US3697526A
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Crystalline perylenetetracarboxylic acid dibenzoylhydrazide
Assignee: Novartis AG
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Filing: 1970-11-17
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Granted: 1972-10-10
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Expires: 1990-11-17
Abstract
Abstract Crystalline perylenetetracarboxylic acid dibenzoyl-hydrazide is prepared by condensing perylenetetracarboxylic acid dianhydride with benzhydrazide in the presence of non-basic solvents or in the presence of a mixture of basic and non-basic solvents. The compound is used as pigment.
Inventors
- 👤 Andre Pugin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 03:23
CPC Classifications
C; C07; C07D; C07D471/00; C07D471/02; C07D471/06; C09; C09B; C09B5/00; C09B5/62; C09B67/00; C09B67/0025
Claims Analysis
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-10 | 1976-04-10 | 1976-10-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-10 | 1980-04-10 | 1980-10-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-10 | 1984-04-10 | 1984-10-10 | $7700.00 | Window Closed / Lapsed |