US3781279A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stilbene optical brighteners
Assignee: Bayer Corp
•
Filing: 1971-02-23
•
Granted: 1973-12-25
•
Expires: 1991-02-23
Abstract
Abstract BENZOFURANS, BENZOTHIOPHENES, INDOLES, NAPHTHOFURANS AND BENZOFURANOBENZOFURANS WHICH ARE SUBSTITUTED BY 4VINYLPHENYL GROUPS WHEREIN THE 2-POSITION OF THE VINYL IS SUBSTITUTED BY A MONOVALENT AROMATIC RADICAL HAVING ONE TO THREE AROMATIC RINGS ARE OPTICAL BRIGHTENING AGENTS USEFUL FOR WHITENING AND BRIGHTENING NATURAL AND SYNTHETIC FIBERS, PAPERS, RESINS AND THE LIKE. THE COMPOUNDS ARE CONVENIENTLY PREPARED BY INTERACTING BENZOFURANS, BENZOTHIOPHENES, INDOLES, NAPHTHOFURANS OF BENZOFURANOBENZOFURANS WHICH ARE SUBSTITUTED BY A P-TOLYL GROUP, WITH AN AROMATIC ALDEHYDE OR PREFERABLY THE ANIL DERIVATIVE THEREOF.
Inventors
- 👤 N Crounse
- 👤 K Desai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 16:26
CPC Classifications
C; C07; C07D; C07D307/00; C07D307/77; C07D307/92; C07C; C07C45/00; C07C45/61; C07C45/67; C07C45/68; C07C45/70; C07C45/71; C07D209/00; C07D209/02; C07D209/04; C07D209/08; C07D307/78; C07D307/79; C07D333/00; C07D333/50; C07D333/52; C07D333/54; C07D333/56
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
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) | 1976-12-24 | 1977-06-25 | 1977-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-24 | 1981-06-25 | 1981-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-24 | 1985-06-25 | 1985-12-25 | $7700.00 | Window Closed / Lapsed |