Patent US2640846A successfully refreshed from Google Patents.
US2640846A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing organic isocyanates
Assignee: Rohm and Haas Co
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Filing: 1950-06-30
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Granted: 1953-06-02
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Expires: 1970-06-30
Abstract
No abstract record available.
Inventors
- 👤 Melvin D Hurwitz
- 👤 Robert W Auten
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 20:45
CPC Classifications
C; C07; C07C; C07C263/00
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
36 words
A PROCESS FOR PREPARING ALKYL ISOCYANATES HAVING THE FORMULA R-NCO WHICH COMPRISES DEHYDROCHLORINATING IN THE PRESENCE OF AN ORGANIC BASE WHICH IS FREE OF PRIMARY AND SECONDARY AMINO GROUPS A SUBSTITUTED N-CHLOROFORMAMIDE HAVING THE GENERAL FORMULA
References Cited (Backward Citations)
US2480088A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-06-01 | 1956-12-01 | 1957-06-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-06-01 | 1960-12-01 | 1961-06-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-06-01 | 1964-12-01 | 1965-06-02 | $7700.00 | Window Closed / Lapsed |