Patent US2592370A successfully refreshed from Google Patents.
US2592370A
Expired / Lapsed
US
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Compounds of the quinophthalone series and method for their production
Assignee: EIDP Inc
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Filing: 1950-02-18
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Granted: 1952-04-08
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Expires: 1970-02-18
Abstract
No abstract record available.
Inventors
- 👤 Zwilgmeyer Frithjof
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 20:03
CPC Classifications
C; C09; C09B; C09B25/00; Y; Y10; Y10S; Y10S56/00; Y10S56/02
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
23 words
A COMPOUND OF THE GROUP CONSISTING OF THE FREE ACID FORM, ANHYDRIDES AND SALTS OF THE QUINOPHTHALONE-DICARBOXYLIC ACIDS REPRESENTED BY THE GENERAL FORMULA
Claim 2
Dependent Claim
23 words
A COMPOUND OF THE GROUP CONSISTING OF THE FREE ACID FORM, ANHYDRIDES AND SALTS OF THE QUINOPHTHALONE-DICARBOXYLIC ACIDS REPRESENTED BY THE GENERAL FORMULA
References Cited (Backward Citations)
US2006022A
Cited
FR816991A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1955-04-08 | 1955-10-08 | 1956-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1959-04-08 | 1959-10-08 | 1960-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1963-04-08 | 1963-10-08 | 1964-04-08 | $7700.00 | Window Closed / Lapsed |