| 摘要 |
A foaming concentrate for use with water comprises one part by weight of an anionic or non-ionic surfactant foaming agent and from 0.1 to 5 parts of a water dispersable, water-swellable polymer. Specified surfactants are sodium N - methyl - N - oleoyl taurte, monosodium N - lauryl - b - iminodipropionate, dioctyl sodium sulphosuccinate, sodium b -oleoyl ethane sulphonate, sulphated castor oil, sodium and potassium alkyl aryl sulphonates, ethylene oxide adducts of alkylphenols and non-ionic, water-soluble cellulose ethers. Specified polymers include lightly cross-linked, water-soluble polyalkanes having anionic groups (e.g. carboxylate and sulphonate groups) attached to the polyalkane chain, e.g. salts of polyacrylic, polymethacrylic, polysulphoethyl acrylic, polysulphoethyl methacrylic and polysulphoethyl itaconic acids, lightly cross-linked copolymers of acrylic, methacrylic and sulphoethylacrylic acids and monvalent cation salts thereof, with acrylamide, methacrylamide, N-alkyl substituted acrylamides, N-vinyl-2-oxazolidinone and N-vinyl pyrrolidinone; homopolymers of alkali metal vinyl aromatic sulphonates and co-polymers thereof with acrylamide, sodium acrylate and potassium methacrylate. Other suitable polymers may also include water-insoluble co-monomers such as styrene, methyl-and ethyl-methacrylate, acrylonitrile and vinyl acetate in addition to the above water-soluble components.ALSO:A copolymer is produced by copolymerizing acrylamide with about 0.015% by weight of methylene bisacrylamide and subsequently hydrolysing the copolymer with NaOH to convert approximately 30% of the initially available carboxamide groups to sodium carboxylate groups. The resulting polymer, together with numerous other water-swellable, water-disposable polymers which are mentioned, may be mixed with an anionic or non-ionic surfactant and water to produce a mixture capable of forming "gelled" foams suitable for firefighting.ALSO:A concentrate for use in making gelled, aqueous, fire-extinguishing foams comprises 1 part by weight of a water-soluble foaming agent (e.g. an anionic or nonionic surfactant) and from 0.1 to 5 parts of a water-dispersible, water-swellable polymer, e.g. lightly crosslinked, water-soluble polyalkanes having a plurality of carboxylate or sulphonate groups, e.g. salts of polyacrylic and polysulphoethyl acrylic acids lightly cross-linked e.g. with acrylamides and alkali metal vinyl aromatic sulphonates and co-polymers thereof with acrylamide or acrylates. |
