US3658757A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of polyesters from bisphenolic compounds and aromatic sulfonic acids
Assignee: Gevaert Photo Producten NV
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Filing: 1970-01-16
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Granted: 1972-04-25
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Expires: 1990-01-16
Abstract
Abstract THE PRESENT INVENTION IS CONCERNED WITH THE PRODUCTION OF HIGH MOLECULAR WITH LINEAR AROMATIC POLYESTERS BY REACTING AROMACTIC SULFONIC ACIDS WITH BIS-PHENOLIC COMPOUNDS IN THE PRESENCE OF A CATALYST OF THE GROUP CONSISTING OF A QUATERNARY AMMONIUM COMPOUND, A QUATERNARY ARSONIUM COMPOUND, A QUATERNARY PHOSPHONIUM COMPOUND AND A TERITIARY SULFONIUM COMPOUND.
Inventors
- 👤 Andre Jan Conix
- 👤 Urbain Leopold Laridon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 19:36
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/68; C08G63/688; C08G63/6884; C08G63/6886; C08G75/00; C08G75/24
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) | 1975-04-25 | 1975-10-25 | 1976-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-25 | 1979-10-25 | 1980-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-25 | 1983-10-25 | 1984-04-25 | $7700.00 | Window Closed / Lapsed |