Fire extinguishing agent composition

Abstract

To provide a fire extinguishing agent composition that does not contain fluorine-based surfactants and has high fire extinguishing performance. [Solution] A fire extinguishing agent composition comprising (A) a thermopolymer having a structure to which a water-soluble functional group is attached, an alkali metal salt thereof, or an alkaline earth metal salt thereof, and (B) a thickener. (A) The thermopolymer having a structure to which a water-soluble functional group is attached preferably has a structure represented by a specific chemical formula. In the case of an alkali metal salt, sodium (Na) salt, potassium (K) salt, etc. can be used. In the case of an alkaline earth metal salt, calcium (Ca) salt, magnesium (Mg) salt, etc. can be used.

Description

Technical Field

[0001] The present invention relates to a fire extinguishing agent composition for use in fires.

Background Art

[0002] Various fire extinguishing agents have heretofore been developed to enhance the fire extinguishing effect of water. Examples include (a) inorganic phosphate compound-based fire extinguishing agents, (b) synthetic surfactant-based fire extinguishing agents, and the like. Ammonium phosphate has a composition similar to components used in fertilizers, and thus environmental problems have been pointed out, such as causing eutrophication in spread soil. In addition, since synthetic surfactants do not lose their surfactant activity for a certain period of time even when released into the environment, there are concerns about their toxicity to aquatic organisms. (Patent Document 1)

Prior Art Literature

Patent Literature

[0003]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0004] Although excellent fire extinguishing agents have been developed as described above, each of them has its own problems. Furthermore, there is no fire extinguishing agent suitable for extinguishing large-scale forest fires, so countermeasures against forest fires have become a major global social issue. In addition, fires caused by lithium-ion batteries, for example fires in electric vehicles (EV), are also said to be unextinguishable with general fire extinguishing agents.

[0005] The present invention has been made in view of the above problems, and an object thereof is to provide a fire extinguishing agent composition that has high fire extinguishing performance and can be easily extinguished by spraying.

Means for Solving the Problem

[0006] The present invention provides a fire extinguishing agent composition containing, as a component of the fire extinguishing agent, (A) a thermodepolymer having a structure to which a water-soluble functional group is attached, an alkali metal salt thereof, or an alkaline earth metal salt thereof, and (B) a thickening agent (Invention 1).

[0007] In the above invention (Invention 1), it is preferable that the thermally depolymerizable polymer having the structure to which the water-soluble functional group (A) is attached has the structure shown by the following chemical formula (Invention 2). [ka] (In the formula, X is hydrogen (H) or an alkyl group having 1 to 3 carbon atoms, and Y is COOH, SO3H, OCOOH, OSO3H, COO(CH2)) m COOH, COO(CH2) m SO3H, benzene ring-COOH, or benzene ring-SO3H, where n is a positive integer between 5 and 27,000, and m is a positive integer between 1 and 5.

[0008] In the above invention (Invention 1), it is preferable that the alkali metal salt is a K salt or a Na salt (Invention 3).

[0009] In the above invention (Invention 1), it is preferable that the alkaline earth metal salt is a Ca salt or an Mg salt (Invention 4).

[0010] In the above invention (Invention 2), it is preferable that the fire extinguishing agent composition further contains (C) water, and the content of (A) a thermopolymerizable polymer having a water-soluble functional group, its alkali metal salt, or its alkaline earth metal salt is 0.1 to 20% by weight, with the total of (A) + (B) + (C) being 100% by weight (Invention 5).

[0011] In the above invention (Invention 2), it is preferable that the weight-average molecular weight (MW) of the thermally depolymerizable polymer having the structure to which the water-soluble functional group (A) is attached, its alkali metal salt, or its alkaline earth metal salt is 1,000,000 or less (Invention 6).

[0012] In the above invention (Invention 1), the fire extinguishing agent composition may contain two or more of the following: a thermodepolymer having a structure to which the (A) water-soluble functional group is attached, an alkali metal salt thereof, or an alkaline earth metal salt thereof (Invention 7).

[0013] In the above inventions (Inventions 1 to 7), it is preferable that the pyropolymer with the structure to which the water-soluble functional group is attached is poly(methacrylic acid) (Invention 8).

[0014] According to these inventions (Inventions 1-8), due to the effect of a thermally depolymerizable polymer with a structure to which water-soluble functional groups are attached, particularly poly(methacrylic acid), and the effect of a thickening agent, the fire extinguishing agent composition remains on the target of the fire and does not flow away, thereby enabling efficient fire extinguishing with a small amount of water. [Effects of the Invention]

[0015] According to the fire extinguishing agent composition of the present invention, due to the effect of a thermally depolymerizable polymer with a structure to which water-soluble functional groups are attached, particularly poly(methacrylic acid), fires can be efficiently extinguished with a smaller amount of water than when water is used alone. Furthermore, due to the effect of the thickening agent, the fire extinguishing agent composition remains on the object being extinguished and does not flow away, allowing the fire to be extinguished using the limited amount of water resources at the fire scene, and furthermore, secondary damage caused by the extinguishing water is suppressed. The fire extinguishing agent composition of the present invention is effective against all types of fires that are extinguished using water, such as forest fires, house fires, and electric vehicle (EV) fires. [Modes for carrying out the invention]

[0016] The fire extinguishing agent composition of the present invention will be described in detail based on the following embodiments.

[0017] [Fire extinguishing agent composition] The fire extinguishing agent composition of the present embodiment comprises, as fire extinguishing agent components: (A) a polymer having a structure in which water-soluble functional groups such as carboxylic acid groups and sulfonic acid groups are introduced into a thermally depolymerizable polymer, an alkali metal salt thereof, or an alkaline earth metal salt thereof (these may be collectively referred to as the polymer component hereinafter); and further comprises (B) a thickener.

[0018] (A) Polymer component In the present embodiment, the thermally depolymerizable polymer having a structure provided with water-soluble functional groups preferably has a structure represented by the following chemical formula.

[0019]

Chemical Formula

[0020] (wherein X is hydrogen (H) or an alkyl group having 1 to 3 carbon atoms; Y is COOH, SO₃H, OCOOH, OSO₃H, COO(CH₂)mCOOH, COO(CH₂)mSO₃H, benzene ring-COOH or benzene ring-SO₃H; n is a positive integer of 5 to 27,000; and m is a positive integer of 1 to 5.)

[0021] As such a thermally depolymerizable polymer having a structure provided with water-soluble functional groups, poly(methacrylic acid) can be suitably used.

[0022] Further, as the alkali metal salt of the thermally depolymerizable polymer having a structure provided with water-soluble functional groups, sodium (Na) salt, potassium (K) salt or the like can be used. As the alkaline earth metal salt, calcium (Ca) salt, magnesium (Mg) salt or the like can be used.

[0023] These (A) polymer components are preferably those with a weight-average molecular weight (MW) of 1,000,000 or less, and particularly preferably 100,000 or less. If the weight-average molecular weight (MW) exceeds 1,000,000, not only will the solubility in water decrease, but the efficiency of polymer production will also decrease. There is no particular lower limit to the weight-average molecular weight (MW) as long as it is in polymer form, but it should be 500 or more, and particularly 1,000 or more.

[0024] In the fire extinguishing agent composition of this embodiment, the content of (A) polymer component is preferably 0.1 to 20% by weight, particularly 0.1 to 10% by weight, and more preferably 0.1 to 5% by weight, with the total of (A) polymer component + (B) thickener + (C) water being 100% by weight. If the content of (A) polymer component is less than 0.1% by weight, sufficient fire extinguishing performance cannot be obtained, and a large amount (volume) of fire extinguishing agent must be sprayed. On the other hand, if it exceeds 5% by weight, not only is no further improvement in fire extinguishing performance not obtained, but the viscosity of the aqueous solution of the fire extinguishing agent increases, making it difficult to handle, which is undesirable.

[0025] In this embodiment, each polymer component (A) may be used individually or in combination of two or more. When using two or more in combination, two or more raw fire extinguishing agent compositions, each containing a predetermined amount of polymer component (A), thickener (B), and water (C), may be mixed together, or two or more polymer components (A) may be mixed with thickener (B) and water (C).

[0026] (B) Thickener In this embodiment, the thickening agent can be water-soluble and capable of imparting a constant viscosity. Specifically, sodium carboxymethylcellulose, calcium carboxymethylcellulose, sodium alginate, propylene glycol alginate, sodium caseinate, sodium chondroitin sulfate, calcium cellulose glycolate, sodium cellulose glycolate, sodium starch glycolate, sodium starch phosphate, sodium polyacrylate, etc. can be used. Thickening polysaccharides such as guar gum, xanthan gum, carrageenan, and manna can also be used. These thickening agents are preferably in granular or powder form.

[0027] In the fire extinguishing agent composition of this embodiment, the content of (B) thickener is not particularly limited as long as the fire extinguishing agent composition gels, but it is preferably 0.1 to 5% by weight, and particularly 0.3 to 1% by weight, based on the total of (A) polymer component + (B) thickener + (C) water being 100% by weight. If the content of (B) thickener is less than 0.1% by weight, a sufficiently gelled fire extinguishing agent composition cannot be obtained, while if it exceeds 5% by weight, the viscosity of the resulting fire extinguishing agent composition becomes too high, which is undesirable as it reduces the handlingability as a fire extinguishing agent.

[0028] (C)Water The fire extinguishing agent composition of this embodiment generally further contains (C) water. The water content is the remainder of (A) polymer component + (B) thickener, with the total of (A) polymer component + (B) thickener + (C) water being 100% by weight.

[0029] [Fire extinguishing method using fire extinguishing agent composition] The fire extinguishing agent compositions described above can be supplied directly to the flames during firefighting, but in terms of fire extinguishing efficiency per unit volume of the fire extinguishing agent composition, it is preferable to apply them to the flames in liquid form. For example, for large-scale fires such as forest fires, they can be sprayed from above using helicopters, drones, or aircraft. They can also be made into spray cans or spray guns to create simple household fire extinguishing aids. Furthermore, they can be used as the extinguishing agent in ordinary fire extinguishers and can be used against general fires and electric vehicle (EV) fires.

[0030] The fire extinguishing agent composition of this embodiment exhibits approximately eight times more fire extinguishing performance per unit volume than when water is used alone, and approximately twice as much fire extinguishing performance per unit volume than when a fire extinguishing agent is used alone. Therefore, fires can be efficiently extinguished with a small amount of water. This allows for effective fire extinguishing using the limited water resources at the fire scene, and also reduces secondary damage caused by the extinguishing water. For this reason, it is particularly suitable as a fire extinguishing agent for large-scale fires such as forest fires and widespread fires. It can also be used to extinguish fires caused by lithium-ion batteries, such as those in electric vehicles (EVs).

[0031] The fire extinguishing agent composition of the present invention has been described above, but the present invention is not limited in any particular way in which the active ingredient of the fire extinguishing agent is an aqueous solution containing a thermally depolymerizable polymer having a structure to which a water-soluble functional group has been attached, an alkali metal salt thereof, or an alkaline earth metal salt thereof, and a thickener. Furthermore, depending on the purpose of use, the fire extinguishing agent composition of the present invention may be blended with various additives such as a colorant for use as a fire extinguishing agent for forest fires, other fire extinguishing agents, pH adjusters, neutralizing agents, thickeners, and rust inhibitors. [Examples]

[0032] The present invention will be described in more detail based on the following specific examples, but the present invention is not limited to the following examples.

[0033] (Fire extinguishing test) The fire extinguishing test was conducted using the following method. A mini bonfire stand Tetra ST-941 (manufactured by Shin Fuji Burner Co., Ltd.) was assembled as the combustion platform. One pellet (12g) of Aomori Mirai Pellets (manufactured by Takahashi HD Co., Ltd.) was placed inside, and the combustion material was ignited with a gas burner. When the flame height of the combustion material exceeded 10cm, the extinguishing agent composition was sprayed using a spray gun capable of spraying approximately 0.7mL of liquid in a single spray, and the amount of extinguishing agent required to completely extinguish the flame was measured. It was also checked whether the flame reignited during the extinguishing process.

[0034] (Example 1, Comparative Examples 1 and 2) Using a fire extinguishing agent composition (Example 1) prepared by dissolving 0.5 parts by weight of poly(methacrylate) potassium salt as solid content and 0.5 parts by weight of sodium polyacrylate as a thickening agent as solid content in 99 parts by weight of water to make an aqueous solution, the above fire extinguishing test was conducted, and the number of sprays from the spray gun until the fire was extinguished was measured, the required amount of fire extinguishing agent was calculated, and the presence or absence of re-flaming was confirmed. The results are shown in Table 1, along with the composition ratio of the fire extinguishing agent composition and the weight-average molecular weight of the polymer components used. For comparison, the number of sprays from the spray gun until the fire was extinguished, the required amount of fire extinguishing agent was calculated, and the presence or absence of re-flaming was confirmed in the cases where only the fire extinguishing agent was dissolved in water (Comparative Example 1) and when only water was used (Comparative Example 2). The results are also shown in Table 1.

[0035] [Table 1]

[0036] As is clear from Table 1, the fire extinguishing agent composition of Example 1 required 1 / 8 or less of the amount of fire extinguishing agent composition needed to extinguish the fire compared to Comparative Example 2, which used water, and 1 / 2 or less of the amount of fire extinguishing agent composition needed to extinguish the fire compared to Comparative Example 1, which used only the fire extinguishing agent. It was confirmed that there was no re-flare and that it exhibited excellent fire extinguishing performance.

[0037] [Table 2]

[0038] As is clear from Table 2, the fire extinguishing agent composition of Example 2 required 1 / 8 or less of the amount of fire extinguishing agent composition needed to extinguish the fire compared to Comparative Example 4, which used water, and 1 / 2 or less of the amount of fire extinguishing agent composition needed to extinguish the fire compared to Comparative Example 3, which used only the fire extinguishing agent. It was confirmed that there was no re-flare and that it exhibited excellent fire extinguishing performance.

[0039] (Example 3, Comparative Examples 5, 6) A lithium-ion battery was ignited during an overcharge test, and a fire extinguishing test was conducted while the flames were still present. In the lithium-ion battery overcharge test, a 3.4V, 3.2Ah laminated lithium-ion single cell was used and overcharged under conditions of 15V, 9.6A (3C). As a result, a violent explosion and ignition occurred approximately 19 minutes later, and the flames continued.

[0040] For this ongoing fire, a fire extinguishing agent composition (Example 3) was used, prepared by dissolving 4 parts by weight of potassium poly(methacrylate) salt as a solid component and 0.5 parts by weight of sodium polyacrylate as a thickening agent as a solid component in 95.5 parts by weight of water to make an aqueous solution. The number of sprays from the spray gun until the fire was extinguished was measured, the required amount of fire extinguishing agent was calculated, and the presence or absence of re-flaming was checked. The results are shown in Table 3, along with the composition ratio of the fire extinguishing agent composition and the weight-average molecular weight of the polymer components used. For comparison, the number of sprays from the spray gun until the fire was extinguished, the required amount of fire extinguishing agent was calculated, and the presence or absence of re-flaming was checked in the same manner when only the fire extinguishing agent was dissolved in water (Comparative Example 5) and when only water was used (Comparative Example 6). The results are also shown in Table 3.

[0041] [Table 3]

[0042] As is clear from Table 3, the fire extinguishing agent composition of Example 3 required less than 1 / 10 of the amount of fire extinguishing agent composition to extinguish the fire compared to Comparative Example 6, which used water, and less than 1 / 2 of the amount of fire extinguishing agent composition required to extinguish the fire compared to Comparative Example 5, which used only the fire extinguishing agent. It was confirmed that there was no re-flare and that it exhibited excellent fire extinguishing performance.

Claims

1. A fire extinguishing agent composition comprising (A) a thermodepolymer having a structure to which a water-soluble functional group has been conjugated, an alkali metal salt thereof, or an alkaline earth metal salt thereof, and (B) a thickening agent.

2. The fire extinguishing agent composition according to claim 1, wherein the thermally depolymerizable polymer having the structure to which the (A) water-soluble functional group is attached has the structure shown by the following chemical formula. 【Chemistry 1】 (In the formula, X is hydrogen (H) or an alkyl group having 1 to 3 carbon atoms, and Y is COOH or SO ３ H, OCOOH, OSO ３ H, COO (CH ２ ) ｍ COOH, COO(CH ２ ) ｍ SO ３ H, benzene ring-COOH or benzene ring-SO ３ H is a positive integer between 5 and 27,000, and m is a positive integer between 1 and 5.

3. The fire extinguishing agent composition according to claim 1, wherein the alkali metal salt is a K salt or a Na salt.

4. The fire extinguishing agent composition according to claim 1, wherein the alkaline earth metal salt is a Ca salt or a Mg salt.

5. The fire extinguishing agent composition according to claim 2, wherein the fire extinguishing agent composition further contains (C) water, and the content of (A) a thermally depolymerizable polymer having a structure to which a water-soluble functional group is provided, an alkali metal salt thereof, or an alkaline earth metal salt thereof is 0.1 to 20% by weight, where the total of (A) + (B) + (C) is 100% by weight.

6. The fire extinguishing agent composition according to claim 2, wherein the weight-average molecular weight (MW) of the thermally depolymerizable polymer having the structure to which the (A) water-soluble functional group is attached, the alkali metal salt thereof, or the alkaline earth metal salt thereof is 1,000,000 or less.

7. The fire extinguishing agent composition according to claim 1, wherein the fire extinguishing agent composition contains two or more types of thermally depolymerizable polymer having a structure to which the (A) water-soluble functional group is attached, an alkali metal salt thereof, or an alkaline earth metal salt thereof.

8. The fire extinguishing agent composition according to any one of claims 1 to 7, wherein the thermally depolymerizable polymer having a structure to which a water-soluble functional group is attached is poly(methacrylic acid).

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