US3880857A
Expired / Lapsed
US
⏱️ 0.0 years remaining
4-Alkoxy-N-aminonaphthalic acid imides as optical brightners
Assignee: BASF SE
•
Filing: 1971-08-26
•
Granted: 1975-04-29
•
Expires: 1991-08-26
Abstract
Abstract Optical brighteners of the formula: DERIVED FROM 4-ALKOXY-N-aminonaphthalic acid imides. The compounds are useful for brightening acrylonitrile polymers, polyamides, cellulose esters and polyesters.
Inventors
- 👤 Horst Scheuermann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 02:13
CPC Classifications
C; C07; C07D; C07D221/00; C07D221/02; C07D221/04; C07D221/06; C07D221/14; C07D211/00; C07D211/04; C07D211/06; C07D211/08; C07D211/10; C07D211/14
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
6 words
THE OPTICAL BRIGHTENER OF THE FORMULA
Claim 2
Dependent Claim
6 words
THE OPTICAL BRIGHTENER OF THE FORMULA
References Cited (Backward Citations)
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Cited
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-28 | 1978-10-28 | 1979-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-28 | 1982-10-28 | 1983-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-28 | 1986-10-28 | 1987-04-29 | $7700.00 | Window Closed / Lapsed |