Composition for fire-extinguishing material, fire-extinguishing material, and method for producing same

Abstract

This fire-extinguishing material comprises a base material and a fire-extinguishing agent layer formed on at least one surface of the base material. The fire-extinguishing agent layer contains a fire-extinguishing agent and a binder resin. The fire-extinguishing agent content of the fire-extinguishing agent layer is 60-98 mass% with reference to the mass of the fire-extinguishing agent layer. The tensile elongation at break of the binder resin is 45 mm or greater.

Description

Composition for fire extinguishing material, fire extinguishing material and method for producing the same

[0001] The present disclosure relates to a fire-extinguishing composition, a fire-extinguishing material, and a method for producing the same.

[0002] Lithium-ion batteries are one of the most common secondary batteries. Lithium-ion batteries can experience thermal runaway due to short circuits caused by strong external impacts or overcharging. Thermal runaway in lithium-ion batteries can release large amounts of flammable gas, potentially causing serious fires. Patent Document 1 discloses the placement of flame-retardant heat-insulating sheets between multiple power storage units to prevent heat transfer between them. Meanwhile, the placement of fire extinguishing agents in advance in locations where fires may occur has also been considered. For example, Patent Document 2 discloses an aerosol fire extinguishing composition that generates an aerosol upon combustion and can extinguish fires.

[0003] JP 2019-147357 A Patent No. 6443882 A

[0004] Although the flame-retardant heat insulating sheet described in Patent Document 1 can suppress the spread of fire, it does not have fire-extinguishing properties and cannot suppress the outbreak of fire or the generation of high-temperature gas from an electricity storage unit that has already experienced thermal runaway. On the other hand, Patent Document 2 discloses the use of a fire extinguisher composition molded into granules, pellets, tablets, spheres, or disks, but does not mention measures that should be taken to ensure that the molded product of the fire extinguisher composition maintains its fire-extinguishing properties over a long period of time.

[0005] A fire-extinguishing material applied to a secondary battery is required to maintain its fire-extinguishing performance throughout the service life of the secondary battery. According to the investigations of the present inventors, the molded body described in Patent Document 2 is prone to cracking during molding or use, and moisture entering the interior through the cracks can impair the stability of the fire-extinguishing performance, leaving room for improvement.

[0006] The present disclosure has been made in view of the above-mentioned problems, and provides a fire-extinguishing material that is less likely to crack and a method for producing the same. The present disclosure also provides a fire-extinguishing material composition that is useful for producing the fire-extinguishing material that is less likely to crack.

[0007] The fire extinguishing material according to the present disclosure comprises a substrate and a fire extinguishing agent layer formed on at least one surface of the substrate, the fire extinguishing agent layer containing a fire extinguishing agent and a binder resin, the content of the fire extinguishing agent in the fire extinguishing agent layer being 60% by mass to 98% by mass based on the mass of the fire extinguishing agent layer, and the tensile breaking elongation of the binder resin being 45 mm or more. The tensile breaking elongation is the elongation at break of a sample measured in a tensile test in accordance with JIS K 7127 under conditions of a sample chuck distance of 10 cm and a pulling rate of 50 mm / min, the sample being a test piece type 2 specified in JIS K 7127, and consisting of a 90 μm thick film composed of the binder resin recovered from the fire extinguishing agent layer.

[0008] According to the above fire extinguishing material, even if the fire extinguishing agent layer contains a sufficient amount of fire extinguishing agent, the inclusion of the binder resin gives the fire extinguishing agent layer excellent flexibility and bendability, thereby sufficiently suppressing the occurrence of cracks in the fire extinguishing agent layer during production and use of the fire extinguishing material. Since cracks are less likely to occur in the fire extinguishing agent layer, moisture is less likely to penetrate into the fire extinguishing agent layer, and fire extinguishing performance can be maintained over a long period of time. The above fire extinguishing material has excellent bendability, for example, with a mandrel diameter of 18 mm or less. The mandrel diameter is the smallest mandrel diameter at which no cracks are observed in the substrate or the fire extinguishing agent layer when a Type 1 mandrel test is performed on the fire extinguishing material in accordance with JIS K5600-5-1.

[0009] The fire extinguishing composition according to the present disclosure includes a fire extinguishing agent and a binder resin, the content of the fire extinguishing agent being 60% by mass to 98% by mass based on the total mass of the solid content of the fire extinguishing composition, and the tensile elongation at break of the binder resin being 45 mm or more.

[0010] The fire extinguishing composition contains a sufficient amount of fire extinguishing agent, but the inclusion of the binder resin allows the formation of a fire extinguishing agent layer with excellent flexibility and flexibility. This sufficiently prevents cracks from occurring in the fire extinguishing agent layer during the production of a fire extinguishing material having a fire extinguishing agent layer and during use of the fire extinguishing material. When the fire extinguishing composition is used as a coating liquid, the fire extinguishing composition preferably further contains a liquid medium, and the viscosity of the coating liquid is preferably 1600 mPa·s or more. This viscosity refers to the value measured using a Brookfield viscometer at a rotation speed of 12 rpm. The fire extinguishing agent layer obtained by forming the fire extinguishing composition into a sheet with a thickness of 150 μm has excellent flexibility, and for example, the mandrel diameter is 18 mm or less.

[0011] The method for producing a fire extinguishing material according to the present disclosure includes (a) a step of forming a coating film of the fire extinguishing composition on at least one surface of a substrate by a wet coating method, and (b) a step of drying the coating film to form a fire extinguishing agent layer on the surface of the substrate, wherein the maximum temperature during drying of the coating film in step (b) is 100°C or less, and the temperature is increased stepwise or continuously after the start of step (b) until the maximum temperature is reached. The boiling point of the liquid medium contained in the fire extinguishing composition (coating liquid) is preferably 60°C to 90°C.

[0012] According to the method for producing a fire-extinguishing material of the present disclosure, by setting the maximum temperature in step (b) to 100°C or less and increasing the temperature stepwise or continuously until the maximum temperature is reached, a fire-extinguishing agent layer with excellent smoothness and sufficiently few defects can be formed. Such a fire-extinguishing agent layer is less likely to crack. The wet coating method is preferably a coating method selected from the group consisting of comma coating, gravure coating, curtain coating, and die coating.

[0013] According to the present disclosure, a fire extinguishing material that is less likely to crack and a method for producing the same are provided. Also, according to the present disclosure, a fire extinguishing material composition that is useful for producing a fire extinguishing material that is less likely to crack is provided.

[0014] Fig. 1 is a cross-sectional view schematically showing one embodiment of a fire extinguishing material according to the present disclosure, and Fig. 2 is a cross-sectional view schematically showing another embodiment of a fire extinguishing material according to the present disclosure.

[0015] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. However, the present disclosure is not limited to the following embodiments.

[0016] <Fire Extinguishing Material> The fire extinguishing material of this embodiment includes a fire extinguishing agent layer in which the fire extinguishing composition is formed into a sheet shape. This fire extinguishing material is used, for example, by being attached to an object that may catch fire. When the object catches fire, the fire extinguishing composition receives the heat energy and releases chemical species with fire extinguishing properties, thereby extinguishing the flame. Because there is no need to use a fire extinguisher or fire extinguishing device to extinguish the fire, such a fire extinguishing material is said to be "self-extinguishing."

[0017] The object to be extinguished is not particularly limited as long as it is something that may catch fire, such as electric wires, distribution boards, control panels, storage batteries (lithium ion batteries, etc.), building materials such as wallpaper for building materials and ceiling materials, boxes for collecting lithium ion batteries (recycling boxes), trash cans, automobile-related parts, electrical outlets, and electrical outlet covers.

[0018] The fire extinguishing material 1 shown in Fig. 1 includes a substrate 2 and a fire extinguishing agent layer 3 formed on one surface of the substrate 2. The mandrel diameter of the fire extinguishing material 1 may be 18 mm or less, 12 mm or less, 6 mm or less, or 3 mm or less. The "mandrel diameter" referred to here refers to the minimum diameter of the mandrel at which no cracks are observed in the substrate 2 and the fire extinguishing agent layer 3 when a Type 1 mandrel test is performed on the fire extinguishing material 1 in accordance with JIS K5600-5-1. The minimum mandrel diameter possible in the test is 2 mm.

[0019] (Substrate) The substrate 2 is a film that serves as a support when the fire extinguishing agent layer 3 is formed into a sheet. Considering that the temperature of a flame is generally about 700°C to 900°C, a resin substrate can be selected for the substrate 2. Examples of resins include polyolefins (LLDPE, PP, COP, CPP, etc.), polyesters (PET, etc.), fluororesins (PTFE, ETFE, EFEP, PFA, FEP, PCTFE, etc.), PVC, PVA, acrylic resins, epoxy resins, polyamides, polyimides, etc. These resins can be perforated by heat. Furthermore, selecting a transparent material facilitates visual inspection of the fire extinguishing material 1 and confirmation of replacement timing. It is preferable that the substrate 2 have greater flexibility and bendability than the fire extinguishing agent layer 3.

[0020] The substrate 2 may contain a fire extinguishing agent described below. From the viewpoint of adjusting the water vapor permeability, the substrate 2 may be provided with a vapor-deposited layer (alumina vapor-deposited layer or silica vapor-deposited layer) having water vapor barrier properties.

[0021] The thickness and breaking strength of the substrate 2 can be appropriately selected depending on the amount of heat generated at the time of fire outbreak, impact, allowable space, etc. For example, a thick substrate provides strength and rigidity, a highly flat form, and easy handling. Furthermore, a thin substrate allows the fire extinguishing element to be installed in a narrow space and can be perforated in a short time, thereby shortening the time required to start extinguishing the fire. The thickness of the substrate 2 can be, for example, 4.5 to 100 μm, and may be 12 to 50 μm. The substrate 2 may be a laminate of multiple substrates. The substrate 2 and the object may be bonded by an adhesive layer. It is also possible to form a fire extinguishing agent layer directly on the fire extinguishing agent encapsulation film without using a substrate.

[0022] (Fire Extinguishing Agent Layer) The fire extinguishing agent layer 3 is formed into a sheet from the fire extinguishing material composition described below. The thickness of the fire extinguishing agent layer 3 may be 70 μm to 500 μm, 90 μm to 300 μm, or 110 μm to 200 μm. The mandrel diameter of the fire extinguishing agent layer 3 may be 18 mm or less, 12 mm or less, 6 mm or less, or 3 mm or less. The "mandrel diameter" referred to here refers to the smallest diameter at which no cracks are observed in the fire extinguishing agent layer 3 when a Type 1 mandrel test is performed on the fire extinguishing agent layer 3 alone in accordance with JIS K5600-5-1. The smallest diameter possible in the test is 2 mm.

[0023] <Fire Extinguishing Material Composition> The fire extinguishing material composition contains a fire extinguishing agent and a binder resin. The content of the fire extinguishing agent in the fire extinguishing agent layer is 60% by mass to 98% by mass, and may be 80% by mass to 90% by mass, based on the mass of the fire extinguishing agent layer in a dry state. The content of the binder resin in the fire extinguishing agent layer is 2% by mass to 40% by mass, and may be 5% by mass to 15% by mass, based on the mass of the fire extinguishing agent layer in a dry state. The total amount of the fire extinguishing agent and the binder resin in the fire extinguishing agent layer is, for example, 80% by mass to 100% by mass, based on the mass of the fire extinguishing agent layer in a dry state. The fire extinguishing material composition may contain a curing agent component and a flexibility imparting agent, and may contain any additives such as a surfactant, a silane coupling agent, or an antiblocking agent from the viewpoint of property stability.

[0024] (Fire Extinguishing Agent) As the fire extinguishing agent, organic salts and inorganic salts can be used alone or in combination. Examples of organic salts include potassium salts, sodium salts, and ammonium salts. Examples of organic salts that can be used include potassium salts. Examples of organic potassium salts include potassium carboxylates such as potassium acetate, potassium citrate (monopotassium citrate, dipotassium citrate, and tripotassium citrate), potassium tartrate, potassium lactate, potassium oxalate, and potassium maleate. Among these, potassium citrate can be preferably used from the viewpoint of its usefulness in the negative catalytic effect of combustion.

[0025] Examples of inorganic salts include potassium salts and sodium salts. Potassium salts can be used as the inorganic salt. Examples of inorganic potassium salts include potassium tetraborate, potassium carbonate, potassium bicarbonate, potassium dihydrogen phosphate, and dipotassium hydrogen phosphate. The fire extinguishing agent may also contain a compound with oxidizing properties. Examples of compounds with oxidizing properties include chlorates such as potassium chlorate, sodium chlorate, strontium chlorate, ammonium chlorate, and magnesium chlorate. These potassium salts can generate aerosols when exposed to the thermal energy of a fire.

[0026] (Binder Resin) Thermoplastic resins and thermosetting resins can be used as the binder resin. Examples of the thermoplastic resin include polyolefin resins such as polypropylene resins, polyethylene resins, poly(1-)butene resins, and polypentene resins, polystyrene resins, acrylonitrile-butadiene-styrene resins, methyl methacrylate-butadiene-styrene resins, ethylene-vinyl acetate resins, ethylene-propylene resins, polycarbonate resins, polyphenylene ether resins, acrylic resins, polyamide resins, polyvinyl chloride resins, polyvinyl alcohol (PVA), and polyvinyl butyral (PVB). Examples of thermosetting resins include rubbers such as natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), 1,2-polybutadiene rubber (1,2-BR), styrene-butadiene rubber (SBR), chloroprene rubber (CR), nitrile rubber (NBR), butyl rubber (IIR), ethylene-propylene rubber (EPR, EPDM), chlorosulfonated polyethylene (CSM), acrylic rubber (ACM, ANM), epichlorohydrin rubber (CO, ECO), multi-vulcanized rubber (T), silicone rubber (Q), fluororubber (FKM, FZ), and urethane rubber (U); polyurethane resins, phenolic resins, epoxy resins, and polyvinyl ether (PMVE)-maleic anhydride resins.

[0027] By using an elastic resin as the binder resin, cracking of the fire extinguishing agent layer can be suppressed during formation and use. Specifically, the tensile elongation at break of the binder resin is 45 mm or more, and may be, for example, 50 mm to 500 mm or 100 mm to 500 mm. This tensile elongation at break means the elongation at break when a 90 μm thick film made of the binder resin is prepared and used to perform a tensile test in accordance with JIS K 7127 under the following conditions. The film can be obtained, for example, by recovering the binder resin from the fire extinguishing composition or the fire extinguishing agent layer and forming it into a film with a thickness of 90 μm. <Test Conditions> Test piece type: 2 Sample width: 25 mm Sample chuck distance: 10 cm Pulling speed: 50 mm / min

[0028] The binder resin may contain a compound having an acid anhydride group and an alkoxysilyl group. The inclusion of this compound in the fire extinguishing agent layer allows the properties of the fire extinguishing agent layer to be stably maintained for a long period of time. While the reason for this is unclear, it is presumed that this is due to the fact that the acid anhydride group can react with water, so that even if water penetrates the fire extinguishing agent layer, this compound traps the water and prevents the fire extinguishing agent from deliquescing, and / or that after the alkoxysilane is hydrolyzed, a self-reaction occurs to form a siloxane, thereby improving water resistance and film density, and suppressing contact between the deliquescent salt and water.

[0029] When the fire extinguishing composition is used as a coating liquid, the fire extinguishing composition further contains a liquid medium. Hereinafter, a fire extinguishing composition containing a liquid medium may be referred to as a "coating liquid." The coating liquid used for coating must have fluidity. However, if the fluidity of the coating liquid is too high, i.e., if the viscosity of the coating liquid is too low, the coating liquid may locally flow before the fire extinguishing agent layer is formed, which may result in local cracks in the fire extinguishing agent layer or uneven thickness within the surface. From the viewpoint of forming a sufficiently smooth and uniformly thick fire extinguishing agent layer, the viscosity of the coating liquid is preferably 1600 mPa·s or more. This viscosity refers to the value measured using a Brookfield viscometer (spindle BL type No. 3) at a rotation speed of 12 rpm. The lower limit of the viscosity may be 2000 mPa·s or 3000 mPa·s. The upper limit of the viscosity may be 7000 mPa·s or 5000 mPa·s.

[0030] (Liquid Medium) Examples of the liquid medium include organic solvents. Examples of organic solvents include water-soluble solvents, such as alcohols such as methanol (boiling point: 64.7 ° C), ethanol (boiling point: 78.3 ° C), isopropyl alcohol (IPA, boiling point: 82.4 ° C), and n-propyl alcohol; esters such as ethyl acetate (boiling point: 77.1 ° C); ketones such as acetone (boiling point: 56 ° C) and methyl ethyl ketone (boiling point: 79.6 ° C); glycols such as ethylene glycol (boiling point: 197.3 ° C) and diethylene glycol (boiling point: 244.3 ° C); glycol ethers such as N-methylpyrrolidone (NMP, boiling point: 202 ° C), tetrahydrofuran (boiling point: 66 ° C), and butyl cellosolve (boiling point: 171.2 ° C). From the perspective of being used together with a hygroscopic fire extinguishing agent, the liquid medium may be an alcohol-based solvent, specifically a mixed solvent of ethanol and isopropyl alcohol. As the liquid medium, a mixed solvent of ethanol and ethyl acetate may be used.

[0031] The amount of the liquid medium may be adjusted appropriately depending on the coating method, but can be set to 40 to 95% by mass based on the total amount of the coating liquid.

[0032] <Method for manufacturing the fire extinguishing material> The fire extinguishing material 1 shown in Figure 1 is manufactured through the following steps: (a) a step of forming a coating film on at least one surface of a substrate 2 by wet coating with the coating liquid; and (b) a step of drying the coating film to form a fire extinguishing agent layer 3 on the surface of the substrate 2. In step (b), the maximum temperature when drying the coating film is 100°C or less, and after the start of step (b), the temperature is increased stepwise or continuously until the maximum temperature is reached. In order to dry the coating film at a maximum temperature of 100°C or less, the boiling point of the liquid medium is preferably 90°C or less, more preferably 80°C or less. The boiling point of the liquid medium is preferably 60°C or more, more preferably 70°C or more. The maximum temperature is preferably 100°C, more preferably 90°C, and even more preferably 80°C.

[0033] Wet coating methods include comma coating, gravure coating, curtain coating, and die coating. Of these, comma coating and die coating are preferred from the viewpoint of controlling the thickness of a thick fire-extinguishing agent layer. These methods involve applying a coating liquid to a substrate in any shape or all over the surface, followed by evaporating the liquid medium by applying hot air or the like in a drying oven to form a fire-extinguishing agent layer. If drying is performed at high temperatures while a large amount of liquid medium remains, only the very surface layer of the coating film will dry rapidly, forming a skin, inhibiting the evaporation of the liquid medium in the film, resulting in poor film formation and a decrease in the strength and flexibility of the fire-extinguishing agent layer. Therefore, as mentioned above, the maximum temperature during drying is preferably 100°C or less.

[0034] In step (b), when the first heating treatment is carried out at a preheating temperature lower than the maximum temperature and then the second heating treatment is carried out at the maximum temperature, the preheating temperature is preferably lower than the boiling point of the liquid medium, for example, preferably 50 to 60°C. It is preferable to heat the entire coating film at the preheating temperature for 1 to 3 minutes, and then carry out the second heating treatment. From the viewpoint of sufficiently volatilizing the liquid medium, it is preferable to carry out the second heating treatment for a longer time than the first heating treatment, for example, for 4 to 6 minutes.

[0035] Although the embodiments of the present disclosure have been described in detail above, the present invention is not limited to the above embodiments. In the above embodiments, an example in which the fire extinguishing agent layer 3 is formed on one side of the substrate 2 has been illustrated. However, both sides of the fire extinguishing agent layer 3 may be covered with a resin layer. For example, the fire extinguishing material 10 shown in FIG. 2 includes resin layers 4, 4 covering both sides of the fire extinguishing agent layer 3, and further includes water vapor barrier layers 6, 6 on both sides via adhesive layers 5, 5. Furthermore, an adhesive layer 7 is further provided on one side of the water vapor barrier layer 6, and a release film 8 is laminated on this. The release film 8 is peeled off when the fire extinguishing material 10 is attached to a desired location and may be made of resin or paper. The mandrel diameter of the fire extinguishing material 10 may be 18 mm or less, 12 mm or less, 6 mm or less, or 3 mm or less.

[0036] Examples of materials for the resin layers 4 include polyolefins (PE, PP, COP, etc.), polyesters (PET, etc.), fluororesins (PTFE, ETFE, EFEP, PFA, FEP, PCTFE, etc.), vinyl resins (PVC, PVA, etc.), acrylic resins, epoxy resins, polyamides, and polyimides. The resin layers 4 may be heat-fusible (thermally adhesive). Examples of heat-fusible resins include polyolefin-based resins. That is, the resin layers 4 may contain polyolefin-based resins. Examples of polyolefin-based resins include low-density polyethylene resin (LDPE), linear low-density polyethylene resin (LLDPE), medium-density polyethylene resin (MDPE), and unstretched polypropylene resin (CPP); polyethylene-based resins such as ethylene-vinyl acetate copolymers and ethylene-α-olefin copolymers; and polypropylene-based resins such as propylene-ethylene random copolymers, propylene-ethylene block copolymers, and propylene-α-olefin copolymers. Among these, the polyolefin resin may include low-density polyethylene resin (LDPE), linear low-density polyethylene resin (LLDPE), or unoriented polypropylene resin (CPP) from the viewpoint of excellent heat-sealing properties, low water vapor permeability, and ease of suppressing deterioration of the fire-extinguishing agent. These resins are transparent, facilitating visual inspection of the fire-extinguishing agent. This makes it easy to check the replacement time of the fire-extinguishing material laminate.

[0037] The resin layers 4, 4 have a larger area than the fire-extinguishing agent layer 3, and the contacting portions of the resin layers 4, 4 can be heat-sealed to seal the fire-extinguishing agent layer 3. Although the fire-extinguishing agent layer 3 is used in a state in which the substrate 2 is peeled off from the fire-extinguishing material 1 in Fig. 2, the fire-extinguishing material 1 itself may be sealed by the resin layers 4, 4 without peeling off the substrate 2. The thickness of the resin layers 4, 4 alone can be 25 µm to 150 µm, or may be 30 µm to 100 µm.

[0038] Examples of adhesives constituting the adhesive layers 5, 5 include acrylic adhesives, epoxy adhesives, silicone adhesives, polyolefin adhesives, urethane adhesives, polyvinyl ether adhesives, and synthetic adhesives thereof. Among these, an epoxy-urethane synthetic adhesive is preferably used as the adhesive from the viewpoint of achieving both low cost and good adhesion to the resin layers 4, 4 at high temperatures and high humidity of 85°C-85% RH.

[0039] The water vapor barrier layers 6, 6 are likely to maintain water vapor barrier properties to the extent that the properties of the fire extinguishing agent do not change significantly, regardless of the installation location or usage environment of the fire extinguishing material 10. The water vapor permeability of the water vapor barrier layers 6, 6 (in accordance with JIS K 7129 under conditions of 40°C / 90% RH) is not particularly limited as it can be designed according to the type of fire extinguishing agent, but is preferably 10 g / m ２ / day or less, and ２ / day or less. From the viewpoint of adjusting the water vapor permeability, the water vapor barrier layers 6, 6 may be a polyester resin layer (e.g., a PET layer) provided with a metal oxide vapor-deposited layer such as an alumina vapor-deposited layer or a silica vapor-deposited layer, or a metal foil such as aluminum foil. When the water vapor barrier layer includes a metal oxide vapor-deposited layer, the metal oxide vapor-deposited layer may face the fire extinguishing agent side. The thickness of the water vapor barrier layers 6, 6 alone may be 4.5 μm to 25 μm, or may be 7 μm to 12 μm.

[0040] A known adhesive layer can be used as the adhesive layer 7. When the substrate 2 is sealed together with the fire extinguishing agent layer 3, the adhesive layer 7 is provided on the side where the substrate 2 is present. The adhesive layer 7 enables the fire extinguishing material 10 to be attached to an object. When the object to which the fire extinguishing material 10 is attached catches fire, the heat energy melts the water vapor barrier layer 6, adhesive layer 5, and resin layer 4, and chemical species having fire-extinguishing properties are released from the fire extinguishing agent layer 3, thereby extinguishing the flames.

[0041] From the viewpoint of ensuring the stability of the properties of the fire extinguishing agent layer, the fire extinguishing agent layer may be enclosed in a packaging film. Any resin film can be used as the packaging film. For example, polyolefin resin, polyester resin, fluororesin, vinyl resin, acrylic resin, epoxy resin, polyamide, polyimide, urethane resin, styrene resin, polycarbonate, ketone resin, sulfone resin, cellulose resin, etc. The packaging film desirably has water vapor barrier properties, and the water vapor permeability (in accordance with JIS K 7129 under conditions of 40°C / 90% RH) is 2 x 10 ２ / m ２ / day or less, and ２ g / m ２ / day or less. From the viewpoint of adjusting the water vapor permeability, examples of films having water vapor barrier properties include polyester resin layers (e.g., PET layers) provided with inorganic metal oxide vapor-deposited layers such as alumina vapor-deposited layers and silica vapor-deposited layers, and metal foils such as aluminum foils. When the water vapor barrier layer includes a metal oxide vapor-deposited layer, the metal oxide vapor-deposited layer may face the fire extinguishing agent layer.

[0042] The packaging film may have an adhesive layer to seal the fire extinguishing material. The adhesive layer can be formed from materials such as heat sealing materials, adhesives, and pressure-sensitive adhesives. The fire extinguishing material may also have a sealing portion. By joining the packaging films around the edges of the fire extinguishing agent layer together via the sealing portion, the fire extinguishing agent layer is prevented from coming into contact with air, thereby suppressing deterioration of its stability. If the sealing portion has heat sealing properties, it may be formed by heat fusion. The adhesion strength between the substrates at the sealing portion may be 5 N / 15 mm or more. From the viewpoint of stably enclosing the fire extinguishing agent layer, it may be 7 N / 15 mm or more, or even 10 N / 15 mm or more. The adhesion strength can be varied by adjusting the resin layer, the adhesive, and the heat sealing conditions (heat sealing temperature, pressure, time). The adhesion strength between the substrates is measured as follows. That is, a sample is prepared in which the resin layers of the substrates are bonded together by heat fusion or adhesive. The heat-sealed or adhesive portion of this sample is cut into a width of 15 mm, and T-peel is performed at a peel rate of 300 mm / min using a tensile tester placed in an environment of room temperature of 23°C in accordance with JIS K6854-3. The average strength from the start of peeling until the heat-sealed or adhesive portion separates is taken as the adhesion strength between the substrates.

[0043] The present disclosure will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[0044] Example 1 Potassium chlorate (KClO ３A fire extinguishing agent was prepared by grinding potassium chlorate and tripotassium citrate in an agate mortar to an average particle size D50 of 12 μm or less. This fire extinguishing agent was mixed with various materials in the following mixing ratios to obtain a fire extinguishing composition. (1) Fire extinguishing agent (potassium chlorate, tripotassium citrate) 87 parts by mass (2) Binder resin (2-1) Polyvinyl butyral resin solution (a solution obtained by dissolving 11 parts by mass of polyvinyl butyral resin in 80 parts by mass of ethanol and 9 parts by mass of isopropyl alcohol) 50.1 parts by mass (2-2) EX-991L (epoxy resin, Nagase ChemteX, solid content 100%) 4.7 parts by mass (2-3) X-12-1287A (silane coupling agent having an acid anhydride group and an alkoxysilyl group, Shin-Etsu Chemical Co., Ltd., solid content 100%) 2.8 parts by mass (3) Liquid medium (ethanol) 87 parts by mass

[0045] The fire extinguishing composition was applied to one surface of a polyethylene terephthalate (PET) substrate (product name: E7002, manufactured by Toyobo Co., Ltd., thickness: 50 μm) using an applicator so that the thickness of the fire extinguishing agent layer after drying would be 150 μm. The coating film was heated at a preheating temperature of 55° C. for 2 minutes, and then dried at 75° C. (maximum temperature) for 5 minutes to obtain a fire extinguishing material.

[0046] Example 2 A fire extinguishing material was prepared in the same manner as in Example 1, except that the coating film was heated at a preheating temperature of 60°C for 2 minutes and then dried at 90°C (maximum temperature) for 5 minutes.

[0047] Example 3 A fire extinguishing material was prepared in the same manner as in Example 1, except that a fire extinguishing material composition having the following composition was used: (1) Fire extinguishing agent (potassium chlorate, tripotassium citrate) 87 parts by mass (2) Binder resin (2-1) Polyvinyl butyral resin solution (solution obtained by dissolving 11 parts by mass of polyvinyl butyral resin in 80 parts by mass of ethanol and 9 parts by mass of isopropyl alcohol) 84.4 parts by mass (2-2) EX-991L (epoxy resin, Nagase ChemteX, solid content 100%) 3.7 parts by mass (3) Liquid medium (ethanol) 87 parts by mass

[0048] Example 4 A fire extinguishing material was prepared in the same manner as in Example 1, except that a fire extinguishing material composition having the following composition was used: (1) Fire extinguishing agent (potassium chlorate, tripotassium citrate) 87 parts by mass (2) Binder resin (2-1) Polyvinyl butyral resin solution (solution obtained by dissolving 11 parts by mass of polyvinyl butyral resin in 80 parts by mass of ethanol and 9 parts by mass of isopropyl alcohol) 107.4 parts by mass (2-2) EX-991L (epoxy resin, Nagase ChemteX, solid content 100%) 1.2 parts by mass (3) Liquid medium (ethanol) 87 parts by mass

[0049] Example 5 A fire extinguishing material was prepared in the same manner as in Example 1, except that a fire extinguishing material composition having the following composition was used: (1) Fire extinguishing agent (potassium chlorate, tripotassium citrate) 87 parts by mass (2) Binder resin (2-1) Polyvinyl butyral resin solution (solution obtained by dissolving 11 parts by mass of polyvinyl butyral resin in 80 parts by mass of ethanol and 9 parts by mass of isopropyl alcohol) 107.4 parts by mass (2-2) EX-861 (epoxy resin, Nagase ChemteX, solid content 100%) 1.2 parts by mass (3) Liquid medium (ethanol) 87 parts by mass

[0050] Example 6 A fire extinguishing material was prepared in the same manner as in Example 1, except that a fire extinguishing material composition having the following composition was used: (1) Fire extinguishing agent (potassium chlorate, tripotassium citrate) 87 parts by mass (2) Binder resin (2-1) AD-393 (modified urethane resin, Toyo-Morton, solid content ratio 50%) 22.14 parts by mass (2-2) CAT-EP1 (isocyanate curing agent, Toyo-Morton, solid content ratio 100%) 1.46 parts by mass (3) Liquid medium (3-1) Ethanol 87 parts by mass (3-2) IPA 1.46 parts by mass

[0051] Example 7 A fire extinguishing material was prepared in the same manner as in Example 1, except that a fire extinguishing composition having the following composition was used: (1) Fire extinguishing agent (potassium chlorate, tripotassium citrate) 87 parts by mass (2) Binder resin Takelac TE5899 (urethane resin, Mitsui Chemicals, solid content ratio 30%) 41.77 parts by mass (3) Liquid medium (3-1) Ethanol 87 parts by mass (3-2) Ethyl acetate 10.44 parts by mass

[0052] Example 8 A fire extinguishing material was prepared in the same manner as in Example 1, except that a fire extinguishing material composition having the following composition was used: (1) Fire extinguishing agent (potassium chlorate, tripotassium citrate) 87 parts by mass (2) Binder resin 40.3 parts by mass of ether-based polyurethane resin solution (a solution obtained by dissolving 100 parts by mass of ether-based polyurethane resin in 210 parts by mass of isopropyl alcohol) (3) Liquid medium (ethanol) 87 parts by mass

[0053] Comparative Example 1 A fire extinguishing material was prepared in the same manner as in Example 1, except that a fire extinguishing composition having the following composition was used: (1) Fire extinguishing agent (potassium chlorate, tripotassium citrate) 87 parts by mass (2) Binder resin (2-1) Maxieve M-100 (epoxy resin, Mitsubishi Gas Chemical, solid content ratio 100%) 2.76 parts by mass (2-2) Maxieve C-97 (amine-based curing agent, Mitsubishi Gas Chemical, solid content ratio 65%) 13.64 parts by mass (3) Liquid medium (3-1) Ethanol 91.7 parts by mass (3-2) Ethyl acetate 3.1 parts by mass

[0054] Comparative Example 2 A fire extinguishing material was prepared in the same manner as in Example 1, except that a fire extinguishing material composition having the following composition was used: (1) Fire extinguishing agent (potassium chlorate, tripotassium citrate) 87 parts by mass (2) Binder resin (2-1) Polyvinyl butyral resin solution (solution obtained by dissolving 11 parts by mass of polyvinyl butyral resin in 80 parts by mass of ethanol and 9 parts by mass of isopropyl alcohol) 84.4 parts by mass (2-2) X-12-1287A (silane coupling agent having an acid anhydride group and an alkoxysilyl group, Shin-Etsu Chemical, solids content 100%) 3.7 parts by mass (3) Liquid medium (ethanol) 87 parts by mass

[0055] Comparative Example 3 A fire extinguishing material was prepared in the same manner as in Example 1, except that a fire extinguishing material composition having the following composition was used: (1) Fire extinguishing agent (potassium chlorate, tripotassium citrate) 87 parts by mass (2) Binder resin (2-1) Polyvinyl butyral resin solution (solution obtained by dissolving 11 parts by mass of polyvinyl butyral resin in 80 parts by mass of ethanol and 9 parts by mass of isopropyl alcohol) 107.4 parts by mass (2-2) X-12-1267B (silane coupling agent having an acid anhydride group and an alkoxysilyl group, Shin-Etsu Chemical, solids content 100%) 1.2 parts by mass (3) Liquid medium (ethanol) 87 parts by mass

[0056] Reference Example 4 A fire extinguishing material was prepared in the same manner as in Example 1, except that a fire extinguishing composition having the following composition was used: (1) Fire extinguishing agent (potassium chlorate, tripotassium citrate) 87 parts by mass (2) Binder resin 40.3 parts by mass of ether-based polyurethane resin solution (a solution obtained by dissolving 100 parts by mass of ether-based polyurethane resin in 210 parts by mass of isopropyl alcohol) (3) Liquid medium (ethanol) 174 parts by mass

[0057] Reference Example 5 A fire extinguishing material was prepared in the same manner as in Example 1, except that a fire extinguishing material composition having the following composition was used: (1) Fire extinguishing agent (potassium chlorate, tripotassium citrate) 87 parts by mass (2) Binder resin (2-1) Polyvinyl butyral resin solution (solution obtained by dissolving 11 parts by mass of polyvinyl butyral resin in 80 parts by mass of ethanol and 9 parts by mass of isopropyl alcohol) 50.1 parts by mass (2-2) EX-991L (epoxy resin, Nagase ChemteX, solid content 100%) 4.7 parts by mass (2-3) X-12-1287A (silane coupling agent having an acid anhydride group and an alkoxysilyl group, Shin-Etsu Chemical Co., Ltd., solid content 100%) 2.8 parts by mass (3) Liquid medium (ethanol) 174 parts by mass

[0058] <Reference Example 6> A fire extinguishing material was prepared in the same manner as in Example 1, except that the coating film was heated at a preheating temperature of 90°C for 2 minutes and then dried at 110°C (maximum temperature) for 5 minutes.

[0059] Reference Example 7 A fire extinguishing material was prepared in the same manner as in Example 1, except that the coating was dried at 90° C. (maximum temperature) for 7 minutes.

[0060] <Reference Example 8> A fire extinguishing composition with a low content of fire extinguishing agent was prepared, and a fire extinguishing material was produced using this. That is, a fire extinguishing material was produced in the same manner as in Example 1, except that the following fire extinguishing composition was used. (1) Fire extinguishing agent (potassium chlorate, tripotassium citrate) 50 parts by mass (2) Binder resin (2-1) Polyvinyl butyral resin solution (solution obtained by dissolving 11 parts by mass of polyvinyl butyral resin in 80 parts by mass of ethanol and 9 parts by mass of isopropyl alcohol) 192.6 parts by mass (2-2) EX-991L (epoxy resin, Nagase ChemteX, solid content 100%) 18.2 parts by mass (2-3) X-12-1287A (silane coupling agent having an acid anhydride group and an alkoxysilyl group, Shin-Etsu Chemical Co., Ltd., solid content 100%) 10.6 parts by mass (3) Liquid medium (ethanol) 50 parts by mass

[0061] Reference Example 9 A fire extinguishing composition with a low binder resin content was prepared, and a fire extinguishing material was produced using this. That is, a fire extinguishing material was produced in the same manner as in Example 1, except that the following fire extinguishing composition was used. (1) Fire extinguishing agent (potassium chlorate, tripotassium citrate) 99 parts by mass (2) Binder resin (2-1) Polyvinyl butyral resin solution (solution obtained by dissolving 11 parts by mass of polyvinyl butyral resin in 80 parts by mass of ethanol and 9 parts by mass of isopropyl alcohol) 3.9 parts by mass (2-2) EX-991L (epoxy resin, Nagase ChemteX, solid content 100%) 0.4 parts by mass (2-3) X-12-1287A (silane coupling agent having an acid anhydride group and an alkoxysilyl group, Shin-Etsu Chemical Co., Ltd., solid content 100%) 0.2 parts by mass (3) Liquid medium (ethanol) 99 parts by mass

[0062] <Presence or Absence of Coating Cracks and Unevenness> After forming a coating film on the surface of the substrate, the presence or absence of coating cracks and unevenness was visually confirmed during the process of drying the coating film.

[0063] <Measurement of Tensile Elongation at Break of Binder Resin> Each binder resin solution was applied to a release-treated PET film using an applicator. The coating amount was adjusted so that the film thickness after drying would be 90 μm. After drying the coating, the binder resin film was recovered. A test piece type 2 (sample width 25 mm) according to JIS K 7127 was obtained from this film. This sample was held so that the chuck width was 10 cm and pulled at a rate of 50 mm / min using an autograph testing machine AGS-X (Shimadzu Corporation), and the elongation at break was measured.

[0064] <Measurement of Viscosity of Coating Liquid> A BL type No. 3 spindle was attached to a B-type viscometer BL type (Toki Sangyo Co., Ltd.), and the viscosity of the coating liquid was measured at a rotation speed of 12 rpm.

[0065] <Mandrel test> A fire-extinguishing material cut to 100 mm x 50 mm was bent in a Type 1 mandrel test in accordance with JIS K5600-5-1, and if the fire-extinguishing agent layer bent at a diameter of 18 mm without cracking, it was marked as "Good", and if it cracked, it was marked as "Poor".

[0066] <Fire extinguishing test> A 1 cm square piece of solid fuel was ignited. The fire extinguishing material was placed 8 cm above the solid fuel so that the layer of fire extinguishing agent faced the burning solid fuel, and it was confirmed whether or not the fire could be extinguished. If the fire was extinguished, it was marked "○", and if it was not extinguished, it was marked "×".

[0067] The results are shown in Tables 1 to 4. In the tables, "-" means that the measurement was not performed or that the evaluation was not possible.

[0068]

[0069]

[0070]

[0071]

[0072] Good results were obtained in Examples 1 to 8. This is presumably because the tensile elongation at break of the binder resin was 45 mm or more, the viscosity of the coating liquid was adjusted to 1600 mPa s or more, the heat treatment was performed in two stages, and the maximum temperature of the heat treatment was set to 100°C or less.

[0073] In Comparative Examples 1, 2, and 3, the tensile elongation at break of the binder resin was less than 45 mm, so cracks occurred when bent 18 mm in the mandrel test. In Reference Examples 4 and 5, the viscosity of the coating liquid was low, so cracks in the coating film and non-uniformity due to high fluidity occurred. In Reference Examples 6 and 7, film cracks occurred due to rapid drying. In Reference Example 8, the content of the fire extinguishing agent was low, so the fire extinguishing ability was reduced. In Reference Example 9, the content of the binder resin was low, so a coating film could not be formed.

[0074] REFERENCE SIGNS LIST 1, 10... fire extinguishing material, 2... substrate, 3... fire extinguishing agent layer, 4... resin layer, 5... adhesive layer, 6... water vapor barrier layer, 7... adhesive layer, 8... release film

Claims

1. A fire-extinguishing material comprising: a substrate; and an extinguishing agent layer formed on at least one surface of the substrate; the extinguishing agent layer contains an extinguishing agent and a binder resin; the content of the extinguishing agent in the extinguishing agent layer is 60% by mass to 98% by mass based on the mass of the extinguishing agent layer; and the tensile breaking elongation of the binder resin is 45 mm or more.

2. The fire extinguishing material according to claim 1, wherein the content of the binder resin in the fire extinguishing agent layer is 2% by mass to 40% by mass based on the mass of the fire extinguishing agent layer.

3. The fire extinguishing material according to claim 1 or 2, wherein the total amount of the fire extinguishing agent and the binder resin in the fire extinguishing agent layer is 80% by mass to 100% by mass based on the mass of the fire extinguishing agent layer.

4. The fire extinguishing material according to any one of claims 1 to 3, wherein the thickness of the fire extinguishing agent layer is 70 μm to 500 μm.

5. The fire extinguishing material according to any one of claims 1 to 4, wherein the binder resin comprises at least one resin selected from the group consisting of polyvinyl butyral resin, epoxy resin, urethane resin, modified urethane resin, and ether-based polyurethane resin.

6. The fire extinguishing material according to any one of claims 1 to 5, wherein the binder resin contains a compound having an acid anhydride group and an alkoxysilyl group.

7. The fire extinguishing material according to claim 1, wherein the tensile elongation at break is the elongation at break of a sample measured by carrying out a tensile test in accordance with JIS K 7127 under conditions of a sample chucking distance of 10 cm and a tensile speed of 50 mm / min, and the sample is a test piece type 2 sample specified in JIS K 7127 and is made of a 90 μm thick film composed of the binder resin recovered from the fire extinguishing agent layer.

8. The fire extinguishing material according to any one of claims 1 to 7, wherein the mandrel diameter is 18 mm or less.

9. The fire-extinguishing material according to claim 8, wherein the mandrel diameter is the minimum diameter of the mandrel at which no cracks are found in the substrate and the fire-extinguishing agent layer when a type 1 mandrel test is carried out on the fire-extinguishing material in accordance with JIS K5600-5-1.

10. A fire extinguishing composition comprising a fire extinguishing agent and a binder resin, wherein the content of the fire extinguishing agent is 60% by mass to 98% by mass based on the total mass of the solid content of the fire extinguishing composition, and the tensile breaking elongation of the binder resin is 45 mm or more.

11. The fire extinguishing composition according to claim 10, further comprising a liquid medium, and having a viscosity of 1,600 mPa·s or more as measured at 12 rpm using a B-type viscometer.

12. The fire extinguishing composition according to claim 11, wherein the boiling point of the liquid medium is from 60°C to 90°C.

13. A method for producing a fire extinguishing material, comprising: (a) a step of applying the fire extinguishing composition according to claim 12 by a wet coating method onto at least one surface of a substrate to form a coating film; and (b) a step of drying the coating film to form a fire extinguishing agent layer on the surface of the substrate, wherein the maximum temperature during drying of the coating film in step (b) is 100°C or less, and after the start of step (b), the temperature is increased stepwise until the maximum temperature is reached.

14. A method for producing a fire extinguishing material, comprising: (a) a step of forming a coating film on at least one surface of a substrate using the fire extinguishing composition according to claim 12 by a wet coating method; and (b) a step of drying the coating film to form a fire extinguishing agent layer on said surface of the substrate, wherein the maximum temperature during drying of the coating film in step (b) is 100°C or less, and after the start of step (b), the temperature is continuously increased until the maximum temperature is reached.

15. The method for producing a fire extinguishing material according to claim 13 or 14, wherein the wet coating method is a coating method selected from the group consisting of comma coating, gravure coating, curtain coating and die coating.

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