US3331822A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of polytetrafluoroethylene molding powders by the aqueous suspension polymerization of tetrafluoroethylene with small amounts of perfluoroolefins containing from 3 to 4 carbon atoms
Assignee: Zeneca Inc
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Filing: 1963-08-20
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Granted: 1967-07-18
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Expires: 1983-08-20
Abstract
No abstract record available.
Inventors
- 👤 Kometani Yutaka
- 👤 Tatemoto Masayoshi
- 👤 Fumoto Syozo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 17:29
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/12; C08F; C08F214/00; C08F214/18; C08F214/26; C08J2327/00; C08J2327/02; C08J2327/12; C08J2327/18; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
124 words
IN A PROCESS FOR THE PRODUCTION OF POLYTETRAFLUOROETHYLENE MOLDING POWDER BY THE AQUEOUS SUSPENSION POLYMERIZATION OF TETRAFLUOROETHYLENE, IN WHICH MONOMERIC TETRAFLUOROETHYLENE IS POLYMERIZED BY BRINGING THE MONOMER INTO CONTACT WITH AN AQUEOUS MEDIUM CONTAINING A FREE RADICAL CATALYST SYSTEM THE IMPROVEMENT WHICH CONSISTS ESSENTIALLY OF INCREASING THE BULK DENSITY AND ENHANCING THE FLOW CHARACTERISTICS OF THE POLYMER BY COPOLYMERIZING THE MONOMERIC TETRAFLUOROETHYLENE WITH FROM 0.5 TO 2 PERCENT BY WEIGHT OF A PERFLUOROOLEFIN CONTAINING FROM 3 TO 4 CARBON ATOMS THROUGHT THE ADDITION OF THE PERFLUOROOLEFIN TO THE AQUEOUS SUSPENSION POLYMERIZATION MEDIUM, THEREBY PRODUCING A MOLDING POWDER SUBSTANTIALLY COMPOSED OF SPHEROIDAL PARTICLES HAVING A BULK DENSITY IN THE RANGE FROM 0.5 TO 0.7 GRAM PER CUBIC CENTIMETER AND CHARACTERIZED BY IMPROVED RESISTANCE TO COALESCENCE.
Claim 2
Dependent Claim
124 words
IN A PROCESS FOR THE PRODUCTION OF POLYTETRAFLUOROETHYLENE MOLDING POWDER BY THE AQUEOUS SUSPENSION POLYMERIZATION OF TETRAFLUOROETHYLENE, IN WHICH MONOMERIC TETRAFLUOROETHYLENE IS POLYMERIZED BY BRINGING THE MONOMER INTO CONTACT WITH AN AQUEOUS MEDIUM CONTAINING A FREE RADICAL CATALYST SYSTEM THE IMPROVEMENT WHICH CONSISTS ESSENTIALLY OF INCREASING THE BULK DENSITY AND ENHANCING THE FLOW CHARACTERISTICS OF THE POLYMER BY COPOLYMERIZING THE MONOMERIC TETRAFLUOROETHYLENE WITH FROM 0.5 TO 2 PERCENT BY WEIGHT OF A PERFLUOROOLEFIN CONTAINING FROM 3 TO 4 CARBON ATOMS THROUGHT THE ADDITION OF THE PERFLUOROOLEFIN TO THE AQUEOUS SUSPENSION POLYMERIZATION MEDIUM, THEREBY PRODUCING A MOLDING POWDER SUBSTANTIALLY COMPOSED OF SPHEROIDAL PARTICLES HAVING A BULK DENSITY IN THE RANGE FROM 0.5 TO 0.7 GRAM PER CUBIC CENTIMETER AND CHARACTERIZED BY IMPROVED RESISTANCE TO COALESCENCE.
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) | 1970-07-17 | 1971-01-16 | 1971-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-07-17 | 1975-01-16 | 1975-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-07-17 | 1979-01-16 | 1979-07-18 | $7700.00 | Window Closed / Lapsed |