Patent US4124250A successfully refreshed from Google Patents.
Patent US2912442A successfully refreshed from Google Patents.
US2912442A
Expired / Lapsed
US
⏱️ 0.0 years remaining
2, 3, 6, 7 naphthalenetetracarboxylic acid and its functional derivatives
Assignee: EIDP Inc
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Filing: 1956-11-23
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Granted: 1959-11-10
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Expires: 1976-11-23
Abstract
No abstract record available.
Inventors
- 👤 Webster Owen Wright
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 23:25
CPC Classifications
C; C07; C07C; C07C63/00; C07C63/33; C07C63/337; C07C63/34; C07C63/40
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
2 words
2,3,6,7-NAPHTHALENETETRACARBOXYLIC DIANHYDRIDE.
Claim 2
Dependent Claim
27 words
A COMPOUND OF THE GROUP CONSISTING OF 2,3,6,7NAPHTHALENETETRACARBOXYLIC ACID, 2,3,6,7,-NAPHTHALENETETRACARBOXYLIC ANHYDRIDE, 2,3,6,7-NAPHTHALENETETRACARBONITRILE, 2,3,6,7,-NAPHTHALENETETRACARBAMIDE, 2,3,6,7-NAPHTHALENETETRACARBACYL CHLORIDE, 2,3,6,7,-NAPHTHALENETETRACARBACYL BROMIDE AND ESTERS OF 2,3,6,7,-NAPHTHALENETETRACARBACYL ACID, SAID ESTERS HAVING THE 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) | 1962-11-09 | 1963-05-11 | 1963-11-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-11-09 | 1967-05-11 | 1967-11-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-11-09 | 1971-05-11 | 1971-11-10 | $7700.00 | Window Closed / Lapsed |