Patent US3657408A successfully refreshed from Google Patents.
US3657408A
Expired / Lapsed
US
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Process for shaping acrylonitrile polymers
Assignee: Wyeth Holdings LLC
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Filing: 1970-04-24
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Granted: 1972-04-18
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Expires: 1990-04-24
Abstract
Abstract SHAPED SUBSTANTIALLY NON-POOUS POLYMERS CONTAINING AT LEAST ABOUT 70 PERCENT BY WEIGHT ARCYLONITRILE AND HAVING A NOVEL CRENULATED SURFACE HAVING IMPROVED RESISTANCE TO SOILING ARE PROVIDED. SUCH PRODUCTS ARE PREPARED BY DISSOLVING THE POLYMER IN AQUEOUS SODIUM THIOCYANATE, EXTRUDING OR OTHERWISE SHAPING THE SOLUTION AND THEREAFTER COAGULATING THE SHAPED PRODUCT WITH AN AQUEOUS SOLUTION CONTAINING ALUMINUM CHLORIDE, MAGNESIUM CHLORIDE OR CALCIUM CHLORIDE OR BY DISSOLVING THE POLYMER IN AN ORGANIC SOLVENT THEREFOR, SHAPING AND THEREAFTER COAGULATING THE SHAPED PRODUCT IN AN AQUEOUS SOLUTION CONTAINING ALUMINUM CHLORIDE OR MAGNESIUM CHLORIDE.
Inventors
- 👤 Suresh N Chinai
- 👤 Edmund Brigmanis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:11
CPC Classifications
D; D01; D01F; D01F6/00; D01F6/02; D01F6/18; D01F6/28; D01F6/38
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) | 1975-04-18 | 1975-10-18 | 1976-04-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-18 | 1979-10-18 | 1980-04-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-18 | 1983-10-18 | 1984-04-18 | $7700.00 | Window Closed / Lapsed |