| 摘要 |
1,272,481. Fire extinguishing with silicone foams. UNION CARBIDE CORP. 29 April, 1969 [30 April, 1968], No. 21663/69. Heading A5A. An aqueous fire-extinguishing foam comprises a foamed aqueous liquid containing 0.01-10% by wt of an amphoteric silicone surfactant Z 3 SiO[M<SP>1</SP>O 3 SLSi(R)O] n SiZ 3 wherein Z and R are C 1 -C 18 hydrocarbon radicals free of aliphatic unsaturation, M<SP>1</SP> is a monovalent cation, preferably alkali metal or ammonium, n has an average value of 1-3, and L is -R<SP>1</SP>- or -R<SP>2</SP>N(R<SP>3</SP>)R<SP>1</SP>- in which R<SP>1</SP> is C 3 -C 18 hydroxysubstituted alkylene, cycloalkylene, oxyalkylene or cyclooxyalkylene, R<SP>2</SP> is a C 2 -C 10 hydrocarbon radical, and R<SP>3</SP> is H or a C 1 -C 8 hydrocarbon radical, with the proviso that the hydroxyl substituent of R' is bonded to a carbon atom next to the carbon atom to which the sulphonate group is attached when L is R<SP>1</SP>, and is bonded to a carbon atom next to the nitrogen-bonded carbon atom when L is -R<SP>2</SP>N(R<SP>3</SP>)R<SP>1</SP>-. The silicone surfactant may be the major foam-forming constituent or a minor one used in conjunction with e.g. a hydrolysed protein foam, and/or may be used in conjunction with a dry powder extinguishant e.g. sodium or potassium bicarbonate, potassium sulphate or ammonium dihydrogen phosphate which may be mixed or coated with a wax or silicone, or with aluminium or magnesium stearate, mica, talc, magnesium oxide, silica or starch. Optionally the composition may include a drainage retardant e.g. asbestos, bentonite clay, carboxymethyl- or hydroxyethylcellulose, polyethylene oxide, polyvinyl alcohol, sodium polyacrylate, powdered licorice, glue, saponin, glycerin, glucose, sodium sulphonate or quillaia bark. Aqueous liquid concentrates contain 1.5-80% by wt. of the silicone surfactant. Examples disclose silicones Me 3 SiO[NaO 3 SCH 2 CH(OH)CH 2 OC 3 H 6 SiMeO] SiMe 3 ; and Me 3 SiO[NaO 3 SC 2 H 4 (N(Me)CH 2 CH(OH)CH 2 OC 3 H 6 SiMeO] n SiMe 3 where n is 1 and 1.5.
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