US2503797A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the manufacture of diamino-diphenyl-ureas
Assignee: BASF Schweiz AG
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Filing: 1947-11-07
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Granted: 1950-04-11
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Expires: 1967-11-07
Abstract
No abstract record available.
Inventors
- 👤 Brunner Albert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 22:45
CPC Classifications
C; C07; C07C; C07C273/00; C07C273/18; C07C273/1854; C07C273/1863
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
40 words
A PROCESS FOR THE MANUFACTURE OF A DIAMINO-DIPHENYL-UREA WHICH COMPRISES CONDENSING TWO MOLECULAR PROPORTIONS OF A DIAMINOBENZENE SELECTED FROM THE GROUP CONSISTING OF 1:3 AND 1:4-DIAMINOBENZENES, WITH ABOUT ONE MOLECULAR PROPORTION OF UREA IN AN AQUEOUS MEDIUM AT ABOUT 100*C.
References Cited (Backward Citations)
DE367611C
Cited
US1617847A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1953-04-10 | 1953-10-10 | 1954-04-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-04-10 | 1957-10-10 | 1958-04-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-04-10 | 1961-10-10 | 1962-04-11 | $7700.00 | Window Closed / Lapsed |