US2554424A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Urea-aldehyde reaction products and process of preparing same
Assignee: Wyeth Holdings LLC
•
Filing: 1947-03-05
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Granted: 1951-05-22
•
Expires: 1967-03-05
Abstract
No abstract record available.
Inventors
- 👤 Suen Tzeng-Jiueq
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 02:29
CPC Classifications
C; C08; C08G; C08G12/00; C08G12/02; C08G12/04; C08G12/10; C08G12/12
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
56 words
A PROCESS COMPRISING REACTING AN AQUEOUS SOLUTION OF FORMALDEHYDE AND UREA UNDER ALKALINE CONDITIONS AT A TEMPERATURE BETWEEN 70* C. AND REFLUX FOR ABOUT 30 MINUTES, WHEREIN THE MOL RATIO IS FROM ABOUT 2.2:1-2.8:1 RESPECTIVELY, ADJUSTING THE PH TO 1-4 AND REDUCING THE TEMPERATURE TO A POINT BETWEEN ABOUT 40-55* C. TO EFFECT A VISCOSITY INCREASE.
Claim 2
Dependent Claim
56 words
A PROCESS COMPRISING REACTING AN AQUEOUS SOLUTION OF FORMALDEHYDE AND UREA UNDER ALKALINE CONDITIONS AT A TEMPERATURE BETWEEN 70* C. AND REFLUX FOR ABOUT 30 MINUTES, WHEREIN THE MOL RATIO IS FROM ABOUT 2.2:1-2.8:1 RESPECTIVELY, ADJUSTING THE PH TO 1-4 AND REDUCING THE TEMPERATURE TO A POINT BETWEEN ABOUT 40-55* C. TO EFFECT A VISCOSITY INCREASE.
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) | 1954-05-21 | 1954-11-20 | 1955-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-05-21 | 1958-11-20 | 1959-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-05-21 | 1962-11-20 | 1963-05-22 | $7700.00 | Window Closed / Lapsed |