US2821550A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of preparing 4-nitro-2-stilbene sulfonic acid salts
Assignee: GAF Chemicals Corp
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Filing: 1956-12-27
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Granted: 1958-01-28
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Expires: 1976-12-27
Abstract
No abstract record available.
Inventors
- 👤 Albert F Strobel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 09:05
CPC Classifications
C; C07; C07C; C07C303/00; C07C303/32; C09; C09B; C09B56/00; C09B56/04
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
22 words
THE PROCESS OF PREPARING P-NITROSTILBENE-2-SULFONIC ACID SALT WHICH COMPRISES CONDENSING AN AROMATIC ALDEHYDE WITH A P-NITROTOLUENE-2-SULFONIC ACID SALT, HAVING THE FOLLOWING FORMULA:
Claim 2
Dependent Claim
22 words
THE PROCESS OF PREPARING P-NITROSTILBENE-2-SULFONIC ACID SALT WHICH COMPRISES CONDENSING AN AROMATIC ALDEHYDE WITH A P-NITROTOLUENE-2-SULFONIC ACID SALT, HAVING THE FOLLOWING FORMULA:
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) | 1961-01-27 | 1961-07-29 | 1962-01-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-01-27 | 1965-07-29 | 1966-01-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-01-27 | 1969-07-29 | 1970-01-28 | $7700.00 | Window Closed / Lapsed |