EP2198932A2 - Use of amphoteric tensides for creating foam - Google Patents

Abstract

Containing foam-forming compositions for firefighting,
a) one or more amphoteric surfactants from the group of amphoacetates and amphodiacetates, hydroxysultaines, glycinates, amine oxides, betaines and / or sulfobetaines, and
b) one or more carboxylic acids,
c) optionally one or more solubilizers, for example monohydric or polyhydric alcohols, glycols, glycol ethers or glycol ether acetates,
d) optionally water and / or
e) optionally further auxiliaries and further additives, with the proviso that the surface tension of a dilute aqueous solution of the composition at room temperature below 25 mN · m ^-1 , as well as their use.

Description

The invention relates to foam-forming aqueous compositions containing amphoteric surfactants and fatty acids and their use.

Aqueous foams are suitable for a variety of applications, for example in the field of cosmetics for the production of shaving or hair care products, domestic or industrial cleaning, suppression of dust, papermaking, dyeing, fractionation or separation of metals or their salts, for Isolation of ice surfaces, concrete or cement production, protection of surfaces, structures or vegetation against fire and / or heat, for fire fighting, including fires in mines, and for frost protection of plants. For a more detailed explanation of some of these applications be on AR Aidun, CS Grove Jr., DN Meldrum, Novel Uses of Aqueous Foams, Chem. Eng. 1964, 71, 145-148 directed. In addition, there is a need for foams for applications where the foam contacts non-aqueous liquids, such as organic solvents or petrochemical fuels, and where the foam must have sufficient stability and flowability. These applications include the cleaning of facilities such as tank farms, pipes, pipelines or boilers, the reduction of evaporation losses of volatile hydrocarbons or other organic solvents, or the firefighting. Thus, it is known to combat fires, especially of fuels, by giving up coherent foam blankets. Such foam blankets are also suitable for preventing the occurrence of fires. To produce these foams, foaming agents are usually used, which are based on the Spit surfaces of flammable liquids spontaneously and form a thin, water-containing film between foam and flammable liquid ("Aqueous Film Forming Foam" - AFFF or A3F). This film ensures the rapid spread of the foam and a vapor-tight barrier, preventing re-ignition. As an essential ingredient, AFFFs contain surfactants with perfluorinated groups. Such foaming agent compositions are for example in the publications DE-1 216 116 . EP-A-0 595 772 . US 4,420,434 . DE-2 357 281 described.

Another application of perfluorinated surfactants relates to the control of solid fires. To improve the effect on hydrophobic, solid surfaces, a surfactant is added to the extinguishing water. Examples of such surfaces are plastic, waxed paper or hard coal. The addition of a surfactant improves the wetting effect or the penetration depth of the extinguishing water, and thus the effectiveness with the hydrophobic solids can be cooled.

However, in the context of increasing environmental awareness, compounds with perfluorinated groups have come under increasing criticism in recent years due to their extremely low biodegradability and sometimes high residence time in organisms. M. Fricke, U. Lahl, Risk assessment of perfluorosurfactants as a contribution to the current discussion on the REACH dossier of the European Commission, UWSF - Z. Umweltchem. Ökotox. 2005, 17, 36-49 ). In 2005, the country proposed a worldwide ban on perfluorooctane sulfonates (PFOS) - common ingredients and source materials for AFFF - as part of the Stockholm Convention on Persistent Organic Pollutants. One skilled in the art can expect to restrict the use of surfactants with perfluorinated groups in the future for environmental and health reasons, and these, even if their use for extinguishing applications exceptionally permitted, due to the reduced volume of production, will only be available at rising prices.

There is therefore a need for foaming or wetting agents which are suitable for combating solvent, fuel, fuel or solid fires and which manage without or at least with a significantly reduced proportion of surfactants having perfluorinated groups.

Highly foaming surfactants are, for example, the so-called amphoteric surfactants, also called amphoteric surfactants or ampholytic surfactants. These are surfactants which are anionic or cationic depending on the pH. Examples of amphoteric surfactants are amphoacetates and amphodiacetates, amphopropionates and amphodipropionates, hydroxysultaines, glycinates, amine oxides, betaines and sulfobetaines. A particular class of amphoteric surfactants are the sulfobetaines and the betaines which exist in solution at neutral pHs as zwitterionic surfactants. The prior art relating to the use of organic, amphoteric surfactants for fire fighting is summarized here.

He and Scripture DE-29724835 corresponding surfactant concentrates containing only 0.05 to 2 parts of an amphoteric fluorosurfactant have been described as a film former and an organic amphoteric surfactant as a foaming agent. The writings DE-19708733 and WO-9604961 describe similar surfactant concentrates, also containing an amphoteric fluorosurfactant as a film former and an organic amphoteric surfactant as a foaming agent. In Scripture WO-9927373 are surfactant concentrates containing partly a surfactant from the group of Hydroxysultaine, dipropionates and propionates, diacetates and acetates, betaines, Amidopropylsultaine and hydroxy-substituted, amphoteric sulfonates, and partly a perfluorinated amine oxide. The font WO-9746283 describes similar mixtures.

In order to enable the aforementioned film formation on the surfaces of combustible liquids, according to equation (1), the value of the spreading coefficient S must be positive. Otherwise, the aqueous phase forms a lens on the flammable liquid. $$\mathrm{S}\mathrm{=}{\mathrm{\sigma }}_{\mathrm{oa}}\mathrm{-}{\mathrm{\sigma }}_{\mathrm{wa}}\mathrm{-}{\mathrm{\sigma }}_{\mathrm{ow}}$$

S =

Spreitkoeffizient

σ_oa =

Oberflächenspannung der brennbaren Flüssigkeit

σ_wa =

Oberflächenspannung der wässrigen Lösung

σ_ow =

Grenzflächenspannung zwischen wässriger Lösung und brennbarer Flüssigkeit.

In this mean:

S =

spreading coefficient

σ _oa =

Surface tension of the flammable liquid

σ _wa =

Surface tension of the aqueous solution

σ _ow =

Interfacial tension between aqueous solution and combustible liquid.

As can be seen from Equation (1), the surface tension of the flammable liquid provides an upper limit to the surface tension of a spreading aqueous solution. The surface tension of flammable liquids is typically below 25 mN · m ^-1 at room temperature. Cyclohexane, for example, has a surface tension of 24.65 mN · m ^-1 at 25 ° C., n-heptane has a surface tension of 19.65 mN · m ^-1 ( Source: CRC Handbook of Chemistry and Physics, 83rd Edition, CRC Press, Boca Raton, 2002 ). In contrast, the surface tension of solutions of organic surfactants above the critical micelle concentration is typically above 30 mN · m ^-1 . Pure conventional organic surfactants are therefore not able to take over the role of perfluorinated surfactants.

The same analysis generally applies to the wetting of hydrophobic solid surfaces. The surface tension of flammable liquids should be replaced by the surface energy of flammable solids. In order to enable wetting on hydrophobic, solid surfaces, according to equation (1), the value of the spreading coefficient S must also be positive. Otherwise, the aqueous phase forms a hemisphere on the surface.

The physical properties of surfactant mixtures in some cases differ greatly from the properties of the individual components. Thus, the surface tension of mixtures of surfactants is often lower than that of the pure substances. Such mixtures have been described in the literature. In the scriptures US 5,946,026 and US 6,139,775 are mixtures of 4 to 40 parts of C ₁₆ -C ₁₈ tallow fatty amine with 2-10 0 ethoxy units per molecule, 1 to 15 parts of C ₆ -C ₁₆ fatty acid, 1 to 6 parts of C ₆ -C ₁₆ fatty alcohol, and 1 to 10 parts of C ₄ or shorter chain alcohols have been described. In Scripture WO-2003006110 a hexanoic acid neutralized mixture of C ₁₄ -C ₁₈ tallow fatty amine with 5 ethoxy units per molecule, and coconut fatty amine with both 2 and 5 ethoxy units has been described. 33 parts of this mixture were mixed with 3 parts of a 2-ethoxylated C ₆ -C ₁₆ fatty alcohol and 10 to 15 parts of sodium dodecyl sulfate. However, aqueous solutions of the nonionic, ethoxylated fatty amines used have a cloud point, depending on the number of ethoxy units. Above the cloud point, there is a destabilization of the foam. It is therefore advisable to dispense with the use of surfactant concentrates on the use of ethoxylated surfactants. In addition, C ₁₆ -C ₁₈ tallow fatty amines with, for example, 5 ethoxy units as (CESIO Recommendations for anionic and non-ionic surfactants, Bruxelles, 2000, p.17) so that their use can not be recommended. The same applies to coconut fat amines with 2 or 5 ethoxy units.

In Scripture JP-51084197 is a mixture of 10 to 40 parts of C ₁₂ -C ₁₈ Alkyldimethylbetain, 5 to 30 parts of Al, Mg or Ca soap based on C ₁₂ -C ₁₈ fatty acids, 1 to 5 parts of C ₁₂ -C ₁₄ alkanol and solvent described Service. However, C ₁₂ -alkanol or lauryl alcohol is considered to be hazardous to the environment and very toxic to aquatic organisms. Al, Mg or Ca soaps based on fatty acids are often used because of their defoaming action. Their use in fire-fighting foams can therefore only be recommended to a limited extent ( Source: Defoaming - Theory and Industrial Applications, Surfactant Science Series Volume 45, Marcel Dekker Inc., New York, 1993, p.204 ).

In Scripture US-7172709 9 is the application of high molecular weight polymers with a molecular weight of 5,000 to 2,000,000 described. The polymers carry both acid groups with corresponding counterions as well as hydrophobic alkyl groups. Although the addition of surfactant concentrates with such polymers improves the foaming, the drainage of the foams produced and their fluidity, this does not solve the fundamental problem - the surface tension and the spreading of the surfactants used.

It is therefore an object of the present invention to provide blends of environmentally friendly, fully or predominantly biodegradable organic surfactants which do not have one or more disadvantages of the prior art. Particularly preferred are those from the aqueous Solutions containing the mixtures of organic surfactants according to the invention, foams obtained without the addition or at least with reduced addition of compounds with perfluorinated groups have a high stability to hydrophobic liquids. The blends of organic surfactants according to the invention should preferably also be simple and inexpensive to produce.

Surprisingly, it has been found that the inventive task can be achieved by mixing amphoteric surfactants with carboxylic acids.

1. a) ein oder mehrere amphotere Tenside aus der Gruppe der Amphoacetate und Amphodiacetate, Hydroxysultaine, Glycinate, Aminoxide, Betaine und/oder Sulfobetaine, sowie
2. b) eine oder mehrere Carbonsäuren,
3. c) gegebenenfalls ein oder mehrere Löslichkeitsvermittler, beispielsweise ein- oder mehrwertige Alkohole, Glykole, Glykolether und/oder Glykoletheracetate,
4. d) gegebenenfalls Wasser und/oder
5. e) gegebenenfalls weitere Hilfsstoffe und weitere Zusätze, mit der Maßgabe, dass die Oberflächenspannung einer verdünnten wässrigen Lösung der Zusammensetzung bei Raumtemperatur unterhalb 25 mN·m^-1 liegt, sowie deren Verwendung.

The present invention therefore provides foam-forming or wetting compositions for firefighting,

1. a) one or more amphoteric surfactants from the group of amphoacetates and amphodiacetates, hydroxysultaines, glycinates, amine oxides, betaines and / or sulfobetaines, and
2. b) one or more carboxylic acids,
3. c) optionally one or more solubilizers, for example monohydric or polyhydric alcohols, glycols, glycol ethers and / or glycol ether acetates,
4. d) optionally water and / or
5. e) optionally further auxiliaries and further additives, with the proviso that the surface tension of a dilute aqueous solution of the composition at room temperature below 25 mN · m ^-1 , as well as their use.

ein Amphoacetat der allgemeinen Formel (II),

oder ein Amphodiacetat der allgemeinen Formel (III)

allein oder in Mischungen miteinander enthalten.Particular preference is given to foam-forming compositions which as component a) are a betaine of the general formula (I),

an amphoacetate of the general formula (II),

or an amphodiacetate of the general formula (III)

contained alone or in mixtures with one another.

M ⁺ is an alkali metal, ammonium and / or an organically substituted ammonium ion. Preferred alkali metal are sodium and potassium. The particularly preferred component a) according to the invention of the general formula (I), (II) or (III) has as radical R a saturated or unsaturated, linear or branched aliphatic carbon chain having 5 to 30 carbon atoms or a saturated or unsaturated, linear one or branched aliphatic carbon chain having inserted into the carbon chain heteroatoms having between 5 and 40 atoms in the carbon heteroatom chain, from. Cocamidopropyl betaine, C ₈ -C ₁₀ alkylamidopropyl betaine, cocoamphoacetate, C ₈ -C ₁₀ alkyl amphoacetate, cocoamphodiacetate, C ₈ -C ₁₀ alkyl amphodiacetate or mixtures thereof are particularly preferably used as component a). Heteroatoms can be an or multiple oxygen, nitrogen and / or sulfur atoms are present in the carbon chain. Betaine, amphoacetates and amphodiacetates may contain a high salt load due to their production, which does not adversely affect the application; in particular, up to 10% by weight of sodium chloride may be contained.

The compounds of the formulas (I), (II) and (III) are typically technical products whose main constituents correspond to the formulas given (source: fats • soaps • paints 80, 448, 1978).

The carboxylic acids of component b) may, for. B. be selected from mono- or polybasic, saturated or unsaturated, linear or branched aliphatic carboxylic acids having 5 to 30 carbon atoms. Examples of suitable carboxylic acids are the unbranched saturated carboxylic acids n-decanoic acid, n-dodecanoic acid, n-tetradecanoic acid, n-hexadecanoic acid and n-octadecanoic acid. The carboxylic acids may be technical mixtures of molecules with different carbon chain lengths. C ₈ -C ₁₀ fatty acid, n-decanoic acid, n-dodecanoic acid or mixtures thereof are particularly preferably used as the carboxylic acid (component b)).

The mass ratio of betaines as component a) to component b) in the concentrate in the composition according to the invention is preferably from 99% by weight to 1% by weight to 80% by weight to 20% by weight, and particularly preferred from 95 wt% to 5 wt% to 85 wt% to 15 wt%. In the case of amphoacetates and diacetates as component a), the ratio to component b) in the composition according to the invention is 80% by weight to 20% by weight to 20% by weight to 80% by weight and particularly preferably 70% by weight. from 30% to 30% by weight to 70% by weight.

When using mixtures of betaines and amphoacetates or amphodiacetates as component a) the ratio is to component b) in the composition according to the invention 99% by weight to 1% by weight to 20% by weight to 80% by weight and particularly preferably 95% by weight to 5% by weight to 30% by weight % to 70% by weight.

In addition, mono- or polyhydric alcohols, glycols, glycol ethers or glycol ether acetates are used as solubility promoter as inventive component c). As component (c) one or more substances can be selected from the group comprising ethanol, n-propanol, isopropanol, 1,3-propanediol, 1,3-butanediol, 2,3-butanediol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, Dipropylene glycol, tripropylene glycol, propylene glycol methyl ether, dipropylene glycol methyl ether, tripropylene glycol methyl ether, propylene glycol ethyl ether, dipropylene glycol ethyl ether, tripropylene glycol ethyl ether, propylene glycol n-propyl ether, dipropylene glycol n-propyl ether, tripropylene glycol n-propyl ether, propylene glycol n-butyl ether, dipropylene glycol n-butyl ether, dipropylene glycol dimethyl ether, tripropylene glycol n-butyl ether, ethylene glycol methyl ether, diethylene glycol methyl ether, triethylene glycol methyl ether, ethylene glycol ethyl ether, diethylene glycol ethyl ether, triethylene glycol ethyl ether, ethylene glycol n-propyl ether, diethylene glycol n-propyl ether, triethylene glycol n-propyl ether, ethylene glycol n-butyl ether, diethylene glycol n-butyl ether, diethylene glycol dimethyl ether, triethylene glycol n-butyl ether, propylene glycol ether acetate, 3-butoxy-2-propanol, hexylene glycol, glycerol and trimethylolpropane.

The inventive compositions can be marketed as a solid mixture or highly concentrated aqueous solutions and then, if necessary, brought to an application concentration with (further) water having a surface tension of less than 25 mN / m.sup.- ¹ at 25.degree. The highly concentrated solution of the components may contain up to 75% by weight of the mixture of components a) and b) preferably, the concentration is between 20 and 65 wt .-%. The solvent used is preferably water (component d)). The concentrations of a) and b) and their ratio to c) and d) depend mainly on the production conditions of the amphoteric surfactant and the desired use concentrations and viscosities. The required concentrations are familiar to the person skilled in the art or easily determinable according to the intended use.

As component (e), the typical auxiliaries and additives may be anionic, nonionic or cationic hydrocarbon surfactants, perfluorosurfactants, polymeric foam stabilizers and / or thickeners, high molecular weight acidic polymers and / or coordinating salts, antifreeze agents, sequestering agents, corrosion inhibitors, film-forming additives, preservatives, water and additives which are obvious to the person skilled in the art. The addition of perfluorosurfactants can result in an extinguishing foam which, in use, has a further improved extinguishing rate and a reduced risk of re-ignition. The compositions of the invention preferably have less than 1.0% by weight of perfluorosurfactant, based on the weight of the composition of the invention, or less than 0.1% by weight of perfluorosurfactant in the foam, resulting from the dilution of the composition to the application concentration. The teaching according to the prior art, as z. As the above-mentioned writings US 3,849,315 . US 4,038,195 . US 3,957,657 and US 3,957,658 as well as the writings of the font family DE-A-28 26 224 . WO-A-80/01883 . US 4,464,267 . US 4,387,032 . US 4,060,489 . US 4,149,599 and US 4,060,132 can be removed, requires a five to tenfold concentration of surfactants with perfluorinated groups.

The desired surface tension at room temperature of an aqueous solution of the composition according to the invention consisting of the components a), b) and c) is below 25 mN · m ^-1 , disregarding the customary auxiliaries and additives (which can further lower the surface tension).

With the foams prepared from the dilute solutions of the compositions of the invention, fires can be avoided by covering the possible combustible with a foam carpet. Furthermore, even existing fires can be deleted. Particularly suitable is the foam prepared with the use of the composition according to the invention for controlling fires of hydrophobic materials, in particular liquids. In particular, fires different solvents, fuels and / or fuels or mixtures thereof with the foam, prepared with the concomitant use of the dilute aqueous solutions of the composition according to the invention, be deleted. Another application of the composition according to the invention relates to the control of solid fires. To improve the wetting effect or the penetration depth of the extinguishing water on / in hydrophobic, solid surfaces, the composition of the invention is added to the extinguishing water. Thus, the effectiveness with the hydrophobic solid can be cooled, increased.

Surprisingly, in the compositions according to the invention, the amount of active substance, that is the composition of amphoteric surfactant and carboxylic acid according to the invention - that is without further customary additives and auxiliaries - in an aqueous solution to produce a surface tension of less than 25 mN / m ^-1 , less than 5 wt .-%, preferably less than 3.0 wt .-% and in particular less than 0.6 wt .-%. Suitable extinguishing foams can then be used by methods familiar to the person skilled in the art generate, as z. In " Holger de Vries, Fire fighting with water and foam - technology and tactics, ecomed Verlagsgesellschaft AG & Co. KG, 1st edition 2002 , to be discribed. In practical application, however, the application concentration is linked to the circumstances of the equipment provided for deletion. In particular, the mixing plants and pumps used are designed for standard conditions between the foaming agent and the extinguishing water. Thus, typically, the ratio of the inventive concentrate to water is from 1% to 6% by weight. Depending on the ratio of water plus surfactant concentrate to air, it can be used to produce a heavy foam, a medium foam or a light foam.
For use as a wetting agent typically results in a ratio of the inventive concentrate to water of 0.5 wt .-% to 2 wt .-%.

Due to the high effectiveness of the inventive composition, the amount of amphoteric surfactant mixture and carboxylic acid compared to foam systems according to the prior art is significantly reduced in order to achieve at least comparable foam effect, which allows significant financial savings and a discharge of the environment.

The compositions according to the invention have the advantage that the foam obtained therefrom is also sufficiently stable on hydrophobic and optionally combustible materials, in particular liquids, and can thus be applied to such materials. As a result, the aqueous foams obtained from the compositions according to the invention are outstandingly suitable as fire-extinguishing foams or covering foams, in particular for use in the presence of hydrophobic materials, in particular hydrophobic liquids.

The stability of the foam prepared from the compositions according to the invention without the addition of surfactants having perfluorinated groups has the advantage that no fluoro-organic or other environmentally harmful compounds in the environment when using the composition according to the invention for the production of foam.

The compositions according to the invention and a process for their preparation and their use are described below by way of example, without the invention being restricted to these exemplary embodiments. Given below, ranges, general formulas, or classes of compounds are intended to encompass not only the corresponding regions or groups of compounds explicitly mentioned, but also all sub-regions and sub-groups of compounds obtained by removing individual values (ranges) or compounds can be. If documents are cited in the context of the present description, their contents are intended to form part of the disclosure content of the present invention.

1. a) anionische Kohlenwasserstofftenside wie beispielsweise Alkylcarboxylate, -sulfate, -sulfonate und deren ethoxylierten Derivate. Als Beispiele seien Natriumdodecylsulfat und Natriumdodecylbenzolsulfonat angeführt.
2. b) nichtionische Kohlenwasserstofftenside wie beispielsweise alkoxylierte Alkylphenole, alkoxylierte lineare oder verzweigte Alkohole, alkoxylierte Fettsäuren, alkoxylierte Alkylamine, alkoxylierte Alkylamide, alkoxylierte Acetylenglykole, alkoxylierte als auch nicht-alkoxylierte Sorbitanester, Gemini-Tenside wie beispielsweise Surfynol 104 (AirProducts), Alkylglycoside und Polyglycoside wie in US-5,207,932 beschrieben, und Ethylenoxid-Propylenoxid-Blockcopolyether.
3. c) Kationische Kohlenwasserstofftenside, wie beispielsweise quartäre Ammoniumverbindungen, Alkylpyridiniumsalze oder Alkylimidazoliniumsalze. Als Beispiel sei Cetyltrimethylammoniumchlorid angeführt.
4. d) Perfluortenside, beispielsweise solche wie in den US-Schriften 4,060,489 , 4,420,434 , 4,472,286 , 4,999,119 , 5,085,786 , 5,218,021 oder 5,616,273 beschrieben. Auf diese Weise kann ein Löschschaum erhalten werden, der bei der Verwendung eine weiter verbesserte Löschgeschwindigkeit und eine verminderte Wiederentzündungsgefahr aufweist. Erfindungsgemäß können die Zusammensetzungen 0 Gew.-% bis 2 Gew.-%, bevorzugt 0,01 Gew.-% bis 1 Gew.-% perfluorierte Tenside enthalten. In einer weiteren Ausgestaltung der Erfindung sind die Zusammensetzungen jedoch frei von perfluorierten Tensiden.
5. e) Polymere Schaumstabilisatoren und Verdicker wie beispielsweise Proteine oder deren Abbauprodukte wie beispielsweise teilhydrolysierte Proteine, Stärke, Polyvinylharze wie beispielsweise Polyvinylalkohol, Polyacrylamide, Carboxyvinylpolymere oder Polypyrrolidine,
6. f) die in WO-A-2004/112907 offenbarte Kombination mit hochmolekularen sauren Polymeren und koordinierenden Salzen,
7. g) Gefrierschutzmittel, wie beispielsweise Alkali- oder Erdalkalichloride, Harnstoff, Glycole, Glycolether oder Glycerin,
8. h) Sequestriermittel gegen Ausflockungen oder Separation wie beispielsweise Citrate, Ethylendiamintetraacetat, Polyaminopolycarbonsäuren oder Phosphonate,
9. i) Korrosioninhibitoren wie Alkanolamine, Phosphatester oder Triazole,
10. j) Film-bildende Zusätze wie beispielsweise die in der Schriftenfamilie DE-A-28 262 24 , WO-A-80/01883 , US-,464,267 , US-4,387,032 , US-4,060,489 , US-4,149,599 und US-4,060,132 beschriebenen Polysaccaride aber auch beispielsweise Xanthan, Pectin, Algin, Agar, Karrageen, Pectinsäure, Stärke, modifizierte Stärke, Alginsäure, gummi arabicum, Dextrane, Cellulose, Hydroxyalkylcellulosen, Celluloseether und -ester und dergleichen,
11. k) Konservierungsmittel wie beispielsweise Kathon CG/ICP (Rohm & Haas) oder Givgard G-4-40 (Givaudan), und/oder
12. l) weitere Zusätze, die für den Fachmann nahe liegend sind und hier nicht weiter aufgeführt sind.

The blends of amphoteric surfactants with carboxylic acids alone can form the composition of the invention. However, the compositions according to the invention may also comprise further additives which are suitable in particular for the production of foams. This can z. For example:

1. a) anionic hydrocarbon surfactants such as alkyl carboxylates, sulfates, sulfonates and their ethoxylated derivatives. As examples, mention may be made of sodium dodecylsulfate and sodium dodecylbenzenesulfonate.
2. b) nonionic hydrocarbon surfactants such as, for example, alkoxylated alkylphenols, alkoxylated linear or branched alcohols, alkoxylated fatty acids, alkoxylated alkylamines, alkoxylated alkylamides, alkoxylated acetylene glycols, alkoxylated as well as non-alkoxylated sorbitan esters, gemini surfactants such as Surfynol 104 (AirProducts), alkyl glycosides and polyglycosides as in US 5,207,932 and ethylene oxide-propylene oxide block copolyethers.
3. c) Cationic hydrocarbon surfactants, such as, for example, quaternary ammonium compounds, alkylpyridinium salts or alkylimidazolinium salts. As an example, cetyltrimethylammonium chloride is mentioned.
4. d) perfluorosurfactants, for example those as in U.S. Patents 4,060,489 . 4,420,434 . 4,472,286 . 4,999,119 . 5,085,786 . 5,218,021 or 5,616,273 described. In this way, an extinguishing foam can be obtained, which in use has a further improved extinguishing speed and a reduced risk of re-ignition. According to the invention, the compositions may contain from 0% to 2%, preferably from 0.01% to 1% by weight of perfluorinated surfactants. In a further embodiment of the invention, however, the compositions are free of perfluorinated surfactants.
5. e) polymeric foam stabilizers and thickeners such as proteins or their degradation products such as partially hydrolyzed proteins, starch, polyvinyl resins such as polyvinyl alcohol, polyacrylamides, carboxyvinyl polymers or polypyrrolidines,
6. f) the in WO 2004/112907 disclosed combination with high molecular weight acidic polymers and coordinating salts,
7. g) antifreeze agents, such as, for example, alkali metal or alkaline earth metal chlorides, urea, glycols, glycol ethers or glycerol,
8. h) flocculation or separation sequestrants such as citrates, ethylenediaminetetraacetate, polyaminopolycarboxylic acids or phosphonates,
9. i) corrosion inhibitors such as alkanolamines, phosphate esters or triazoles,
10. j) Film-forming additives such as those in the font family DE-A-28 262 24 . WO-A-80/01883 . US, 464.267 . US 4,387,032 . US 4,060,489 . US 4,149,599 and US 4,060,132 but also, for example, xanthan, pectin, algin, agar, carrageenan, pectin acid, starch, modified starch, alginic acid, gum arabic, dextrans, cellulose, hydroxyalkylcelluloses, cellulose ethers and esters and the like,
11. k) preservatives such as Kathon CG / ICP (Rohm & Haas) or Givgard G-4-40 (Givaudan), and / or
12. l) other additives which are obvious to the person skilled in the art and are not listed further here.

The compositions of the invention may be used to prepare a foam, preferably an aqueous foam. The compositions according to the invention can be used in particular for the production of fire-extinguishing foams or foams for reducing evaporation losses of volatile hydrocarbons or other organic solvents and for preventing the occurrence of fires. The compositions according to the invention or the mixtures of amphoteric surfactants and carboxylic acids contained in the compositions can also be used for the production of toxicologically acceptable foams for exercise purposes.

The composition according to the invention can be used in particular for producing aqueous foam which is applied to or produced on a hydrophobic surface or a liquid, preferably on a hydrophobic liquid. By virtue of the fact that the compositions according to the invention can be processed into aqueous foams which are based on hydrophobic materials, in particular liquids are relatively stable, can be avoided or prevented with such a foam that a combustible vapor escapes from a liquid or the fire of a combustible liquid are extinguished.

Another object of the invention are firefighting foams prepared using the compositions of the invention.

Another object of the invention are practice foams prepared using the compositions of the invention. These practice foams are free from perfluorinated surfactants, in particular for reasons of environmental protection.

Further embodiments of the invention will become apparent from the claims, the disclosure of which is fully incorporated in this description.
The compositions of the invention can be prepared in a variety of ways and at various concentrations. In particular, they can be prepared by mixing. Preference is given to compositions which are prepared by mixing the described amphoteric surfactants, fatty acids and solubilizers with anionic, nonionic or cationic hydrocarbon surfactants, perfluorosurfactants, polymeric foam stabilizers and / or thickeners, high molecular weight acidic polymers and / or coordinating salts, antifreezes, sequestering agents, corrosion inhibitors, film-forming agents Additives, preservatives, water and additives, which are obvious to those skilled, are used. at the concentrations taught by the references listed in this application.

Examples:

In the examples given below, the present invention is described by way of example, without the invention, the scope of application of which is apparent from the entire description and the claims, to be limited to the embodiments mentioned in the examples.

Concentration data relate - unless otherwise stated - to the weight.

Surface Tension:

The determination of the surface tension of the investigated foam solutions was carried out with the aid of a device of the type OCA 35 from Dataphysics Instruments GmbH, Filderstadt, and associated evaluation software. This device works computer-controlled according to the principle of the pendant-drop method. This is a method for determining the surface tension of liquids against a gas phase by means of a drop hanging on a capillary. Based on the drop shape, which is dependent on the balance of forces between gravity and surface tension, and can be mathematically described using the Young-Laplace equation, the surface tension of the liquid is determined.

Verschäumungsversuche:

The ability of organic surfactants to produce aqueous foams was tested by determining the expansion factor. The foaming number (VZ) is the ratio of the volume of the finished foam to the volume of the water-foaming agent mixture. A detailed description of this parameter can be found for example in G. Rodewald, A. Rempe: "Fire Extinguishing Agents - Properties - Effect - Application"; Kohlhammer Verlag, Stuttgart, 2005 , When performing the test was a Stirring mixer from Braun (type: Power Blend MX 2050) used.

Stability tests:

The kerosene stability of the foam at room temperature was measured by applying 100 mL of jet A1 kerosene produced in 100 mL of the described manner to the foam, which was in a 10.8 cm diameter metal dish. The time to rupture of the foam blanket was measured.

Extinguishing tests:

Fresh foam produced in the manner previously described was also used to extinguish kerosene fires. This was analogous to the published patent application DE-2 240 263 a metal funnel with a funnel opening of 18 mm with the opening placed over a 10.8 cm diameter metal dish containing 100 g of Jet A1 kerosene. The kerosene was lit. After prewaxing for a maximum of 15 seconds, quenching was started by applying 100 mL of the immediately generated foam to the side.

Example 1:

An aqueous solution containing 0.45% by weight of a surfactant or a mixture of 2 different surfactants and 1.0% butyl diglycol was prepared. The surface tension was measured by pendant-drop method. The results are shown in Table 1. Mixing ratio and surfactant content are always based on the active content of the individual surfactant solutions. Marlon ^® A315 is the sodium salt of dodecylbenzenesulfonic acid.
Forafac 1157 ^® is a perfluorinated surfactant.

The foamable aqueous composition of SYNDURA ^® (from Angus Fire), a commercially available, fluorine-free surfactant concentrate for the production of fire-fighting foams represents a 6 wt .-% dilution. Thus, the measured surface voltage refers in SYNDURA ^® on the manufacturer's recommended dilution of 6 wt .-%. Table 1: surface tension Surfactant A Surfactant B Mass ratio A: B σ mN · m ^-1 TEGO ^® Betain F50 - - 28.6 TEGO ^® betaine 810 - - 29.8 TEGO ^® betaine C60 - - 31.5 Sodium dodecyl sulfate - - 37.6 Marlon A315 - - 34.0 Rewoteric® AM C - - 36.3 Rewoteric® AM V - - 24.0 Rewoteric® AM 2C NM - - 35.4 TEGO ^® Betain F50 lauric acid 97.5: 2.5 26.0 TEGO ^® Betain F50 lauric acid 95: 5 25.3 TEGO ^® Betain F50 lauric acid 90:10 23.2 TEGO ^® Betain F50 lauric acid 85:15 23.8 TEGO ^® Betain F50 lauric acid 80:20 24.4 TEGO ^® Betain F50 lauric acid 75:25 23.6 TEGO ^® betaine C60 lauric acid 90:10 24.4 TEGO ^® betaine 810 capric acid 90:10 23.0 TEGO ^® Betain F50 Na dodecyl sulfate 90:10 27.3 Tego ^® Betain F50 Marlon A315 90:10 27.8 Rewoteric® AM C lauric acid 90:10 31.8 Rewoteric® AM C lauric acid 80:20 26.8 Rewoteric® AM C lauric acid 70:30 23.5 Rewoteric® AM C lauric acid 60:40 23.6 Rewoteric® AM C lauric acid 50:50 22.9 Rewoteric® AM V capric acid 60:40 23.6 Rewoteric® AM 2C NM lauric acid 60:40 22.6 Forafac ^® 1157 - - 16.4 SYNDURA ^® - - 23.9

The surface tension of TEGO ^® Betain F50 in the mixture with lauric acid strongly depends on the mixing ratio. At a mixing ratio of 90 parts TEGO ^® F50 Betaine to 10 parts of lauric acid, the surface tension reaches a minimum of 23 mN · m ^-1. The same applies to the surface tension of the Rewoteric® AM C. The minimum of 22.9 mN · m ^-1 is achieved with a mixing ratio of 50 parts of Rewoteric® AM C to 50 parts of lauric acid.
SYNDURA ^® shows a slightly higher surface tension at the application concentration of 6% by weight.

Example 2:

There were 100 ml of a solution of 0.45 wt .-% of a mixture of organic surfactants and 1.0 wt .-% of the foam aid butyldiglycol in tap water of about 8 ° German hardness foamed for 30 seconds with the aid of a stirring mixer from Braun (Type: Power Blend MX 2050) at level 5. The volume of the foam formed was determined in a graduated cylinder. The results obtained are summarized in Table 2, with 50% drainage time (DZ) being understood as the time that elapses until the recovery of half of the liquid. Table 2: Foaming factor (VZ), drainage time (DZ) and time to rupture of the foam blanket on kerosene at room temperature (ZA) Surfactant A Surfactant B mass ratio VZ mL DZ Min: sec ZA Min: sec TEGO ^® Betain F50 - - 8.4 4:30 > 30:00 TEGO ^® betaine 810 - - 4.0 1:40 12:10 Rewoteric® AM C - - 8.5 5:02 > 30:00 Rewoteric® AM V - - 4.4 3:40 > 30:00 Rewoteric® AM 2C NM - - 8.5 6:10 > 30:00 TEGO ^® Betain F50 lauric acid 90:10 5.9 7:45 1:20 TEGO ^® betaine 810 Dean acid 90:10 6.5 10:14 12:54 Rewoteric® AM C lauric acid 70:30 10.0 7:13 > 30:00 Rewoteric® AM C lauric acid 60:40 9.0 5:30 > 30:00 Rewoteric® AM C lauric acid 50:50 6.2 4:30 > 30:00 Rewoteric® AM V capric acid 60:40 4.8 4:00 > 30:00 Rewoteric® AM 2C NM lauric acid 60:40 5.6 5:10 > 30:00 Syndura ^® - - 5.4 14:10 10:00 Forafac ^® 1157 - - 3.0 5:00 > 30:00

The results show that in the compositions according to the invention of betaine or amphoacetate and carboxylic acid an increased water retention capacity, recognizable by the significantly increased DZ values, is present. The TEGO Betain F50 alone shows a low DZ combined with a high ZA. This is a characteristic of a very dry foam, which is no longer able to retain flammable gases / vapors and therefore appears unsuitable as a covering foam.

Example 3:

There were 100 ml of a solution of 0.45 wt .-% of a mixture of organic surfactants and 1.0 wt .-% of the foam aid butyldiglycol in tap water of about 8 ° German hardness foamed for 30 seconds with the aid of a stirring mixer from Braun (Type: Power Blend MX 2050) at level 5. 100 mL of generated foam was applied to 100 mL of Jet A1 kerosene in a 10.8 cm diameter metal dish. The foam forms a closed cover on the kerosene. The time to rupture of the foam blanket was measured, that is the time until the first hole appeared. The results obtained are summarized in Table 2.

Example 4:

There were 100 ml of a solution of 0.45 wt .-% of a mixture of organic surfactants and 1.0 wt .-% of the foam aid butyldiglycol in tap water of about 8 ° German hardness foamed for 30 seconds with the aid of a stirring mixer from Braun (Type: Power Blend MX 2050) at level 5. 100 g Jet A1 kerosene was ignited in a metal shell of 10.8 cm diameter. After a pre-firing time of a maximum of 15 s, the deletion was by the lateral application of 100 mL of the immediately before started foam produced. The time in seconds until complete extinguishment of the fire is indicated. Table 3: Delete time Surfactant A Surfactant B Mixing ratio (mass ratio) Extinguishing time [s] TEGO ^® Betain F50 keeps burning TEGO ^® Betain F50 lauric acid 90:10 10 TEGCO ^® betaine 810 Dean acid 90:10 30 Rewoteric® AM C lauric acid 70:30 1 Rewoteric® AM C lauric acid 60:40 1 Rewoteric® AM C lauric acid 50:50 1 Angus Fire Syndura ^® Keep burning

TEGO and Rewoteric are registered trademarks of Evonik Goldschmidt GmbH, Syndura is a registered trademark of Angus Fire Corp.

It is apparent from Examples 1 to 4, with the deliberately simply selected formulations, that the foams obtained from the compounds according to the invention are suitable for extinguishing fuels and heating fuels. Überrascherderweise the formulations of Rewoteric AM C and lauric acid commercially available formulations, especially with organic surfactants (Angus Fire Syndura ^® in Table 3) clearly superior.

Claims (25)

Containing compositions for firefighting, a) one or more amphoteric surfactants from the group of amphoacetates, amphodiacetates, hydroxysultaines, glycinates, amine oxides, betaines and / or sulfobetaines, and b) one or more carboxylic acids, c) optionally one or more solubilizers, for example monohydric or polyhydric alcohols, glycols, glycol ethers or glycol ether acetates, d) optionally water and / or e) optionally further auxiliaries and further additives, with the proviso that the surface tension of a dilute aqueous solution of the composition at room temperature is below 25 mN · m-1. A composition according to claim 1, comprising as component (a) at least one betaine. A composition according to claim 1, comprising as component (a) at least one amphoacetate or amphodiacetate. A composition according to claim 1, comprising as component (a) at least one betaine and one amphoacetate or amphodiacetate. A solid mixture containing a composition according to at least one of claims 1 to 4. An aqueous concentrate of the composition according to at least one of claims 1 to 4. Concentrate of the composition according to at least one of claims 1 to 5 dissolved in component (c) and / or (d). Use of a foam-forming aqueous solution of a composition according to at least one of Claims 1 to 7 for combating solvent, fuel and / or fuel fires. Use of a foam-forming composition according to at least one of claims 1 to 7 in foams for combating fires of hydrophobic materials and surfaces. Use of a composition according to at least one of claims 1 to 7 as wetting water wetting agent for controlling fires of hydrophobic materials and surfaces. Composition according to Claim 2, characterized in that cocamidopropyl betaine, C ₈ -C ₁₀ alkylamidopropyl betaine or mixtures thereof are used as component (a). Composition according to claim 3, characterized in that as component (a) cocoamphoacetate, C ₈ -C ₁₀ alkylamphoacetate, cocoamphodiacetate, C ₈ -C ₁₀ alkylamphodiacetate or mixtures thereof are used. Composition according to Claim 4, characterized in that the betaine used is a cocamidopropyl betaine, C ₈ -C ₁₀ alkylamidopropyl betaine or mixtures thereof, in which the amphoacetate is cocoamphoacetate, C ₈ -C ₁₀ alkylamphoacetate or mixtures thereof, and the amphodiacetate Cocoamphodiacetate, C ₈ -C ₁₀ alkyl amphodiacetate or mixtures thereof. A composition according to any one of claims 11 to 13, characterized in that as component (b) mono- or polybasic, saturated or unsaturated, linear or branched aliphatic carboxylic acids having 5 to 30 carbon atoms are used. A composition according to any one of claims 11 to 13, characterized in that as component (b) C ₈ -C ₁₀ fatty acid, n-decanoic acid, n-dodecanoic acid or mixtures thereof are used. Composition according to at least one of claims 11, 14 or 15, characterized in that the components (a) and (b) in the mass ratio of 99 wt .-% to 1 wt .-% to 80 wt .-% to 20 wt. % be used. Composition according to at least one of claims 12, 14 or 15, characterized in that the components (a) and (b) in a mass ratio of 70 wt .-% to 30 wt .-% to 30 wt .-% to 70 wt. % be used. Composition according to at least one of claims 13, 14 or 15, characterized in that the components (a) and (b) in a mass ratio of 99 wt .-% to 1 wt .-% to 30 wt .-% to 70 wt. % be used. Compositions according to at least one of claims 1 to 7, characterized in that as component (c) one or more substances can be selected from the group comprising ethanol, n-propanol, isopropanol, 1,3-propanediol, 1,3-butanediol, 2,3-butanediol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, Propylene glycol methyl ether, dipropylene glycol methyl ether, tripropylene glycol methyl ether, propylene glycol ethyl ether, dipropylene glycol ethyl ether, tripropylene glycol ethyl ether, propylene glycol n-propyl ether, dipropylene glycol n-propyl ether, tripropylene glycol n-propyl ether, propylene glycol n-butyl ether, dipropylene glycol n-butyl ether, dipropylene glycol dimethyl ether, tripropylene glycol n-butyl ether, Ethylene glycol methyl ether, diethylene glycol methyl ether, triethylene glycol methyl ether, ethylene glycol ethyl ether, diethylene glycol ethyl ether, triethylene glycol ethyl ether, ethylene glycol n-propyl ether, diethylene glycol n-propyl ether, triethylene glycol n-propyl ether, ethylene glycol n-butyl ether, diethylene glycol n-butyl ether, diethylene glycol dimethyl ether, triethylene glycol n-butyl ether. Propylene glycol ether acetate 3-butoxy-2-propanol, hexylene glycol, glycerol and / or trimethylolpropane. Compositions according to at least one of claims 1 to 7, containing as component (e) anionic, nonionic or cationic hydrocarbon surfactants, perfluorosurfactants, polymeric foam stabilizers and / or thickeners, high molecular acid polymers and / or coordinating salts, antifreezes, sequestering agents, corrosion inhibitors, film-forming additives and / or preservatives as further additives and auxiliaries. A composition according to claim 13, containing from 0.01% to 1% by weight perfluorinated surfactants. Composition according to Claim 13, characterized in that it is free from perfluorinated surfactants. Fire fighting foam made using a composition according to claim 20. Exercise foam made using a composition according to claim 20. Exercise foam according to claim 24, characterized in that it is free of perfluorinated surfactants.