MXPA01005972A - Aqueous foaming compositions, foam compositions, and preparation of foam compositions - Google Patents

Abstract

Described are compositions and methods useful for preparing foam compositions. The compositions and method relate to the production of a foam from a composition containing non-hydrated thickener.

Description

FOAMING AQUEOUS COMPOSITIONS, FOAM COMPOSITIONS AND PREPARATION OF FOAM COMPOSITIONS Field of the Invention The invention relates to a process for forming a foaming composition, chemical compositions useful for preparing such foaming compositions, and foaming compositions. Background of the Invention Foamy materials are a class of chemical-based materials, commercially and industrially important. The foams can be prepared by aerating a foaming composition (i.e., trapping air in a foaming composition), which can be obtained by diluting a concentrated precursor. Many foams require that certain physical properties be appropriately useful in the desired applications. Among the preferred physical properties for foams are stability property, to allow the foam to be in a useful form for an extended period of time and therefore useful where a particularly stable foam may be desirable, for example, fire prevention, extinction of REF: 129894 fire, suppression of steam, protection against freezing of crops, etc. An important class of commercial foams, include film-forming aqueous foams (e.g., AFFFs), aqueous compositions, typically contain fluorochemical surfactants, non-fluorinated surfactants (e.g., hydroons), and aqueous or non-aqueous solvents. These foams can be prepared from concentrates, diluting them with water (pure or seawater) to form a "premix" and then aerating the premix to form a foam. The foam can be dispersed in a liquid chemical, to form a thick foam blanket that extinguishes a fire and extinguishes it by suffocation. These foams also find utility as vapor suppressor foams that can be applied to non-flammable but volatile liquids, for example, volatile liquids or solid chemicals and spills of chemicals, to prevent the evolution of toxic, noxious, flammable, or dangerous vapors from another mode. The individual components of a foaming composition contribute different physical and chemical properties of the premix and the foam. Fluorinated and non-fluorinated surfactants can exhibit a low surface tension, high foam-forming ability, and good film-forming properties, i.e., the ability to drain from the foam to distribute and form a film on the surface of another liquid. The organic solvents can be included to promote the solubility of the surfactants, to promote the shelf life of the concentrate and to stabilize the aqueous foam. Thickening agents can be used to increase the viscosity and stability of the foam. The especially preferred properties of the foams are stability, vapor suppression and resistance to re-burning or return of fire. Stability refers to the ability of a foam to maintain for a while, its physical state as a useful foam. Some fire fighting foams, for example, foams prepared from pre-mix foaming compositions, containing surfactants and hydrated thickeners, are stable for periods of hours, or less than an hour and are often reapplied regularly. Longer periods of stability can be achieved by the addition of ingredients such as prepolymers and reactive crosslinkers, ionic polyvalent complexing agents, proteins, etc.

There is a continuing need for foaming compositions, foam compositions, and methods of preparing foaming compositions and foams useful for application to a liquid chemical or other substrate, which may be volatile, flammable, otherwise dangerous, or not at all dangerous. but desirably protected from potential ignition. This includes, a particular need to prepare foam compositions that are stable in the form of a useful foam for extended periods of time, for example, up to or greater than 12, 24 or 36 hours. Brief Description of the Drawings Figures 1 and 2 each illustrate the embodiments of the inventive method for preparing a foaming composition and a foam composition. Brief Description of the Invention The invention relates to chemical compositions that can be aerated to form a foam composition (also called a "foam"). The foam can be used in various applications, including any application understood to be useful in the aqueous foamy materials technique. The foam may be useful for containing or suppressing volatile, noxious, explosive, flammable or otherwise dangerous vapors. Vapors can evolve from a chemical, such as a chemical storage tank, a liquid or solid chemical, or a chemical spill. The foam can also be used to extinguish a chemical fire or to prevent the ignition or re-ignition of a chemical. These applications will be collectively called for the purposes of the present invention as "application to a chemical" or application to a "liquid chemical". The compositions are especially useful for extinguishing and securing extremely flammable chemicals (for example, with low boiling point and high vapor pressure) and difficult to secure, for example, transportation fuels, such as methyl-t-butyl ether (MTBE ) and ether / gasoline mixtures. Additionally, the foam can be applied to other substrates that are not necessarily hazardous, volatile, ignitable or flammable. As an example, foam can be applied to earth, buildings or other physical or real property in the potential trajectory of a fire, such as a firebreaker, for example, to prevent such property from being trapped by fire. The invention also relates to methods of preparing a foam composition. According to the invention, an aqueous foaming composition, which contains a non-hydrated thickener, is aerated to a foam. After foaming, the thickener not hydrated in the foam is hydrated to provide a stable foam. Since the foaming composition includes the thickener in a non-hydrated state in the aeration, the foaming composition, and hence the resulting foam composition, may contain more thickener than if the thickener was hydrated in the aeration. Thus, the foaming compositions and the foams of the invention may contain relatively more thickener than the prior art compositions (containing hydrated thickener), giving the foam compositions of the invention, increase their stability. In one aspect, the invention relates to a process for foaming a foam, the process includes the passage of, aerating an aqueous composition containing non-hydrated thickener, for example, a foaming composition containing surfactant, water and non-hydrated thickener. In another aspect, the invention relates to a process for preparing a foaming composition. The process includes the steps of adding to a water flow. Preferably water flowing through a hose, such as a fire hose, the surfactant and the unhydrated thickener. The foaming composition containing the non-hydrated thickener can be aerated to a foam. In another aspect, the invention relates to a composition that includes water, from about 0.05 to about 1 weight percent surfactant, and at least about 0.5 weight percent thickener, based on the weight of the composition. The composition may be in the form of a foaming composition containing non-hydrated thickener and optionally hydrated thickener, or in the form of a foam containing non-hydrated thickener, hydrated thickener or both. Even in another aspect, the invention relates to a composition of ingredients, which includes surfactant, non-hydrated thickener, an organic solvent and substantially no water. In a final aspect, the invention relates to a process for improving the stability of a foam. The process includes the step of adding non-hydrated thickener to a foaming composition and aerating the foaming composition containing the non-hydrated thickener. As used herein, the term "foam" is used according to its industrially accepted meaning, to refer to a foam made by physically mixing a gaseous phase (e.g., air), in an aqueous liquid to form a system of two phases of a discontinuous gas phase (eg, air) and a continuous aqueous phase. Detailed Description Thickeners "or thickening agents", useful in aqueous foams, are chemical materials that are well known in the art of aqueous foams and the production of aqueous foams. See in general, for example, Davidson, Handbook of Water-Soluble Gums and Resins, 1980 and Meltzer, Water-Soluble Polymers Recent Developments, (1979). Thickeners are known specifically and are understood to be useful in foam applications for fire fighting, see, for example, U.S. Patent Nos. 4,060,489, 4,149,599 and 5,026,735. Thickeners may generally exist in their substantially pure forms as solids, for example, in the form of a non-crystalline powder. In this solid form, the preferred thickeners can be suspended or dispersed, even if not significantly dissolved in an organic solvent. A thickener, after significant exposure or contact with water, for example in an aqueous composition, will become hydrated by water, i.e., associated with, dissolved or become dispersed in water. After hydration, the thickener causes a thickener effect or an increase in the viscosity of the aqueous composition, which is thought to occur through a chemical mechanism involving hydrogen bonds. The thickeners are typically of a relatively high molecular weight, and upon exposure to water, do not immediately cause this thickening effect. Instead, a thickener will dissolve or disperse in an aqueous composition for a short period of time to create a solution, a colloidal dispersion or if sufficient thickener, a gel of increased thickness or viscosity is present. Complete or integral hydration of a quantity of thickener in an aqueous composition occurs after an essentially finite period of time called here as a "hydration period". The extension of the hydration period will depend on factors such as the relative amounts of thickener and water in the aqueous composition, the temperature and pressure, and the chemical nature of the thickener. A period of hydration may typically be in the range from less than one minute to more than 5 or 10 minutes. In practice, the thickener introduced into an aqueous solution (although possibly containing adventitious water) is initially a completely non-hydrated solid. The thickener becomes progressively hydrated during the time that the thickener is associated with water, at which time some of the thickener exists in a hydrated state and something exists in an unhydrated state, and finally, after sufficient time has passed, given a sufficient amount of water, the total amount of thickener will become hydrated to provide a total thickening effect. This state of hydration is called complete, full or balanced hydration. The term "non-hydrated", when referring to a thickener-containing composition, is used in the present description to describe an aqueous thickener-containing composition, wherein the composition contains some amount of thickener which is not hydrated, i.e. it is not associated with water in the manner described above to cause a thickening effect. The composition is considered to contain "unhydrated" thickener even if the composition also contains something or a significant portion of thickener that is hydrated, that is, associated with water, to thicken the composition. An amount of thickener in a composition is considered to be "substantially unhydrated" if the composition satisfies one of the definitions presented infra, or alternatively if only a minor portion of the total amount of thickener in a composition (eg, less than about 50). percent by weight) has been associated with water to cause a thickening effect. The hydration state of the thickener in an aqueous composition, for example, whether a quantity of thickener is unhydrated, substantially hydrated or in a state of balanced hydration, can be measured by various analyzes. As examples of the methods that can be used to identify the degree of hydration of a quantity of thickener, this can be measured by the extent to which the thickener caused a thickening effect of the aqueous composition, by the amount of time after wherein the thickener has been exposed to the aqueous composition and the water contained therein, or by the extent to which the thickener has dissolved or remains undissolved in the aqueous composition. Those that follow are specific examples. The degree of hydration of a thickener in an aqueous composition can be measured by the amount of time the thickener has been contained in an aqueous composition, i.e. in contact with sufficient water to cause hydration. Since the balanced hydration of a quantity of thickener occurs after a period of hydration, the thickener present in the aqueous composition for a time less than the hydration period will not be completely hydrated and the composition will contain non-hydrated thickener. A thickener that has been exposed to water for a smaller fraction of the hydration time, ie less than half the hydration time, for example, for a time of 2 minutes, 1 minute, 30 seconds or 10, 5 or 1 second or less, can be considered to be substantially unhydrated. In the alternative, the degree of hydration of a quantity of thickener in an aqueous composition can be measured in terms of the degree to which the thickener provides an increase in the thickness or viscosity of the composition. An aqueous composition containing a thickener in a state of complete or integrated hydration, that is to say balanced, will achieve a maximum or equilibrium viscosity. If an aqueous thickener-containing composition has a viscosity that is measurably less than this equilibrium viscosity, the composition is considered to contain non-hydrated thickener. The composition can be considered to contain thickener substantially not hydrated if the viscosity of the composition is equal to or less than a fraction of the equilibrium viscosity, eg, 50 percent, 25% or 10 or 5 percent of the viscosity of the composition. Balance. The degree of a thickening effect can also be measured with respect to the ability of the composition to be aerated to a foam. In a sense, a foaming composition is useful if it can be formed into a foam. If a composition contains an excessive level of hydrated thickener, the foaming composition can achieve a thickening, that is, viscosity, which will not allow aeration to a useful foam. A useful foam is one that achieves any of the various purposes of such foam compositions, for example, extinguishing or preventing fire, vapor suppression, etc. A foam composition can be considered to contain non-hydrated thickener if the foaming composition can be aerated to a useful foam even if the foaming composition contains a sufficient amount of thickener since if the thickener was completely hydrated the foaming composition would not be aerated to a foam Useful. A foam does not need to be uniform to be useful, but, for applications such as the use of a foam to extinguish a fire, a foam can exhibit a substantially uniform consistency. A foaming composition can be considered to contain thickener substantially not hydrated if the foaming composition can be aerated to form a foam of an essentially uniform consistency, although the foam composition contains a sufficient amount of thickener since if the thickener was completely hydrated the foaming composition would not be aerated to form a substantially uniform foam. A foam that is not substantially uniform due to a high level of hydration of the hydrated thickener in the aeration may contain relatively harder or gelled portions caused by an inability of the foaming composition to entrap air by aeration due to excessive thickening or viscosity of the composition. foaming composition. This effect can, of course, depend on the aeration equipment that is being used for aeration. It is noted that although some applications may prefer the production of a substantially uniform foam, a foam that is not substantially uniform may still be useful in these and other applications, and it is further noted that the production of a foam that may not be substantially uniform is contemplated to be within the scope of the present invention if, as stated above, the foaming composition contains thickener not hydrated (in any amount) in the aeration. For thickeners that exist as solids prior to hydration, and that dissolve or disperse upon exposure to water and hydration, the degree of hydration of a thickener in a foaming composition can be measured in terms of the degree to which the thickener is dissolves or disperses in the composition. An aqueous composition can be considered to contain non-hydrated thickener if the composition contains undissolved thickener in any amount. The presence of undissolved thickener may in some cases be identifiable by single vision, for example, by the presence of gelled spheres of non-hydrated thickener in a foam composition. On the other hand, undissolved thickener may not necessarily be detectable by single vision. The definitions above that refer to thickeners not hydrated and substantially not hydrated, are presented as examples, alternative and non-exclusive definitions that may be useful for identifying the non-hydrated thickener in a foaming or foaming composition. If a thickener in a composition conforms to one of these definitions, that thickener is considered to be either not hydrated or substantially not hydrated; but, only because a thickener does not fall within one or more of the alternative definitions (for example, if the undissolved thickener can not be detected by single vision in a foam), or even if a thickener does not satisfy any of these exemplary definitions, this does not mean that the composition does not contain unhydrated thickener, if the unhydrated thickener can be otherwise shown to be present in the composition. Thickening agents are well known in the chemistry and polymer arts, and include, inter alia, polyacrylamides, cellulosic resins and functionalized cellulosic resins, polyacrylic acids, polyethylene oxides and the like. One class of thickener that may be preferred for use in the foaming compositions and methods of the invention is the water-soluble class, polyhydroxy polymers, especially the polysaccharides. The class of polysaccharides includes a number of water-soluble organic polymers, organic polymers that can increase the thickening, viscosity or stability of a foam composition. Preferred polysaccharide thickeners include polysaccharides having at least 100 saccharide units or an average molecular number of at least 18,000. Specific examples of such preferred polysaccharides include xanthan gum, scleroglucan, heteropolysaccharide 7, locust bean gum, partially hydrolyzed starch, guar gum and derivatives thereof. Examples of useful polysaccharides are described, for example, in U.S. Patent Nos. 4,060,489 and 4,149,599. These thickeners generally exist in the form of water-soluble solids, for example powders. While they are soluble in water, in their powder form, they can and typically contain a small amount of adventitious or innate water, which is adsorbed or otherwise associated with the polysaccharide. Guar gum is a particularly preferred polysaccharide thickener. The term guar gum, as used herein, refers to materials generally understood to be the class of materials known in the chemistry art as "guar gum", including the plant mucilage obtained from the water-soluble Cyanopsis tetragonoloba. These materials typically contain units of the galactose and mannose saccharides in the form of an alternating linear copolymer (see, for example, pages 6-3 and 6-4 of "Handbook of Water-Soluble Gums and Resins,") which has cis-groupings. 1,2-diol in the saccharide units. The structure can be represented as repeating unit of guar gum Guar gum derivatives such as those formed by the etherification and esterification reactions with hydroxy functionalities are also useful as thickeners. Preferred such derivatives may be those prepared by etherification, for example, hydroxyethylation with ethylene oxide, hydroxypropylation with propylene oxide, carboxymethylation with monochloroacetic acid, and quaternization with several quaternary amine compounds, containing reactive sites of chlorine or epoxy. . In the case of guar gum, each saccharide ring contains an average of 3 hydroxy-containing substituents. For the guar gum derivatives, the molar substitution of the hydroxy groups should preferably not exceed an average of a hydroxy group substitution per saccharide ring. A preferred range of molar substitution of hydroxy-containing groups, such as hydroxypropyl, may be in the range from about 0.1 to 2 substituents per repeating unit, more preferably from 0.2 to 0.6 substituents per repeating unit. An especially preferred guar gum derivative is hydroxypropyl guar gum, a commercially available example of which is JAGUAROHP-11, with an average of 0.35 to 0.45 moles of hydroxypropyl per each anhydrohexose unit. Other useful guar gums include the Jaguar ™ series of commercially available guar gum products, including the Jaguar ™ GCP15, T4072, T4111, T4150, T4315, 6003 (2243), locust bean gum J8801 and the Jaguar ™ 6003 ( 2243) non-derivative, high molecular weight. The combinations of different thickeners can also be used in a simple foaming composition. For example, it has been found that xanthan gum is especially useful in combination with other galactomannans; Mixtures of xanthan gum and guar gum, and xanthan gum and locust bean gum have been found to be especially useful. A foaming composition (also referred to in the fire fighting technique as a "premix"), may include ingredients other than the thickener and water, for example, surfactant. The surfactant can reduce the surface tension of a foaming composition and thereby facilitate the formation of a foam after aeration. Useful surfactants include non-fluorinated surfactants (including non-ionic, anionic and amphoteric non-fluorinated surfactants), and fluorinated surfactants, all of which are generally known in the art of aqueous compositions, including foaming and foam compositions. to fight the fire. The surfactants can provide a foaming composition or foam composition with a low surface tension. In fire fighting applications, a fluorochemical surfactant can reduce the surface tension of a foaming composition to a level below the surface tension of a liquid chemical to which the composition is applied. In this case, the drainage from the aqueous phase of the composition can be distributed easily distributed as an aqueous film that seals the vapor onto a liquid chemical. Films that originate from the drainage of these compositions may have a strong tendency to reform if they are altered or broken, thereby reducing the tendency of the liquid chemical to be ignited or re-ignited. Fluorochemical surfactants include those known in the art of foam compositions to be useful within aqueous foam compositions for fire fighting. Many varieties of fluorochemical surfactants are well known, and a particular fluorochemical surfactant, used in the compositions and methods of the present invention, can be any surfactant of the various surfactants known in the chemistry art. A preferred class of fluorochemical surfactants includes those compounds that contain one or more fluorinated aliphatic radicals (Rf) and one or more polar solubilizing groups (Z), wherein the radical and the solubilizing groups are connected by a suitable linking group (Q), and wherein the surfactant preferably contains at least about 20 weight percent of fluorine bonded to a carbon. The aliphatic fluorinated radical Rf can generally be a fluorinated, saturated, monovalent, non-aromatic radical, preferably having at least 3 carbon atoms. The aliphatic chain may be linear, branched or if it is sufficiently long, cyclic and may include catenary oxygen atoms, trivalent nitrogen or hexavalent sulfur. A fully fluorinated radical Rf may be preferred, but hydrogen or chlorine may be present as substituents, provided that no more than one atom of any, is preferably present for every two carbon atoms and also preferably, the radical contains at least one terminal perfuoromethyl group. While radicals containing large numbers of carbon atoms will function properly, compounds containing no more than 20 carbon atoms are preferred since longer radicals usually represent a less efficient use of fluorine. Fluoroaliphatic radicals containing about 4 to 12 carbon atoms are most preferred. The polar solubilizing group Z may be an anionic, cationic, nonionic or amphoteric moiety or radical or a combination thereof. Typical anionic moieties or moieties include the carboxylate, sulfonate, sulfate, ether sulfate or phosphate moieties. Typical cationic portions include the portions of quaternary ammonium, protonated ammonium, sulfonium and phosphonium. Typical nonionic portions include the polyoxyethylene and polyoxypropylene portions. Typical amphoteric portions include the betaine, sulfobetaine, aminocarboxylate, amine oxide and the various combinations of the anionic and cationic portions. The linker group Q can be a multivalent, generally divalent linking group such as alkylene, arylene, sulfonamidoalkylene, carbonamidoalkylene, alkylene sulfonamidoalkylene or alkylenethioalkylene. A particularly useful class of surfactants, include those of the formula (Rf) n (Q) m (Z) p, where Rf, Q and Z are as defined and n is 2, m is 0 to 2 and p is 2 The representative fluorochemical surfactants according to this formula include the following: C8F17S03-K + C? OF2? S03 K CgFi7CH4S03 K C12F23OC6H, 3S03"Na + C8F17S02N (C2H5) CH2COO ~ K + C8Fi7C2H4SC2H4N + (CH3) 2CH2COO" C8F17C2H4SC2H4COO "Li + C3F70 (C3F60 ) 3CF (CF3) CH2CH (OH) CH2N (CH3) CH2COO "K + C8F17S? 2N (C2H5) C2H4OS? 3" Na + C8F17S02N (C2H5) C2H4OP (O) (0"NH4 +) 2 C4F9S02N (H) C3H6N + (CH3) ~ C8F? 7S02N (H) C3H6N + (CH3) 20 ~ C10F21SO2N (H) C3H6N + (CH3) 20 ~ C7F15CF (CF3) S02N (H) C3H6N + (CH3) 2 C7F15CON (H) C3H6N + (CH3) 20" C6F13C2H4S02N (H) C3H6N + (CH3) 20"C6F13S02N (C2H4COO ~) C3H6N + (CH3) 2H C8F? 7C2H4CONHC3H6N + (CH3) 2C2H4COO" C6F13S02N (C3H6S03 ~) C3H6N + (CH3) 2C2H4OH C6F? 3S02N (CH2CHOHCH2S03 ~) C3H6N + (CH3) 2C2H4OH C7F? 5CF = CHCH2N (CH3) CH2CH2OS03 ~ Na + C8F17S02N (H) C3H6N + (CH3) 3C1"C6F? 3S02N (H) C3H6N + (CH3) 3CH3OS03 ~ C6F13S02N (C2H5) C3H6N (H) CH2CH (OH) CH2S03 ~ Na + C6 13C2H4SO2N (CH3) C2H4N + (CH3) 2C2H4COO "C6F13C2H4S02N (H) C3H6N + (CH3) 2C2H4COO" C6F? 3CH2CH (OCOCH3) CH2N + (CH3) 2CH2COO "C8F17S02N (C2H5) (C2H4?) 7CH3 C8F? 7 (C2H40)? OOH The Examples of these and other fluorochemical surfactants are described, for example, in U.S. Patent Nos. 3,772,195 (Francen), 4,090,967 (Falk), 4,099,574 (Cooper et al.), 4,242,516 (Mueller), 4,359,096 (Berger), 4,383, 929 (Bertocchio et al.), 4,472,286 (Falk), 4,536,298 (Kamei et al.), 4, 795, 76 (Alm et al.), 4,983,769 (Bertocchio et al.) And 5,085,786 (Alm et al.). Non-fluorinated surfactants can be included in the foaming composition to facilitate foaming after aeration, to promote distribution of the drainage of the foam composition as a vapor sealing film on a liquid chemical and where desired, to provide the compatibility of a fluorochemical surfactant with the extra water. Non-fluorinated surfactants include water-soluble hydrocarbon surfactants and silicone surfactants, and may be non-ionic, anionic, cationic or amphoteric. Particularly useful non-fluorinated surfactants include hydrocarbon surfactants which are anionic, amphoteric or cationic, for example, anionic surfactants preferably having a carbon chain length containing from about 6 to about 12 or 20 carbon atoms. . Examples of nonionic, non-fluorinated surfactants include ethylene oxide-based surfactants such as CnH2n + O (C2H4?) MH, where n is an integer between about 8 and 18 and m is greater than or equal to about 10; the ethoxylated alkylphenols, such as wherein p is an integer between about 4 and about 12 and z is greater than or equal to about 10, and block copolymers of ethylene oxide and propylene oxide, such as the surfactant Pluronic ™ F-77 (containing at least 30% by weight of ethylene oxide) available from BASF Corp. Wyandotte, Michigan. Examples of useful fluorine-free anionic surfactants include alkyl sulfates, such as sodium octyl sulfate (eg, Sipex ™, commercially available from Rhone-Poulenc Corp., Cranberry, New Jersey) and sodium decyl sulfate ( for example, Polistep ™ B-25, commercially available from Stepan Co., Northfield, Illinois); the alkyl ether sulfates, such as CnH2n +? (OC2H4) 2OS03Na, where 6 = n < 12 (for example, Wircolate ™ 7093, commercially available from Wytco Corp., Chicago, Illinois), and alkyl sulfonates such as CnH2n +? S03Na, where 6 < n < 12. Examples of useful nonfluorinated amphoteric surfactants include amine oxides, aminopropionates, sultaines, alkyl betaines, alkylamidobetaines, dihydroxyethyl glycinates, imiadazoline acetates, imidazoline propionates, and imidazoline sulphonates. Preferred non-fluorinated amphoteric surfactants include the salts of n-octyl amino-propionic acid, for example, C8H? 7N (CH2CH2COOM) 2, where M is sodium or potassium; Mirataine ™ H2C-HA (sodium laurimino propionate), Miranol ™ C2M-SF Conc. (Sodium cocoamide propionate), Mirataine ™ CB (cocamidopropyl betaine), Mirataine ™ CBS (cocamidopropyl hydroxysultaine), and Miranol ™ JS Conc. (Caprilamfo) hydroxypropyl sultaine sodium) all commercially available from Rhone-Poulenc Corp .; and those imidazole-based surfactants, described in U.S. Patent No. 3,957,657 (Chiesa, Jr).

The organic solvent can be included in a foaming composition to promote the solubility of a surfactant, to improve the shelf life of a concentrated adaptation of the foaming composition, to stabilize the foam, and in some cases, to provide protection against freezing. Organic solvents useful in the foaming composition include, but are not limited to diethylene glycol n-butyl ether, dipropylene glycol n-propyl ether, hexylene glycol, ethylene glycol, dipropylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monopropyl ether, propylene glycol, glycerol, polyethylene glycol (PEG) and sorbitol. Other optional ingredients may be included in a foaming composition, when needed and in amounts that will be readily understood by those skilled in the art of aqueous foam compositions. Such optional ingredients may include corrosion inhibitors, buffers, antimicrobial agents, divalent ion salts and humectants (eg, sucrose, corn syrup, etc.). It is also known in the art of foam compositions, the use of additional agents to stabilize a foam for a while. These include, for example, polyvalent ion complexing agents, which stabilize through the crosslinking of hydrogen bonds, protein hydrosylates and prepolymers, (for example, polyisocyanates) and crosslinking agents which react upon formation of the foam to form a stabilizing polymer through covalent crosslinking. See for example, US Patents Nos. 5,026,735, 5,225,095, 4,795,764 and 4,795,590. Specific examples of complexing agents include alkali metal borates, pyroantimonates of alkali metals, titanates, chromates, vandanatos, etc. While such stabilizing additives, polyvalent ion complexing agents, protein hydrosylates and reactive polymers and crosslinkers can be used to further stabilize the foam compositions of the present invention, they are not required and in most or many applications, the compositions of the present invention and compositions for use in the process of the present invention can preferably and advantageously exclude such complexing agents. The thickener can be included in the foaming or foam composition in any amount that if hydrated can stabilize a foam. While a foaming composition of the invention contains thickener not hydrated in aeration, a foaming composition may also include some amounts of hydrated thickener. This may be because the residence time of the thickener in the foaming composition before aeration is sufficiently long to allow the hydration of some amount of the thickener, since the hydrated thickener has been added as part of a concentrate containing surfactant, or for some other reason. The hydrated thickener will increase the thickness and viscosity of the foaming composition and at some threshold concentration of hydrated thickener, the viscosity of the foaming composition will become too high to allow efficient practical aeration of the foaming composition to form a foam. Thus, a foaming composition may contain hydrous thickener, but preferably contains a minimum amount of hydrated thickener, or an amount not large enough to prevent aeration of the foaming composition to a useful foam. The foaming composition contains non-hydrated thickener which does not prevent the foam composition from being aerated to a useful foam, and which will hydrate after foam formation and further stabilize the foam composition. An advantage of the method of the invention is that since the foaming composition contains non-hydrated thickener, that is, since the foaming composition is aerated while the thickener in the composition is completely, substantially, or even partially not hydrated, the foaming composition, and the resulting foam, may contain thickener in larger amounts than if the thickener was fully hydrated in the aeration. The relative amount of non-hydrated thickener versus that of hydrated thickener in a foaming composition can be maximized by aerating the foaming composition (aeration is detailed infra) as soon as or immediately after introduction of the non-hydrated thickener into the foaming composition. . Preferred foaming compositions contain a sufficient amount of thickener to provide a highly stable foam. This can mean, for example, that a foam composition containing for example water, surfactant, and thickener, and preferably without polyvalent ion complexing agent, without protein hydrosylate and without polymeric agents or reactive crosslinkers, can remain in the form of a useful foam for up to 24 hours, or even up to 48 hours or more. As measured by the National Fire Protection Association (NFPA) standard number 412, a preferred foam composition may contain sufficient thickener, in the absence of crosslinker, polyvalent ion complexing agent, or protein hydrosylate, etc., to exhibit 75% of draining time of at least ninety minutes, more preferably 3 hours, 8 hours, 12 hours, 24 hours, or more. Examples of the specific amounts of 'thickener in a foaming or foaming composition may be in the range from about 0.001 to 10 weight percent of thickener (which means the total amount of thickened hydrate or non-hydrated), based on the total weight of the composition, with ranges from about 0.01 to about 5, and from about 0.05 to about 1.5, 2 or 3 percent by weight that are preferred, and with the range from about 0.1 to about 1.0, for example, about 0.5 percent by weight of thickener that is particularly preferred.

The amounts of other ingredients in a foaming composition can vary significantly and those skilled in the aqueous foam art will understand the useful ranges. The main portion of the foaming composition may be water, which may be either salt water (eg, sea water), or pure water. The amount of water may be an amount that provides the sufficiently low viscosity of the foaming composition to permit efficient handling and aeration to a foam. Generally, the water will comprise at least 50 percent by weight of the foaming composition, for example, from about 55 to 99.5 percent by weight of the foaming composition. The amounts of surfactant, generally, and fluorochemical surfactant and non-fluorinated surfactant specifically, the amounts of optional organic solvent, to be used in a foaming composition, are well known and understood in the art of aqueous foam compositions. As examples of the useful ranges, the foaming and foam compositions may preferably contain from about 0.05 to 1 weight percent of surfactant, based on the total weight of the composition, for example, from about 0.05 to 0.3 percent by weight. weight of fluorochemical surfactant, from zero to about 0.95 weight percent of fluorine-free surfactant; and from about 0.05 and 5.0 weight percent of organic solvent, based on the total weight of the composition. A foaming composition can be prepared by mixing or combining together its ingredients, for example, water, thickener, and surfactant, plus any of the additional ingredients desired. For example, a foaming composition can be prepared by providing water, for example, a fixed amount within a reaction vessel or other container, or preferably a flow of water traveling through a hose or tube, more preferably a hose, and then adding the ingredients that are not water (for example, the surfactant, thickener, etc.) to the water. Ingredients that are not water can be added to the water individually or as one or more mixtures and in any desired order. While both, the surfactant and the thickener can be added to a flow of water at any convenient point in the flow, the non-hydrated thickener can preferably be added to a water flow at a position close to the point of aeration, so that in the aeration, as thickening as possible, remains in a non-hydrated state. The residence time of the non-hydrated thickener in a foaming composition flowing through a hose, prior to aeration, should be short enough so that the thickener does not become completely hydrated before aeration. The preferred residence times of the thickener in the foaming composition, prior to aeration, are short enough to provide a thickener that is substantially not hydrated in the aeration; examples of particularly preferred residence times may be below one minute, for example, 30 seconds, and may more preferably be less than 10 seconds, eg, 5 seconds, 1 second, or less. A foaming composition can be prepared using foam production equipment known in the fire fighting art. Such equipment may include a conventional hose for conveying a water flow, plus accessory equipment for injecting, evacuating or otherwise adding non-aqueous ingredients to the water flow. Water can flow under pressure through a fire hose, and the surfactant, thickener and other nonaqueous ingredients can be injected or dragged (eg, evacuated by the Venturi effect) to the water flow. In one embodiment of the method, a foaming composition can be prepared by evacuating the thickener and the surfactant to the flow of water flowing through a hose., wherein the thickener and the surfactant are evacuated as two separate streams of ingredients, a concentrate comprising a concentrated solution of surfactant and a suspension of thickener, comprising thickener and a non-aqueous solvent. This method is illustrated in Figure 1. Figure 1 illustrates a flow of water 2 through a hose 4. The suspension 6 of thickener is evacuated to water 2 in an eductor 8. The surfactant 10, optionally and preferably a concentrate in solution or mixed with other desired ingredients, it is evacuated to water 2 in an eductor 12. (While Figure 1 shows the evacuation of the slurry suspension 6, upstream of the concentrate 10, the surfactant and the thickener can be added in any order). The addition of the suspension 6 of thickener and concentrate 10 to water 2, provides a foaming composition 14, containing non-hydrated thickener. The foaming composition 14 flows to and through the aerator 16, where it is aerated to form the foam 18. The non-hydrated thickener may or may not be uniformly dispersed in the foaming composition 14, but the aeration of the foaming composition will substantially disperse uniform the thickener in the resulting foam. The foam 18, initially contains non-hydrated thickener, which becomes hydrated after a while, to stabilize the foam. In one embodiment, a concentrate, for example, containing the surfactant 10 of Figure 1, may include the surfactant (eg, fluorinated surfactant, non-fluorinated surfactant, or both), the organic solvent, water, and optionally thickener. If the thickener and water are both present in the concentrate, the thickener will probably be hydrated (if present for a sufficient amount of time, equal to or greater than the hydration period), and as stated above, the amount of thickener hydrated in the foaming composition in aeration, it should preferably be sufficiently low to allow effective foaming. Although the composition of a concentrate may vary, and the amounts outside the following ranges may also be useful, many useful and commercially available concentrates contain from about 1 to 10 weight percent of fluorochemical surfactant, from about 1 to 30 parts by weight of fluorine-free surfactant, and from about 0.7 to 1.5 parts by weight of thickener, based on 100 parts of concentrate, with the remainder being water. Many commercially available concentrates may contain amounts of solids as identified above, from about 5 to 50 parts by weight of organic solvent, and the balance water or organic solvent (based on 100 parts by weight of the concentrate). Such commercially available concentrates are well known in the fire fighting art as AFFF concentrates (aqueous film forming foam) and are available, for example, from 3M Company of St Paul MN, and of National Foam, Inc., of Lionville PA. The relative amounts of the ingredients included in a concentrate may depend on whether the concentrate is designated a 1%, 3% or 6% concentrate. These designations are understood in the art of combating fire, that is, concentrates can generally be called as concentrates at "6%", "3%" or "1%", which means that the concentrate can be diluted 15.7, 32.3 or 99 times in volume, with fresh or sea water to form a foaming composition. A thickener suspension such as the thickener suspension 6 of Figure 1 may contain non-hydrated thickener, preferably in the form of a solid (eg, powder), dispersed or suspended in a non-aqueous solvent, and preferably does not substantially contain water . The thickener suspensions may preferably contain from about 1 to 66 weight percent of thickener, for example, from about 1 to 33 weight% of thickener, in a non-aqueous solvent. Non-aqueous solvents suitable for thickener suspension include glycol ethers such as dipropylene glycol methyl ether, dipropylene glycol n-propyl ether, dipropylene glycol n-butyl ether, tripropylene glycol methyl ether and diethylene glycol n-butyl ether and propylene glycol ethers. glycols having molecular weights ranging from 200 to 600. Glycolic esters provide suspensions having lower viscosities (eg, from 100 to 300 centipoise), but are not stable, while polyethylene glycols can provide suspensions that are more stable but they have higher viscosities (for example, from 1000 to 300 centipoise). The non-aqueous solvent may be present in the suspension, in about 50 to 80% by weight. Preferably, a mixture of glycolic ether and polyethylene glycol, such as the non-aqueous solvent, can be used with the glycolic ether present in about 5 to 50 weight percent, preferably about 10 weight% of the solvent mixture. The thickener suspension may optionally contain an anti-settling agent, such as MPA-1075, Rheolate ™ 225, kaolin and bentonite, used at concentrations in the nonaqueous suspension from about 0.1 to 1.5% by weight. In another embodiment, all non-aqueous ingredients of the foaming composition can be added to the water as a single concentrate. This may be in the form of a preferred concentrate containing surfactant, non-hydrated thickener, organic solvent and substantially no water, for example, less than 10% by weight, preferably less than about 5% by weight, 1% by weight, 0.5% by weight, or 0.1% by weight and more preferably without water. The amounts of the ingredients in such concentrate may vary, and may be any of the amounts that will allow the preparation of a useful foam composition from the concentrate, for example, having the amounts of the ingredients as specified above. Particularly, the amounts of the ingredients in a concentrate may depend on the amount of water expected to be combined with the concentrate to prepare a foaming composition, for example, if the concentrate needs to be diluted with water, approximately 16, 33 or 99 times, or some other multiple. The exemplary ranges of organic solvent, thickener and surfactant in this type of concentrate, may be, for example, in the range from about 1 to about 66 weight percent and from 1 to about 25 weight percent of surfactant, with the balance that is the organic solvent. The preferred amounts may be in the ranges from about 5 to 50 weight percent thickener, 1 to 10 weight percent of fluorinated surfactant, 1 to 10 weight percent non-fluorinated surfactant, and 30 to 95 weight percent of organic solvent, based on the total amount of concentrate. A concentrate containing both thickener (preferably not hydrated) and surfactant, can be added to a water flow as a single inlet stream, as shown in Figure 2, where the concentrate containing non-hydrated thickener, surfactant and organic solvent, becomes a waste in water 2 flowing through a hose 4 to an eductor 8. The addition of concentrate 20 to water 2, provides a foaming composition 14, containing non-hydrated thickener and surfactant. Foaming composition 14 flows to and through aerator 16 where it is aerated to form foam 18. The foaming composition containing the ingredients as described above, preferably exists as a transient composition as a water flow in a hose to fight the fire, more preferably in a position on the hose, immediately preceding the aeration equipment. After formation of the foaming composition, and after complete hydration of the thickener, the foaming composition can be aerated by methods that are well understood in the art of foam compositions, for example, using a nozzle that draws in air, to form a foam composition comprising a vapor phase (e.g., air) trapped in a liquid (e.g., aqueous) phase. The amount of air, generally included in the foam, can be such that air will be the main component by volume of the foam, for example, greater than about 50 volume percent, preferably in the range from 75 to 98 percent by volume. hundred in volume of air. The foam for most applications will preferably have a density of less than 1 gram per cubic centimeter, and preferably an expansion value (foam volume in me per weight of the foam in grams), generally greater than 1.5, preferably from about 2 to 20, optionally as high as 200 or even 1000. The liquid phase has the same chemical composition as the chemical composition of the foaming composition, and includes a larger amount of water, plus non-aqueous ingredients, including the surfactant and the thickener, with some thickener, preferably a substantial amount of the thickener, which is initially not hydrated and which remains substantially unhydrated until aeration to a foam. After a relatively short period of time, for example, in a matter of minutes or less, the thickener in the aqueous phase of the foam will hydrate to stabilize the foam. While not wishing to be bound by any particular theory, it is believed that in r to produce a foam with a long draining time, the viscosity of the foaming composition may preferably be as low as possible before generation of the foam and viscosity of the aqueous phase of the foam should increase as fast as possible, subsequent to the generation of the foam. To achieve this, the thickener can be incorporated into the solution of the foaming composition, just before aeration through the nozzle that sucks fire-fighting air (aerator). The foam composition can be applied to a variety of substrates, as already established, including liquid chemicals. The foam can be distributed quickly as a thick savanna still mobile, on a surface of a liquid chemical, for rapid coverage and / or extinction of. a fire. In the case of an ignited liquid chemical, the drainage of the foam composition (ie the aqueous phase) can be drained and distributed as a film on the surface of the liquid chemical which, if the film becomes altered or broken, tends to reform to seal the vapors (sometimes existing at elevated temperatures) and prevent the ignition or re-ignition of the liquid chemical. The foam composition may preferably remain in the form of a foam sheet over the liquid chemical to provide continuous vapor suppression and resistance to ignition or re-ignition (i.e., resistance to burning again) of the liquid chemical for a significant time after extinction. Preferably, the foam may remain in a stable and useful foam state for a period of up to and exceeding 24 or even 48 hours after formation, may provide a vapor suppression for a period greater than 6 hours and may preferably provide a resistance to re-burning from a chemical fire for 30 minutes. Methods of Testing Foaming procedure 100 g (100 mL) of the desired premix was placed in a Waring laboratory mixer (model 31BL91 7010), followed by 3 mL of a desired non-aqueous thickener suspension containing non-hydrated thickener. The resulting mixture was immediately aerated by high speed mixing for 10 seconds to produce a stabilized foam. Foam Expansion To run the Generation Procedure of the Foam, the expansion is calculated as the volume in millimeters, measured by the graduations in the mixer, of the foam generated, divided by the initial premix volume (typically 100 mL).

Foam Stability Tests The stability of a foam was measured by determining the 25% Drain Time, 75% Drain Time, Foam persistence, and / or Foam height over time. 25% Drain Time The 25% Drain time of a foam was determined by measuring the amount of time required for 25 mL of the 100 mL of liquid in the foam, generated using the Foam Generation Procedure, for Drain it from the foam. This was done by transferring the foam generated from the mixer to a graduated cylinder and taking the time when 25 mL of liquid accumulated in the bottom of the graduated cylinder. 75% Drain Time The Drain Time to 75% of a foam was determined by measuring the amount of time required for 75 percent of the liquid (typically approximately 100 mL) in the foam to drain. The foam was generated by placing 95 g of the desired premix and 3 ml of the thickener slurry in a Hobart mixer (model N-50) and mixing them immediately in the high speed settler for 15 seconds. All the foam was quickly transferred from the Hobart mixer to a 2000 mL graduated beaker, and the time was recorded when 75 mL of the liquid accumulated in the bottom of the beaker. Foam Persistence The persistence of the foam was measured by transferring the foam generated using the Foam Generation Process to an aluminum vessel (12.7 cm x 10.2 cm x 7.6 cm depth) and observing the behavior of the foam. . The persistence of the foam was determined according to the time required for the foam to completely melt or collapse. Foam height The height of the foam was measured by transferring the foam generated using the Foam Generation Process to an aluminum vessel (12.7 cm x . 2 cm x 7.6 cm deep) and measuring the depth of the foam with a small ruler at various times. Vapor Suppression Test A round metal vessel, 16.5 cm in diameter and 7.5 cm in height, was filled with 250 g of flammable liquid fuel as indicated in the data tables. 100 g of foam generated using the Foam Generation Process was poured on top of the fuel surface. After each 1 minute interval, an attempt of 10 seconds was made to ignite the fuel vapors by passing a match in 2 centimeters of the perimeter of the vessel. The end point of the test was defined as the time in minutes elapsed when the foam was no longer able to suppress the fuel vapors and ignition resulted. Test of resistance to re-burning or return of fire of 50% A round metal vessel of 16 cm in diameter by 7.5 cm high, was filled with 250 g of flammable liquid fuel. A small copper tube 3.5 cm in diameter and 4.7 cm high, was placed in the center of the vessel containing the fuel. 100 g of the foam generated using the foam generation process was poured on top of the fuel surface in the annular space between the tube and the vessel, leaving the central area inside the tube open. After 15 minutes, the fuel inside the copper tube was ignited and allowed to burn for 3 minutes. Then, the copper tube was gently removed from the vessel, allowing the flames to come into direct contact with the foam layer or blanket and a timing was started. The fire was allowed to expand until 50% of the foam blanket had been destroyed by the heat of the blazing fire, and the time of this event was recorded as 50% of the time of re-burning or return of the fire. Fire Extinction Test A round metal vessel measuring 16.5 cm in diameter and 7.5 cm in height, was filled with 250 g of flammable liquid fuel. The fuel was ignited and allowed to burn for 60 seconds. The foam to be tested was poured over the burning fuel at a slow, steady speed until the fire died out. The length of time (sec.) Required for the fire to extinguish, and the amount (grams) of foam used to extinguish the fire were recorded. The speed of application was calculated from these values. Glossary of Materials Jaguar ™ 2243 - a guar gum available from Rhone Poulanc MPA-1075 - an anti-sedimentation agent available from Rheox, Inc. PEG 300 - Poly (ethylene glycol) having a number average molecular weight (Mn) of approximately 300 , available from Union Carbide Corp., Danbury, Conneticut as Carbowax ™ 300 glycol.

ATC-603 - a 3M ™ Ligth Water ™ AR-AFFF foam concentrate designed to quench both polar and non-polar organic liquids, available from 3M Company, St. Paul, Minnesota.

Xanthan gum - a polysaccharide containing mannose, glucose and glucuronic acid salts, available from Kelco as Kelzan ™. Carob bean gum - a polysaccharide containing galactose and mannose, available from Gumix International. IPA - isopropyl alcohol MTBE - methyl t-butyl ether Actigum CX9YL1M - a xanthan gum, available from Sanofi Bio Industries Kaolin - a very fine particle size clay, available from Engelhard Corp. FC-203CF - a 3M ™ foam concentrate - gth WaterTM AFF, available from 3M Company, St Paul, Minnesota. Pusher 500 - a polyacrylamide, available from Dow Chemical Company Elvanol 72-60 - a polyvinyl alcohol, available from DuPont. Soluble Starch - suitable for iodometry, available from Merck.

Gelatin GX45 L404 - available from Matheson Coleman & Bell Mfg. Chemists, Norwood, Ohio. Cyanamer A-370 - a polyacrylonitrile that has undergone 70% hydrolysis with potassium hydroxide to polyacrylate / acrylonitrile, available from Cytec Ind. Klucel type J - hydroxypropylcellulose, available from Hercules Corp. Sodium Carboxymethylcellulose (DHT) - available from Penn Carbose Inc. Jaguar Plus - a cationic high molecular weight guar derivative, available from Stein May. Amine Oxide Foaming Agent A - a fluorinated amine oxide surfactant (86% in water) made as described in WO 9746283. Amine oxide foaming agent B - a fluorinated amine oxide surfactant (605 in water), made as described in WO 9746283. Miranol C2M-SF A - an amphoteric hydrocarbon surfactant (70% in water), available from Rhone Poulanc. Miranol C2M-SF B - an amphoteric hydrocarbon surfactant (39% in water), available from Rhone Poulanc. Mirataina CBS - an amphoteric hydrocarbon surfactant, available from Rhone Poulanc.

SOS - sodium octyl sulfate SLS - sodium lauryl sulfate Witcolate 7093 - a C6-C alkyl ester or sodium sulphate ether, available from Witco, Greenwich CT. SDS -sodium sulfate. Toliltriazole - a corrosion inhibitor, available from PMC Specialties. DPnP - di (propylene glycol) n-propyl ether DPM - didpropylene glycol) methyl ether KelzanTM - xanthan gum, available from Kelco Company Starch H2777 - a modified corn starch, available from Staley Mfg. Co. Rheolate 2001 - an anti-settlement agent / stabilizer, available from Rheox, Inc. Bentone SD2 - an anti-settlement agent, available from Rheox, Inc. Stanpol 530 - hydroxy propyl corn starch, from A.E.

Staley Mfg. Co. , Decatur IL. Dupanol ME - now Supralato ME Seco, available from Witco. Example L A non-hydrated thickener suspension was prepared by thoroughly combining and mixing the following components until a uniform, homogeneous consistency had been achieved. Component Parts by weight Jaguar ™ 2243 (thickener) 33 MPA-1075. { anti-settling agent) 0.7 (solids) Di (propylene glycol) methyl ether (organic solvent 4) PEG300 (organic solvent) 62.3 Using the Foam Generation Procedure, a stabilized foam was made with air stabilized with a mixture of water solution of the 3% tap of ATC-603 and the thickener suspension above. The test of Foam Persistence and Expansion were run over the stabilized foam, and the results are shown in Table 1. The procedure above was repeated, except that the stabilized foam was immediately transferred to a clean graduated cylinder for observation of the Time of Drained to 25%. The results are shown in Table 1. Example 2 A suspension of thickener was prepared as in example 1, with the following components. Component Parts by weight Xanthan gum / locust bean gum (1: 1) (thickener) 4.1 MPA-1075 (anti-settling agent) 0.7 (solids) Di (propylene glycolmethyl ether (organic solvent) 4 PEG300 (organic solvent) 91.2 The slurry suspension was mixed and subjected to aeration with ATC-603, using the Foam Generation Procedure. Foam Expansion, Persistence was determined of the Foam and the 25% Drain Time as in Example 1. the results are shown in Table 1. Comparative Example Cl A foam was prepared from a solution of 3% tap water of ATC-603 alone , using the Foam Generation Procedure The results of the Foam Expansion, Foam Persistence and 25% Drain Time tests, determined as in Example 1, are shown in Table 1.

Table 1 X / L xanthan gum / locust bean gum (1: 1) The 25% drainage time and Foam Persistence data in Table 1 demonstrate an extremely large increase in foam stability, while maintaining a good Foam Expansion, as a result of the addition of thickener suspensions. Example 3 The foam preparation of Example 1 was repeated and the foam was tested on various flammable liquids for vapor suppression. The results are shown in Table 2. Example 4 The foam preparation of Example 2 was repeated and the foam was tested in various flammable liquids for vapor suppression. The results are shown in Table 2. Comparative Example C2 The foam preparation of Comparative Example 1 was repeated and the foam was tested on various flammable liquids for vapor suppression. The results are shown in Table 2. Table 2 The data in Table 2 show that the addition of the thickener suspensions of the present invention greatly increases the length of time in which the emergence of steam from a wide range of flammable liquids is suppressed. Example 5 The preparation of the foam of Example 1 was repeated, and the foam was tested on various flammable liquids for its 50% re-burning resistance. The results are shown in Table 3 Comparative Example C3 The preparation of the foam of Comparative Example Cl was repeated, and the foam was tested on various flammable liquids for its re-burned or 50% fire return resistance. The results are shown in Table 3. Table 3 1 The minus sign indicates that the re-burning or return of the fire to 50% occurred many seconds before the usual 3 minute mark (time = 0 for the Resistance to burn again) for the removal of the copper tube, which It resulted in a failure to achieve resistance to burn again. 2 Because of the high resistance to re-burning or return of fire, the percentage that burns again in 960 seconds was only 27.5% for the IPA and 32.5% for the acetone, significantly less than the full 50% normally used as the final point. 3 Since it continued to self-extinguish, the result of the Resistance to burn or return from fire test should be considerably larger than 350 seconds. EXAMPLE 6 The preparation of the foam of Example 1 was repeated, the Foam Expansion was measured and the stability of the foam was tested, by measuring the Foam Height initially, at 24 hours and 48 hours, or by observation of the presence of foam in these times. The results are shown in Table 4. Example 7 A thickener solution was prepared as in Example 1 with the following components: Component Parts by weight Actigum CX9YL1M (thickener) 33 Di (propylene glycol) met ether (organic solvent) 67 A 3% aqueous solution of ATC-603 (100 ml) was placed in a mixer with 3 ml of the suspension of thickener The mixture was immediately subjected to aeration by mixing for 10 seconds at high speed and the expansion of the foam was observed. The foam was transferred to a small aluminum tray, and the height of the foam was initially measured at 24 hours and 48 hours. The results are shown in Table 4. Example 8 A thickener solution was prepared and tested as in Example 7, using Jaguar ™ 2243 instead of Actigum. The results are shown in Table 4. Example 9 A thickener solution was prepared as in Example 1, using Kaolin (in an equal amount) instead of MPA-1075, was tested as in Example 7. The results are shown in Table 4. Comparative Example C4 The foam preparation of Example was repeated Comparative Cl, Foam Expansion was measured, and foam stability was tested by measuring the Foam Height initially, at 24 hours, and at 48 hours. The results are shown in Table 4. Table 4 The data in Table 4 show that the addition of the thickener suspensions of the present invention makes the foam stable for a much longer period of time than without the thickener suspensions, while at the same time allowing good expansion to occur. of the foam. Comparative Example C5 A solution with tap water of FC-203CF (100g) was mixed for 15 seconds in a Hobart mixer (model N-50), placed at high speed. The resulting foam was poured into a 2000 mL glass cuvette, the foam volume was measured to calculate the Foam Expansion and the foam was observed for the 75% Drain Time. The results are shown in Table 5. Comparative Example C6 Three milliliters of PEG 300 were added to 97 g of a solution with tap water of FC-203CF in a Hobart mixer. The foam was originated and tested as in Comparative Example C5. The results are shown in the Table 5. Examples 10-19 Three milliliters of a 33% slurry of PEG 300 thickener were added to 97 g of a solution with tap water of FC-203CI in a Hobart mixer. This was mixed immediately at high speed for 15 minutes and the resulting foam was poured into a 2000 mL glass beaker. The volume of the foam was measured to calculate the Foam Expansion and the foam was observed for the 75% Drain Time. The results are shown in Table 5. Table 5 The data in Table 5 show the addition of a variety of thickener suspensions, increases the stability of the foam, while allowing excellent expansion of the foam.

EXAMPLE 20 Several concentrates in simple solutions (SSC), which contained both foam concentrate and thickener suspension, were prepared by combining the ingredients, and mixing for approximately 60 seconds in a mixer, until a uniform suspension was obtained and creamy The amounts of each components of the SSCs, (in parts by weight of solids, for the solid components, and in parts by weight of solvents for the solvents), are given in Table 6; the amount of water indicated in Table 6 is the maximum amount of water that may be present in the SSC due to the presence of water in one or more of the components. Table 6 EXAMPLES 21-25 Each concentrate in simple solution prepared in Example 20 was combined in the amount of 3 mL with 97 mL of tap water in a Waring blender (model 31BL91 7010), and mixed at a high rate set for 10 seconds. . Foam Expansion and Foam Height were measured. In addition, the consistency of the foam was evaluated according to the following criteria: firm foam - a foam, which will form a persistent peak (similar to whipped cream) thick foam - a foam, which will form but not maintain a normal foam peak - a foam, which will not always form a peak (This is the consistency of the foam generated when mixing in the Waring mixer at a high speed for 10 seconds, only ATC-603 at 3% in tap water). results are shown in Table 7. Example 26 A combination of 97 g of 3% ATC-603 in tap water and 3 mL of Jaguar ™ 2243 in DP was prepared and mixed immediately in the Waring blender setting a high speed for 10 seconds. The resulting foam was tested as in Examples 21-25, and the results are reported in Table 7 as Foam Expansion (FX), Foam Height (FH) Over Time, and Foam Consistency of Concentrates in Simple Aerated Solution (SSC).

Table 7 The data in Table 7 indicate that simple concentrates in solution provide good expansion of the foam and excellent foam stability (comparable to or better than the combined separate mixtures of foam concentrates and thickener suspension shown in Example 26) although low levels (< -5%) of water are present in the concentrates. Example 27 A simple concentrate in solution was prepared by combining and mixing the following components in a Waring laboratory mixer (model 31BL91 7010) for 60 seconds setting a high speed. A uniform and creamy suspension was produced. Component Parts by weight Powder of Dupanol ME 8.0 Kelzan TM 1.0 Starpol 530 1.0 Jaguar ™ 2243 33.0 MPA 1075 1.5 (solids) Bentona SD2 0.5 DPM 55.0 An aerated foam was prepared from the above concentrate and water, using the Generation Procedure Foam and was evaluated with the Fire Extinction Test. The results are shown in Table 8. Table 8 The data in Table 8, show the effective extinguishing capacity of the fire, of an aerated foam, prepared with a concentrate in simple solution without a fluorocarbon component. EXAMPLE 28 A slurry of thickener was prepared as in Example 1 with the following components: Component Parts by weight MPA 1075 0.7 (solids) Bentona SD2 0.4 JaguarTM 2243 33 DPM 65.04 An aerated foam was prepared, with the overhead thickener suspension in a 3% premix with FC-203CF tap water, according to the Foam Generation Procedure, and evaluated with the Fire Extinguishing Test. The results are shown in Table 9. Table 9 The data in Table 9, show the effective fire extinguishing capacity of an aerated foam, prepared with the addition of a thickener suspension. It is noted that with respect to this date, the best method known to the applicant to carry out the aforementioned invention is that which is clear from the present description of the invention.

Claims (28)

1. CLAIMS Having described the invention as above, the content of the following claims is claimed as property: 1. A process for the preparation of an aqueous foam, the process characterized in that it comprises the step of aerating a composition, comprising water, a thickener not hydrated and a fluorinated surfactant.
2. 2. The process of claim 1, characterized in that the composition contains from about 0.001 to about 10 parts by weight of thickener.
3. 3. The process of claim 1, characterized in that the composition contains from about 0.1 to about 1 part by weight of thickener.
4. The process of claim 1, characterized in that the composition, which is capable of being aerated to form a useful foam, comprises an amount of non-hydrated thickener, such that if the thickener was completely hydrated, the composition does not it could be aerated to produce a useful foam.
5. 5. The process of claim 1, characterized in that the composition has a viscosity below the viscosity that would be reached after complete hydration of the thickener.
6. 6. The process of claim 1, characterized in that the thickener has been in contact with the water for a period of time shorter than the period of hydration of the thickener.
7. The process of claim 6, characterized in that the thickener has contacted the water less than 10 seconds.
8. 8. The process of claim 1, characterized in that the foaming composition contains undissolved thickener.
9. 9. The process of claim 1, characterized in that the thickener is substantially not hydrated.
10. The process of claim 1, characterized in that the viscosity of the foaming composition is less than 50% of the viscosity of the foaming composition if the thickener is completely hydrated.
11. The process of claim 1, characterized in that the foaming composition substantially does not contain polyvalent ion complexing agent, crosslinking agent and protein hydrosylate.
12. 12. The process of claim 1, characterized in that, the thickener comprises a polysaccharide.
13. The process of claim 12, characterized in that, the polysaccharide is selected from the group consisting of xanthan gum, scleroglucan, heteropolysaccharide-7, locust bean gum, partially hydrolyzed starch, guar gum, guar gum derivatives , starch, sodium carboxymethylcellulose, and mixtures thereof.
14. The process of claim 12, characterized in that, the polysaccharide comprises a polysaccharide having at least 100 units of saccharide or a number average molecular weight of at least 18,000.
15. 15. The process of claim 12, characterized in that the thickener comprises guar gum, xanthan gum, or both.
16. 16. The process of claim 1, characterized in that the composition further comprises a non-fluorinated surfactant.
17. 17. The process of claim 1, characterized in that the composition is prepared by conversion to a residue of the fluorinated surfactant in a water flow.
18. 18. The process of claim 1, characterized in that the composition is prepared by converting a non-hydrated thickener residue into a water stream.
19. The process of claim 18, characterized in that the composition is prepared by converting a slurry of thickener comprising non-hydrated thickener and non-aqueous solvent to a residue in the water stream.
20. The process of claim 1, characterized in that it further comprises the step of applying the foam to a liquid chemical.
21. The process of claim 1, characterized in that it further comprises the step of applying the foam to a substrate found in the path of a fire.
22. 22. A process for preparing a foaming composition comprising water, a fluorinated surfactant and a non-hydrated thickener, the process, characterized in that it comprises the steps of providing water flowing through a hose, and adding the non-hydrated thickener to the water flow.
23. 23. The process of claim 22, characterized in that it further comprises the step of adding the fluorinated surfactant to the water flow.
24. 24. The process of claim 22, characterized in that the non-hydrated thickener is converted to a waste in the water flow.
25. 25. The process of claim 22 ,. characterized in that, the non-hydrated thickener is converted to a waste in the water flow as a concentrate comprising non-hydrated thickener, the optional non-fluorinated surfactant, the fluorinated surfactant, the organic solvent and substantially without water.
26. 26. The process of claim 22, characterized in that it further comprises the step of aerating the foaming composition comprising non-hydrated thickener to form a foam. The process of claim 26, characterized in that the foaming composition is aerated to a foam less than 10 seconds after the addition of the non-hydrated thickener to the water flow. The process of claim 26, characterized in that the composition is aerated to a foam while the composition contains undissolved thickener.