Patent ID: 7608208

Claim:
A method of using water-swellable polymers in fire prevention or fire fighting comprising: (i) adding a salt containing water having common salt (NaCl) as the largest saline moiety and between about 2 and 28 weight-% total salt content and a quantity of an additive comprising a water-swellable polymer at least partially based on at least one sulfonic acid group containing unsaturated monomer to make a fire extinguishing water composition, the water-swellable polymer comprising at least: (a) between about 50 and 70 mol-% of at least one sulfonic acid group containing monomer, (b) between about 10 and 60 mol-% of at least one nonionic monomer selected from any one of methacrylamide, n-alkyl-substituted acrylamide, 2-hydroxyethylacrlate, 2-hydroxyethylmethacrylate, hydroxypropylacrylate, hydroxypropylmethacrylate, C 1 -C 4 alkyl(meth)acrylate, vinyl acetate, acrylamide, or combinations thereof, and (c) between about 0.1 to 3 mol-% of at least one cross-linking agent; and (ii) applying the fire extinguishing water composition to a surface for fire protection or fire fighting, wherein the quantity of the additive used in the fire extinguishing water composition is an amount that provides an amount of electrolyte sufficient to raise a viscosity of the fire extinguishing water composition to over about 1000 mPas.