Patent US2981979A successfully refreshed from Google Patents.
US2981979A
Expired / Lapsed
US
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Fabrication of porous articles from polyethylene
Assignee: Phillips Petroleum Co
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Filing: 1959-09-17
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Granted: 1961-05-02
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Expires: 1979-09-17
Abstract
No abstract record available.
Inventors
- 👤 Charles L Seefluth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 15:40
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/24; Y; Y10; Y10S; Y10S521/00; Y10S521/919
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
131 words
A METHOD OF MAKING A POROUS ARTICLE FROM POLYETHYLENE COMPRISING MIXING POLYETHYLENE POWDER HAVING A PARTICLE SIZE IN THE RANGE OF 50 TO 80 MESH WITH A MIXTURE OF TALC AND METAL STEARATE EACH HAVING A PARTICLE SIZE OF LESS THAN 200 MESH, SAID TALC BEING PRESENT IN AN AMOUNT OF AT LEAST 50 PERCENT BY WEIGHT OF THE MIXTURE OF TALC AND METAL STEARATE, THE AMOUNT OF SAID TALC AND METAL STEARATE BEING 18 TO 25 PERCENT BY WEIGHT OF THE MIXTURE OF POLYETHYLENE, TALC, AND METAL STEARATE, PRESSING THE MIXTURE TO THE DESIRED FORM USING A PRESSURE IN THE RANGE OF 150 TO 30,000 P.S.I., SINTERING THE PRESSED ARTICLE AT A TEMPERATURE OF 300 TO 350*F. FOR 10 TO 30 MINUTES, AND WASHING METAL STEARATE FROM THE SINTERED ARTICLE.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-05-01 | 1964-10-31 | 1965-05-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-05-01 | 1968-10-31 | 1969-05-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-05-01 | 1972-10-31 | 1973-05-02 | $7700.00 | Window Closed / Lapsed |