GB1001312A - Dry, powdered compositions for extinguishing metal fires - Google Patents

Abstract

The invention comprises dihydrocarbontin dialkylbenzene a ,a 1-dimercaptides of the formula <FORM:1001312/C2/1> for example <FORM:1001312/C2/2> where R is an aralkyl, alkyl, or phenyl radical, R1 and R11 are alkylene radicals containing 1-3 C atoms, and x is at least one, and the preparation thereof by mixing substantially equimolar portions of <FORM:1001312/C2/3> and <FORM:1001312/C2/4> in an inert diluent and heating to at least 60 DEG C. The -SR1- and -R11S- groups in starting material and product may be o-, m- or pto each other. The benzene ring may contain other inert substituents, e.g. CH3-. Examples of starting materials are <FORM:1001312/C2/5> and R2SnO, where R is methyl, ethyl, butyl, isobutyl, tert-butyl, amyl, hexyl, heptyl, octyl, nonyl or dodecyl. Examples of inert diluents are benzene, toluene, petroleum naphtha, hexane and heptane. Example 1 describes the preparation of dibutyltin p-xylene a ,a 1-dimercaptide. Other examples show the reaction of (2) d-n-octyltin oxide with a ,a 1-dimercapto-p-xylene, (3) diphenyltin oxide with a ,a 1-dimercapto - p - xylene, (4) di - n - butyltin oxide with a ,a 1 - dimercapto - m - diethyl benzene, (5) di-p-tolytin oxide with a ,a 1-dimercapto-p-dipropyl benzene, (6) di-n-amyltin oxide with a ,a -dimercapto-o-xylene, (7) di-cyclohexyl tin oxide with a ,a 1-dimercapto-p-diethylbenzene, (8) diallyltin oxide with a ,a 1-dimercapto-m-xylene, (9) dibenzyltin oxide with a ,a 1-dimercapto-p-xylene.ALSO:A fire-extinguishing composition for metal fires comprises a powdered dry mixture of from 40 to 60% by weight of polyvinyl chloride and 60 to 40% by weight of sodium borate. Preferably, the bulk of the composition is of particle size 10 to 100 microns and contains one or more flow-improving additives and/or water-proofing agents e.g. talc, mica, kieselguhr, calcium phosphate, zinc, magnesium and aluminium stearates.