Patent US3758424A successfully refreshed from Google Patents.
US3758424A
Expired / Lapsed
US
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Foamed polymeric materials
Assignee: Imperial Chemical Industries Ltd
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Filing: 1972-05-05
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Granted: 1973-09-11
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Expires: 1992-05-05
Abstract
Abstract MANUFACTURE OF POLYAMIDE FOAM, BY MIXING POLYAMIDE WITH A BLOWING AGENT COMPRISING AN OXALIC ACID DERIVATIVE WHEREIN ONE COOH GROUP HAS BEEN ESTERFIED WITH AN ALCOHOL OR POLYOL AND THE OTHER HAS BEEN EITHER ESTERIFIED WITH AN ALCOHOL, POLYOL OR PHENOL OR CONVERTED TO A SUBSTITUTED AMIDE, AND HEATING ABOVE THE METLING POINT. ESTERIFICATION PRODUCTS OF OXALIC ACID WITH POLYOLS, ESPECIALLY ETHYLENE GLYCOL, ARE PREFERRED.
Inventors
- 👤 N Anderson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 15:35
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/04; C08J9/06; C08J9/08; C08J2377/00; Y; Y10; Y10S; Y10S521/00; Y10S521/911
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) | 1976-09-10 | 1977-03-12 | 1977-09-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-10 | 1981-03-12 | 1981-09-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-10 | 1985-03-12 | 1985-09-11 | $7700.00 | Window Closed / Lapsed |