Fire-fighting foam composition

Abstract

A fire-fighting composition includes a sugar component comprising a monosaccharide sugar, a disaccharide sugar, a sugar alcohol, or a combination of any two or more thereof; a surfactant component comprising an anionic surfactant, a zwitterionic surfactant, a nonionic surfactant, or a combination of any two or more thereof; a water-miscible organic solvent; and at least about 30 wt.% water, where the composition is substantially free of a polysaccharide thickener; and wherein the aqueous fire-fighting foam composition exhibits: a PFAS content that is non-detectable; or a maximum viscosity at 5⁰C of 300 centistokes; or a minimum biodegradability, BOD20 / COD, of 0.65; or any two or more thereof.

Description

FIRE-FIGHTING FOAM COMPOSITIONCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority to U.S. Provisional Application No. 63 / 567,722, filed March 20, 2024, the contents of which are incorporated herein by reference in their entirety.TECHNOLOGY

[0002] This application is generally directed to firefighting foams and more specifically to foams that do not include thickener.BACKGROUND

[0003] Firefighting foams are often deployed to suppress or extinguish Class B fires. Class B fires are those involving flammable liquid fuels, gasoline, and other hydrocarbons and are difficult to extinguish. Most flammable liquids exhibit high vapor pressure along with low fire and flash points. This typically results in a wide flammability range. In this type of fire, the use of water as the sole firefighting agent is generally ineffective because the only means of fighting fire with water is through cooling and the hydrophobic nature of the liquids involved may result in the water spreading the fuel around rather than extinguishing the fire.

[0004] Conventional foam-forming firefighting compositions commonly include fluorinated and perfluorinated surfactants. Environmental concerns related to fluorinated and perfluorinated surfactants have developed. As a result, there is a strong desire in the marketplace to replace fluorinated and perfluorinated firefighting products with nonfluorinated products. There is therefore a continuing need to produce fluorine-free AFFF firefighting compositions that can be deployed to effectively fight and suppress Class B fires.SUMMARY

[0005] The present application is directed to aqueous fire-fighting compositions, typically in the form of foam concentrates, which can be diluted with an aqueous diluent toprovide a foam precursor composition. The more dilute foam precursor composition can be aerated to form a firefighting foam, which may be used to suppress vapors and / or fight a fire. The compositions may be particularly advantageous for use in forming foam to fight and / or suppress hydrocarbon or volatile solvent fires (e.g., Class B fires).

[0006] In one aspect, an aqueous fluorine-free, fire-fighting foam composition is provided, which includes a sugar component comprising a monosaccharide sugar, a disaccharide sugar, a sugar alcohol, or a combination of any two or more thereof; a surfactant component comprising an anionic surfactant, a zwitterionic surfactant, a nonionic surfactant, or a combination of any two or more thereof; a water-miscible organic solvent; and at least about 30 wt.% water. Such a composition is substantially free of, and in many instances does not contain, a polysaccharide thickener. The aqueous fire-fighting foam composition exhibits: a per- and polyfluoroalkyl substances (PFAS) content that is non-detectable; or a maximum viscosity at 5°C of 300 centistokes; or a minimum biodegradability,of 0.65;or any two or more thereof.

[0007] In some embodiments, the aqueous fire-fighting foam composition exhibits: a pH of 6.5 to 9.0; or a minimum refractive index of 1.36; or a maximum variation of surface tension of 15%; or a maximum variation of interfacial tension of 75%; or a minimum foam expansion of 7.0; a minimum foam 25% drainage time of 3.5 minutes; a maximum corrosion rate for cold-rolled, low carbon steel (UNS G10100) of 0.5 milli-inch / year; or a maximum corrosion rate for brass (UNS C46400) of 1.0 milli-inch / year; or a maximum corrosion rate for bronze (UNS C90500) of 100 milligrams; or a maximum corrosion rate for copper-nickel (90-10) (UNS C70600) of 1.0 milli-inch / year; or a maximum corrosion rate for nickel-copper (70-30) (UNS N04400) of 1.0 milli-inch / year; or no pits in corrosion-resistant steel (CRES) (UNS S30400 and S31600); or a minimum aquatic acute toxicity, LC50, of 30 mg / mL; or a maximum chemical oxygen demand (COD) of 900K mg / L; or no visible stratification; or a maximum precipitation of 0.10 vol%; or any two or more thereof. In some embodiments, the aqueous fire-fighting foam compositions described herein exhibit three or more of the listed attributes. In some embodiments, the aqueous fire-fighting foam compositions described herein exhibit all of the listed attributes.

[0008] In some embodiments, an unaged full-strength aqueous fire-fighting foam composition exhibits: a maximum extinguishing time for a 28-ft2jet A fuel fire of 30 seconds; or a maximum extinguishing time for a 28-ft2gasoline fire of 60 seconds; or a maximum extinguishing time for a 50-ft2jet A fuel fire of 60 seconds; or a minimum burnback time for a 28-ft2jet A fuel fire of 300 seconds; or a minimum bumback time for a 28-ft2gasoline fire of 240 seconds; or a minimum burnback time for a 50-ft2jet A fuel fire of 270 seconds; or any two or more thereof; an unaged half-strength aqueous fire-fighting foam composition exhibits: a maximum extinguishing time for a 28-ft2jet A fuel fire of 30 seconds; or a minimum burnback time for a 28-ft2jet A fuel fire of 300 seconds; or any two or more thereof; an unaged double-strength aqueous fire-fighting foam composition exhibits: a maximum extinguishing time for a 28-ft2jet A fuel fire of 30 seconds; or a minimum burnback time for a 28-ft2jet A fuel fire of 300 seconds; or any two or more thereof; an aged full-strength aqueous fire-fighting foam composition exhibits: a maximum extinguishing time for a 28-ft2jet A fuel fire of 30 seconds; or a maximum extinguishing time for a 28-ft2gasoline fire of 60 seconds; or a minimum bumback time for a 28-ft2jet A fuel fire of 300 seconds; or a minimum burnback time for a 28-ft2gasoline fire of 240 seconds; or any two or more thereof; an aged half-strength aqueous fire-fighting foam composition exhibits: a maximum extinguishing time for a 28-ft2jet A fuel fire of 30 seconds; or a minimum burnback time for a 28-ft2jet A fuel fire of 300 seconds; or any two or more thereof. In some embodiments, the aqueous fire-fighting foam compositions described herein exhibit three or more of the listed attributes. In some embodiments, the aqueous fire-fighting foam compositions described herein exhibit all of the listed attributes.

[0009] In some embodiments, the aqueous fire-fighting foam composition comprises: about 5 to 25 wt.% of a sugar component comprising a monosaccharide sugar, a disaccharide sugar, a sugar alcohol, or a combination of any two or more thereof; about 1 to 30 wt.% of a surfactant component comprising an anionic surfactant, a zwitterionic surfactant, a nonionic surfactant, or a combination of any two or more thereof; about 5 to 30 wt.% of a water- miscible organic solvent; and at least about 30 wt.% water.

[0010] In some embodiments, the sugar component comprises glucose, fructose, mannose, xylose, sucrose, lactose, maltose, trehalose, lactulose, cellobiose, chitobiose,xylitol, sorbitol, mannitol, or a combination of any two or more thereof. In some embodiments, the sugar component comprises fructose, sucrose, sorbitol, or a combination of any two or more thereof.

[0011] In some embodiments, the anionic surfactant comprises an aliphatic sulfate surfactant, an aliphatic sulfonate surfactant, an aliphatic succinate salt, an aliphatic ether sulfate surfactant, or a mixture of any two or more thereof. In some embodiments, the anionic surfactant comprises Cs-C alkyl sulfate, Cs-C alkyl sulfonate, C10-C14 alkyl ether sulfate, or a mixture of any two or more thereof. In some embodiments, the anionic surfactant comprises a Cs-Ci4 alkyl sulfate, or a mixture of any two or more thereof. In some embodiments, the anionic surfactant comprises an octyl sulfate salt, a decyl sulfate salt, a lauryl sulfate salt, or a mixture of any two or more thereof. In some embodiments, the composition comprises about 5 to 20 wt.% of the anionic surfactant.

[0012] In some embodiments, the zwitterionic surfactant comprises an aliphatic amidoalkyl betaine, an aliphatic sulfobetaine, an aliphatic amidoalkyl hydroxysultaine, an aliphatic hydroxysultaine, or a mixture of any two or more thereof. In some embodiments, the zwitterionic surfactant comprises an aliphatic amidoalkyl betaine. In some embodiments, the composition comprises about 1 to 10 wt.% of the zwitterionic surfactant.

[0013] In some embodiments, the non-ionic surfactant comprises an alkyl polyglycoside, an aliphatic alcohol-based nonionic surfactant, or a mixture of any two or more thereof. In some embodiments, the nonionic surfactant comprises an alkyl polyglucoside, an aliphatic alcohol, an aliphatic alcohol ethoxylate, or a mixture of any two or more thereof. In some embodiments, the composition comprises about 1 to 10 wt.% of the nonionic surfactant.

[0014] In some embodiments, the water-miscible organic solvent comprises a triol, an alkylene glycol, an alkylene glycol monoalkyl ether, or a mixture of any two or more thereof. In some embodiments, the water-miscible organic solvent comprises glycerol, hexylene glycol, diethylene glycol monobutyl ether, or a mixture of any two or more thereof. In some embodiments, the composition comprises about 5 to 30 wt.% of the water-miscible organic solvent.

[0015] In some embodiments, the aqueous fire-fighting foam composition further comprises a corrosion inhibitor, a reducing agent, a metallic salt, a chelator, a buffer, a preservative, or a mixture of any two or more thereof.

[0016] In an aspect, provided is a method of forming a firefighting foam, the method comprising aerating a foam precursor composition comprising any one of the aqueous firefighting foam compositions described herein to form the firefighting foam.

[0017] In an aspect, provided is a method of forming a firefighting foam, the method comprising mixing any one of the aqueous fire-fighting foam compositions described herein with an aqueous diluent to form a foam precursor solution; and aerating the foam precursor solution to form the firefighting foam. In some embodiments, the aqueous diluent is selected from the group consisting of fresh water, brackish water, sea water, and a combination of any two or more thereof. In some embodiments, the aqueous diluent comprises water from a municipal water source.

[0018] In an aspect, provided is a firefighting foam comprising any one of the aqueous fire-fighting foam compositions described herein and an aqueous diluent.

[0019] In an aspect, provided is a method of fighting a fire comprising applying any one of the firefighting foams described herein to the fire.DETAILED DESCRIPTION

[0020] Various embodiments are described hereinafter. It should be noted that the specific embodiments are not intended as an exhaustive description or as a limitation to the broader aspects discussed herein. One aspect described in conjunction with a particular embodiment is not necessarily limited to that embodiment and can be practiced with any other embodiment s).

[0021] As used herein, “about” will be understood by persons of ordinary skill in the art and will vary to some extent depending upon the context in which it is used. If there are uses of the term which are not clear to persons of ordinary skill in the art, given the context in which it is used, “about” will mean up to plus or minus 10% of the particular term.

[0022] The use of the terms “a” and “an” and “the” and similar referents in the context of describing the elements (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the embodiments and does not pose a limitation on the scope of the claims unless otherwise stated. No language in the specification should be construed as indicating any non-claimed element as essential.

[0023] In one aspect, the aqueous fire-fighting foam compositions of the present disclosure include a sugar component comprising a monosaccharide sugar, a disaccharide sugar, a sugar alcohol, or a combination of any two or more thereof; a surfactant component comprising an anionic surfactant, a zwitterionic surfactant, a nonionic surfactant, or a combination of any two or more thereof; a water-miscible organic solvent; and at least about 30 wt.% water, and the compositions are substantially free of a polysaccharide thickener. Such compositions meet one or more of the fire performance criteria set in the MIL-PRF- 32725(11) fire test standard.

[0024] Saccharides for use in the present aqueous fire-fighting compositions are generally simple monosaccharide sugars and may include other carbohydrates, such as common sugar (sucrose / dextrose) derived from sugar cane or sugar beets. Sucrose is a disaccharide composed from the basic, simple sugar molecules glucose and fructose. Mixtures where the majority of the sucrose has been broken down into its monosaccharide components, glucose and fructose (e.g., invert sugar), are quite suitable for use in the present compositions. Sucrose is readily available in view of its world production from cane and sugar beet on the order of millions of tons per annum. Those skilled in the art will also be aware that other commercially available simple monosaccharides and related sugar alcohols can be utilized in the present compositions. Examples of suitable monosaccharides for use inthe present compositions include one or more of glucose, fructose, mannose, xylose and galactose. Examples of suitable disaccharides for use in the present foam compositions include one or more of sucrose, lactose, maltose, trehalose, lactulose, cellobiose, and chitobiose. Examples of suitable sugar alcohols for use in the present compositions include one or more of a four carbon sugar alcohol, such as erythritol, a five carbon alditol, such as xylitol, a six carbon alditol, such as mannitol and / or sorbitol, and other sugar alcohols, such as isomalt. Commonly, the sugar alcohol is one derived from a monosaccharide.

[0025] The present aqueous fluorine-free, fire-fighting foam compositions include a sugar component comprising a monosaccharide sugar, a disaccharide sugar, and / or a sugar alcohol. Suitable examples include a sugar component containing one or more of glucose, fructose, mannose, sucrose, lactose, maltose, trehalose, lactulose, cellobiose, chitobiose, xylose, sorbitol, xylitol and mannitol. The aqueous fire-fighting foam composition includes about 5 to 25 wt% of the sugar component. In other embodiments, the aqueous fire-fighting foam composition includes about 10 to 20 wt% of the sugar component. In some embodiments, the aqueous fire-fighting foam concentrate comprises about 5 wt.%, about 10 wt.%, about 15 wt.%, about 20 wt.%, or about 25 wt.% of the sugar component.

[0026] Illustrative anionic surfactants include an alkyl sulfate surfactant, an alkyl sulfonate surfactant, alkyl ether sulfate surfactant, an alkyl ether sulfonate surfactant, or a mixture of any two or more thereof. In some embodiments, the anionic surfactant may include an alkyl sulfate surfactant and / or an alkyl sulfonate surfactant. In some embodiments, the alkyl sulfate salt surfactant includes a Cs-i2-alkyl sulfate salt. Non-limiting examples of the Cs-i2-alkyl sulfate salt include a dodecyl sulfate salt, a decyl sulfate salt, an octyl sulfate salt, or a mixture of any two or more thereof. In some embodiments, the alkyl sulfate salt includes an alkyl sulfate sodium salt, such as a sodium decyl sulfate, sodium octyl sulfate, or a mixture of any two or more thereof. In some embodiments, the alkyl sulfate salt includes an alkyl sulfate ammonium salt, such as an ammonium decyl sulfate, ammonium octyl sulfate, ammonium lauryl sulfate, or a mixture of any two or more thereof. In some embodiments, the anionic surfactant includes a Cx-14-alkyl sulfate salt and / or a Cx-14-alkyl sulfonate salt. In some embodiments, the firefighting composition further includes an anionic surfactant, which comprises one or more surfactants selected from Cs-i2-alkyl sulfate saltsand / or a Cs-i2-alkyl sulfonate salts. As a non-limiting example, one or more of octyl sulfate salts, decyl sulfate salts, dodecyl sulfate salts and tetradecyl sulfate salts may be used as anionic surfactants in the present firefighting compositions. In some embodiments, the aqueous fire-fighting foam concentrates include about 2 to 25 wt% of the anionic surfactant. In some embodiments, the aqueous firefighting foam concentrates include about 2 to 20 wt%, about 2 to 15 wt%, or about 5 to 20 wt% of the anionic surfactant.

[0027] Illustrative zwitterionic surfactants include an alkylamidoalkyl betaine surfactant, an alkyl betaine surfactant, an alkyl sulfobetaine surfactant, an alkylamidoalkylene hydroxysultaine surfactant, such as an alkylamidopropyl hydroxysultaine surfactant, or a mixture of two or more thereof. As a non-limiting example, the firefighting composition includes a zwitterionic surfactant, which comprises one or more of a Cs-is-alkylamidopropyl hydroxysultaine surfactant, a Cs-is-alkylamidopropyl betaine surfactant, a Cs-is-alkyl sulfobetaine surfactant, a Cs-is-alkyl betaine surfactant, or a mixture of two or more thereof. Non-limiting examples of the alkyl amidoalkylene hydroxysultaine surfactant include a Cs-is- alkylamidopropyl hydroxysultaine surfactant, such as a cocamidopropyl hydroxysultaine surfactant, which includes a lauryl amidopropyl hydroxysultaine and a myristyl amidopropyl hydroxysultaine. Non-limiting examples of the alkylamidoalkyl betaine surfactant include a Cs-is-alkylamidoalkyl betaine surfactant, such as a cocamidopropyl betaine, a tallowamidopropyl betaine, a lauryl amidopropyl betaine or a myristyl amidopropyl betaine. In some embodiments, the zwitterionic surfactant includes a Cx-14-alkylamidopropyl hydroxysultaine, such as a cocamidopropyl hydroxysultaine. In some embodiments, the zwitterionic surfactant includes lauryl amidopropyl hydroxysultaine and / or myristyl amidopropyl hydroxysultaine. In some embodiments, the aqueous firefighting foam composition includes about 2 to 15 wt.% of the zwitterionic surfactant. In some embodiments, the aqueous firefighting foam composition includes about 5 to 15 wt.% of the zwitterionic surfactant.

[0028] Illustrative non-ionic surfactants include an alkyl polyglycoside, an aliphatic alcohol-based nonionic surfactant, or a mixture thereof. In some embodiments, the non-ionic surfactant comprises an alkyl polyglucoside, an aliphatic alcohol, an aliphatic alcohol ethoxylate, or a mixture of two or more thereof. A suitable alkyl polyglucoside for use as anon-ionic surfactant includes a Cs-i6 alkyl polyglucoside. In some embodiments, the alkyl polyglucoside is a Cs-alkyl polyglucoside. As a non-limiting example, the fire-fighting compositions may include an aliphatic alcohol-based nonionic surfactant including an aliphatic alcohol having 8 to 14 carbon atoms and / or an aliphatic alcohol ethoxylate having 10 to 16 carbon atoms in its alcohol portion. The aliphatic alcohol ethoxylate may has an average degree of polymerization (i.e., the average number of ethylene oxide units) of about 0.7-2.0 and often of no more than about 1.5, no more than about 1.2, or no more than about 1.0. Aliphatic alcohols, which include a linear Cs-u-aliphatic alcohol, such as a Cs-u-fatty alcohol, may be used as a nonionic surfactant in the present firefighting compositions. Nonlimiting examples of such alcohols include one or more of octyl alcohol, decyl alcohol, lauryl alcohol and myristyl alcohol. The firefighting composition may include an aliphatic alcohol ethoxylate having an average of no more than about 2 ethylene oxide units. In some embodiments, the aliphatic alcohol portion of such ethoxylates has about 10 to 16 carbon atoms. Non-limiting examples include decyl alcohol ethoxylates, lauryl alcohol ethoxylates and / or myristyl alcohol ethoxylates. In some embodiments, the alcohol ethoxylates have an average of no more than about 2 ethylene oxide units, no more than about 1.5 ethylene oxide units, no more than about 1.2 ethylene oxide units and, in some instances, no more than about 1 ethylene oxide units. In some embodiments, the aliphatic alcohol ethoxylate comprises an ethoxylate of a linear Cs-u-aliphatic alcohol having no more than about 1.2 ethylene oxide units.

[0029] In some embodiments, the aqueous fire-fighting foam composition includes about 1 to 15 wt% of the non-ionic surfactant. In some embodiments, the aqueous firefighting foam composition includes about 1 to 10 wt%, about 3 to 10 wt%, or about 5 to 10 wt% of the non-ionic surfactant. In some embodiments, the aqueous fire-fighting foam compositions include about 1 wt%, about 3 wt%, about 5 wt%, about 10 wt%, or about 15 wt% of the non-ionic surfactant.

[0030] The water miscible organic solvent may suitably include one or more of a glycol, a glycol ether, glycerin (i.e., glycerol) and a water-soluble polyethylene glycol. Examples of suitable water miscible organic solvents include diethylene glycol n-butyl ether, dipropylene glycol n-propyl ether, hexylene glycol, ethylene glycol, propylene glycol,diethylene glycol, dipropylene glycol, tripropylene glycol, dipropylene glycol monobutyl ether, dipropylene glycol monomethyl ether, diethylene glycol monobutyl ether, ethylene glycol monobutyl ether, tripropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, glycerol, and mixtures of two or more thereof. In some embodiments, the water miscible organic solvent includes a mixture of an alkylene glycol and a glycol ether, such as a glycol butyl ether. In some embodiments, the water miscible organic solvent includes an alkylene glycol ether, such as ethylene glycol monoalkyl ether, propylene glycol monoalkyl ether, dipropylene glycol monoalkyl ether, and / or diethylene glycol monoalkyl ether. In some embodiments, the water miscible organic solvent includes an alkylene glycol, such as ethylene glycol, propylene glycol, dipropylene glycol and / or di ethylene glycol. In some embodiments, the water miscible organic solvent may include a mixture of a glycol ether, such as diethylene glycol monobutyl ether, and a glycol, such as ethylene glycol and / or propylene glycol. For example, the water miscible organic solvent can include ethylene glycol and diethylene glycol monobutyl ether. In another suitable example, the water miscible organic solvent includes propylene glycol and diethylene glycol monobutyl ether.

[0031] The foam compositions may include about 1 to about 20 wt.% of the water miscible organic solvent. This may include from about 1 to about 20 wt.%, about 1 to about 15 wt.%, or about 1 to about 10 wt.% of the water miscible organic solvent. In many embodiments, the aqueous firefighting foam composition includes a water miscible organic solvent including one or more of an alkylene glycol, glycerol, and a glycol ether. The alkylene glycol typically includes propylene glycol and / or ethylene glycol. The glycol ether typically includes ethylene glycol monoalkyl ether, diethylene glycol monoalkyl ether, dipropylene glycol monoalkyl ether, triethylene glycol monoalkyl ether, and 1-butoxyethoxy- 2-propanol. In some embodiments, the water miscible organic solvent may be a mixture of an alkylene glycol and a glycol ether. In some embodiments, the water miscible organic solvent may be a mixture of glycerin and a glycol ether. In some embodiments, the water miscible organic solvent may be a mixture of propylene glycol and a glycol ether. In such embodiments, the water miscible organic solvent includes the alkylene glycol and glycol ether in a weight ratio of about 0.1:1 to about 10:1 or about 0.2:1 to about 5:1. In some embodiments, the water miscible organic solvent may be a mixture of glycerin and diethylene glycol monobutyl ether. In some embodiments, the water miscible organic solvent mayinclude about 1 to about 20 wt.% or about 1 to about 15 wt.% of alkylene glycol, such as ethylene glycol, or glycerin together with about 1 to about 15 wt.% or about 1 to about 10 wt.% of a glycol ether, such as diethylene glycol monobutyl ether.

[0032] In some embodiments, the present aqueous firefighting foam composition may include an alkanolamine, which can act as a pH adjusting agent and / or buffer. Suitable alkanolamines comprise monoethanolamine, diethanolamine, diisopropanolamine, and / or triethanolamine. In some embodiments, any one of the compositions described herein includes triethanolamine. The triethanolamine may be present in only a relatively small amount, e.g., about 0.1 to 0.3 wt.% when included primarily as a pH adjusting agent. In other instances, the alkanolamine may be present in a higher amount, whether introduced per se as an ingredient and / or in the form of a cation as part of one of the surfactants present in the composition. In such instances, an alkanolamine, such as triethanolamine, may suitably be present as about 2 to 10 wt.%, about 3 to 10 wt.%, about 3 to 8 wt.%, and in some instances, about 3 to 7 wt.% of the composition.

[0033] As discussed above, the aqueous firefighting foam composition includes water. In some embodiments, the water is water from a municipal water source (e.g., tap water). In some embodiments, the water is a purified water, such as purified water that meets the standards set forth in the United States Pharmacopeia, which is incorporated by reference herein in relevant part. In some embodiments, the aqueous firefighting foam composition includes at least about 30 wt.% water, often at least about 40 wt.% water and, more commonly, at least about 50 wt.% water. In some embodiments, the aqueous firefighting foam composition includes greater than about 60 wt.% water. In some embodiments, the aqueous firefighting foam composition may be produced using a source of water that has a total concentration of fluorine atoms on a weight percentage basis of no more than about 1 ppm F. In further embodiments, the aqueous firefighting foam composition may be produced using a source of water that has an amount of fluorine that is below detection limits.

[0034] The present aqueous firefighting foam compositions may be substantially free of any fluorinated compounds. As used herein, the “phrase substantially free of fluorinated compounds” means that the aqueous firefighting foam composition includes no more than 0.1 wt% fluorinated compounds. In some embodiments, the aqueous firefighting foamcomposition includes no more than 0.01 wt% and, in some instances, no more than about 0.005 wt% fluorinated compounds. The aqueous firefighting foam composition may be substantially free of fluorine in any form. As used herein, the phrase “substantially free of fluorine” means that the aqueous firefighting foam concentrate has a total concentration of fluorine atoms on a weight percentage basis of no more than about 1 ppm F. In some embodiments, the aqueous firefighting foam composition has a total concentration of fluorine atoms of less than 0.01 wt.%. In some embodiments, the aqueous firefighting foam composition has a total concentration of fluorine atoms of less than 0.005 wt.%. In some embodiments, the aqueous firefighting foam composition has a total concentration of fluorine atoms on a weight percentage basis of no more than about 70 parts per trillion (ppt) F. The aqueous firefighting foam composition may include substantially less than 70 ppt F. In some embodiments, the total concentration of fluorine in the aqueous firefighting foam composition is below detection limits.

[0035] In any of the above embodiments, the aqueous firefighting foam composition includes one or more chelators or sequestering buffers. Illustrative and non-limiting chelators and sequestering buffers include agents that sequester and chelate metal ions, including polyaminopolycarboxylic acids, ethylenediaminetetraacetic acid, citric acid, tartaric acid, nitrilotriacetic acid, hydroxyethylethylenediaminetriacetic acid and salts thereof. Illustrative buffers include Sorensen's phosphate or Mcllvaine's citrate buffers.

[0036] In any of the above embodiments, the aqueous firefighting foam composition includes one or more corrosion inhibitors. Illustrative and non-limiting corrosion inhibitors includes ortho-phenylphenol, tolyltriazole, and phosphate ester acids. In some embodiments, the corrosion inhibitor is tolyltri azole.

[0037] In any of the above embodiments, the aqueous firefighting foam composition may also include a metallic salt, typically a metallic salt, which includes a multi-valent cation. For example, suitable salts may include a cation selected from the group consisting of aluminum, calcium, copper, iron, magnesium, potassium, and calcium cations. The counter anion may suitably be a sulfate, bicarbonate, and / or phosphate anion. In one embodiment, the metallic salt may include magnesium sulfate. In some embodiments, the metallic salt includes potassium bicarbonate.

[0038] In any of the above embodiments, the aqueous firefighting foam composition may include a reducing agent. When present, the reducing agent may be present in the foam composition from about 0.01 wt% to about 5 wt%. This may include from about 0.01 wt% to about 3 wt%, from about 0.05 wt% to about 5 wt%, from about 1 wt% to about 5 wt%, or from about 1 wt% to about 3 wt% of the reducing agent. The reducing agent may be selected such that it is more readily oxidized compared to other components of the composition. For example, the reducing agent may be oxidized more readily than the sugar component. Illustrative reducing agents include, but are not limited to, sodium sulfite, sodium bisulfite, sodium metabisulfite, or a mixture of any two or more thereof.

[0039] In any of the above embodiments, the aqueous firefighting foam composition may also include a preservative, such as one or more antimicrobial compounds and / or biocidal compounds. Examples include Kathon CG / ICP (Rohm & Haas Company), Givgard G-4 40 (Givaudan, Inc.), Dowicil 75, and Dowacide A (Dow Chemical Company).

[0040] In any of the above embodiments, the aqueous firefighting foam composition may further include microfibrous cellulose. The microfibrous cellulose included in the aqueous firefighting foam compositions may include microfibrous cellulose produced by mechanically disrupting / altering cellulose fibers, e.g., cereal, wood, and / or cotton-based cellulose fibers - commonly referred to as microfibrillated cellulose (MFC). Microfibrillated cellulose can be obtained through a fibrillation process of cellulose fibers. In such a process, the mechanical shearing can strip away the outer layer of the cellulose fibers, exposing the fibril bundles. The macroscopic fibers are typically mechanically sheared until the fibrils are released, resulting in separation of the cellulose fibers into a three dimensional network of microfibrils with a very large surface area. The exposed fibrils are much smaller in diameter compared to the original fibers and can form a network or a web-like structure.

[0041] An illustrative and non-limiting example of microfibrillated cellulose is Exilva™ microfibrillated cellulose (available from Borregaard, Sarpsborg, Norway). Exilva™ microfibrillated cellulose is a pre-activated product, available as a 2% suspension or a 10% paste, that is produced from mechanically disrupting cellulose sourced from Norway spruce. Exilva™ microfibrillated cellulose is reported to be an insoluble microfibrillated cellulose consisting of an entanglement of the cellulose fibers, which has the ability tointeract both physically through its extreme surface area and chemically through hydrogen bonding. Other commercial sources of microfibrous cellulose include Celova® microfibrillated cellulose (available from Weidmann Electrical Technology AG (Rapperswil, Switzerland) and Curran® microfibrillated cellulose (available from CelluComp, Fife, Scotland). Curran® microfibrillated cellulose is produced from extraction of nanocellulose fibers from waste streams of root vegetables, primarily carrots and sugar beet pulp.

[0042] Another illustrative and non-limiting example of a source of microfibrillated cellulose for use in the present aqueous firefighting foam concentrates is microfibrillated cellulose-mineral composite commercially available from FiberLean® Technologies (Par Moor Centre, United Kingdom). The FiberLean® MFC-composite is reportedly produced by fibrillating the cellulose fibers in the presence of one of a number of different minerals, such as calcium carbonate, clay (e.g., kaolin or bentonite), alumina, zirconia, graphite, silicate or talc, to obtain a nano-fibrillar cellulose suspension.

[0043] When included in the aqueous firefighting foam composition, the microfibrous cellulose may include a fermentation-derived cellulose, such as a microfibrous cellulose derived from a microbial fermentation process. The microfibrous cellulose may include cellulose derived from a bacterial fermentation process, e.g., from fermentation of a Komagataeibacter xylinus strain or an Acetobacter xylinum strain. Fermentation-derived cellulose (FDC) produced by such a method may have an average fiber diameter of about 0.1- 0.2 pm. This very small fiber size and diameter means that a given weight of FDC can have up to 200 times more surface area than other common forms of cellulose.

[0044] The microfibrous cellulose employed in the present aqueous firefighting foam compositions may have an average fiber diameter of no more than about 10 pm, no more than about 1 pm, and in some instances about 50 to 300 nm (0.05-0.3 pm). Quite often, the microfibrous cellulose is a derived from microbial fermentation. Prior to inclusion in the aqueous firefighting foam compositions, such microbial fermentation derived cellulose may be activated by combining a powdered microfibrous cellulose and any optional co-agent with water and then mixing with high shear.

[0045] In any of the above embodiments, the aqueous fire-fighting foam composition exhibits one or more of the following properties: a pH of 6.5 to 9.0; a PF AS content that is non-detectable; a maximum viscosity at 5°C of 300 centistokes; a minimum refractive index of 1.36; a maximum variation of surface tension of 15%; a maximum variation of interfacial tension of 75%; a minimum foam expansion of 7.0; a minimum foam 25% drainage time of 3.5 minutes; or a maximum corrosion rate for cold-rolled, low carbon steel (UNS G10100) of 0.5 milli-inch / year. In some embodiments, the aqueous fire-fighting foam composition exhibits a maximum viscosity at 5°C of 300 centistokes. The present aqueous fire-fighting foam compositions exhibit a low viscosity so that the aqueous fire-fighting foam compositions can be compatible with the same equipment at the cost of performance. The resulting aqueous fire-fighting foam compositions are thus unable to use a polysaccharide thickener.

[0046] In any of the above embodiments, the aqueous fire-fighting foam composition may exhibit one or more of the following properties: a maximum corrosion rate for brass (UNS C46400) of 1.0 milli-inch / year; a maximum corrosion rate for bronze (UNS C90500) of 100 milligrams; a maximum corrosion rate for copper-nickel (90-10) (UNS C70600) of 1.0 milli-inch / year; a maximum corrosion rate for nickel-copper (70-30) (UNS N04400) of 1.0 milli-inch / year; or no pits in corrosion-resistant steel (CRES) (UNS S30400 and S31600).

[0047] In any of the above embodiments, the aqueous fire-fighting foam composition may exhibit one or more of the following properties: a minimum aquatic acute toxicity, LC50, of 30 mg / mL; a maximum chemical oxygen demand (COD) of 900K mg / L; a minimum biodegradability,of 0.65; no visible stratification; or a maximumprecipitation of 0.10 vol%.

[0048] In any of the above embodiments, the aqueous fire-fighting foam composition exhibits one or more of the characteristics listed in Table 1 and / or Table 2. In some embodiments, the aqueous fire-fighting foam compositions described herein exhibit three or more of the characteristics listed in Table 1 and / or Table 2. In some embodiments, the aqueous fire-fighting foam compositions described herein exhibit all of the characteristics listed in Table 1 and / or Table 2.Table 1Table 2Method of Producing a Firefighting Foam

[0049] The aqueous firefighting foam compositions described herein may be mixed with an aqueous diluent to form firefighting foam precursor solution, i.e., a use strength composition. The firefighting foam precursor solution may be aerated (e.g., using a nozzle) to produce a firefighting foam including the aqueous firefighting foam composition and the diluent. Illustrative aqueous diluents may include water, such as fresh water, brackish water, sea water, and mixtures of any two or more thereof. In some embodiments, the firefighting foam compositions described above may be 1 vol.%, 3 vol.%, or 5 vol.% concentrate solutions, meaning that the firefighting foam compositions are mixed with 99 vol.%, 97 vol. %, or 95 vol.% aqueous diluent, respectively, to form the firefighting foam precursor solution.Method of Fighting a Fire

[0050] The firefighting foam compositions described herein may be used to fight a fire and / or to suppress flammable vapors by mixing the aqueous firefighting foam compositions with a diluent, aerating the resulting firefighting foam precursor solution to form a firefighting foam, and applying or administering the firefighting foam to a fire or applying the firefighting foam to the surface of a volatile flammable liquid (e.g., gasoline or other flammable hydrocarbon or a flammable polar solvent).

[0051] The present invention, thus generally described, will be understood more readily by reference to the following examples, which are provided by way of illustration and are not intended to be limiting of the present invention.EXAMPLES

[0052] The following examples more specifically illustrate formulations for preparing aqueous firefighting compositions according to various embodiments described above. These examples should in no way be construed as limiting the scope of the present technology.

[0053] Table 3 below provides an illustration of a suitable formulation of the present firefighting foam composition designed to be combined with a diluent, then aerated and administered to fight a fire in the form of a firefighting foam.Table 3

[0054] Tables 4 - 7 below show the composition of a number of illustrative formulations of the present aqueous firefighting foam composition. The amounts shown in these tables represent the weight percentage of the particular component based on the total weight of the composition. The formulations include a) a sugar component; b) a surfactant component including an anionic surfactant, a zwitterionic surfactant, and / or a nonionic surfactant, c) a water miscible organic solvent including one or more of an alkylene glycol, glycerol and a glycol ether, and d) at least about 30 wt.% water.Table 4Table 5Table 6Table 7

[0055] While certain embodiments have been illustrated and described, it should be understood that changes and modifications can be made therein in accordance with ordinary skill in the art without departing from the technology in its broader aspects.

[0056] The embodiments illustratively described herein may suitably be practiced in the absence of any element or elements, limitation or limitations, not specifically disclosed herein. Thus, for example, the terms “comprising,” “including,” “containing,” shall be read expansively and without limitation. Additionally, the terms and expressions employed herein have been used as terms of description and not of limitation, and there is no intention in the use of such terms and expression of excluding any equivalents of the features shown and described or potions thereof, but it is recognized that various modifications are possible within the scope of the claimed technology. Additionally, the phrase “consisting essentially of’ will be understood to include those elements specifically recited and those additional elements that do not materially affect the basic and novel characteristics of the claimed technology. The phrase “consisting of’ excludes any element not specified.

[0057] Additionally, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will realize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group.

[0058] As will be understood by one skilled in the art, for any and all purposes, particularly in terms of providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of subranges thereof.

Claims

WHAT IS CLAIMED IS:

1. An aqueous fire-fighting foam composition comprising: a sugar component comprising a monosaccharide sugar, a disaccharide sugar, a sugar alcohol, or a combination of any two or more thereof; a surfactant component comprising an anionic surfactant, a zwitterionic surfactant, a nonionic surfactant, or a combination of any two or more thereof; a water-miscible organic solvent; and at least about 30 wt.% water, wherein the composition is substantially free of a polysaccharide thickener; and wherein the aqueous fire-fighting foam composition exhibits: a maximum viscosity at 5°C of 300 centistokes; ora minimum biodegradability, of 0.65; orany two or more thereof.

2. The aqueous fire-fighting foam composition of claim 1, wherein the aqueous fire-fighting foam composition exhibits: a pH of 6.5 to 9.0; or a minimum refractive index of 1.36; or a maximum variation of surface tension of 15%; or a maximum variation of interfacial tension of 75%; or a minimum foam expansion of 7.0; or a minimum foam 25% drainage time of 3.5 minutes; or a maximum corrosion rate for cold-rolled, low carbon steel (UNS G10100) of 0.5 milli-inch / year; or a maximum corrosion rate for brass (UNS C46400) of 1.0 milli-inch / year; or a maximum corrosion rate for bronze (UNS C90500) of 100 milligrams; or a maximum corrosion rate for copper-nickel (90-10) (UNS C70600) of 1.0 milli- inch / year; or a maximum corrosion rate for nickel-copper (70-30) (UNS N04400) of 1.0 milli- inch / year; or no pits in corrosion-resistant steel (CRES) (UNS S30400 and S31600); ora minimum aquatic acute toxicity, LC50, of 30 mg / mL; or a maximum chemical oxygen demand (COD) of 900K mg / L; or no visible stratification; or a maximum precipitation of 0.10 vol%; or any two or more thereof.

3. The aqueous fire-fighting foam composition of claim 2 exhibiting three or more of the listed attributes.

4. The aqueous fire-fighting foam composition of any one of claims 1-3, wherein an unaged full-strength aqueous fire-fighting foam composition exhibits: a maximum extinguishing time for a 28-ft2jet A fuel fire of 30 seconds; or a maximum extinguishing time for a 28-ft2gasoline fire of 60 seconds; or a maximum extinguishing time for a 50-ft2jet A fuel fire of 60 seconds; or a minimum burnback time for a 28-ft2jet A fuel fire of 300 seconds; or a minimum burnback time for a 28-ft2gasoline fire of 240 seconds; or a minimum burnback time for a 50-ft2jet A fuel fire of 270 seconds; or an unaged half-strength aqueous fire-fighting foam composition exhibits: a maximum extinguishing time for a 28-ft2jet A fuel fire of 30 seconds; or a minimum burnback time for a 28-ft2jet A fuel fire of 300 seconds; or an unaged double-strength aqueous fire-fighting foam composition exhibits: a maximum extinguishing time for a 28-ft2jet A fuel fire of 30 seconds; or a minimum burnback time for a 28-ft2jet A fuel fire of 300 seconds; or an aged full-strength aqueous fire-fighting foam composition exhibits: a maximum extinguishing time for a 28-ft2jet A fuel fire of 30 seconds; or a maximum extinguishing time for a 28-ft2gasoline fire of 60 seconds; or a minimum burnback time for a 28-ft2jet A fuel fire of 300 seconds; or a minimum burnback time for a 28-ft2gasoline fire of 240 seconds; or an aged half-strength aqueous fire-fighting foam composition exhibits: a maximum extinguishing time for a 28-ft2jet A fuel fire of 30 seconds; or a minimum burnback time for a 28-ft2jet A fuel fire of 300 seconds; or any two or more thereof.

5. The aqueous fire-fighting foam composition of claim 4 exhibiting three or more of the listed attributes.

6. The aqueous fire-fighting foam composition of any of the preceding claims comprising: about 5 to 25 wt.% of a sugar component comprising a monosaccharide sugar, a disaccharide sugar, a sugar alcohol, or a combination of any two or more thereof; about 1 to 30 wt.% of a surfactant component comprising an anionic surfactant, a zwitterionic surfactant, a nonionic surfactant, or a combination of any two or more thereof; about 5 to 30 wt.% of a water-miscible organic solvent; and at least about 30 wt.% water.

7. The aqueous fire-fighting foam composition of any of the preceding claims, wherein the sugar component comprises glucose, fructose, mannose, xylose, sucrose, lactose, maltose, trehalose, lactulose, cellobiose, chitobiose, xylitol, sorbitol, mannitol, or a combination of any two or more thereof.

8. The aqueous fire-fighting foam composition of any of the preceding claims, wherein the sugar component comprises fructose, sucrose, sorbitol, or a combination of any two or more thereof.

9. The aqueous fire-fighting foam composition of any of the preceding claims, wherein the anionic surfactant comprises an aliphatic sulfate surfactant, an aliphatic sulfonate surfactant, an aliphatic succinate salt, an aliphatic ether sulfate surfactant, or a mixture of any two or more thereof.

10. The aqueous fire-fighting foam composition of any of the preceding claims, wherein the anionic surfactant comprises Cs-Ci4 alkyl sulfate, Cs-Ci4 alkyl sulfonate, C10-C14 alkyl ether sulfate, or a mixture of any two or more thereof.

11. The aqueous fire-fighting foam composition of any of the preceding claims, wherein the anionic surfactant comprises a Cs-Ci4 alkyl sulfate, or a mixture of any two or more thereof.

12. The aqueous fire-fighting foam composition of any of the preceding claims, wherein the anionic surfactant comprises an octyl sulfate salt, a decyl sulfate salt, a lauryl sulfate salt, or a mixture of any two or more thereof.

13. The aqueous fire-fighting foam composition of any of the preceding claims, wherein the composition comprises about 5 to 20 wt.% of the anionic surfactant.

14. The aqueous fire-fighting foam composition of any of the preceding claims, wherein the zwitterionic surfactant comprises an aliphatic amidoalkyl betaine, an aliphatic sulfobetaine, an aliphatic amidoalkyl hydroxysultaine, an aliphatic hydroxysultaine, or a mixture of any two or more thereof.

15. The aqueous fire-fighting foam composition of any of the preceding claims, wherein the zwitterionic surfactant comprises an aliphatic amidoalkyl betaine.

16. The aqueous fire-fighting foam composition of any of the preceding claims comprising about 1 to 10 wt.% of the zwitterionic surfactant.

17. The aqueous fire-fighting foam composition of any of the preceding claims, wherein the non-ionic surfactant comprises an alkyl polyglycoside, an aliphatic alcohol-based nonionic surfactant, or a mixture of any two or more thereof.

18. The aqueous fire-fighting foam composition of any of the preceding claims, wherein the nonionic surfactant comprises an alkyl polyglucoside, an aliphatic alcohol, an aliphatic alcohol ethoxylate, or a mixture of any two or more thereof.

19. The aqueous fire-fighting foam composition of any of the preceding claims comprising about 1 to 10 wt.% of the nonionic surfactant.

20. The aqueous fire-fighting foam composition of any of the preceding claims, wherein the water-miscible organic solvent comprises a triol, an alkylene glycol, an alkylene glycol monoalkyl ether, or a mixture of any two or more thereof.

21. The aqueous fire-fighting foam composition of any of the preceding claims, wherein the water-miscible organic solvent comprises glycerol, hexylene glycol, diethylene glycolmonobutyl ether, or a mixture of any two or more thereof.

22. The aqueous fire-fighting foam composition of any of the preceding claims comprising about 5 to 30 wt.% of the water-miscible organic solvent.

23. The aqueous fire-fighting foam composition of any of the preceding claims further comprising a corrosion inhibitor, a reducing agent, a metallic salt, a chelator, a buffer, a preservative, or a mixture of any two or more thereof.

24. A method of forming a firefighting foam, the method comprising aerating a foam precursor composition comprising the aqueous fire-fighting foam composition of any of the preceding claims to form the firefighting foam.

25. A method of forming a firefighting foam, the method comprising: mixing the aqueous fire-fighting foam composition of any one of claims 1-23 with an aqueous diluent to form a foam precursor solution; and aerating the foam precursor solution to form the firefighting foam.

26. The method of claim 25, wherein the aqueous diluent is selected from the group consisting of fresh water, brackish water, sea water, and a combination of any two or more thereof.

27. The method of claim 25 or claim 26, wherein the aqueous diluent comprises water from a municipal water source.

28. A firefighting foam comprising the firefighting foam composition of any one of claims 1-23 and an aqueous diluent.

29. A method of fighting a fire comprising applying the firefighting foam of claim 28 to the fire.

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