Patent US2803652A successfully refreshed from Google Patents.
US2803652A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Intermediate product and process for making it
Assignee: BASF Schweiz AG
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Filing: 1955-01-03
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Granted: 1957-08-20
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Expires: 1975-01-03
Abstract
No abstract record available.
Inventors
- 👤 Riat Henri
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 16:21
CPC Classifications
C; C07; C07C; C07C309/00; C07C309/01; C07C309/28; C07C309/45; C07C309/49; C07C309/50
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
16 words
2-$NAPHTHYL-(1'')-AMION$ - 8 - HYDROXYNAPHTHALENE6:6''-DISULFONIC ACID, WHICH IN ITS FREE ACID STATE CORRESPONDS TO THE FORMULA
Claim 2
Dependent Claim
16 words
2-$NAPHTHYL-(1'')-AMION$ - 8 - HYDROXYNAPHTHALENE6:6''-DISULFONIC ACID, WHICH IN ITS FREE ACID STATE CORRESPONDS TO THE FORMULA
References Cited (Backward Citations)
US649714A
Cited
US2347042A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-08-19 | 1961-02-18 | 1961-08-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-08-19 | 1965-02-18 | 1965-08-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-08-19 | 1969-02-18 | 1969-08-20 | $7700.00 | Window Closed / Lapsed |