US3190748A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of oxalate magnetic particles
Assignee: Ampex Corp
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Filing: 1963-02-28
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Granted: 1965-06-22
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Expires: 1983-02-28
Abstract
No abstract record available.
Inventors
- 👤 William C Landgraf
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 11:38
CPC Classifications
H; H01; H01F; H01F1/00; H01F1/42; B; B22; B22F; B22F9/00; B22F9/16; B22F9/18; B22F9/20; B22F9/22; C; C07; C07C; C07C51/00; C07C51/41; C07C51/412; C09; C09C; C09C1/00; C09C1/22; G; G11; G11B; G11B5/00; G11B5/84; G11B5/8412; H01F1/01; H01F1/03; H01F1/032; H01F1/04; H01F1/06; H01F1/065; H01F1/12; H01F1/34; H01F1/36; C01; C01P; C01P2002/00; C01P2002/50; C01P2002/52; C01P2006/00; C01P2006/42
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
80 words
IN A PROCESS WHERE AN AQUEOUS MIXTURE OF METAL SALTS COMPRISING IRON AND COBALT SALTS SELECTED FROM THE CLASS CONSISTING OF SULFATES AND CHLORIDES IS REACTED WITH AN OXALIC COMPOUND SELECTED FROM THE CLASS CONSISTING OF OXALIC ACID AND ORGANIC ESTERS OF OXALIC ACID TO PRECIPITATE IRON AND COBALT OXALATES, THE PRECIPITATE RECOVERED AND REDUCED TO FORM A MAGNETIC PIGMENT, THE IMPROVEMENTS COMPRISING: SUBJECTING THE MIXTURE OF SAID METAL SALTS AND SAID OXALIC COMPOUND TO THE ACTION OF ULTRASONIC VIBRATIONS.
Claim 2
Dependent Claim
80 words
IN A PROCESS WHERE AN AQUEOUS MIXTURE OF METAL SALTS COMPRISING IRON AND COBALT SALTS SELECTED FROM THE CLASS CONSISTING OF SULFATES AND CHLORIDES IS REACTED WITH AN OXALIC COMPOUND SELECTED FROM THE CLASS CONSISTING OF OXALIC ACID AND ORGANIC ESTERS OF OXALIC ACID TO PRECIPITATE IRON AND COBALT OXALATES, THE PRECIPITATE RECOVERED AND REDUCED TO FORM A MAGNETIC PIGMENT, THE IMPROVEMENTS COMPRISING: SUBJECTING THE MIXTURE OF SAID METAL SALTS AND SAID OXALIC COMPOUND TO THE ACTION OF ULTRASONIC VIBRATIONS.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-06-21 | 1968-12-21 | 1969-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-06-21 | 1972-12-21 | 1973-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-06-21 | 1976-12-21 | 1977-06-22 | $7700.00 | Window Closed / Lapsed |