IL41860A - Aqueous fire-extinguishing compositions - Google Patents

Claims (3)

41860/2 C L A I M S

1. An aqueous compositions useful for extinguishing fires of highly volatile hydrocarbons comprising water, a mixed water-soluble fluoroaliphatic surfactant system and a water-soluble synthetic imputrescible hydrocarbon-congruous organic fluorine -free surfactant, wherein the mixed fluoroaliphatic surfactant system comprises a fluoroaliphatic ampholytic surfactant containing in addition to a terminal fluoroaliphatic radical, at least one terminal cationic or cationically ionizable center and at least one terminal anionic or anionically ionizable center and an anionic fluoro-aliphatic surfactant containing at least one fluoroaliphatic radical of at least four carbon atoms including a terminal perfluoromethyl group and an anionic group, said composition being substantially free from volatile flammable materials and being capable of forming a tough, durable, rapidly-forming and spreading film on the surface of the hydrocarbon thereby inhibiting the release of flammable vapors therefrom.

2. A composition according to claim 1 wherein the fluoroaliphatic ampholytic surfactant is characterized by the general formula + 41860/2 wherein R^, is a fluoroaliphatic radical containing 1 to about 20 or more carbon atoms and b is an integer from 1 to 3; B is a hydrolytically stable organic radical free of ionizable groups,' whose valence is equal to (b+2); the carbon-bonded fluorine of the Rf radical constituting at least 10 by weight of the surfactant; R_ is three like or different unsubstituted alkyls of 1 to about 18 carbon atoms or alkyls of 1 to about 18 carbon atoms substituted by water solubilizing groups, or in combination with the nitrogen atom to which attached is a heterocyclic radical in combination with no more than one lower alkyl group; and Y are divalent hydrocarbylene radicals containing 1 to about 12 carbon atoms; and A, the anionic center, is the radical of an acid having an ionization constant in water at about 25°C. of at least 1 x 10"^ and the salts of said ampholytic fluoroaliphatic surfactant.

3. A composition according to claim 1 wherein the fluoroaliphatic ampholytic surfactant is characterized by the formula -NR R„X QN f p y-A wherein Rf is a fluoroaliphatic radical containing 1 to about 20 carbon atoms; X is a divalent linking radical of 1 to about 12 ψ carbon atoms; p is 0 or 1; Q is -S02- or -CO-; R^ is three like or different unsubstituted alkyls of 1 to about 18 carbon atoms or alkyls of 1 to about 18 carbon atoms substituted by water solubilizing groups, or in combination with the nitrogen atom to which attached R^ is a heterocyclic radical in combination with no more than one lower alkyl group; W is a divalent hydrocarbylene radical containing 2 to about 12 carbon atoms; Y is a divalent hydrocarbylene radical containing 1 to about 12 carbon atoms; A is the radical of an acid having an ionization -5 constant in water at about 25°C. of at least about 1 x 10 ; and the salts of said ampholytic fluoroaliphatlc surfactant ; and the anionic fluoroaliphatlc surfactant is a fluoroaliphatlc radical containing sulfonate characterized by the general formula wherein Rf and Xp are as defined hereinabove; and the salts thereof. ^ ". An aqueous concentrate composition useful for extinguishing fires of highly volatile hydrocarbons com-prising (a) mixed fluoroaliphatlc surfactant systems of an ampholytic fluoroaliphatlc surfactant and an anionic fluoroaliphatlc surfactant in a ratio between 1:4 and 4:1; (b) a synthetic imputrescible hydrocarbon-congruous organic fluorine-free surfactant, the ratio of the fluorine-containing and fluorine-free surfactants being between 1:10 and 10:1; (c) a water-soluble stabilizer selected from the group consisting of alkyl ethers of alkylene glycol and glycerol; and (d) water said concentrate composition upon dilution with about sixteen parts by weight water being capable of forming a fire extinguishing foam which upon disintegration forms a tough, durable ,· rapidly-forming and spreading film on the surface of the hydrocarbon thereby inhibiting the release of flammable, vapors therefrom. 5 f>, . . A composition according to any one of the preceding claims, substantially as herein described*