Patent EP0296706A2 successfully refreshed from Google Patents.
Patent US3749698A successfully refreshed from Google Patents.
US3749698A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Treatment of polyamide granules with formic acid
Assignee: Hag AG
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Filing: 1971-04-30
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Granted: 1973-07-31
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Expires: 1991-04-30
Abstract
Abstract INACTIVATED POLYAMIDE GRANULES ARE REACTIVATED AND EXHIBIT IMPROVED ABSORPTIVITY BY TREATMENT WITH FORMIC ACID, SUCH AS AN AQUEOUS FORMIC ACID SOLUTION HAVING A CONCENTRATION IN A RANGE ABOUT 40-70% BY WEIGHT FORMIC ACID, AT A TEMPERATURE IN THE RANGE 0-80*C. THE FORMIC ACID TREATMENT IS USUALLY CARRIED OUT FOR A PERIOD OF FROM ABOUT ONE TO EIGHT HOURS. AFTER TREATMENT RESULTING POLYAMIDE GRANULES ARE SEPARATED SUCH AS BY FILTRATION AND RINSED WITH WATER.
Inventors
- 👤 G Lehmann
- 👤 O Neunhoeffer
- 👤 W Roselius
- 👤 O Vitzthum
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 04:02
CPC Classifications
C; C08; C08J; C08J3/00; C08G; C08G69/00; C08G69/48; C08J2377/00
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) | 1976-07-30 | 1977-01-29 | 1977-07-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-30 | 1981-01-29 | 1981-07-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-30 | 1985-01-29 | 1985-07-31 | $7700.00 | Window Closed / Lapsed |