US2750356A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stable condensates of urea and formaldehyde in the presence of methanol
Assignee: Rohm and Haas Co
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Filing: 1952-06-10
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Granted: 1956-06-12
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Expires: 1972-06-10
Abstract
No abstract record available.
Inventors
- 👤 Melvin D Hurwitz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 08:40
CPC Classifications
C; C08; C08G; C08G12/00; C08G12/02; C08G12/04; C08G12/10; C08G12/12
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
135 words
A PROCESS FOR PREPARING WATER-SOLUBLE, STABLE UREAFORMALDEHYDE CONDENSATES WHICH COMPRISES REACTING UREA AND FORMALDEHYDE TOGETHER IN A MOLE RATIO BETWEEN 1:2.5 AND 1:3 AT A TEMPERATURE BETWEEN 60* AND 80* C. AND AT A PH BETWEEN 7.5 AND ABOUT 9 IN AN AQUEOUS SOLUTION CONTAINING LESS THAN ABOUT 30% OF WATER, CONTINUING THE REACTION IN THE PRESENCE OF ABOUT 5% TO 30% OF WATER UNTIL AT LEAST 85% OF THE FORMALDEHYDE APPEARS CHEMICALLY BOUND, AS DETERMINED BY TITRATION OF ALKALINITY OF A COLD SODIUM SULFITE SOLUTION OF A SAMPLE OF THE REACTION MIXTURE, ADJUSTING THE PH OF THE REACTION MIXTURE TO A VALUE FROM 3.8 TO 3, AND WITH METHANOL PRESENT IN A MOLE RATIO TO THE UREA TAKEN OF 2.5:1 TO 4:1 HEATING THE ACIDIC REACTION MIXTURE UNDER REFLUX FOR 5 TO 60 MINUTES.
Claim 2
Dependent Claim
135 words
A PROCESS FOR PREPARING WATER-SOLUBLE, STABLE UREAFORMALDEHYDE CONDENSATES WHICH COMPRISES REACTING UREA AND FORMALDEHYDE TOGETHER IN A MOLE RATIO BETWEEN 1:2.5 AND 1:3 AT A TEMPERATURE BETWEEN 60* AND 80* C. AND AT A PH BETWEEN 7.5 AND ABOUT 9 IN AN AQUEOUS SOLUTION CONTAINING LESS THAN ABOUT 30% OF WATER, CONTINUING THE REACTION IN THE PRESENCE OF ABOUT 5% TO 30% OF WATER UNTIL AT LEAST 85% OF THE FORMALDEHYDE APPEARS CHEMICALLY BOUND, AS DETERMINED BY TITRATION OF ALKALINITY OF A COLD SODIUM SULFITE SOLUTION OF A SAMPLE OF THE REACTION MIXTURE, ADJUSTING THE PH OF THE REACTION MIXTURE TO A VALUE FROM 3.8 TO 3, AND WITH METHANOL PRESENT IN A MOLE RATIO TO THE UREA TAKEN OF 2.5:1 TO 4:1 HEATING THE ACIDIC REACTION MIXTURE UNDER REFLUX FOR 5 TO 60 MINUTES.
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) | 1959-06-12 | 1959-12-12 | 1960-06-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-06-12 | 1963-12-12 | 1964-06-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-06-12 | 1967-12-12 | 1968-06-12 | $7700.00 | Window Closed / Lapsed |