US2993755A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of tungstic oxide
Assignee: Union Carbide Corp
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Filing: 1958-08-13
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Granted: 1961-07-25
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Expires: 1978-08-13
Abstract
No abstract record available.
Inventors
- 👤 William H Redanz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 14:33
CPC Classifications
C; C01; C01G; C01G41/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
98 words
THE METHOD OF PRODUCING TUNGSTIC OXIDE HAVING A PARTICLE SIZE BETWEEN 1.0 AND 5.0 MICRONS FROM AN AMMONIUM TUNGSTATE SOLUTION, WHICH COMPRISES ADDING TO SAID AMMONIUM TUNGSTATE SOLUTION HYDROCHLORIC ACID IN AN AMOUNT SUFFICIENT TO LOWER THE PH OF SAID SOLUTION TO A VALUE BETWEEN 5.0 AND 8.0 MAINTAINING SAID SOLUAND 50*C. TO PRECIPATE AMMONIUM PARATUNGSTATE AND 50*C. TO PRECIPATE AMMONIUM PARATUNGSTATE THEREFROM, REMOVING SAID AMMONIUM PARATUNGSTATE FROM SAID SOLUTION, CALCINING SAID AMMONIUM PARATUNGSTATE AT A TEMPERATURE BETWEEN ABOUT 500*C. AND 800*C. FOR A TIME SUFFICIENT TO REMOVE THE AMMONIA AND WATER THEREFROM TO PRODUCE SAID TUNGSTIC OXIDE.
Claim 2
Independent Claim
98 words
THE METHOD OF PRODUCING TUNGSTIC OXIDE HAVING A PARTICLE SIZE BETWEEN 1.0 AND 5.0 MICRONS FROM AN AMMONIUM TUNGSTATE SOLUTION, WHICH COMPRISES ADDING TO SAID AMMONIUM TUNGSTATE SOLUTION HYDROCHLORIC ACID IN AN AMOUNT SUFFICIENT TO LOWER THE PH OF SAID SOLUTION TO A VALUE BETWEEN 5.0 AND 8.0 MAINTAINING SAID SOLUAND 50*C. TO PRECIPATE AMMONIUM PARATUNGSTATE AND 50*C. TO PRECIPATE AMMONIUM PARATUNGSTATE THEREFROM, REMOVING SAID AMMONIUM PARATUNGSTATE FROM SAID SOLUTION, CALCINING SAID AMMONIUM PARATUNGSTATE AT A TEMPERATURE BETWEEN ABOUT 500*C. AND 800*C. FOR A TIME SUFFICIENT TO REMOVE THE AMMONIA AND WATER THEREFROM TO PRODUCE SAID TUNGSTIC OXIDE.
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) | 1964-07-24 | 1965-01-23 | 1965-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-07-24 | 1969-01-23 | 1969-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-07-24 | 1973-01-23 | 1973-07-25 | $7700.00 | Window Closed / Lapsed |