Encapsulating agents, encapsulating sheets, electronic devices, and perovskite solar cells

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 a encapsulant for electronic devices having a lead-containing portion, and to a encapsulation sheet, an electronic device, and a perovskite solar cell using the same. [Background technology]

[0002] One electronic device that has attracted attention in recent years is the perovskite solar cell. A perovskite solar cell generally comprises electrodes and a photoelectric conversion layer containing a perovskite compound. Furthermore, to protect the electrodes and the photoelectric conversion layer from water, a sealing portion is usually provided in a perovskite solar cell. 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 [Overview of the project] [Problems that the invention aims to solve]

[0004] The photoelectric conversion layer of perovskite solar cells may contain lead. If moisture penetrates this photoelectric conversion layer, lead may leach out and leak out of the solar cell. Such lead leakage can also occur in electronic devices other than perovskite solar cells that contain lead-containing parts such as the photoelectric conversion layer mentioned above. From both an environmental and safety perspective, it is desirable to suppress lead leakage.

[0005] The present invention was devised in view of the above-mentioned problems, and aims to provide a sealant for electronic devices that can suppress the intrusion of moisture and suppress the leakage of lead from the lead-containing part to the outside of the electronic device; a sealing sheet containing the sealant; and an electronic device and a perovskite solar cell using the sealant for sealing. [Means for solving the problem]

[0006] The inventors diligently studied to solve the aforementioned problems. As a result, the inventors discovered that the aforementioned problems can be solved by appropriately combining inorganic fillers and resins, and thus completed the present invention. In other words, the present invention includes the following:

[0007] [1] A sealant for electronic devices having a lead-containing portion, The sealing agent comprises an inorganic filler and a resin, The lead adsorption parameter of the aforementioned encapsulant is 10 μg / m³. 2 That's all. The water vapor intrusion barrier parameter of the aforementioned sealant is 0.025 cm / h 0.5 It is less than, The aforementioned lead adsorption parameter was determined when a lead adsorption capacity evaluation test was performed on a 1 m layer of the sealant. 2 This represents the mass of lead adsorbed per unit area. In the lead adsorption capacity evaluation test, a first test sheet measuring 16 cm in length and 24 cm in width is prepared, comprising a polyethylene terephthalate film and a 20 μm thick layer of the sealant formed on the polyethylene terephthalate film; a nylon mesh cloth is laminated to the sealant layer side of the first test sheet; the first test sheet with the mesh cloth laminated is cut into 1 cm squares; the cut first test sheet is immersed 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 stirred for 15 minutes. The aforementioned water vapor barrier parameter represents the constant K obtained from the following formula (1) when a water vapor barrier performance evaluation test is performed. In the water vapor barrier performance evaluation test, a second test sheet comprising a support film having a 30 μm thick aluminum foil and a 25 μm thick polyethylene terephthalate film, and a layer of the sealant formed on the aluminum foil of the support film, 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 deposited on one side of the glass plate, excluding the area 0 mm to 2 mm from the edge of the glass plate, to form a calcium film with a thickness of 200 nm; and the second test sheet is dried in a nitrogen atmosphere. A sealant comprising: bonding the layer of the sealant to the calcium film side of the glass plate to obtain an evaluation sample; measuring the distance X2 [mm] between the edge of the evaluation sample and the edge of the calcium film; placing the evaluation sample in a constant temperature and humidity chamber at a temperature of 85°C and a humidity of 85%RH; measuring the time t [hours] from the time the evaluation sample is placed in the constant temperature and humidity chamber until the time when the distance X1 [mm] between the edge of the evaluation sample placed in the constant temperature and humidity chamber and the edge of the calcium film becomes "X2 + 0.1 mm"; and calculating a constant K based on the following formula (1).

number

[10] comprising a first electrode, a perovskite layer containing lead atoms, a second electrode, and a sealing portion that seals the perovskite layer, A perovskite solar cell in which the sealing portion contains the sealing agent described in any one of items [1] to [7]. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a sealant for electronic devices that can suppress the intrusion of moisture and suppress the leakage of lead from the lead-containing part to the outside of the electronic device; a sealing sheet containing the sealant; and an electronic device and a perovskite solar cell using the sealant for sealing. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a schematic cross-sectional view showing an evaluation sample produced in a water vapor barrier performance evaluation test. [Figure 2]Figure 2 is a schematic plan view showing the evaluation sample as seen from the glass plate side before it is placed in the constant temperature and humidity chamber. [Figure 3] Figure 3 is a schematic plan view showing the evaluation sample as seen from the glass plate side after it has been placed in a constant temperature and humidity chamber. [Figure 4] Figure 4 is a schematic cross-sectional view showing an example of a perovskite solar cell according to one embodiment of the present invention. [Modes for carrying out the invention]

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

[0011] [1. Overview of the encapsulant according to the first embodiment] The encapsulant according to the first embodiment of the present invention comprises an inorganic filler and a resin. The resin typically plays a role in binding and holding the inorganic filler, and may be appropriately referred to as a "binder resin." In addition to the inorganic filler and the binder resin, the encapsulant according to this embodiment may further contain any other components. Furthermore, the encapsulant according to this embodiment has lead adsorption parameters within a specific range. Moreover, the encapsulant according to this embodiment has water vapor infiltration barrier parameters within a specific range. When used for encapsulating electronic devices that contain lead, this encapsulant can suppress the infiltration of moisture into the lead-containing portion and suppress the leakage of lead from the lead-containing portion to the outside of the electronic device.

[0012] [2. Lead adsorption parameters of the sealant according to the first embodiment] The lead adsorption parameter of the encapsulant according to the first embodiment of the present invention is typically 10 μg / m³. 2 Preferably 11 μg / m² 2 More preferably 12 μg / m² 2 In particular, 13 μg / m² is preferred. 2The above is the case. The higher the upper limit of the lead adsorption parameter, the more preferable it is. For example, it can be 200 μg / m 2 or less, 100 μg / m 2 or less, 50 μg / m 2 or less, etc.

[0013] The lead adsorption parameter represents the mass of lead adsorbed per 1 m 2 of the layer of the sealant when the following lead adsorption ability evaluation test is conducted.

[0014] In the above-mentioned lead adsorption ability evaluation test, prepare a first test sheet; bond a nylon mesh cloth to the sealant layer side of the first test sheet; cut the first test sheet bonded with the mesh cloth into 1 cm squares; immerse the cut first test sheet in 50 ml of an aqueous solution containing lead ions with a lead ion concentration adjusted to 20 μg / L at 20°C to 25°C and stir for 15 minutes. The first test sheet refers to a sheet with a length of 16 cm and a width of 24 cm, comprising a polyethylene terephthalate film and a layer of sealant with a thickness of 20 μm formed on this polyethylene terephthalate film. The reason for bonding the first test sheet and the mesh cloth in the lead adsorption ability evaluation test is to prevent the first test sheets from adhering to each other in the aqueous solution containing lead ions. Also, when the sealant is a thermosetting sealant, usually, after bonding the mesh cloth, the sealant is thermally cured under the conditions of 100°C for 60 minutes, and then the first test sheet is cut.

[0015] Therefore, for example, when the sealant is an adhesive sealant, in the lead adsorption ability evaluation test, it is possible to prepare a first test sheet; bond a nylon mesh cloth to the sealant layer side of the first test sheet; cut the first test sheet bonded with the mesh cloth into 1 cm squares; immerse the cut first test sheet in 50 ml of an aqueous solution containing lead ions with a lead ion concentration adjusted to 20 μg / L at 20°C to 25°C and stir for 15 minutes.

[0016] Furthermore, for example, if the sealant is a thermosetting sealant, the lead adsorption capacity evaluation test may involve: preparing a first test sheet; laminating a nylon mesh cloth to the sealant layer side of the first test sheet and thermosetting the sealant at 100°C for 60 minutes; cutting the first test sheet with the mesh cloth laminated 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] When a lead adsorption capacity evaluation test is performed, the mass of lead adsorbed onto the sealant layer 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 detector (model HSA-1000, manufactured by HACH). The specific measurement method can be the one described later in the examples.

[0018] The lead adsorption parameter represents the ability of a sealant to adsorb lead. Specifically, a larger lead adsorption parameter indicates a greater ability of the sealant to adsorb lead. When a sealant having a lead adsorption parameter within the aforementioned range is used to seal lead-containing parts in electronic devices, it can effectively adsorb lead leaking from those parts. Therefore, it can suppress lead leakage from electronic devices to the outside. This effect of suppressing lead leakage is beneficial in various situations, such as during storage, transportation, use, and damage to electronic devices.

[0019] Lead adsorption parameters can be adjusted, for example, by the type and amount of inorganic filler.

[0020] [3. Water vapor infiltration barrier parameters of the sealant according to the first embodiment] The water vapor penetration barrier parameter of the sealant according to the first embodiment of the present invention is typically 0.025 cm / h 0.5 Less than 0.024 cm / h 0.5 Less than, more preferably 0.0230 cm / h 0.5 Less than, more preferably 0.022 cm / h 0.5 Less than 0.021 cm / h, particularly preferably 0.021 cm / h0.5 It is less than 0.000 cm / h. The lower limit of the water vapor infiltration barrier parameter is ideally 0.000 cm / h. 0.5 That's all, except for 0.001 cm / h 0.5 That's fine too.

[0021] The water vapor barrier parameter is represented by the constant K obtained from equation (1) when the following water vapor barrier performance evaluation test is performed.

[0022] In the water vapor barrier performance evaluation test described above, 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 deposited on the central part of one side of the glass plate to form a calcium film with a thickness of 200 nm; the sealant layer of the second test sheet and the side of the glass plate with the calcium film 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; the time T when the evaluation sample is placed in the constant temperature and humidity chamber is measured. P1 From there, at the point T when the sealing distance X1 [mm] of the evaluation sample stored in the constant temperature and humidity chamber becomes "X2 + 0.1 mm", P2The following steps are taken: measure the time t [hours] until the specified time; and calculate the 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". If the sealant is curable, the sealant layer of the second test sheet is usually bonded 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, those described later in the examples. Specific curing conditions may be, for example, 100°C for 60 minutes. It is also preferable to thoroughly dry the second test sheet used in the water vapor barrier performance evaluation test. Specific drying conditions may be at least one of 130°C for 60 minutes and 100°C for 5 minutes. In a water vapor barrier performance evaluation test including drying under at least one of the following conditions: 130°C for 60 minutes and 100°C for 5 minutes, if the water vapor penetration barrier parameters within the above range are obtained, the sealant can suppress the penetration of moisture and suppress the leakage of lead from the lead-containing part to the outside of the electronic device. Typically, if the sealant is an adhesive type sealant, drying is performed under the condition of 130°C for 60 minutes. Typically, if the sealant is a thermosetting type sealant, drying is performed under the condition of 100°C for 5 minutes.

[0023] Therefore, for example, if the sealant is an adhesive sealant, in the water vapor barrier performance evaluation test, the second test sheet is dried at 130°C for 60 minutes; a 50 mm square glass plate made of alkali-free glass is washed with boiled isopropyl alcohol for 5 minutes and dried; calcium is deposited on the central part of one side of the glass plate to form a calcium film with a thickness of 200 nm; the sealant layer of the second test sheet and the side of the glass plate with the calcium film 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; the time T when the evaluation sample is placed in the constant temperature and humidity chamber is measured. P1 From there, at the point T when the sealing distance X1 [mm] of the evaluation sample stored in the constant temperature and humidity chamber becomes "X2 + 0.1 mm", P2 It is possible to measure the time t [hours] at which the decrease begins; and to calculate the constant K based on the following formula (1).

[0024] Furthermore, for example, if the sealant is a thermosetting sealant, the water vapor barrier performance evaluation test involves: 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 onto the central part of one side of the glass plate to form a 200 nm thick calcium film; bonding the sealant layer of the second test sheet and the calcium film side of the glass plate in a nitrogen atmosphere, and curing it at 100°C for 60 minutes to obtain an evaluation sample; measuring the sealing distance X2 [mm] of the evaluation sample; placing the evaluation sample in a constant temperature and humidity chamber at 85°C and 85% RH; and determining the time T when the evaluation sample is placed in the constant temperature and humidity chamber. P1 From there, at the point T when the sealing distance X1 [mm] of the evaluation sample stored in the constant temperature and humidity chamber becomes "X2 + 0.1 mm", P2 It is possible to measure the time t [hours] at which the decrease begins; and to calculate the constant K based on the following formula (1).

[0025] The second test sheet refers to a sheet comprising a support film having a 30 μm thick aluminum foil and a 25 μm thick polyethylene terephthalate film, and a layer of 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 the portion of one side of the glass plate excluding the peripheral area. Furthermore, the peripheral area of ​​one side of the glass plate refers to the area of ​​one side of the glass plate from 0 mm to 2 mm 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 coincides with the distance between the edge of the sealant layer and the edge of the calcium film.

[0026]

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[0027] (In equation (1), X1 is the sealing distance [mm] from the edge of the evaluation sample to the edge of the calcium film after immersion in a constant temperature and humidity chamber. t is the time [in hours] when the decrease begins so that X1 = X2 + 0.1. X2 is the sealing distance [mm] from the edge of the evaluation sample to the edge of the calcium membrane before immersion in the constant temperature and humidity chamber.

[0028] The following diagrams illustrate the mechanism of the aforementioned water vapor barrier performance evaluation test and the significance of the constant K, which is a water vapor penetration barrier parameter determined by this test.

[0029] Figure 1 is a schematic cross-sectional view showing an evaluation sample 10 produced in a water vapor barrier performance evaluation test. As shown in Figure 1, the evaluation sample 10 produced in a water vapor barrier performance evaluation test comprises a square glass plate 100 washed with boiled isopropyl alcohol, a calcium film 200 formed on one side 100U of the glass plate 100, and a second test sheet 300 bonded to the surface 100U of the glass plate 100. The calcium film 200 is not formed in the peripheral area 110U of the surface 100U of the glass plate 100, at a distance L from the edge 100E of the glass plate 100 to 2 mm. On the other hand, the calcium film 200 is formed in the 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 vapor deposition using a mask (not shown) that covers the peripheral area 110U, and has high purity (e.g., purity of 99.8% or higher). Furthermore, the second test sheet 300 comprises a sealant layer 310 and a support film 320 comprising a polyethylene terephthalate film 321 and aluminum foil 322, with the sealant layer 310 being bonded 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 support film 320 of the evaluation sample 10 have a sufficiently high ability to block moisture. Therefore, moisture surrounding the evaluation sample 10 can pass through the edge 310E of the sealant layer 310, move within the sealant layer 310 in the in-plane direction (perpendicular to the thickness direction), and penetrate the calcium film 200, as indicated by arrow A1. Consequently, the calcium film 200 of the evaluation sample 10 stored in a constant temperature and humidity chamber can be gradually oxidized from the edge 200E toward the center 200C.

[0031] Figure 2 is a schematic plan view showing the evaluation sample 10 as seen from the glass plate 100 side before it is placed in the constant temperature and humidity chamber. Figure 3 is a schematic plan view showing the evaluation sample 10 as seen from the glass plate 100 side after it has been placed in the constant temperature and humidity chamber. As shown in Figure 2, before being placed in the constant temperature and humidity chamber, the evaluation sample 10 shows no oxidation of the calcium film 200 due to moisture infiltration. Therefore, the sealing distance X2 between the end 10E of the evaluation sample 10 and the end 200E of the calcium film 200 can normally maintain the dimensions of the calcium film 200 immediately after its formation. However, when the evaluation sample 10 is placed in the constant temperature and humidity chamber, moisture infiltrates the calcium film 200 through the sealant layer 310 (see Figure 1), and the calcium that comes into contact with the water is oxidized, potentially becoming transparent calcium oxide. Therefore, as shown in Figure 3, the calcium film 200 may gradually change from the end 200E towards the center 200C due to moisture infiltration, becoming a transparent calcium oxide film 210. This change is observed as a reduction in the calcium film 200. Therefore, after the evaluation sample 10 is placed in a constant temperature and humidity chamber, 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 equation. Therefore, in the water vapor barrier performance evaluation test, the decrease start time t (i.e., the time when the evaluation sample 10 is placed in the constant temperature and humidity chamber) is used as the time required for moisture to move through the sealant layer 310 over a sealing distance X1. P1From there, at the point T when the sealing distance X1 [mm] of the evaluation sample 10 stored in the constant temperature and humidity chamber becomes "X2 + 0.1 mm", P2 The time elapsed and the distance traveled (X1) are applied to Fick's diffusion equation, represented by equation (1), to derive the constant K as a water vapor intrusion barrier parameter.

[0033] Therefore, the evaluation sample 10 corresponds to a model of an electronic device, and the calcium film 200 can correspond to a lead-containing part that should be sealed by the sealant. The water vapor intrusion barrier parameter represents the degree of the sealant's ability to suppress the in-plane penetration of moisture provided in the electronic device. Specifically, a smaller water vapor intrusion barrier parameter indicates that the sealant is more effective at suppressing moisture intrusion. When a sealant having a water vapor intrusion barrier parameter within the above range is used to seal a lead-containing part in an electronic device, it can suppress the intrusion of moisture into the lead-containing part. Therefore, it can suppress the oxidation of components contained in the lead-containing part and suppress the outflow of lead from the lead-containing part.

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

[0035] [4. Inorganic fillers that the sealant according to the first embodiment may contain] The encapsulant according to the first embodiment of the present invention includes an inorganic filler. Part or all of the inorganic filler can exhibit hygroscopicity and lead adsorption in the encapsulant, which is a resin composition containing the inorganic filler and a binder resin. One type of inorganic filler may be used alone, or two or more types may be used in any ratio. For example, an inorganic filler that can exhibit hygroscopicity in the encapsulant may be used in combination with another inorganic filler that can exhibit lead adsorption in the encapsulant. The fact that a lead-adsorbing inorganic filler can exhibit lead adsorption in a encapsulant, which is a resin composition containing a binder resin, is a phenomenon that the present inventors have discovered for the first time.

[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, such as represented by 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 is, 0≦m i Represents a number that satisfies <1, ni represents a positive number.

[0039] In equation (I), Mi 2+ Preferably Mg 2+ It represents Mi 3+ Preferably Al 3+ It represents Ai ni- Preferably CO3 2- It represents.

[0040] Mii 2+ xii Al2(OH) 2xii+6-niizii (Aii nii- ) zii ·m ii H2O (II) (In equation (II), Mii 2+ Mg 2+ Zn 2+ These represent divalent metal ions, Aii nii- CO3 2- Cl - NO 3- These represent anions with a nii valency, xii represents a positive number greater than or equal to 2. zii represents a positive number less than or equal to 2, m ii This represents a positive number, nii represents a positive number.

[0041] In equation (II), Mii 2+ Preferably Mg 2+ It represents Aii. nii- Preferably CO3 2- It represents.

[0042] Uncalcined hydrotalcite can exhibit excellent lead adsorption properties in the sealant. Therefore, for example, when uncalcined hydrotalcite is appropriately combined with an inorganic filler that can exhibit hygroscopic properties in the sealant, a sealant having lead adsorption parameters and water vapor penetration barrier parameters within the above-mentioned range can be obtained.

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

[0044] Weigh 1.5 g of hydrotalcite using a balance and measure its initial mass. Place the weighed hydrotalcite in a small environmental test chamber (SH-222, manufactured by ESPEC Corporation) set to atmospheric pressure, 60°C, and 90% RH (relative humidity) for 200 hours to allow it to absorb moisture, and measure its mass after moisture absorption. Then, calculate the saturation water absorption rate using the following formula (i). Saturation 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 typically 15% by mass or more, preferably 15.1% by mass or more, and particularly preferably 15.2% by mass or more.

[0046] The thermogravimetric analysis 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 the pan open without a lid, under a nitrogen flow rate of 200 mL / min, and heating from 30°C to 550°C at a rate of 10°C / min. The thermogravimetric analysis result can be used to calculate the thermogravimetric analysis result using the following formula (ii). Thermal weight loss rate (mass%) = 100 × (mass before heating - mass when the specified temperature is reached) / mass before heating (ii)

[0047] When measuring powder X-ray diffraction of uncalcined hydrotalcite, typically there is only one peak around 2θ of 8° to 18°, or the relative intensity ratio of low-angle diffraction intensity to high-angle diffraction intensity (low-angle diffraction intensity / high-angle diffraction intensity) is outside the range of 0.001 to 1,000. Low-angle diffraction intensity refers to the diffraction intensity of the peak or shoulder that appears at the low-angle side (smaller 2θ). High-angle diffraction intensity refers to the diffraction intensity of the peak or shoulder that appears at the high-angle side (larger 2θ).

[0048] Powder X-ray diffraction measurements of hydrotalcite, such as uncalcined hydrotalcite, can be performed using a powder X-ray diffractometer (Empyrean, PANalytical). Powder X-ray diffraction measurements can be performed under the following conditions: counter cathode CuKα (1.5405 Å), voltage: 45 V, current: 40 mA, sampling width: 0.0260°, scanning speed: 0.0657° / s, and measurement diffraction angle range (2θ): 5.0131~79.9711°. 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 the second derivative.

[0049] Examples of uncalcined hydrotalcite include "Alma Kaiser 1" (average particle size: 620 nm), "Magcellar 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.). Uncalcined hydrotalcite may be used individually or in combination of two or more types in any ratio.

[0050] Semi-calcined hydrotalcite refers to a metal hydroxide with a layered crystalline structure obtained by calcining uncalcined hydrotalcite, where the amount of interlayer water is reduced or eliminated. "Interlayer water," when explained using the chemical formula, refers to "H2O" as shown in the chemical formula of the uncalcined natural hydrotalcite and hydrotalcite-like compounds mentioned above.

[0051] Semi-calcined hydrotalcite exhibits excellent lead adsorption and hygroscopic properties in the sealant. Therefore, when semi-calcined hydrotalcite is used appropriately, a sealant having lead adsorption parameters and water vapor penetration barrier parameters within the above-mentioned range can be obtained. The lead adsorption properties of semi-calcined hydrotalcite were discovered for the first time by the present inventors.

[0052] Semi-calcined hydrotalcite typically has a different saturation water absorption rate than uncalcined hydrotalcite, and can therefore be distinguished by this rate. The saturation water absorption rate of semi-calcined hydrotalcite is usually 1% by mass or more, preferably 3% by mass or more, more preferably 5% by mass or more, and is usually less than 20% by mass. The saturation water absorption rate of semi-calcined hydrotalcite can be measured in the same way as the saturation water absorption rate of uncalcined hydrotalcite.

[0053] Semi-calcined hydrotalcite typically has a different thermal weight loss rate than uncalcined hydrotalcite, and can therefore be distinguished by this 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. Furthermore, 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 in the same way as the thermal weight loss rate of uncalcined hydrotalcite.

[0054] Partially calcined hydrotalcite can usually be distinguished from uncalcined hydrotalcite by powder X-ray diffraction, as the peaks and relative intensity ratios measured by powder X-ray diffraction differ. When powder X-ray diffraction is measured for partially calcined hydrotalcite, it typically shows a peak split into two around 2θ of 8° to 18°, or a peak with a shoulder formed by the combination of two peaks, and the relative intensity ratio (low-angle diffraction intensity / high-angle diffraction intensity) is 0.001 to 1,000. Powder X-ray diffraction of partially calcined hydrotalcite can be performed using the same method as powder X-ray diffraction of uncalcined hydrotalcite.

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

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

[0057] Calcined hydrotalcite exhibits excellent lead adsorption and hygroscopic properties in the sealant. Therefore, when calcined hydrotalcite is used appropriately, a sealant having lead adsorption parameters and water vapor penetration barrier parameters within the above-mentioned range can be obtained. The lead adsorption properties of calcined hydrotalcite were discovered for the first time by the present inventors.

[0058] Calcined hydrotalcite typically has a different saturation water absorption rate than uncalcined hydrotalcite and semi-calcined hydrotalcite, and can therefore be distinguished by their saturation water absorption rates. The saturation 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 saturation water absorption rate of calcined hydrotalcite can be measured in the same way as the saturation water absorption rate of uncalcined hydrotalcite.

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

[0060] Calcined hydrotalcite typically exhibits different peaks and relative intensity ratios measured by powder X-ray diffraction compared to uncalcined and partially calcined hydrotalcite, thus allowing them to be distinguished by these parameters. When calcined hydrotalcite is measured by powder X-ray diffraction, it typically does not have a characteristic peak in the 2θ range of 8° to 18°, but has a characteristic peak at 2θ of 43°. The measurement of powder X-ray diffraction of calcined hydrotalcite can be performed using the same method as that used for uncalcined hydrotalcite.

[0061] Examples of calcined hydrotalcite include "KW-2200" (manufactured by Kyowa Chemical Industry Co., Ltd., average particle size: 400 nm). Calcined hydrotalcite may be used alone or in combination of two or more types in any ratio.

[0062] (4.2. Calcium Oxide) Another example of an inorganic filler is calcium oxide. Calcium oxide can exhibit excellent lead adsorption and hygroscopic properties in sealants. Therefore, when calcium oxide is used appropriately, a sealant having lead adsorption parameters and water vapor penetration barrier parameters within the above-mentioned range can be obtained. The lead adsorption properties of calcium oxide were discovered for the first time by the present inventors. Calcium oxide may also be used in a mixture with other inorganic fillers. Examples of such mixtures include calcined dolomite (a mixture containing calcium oxide and magnesium oxide).

[0063] (4.3. Zeolite) Another example of an inorganic filler is zeolite. Zeolite can exhibit excellent lead adsorption properties in sealants. Furthermore, by appropriately adjusting its composition, zeolite can exhibit excellent hygroscopic properties in sealants. Therefore, when zeolite is used appropriately, a sealant having lead adsorption parameters and water vapor penetration barrier parameters within the above-mentioned range can be obtained.

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

[0065] Zeolites typically have pores. The pore size of the zeolite is preferably adjusted to achieve high lead adsorption and hygroscopic properties. The pore size of the zeolite is preferably 6 Å or less, more preferably 5 Å or less, and even more preferably 4 Å or less. ("Å" is 1.0 × 10⁻¹⁴) -10 This represents m. The pore size of zeolite can be measured by gas adsorption or mercury intrusion.

[0066] (4.4. Examples of other inorganic fillers) Another example of an inorganic filler is a hygroscopic metal oxide 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 hygroscopic properties in the sealant. Therefore, for example, by appropriately combining a hygroscopic metal oxide with an inorganic filler that can exhibit lead adsorption properties in the sealant, a sealant having lead adsorption parameters and water vapor penetration barrier parameters within the ranges mentioned above can be obtained.

[0067] (4.5. Preferred inorganic fillers) Among the examples mentioned above, semi-calcined hydrotalcite, calcined hydrotalcite, calcium oxide, and zeolite are preferred as inorganic fillers. These exhibit excellent lead adsorption and hygroscopic properties in the sealant, allowing the lead adsorption parameters and water vapor infiltration barrier parameters of the sealant to be easily adjusted to the aforementioned ranges. 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 fillers) Inorganic fillers may be those that have been surface-treated with an appropriate surface treatment agent. Unless otherwise specified, surface-treated fillers are also included in the term "inorganic filler." Examples of surface treatment agents include higher fatty acids, alkylsilane compounds, and silane coupling agents, with higher fatty acids and alkylsilane compounds being preferred. Surface treatment agents may be used individually or in combination of two or more types in any ratio.

[0069] Examples of higher fatty acids include stearic acid, montanic acid, myristic acid, and palmitic acid, which have 18 or more carbon atoms. Among these, stearic acid is preferred.

[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 silane coupling agents 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-aminopropyl Examples of such coupling agents include amino silane coupling agents such as pyrdimethoxymethylsilane; ureido silane coupling agents such as 3-ureidopropyltriethoxysilane; vinyl silane coupling agents such as vinyltrimethoxysilane, vinyltriethoxysilane, and vinylmethyldiethoxysilane; styryl silane coupling agents such as p-styryltrimethoxysilane; acrylate silane coupling agents such as 3-acrylooxypropyltrimethoxysilane and 3-methacryloxypropyltrimethoxysilane; isocyanate silane coupling agents such as 3-isocyanatetopropyltrimethoxysilane; sulfide silane coupling agents such as bis(triethoxysilylpropyl)disulfide and bis(triethoxysilylpropyl)tetrasulfide; phenyltrimethoxysilane; methacryloxypropyltrimethoxysilane; imidazole silane; triazine silane; and others.

[0072] The amount of surface treatment agent may vary depending on the type of inorganic filler and surface treatment agent. The amount of surface treatment agent used for surface treatment per 100 parts by mass of untreated inorganic filler is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, particularly preferably 1.0 part by mass or more, preferably 10 parts by mass or less, more preferably 8 parts by mass or less, and particularly preferably 6 parts by mass or less. When surface treatment is performed with an amount of surface treatment agent within the above range, aggregation can be suppressed and the surface area of ​​the inorganic filler can be increased, making it easier for the inorganic filler to exhibit lead adsorption and hygroscopic properties.

[0073] There are no restrictions on the surface treatment method for inorganic fillers; for example, the inorganic filler may be mixed with a surface treatment agent for surface treatment. In particular, when hydrotalcite such as semi-calcined hydrotalcite is used as the inorganic filler, it is preferable to perform the surface treatment by, for example, spraying the surface treatment agent while stirring the untreated hydrotalcite in a mixer. The treatment temperature is preferably room temperature. Furthermore, stirring is preferably carried out for 5 to 60 minutes. Examples of mixers 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. Alternatively, for example, the surface treatment may be performed by crushing the hydrotalcite and simultaneously mixing the hydrotalcite with the surface treatment agent.

[0074] (4.7. Particle size of inorganic fillers) 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, 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, also preferably 1,000 nm or less, and particularly preferably 800 nm or less. Furthermore, 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, also preferably less than 10 μm, and particularly preferably less than 5 μm. When an inorganic filler having an average particle size within this range is used, the processability of the sealant is good, and the sealant sheet can be easily manufactured.

[0075] The average particle size of inorganic fillers can be determined by measuring the particle size distribution on a volume basis using laser diffraction scattering particle size distribution measurement (JIS Z 8825) and finding the median diameter of that particle size distribution.

[0076] (4.8. Specific surface area of ​​inorganic fillers) The BET specific surface area of ​​the inorganic filler is preferably 1 m². 2 / g or more, comfortable 5m 2 It is 1 / g or more, preferably 250m 2 / g or less, more preferably 200m 2 The amount is less than or equal to / g. In particular, when the inorganic filler contains hydrotalcite such as semi-calcined hydrotalcite, it is preferable that the hydrotalcite has a BET specific surface area within the above range. When an inorganic filler having such a BET specific surface area is used, the processability of the sealant is improved, and the sealant sheet can be easily manufactured.

[0077] The BET specific surface area of ​​inorganic fillers can be calculated using the BET method by adsorbing nitrogen gas onto the sample surface using a specific surface area measuring device (Macsorb HM Model 1210, manufactured by Mountec Co., Ltd.) and then using the BET multi-point method.

[0078] (4.9. Amount of inorganic filler) The amount of inorganic filler relative to 100% by mass of the nonvolatile components of the sealant 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, preferably 80% by mass or less, more preferably 75% by mass or less, even more preferably 70% by mass or less, and may be, for example, 65% by mass or less or 60% by mass or less. When the amount of inorganic filler is above the lower limit of the above range, the lead adsorption and hygroscopic properties of the inorganic filler are greatly exhibited, making it easy to adjust the lead adsorption parameter and water vapor intrusion barrier parameter of the sealant to the above range. Furthermore, when the amount of inorganic filler is below the upper limit of the above range, the viscosity and wettability of the sealant can be improved, thereby improving the adhesion between the sealant and the target to be sealed, such as lead-containing parts and electrodes. Therefore, the formation of gaps between the target to be sealed and the sealant can be effectively suppressed, thereby improving sealing performance, and particularly effectively suppressing moisture intrusion and lead leakage.

[0079] [5. Overview of components other than inorganic fillers that may be included in the sealant according to the first embodiment] The sealant according to the first embodiment of the present invention includes a binder resin in combination with the inorganic filler described above. The binder resin can perform some or all of the following functions: suppressing the entry of foreign matter such as dust into electronic devices; holding the inorganic filler so that it does not detach from the sealing portion; ensuring that the sealant adheres tightly to the sealing target such as a lead adsorption portion; and suppressing the intrusion of moisture.

[0080] Furthermore, the encapsulant according to the first embodiment of the present invention may contain any components in combination with the inorganic filler and binder resin. The type and ratio of the binder resin and any components can be appropriately selected according to the type and amount of inorganic filler and the properties required of the encapsulant.

[0081] The following describes binder resins and optional components, using examples of components suitable for adhesive sealants and thermosetting sealants. An adhesive sealant is a type of sealant that exhibits adhesiveness and can seal objects by pressure. Adhesive sealants can usually be bonded by applying pressure for a relatively short time at room temperature, and therefore can function as pressure-sensitive adhesives. A thermosetting sealant is a type of sealant that achieves sealing by heat curing while in contact with the object to be sealed. However, the components contained in a sealant are not limited to the examples described below. Therefore, components shown as examples suitable for adhesive sealants may also be used in other sealants (e.g., thermosetting sealants). Similarly, components shown as examples suitable for thermosetting sealants may also be used in other sealants (e.g., adhesive sealants).

[0082] [6. Description of components suitable for the adhesive sealant according to the first embodiment] (6.1. Thermoplastic resins as binder resins) Examples of components that can be included in a encapsulant in combination with an inorganic filler include thermoplastic resins. Thermoplastic resins are preferred as binder resins for adhesive encapsulants. Thermoplastic resins may be used individually or in combination of two or more types in any ratio.

[0083] There are no particular restrictions on the thermoplastic resin; for example, a thermoplastic resin suitable as a binder resin for thermosetting encapsulants, as described later, may be used. Among these, polyolefin resins are a preferred example of thermoplastic resins. When polyolefin resins are combined with an inorganic filler containing one or more selected from the group consisting of semi-calcined hydrotalcite, calcined hydrotalcite, and calcium oxide, an encapsulant with excellent transparency can be obtained.

[0084] As the polyolefin resin, a resin having a skeleton derived from an olefin monomer can be used. Examples of polyolefin resins include those described in International Publication No. 2011 / 62167 and International Publication No. 2013 / 108731. Among these, the isobutylene-modified resin described in International Publication No. 2011 / 62167 and the styrene-isobutylene-modified resin described in International Publication No. 2013 / 108731 are preferred. Further preferred polyolefin resins include, for example, polyethylene resins, polypropylene resins, polybutene resins, and polyisobutylene resins. The polyolefin resin may be a homopolymer or a copolymer. The copolymer may be a random copolymer or a block copolymer.

[0085] Examples of copolymers include copolymers of two or more olefins; copolymers of olefins with monomers other than olefins, such as non-conjugated dienes and styrene. Examples of preferred copolymers include ethylene-non-conjugated diene copolymers, ethylene-propylene copolymers, ethylene-propylene-non-conjugated diene copolymers, ethylene-butene copolymers, propylene-butene copolymers, propylene-butene-non-conjugated diene copolymers, styrene-isobutylene copolymers, and styrene-isobutylene-styrene copolymers.

[0086] The polyolefin resin may include 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 adhesion and heat and humidity resistance of the sealant can be improved.

[0087] Examples of acid anhydride groups include groups derived from succinic anhydride, maleic anhydride, and glutaric anhydride. There may be one or more types of acid anhydride groups. Polyolefin resins having acid anhydride groups can be produced, for example, by graft modification of a polyolefin resin with an unsaturated compound having acid anhydride groups under radical reaction conditions. Alternatively, polyolefin resins having acid anhydride groups can be produced, for example, by radical copolymerization of an unsaturated compound having acid anhydride groups with an olefin.

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

[0089] The amount of polyolefin resin having acid anhydride groups, relative to 100% by mass of the total amount of polyolefin resin, is preferably 0% by mass or more, more preferably 10% by mass or more, particularly preferably 11% by mass or more, 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 include a polyolefin resin having epoxy groups. When a polyolefin resin having epoxy groups is used, the adhesion and heat and humidity resistance of the sealant can be improved.

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

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

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

[0094] Polyolefin resins may be used individually or in combination of two or more types in any ratio. In particular, it is preferable to use a combination of a polyolefin resin having acid anhydride groups and a polyolefin resin having epoxy groups. When a polyolefin resin having acid anhydride groups and a polyolefin resin having epoxy groups are used in combination, a crosslinked structure can be formed by the reaction between the acid anhydride groups and the epoxy groups, thereby effectively enhancing the ability of the sealant to suppress moisture penetration. In this case, the molar ratio of epoxy groups to acid anhydride groups (epoxy groups:acid anhydride groups) is preferably 100:10 to 100:400, more preferably 100:50 to 100:200, and particularly preferably 100:90 to 100:150.

[0095] The following describes specific examples of polyolefin resins. Specific examples of polyisobutylene resins include BASF's "Opanol B100" (viscosity-average molecular weight: 1,110,000) and BASF's "B50SF" (viscosity-average molecular weight: 400,000).

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

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

[0098] Specific examples of polyethylene-based 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 Seikoh PMC's "T-YP341" (glycidyl methacrylate-modified propylene-butene random copolymer, amount of butene units per 100% total mass of propylene and butene units: 29% by mass, epoxy group concentration: 0.638 mmol / g, number average molecular weight: 155,000) and Seikoh PMC's "T-YP279" (maleic anhydride-modified propylene-butene random copolymer, amount of butene units per 100% total mass of propylene and butene units: 36% by mass, acid anhydride group concentration: 0.464 mmol / g, number average molecular weight: 35,000), Seikoh PMC's "T-YP276" (glycidyl methacrylate-modified propylene-butene random copolymer, amount of butene units per 100% mass of total propylene and butene units: 36% by mass, epoxy group concentration: 0.638 mmol / g, number average molecular weight: 57,000), Seikoh PMC's "T-YP312" (maleic anhydride-modified propylene-butene random copolymer, amount of butene units per 100% mass of total propylene and butene units: 29% by mass, acid anhydride) Epoxy group concentration: 0.464 mmol / g, number average molecular weight: 60,900), Seikoh PMC's "T-YP313" (glycidyl methacrylate-modified propylene-butene random copolymer, amount of butene units per 100% by mass of total propylene and butene units: 29% by mass, epoxy group concentration: 0.638 mmol / g, number average molecular weight: 155,000), Seikoh PMC's "T-YP429" (maleic anhydride-modified ethylene-methyl methacrylate copolymer, amount of methyl methacrylate per 100% by mass of total ethylene and methyl methacrylate units) (Amount of methyl methacrylate units: 32% by mass, acid anhydride group concentration: 0.46 mmol / g, number average molecular weight: 2,300), Seikoh PMC's "T-YP430" (maleic anhydride-modified ethylene-methyl methacrylate copolymer, amount of methyl methacrylate units per 100% by mass of total ethylene and methyl methacrylate units: 32% by mass, acid anhydride group concentration: 1.18 mmol / g, number average molecular weight: 4,500), Seikoh PMC's "T-YP431" (glycidyl methacrylate-modified ethylene-methyl methacrylate copolymer, epoxy group concentration: 0.Examples include "T-YP432" (glycidyl methacrylate-modified ethylene-methyl methacrylate copolymer, epoxy group concentration: 1.63 mmol / g, number average molecular weight: 3,100) manufactured by Seikoh PMC Co., Ltd. (64 mmol / g, number average molecular weight: 2,400).

[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 a thermoplastic resin having a number average molecular weight within this range is used, the repulsion of the varnish of the sealant during application can be suppressed, thereby effectively increasing the ability of the sealed part to suppress moisture penetration and increasing the mechanical strength of the sealed part. Furthermore, 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 using thermoplastic resins with a number-average molecular weight within this range, it is possible to improve the coatability of the sealant varnish and enhance the compatibility between the thermoplastic resin and other components.

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

[0102] The weight-average molecular weight of thermoplastic resins 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, preferably 1,000,000 or less, more preferably 800,000 or less, even more preferably 600,000 or less, and particularly preferably 500,000 or less.

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

[0104] Thermoplastic resins are preferably amorphous. Amorphous means that the resin does not have a distinct melting point. Specifically, amorphous means that when the melting point is measured by DSC (Differential Scanning Calorimetry), no distinct peak is observed. When amorphous thermoplastic resins are used, the thickening of the sealant varnish can be suppressed, thus improving the fluidity of the varnish.

[0105] The amount of thermoplastic resin is preferably 1% by mass or more, more preferably 3% by mass or more, even more preferably 5% by mass or more, even more preferably 7% by mass or more, even more preferably 10% by mass or more, even more preferably 15% by mass or more, and particularly preferably 20% by mass or more, relative to 100% by mass of the nonvolatile components of the sealant. When the amount of thermoplastic resin is within this range, the ability of the sealant to suppress moisture penetration can be effectively enhanced, and the transparency of the sealant can be improved. Furthermore, the amount of thermoplastic resin is preferably 80% by mass or less, more preferably 75% by mass or less, even more preferably 70% by mass or less, even more preferably 60% by mass or less, even more preferably 55% by mass or less, and particularly preferably 50% by mass or less, relative to 100% by mass of the nonvolatile components of the sealant. When the amount of thermoplastic resin is within this range, the coatability and compatibility of the sealant with the varnish are improved, so the ability of the sealant to suppress moisture penetration can be effectively enhanced, and the handling of the sealant can be improved (e.g., suppression of tack).

[0106] The amount of 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, preferably 300 parts by mass or less, more preferably 200 parts by mass or less, and particularly preferably 150 parts by mass or less, per 100 parts by mass of inorganic filler. In particular, when the thermoplastic resin contains a polyolefin resin having acid anhydride groups, the amount of the polyolefin resin having acid anhydride groups is preferably 1 part by mass or more, preferably 3 parts by mass or more, particularly preferably 5 parts by mass or more, preferably 30 parts by mass or less, more preferably 25 parts by mass or less, and particularly preferably 23 parts by mass or less, per 100 parts by mass of inorganic filler. Furthermore, when the thermoplastic resin contains a polyolefin resin having epoxy groups, the amount of the polyolefin resin having epoxy groups is preferably 1 part by mass or more, preferably 2 parts by mass or more, particularly preferably 3 parts by mass or more, preferably 30 parts by mass or less, more preferably 28 parts by mass or less, and particularly preferably 26 parts by mass or less, per 100 parts by mass of 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 requirements. When thermoplastic resin is used in such quantities, the sealant can particularly effectively suppress the infiltration of moisture and the leakage of lead.

[0107] (6.2. Tackifiers) Examples of components that can be included in an inorganic filler in a encapsulant include tackifiers. Tackifiers are compounds that can improve the tackiness of an encapsulant when used in combination with a plastic resin, and are also called "tackifiers." Tackifiers are suitable for adhesive-type encapsulants, and therefore are preferably used in combination with thermoplastic resins. One type of tackifier may be used alone, or two or more types may be used in any ratio.

[0108] Examples of tackifying resins include terpene resins, modified terpene resins (hydrogenated terpene resins, terpene-phenol copolymer resins, aromatically 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 their hydrides, etc.).

[0109] Among the examples mentioned above, petroleum resins are preferred from the viewpoint of adhesion of the sealant, ability to suppress moisture penetration, and transparency. Examples of petroleum resins include aliphatic petroleum resins, aromatic petroleum resins, aliphatic aromatic copolymer petroleum resins, and hydrogenated hydrocarbon petroleum resins. From the viewpoint of adhesion, ability to suppress moisture penetration, and compatibility, aromatic petroleum resins, aliphatic aromatic copolymer petroleum resins, hydrogenated hydrocarbon petroleum resins, dicyclopentadiene petroleum resins, and their hydrides are more preferred. Furthermore, from the viewpoint of transparency, hydrogenated hydrocarbon petroleum resins and dicyclopentadiene petroleum resins are particularly preferred.

[0110] As the hydrogenated hydrocarbon petroleum resin, an aromatic petroleum resin that has been hydrogenated may be used. 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%. Hydrogenated hydrocarbon petroleum resins having a hydrogenation rate within the above range have little discoloration, excellent transparency, and can be manufactured at a low production cost. The hydrogenation rate is the ratio of hydrogen atoms in the aromatic ring before hydrogenation to hydrogenation. 1 This can be determined from the ratio of peak intensities in 1H-NMR.

[0111] As hydrogenated hydrocarbon petroleum resins, cyclohexane ring-containing hydrogenated petroleum resins and dicyclopentadiene-based hydrogenated petroleum resins are particularly preferred.

[0112] The following are specific examples of petroleum resins. 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 aromatically 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 the Clearon P, Clearon M, and Clearon K series (all manufactured by Yasuhara Chemical Co., Ltd.). Examples of terpene phenol copolymer resins 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 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 the Escorez 5300 series and 5600 series (both manufactured by ExxonMobil); T-REZ OP501, T-REZ PR801, T-REZ PR803, T-REZ HA085, T-REZ HA103, T-REZ HA105, T-REZ HA125, T-REZ HB103, T-REZ HB125 (all hydrogenated dicyclopentadiene petroleum resins, manufactured by JXTG Energy Corporation); Quintone 1325, Quintone 1345 (both manufactured by Nippon Zeon Corporation); iMarb S-100, iMarb S-110, iMarb P-100, iMarb P-125, iMarb P-140 (all hydrogenated dicyclopentadiene petroleum resins, manufactured by Idemitsu Kosan Co., Ltd.). Examples of aromatic petroleum resins include ENDEX155 (manufactured by Eastman Corporation); 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 Energy Corporation); Petocol LX, Petocol 120, Petocol 130, Petocol 140 (all manufactured by Tosoh Corporation). Examples of aliphatic aromatic copolymer petroleum resins include Quintone D100 (manufactured by Zeon Corporation), T-REZ RD104, and T-REZ PR802 (manufactured by JXTG Energy Corporation). Examples of cyclohexane ring-containing hydrogenated petroleum resins include Alcon P-90, Alcon P-100, Alcon P-115, Alcon P-125, Alcon P-140, Alcon M-90, Alcon M-100, Alcon M-115, and Alcon M-135 (all manufactured by Arakawa Chemical Co., Ltd.). Examples of cyclohexane ring-containing saturated hydrocarbon resins include TFS13-030 (manufactured by Arakawa Chemical Co., Ltd.). Examples of ultra-pale 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 Co., Ltd.).

[0113] The number-average molecular weight of the tackifier is preferably 100 to 2,000, more preferably 700 to 1,500, and even more preferably 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 even more preferably 100°C to 150°C. The softening point can be measured by the ring-and-ball method in accordance with JIS K2207. When using a tackifier with such a softening point, sealing with a sealing sheet using a sealing agent can be facilitated, and the heat resistance of the sealing agent can be improved.

[0115] The amount of tackifier is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more, relative to 100% by mass of the non-volatile components of the sealant. When the amount of tackifier is within this range, the adhesion of the sealant can be effectively enhanced. Furthermore, the amount of 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, relative to 100% by mass of the non-volatile components of the sealant. When the amount of tackifier is within this range, the ability of the sealant to suppress moisture penetration can be effectively enhanced.

[0116] (6.3. Crosslinking agents and crosslinking accelerators) Examples of components that a encapsulant may contain in combination with an inorganic filler include crosslinking agents and crosslinking accelerators. Crosslinking agents and crosslinking accelerators can react with reactive groups of other components to form a crosslinked structure. For example, if a thermoplastic resin has reactive groups such as acid anhydride groups and epoxy groups, the crosslinking agent and crosslinking accelerator can react with these reactive groups to form a crosslinked structure. However, the thermoplastic resin and tackifier mentioned above are not included in the crosslinking agent and crosslinking accelerator. Crosslinking agents and crosslinking accelerators may be used individually or in combination of two or more types in any ratio.

[0117] Examples of crosslinking agents and crosslinking accelerators include amine compounds, guanidine compounds, imidazole compounds, phosphonium compounds, and phenolic compounds.

[0118] Examples of 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, DBU-p-toluenesulfonate, DBU-formate, and DBU-phenol novolac resin salt; tertiary amines such as benzyldimethylamine, 2-(dimethylaminomethyl)phenol, and 2,4,6-tris(diaminomethyl)phenol and their salts; 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]deca-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0]deca-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-methylimidazole, 2-phenyl-4-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 2-phenyl-4,5-bis(hydroxymethyl)imidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-dodecylimidazole, 2-heptadecylimidazole, and 1,2-dimethylimidazole.

[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 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 Toto Kasei Co., Ltd.), and TD2090 (manufactured by DIC Corporation). In particular, a specific example of a triazine skeleton-containing phenolic compound is LA3018 (manufactured by DIC Corporation). Specific examples of triazine skeleton-containing phenol novolac compounds include LA7052, LA7054, and LA1356 (manufactured by DIC Corporation).

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

[0124] Examples of crosslinking agents include resins having functional groups that can react with epoxy groups. Examples of 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 acid anhydride groups include groups derived from succinic anhydride, maleic anhydride, and glutaric anhydride. As resins having functional groups that can react with epoxy groups, for example, the resin described in International Publication No. 2017 / 057708 can be used.

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

[0126] The amount of the crosslinking agent and 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 nonvolatile components of the sealant. When the amount of the crosslinking agent and crosslinking accelerator is within this range, the handling properties of the sealant can be improved (e.g., tack suppression). Furthermore, the amount of the crosslinking agent and crosslinking accelerator is preferably 5% by mass or less, and more preferably 2.5% by mass or less, based on 100% by mass of the nonvolatile components of the sealant. When the amount of the crosslinking agent and crosslinking accelerator is within this range, the ability of the sealant to suppress moisture penetration can be effectively enhanced.

[0127] (6.4. Other components suitable for adhesive sealants) Among the components that can be included in a sealant, plasticizers are an example of components suitable for adhesive sealants. Plasticizers can improve the flexibility and moldability of the sealant. As plasticizers, materials that are liquid at room temperature (25°C) are preferred. Examples of plasticizers include paraffinic process oils, naphthenic process oils, liquid paraffin, polyethylene wax, polypropylene wax, mineral oils such as petrolatum, 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. From the viewpoint of adhesion, the weight-average molecular weight of the plasticizer is preferably 500 to 5,000, and more preferably 1,000 to 3,000. One type of plasticizer may be used alone, or two or more types may be used in any ratio. The amount of plasticizer is preferably 50% by mass or less relative to 100% by mass of the non-volatile components in the encapsulant.

[0128] Examples of components suitable for adhesive-type sealants among the components that can be included in a sealant 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 powder, nylon powder, and fluororesin powder; thickeners such as Olbene and Benton; silicone-based, fluorine-based, and polymer-based defoaming or leveling agents; adhesion-improving agents such as triazole compounds, thiazole compounds, triazine compounds, and porphyrin compounds; antioxidants; and the like. Furthermore, adhesive-type sealants may also contain components that are listed below as components that can be included in thermosetting sealants.

[0129] [7. Description of components suitable for the thermosetting sealant according to the first embodiment] (7.1. Thermosetting resins as binder resins) Examples of components that can be included in combination with an inorganic filler in a encapsulant include thermosetting resins. Thermosetting resins are preferred as binder resins for thermosetting encapsulants. A single type of thermosetting resin may be used alone, or two or more types may be used in any ratio.

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

[0131] Epoxy resins preferably have two or more epoxy groups per molecule on average. Examples of epoxy resins include hydrogenated epoxy resins (hydrogenated bisphenol A type epoxy resin, hydrogenated bisphenol F type epoxy resin, etc.), fluorine-containing epoxy resins, linear aliphatic epoxy resins, cyclic aliphatic 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, and aromatic glycidylamine type epoxy resins (e.g., tetraglycidyldiaminodiphen Examples include ylmethane, triglycidyl-p-aminophenol, diglycidyl toluidine, diglycidylaniline, 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 naphthalenediols, diglycidyl ethers of phenols, and diglycidyl ethers of alcohols, as well as 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 both. "Liquid epoxy resin" refers to an epoxy resin that is liquid at room temperature (25°C) and atmospheric pressure (1 atm). "Solid epoxy resin" refers to an epoxy resin that is solid at room temperature (25°C) and atmospheric pressure (1 atm). From the viewpoint of coating properties, processability, and adhesion, it is preferable that 10% or more by mass of the total epoxy resin is liquid epoxy resin. Furthermore, from the viewpoint of kneadability with inorganic fillers and varnish viscosity, it is particularly preferable to use a combination of liquid epoxy resin and solid epoxy resin. The mass ratio of liquid epoxy resin to solid epoxy resin (liquid epoxy resin:solid epoxy resin) is preferably 1:2 to 1:0, and more preferably 1:1.5 to 1:0.

[0133] Preferred epoxy resins include hydrogenated epoxy resins, fluorine-containing epoxy resins, linear aliphatic epoxy resins, cyclic aliphatic epoxy resins, and alkylphenol-type epoxy resins. Among these, hydrogenated epoxy resins, fluorine-containing epoxy resins, linear aliphatic epoxy resins, and cyclic aliphatic epoxy resins are more preferred. Using these epoxy resins can improve the transparency of the encapsulant.

[0134] "Hydrogenated epoxy resin" refers to an epoxy resin obtained by hydrogenating an epoxy resin containing aromatic rings. The hydrogenation rate of the hydrogenated epoxy resin is preferably 50% or more, more preferably 70% or more. Hydrogenated bisphenol A type epoxy resins and hydrogenated bisphenol F type epoxy resins are preferred as hydrogenated epoxy resins. Examples of hydrogenated bisphenol A type epoxy resins include liquid hydrogenated bisphenol A type epoxy resins (e.g., "YX8000" (manufactured by Mitsubishi Chemical Corporation, epoxy equivalent: approximately 205), "Denacol EX-252" (manufactured by Nagase ChemteX Corporation, epoxy equivalent: approximately 213)) and solid hydrogenated bisphenol A type epoxy resins (e.g., "YX8040" (manufactured by Mitsubishi Chemical Corporation, epoxy equivalent: approximately 1000)).

[0135] Examples of fluorine-containing epoxy resins include the fluorine-containing epoxy resin described in International Publication No. 2011 / 089947.

[0136] "Chain-like aliphatic epoxy resin" refers to an epoxy resin having linear or branched alkyl chains or alkyl ether chains. Examples of chain-like aliphatic epoxy resins include polyglycerol polyglycidyl ether (e.g., "Denacol EX-512", "Denacol EX-521", manufactured by Nagase ChemteX), pentaerythritol polyglycidyl ether (e.g., "Denacol EX-411", manufactured by Nagase ChemteX), diglycerol polyglycidyl ether (e.g., "Denacol EX-421", manufactured by Nagase ChemteX), and glycerol polyglycidyl ether. Lysidyl ethers (e.g., "Denacol EX-313", "Denacol EX-314", manufactured by Nagase ChemteX), trimethylolpropane polyglycidyl ethers (e.g., "Denacol EX-321", manufactured by Nagase ChemteX), neopentyl glycol diglycidyl ethers (e.g., "Denacol EX-211", manufactured by Nagase ChemteX), 1,6-hexanediol diglycidyl ethers (e.g., "Denacol EX-21 2"), ethylene glycol diglycidyl ether (e.g., "Denacol EX-810", "Denacol EX-811", manufactured by Nagase ChemteX), diethylene glycol diglycidyl ether (e.g., "Denacol EX-850", "Denacol EX-851", manufactured by Nagase ChemteX), polyethylene glycol diglycidyl ether (e.g., "Denacol EX-821", "Denacol EX-830") Examples include "Denacol EX-832", "Denacol EX-841", "Denacol EX-861" (manufactured by Nagase ChemteX), propylene glycol diglycidyl ether (e.g., "Denacol EX-911" (manufactured by Nagase ChemteX), polypropylene glycol diglycidyl ether (e.g., "Denacol EX-941", "Denacol EX-920", "Denacol EX-931" (manufactured by Nagase ChemteX)).

[0137] A "cyclic aliphatic epoxy resin" refers to an epoxy resin that has a cyclic aliphatic skeleton (e.g., a cycloalkane skeleton) within its molecule. Examples of cyclic aliphatic epoxy resins include "EHPE-3150" manufactured by Daicel Chemical Industries, Ltd. and "TOPR-300" manufactured by Nippon Steel Chemical & Material Co., Ltd.

[0138] "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, wherein 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 & Sumitomo Metal 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. An aromatic ring-containing epoxy resin refers to an epoxy resin that contains an aromatic ring in its molecule. When an aromatic ring-containing epoxy resin is used, the reactivity of the sealant, the glass transition temperature of the sealant after curing, and the adhesion, or any one of these tend to improve. Examples of aromatic ring-containing epoxy resins include alkylphenol-type epoxy resins and fluorine-containing aromatic-type epoxy resins.

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

[0141] Examples of bisphenol A type epoxy resins include "828EL," "1001," and "1004AF" from Mitsubishi Chemical Corporation; "840" and "850-S" from DIC Corporation; and "YD-128" from Nippon Steel & Sumitomo Metal Chemical Industries Ltd. Furthermore, an example of a mixture of liquid bisphenol A type epoxy resin and liquid bisphenol F type epoxy resin is "ZX-1059" (epoxy equivalent: approximately 165) from Nippon Steel Chemical Industries 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 & Sumitomo Metal Chemical Corporation.

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

[0144] "Biphenyl aralkyl 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 biphenyl aralkyl epoxy resins include "NC-3000," "NC-3000L," and "NC-3100" manufactured by Nippon Kayaku Co., Ltd.

[0145] "Fluorene-type epoxy resin" refers to epoxy resin that has a fluorene skeleton. Examples of fluorene-type epoxy resins include "OGSOL PG-100," "CG-500EG-200," and "EG-280" manufactured by Osaka Gas Chemical Co., Ltd.

[0146] "Fluorine-containing aromatic epoxy resin" refers to a fluorine-containing epoxy resin having an aromatic ring. Examples of fluorine-containing aromatic epoxy resins include the fluorine-containing aromatic epoxy resin described in International Publication No. 2011 / 089947.

[0147] Aromatic ring-containing epoxy resins generally have a high refractive index. Therefore, from the viewpoint of bringing the refractive index of the resin and the inorganic filler closer together to improve the transparency of the encapsulant, 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. Examples of epoxy resins that do not contain an aromatic ring structure and are suitable for combination with aromatic ring-containing epoxy resins 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 even more preferred, and hydrogenated bisphenol A type epoxy resins are particularly preferred. In this case, the amount of aromatic ring-containing epoxy resin is preferably 0.5% to 40% by mass, more preferably 1% to 35% by mass, and particularly preferably 2% to 30% by mass, relative to 100% by mass of the total of aromatic ring-containing epoxy resin and epoxy resin without aromatic ring structure.

[0148] The epoxy equivalent of the epoxy resin is preferably 50 to 5,000, more preferably 50 to 3,000, even more preferably 80 to 2,000, and particularly preferably 100 to 1,500, from the viewpoint of reactivity. "Epoxy equivalent" refers to the number of grams (g / eq) of resin containing 1 gram equivalent of epoxy groups, 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 even more preferably 400 to 1,500. The weight-average molecular weight of the thermosetting resin can be measured as a polystyrene equivalent by gel permeation chromatography (GPC).

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

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

[0152] (7.2. Thermoplastic resins as binder resins) Thermosetting encapsulants may contain a thermoplastic resin in combination with a thermosetting resin as a binder 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 encapsulant and the varnish coating properties (suppression of repulsion) of the encapsulant. The thermoplastic resin may be used alone or in combination of two or more types in any ratio.

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

[0154] Phenoxy resins are preferred as thermoplastic resins to be combined with thermosetting resins. Phenoxy resins have good compatibility with thermosetting resins (especially epoxy resins). Furthermore, when phenoxy resins are used, the ability of the sealant to suppress moisture penetration can be effectively enhanced. Preferred phenoxy resins are those having one or more skeletons selected from bisphenol A skeleton, bisphenol F skeleton, bisphenol S skeleton, bisphenolacetophenone skeleton, novolac skeleton, biphenyl skeleton, fluorene skeleton, dicyclopentadiene skeleton, and norbornene skeleton.

[0155] Examples of commercially available phenoxy resins include 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 weight-average molecular weight range of the thermoplastic resin combined with the thermosetting resin may be the same as that of the thermoplastic resin described above as a binder resin suitable for adhesive-type encapsulants. Thermoplastic resins having a weight-average molecular weight within this range can improve the flexibility of the encapsulant, the coatability of the varnish on the encapsulant (suppression of repulsion), and the compatibility between the thermosetting resin and the thermoplastic resin. In particular, the weight-average molecular weight of the phenoxy resin is preferably 10,000 to 500,000, and 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 to be combined with the thermosetting resin is preferably 0.1% by mass or more, more preferably 3% by mass or more, particularly preferably 5% by mass or more, preferably 60% by mass or less, more preferably 50% by mass or less, even more preferably 25% by mass or less, and particularly preferably 15% by mass or less, based on 100% by mass of the nonvolatile components of the sealant.

[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, particularly preferably 10 parts by mass or more, preferably 90 parts by mass or less, more preferably 70 parts by mass or less, and particularly preferably 50 parts by mass or less, per 100 parts by mass of inorganic filler.

[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, particularly preferably 10 parts by mass or more, preferably 80 parts by mass or less, more preferably 60 parts by mass or less, and particularly preferably 40 parts by mass or less, per 100 parts by mass of the thermosetting resin.

[0160] (7.3. Hardeners and curing accelerators) An example of a component that a encapsulant may contain in combination with an inorganic filler is a curing agent. When used in combination with a thermosetting resin, the curing agent has the function of reacting with the thermosetting resin to cure the encapsulant. From the viewpoint of suppressing thermal degradation of electronic devices during the curing of the encapsulant, it is preferable that the curing agent be able to react with the thermosetting resin at a temperature of 140°C or lower (preferably 120°C or lower). The curing agent may be used alone, or two or more types may be used in any ratio.

[0161] The type of curing agent can be selected according to the type of thermosetting resin. Below, curing agents corresponding to epoxy resins, which are 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, and primary and secondary amine compounds. 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 encapsulant 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 can be selected according to the type of thermosetting resin. Below, curing accelerators corresponding to epoxy resins, which are 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 these, imidazole compounds, tertiary amine compounds, and dimethylurea compounds are preferred.

[0163] The ionic liquid used as a curing agent is preferably one that can cure thermosetting resins (especially epoxy resins) at temperatures of 140°C or lower (preferably 120°C or lower). That is, the ionic liquid is preferably a salt that can melt in the temperature range of 140°C or lower (preferably 120°C or lower) and has a curing effect on thermosetting resins (especially epoxy resins). The ionic liquid is preferably used in a state where it is uniformly dissolved in the thermosetting resin (especially 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 cations such as imidazolium ion, piperidinium ion, pyrrolidinium ion, pyrazonium ion, guanidinium ion, and pyridinium ion; phosphonium cations such as tetraalkylphosphonium cations (e.g., tetrabutylphosphonium ion, tributylhexylphosphonium ion, etc.); and sulfonium cations such as triethylsulfonium ion.

[0165] Anions that constitute the ionic liquid as a curing agent include, for example, halogenated anions such as fluoride ions, chloride ions, bromide ions, and iodide ions; alkyl sulfate anions such as methanesulfonate ions; fluorine-containing compound anions such as trifluoromethanesulfonate ions, hexafluorophosphonate ions, trifluorotris(pentafluoroethyl)phosphonate ions, bis(trifluoromethanesulfonyl)imide ions, trifluoroacetate ions, and tetrafluoroborate ions; phenol ions, 2-methoxyphenol ions, and 2,6-di-tert-butylphenyl Examples include phenolic anions such as nol ions; acidic amino acid ions such as aspartate ions and glutamate ions; neutral amino acid ions such as glycine ions, alanine ions and phenylalanine ions; N-acyl amino acid ions represented by the following formula (A), such as N-benzoylalanine ions, N-acetylphenylalanine ions and N-acetylglycine ions; and carboxylic acid anions such as formate ions, acetate ions, decanoate ions, 2-pyrrolidone-5-carboxylate ions, α-lipoate ions, lactate ions, tartrate ions, hippurate ions, N-methylhippurate ions and benzoate ions.

[0166] [ka]

[0167] In equation (A), R A X represents a linear or branched alkyl group having 1 to 5 carbon atoms, or a substituted or unsubstituted phenyl group. A The 'a' represents the side chain of an amino acid. Examples of amino acids in formula (A) include aspartic acid, glutamic acid, glycine, alanine, and phenylalanine, with glycine being preferred.

[0168] Among the above, ammonium-based cations and phosphonium-based cations are preferred, and imidazolium ions and phosphonium ions are more preferred. Examples of imidazolium ions include 1-ethyl-3-methylimidazolium ions, 1-butyl-3-methylimidazolium ions, and 1-propyl-3-methylimidazolium ions.

[0169] Furthermore, the anions are preferably phenolic anions, N-acylamino acid ions represented by formula (A), and carboxylic acid anions, with N-acylamino acid ions and carboxylic acid anions being more preferred.

[0170] A specific example of a phenolic anion is the 2,6-di-tert-butylphenol ion. Specific examples of carboxylic acid anions include acetate ion, decanoate ion, 2-pyrrolidone-5-carboxylate ion, formate ion, α-lipoate ion, lactate ion, tartrate ion, hippurate ion, and N-methylhippurate ion. Among 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 even more preferred. Specific examples of the N-acylamino acid ion represented by formula (A) include N-benzoylalanine ion, N-acetylphenylalanine ion, aspartate ion, glycine ion, and N-acetylglycine ion. Among these, N-benzoylalanine ion, N-acetylphenylalanine ion, and N-acetylglycine ion are preferred, and N-acetylglycine ion is even 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 salt, tetrabutylphosphonium lactate, bis(tetrabutylphosphonium) tartrate salt, tetrabutylphosphonium hippurate salt, N-methylhippurate tetrabutylphosphonium salt, benzoyl-DL-alanine tetrabutylphosphonium salt, N-acetylphenylalanine tetrabutylphosphonium salt, 2,6-di-tert-butylphenol tetrabutylphosphonium salt, L-aspartate monotetrabutylphosphonium salt, and glycine tetra Butylphosphonium salt, N-acetylglycine tetrabutylphosphonium salt, 1-ethyl-3-methylimidazolium lactate, 1-ethyl-3-methylimidazolium acetate, 1-ethyl-3-methylimidazolium formate salt, 1-ethyl-3-methylimidazolium hippurate salt, N-methylhippurate 1-ethyl-3-methylimidazolium salt, bis(1-ethyl-3-methylimidazolium) tartrate salt, and N-acetylglycine 1-ethyl-3-methylimidazolium salt are preferred, and tetrabutylphosphonium decanoate, N-acetylglycine tetrabutylphosphonium salt, 1-ethyl-3-methylimidazolium acetate, 1-ethyl-3-methylimidazolium formate salt, 1-ethyl-3-methylimidazolium hippurate salt, and N-methylhippurate 1-ethyl-3-methylimidazolium salt are even more preferred.

[0172] One method for synthesizing ionic liquids is the anion exchange method, in which a precursor composed of a cationic moiety such as alkylimidazolium, alkylpyridinium, alkylammonium, and alkylsulfonium ions and an anionic moiety containing a halogen is reacted with NaBF4, NaPF6, CF3SO3Na, LiN(SO2CF3)2, etc. Another method for synthesizing ionic liquids is the acid ester method, in which an amine substance is reacted with an acid ester to introduce an alkyl group while the organic acid residue becomes a counter-anion. Yet another method for synthesizing ionic liquids is the neutralization method, in which amines are neutralized with an organic acid to obtain a salt. In the neutralization method using anions, cations, and solvents, equal amounts of anions and cations are used, and the solvent in the resulting reaction solution may be removed by distillation and used as is. Alternatively, the resulting reaction solution may be mixed with an organic solvent (methanol, toluene, ethyl acetate, acetone, etc.), concentrated, and then used.

[0173] Examples of acid anhydride compounds used as curing agents include tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, and dodecenyl succinic anhydride. Specific examples of acid anhydride compounds include Ricacid TH, TH-1A, HH, MH, MH-700, and MH-700G (all manufactured by Shin-Nippon Rika Co., Ltd.).

[0174] Examples of imidazole compounds used as curing agents or curing accelerators include 1H-imidazole, 2-methylimidazole, 2-phenyl-4-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 2-undecylimidazole, 1-cyanoethyl-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-phenylimidazole, 2-dodecyl- Examples of imidazole compounds include imidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 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 adducts. Specific examples of imidazole compounds include Cureazole 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 Chemicals Co., Ltd.).

[0175] Specific examples of tertiary amine compounds used 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, DBU organic salts such as U-CAT SA 102 (manufactured by Sunapro: octylate of DBU), and formate of DBU, as well as tris(dimethylaminomethyl)phenol (TAP).

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

[0177] Examples of amine adduct compounds used as curing agents or curing accelerators include epoxy adduct compounds obtained by stopping the addition reaction of a tertiary amine to an epoxy resin midway through the process. Specific examples of amine adduct compounds 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 organic acid dihydrazide compounds used as curing agents include Amicure VDH-J, Amicure UDH, and Amicure LDH (all manufactured by Ajinomoto Fine Techno Co., Ltd.).

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

[0180] Examples of dicyandiamide compounds used as curing agents include dicyandiamide itself. Specific examples of dicyandiamide compounds include DICY7 and DICY15 (both manufactured by Mitsubishi Chemical Corporation), which are finely ground dicyandiamide products.

[0181] Examples of primary and secondary amine compounds used as curing agents include aliphatic amines such as diethylenetriamine, triethylenetetraamine, tetraethylenepentamine, trimethylhexamethylenediamine, 2-methylpentamethylenediamine, 1,3-bisaminomethylcyclohexane, diproprendiamine, diethylaminopropylamine, bis(4-aminocyclohexyl)methane, norbornenediamine, and 1,2-diaminocyclohexane; alicyclic amines such as N-aminoethylpiberazine and 1,4-bis(3-aminopropyl)piperazine; and aromatic amines such as diaminodiphenylmethane, m-phenylenediamine, m-xylenediamine, 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 aforementioned crosslinking agents and crosslinking accelerators are capable of reacting with thermosetting resins to cure the encapsulant, those crosslinking agents and crosslinking accelerators may be used as curing agents.

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

[0184] The amount of curing agent is preferably 0.1% to 40% by mass, more preferably 0.5% to 38 parts by mass, and even more preferably 1% to 35 parts by mass, based on 100% by mass of the nonvolatile components of the sealant. When the amount of curing agent is above the lower limit of the above range, the curing of the sealant can proceed sufficiently. Also, when the amount of curing agent is below the upper limit of the above range, the storage stability of the sealant can be improved. In particular, the amount of ionic liquid as curing agent is preferably 20% by mass or less, more preferably 18% by mass or less, and especially preferably 15% by mass or less, based on 100% by mass of the nonvolatile components of the sealant. When the amount of ionic liquid is within the above range, the ability of the sealant to suppress moisture penetration can be effectively enhanced.

[0185] The amount of the curing accelerator is preferably 0.05% to 10% by mass, more preferably 0.1% to 8% by mass, and even more preferably 0.5% to 5% by mass, based on 100% by mass of the nonvolatile components of the sealant. When the amount of the curing accelerator is above the lower limit of the above range, the curing of the sealant can be accelerated. Furthermore, when the amount of the curing accelerator is below 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 can be included in a encapsulant, coupling agents are an example of components suitable for thermosetting encapsulants. When a encapsulant contains a coupling agent, the aggregation of inorganic fillers is suppressed, and the surface area of ​​the inorganic fillers can be increased, making it easier for the inorganic fillers to exhibit lead adsorption and hygroscopic properties. A single type of coupling agent may be used alone, or two or more types may be used in any ratio.

[0187] Examples of coupling agents include silane coupling agents, aluminate coupling agents, and titanate coupling agents.

[0188] Examples of silane coupling agents 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- Examples of silane coupling agents include amino-based silane coupling agents such as minopropyldimethoxymethylsilane; 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-acrylooxypropyltrimethoxysilane and 3-methacryloxypropyltrimethoxysilane; isocyanate-based silane coupling agents such as 3-isocyanatetopropyltrimethoxysilane; sulfide-based silane coupling agents such as bis(triethoxysilylpropyl)disulfide and bis(triethoxysilylpropyl)tetrasulfide; and phenyltrimethoxysilane, methacryloxypropyltrimethoxysilane, imidazolesilane, and triazinesilane. Among these, vinyl-based silane coupling agents and epoxy-based silane coupling agents are preferred, and epoxy-based silane coupling agents are particularly preferred.

[0189] Examples of aluminate coupling agents include alkylacetate aluminum diisopropylate (e.g., "PlenAct AL-M," manufactured by Ajinomoto Fine Techno Co., Ltd.).

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

[0191] The amount of coupling agent is preferably 0% to 15% by mass, and more preferably 0.5% to 10% by mass, relative to 100% by mass of the nonvolatile components of the encapsulant.

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

[0193] Examples of components that may be included in a sealant and are suitable for a thermosetting sealant include: organic fillers such as rubber particles, silicone powder, nylon powder, and fluororesin powder; thickeners such as olbene and bentonite; silicone-based, fluorine-based, and polymer-based defoamers or leveling agents; and adhesion-improving agents such as triazole compounds, thiazole compounds, triazine compounds, and porphyrin compounds. Furthermore, thermosetting sealants may also contain the same components as those found in adhesive sealants.

[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 line transmittance for D65 light. Specifically, the parallel line transmittance of a 20 μm thick layer of sealant is preferably 80% to 100%, and more preferably 85% to 100%. The parallel line transmittance of the sealant is calculated by forming a laminate on a glass plate and using air as a reference. Specifically, the parallel line transmittance can be measured by the following method.

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

[0196] [9. Sealant according to the second embodiment] The encapsulant according to the second embodiment of the present invention comprises an inorganic filler containing one or more 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 exhibit excellent lead adsorption and hygroscopic properties in the encapsulant, when the encapsulant is used for encapsulating an electronic device having a lead-containing portion, it can suppress the intrusion of moisture into the lead-containing portion and suppress 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 parameters and water vapor penetration barrier parameters within the range described above. Furthermore, 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. Except as described 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 for manufacturing encapsulating agent] The method for manufacturing the encapsulant is not particularly limited. The encapsulant can be manufactured by mixing the constituent components using a mixing device such as a kneading roller and a rotary mixer. In addition, a solvent may be mixed in combination with the constituent components during the mixing process.

[0199] [11. Uses of encapsulants] When used for sealing purposes, the encapsulant can suppress the ingress of moisture and the leakage of lead. Therefore, it is preferable to use it for sealing electronic devices that contain lead. There are no restrictions on the type of such electronic device. Examples of electronic devices include solar cells such as perovskite solar cells; secondary batteries such as lead-acid batteries; and electronic components containing leaded solder.

[0200] [12. Sealing Sheet] (12.1. Packaging Sheet Configuration) An embodiment of the present invention provides a sealing sheet comprising a support and a layer of the sealing agent formed on the support. The sealing agent layer is a layer formed of the sealing agent and therefore contains the sealing agent described above. Such a sealing sheet can achieve sealing of an object to be sealed by laminating it so that the sealing agent layer is in contact with the object to be sealed. Typically, lamination is performed so that the object to be sealed and the sealing agent layer are in direct contact. "Direct" contact between two members means that there are no other members between them.

[0201] The thickness of the encapsulant layer can be set according to the object to be encapsulated. The specific thickness of the encapsulant 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. If the thickness of the encapsulant layer is greater than or equal to the lower limit of the above range, damage to the object to be encapsulated due to lamination with the encapsulant sheet can be suppressed, and the uniformity of the thickness of the encapsulated portion obtained as an encapsulant layer after lamination can be increased. Also, if the thickness of the encapsulant layer is less than or equal to 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 comprising a first substrate and a second substrate, the thinner the encapsulated portion as an encapsulant layer, the smaller the surface area of ​​the side of the encapsulated portion that comes into contact with the outside air can be, thus effectively suppressing the intrusion of moisture (see Figure 4 described later).

[0202] Typically, a film made of an appropriate material is used as the support. Examples of support materials 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, polycarbonate and polyimide; and metal foils such as aluminum foil, stainless steel foil and copper foil. Alternatively, a composite film made by laminating a metal foil and a plastic film may be used as the support.

[0203] The support may be provided with a barrier layer to enhance its moisture resistance. In particular, when the support includes a plastic film, it is preferable to use a support that has an appropriate barrier layer in combination with the plastic film. Examples of materials for the barrier layer include inorganic materials. Examples of such inorganic materials 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 so on. The barrier layer can be formed, for example, by vapor deposition of the above-mentioned material.

[0204] The support material may be subjected to surface treatment. Examples of surface treatments include matte finish, corona treatment, and mold release treatment. Examples of mold release treatments include mold release using mold release agents such as silicone resin-based mold release agents, alkyd resin-based mold release agents, and fluororesin-based mold release agents.

[0205] Specific examples of support materials include commercially available polyethylene terephthalate films with aluminum foil, such as "PET-Tsuki AL1N30" from Tokai Toyo Aluminum Sales Co., Ltd., "PET-Tsuki AL3025" from Fukuda Metal Co., Ltd., and "Alpet" from Panac Co., Ltd. Other specific examples of support materials include the Tech Barrier HX, AX, LX, and L series (manufactured by Mitsubishi Plastics Corporation); and X-BARRIER (manufactured by Mitsubishi Plastics Corporation), which offers even greater moisture resistance than the Tech Barrier HX, AX, LX, and L series.

[0206] The thickness of the support is not particularly limited, but from the viewpoint of handling and other factors, it is preferably 10 μm or more, more preferably 20 μm or more, 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 sealing sheet may include a protective film as needed. For example, the sealing sheet may comprise a support, a layer of sealing agent, and a protective film in that order, with the protective film protecting the layer of sealing agent. Protection with a protective film can suppress the adhesion of dust and scratches to the surface of the layer of sealing agent.

[0208] As the protective film, for example, a plastic film similar to that of the support can be used. The protective film may also be surface-treated, similar to that of 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. Method for manufacturing sealing sheets) The aforementioned sealing sheet can be manufactured by a manufacturing method that includes forming a layer of sealing agent on a support. The layer of sealing agent can be formed, for example, by a method that includes preparing a varnish containing a sealing agent and a solvent, applying this varnish to the support, and drying the applied varnish.

[0210] Typically, organic solvents are used as solvents. Examples of organic solvents include ketone solvents such as acetone, methyl ethyl ketone (hereinafter also abbreviated as "MEK"), and cyclohexanone; acetic acid 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 "Swazole" (manufactured by Maruzen Petroleum Co., Ltd., trade name) and "Ipsol" (manufactured by Idemitsu Kosan Co., Ltd., trade name). One type of solvent may be used alone, or two or more types may be used in any ratio.

[0211] The varnish can be dried using methods such as heating or hot air blowing. There are no particular restrictions on the drying conditions, 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, preferably 60 minutes or less, and more preferably 15 minutes or less. After applying the varnish to the support, the solvent is removed by drying the applied varnish, and a sealant layer is obtained on the support.

[0212] The method for manufacturing the sealing sheet may, if necessary, include heating the sealing layer. Heating allows the reaction of reactive groups contained in the sealing agent to proceed, thereby allowing reactions such as crosslinking and polymerization to proceed to an appropriate degree and increasing the hardness of the sealing layer. This heating is preferable when using an adhesive sealing agent. In particular, it is preferable to perform the above heating when using an adhesive sealing agent containing a polyolefin resin having reactive groups such as acid anhydride groups and epoxy groups. Such heating before sealing can prevent thermal degradation of components contained in the object to be sealed. There are no particular restrictions 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 manufacturing the sealing sheet may include providing a protective film as needed. The protective film can be provided, for example, by laminating the protective film with the sealing agent layer. When heating the sealing agent layer, the protective film may be provided before heating the sealing agent layer or after heating the sealing agent layer.

[0214] (12.3. How to use sealing sheets) The aforementioned sealing sheet can be used to seal objects such as lead-containing parts and electrodes. The sealing method using the sealing sheet usually involves laminating the sealing agent layer of the sealing sheet onto the object to be sealed. If the sealing sheet includes a protective film, the lamination is usually performed after peeling off the protective film. The lamination method may be batch-type or continuous-type using rolls.

[0215] Typically, according to the lamination described above, a layer of sealant 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 by the layer of sealant and the support. In a sealing method using a sealing sheet, it is also possible to obtain a state in which the object to be sealed is covered with a layer of sealant and a support without peeling off the support. In this state, the object to be sealed is sealed not only by the layer of sealant but also by the support, so the intrusion of moisture can be effectively suppressed. For example, when using a sealing sheet equipped with a support that has high moisture resistance, such as a support equipped with a barrier layer or a support equipped with metal foil, it is preferable to seal with a layer of sealant and a support as described above.

[0216] In a sealing method using a sealing sheet, for example, the support may be peeled off after lamination to obtain a state in which the object to be sealed is covered with a layer of sealing agent. Even in this state, the layer of sealing agent sealing the object to be sealed can effectively suppress the intrusion of moisture. For example, when using a sealing sheet with a support that does not have high moisture resistance, such as a support without a barrier layer or a support without metal foil, it is preferable to seal with a layer of sealing agent as described above.

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

[0218] The sealing method using a sealing sheet may, for example, include curing the layer of the sealant after lamination. Usually, by applying heat to the layer of the sealant, reactions such as crosslinking reaction and polymerization reaction of the reactive groups contained in the sealant are advanced to thermally cure the layer of the sealant. Thereby, the adhesion between the object to be sealed and the sealant can be improved, or the mechanical strength of the layer of the sealant can be improved, so that the sealing ability of the sealant is enhanced. Therefore, the intrusion of moisture and the leakage of lead can be particularly effectively suppressed. Such post-lamination thermal curing is suitable when using a thermosetting sealant.

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

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

[0221] [13. Electronic device] An electronic device according to an embodiment of the present invention includes a lead-containing part and a sealing part that seals this lead-containing part. The sealing part contains the above-described sealant. At this time, the sealant contained in the sealing part may be cured. The sealing part containing such a cured sealant is included in the "sealing part containing a sealant". In such an electronic device, the intrusion of moisture into the lead-containing part can be suppressed by the sealing part. Also, the leakage of lead from the lead-containing part to the outside of the electronic device can be suppressed by the sealing part.

[0222] The lead-containing part is the part containing lead atoms, and a wide range of materials can be included depending on the type of electronic device. Hereinafter, taking a perovskite solar cell including a perovskite layer as the lead-containing part as an example, the electronic device will be specifically described.

[0223] FIG. 4 is a cross-sectional view schematically showing an example of a perovskite solar cell 400 according to an embodiment of the present invention. As shown in FIG. 4, as an example, the perovskite solar cell 400 includes a first electrode 410, a perovskite layer 420 containing lead atoms, a second electrode 430, and a sealing portion 440 including 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 the charges generated in the perovskite layer 420 as the photoelectric conversion layer can be taken out 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. There is no limitation on the type of the conductive material, but 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), GZO (gallium zinc oxide); conductive polymers; and the like.

[0225] The perovskite layer 420 contains a perovskite compound, and this perovskite layer 420 can generate charges when irradiated with light. Examples of the perovskite compound include 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 has no particular limitation, 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, carbazole, and the like. Examples of the ion of the monovalent organic molecule include methylammonium (CH3NH3), phenethylammonium, and the like. Among them, methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine and their ions, and phenethylammonium are preferable, and methylamine, ethylamine, propylamine and their ions are more preferable.

[0228] In formula (P), M p represents a divalent metal atom. M p preferably contains lead as the divalent metal atom. Further, M 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, europium, and the like. These metal atoms may be used alone or in combination of two or more.

[0229] In formula (P), X prepresents a halogen atom or a chalcogen atom. There are no particular restrictions on halogen atoms, but examples include chlorine, bromine, iodine, and sulfur. Similarly, there are no particular restrictions on chalcogen atoms, but selenium is an example. These may be used individually or in combination of two or more types.

[0230] Specific examples of the aforementioned perovskite compounds include, for example, those described in International Publication No. 2014 / 045021, Japanese Patent Publication No. 2014-49596, and Japanese Patent Publication No. 2016-82003.

[0231] Among those mentioned above, compounds containing lead atoms, such as CH3NH3PbI3, are preferred as perovskite compounds. Perovskite compounds may be used individually or in combination of two or more in any ratio. Furthermore, 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, part or all 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 Figure 4, an example is described in which the portion 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 space between the perovskite layer 420 and the outside air is sealed by the sealing portion 440. Therefore, it is possible to suppress the intrusion of moisture from the outside air into the perovskite layer 420. In addition, it is possible to suppress the leakage of lead contained in the perovskite layer 420 to the outside of the solar cell 400. Normally, 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] Preferably, the solar cell 400 further comprises a first substrate 450 and a second substrate 460. Typically, one of the first substrate 450 and the second substrate 460 is used as a support substrate to support the solar cell 400 or its manufacturing intermediate during manufacturing and use. The other of the first substrate 450 and the second substrate 460 is typically used as a sealing substrate to seal a wide area of ​​the main surface of the solar cell 400. 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 Figure 4, the sealing portion 440 can be provided to fill the space between the first substrate 450 and the second substrate 460, so that the components such as the first electrode 410, the perovskite layer 420, and the second electrode 430 provided between the first substrate 450 and the second substrate 460 can all be sealed by the sealing portion 440.

[0234] Generally, the first substrate 450 and the second substrate 460 are formed from materials that do not easily permeate moisture or have a large thickness, so the intrusion of moisture can be suppressed to a high degree. Therefore, in the solar cell 400 according to the above example, the path for moisture to penetrate into the perovskite layer 420 can be limited to an in-plane penetration path A4 that passes through the side portion 440S of the sealing portion 440. The sealing agent described above can particularly effectively suppress the intrusion of moisture in such a penetration path A4. Therefore, when used to seal the perovskite layer 420 provided between the first substrate 450 and the second substrate 460, the sealing agent described above can particularly demonstrate the effects of suppressing the intrusion 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 have an arbitrary layer between the first electrode 410 and the perovskite layer 420. Also, for example, the perovskite solar cell 400 may have an arbitrary layer between the perovskite layer 420 and the second electrode 430. Examples of arbitrary layers include electron transport layers and hole transport layers.

[0236] There are no restrictions on the manufacturing method of electronic devices. For example, they can be manufactured by a method that includes forming a lead-containing layer and forming a sealing portion that seals the lead-containing layer. The sealing portion can be formed, for example, as a layer of sealing agent that covers the lead-containing layer by laminating a layer of sealing agent using a sealing sheet. To give a specific example, a perovskite solar cell 400 can be manufactured by a method that includes 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 sealing agent of a sealing sheet (not shown) so as to cover part or all of the first electrode 410, the perovskite layer 420 and the second electrode 430, thereby providing a sealing portion 440 as a layer of sealing agent. In this case, the support of the sealing sheet may be used as the second substrate 460. Alternatively, after peeling off the support of the sealing sheet, another second substrate 460 may be provided on the sealing portion 440. [Examples]

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

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

[0239] The sealing sheets produced in the examples and comparative examples were cut into a length of 16 cm and a width of 24 cm to obtain the first test sheets. After laminating a mesh cloth (Vorting Cloth (nylon) Mesh 40 NB-40, manufactured by AS ONE Corporation) on the sealing agent layer side of this first test sheet, it was finely cut into 1 cm squares, placed in 50 ml of an aqueous solution containing lead ions, and stirred for 15 minutes with a high-speed rotary mixer (Rentarou ARE-310, rotation speed 2000 rpm) (lead adsorption capacity evaluation test). At this time, in Examples 5 to 6 and Comparative Example 4 related to the thermosetting sealing agent, after laminating the mesh cloth, the sealing agent was thermally cured under the conditions of 100 °C for 60 minutes, and then the first test sheet was finely cut. The lead ion concentration M1 of the aqueous solution containing lead ions after stirring was measured.

[0240] The change amount of the lead ion concentration was obtained by subtracting the lead ion concentration M1 of the aqueous solution containing lead ions after immersing the first test sheet from the lead ion concentration of 20 μg / L of the aqueous solution containing lead ions before immersing the first test sheet. The volume of 50 mL of the aqueous solution containing lead ions was multiplied by this change amount to calculate the lead adsorption amount. The calculated lead adsorption amount was divided by the area of 384 cm 2 of the sealing agent layer provided in the first test sheet used, and the mass X (μg / m 2 ) of lead adsorbed per 1 m 2 of the sealing agent layer was calculated. This mass X of the adsorbed lead corresponds to the lead adsorption parameter. Based on the mass X of the adsorbed lead, the lead adsorption capacity of the sealing agent was evaluated according to the following criteria.

[0241] (Criteria for lead adsorption capacity) "Good": The mass X of the adsorbed lead is 10 μg / m 2 or more. "Poor": The mass X of the adsorbed lead is less than 10 μg / m 2 .

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

[0243] [Method for evaluating the water vapor barrier properties of sealants] As a 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 aluminum foil and polyethylene terephthalate film was prepared. Except for using this support film in place of the support material, a layer of sealant was formed on the aluminum foil side of the support film in the same manner as the manufacturing method of the sealing sheet in each example and comparative example. This obtained a second test sheet comprising the support film and the sealant layer. The obtained second test sheet was dried under a nitrogen atmosphere to remove adsorbed water contained in the sealant layer. Drying was carried out at 130°C for 60 minutes in Examples 1-4 and Comparative Examples 1-3, which used adhesive sealants. Drying was carried out at 100°C for 5 minutes in Examples 5-6 and Comparative Example 4, which used thermosetting sealants.

[0244] A 50mm x 50mm square glass plate made of alkali-free 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 onto one side of the glass plate using a mask that covered the peripheral area from 0mm to 2mm from the edge of the glass plate. As a result, a 200nm thick calcium film (99.8% purity) was formed on the central portion of one side of the glass plate, excluding the peripheral area from 0mm to 2mm from the edge.

[0246] In a nitrogen atmosphere, the sealant layer of the second test sheet described above and the calcium film side of the glass plate were bonded together using a thermal laminator (Fujiplas Lamipacker DAiSY A4 (LPD2325)) to obtain a laminate. In Examples 1-4 and Comparative Examples 1-3 relating to adhesive sealants, the obtained laminates were used as evaluation samples. In Examples 5-6 and Comparative Example 4 relating to thermosetting sealants, the obtained laminates were heated at 100°C for 60 minutes to cure the sealant layer and obtain evaluation samples.

[0247] Generally, when calcium comes into contact with water, it becomes transparent as calcium oxide. Furthermore, in the aforementioned evaluation sample, the glass plate and aluminum foil have sufficiently high water vapor penetration barrier properties, so moisture can normally move in-plane (perpendicular to the thickness direction) through the edges of the sealant layer and reach the calcium film. Therefore, when moisture penetrates the evaluation sample, the calcium film gradually oxidizes from the edges and becomes transparent, and a shrinkage of the calcium film is observed. Thus, moisture penetration into the evaluation sample can be evaluated by measuring the sealing distance [mm] from the edge of the evaluation sample to the calcium film. For this reason, the evaluation sample containing the calcium film can be used as a model for lead-containing electronic devices.

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

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

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

[0251]

number

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

[0253] (Standards for water vapor barrier properties) "Good": Constant K is 0.025 cm / h 0.5 less than. "Defective": Constant K is 0.025 cm / h 0.5 That's all.

[0254] [Synthesis Example 1: Synthesis of Ionic Liquid Curing Agent] N-acetylglycine tetrabutylphosphonium salt, an ionic liquid curing agent, was synthesized using the following procedure. To 20.0 g of a 41.4% aqueous solution of tetrabutylphosphonium hydrooxide (manufactured by Hokko Chemical Industry Co., Ltd.), 3.54 g of N-acetylglycine (manufactured by Tokyo Chemical Industry Co., Ltd.) was added at 0°C and stirred for 10 minutes. After stirring, the reaction solution was concentrated using an evaporator at a pressure of 40 mmHg to 50 mmHg at 60°C to 80°C for 2 hours and then at 90°C for 5 hours. The obtained concentrate was dissolved in 14.2 ml of ethyl acetate (manufactured by Junsei Chemical Co., Ltd.) at room temperature to prepare a solution. The obtained solution was concentrated using an evaporator at a pressure of 40 mmHg to 50 mmHg at 70°C to 90°C for 3 hours to obtain 11.7 g 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 solution of dicyclopentadiene-based petroleum resin (T-REZ HA105, manufactured by JXTG Energy Corporation, softening point 105°C) as a tackifier was prepared in a volume of 77.5 parts (60% non-volatile component), and then 2.3 parts of an antioxidant (Irganox 1010, manufactured by BASF Corporation) 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 Energy Corporation, number average molecular weight: 2,900), and commercially available semi-calcined hydrotalcite A (semi-calcined hydrotalcite, BET specific surface area: 13 m²) as an inorganic filler were added. 2 100 parts of ( / g, average particle size: 400 nm) were dispersed in a three-roll mill to obtain a mixture.

[0256] To the obtained mixture, 20 parts of a Swarzol solution (20% non-volatile component) of a glycidyl methacrylate-modified propylene-butene random copolymer (T-YP341, manufactured by Seikoh PMC, propylene units / butene units: 71% / 29%, epoxy group concentration: 0.638 mmol / g, number average molecular weight: 155,000), 0.1 parts of an amine compound (2,4,6-tris(diaminomethyl)phenol, sometimes abbreviated as "TAP", manufactured by Kayaku Akzo), and 210 parts of toluene were added and uniformly dispersed in a high-speed rotary mixer to obtain a varnish containing a sealant.

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

[0258] [Example 2] The type of inorganic filler will change from semi-calcined hydrotalcite A to commercially available calcined hydrotalcite C (calcined hydrotalcite, BET specific surface area: 190 m²). 2 The values ​​were changed to ( / g, average particle size: 400 nm). Except for the above, a sealing sheet comprising a varnish containing a sealing agent and a 20 μm thick layer of sealing agent was manufactured using the same method as in Example 1.

[0259] [Example 3] The type of inorganic filler will be changed from semi-calcined hydrotalcite A to commercially available calcium oxide (BET specific surface area: 5m²). 2 The values ​​were changed to ( / g, average particle size: 4000 nm). Except for the above, a sealing sheet comprising a varnish containing a sealing agent and a 20 μm thick layer of sealing agent was manufactured using the same method as in Example 1.

[0260] [Example 4] The type of inorganic filler was changed from semi-calcined hydrotalcite A to nanozeolite (Zeoal 4A, manufactured by Nakamura Superhard Co., Ltd., average particle size 300 nm, pore size 4 Å). Except for the above, a sealing sheet comprising a varnish containing a sealing agent and a 20 μm thick layer of sealing agent was manufactured using the same method as in Example 1.

[0261] [Comparative Example 1] Semi-calcined hydrotalcite A was not used as an inorganic filler. Except for the above, a sealing sheet comprising a varnish containing a sealing agent and a 20 μm thick layer of sealing agent was manufactured in the same manner as in Example 1.

[0262] [Comparative Example 2] The type of inorganic filler will be changed from semi-calcined hydrotalcite A to commercially available uncalcined hydrotalcite D (BET specific surface area: 10m²). 2 The values ​​were changed to ( / g, average particle size: 400 nm). Except for the above, a sealing sheet comprising a varnish containing a sealing agent and a 20 μm thick layer of sealing agent was manufactured using the same method 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, average particle size: 6.0 μm). Except for the above, a sealing sheet comprising a varnish containing a sealing agent and a 20 μm thick layer of sealing agent was manufactured using the same method as in Example 1.

[0264] [evaluation] The lead adsorption capacity and water vapor penetration barrier properties of the sealants were evaluated using the varnishes and sealing sheets obtained in each example and comparative example, according to the evaluation method described above. The evaluation results are shown in Table 1 below.

[0265] [Table 1]

[0266] [II. Examples and Comparative Examples Related to Thermosetting Sealants] [Example 5] (Varnish manufacturing) 162 parts of a mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin (manufactured by Nippon Steel Chemical & Material Co., Ltd., "ZX1059"), and commercially available semi-calcined hydrotalcite A as an inorganic filler (semi-calcined hydrotalcite, BET specific surface area: 13 m²). 2 150 parts of (1 / g, average particle size: 400 nm) and 7.5 parts of a silane coupling agent (Shin-Etsu Chemical Co., Ltd. "KMB403", 3-glycidyloxypropyltriethoxysilane) were kneaded together, and then dispersed in a three-roll mill to obtain a mixture.

[0267] 7.5 parts of a curing accelerator (SunApro "U-CAT3512T") was dissolved in 163 parts of a phenoxy resin solution (Mitsubishi Chemical "YX7200B35", solvent: methyl ethyl ketone, non-volatile component: 35%) (57 parts of resin). 108 parts of an alicyclic skeleton-containing epoxy resin (Nippon Steel Chemical & Material "TOPR-300"), the previously prepared mixture, and 9 parts of the ionic liquid curing agent (N-acetylglycine tetrabutylphosphonium salt) synthesized in Synthesis Example 1 were added to this solution and uniformly dispersed using a high-speed rotary mixer to obtain a varnish containing a sealant.

[0268] (Manufacturing of sealing sheets) A polyethylene terephthalate film (38 μm thick, sometimes referred to as "release PET film") having a surface treated with an alkyd-based release agent (release-treated surface) was prepared as a support. 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 would be 20 μm, and the film was dried at 80°C for 5 minutes to form a sealant layer. Subsequently, a release PET film was placed on the surface of the sealant layer as a protective film, and a sealing sheet was obtained comprising the support, sealant layer, and release PET film in this order.

[0269] [Example 6] The type of inorganic filler will be changed from semi-calcined hydrotalcite A to commercially available calcium oxide (BET specific surface area: 5m²). 2The values ​​were changed to ( / g, average particle size: 4000 nm). Except for the above, a sealing sheet comprising a varnish containing a sealing agent and a 20 μm thick layer of sealing agent was manufactured using the same method as in Example 5.

[0270] [Comparative Example 4] The type of inorganic filler will be changed from semi-calcined hydrotalcite A to commercially available uncalcined hydrotalcite D (BET specific surface area: 10m²). 2 The values ​​were changed to ( / g, average particle size: 400 nm). Except for the above, a sealing sheet comprising a varnish containing a sealing agent and a 20 μm thick layer of sealing agent was manufactured using the same method as in Example 5.

[0271] [evaluation] Using the varnishes and sealing sheets obtained in each example and comparative example, the lead adsorption capacity and water vapor penetration barrier properties of the sealing agents were evaluated using the evaluation method described above. However, in the method for evaluating lead adsorption capacity, the first test sheet was obtained by cutting the sealing film and then peeling off the release PET film, which served as a protective film. Therefore, the method for evaluating lead adsorption capacity was performed using the first test sheet, which had a layer of sealing agent with one side exposed. Furthermore, in the evaluation method for water vapor penetration barrier properties, the release PET film used as a protective film was peeled off 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 sealing sheet in Example 1] The sealing layer of the sealing sheet manufactured in Example 1 and a reference film (polyethylene terephthalate film "Lumirror 38 R80", 35 μm thick, manufactured by Toray Sales Co., Ltd.) with a known water vapor transmission rate P2 were laminated using a batch-type vacuum laminator (V-160, manufactured by Nichigo Morton Co., Ltd.). The lamination conditions were a temperature of 80°C, a depressurization time of 30 seconds, followed by pressurization at a pressure of 0.3 MPa for 30 seconds. After that, the support was peeled off to obtain a resin sheet comprising the sealing 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. 2 The 24-hour measurement was taken using a water vapor transmission rate measuring device (MOCON PERMATRAN-W 3 / 34) under conditions of 40°C and 90% relative humidity.

[0275] The water vapor transmission rate P1 of the sealant layer was calculated by substituting the water vapor transmission rate P0 of the resin sheet and the water vapor transmission rate P2 of the reference film into the following formula (2). Here, the water vapor transmission rate P2 of the reference film is 15 g / m². 2 • It was set to 24 hours. 1 / P0 = 1 / P1 + 1 / P2 (2)

[0276] [Reference Example 2: Evaluation of the sealing sheet in 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 sealant sheet manufactured in Comparative Example 1 was used instead of the sealant sheet manufactured in Example 1.

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

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

[0279] [Table 3]

[0280] The WVTR measurement method used in Reference Examples 1-3 measures the transmittance of water vapor that permeates through the sealant layer in the thickness direction. As can be seen from the results of Reference Examples 1-3, Reference Example 1 is superior to Reference Example 2 in its ability to suppress moisture penetration in the thickness direction, but Reference Example 3 is even superior. However, as can be seen from the water vapor penetration barrier properties of Example 1 and Comparative Examples 1 and 3, Example 1, corresponding to Reference Example 1, is superior to Comparative Examples 1 and 3, corresponding to Reference Examples 2 and 3, in its ability to suppress moisture penetration in the in-plane direction perpendicular to the thickness direction. Therefore, it can be seen that the ability of a sealant to suppress moisture penetration may differ depending on the direction of water vapor penetration. Furthermore, it can be seen that the sealants in the examples exhibit particularly high water vapor penetration barrier properties in the in-plane direction.

[0281] [IV. Evaluation of the physical properties of hydrotalcite] [Reference examples 4~6] (Measurement of hydrotalcite water absorption rate) Each hydrotalcite sample used in the above-described examples and comparative examples was weighed at 1.5 g using a balance, and its initial mass was measured. Each weighed hydrotalcite sample was then placed in a small environmental test chamber (ESPEC SH-222) set to atmospheric pressure, 60°C, and 90% RH (relative humidity) for 200 hours to allow it to absorb moisture, and its mass after moisture absorption was measured. From the measured mass, the saturation water absorption rate was calculated using the following formula (i). Saturation water absorption rate [mass %] = 100 × (mass after moisture absorption - initial mass) / initial mass (i)

[0282] (Measurement of the thermogravimetric loss rate of hydrotalcite) Thermogravimetric analysis of each hydrotalcite sample used in the above-described examples and comparative examples was performed using a thermal analyzer (TG / DTA EXSTAR6300, manufactured by Hitachi High-Tech Science Corporation). 10 mg of hydrotalcite was weighed into an aluminum sample pan and heated from 30°C to 550°C at a rate of 10°C / min under a nitrogen atmosphere with a flow rate of 200 mL / min, without a lid. The thermogravimetric loss rates at 280°C and 380°C were determined using the following formula (ii). Thermal weight loss rate [mass %] = 100 × (mass before heating - mass when the specified temperature is reached) / mass before heating (ii)

[0283] (Measurement of hydrotalcite powder X-ray diffraction) Powder X-ray diffraction measurements were performed for each hydrotalcite used in the above-described examples and comparative examples. Powder X-ray diffraction measurements were performed 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, and measurement diffraction angle range (2θ): 5.0131~79.9711°. Peak search was 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 the second derivative. Two split peaks appearing within the range of 2θ from 8° to 18°, or a peak with a shoulder formed by the combination of two peaks, were detected. The diffraction intensity of the peak or shoulder appearing on the low-angle side (=low-angle diffraction intensity) and the diffraction intensity of the peak or shoulder appearing 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 for each hydrotalcite are shown in Table 4 below.

[0285] [Table 4]

[0286] Based on the results of the saturation water absorption rate, thermogravimetric loss rate, and powder X-ray diffraction, hydrotalcite A is "partially calcined hydrotalcite," hydrotalcite C is "calcined hydrotalcite," and hydrotalcite D is "uncalcined hydrotalcite." [Explanation of symbols]

[0287] 10 evaluation samples 100 glass plates 200 Calcium membrane 300 Sheets for the second test 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 the 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 an inorganic filler comprising one or more selected from the group consisting of semi-calcined hydrotalcite, calcined hydrotalcite, and calcium oxide, and a sealant comprising 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 nonvolatile components of the sealant. The aforementioned resin includes a polyolefin resin having an acid anhydride group, A lead-acid battery in which the amount of polyolefin resin having acid anhydride groups is 1 part by mass or more and 23 parts by mass or less per 100 parts by mass of inorganic filler.

2. The lead-acid battery according to claim 1, wherein the inorganic filler is semi-calcined hydrotalcite.

3. The lead-acid battery according to claim 1, wherein the inorganic filler is calcined hydrotalcite.

4. The lead-acid battery according to claim 1, wherein the inorganic filler is calcium oxide.

5. The lead-acid battery according to any one of claims 1 to 4, wherein the resin comprises an epoxy resin.

6. The lead-acid battery according to any one of claims 1 to 5, wherein the resin comprises a polyolefin resin having epoxy groups.

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