Foam fire extinguishing agent

Abstract

The present invention provides a foam extinguishing agent which does not contain a fluorine compound and which also exhibits sufficient fire extinguishing ability for a water-soluble fuel. The non-fluorine-based foam extinguishing agent for a water-soluble fuel of the present invention is characterized by not containing an organic fluorine compound and by containing water, a hydrocarbon-based surfactant, a water-soluble polymer, a salt of a divalent metal, and an anionic surfactant.

Description

Technical Field

[0001] This invention relates to a foam extinguishing agent for water-soluble fuels, and more particularly to a non-fluorine-based foam extinguishing agent for water-soluble fuels that does not contain fluorine compounds but has excellent fire extinguishing performance. Background Technology

[0002] Foam extinguishing agents are the primary extinguishing agents used for fires involving flammable liquids classified as Class IV hazardous materials. They are supplied in a foaming state. The supplied foam extinguishes the fire by rapidly spreading over the flammable liquid.

[0003] In the case of fires involving water-soluble fuels such as alcohols, ketones, esters, ethers, or amines, when using conventional petroleum fire extinguishing agents, the foam from the extinguishing agent immediately deflates upon contact with the burning liquid surface, failing to extinguish the fire effectively.

[0004] Foam extinguishing agents used for fires involving such water-soluble fuels have been proposed and used to date, including, for example, foam extinguishing agents (fluorinated proteins) containing fluorinated surfactants added to protein hydrolysates, and foam extinguishing agents containing water-soluble polymers added to fluorinated surfactants (e.g., Patent Document 1: Japanese Patent Application Publication No. 2007-252731; Patent Document 2: Japanese Patent Application Publication No. 2001-269421).

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2007-252731

[0008] Patent Document 2: Japanese Patent Application Publication No. 2001-269421 Summary of the Invention

[0009] The technical problem that the invention aims to solve

[0010] However, in recent years, from an environmental perspective, the use of organic fluorine compounds has been avoided. Using fire extinguishing agents that do not use organic fluorine compounds has led to a decrease in alcohol resistance. In response, the use of water-soluble polymers and hydrocarbon surfactants has been considered, but they have not been effective in fires involving water-soluble fuels, and there is still room for improvement.

[0011] Therefore, the object of the present invention is to provide a foam fire extinguishing agent that does not contain organic fluorine compounds but also has sufficient fire extinguishing capability for fires involving water-soluble fuels.

[0012] Technical solutions for solving technical problems

[0013] To solve the above-mentioned technical problems, the inventors conducted repeated and meticulous experiments and research, and discovered that by further adding a divalent metal salt (CaCl2) and an anionic surfactant (sodium alkyl sulfate) to a foam extinguishing agent containing polysaccharides as water-soluble polymers and alkylamine oxides as hydrocarbon surfactants, a foam extinguishing agent that can exert sufficient fire extinguishing ability against isopropanol (IPA) fires can be achieved even without the use of fluorine compounds, thus completing the present invention.

[0014] That is, the foam fire extinguishing agent of the present invention is characterized in that it does not contain organic fluorine compounds and contains: water, hydrocarbon surfactants, water-soluble polymers, divalent metal salts and anionic surfactants.

[0015] In the foam fire extinguishing agent of the present invention, the anionic surfactant is preferably sodium alkyl sulfate.

[0016] In the foam fire extinguishing agent of the present invention, the concentration of the anionic surfactant in the foam fire extinguishing agent is preferably 0.2% to 3.5% by mass.

[0017] Furthermore, in the foam fire extinguishing agent of the present invention, the salt of the divalent metal is preferably a Ca salt or a Mg salt.

[0018] In the foam fire extinguishing agent of the present invention, the Ca salt or the Mg salt is preferably CaCl2 or MgCl2.

[0019] The effects of the invention

[0020] According to the present invention, a foam extinguishing agent (i.e., a non-fluorinated foam extinguishing agent for water-soluble fuels) is capable of providing sufficient fire extinguishing capability for fires involving water-soluble fuels without containing fluorine compounds. Detailed Implementation

[0021] Hereinafter, the foam fire extinguishing agent according to representative embodiments of the present invention will be described in detail with reference to the examples shown in the table. However, the present invention is not limited to these embodiments.

[0022] 1. Ingredients

[0023] The foam extinguishing agent involved in this embodiment is a water-soluble fuel non-fluorinated foam extinguishing agent (i.e., having a composition other than that containing fluorine compounds), characterized in that it contains: at least water as a mother liquor, a hydrocarbon surfactant, a water-soluble polymer; a divalent metal salt; and an anionic surfactant. Hereinafter, these essential and optional components will be described.

[0024] (1) Hydrocarbon surfactants

[0025] As a hydrocarbon-based surfactant, any substance that achieves foaming when air and foam extinguishing agent are mixed is acceptable. Examples include hydrocarbon-based surfactants such as alkyl sulfonic acid surfactants, alkyl amino surfactants, alkyl-polyoxyethylene and / or polyoxypropylene surfactants, alkyl betaine surfactants, and polyoxyethylene alkylphenol surfactants. Among these, alkyl amino hydrocarbon surfactants are preferred, and alkyl amine oxides are preferred, with coconut oil alkyl dimethyl amine oxide being more preferred. As an alkyl amine oxide, commercially available products from companies such as Lion Corporation, Nippon Oil Co., Ltd., Takemoto Oils & Fats Co., Ltd., and Kao Corporation can be used.

[0026] (2) Water-soluble polymers

[0027] As a water-soluble polymer, any substance that is soluble in water and can precipitate insoluble substances in water-soluble fuels is acceptable. Examples include cellulose derivatives (methylcellulose, hydroxyethylcellulose, etc.), polyvinyl alcohol, sodium alginate, polyethylene ether, polyethylene glycol, tamarind gum, alginate, xanthan gum, and pullulan xanthan gum, among other polysaccharides. Tamarind gum, alginate, xanthan gum, and pullulan xanthan gum are preferred, and xanthan gum is even more preferred. For example, commercially available products from Mitsubishi Corporation Life Sciences, KIMICA Corporation, Higuchi Shokai Co., Ltd., Tsuruya Chemical Industries, Ltd., FC Chemical Co., Ltd., and CPKelco can be used.

[0028] (3) Water

[0029] As for water, there are no particular restrictions as long as it does not impair the effect of the present invention; tap water, river water, seawater, etc., can be used.

[0030] (4) Salts of divalent metals

[0031] As described above, the inventors discovered that by further adding a divalent metal salt to a foam fire extinguishing agent containing a polysaccharide as a water-soluble polymer and an alkylamine oxide as a hydrocarbon surfactant, sufficient fire extinguishing capability can be achieved against fires involving isopropanol (IPA), a water-soluble fuel, thus completing the present invention. Details of the rationale are not yet known, but it is speculated that the interaction between the metal ions and the polysaccharide generates precipitates that are not easily impregnated by the water-soluble fuel.

[0032] The salt of the divalent metal is preferably a salt of an alkaline earth metal, and the alkaline earth metal is preferably Mg, Ca, Sr, or Ba. Furthermore, from the viewpoint of low toxicity, common availability, and ease of supply and processing, Ca or Mg is particularly preferred.

[0033] (5) Anionic surfactants

[0034] Furthermore, the foam fire extinguishing agent according to the present invention contains anionic surfactants. Examples of such anionic surfactants include compounds having any hydrophilic groups such as carboxylic acid, sulfonic acid, sulfate ester, and phosphate ester groups, and any hydrophobic groups such as aliphatic and aromatic groups. The inventors have discovered that by using sodium alkyl sulfate, an anionic surfactant in addition to divalent metal salts, the fire extinguishing performance is further improved. The details of the reason are not yet known, but the inventors speculate that it is due to increased foam stability and water retention, and improved heat resistance.

[0035] More specifically, as anionic surfactants, examples include alkylbenzene sulfonic acids or their salts such as sodium dodecylbenzene sulfonate; dialkyl sulfosuccinates such as sodium diethylhexyl sulfosuccinate and sodium diisotridecyl sulfosuccinate; di(polyoxyethylene 2-ethylhexyl ether) sulfosuccinates such as sodium di(polyoxyethylene isotridecyl ether) sulfosuccinates such as sodium dipolyoxyethylene alkyl ether sulfosuccinate or their salts; sodium lauryl ether sulfate such as sodium lauryl sulfate; sodium myristyl ether sulfate; sodium alkyl sulfate such as sodium polyoxyethylene alkyl ether sulfate; polyoxyethylene alkyl ether sulfates such as ammonium polyoxyethylene alkyl ether sulfate; sodium polyoxyethylene alkylphenyl ether sulfate; ammonium polyoxyethylene alkylphenyl ether sulfate; and polyoxyethylene polycyclic phenyl ether sulfates such as sodium polyoxyethylene polycyclic phenyl ether sulfate and ammonium polyoxyethylene polycyclic phenyl ether sulfate. Salts, polyoxyethylene-polyoxypropylene glycol ether sulfuric acid or its salts, sodium lauryl sulfate, sodium higher alcohol sulfate, triethanolamine lauryl sulfate, ammonium lauryl sulfate and other alkyl sulfuric acids or their salts, potassium oleate, sodium oleate, sodium semi-hardened tallow fatty acid and other fatty acids or their salts, dodecyl diphenyl ether disulfonic acid diammonium, dodecyl diphenyl ether disulfonic acid sodium, dodecyl diphenyl ether disulfonic acid calcium, alkyl diphenyl ether disulfonic acid sodium, etc., condensates of aromatic sulfonic acids and formaldehyde, condensates of aromatic sulfonic acids and formaldehyde such as sodium naphthalene sulfonic acid formaldehyde condensate, N-acyl sarcosine salts such as sodium lauroyl sarcosine, higher fatty acid amide sulfonic acids such as sodium N-myristoyl-N-methyl taurate, methyl taurate of coconut oil fatty acids and other higher fatty acid amide sulfonic acids or their salts, and N-acyl glutamate such as disodium N-stearoyl glutamate, monosodium N-stearoyl glutamate and other N-acyl glutamate or their salts, etc.

[0036] (6) Any component

[0037] As other components, the foam fire extinguishing agent of the present invention may contain various components added to existing foam fire extinguishing agents to a extent that does not impair the effects of the present invention.

[0038] (6-1) Solvent

[0039] Water-soluble organic solvents that are miscible with water can be listed. Examples include alcohols and esters. Specifically, examples include propylene glycol, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, dipropylene glycol, n-propanol, n-butanol, octanol, 1,3-butanediol, hexanediol, 3-methoxy-3-methyl-1-butanol, 3-methyl-1,5-pentanediol, diethylene glycol monobutyl ether (butyl carbitol), propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether, methyl glycolate, triethyl citrate, sodium lactate, and glycerol, etc.

[0040] (6-2) Surfactants

[0041] The foam fire extinguishing agent of the present invention may also contain other surfactants (nonionic surfactants, cationic surfactants) that are not classified as hydrocarbon surfactants (1) above or anionic surfactants (5) above.

[0042] Examples of nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkylphenols, polyoxyethylene alkylamines, polyoxyethylene alkylamides, polyoxyethylene fatty acid esters, propylene glycol fatty acid esters, propylene glycol fatty acid dimer polyoxyethylene lanolin ethers, aliphatic alkanolamides, polyoxyethylene castor oil, polyoxyethylene polyols, polyol fatty acid esters, and polyoxyethylene polyol fatty acid esters.

[0043] Examples of cationic surfactants include monoalkylammonium chloride, dialkylammonium chloride, EO addition ammonium chloride, tetramethylammonium chloride, and benzyltrimethylammonium chloride.

[0044] (6-3) Other

[0045] In addition, without impairing the effects of the present invention, it may also contain preservatives (e.g., preservatives obtainable from TAISHOTCHNOS Co., Ltd., Showa Denko Materials Co., Ltd., ADEKA Corporation, and Sanyo Chemical Manufacturing Co., Ltd.), freezing point depressants (e.g., lower alcohols such as isopropanol, butanol, and octanol; glycols such as ethylene glycol and propylene glycol; polyacrylamide, polyethyleneimine, urea, or various inorganic salts, etc.).

[0046] 2. Mixing ratio of each component

[0047] As described above, the foam fire extinguishing agent of the present invention is characterized by containing at least water, a hydrocarbon-based surfactant, a water-soluble polymer, a divalent metal salt, and an anionic surfactant. The mixing ratio of these essential components can be appropriately adjusted within a range that does not impair the effectiveness of the foam fire extinguishing agent of the present invention. From the viewpoint of reliably obtaining the effects of the present invention, the mixing ratio of the anionic surfactant in the foam fire extinguishing agent (total 100% by mass) is preferably 0.2% to 3.5% by mass.

[0048] In addition, the contents of hydrocarbon surfactants and water-soluble polymers in the mother liquor are preferably 8-15% by mass and 0.5-2.0% by mass, respectively, with the remainder being water (total 100% by mass).

[0049] Thus, the foam fire extinguishing agent of the present invention, even when formulated without fluorine-based compounds, possesses excellent heat resistance that is currently difficult to achieve, and other properties are also good. In addition, the raw materials are readily available.

[0050] Example

[0051] 1. Preparation of foam extinguishing agents

[0052] Mix the components shown in Table 1 at the mixing ratios shown in Tables 1 and 2 (total 100% by mass).

[0053] [Table 1]

[0054]

[0055] 2. Evaluation Test

[0056] The foam extinguishing agent obtained as described above was diluted with water to a volume percentage of 6% to prepare a foam aqueous solution. For each foam aqueous solution sample, a benchtop fire extinguishing test was conducted according to the following procedure, and the results are shown in Table 2.

[0057] (1) Add 200ml of isopropanol (IPA) to the tray with the top opening and then ignite it.

[0058] (2) After 2 minutes from ignition, use a mixer to make the foamy aqueous solution foam, scoop it out with a spoon and put it into a tray.

[0059] (3) Continuously add foam extinguishing agent until the fire is extinguished, and confirm the time and amount added until the fire is extinguished.

[0060] [Table 2]

[0061]

[0062] As shown in Table 2, the foam extinguishing agent of this invention, when containing anionic surfactant (sodium alkyl sulfate) in addition to divalent metal salts, rapidly exerts its extinguishing ability on water-soluble fuels with a small dosage (the mixing ratio of anionic surfactant in the foam extinguishing agent (total mass%) is 0.2% to 3.5% by mass). Specifically, at a dosage of 1.0% to 3.0% by mass, a good balance is achieved between short extinguishing time and low dosage. However, if turbidity occurs, the foaming ratio decreases, and the nozzle is prone to clogging when the foam extinguishing agent is sprayed from the nozzle, which is undesirable.

[0063] Furthermore, when MgCl2 was used as a salt of a divalent metal, the same results were obtained. Therefore, it can be concluded that not only CaCl2, but also MgCl2 is preferred.

Claims

1. A foam fire extinguishing agent that does not contain organofluorine compounds, characterized in that, It contains: water, hydrocarbon surfactants, water-soluble polymers, divalent metal salts, and anionic surfactants.

2. The foam extinguishing agent as described in claim 1, characterized in that, The anionic surfactant is sodium alkyl sulfate.

3. The foam extinguishing agent as described in claim 1, characterized in that, The concentration of the anionic surfactant in the foam extinguishing agent is 0.2% to 3.5% by mass.

4. The foam extinguishing agent as described in claim 1, characterized in that, The salt of the divalent metal is a Ca salt or a Mg salt.

5. The foam extinguishing agent as described in claim 4, characterized in that, The Ca salt or the Mg salt is CaCl2 or MgCl2.

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