US3775442A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the manufacture of a triarylmethane compound
Assignee: Imperial Chemical Industries Ltd
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Filing: 1971-07-29
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Granted: 1973-11-27
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Expires: 1991-07-29
Abstract
Abstract A PROCESS FOR THE MANUFACTURE OF A TRIAMINOTRIARYLMETHANE COMPRISING REACTING A DIAMINOBENZHYDROL SUCH AS MICHLER''S HYDROL WITH AN OPTIONALLY SUBSTITUTED ARONATIC SECONDARY OR TERTIARY AMINE IN THE PRESENCE OF PHOSPHORIC ACID.
Inventors
- 👤 N Hughes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 04:56
CPC Classifications
C; C09; C09B; C09B11/00; C09B11/04; C09B11/10; C09B11/12; C09B11/16
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) | 1976-11-26 | 1977-05-28 | 1977-11-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-26 | 1981-05-28 | 1981-11-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-26 | 1985-05-28 | 1985-11-27 | $7700.00 | Window Closed / Lapsed |