US3755446A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical brighteners of the bisstyrylbenzene series
Assignee: BASF SE
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Filing: 1971-08-03
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Granted: 1973-08-28
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Expires: 1991-08-03
Abstract
Abstract BISSTYRYLBENZENE DERIVATIVES HAVING THE FORMULA (2-Y,4-X,5-R-PHENYL)-CH=CH-((Z)2-1,4-PHENYLENE)-CH=CH- (2-Y,5-R1-1,4-PHENYLENE)-X IN WHICH THE MOST IMPORTANT SUBSTITUENTS R AND R1 ARE CARBOXYL GROUPS OR CAROBYLIC ESTER OR AMIDE GROUPS. THE COMPOUNDS ARE USEFUL AS OPTICAL BRIGHTENERS, PARTICULARLY FOR PAPER.
Inventors
- 👤 H Scheuermann
- 👤 P Hell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 00:53
CPC Classifications
C; C07; C07D; C07D295/00; C07D295/16; C07D295/18; C07D295/182; C07D295/192; C07C; C07C243/00; C07C243/24; C07C243/38; C07C63/00; C07C63/68; C07C63/74
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) | 1976-08-27 | 1977-02-26 | 1977-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-27 | 1981-02-26 | 1981-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-27 | 1985-02-26 | 1985-08-28 | $7700.00 | Window Closed / Lapsed |