Patent US2846397A successfully refreshed from Google Patents.
US2846397A
Expired / Lapsed
US
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Water-soluble salts of derivatives of 4:4'-diaminostilbene-2:2'-disulfonic acid for enhancing the brightness of organic fibrous material
Assignee: BASF Schweiz AG
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Filing: 1950-10-02
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Granted: 1958-08-05
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Expires: 1970-10-02
Abstract
No abstract record available.
Inventors
- 👤 Ackermann Franz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 04:05
CPC Classifications
C; C07; C07D; C07D417/00; C07D417/14
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
43 words
A PROCESS FOR ENHANCING THE BRIGHTNESS OF ORGANIC FIBROUS MATERIAL WHICH COMPRISES IMPREGNATING THE MATERIAL WITH AN AQUEOUS SOLUTION OF AN OPTICAL BLEACHING AGENT CONSISTING ESSENTIALLY OF A WATER-SOLUBLE SALT OF A COLORLESS TO SUBSTANTIALLY COLORLESS DERIVATIVE OF 4:4''-DIAMINO-STILBENE-2:2''-DISULFONIC ACID OF THE FORMULA
Claim 2
Dependent Claim
13 words
FLUORESCENT AGENTS WHICH IN THE FORM OF THE FREE ACID HAVE THE FORMULA
References Cited (Backward Citations)
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US2376743A
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Cited
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Cited
US2539766A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-08-04 | 1962-02-03 | 1962-08-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-08-04 | 1966-02-03 | 1966-08-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-08-04 | 1970-02-03 | 1970-08-05 | $7700.00 | Window Closed / Lapsed |