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US2593583A
Expired / Lapsed
US
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Method for coagulating aqueous dispersions of polytetrafluoroethylene
Assignee: EIDP Inc
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Filing: 1951-03-14
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Granted: 1952-04-22
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Expires: 1971-03-14
Abstract
No abstract record available.
Inventors
- 👤 John F Lontz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:01
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/12; C08J3/16; B; B29; B29C; B29C43/00; B29C43/006; C08J2327/00; C08J2327/02; C08J2327/12; C08J2327/18; Y; Y10; Y10S; Y10S425/00; Y10S425/101
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
150 words
IN A PROCESS FOR PREPARING TETRAFLUOROETHYLENE POLYMER ARTICLES, THE STEPS WHICH COMPRISES IMPARTING ENERGY TO AN AQUEOUS COLLOIDAL DISPERSION CONSISTING ESSENTIALLY OF WATER AND TETRAFLUOROETHYLENE POLYMER, WHICH DISPERSION IS STABLE ON STORAGE AND WHICH HAS A TETRAFLUOROETHYLENE POLYMER CONTENT OF 10% TO 50% BY WEIGHT, BY MEANS OF INTERNAL ROTARY STIRRING IN OPPOSITION TO BAFFLES, SAID IMPARTING OF ENERGY BEING EFFECTIVE THROUGHOUT A MAJOR PART OF THE SAID DISPERSION, THE TEMPERATURE OF THE DISPERSION BEING FROM 32* F. TO 185* F., THE AMOUNT OF POWER THUS SUPPLIED TO THE DISPERSION BEING IN THE RANGE OF 0.02 TO 1.00 HORSEPOWER PER GALLON OF THE DISPERSION, WHEREBY PARTICLES OF TETRAFLUOROETHYLENE POLYMER COAGULATE, AND REMOVING THE SAID COAGULATED PARTICLES FROM THE MIXTURE, WHEREBY THERE IS FORMED A FREE-FLOWING GRANULAR PRODUCT WHICH CAN BE CONSOLIDATED UNDER PRESSURE AND CONVERTED TO A SINTERED ARTICLE BY HEATING AT A TEMPERATURE OF 621* F. TO 932* F.
Claim 2
Dependent Claim
150 words
IN A PROCESS FOR PREPARING TETRAFLUOROETHYLENE POLYMER ARTICLES, THE STEPS WHICH COMPRISES IMPARTING ENERGY TO AN AQUEOUS COLLOIDAL DISPERSION CONSISTING ESSENTIALLY OF WATER AND TETRAFLUOROETHYLENE POLYMER, WHICH DISPERSION IS STABLE ON STORAGE AND WHICH HAS A TETRAFLUOROETHYLENE POLYMER CONTENT OF 10% TO 50% BY WEIGHT, BY MEANS OF INTERNAL ROTARY STIRRING IN OPPOSITION TO BAFFLES, SAID IMPARTING OF ENERGY BEING EFFECTIVE THROUGHOUT A MAJOR PART OF THE SAID DISPERSION, THE TEMPERATURE OF THE DISPERSION BEING FROM 32* F. TO 185* F., THE AMOUNT OF POWER THUS SUPPLIED TO THE DISPERSION BEING IN THE RANGE OF 0.02 TO 1.00 HORSEPOWER PER GALLON OF THE DISPERSION, WHEREBY PARTICLES OF TETRAFLUOROETHYLENE POLYMER COAGULATE, AND REMOVING THE SAID COAGULATED PARTICLES FROM THE MIXTURE, WHEREBY THERE IS FORMED A FREE-FLOWING GRANULAR PRODUCT WHICH CAN BE CONSOLIDATED UNDER PRESSURE AND CONVERTED TO A SINTERED ARTICLE BY HEATING AT A TEMPERATURE OF 621* F. TO 932* F.
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) | 1955-04-22 | 1955-10-22 | 1956-04-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1959-04-22 | 1959-10-22 | 1960-04-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1963-04-22 | 1963-10-22 | 1964-04-22 | $7700.00 | Window Closed / Lapsed |