Patent US3342823A successfully refreshed from Google Patents.
US3342823A
Expired / Lapsed
US
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Preparation of quinacridones using polyphosphoric acid
Assignee: Honeywell International Inc
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Filing: 1960-10-24
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Granted: 1967-09-19
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Expires: 1980-10-24
Abstract
No abstract record available.
Inventors
- 👤 Chi K Dien
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:30
CPC Classifications
C; C09; C09B; C09B48/00
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
35 words
THE IMPROVEMENT IN THE PROCESS OF PREPARING A QUINACRIDONE BY RING-CLOSURE OF A 2,5-DIARYLAMINO-TEREPHTHALIC COMPOUND, WHICH COMPRISES CARRYING OUT RINGCLOSURE OF THE 2,5-DIARYLAMINO-TEREPHTHALIC COMPOUND WITH THE AID OF A POLYPHOSPHORIC ACID AS A RING-CLOSING AGENT.
Claim 2
Dependent Claim
35 words
THE IMPROVEMENT IN THE PROCESS OF PREPARING A QUINACRIDONE BY RING-CLOSURE OF A 2,5-DIARYLAMINO-TEREPHTHALIC COMPOUND, WHICH COMPRISES CARRYING OUT RINGCLOSURE OF THE 2,5-DIARYLAMINO-TEREPHTHALIC COMPOUND WITH THE AID OF A POLYPHOSPHORIC ACID AS A RING-CLOSING AGENT.
Claim 3
Dependent Claim
15 words
A PROCESS OF PREPARING A QUINACRIDONE WHICH COMPRISES HEATING A 2,5-DIARYLAMINO-TEREPHTHALIC ACID HAVING THE FORMULA
Claim 4
Dependent Claim
15 words
A PROCESS OF PREPARING A QUINACRIDONE WHICH COMPRISES HEATING A 2,5-DIARYLAMINO-TEREPHTHALIC ACID HAVING THE FORMULA
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-09-18 | 1971-03-20 | 1971-09-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-09-18 | 1975-03-20 | 1975-09-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-09-18 | 1979-03-20 | 1979-09-19 | $7700.00 | Window Closed / Lapsed |