US3677827A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Composition and method for blackening metal articles
Assignee: Oxford Chemicals Inc
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Filing: 1969-09-09
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Granted: 1972-07-18
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Expires: 1989-09-09
Abstract
Abstract A COMPOSITION FOR PRODUCING BLACK OXIDE COATINGS ON FERROUS METALS COMPRISING A LIQUID MIXTURE OF SODIUM HYDROXIDE, SODIUM NITRATE, SODIUM NITRITE, AND WATER IS IMPROVED BY THE ADDITION OF TRIETHANOLAMINE OR OTHER IRON SEQUESTRANTS.
Inventors
- 👤 Roger Weaver
- 👤 Eugene Schaffstall
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:45
CPC Classifications
C; C23; C23C; C23C22/00; C23C22/05; C23C22/60; C23C22/62
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-18 | 1976-01-17 | 1976-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-18 | 1980-01-17 | 1980-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-18 | 1984-01-17 | 1984-07-18 | $7700.00 | Window Closed / Lapsed |