Patent ID: 6183649
Filing Date: 2001-02-06
Classification: C02F,C23F

Abstract:
A method for treating a water-circulating system and preventing, inhibiting and/or removing white rust, comprising the step of treating the water in said system with a composition comprising:I) R.sup.3 (COOM).sub.3 (PO.sub.3 M'.sub.2) wherein R.sup.3 is an aliphatic group having 3 carbon atoms, M and M' are the same or different and are hydrogen or an alkali metal,II) an alkali metal polyacrylate homopolymer,III) a polymer containing alkali metal salt units of the following formulas: --(--CH.sub.2 --C[R.sup.4 ][COOM""]--)--, ##STR3##wherein R.sup.4 through R.sup.8 are the same or different and are alkyl groups of 1 to 4 carbon atoms, Ar is an aromatic ring, and the M"" cations, which can be the same or different, are alkali metal cations,IV) alkali metal molybdate,V) an alkali metal salt of unsubstituted or substituted 1-H-benzotriazole, wherein the fused benzene ring of the benzotriazole is optionally substituted with a least one alkyl group of 1 to 4 carbon atoms,VI) optionally, an alkali metal bromide, andVII) optionally, sufficient alkali metal hydroxide to raise the pH of said composition to about 10.5 to about 12, and sufficient water to provide an aqueous solvent medium for the components of said compositionwherein the water circulating system includes metallic elements, and wherein at least one metallic element comprises galvanized metal, and wherein said composition is brought into contact with the galvanized metal, and thereby preventing, inhibiting and/or removing white rust.