US2579451A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polymeric materials
Assignee: EIDP Inc
•
Filing: 1948-12-31
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Granted: 1951-12-18
•
Expires: 1968-12-31
Abstract
No abstract record available.
Inventors
- 👤 Allen E Polson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:48
CPC Classifications
D; D01; D01F; D01F6/00; D01F6/02; D01F6/18; C; C08; C08F; C08F8/00
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
99 words
A PROCESS FOR OBTAINING SHAPED ARTICLES WHICH COMPRISES THE STEPS OF DISSOLVING AT A TEMPERATURE OF -10* C. TO 35* C. POLYACRYLONITRILE IN AN OXY ACID FROM THE GROUP CONSISTING OF NITRIC ACID, PHOSPHORIC ACID, AND SULPHURIC ACID, MAINTAINING THE SOLUTION AT SAID TEMPERATURE UNTIL FROM 2% TO 75% OF THE NITRILE GROUPS IN THE POLYACRYLONITRILE HAVE BEEN CONVERTED INTO AMIDE GROUPS, EDTRUDING THE SOLUTION THUS OBTAINED INTO A LIQUID COAGULATING BATH WHICH IS A NONOSOLVENT FOR THE DISSOLVED POLYMER BUT WHICH IS A SOLVENT FOR SAID ACID, WATER BEING PRESENT IN AT LEAST ONE OF THESE TWO STEPS.
References Cited (Backward Citations)
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Cited
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-12-17 | 1955-06-18 | 1955-12-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-12-17 | 1959-06-18 | 1959-12-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-12-17 | 1963-06-18 | 1963-12-18 | $7700.00 | Window Closed / Lapsed |