Patent US3574146A successfully refreshed from Google Patents.
US3574146A
Expired / Lapsed
US
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Process for the production of polyamide foams
Assignee: Bayer AG
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Filing: 1967-12-15
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Granted: 1971-04-06
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Expires: 1987-12-15
Abstract
Abstract A PROCESS FOR THE CONTINUOUS PRODUCTION OF A POLYAMIDE FOAM BY INTRODUCING (1) A MIXTURE OF A LACTAM AND AN ALKALINE CATALYST E.G. SODIUM BOROHYDRIDE, AND (2) A MIXTURE OF A LACTAM AND AN ACTIVATOR, E.G. HEXAMETHYLENE DIISOCYANATE, IN A MIXING CHAMBER. PREFERABLY, HEATING IS ACCOMPLISHED IN THE MIXING CHAMBER BY HEAT EXHANGE WHEREIN MIXTURE (1) IS INTRODUCED JUST ABOVE THE LACTAM MELTING POINT AND MIXTURE (2) IS ABOVE THE REACTION TEMPERATURE. THE COMBINED MIXTURES ARE INTRODUCED INTO A HEATED MOLD FOR POLYMERIZATION AND FOAMING.
Inventors
- 👤 Hermann Schnell
- 👤 Kurt Schneider
- 👤 Heinrich Gilch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 15:33
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/04; C08J9/06; C08J9/08; C08J2377/00; C08J2377/02
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) | 1974-04-05 | 1974-10-05 | 1975-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-05 | 1978-10-05 | 1979-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-05 | 1982-10-05 | 1983-04-06 | $7700.00 | Window Closed / Lapsed |