Patent US3780138A successfully refreshed from Google Patents.
US3780138A
Expired / Lapsed
US
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Method for separating metal contaminant from organic polymers
Assignee: Shell USA Inc
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Filing: 1971-09-14
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Granted: 1973-12-18
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Expires: 1991-09-14
Abstract
Abstract A METHOD IS PROVIDED FOR SEPARATING METAL CATALYST CONTAMINANTS FROM ORGANIC POLYMERS, TYPICALLY POLYMERS DERIVED FROM DIENES AND/OR VINYL ARENES, BY TREATMENT WITH AN AQUEOUS SOLUTION OF CITRIC ACID, AN OXIDANT, AND OPTIONALLY, A LOWER ALIPHATIC ALCOHOL, THEN SEPARATING THE AQUEOUS PHASE TO REMOVE THE CONTAMINATING METAL. ALTERNATIVELY, THE POLYMER MAY BE CONTACTED WITH AN OXIDANT BEFORE TREATMENT WITH THE AQUEOUS SOLUTION.
Inventors
- 👤 H Hassell
- 👤 J Watson
- 👤 B Shaw
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 08:10
CPC Classifications
C; C08; C08C; C08C2/00; C08C2/02; C08C2/04; C08F; C08F6/00; C08F6/02
Claims Analysis
Total Claims: 0
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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) | 1976-12-17 | 1977-06-18 | 1977-12-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-17 | 1981-06-18 | 1981-12-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-17 | 1985-06-18 | 1985-12-18 | $7700.00 | Window Closed / Lapsed |