Patent US3557079A successfully refreshed from Google Patents.
US3557079A
Expired / Lapsed
US
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Production of stilbene azo dyes
Assignee: Honeywell International Inc
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Filing: 1967-02-01
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Granted: 1971-01-19
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Expires: 1987-02-01
Abstract
Abstract PRODUCTION OF STILBENE AZO DYES HAVING EXCELLENT SOLUBILITY IN COLD WATER BY HEATING P-NITROTOLUENE-O-SULFONIC ACID IN THE PRESENCE OF AN AQUEOUS CAUSTIC ALKALI AND REDUCING THE RESULTANT REACTION MASS CONSISTING ESSENTIALLY OF 4,4''-DINITRO-2,2''-STILBENE DISULFONIC ACID OR AN ALKALI METAL SALT THEREOF WITH SODIUM SULFIDE IN AMOUNT FROM ABOUT 5 TO 15%, BY WEIGHT, OF THE P-NITROTOLUENE-O-SULFONIC ACID EMPLOYED.
Inventors
- 👤 Jeremiah J Doody
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 16:53
CPC Classifications
C; C09; C09B; C09B56/00; C09B56/04; C09B56/06; Y; Y10; Y10S; Y10S8/00; Y10S8/916; Y10S8/919
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) | 1974-01-18 | 1974-07-20 | 1975-01-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-18 | 1978-07-20 | 1979-01-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-18 | 1982-07-20 | 1983-01-19 | $7700.00 | Window Closed / Lapsed |