Patent US2556200A successfully refreshed from Google Patents.
US3674762A
Expired / Lapsed
US
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Method for preparing polytetrafluoroethylene molding powder
Assignee: Daikin Industries Ltd
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Filing: 1970-07-17
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Granted: 1972-07-04
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Expires: 1990-07-17
Abstract
Abstract Preparation of a free-flowing polytetrafluoroethylene molding powder by mechanically agitating polytetrafluoroethylene powder under a reduced pressure less than 500 mmHg (absolute). The obtained granular powder has good flowability, extremely little aggregates and high bulk density.
Inventors
- 👤 Masanori Izumo
- 👤 Tatsushiro Yoshimura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 06:49
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/12; C08J2327/00; C08J2327/02; C08J2327/12; C08J2327/18
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
16 words
The method of claim 1, wherein the reduced pressure is less than 300 mm Hg (absolute).
Claim 2
Dependent Claim
16 words
The method of claim 1, wherein the reduced pressure is less than 100 mm Hg (absolute).
Claim 3
Dependent Claim
14 words
The method of claim 1, wherein the temperature ranges from 25* to 75* C.
Claim 4
Dependent Claim
22 words
The method of claim 1, wherein the average particle size of the powder of tetrafluoroethylene polymer is smaller than 200 Mu .
Claim 5
Dependent Claim
20 words
The method of claim 1, wherein said co-polymerizable monomer unit is selected from the group consisting of hexafluoropropylene and trifluorochloroethylene.
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) | 1975-07-04 | 1976-01-03 | 1976-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-04 | 1980-01-03 | 1980-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-04 | 1984-01-03 | 1984-07-04 | $7700.00 | Window Closed / Lapsed |