US3579447A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of removing copper deposits from ferrous metal surfaces using hydroxyalkyl thiourea
Assignee: Richardson Co
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Filing: 1968-09-30
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Granted: 1971-05-18
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Expires: 1988-09-30
Abstract
Abstract REMOVAL OF COPPER-CONTAINING INCRUSTATIONS FROM FERROUS METAL SURFACES ACCOMPLISHED IN IMPROVED MANNER BY ADDITION OF A HYDROXYALKYL THIOUREA HAVING AT LEAST TWO CARBON ATOMS IN THE ALKYL GROUP SUCH AS 1-HYDROXYETHYL-3METHYL THIOUREA TO AN AQUEOUS TREATING SOLUTION AND SUBSEQUENT TREATMENT OF FERROUS METAL SURFACES WHEREIN REDUCED SLUDGE FORMATION ACCOMPLISHES REMOVAL OF COPPER AND THE AVOIDANCE OF COPPER PLATING.
Inventors
- 👤 Thanddeus M Muzyczko
- 👤 William J Ludwig
- 👤 Jon A Loboda
- 👤 Samuel Shore
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 12:28
CPC Classifications
C; C23; C23G; C23G1/00; C23G1/02; C23G1/08
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) | 1974-05-17 | 1974-11-16 | 1975-05-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-17 | 1978-11-16 | 1979-05-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-17 | 1982-11-16 | 1983-05-18 | $7700.00 | Window Closed / Lapsed |