Patent US2882280A successfully refreshed from Google Patents.
US2882280A
Expired / Lapsed
US
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Dibenzanthrone vat dyestuffs
Assignee: Pittsburgh Coke and Chemical Co
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Filing: 1955-02-14
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Granted: 1959-04-14
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Expires: 1975-02-14
Abstract
No abstract record available.
Inventors
- 👤 Gruenebaum Heinz
- 👤 Masciantonio Philip
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 23:43
CPC Classifications
C; C09; C09B; C09B3/00; C09B3/22; C09B3/30
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
43 words
THE PROCESS COMPRISING REACTING AN ALDEHYDE HAVING AT LEAST TWO CARBON ATOMS ON THE LEUCO FORM OF A DIALKYL ETHER OF DIBENZANTHRONE, SAID REACTION BEING CARRIED OUT AT A PH OF AT LEAST 7 IN THE PRESENCE OF WATER AND A REDUCING AGENT.
References Cited (Backward Citations)
US2183626A
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US2389245A
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US2082560A
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US2148042A
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US2487197A
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US2447993A
Cited
US2592852A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1962-04-13 | 1962-10-13 | 1963-04-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-04-13 | 1966-10-13 | 1967-04-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-04-13 | 1970-10-13 | 1971-04-14 | $7700.00 | Window Closed / Lapsed |