Process of inhibiting scale formation with mixtures of thio-, oxygen or thio-oxygen phosphates and pyrophosphates
AssigneePetrolite Corporation
InventorsDerek Redmore, Alfred E. Woodson
Life of this patent
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Abstract
Mixtures of Thiophosphates, pyrophosphates containing both oxygen and sulfur, and oxygen phosphates are effective as scale inhibitors. The mixtures are synergistically more effective as scale inhibitors than each component individually. These synergistic mixtures are also effective for other uses such as for inhibiting corrosion, particularly in aqueous and/or oxygenated systems.
Claims14
A process of inhibiting scale formation in a system which comprises treating said system with a composition comprising a mixture of thiophosphate, pyrophosphate containing both oxygen and sulfur, and oxygen phosphate esters of alcohols selected from the group consisting of alkanols having at least seven carbon atoms and alcohols of the formula R'(OA).sub.n OH where R' is alkyl, cycloalkyl, alkenyl, aryl, aralkyl, alkaryl, or heterocyclic, A is an alkylene moiety and n is from 1 to 100, said pyrophosphate esters being the major part of the combined thiophosphate and pyrophosphate esters and the weight ratio of said combined esters to the oxygen phosphate esters being from about 10:1 to 1:10.
Dependencies are inferred from the claim text.