US2643993A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Continuous process for copolymerizing styrene and isobutylene
Assignee: Standard Oil Development Co
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Filing: 1949-09-13
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Granted: 1953-06-30
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Expires: 1969-09-13
Abstract
No abstract record available.
Inventors
- 👤 Bruce R Tegge
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 02:52
CPC Classifications
C; C08; C08F; C08F210/00; C08F210/16; C08F10/00; C08F2/00; C08F2/001; C08F2/04; C08F2/06; C08F212/00; C08F212/02; C08F212/04; C08F212/06; C08F212/08; C08F2500/00; C08F2500/03
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
127 words
IN THE PROCESS OF COPOLYMERIZING STYRENE AND ISOBUTYLENE AT A TEMPERATURE OF ABOUT -100* F. TO -140* F. IN THE PRESENCE OF ABOUT 1 TO 5 VOLUMES OF METHYL CHLORIDE PER VOLUME OF REACTANS, AND IN THE PRESNECE OF A FRIEDEL-CRAFTS CATALYST, USING PROPORTION OF REACTANTS TO PRODUCE COPOLYMERS HAVING A COMBINED STYRENE CONTENT OF ABOUT 40 TO 70% BY WRIGHT, THE IMPROVEMENT COMPRISING EFFECTING THE POLYMERIZATION CONTINUOUSLY IN THREE STAGES, IN THE FIRST ONE OF WHICH THE POLYMERIZATION IS CARRIER OUT TO A CONVERSION OF ABOUT 30 TO 70%, IN THE SECOND STAGE TO A TOTAL OF ABOUT 60 TO 90%, AND IN THE THIRD STAGE TO SUBSTANTIAL COMPLETION, THE AMOUNT OF SAID CONVERSION BEING CONTROLLED BY ADDING INCREASING AMOUNTS OF CATALYST IN THE SUCCESSIVE STAGES.
Claim 2
Dependent Claim
127 words
IN THE PROCESS OF COPOLYMERIZING STYRENE AND ISOBUTYLENE AT A TEMPERATURE OF ABOUT -100* F. TO -140* F. IN THE PRESENCE OF ABOUT 1 TO 5 VOLUMES OF METHYL CHLORIDE PER VOLUME OF REACTANS, AND IN THE PRESNECE OF A FRIEDEL-CRAFTS CATALYST, USING PROPORTION OF REACTANTS TO PRODUCE COPOLYMERS HAVING A COMBINED STYRENE CONTENT OF ABOUT 40 TO 70% BY WRIGHT, THE IMPROVEMENT COMPRISING EFFECTING THE POLYMERIZATION CONTINUOUSLY IN THREE STAGES, IN THE FIRST ONE OF WHICH THE POLYMERIZATION IS CARRIER OUT TO A CONVERSION OF ABOUT 30 TO 70%, IN THE SECOND STAGE TO A TOTAL OF ABOUT 60 TO 90%, AND IN THE THIRD STAGE TO SUBSTANTIAL COMPLETION, THE AMOUNT OF SAID CONVERSION BEING CONTROLLED BY ADDING INCREASING AMOUNTS OF CATALYST IN THE SUCCESSIVE STAGES.
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) | 1956-06-29 | 1956-12-29 | 1957-06-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-06-29 | 1960-12-29 | 1961-06-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-06-29 | 1964-12-29 | 1965-06-30 | $7700.00 | Window Closed / Lapsed |