Aqueous solution covering oil surface, and extinction agent using the same

Abstract

To provide an aqueous solution capable of covering an oil surface, while avoiding use of PFAS.SOLUTION: Provided is an aqueous solution containing silicone-based surfactants as effective ingredients for covering an oil surface. This aqueous solution can further contain hydrocarbon-based surfactants as effective ingredients. Additionally, it is preferable that the silicone-based surfactants are non-reactive silicone oil side-chain type polyether-modified surfactants, blended in an amount of 1 to 40 wt.%.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an aqueous solution for covering an oil surface, and a fire extinguishing agent using this aqueous solution. [Background technology]

[0002] Foam extinguishing agents include protein foam extinguishing agents, synthetic surfactant foam extinguishing agents, and aqueous film-forming foam extinguishing agents. Furthermore, extinguishing agents for fire extinguishers include powder-based extinguishing agents, liquid-based extinguishing agents, and gas-based extinguishing agents. For aqueous film-forming foam extinguishing agents and mechanical foam extinguishing agents among the liquid extinguishing agents for fire extinguishers, the Japan Fire Equipment Inspection Association has published detailed inspection regulations, and the detailed inspection regulations for foam extinguishing agents, Chapter 1, "Implementation policy of the standard," Section 3, "Aqueous film-forming test," describes aqueous film formation and aqueous film-forming test methods, and for detailed inspection regulations for fire extinguisher extinguishing agents, Chapter 1, "Implementation policy of the standard," Section 5, "Mechanical foam extinguishing agents," 2, "Performance of mechanical foams," (2), "Aqueous film formation," describes aqueous film formation and aqueous film-forming test methods.

[0003] In these extinguishing agents, PFAS (perfluoroalkyl substances) are generally blended into the agent to form an aqueous film. Here, PFAS is a general term for organic fluorine compounds. In this specification, aqueous film means "an aqueous film that flows over and covers the oil surface."

[0004] The following Patent Document 1 describes a foam fire extinguishing agent that uses PFAS in combination with a polymer compound, a hydrocarbon surfactant, etc. This technology is said to be able to form an aqueous film by including PFAS.

[0005] PFAS has hydrophobic and hydrophilic groups, and because the intermolecular forces of the hydrophobic groups are weak, it has a lower surface tension than surfactants that do not contain fluorine. Therefore, adding a small amount of PFAS to inks and paints can significantly reduce the surface tension. This is effective in improving wettability and reducing pinholes. In addition, due to its wettability, it is applied to glass and plastic parts such as the lenses of glasses, goggles, and face shields, and used as an anti-fog agent. In addition, because it has a water-repellent effect after drying, it is also used as an anti-fog agent for windshields, including vehicle windshields.

[0006] Thus, PFAS have been used in a wide range of applications due to their excellent performance. PFAS are chemically stable substances, so they are hardly decomposed in nature. In particular, among the PFAS used in foam fire extinguishing agents, PFOS (perfluorooctane sulfonate) and PFOA (perfluorooctanoic acid) are subject to restrictions on use or require strict management due to their properties of being difficult to decompose, highly accumulating, and long-distance mobile. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Special Publication No. 6-2169 Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention has been made in view of the above-mentioned circumstances. An object of the present invention is to provide an aqueous solution that can cover an oil surface while avoiding the use of PFAS. [Means for solving the problem]

[0009] The aqueous solution for covering an oily surface according to the present invention contains a silicone surfactant as an active ingredient. This aqueous solution preferably further contains a hydrocarbon surfactant as an active ingredient. This aqueous solution can be foamed into bubbles and placed on the oily surface. Effect of the Invention

[0010] By using the aqueous solution of the present invention, the oil surface can be covered with the aqueous solution. Here, since the aqueous solution of the present invention does not contain fluorine (i.e., does not use PFAS), the burden on the human body, living organisms, and the environment can be greatly reduced. Therefore, it can also contribute to the SDGs (Sustainable Development Goals). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] As the silicone surfactant in the present invention, for example, a non-reactive silicone oil side chain type polyether modified surfactant can be used, preferably a polyether modified siloxane, and more preferably a polyether modified organosiloxane.

[0012] The hydrocarbon surfactant in the present invention includes hydrocarbon anionic surfactants, hydrocarbon amphoteric surfactants, hydrocarbon nonionic surfactants, and hydrocarbon cationic surfactants, and hydrocarbon anionic surfactants and hydrocarbon amphoteric surfactants are particularly effective.

[0013] The hydrocarbon anionic surfactant must be one that does not inhibit the formation of an aqueous foam film in order to form an aqueous solution that covers the oil surface. Examples of such surfactants include alkyl ether sulfates, alpha olefin sulfonates, alkyl benzene sulfonic acids and their salts, alkyl sulfates, ether sulfonates, ether carboxylates, sulfosuccinates, methyl taurates, and alaninates and their salts.

[0014] The hydrocarbon amphoteric surfactant must be one that does not inhibit the formation of an aqueous foam film in order to form an aqueous solution that covers the oil surface, and examples of such surfactants include alanine type, imidazolinium betaine type, aminopropyl betaine type, and aminodipropione type. Preferably, imidazolinium betaine type is used.

[0015] The hydrocarbon nonionic surfactant must be one that does not inhibit the formation of an aqueous foam film in order to form an aqueous solution that covers the oil surface, and examples of such surfactants include polyoxyethylene alkyl ether type, polyoxyethylene alkylphenol type, polyoxyethylene alkylamine type, polyoxyethylene alkylamide type, polyoxyethylene fatty acid ester type, propylene glycol fatty acid ester type, propylene glycol fatty acid dipolyoxyethylene lanolin ether type, aliphatic alkanolamide type, polyoxyethylene castor oil type, polyoxyethylene polyhydric alcohol type, polyhydric alcohol fatty acid ester type, polyoxyethylene polyhydric alcohol fatty acid ester type, etc. Here, the aqueous foam film means "an aqueous film that flows over the oil surface and covers the oil surface" and / or "an aqueous film containing air bubbles that flows over the oil surface and covers the oil surface".

[0016] The hydrocarbon cationic surfactant must be one that does not inhibit the formation of an aqueous foam film in order to form an aqueous solution that covers the oil surface. Examples of such surfactants include monoalkyl ammonium chloride, dialkyl ammonium chloride, EO-added ammonium chloride, tetramethyl ammonium chloride, and benzyl trimethyl ammonium chloride.

[0017] The aqueous solution according to the present invention may be used in combination with water-soluble organic solvents, alcohols, flame retardants, fire retardants, fatty acids, metal soaps, water-soluble inorganic metal salts, water-soluble polymers, thickeners, polysaccharides, dispersants, etc. as necessary. In addition, a pH adjuster, etc. may be used. In particular, flame retardants and fire retardants have the effect of enhancing the flame retardant performance (fire extinguishing performance) of the aqueous solution.

[0018] Examples of the water-soluble organic solvent include cellosolve-based solvents (methyl cellosolve, ethyl cellosolve, butyl cellosolve, etc.), carbitols (ethyl carbitol, butyl carbitol, etc.), polyoxyethylene lower alkyl ethers having an added mole number of ethylene oxide of 3 to 10, glycols (ethylene glycol, diethylene glycol, propylene glycol, etc.), etc. Examples of the alcohols include polyhydric alcohols such as glycerin, oleyl alcohol, lauryl alcohol, myristyl alcohol, stearyl alcohol, cetanol, etc.

[0019] Examples of the flame retardant include halogen-based flame retardants (tetrabromobisphenol A, halogen-containing polyphosphate, etc.), phosphorus-based flame retardants (phosphate ester, ammonium phosphate, tricresyl phosphate, diethyl phosphite, etc.), inorganic flame retardants (red phosphorus, tin oxide, antimony trioxide, etc.), etc. Examples of the flame retardant include guanidine (guanidine sulfamate, guanidine phosphate, etc.), urea, ammonia, etc.

[0020] The fatty acids may be straight-chain or branched, natural or synthetic, saturated or unsaturated, and include, for example, caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, beef tallow fatty acid, oleic acid, hardened castor fatty acid, linoleic acid, palmitoleic acid, linolenic acid, etc. Examples of metal soaps include potassium soap, sodium soap, calcium soap, iron soap, aluminum soap, etc.

[0021] Examples of water-soluble inorganic metal salts include sodium salts (sodium sulfate, sodium chloride, etc.), potassium salts (potassium sulfate, potassium chloride, etc.), magnesium salts (magnesium sulfate, magnesium chloride, etc.), and calcium salts (calcium sulfate, calcium chloride, etc.).

[0022] Examples of water-soluble polymers include cellulose derivatives (methyl cellulose, hydroxyethyl cellulose, etc.), polyvinyl alcohol, polyvinyl ether, polyethylene glycol, etc. Examples of thickeners include sodium alginate, sodium carboxymethyl cellulose, etc. Examples of polysaccharides include xanthan gum, gellan gum, etc.

[0023] Examples of the dispersant include naphthalenesulfonic acid-based, alkylnaphthalenesulfonic acid-based, polycarboxylic acid-based, polystyrenesulfonic acid-based, alkylamine-based, and alkylphenol-based dispersants.

[0024] Examples of pH adjusters include amines (monoethanolamine, diethanolamine, triethanolamine, etc.), sodium tetraborate, sodium hydroxide, potassium hydroxide, citric acid, acetic acid, sulfuric acid, nitric acid, and hydrochloric acid.

[0025] The aqueous solution of the present invention can be used as a fire extinguishing agent such as a foam fire extinguishing agent or a liquid fire extinguisher agent. This aqueous solution can be used as is, or it can be diluted at any ratio with a suitable medium such as groundwater, tap water, seawater, or ion-exchanged water. However, in order to generate an aqueous foam film, it is preferable that the concentration of the silicon-based surfactant in the diluted aqueous solution is in the range of 1 to 40 weight percent.

[0026] In addition, for preparing this aqueous solution, an aqueous medium such as groundwater, tap water, seawater, or ion-exchanged water can be used. EXAMPLES

[0027] The effects of the present invention will be specifically described below with reference to examples, but the present invention is not limited thereto.

[0028] <Examples 1 to 6> <Comparative Examples 1 to 4> In Examples 1 to 6, "KF-644" (trade name) manufactured by Shin-Etsu Chemical Co., Ltd. was used as a polyether-modified siloxane as a non-reactive silicone oil side chain type polyether modification, which is a type of silicon-based surfactant, "EMAL TD", "EMAL 125HP", and "EMAL E-27C" (trade names) manufactured by Kao Corporation were used as a hydrocarbon-based anionic surfactant, and "Obazoline LB-SF" (trade name) manufactured by Toho Chemical Industry Co., Ltd. was used as a hydrocarbon-based amphoteric surfactant as a hydrocarbon-based surfactant. In addition, an aqueous solution was prepared using ion-exchanged water according to the composition shown in Table 1.

[0029] After preparing the aqueous solution, the state of the aqueous solution, foaming property, and the diffusibility of the aqueous foam film (i.e., whether or not an aqueous foam film spreading on the oil surface is generated) were observed. As described above, an aqueous foam film means "an aqueous film that flows on the oil surface and covers the oil surface" and / or "an aqueous film containing air bubbles that flows on the oil surface and covers the oil surface."

[0030] The state of the aqueous solution was visually observed. Foamability was confirmed by placing 30 mL of the aqueous solution in a 100 mL container and shaking it at least 20 times to create foam. The diffusivity of the aqueous foam film was observed by pouring 3 mL of foamed aqueous solution into one side of a Φ10 cm x h2 cm petri dish containing 50 mL (20±2°C) of Kanto Chemical Co., Ltd.'s special grade cyclohexane. In order to confirm the aqueous foam film, a coloring agent, "Indigo Carmine" (blue colorant: product name) manufactured by Tokyo Chemical Industry Co., Ltd., was diluted to 20%, and 10 drops of the solution were added to the test liquid to confirm.

[0031] As Comparative Example 1, a similar test was conducted using "Capstone 1157" (a surfactant using PFAS: product name) manufactured by Chemours Corporation and "Obazoline LB-SF" (an amphoteric surfactant) manufactured by Toho Chemical Industry Co., Ltd., in the formulation shown in Table 2. As Comparative Example 2, "Surf Water III" (a product using PFAS: product name) manufactured by Nippon Dry Chemical Co., Ltd., which is a commonly sold aqueous film-forming foam fire extinguishing agent, was diluted to 3% by volume and a similar test was conducted. As Comparative Examples 3 and 4, tests were conducted at high concentrations using "KF-644" manufactured by Shin-Etsu Chemical Co., Ltd.

[0032] (Terminology explanation) Aqueous solution state: "Cloudy solution": A cloudy aqueous solution "Transparent liquid" Transparent aqueous solution Foaming: "Good": Expands 4 times or more "Slightly good": foams 2 to 4 times "No foaming" - Almost no foaming w%: weight percent v%: volume percent Incidentally, only Surfwater III (Comparative Example 2) was blended in volume percent, and the rest were all blended in weight percent.

[0033] [Table 1]

[0034] [Table 2]

[0035] From the above results, it can be seen that the diluted solution of the silicone surfactant becomes a cloudy solution (Examples 1 to 3), but has good foaming properties, and can form an aqueous foam film (i.e., a film) on the oil surface at a concentration of 40% or less. However, it can be seen that there is almost no foaming property when the concentration of the silicone surfactant is 50% or more (Comparative Examples 3 and 4).

[0036] In addition, it was found that by combining a silicone surfactant and a hydrocarbon surfactant, the aqueous solution was not cloudy, had good foaming properties, and could produce an aqueous foam film (Examples 4 to 6).

[0037] As can be seen from the above, when the aqueous solution of the present invention is used as an aqueous film-forming foam extinguishing agent in a foam extinguishing agent, or as a mechanical foam extinguishing agent in a liquid extinguishing agent in a fire extinguisher, it is expected to be able to produce an aqueous foam film well and exhibit high fire extinguishing capabilities.

Claims

1. An aqueous solution for coating an oily surface, comprising a silicone surfactant as an active ingredient.

2. 2. The aqueous solution according to claim 1, further comprising a hydrocarbon surfactant as an active ingredient.

3. 3. The aqueous solution according to claim 1, wherein the silicone surfactant is a non-reactive silicone oil side chain type polyether modified surfactant blended in the aqueous solution in an amount of 1 to 40 weight percent.

4. The aqueous solution according to claim 2 , wherein the hydrocarbon surfactant is a hydrocarbon anionic surfactant and / or a hydrocarbon amphoteric surfactant.

5. 3. A method for forming a film on an oil surface, comprising the steps of: forming the aqueous solution according to claim 1 into bubbles; and placing the aqueous solution in the bubbly state on the oil surface to cover the oil surface with the aqueous solution.

6. A fire extinguishing agent comprising the aqueous solution according to claim 1 or 2.

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