Patent US3665067A successfully refreshed from Google Patents.
US3665067A
Expired / Lapsed
US
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Polytetrafluoroethylene fabrication with hexafluorobenzene
Assignee: Imperial Smelting Corp Ltd
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Filing: 1970-07-24
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Granted: 1972-05-23
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Expires: 1990-07-24
Abstract
Abstract Polytetrafluoroethylene (ptfe) is fabricated into shaped products with the use of hexafluorobenzene as a plasticizer. The ptfe may be particulate, and may be fabricated by ram extrusion. From 8 to 16 percent by volume of the hexafluorobenzene is mixed with the ptfe and maintained in contact with it for long enough to be absorbed onto and just into the surface of the ptfe.
Inventors
- 👤 William Hopkin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 22:14
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/022; B29C48/03; B29C48/04; B29C48/05; B29C48/06; B29C48/09; B29K; B29K2027/00; B29K2027/12; B29K2027/18
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
59 words
A method as claimed in claim 1 wherein the hexafluorobenzene and the polytetrafluoroethylene are maintained in contact for a period of time not exceeding 1 hour when 5 percent of hexafluorobenzene is used and not exceeding 24 hours when 15 percent of hexafluorobenzene is used, the maximum contact time for intermediate proportions of hexafluorobenzene being intermediate the periods stated.
Claim 2
Independent Claim
26 words
A method as claimed 1 wherein the range of hexafluorobenzene is from 8 to 16 percent by volume as compared to the volume of the polytetrafluoroethylene.
Claim 3
Dependent Claim
15 words
A method as claimed in claim 1 wherein the fabrication is performed by ram extrusion.
Claim 4
Dependent Claim
21 words
A method as claimed in claim 4 wherein the extrusion is performed at a pressure of not more than 5,000 psi.
Claim 5
Dependent Claim
21 words
A method as claimed in claim 5, wherein the extrusion is performed at a pressure of from 2,000 to 3,000 psi.
Claim 6
Dependent Claim
46 words
Finely divided granules or particles of polytetrafluoroethylene softened with and swollen by 5 to 20 percent volume of the polytetrafluoroethylene of hexafluorobenzene, said hexafluorobenzene being present in an amount in excess of that which is absorbed by said polytetrafluoroethylene in order to bring about said swelling.
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) | 1975-05-23 | 1975-11-22 | 1976-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-23 | 1979-11-22 | 1980-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-23 | 1983-11-22 | 1984-05-23 | $7700.00 | Window Closed / Lapsed |