Patent US3271268A successfully refreshed from Google Patents.
US2935540A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Purification of isoprene
Assignee: Goodrich Gulf Chemicals Inc
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Filing: 1957-04-22
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Granted: 1960-05-03
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Expires: 1977-04-22
Abstract
No abstract record available.
Inventors
- 👤 John S B Wolfe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 11:43
CPC Classifications
C; C07; C07C; C07C7/00; C07C7/005; C07C7/148; C07C7/14833; C07C7/14841
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
168 words
A PROCESS FOR PREPARING A POLYMERIZATION GRADE ISOPRENE CONTAINING LESS THAN 0.1%/WT. OF TOTAL POLYMERIZATION RETARDING IMPURITIES FROM A CRUDE ISOPRENE DERIVED FROM THE CRACKING OF PETROLEUM AND INCLUDING, AS IMPURITIES, ALPHA-ACETYLENES AND 2-BUTYNE WHICH COMPRISES THE STEPWISE TREATMENT, CARRIED OUT IN THE ORDER GIVEN BELOW AND UNDER AN INERT ATMOSPHERE, OF (1) MIXING THE SAID CRUDE ISOPRENE WITH AN EXCESS OF SODIUM METAL IN THE FORM OF COLLOIDAL PARTICLES FROM 1 TO 10 MICRONS IN DIAMETER, SAID EXCESS OF SODIUM METAL BEING NOT GREATER THAN 75% MORE THAN THE AMOUNT REQUIRED TO REACT WITH THE SAID ALPHA-ACETYLENES IN SAID CRUDE ISOPRENE, (2) AGITATING THE RESULTING MIXTURE, AT A TEMPERATURE BELOW 40* C. UNTIL THE SAID COLLOIDAL PARTICLES OF SODIUM HAVE REACTED WITH THE SAID ALPHA-ACETYLENES, (3) FILTERING THE SAID COLLOIDAL SODIUM PARTICLES FROM THE REMAINING ISOPRENE, AND (4) CONTACTING THE RESULTING SODIUM-TREATED ISOPRENE WITH MOLECULR SIEVES HAVING A CHANNEL DIAMETER OF 5 ANGSTROM UNITS TO PRODUCE ISOPRENE CONTAINING LESS THAN ABOUT 0.1%/WT. OF TOTAL POLYMERIZATION RETARDING IMPURITIES.
Claim 2
Dependent Claim
168 words
A PROCESS FOR PREPARING A POLYMERIZATION GRADE ISOPRENE CONTAINING LESS THAN 0.1%/WT. OF TOTAL POLYMERIZATION RETARDING IMPURITIES FROM A CRUDE ISOPRENE DERIVED FROM THE CRACKING OF PETROLEUM AND INCLUDING, AS IMPURITIES, ALPHA-ACETYLENES AND 2-BUTYNE WHICH COMPRISES THE STEPWISE TREATMENT, CARRIED OUT IN THE ORDER GIVEN BELOW AND UNDER AN INERT ATMOSPHERE, OF (1) MIXING THE SAID CRUDE ISOPRENE WITH AN EXCESS OF SODIUM METAL IN THE FORM OF COLLOIDAL PARTICLES FROM 1 TO 10 MICRONS IN DIAMETER, SAID EXCESS OF SODIUM METAL BEING NOT GREATER THAN 75% MORE THAN THE AMOUNT REQUIRED TO REACT WITH THE SAID ALPHA-ACETYLENES IN SAID CRUDE ISOPRENE, (2) AGITATING THE RESULTING MIXTURE, AT A TEMPERATURE BELOW 40* C. UNTIL THE SAID COLLOIDAL PARTICLES OF SODIUM HAVE REACTED WITH THE SAID ALPHA-ACETYLENES, (3) FILTERING THE SAID COLLOIDAL SODIUM PARTICLES FROM THE REMAINING ISOPRENE, AND (4) CONTACTING THE RESULTING SODIUM-TREATED ISOPRENE WITH MOLECULR SIEVES HAVING A CHANNEL DIAMETER OF 5 ANGSTROM UNITS TO PRODUCE ISOPRENE CONTAINING LESS THAN ABOUT 0.1%/WT. OF TOTAL POLYMERIZATION RETARDING IMPURITIES.
References Cited (Backward Citations)
US2398973A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-05-03 | 1963-11-02 | 1964-05-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-05-03 | 1967-11-02 | 1968-05-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-05-03 | 1971-11-02 | 1972-05-03 | $7700.00 | Window Closed / Lapsed |