Patent US3578509A successfully refreshed from Google Patents.
US3578509A
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US
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Conditioning ferrous metal substrates
Assignee: Diamond Shamrock Corp
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Filing: 1968-05-17
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Granted: 1971-05-11
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Expires: 1988-05-17
Abstract
Abstract TO PREPARE A FERROUS METAL SURFACE FOR RECEIVING A HEXAVALENT-CHROMIUM-CONTAINING COATING COMPOSITION, THE SURFACE IS FIRST CONTACTED WITH AN AQUEOUS SOLUTION HAVING A PH OF BETWEEN ABOUT 2-6 AND CONTAINING UP TO ABOUT 50 WEIGHT PERCENT OF AMMONIUM DIHYDROGEN PHOSPHATE AND /OR ALKALI METAL DIHYDROGEN PHOSPHATE. THE RESULTING CONTACTED SURFACE IS THEN RINSED AND MAY BE DRIED. THE SOLUTION MAY ALSO CONTAIN, FOR EXAMPLE, OXIDIZING IONS AND SURFACE ACTIVE AGENTS. AFTER THIS PREPARATION AND THE ESTABLISHMENT OF THE ABOVE-NOTED COATING, SUBSTRATES EXHIBIT WELDABILITY AND ENHANCED PAINT ADHESION.
Inventors
- 👤 Bert E Palm
- 👤 William Wayne Warner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 15:16
CPC Classifications
C; C23; C23C; C23C22/00; C23C22/82; C23C22/83; Y; Y10; Y10T; Y10T428/00; Y10T428/27; Y10T428/273; Y10T428/29; Y10T428/2913; Y10T428/2933; Y10T428/294; Y10T428/2942
Claims Analysis
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References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-05-10 | 1974-11-09 | 1975-05-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-10 | 1978-11-09 | 1979-05-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-10 | 1982-11-09 | 1983-05-11 | $7700.00 | Window Closed / Lapsed |