US3629219A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for increasing the surface area of granular polytetrafluoroethylene resin
Assignee: EIDP Inc
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Filing: 1968-10-09
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Granted: 1971-12-21
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Expires: 1988-10-09
Abstract
Abstract TETRAFLUOROETHYLENE IS POLYMERIZED TO GRANULAR POLYMER IN AN AQUEOUS POLYMERIZATION SYSTEM CONTAINING FREE RADICAL INITIATOR AND DISPERSING AGENT WHICH PRODUCES POLYMER OF INCREASED SPECIFIC SURFACE AREA. TITRATION OF THE BUFFER INTO THE SYSTEM DURING POLYMERIZATION OR ELIMINATION OF THE BUFFER ENTIRELY FURTHER INCREASE THE SPECIFIC SURFACE AREA OF THE GRANULAR POLYMER PRODUCED.
Inventors
- 👤 Richard B Esker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 21:21
CPC Classifications
C; C08; C08F; C08F14/00; C08F14/18; C08F14/26
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) | 1974-12-20 | 1975-06-21 | 1975-12-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-20 | 1979-06-21 | 1979-12-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-20 | 1983-06-21 | 1983-12-21 | $7700.00 | Window Closed / Lapsed |