Noncorrosive urea-sulfuric acid reaction products
AssigneeUnion Oil Company of California
InventorDonald C. Young
Life of this patent
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Abstract
Improved liquid, urea-sulfuric acid compositions noncorrosive to stainless steel contain about 5 to about 75 weight percent urea, about 5 to about 85 weight percent sulfuric acid, 0 to about 75 weight percent water and a corrosion inhibiting amount of a cupric ion-containing compound, in which the urea and sulfuric acid together comprise at least about 25 weight percent of the composition, and in which at least a portion of the urea and sulfuric acid are present as monourea sulfate, diurea sulfate or combinations thereof. The compositions may also contain amounts of selected dialkylthioureas sufficient to reduce their corrosivity to carbon steel.
Claims12
A composition of matter comprising about 5 to about 75 weight percent urea, about 5 to about 85 weight percent sulfuric acid and about 0 to about 75 weight percent water in which said urea and sulfuric acid, in combination, constitute at least about 25 weight percent of said composition and in which at least a portion of said urea and sulfuric acid are present as a member selected from the group consisting of monourea sulfate, diurea sulfate, and combinations thereof, containing a corrosion inhibiting amount of a cupric ion-containing compound sufficient to reduce the corrosivity of said composition to stainless steel.
A composition of matter relatively noncorrosive to stainless steel comprising a liquid urea-sulfuric acid reaction product containing about 10 to about 70 weight percent urea, about 10 to about 80 weight percent sulfuric acid and about 0 to about 25 weight percent water in which said urea and sulfuric acid, in combination, constitute at least about 75 weight percent of said composition and in which at least a portion of said urea and said sulfuric acid are present as a member selected from the group consisting of monourea sulfate, diurea sulfate, and combinations thereof, containing a corrosion inhibiting amount of a cupric ion-containing compound corresponding to a cupric ion concentration of at least about 50 ppm sufficient to reduce the corrosivity of said composition to stainless steel.
Dependencies are inferred from the claim text.