Process and composition for providing reduced discoloration of pyrithiones
AssigneeOlin Corporation
InventorsCheryl B. French, Gene A. Hyde
Life of this patent
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Abstract
Aqueous pyrithiones and a process and composition for providing reduced discoloration of these pyrithiones using an alkali metal or alkaline earth metal salt of 1-hydroxyethane-1,1-diphosphonic acid.
Claims13
A process for reducing or inhibiting the formation of a blue coloration in a metalworking fluid, said blue coloration being due to the presence of ferric ion and sodium pyrithione in said metalworking fluid, which comprises adding to said metalworking fluid an effective amount of an alkali metal or alkaline earth metal salt of 1-hydroxyethane-1,1-diphosphonic acid.
A process for reducing or inhibiting the formation of a blue coloration in an aqueous concentrate of a metalworking fluid, said blue coloration being due to the presence of ferric ion and sodium pyrithione in said aqueous concentrate, which comprises adding to said aqueous concentrate an effective amount of an alkali metal or alkaline earth metal salt of 1-hydroxyethane-1,1-diphosphonic acid, the amount of said sodium pyrithione in said aqueous concentrate being between about 450 ppm and about 5000 ppm.
In an improved metalworking fluid composition containing ferric ion and sodium pyrithione, the improvement comprising said composition additionally containing an alkali metal or alkaline earth metal salt of 1-hydroxyethane-1,1-diphosphonic acid in an amount sufficient to inhibit or prevent any blue coloration in said metalworking fluid caused by the presence of said ferric ion and said sodium pyrithione.
Dependencies are inferred from the claim text.