US2768203A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of guanidine sulfate
Assignee: Wyeth Holdings LLC
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Filing: 1954-08-30
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Granted: 1956-10-23
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Expires: 1974-08-30
Abstract
No abstract record available.
Inventors
- 👤 Richard W Hamilton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 13:23
CPC Classifications
C; C07; C07C; C07C277/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
68 words
A PROCESS OF MAKING SUBSTANTIALLY COLORLESS GUANIDINE SULFATE WHICH COMPRISES: AT A TEMPERATURE OF FROM ABOUT 190* C. TO ABOUT 300* C., CONFININE A REACTIVE MIXTURE COMPRISING UREA, SULFUR DIOXIDE AND AMMONIA IN A CLOSED VESSEL AT LEAST THE INNER SURFACE OF WHICH IS METALLIC TITANIUM, HEATING SO-CONFINED MIXTURE SUFFICIENTLY TO MAINTAIN SAID TEMPERATURE UNTIL REACTION OF UREA SUBSTANTIALLY CEASES, STOPPING THE HEATING AND COLLECTING RESULTANT GUANIDINE SULFATE.
Claim 2
Dependent Claim
68 words
A PROCESS OF MAKING SUBSTANTIALLY COLORLESS GUANIDINE SULFATE WHICH COMPRISES: AT A TEMPERATURE OF FROM ABOUT 190* C. TO ABOUT 300* C., CONFININE A REACTIVE MIXTURE COMPRISING UREA, SULFUR DIOXIDE AND AMMONIA IN A CLOSED VESSEL AT LEAST THE INNER SURFACE OF WHICH IS METALLIC TITANIUM, HEATING SO-CONFINED MIXTURE SUFFICIENTLY TO MAINTAIN SAID TEMPERATURE UNTIL REACTION OF UREA SUBSTANTIALLY CEASES, STOPPING THE HEATING AND COLLECTING RESULTANT GUANIDINE SULFATE.
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) | 1959-10-23 | 1960-04-23 | 1960-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-10-23 | 1964-04-23 | 1964-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-10-23 | 1968-04-23 | 1968-10-23 | $7700.00 | Window Closed / Lapsed |