US2640059A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of preparing hydroxyalkylthio anthraquinones
Assignee: Celanese Corp
•
Filing: 1949-07-20
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Granted: 1953-05-26
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Expires: 1969-07-20
Abstract
No abstract record available.
Inventors
- 👤 Victor S Salvin
- 👤 Edward F Landau
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 09:44
CPC Classifications
C; C09; C09B; C09B1/00; C09B1/56; C09B1/58; C09B1/60
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
15 words
PROCESS FOR PREPARING HYDROXYALKYLTHIO ANTHRAQUINONES WHICH COMPRISES REACTING AN ANTHRAQUINONE OF THE FOLLOWING GENERAL FORMULA
Claim 2
Dependent Claim
15 words
PROCESS FOR PREPARING HYDROXYALKYLTHIO ANTHRAQUINONES WHICH COMPRISES REACTING AN ANTHRAQUINONE OF THE FOLLOWING GENERAL FORMULA
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) | 1956-05-25 | 1956-11-24 | 1957-05-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-05-25 | 1960-11-24 | 1961-05-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-05-25 | 1964-11-24 | 1965-05-26 | $7700.00 | Window Closed / Lapsed |