Patent US3679641A successfully refreshed from Google Patents.
US3679641A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of acrylonitrile unsaturated sulfonic acid copolymers
Assignee: Japan Exlan Co Ltd
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Filing: 1970-05-27
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Granted: 1972-07-25
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Expires: 1990-05-27
Abstract
Abstract COPOLYMERS OF AT LEAST 80% OF ACRYLONITRILE, ABOUT 0.1 TO 5% OF AN ETHYLENICALLY UNSATURATED ORGANIC SULFONIC ACID OR SALT THEREOF AND UP TO 19.9% OF AT LEAST ONE ETHYLENICALLY UNSTURATED MONOMER WHICH IS COPOLYMERIZABLE WITH ACRYLONITRILE AND THE AFORESAID SULFONIC ACID OR ITS SALT, ARE PREPARED IN AQUEOUS POLYMERIZATION MEDIUM IN THE PRESENCE OF AN ORGANIC COMPOUND WHICH IS A NON-SOLVENT FOR THE COPOLYMER BUT IS A SOLVENT FOR THE MONOMER(S) OTHER THAN THE SULFONIC ACID O ITS SALT.
Inventors
- 👤 Kenji Takeya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 05:19
CPC Classifications
C; C08; C08F; C08F220/00; C08F220/02; C08F220/42; C08F220/44; C08F220/46; C08F28/00
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) | 1975-07-25 | 1976-01-24 | 1976-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-25 | 1980-01-24 | 1980-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-25 | 1984-01-24 | 1984-07-25 | $7700.00 | Window Closed / Lapsed |