Fire extinguishing sheet and device equipped with same and having automatic fire extinguishing function

Abstract

To provide a fire extinguishing sheet that can maintain excellent fire extinguishing performance for a long period of time, and to provide a device having an automated fire extinguishing function equipped with the fire extinguishing sheet.SOLUTION: A fire extinguishing sheet has a layered structure including a first fire extinguishing agent layer and a second fire extinguishing agent layer. The first and second fire extinguishing agent layers include fire extinguishing agents respectively. The fire extinguishing agent contains salts of at least one of an organic salt and an inorganic salt having deliquescence, and the second fire extinguishing agent layer further contains a deliquescence suppression component. A device having an automated fire extinguishing function includes a fire extinguishing object having the possibility of ignition and the fire extinguishing sheet disposed to face the fire extinguishing object.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a fire extinguishing sheet and a device equipped with the same and having an automatic fire extinguishing function. [Background technology]

[0002] In recent years, with the advancement of technology, our lives have become more and more comfortable. On the other hand, a large amount of energy is required to produce this comfort, and high safety is required in each scene, such as packing and storing it at high density, transporting it, and using it. Taking automobiles as an example, there is a risk of ignition and fire when mining fossil fuels such as gasoline, refining fossil fuels into gasoline, transporting it, etc. Taking electronics as an example, there is a similar risk of ignition and fire when transferring electrical energy through electric wires, adjusting electrical energy at substations and transformers, using electrical equipment in homes and factories, or temporarily storing electrical energy in storage batteries.

[0003] From the viewpoint of minimizing damage caused by fire, it is desirable to carry out some kind of fire-extinguishing work, i.e., initial fire-extinguishing, soon after the fire breaks out. Therefore, a method is considered in which a self-extinguishing molded product is made by mixing a fire-extinguishing agent that generates an aerosol when burned with a binder and molding the mixture into a sheet, and placing it near an object that is likely to catch fire in advance. By doing so, it is expected that the self-extinguishing molded product will complete the fire-extinguishing process before a person senses that the object has caught fire (see Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2021 / 149766 [Patent Document 2] International Publication No. 2018 / 047762 Summary of the Invention [Problem to be solved by the invention]

[0005] However, conventional self-extinguishing molded products have room for improvement in that the potassium salt contained as a fire extinguishing agent has deliquescent properties, and therefore the fire extinguishing performance may decrease over time depending on the storage environment. The present disclosure has been made in consideration of the above circumstances, and provides a fire extinguishing sheet that can maintain excellent fire extinguishing performance for a long period of time, and a device equipped with the same that has an automatic fire extinguishing function. [Means for solving the problem]

[0006] As a result of extensive research, the inventors have discovered that by employing a laminated structure including at least two extinguishing agent layers having different compositions and incorporating a relatively large amount of a component that suppresses the deliquescence of the extinguishing agent (hereinafter referred to as a "demeliscescence suppressing component") in one of the extinguishing agent layers, excellent fire extinguishing performance can be maintained for a long period of time, and have completed the following invention relating to the present disclosure.

[0007] One aspect of the present disclosure relates to a fire extinguishing sheet having a laminated structure including a first extinguishing agent layer and a second extinguishing agent layer, the first and second extinguishing agent layers each including an extinguishing agent, the extinguishing agent including at least one salt of an organic salt and an inorganic salt having deliquescence, and the second extinguishing agent layer further including a deliquescence suppressing component.

[0008] According to the above fire extinguishing sheet, the second extinguishing agent layer containing the deliquescence suppressing component covers at least a part of the surface of the first extinguishing agent layer, so that the contact area between the first extinguishing agent layer and the air is reduced, and the deliquescence of the extinguishing agent contained in the first extinguishing agent layer can be suppressed. In addition, since the second extinguishing agent layer itself has fire extinguishing performance, it can exhibit superior fire extinguishing performance compared to, for example, a case where a gas barrier film without fire extinguishing performance is laminated. Note that the first extinguishing agent layer may or may not contain a deliquescence suppressing component. When the first extinguishing agent layer contains a deliquescence suppressing component, the content of the component in the first extinguishing agent layer may be sufficiently smaller than that in the second extinguishing agent layer.

[0009] The deliquescence inhibitor is, for example, a compound having an acid anhydride group. A specific example of such a compound is a silane coupling agent having a carboxylic acid anhydride group and an alkoxysilyl group.

[0010] From the viewpoint of achieving high stability of the properties of the fire extinguishing sheet, it is preferable that the second extinguishing agent layer has excellent hydrophobicity, and it is preferable that when a 2.0 μL water droplet is dropped onto the second extinguishing agent layer, the contact angle 0.2 seconds after the drop is dropped is 75° or more.

[0011] The fire extinguisher sheet preferably has a change Δ in total light transmittance of 50 or less, calculated by the following formula (1) based on the results of a property stability evaluation test. Change in total light transmittance Δ = total light transmittance value after storage - initial total light transmittance value (1) The "property stability evaluation test" here means a test in which the initial total light transmittance of a fire extinguishing sheet sealed in a barrier film is measured in accordance with the test method for total light transmittance of transparent materials described in JIS K7361-1:1997, and then the total light transmittance of the fire extinguishing sheet is measured in the same manner as the initial one after storing the fire extinguishing sheet in a thermo-hygrostat at a temperature of 85°C and a relative humidity of 85% for 168 hours. The "barrier film" referred to here is a film having a water vapor transmission rate of 0.2 to 0.6 g / m2 measured under conditions of a temperature of 40°C and a relative humidity of 90%. 2 It means / day film.

[0012] From the viewpoint of maintaining the performance of the first and second fire extinguishing agent layers for a long period of time, the fire extinguishing sheet is preferably housed in a packaging bag having gas barrier properties.

[0013] One aspect of the present disclosure relates to an apparatus having an automatic fire extinguishing function. The apparatus has an automatic fire extinguishing function and includes an object to be extinguished that may catch fire and a fire extinguishing sheet arranged to face the object to be extinguished, in which the first and second extinguishing agent layers each contain an extinguishing agent that is ejected in response to a flame, the extinguishing agent contains at least one salt of an organic salt and an inorganic salt having deliquescence, and the second extinguishing agent layer further contains a deliquescence suppressing component. When the object to be extinguished is, for example, at least one selected from the group consisting of a switchboard, a distribution board, a control panel, a storage battery, and an outlet, the fire extinguishing sheet may be arranged on the inner surface of a housing that contains the object to be extinguished.

[0014] According to the study by the present inventors, the reactivity of the extinguishing agent layer against a flame can be reduced as the content of the deliquescence suppressing component in the extinguishing agent layer is increased. On the other hand, if the content of the deliquescence suppressing component in the extinguishing agent layer is sufficiently small, the extinguishing performance inherent to the extinguishing agent can be fully exhibited. By containing the deliquescence suppressing component in the second extinguishing agent layer, the reactivity of the second extinguishing agent layer against a flame can be reduced, and the reactivity of the first extinguishing agent layer against a flame can be relatively increased. By utilizing such a difference in reactivity, the extinguishing agent ejected from the fire extinguishing sheet can be made directional depending on the direction of the fire extinguishing sheet relative to the object to be extinguished, and earlier extinguishing can be achieved.

[0015] That is, by disposing the second extinguishing agent layer containing the deliquescent component near the object to be extinguished, it is possible to cause the extinguishing agent ejected from the extinguishing sheet to have directionality. For example, when the extinguishing sheet is heated by a flame from below the lower surface of the extinguishing sheet, which is disposed in such a manner that the first extinguishing agent layer is located above and the second extinguishing agent layer is located below, the area of ​​the reaction region in the second extinguishing agent layer is smaller than that in the first extinguishing agent layer (see Fig. 4(a) to Fig. 4(c)). Since the area of ​​the reaction region in the second extinguishing agent layer is small, the opening formed in the second extinguishing agent layer by the reaction of the flame and the extinguishing agent caused by the flame plays a role like an injection nozzle, and the extinguishing agent ejected can have directionality. By injecting a large amount of extinguishing agent toward the flame, it is possible to realize initial extinguishing with a sufficiently high probability.

[0016] On the other hand, by arranging the first extinguishing agent layer, which has a high reactivity to flames, closer to the object to be extinguished than the second extinguishing agent layer, the extinguishing agent can be ejected from the fire extinguishing sheet earlier. For example, when the fire extinguishing sheet is arranged on a plane extending in the vertical direction and is arranged at a position horizontally distant from the object to be extinguished, the heat of the flame is less likely to be transmitted from the object to be extinguished to the fire extinguishing sheet compared to when the fire extinguishing sheet is arranged above the object to be extinguished. Even under such a situation, the first extinguishing agent layer, which has a high reactivity to flames, can achieve initial extinguishing. Effect of the Invention

[0017] According to the present disclosure, there is provided a fire extinguishing sheet capable of maintaining excellent fire extinguishing performance for a long period of time, and a device having an automatic fire extinguishing function equipped with the same. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a perspective view showing a schematic diagram of one embodiment of a device having an automatic fire extinguishing function according to the present disclosure. [Diagram 2] FIG. 2 is a perspective view showing a schematic diagram of one embodiment of a fire extinguishing sheet according to the present disclosure. [Diagram 3] FIG. 3 is a cross-sectional view showing a schematic internal structure of the fire extinguishing sheet shown in FIG. [Figure 4] FIG. 4(a) is a cross-sectional view showing the first and second extinguishing agent layers after the reaction, FIG. 4(b) is a plan view showing the surface of the first extinguishing agent layer after the reaction, and FIG. 4(c) is a plan view showing the surface of the second extinguishing agent layer after the reaction. [Diagram 5] FIG. 5 is a perspective view showing a schematic view of another embodiment of the fire extinguishing sheet according to the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, embodiments of the present disclosure will be described in detail. However, the present disclosure is not limited to the following embodiments.

[0020] <Devices with automatic fire extinguishing function> The device with an automatic fire extinguishing function includes an object to be extinguished that may catch fire, and a fire extinguishing sheet arranged to face the object to be extinguished. Examples of the device with an automatic fire extinguishing function include electrical system equipment equipped with electrical wiring, cables, transformers, and electrical circuits. More specific examples include switchboards, distribution boards, storage batteries (e.g., lithium ion batteries), and power storage systems equipped with these. Examples of storage batteries include mobile batteries, batteries for tools, and batteries for electric vehicles. In addition to these examples, there are also other locations where there is a risk of unintended ignition, such as collection boxes for storage batteries, trash cans, and outlet covers. Below, an example of electrical equipment with an automatic fire extinguishing function will be described.

[0021] The electrical equipment includes an electrical device and a housing that accommodates the electrical device. Examples of the electrical equipment include substation equipment such as a distribution board and a switchboard, and equipment such as an operation board and a control board for production equipment. Examples of the electrical equipment include terminal blocks, transformers, breakers, capacitors, earth leakage breakers, electrical wiring, storage batteries, and outlets that are provided on these boards. These electrical devices can be said to be parts of the electrical equipment that are at risk of fire. The electrical equipment usually includes a plurality of electrical devices, and the fire extinguishing sheet may be provided for at least one of the electrical devices, or may be provided for each of all of the electrical devices. One fire extinguishing sheet may be provided so as to face a plurality of electrical devices. By providing the above-mentioned fire extinguishing sheet, which has excellent initial fire extinguishing properties, in advance in these electrical equipment, the occurrence and spread of a fire can be prevented.

[0022] FIG. 1 is a perspective view showing a schematic diagram of an electrical equipment according to the present embodiment. FIG. 1 shows a switchboard as an example of the electrical equipment. The electrical equipment 100 mainly includes a housing 101 having a storage section 101a and an opening / closing door 101b for storing electrical equipment, and a breaker 103 and wiring 104 as electrical equipment. A part of the wiring 104 is stored together in a wiring cover 102. The electrical equipment 100 can include, for example, a fire extinguishing sheet 30a on the side of the opening / closing door 101b facing the electrical equipment, a fire extinguishing sheet 30b on the top surface of the storage section 101a facing the electrical equipment, a fire extinguishing sheet 30c (the approximate installation position is shown in the figure for simplicity) on the bottom surface of the wiring cover 102 facing the electrical equipment, and a fire extinguishing sheet 30d on the side of the rear surface of the storage section 101a facing the electrical equipment, i.e., the back side of the electrical equipment.

[0023] The position of the fire extinguishing sheet is not limited to the embodiment shown in Fig. 1, and the position can be adjusted appropriately according to the location of electrical equipment, etc., which is a location at which there is a risk of fire. In addition, if the distance between the fire extinguishing sheet and the electrical equipment is far, a member for adjusting the distance may be provided and then the fire extinguishing sheet may be provided on the member.

[0024] The distance between the electric equipment and the fire extinguishing sheet can be adjusted as appropriate. This distance is preferably 200 mm or less, more preferably 150 mm or less, and even more preferably 120 mm or less or 100 mm or less. This allows for more efficient initial fire extinguishing. The distance between the electric equipment and the fire extinguishing sheet refers to the shortest distance between the electric equipment and the fire extinguishing sheet provided so as to face it. For example, for an electric equipment located directly under the top surface of the storage section 101a and 200 mm or less away from the top surface, the fire extinguishing sheet can be provided on the top surface. Also, for an electric equipment located facing the opening and closing door 101b and 200 mm or less away from the opening and closing door 101b, the fire extinguishing sheet can be provided on the opening and closing door 101b. It is desirable to install the fire extinguishing sheet close to the electric equipment, but if it is too close, there is a risk of the two coming into contact, so it is preferable to leave a distance of at least 1 mm between the two.

[0025] <Fire extinguishing sheet> Next, the fire extinguishing sheet will be specifically described. At least one of the fire extinguishing sheets 30a, 30b, 30c, and 30d shown in FIG. 1 has a laminated structure including a first extinguishing agent layer and a second extinguishing agent layer. The fire extinguishing sheet having a laminated structure will be described with reference to FIGS. 2 and 3. The fire extinguishing sheet 30 shown in these figures includes a laminated body composed of a first extinguishing agent layer 31 and a second extinguishing agent layer 32, and a packaging bag 38 that contains the laminated body. The packaging bag 38 includes a base layer 38a and a heat seal layer 38b. The fire extinguishing sheet 30 has a seal portion 30s formed on the periphery. The fire extinguishing sheet 30 has a surface 1F on the first extinguishing agent layer 31 side and a surface 2F on the second extinguishing agent layer 32 side.

[0026] In this embodiment, the first and second extinguishing agent layers 31, 32 each contain an extinguishing agent that is ejected in response to a flame. The second extinguishing agent layer 32 has a lower reactivity to flame than the first extinguishing agent layer 31. Here, "low reactivity to flame" means that the extinguishing agent is less likely to eject even when heated by a flame. In other words, the first extinguishing agent layer 31 has a higher reactivity to flame than the second extinguishing agent layer 32. "High reactivity to flame" means that the extinguishing agent is more likely to eject even when heated by a flame.

[0027] The second extinguishing agent layer 32, which has a relatively low reactivity to flames, may be disposed closer to the object to be extinguished than the first extinguishing agent layer 31. That is, the fire extinguishing sheet 30 may be disposed relative to the object to be extinguished, with the surface 2F of the fire extinguishing sheet 30 facing the object to be extinguished. By disposing the fire extinguishing sheet 30 in such a direction, as described above, the opening formed in the second extinguishing agent layer due to the flame plays a role like an injection nozzle, and the extinguishing agent to be ejected can be made directional. Here, referring to FIG. 1, the fire extinguishing sheets 30b and 30c are disposed above the object to be extinguished. It is preferable to dispose the fire extinguishing sheets 30b and 30c in such a direction.

[0028] FIG. 4(a) is a cross-sectional view showing the first and second extinguishing agent layers 31 and 32 after the reaction. FIG. 4(b) is a plan view showing the surface of the first extinguishing agent layer 31 after the reaction. FIG. 4(c) is a plan view showing the surface of the second extinguishing agent layer 32 after the reaction. The black areas in these figures indicate the reaction areas of the first and second extinguishing agent layers 31 and 32, and indicate that the area of ​​the reaction area R2 in the second extinguishing agent layer 32 is smaller than the reaction area R1 in the first extinguishing agent layer 31. Note that the reaction area of ​​an actual fire extinguishing sheet is often composed of a central part where a cavity is formed by the ejection of the extinguishing material and a peripheral part where the extinguishing material has turned black due to soot. The appearance of the fire extinguishing sheets after the reaction in Examples 1 and 3 described later was confirmed to be the same as that shown in FIG. 4(b) and FIG. 4(c).

[0029] The first extinguishing agent layer 31, which has a relatively high reactivity to flames, may be disposed closer to the object to be extinguished than the second extinguishing agent layer 32. That is, the fire extinguishing sheet 30 may be disposed relative to the object to be extinguished such that the surface 1F of the fire extinguishing sheet 30 faces the object to be extinguished. By disposing the fire extinguishing sheet 30 in such a direction, as described above, the extinguishing agent can be ejected from the fire extinguishing sheet 30 at an earlier stage. Here, referring to FIG. 1, the fire extinguishing sheets 30a and 30d are disposed above the object to be extinguished. It is preferable to dispose the fire extinguishing sheets 30a and 30d in such a direction.

[0030] The average thickness of the first and second extinguishing agent layers 31, 32 can be, for example, 30 to 600 μm, and may be 40 μm or more, 100 μm or more, or 150 μm or more, or may be 300 μm or less. When the average thickness is equal to or more than the above lower limit, the extinguishing performance is easily exhibited, and when the average thickness is equal to or less than the above upper limit, the coating film is easily formed and the bending resistance is good. From the viewpoint of extinguishing performance, the average thickness of the first extinguishing agent layer 31 may be 100 μm or more or 150 μm or more. From the viewpoint of realizing excellent extinguishing performance and excellent property stability, the average thickness of the second extinguishing agent layer 32 may be 30 μm or more, 40 μm or more, 70 μm or more, or 100 μm or more, and from the viewpoint of excellent handling, it may be 150 μm or less, 130 μm or less, or 120 μm or less. From the above viewpoint, the average thickness of the second extinguishing agent layer may be 100 μm or more and 120 μm or less.

[0031] From the viewpoint of realizing excellent fire extinguishing performance, the ratio T1 / T2 of the average thickness T1 of the first extinguishing agent layer 31 to the average thickness T2 of the second extinguishing agent layer 32 is preferably 0.8 or more, more preferably 1.1 or more, even more preferably 1.5 or more, and particularly preferably 1.8 or more. The upper limit value of the ratio T1 / T2 is, for example, 5.0. The average thickness of the extinguishing agent layers 31 and 32 means the average value of thicknesses at any five points in an enlarged image of the cross section of the extinguishing sheet. The area of ​​the main surface of the extinguishing agent layer may be appropriately set depending on the application and installation location of the extinguishing sheet.

[0032] The first and second extinguishing agent layers 31, 32 are composed of extinguishing materials with different compositions. The extinguishing material is formed by molding a composition (composition for forming extinguishing material) containing an extinguishing agent, a binder resin, and a deliquescent component that is mixed as necessary. By molding the extinguishing material using a binder resin, the properties of the extinguishing agent are easily maintained, and the frequency of replacing the fire extinguishing sheet can be reduced. The extinguishing material may further contain a liquid medium. The components contained in the extinguishing agent layers 31, 32 will be described below.

[0033] (Deliquescence suppressing ingredient) The deliquescence inhibitor is a component that is blended in the second extinguishing agent layer 32 to improve resistance to deliquescence. The first extinguishing agent layer 31 in this embodiment does not contain a deliquescence inhibitor. The contact angle when a water droplet is dropped onto the extinguishing agent layer varies depending on the deliquescence resistance of the extinguishing agent of the extinguishing agent layer onto which the water droplet is dropped, and the higher the deliquescence resistance, the larger the contact angle. The contact angle can be measured, for example, using a portable contact angle meter PCA-1 (manufactured by Kyowa Interface Science Co., Ltd.). From the viewpoint of obtaining a fire extinguishing sheet with excellent property stability, when a 2.0 μL water droplet is dropped onto the second extinguishing agent layer 32 of the fire extinguishing sheet, the contact angle 0.2 seconds after the drop may be 75° or more, 85° or more, or 90° or more.

[0034] The deliquescence inhibitor does not particularly contribute to extinguishing, but also plays a role in reducing the reactivity of the extinguishing agent layer to flames. An example of the deliquescence inhibitor is a compound having an acid anhydride group. The reason why the compound having an acid anhydride group exhibits a deliquescence inhibitory effect is unclear, but it is speculated that the acid anhydride group can react with water, so that it traps water that has entered the extinguishing agent layer, thereby preventing the deliquescence of the salt contained in the extinguishing agent layer. It is also speculated that the compound having an acid anhydride group modifies the surface of the salt, improving its hydrophobicity and suppressing contact with water.

[0035] The compound having an acid anhydride group is not particularly limited as long as it has one or more acid anhydride groups in the molecule, which are formed by dehydration condensation of two oxoacid molecules. Examples of oxoacids that form an acid anhydride group include carboxylic acid, sulfuric acid, nitric acid, phosphoric acid, etc. Among these, the oxoacid that forms an acid anhydride group is preferably a carboxylic acid. Examples of compounds having a carboxylic acid anhydride group include simple carboxylic acid anhydrides such as phthalic anhydride, succinic anhydride, and maleic anhydride, and copolymers in which a carboxylic acid anhydride having an unsaturated bond such as maleic anhydride is used as a monomer.

[0036] The compound having an acid anhydride group may further have an alkoxysilyl group in the molecule. The compound having an acid anhydride group contained in the extinguishing agent layer may further have an alkoxysilyl group in the molecule, so that the properties of the molded product can be more stably maintained for a long period of time. The reason for this is unclear, but it is presumed that after the alkoxysilane is hydrolyzed, a self-reaction occurs to form a siloxane, thereby improving water resistance and improving film density, and suppressing contact between the deliquescent salt and water. For example, a silane coupling agent may be used as the compound having an acid anhydride group and an alkoxysilyl group in the molecule. The silane coupling agent used as the compound having an acid anhydride group may have the same function as the binder resin in the extinguishing agent layer.

[0037] The content of the compound having an acid anhydride group in the second extinguishing agent layer 32 may be 10 to 250 parts by mass, or may be 50 to 200 parts by mass, based on 100 parts by mass of the binder resin contained in the second extinguishing agent layer 32. When the content of the compound having an acid anhydride group is equal to or less than the upper limit, not only is the coating suitability of the second extinguishing agent layer 32 increased and film formation is facilitated, but also cracking of the film can be suppressed, and when the content of the compound having an acid anhydride group is equal to or more than the lower limit, deliquescence of the salt can be easily suppressed and sufficient fire extinguishing performance can be easily exhibited.

[0038] Here, the case where the second extinguishing agent layer 32 contains a deliquescent component while the first extinguishing agent layer 31 does not contain a deliquescent component has been described, but the first extinguishing agent layer 31 may also contain a deliquescent component. In this case, the content of the compound having an acid anhydride group in the first extinguishing agent layer 31 may be sufficiently smaller than that in the second extinguishing agent layer 32. The content of the compound having an acid anhydride group in the first extinguishing agent layer 31 may be, for example, 35 parts by mass or less, or 10 parts by mass or less, assuming that the mass of the binder resin contained in the first extinguishing agent layer 31 is 100 parts by mass.

[0039] (Fire extinguishing agent) The extinguishing agent has a property of being ejected in response to a flame. As the extinguishing agent, one having the four elements of fire extinguishing (removal action, cooling action, smothering action, negative catalytic action) can be appropriately used according to the target of extinguishing. The extinguishing agent may contain at least one salt of an organic salt and an inorganic salt having deliquescent properties, which generally have fire extinguishing performance. The organic salt and the inorganic salt may be used alone, or two or more kinds may be used in combination. The first extinguishing agent layer 31 contains a first extinguishing agent, and the second extinguishing agent layer 32 contains a second extinguishing agent.

[0040] The salt contained in the first extinguishing agent may be the same compound as the salt contained in the second extinguishing agent, or may be a different compound. When the salt contained in the first extinguishing agent is the same compound as the salt contained in the second extinguishing agent, the production efficiency of the fire extinguishing sheet can be improved. When the salt contained in the first extinguishing agent is a different compound from the salt contained in the second extinguishing agent, this can cause a difference in the reactivity to flame between the first and second extinguishing agent layers.

[0041] Examples of organic salts that function as fire extinguishing agents include potassium salts, sodium salts, and ammonium salts. From the viewpoint of usefulness in terms of the negative catalytic effect, potassium salts can be suitably used as the organic salts. Examples of organic potassium salts include potassium acetate, potassium citrate (monopotassium citrate, dipotassium citrate, tripotassium citrate), potassium tartrate, potassium lactate, potassium oxalate, potassium maleate, and other potassium carboxylates. Among these, examples of organic potassium salts that have deliquescent properties include potassium acetate, potassium citrate, potassium tartrate, and potassium lactate. Among these, potassium citrate can be used from the viewpoint of reaction efficiency of the negative catalytic effect of combustion.

[0042] Examples of inorganic salts that function as fire extinguishing agents include potassium salts and sodium salts. From the viewpoint of usefulness in terms of the negative catalytic effect, potassium salts can be suitably used as the inorganic salt. Examples of inorganic potassium salts include potassium tetraborate, potassium carbonate, potassium hydrogen carbonate, potassium dihydrogen phosphate, and dipotassium hydrogen phosphate. Among these, examples of inorganic potassium salts that have deliquescent properties include potassium carbonate, potassium dihydrogen phosphate, and dipotassium hydrogen phosphate. Among these, potassium carbonate can be used from the viewpoint of reaction efficiency of the negative catalytic effect of combustion.

[0043] The salt may be granular. The average particle diameter D50 of the salt may be 1 to 100 μm, or may be 3 to 40 μm. When the average particle diameter D50 is equal to or greater than the lower limit, the salt is easily dispersed in the coating liquid. When the average particle diameter D50 is equal to or less than the upper limit, the salt tends to have improved stability in the coating liquid, leading to improved smoothness of the coating film, and also to an easy realization of a desired glossiness on the surface of the extinguishing agent layer. The average particle diameter D50 can be calculated by wet measurement using a laser diffraction particle size distribution measuring device.

[0044] The amount of the extinguishing agent can be 70 to 97% by mass, or may be 85 to 92% by mass, based on the total amount of the extinguishing agent and the binder resin (which may be the total amount of the extinguishing agent layer). When the amount of the extinguishing agent is equal to or less than the upper limit, in the case where the salt has deliquescence, it is easy to suppress the deliquescence of the salt and to form a uniform fire-extinguishing sheet, and when the amount of the extinguishing agent is equal to or more than the lower limit, it is easy to maintain sufficient fire-extinguishing properties.

[0045] The extinguishing agent may contain other components besides the above-mentioned salt. Examples of other components include oxidizing agents for improving the reactivity of the salt, specifically potassium chlorate, sodium chlorate, strontium chlorate, ammonium chlorate, magnesium chlorate, potassium nitrate, sodium nitrate, strontium nitrate, ammonium perchlorate, potassium perchlorate, basic copper nitrate, copper oxide (I), copper oxide (II), iron oxide (II), iron oxide (III), molybdenum trioxide, etc. Among them, it is preferable to use potassium chlorate. From the viewpoint of further improving the fire extinguishing performance of the fire extinguishing sheet, at least one of the first and second extinguishing agents may contain an oxidizing agent, or both of the first and second extinguishing agents may contain an oxidizing agent.

[0046] (binder resin) The binder resin contains at least one of a thermoplastic resin and a thermosetting resin as a resin.

[0047] Examples of the thermoplastic resin include polyolefin resins such as polypropylene resins, polyethylene resins, poly(1-)butene resins, and polypentene resins, polystyrene resins, acrylonitrile-butadiene-styrene resins, methyl methacrylate-butadiene-styrene resins, ethylene-vinyl acetate resins, ethylene-propylene resins, polycarbonate resins, polyphenylene ether resins, acrylic resins, polyamide resins, polyvinyl chloride resins, polyvinyl alcohol (PVA), polyvinyl acetal resins, and polyurethane resins. Among these resins, polyvinyl acetal resins and polyurethane resins can be preferably used from the viewpoint of film-forming properties. Examples of polyvinyl acetal resins include polyvinyl butyral (PVB). Among the above thermoplastic resins, polyurethane resins can be preferably used from the viewpoint of both film-forming properties and improved reactivity. In addition to these properties, ether-based polyurethane resins can be preferably used from the viewpoint of imparting flexibility to the film and water resistance to the fire extinguishing material.

[0048] Examples of thermosetting resins include rubbers such as natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), 1,2-polybutadiene rubber (1,2-BR), styrene-butadiene rubber (SBR), chloroprene rubber (CR), nitrile rubber (NBR), butyl rubber (IIR), ethylene-propylene rubber (EPR, EPDM), chlorosulfonated polyethylene (CSM), acrylic rubber (ACM, ANM), epichlorohydrin rubber (CO, ECO), multi-vulcanized rubber (T), silicone rubber (Q), fluororubber (FKM, FZ), and urethane rubber (U), polyurethane resins, polyisocyanate resins, polyisocyanurate resins, phenolic resins, epoxy resins, and polyvinyl ether (PMVE)-maleic anhydride resins.

[0049] The binder resin may contain other components in addition to the above-mentioned resins (thermoplastic resin and thermosetting resin). Examples of the other components include a curing agent, and from the viewpoint of property stability, other components include a surfactant, a silane coupling agent, an antiblocking agent, an adhesion promoter, etc. These other components can be appropriately selected depending on the type of resin. The amount of other components contained in the binder resin can be 70% by mass or less based on the total amount of the binder resin, and may be 30% by mass or less, or may be 0% by mass.

[0050] (Liquid medium) The liquid medium may be an organic solvent. The organic solvent may be a water-soluble solvent, for example, alcohols such as methanol, ethanol, isopropyl alcohol, n-propyl alcohol, etc.; ketones such as acetone, methyl ethyl ketone, etc.; glycols such as ethylene glycol, diethylene glycol, etc.; glycol ethers such as N-methylpyrrolidone (NMP), tetrahydrofuran, butyl cellosolve, etc. From the viewpoint that the organic salt and the inorganic salt have deliquescent properties, the liquid medium may be an alcohol-based solvent, specifically, ethanol.

[0051] (Other ingredients) Examples of other components contained in the fire extinguishing material include colorants, antioxidants, flame retardants, inorganic fillers, fluidity imparting agents, moisture-proofing agents, dispersants, UV absorbers, flexibility imparting agents, adhesion imparting agents, catalysts, etc. These components can be appropriately selected depending on the type of salt and the type of binder resin. The amount of other components contained in the fire extinguishing material can be 40% by mass or less based on the total amount of the fire extinguishing material, and may be 10% by mass or less, or may be 0% by mass.

[0052] As shown in Figs. 2 and 3, the first and second extinguishing agent layers 31 and 32 are contained in a packaging bag 38. The packaging bag can be formed, for example, by heat-sealing the four sides of two resin films. Examples of resins constituting the resin film include polyolefins (LLDPE, PP, COP, CPP, etc.), polyesters (PET, etc.), fluororesins (PTFE, ETFE, EFEP, PFA, FEP, PCTFE, etc.), PVC, PVA, acrylic resins, epoxy resins, polyamides, polyimides, etc. These resins melt due to the heat of a flame (generally about 700 to 900°C), and the internal fire extinguishing sheet is easily exposed. In addition, by selecting such transparent materials, it becomes easier to inspect the appearance of the fire extinguishing sheet and check the replacement time. The resin film may contain the above-mentioned fire extinguishing agent.

[0053] The water vapor permeability of the resin film (JIS K 7129 compliant under 40℃ / 90%RH conditions) is not particularly limited because it can be designed according to the type of fire extinguishing agent, but it should not exceed 10.0g / (m 2 ·day) or less, and can be 1.0g / (m 2 ·day) or less.

[0054] From the viewpoint of adjusting the water vapor permeability, the resin film may be provided with a vapor deposition layer (alumina vapor deposition layer or silica vapor deposition layer) having a water vapor barrier property. The vapor deposition layer may be provided on one side or both sides of the resin film. From the viewpoint of obtaining a high level of gas barrier property, the film constituting the packaging bag may have a layer structure including a metal foil (e.g., aluminum foil).

[0055] <Fire extinguishing sheet manufacturing method> First, the extinguishing agent and the binder resin are mixed with the liquid medium to prepare a composition for forming an extinguishing agent layer. The amount of the extinguishing agent and the binder resin may be adjusted so that the amount of each of them in the extinguishing agent layer is the desired amount. The amount of the liquid medium may be appropriately adjusted according to the method of using the composition for forming an extinguishing agent layer, and may be, for example, 40 to 95 mass% based on the total amount of the composition for forming an extinguishing agent layer. The composition for forming an extinguishing agent layer containing the liquid medium may be called a coating liquid for forming an extinguishing agent layer.

[0056] The extinguishing agent layer can be produced by applying a coating liquid for forming an extinguishing agent layer onto a resin substrate and drying the coating liquid to form an extinguishing agent layer. As described above, the glossiness of the surface of the extinguishing agent layer exposed to the atmosphere needs to be appropriately controlled, but by forming the extinguishing agent layer by a coating method, it is easy to achieve an appropriate glossiness on both the front and back surfaces of the extinguishing agent layer. This is an advantage unique to the coating method in which no strong external pressure is applied during layer formation, and it is presumed that this is difficult to obtain by molding methods such as press molding. The coating thickness can be appropriately adjusted so that the extinguishing agent layer of the desired thickness can be obtained, taking into account the pressure applied to the extinguishing agent layer.

[0057] A coating liquid for forming a fire extinguishing agent layer is further applied onto the surface of the obtained laminate of the fire extinguishing agent layer and the resin substrate, and a fire extinguishing agent layer is formed in the same manner, thereby forming a laminate having a laminate structure of the fire extinguishing agent layer. The coating can be performed by a wet coating method. Examples of the wet coating method include gravure coating, comma coating, dip coating, curtain coating, spin coating, sponge roll coating, and die coating.

[0058] The method for producing a fire extinguishing sheet may further include pressurizing the fire extinguishing agent layer. This makes it easier to improve the glossiness. From the viewpoint of easily obtaining a desired glossiness, the pressurizing condition may be 0.2 MPa or more, and may be 2.0 MPa or more. The upper limit of the pressurizing condition may be 2.5 MPa or less from the viewpoint of flexibility of the coating film. By putting the laminate produced through these steps into a packaging bag, the fire extinguishing sheet 30 shown in Figs. 2 and 3 is obtained.

[0059] Although the embodiments of the present disclosure have been described in detail above, the present disclosure is not limited to the above embodiments. For example, in the above embodiments, a two-layer laminate composed of the first and second extinguishing agent layers 31 and 32 is contained in a packaging bag, but as shown in FIG. 5, the laminate may have a three-layer structure in which the second extinguishing agent layer 32 / the first extinguishing agent layer 31 / the second extinguishing agent layer 32 are laminated in this order.

[0060] In the above embodiment, the laminate composed of a plurality of extinguishing agent layers is housed in a packaging bag. However, for example, a laminate containing a resin substrate used in coating the extinguishing agent layer may be housed in a packaging bag. Examples of resins constituting the resin substrate include polyolefin (LLDPE, PP, COP, CPP, etc.), polyester (PET, etc.), fluororesin (PTFE, ETFE, EFEP, PFA, FEP, PCTFE, etc.), PVC, PVA, acrylic resin, epoxy resin, polyamide, polyimide, etc. Even if the extinguishing sheet is installed so that the resin substrate side faces the flame, these resins melt due to the heat of the flame (generally about 700 to 900°C) and easily expose the extinguishing agent layer. In addition, by selecting such a transparent material, it becomes easier to inspect the appearance of the extinguishing agent layer and to check the replacement time of the extinguishing agent layer. The resin substrate may contain the above extinguishing agent.

[0061] From the viewpoint of adjusting the water vapor permeability, the resin substrate may be provided with a vapor deposition layer (alumina vapor deposition layer or silica vapor deposition layer) having a water vapor barrier property. The vapor deposition layer may be provided on one side or both sides of the resin substrate. The thickness of the resin substrate can be appropriately adjusted according to the expected heat amount at the time of fire outbreak, impact, allowable installation space, etc. For example, a thick substrate can easily obtain the strength and rigidity required for a fire extinguishing sheet, and handling becomes easy. In addition, a thin substrate can be provided with a fire extinguishing sheet in a narrow space, and also improves initial fire extinguishing properties because it melts in a short time when heated by a flame. The thickness of the resin substrate can be, for example, 4.5 to 100 μm, and may be 12 to 50 μm. The resin substrate may be a laminate having a plurality of resin layers.

[0062] In the above embodiment, an example is given of a laminate including multiple extinguishing agent layers contained in a packaging bag, but depending on the environment in which the fire extinguishing sheet is used, the laminate may be used as a fire extinguishing sheet as is without being contained in a packaging bag. EXAMPLES

[0063] The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

[0064] The following materials were used in the examples and comparative examples. (Fire extinguishing agent) Organic potassium salts: tripotassium citrate Oxidizing agent: Potassium chlorate (KClO3) Tripotassium citrate is a deliquescent salt. (binder resin) An ether-based polyurethane resin solution obtained by dissolving 100 parts by mass of ether-based polyurethane resin in 210 parts by mass of isopropyl alcohol. (Liquid medium) ethanol (Resin substrate) Polyethylene terephthalate (PET) substrate (Toyobo Co., Ltd., product name: E7002, thickness 50 μm) (Deliquescence suppressing ingredient) A silane coupling agent having an acid anhydride group and an alkoxysilyl group (manufactured by Shin-Etsu Chemical Co., Ltd., product name: X-12-1287A)

[0065] (Preparation of the first fire extinguishing agent layer forming composition) A mixture of tripotassium citrate and potassium chlorate (KClO3) was pulverized in an agate mortar so that the average particle diameter D50 was 12 μm or less. 87.4 parts by mass of the pulverized mixture, 39.4 parts by mass of an ether-based polyurethane resin solution, and 87 parts by mass of ethanol were mixed to obtain a first extinguishing agent layer forming composition.

[0066] (Preparation of second fire extinguishing agent layer forming composition) A mixture of tripotassium citrate and potassium chlorate (KClO3) was pulverized in an agate mortar so that the average particle size D50 was 12 μm or less. 87.4 parts by mass of the pulverized mixture, 19.7 parts by mass of an ether-based polyurethane resin solution, 6.3 parts by mass of a silane coupling agent, and 87 parts by mass of ethanol were mixed to obtain a second extinguishing agent layer forming composition.

[0067] Example 1 A first extinguishing agent layer forming composition was applied to the release-treated surface of the PET substrate using an applicator, and then dried at 75° C. for 7 minutes to obtain a laminate in which a first extinguishing agent layer having an average thickness of 200 μm was formed on the PET substrate. A second extinguishing agent layer forming composition was applied to the first extinguishing agent layer of the obtained laminate using an applicator, and then dried at 75° C. for 7 minutes to obtain a laminate in which a second extinguishing agent layer having an average thickness of 100 μm was formed on the first extinguishing agent layer. The PET substrate was peeled off from this laminate to obtain a fire extinguishing sheet having a two-layer structure (first extinguishing agent layer / second extinguishing agent layer).

[0068] Example 2 A second extinguishing agent layer forming composition was applied to the release-treated surface of the PET substrate using an applicator, and then dried at 75° C. for 7 minutes to obtain a laminate in which a second extinguishing agent layer having an average thickness of 70 μm was formed on the PET substrate. A first extinguishing agent layer forming composition was applied to the second extinguishing agent layer of the obtained laminate using an applicator, and then dried at 75° C. for 7 minutes to obtain a laminate in which a first extinguishing agent layer having an average thickness of 160 μm was formed on the second extinguishing agent layer. A second extinguishing agent layer forming composition was applied to the first extinguishing agent layer of the obtained laminate using an applicator, and then dried at 75° C. for 7 minutes to obtain a laminate in which a second extinguishing agent layer having an average thickness of 70 μm was further formed on the first extinguishing agent layer. The PET substrate was peeled off from this laminate to obtain a three-layer structure (second extinguishing agent layer / first extinguishing agent layer / second extinguishing agent layer) fire extinguishing sheet.

[0069] Example 3 A fire extinguishing sheet was obtained in the same manner as in Example 1, except that the first fire extinguishing layer forming composition was applied to the non-release-treated side of the PET substrate and the PET substrate was not peeled off.

[0070] Comparative Example 1 A first extinguishing agent layer-forming composition was applied to the release-treated surface of a PET substrate using an applicator, and then dried at 75° C. for 7 minutes to obtain a laminate in which a first extinguishing agent layer having an average thickness of 300 μm was formed on the PET substrate. The PET substrate was peeled off from this laminate to obtain a single-layer fire extinguishing sheet consisting of only the first extinguishing agent layer.

[0071] Comparative Example 2 A second extinguishing agent layer-forming composition was applied to the release-treated surface of the PET substrate using an applicator, and then dried at 75° C. for 7 minutes to obtain a laminate in which a second extinguishing agent layer having an average thickness of 300 μm was formed on the PET substrate. The PET substrate was peeled off from this laminate to obtain a single-layer fire extinguishing sheet consisting of only the second extinguishing agent layer.

[0072] (Examples 4 to 10) A fire extinguishing sheet was obtained in the same manner as in Example 3, except that the thicknesses of the first and second fire extinguishing agent layers were changed to those shown in Tables 2 and 3.

[0073] Example 11 A fire extinguishing sheet was obtained in the same manner as in Example 2, except that the second fire extinguishing agent layer-forming composition was applied to the non-release-treated surface of the PET substrate, the PET substrate was not peeled off, and the thicknesses of the first fire extinguishing agent layer and the second fire extinguishing agent layer were changed to those shown in Table 3.

[0074] <Various evaluations> A barrier film (water vapor permeability is 0.2 to 0.6 g / (m)) comprising a sealant layer (L-LDPE (linear low-density polyethylene) resin, thickness 30 μm) and a substrate layer (PET (polyethylene terephthalate) resin with a silica deposition layer, thickness 12 μm) 2 A fire extinguishing sheet (50mm x 50mm) obtained in each example was covered with two of these barrier films, and the four sides of the barrier film were heat sealed to enclose the fire extinguishing sheet. The heat sealing conditions were 140°C and 2 seconds. The heat seal width of each side was 10mm. As a result, a fire extinguishing material package (fire extinguishing sheet contained in a packaging bag) with outer dimensions of 70mm x 70mm was obtained. This was used as an evaluation sample. Evaluation tests were performed on the evaluation samples obtained from each example as follows. The results are shown in Tables 1 to 3.

[0075] (Fire extinguishing performance evaluation test) In this test, the extinguishing material package was placed above the flame, and the performance of the extinguishing material package was evaluated. That is, an iron container with a length of 20 cm, a width of 30 cm, and a height of 40 cm was prepared. To prevent the ignited solid fuel from suffocating, five circular vents with a diameter of 8.5 mm were provided on each side of the container at heights of 5.0 cm, 12.5 cm, 20.0 cm, 27.5 cm, and 35.0 cm from the top. The extinguishing material package (evaluation sample) was attached to the center of the top of the container with double-sided tape. 1.5 g of solid fuel (Captain Stag Co., Ltd. solid fuel fire block ignition agent) with a length of 15 mm, a width of 15 mm, and a height of 10 mm was placed in the center of the bottom of the container. The distance between the solid fuel and the evaluation sample was adjusted to 10 cm, 15 cm, and 20 cm, and a test was conducted at each distance to see if the evaluation sample could extinguish the fire within 180 seconds after the solid fuel was ignited. Of the first and second extinguishing agent layers, the layer facing the flame was as shown in Table 1.

[0076] (Property stability evaluation test) The total light transmittance of the evaluation sample was measured using a haze meter (BYK-Gardner Haze-Guard Plus manufactured by BYK) in accordance with JIS K 7361-1. The evaluation sample was a fire extinguishing material package prepared by leaving the fire extinguishing sheet obtained in each example at rest for 24 hours under 25°C / 30%RH conditions and then sealing it in a barrier film. Measurements were performed before being placed in a constant temperature and humidity chamber (under 85°C / 85%RH conditions) (initial total light transmittance) and after 168 hours had passed since being placed therein (total light transmittance after storage), and the change amount Δ in total light transmittance before and after storage was calculated according to the following formula. When salt deliquescence occurs, the transparency of the fire extinguishing sheet increases, so the degree of deliquescence was evaluated by checking this change amount Δ. When salt deliquescence is less likely to occur, the property stability of the fire extinguishing sheet is high. Change in total light transmittance Δ = total light transmittance value after storage - initial total light transmittance value The evaluation was based on the following criteria: A: The change in total light transmittance Δ is 30 or less. B: The change Δ in total light transmittance is more than 30 and 50 or less. C: The change Δ in total light transmittance is more than 50.

[0077] [Table 1]

[0078] [Table 2]

[0079] [Table 3] In Tables 1 to 3, the numbers in parentheses for the extinction rate mean (number of successful extinguishing attempts / number of tests). The "distance" related to the extinction rate means the distance from the solid fuel to the evaluation sample.

[0080] The evaluation samples according to Example 1 and Comparative Examples 1 and 2 were further evaluated as follows.

[0081] (Fire extinguishing performance evaluation test 1) In this test, the extinguishing material package was placed above the flame, and the performance of the extinguishing material package was evaluated. That is, an iron container with the same configuration as above was prepared. The extinguishing material package (evaluation sample) was attached to the center of the top surface of the container with double-sided tape. 1.5 g of solid fuel (Captain Stag Co., Ltd. solid fuel fire block ignition agent) with a length of 15 mm, width of 15 mm, and height of 10 mm was placed in the center of the bottom surface of the container. After the solid fuel was ignited, the distance between the solid fuel and the evaluation sample was adjusted to 10 cm, 15 cm, and 20 cm, and a test was performed at each distance to see if the evaluation sample could extinguish the fire within 180 seconds. Of the first and second extinguishing agent layers, the layer facing the flame was as shown in Table 4. The evaluation was performed based on the following criteria. A: The fire can be extinguished when the distance between the solid fuel and the evaluation sample is 20 cm. B: The fire can be extinguished when the distance between the solid fuel and the evaluation sample is 10 cm. C: The distance between the solid fuel and the evaluation sample is 10 cm and the fire cannot be extinguished.

[0082] (Fire extinguishing performance evaluation test 2) In this test, the extinguishing material package was placed vertically at a position horizontally away from the flame, and the performance of the extinguishing material package was evaluated. That is, an iron container with the same configuration as above was prepared. The extinguishing material package (evaluation sample) was attached to the center of the inside back of the container with double-sided tape. 1.5 g of solid fuel (Captain Stag Co., Ltd. solid fuel fire block ignition agent) with a length of 15 mm, a width of 15 mm, and a height of 10 mm was placed in front of the evaluation sample and at the same height as the bottom side of the evaluation sample. After the solid fuel was ignited, the horizontal distance between the solid fuel and the evaluation sample was adjusted to 5 mm and 10 mm, and a test was performed at each distance to see if the fire could be extinguished within 180 seconds. Of the first and second extinguishing agent layers, the layer facing the flame was as shown in Table 4. The evaluation was performed based on the following criteria. A: The fire can be extinguished when the distance between the solid fuel and the evaluation sample is 10 mm. B: The fire can be extinguished when the distance between the solid fuel and the evaluation sample is 5 mm. C: The solid fuel was not extinguished when the evaluation sample was 5 mm away.

[0083] [Table 4]

[0084] As shown in Table 4, the result of the fire extinguishing performance evaluation test 2 for Example 1 was B. This is presumably because the flame was small and the fire extinguishing sheet placed next to the flame was not easily heated. For example, against an intense flame such as that caused by a switchboard catching fire, the fire extinguishing function can be expected to be exerted even if the fire extinguishing sheet is located at a certain distance.

[0085] The present disclosure relates to the following inventions: [1] A fire extinguishing sheet having a laminated structure including a first extinguishing agent layer and a second extinguishing agent layer, the first and second extinguishing agent layers each contain an extinguishing agent; The extinguishing agent contains at least one salt selected from the group consisting of an organic salt and an inorganic salt having deliquescent properties, The fire extinguishing sheet, wherein the second fire extinguishing agent layer further comprises a deliquescence suppressing component. [2] The fire extinguisher sheet according to [1], wherein the deliquescent component contains a compound having an acid anhydride group. [3] The fire extinguishing sheet according to [2], wherein the compound having an acid anhydride group is a silane coupling agent having a carboxylic acid anhydride group and an alkoxysilyl group. [4] the first extinguishing agent layer comprises a first extinguishing agent; the second extinguishing agent layer comprises a second extinguishing agent; The fire extinguishing sheet according to any one of [1] to [3], wherein the salt contained in the first fire extinguishing agent is the same compound as the salt contained in the second fire extinguishing agent. [5] the first extinguishing agent layer comprises a first extinguishing agent; the second extinguishing agent layer comprises a second extinguishing agent; The fire extinguishing sheet according to any one of [1] to [4], wherein at least one of the first and second fire extinguishing agents further contains an oxidizing agent. [6] The fire extinguishing sheet according to any one of [1] to [5], wherein when a 2.0 μL water droplet is dropped onto the second fire extinguishing agent layer, the contact angle 0.2 seconds after the drop is dropped is 75° or more. [7] The fire extinguisher sheet according to any one of [1] to [6], wherein a change Δ in total light transmittance calculated by the following formula (1) based on the results of a property stability evaluation test is 50 or less. Change in total light transmittance Δ = total light transmittance value after storage - initial total light transmittance value (1) [8] The fire extinguishing sheet according to any one of [1] to [7], which is contained in a packaging bag having gas barrier properties. [9] Objects to be extinguished that may catch fire, A fire extinguishing sheet arranged to face the object to be extinguished; An apparatus having an automatic fire extinguishing function, comprising: The fire extinguishing sheet has a laminated structure including a first fire extinguishing agent layer and a second fire extinguishing agent layer, The first and second extinguishing agent layers each contain an extinguishing agent that is ejected in response to a flame, The extinguishing agent contains at least one salt selected from the group consisting of an organic salt and an inorganic salt having deliquescent properties, The device having an automatic fire extinguishing function, wherein the second fire extinguishing agent layer further contains a deliquescence suppressing component.

[10] An apparatus having an automatic fire extinguishing function as described in [9], wherein the object to be extinguished is one selected from the group consisting of a distribution board, a distribution board, a control panel, a storage battery, and an outlet, and the fire extinguishing sheet is arranged on the inner surface of a housing that contains the object to be extinguished.

[11] The second extinguishing agent layer has a lower reactivity to flames than the first extinguishing agent layer and is positioned closer to the object to be extinguished than the first extinguishing agent layer. An apparatus with an automatic fire extinguishing function as described in [9] or

[10] .

[12] An apparatus having an automatic fire extinguishing function as described in

[11] , wherein the fire extinguishing sheet is positioned above the object to be extinguished.

[13] An apparatus having an automatic fire extinguishing function described in [9] or

[10] , wherein the first extinguishing agent layer has a higher reactivity to flame than the second extinguishing agent layer and is positioned closer to the object to be extinguished than the second extinguishing agent layer.

[14] An apparatus having an automatic fire extinguishing function as described in

[13] , wherein the fire extinguishing sheet is positioned horizontally away from the object to be extinguished. [Explanation of symbols]

[0086] 30, 30a, 30b, 30c, 30d...fire extinguishing sheet, 30s...sealing portion, 31...first fire extinguishing agent layer, 32...second fire extinguishing agent layer, 38...packaging bag, 1F...surface of the fire extinguishing sheet facing the first fire extinguishing agent layer, 2F...surface of the fire extinguishing sheet facing the second fire extinguishing agent layer, 100...electrical equipment (device with automatic fire extinguishing function), 101...housing, 101a...storage portion, 101b...opening / closing door, 102...wiring cover, 103...breaker, 104...wiring.

Claims

1. A fire extinguishing sheet having a laminated structure including a first extinguishing agent layer and a second extinguishing agent layer, the first and second extinguishing agent layers each contain an extinguishing agent; The extinguishing agent contains at least one salt selected from the group consisting of an organic salt and an inorganic salt having deliquescent properties, The fire extinguishing sheet, wherein the second fire extinguishing agent layer further comprises a deliquescence suppressing component.

2. The fire extinguishing sheet according to claim 1 , wherein the deliquescent component comprises a compound having an acid anhydride group.

3. The fire extinguishing sheet according to claim 2, wherein the compound having an acid anhydride group is a silane coupling agent having a carboxylic acid anhydride group and an alkoxysilyl group.

4. the first extinguishing agent layer comprises a first extinguishing agent; the second extinguishing agent layer comprises a second extinguishing agent; 3. The fire extinguishing sheet according to claim 1, wherein the salt contained in the first extinguishing agent is the same compound as the salt contained in the second extinguishing agent.

5. the first extinguishing agent layer comprises a first extinguishing agent; the second extinguishing agent layer comprises a second extinguishing agent; The fire extinguishing sheet according to claim 1 or 2, wherein at least one of the first and second extinguishing agents further comprises an oxidizer.

6. 3. The fire extinguishing sheet according to claim 1 or 2, wherein when a 2.0 μL water droplet is dropped onto the second fire extinguishing agent layer, the contact angle 0.2 seconds after the drop is dropped is 75° or more.

7. 3. The fire extinguishing sheet according to claim 1 or 2, wherein a change Δ in total light transmittance calculated by the following formula (1) based on the results of a property stability evaluation test is 50 or less: Change in total light transmittance Δ=total light transmittance value after storage−initial total light transmittance value (1)

8. The fire extinguishing sheet according to claim 1 or 2, which is contained in a packaging bag having gas barrier properties.

9. Objects to be extinguished that may catch fire, A fire extinguishing sheet arranged to face the object to be extinguished; An apparatus having an automatic fire extinguishing function, comprising: The fire extinguishing sheet has a laminated structure including a first fire extinguishing agent layer and a second fire extinguishing agent layer, The first and second extinguishing agent layers each contain an extinguishing agent that is ejected in response to a flame, The extinguishing agent contains at least one salt selected from the group consisting of an organic salt and an inorganic salt having deliquescent properties, The device having an automatic fire extinguishing function, wherein the second fire extinguishing agent layer further contains a deliquescence suppressing component.

10. An apparatus with an automatic fire extinguishing function as described in claim 9, wherein the object to be extinguished is one selected from the group consisting of a distribution board, a distribution board, a control panel, a storage battery, and an outlet, and the fire extinguishing sheet is arranged on the inner surface of a housing that contains the object to be extinguished.

11. The device having an automatic fire extinguishing function according to claim 9 or 10, wherein the second extinguishing agent layer has a lower reactivity to flame than the first extinguishing agent layer and is disposed closer to the object to be extinguished than the first extinguishing agent layer.

12. The device having an automatic fire extinguishing function according to claim 11, wherein the fire extinguishing sheet is disposed above the object to be extinguished.

13. The device having an automatic fire extinguishing function according to claim 9 or 10, wherein the first extinguishing agent layer has a higher reactivity to flame than the second extinguishing agent layer and is disposed closer to the object to be extinguished than the second extinguishing agent layer.

14. The device having an automatic fire extinguishing function according to claim 13, wherein the fire extinguishing sheet is arranged at a position horizontally spaced apart from the object to be extinguished.

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