Fire extinguishing material, fire extinguishing material package, and electric facility

Abstract

This fire extinguishing material includes a fire extinguishing agent layer containing a fire extinguishing agent. This fire extinguishing agent contains: a radical generating agent containing an organic potassium salt; and an oxidizing agent containing a potassium salt. The abundance ratio of potassium on the surface of the fire extinguishing material is 36% or more. The potassium salt may be potassium chlorate. The fire extinguishing agent layer may further contain a binder resin. The fire extinguishing material may further include a base material.

Description

Fire extinguishing materials, fire extinguishing material packages, and electrical equipment

[0001] The present disclosure relates to fire extinguishing materials, fire extinguishing material packages, and electrical equipment.

[0002] In electrical equipment such as switchboards and distribution boards, ignition may occur due to a short circuit or the like. Therefore, it is known to pre-place a fire extinguishing material containing a fire extinguishing agent near a fire target that may catch fire. For example, in Patent Document 1 below, a sheet-like fire extinguishing material containing a component that burns a chlorate and a potassium salt and decomposes the potassium salt together with the chlorate to generate an aerosol containing potassium radicals in a predetermined blending ratio is proposed.

[0003] Japanese Unexamined Patent Application Publication No. 2021 - 164664

[0004] By the way, especially in recent years, due to the development of mechanization in various industries, electrical equipment such as switchboards and distribution boards may be installed in various places where it is difficult to notice. In electrical equipment, it is assumed that a relatively small ignition source that burns the coating of the wiring may occur during a short circuit, and there is a possibility that the fire spreading caused by this ignition source may progress to a house or other buildings. Therefore, it is desirable to complete the extinguishing of such a relatively small ignition source at an early stage. However, the fire extinguishing material described in Patent Document 1 above cannot be said to have sufficient reactivity to a relatively small ignition source, and there is still room for improvement in terms of the fire extinguishing performance against a small ignition source.

[0005] Therefore, an object of the present disclosure is to provide a fire extinguishing material, a fire extinguishing material package, and electrical equipment that can effectively extinguish even a small ignition source.

[0006] One aspect of this disclosure is a fire extinguishing material comprising a fire extinguishing layer containing a fire extinguishing agent, wherein the fire extinguishing agent comprises a radical generating agent containing an organic potassium salt and an oxidizing agent containing a potassium salt, and the proportion of potassium on the surface of the fire extinguishing material is 36% or more. In the fire extinguishing material of this disclosure, because the fire extinguishing agent comprises a radical generating agent containing an organic potassium salt and an oxidizing agent containing a potassium salt, and the proportion of potassium on the surface of the fire extinguishing material is 36% or more, the reactivity of the fire extinguishing material to flames can be improved, making it easier to release aerosols (potassium radicals), and thus even small fires can be effectively extinguished.

[0007] In the above-mentioned fire extinguishing material, the proportion of potassium on the surface of the fire extinguishing material may be 60% or less. When the proportion of potassium on the surface of the fire extinguishing material is 60% or less, the fire extinguishing layer is more easily maintained.

[0008] In the above-mentioned fire extinguishing material, the potassium salt may be potassium chlorate. In this case, aerosols can be effectively generated from the radical generating agent, and the fire extinguishing material can extinguish even small fires more effectively.

[0009] In the above-mentioned fire extinguishing material, the organic potassium salt may contain at least one of a potassium carboxylate salt and its hydrate. When the organic potassium salt contains at least one of a potassium carboxylate salt and its hydrate, the efficiency of the negative catalytic effect on combustion is further improved.

[0010] In the above-mentioned fire extinguishing material, the fire extinguishing agent layer may further contain a binder resin. The binder resin is a component that, together with the oxidizing agent, imparts thermal energy to the radical generating agent when exposed to flames. Therefore, it can effectively generate aerosols from the radical generating agent, allowing the fire extinguishing material to extinguish even small fires more effectively.

[0011] In the above-mentioned fire extinguishing material, the amount of the fire extinguishing agent may be 70 to 97% by mass, based on the total amount of the fire extinguishing agent and the binder resin. When the amount of the fire extinguishing agent is 97% by mass or less, even if the fire extinguishing agent is hygroscopic, the deliquescence of the fire extinguishing agent is easily suppressed, and the deterioration of the fire extinguishing function due to moisture absorption of the fire extinguishing agent layer can be suppressed. On the other hand, when the amount of the fire extinguishing agent is 70% by mass or more, the fire extinguishing material has good fire extinguishing function.

[0012] In the above-mentioned fire extinguishing material, the binder resin may contain at least one of a polyvinyl acetal resin and a polyurethane resin. In this case, the film-forming properties of the fire extinguishing agent layer-forming composition containing the binder resin are further improved, and the uniformity of the thickness of the fire extinguishing agent layer is further improved.

[0013] The above-mentioned fire extinguishing material may further include a base material. In this case, even if the fire extinguishing material is placed in an environment with large temperature fluctuations, the base material suppresses the expansion and contraction of the fire extinguishing agent layer, and the shape of the fire extinguishing agent layer is maintained.

[0014] In the above-mentioned fire extinguishing material, the average particle size D50 of the mixture containing the radical generator and the oxidizing agent may be 1 to 100 μm. When the average particle size D50 of the mixture containing the radical generator and the oxidizing agent is 1 μm or more, the homogeneity of the fire extinguishing agent layer tends to improve. Also, when the average particle size D50 of the mixture containing the radical generator and the oxidizing agent is 100 μm or less, the smoothness of the fire extinguishing agent layer tends to improve.

[0015] In the above-mentioned fire extinguishing material, the thickness of the base material may be 4 μm or more and 100 μm or less. If the thickness of the base material is 4 μm or more, the strength and rigidity of the fire extinguishing material are improved, a highly flat shape can be obtained, and the handling of the fire extinguishing material becomes easier. On the other hand, if the thickness of the base material is 100 μm or less, the fire extinguishing material can be installed in a narrow space. Also, even if flames hit the fire extinguishing material from the base material side, holes are formed in the base material in a short time, so that the flames can directly hit the fire extinguishing agent layer, and the time until fire extinguishing can be started can be shortened.

[0016] In the above-mentioned fire extinguishing material, the thickness of the fire extinguishing agent layer may be between 10 μm and 600 μm. A thickness of 10 μm or more in the fire extinguishing agent layer makes it easier for the fire extinguishing agent layer to achieve good fire extinguishing performance. Furthermore, a thickness of 600 μm or less in the fire extinguishing agent layer can further improve the uniformity of the thickness of the fire extinguishing agent layer, and the fire extinguishing material can be installed in a narrow space.

[0017] Another aspect of this disclosure is the provision of a fire extinguishing material package comprising the fire extinguishing material described above and a packaging bag for enclosing the fire extinguishing material. With this fire extinguishing material package, the packaging bag prevents moisture contained in the outside air from entering the packaging bag, thereby suppressing the deterioration of the fire extinguishing function of the fire extinguishing agent layer of the fire extinguishing material due to moisture. As a result, the fire extinguishing material package can suppress the deterioration of the fire extinguishing function over a long period of time. Furthermore, since the fire extinguishing material contained in the fire extinguishing material package can effectively extinguish even small embers, even if a small ember occurs at the object to be extinguished and the fire extinguishing material is exposed and heated by that ember, the fire extinguishing material can effectively extinguish the small ember.

[0018] Another aspect of this disclosure is the provision of an electrical system comprising an object to be extinguished, which consists of an electrical device, and the fire extinguishing material described above. With this electrical system, the fire extinguishing material can effectively extinguish even small embers, so even if a small ember arises in the object to be extinguished and the fire extinguishing material is heated by that ember, the fire extinguishing material can effectively extinguish the small ember.

[0019] Another aspect of this disclosure is the provision of an electrical system comprising an object to be extinguished, which consists of an electrical device, and the fire extinguishing material package described above. With this electrical system, the fire extinguishing material contained in the fire extinguishing material package can effectively extinguish even small embers, so even if a small ember occurs in the object to be extinguished and the fire extinguishing material is exposed and heated by that ember, the fire extinguishing material can effectively extinguish the small ember. In addition, the fire extinguishing material package prevents moisture from the outside air from entering the packaging bag, thus suppressing the deterioration of the fire extinguishing function of the fire extinguishing material due to moisture in the fire extinguishing agent layer. For this reason, the electrical system can suppress the deterioration of the fire extinguishing function over a long period of time.

[0020] The above-mentioned fire extinguishing material further comprises a base material, the fire extinguishing agent layer further contains a binder resin, the potassium content on the surface of the fire extinguishing material is 38% to 45%, the organic potassium salt is tripotassium citrate, the potassium salt is potassium chlorate, the binder resin contains polyurethane resin, the amount of the fire extinguishing agent is 85 to 92% by mass based on the total amount of the fire extinguishing agent and the binder resin, the average particle size D50 of the mixture containing the radical generator and the oxidizing agent is 10 to 20 μm, the thickness of the base material is 4 μm to 100 μm, and the thickness of the fire extinguishing agent layer may be 110 μm to 200 μm. With this fire extinguishing material, even small fires can be extinguished particularly effectively.

[0021] According to this disclosure, a fire extinguishing material, a fire extinguishing material package, and electrical equipment are provided that can effectively extinguish even small embers.

[0022] Figure 1 is a schematic cross-sectional view showing one embodiment of the fire extinguishing material of the present disclosure. Figure 2 is a schematic cross-sectional view showing one embodiment of the fire extinguishing material package of the present disclosure. Figure 3 is a schematic front view showing one embodiment of the electrical equipment of the present disclosure.

[0023] <<Fire Extinguishing Material>> Hereinafter, embodiments of the fire extinguishing material of this disclosure will be described with reference to Figure 1. Figure 1 is a schematic cross-sectional view showing one embodiment of the fire extinguishing material of this disclosure. As shown in Figure 1, the fire extinguishing material 10 comprises a fire extinguishing agent layer 12 containing a fire extinguishing agent. The fire extinguishing agent comprises a radical generating agent containing an organic potassium salt and an oxidizing agent containing a potassium salt. The fire extinguishing material 10 may further comprise a substrate 14 laminated on the fire extinguishing agent layer 12. On the surface of the fire extinguishing material 10, the potassium content is 36% or more. The surface of the fire extinguishing material 10 shown in Figure 1 coincides with the surface of the fire extinguishing agent layer 12.

[0024] According to the fire extinguishing material 10 described above, when a flame occurs in an object to be extinguished, such as an electrical device, and is heated from the side of the fire extinguishing agent layer 12, the heat causes the fire extinguishing agent in the fire extinguishing agent layer 12 to react, activating the fire extinguishing function of the fire extinguishing agent layer 12 and extinguishing the flame. In this case, according to the fire extinguishing material 10, the fire extinguishing agent contains a radical generating agent containing an organic potassium salt and an oxidizing agent containing a potassium salt, and the potassium content on the surface of the fire extinguishing material 10 is 36% or more, which improves the reactivity of the fire extinguishing material 10 to flames and makes it easier to release aerosols (potassium radicals), so even small fires can be extinguished effectively.

[0025] The fire extinguishing material 10 will be described below.

[0026] As previously described, the fire extinguishing material 10 comprises a fire extinguishing agent layer 12 and a base material 14. The potassium content on the surface of the fire extinguishing material 10 is 36% or more. The potassium content is determined by observing the surface of the fire extinguishing material 10 using a scanning electron microscope (JEOL Ltd. JSM-7001F) under conditions of 3000x magnification, 15kV acceleration voltage, and 15mA irradiation current. For an observation area exceeding 30μm × 20μm, elemental mapping of potassium is performed using EDX (Oxford Instruments Inc. IMCA Penta FETx3). The mapped image is converted into an 8-bit (256-level grayscale) image using image processing software (ImageJ), and then automatically binarized (setting condition: Otsu) based on the grayscale threshold for the presence or absence of potassium. The value is obtained as the area ratio of the potassium-containing portion to the total area (area of ​​the mapped image). The potassium content on the surface of the fire extinguishing material 10 may be 38% or more, or 40% or more. Alternatively, the potassium content on the surface of the fire extinguishing material 10 may be 60% or less, 50% or less, 48% or less, 45% or less, or 42% or less. When the potassium content on the surface of the fire extinguishing material 10 is 60% or less, the fire extinguishing agent layer 12 is more easily maintained. The potassium content on the surface of the fire extinguishing material 10 may be 38% to 60%, 38% to 50%, 38% to 50%, 38% to 45%, 40% to 45%, or 40% to 42%. In Figure 1, the surface of the fire extinguishing material 10 coincides with the surface of the fire extinguishing agent layer 12, but if the fire extinguishing material 10 has another layer on the surface of the fire extinguishing agent layer 12, it refers to the surface of that other layer. In other words, the surface of the fire extinguishing material 10 is the outermost surface of the fire extinguishing material 10.

[0027] The thickness of the fire extinguishing material 10 is not particularly limited, but it is preferably 30 μm or more. A thickness of 30 μm or more in the fire extinguishing material 10 effectively extinguishes flames generated at the object to be extinguished, and the increased rigidity makes handling of the fire extinguishing material package 100 easier. From a similar viewpoint, the thickness of the fire extinguishing material 10 may be 50 μm or more, 100 μm or more, or 120 μm or more. From the viewpoint of installation in a narrow space, the thickness of the fire extinguishing material 10 is preferably 1000 μm or less. The thickness of the fire extinguishing material 10 may be 500 μm or less, 400 μm or less, 300 μm or less, 200 μm or less, 180 μm or less, or 150 μm or less. The thickness of the fire extinguishing material 10 may be 30 μm or more and 1000 μm or less, 50 μm or more and 500 μm or less, 100 μm or more and 400 μm or less, or 120 μm or more and 300 μm or less.

[0028] <Fire extinguishing agent layer> The fire extinguishing agent layer 12 contains a fire extinguishing agent. The fire extinguishing agent is a component that generates aerosols (radicals) by combustion and has the effect of stabilizing combustion radicals and suppressing the chain reaction of combustion (negative catalytic effect). The fire extinguishing agent layer 12 can be obtained using a fire extinguishing agent layer forming composition containing a fire extinguishing agent. The fire extinguishing agent layer forming composition may further contain a binder resin and a liquid medium, and may further contain other components.

[0029] The thickness of the fire extinguishing agent layer 12 can be adjusted as appropriate depending on the expected scale of the flames. For example, the thickness of the fire extinguishing agent layer 12 can be 10 μm to 600 μm. A thickness of 10 μm or more in the fire extinguishing agent layer 12 makes it easier for each fire extinguishing agent layer 12 to achieve good fire extinguishing performance. Also, a thickness of 600 μm or less in the fire extinguishing agent layer 12 can further improve the uniformity of the thickness of the fire extinguishing agent layer 12, and the fire extinguishing material 10 can be installed in a narrow space. The thickness of the fire extinguishing agent layer 12 may also be 20 μm or more, 50 μm or more, 100 μm or more, or 110 μm or more. The thickness of the fire extinguishing agent layer 12 may also be 300 μm or less, 200 μm or less, 180 μm or less, or 150 μm or less. The thickness of the fire extinguishing agent layer 12 may be 20 μm or more and 300 μm or less, 50 μm or more and 200 μm or less, 100 μm or more and 200 μm or less, or 110 μm or more and 200 μm or less, or 110 μm or more and 180 μm or less. Note that the thickness of the fire extinguishing agent layer 12 is, for example, the average value of the thickness measured at any five locations in the cross-section of the fire extinguishing agent layer 12.

[0030] The surface area of ​​the fire extinguishing agent layer 12 may be set appropriately depending on the intended use and installation location of the fire extinguishing material 10.

[0031] (Fire extinguishing agent) The fire extinguishing agent contains a radical generating agent containing an organic potassium salt and an oxidizing agent containing a potassium salt.

[0032] The radical generator contains an organic potassium salt and generates potassium radicals that have negative catalytic activity. The radical generator may or may not further contain an inorganic salt.

[0033] Examples of organopotassium salts include potassium carboxylate salts and their hydrates. These may be used individually or in combination of two or more. When the organopotassium salt contains at least one of potassium carboxylate salts and their hydrates, the efficiency of the negative catalytic effect on combustion is further improved.

[0034] Examples of potassium carboxylate salts include potassium acetate, potassium citrate (monotonic citrate, dipotassium citrate, tripotassium citrate), potassium tartrate, potassium lactate, potassium oxalate, and potassium maleate. These may be used individually or in combination of two or more.

[0035] Of these, potassium citrate is particularly preferred from the viewpoint of the efficiency of its negative catalytic effect on combustion.

[0036] Examples of inorganic salts include potassium salts and sodium salts. These may be used individually or in combination of two or more.

[0037] From the viewpoint of usefulness for negative catalytic effect, potassium salts (hereinafter also referred to as "inorganic potassium salts") can be suitably used as inorganic salts. Examples of inorganic potassium salts include potassium tetraborate, potassium carbonate, potassium bicarbonate, potassium dihydrogen phosphate, and dipotassium hydrogen phosphate. These may be used individually or in combination of two or more.

[0038] The oxidizing agent is a compound having an oxidizing effect, which generates an aerosol from the radical generating agent upon receiving the thermal energy of the flame, and contains a potassium salt.

[0039] Examples of potassium salts include inorganic oxidizing agents such as potassium chlorate, potassium perchlorate, and potassium permanganate. These may be used individually or in combination of two or more.

[0040] Among these oxidizing agents, potassium chlorate is preferred. In this case, aerosols can be effectively generated from the radical generating agent, allowing the fire extinguishing material 10 to extinguish even small fires more effectively.

[0041] The mixture containing a radical generator and an oxidizing agent may be granular. In this case, the average particle size D50 of the mixture containing a radical generator and an oxidizing agent is not particularly limited, but is preferably 1 to 100 μm. When the average particle size D50 of the mixture containing a radical generator and an oxidizing agent is 1 μm or more, the dispersibility of the fire extinguishing agent in the coating liquid is improved when the fire extinguishing agent layer 12 is formed using the coating liquid containing the fire extinguishing agent, and the homogeneity of the fire extinguishing agent layer 12 tends to be improved. When the average particle size D50 of the mixture containing a radical generator and an oxidizing agent is 100 μm or less, the stability of the fire extinguishing agent in the coating liquid is improved, and the smoothness of the fire extinguishing agent layer 12 obtained by drying the coating liquid tends to be improved.

[0042] From the viewpoint of improving the homogeneity and smoothness of the fire extinguishing agent layer 12, the average particle size D50 of the mixture containing a radical generator and an oxidizing agent is more preferably 2 to 40 μm, still more preferably 3 to 30 μm, and particularly preferably 3 to 20 μm.

[0043] The average particle size D50 of the mixture may be 3 to 15 μm, 5 to 15 μm, 8 to 15 μm, 10 to 15 μm or 12 to 15 μm, or may be 3 to 10 μm, or 3 to 5 μm.

[0044] The average particle size D50 of the mixture containing a radical generator and an oxidizing agent can be calculated by wet measurement using a laser diffraction particle size distribution measuring device.

[0045] The content of the above radical generator is, for example, 40 to 90 parts by mass, preferably 50 to 80 parts by mass, and more preferably 55 to 65 parts by mass with respect to 100 parts by mass of the total amount of the fire extinguishing agent.

[0046] The content of the above oxidizing agent is, for example, 10 to 60 parts by mass, preferably 20 to 50 parts by mass, and more preferably 35 to 45 parts by mass with respect to 100 parts by mass of the total amount of the fire extinguishing agent.

[0047] The amount of fire extinguishing agent is not particularly limited, but it may be 70-97% by mass or 85-92% by mass, based on the total amount of fire extinguishing agent and binder resin (100% by mass). If the amount of fire extinguishing agent is below the above upper limit, it is easier to suppress the deliquescence of the fire extinguishing agent even if the fire extinguishing agent is hygroscopic, and the deterioration of the fire extinguishing function due to moisture absorption of the fire extinguishing agent layer 12 can be suppressed. On the other hand, if the amount of fire extinguishing agent is above the above lower limit, the fire extinguishing material 10 has good fire extinguishing function.

[0048] (Binder Resin) The binder resin is a component that, together with the oxidizing agent, imparts thermal energy to the radical generating agent when exposed to flame. It enables the formation of the fire extinguishing agent layer 12 and also provides flexibility to the fire extinguishing agent layer 12. When the fire extinguishing agent layer 12 contains the binder resin, it can effectively generate aerosols from the radical generating agent, allowing the fire extinguishing material 10 to extinguish even small fires more effectively.

[0049] The binder resin is a resin obtained using a resin composition containing a thermoplastic resin or a thermosetting resin.

[0050] Examples of thermoplastic resins 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. These may be used individually or in combination of two or more. Among these resins, polyvinyl acetal resins and polyurethane resins can be suitably used. In this case, the film-forming properties of the fire extinguishing agent layer-forming composition containing the binder resin are further improved, and the uniformity of the thickness of the fire extinguishing agent layer 12 is further improved.

[0051] Examples of polyvinyl acetal resins include polyvinyl butyral (PVB).

[0052] Of the thermoplastic resins mentioned above, polyurethane resin can be suitably used from the viewpoint of achieving both film-forming properties and improved reactivity of the fire extinguishing agent. In addition to achieving both film-forming properties and improved reactivity of the fire extinguishing agent, ether-based polyurethane resin can be suitably used from the viewpoint of providing flexibility and water resistance to the fire extinguishing agent layer 12.

[0053] Examples of thermosetting resins include 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), polyvulcanized rubber (T), silicone rubber (Q), fluororubber (FKM, FZ), urethane rubber (U), and other types of rubber, as well as polyurethane resins, polyisocyanate resins, polyisocyanurate resins, phenolic resins, epoxy resins, and polyvinyl ether (PMVE)-anhydrous malee resins. These may be used individually or in combination of two or more types.

[0054] The amount of binder resin may be 3 to 30% by mass or 8 to 15% by mass, based on the total amount of fire extinguishing agent and binder resin (100% by mass). If the amount of binder resin is 30% by mass or less, the proportion of fire extinguishing agent increases relatively, so the fire extinguishing material 10 has good fire extinguishing function. If the amount of binder resin is 3% by mass or more, the shape retention of the fire extinguishing agent layer 12 is improved. In addition, the flexibility of the fire extinguishing agent layer 12 is improved, so the flexibility of the fire extinguishing material 10 is also improved. Furthermore, the combustion of the binder resin can increase the thermal energy supplied to the radical generating agent of the fire extinguishing agent, making it easier to generate potassium radicals, so the fire extinguishing material 10 can have good fire extinguishing function.

[0055] The resin composition may further contain a curing agent in addition to the thermosetting resin.

[0056] (Liquid medium) When the composition for forming a fire extinguishing agent layer contains a liquid medium, an organic solvent can be used as the liquid medium.

[0057] Examples of organic solvents include water-soluble solvents such as methanol, ethanol, isopropyl alcohol, and n-propyl alcohol; ketones such as acetone and methyl ethyl ketone; glycols such as ethylene glycol and diethylene glycol; and glycol ethers such as N-methylpyrrolidone (NMP), tetrahydrofuran, and butyl cellosolve. From the viewpoint of suppressing deliquescence of the radical generator and oxidizing agent, an alcohol-based solvent is preferred as the liquid medium, and ethanol can be used as an alcohol-based solvent, for example.

[0058] (Other components) The fire extinguishing agent layer forming composition may further contain other components such as surfactants, silane coupling agents, and antiblocking agents from the viewpoint of the stability of the properties of the fire extinguishing agent layer 12. These components can be appropriately selected depending on the type of binder resin.

[0059] The amount of the above components may be 40% by mass or less based on the total amount of the fire extinguishing agent layer 12. The amount of the above components may be 10% by mass or less, 0.1% by mass or more, or 0% by mass, based on the total amount of the fire extinguishing agent layer 12.

[0060] <Base Material> The base material 14 is a support for the fire extinguishing agent layer 12. By having the base material 14 in the fire extinguishing material 10, even when the fire extinguishing material 10 is placed in an environment with large temperature changes, the base material 14 suppresses the expansion and contraction of the fire extinguishing agent layer 12, and the shape of the fire extinguishing agent layer 12 is maintained.

[0061] The base material 14 may consist of a single layer or a laminate of multiple layers.

[0062] As for the material included in the base material 14, since the flame temperature is generally around 700°C to 900°C, resin is a good choice.

[0063] Examples of resins include polyolefins (LLDPE, PP, COP, CPP, etc.), polyester resins (PET, etc.), fluororesins (PTFE, ETFE, EFEP, PFA, FEP, PCTFE, etc.), PVC, PVA, acrylic resins, epoxy resins, polyamide resins, and polyimide resins. One of the above resins may be used alone, or two or more may be used in combination.

[0064] If the base material 14 contains the above-mentioned resin, even if the fire extinguishing material 10 is heated by a flame from the base material 14 side, holes are easily formed, allowing the flame to come into direct contact with the fire extinguishing agent layer 12. Furthermore, if a transparent resin (for example, polyolefin resin, acrylic resin, etc.) is selected from the above-mentioned resins, the fire extinguishing agent layer 12 can be easily visually confirmed even when the fire extinguishing material 10 is observed from the base material 14 side, making it easier to perform visual inspection of the fire extinguishing material 10 and to confirm when the fire extinguishing material 10 should be replaced.

[0065] From the viewpoint of appropriately adjusting the heat insulation, heat resistance, and strength of the base material 14, the resin is preferably a polyester resin, and more preferably polyethylene terephthalate (PET).

[0066] The material contained in the base material 14 may consist only of resin, but may also contain the fire extinguishing agent described above.

[0067] The thickness of the base material 14 can be adjusted as appropriate according to the amount of heat from the flame expected when a fire breaks out, the impact from the flame, the allowable space, etc., and is not particularly limited, but the thickness of the base material 14 can be in the range of, for example, 4 to 100 μm.

[0068] If the thickness of the base material 14 is 4 μm or more, the strength and rigidity of the fire extinguishing material 10 are improved, a highly flat shape can be obtained, and the handling of the fire extinguishing material 10 becomes easier.

[0069] On the other hand, if the thickness of the base material 14 is 100 μm or less, the fire extinguishing material 10 can be installed in a narrow space. Also, even if flames hit the fire extinguishing material 10 from the base material 14 side, holes are formed in the base material 14 in a short time, allowing the flames to directly hit the fire extinguishing material layer 12, thus shortening the time until fire extinguishing can begin.

[0070] The lower limit of the thickness of the base material 14 may be 4.5 μm, 12 μm, 20 μm, 30 μm, or 40 μm. By having a thickness of the base material 14 equal to or greater than the above lower limit, the base material 14 can be made to have a more planar shape, making it easier to handle the fire extinguishing material 10.

[0071] The upper limit of the thickness of the base material 14 may be 100 μm, 80 μm, or 50 μm. By keeping the thickness of the base material 14 below the above upper limits, the fire extinguishing material 10 can be installed in a narrower space. In addition, the time from when the flame hits the fire extinguishing material 10 from the base material 14 side until the start of fire extinguishing can be further shortened.

[0072] <Other layers> The fire extinguishing material 10 may further comprise layers other than the base material 14 and the fire extinguishing agent layer 12. For example, the fire extinguishing material 10 may further comprise a vapor-deposited layer having water vapor barrier properties. The vapor-deposited layer can reduce the water vapor permeability.

[0073] Examples of vapor-deposited layers include inorganic metal oxide vapor-deposited layers such as alumina vapor-deposited layers and silica vapor-deposited layers.

[0074] The vapor-deposited layer is preferably provided on the surface of the substrate 14 that is on the side of the fire extinguishing agent layer 12. In this case, it is possible to suppress the penetration of water vapor from the substrate 14 into the fire extinguishing agent layer 12 and the deliquescing of the fire extinguishing agent.

[0075] The vapor-deposited layer may be provided on the surface of the substrate 14 opposite to the fire extinguishing agent layer 12, or it may be provided on both the surface of the substrate 14 on the fire extinguishing agent layer 12 side and the surface of the substrate 14 opposite to the fire extinguishing agent layer 12.

[0076] <<Fire Extinguishing Material Package>> Next, an embodiment of the fire extinguishing material package of the present disclosure will be described with reference to Figure 2. Figure 2 is a schematic cross-sectional view showing one embodiment of the fire extinguishing material package of the present disclosure.

[0077] As shown in Figure 2, the fire extinguishing material package 100 comprises a fire extinguishing material 10 and a packaging bag 50 that encloses the fire extinguishing material 10.

[0078] The packaging bag 50 is a bag made using a film 60, and the film 60 comprises a base material 61 and a sealant layer 62. In Figure 2, the packaging bag 50 is a bag made using two films 60, and the sealant layers 62 of the films 60 are bonded together.

[0079] According to the fire extinguishing material package 100 described above, the packaging bag 50 prevents moisture contained in the outside air from entering the packaging bag 50, thereby suppressing the deterioration of the fire extinguishing function of the fire extinguishing agent layer 12 of the fire extinguishing material 10 due to moisture. For this reason, the fire extinguishing material package 100 can suppress the deterioration of the fire extinguishing function over a long period of time.

[0080] Furthermore, since the fire extinguishing material 10 contained in the fire extinguishing material package 100 can effectively extinguish even small embers, even if a small ember occurs in an object to be extinguished, such as electrical equipment, and the fire extinguishing material 10 is exposed and heated by that ember, the fire extinguishing material 10 can effectively extinguish the small ember.

[0081] (Packaging bag) The packaging bag 50 will be described below.

[0082] The packaging bag 50 is a bag that encloses the fire extinguishing material 10 inside. The packaging bag 50 shown in Figure 1 is formed by overlapping two films 60 with their sealant layers 62 facing each other and heat-sealing the periphery, and comprises a main body and a sealing portion that surrounds the main body. In the main body, the sealant layers 62 of the films 60 are not sealed to each other.

[0083] The packaging bag 50 can also be obtained by folding a single film 60 and heat-sealing the overlapping edges.

[0084] The base material 61 is a layer that provides heat resistance during the sealing process when manufacturing the packaging bag 50, and also provides the packaging bag 50 with processability and mechanical strength.

[0085] A resin film can be used as the base material 61. Examples of resins included in the resin film include polyolefin resin, polyester resin, fluororesin, vinyl resin, acrylic resin, epoxy resin, polyamide resin, polyimide resin, urethane resin, styrene resin, polycarbonate resin, ketone resin, sulfone resin, and cellulose resin. These may be used individually or in combination of two or more.

[0086] The thickness of the base material 61 is not particularly limited as long as it does not impede the fire extinguishing function of the fire extinguishing material package 100, and can be, for example, within the same range as the base material 14 of the fire extinguishing material 10.

[0087] The sealant layer 62 is a layer that imparts heat-sealability to the film 60.

[0088] The sealant layer 62 may contain, for example, a resin material that is heat-fusible (thermally fused). Examples of heat-fusible resin materials include polyolefin resins. In other words, the sealant layer 62 may contain a polyolefin resin.

[0089] Examples of polyolefin resins include polyolefin resins such as low-density polyethylene resin (LDPE), linear low-density polyethylene resin (LLDPE), medium-density polyethylene resin (MDPE), and unoriented polypropylene resin (CPP); polyethylene resins such as ethylene-vinyl acetate copolymer and ethylene-α-olefin copolymer; and polypropylene resins such as propylene-ethylene random copolymer, propylene-ethylene block copolymer, and propylene-α-olefin copolymer. These may be used individually or in combination of two or more. Of these, low-density polyethylene resin (LDPE), linear low-density polyethylene resin (LLDPE), or unoriented polypropylene resin (CPP) are preferred as polyolefin resins because they have excellent heat-sealing properties and low water vapor permeability, which helps to suppress the deterioration of the fire-extinguishing function of the fire extinguishing agent.

[0090] The packaging bag 50 may further include a barrier layer. By further including a barrier layer, the packaging bag 50 can have water vapor barrier properties, which suppresses water vapor on the outside of the packaging bag 50 from permeating through the packaging bag 50 and coming into contact with the fire extinguishing material 10, thereby suppressing deterioration of the fire extinguishing function of the fire extinguishing material 10. The barrier layer may be, for example, a metal foil or a resin film with a vapor deposition layer. If the vapor deposition layer is provided on a resin film, the vapor deposition layer may be provided on the surface of the base material 61 on the side facing the fire extinguishing material 10, on the surface opposite to the fire extinguishing material 10, or on both the surface facing the fire extinguishing material 10 and the surface opposite to the fire extinguishing material 10.

[0091] Examples of metal foils include aluminum foil.

[0092] Examples of vapor-deposited layers include inorganic metal oxide vapor-deposited layers such as alumina vapor-deposited layers and silica vapor-deposited layers.

[0093] Examples of resin films include polyester resin layers (e.g., PET layers).

[0094] The film 60 forming the packaging bag 50 may further have an adhesive layer between the base material 61 and the sealant layer 62. The adhesive layer is formed using an adhesive. Examples of adhesives include acrylic adhesives, epoxy adhesives, silicone adhesives, polyolefin adhesives, urethane adhesives, and polyvinyl ether adhesives. These may be used individually or in combination of two or more. Of these, urethane adhesives are preferably used as the adhesive because they offer both good adhesion and low cost.

[0095] The thickness of the adhesive layer is not particularly limited; for example, it may be 1 to 100 μm, but depending on the adhesive used, it may be 1 to 30 μm or 30 to 100 μm.

[0096] The packaging bag 50 has a density of 10 g / m². ２ It is preferable to have a water vapor transmission rate of 1 g / m³ or less (according to JIS K 7129, under 40°C / 90% RH conditions), and ２ It is preferable to have a water vapor transmission rate of / day or less.

[0097] <<Manufacturing Method for Fire Extinguishing Material Package>> Next, a method for manufacturing the fire extinguishing material package 100 will be described. The manufacturing method for the fire extinguishing material package 100 includes, for example, a fire extinguishing material preparation step of preparing the fire extinguishing material 10, and a sealing step of sealing the fire extinguishing material 10 inside a packaging bag 50 to obtain the fire extinguishing material package 100.

[0098] (1) Fire extinguishing material preparation process The fire extinguishing material preparation process is the process of preparing the fire extinguishing material 10.

[0099] The fire extinguishing material 10 comprises a fire extinguishing agent layer 12 and a base material 14, and can be formed, for example, by applying a fire extinguishing agent layer forming composition onto the base material 14 and drying it.

[0100] Specifically, first, a fire extinguishing agent and a binder resin are mixed with a liquid medium to prepare a composition for forming a fire extinguishing agent layer. The amounts of the fire extinguishing agent and the binder resin should be such that they constitute 70 to 97% by mass, or 85 to 92% by mass, based on the total amount of fire extinguishing agent and binder resin in the fire extinguishing agent layer 12, respectively.

[0101] The amount of liquid medium can be appropriately adjusted according to the viscosity of the fire extinguishing agent layer-forming composition, but it can be, for example, 40 to 95% by mass based on the total amount of the fire extinguishing agent layer-forming composition. The fire extinguishing agent layer-forming composition containing the liquid medium can be called a fire extinguishing agent layer-forming coating liquid.

[0102] Next, a coating liquid for forming a fire extinguishing agent layer is applied to the base material 14 and dried to form a fire extinguishing agent layer 12. In this way, a fire extinguishing material 10 having a fire extinguishing agent layer 12 and a base material 14 is prepared.

[0103] The coating liquid for forming the fire extinguishing agent layer can be applied by a wet coating method. Examples of wet coating methods include gravure coating, comma coating, dip coating, curtain coating, spin coating, sponge roll coating, and die coating.

[0104] The fire extinguishing material preparation process may further include a step of pressurizing the fire extinguishing agent layer 12. This makes it easier to improve the glossiness of the fire extinguishing agent layer 12. From the viewpoint of easily obtaining the desired glossiness, the pressurizing pressure can be 0.2 MPa or higher, and may also be 2.0 MPa or higher. From the viewpoint of the flexibility of the fire extinguishing agent layer 12, the pressurizing pressure can be 2.5 MPa or lower.

[0105] (2) Encapsulation process The encapsulation process is a process of encapsulating the fire extinguishing material 10 into the packaging bag 50 to obtain a fire extinguishing material package 100.

[0106] The packaging bag 50 can be obtained, for example, by stacking two films 60, each comprising a base material 61 and a sealant layer 62, and heat-sealing a portion of the peripheral edge of the films 60. However, the remaining peripheral edge of the films 60 is left unheat-sealed. This unheat-sealed portion of the peripheral edge (unsealed portion) forms an opening in the packaging bag 50.

[0107] Next, the fire extinguishing material 10 is placed inside the packaging bag 50 through the opening of the packaging bag 50, and the unsealed portion of the packaging bag 50 is heat-sealed.

[0108] This is how the fire extinguishing material package 100 is obtained.

[0109] <<Electrical Equipment>> Next, an embodiment of the electrical equipment of this disclosure will be described with reference to Figure 3. Figure 3 is a schematic front view showing an embodiment of the electrical equipment of this disclosure.

[0110] As shown in Figure 3, the electrical equipment 300 comprises an object to be extinguished, consisting of an electrical device 200, and a fire extinguishing material package 100.

[0111] The electrical device 200 mainly comprises an energizing section 210 and a housing 220 that houses the energizing section 210.

[0112] The energized section 210 is the part through which current flows and includes the circuit breaker 203 and wiring 204. A portion of the wiring 204 is housed together in the wiring cover 202.

[0113] The housing 220 comprises a box-shaped storage section 221 having an opening, and an opening / closing door 222 provided in the storage section 221 for opening and closing the opening.

[0114] The fire extinguishing material package 100 is housed inside the casing 220. In Figure 3, the fire extinguishing material package 100 consists of fire extinguishing material packages 100a, 100b, 100c, and 100d. Fire extinguishing material package 100a is positioned on the opening / closing door 222, facing the energized section 210 when the door 222 is closed. Fire extinguishing material package 100b is positioned on the ceiling surface inside the housing 221, facing the energized section 210. Fire extinguishing material package 100c is positioned on the lower side of the wiring cover 202, facing the energized section 210 (breaker 203) (approximate installation position shown in Figure 3 for simplicity). Fire extinguishing material package 100d is positioned on the back side of the inner surface of the housing 221, facing the energized section 210 (i.e., on the back side of the energized section 210).

[0115] According to the electrical equipment 300, the fire extinguishing material 10 contained in the fire extinguishing material package 100 can effectively extinguish even small fires. Therefore, even if a small fire occurs in the electrical device 200, which is the object to be extinguished, and the fire extinguishing material 10 is exposed and heated by the fire, the fire extinguishing material 10 can effectively extinguish the small fire. Furthermore, the fire extinguishing material package 100 prevents moisture from the outside air from entering the packaging bag 50, thus suppressing the deterioration of the fire extinguishing function of the fire extinguishing agent layer 12 of the fire extinguishing material 10 due to moisture. For this reason, according to the electrical equipment 300, the deterioration of the fire extinguishing function can be suppressed over a long period of time.

[0116] The position in which the fire extinguishing material package 100 is placed is not limited to the position shown in Figure 3, and can be appropriately changed depending on the location of the energized part 210 of the electrical device 200 that poses a fire risk and could be the target of fire extinguishing.

[0117] The distance between the energized part 210 of the electrical device 200 and the fire extinguishing material package 100 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 effective initial fire suppression. The distance between the electrical device 200 and the fire extinguishing material package 100 refers to the shortest distance between the electrical device 200 and the fire extinguishing material package 100 which is positioned opposite it.

[0118] For example, for an electrical device 200 located directly below the top surface of the housing section 221 and at a distance of 200 mm or less from the top surface, the fire extinguishing material package 100 can be installed on the top surface. Also, for example, for an electrical device 200 located facing the opening / closing door 222 and at a distance of 200 mm or less from the opening / closing door 222, the fire extinguishing material package 100 can be installed on the opening / closing door 222.

[0119] It is desirable to install the fire extinguishing material package 100 close to the electrical device 200, but if they are too close there is a risk of contact between the two, so it is preferable to leave a distance of at least 1 mm between them.

[0120] If the distance between the fire extinguishing material package 100 and the energized part 210 of the electrical device 200 is large, a member for adjusting the distance may be provided, and the fire extinguishing material package 100 may be placed on said member.

[0121] In the above embodiment, a distribution board is used as the electrical device 200, but instead of a distribution board, electrical equipment, a switchboard, or a battery (for example, a storage battery such as a lithium-ion battery) may be used as the electrical device 200.

[0122] Examples of electrical equipment include devices equipped with terminal blocks, transformers, circuit breakers, capacitors, earth leakage circuit breakers, electrical wiring, or outlets.

[0123] Examples of rechargeable batteries include mobile batteries, power tool batteries, and electric vehicle batteries.

[0124] Furthermore, in the above embodiment, the electrical equipment 300 is equipped with a fire extinguishing material package 100, but the fire extinguishing material 10 may be provided instead of the fire extinguishing material package 100.

[0125] The present disclosure will be further illustrated by the following examples, but the present disclosure is not limited to these examples.

[0126] The following materials were used in the examples and comparative examples.

[0127] (Example 1) Potassium chlorate (KClO) as an oxidizing agent ３A fire extinguishing agent was prepared by grinding a mixture of ( ) and tripotassium citrate, a radical generating agent, in an agate mortar until the average particle size D50 of the mixture was 12 μm or less. Composition 1 for forming a fire extinguishing agent layer was obtained by mixing this fire extinguishing agent with an ether-based polyurethane resin solution and ethanol as follows. <Composition 1 for forming a fire extinguishing agent layer> - Fire extinguishing agent (mixture of potassium chlorate and tripotassium citrate) 90 parts by mass - Ether-based polyurethane resin solution (solution obtained by dissolving 100 parts by mass of ether-based polyurethane resin (PU) in 210 parts by mass of isopropyl alcohol) 31 parts by mass (10 parts by mass of PU) - Ethanol 90 parts by mass - Fire extinguishing agent:binder resin (PU) = 90:10 (mass ratio) Next, using an applicator, Composition 1 for forming a fire extinguishing agent layer was applied to one surface of a polyethylene terephthalate (PET) film (manufactured by Toyobo Co., Ltd., product name: E7002, thickness 50 μm) as a base material, so that the dry thickness (DRY thickness) was 150 μm, and dried in an oven at 75°C for 7 minutes to obtain a fire extinguishing material comprising a fire extinguishing agent layer and a base material. The potassium content on the surface of the obtained fire extinguishing material was 42.45%, as shown in Table 1. The potassium abundance ratio was determined by observing the surface of the obtained fire extinguishing material using a scanning electron microscope (JEOL Ltd. JSM-7001F) under conditions of 3000x magnification, 15kV acceleration voltage, and 15mA irradiation current. For observation areas exceeding 30μm × 20μm, elemental mapping of potassium was performed using EDX (Oxford Instruments Inc. IMCA Penta FETx3). The mapped image was converted to an 8-bit (256-level grayscale) image using image processing software (ImageJ), and then binarized automatically (setting condition: Otsu) based on the grayscale threshold for the presence or absence of potassium. The potassium abundance ratio was then calculated as the area ratio of the potassium-containing area to the total area (area of ​​the mapped image).

[0128] (Example 2) A fire extinguishing material was obtained in the same manner as in Example 1, except that the following fire extinguishing material layer-forming composition 2 was used as the composition for forming the fire extinguishing material, and the ratio of potassium present on the surface of the fire extinguishing material was set to 36.43% as shown in Table 1. <Fire extinguishing material layer-forming composition 2> - Fire extinguishing agent (mixture of potassium chlorate and tripotassium citrate) 80 parts by mass - Ether-based polyurethane resin solution (solution obtained by dissolving 100 parts by mass of ether-based polyurethane resin (PU) in 210 parts by mass of isopropyl alcohol) 62 parts by mass (20 parts by mass of PU) - Ethanol 80 parts by mass - Fire extinguishing agent: Binder resin (PU) = 80:20 (mass ratio)

[0129] (Example 3) A fire extinguishing material was obtained in the same manner as in Example 1, except that the following fire extinguishing material layer-forming composition 3 was used as the fire extinguishing material layer-forming composition, and the ratio of potassium present on the surface of the fire extinguishing material was set to 38.90% as shown in Table 1. <Fire extinguishing material layer-forming composition 3> - Fire extinguishing agent (mixture of potassium chlorate and tripotassium citrate) 85 parts by mass - Ether-based polyurethane resin solution (solution obtained by dissolving 100 parts by mass of ether-based polyurethane resin (PU) in 210 parts by mass of isopropyl alcohol) 46.5 parts by mass (15 parts by mass of PU resin) - Ethanol 85 parts by mass - Fire extinguishing agent: Binder resin (PU) = 85:15 (mass ratio)

[0130] (Example 4) A fire extinguishing material was obtained in the same manner as in Example 1, except that the following fire extinguishing material layer-forming composition 4 was used as the composition for forming the fire extinguishing material, and the ratio of potassium present on the surface of the fire extinguishing material was set to 45.43% as shown in Table 1. <Fire extinguishing material layer-forming composition 4> - Fire extinguishing agent (mixture of potassium chlorate and tripotassium citrate) 95 parts by mass - Ether-based polyurethane resin solution (solution obtained by dissolving 100 parts by mass of ether-based polyurethane resin (PU) in 210 parts by mass of isopropyl alcohol) 15.5 parts by mass (5 parts by mass of PU) - Ethanol 95 parts by mass - Fire extinguishing agent: Binder resin (PU) = 95:5 (mass ratio)

[0131] (Example 5) As the composition for forming the fire extinguishing agent layer, the following fire extinguishing agent layer-forming composition 5 was used, and a fire extinguishing material was obtained in the same manner as in Example 1, except that the ratio of potassium present on the surface of the fire extinguishing material was 40.60%, as shown in Table 1. <Fire extinguishing agent layer-forming composition 5> - Fire extinguishing agent (mixture of potassium chlorate and tripotassium citrate) 87.5 parts by mass - Ether-based polyurethane resin solution (solution obtained by dissolving 100 parts by mass of ether-based polyurethane resin (PU) in 210 parts by mass of isopropyl alcohol) 38.75 parts by mass (PU 12.5 parts by mass) - Ethanol 87.5 parts by mass - Fire extinguishing agent: Binder resin (PU) = 87.5:12.5 (mass ratio)

[0132] (Example 6) As the composition for forming the fire extinguishing agent layer, the following composition 6 for forming the fire extinguishing agent layer was used, and a fire extinguishing material was obtained in the same manner as in Example 1, except that the ratio of potassium present on the surface of the fire extinguishing material was 45.30%, as shown in Table 2. <Composition 6 for forming the fire extinguishing agent layer> - Fire extinguishing agent (mixture of potassium chlorate and tripotassium citrate) 87.5 parts by mass - Polyvinyl butyral resin solution (solution obtained by dissolving 11 parts by mass of polyvinyl butyral resin (PVB) in 80 parts by mass of ethanol and 9 parts by mass of isopropyl alcohol) 90 parts by mass (PVB 9.9 parts by mass) - Epoxy resin (product name: EX-991L, manufactured by Nagase ChemteX Corporation, solid content 100%) 2.6 parts by mass - Ethanol 87.5 parts by mass - Fire extinguishing agent: Binder resin (PVB and epoxy resin) = 87.5:12.5 (mass ratio)

[0133] (Comparative Example 1) A fire extinguishing material was obtained in the same manner as in Example 1, except that the following fire extinguishing material layer-forming composition 7 was used as the composition for forming the fire extinguishing material, and the ratio of potassium present on the surface of the fire extinguishing material was set to 35.25% as shown in Table 2. <Fire extinguishing material layer-forming composition 7> - Fire extinguishing agent (mixture of potassium chlorate and tripotassium citrate) 60 parts by mass - Ether-based polyurethane resin solution (solution obtained by dissolving 100 parts by mass of ether-based polyurethane resin (PU) in 210 parts by mass of isopropyl alcohol) 124 parts by mass (40 parts by mass of PU) - Ethanol 60 parts by mass - Fire extinguishing agent: Binder resin (PU) = 60:40 (mass ratio)

[0134] (Comparative Example 2) Fire extinguishing material was obtained in the same manner as in Comparative Example 1, except that composition 1 for forming the fire extinguishing agent layer was applied to one surface of a polyethylene terephthalate (PET) film as a base material so that the dry thickness (DRY thickness) was 200 μm, and the potassium content ratio on the surface of the fire extinguishing material was 27.80%, as shown in Table 2.

[0135] (Comparative Example 3) A fire extinguishing material was obtained in the same manner as in Example 5, except that an ether-based polyurethane resin solution (a solution obtained by dissolving 100 parts by mass of ether-based polyurethane resin (PU) in 210 parts by mass of isopropyl alcohol) was applied to the surface of the fire extinguishing agent layer using a bar coater to a dry thickness of 10 μm, and dried at 80°C for 1 minute to form a protective layer on the fire extinguishing agent layer, and the potassium content on the surface of the fire extinguishing material was set to 0.00% as shown in Table 2.

[0136] (Example 7) As a composition for forming a fire extinguishing agent layer, the following fire extinguishing agent layer forming composition 8 was used, and a fire extinguishing material was obtained in the same manner as in Example 1, except that the ratio of potassium present on the surface of the fire extinguishing material was 44.12%, as shown in Table 2. <Fire extinguishing agent layer forming composition 8> - Fire extinguishing agent (mixture of potassium chlorate and tripotassium citrate) 80.0 parts by mass - Polyvinyl butyral resin solution (solution obtained by dissolving 11 parts by mass of polyvinyl butyral resin (PVB) in 80 parts by mass of ethanol and 9 parts by mass of isopropyl alcohol) 144 parts by mass (PVB 15.84 parts by mass) - Epoxy resin (product name: EX-991L, manufactured by Nagase ChemteX Corporation, solid content 100%) 4.16 parts by mass - Ethanol 80.0 parts by mass - Fire extinguishing agent: Binder resin (PVB and epoxy resin) = 80:20 (mass ratio)

[0137] (Example 8) As the composition for forming the fire extinguishing agent layer, the following fire extinguishing agent layer forming composition 9 was used, and a fire extinguishing material was obtained in the same manner as in Example 1, except that the ratio of potassium present on the surface of the fire extinguishing material was 43.57%, as shown in Table 3. <Fire extinguishing agent layer forming composition 9> - Fire extinguishing agent (mixture of potassium chlorate and tripotassium citrate) 90.0 parts by mass - Polyvinyl butyral resin solution (solution obtained by dissolving 11 parts by mass of polyvinyl butyral resin (PVB) in 80 parts by mass of ethanol and 9 parts by mass of isopropyl alcohol) 72 parts by mass (PVB 7.92 parts by mass) - Epoxy resin (product name: EX-991L, manufactured by Nagase ChemteX Corporation, solid content 100%) 2.08 parts by mass - Ethanol 90.0 parts by mass - Fire extinguishing agent: Binder resin (PVB and epoxy resin) = 90:10 (mass ratio)

[0138] (Example 9) As the composition for forming the fire extinguishing agent layer, the following fire extinguishing agent layer forming composition 10 was used, and the fire extinguishing agent layer forming composition 10 was applied to one surface of a polyethylene terephthalate (PET) film as a base material so that the dry thickness (DRY thickness) was 200 μm, and a fire extinguishing material was obtained in the same manner as in Example 1, except that the ratio of potassium present on the surface of the fire extinguishing material was 37.25%, as shown in Table 3. <Fire extinguishing agent layer forming composition 10> - Fire extinguishing agent (mixture of potassium chlorate and tripotassium citrate) 80 parts by mass - Ether-based polyurethane resin solution (solution obtained by dissolving 100 parts by mass of ether-based polyurethane resin (PU) in 210 parts by mass of isopropyl alcohol) 62 parts by mass (PU 20 parts by mass) - Ethanol 80 parts by mass - Fire extinguishing agent: Binder resin (PU) = 80:20 (mass ratio)

[0139] (Example 10) As the composition for forming the fire extinguishing agent layer, the following composition for forming the fire extinguishing agent layer 11 was used. The composition for forming the fire extinguishing agent layer 11 was applied to one surface of a polyethylene terephthalate (PET) film as a base material so that the dry thickness (DRY thickness) was 100 μm. Except that the potassium content ratio on the surface of the fire extinguishing material was set to 40.29% as shown in Table 3, a fire extinguishing material was obtained in the same manner as in Example 1. <Composition for forming the fire extinguishing agent layer 11> - Fire extinguishing agent (mixture of potassium chlorate and tripotassium citrate) 87.5 parts by mass - Ether-based polyurethane resin solution (solution obtained by dissolving 100 parts by mass of ether-based polyurethane resin (PU) in 210 parts by mass of isopropyl alcohol) 39.375 parts by mass (PU 12.70 parts by mass) - Ethanol 87.5 parts by mass - Fire extinguishing agent:binder resin (PU) = 87.5:12.5 (mass ratio)

[0140] (Comparative Example 4) A fire extinguishing material was obtained in the same manner as in Example 1, except that the following fire extinguishing material layer-forming composition 12 was used as the composition for forming the fire extinguishing material, and the ratio of potassium present on the surface of the fire extinguishing material was set to 27.44% as shown in Table 3. <Fire extinguishing material layer-forming composition 12> - Fire extinguishing agent (mixture of potassium chlorate and tripotassium citrate) 80 parts by mass - Ether-based polyurethane resin solution (solution obtained by dissolving 100 parts by mass of ether-based polyurethane resin (PU) in 210 parts by mass of isopropyl alcohol) 41.67 parts by mass (PU 20 parts by mass) - Ethanol 80 parts by mass - SC agent (product name: X-12-1287A, manufactured by Shin-Etsu Chemical Co., Ltd., solid content 100%) 6.77 parts by mass - Fire extinguishing agent: Binder resin (PU + SC agent) = 80:20 (mass ratio)

[0141] (Comparative Example 5) A fire extinguishing material was obtained in the same manner as in Example 1, except that the following fire extinguishing material layer-forming composition 13 was used as the fire extinguishing material layer-forming composition, the fire extinguishing material layer-forming composition 13 was applied to one surface of the substrate with an applicator, and then left to stand for 1 hour in a normal temperature and humidity environment, and the ratio of potassium present on the surface of the fire extinguishing material was set to 11.50% as shown in Table 3. <Fire extinguishing material layer-forming composition 13> - Fire extinguishing agent (mixture of potassium chlorate and tripotassium citrate) 87.5 parts by mass - Ether-based polyurethane resin solution (solution obtained by dissolving 100 parts by mass of ether-based polyurethane resin (PU) in 210 parts by mass of isopropyl alcohol) 39.75 parts by mass (PU 12.5 parts by mass) - Ethanol 122.5 parts by mass - Fire extinguishing agent:binder resin (PU) = 87.5:12.5 (mass ratio) In Comparative Example 5, the ratio of potassium present on the surface of the fire extinguishing material is small, which is thought to be due to the following reasons. In Comparative Example 5, the fire extinguishing agent was sufficiently diluted with ethanol, and the composition for forming the fire extinguishing agent layer was left in a normal temperature and humidity environment (i.e., air-dried). This likely resulted in the surface of the fire extinguishing agent layer being more easily covered with a resin layer containing less fire extinguishing agent. This is thought to be because the solvent-rich composition caused the fire extinguishing agent to sink easily, and air-drying formed a skin-like layer (resin layer) on the surface.

[0142] <Evaluation of Fire Extinguishing Properties> The fire extinguishing properties of the fire extinguishing materials of the examples and comparative examples were evaluated as follows. First, a rectangular iron container measuring 20 cm in length, 30 cm in width, and 40 cm in height was prepared. The container had four side walls, one of which was provided with a glass window for observing the interior. The remaining three side walls were each provided with circular vents with a diameter of 8.5 mm at positions 5.0 cm, 12.5 cm, 20.0 cm, 27.5 cm, and 35.0 cm from the top surface, respectively, to prevent the ignited solid fuel from being extinguished by suffocation. In addition, the fire extinguishing material was attached to the center of the inner surface of the top of the container as an evaluation sample using double-sided tape. At this time, the evaluation sample was attached to the inner surface of the top so that the fire extinguishing agent layer faced the bottom surface of the container. A height-adjustable base was placed in the center of the bottom of the container, and a solid fuel (1.5g, Captain Stag Fire Block igniter) measuring 15mm long, 15mm wide, and 10mm high was fixed on the base. The base was adjusted to a height where the distance between the top surface of the solid fuel and the bottom surface of the evaluation sample was 20cm. Then, ignition of the solid fuel was started, and it was checked whether the solid fuel was extinguished by the evaluation sample for 180 seconds after ignition. The results are shown in Tables 1, 2, and 3. In Tables 1, 2, and 3, an evaluation sample in which the solid fuel was extinguished within 180 seconds after ignition is marked with "○", and an evaluation sample in which the solid fuel was not extinguished is marked with "×".

[0143]

[0144]

[0145]

[0146] As shown in Tables 1, 2, and 3, the fire extinguishing materials of Examples 1 to 10 were all able to extinguish small embers within 180 seconds after ignition of the solid fuel. On the other hand, the fire extinguishing materials of Comparative Examples 1 to 5 were not able to extinguish small embers within 180 seconds after ignition of the solid fuel. From the above, it was confirmed that the fire extinguishing materials of this disclosure can effectively extinguish even small embers.

[0147] The disclosure outlines the following: [1] A fire extinguishing material comprising a fire extinguishing layer containing a fire extinguishing agent, wherein the fire extinguishing agent comprises a radical generating agent containing an organic potassium salt and an oxidizing agent containing a potassium salt, and the proportion of potassium on the surface of the fire extinguishing material is 36% or more. [2] The fire extinguishing material according to [1], wherein the proportion of potassium on the surface of the fire extinguishing material is 60% or less. [3] The fire extinguishing material according to [1] or [2], wherein the potassium salt is potassium chlorate. [4] The fire extinguishing material according to any one of [1] to [3], wherein the organic potassium salt comprises at least one of a potassium carboxylate salt and its hydrate. [5] The fire extinguishing material according to any one of [1] to [4], wherein the fire extinguishing layer further contains a binder resin. [6] The fire extinguishing material according to [5], wherein the amount of the fire extinguishing agent is 70 to 97% by mass based on the total amount of the fire extinguishing agent and the binder resin. [7] The fire extinguishing material according to [5] or [6], wherein the binder resin comprises at least one of a polyvinyl acetal resin and a polyurethane resin. [8] The fire extinguishing material according to any one of [1] to [7], further comprising a base material. [9] The fire extinguishing material according to any one of [1] to [8], wherein the average particle size D50 of the mixture containing the radical generator and the oxidizing agent is 1 to 100 μm.

[10] The fire extinguishing material according to [8], wherein the thickness of the base material is 4 μm or more and 100 μm or less.

[11] The fire extinguishing material according to any one of [1] to

[10] , wherein the thickness of the fire extinguishing agent layer is 10 μm to 600 μm.

[12] A fire extinguishing material package comprising the fire extinguishing material according to any one of [1] to

[11] and a packaging bag for enclosing the fire extinguishing material.

[13] An electrical device comprising a fire target consisting of an electrical device and the fire extinguishing material according to any one of [1] to

[11] .

[14] An electrical device comprising an object to be extinguished consisting of an electrical device and the fire extinguishing material package described in

[12] .

[15] The fire extinguishing material according to [1], wherein the fire extinguishing material further comprises a base material, the fire extinguishing agent layer further contains a binder resin, the proportion of potassium on the surface of the fire extinguishing material is 38% or more and 45% or less, the organic potassium salt is tripotassium citrate, the potassium salt is potassium chlorate, the binder resin contains polyurethane resin, the amount of the fire extinguishing agent is 85 to 92% by mass based on the total amount of the fire extinguishing agent and the binder resin, the average particle size D50 of the mixture containing the radical generator and the oxidizing agent is 10 to 20 μm, the thickness of the base material is 4 μm or more and 100 μm or less, and the thickness of the fire extinguishing agent layer is 110 μm to 200 μm.

[0148] The fire extinguishing material disclosed herein can effectively extinguish even small embers, and therefore can be used in electrical equipment such as electrical appliances, switchboards, and distribution boards, where there is a particular need to prevent the spread of fire caused by small embers.

[0149] 10...Fire extinguishing material, 12...Fire extinguishing agent layer, 14...Base material, 50...Packaging bag, 100...Fire extinguishing material package, 200...Electrical device, 300...Electrical equipment.

Claims

1. A fire extinguishing material comprising a fire extinguishing layer containing a fire extinguishing agent, wherein the fire extinguishing agent comprises a radical generating agent containing an organic potassium salt and an oxidizing agent containing a potassium salt, and the proportion of potassium on the surface of the fire extinguishing material is 36% or more.

2. The fire extinguishing material according to claim 1, wherein the ratio of potassium present on the surface of the fire extinguishing material is 60% or less.

3. The fire extinguishing material according to claim 1 or 2, wherein the potassium salt is potassium chlorate.

4. The fire extinguishing material according to claim 1 or 2, wherein the organic potassium salt comprises at least one of a potassium carboxylate salt and its hydrate.

5. The fire extinguishing material according to claim 1 or 2, wherein the fire extinguishing agent layer further contains a binder resin.

6. The fire extinguishing material according to claim 5, wherein the amount of the fire extinguishing agent is 70 to 97% by mass, based on the total amount of the fire extinguishing agent and the binder resin.

7. The fire extinguishing material according to claim 5, wherein the binder resin comprises at least one of a polyvinyl acetal resin and a polyurethane resin.

8. The fire extinguishing material according to claim 1 or 2, further comprising a base material.

9. The fire extinguishing material according to claim 1 or 2, wherein the average particle size D50 of the mixture containing the radical generating agent and the oxidizing agent is 1 to 100 μm.

10. The fire extinguishing material according to claim 7, wherein the thickness of the base material is 4 μm or more and 100 μm or less.

11. The fire extinguishing material according to claim 1 or 2, wherein the thickness of the fire extinguishing agent layer is 10 μm to 600 μm.

12. A fire extinguishing material package comprising a fire extinguishing material according to claim 1 or 2 and a packaging bag for enclosing the fire extinguishing material.

13. An electrical system comprising an object to be extinguished, which consists of an electrical device, and a fire extinguishing material according to claim 1 or 2.

14. An electrical system comprising an object to be extinguished consisting of an electrical device and the fire extinguishing material package described in claim 12.

15. The fire extinguishing material according to claim 1, wherein the fire extinguishing material further comprises a base material, the fire extinguishing agent layer further contains a binder resin, the proportion of potassium on the surface of the fire extinguishing material is 38% or more and 45% or less, the organic potassium salt is tripotassium citrate, the potassium salt is potassium chlorate, the binder resin contains polyurethane resin, the amount of the fire extinguishing agent is 85 to 92% by mass based on the total amount of the fire extinguishing agent and the binder resin, the average particle size D50 of the mixture containing the radical generator and the oxidizing agent is 10 to 20 μm, the thickness of the base material is 4 μm or more and 100 μm or less, and the thickness of the fire extinguishing agent layer is 110 μm to 200 μm.

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