US2847391A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vapor-phase polymerization of tetrafluoroethylene in the presence of fillers
Assignee: EIDP Inc
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Filing: 1955-02-24
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Granted: 1958-08-12
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Expires: 1975-02-24
Abstract
No abstract record available.
Inventors
- 👤 Wheeler Ahlborn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 02:35
CPC Classifications
C; C08; C08F; C08F14/00; C08F14/18; C08F14/26
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
60 words
A PROCESS FOR PREPARING FILLED COMPOSITIONS OF POLYTETRAFLUOROETHYLENE AND INORGANIC FILLERS, CONTAINING AT LEAST 20% BY WEIGHT OF HYDRATED SILICA, COMPRISING HEATING THE FILLER TO AT LEAST 400*C. AND COOLING TO BELOW 150*C. IN THE ABSENCE OF WATER AND ADMIXING WITH TETRAFLUOROETHYLENE WITHIN THE RANGE OF -20*C. TO 150*C. TO CAUSE POLYMERIZATION OF THE TETRAFLUOETHYLENE IN THE ABSENCE OF WATER.
References Cited (Backward Citations)
US2692868A
Cited
US2728732A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-08-11 | 1962-02-10 | 1962-08-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-08-11 | 1966-02-10 | 1966-08-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-08-11 | 1970-02-10 | 1970-08-12 | $7700.00 | Window Closed / Lapsed |