufactured by Kyowa Chemical Industry Co., Ltd., average particle size: 400 nm); etc. One type of semi-calcined hydrotalcite may be used alone, or two or more types may be used in combination at any ratio.

[0056] Calcined hydrotalcite is obtained by calcining uncalcined hydrotalcite or semi-calcined hydrotalcite, and refers to a metal oxide having an amorphous structure in which not only interlayer water but also hydroxyl groups have disappeared through condensation dehydration.

[0057] Calcined hydrotalcite can exhibit excellent lead adsorption and moisture absorption in a sealant. Therefore, when calcined hydrotalcite is appropriately used, a sealant having a lead adsorption parameter and a water vapor penetration barrier parameter within the above-mentioned range can be obtained. The inventors were the first to discover that calcined hydrotalcite exhibits lead adsorption.

[0058] Calcined hydrotalcite usually has a different saturated water absorption rate from uncalcined hydrotalcite and semi-calcined hydrotalcite, so they can be distinguished by their saturated water absorption rates. The saturated water absorption rate of calcined hydrotalcite is usually 20% by mass or more, preferably 30% by mass or more, and particularly preferably 40% by mass or more. The saturated water absorption rate of calcined hydrotalcite can be measured in the same manner as the saturated water absorption rate of uncalcined hydrotalcite.

[0059] Calcined hydrotalcite usually has a different thermal weight loss rate from uncalcined hydrotalcite and semi-calcined hydrotalcite, so they can be distinguished by the thermal weight loss rate. The thermal weight loss rate of calcined hydrotalcite at 380°C is usually less than 12 mass%, preferably less than 10 mass%, particularly preferably less than 7 mass%. The thermal weight loss rate of calcined hydrotalcite can be measured in the same manner as the thermal weight loss rate of uncalcined hydrotalcite.

[0060] Calcined hydrotalcite usually has different peaks and relative intensity ratios measured by powder X-ray diffraction from uncalcined hydrotalcite and semi-calcined hydrotalcite, so they can be distinguished by the peaks and relative intensity ratios measured by powder X-ray diffraction. When powder X-ray diffraction of calcined hydrotalcite is measured, it usually does not have a characteristic peak in the region of 2θ of 8° to 18°, but has a characteristic peak at 2θ of 43°. The powder X-ray diffraction of calcined hydrotalcite can be measured by the same method as the powder X-ray diffraction of uncalcined hydrotalcite.

[0061] An example of the calcined hydrotalcite is "KW-2200" (manufactured by Kyowa Chemical Industry Co., Ltd., average particle size: 400 nm). One type of calcined hydrotalcite may be used alone, or two or more types may be used in combination at any ratio.

[0062] (4.2. Calcium oxide) Another example of the inorganic filler is calcium oxide. Calcium oxide can exhibit excellent lead adsorption and moisture absorption in the sealant. Therefore, when calcium oxide is used appropriately, a sealant having the lead adsorption parameter and water vapor infiltration barrier parameter in the above-mentioned range can be obtained. The present inventors were the first to discover that calcium oxide exhibits lead adsorption. Calcium oxide may be used in a state of being contained in a mixture with other inorganic fillers. An example of such a mixture is calcined dolomite (a mixture containing calcium oxide and magnesium oxide).

[0063] (4.3. Zeolite) Another example of the inorganic filler is zeolite. Zeolite can exhibit excellent lead adsorption in the sealant. In addition, zeolite can exhibit excellent moisture absorption in the sealant, for example, by appropriately adjusting the composition. Therefore, when zeolite is appropriately used, a sealant having the lead adsorption parameter and water vapor penetration barrier parameter in the above-mentioned ranges can be obtained.

[0064] In order to enhance the hygroscopicity of zeolite, it is preferable that zeolite has high hydrophilicity. The hydrophilicity of zeolite can be adjusted, for example, by the molar ratio of silica and alumina contained in zeolite. The specific molar ratio of silica and alumina (silica / alumina) of zeolite is preferably less than 100, more preferably less than 50, and even more preferably less than 25.

[0065] Zeolite usually has pores. The pore size of the zeolite is preferably adjusted so as to obtain high lead adsorption and hygroscopicity. The pore size of the zeolite is preferably 6 Å or less, more preferably 5 Å or less, and further preferably 4 Å or less. "Å" is expressed as 1.0×10 -10 The pore size of zeolite can be measured by gas adsorption method or mercury intrusion method.

[0066] (4.4. Other examples of inorganic fillers) Further examples of inorganic fillers include hygroscopic metal oxides other than those mentioned above. Examples of such hygroscopic metal oxides include magnesium oxide, strontium oxide, aluminum oxide, and barium oxide. Hygroscopic metal oxides can exhibit excellent hygroscopicity in a sealant. Therefore, for example, when a hygroscopic metal oxide is appropriately combined with an inorganic filler that can exhibit lead adsorption in a sealant, a sealant having a lead adsorption parameter and a water vapor penetration barrier parameter within the above-mentioned ranges can be obtained.

[0067] (4.5. Preferred Inorganic Fillers) Among the above-mentioned examples, semi-calcined hydrotalcite, calcined hydrotalcite, calcium oxide, and zeolite are preferable as the inorganic filler. These can exhibit excellent lead adsorption and moisture absorption in the sealant, and therefore the lead adsorption parameter and water vapor barrier parameter of the sealant can be easily adjusted to the above-mentioned range. Therefore, it is preferable that the sealant contains one or more inorganic fillers selected from the group consisting of semi-calcined hydrotalcite, calcined hydrotalcite, calcium oxide, and zeolite.

[0068] (4.6. Surface treatment of inorganic filler) The inorganic filler may be surface-treated with a suitable surface treatment agent. Unless otherwise specified, the term "inorganic filler" also includes surface-treated fillers. Examples of the surface treatment agent include higher fatty acids, alkylsilane compounds, and silane coupling agents, and higher fatty acids and alkylsilane compounds are preferred. One type of surface treatment agent may be used alone, or two or more types may be used in combination at any ratio.

[0069] Examples of higher fatty acids include higher fatty acids having 18 or more carbon atoms, such as stearic acid, montanic acid, myristic acid, palmitic acid, etc. Among these, stearic acid is preferable.

[0070] Examples of alkylsilane compounds include methyltrimethoxysilane, ethyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane, decyltrimethoxysilane, octadecyltrimethoxysilane, dimethyldimethoxysilane, octyltriethoxysilane, and n-octadecyldimethyl(3-(trimethoxysilyl)propyl)ammonium chloride.

[0071] Examples of the silane coupling agent include epoxy-based silane coupling agents such as 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxypropyl(dimethoxy)methylsilane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; mercapto-based silane coupling agents such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, and 11-mercaptoundecyltrimethoxysilane; 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyldimethoxymethylsilane, N-phenyl-3-aminopropyltrimethoxysilane, N-methylaminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, and N-(2-aminoethyl)-3-aminopropyltrimethoxysilane. Examples of the silane coupling agents include amino-based silane coupling agents such as phenyldimethoxymethylsilane; ureido-based silane coupling agents such as 3-ureidopropyltriethoxysilane; vinyl-based silane coupling agents such as vinyltrimethoxysilane, vinyltriethoxysilane, and vinylmethyldiethoxysilane; styryl-based silane coupling agents such as p-styryltrimethoxysilane; acrylate-based silane coupling agents such as 3-acryloxypropyltrimethoxysilane and 3-methacryloxypropyltrimethoxysilane; isocyanate-based silane coupling agents such as 3-isocyanatepropyltrimethoxysilane; sulfide-based silane coupling agents such as bis(triethoxysilylpropyl)disulfide and bis(triethoxysilylpropyl)tetrasulfide; phenyltrimethoxysilane; methacryloxypropyltrimethoxysilane; imidazole silane; triazine silane; and the like.

[0072] The amount of the surface treatment agent may vary depending on the type of inorganic filler and the surface treatment agent. The amount of the surface treatment agent used for the surface treatment relative to 100 parts by mass of inorganic filler that has not been surface-treated is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, particularly preferably 1.0 parts by mass or more, and preferably 10 parts by mass or less, more preferably 8 parts by mass or less, particularly preferably 6 parts by mass or less. When the surface treatment is performed with the surface treatment agent in the amount within the above range, aggregation can be suppressed and the surface area of ​​the inorganic filler can be increased, so that the inorganic filler can easily exhibit its lead adsorption and moisture absorption properties.

[0073] There is no limitation on the surface treatment method of the inorganic filler, and for example, the surface treatment may be performed by mixing the inorganic filler with a surface treatment agent. In particular, when hydrotalcite such as semi-calcined hydrotalcite is used as the inorganic filler, the surface treatment is preferably performed by, for example, spraying the surface treatment agent while stirring the untreated hydrotalcite with a mixer. The treatment temperature is preferably room temperature. In addition, stirring is preferably performed for 5 to 60 minutes. Examples of the mixer include blenders such as V blenders, ribbon blenders, and bubble cone blenders; mixers such as Henschel mixers and concrete mixers; and mills such as ball mills and cutter mills. In addition, for example, the surface treatment may be performed by pulverizing the hydrotalcite and simultaneously mixing the hydrotalcite with the surface treatment agent.

[0074] (4.7. Particle size of inorganic filler) The average particle size of the inorganic filler is preferably 1 nm or more, more preferably 10 nm or more, even more preferably 100 nm or more, particularly preferably 200 nm or more, and preferably less than 10 μm, more preferably less than 5 μm, even more preferably 1 μm or less, and particularly preferably 800 nm or less. In particular, when hydrotalcite such as semi-calcined hydrotalcite is used as the inorganic filler, the average particle size of the hydrotalcite is preferably 1 nm or more, particularly preferably 10 nm or more, and also preferably 1,000 nm or less, and particularly preferably 800 nm or less. Furthermore, in particular, when zeolite is used as the inorganic filler, the average particle size of the zeolite is preferably 100 nm or more, more preferably 200 nm or more, and also preferably less than 10 μm, and particularly preferably less than 5 μm. When an inorganic filler having an average particle size in such a range is used, the processability of the encapsulant is improved, and the encapsulating sheet can be easily produced.

[0075] The average particle size of the inorganic filler can be determined as the median size of the particle size distribution measured on a volume basis by a laser diffraction / scattering particle size distribution measurement method (JIS Z 8825).

[0076] (4.8. Specific surface area of ​​inorganic filler) The BET specific surface area of ​​the inorganic filler is preferably 1 m 2 / g or more, more preferably 5m 2 / g or more, preferably 250m 2 / g or less, more preferably 200m 2 / g or less. In particular, when the inorganic filler contains hydrotalcite such as semi-calcined hydrotalcite, the hydrotalcite preferably has a BET specific surface area in the above range. When an inorganic filler having a BET specific surface area in such a range is used, the processability of the encapsulant becomes good, and the encapsulating sheet can be easily produced.

[0077] The BET specific surface area of ​​the inorganic filler can be calculated according to the BET method by adsorbing nitrogen gas onto the surface of a sample using a specific surface area measuring device (Macsorb HM Model 1210, manufactured by Mountech Co., Ltd.) and using the BET multipoint method.

[0078] (4.9. Amount of inorganic filler) The amount of the inorganic filler is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 20% by mass or more, particularly preferably 25% by mass or more, and is preferably 80% by mass or less, more preferably 75% by mass or less, even more preferably 70% by mass or less, for example, 65% by mass or less, or 60% by mass or less, based on 100% by mass of the non-volatile components of the sealant. When the amount of the inorganic filler is equal to or greater than the lower limit of the above range, the lead adsorption and hygroscopic properties of the inorganic filler are significantly exhibited, so that it is easy to adjust the lead adsorption parameter and water vapor intrusion barrier parameter of the sealant to the above range. When the amount of the inorganic filler is equal to or less than the upper limit of the above range, the viscosity and wettability of the sealant can be improved, so that the adhesion between the sealant and the object to be sealed, such as a lead-containing part or an electrode, can be improved. Therefore, the formation of a gap between the object to be sealed and the sealant can be effectively suppressed, and therefore the sealing property can be improved, so that the intrusion of moisture and the leakage of lead can be particularly effectively suppressed.

[0079] [5. Overview of Components Other than Inorganic Filler That May Be Contained in the Sealant According to the First Embodiment] The sealant according to the first embodiment of the present invention contains a binder resin in combination with the inorganic filler described above. The binder resin can exert some or all of the following functions: a function to prevent foreign matter such as dust from entering the electronic device, a function to hold the inorganic filler so that it does not come off the sealing portion, a function to make the sealant adhere to the sealing target such as a lead adsorption portion, a function to prevent moisture from entering, etc.

[0080] The sealant according to the first embodiment of the present invention may contain an optional component in combination with the inorganic filler and the binder resin. The types and ratios of the binder resin and the optional components can be appropriately selected depending on the type and amount of the inorganic filler and the properties required for the sealant.

[0081] Hereinafter, the binder resin and optional components will be described using components suitable for an adhesive sealant and a thermosetting sealant as examples. An adhesive sealant refers to a type of sealant that exhibits adhesiveness and can seal an object to be sealed by pressure bonding. An adhesive sealant can usually function as a pressure-sensitive adhesive since it can be bonded by applying pressure for a relatively short time at room temperature. A thermosetting sealant refers to a type of sealant that can achieve sealing by thermally curing the sealant in contact with an object to be sealed. However, the components contained in the sealant are not limited to the examples described below. Therefore, the components shown as examples suitable for an adhesive sealant may be used for other sealants (for example, a thermosetting sealant). The components shown as examples suitable for a thermosetting sealant may be used for other sealants (for example, an adhesive sealant).

[0082] [6. Description of components suitable for the pressure-sensitive adhesive sealant according to the first embodiment] (6.1. Thermoplastic resin as binder resin) An example of a component that the sealant may contain in combination with the inorganic filler is a thermoplastic resin. The thermoplastic resin is preferable as a binder resin for the adhesive sealant. The thermoplastic resin may be used alone or in combination of two or more kinds in any ratio.

[0083] The thermoplastic resin is not particularly limited, and for example, a thermoplastic resin described later as a binder resin suitable for a thermosetting sealant may be used. Among them, a preferred example of the thermoplastic resin is a polyolefin resin. When the polyolefin resin is combined with an inorganic filler containing at least one selected from the group consisting of semi-calcined hydrotalcite, calcined hydrotalcite, and calcium oxide, a sealant having excellent transparency can be obtained.

[0084] As the polyolefin resin, a resin having a skeleton derived from an olefin monomer can be used. As the polyolefin resin, for example, polyolefin resins described in WO 2011 / 62167 and WO 2013 / 108731 can be mentioned. Among them, isobutylene-modified resins described in WO 2011 / 62167 and styrene-isobutylene-modified resins described in WO 2013 / 108731 are preferred. Furthermore, as preferred polyolefin resins, for example, polyethylene resins, polypropylene resins, polybutene resins, and polyisobutylene resins can be mentioned. The polyolefin resin may be a homopolymer or a copolymer. Furthermore, the copolymer may be a random copolymer or a block copolymer.

[0085] The copolymer may be a copolymer of two or more kinds of olefins, or a copolymer of an olefin and a monomer other than an olefin, such as a non-conjugated diene, styrene, etc. Preferred examples of the copolymer include an ethylene-non-conjugated diene copolymer, an ethylene-propylene copolymer, an ethylene-propylene-non-conjugated diene copolymer, an ethylene-butene copolymer, a propylene-butene copolymer, a propylene-butene-non-conjugated diene copolymer, a styrene-isobutylene copolymer, and a styrene-isobutylene-styrene copolymer.

[0086] The polyolefin resin may contain a polyolefin resin having an acid anhydride group (i.e., a carbonyloxycarbonyl group (-CO-O-CO-)). When a polyolefin resin having an acid anhydride group is used, the adhesiveness and moist heat resistance of the sealant can be improved.

[0087] Examples of the acid anhydride group include a group derived from succinic anhydride, a group derived from maleic anhydride, and a group derived from glutaric anhydride. The type of acid anhydride group may be one type or two or more types. The polyolefin resin having an acid anhydride group can be produced, for example, by graft-modifying a polyolefin resin with an unsaturated compound having an acid anhydride group under radical reaction conditions. The polyolefin resin having an acid anhydride group can also be produced, for example, by radical copolymerizing an unsaturated compound having an acid anhydride group with an olefin.

[0088] The concentration of the acid anhydride group in the polyolefin resin having the acid anhydride group is preferably 0.05 mmol / g or more, more preferably 0.1 mmol / g or more, and preferably 10 mmol / g or less, more preferably 5 mmol / g or less. The concentration of the acid anhydride group is obtained from the acid value, which is defined as the number of milligrams of potassium hydroxide required to neutralize the acid present in 1 g of the resin, according to the description of JIS K 2501.

[0089] The amount of polyolefin resin having an acid anhydride group, relative to the total amount of polyolefin resins (100% by mass), is preferably 0% by mass or more, more preferably 10% by mass or more, and particularly preferably 11% by mass or more, and is preferably 70% by mass or less, more preferably 50% by mass or less, and particularly preferably 40% by mass or less.

[0090] The polyolefin resin may contain a polyolefin resin having an epoxy group. When a polyolefin resin having an epoxy group is used, the adhesiveness and moist heat resistance of the sealant can be improved.

[0091] Polyolefin resins having epoxy groups can be produced by, for example, graft-modifying polyolefin resins with unsaturated compounds having epoxy groups, such as glycidyl (meth)acrylate, 4-hydroxybutyl acrylate glycidyl ether, and allyl glycidyl ether, under radical reaction conditions. Here, the term "glycidyl (meth)acrylate" includes both glycidyl acrylate and glycidyl methacrylate. Polyolefin resins having epoxy groups can also be produced by, for example, radical copolymerization of unsaturated compounds having epoxy groups with olefins.

[0092] The epoxy group concentration in the polyolefin resin having epoxy groups is preferably 0.05 mmol / g or more, more preferably 0.1 mmol / g or more, and preferably 10 mmol / g or less, more preferably 5 mmol / g or less. The epoxy group concentration is determined from the epoxy equivalent obtained based on JIS K 7236-1995.

[0093] The amount of polyolefin-based resin having an epoxy group, relative to the total amount of polyolefin-based resins (100% by mass), is preferably 0% by mass or more, more preferably 10% by mass or more, and particularly preferably 11% by mass or more, and is preferably 70% by mass or less, more preferably 50% by mass or less, and particularly preferably 30% by mass or less.

[0094] The polyolefin resin may be used alone or in combination of two or more kinds at any ratio. In particular, it is preferable to use a polyolefin resin having an acid anhydride group in combination with a polyolefin resin having an epoxy group. When a polyolefin resin having an acid anhydride group in combination with a polyolefin resin having an epoxy group is used, a crosslinked structure can be formed by the reaction between the acid anhydride group and the epoxy group, so that the ability of the sealant to suppress the penetration of moisture can be effectively improved. In this case, the molar ratio of the epoxy group to the acid anhydride group (epoxy group:acid anhydride group) is preferably 100:10 to 100:400, more preferably 100:50 to 100:200, and particularly preferably 100:90 to 100:150.

[0095] Specific examples of polyolefin resins will be described below. Specific examples of polyisobutylene resins include BASF's "OPPANOL B100" (viscosity average molecular weight: 1,110,000) and BASF's "B50SF" (viscosity average molecular weight: 400,000).

[0096] Specific examples of polybutene resins include "HV-1900" manufactured by JX Nippon Oil & Energy Corporation (polybutene, number average molecular weight: 2,900) and "HV-300M" manufactured by Toho Chemical Industry Co., Ltd. (maleic anhydride modified liquid polybutene (modified product of "HV-300" (number average molecular weight: 1,400)), number average molecular weight: 2,100, number of carboxy groups constituting the acid anhydride group: 3.2 / molecule, acid value: 43.4 mgKOH / g, acid anhydride group concentration: 0.77 mmol / g).

[0097] Specific examples of styrene-isobutylene copolymers include Kaneka's "SIBSTAR T102" (styrene-isobutylene-styrene block copolymer, number average molecular weight: 100,000, styrene content: 30% by mass), Seiko PMC's "T-YP757B" (maleic anhydride-modified styrene-isobutylene-styrene block copolymer, acid anhydride group concentration: 0.464 mmol / g, number average molecular weight: 100,000), Seiko PMC's "T-YP766" (glycidyl methacrylate-modified styrene-isobutylene-styrene block copolymer, epoxy Examples of the epoxy group concentration include "T-YP8920" manufactured by Seiko PMC (maleic anhydride-modified styrene-isobutylene-styrene copolymer, acid anhydride group concentration: 0.464 mmol / g, number average molecular weight: 35,800), and "T-YP8930" manufactured by Seiko PMC (glycidyl methacrylate-modified styrene-isobutylene-styrene copolymer, epoxy group concentration: 0.638 mmol / g, number average molecular weight: 48,700).

[0098] Specific examples of polyethylene-based resins or polypropylene-based resins include Mitsui Chemicals' "EPT X-3012P" (ethylene-propylene-5-ethylidene-2-norbornene copolymer), Mitsui Chemicals' "EPT1070" (ethylene-propylene-dicyclopentadiene copolymer), and Mitsui Chemicals' "TAFMER A4085" (ethylene-butene copolymer).

[0099] Specific examples of propylene-butene copolymers include "T-YP341" manufactured by Seiko PMC (glycidyl methacrylate modified propylene-butene random copolymer, amount of butene units per 100% by mass of propylene units and butene units: 29% by mass, epoxy group concentration: 0.638 mmol / g, number average molecular weight: 155,000), and "T-YP279" manufactured by Seiko PMC (maleic anhydride modified propylene-butene random copolymer, amount of butene units per 100% by mass of propylene units and butene units: 36% by mass, acid anhydride group concentration: 0.464mmol / g, number average molecular weight: 35,000), Seiko PMC's "T-YP276" (glycidyl methacrylate modified propylene-butene random copolymer, amount of butene units per 100% by mass of propylene units and butene units: 36% by mass, epoxy group concentration: 0.638mmol / g, number average molecular weight: 57,000), Seiko PMC's "T-YP312" (maleic anhydride modified propylene-butene random copolymer, amount of butene units per 100% by mass of propylene units and butene units: 29% by mass, acid anhydride Epoxy group concentration: 0.464mmol / g, number average molecular weight: 60,900), Seiko PMC's "T-YP313" (glycidyl methacrylate modified propylene-butene random copolymer, amount of butene units per 100% by mass of propylene units and butene units: 29% by mass, epoxy group concentration: 0.638mmol / g, number average molecular weight: 155,000), Seiko PMC's "T-YP429" (maleic anhydride modified ethylene-methyl methacrylate copolymer, amount of methyl methacrylate per 100% by mass of ethylene units and methyl methacrylate units: 29% by mass, epoxy group concentration: 0.638mmol / g, number average molecular weight: 155,000). Amount of acrylate units: 32% by mass, acid anhydride group concentration: 0.46 mmol / g, number average molecular weight: 2,300), Seiko PMC's "T-YP430" (maleic anhydride modified ethylene-methyl methacrylate copolymer, amount of methyl methacrylate units per 100% by mass of ethylene units and methyl methacrylate units: 32% by mass, acid anhydride group concentration: 1.18 mmol / g, number average molecular weight: 4,500), Seiko PMC's "T-YP431" (glycidyl methacrylate modified ethylene-methyl methacrylate copolymer, epoxy group concentration: 0.64mmol / g, number average molecular weight: 2,400) and Seiko PMC's "T-YP432" (glycidyl methacrylate modified ethylene-methyl methacrylate copolymer, epoxy group concentration: 1.63mmol / g, number average molecular weight: 3,100).

[0100] The number average molecular weight of the thermoplastic resin is preferably 1,000 or more, more preferably 3,000 or more, even more preferably 5,000 or more, even more preferably 10,000 or more, even more preferably 30,000 or more, and particularly preferably 50,000 or more. When using a thermoplastic resin having a number average molecular weight in such a range, repelling during application of the sealant varnish can be suppressed, so that the ability of the sealing part to suppress the intrusion of moisture can be effectively improved and the mechanical strength of the sealing part can be improved. In addition, the number average molecular weight of the thermoplastic resin is preferably 1,000,000 or less, more preferably 800,000 or less, even more preferably 700,000 or less, even more preferably 600,000 or less, even more preferably 500,000 or less, even more preferably 450,000 or less, and particularly preferably 400,000 or less. When a thermoplastic resin having a number average molecular weight in such a range is used, the coatability of the sealant varnish can be improved, and the compatibility of the thermoplastic resin with other components can be improved.

[0101] The number average molecular weight can be measured in terms of polystyrene by gel permeation chromatography (GPC). Specifically, the number average molecular weight by GPC is measured at a column temperature of 40° C. using Shimadzu Corporation's LC-9A / RID-6A as a measuring device, Showa Denko Corporation's Shodex K-800P / K-804L / K-804L as a column, and toluene or the like as a mobile phase, and can be calculated using a calibration curve of standard polystyrene.

[0102] The weight average molecular weight of the thermoplastic resin is usually greater than 5,000, preferably 8,000 or more, more preferably 10,000 or more, even more preferably 15,000 or more, particularly preferably 20,000 or more, and preferably 1,000,000 or less, more preferably 800,000 or less, even more preferably 600,000 or less, particularly preferably 500,000 or less.

[0103] The weight average molecular weight can be measured in terms of polystyrene by gel permeation chromatography (GPC). Specifically, the weight average molecular weight by GPC is measured at a column temperature of 40° C. using a measuring device LC-9A / RID-6A manufactured by Shimadzu Corporation, a column Shodex K-800P / K-804L / K-804L manufactured by Showa Denko K.K., and chloroform or the like as a mobile phase, and can be calculated using a calibration curve of standard polystyrene.

[0104] The thermoplastic resin is preferably amorphous. Amorphous means that the resin does not have a clear melting point. Specifically, amorphous means that no clear peak is observed when the melting point is measured by DSC (differential scanning calorimetry). When a thermoplastic resin having amorphous properties is used, the thickening of the varnish of the sealant can be suppressed, and the flowability of the varnish can be improved.

[0105] The amount of the thermoplastic resin is preferably 1% by mass or more, more preferably 3% by mass or more, more preferably 5% by mass or more, more preferably 7% by mass or more, more preferably 10% by mass or more, more preferably 15% by mass or more, and particularly preferably 20% by mass or more, based on 100% by mass of the non-volatile components of the sealant. When the amount of the thermoplastic resin is in such a range, the ability of the sealant to suppress the intrusion of moisture can be effectively increased, and the transparency of the sealant can be improved. Furthermore, based on 100% by mass of the non-volatile components of the sealant, the amount of the thermoplastic resin is preferably 80% by mass or less, more preferably 75% by mass or less, more preferably 70% by mass or less, more preferably 60% by mass or less, more preferably 55% by mass or less, and particularly preferably 50% by mass or less. When the amount of the thermoplastic resin is in such a range, the coatability and compatibility of the sealant varnish are improved, so that the ability of the sealant to suppress the intrusion of moisture can be effectively increased, and the handleability of the sealant can be improved (for example, suppression of tackiness) can be achieved.

[0106] The amount of the thermoplastic resin is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, particularly preferably 30 parts by mass or more, and preferably 300 parts by mass or less, more preferably 200 parts by mass or less, and particularly preferably 150 parts by mass or less, relative to 100 parts by mass of the inorganic filler. In particular, when the thermoplastic resin contains a polyolefin resin having an acid anhydride group, the amount of the polyolefin resin having an acid anhydride group is preferably 1 part by mass or more, preferably 3 parts by mass or more, particularly preferably 5 parts by mass or more, and preferably 30 parts by mass or less, more preferably 25 parts by mass or less, and particularly preferably 23 parts by mass or less, relative to 100 parts by mass of the inorganic filler. In addition, when the thermoplastic resin contains a polyolefin resin having an epoxy group, the amount of the polyolefin resin having an epoxy group is preferably 1 part by mass or more, preferably 2 parts by mass or more, particularly preferably 3 parts by mass or more, and preferably 30 parts by mass or less, more preferably 28 parts by mass or less, and particularly preferably 26 parts by mass or less, relative to 100 parts by mass of the inorganic filler. In particular, when the inorganic filler is semi-calcined hydrotalcite, it is desirable that the mass ratio of the semi-calcined hydrotalcite to the thermoplastic resin satisfies the above-mentioned requirement. When the thermoplastic resin is used in such an amount, the sealant can particularly effectively suppress the intrusion of moisture and the leakage of lead.

[0107] (6.2. Tackifiers) An example of a component that the sealant may contain in combination with the inorganic filler is a tackifier. A tackifier is a compound that can improve the adhesion of the sealant when used in combination with a plastic resin, and is also called a "tackifier." Tackifiers are suitable for adhesive sealants, and are therefore preferably used in combination with a thermoplastic resin. The tackifier may be used alone or in combination of two or more types in any ratio.

[0108] Examples of tackifying resins include terpene resins, modified terpene resins (hydrogenated terpene resins, terpene-phenol copolymer resins, aromatic modified terpene resins, etc.), coumarone resins, indene resins, and petroleum resins (aliphatic petroleum resins, hydrogenated hydrocarbon petroleum resins, aromatic petroleum resins, aliphatic-aromatic copolymer petroleum resins, dicyclopentadiene petroleum resins and hydrogenated versions thereof).

[0109] Among the above examples, petroleum resins are preferred from the viewpoints of the adhesiveness of the sealant, the ability to inhibit moisture penetration, transparency, etc. Examples of petroleum resins include aliphatic petroleum resins, aromatic petroleum resins, aliphatic aromatic copolymer petroleum resins, and hydrogenated hydrocarbon petroleum resins. From the viewpoints of adhesiveness, the ability to inhibit moisture penetration, and compatibility, aromatic petroleum resins, aliphatic aromatic copolymer petroleum resins, hydrogenated hydrocarbon petroleum resins, dicyclopentadiene petroleum resins, and hydrogenated products thereof are more preferred. Furthermore, from the viewpoint of transparency, hydrogenated hydrocarbon petroleum resins and hydrogenated products of dicyclopentadiene petroleum resins are particularly preferred.

[0110] The hydrogenated hydrocarbon petroleum resin may be one obtained by hydrogenating an aromatic petroleum resin. In this case, the hydrogenation rate of the hydrogenated hydrocarbon petroleum resin is preferably 30% to 99%, more preferably 40% to 97%, and even more preferably 50% to 90%. A hydrogenated hydrocarbon petroleum resin having a hydrogenation rate within the above range has little coloring, is excellent in transparency, and can be produced at low production costs. The hydrogenation rate is the ratio of hydrogen in the aromatic ring before and after hydrogenation. 1 It can be determined from the ratio of H-NMR peak intensities.

[0111] As the hydrogenated hydrocarbon petroleum resin, in particular, cyclohexane ring-containing hydrogenated petroleum resin and dicyclopentadiene-based hydrogenated petroleum resin are preferred.

[0112] Specific examples of petroleum resins will be described below. Examples of terpene resins include YS Resin PX1000, YS Resin PX1150, YS Resin PX1150N, YS Resin PX1250, YS Resin TH130, and YS Resin TR105 (all manufactured by Yasuhara Chemical Co., Ltd.). Examples of aromatic modified terpene resins include YS Resin TO85, YS Resin TO105, YS Resin TO115, and YS Resin TO125 (all manufactured by Yasuhara Chemical Co., Ltd.). Examples of hydrogenated terpene resins include Clearon P, Clearon M, and Clearon K series (all manufactured by Yasuhara Chemical Co., Ltd.). Examples of the terpene phenol copolymer resin include YS Polystar 2000, Polystar U, Polystar T, Polystar S, and Mighty Ace G (all manufactured by Yasuhara Chemical Co., Ltd.). Examples of liquid resins include YS Resin LP and YS Resin CP (both manufactured by Yasuhara Chemical Co., Ltd.). Examples of hydrocarbon resins include T-REZ RB093, T-REZ RC100, T-REZ RC115, T-REZ RC093, T-REZ RE100 (all manufactured by JXTG Nippon Oil & Energy Corporation); Petrotac 60, Petrotac 70, Petrotac 90, Petrotac 90HS, Petrotac 90V, Petrotac 100V (all manufactured by Tosoh Corporation). Examples of hydrogenated hydrocarbon petroleum resins include Escorez 5300 series and 5600 series (all manufactured by Exxon Mobil Corporation); T-REZ OP501, T-REZ PR801, T-REZ PR803, T-REZ HA085, T-REZ HA103, T-REZ HA105, T-REZ HA125, T-REZ HB103, and T-REZ HB125 (all hydrogenated dicyclopentadiene-based petroleum resins manufactured by JXTG Nippon Oil & Energy Corporation); Quintone 1325 and Quintone 1345 (all manufactured by Zeon Corporation); Imave S-100, Imave S-110, Imave P-100, Imave P-125, and Imave P-140 (all hydrogenated dicyclopentadiene-based petroleum resins manufactured by Idemitsu Kosan Co., Ltd.). Examples of aromatic petroleum resins include ENDEX155 (manufactured by Eastman Co.); Neopolymer L-90, Neopolymer 120, Neopolymer 130, Neopolymer 140, Neopolymer 150, Neopolymer 170S, Neopolymer 160, Neopolymer E-100, Neopolymer E-130, Neopolymer M-1, Neopolymer S, Neopolymer S100, Neopolymer 120S, Neopolymer 130S, Neopolymer EP-140 (all manufactured by JXTG Nippon Oil & Energy Corporation), Petocol LX, Petocol 120, Petocol 130, and Petocol 140 (all manufactured by Tosoh Corporation). Examples of the aliphatic aromatic copolymer petroleum resin include Quintone D100 (manufactured by Zeon Corporation), T-REZ RD104, and T-REZ PR802 (manufactured by JXTG Nippon Energy Corporation). Examples of cyclohexane ring-containing hydrogenated petroleum resins include Arcon P-90, Arcon P-100, Arcon P-115, Arcon P-125, Arcon P-140, Arcon M-90, Arcon M-100, Arcon M-115, and Arcon M-135 (all manufactured by Arakawa Chemical Industries, Ltd.). An example of the cyclohexane ring-containing saturated hydrocarbon resin is TFS13-030 (manufactured by Arakawa Chemical Industries, Ltd.). Examples of ultra-light-colored rosin resins include Pine Crystal ME-H, Pine Crystal ME-D, Pine Crystal ME-G, Pine Crystal KR-85, Pine Crystal KE-311, Pine Crystal KE-359, Pine Crystal D-6011, Pine Crystal PE-590, Pine Crystal KE-604, and Pine Crystal PR-580 (all manufactured by Arakawa Chemical Industries, Ltd.).

[0113] The number average molecular weight of the tackifier is preferably from 100 to 2,000, more preferably from 700 to 1,500, and even more preferably from 500 to 1,000.

[0114] The softening point of the tackifier is preferably 50° C. to 200° C., more preferably 90° C. to 180° C., and further preferably 100° C. to 150° C. The softening point can be measured by a ring and ball method in accordance with JIS K2207. When a tackifier having such a softening point is used, sealing using a sealing sheet with a sealant can be facilitated, and the heat resistance of the sealant can be improved.

[0115] The amount of the tackifier is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more, based on 100% by mass of the non-volatile components of the sealant. When the amount of the tackifier is within such a range, the adhesiveness of the sealant can be effectively increased. Furthermore, the amount of the tackifier is preferably 80% by mass or less, more preferably 60% by mass or less, even more preferably 50% by mass or less, and particularly preferably 40% by mass or less, based on 100% by mass of the non-volatile components of the sealant. When the amount of the tackifier is within such a range, the ability of the sealant to suppress the intrusion of moisture can be effectively increased.

[0116] (6.3. Crosslinking Agents and Crosslinking Accelerators) Examples of components that the sealant may contain in combination with the inorganic filler include a crosslinking agent and a crosslinking accelerator. The crosslinking agent and the crosslinking accelerator may react with reactive groups of other components to form a crosslinked structure. For example, when a thermoplastic resin has reactive groups such as an acid anhydride group and an epoxy group, the crosslinking agent and the crosslinking accelerator may react with the reactive groups to form a crosslinked structure. However, the crosslinking agent and the crosslinking accelerator do not include the above-mentioned thermoplastic resin and tackifier. The crosslinking agent and the crosslinking accelerator may be used alone or in combination of two or more types in any ratio.

[0117] Examples of the crosslinking agent and the crosslinking accelerator include amine-based compounds, guanidine-based compounds, imidazole-based compounds, phosphonium-based compounds, and phenol-based compounds.

[0118] Examples of the amine compounds include quaternary ammonium salts such as tetramethylammonium bromide and tetrabutylammonium bromide; diazabicyclo compounds such as DBU (1,8-diazabicyclo[5.4.0]undecene-7), DBN (1,5-diazabicyclo[4.3.0]nonene-5), DBU-phenol salt, DBU-octylate salt, DBU-p-toluenesulfonate, DBU-formate salt, and DBU-phenol novolac resin salt; tertiary amines and salts thereof such as benzyldimethylamine, 2-(dimethylaminomethyl)phenol, and 2,4,6-tris(diaminomethyl)phenol; and dimethylurea compounds such as aromatic dimethylurea, aliphatic dimethylurea, and aromatic dimethylurea.

[0119] Examples of guanidine compounds include dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1-(o-tolyl)guanidine, dimethylguanidine, diphenylguanidine, trimethylguanidine, tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 1-methylbiguanide, 1-ethylbiguanide, 1-n-butylbiguanide, 1-n-octadecylbiguanide, 1,1-dimethylbiguanide, 1,1-diethylbiguanide, 1-cyclohexylbiguanide, 1-allylbiguanide, 1-phenylbiguanide, and 1-(o-tolyl)biguanide.

[0120] Examples of imidazole compounds include 1H-imidazole, 2-methyl-imidazole, 2-phenyl-4-methylimidazole, 1-cyanoethyl-2-ethyl-4-methyl-imidazole, 2-phenyl-4,5-bis(hydroxymethyl)-imidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 2-ethyl-4-methylimidazole, 2-phenyl-imidazole, 2-dodecyl-imidazole, 2-heptadecylimidazole, and 1,2-dimethyl-imidazole.

[0121] Examples of phosphonium compounds include triphenylphosphine, phosphonium borate compounds, tetraphenylphosphonium tetraphenylborate, n-butylphosphonium tetraphenylborate, tetrabutylphosphonium decanoate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, and butyltriphenylphosphonium thiocyanate.

[0122] Examples of the types of phenolic compounds include MEH-7700, MEH-7810, MEH-7851 (manufactured by Meiwa Kasei Co., Ltd.), NHN, CBN, GPH (manufactured by Nippon Kayaku Co., Ltd.), SN170, SN180, SN190, SN475, SN485, SN495, SN375, SN395 (manufactured by Tohto Kasei Co., Ltd.), and TD2090 (manufactured by DIC Corporation). In particular, specific examples of triazine skeleton-containing phenolic compounds include LA3018 (manufactured by DIC Corporation). Specific examples of triazine skeleton-containing phenolic novolac compounds include LA7052, LA7054, and LA1356 (manufactured by DIC Corporation).

[0123] Examples of the crosslinking agent include resins having functional groups that can react with acid anhydride groups. Examples of the functional groups that can react with acid anhydride groups include hydroxyl groups, primary or secondary amino groups, thiol groups, epoxy groups, oxetane groups, etc., and epoxy groups are preferred. Examples of the resins having functional groups that can react with acid anhydride groups include resins described in International Publication No. WO 2017 / 057708.

[0124] Examples of the crosslinking agent include resins having functional groups that can react with epoxy groups. Examples of the functional groups that can react with epoxy groups include hydroxyl groups, phenolic hydroxyl groups, amino groups, carboxyl groups, and acid anhydride groups, with acid anhydride groups being preferred. Examples of the acid anhydride groups include groups derived from succinic anhydride, groups derived from maleic anhydride, and groups derived from glutaric anhydride. Examples of the resins having functional groups that can react with epoxy groups include resins described in International Publication No. WO 2017 / 057708.

[0125] Furthermore, if any of the curing agents described below can react with a reactive group contained in a component of the sealing agent, that curing agent may be used as a crosslinking agent or crosslinking accelerator.

[0126] The amount of the crosslinking agent and the crosslinking accelerator is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, and particularly preferably 0.02% by mass or more, based on 100% by mass of the non-volatile components of the sealant. When the amount of the crosslinking agent and the crosslinking accelerator is within such a range, the handleability of the sealant can be improved (for example, tackiness can be suppressed). Furthermore, the amount of the crosslinking agent and the crosslinking accelerator is preferably 5% by mass or less, more preferably 2.5% by mass or less, based on 100% by mass of the non-volatile components of the sealant. When the amount of the crosslinking agent and the crosslinking accelerator is within such a range, the ability of the sealant to suppress the intrusion of moisture can be effectively improved.

[0127] (6.4. Other ingredients suitable for adhesive sealants) Among the components that the sealant may contain, an example of a component suitable for an adhesive sealant is a plasticizer. The plasticizer can improve the flexibility and moldability of the sealant. The plasticizer is preferably a material that is liquid at room temperature (25°C). Examples of the plasticizer include mineral oils such as paraffin-based process oil, naphthene-based process oil, liquid paraffin, polyethylene wax, polypropylene wax, and Vaseline, vegetable oils such as castor oil, cottonseed oil, rapeseed oil, soybean oil, palm oil, coconut oil, and olive oil, and liquid poly-α-olefin compounds such as liquid polybutene, hydrogenated liquid polybutene, liquid polybutadiene, and hydrogenated liquid polybutadiene. The weight average molecular weight of the plasticizer is preferably 500 to 5,000, more preferably 1,000 to 3,000, from the viewpoint of adhesiveness. One type of plasticizer may be used alone, or two or more types may be used in combination at any ratio. The amount of the plasticizer is preferably 50% by mass or less relative to 100% by mass of the non-volatile components in the sealant.

[0128] Among the components that the sealant may contain, examples of components suitable for adhesive sealants include resins other than those mentioned above (e.g., epoxy resins, urethane resins, acrylic resins, polyamide resins, etc.); organic fillers such as rubber particles, silicone powders, nylon powders, and fluororesin powders; thickeners such as Orben and Bentone; silicone-based, fluorine-based, and polymer-based defoamers or leveling agents; adhesion-imparting agents such as triazole compounds, thiazole compounds, triazine compounds, and porphyrin compounds; antioxidants; etc. Furthermore, the adhesive sealant may contain the components described below as components that the thermosetting sealant may contain.

[0129] [7. Description of components suitable for the thermosetting sealant according to the first embodiment] (7.1. Thermosetting resin as binder resin) An example of a component that the sealant may contain in combination with the inorganic filler is a thermosetting resin. The thermosetting resin is preferred as a binder resin for the thermosetting sealant. The thermosetting resin may be used alone or in combination of two or more kinds in any ratio.

[0130] Examples of the thermosetting resin include epoxy resin, cyanate ester resin, phenol resin, bismaleimide-triazine resin, polyimide resin, acrylic resin, vinylbenzyl resin, etc., and epoxy resin is preferred. When the epoxy resin is combined with an inorganic filler containing at least one selected from the group consisting of semi-calcined hydrotalcite and calcium oxide, a sealant having excellent transparency can be obtained.

[0131] The epoxy resin preferably has two or more epoxy groups per molecule on average. Examples of the epoxy resin include hydrogenated epoxy resins (hydrogenated bisphenol A type epoxy resins, hydrogenated bisphenol F type epoxy resins, etc.), fluorine-containing epoxy resins, linear aliphatic type epoxy resins, cyclic aliphatic type epoxy resins, bisphenol A type epoxy resins, biphenyl type epoxy resins, biphenyl aralkyl type epoxy resins, fluorene type epoxy resins, naphthol type epoxy resins, naphthalene type epoxy resins, bisphenol F type epoxy resins, phosphorus-containing epoxy resins, bisphenol S type epoxy resins, aromatic glycidylamine type epoxy resins (e.g., tetraglycidyldiaminodiphenyl) diglycidylmethane, triglycidyl-p-aminophenol, diglycidyl toluidine, diglycidyl aniline, etc.), alicyclic epoxy resins, phenol novolac type epoxy resins, alkylphenol type epoxy resins, cresol novolac type epoxy resins, bisphenol A novolac type epoxy resins, epoxy resins having a butadiene structure, diglycidyl ethers of bisphenols, diglycidyl ethers of naphthalenediol, diglycidyl ethers of phenols, diglycidyl ethers of alcohols, and alkyl substituted versions of these epoxy resins.

[0132] The epoxy resin may be a liquid epoxy resin, a solid epoxy resin, or a combination of a liquid epoxy resin and a solid epoxy resin. The term "liquid epoxy resin" refers to an epoxy resin that is liquid at room temperature (25°C) and normal pressure (1 atm). The term "solid epoxy resin" refers to an epoxy resin that is solid at room temperature (25°C) and normal pressure (1 atm). From the viewpoints of coatability, processability, and adhesiveness, it is preferable that 10 mass% or more of the total epoxy resin is a liquid epoxy resin. From the viewpoints of kneadability with inorganic fillers and varnish viscosity, it is particularly preferable to use a liquid epoxy resin and a solid epoxy resin in combination. The mass ratio of the liquid epoxy resin to the solid epoxy resin (liquid epoxy resin:solid epoxy resin) is preferably 1:2 to 1:0, more preferably 1:1.5 to 1:0.

[0133] As the epoxy resin, hydrogenated epoxy resin, fluorine-containing epoxy resin, linear aliphatic epoxy resin, cyclic aliphatic epoxy resin, and alkylphenol epoxy resin are preferred. Among them, hydrogenated epoxy resin, fluorine-containing epoxy resin, linear aliphatic epoxy resin, and cyclic aliphatic epoxy resin are more preferred. When these epoxy resins are used, the transparency of the sealant can be improved.

[0134] "Hydrogenated epoxy resin" means an epoxy resin obtained by hydrogenating an aromatic ring-containing epoxy resin. The hydrogenation rate of the hydrogenated epoxy resin is preferably 50% or more, more preferably 70% or more. As the hydrogenated epoxy resin, hydrogenated bisphenol A type epoxy resin and hydrogenated bisphenol F type epoxy resin are preferred. As the hydrogenated bisphenol A type epoxy resin, for example, liquid hydrogenated bisphenol A type epoxy resin (e.g., "YX8000" (manufactured by Mitsubishi Chemical Corporation, epoxy equivalent: about 205), "Denacol EX-252" (manufactured by Nagase ChemteX Corporation, epoxy equivalent: about 213)) and solid hydrogenated bisphenol A type epoxy resin (e.g., "YX8040" (manufactured by Mitsubishi Chemical Corporation, epoxy equivalent: about 1000)) can be mentioned.

[0135] Examples of the fluorine-containing epoxy resin include the fluorine-containing epoxy resins described in WO 2011 / 089947.

[0136] The term "chain aliphatic epoxy resin" refers to an epoxy resin having a linear or branched alkyl chain or alkyl ether chain. Examples of chain aliphatic epoxy resins include polyglycerol polyglycidyl ether (e.g., "Denacol EX-512" and "Denacol EX-521", manufactured by Nagase ChemteX Corporation), pentaerythritol polyglycidyl ether (e.g., "Denacol EX-411", manufactured by Nagase ChemteX Corporation), diglycerol polyglycidyl ether (e.g., "Denacol EX-421", manufactured by Nagase ChemteX Corporation), glycerol polyglycidyl ether (e.g., "Denacol EX-421", manufactured by Nagase ChemteX Corporation), and glycerol polyglycidyl ether (e.g., "Denacol EX-421", manufactured by Nagase ChemteX Corporation). glycidyl ether (e.g., "Denacol EX-313" and "Denacol EX-314", manufactured by Nagase ChemteX Corporation), trimethylolpropane polyglycidyl ether (e.g., "Denacol EX-321", manufactured by Nagase ChemteX Corporation), neopentyl glycol diglycidyl ether (e.g., "Denacol EX-211", manufactured by Nagase ChemteX Corporation), 1,6-hexanediol diglycidyl ether (e.g., "Denacol EX-211", manufactured by Nagase ChemteX Corporation), 2", manufactured by Nagase ChemteX Corporation), ethylene glycol diglycidyl ether (e.g., "Denacol EX-810", "Denacol EX-811", manufactured by Nagase ChemteX Corporation), diethylene glycol diglycidyl ether (e.g., "Denacol EX-850", "Denacol EX-851", manufactured by Nagase ChemteX Corporation), polyethylene glycol diglycidyl ether (e.g., "Denacol EX-821", "Denacol EX-830", manufactured by Nagase ChemteX Corporation), ", "Denacol EX-832", "Denacol EX-841", "Denacol EX-861", manufactured by Nagase ChemteX Corporation), propylene glycol diglycidyl ether (for example, "Denacol EX-911", manufactured by Nagase ChemteX Corporation), polypropylene glycol diglycidyl ether (for example, "Denacol EX-941", "Denacol EX-920", "Denacol EX-931", manufactured by Nagase ChemteX Corporation).

[0137] The term "alicyclic epoxy resin" refers to an epoxy resin having an alicyclic skeleton (e.g., a cycloalkane skeleton) in the molecule. Examples of alicyclic epoxy resins include "EHPE-3150" manufactured by Daicel Chemical Industries, Ltd. and "TOPR-300" manufactured by Nippon Steel Chemical & Material Co., Ltd.

[0138] The term "alkylphenol type epoxy resin" refers to an epoxy resin having a benzene ring skeleton with one or more alkyl groups and one or more hydroxyl groups as substituents, and the hydroxyl groups are converted to glycidyl ether groups. Examples of alkylphenol type epoxy resins include "HP-820" manufactured by DIC Corporation, "YDC-1312" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., and "EX-146" manufactured by Nagase ChemteX Corporation.

[0139] In one embodiment, the thermosetting resin preferably contains an aromatic ring-containing epoxy resin. The aromatic ring-containing epoxy resin refers to an epoxy resin containing an aromatic ring in the molecule. When an aromatic ring-containing epoxy resin is used, any one or all of the reactivity of the sealant, the glass transition temperature of the sealant after curing, and the adhesion tend to be improved. Examples of aromatic ring-containing epoxy resins include alkylphenol-type epoxy resins and fluorine-containing aromatic epoxy resins.

[0140] Examples of aromatic ring-containing epoxy resins include bisphenol A type epoxy resins, bisphenol F type epoxy resins, phenol novolac type epoxy resins, biphenyl aralkyl type epoxy resins, fluorene type epoxy resins, and fluorine-containing aromatic type epoxy resins. Among these, bisphenol type epoxy resins and fluorine-containing aromatic type epoxy resins are preferred, bisphenol type epoxy resins are more preferred, and bisphenol A type epoxy resins and bisphenol F type epoxy resins are even more preferred.

[0141] Examples of bisphenol A type epoxy resins include "828EL", "1001" and "1004AF" manufactured by Mitsubishi Chemical Corporation, "840" and "850-S" manufactured by DIC Corporation, and "YD-128" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. Examples of mixtures of liquid bisphenol A type epoxy resins and liquid bisphenol F type epoxy resins include "ZX-1059" (epoxy equivalent: about 165) manufactured by Nippon Steel Chemical Co., Ltd.

[0142] Examples of bisphenol F type epoxy resins include "807" manufactured by Mitsubishi Chemical Corporation, "830" manufactured by DIC Corporation, and "YDF-170" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.

[0143] Examples of phenol novolac type epoxy resins include "N-730A", "N-740", "N-770" and "N-775" manufactured by DIC Corporation; "152" and "154" manufactured by Mitsubishi Chemical Corporation.

[0144] The term "biphenylaralkyl type epoxy resin" refers to an epoxy resin having a main chain in which a novolac structure and a divalent biphenyl structure are bonded. Examples of biphenylaralkyl type epoxy resins include "NC-3000", "NC-3000L" and "NC-3100" manufactured by Nippon Kayaku Co., Ltd.

[0145] The term "fluorene-type epoxy resin" refers to an epoxy resin having a fluorene skeleton. Examples of the fluorene-type epoxy resin include "OGSOL PG-100", "CG-500EG-200" and "EG-280" manufactured by Osaka Gas Chemicals Co., Ltd.

[0146] The term "fluorine-containing aromatic epoxy resin" refers to a fluorine-containing epoxy resin having an aromatic ring. Examples of the fluorine-containing aromatic epoxy resin include the fluorine-containing aromatic epoxy resins described in WO 2011 / 089947.

[0147] Aromatic ring-containing epoxy resins generally have a high refractive index. Therefore, from the viewpoint of increasing the transparency of the sealant by bringing the refractive index of the resin and the inorganic filler closer to each other, the refractive index of the entire epoxy resin may be adjusted by combining an aromatic ring-containing epoxy resin with an epoxy resin that does not contain an aromatic ring structure. Among the epoxy resins that do not contain an aromatic ring structure, examples suitable for combining with an aromatic ring-containing epoxy resin include hydrogenated epoxy resins, fluorine-containing epoxy resins, linear aliphatic epoxy resins, and cyclic aliphatic epoxy resins. Among these, hydrogenated epoxy resins, fluorine-containing epoxy resins, and cyclic aliphatic epoxy resins are preferred. Furthermore, hydrogenated bisphenol A type epoxy resins, hydrogenated bisphenol F type epoxy resins, and fluorine-containing epoxy resins are preferred, hydrogenated bisphenol A type epoxy resins and hydrogenated bisphenol F type epoxy resins are more preferred, and hydrogenated bisphenol A type epoxy resins are particularly preferred. In this case, the amount of the aromatic ring-containing epoxy resin relative to the total of the aromatic ring-containing epoxy resin and the epoxy resin not containing an aromatic ring structure (100% by mass) is preferably 0.5% by mass to 40% by mass, more preferably 1% by mass to 35% by mass, and particularly preferably 2% by mass to 30% by mass.

[0148] From the viewpoint of reactivity, the epoxy equivalent of the epoxy resin is preferably 50 to 5,000, more preferably 50 to 3,000, further preferably 80 to 2,000, and particularly preferably 100 to 1,500. The "epoxy equivalent" refers to the number of grams of a resin containing 1 gram equivalent of epoxy groups (g / eq), and can be measured according to the method specified in JIS K 7236.

[0149] The weight average molecular weight of the thermosetting resin is preferably 100 to 5,000, more preferably 250 to 3,000, and further preferably 400 to 1500. The weight average molecular weight of the thermosetting resin can be measured by gel permeation chromatography (GPC) as a polystyrene-equivalent value.

[0150] The amount of the thermosetting resin is preferably 10 mass% or more, more preferably 20 mass% or more, even more preferably 30 mass% or more, particularly preferably 45 mass% or more, and is preferably 95 mass% or less, more preferably 90 mass% or less, particularly preferably 85 mass% or less, based on 100 mass% of the non-volatile components of the sealant.

[0151] The amount of the thermosetting resin is preferably 50 parts by mass or more, more preferably 100 parts by mass or more, and particularly preferably 160 parts by mass or more, relative to 100 parts by mass of the inorganic filler, and is preferably 300 parts by mass or less, more preferably 250 parts by mass or less, and particularly preferably 200 parts by mass or less.

[0152] (7.2. Thermoplastic resin as binder resin) The thermosetting sealant may contain a thermoplastic resin as a binder resin in combination with a thermosetting resin. When the binder resin contains a combination of a thermosetting resin and a thermoplastic resin, it is possible to improve the flexibility of the sealant and the coatability (suppression of repelling) of the sealant varnish. The thermoplastic resin may be used alone or in combination of two or more kinds in any ratio.

[0153] Examples of the thermoplastic resin include phenoxy resin, polyvinyl acetal resin, polyimide resin, polyamideimide resin, polyethersulfone resin, polysulfone resin, polyester resin, (meth)acrylic resin, etc. Here, the term "(meth)acrylic resin" includes both acrylic resin and methacrylic resin. As the thermoplastic resin to be combined with the thermosetting resin, the above-mentioned thermoplastic resin as a binder resin suitable for the adhesive sealant may be used.

[0154] As a thermoplastic resin to be combined with a thermosetting resin, a phenoxy resin is preferable. Phenoxy resin has good compatibility with thermosetting resins (especially epoxy resins). In addition, when a phenoxy resin is used, the ability of the sealant to suppress the penetration of moisture can be effectively improved. As the phenoxy resin, a phenoxy resin having one or more skeletons selected from a bisphenol A skeleton, a bisphenol F skeleton, a bisphenol S skeleton, a bisphenol acetophenone skeleton, a novolac skeleton, a biphenyl skeleton, a fluorene skeleton, a dicyclopentadiene skeleton, and a norbornene skeleton is preferable.

[0155] Commercially available phenoxy resins include, for example, YX7200B35 (manufactured by Mitsubishi Chemical Corporation: phenoxy resin containing a biphenyl skeleton), 1256 (manufactured by Mitsubishi Chemical Corporation: phenoxy resin containing a bisphenol A skeleton), and YX6954BH35 (manufactured by Mitsubishi Chemical Corporation: phenoxy resin containing a bisphenol acetophenone skeleton).

[0156] The range of the weight average molecular weight of the thermoplastic resin combined with the thermosetting resin can be the same as the weight average molecular weight of the thermoplastic resin described above as a binder resin suitable for the pressure-sensitive adhesive sealant. A thermoplastic resin having a weight average molecular weight in such a range can improve the flexibility of the sealant, the coatability of the sealant varnish (suppression of repellency), and the compatibility of the thermosetting resin and the thermoplastic resin. Among them, the weight average molecular weight of the phenoxy resin is preferably 10,000 to 500,000, more preferably 20,000 to 300,000. The method for measuring the weight average molecular weight is as described above.

[0157] The amount of thermoplastic resin combined with the thermosetting resin is preferably 0.1 mass % or more, more preferably 3 mass % or more, and particularly preferably 5 mass % or more, relative to 100 mass % of the non-volatile components of the sealant, and is preferably 60 mass % or less, more preferably 50 mass % or less, even more preferably 25 mass % or less, and particularly preferably 15 mass % or less.

[0158] The amount of thermoplastic resin to be combined with the thermosetting resin is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and particularly preferably 10 parts by mass or more, per 100 parts by mass of the inorganic filler, and is preferably 90 parts by mass or less, more preferably 70 parts by mass or less, and particularly preferably 50 parts by mass or less.

[0159] The amount of thermoplastic resin to be combined with the thermosetting resin is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and particularly preferably 10 parts by mass or more, per 100 parts by mass of the thermosetting resin, and is preferably 80 parts by mass or less, more preferably 60 parts by mass or less, and particularly preferably 40 parts by mass or less.

[0160] (7.3. Hardeners and hardening accelerators) An example of a component that the sealant may contain in combination with the inorganic filler is a curing agent. When the curing agent is used in combination with a thermosetting resin, the curing agent has a function of reacting with the thermosetting resin to cure the sealant. From the viewpoint of suppressing thermal deterioration of the electronic device during curing of the sealant, the curing agent is preferably one that can react with the thermosetting resin at a temperature of 140° C. or less (preferably 120° C. or less). The curing agent may be used alone or in combination of two or more kinds in any ratio.

[0161] The type of curing agent can be selected according to the type of thermosetting resin. Hereinafter, curing agents corresponding to epoxy resins as preferred thermosetting resins will be described. Examples of curing agents corresponding to epoxy resins include ionic liquids, acid anhydride compounds, imidazole compounds, tertiary amine compounds, dimethylurea compounds, amine adduct compounds, organic acid dihydrazide compounds, organic phosphine compounds, dicyandiamide compounds, primary and secondary amine compounds, etc. Among these, ionic liquids, acid anhydride compounds, imidazole compounds, tertiary amine compounds, dimethylurea compounds, and amine adduct compounds are preferred. Furthermore, ionic liquids, acid anhydride compounds, imidazole compounds, tertiary amine compounds, and dimethylurea compounds are more preferred.

[0162] The sealant may contain a curing accelerator in combination with the curing agent. Only one type of curing accelerator may be used, or two or more types may be used in combination. The type of curing accelerator may be selected according to the type of thermosetting resin. Hereinafter, curing accelerators corresponding to epoxy resins as preferred thermosetting resins will be described. Examples of curing accelerators corresponding to epoxy resins include imidazole compounds, tertiary amine compounds, dimethylurea compounds, and amine adduct compounds. Among them, imidazole compounds, tertiary amine compounds, and dimethylurea compounds are preferred.

[0163] The ionic liquid as the curing agent is preferably an ionic liquid capable of curing a thermosetting resin (particularly an epoxy resin) at a temperature of 140° C. or less (preferably 120° C. or less). That is, the ionic liquid is preferably a salt that can melt in a temperature range of 140° C. or less (preferably 120° C. or less) and has a curing action for a thermosetting resin (particularly an epoxy resin). The ionic liquid is preferably used in a state where it is uniformly dissolved in the thermosetting resin (particularly an epoxy resin). The ionic liquid can usually effectively enhance the ability of the sealant to suppress the penetration of moisture.

[0164] Examples of cations constituting the ionic liquid as a curing agent include ammonium-based cations such as imidazolium ion, piperidinium ion, pyrrolidinium ion, pyrazonium ion, guanidinium ion, and pyridinium ion; phosphonium-based cations such as tetraalkylphosphonium cation (e.g., tetrabutylphosphonium ion, tributylhexylphosphonium ion, and the like); and sulfonium-based cations such as triethylsulfonium ion.

[0165] Examples of anions constituting the ionic liquid as a curing agent include halide anions such as fluoride ion, chloride ion, bromide ion, and iodide ion; alkyl sulfate anions such as methanesulfonate ion; fluorine-containing compound anions such as trifluoromethanesulfonate ion, hexafluorophosphonate ion, trifluorotris(pentafluoroethyl)phosphonate ion, bis(trifluoromethanesulfonyl)imide ion, trifluoroacetate ion, and tetrafluoroborate ion; phenol ion, 2-methoxyphenol ion, 2,6-di-tert-butylphenol ion, and the like. acidic amino acid ions such as aspartate ion and glutamate ion; neutral amino acid ions such as glycine ion, alanine ion and phenylalanine ion; N-acylamino acid ions represented by the following formula (A) such as N-benzoylalanine ion, N-acetylphenylalanine ion and N-acetylglycine ion; and carboxylate anions such as formate ion, acetate ion, decanoate ion, 2-pyrrolidone-5-carboxylate ion, α-lipoic acid ion, lactate ion, tartrate ion, hippurate ion, N-methylhippurate ion and benzoate ion.

[0166] [ka]

[0167] In formula (A), R A represents a linear or branched alkyl group having 1 to 5 carbon atoms or a substituted or unsubstituted phenyl group; X A represents the side chain of an amino acid. Examples of the amino acid in formula (A) include aspartic acid, glutamic acid, glycine, alanine, phenylalanine, etc., and among these, glycine is preferable.

[0168] Among the above, the cation is preferably an ammonium-based cation or a phosphonium-based cation, more preferably an imidazolium ion or a phosphonium ion. Examples of the imidazolium ion include a 1-ethyl-3-methylimidazolium ion, a 1-butyl-3-methylimidazolium ion, and a 1-propyl-3-methylimidazolium ion.

[0169] The anion is preferably a phenol-based anion, an N-acylamino acid ion represented by the formula (A), or a carboxylate-based anion, and more preferably an N-acylamino acid ion or a carboxylate-based anion.

[0170] A specific example of a phenolic anion is 2,6-di-tert-butylphenol ion. Specific examples of carboxylate anions include acetate ion, decanoate ion, 2-pyrrolidone-5-carboxylate ion, formate ion, α-lipoic acid ion, lactate ion, tartrate ion, hippurate ion, and N-methylhippurate ion. Of these, acetate ion, 2-pyrrolidone-5-carboxylate ion, formate ion, lactate ion, tartrate ion, hippurate ion, and N-methylhippurate ion are preferred, and acetate ion, decanoate ion, N-methylhippurate ion, and formate ion are more preferred. Specific examples of the N-acylamino acid ion represented by formula (A) include an N-benzoylalanine ion, an N-acetylphenylalanine ion, an aspartic acid ion, a glycine ion, and an N-acetylglycine ion. Among these, the N-benzoylalanine ion, the N-acetylphenylalanine ion, and the N-acetylglycine ion are preferred, and the N-acetylglycine ion is more preferred.

[0171] Examples of ionic liquids include 1-butyl-3-methylimidazolium lactate, tetrabutylphosphonium-2-pyrrolidone-5-carboxylate, tetrabutylphosphonium acetate, tetrabutylphosphonium decanoate, tetrabutylphosphonium trifluoroacetate, tetrabutylphosphonium α-lipoate, tetrabutylphosphonium formate, tetrabutylphosphonium lactate, bis(tetrabutylphosphonium)tartrate, tetrabutylphosphonium hippurate, N-methylhippurate tetrabutylphosphonium salt, benzoyl-DL-alanine tetrabutylphosphonium salt, N-acetylphenylalanine tetrabutylphosphonium salt, 2,6-di-tert-butylphenol tetrabutylphosphonium salt, L-aspartic acid monotetrabutylphosphonium salt, glycine tetrabutylphosphonium salt, ... Butyl phosphonium salt, N-acetylglycine tetrabutyl phosphonium salt, 1-ethyl-3-methylimidazolium lactate, 1-ethyl-3-methylimidazolium acetate, formate 1-ethyl-3-methylimidazolium salt, hippuric acid 1-ethyl-3-methylimidazolium salt, N-methylhippuric acid 1-ethyl-3-methylimidazolium salt, tartrate bis(1-ethyl-3-methylimidazolium) salt, N-acetylglycine 1-ethyl-3-methylimidazolium salt are preferred, and tetrabutyl phosphonium decanoate, N-acetylglycine tetrabutyl phosphonium salt, 1-ethyl-3-methylimidazolium acetate, formate 1-ethyl-3-methylimidazolium salt, hippuric acid 1-ethyl-3-methylimidazolium salt, N-methylhippuric acid 1-ethyl-3-methylimidazolium salt are more preferred.

[0172] As a synthesis method of ionic liquids, for example, an anion exchange method is mentioned in which a precursor composed of a cationic portion such as an alkylimidazolium, alkylpyridinium, alkylammonium, and alkylsulfonium ion and an anionic portion containing a halogen is reacted with NaBF4, NaPF6, CF3SO3Na, LiN(SO2CF3)2, etc. Another synthesis method of ionic liquids is, for example, an acid ester method in which an amine-based substance is reacted with an acid ester to introduce an alkyl group while an organic acid residue becomes a counter anion. Another synthesis method of ionic liquids is, for example, a neutralization method in which amines are neutralized with an organic acid to obtain a salt. In the neutralization method using an anion, a cation, and a solvent, an anion and a cation are used in equal amounts, and the solvent in the obtained reaction liquid is distilled off and the liquid may be used as it is. Alternatively, the obtained reaction liquid may be mixed with an organic solvent (methanol, toluene, ethyl acetate, acetone, etc.) and then concentrated for use.

[0173] Examples of the acid anhydride compound as a curing agent include tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, dodecenylsuccinic anhydride, etc. Specific examples of the acid anhydride compound include Rikacid TH, TH-1A, HH, MH, MH-700, MH-700G (all manufactured by New Japan Chemical Co., Ltd.), etc.

[0174] Examples of imidazole compounds as curing agents or curing accelerators include 1H-imidazole, 2-methyl-imidazole, 2-phenyl-4-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-ethyl-4-methyl-imidazole, 2-undecylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 2,4-diamino-6-(2'-undecylimidazolyl-(1'))-ethyl-s-triazine, 2-phenyl-4,5-bis(hydroxymethyl)-imidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 2-phenyl-imidazole, 2-dodecyl- Examples of the imidazole compound include imidazole, 2-heptadecylimidazole, 1,2-dimethyl-imidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,4-diamino-6-(2'-methylimidazolyl-(1')-ethyl-s-triazine, and 2,4-diamino-6-(2'-methylimidazolyl-(1'))-ethyl-s-triazine isocyanuric acid adduct. Specific examples of the imidazole compound include Curesol 2MZ, 2P4MZ, 2E4MZ, 2E4MZ-CN, C11Z, C11Z-CN, C11Z-CNS, C11Z-A, 2PHZ, 1B2MZ, 1B2PZ, 2PZ, C17Z, 1.2DMZ, 2P4MHZ-PW, 2MZ-A, and 2MA-OK (all manufactured by Shikoku Chemical Industry Co., Ltd.).

[0175] Specific examples of tertiary amine compounds as curing agents or curing accelerators include DBN (1,5-diazabicyclo[4.3.0]non-5-ene), DBU (1,8-diazabicyclo[5.4.0]undec-7-ene), 2-ethylhexanoate of DBU, phenol salt of DBU, p-toluenesulfonate of DBU, U-CAT SA 102 (manufactured by San-Apro: octylate of DBU), DBU formate and other DBU-organic acid salts, tris(dimethylaminomethyl)phenol (TAP), and the like.

[0176] Specific examples of dimethylurea compounds as curing agents or curing accelerators include aromatic dimethylureas such as DCMU (3-(3,4-dichlorophenyl)-1,1-dimethylurea) and U-CAT3512T (manufactured by San-Apro Co., Ltd.); and aliphatic dimethylureas such as U-CAT3503N (manufactured by San-Apro Co., Ltd.). Among these, aromatic dimethylureas are preferred from the viewpoint of curability.

[0177] Examples of the amine adduct compound as a curing agent or curing accelerator include epoxy adduct compounds obtained by stopping the addition reaction of a tertiary amine to an epoxy resin midway, etc. Specific examples of the amine adduct compound include Amicure PN-23, Amicure MY-24, Amicure PN-D, Amicure MY-D, Amicure PN-H, Amicure MY-H, Amicure PN-31, Amicure PN-40, and Amicure PN-40J (all manufactured by Ajinomoto Fine-Techno Co., Ltd.).

[0178] Specific examples of the organic acid dihydrazide compound as a curing agent include Amicure VDH-J, Amicure UDH, and Amicure LDH (all manufactured by Ajinomoto Fine-Techno Co., Ltd.).

[0179] Examples of organic phosphine compounds as a curing agent or curing accelerator include triphenylphosphine, tetraphenylphosphonium tetra-p-tolylborate, tetraphenylphosphonium tetraphenylborate, tri-tert-butylphosphonium tetraphenylborate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, butyltriphenylphosphonium thiocyanate, triphenylphosphine triphenylborane, etc. Specific examples of organic phosphine compounds include TPP, TPP-MK, TPP-K, TTBuP-K, TPP-SCN, TPP-S (manufactured by Hokko Chemical Industry Co., Ltd.), etc.

[0180] An example of the dicyandiamide compound as a curing agent is dicyandiamide. Specific examples of the dicyandiamide compound include DICY7 and DICY15 (both manufactured by Mitsubishi Chemical Corporation), which are finely ground dicyandiamide products.

[0181] Examples of primary and secondary amine compounds as curing agents include aliphatic amines such as diethylenetriamine, triethylenetetraamine, tetraethylenepentamine, trimethylhexamethylenediamine, 2-methylpentamethylenediamine, 1,3-bisaminomethylcyclohexane, dipropylenediamine, diethylaminopropylamine, bis(4-aminocyclohexyl)methane, norbornenediamine, and 1,2-diaminocyclohexane; alicyclic amines such as N-aminoethylpiperazine and 1,4-bis(3-aminopropyl)piperazine; and aromatic amines such as diaminodiphenylmethane, m-phenylenediamine, m-xylylenediamine, metaphenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, and diethyltoluenediamine. Specific examples of primary and secondary amine compounds include Kayahard AA (manufactured by Nippon Kayaku Co., Ltd.: 4,4'-diamino-3,3'-dimethyldiphenylmethane).

[0182] Furthermore, if any of the above-mentioned crosslinking agents and crosslinking accelerators can react with the thermosetting resin to cure the sealing agent, the crosslinking agent and crosslinking accelerator may be used as the curing agent.

[0183] It is preferable to use a combination of a curing agent and a curing accelerator. Preferred combinations of a curing agent and a curing accelerator include two or more selected from an ionic liquid, an acid anhydride compound, an imidazole compound, a tertiary amine compound, a dimethylurea compound, and an amine adduct compound.

[0184] The amount of the curing agent is preferably 0.1% by mass to 40% by mass, more preferably 0.5% by mass to 38 parts by mass, and even more preferably 1% by mass to 35 parts by mass, based on 100% by mass of the non-volatile components of the sealant. When the amount of the curing agent is equal to or more than the lower limit of the above range, the curing of the sealant can be sufficiently promoted. When the amount of the curing agent is equal to or less than the upper limit of the above range, the storage stability of the sealant can be improved. In particular, the amount of the ionic liquid as the curing agent is preferably 20% by mass or less, more preferably 18% by mass or less, and particularly preferably 15% by mass or less, based on 100% by mass of the non-volatile components of the sealant. When the amount of the ionic liquid is within the above range, the ability of the sealant to suppress the intrusion of moisture can be effectively improved.

[0185] The amount of the curing accelerator is preferably 0.05% by mass to 10% by mass, more preferably 0.1% by mass to 8% by mass, and even more preferably 0.5% by mass to 5% by mass, based on 100% by mass of the non-volatile components of the sealant. When the amount of the curing accelerator is equal to or greater than the lower limit of the above range, the curing of the sealant can be rapidly promoted. When the amount of the curing accelerator is equal to or less than the upper limit of the above range, the storage stability of the sealant can be improved.

[0186] (7.4. Other components suitable for thermosetting sealants) Among the components that the sealant may contain, an example of a component suitable for a thermosetting sealant is a coupling agent. When the sealant contains a coupling agent, the aggregation of the inorganic filler is suppressed and the surface area of ​​the inorganic filler can be increased, so that the inorganic filler can easily exhibit its lead adsorption and moisture absorption properties. The coupling agent may be used alone or in combination of two or more types in any ratio.

[0187] Examples of the coupling agent include a silane coupling agent, an aluminate coupling agent, and a titanate coupling agent.

[0188] Examples of the silane coupling agent include epoxy-based silane coupling agents such as 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxypropyl(dimethoxy)methylsilane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; mercapto-based silane coupling agents such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, and 11-mercaptoundecyltrimethoxysilane; 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyldimethoxymethylsilane, N-phenyl-3-aminopropyltrimethoxysilane, N-methylaminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, and N-(2-aminoethyl)-3-aminopropyltrimethoxysilane. Examples of the silane coupling agents include aminopropyldimethoxymethylsilane, ureidosilane coupling agents such as 3-ureidopropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinylmethyldiethoxysilane, styrylsilane coupling agents such as p-styryltrimethoxysilane, acrylatesilane coupling agents such as 3-acryloxypropyltrimethoxysilane and 3-methacryloxypropyltrimethoxysilane, isocyanatesilane coupling agents such as 3-isocyanatepropyltrimethoxysilane, sulfidesilane coupling agents such as bis(triethoxysilylpropyl)disulfide and bis(triethoxysilylpropyl)tetrasulfide, phenyltrimethoxysilane, methacryloxypropyltrimethoxysilane, imidazolesilane, triazinesilane, etc. Among these, vinylsilane coupling agents and epoxysilane coupling agents are preferred, and epoxysilane coupling agents are particularly preferred.

[0189] An example of the aluminate coupling agent is alkylacetoacetate aluminum diisopropylate (eg, "Plenact AL-M" manufactured by Ajinomoto Fine-Techno Co., Ltd.).

[0190] Specific examples of titanate-based coupling agents include PLENACT TTS, PLENACT 46B, PLENACT 55, PLENACT 41B, PLENACT 38S, PLENACT 138S, PLENACT 238S, PLENACT 338X, PLENACT 44, and PLENACT 9SA (all manufactured by Ajinomoto Fine-Techno Co., Ltd.).

[0191] The amount of the coupling agent is preferably from 0 to 15% by mass, and more preferably from 0.5 to 10% by mass, relative to 100% by mass of the non-volatile components of the sealant.

[0192] The amount of the coupling agent is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, and particularly preferably 1 part by mass or more, relative to 100 parts by mass of the inorganic filler, and is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, and particularly preferably 10 parts by mass or less.

[0193] Among the components that the sealant may contain, examples of components suitable for a thermosetting sealant include organic fillers such as rubber particles, silicone powder, nylon powder, and fluororesin powder; thickeners such as Orben and Bentone; silicone-based, fluorine-based, and polymer-based defoamers or leveling agents; adhesion imparting agents such as triazole compounds, thiazole compounds, triazine compounds, and porphyrin compounds; etc. Furthermore, the thermosetting sealant may contain the components described above as components that the adhesive sealant may contain.

[0194] [8. Transparency of the Sealant According to the First Embodiment] The sealant according to the first embodiment of the present invention preferably has high transparency. The transparency of the sealant can be expressed by the parallel ray transmittance to D65 light. Specifically, the parallel ray transmittance of a sealant layer having a thickness of 20 μm is preferably 80% to 100%, more preferably 85% to 100%. The parallel ray transmittance of the sealant is calculated by forming a laminate by laminating the sealant on a glass plate, and using air as a reference. Specifically, the parallel ray transmittance can be measured by the following method.

[0195] A sealing sheet having a layer of a sealant having a thickness of 20 μm is prepared. This sealing sheet is cut to a length of 70 mm and a width of 25 mm, and the sealing sheet is laminated to a glass plate (a microslide glass having a length of 76 mm, a width of 26 mm, and a thickness of 1.2 mm, a white slide glass S1112, edge polished No. 2, manufactured by Matsunami Glass Industry Co., Ltd.) using a batch type vacuum laminator (manufactured by Nichigo-Morton Co., Ltd., V-160) to obtain a laminate. The lamination conditions are a temperature of 80°C, a decompression time of 30 seconds, and then a pressure of 0.3 MPa for 30 seconds. In the case of a thermosetting sealant, this laminate is heated in a heat circulation oven at 100°C for 60 minutes to obtain a sample. Using a haze meter HZ-V3 (halogen lamp) manufactured by Suga Test Instruments Co., Ltd., the parallel ray transmittance (%) of the sample is measured with D65 light, with air as a reference.

[0196] [9. Sealant according to the second embodiment] The sealant according to the second embodiment of the present invention includes an inorganic filler including at least one selected from the group consisting of semi-calcined hydrotalcite, calcined hydrotalcite, and calcium oxide, and a binder resin. Since the semi-calcined hydrotalcite, calcined hydrotalcite, and calcium oxide can exhibit excellent lead adsorption and moisture absorption in the sealant, when the sealant is used to seal an electronic device having a lead-containing portion, the sealant can suppress the intrusion of moisture into the lead-containing portion and the leakage of lead from the lead-containing portion to the outside of the electronic device.

[0197] The sealant according to the second embodiment of the present invention may or may not have the lead adsorption parameter and water vapor barrier parameter in the above-mentioned ranges. In addition, the sealant according to the second embodiment of the present invention contains one or more inorganic fillers selected from the group consisting of semi-calcined hydrotalcite, calcined hydrotalcite, and calcium oxide. Other than the above, the sealant according to the second embodiment of the present invention may have the same composition and physical properties as the sealant according to the first embodiment, and therefore can obtain the same advantages as the sealant according to the first embodiment.

[0198] [10. Method of manufacturing sealant] The method for producing the sealant is not particularly limited. The sealant can be produced by a method in which the components are mixed using a mixing device such as a kneading roller or a rotary mixer. In addition, during the mixing, a solvent may be mixed in combination with the components.

[0199] [11. Applications of sealants] When used for sealing purposes, the sealant can suppress the intrusion of moisture and the leakage of lead. Therefore, it is preferable to use the sealant for sealing electronic devices having lead-containing parts. There is no limitation on the type of such electronic devices. Examples of electronic devices include solar cells such as perovskite solar cells, secondary batteries such as lead-acid batteries, and electronic components containing lead-containing solder.

[0200] [12. Encapsulating sheet] (12.1. Composition of Encapsulating Sheet) The encapsulating sheet according to one embodiment of the present invention includes a support and a layer of the encapsulant formed on the support. The layer of the encapsulant is a layer formed of a encapsulant, and therefore contains the above-mentioned encapsulant. Such an encapsulating sheet can achieve encapsulation of the encapsulated object with the encapsulant by laminating the layer of the encapsulant to the encapsulated object. Usually, lamination is performed so that the encapsulated object and the layer of the encapsulant are in direct contact. Two members being in "direct" contact means that there is no other member between the members.

[0201] The thickness of the sealant layer can be set according to the object to be sealed. The specific thickness of the sealant layer is usually in the range of 3 μm to 200 μm, preferably 5 μm to 175 μm, and more preferably 5 μm to 150 μm. When the thickness of the sealant layer is equal to or greater than the lower limit of the above range, damage to the object to be sealed due to lamination with the sealing sheet can be suppressed, and the uniformity of the thickness of the sealing part obtained as the sealant layer after lamination can be increased. In addition, when the thickness of the sealant layer is equal to or less than the upper limit of the above range, the intrusion of moisture into the electronic device can be effectively suppressed. For example, in a perovskite solar cell having a first substrate and a second substrate, the thinner the sealing part as the sealant layer, the smaller the area of ​​the side where the sealing part comes into contact with the outside air can be, so that the intrusion of moisture can be effectively suppressed (see FIG. 4 described later).

[0202] The support is usually a film made of an appropriate material. Examples of the support include plastic films such as polyethylene, polypropylene, polyvinyl chloride, and other polyolefins, cycloolefin polymers, polyethylene terephthalate (hereinafter sometimes abbreviated as "PET"), polyethylene naphthalate, and other polyesters, polycarbonates, and polyimides; and metal foils such as aluminum foil, stainless steel foil, and copper foil. A composite film formed by laminating a metal foil and a plastic film may also be used as the support.

[0203] The support may have a barrier layer from the viewpoint of increasing moisture permeability resistance. In particular, when the support has a plastic film, it is preferable to use a support having an appropriate barrier layer in combination with the plastic film. Examples of materials for the barrier layer include inorganic substances. Examples of such inorganic substances include nitrides such as silicon nitride and SiCN; oxides such as silicon oxide and aluminum oxide; amorphous silicon; metals such as stainless steel and aluminum; and the like. The barrier layer can be formed, for example, by vapor deposition of the above-mentioned materials.

[0204] The support may be subjected to a surface treatment. Examples of the surface treatment include matte treatment, corona treatment, release treatment, etc. Examples of the release treatment include release treatment using a release agent such as a silicone resin-based release agent, an alkyd resin-based release agent, or a fluororesin-based release agent.

[0205] Specific examples of the support include commercially available aluminum foil-attached polyethylene terephthalate films such as "PET AL1N30" manufactured by Tokai Toyo Aluminium Sales Co., Ltd., "PET AL3025" manufactured by Fukuda Metals Co., Ltd., and "Alpet" manufactured by Panac Corp. Other specific examples of the support include Techbarrier HX, AX, LX, and L series (manufactured by Mitsubishi Plastics, Inc.), and X-BARRIER (manufactured by Mitsubishi Plastics, Inc.), which has an even higher moisture-proofing effect than the Techbarrier HX, AX, LX, and L series.

[0206] The thickness of the support is not particularly limited, but from the viewpoint of handleability, etc., it is preferably 10 μm or more, more preferably 20 μm or more, and preferably 200 μm or less, more preferably 150 μm or less, even more preferably 125 μm or less, and particularly preferably 100 μm or less.

[0207] The encapsulating sheet may have a protective film as necessary. For example, the encapsulating sheet may have a support, a sealant layer, and a protective film in this order, so that the sealant layer is protected by the protective film. By protecting the sealant layer with the protective film, it is possible to suppress adhesion of dirt and scratches on the surface of the sealant layer.

[0208] The protective film may be, for example, the same plastic film as the support. The protective film may be surface-treated like the support. The thickness of the protective film is not particularly limited, and is usually 1 μm or more, preferably 10 μm or more, and usually 150 μm or less, preferably 100 μm or less, more preferably 40 μm or less, and even more preferably 30 μm or less.

[0209] (12.2. Manufacturing method of encapsulating sheet) The encapsulating sheet can be produced by a production method including forming a layer of an encapsulant on a support. The layer of the encapsulant can be formed by a method including, for example, preparing a varnish containing an encapsulant and a solvent, applying the varnish on a support, and drying the applied varnish.

[0210] As the solvent, an organic solvent is usually used. Examples of the organic solvent include ketone solvents such as acetone, methyl ethyl ketone (hereinafter also abbreviated as "MEK"), and cyclohexanone; acetate ester solvents such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, and carbitol acetate; carbitol solvents such as cellosolve and butyl carbitol; aromatic hydrocarbon solvents such as toluene and xylene; amide solvents such as dimethylformamide, dimethylacetamide, and N-methylpyrrolidone; and aromatic mixed solvents such as solvent naphtha. Examples of aromatic mixed solvents include "Swasol" (manufactured by Maruzen Oil Co., Ltd., product name) and "Ipsol" (manufactured by Idemitsu Kosan Co., Ltd., product name). The solvent may be used alone or in combination of two or more types at any ratio.

[0211] The varnish can be dried, for example, by a heating method or a hot air blowing method. The drying conditions are not particularly limited, and the temperature can be, for example, 50°C to 100°C. The drying time is preferably 1 minute or more, more preferably 3 minutes or more, and preferably 60 minutes or less, more preferably 15 minutes or less. After the varnish is applied onto the support, the applied varnish is dried to remove the solvent and obtain a layer of the sealant on the support.

[0212] The method for producing the encapsulating sheet may include heating the layer of the encapsulant as necessary. Heating can promote the reaction of reactive groups contained in the encapsulant, so that reactions such as crosslinking and polymerization can be promoted to an appropriate degree to increase the hardness of the encapsulant layer. This heating is suitable when a pressure-sensitive adhesive encapsulant is used. In particular, when a pressure-sensitive adhesive encapsulant containing a polyolefin resin having reactive groups such as an acid anhydride group and an epoxy group is used, the above-mentioned heating is preferably performed. Such heating before encapsulation can prevent thermal deterioration of the components contained in the encapsulation target. There are no particular limitations on the heating conditions. The heating temperature is preferably 50°C to 200°C, more preferably 100°C to 180°C, and even more preferably 120°C to 160°C. The heating time is preferably 15 minutes to 120 minutes, and more preferably 30 minutes to 100 minutes.

[0213] The method for producing the encapsulating sheet may include providing a protective film as necessary. The protective film may be provided, for example, by laminating the protective film and the encapsulant layer. When the encapsulant layer is heated, the protective film may be provided before or after the encapsulant layer is heated.

[0214] (12.3. How to use the encapsulating sheet) The sealing sheet can be used to seal objects such as lead-containing parts and electrodes. A sealing method using the sealing sheet usually includes laminating a layer of a sealant of the sealing sheet to an object to be sealed. When the sealing sheet has a protective film, the lamination is usually performed after peeling off the protective film. The lamination method may be a batch method or a continuous method using a roll.

[0215] Usually, according to the lamination, a sealant layer and a support are provided on the object to be sealed in this order. Therefore, the object to be sealed after lamination can be covered with the sealant layer and the support. In the sealing method using the sealing sheet, the object to be sealed may be covered with the sealant layer and the support without peeling off the support. In this state, the object to be sealed is sealed not only by the sealant layer but also by the support, so that the intrusion of moisture can be effectively suppressed. For example, when using a sealing sheet having a support with high moisture permeability resistance, such as a support having a barrier layer or a support having a metal foil, it is preferable to seal with the sealant layer and the support as described above.

[0216] In the sealing method using the sealing sheet, for example, the support may be peeled off after the lamination to obtain a state in which the sealing target is covered with a sealant layer. Even in this state, the sealant layer that seals the sealing target can effectively suppress the intrusion of moisture. For example, when using a sealing sheet having a support that does not have high moisture permeability resistance, such as a support that does not have a barrier layer or a support that does not have a metal foil, it is preferable to perform sealing with a sealant layer as described above.

[0217] The sealing method using the sealing sheet may further include, for example, providing a sealing substrate. In particular, when the support is peeled off as described above, it is preferable to provide a suitable sealing substrate on the surface of the sealant layer exposed by peeling off the support. As such a sealing substrate, for example, the same film as the above-mentioned support may be used, or a rigid plate material such as a glass plate, a metal plate, or a steel plate may be used. By providing a sealing substrate, the intrusion of moisture can be more effectively suppressed.

[0218] The sealing method using the sealing sheet may include, for example, curing the sealant layer after lamination. Usually, the sealant layer is thermally cured by applying heat to the sealant layer to promote reactions such as crosslinking and polymerization of reactive groups contained in the sealant. This improves the adhesion between the object to be sealed and the sealant, and improves the mechanical strength of the sealant layer, thereby enhancing the sealing ability of the sealant. Therefore, the intrusion of moisture and the leakage of lead can be particularly effectively suppressed. Such thermal curing after lamination is suitable when a thermosetting sealant is used.

[0219] During the above-mentioned thermal curing, the sealant layer is usually heated by an appropriate heat treatment device. Examples of the heat treatment device include a hot air circulation oven, an infrared heater, a heat gun, and a high-frequency induction heating device. In addition, the sealant layer may be heated, for example, by pressing a heat tool against the sealant layer. From the viewpoint of increasing the adhesion between the sealant layer and the object to be sealed, the curing temperature is preferably 50°C or higher, more preferably 55°C or higher, and particularly preferably 60°C or higher. In addition, from the viewpoint of suppressing thermal deterioration of the components contained in the object to be sealed, the curing temperature is preferably 150°C or lower, more preferably 100°C or lower, and even more preferably 80°C or lower. The curing time is preferably 10 minutes or longer, more preferably 20 minutes or longer.

[0220] In any of the above-mentioned sealing methods, sealing is achieved by a layer of sealant. Therefore, when the object to be sealed includes a lead-containing part, not only can the intrusion of moisture into the lead-containing part be suppressed, but also the leakage of lead from the lead-containing part can be suppressed.

[0221] [13. Electronic Devices] An electronic device according to an embodiment of the present invention includes a lead-containing portion and a sealing portion that seals the lead-containing portion. The sealing portion includes the above-mentioned sealant. In this case, the sealant included in the sealing portion may be cured. A sealing portion that includes a hardened sealant in this manner is included in the "sealing portion that includes a sealant." In such an electronic device, the sealing portion can prevent moisture from penetrating into the lead-containing portion. Furthermore, the sealing portion can prevent lead from leaking from the lead-containing portion to the outside of the electronic device.

[0222] The lead-containing portion is a portion that contains lead atoms and can include a wide range of electronic devices depending on the type of electronic device. Hereinafter, the electronic device will be specifically described using a perovskite solar cell that contains a perovskite layer as the lead-containing portion.

[0223] 4 is a cross-sectional view showing an example of a perovskite solar cell 400 according to an embodiment of the present invention. As shown in FIG. 4, the perovskite solar cell 400 as an example includes a first electrode 410, a perovskite layer 420 containing lead atoms, a second electrode 430, and a sealing part 440 containing a sealing agent that may be cured. In this solar cell 400, the perovskite layer 420 is provided between the first electrode 410 and the second electrode 430 so that charges generated in the perovskite layer 420 as a photoelectric conversion layer can be extracted through the first electrode 410 and the second electrode 430.

[0224] The first electrode 410 and the second electrode 430 are formed of a conductive material. Although there is no limitation on the type of conductive material, it is preferable that one or both of the first electrode 410 and the second electrode 430 are formed of a transparent conductive material. Examples of such materials include conductive oxides such as ITO (indium tin oxide), SnO2, AZO (aluminum zinc oxide), IZO (indium zinc oxide), and GZO (gallium zinc oxide); conductive polymers; and the like.

[0225] The perovskite layer 420 contains a perovskite compound, and can generate charges when irradiated with light. An example of the perovskite compound is a compound represented by the following formula (P). A P k M P X P (k+2) (P)

[0226] In formula (P), k represents an integer of 1 or 2.

[0227] In formula (P), A p represents a monovalent organic molecule or its ion. The monovalent organic molecule is not particularly limited, and examples thereof include methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, dimethylamine, dimethylamine, dipropylamine, dibutylamine, dipentylamine, dihexylamine, trimethylamine, triethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, ethylmethylamine, methylpropylamine, butylmethylamine, methylpentylamine, hexylmethylamine, ethylpropylamine, ethylbutylamine, imidazole, azole, pyrrole, aziridine, azirine, azetidine, azeto, azole, imidazoline, and carbazole. Examples of the monovalent organic molecule ion include methylammonium (CH3NH3) and phenethylammonium. Of these, methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, and ions thereof, and phenethylammonium are preferred, and methylamine, ethylamine, propylamine, and ions thereof are more preferred.

[0228] In formula (P), M p represents a divalent metal atom. p It is preferable that M contains lead as a divalent metal atom. p may contain a metal atom other than lead in combination with lead. Examples of the metal atom other than lead include tin, zinc, titanium, antimony, bismuth, nickel, iron, cobalt, silver, copper, gallium, germanium, magnesium, calcium, indium, aluminum, manganese, chromium, molybdenum, and europium. One type of these metal atoms may be used alone, or two or more types may be used in combination.

[0229] In formula (P), X prepresents a halogen atom or a chalcogen atom. The halogen atom is not particularly limited, but examples thereof include chlorine, bromine, iodine, and sulfur. The chalcogen atom is not particularly limited, but examples thereof include selenium. These may be used alone or in combination of two or more.

[0230] Specific examples of the perovskite compound include the perovskite compounds described in International Publication No. 2014 / 045021, JP 2014-49596 A, JP 2016-82003 A, and the like.

[0231] Among the above, the perovskite compound is preferably a compound containing a lead atom, such as CH3NH3PbI3. The perovskite compound may be used alone or in combination of two or more kinds at any ratio. The perovskite layer 420 may contain any component, such as an oxide semiconductor, in combination with the perovskite compound.

[0232] The sealing portion 440 is provided to seal the perovskite layer 420. Therefore, a part or the whole of the surface of the perovskite layer 420 is covered by the sealing portion 440, and the surface of the perovskite layer 420 is not exposed. In the example shown in FIG. 4, an example will be described in which a part of the surface of the perovskite layer 420 that is not in contact with the first electrode 410 or the second electrode 430 is covered by the sealing portion 440. In such a perovskite layer, the sealing portion 440 seals between the outside air and the perovskite layer 420. Therefore, it is possible to suppress the moisture in the outside air from penetrating into the perovskite layer 420. In addition, it is possible to suppress the lead contained in the perovskite layer 420 from leaking out of the solar cell 400. Usually, not only the perovskite layer 420 but also the first electrode 410 and the second electrode 430 are sealed by the sealing portion 440, and protection from water is achieved.

[0233] The solar cell 400 preferably further comprises a first substrate 450 and a second substrate 460. Usually, one of the first substrate 450 and the second substrate 460 is used as a support substrate for supporting the solar cell 400 or its intermediate during manufacture and use. The other of the first substrate 450 and the second substrate 460 is usually used as a sealing substrate for sealing the main surface of the solar cell 400 over a wide area. The first electrode 410, the perovskite layer 420, and the second electrode 430 are generally provided in the space between the first substrate 450 and the second substrate 460. Therefore, as shown in FIG. 4, the sealing portion 440 can be provided so as to fill the space between the first substrate 450 and the second substrate 460, and therefore the first electrode 410, the perovskite layer 420, the second electrode 430, and other members provided between the first substrate 450 and the second substrate 460 can all be sealed by the sealing portion 440.

[0234] In general, the first substrate 450 and the second substrate 460 are formed of a material that is difficult for moisture to permeate, or have a large thickness, so that the infiltration of moisture can be suppressed to a high degree. Therefore, in the solar cell 400 according to the above example, the infiltration path of moisture into the perovskite layer 420 can be limited to the infiltration path A4 in the in-plane direction passing through the side portion 440S of the sealing portion 440. The above-mentioned sealant can particularly effectively suppress the infiltration of moisture through such infiltration path A4. Therefore, when used to seal the perovskite layer 420 provided between the first substrate 450 and the second substrate 460, the above-mentioned sealant can particularly significantly exhibit the effects of suppressing the infiltration of moisture and the leakage of lead.

[0235] The perovskite solar cell 400 may be further modified. For example, the perovskite solar cell 400 may include an optional layer between the first electrode 410 and the perovskite layer 420. Furthermore, for example, the perovskite solar cell 400 may include an optional layer between the perovskite layer 420 and the second electrode 430. Examples of the optional layer include an electron transport layer and a hole transport layer.

[0236] There is no limitation on the manufacturing method of the electronic device. For example, it can be manufactured by a method including forming a lead-containing layer and forming a sealing portion that seals the lead-containing layer. The sealing portion can be formed as a layer of sealant that covers the lead-containing portion, for example, by laminating a layer of sealant using an encapsulating sheet. As a specific example, a perovskite solar cell 400 including a sealing portion 440 as a layer of sealant can be manufactured by a method including forming a first electrode 410, a perovskite layer 420, and a second electrode 430 on a first substrate 450, and then laminating a layer of sealant of an encapsulating sheet (not shown) so as to cover a part or the whole of the first electrode 410, the perovskite layer 420, and the second electrode 430. At this time, the support of the encapsulating sheet may be used as the second substrate 460. Also, after peeling off the support of the encapsulating sheet, another second substrate 460 may be provided on the sealing portion 440. EXAMPLES

[0237] The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to the following examples. In the following description, "parts" and "%" indicating amounts represent "parts by mass" and "% by mass" unless otherwise specified.

[0238] [Evaluation method] [Method for evaluating the lead adsorption capacity of sealants] 10 μL of the lead standard solution was added to 500 mL of water and purified to prepare an aqueous solution containing lead ions with a lead ion concentration of 20 μg / L and a water temperature of 20° C. to 25° C.

[0239] The sealing sheet produced in the examples and comparative examples was cut to a length of 16 cm and a width of 24 cm to obtain a first test sheet. A mesh cloth (bolting cloth (nylon) mesh 40 NB-40, manufactured by AS ONE Corporation) was attached to the sealant layer side of this first test sheet, and then the sheet was finely chopped into 1 cm square pieces, placed in 50 ml of a lead ion-containing aqueous solution, and stirred for 15 minutes with a high-speed rotating mixer (Mixer ARE-310, rotation speed 2000 rpm) (lead adsorption ability evaluation test). At this time, in Examples 5 to 6 and Comparative Example 4 relating to the thermosetting sealant, after the mesh cloth was attached, the sealant was thermally cured under conditions of 100°C for 60 minutes, and then the first test sheet was finely chopped. The lead ion concentration M1 of the lead ion-containing aqueous solution after stirring was measured.

[0240] The lead ion concentration M1 of the lead ion-containing aqueous solution after the first test sheet was immersed was subtracted from the lead ion concentration of 20 μg / L of the lead ion-containing aqueous solution before the first test sheet was immersed to obtain the change in lead ion concentration. The amount of lead adsorption was calculated by multiplying this change by the volume of the lead ion-containing aqueous solution, 50 mL. The calculated amount of lead adsorption was multiplied by the area of ​​the sealant layer of the first test sheet used, 384 cm. 2 Divide by 1m of sealant layer. 2 Mass of lead adsorbed per unit mass X (μg / m 2 ) was calculated. This mass X of adsorbed lead corresponds to the lead adsorption parameter. Based on the mass X of adsorbed lead, the lead adsorption ability of the sealant was evaluated according to the following criteria.

[0241] (Lead adsorption capacity standard) "Good": The mass of adsorbed lead X is 10 μg / m 2 The end. "Bad": The mass of adsorbed lead X is 10 μg / m 2 less than.

[0242] The lead ion concentration of the lead ion-containing aqueous solution was measured by the following method. 5 ml of the lead ion-containing aqueous solution was placed in a test tube in a lead sensor pack (manufactured by HACH) and a reagent tablet (a measuring reagent included in the lead sensor pack) was dissolved in the aqueous solution. Then, a test electrode was immersed in the lead ion-containing aqueous solution, and the lead ion concentration was measured using a portable scanning lead meter (model HSA-1000, manufactured by HACH).

[0243] [Method for evaluating the water vapor barrier properties of sealants] As the support film, a composite film "PET Tsuki AL1N30" (aluminum foil thickness 30 μm, polyethylene terephthalate film thickness 25 μm, manufactured by Tokai Toyo Aluminum Sales Co., Ltd.) comprising an aluminum foil and a polyethylene terephthalate film was prepared. A layer of a sealant was formed on the aluminum foil side of the support film in the same manner as in the manufacturing method of the sealing sheet in each Example and Comparative Example, except that this support film was used instead of a support. Thereby, a second test sheet comprising a support film and a layer of a sealant was obtained. The obtained second test sheet was dried under a nitrogen atmosphere to remove adsorbed water contained in the layer of the sealant. In Examples 1 to 4 and Comparative Examples 1 to 3 using a pressure-sensitive adhesive sealant, the drying was performed at 130° C. for 60 minutes. In addition, in Examples 5 to 6 and Comparative Example 4 using a thermosetting sealant, the drying was performed at 100° C. for 5 minutes.

[0244] A 50 mm×50 mm square glass plate made of non-alkali glass was prepared. This glass plate was washed with boiled isopropyl alcohol for 5 minutes and dried at 150° C. for 30 minutes or more.

[0245] Calcium was deposited on one side of the glass plate using a mask that covered the peripheral area 0 mm to 2 mm away from the edge of the glass plate, forming a calcium film (purity 99.8%) with a thickness of 200 nm on the central portion of one side of the glass plate except for the peripheral area 0 mm to 2 mm away from the edge of the glass plate.

[0246] In a nitrogen atmosphere, the sealant layer of the second test sheet and the calcium film side surface of the glass plate were bonded together using a thermal laminator (Fujipla Lamipacker DAiSY A4 (LPD2325)) to obtain a laminate. In Examples 1 to 4 and Comparative Examples 1 to 3 relating to the adhesive sealant, the obtained laminate was obtained as an evaluation sample. In Examples 5 to 6 and Comparative Example 4 relating to the thermosetting sealant, the obtained laminate was heated at a temperature of 100°C for 60 minutes to cure the sealant layer, thereby obtaining an evaluation sample.

[0247] Generally, when calcium comes into contact with water and becomes calcium oxide, it becomes transparent. In addition, in the above-mentioned evaluation sample, since the glass plate and aluminum foil have sufficiently high water vapor intrusion barrier properties, moisture can usually move in the in-plane direction (direction perpendicular to the thickness direction) through the edge of the sealant layer and reach the calcium film. Therefore, when moisture infiltrates into the evaluation sample, the calcium film is gradually oxidized from the edge and becomes transparent, so that the calcium film is observed to shrink. Therefore, the moisture infiltration into the evaluation sample can be evaluated by measuring the sealing distance [mm] from the edge of the evaluation sample to the calcium film. Therefore, the evaluation sample containing the calcium film can be used as a model of an electronic device containing lead.

[0248] First, the sealing distance X2 [mm] from the end of the evaluation sample to the end of the calcium film was measured using a microscope (Measuring Microscope MF-U, manufactured by Mitutoyo Corporation). Hereinafter, this sealing distance X2 may be referred to as the initial sealing distance X2.

[0249] Next, the evaluation sample was placed in a thermo-hygrostat chamber set at a temperature of 85°C and a humidity of 85% RH. When the sealing distance X1 (mm) between the end of the evaluation sample placed in the thermo-hygrostat chamber and the end of the calcium film increased by 0.1 mm from the initial sealing distance X2, the evaluation sample was removed from the thermo-hygrostat chamber. The time from when the evaluation sample was placed in the thermo-hygrostat chamber to when it was removed from the thermo-hygrostat chamber was calculated as the decrease start time t [hours]. This decrease start time t was calculated as the time T when the evaluation sample was placed in the thermo-hygrostat chamber.P1 From the time T, the sealing distance X1 [mm] between the end of the evaluation sample stored in the temperature and humidity chamber and the end of the calcium film becomes "X2 + 0.1 mm". P2 corresponds to the time until

[0250] The sealing distance X1 and decrease start time t were applied to the Fick's diffusion equation of formula (1) to calculate a constant K as a water vapor penetration barrier property parameter.

[0251]

number

[0252] Using the obtained constant K, the water vapor barrier property, which is the ability of the sealant to suppress the penetration of moisture, was evaluated according to the following criteria. The smaller the value of the constant K, the higher the water vapor barrier property. "h" means "hours."

[0253] (Water vapor barrier standard) "Good": Constant K is 0.025 cm / h 0.5 less than. "Bad": Constant K is 0.025 cm / h 0.5 The end.

[0254] [Synthesis Example 1: Synthesis of ionic liquid curing agent] The ionic liquid curing agent, N-acetylglycine tetrabutylphosphonium salt, was synthesized by the following procedure. 3.54g of N-acetylglycine (Tokyo Chemical Industry Co., Ltd.) was added to 20.0g of 41.4% tetrabutylphosphonium hydroxide aqueous solution (Hokuko Chemical Industry Co., Ltd.) at 0°C and stirred for 10 minutes. After stirring, the reaction solution was concentrated using an evaporator at a pressure of 40mmHg to 50mmHg at 60°C to 80°C for 2 hours and at 90°C for 5 hours. The resulting concentrate was dissolved in 14.2ml of ethyl acetate (Junsei Chemical Co., Ltd.) at room temperature to prepare a solution. The resulting solution was concentrated using an evaporator at a pressure of 40mmHg to 50mmHg at 70°C to 90°C for 3 hours to obtain 11.7g of N-acetylglycine tetrabutylphosphonium salt (purity: 96.9%) as an oily compound.

[0255] [I. Examples and Comparative Examples of Adhesive Sealant] [Example 1] (Varnish manufacturing) A 77.5-part Swazol solution (60% non-volatile content) of dicyclopentadiene-based petroleum resin (T-REZ HA105, manufactured by JXTG Nippon Oil & Energy Corporation, softening point 105°C) was prepared as a tackifier, and 2.3 parts of an antioxidant (Irganox1010, manufactured by BASF) were added and dissolved. To this solution, 21 parts of maleic anhydride-modified liquid polybutene (HV-300M, manufactured by Toho Chemical Industry Co., Ltd., acid anhydride group concentration: 0.77 mmol / g, number average molecular weight: 2,100), 94 parts of polybutene (HV-1900, manufactured by JX Nippon Oil & Energy Corporation, number average molecular weight: 2,900), and commercially available semi-calcined hydrotalcite A (semi-calcined hydrotalcite, BET specific surface area: 13 m) were added as an inorganic filler. 2 100 parts of the cellulose acetate copolymer (100 parts by weight, average particle size: 400 nm) was dispersed in a three-roll mill to obtain a mixture.

[0256] The resulting mixture was mixed with 20 parts of a Swazol solution (20% non-volatile content) of a glycidyl methacrylate-modified propylene-butene random copolymer (T-YP341, Seiko PMC Corporation, propylene unit / butene unit: 71% / 29%, epoxy group concentration: 0.638 mmol / g, number average molecular weight: 155,000) in terms of the amount of non-volatile content, 0.1 parts of an amine compound (2,4,6-tris(diaminomethyl)phenol, hereinafter sometimes abbreviated as "TAP", Kayaku Akzo Co., Ltd.), and 210 parts of toluene, and the mixture was uniformly dispersed in a high-speed rotating mixer to obtain a varnish containing a sealant.

[0257] (Manufacturing of encapsulating sheets) A polyethylene terephthalate film (PET thickness 50 μm; SP3000, manufactured by Toyo Cross Co., Ltd.) having a surface (release-treated surface) treated with a silicone-based release agent was prepared as a support. The varnish was uniformly applied onto the release-treated surface of the support using a die coater, and heated at 140° C. for 30 minutes to obtain an encapsulating sheet having a 20 μm-thick layer of encapsulant.

[0258] [Example 2] The type of inorganic filler was varied from semi-calcined hydrotalcite A to commercially available calcined hydrotalcite C (calcined hydrotalcite, BET specific surface area: 190 m 2 / g, average particle size: 400 nm). Except for the above, a varnish containing a sealant and an encapsulating sheet having a sealant layer with a thickness of 20 μm were produced in the same manner as in Example 1.

[0259] [Example 3] The type of inorganic filler was varied from semi-calcined hydrotalcite A to commercially available calcium oxide (BET specific surface area: 5 m 2 / g, average particle size: 4000 nm). Except for the above, a varnish containing a sealant and an encapsulating sheet having a sealant layer with a thickness of 20 μm were produced in the same manner as in Example 1.

[0260] [Example 4] The type of inorganic filler was changed from semi-calcined hydrotalcite A to nano zeolite (Zeoal 4A, Nakamura Choukou Co., Ltd., average particle size 300 nm, pore size 4 Å). Except for the above, a varnish containing a sealant and a sealing sheet having a sealant layer with a thickness of 20 μm were produced in the same manner as in Example 1.

[0261] [Comparative Example 1] Semi-calcined hydrotalcite A was not used as an inorganic filler. Except for the above, a varnish containing a sealant and a sealing sheet having a sealant layer with a thickness of 20 μm were produced in the same manner as in Example 1.

[0262] [Comparative Example 2] The type of inorganic filler was varied from semi-calcined hydrotalcite A to commercially available uncalcined hydrotalcite D (BET specific surface area: 10 m 2 / g, average particle size: 400 nm). Except for the above, a varnish containing a sealant and an encapsulating sheet having a sealant layer with a thickness of 20 μm were produced in the same manner as in Example 1.

[0263] [Comparative Example 3] The type of inorganic filler was changed from semi-calcined hydrotalcite A to synthetic mica (PDM-5B, manufactured by Topy Industries, Ltd., average particle size: 6.0 μm). Except for the above, a varnish containing a sealant and a sealing sheet having a sealant layer with a thickness of 20 μm were produced in the same manner as in Example 1.

[0264] [evaluation] The varnishes and sealing sheets obtained in the respective Examples and Comparative Examples were used to evaluate the lead adsorption capacity and water vapor barrier property of the sealing agents by the above-mentioned evaluation methods. The evaluation results are shown in Table 1 below.

[0265] [Table 1]

[0266] [II. Examples and Comparative Examples of Thermosetting Sealant] [Example 5] (Varnish manufacturing) A mixture of bisphenol A epoxy resin and bisphenol F epoxy resin (ZX1059 manufactured by Nippon Steel Chemical & Material Co., Ltd.) (162 parts) and commercially available semi-calcined hydrotalcite A (semi-calcined hydrotalcite, BET specific surface area: 13 m) as an inorganic filler were used. 2 A mixture was obtained by kneading 150 parts of polyaniline (1.0 parts by weight, average particle size: 400 nm) with 7.5 parts of a silane coupling agent (Shin-Etsu Chemical Co., Ltd.'s "KMB403", 3-glycidyloxypropyltriethoxysilane) and dispersing the mixture with a three-roll mill.

[0267] A solution of 7.5 parts of a curing accelerator ("U-CAT3512T" manufactured by San-Apro Co., Ltd.) dissolved in 163 parts of a phenoxy resin solution ("YX7200B35" manufactured by Mitsubishi Chemical Corporation, solvent: methyl ethyl ketone, non-volatile components: 35%) (57 parts of resin) was mixed with 108 parts of an alicyclic skeleton-containing epoxy resin ("TOPR-300" manufactured by Nippon Steel Chemical & Material Co., Ltd.), the mixture prepared above, and 9 parts of the ionic liquid curing agent (N-acetylglycine tetrabutylphosphonium salt) synthesized in Synthesis Example 1, and the mixture was uniformly dispersed in a high-speed rotating mixer to obtain a varnish containing a sealant.

[0268] (Manufacturing of encapsulating sheets) As a support, a polyethylene terephthalate film (thickness 38 μm, hereinafter sometimes referred to as "release PET film") having a surface (release treated surface) treated with an alkyd-based release agent was prepared. The varnish was uniformly applied to the release treated surface of this support using a die coater so that the thickness of the sealant layer after drying was 20 μm, and the varnish was dried at 80 ° C. for 5 minutes to form a sealant layer. Thereafter, a release PET film was placed as a protective film on the surface of the sealant layer to obtain a sealing sheet having a support, a sealant layer, and a release PET film in this order.

[0269] [Example 6] The type of inorganic filler was varied from semi-calcined hydrotalcite A to commercially available calcium oxide (BET specific surface area: 5 m 2 / g, average particle size: 4000 nm). Except for the above, a varnish containing a sealant and an encapsulating sheet having a sealant layer with a thickness of 20 μm were produced in the same manner as in Example 5.

[0270] [Comparative Example 4] The type of inorganic filler was varied from semi-calcined hydrotalcite A to commercially available uncalcined hydrotalcite D (BET specific surface area: 10 m 2 / g, average particle size: 400 nm). Except for the above, a varnish containing a sealant and an encapsulating sheet having a sealant layer with a thickness of 20 μm were produced in the same manner as in Example 5.

[0271] [evaluation] Using the varnishes and sealing sheets obtained in each of the Examples and Comparative Examples, the lead adsorption ability and water vapor barrier property of the sealing compounds were evaluated by the above-mentioned evaluation methods. However, in the method for evaluating the lead adsorption ability, the sealing film was cut, and then the release PET film as a protective film was peeled off to obtain a first test sheet. Thus, the method for evaluating the lead adsorption ability was performed using a first test sheet having a sealant layer with one side exposed. In addition, in the evaluation method for the water vapor barrier property, the release PET film serving as a protective film was peeled off from the second test sheet, and then the second test sheet was dried. The evaluation results are shown in Table 2 below.

[0272] [Table 2]

[0273] [III. Measurement of water vapor transmission rate using the water vapor transmission rate test method (WVTR measurement method)] [Reference Example 1: Evaluation of the encapsulating sheet of Example 1] The sealant layer of the encapsulant sheet produced in Example 1 and a reference film with a known water vapor transmission rate P2 (polyethylene terephthalate film "Lumirror 38 R80", thickness 35 μm, manufactured by Toray Sales Co., Ltd.) were laminated using a batch vacuum laminator (V-160, manufactured by Nichigo-Morton Co., Ltd.). The lamination conditions were a temperature of 80°C, a decompression time of 30 seconds, and then a pressure of 0.3 MPa for 30 seconds. Thereafter, the support was peeled off to obtain a resin sheet provided with a sealant layer and the reference film.

[0274] The water vapor transmission rate P0 of the obtained resin sheet was determined by an infrared sensor method in accordance with JIS K7129B. Water vapor transmission rate (g / m 2 The water vapor transmission rate (T / 24 hours) was measured using a water vapor transmission rate measuring device (MOCON, PERMATRAN-W 3 / 34) under an atmosphere of 40°C and 90% relative humidity.

[0275] The water vapor transmission rate P0 of the resin sheet and the water vapor transmission rate P2 of the reference film were applied to the following formula (2) to calculate the water vapor transmission rate P1 of the sealant layer. Here, the water vapor transmission rate P2 of the reference film was 15 g / m 2 -24 hours. 1 / P0=1 / P1+1 / P2 (2)

[0276] [Reference Example 2: Evaluation of the encapsulating sheet of Comparative Example 1] The water vapor transmission rate P1 of the sealant layer was measured in the same manner as in Reference Example 1, except that the encapsulating sheet produced in Comparative Example 1 was used instead of the encapsulating sheet produced in Example 1.

[0277] [Reference Example 3: Evaluation of the encapsulating sheet of Comparative Example 3] The water vapor transmission rate P1 of the sealant layer was measured in the same manner as in Reference Example 1, except that the encapsulating sheet produced in Comparative Example 3 was used instead of the encapsulating sheet produced in Example 1.

[0278] [result] The results of Reference Examples 1 to 3 are shown in the following Table 3. Table 3 also shows the evaluation of the water vapor barrier properties in Example 1, which corresponds to Reference Examples 1 to 3, and Comparative Examples 1 and 3.

[0279] [Table 3]

[0280] In the WVTR measurement method employed in Reference Examples 1 to 3, the permeability of water vapor passing through the sealant layer in the thickness direction is measured. As can be seen from the results of Reference Examples 1 to 3, in terms of the ability to suppress moisture penetration in the thickness direction, Reference Example 1 is superior to Reference Example 2, but Reference Example 3 is even superior. However, as can be seen from the results of the water vapor penetration barrier properties of Example 1 and Comparative Examples 1 and 3, in terms of the ability to suppress moisture penetration in the in-plane direction perpendicular to the thickness direction, Example 1 corresponding to Reference Example 1 is superior to Comparative Examples 1 and 3 corresponding to Reference Examples 2 and 3. Therefore, it can be seen that the ability of the sealant to suppress moisture penetration can vary depending on the direction of penetration of the water vapor. It can also be seen that the sealant according to the examples exhibits a specifically high water vapor penetration barrier property in the in-plane direction.

[0281] [IV. Evaluation of the physical properties of hydrotalcite] [Reference examples 4~6] (Measurement of water absorption rate of hydrotalcite) 1.5 g of each hydrotalcite used in the above-mentioned Examples and Comparative Examples was weighed out on a balance and the initial mass was measured. Each weighed hydrotalcite was left to stand in a small environmental tester (SH-222 manufactured by ESPEC Corp.) set at atmospheric pressure, 60°C, and 90% RH (relative humidity) for 200 hours to absorb moisture, and then the mass after moisture absorption was measured. The saturated water absorption rate was calculated from the measured mass using the following formula (i). Saturation water absorption rate [mass%] = 100 × (mass after moisture absorption – initial mass) / initial mass (i)

[0282] (Measurement of Thermal Weight Loss Rate of Hydrotalcite) Using a thermal analyzer (TG / DTA EXSTAR6300, manufactured by Hitachi High-Tech Science Corporation), thermogravimetric analysis was performed on each of the hydrotalcites used in the above-mentioned Examples and Comparative Examples. 10 mg of hydrotalcite was weighed out into an aluminum sample pan, and the pan was heated from 30°C to 550°C at a rate of 10°C / min in an open, uncovered state in a nitrogen atmosphere with a flow rate of 200 mL / min. The thermal weight loss rates at 280°C and 380°C were calculated using the following formula (ii). Thermal weight loss rate [mass%] = 100 × (mass before heating - mass when reaching a specified temperature) / mass before heating (ii)

[0283] (Measurement of powder X-ray diffraction of hydrotalcite) The powder X-ray diffraction of each hydrotalcite used in the above-mentioned Examples and Comparative Examples was measured. The powder X-ray diffraction was measured using a powder X-ray diffractometer (Empyrean, PANalytical) under the following conditions: anticathode CuKα (1.5405 Å), voltage: 45 V, current: 40 mA, sampling width: 0.0260°, scanning speed: 0.0657° / s, measurement diffraction angle range (2θ): 5.0131 to 79.9711°. Peak search was performed using the peak search function of the software attached to the diffractometer under the conditions of "minimum significance: 0.50, minimum peak tip: 0.01°, maximum peak tip: 1.00°, peak base width: 2.00°, method: minimum value of second derivative". Two split peaks that appeared within the 2θ range of 8° to 18°, or a peak with a shoulder formed by combining two peaks, were detected, and the diffraction intensity of the peak or shoulder that appeared on the low-angle side (= low-angle diffraction intensity) and the diffraction intensity of the peak or shoulder that appeared on the high-angle side (= high-angle diffraction intensity) were measured, and the relative intensity ratio (= low-angle diffraction intensity / high-angle diffraction intensity) was calculated.

[0284] (result) The evaluation results of each hydrotalcite are shown in Table 4 below.

[0285] [Table 4]

[0286] From the results of the saturated water absorption, thermal weight loss and powder X-ray diffraction, it was found that Hydrotalcite A was "semi-calcined hydrotalcite", Hydrotalcite C was "calcined hydrotalcite" and Hydrotalcite D was "uncalcined hydrotalcite". [Explanation of symbols]

[0287] 10 Evaluation sample 100 Glass Plate 200 Calcium membrane 300 Second Test Sheet 310 Sealant layer 320 Support Film 321 Aluminum foil 322 Polyethylene terephthalate film 400 Perovskite solar cells 410 First electrode 420 Perovskite layer 430 Second electrode 440 Sealing part 450 First base material 460 Second base material

Claims

1. A lead-acid battery comprising: a first substrate; a second substrate; a lead-containing portion provided in a space between the first substrate and the second substrate; and a sealing portion provided to fill the space between the first substrate and the second substrate and to seal the lead-containing portion, the sealing portion includes a sealant including an inorganic filler including at least one selected from the group consisting of semi-calcined hydrotalcite, calcined hydrotalcite, and calcium oxide, and a resin that binds and holds the inorganic filler; the amount of the inorganic filler is 5% by mass or more and 80% by mass or less relative to 100% by mass of the non-volatile components of the sealant; the resin includes a polyolefin resin having an acid anhydride group, A lead-acid battery, wherein the amount of the polyolefin-based resin having an acid anhydride group is 1 part by mass or more and 23 parts by mass or less per 100 parts by mass of the inorganic filler.

2. A lead-acid battery as described in claim 1, wherein the inorganic filler is semi-calcined hydrotalcite.

3. A lead-acid battery as described in claim 1, wherein the inorganic filler is calcined hydrotalcite.

4. A lead-acid battery as described in claim 1, wherein the inorganic filler is calcium oxide.

5. A lead-acid battery described in any one of claims 1 to 4, wherein the resin includes an epoxy resin.

6. A lead-acid battery described in any one of claims 1 to 5, wherein the resin includes a polyolefin-based resin having an epoxy group.

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