Fire extinguishing sheet

Abstract

To provide a fire extinguishing sheet which is used in places, facilities, devices, tools, structures and the like where a fire may break out, and which makes initial fire extinguishing possible.SOLUTION: A fire extinguishing sheet according to the present invention contains at least a potassium compound, as a fire extinguishing chemical that is thermally decomposed upon reaching a predetermined temperature and generates a fire extinguishing component, and is arranged in places, facilities, devices, tools, structures and the like where a fire may break out. If a fire breaks out, aerosols containing potassium radicals (a potassium compound) are generated from the fire extinguishing sheet, and the chain of combustion is interrupted by a negative catalytic effect, thereby quickly extinguishing or suppressing the fire.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a fire extinguishing sheet that is used in places, facilities, equipment, tools, structures, etc. where a fire may occur, and that enables early extinguishing of a fire. [Background technology]

[0002] Fire extinguishing compositions that generate an aerosol upon combustion to extinguish or suppress a fire are known (e.g., WO2017 / 134703 (Patent Document 1)). Such fire extinguishing compositions can be used, for example, as a liquid such as a dispersion, or as a solid such as a powder or a molded body having a desired shape. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. WO2017 / 134703 Summary of the Invention [Problem to be solved by the invention]

[0004] The molded article described in Patent Document 1 is also called a self-extinguishing molded article, but there is still room for improvement.

[0005] Therefore, an object of the present invention is to provide a fire extinguishing sheet that can be used in places, equipment, tools, structures, etc. where a fire may occur, and that enables early extinguishing of a fire. [Means for solving the problem]

[0006] According to the present invention, there is provided a fire extinguishing sheet containing a fire extinguishing agent that thermally decomposes to generate a fire extinguishing component when a predetermined temperature is reached.

[0007] According to a preferred embodiment of the present invention, the fire-extinguishing component is an aerosol.

[0008] According to a preferred embodiment of the present invention, the fire extinguishing agent contains at least a potassium compound and a binder.

[0009] According to a preferred embodiment of the present invention, the potassium compound contains at least a potassium-containing organic compound and potassium chlorate.

[0010] According to one embodiment of the present invention, the binder is preferably one or more selected from the group consisting of polyester resin, polystyrene, polyolefin resin, polyurethane resin, polyisocyanate, polyimide resin, acrylic resin, cellulose compound, vinyl chloride, ethylene-vinyl acetate copolymer, polyvinylidene fluoride resin, fluororesin binder, synthetic latex, rosin, epoxy resin, phenolic resin, polyvinyl alcohol resin, polyvinyl acetal resin, olefin thermoplastic resin, butadiene thermoplastic resin, styrene thermoplastic resin, styrene-butadiene thermoplastic resin, isoprene thermoplastic resin, urethane thermoplastic resin, ester thermoplastic resin, amide thermoplastic resin, vinyl chloride thermoplastic resin, thermoplastic resin mixed with process oil, tackifying resin, etc., alloy thermoplastic elastomer, dynamically crosslinked thermoplastic elastomer, bentonite, and biobinder Biopoly B.

[0011] According to a preferred embodiment of the present invention, the fire extinguishing sheet contains at least tripotassium citrate and potassium chlorate as potassium compounds, and at least polyvinyl butyral as a binder.

[0012] According to another aspect of the present invention, there is provided a fire extinguishing sheet for lithium ion batteries, which is used by being placed in contact with or adjacent to a lithium ion battery and comprises the fire extinguishing sheet according to the present invention.

[0013] Furthermore, according to another aspect of the present invention, there is provided use of the fire-extinguishing sheet according to the present invention for extinguishing or suppressing a fire in a lithium-ion battery.

[0014] According to another aspect of the present invention, there is provided a method for extinguishing or suppressing a fire in a lithium ion battery, which comprises placing the fire-extinguishing sheet according to the present invention in contact with or adjacent to the lithium ion battery. [Effects of the Invention]

[0015] The present invention provides a fire extinguishing sheet that can be used in places, facilities, equipment, tools, structures, etc. where a fire may occur, and enables early extinguishing of a fire. This fire extinguishing sheet is desirable for productivity, mass production, and mass production. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, a fire extinguishing sheet according to a representative embodiment of the present invention will be described in detail.

[0017] The fire extinguishing sheet according to the present invention contains a fire extinguishing agent that thermally decomposes upon reaching a predetermined temperature to generate a fire extinguishing component. According to one aspect of the present invention, the fire extinguishing sheet is a fire extinguishing agent formed into a sheet. The fire extinguishing sheet generates an aerosol as the fire extinguishing component. The fire extinguishing sheet contains at least a potassium compound and a binder in the fire extinguishing agent.

[0018] According to one embodiment of the present invention, the fire extinguishing agent contains, for example, 0.5 to 30 mass % of a binder (component A) and 10 to 70 mass % of a chlorate (component B), and further contains 30 to 900 mass parts of a potassium salt (component C) per 100 parts by mass of the binder and the chlorate, and the thermal decomposition temperature of the fire extinguishing agent is in the range of more than 90°C to 450°C.

[0019] Preferred examples of component A, i.e., the binder, include polyester resin, polystyrene, polyolefin resin, polyurethane resin, polyisocyanate, polyimide resin, acrylic resin, cellulose-based compound, vinyl chloride, ethylene-vinyl acetate copolymer, polyvinylidene fluoride resin, fluororesin binder, synthetic latex, rosin, epoxy resin, phenolic resin, polyvinyl alcohol resin, polyvinyl acetal resin, olefin-based thermoplastic resin, butadiene-based thermoplastic resin, styrene-based thermoplastic resin, styrene-butadiene-based thermoplastic resin, isoprene-based thermoplastic resin, urethane-based thermoplastic resin, ester-based thermoplastic resin, amide-based thermoplastic resin, vinyl chloride-based thermoplastic resin, thermoplastic resin mixed with process oil, tackifying resin, etc., alloy-type thermoplastic elastomer, dynamically crosslinked thermoplastic elastomer, bentonite, and biobinder Biopoly B, as well as mixtures of two or more thereof.

[0020] Component B, i.e., chlorate, is a powerful oxidizer that generates thermal energy when combusted with component C, i.e., potassium salt, to generate aerosol (potassium radicals). This aerosol releases the fire-extinguishing component, potassium radicals (potassium compounds), and breaks the combustion chain reaction through a negative catalytic effect, achieving rapid fire extinguishing.

[0021] The content ratio of component A (binder) and component B (chlorate) in a total of 100 mass % is as follows. A component: 0.5~30% by mass Preferably 1 to 20% by mass More preferably, 3 to 10% by mass B component: 70~99.5% by mass Preferably 80 to 99 mass% More preferably, 90 to 97% by mass

[0022] Next, component C, i.e., potassium salt, is a component that generates an aerosol (potassium radical) using the thermal energy generated by the combustion of component B.

[0023] Preferred examples of component C, i.e., potassium salts, include potassium acetate, potassium propionate, monopotassium citrate, dipotassium citrate, tripotassium citrate, monopotassium trihydrogen ethylenediaminetetraacetate, dipotassium dihydrogen ethylenediaminetetraacetate, tripotassium monohydrogen ethylenediaminetetraacetate, tetrapotassium ethylenediaminetetraacetate, potassium hydrogen phthalate, dipotassium phthalate, potassium hydrogen oxalate, dipotassium oxalate, potassium hydrogen carbonate, potassium bicarbonate, and mixtures of two or more thereof.

[0024] The content of the C component is preferably 50 to 500 parts by mass, and more preferably 100 to 300 parts by mass, per 100 parts by mass of the A and B components.

[0025] Furthermore, in the present invention, the fire extinguishing agent begins to thermally decompose in the range of more than 90° C. to 450° C., preferably 150° C. to 260° C. Such a range of the thermal decomposition starting temperature can be adjusted by combining the above-mentioned components A, B, and C in the above-mentioned ratios.

[0026] The fire extinguishing sheet of the present invention can be obtained by forming the fire extinguishing agent into a molded product such as a sheet, for example, by mixing the components of the fire extinguishing agent, molding the mixture into a sheet while controlling the coating conditions, and drying it appropriately. The dimensions of the fire extinguishing sheet of the present invention, such as its thickness and area, are determined appropriately depending on the object to be extinguished, such as equipment, devices, machinery, tools, or structures, and the intended use. Multiple sheet-shaped fire extinguishing agents can also be stacked and used.

[0027] The fire extinguishing sheet of the present invention is placed in areas of fire-prone objects such as equipment, devices, machinery, tools, and structures. For example, in the case of equipment or tools, the fire extinguishing sheet is placed in contact with or adjacent to ignitable components such as battery cells, including secondary batteries such as lithium-ion batteries, that may catch fire due to some malfunction such as an accident, as well as their casings, electrodes, connection terminals, and circuit boards. The fire extinguishing sheet may be placed in multiple locations.

[0028] In order to exert a fire-extinguishing effect by the aerosol, the fire extinguishing sheet of the present invention may be sealed inside an object such as equipment, devices, machinery, tools, or structures, or may be sealed together with the ignitable members as described above. [Example]

[0029] The present invention will be described in more detail below using examples and comparative examples. In these examples and comparative examples, fire extinguishing sheets were prepared as follows (1).

[0030] (1) Preparation of fire extinguishing sheets (1-1) Preparation of binder Polyvinyl butyral, which is a binder, was dissolved in a solvent, N-methylpyrrolidone, to prepare an 18% by mass solution of polyvinyl butyral.

[0031] (1-2) Preparation of fire extinguishing agent slurry by powder grinding 187.5 g of tripotassium citrate, 112.5 g of potassium chlorate, 200 g of N-methylpyrrolidone, and 2 kg of 5 mm particle size alumina balls as dispersion media were placed in a 2-liter container and stirred and pulverized for approximately 24 hours in a ball mill set at 60 rpm to obtain a fire extinguishing agent slurry.

[0032] (1-3) Painting (adding a binder to the fire extinguishing agent slurry) 111 g of the 18% by mass solution of polyvinyl butyral (1-1) was added to the total amount of the fire extinguishing agent slurry (1-2) above, and the mixture was further mixed for approximately 24 hours using a ball mill set at 60 rpm to obtain a paste-like (mayonnaise-like) paint with thixotropy. The viscosity of the resulting paint was confirmed to be in the range of 2000-3000 mPa·S when the load (torque) was set to 50% using a B-type viscometer.

[0033] (1-4) Separation (removal of dispersed media) Using a suitable stainless steel sieve, the paint and dispersion media obtained in (1-3) above were separated. The yield was confirmed to be in the range of 50-60%.

[0034] (1-5) Filtration (separation of large particle size chemicals and debris) The paint obtained in the separation step (1-4) above was filtered through a stainless steel sieve with 100 mesh (openings approximately 200 μm) to remove coarse particles and dust.

[0035] (1-6) Coating (Paint sheeting) A 100μm-thick release-treated PET film coated with silicon (Si) or fluorine (F) was placed on the table of a coating machine "β Coater" manufactured by Yasui Seiki Co., Ltd., and the fire extinguishing agent slurry was applied. A round applicator with a 400μm gap was installed as the coating tool (applicator). The PET sheet was coated at a coating speed of approximately 0.5mm / min.

[0036] (1-7) Drying process (removal of solvent) The solvent was removed using a standard circulating thermostatic bath. The PET film coated with the drug was dried at a set temperature of 100°C to obtain a sheet with an average thickness of 220 μm.

[0037] (1-8) Cutting process After the drug coated on the PET film was cooled, it was cut into A4 size (210 mm wide x 297 mm long) using a cutter and subjected to evaluation tests.

[0038] (2) Fire extinguishing sheet evaluation test The fire extinguishing agent prepared in the above procedure (1) was tested as follows.

[0039] (2-1) Placement of lithium-ion battery cells A 3Ah lithium-ion battery cell measuring 100mm wide x 100mm long x 5mm high was placed in the center of a box-shaped container made of SUS304 with dimensions of 300mm wide x 300mm long x 100mm high and 1.2mm thick.

[0040] (2-2) Applying fire extinguishing sheets An acrylic plate measuring 350mm wide x 350mm long x 10mm long, 5mm thick, and with a 10mm diameter hole in the center was used as the top plate of the box-shaped container described in (2-1) above. The A4-sized fire extinguishing sheet prepared in (1) above was attached to the center of one side of this acrylic plate with spray adhesive.

[0041] (2-3) Fixing the acrylic plate The acrylic plate was placed on the box-shaped container with the fire extinguishing sheet adhesive side facing down and fixed in place.

[0042] (2-4) Nail Insertion A 5mm diameter iron nail was inserted at a constant speed into the opening in the acrylic top panel, penetrating the internal cell. A flash of light was emitted when a short circuit occurred, but white smoke from the fire extinguishing sheet immediately began to emerge, and the fire was extinguished without spreading.

[0043] Comparative Example In the evaluation test (2) above, when the series of nail insertion evaluation test operations for the lithium-ion battery cell were carried out as in (2-4) above without attaching the A4 fire extinguishing sheet (2-2) above to the acrylic top plate, the lithium-ion battery cell inside the SUS container exploded violently, causing a fire that spread, and the inside of the container was covered in flames and continued to burn for 5 minutes.

[0044] Although typical embodiments of the present invention have been described above, the present invention is not limited to these, and various design modifications are possible, which are also included in the present invention.

Claims

1. A fire extinguishing sheet containing a fire extinguishing agent that thermally decomposes to generate a fire-extinguishing component when it reaches a specified temperature.

2. The fire-extinguishing sheet according to claim 1 , wherein the fire-extinguishing component is an aerosol.

3. The fire extinguishing sheet according to claim 2, wherein the fire extinguishing agent comprises at least a potassium compound and a binder.

4. 4. The fire extinguishing sheet according to claim 3, wherein the potassium compound comprises at least a potassium-containing organic compound and potassium chlorate.

5. The fire extinguishing sheet according to claim 3, wherein the binder is one or more selected from the group consisting of polyester resin, polystyrene, polyolefin resin, polyurethane resin, polyisocyanate, polyimide resin, acrylic resin, cellulose-based compound, vinyl chloride, ethylene-vinyl acetate copolymer, polyvinylidene fluoride resin, fluororesin binder, synthetic latex, rosin, epoxy resin, phenolic resin, polyvinyl alcohol resin, polyvinyl acetal resin, olefin-based thermoplastic resin, butadiene-based thermoplastic resin, styrene-based thermoplastic resin, styrene-butadiene-based thermoplastic resin, isoprene-based thermoplastic resin, urethane-based thermoplastic resin, ester-based thermoplastic resin, amide-based thermoplastic resin, vinyl chloride-based thermoplastic resin, thermoplastic resin mixed with process oil or tackifying resin, alloy-type thermoplastic elastomer, dynamically crosslinked thermoplastic elastomer, bentonite, and bio-binder Biopoly B.

6. 4. The fire extinguishing sheet according to claim 3, wherein the potassium compound comprises at least tripotassium citrate and potassium chlorate, and the binder comprises at least polyvinyl butyral.

7. A fire extinguishing sheet for lithium ion batteries, comprising the fire extinguishing sheet according to any one of claims 1 to 6, which is used by being placed in contact with or adjacent to a lithium ion battery.

8. The fire extinguishing sheet for lithium ion batteries according to claim 7, which is attached to a lithium ion battery.

9. The fire extinguishing sheet for lithium ion batteries according to claim 7 or 8, wherein the lithium ion battery is mounted on a facility, device, machine, tool, or structure.

10. A facility, device, machine, tool, or structure equipped with a lithium ion battery that is in contact with or adjacent to the fire extinguishing sheet according to any one of claims 1 to 6.

11. Use of the fire-extinguishing sheet according to any one of claims 1 to 6 for extinguishing or suppressing a fire in a lithium-ion battery.

12. A method for extinguishing or suppressing a fire in a lithium ion battery, comprising placing the fire extinguishing sheet according to any one of claims 1 to 6 in contact with or adjacent to the lithium ion battery.

13. 13. The method of claim 12, wherein the lithium ion battery is mounted in a facility, apparatus, machine, tool, or structure.