US3579519A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Crystalline form of quinacridone
Assignee: Eastman Kodak Co
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Filing: 1966-09-08
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Granted: 1971-05-18
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Expires: 1986-09-08
Abstract
Abstract AN IMPROVED QUINACRIDONE HAVING GOOD LIGHT FASTNESS, A MORE-REDDISH SHADE WITH HIGH TINCTORIAL POWER AND A SOFT TEXTURE IS PREPARED BY A PROCESS WHICH COMPRISES DISSOLVING QUINACRIDONE PREPARED BY KNOWN METHODS IN HOT HEXAMETHYL PHOSPHORAMIDE AT A TEMPERATURE ABOVE 100*C. THE SOLUTION IS THEN POURED INTO A COLD NON-SOLVENT SUCH AS METHANOL. THE PRECIPITATED QUINACRIDONE IS SUBSEQUENTLY SEPARATED FROM THE MIXTURE. QUINACRIDONE PREPARED BY THE DESCRIBED PROCEDURE IS USEFUL AS A PIGMENT FOR COLORING DOPES AND MELTS IN THE MANUFACTURE OF MOLDED OBJECTS, FIBERS, FILM, ETC.
Inventors
- 👤 Hans R Schweizer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 03:39
CPC Classifications
C; C09; C09B; C09B48/00; C07; C07F; C07F9/00; C07F9/02; C07F9/06; C07F9/22; C07F9/24
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) | 1974-05-17 | 1974-11-16 | 1975-05-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-17 | 1978-11-16 | 1979-05-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-17 | 1982-11-16 | 1983-05-18 | $7700.00 | Window Closed / Lapsed |