US3631003A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polyamides and their production
Assignee: Imperial Chemical Industries Ltd
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Filing: 1970-02-24
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Granted: 1971-12-28
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Expires: 1990-02-24
Abstract
Abstract POLYAMIDES OF SPECIFIED MINIUMUM MOLECULAR WEIGHT HAVING AT LEAST 50 MOLE PERCENT OF THEIR REPEATING UNIT, UNITS DERIVED FROM DIAMINODIPHENYL SULPHOES AND STRAIGHT-CHAIN A,W-ALKANE DICARBOXYLIC ACIDS HAVING AT LEAST 6 CARBON ATOMS, INCLUDING THE CARBOXY CARBON ATOMS, USEFUL AS STRUCTURAL POLYMERS. ALSO, A PROCESS FOR THE PREPARATION OF SUCH POLYAMIDES WHICH COMPRISES TREATING A DIAMINODIPHENYL SULPHONE WITH THE DIACID HALIDE OF AN X,W-ALKANEDICARBOXYLIC ACID AT OR BELOW ROOM TEMPERATURE IN THE PRESENCE OF AN ORGANIC SOLVENT. THE POLYAMIDES ARE USEFUL IN THE MANUFACTURE OF MOLDED ARTICLES, FILMS, FIBERS AND THE LIKE.
Inventors
- 👤 Isaac Goodman
- 👤 Michael Edward Benet Jones
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:50
CPC Classifications
C; C08; C08G; C08G69/00; C08G69/42
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) | 1974-12-27 | 1975-06-28 | 1975-12-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-27 | 1979-06-28 | 1979-12-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-27 | 1983-06-28 | 1983-12-28 | $7700.00 | Window Closed / Lapsed |