Patent US3753955A successfully refreshed from Google Patents.
US3753955A
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US
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Control of viscosity and polycaproamide degradation during vacuum polycondensation
Assignee: Honeywell International Inc
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Filing: 1971-11-18
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Granted: 1973-08-21
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Expires: 1991-11-18
Abstract
Abstract CONTROL OF POLYCAPROAMIDE DEGRADATION DDURING VACUUM POLYCONDENSATION IN A POLYMER FINISHER IS ACHIEVED BY MANTAINING A PARTIAL PRESSURE OF WATER ABOVE THE POLYMER MELT ABOVE ABOUT 10 MM. HG, PREFERABLY ABOVE ABOUT 30 MM. HG, ABSOLUTE PRESSURE. DEGRADATION IS MINIMIZED TO WITHIN 3, PREFERABLY 2 UNITS OF THE THEORETICAL DIFFERENCE BETWEEN CARBOXYL AND AMINE ENDS. THE WATER EXTRACTABLES CONTENT OF THE POLYMER IS ALSO CONTROLLED TO BELOW ABOUT 3.5% BY WEIGHT, PREFERABLY 2.5%, VISCCOSITY INCREASE OF THE POLYMER MELT LEVELS OUT AFTER LESS THAN 4 HOURS TO LESS THAN 10 FAV UNITS PER HOUR, BY MEANS OF THE INVENTION.
Inventors
- 👤 J Haylock
- 👤 J Wagner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 12:04
CPC Classifications
C; C08; C08G; C08G69/00; C08G69/02; C08G69/08; C08G69/14; C08G69/16
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) | 1976-08-20 | 1977-02-19 | 1977-08-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-20 | 1981-02-19 | 1981-08-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-20 | 1985-02-19 | 1985-08-21 | $7700.00 | Window Closed / Lapsed |