Patent US3845075A successfully refreshed from Google Patents.
US3845075A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Benzoxanthene dyestuffs
Assignee: Hoechst AG
•
Filing: 1973-01-15
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Granted: 1974-10-29
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Expires: 1993-01-15
Abstract
Abstract 1. A DYESTUFF OF THE FORMULA 1-R4,3,5-DI(O=),7-(R3-O-),R1,R2-3,5-DIHYDRO-PYRANO(3,4- C,D)BENZO(KL)XANTHENE WHREIN R1 AND R2 EACH IS HYDROGEN, CHLORINE, BROMINE, LOWER ALKYL OR LOWER ALKOXY; R3 IS LOWER ALKYL, HYDROXY-LOWER ALKYL, PHENYL-LOWER ALKYL OR LOWER ALKANOYLOXY-LOWER ALKYL; AND R4 IS HYDROGEN, NITRO, LOWER ALKOXY OR LOWER ALKANOYLOXY; PROVIDED THAT LOWER MEANS 1 TO 4 CARBON ATOMS.
Inventors
- 👤 O Fuchs
- 👤 H Troster
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 10:38
CPC Classifications
C; C09; C09B; C09B57/00; C09B57/14; Y; Y10; Y10S; Y10S8/00; Y10S8/92; Y10S8/922
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
5 words
A DYESTUFF OF THE FORMULA
Claim 2
Dependent Claim
5 words
A DYESTUFF OF 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) | 1977-10-28 | 1978-04-29 | 1978-10-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-28 | 1982-04-29 | 1982-10-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-28 | 1986-04-29 | 1986-10-29 | $7700.00 | Window Closed / Lapsed |