Patent US3115486A successfully refreshed from Google Patents.
US3115486A
Expired / Lapsed
US
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Process for the preparation of polytetrafluoroethylene molding powder
Assignee: EIDP Inc
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Filing: 1960-11-30
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Granted: 1963-12-24
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Expires: 1980-11-30
Abstract
No abstract record available.
Inventors
- 👤 Weisenberger William Paul
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 14:07
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/12; C08J3/124; C08J2327/00; C08J2327/02; C08J2327/12; C08J2327/18
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
102 words
A PROCESS OF PREPARING A POLYTETRAFLUOROETHYLENE MOLDING POWDER FROM GRANULAR, IRREGULARLY SHAPED POLYTETRAFLUOROETHYLENE CHARACTERIZED BY A TOTAL SURFACE AREA OF FROM 1 TO 4 SQUARE METER GRAM AS MEASURED BY NITROGEN ABSORPTION, CORRESPONDING TO A CALCULATED AVERAGE PARTICLE SIZE OF 0.67 TO 2.67 MM. ON THE ASSUMPTION THAT ALL PARTICLES ARE SPHERICAL, WHICH COMPRISES COMMIINUTING SAID POLYMER AS AN AQUEOUS SLURRY AT A TEMPERATURE OF 0 TO 30*C. WITH A ROTATING CUTTING SURFACE UNTIL AN AVERAGE PARTICLE SIZE OF 200 TO 700 MICRONS IS OBTAINED AND THEN WASHING SAID COMMINUTED POLYMER AS AN AQUEOUS SLURRY AT A TEMPERATURE OF 40 TO 70*C.
Claim 2
Dependent Claim
102 words
A PROCESS OF PREPARING A POLYTETRAFLUOROETHYLENE MOLDING POWDER FROM GRANULAR, IRREGULARLY SHAPED POLYTETRAFLUOROETHYLENE CHARACTERIZED BY A TOTAL SURFACE AREA OF FROM 1 TO 4 SQUARE METER GRAM AS MEASURED BY NITROGEN ABSORPTION, CORRESPONDING TO A CALCULATED AVERAGE PARTICLE SIZE OF 0.67 TO 2.67 MM. ON THE ASSUMPTION THAT ALL PARTICLES ARE SPHERICAL, WHICH COMPRISES COMMIINUTING SAID POLYMER AS AN AQUEOUS SLURRY AT A TEMPERATURE OF 0 TO 30*C. WITH A ROTATING CUTTING SURFACE UNTIL AN AVERAGE PARTICLE SIZE OF 200 TO 700 MICRONS IS OBTAINED AND THEN WASHING SAID COMMINUTED POLYMER AS AN AQUEOUS SLURRY AT A TEMPERATURE OF 40 TO 70*C.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1966-12-23 | 1967-06-24 | 1967-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1970-12-23 | 1971-06-24 | 1971-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1974-12-23 | 1975-06-24 | 1975-12-24 | $7700.00 | Window Closed / Lapsed |