Patent US3574170A successfully refreshed from Google Patents.
US3574170A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the production of bbb type polymer
Assignee: Celanese Corp
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Filing: 1969-10-20
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Granted: 1971-04-06
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Expires: 1989-10-20
Abstract
Abstract AN IMPROVED PROCESS IS PROVIDED FOR THE FORMATION OF BBB TYPE POLYMER, I.E. POLY(BISBENZIMIDAZOBENZOPHENANTHROLINE) AND RELATED NITROGENOUS POLYMERS. THE CONDENSATION REACTION OF AT LEAST ONE ORGANIC TETRAAMINE AND AT LEAST ONE TETRACABOXYLIC ACID (WHICH MAY OPTIONALLY BE IN THE FORM OF THE CORRESPONDING DIANHYDRIDE) IS CONDUCTED IN A PHOSPHORIC ACID POLYMERIZATION MEDIUM HAVING AN H3PO4 CONCENTRATION OF ABOUT 50 TO 110 PERCENT BY WEIGHT. IN A PREFERRED EMBODIMENT OF THE INVENTION THE PHOSPHORIC ACID IS PRESENT IN AN H3PO4 CONCENTRATION OF ABOUT 104 TO 109 PERCENT BY WEIGHT, E.G. SUPERPHOSPHORIC ACID HAVING AN H3PO4 CONCENTRATION OF ABOUT 105 PERCENT BY WEIGHT.
Inventors
- 👤 Edward C Chenevey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 11:58
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/20
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) | 1974-04-05 | 1974-10-05 | 1975-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-05 | 1978-10-05 | 1979-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-05 | 1982-10-05 | 1983-04-06 | $7700.00 | Window Closed / Lapsed |