Powder fire extinguishing agent

Abstract

We provide a powder fire extinguishing agent with high fire extinguishing performance. [Solution] A powder fire extinguishing agent comprising a thermally depolymerizable polymer having a structure to which water-soluble functional groups are attached, an alkali metal salt thereof, or an alkaline earth metal salt thereof, as a component of the fire extinguishing agent. The thermally depolymerizable polymer having a structure to which water-soluble functional groups are attached preferably has a structure represented by a specific chemical formula. In the case of alkali metal salts, sodium (Na) salts, potassium (K) salts, etc. can be used. In the case of alkaline earth metal salts, calcium (Ca) salts, magnesium (Mg) salts, etc. can be used.

Description

Technical Field

[0001] The present invention relates to a powder fire extinguishing agent used in fires. Background Art

[0002] Monoammonium dihydrogen phosphate and ammonium sulfate are known as materials used in conventional ABC powder fire extinguishing agents. In addition, sodium bicarbonate, potassium bicarbonate and the like are also used as the main component of powder fire extinguishing agents. Summary of the Invention Problem to be Solved by the Invention

[0003] However, these materials are not necessarily excellent in performance as fire extinguishing agents, and there is room for improvement in fires that avoid moisture such as oil fires. Furthermore, since there is no fire extinguishing agent suitable for extinguishing fire when a large-scale forest fire occurs, countermeasures against forest fire have become a major social issue worldwide, and a powder fire extinguishing agent that can be suitably applied to large-scale forest fires and the like is demanded. Furthermore, it is said that fires caused by lithium-ion batteries, for example, fires of electric vehicles (EV), cannot be extinguished with general ABC powder fire extinguishers.

[0004] The present invention has been made in view of the above problems, and an object of the present invention is to provide a powder fire extinguishing agent having high fire extinguishing performance. Means for Solving the Problem

[0005] The present invention provides a powder fire extinguishing agent comprising, as a component of the fire extinguishing agent, a thermally depolymerizable polymer having a structure provided with a water-soluble functional group, an alkali metal salt thereof, or an alkaline earth metal salt thereof (Invention 1).

[0006] In the above invention (Invention 1), it is preferable that the thermally depolymerizable polymer having a structure provided with the water-soluble functional group has a structure represented by the following chemical formula (Invention 2). Chemical Formula (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.

[0007] In the above invention (Invention 1), it is preferable that the alkali metal salt is a K salt or a Na salt (Invention 3).

[0008] 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).

[0009] In the above invention (Invention 2), it is preferable that the weight-average molecular weight (Mw) of the pyropolymer with the water-soluble functional group in the powder fire extinguishing agent, its alkali metal salt, or its alkaline earth metal salt is 2,000,000 or less (Invention 5).

[0010] In the above invention (Invention 1), the powder fire extinguishing agent may contain two or more types of pyrolytically polymers having a structure to which the water-soluble functional group is attached, alkali metal salts thereof, or alkaline earth metal salts thereof (Invention 6).

[0011] In the above inventions (Inventions 1 to 6), it is preferable that the pyropolymer with the structure to which the water-soluble functional group is attached is poly(methacrylic acid) (Invention 7).

[0012] According to these inventions (Inventions 1-7), a pyropolymer with a structure to which water-soluble functional groups are attached, particularly poly(methacrylic acid), can be used to efficiently extinguish a fire with a small amount of fire extinguishing agent. [Effects of the Invention]

[0013] According to the present invention, the powder fire extinguishing agent, due to the effect of a thermally depolymerizable polymer with a structure to which water-soluble functional groups are attached, particularly poly(methacrylic acid), can efficiently extinguish fires with a smaller amount of extinguishing agent than conventional powder fire extinguishing agents. As a result, it can be applied to fields where general powder fire extinguishers are used, and because it is a waterless powder fire extinguishing agent, it is also effective against oil fires. [Modes for carrying out the invention]

[0014] The powder fire extinguishing agent of the present invention will be described in detail based on the following embodiments.

[0015] [Powder fire extinguishing agent] The powder fire extinguishing agent of this embodiment includes, as components of the fire extinguishing agent, a polymer having a structure in which water-soluble functional groups such as carboxylic acid groups and sulfonic acid groups are attached to a thermally depolymerizable polymer, an alkali metal salt thereof, or an alkaline earth metal salt thereof (hereinafter, these may be collectively referred to as the polymer component).

[0016] Polymer components In this embodiment, the pyropolymerizable polymer with a water-soluble functional group is preferably structured as shown in the following chemical formula.

[0017] [ka]

[0018] (In the formula, 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 between 5 and 27,000, and m is a positive integer between 1 and 5.)

[0019] Poly(methacrylic acid) can be suitably used as a thermally depolymerizable polymer with such a water-soluble functional group structure.

[0020] Further, as the alkali metal salt of the thermally depolymerizable polymer having a structure provided with a water-soluble functional group, sodium (Na) salt, potassium (K) salt, or the like can be used. Also, as the alkaline earth metal salt, calcium (Ca) salt, magnesium (Mg) salt, or the like can be used.

[0021] These polymer components preferably have a weight average molecular weight (MW) of 2,000,000 or less, particularly 1,000,000 or less. Those with a weight average molecular weight (MW) exceeding 2,000,000 result in decreased production efficiency of the polymer. The lower limit of the weight average molecular weight (MW) is not particularly limited as long as the polymer is in a polymeric form and can be formed into powder, but it is preferably 500 or more, particularly 1,000 or more.

[0022] In the powder fire extinguishing agent of the present embodiment, the thermally depolymerizable polymer having a structure provided with a water-soluble functional group, an alkali metal salt thereof, or an alkaline earth metal salt thereof may each be used alone, or two or more kinds may be used in combination.

[0023] The powder fire extinguishing agent as described above may be sprinkled directly onto a fire, or may be filled into a fire extinguisher and used by being sprayed onto the flame together with a high-pressure gas.

[0024] The powder fire extinguishing agent of the present invention has been described above. The present invention only needs to use, as an active ingredient of the fire extinguishing agent, a thermally depolymerizable polymer having a structure provided with a water-soluble functional group, an alkali metal salt thereof, or an alkaline earth metal salt thereof, and can be formed into a powder fire extinguishing agent as a single fire extinguishing component without containing other powder fire extinguishing components. On the other hand, according to the purpose of use, colorants, other powder fire extinguishing agents, and the like may be appropriately added to the powder fire extinguishing agent of the present invention within a range that does not impair the fire extinguishing effect of the powder fire extinguishing agent of the present invention. [Examples]

[0025] 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.

[0026] (Fire extinguishing test) The fire extinguishing test was conducted using the following method. 5 ml of commercially available tempura oil was placed in a metal container with a diameter of 5 cm and a depth of 3 cm. This container was then placed on a gas stove, and the gas stove was ignited. Heating continued until the oil vaporized, smoke was produced, and the tempura oil ignited. Once the tempura oil ignited, heating on the gas stove was stopped, and 2 g of various powder fire extinguishing agents was added to the burning tempura oil. Containers that extinguished the fire within 30 seconds were rated "○", while those that did not extinguish the fire within 30 seconds were rated "×".

[0027] (Examples 1-2, Comparative Example 1) Powder fire extinguishing agents using poly(potassium methacrylate) as the extinguishing agent material (Example 1), powder fire extinguishing agents using poly(sodium methacrylate) as the extinguishing agent material (Example 2), and powder fire extinguishing agents using monoammonium dihydrogen phosphate as the extinguishing agent material (Comparative Example 1) were each evaluated using the fire extinguishing test method described above. The results, along with the molecular weight of the extinguishing agent components, are shown in Table 1.

[0028] [Table 1]

Claims

1. A powder fire extinguishing agent comprising, as a component of the fire extinguishing agent, a thermally depolymerizable polymer having a structure to which a water-soluble functional group has been added, an alkali metal salt thereof, or an alkaline earth metal salt thereof.

2. The powder fire extinguishing agent according to claim 1, wherein the thermally depolymerizable polymer having the aforementioned water-soluble functional group has the structure shown in 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 powder fire extinguishing agent according to claim 1, wherein the alkali metal salt is a K salt or a Na salt.

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

5. The powder fire extinguishing agent according to claim 2, wherein the weight-average molecular weight (MW) of the thermally depolymerizable polymer having the water-soluble functional group in the powder fire extinguishing agent, the alkali metal salt thereof, or the alkaline earth metal salt thereof is 2,000,000 or less.

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

7. The powder fire extinguishing agent according to any one of claims 1 to 6, wherein the thermally depolymerizable polymer having the structure to which the water-soluble functional group is attached is poly(methacrylic acid).

Images