摘要 |
Concentrates suitable for making fire-fighting liquids upon sixteen-fold dilution are described comprising particular perfluoro ampholytic surfactants, solvents and fluorine-free surfactants. The ampholytic surfactants are of the general formula <IMAGE> wherein n represents an integer of from 1 to 20, a represents an integer of from 2 to 10, q represents an integer of from 0 to 10, p represents an integer from 0 to 10 and each of R1, R2 and R3, which may be the same or different, are hydrogen, C1-6alkyl or CnF2n+1-(CH2)a-SO2 The solvent is a glycol or glycol ether preferably butyldigol or butyl cellosolve. When the preferred fluorine-free surfactants are used the solutions obtainable on dilution will form a film on n-hexane. The concentrates contain less than 2% of the perfluoro surfactant. |