US3639263A
Expired / Lapsed
US
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Corrosion inhibition with a tannin, cyanohydrinated lignosulfonate, and an inorganic metal salt composition
Assignee: ChampionX LLC
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Filing: 1968-07-31
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Granted: 1972-02-01
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Expires: 1988-07-31
Abstract
Abstract A corrosion-inhibiting composition and process consisting of (a) a water-dispersible tannin, (b) a cyanohydrinated lignosulfonate or naphthalene sulfonate, and (c) a polyvalent metal ion masking agent for the chelating system, e.g., zinc nitrate.
Inventors
- 👤 Edwin S Troscinski
- 👤 Reed S Robertson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:59
CPC Classifications
C; C02; C02F; C02F5/00; C02F5/08; C02F5/10; C02F5/105; C23; C23F; C23F11/00; C23F11/08; C02F2303/00; C02F2303/08
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
67 words
The composition of claim 1 wherein said water-dispersible tannin is a natural tannin having been modified by reaction with a material selected from the group consisting of an alkali metal sulfite, an alkali metal bisulfite, ammonium sulfite, ammonium bisulfite, an alkali metal haloacetate, an alkali metal halopropionate, an alkali metal halobutyrate, ammonium cyanide, an alkali metal cyanide, ammonium thiocyanate, alkali metal thiocyanate, nitric acid, and sulfuric acid.
Claim 2
Dependent Claim
19 words
The composition of claim 2 wherein said inorganic salt is zinc sulfate and said cyanohydrinated compound is cyanohydrinated lignosulfonate.
Claim 3
Dependent Claim
31 words
The composition of claim 1 which additionally contains about 2.35 to about 7.8 percent by weight of a compound selected from the group consisting of 2-mercaptobenzothiazole and its alkali metal salts.
Claim 4
Dependent Claim
129 words
A process for inhibiting corrosion of a ferrous metal surface in contact with a corrosive cooling water medium which comprises maintaining contact of said surface with said water which additionally contains a corrosion-inhibiting composition consisting essentially of a chelating system to complex water-dispersible iron species existing in said cooling water which chelating system consists essentially of 10-70 parts by weight of a water-dispersible tannin, and 5-50 parts by weight of a compound selected from the group consisting of cyanohydrinated lignosulfonates and cyanohydrinated naphthalene sulfonates, and 10-60 parts by weight of a masking agent to retard said complexing action of said chelating system which consists essentially of a water-soluble inorganic metal salt containing a multivalent metal ion selected from the group consisting of zinc, cobalt, aluminum, cadmium, manganese and nickel.
Claim 5
Dependent Claim
67 words
The process of claim 5 wherein said water-dispersible tannin is a natural tannin having been modified by reaction with a material selected from the group consisting of an alkali metal sulfite, an alkali metal bisulfite, ammonium sulfite, ammonium bisulfite, alkali metal haloacetate, an alkali metal halopropionate, an alkali metal halobutyrate, ammonium cyanide, an alkali metal cyanide, ammonium thiocyanate, an alkali metal thiocyanate, nitric acid and sulfuric acid.
Claim 6
Dependent Claim
19 words
The process of claim 6 wherein said water-soluble salt is zinc sulfate and said sulfonate compound is cyanohydrinated lignosulfonate.
Claim 7
Dependent Claim
33 words
The process of claim 5 wherein said composition additionally contains about 2.35 to about 7.8 percent by weight of a compound selected from the group consisting of 2-mercaptobenzothiazole and its alkali metal salts.
Claim 8
Dependent Claim
36 words
The process of claim 5 wherein said cooling water has a pH ranging from about 6.0 to 8.0 and said inhibitor composition is present in said cooling water in the amount of 10-500 parts per million.
References Cited (Backward Citations)
US3256203A
Cited
US3352793A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-31 | 1975-08-02 | 1976-02-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-31 | 1979-08-02 | 1980-02-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-31 | 1983-08-02 | 1984-02-01 | $7700.00 | Window Closed / Lapsed |