US3337520A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Isoprene polymerization
Assignee: Phillips Petroleum Co
•
Filing: 1962-10-22
•
Granted: 1967-08-22
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Expires: 1982-10-22
Abstract
No abstract record available.
Inventors
- 👤 Bjornson Geir
- 👤 Edward L Czenkusch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 21:31
CPC Classifications
C; C08; C08F; C08F36/00; C08F36/02; C08F36/04; Y; Y10; Y10S; Y10S152/00; Y10S152/905
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
150 words
A PROCESS FOR THEHOMOPOLYMERIZATION OF ISOPRENE SO AS TO OBTAIN A SOLID RUBBERY PRODUCT HAVING A HIGH TRANS- CONTENT WHICH COMPRISES CONTACTING ISOPRENE UNDER POLYMERIZATION CONDITIONS WITH A CATALYST CONSITING OF THE PRODUCT RESULTING FROM THE TREATING OF FINE GRAIN, NONPOROUS SILICA HAVING A MEAN DIAMETER OF ABOUT 50 TO 1000 ANGSTROMS AND A SPECFIC SURFACE AREA OF ABOUT 10 TO 600 SQUARE METERS PER GRAM WITH A CHROMIUN COMPOUND CALCINABLE TO CHROMIUM OXIDE, ACTIVATING THE RESULTING COMPOSITE FOR A PERIOD UP TO 50 HOURS AT A TEMPERATURE IN THE RANGE OF 450 TO 2100*F. AND THEREAFER CONTACTING THE RESULTING ACTIVE CATALYST HAVING A PORTION OF THE CHROMIUM THEREIN PRESENT IN THE HEXAVALENT STATE WITH CARBON MONOXIDE IN AN OTHERWISE INERT ATMOSPHERE FOR ABOUT 1 TO 90 MINUTES AT A TEMPERATURE OF ABOUT 500 TO 700F. AND RECOVERING THE SOLID RUBBERY HOMOPOLYMER OF ISOPRENE AS A PRODUCT OF THE PROCESS.
Claim 2
Dependent Claim
150 words
A PROCESS FOR THEHOMOPOLYMERIZATION OF ISOPRENE SO AS TO OBTAIN A SOLID RUBBERY PRODUCT HAVING A HIGH TRANS- CONTENT WHICH COMPRISES CONTACTING ISOPRENE UNDER POLYMERIZATION CONDITIONS WITH A CATALYST CONSITING OF THE PRODUCT RESULTING FROM THE TREATING OF FINE GRAIN, NONPOROUS SILICA HAVING A MEAN DIAMETER OF ABOUT 50 TO 1000 ANGSTROMS AND A SPECFIC SURFACE AREA OF ABOUT 10 TO 600 SQUARE METERS PER GRAM WITH A CHROMIUN COMPOUND CALCINABLE TO CHROMIUM OXIDE, ACTIVATING THE RESULTING COMPOSITE FOR A PERIOD UP TO 50 HOURS AT A TEMPERATURE IN THE RANGE OF 450 TO 2100*F. AND THEREAFER CONTACTING THE RESULTING ACTIVE CATALYST HAVING A PORTION OF THE CHROMIUM THEREIN PRESENT IN THE HEXAVALENT STATE WITH CARBON MONOXIDE IN AN OTHERWISE INERT ATMOSPHERE FOR ABOUT 1 TO 90 MINUTES AT A TEMPERATURE OF ABOUT 500 TO 700F. AND RECOVERING THE SOLID RUBBERY HOMOPOLYMER OF ISOPRENE AS A PRODUCT OF THE PROCESS.
References Cited (Backward Citations)
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Cited
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Cited
US3132125A
Cited
US3091605A
Cited
US3037008A
Cited
US3166537A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-08-21 | 1971-02-20 | 1971-08-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-08-21 | 1975-02-20 | 1975-08-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-08-21 | 1979-02-20 | 1979-08-22 | $7700.00 | Window Closed / Lapsed |