Patent US2777839A successfully refreshed from Google Patents.
US2777839A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Grey trisazo dyestuffs
Assignee: Bayer AG
•
Filing: 1954-04-07
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Granted: 1957-01-15
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Expires: 1974-04-07
Abstract
No abstract record available.
Inventors
- 👤 Bockmann Klaus
- 👤 Taube Karl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 10:55
CPC Classifications
C; C09; C09B; C09B31/00; C09B31/16; C09B31/22
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
10 words
TRISAZO DYESTUFF CORRESPONDING AS FREE ACIDS TO THE GENERAL FORMULA
Claim 2
Dependent Claim
10 words
TRISAZO DYESTUFF CORRESPONDING AS FREE ACIDS TO THE 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) | 1960-01-15 | 1960-07-16 | 1961-01-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-01-15 | 1964-07-16 | 1965-01-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-01-15 | 1968-07-16 | 1969-01-15 | $7700.00 | Window Closed / Lapsed |