Scale inhibition
AssigneeChemed Corporation
InventorsChih M. Hwa, Dionisio G. Cuisia
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Abstract
This invention relates to an improved composition for inhibiting deposition of scale in aqueous systems. More specifically, it relates to the use of small quantities of an improved composition for preventing formation of scale and sludge deposits in steam generating boilers. The composition is characterized by the fact that by using a plurality of selected ingredients a synergistic effect is obtained. The ingredients comprise a copolymer of styrene sulfonic acid and maleic anhydride or maleic acid, along with a water soluble organophosphonic acid compound.
Claims8
Composition for inhibiting scale in an aqueous system consisting essentially of (a) a member selected of the group consisting of copolymers of styrene sulfonic acid and maleic anhydride or maleic acid, and water soluble salts of said copolymers, the styrene sulfonic acid moiety in said copolymer being about 50-95 weight % and the molecular weight of the copolymers being about 1500-6000;
- and (b) a water soluble phosphonic acid and its water soluble salts;
- the weight ratio of copolymer to phosphonic acid being about 0.3-4:1.
Composition according to claim in 1 in which the moiety is about 67-90%.
Composition for inhibiting scale in an aqueous system which consists essentially of (a) a member selected of the group consisting of copolymers of styrene sulfonic acid and maleic anhydride or maleic acid, and water soluble salts of said copolymers, the styrene sulfonic acid moiety in said copolymer being about 67-90% and the molecular weight of the copolymers being about 2000-4000;
- and (b) a member selected from a group consisting of hydroxyethylidene diphosphonic acid and its water soluble salts;
- the weight ratio of copolymer to hydroxyethylidene phosphonic acid being about 0.3-4:1.
Dependencies are inferred from the claim text.