Patent ID: 6099755
Filing Date: 2000-08-08
Classification: C02F,C23F

Abstract:
A composition for simultaneously controlling the deposition of scale and the formation of corrosion in a cooling water system comprising a combination of (a) a water soluble terpolymer having the structure: ##STR9## wherein E is a repeat unit obtained after polymerization of an alpha, beta ethylenically unsaturated carboxylic acid or sulfonic acid monomer, amide form thereof, or lower alkyl (C.sub.1 -C.sub.6) ester or hydroxylated lower alkyl (C.sub.1 -C.sub.5) ester of said carboxylic acid, and salts thereof, the molar ratio of x:y:z is approximately 1-10: 1-4: 1-4, R.sub.1 is H or lower (C.sub.1 -C.sub.4) alkyl, F is H.sub.2 or O, M is a water soluble cation, R.sub.2 is (CH.sub.2 --CH.sub.2 --O).sub.n, ##STR10## or mixture of both, n is an integer of from about 1 to about 40, R.sub.3 is H, lower (C.sub.1 -C.sub.4) alkyl or an acetate, and (b) a water soluble acrylic acid/allylhydroxypropyl sulfonate ether copolymer or water soluble salt form thereof, said copolymer having the formula: ##STR11## wherein M.sup.1 is a water soluble cation, the weight ratio of (a):(b) is about 1:1 and the molar ratio x.sup.1 :y.sup.1 is from about 3:1-6:1.