US3641011A
Expired / Lapsed
US
⏱️ 0.0 years remaining
5- and 6-dialkylaminobenzylidene-aminofluorans
Assignee: Appvion LLC
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Filing: 1969-01-21
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Granted: 1972-02-08
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Expires: 1989-01-21
Abstract
Abstract A NOVEL CHROMOGENIC MATERIAL OF NORMALLY COLORLESS FORM IS DISCLOSED, HAVING A STRUCTURALFORMULA: 3-(O=),2''-R1,3''-R,6''-((R3-)2-N-),(R2-CH=N-)SPIRO(PHTHALAN- 1,9''-XANTHENE) WHEREIN R2 REPRESENTS A DIALKYLAMINOPHENYL RADICAL, R AND R1 COMPRISE HYDROGEN, HALOGEN, AND ALKYL RADICALS AND R3 REPRESENTS ALKYL RADICALS HAVING LESS THAN FIVE CARBON ATOMS-SAID MATERIALS ASSUMING A COLORED FORM UPON REACTIVE CONTACT WITH A LEWIS ACID MOLECULE. EXAMPLES INCLUDE 6''-DIETHYLAMINO-5-(P-DIMETHYLAMINOBENZYLIDENE) AMINO - 2'',3'' - DIMETHYLFLUORAN AND 2''-CHLORO -6''-DIETHYLAMINO - 6-(P-DIMETHYLAMINOBENZYLIDENCE)AMINO-3''-METHYLFLUORAN.
Inventors
- 👤 Chao-Han Lin
- 👤 Arthur J Wright
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 13:20
CPC Classifications
C; C09; C09B; C09B11/00; C09B11/04; C09B11/10; C09B11/24; B; B41; B41M; B41M5/00; B41M5/124; B41M5/132; B41M5/136; B41M5/145; B41M5/1455
Claims Analysis
Total Claims: 0
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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) | 1975-02-07 | 1975-08-09 | 1976-02-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-07 | 1979-08-09 | 1980-02-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-07 | 1983-08-09 | 1984-02-08 | $7700.00 | Window Closed / Lapsed |