US3379696A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Solid state preparation of polyamides
Assignee: Glanzstoff AG
•
Filing: 1964-03-16
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Granted: 1968-04-23
•
Expires: 1984-03-16
Abstract
No abstract record available.
Inventors
- 👤 Wiloth Fritz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 11:00
CPC Classifications
C; C08; C08G; C08G69/00; C08G69/02; C08G69/26; C08G69/28; C08G69/30
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
151 words
IN A PROCESS FOR THE PRODUCTION OF POLYAMIDES FROM DICARBOXYLIC ACIDS AND DIAMINES, FROM SALTS OF DICARBOXYLIC ACIDS AND DIAMINES, AND FROM AMINOCARBOXYLIC ACIDS, THE IMPROVEMENT WHICH COMPRISES: MAINTAINING THE POLYAMIDE-FORMING MONOMERS IN A CLOSED VESSEL UNDER AGITATION AND UNDER A NITROGEN ATMOSPHERE AT A TEMPERATURE BELOW THE MELTING POINT OF THE MONOMERS UNTIL A MAXIMUM PRESSURE OF 15 ATMOSPHERES SETS IN AND A PRECONDENSATE IS FORMED HAVING A SOLUTION VISCOSITY OF FROM ABOUT 1.30 TO ABOUT 1.50 MEASURED IN 1% SOLUTION 90% FORMIC ACID AT 25*C. AND THEREAFTER RELEASING THE PRESSURE BUILT UP IN THE CLOSED VESSEL TO A PRESSURE SLIGHTLY ABOVE ATMOSPHERIC PRESSURE WHILE HEATING THE PRECONDENSATE TO A TEMPERATURE OF FROM ABOUT 20 TO ABOUT 60*C. BELOW THE MELTING TEMPERATURE OF THE END CONDENSATION PRODUCT AND CONTINUING THE HEATING OF SAID REACTION MIXTURE FOR FROM ABOUT 1 TO ABOUT 5 HOURS WHILE PASSING NITROGEN THROUGH SAID REACTION MIXTURE.
Claim 2
Dependent Claim
151 words
IN A PROCESS FOR THE PRODUCTION OF POLYAMIDES FROM DICARBOXYLIC ACIDS AND DIAMINES, FROM SALTS OF DICARBOXYLIC ACIDS AND DIAMINES, AND FROM AMINOCARBOXYLIC ACIDS, THE IMPROVEMENT WHICH COMPRISES: MAINTAINING THE POLYAMIDE-FORMING MONOMERS IN A CLOSED VESSEL UNDER AGITATION AND UNDER A NITROGEN ATMOSPHERE AT A TEMPERATURE BELOW THE MELTING POINT OF THE MONOMERS UNTIL A MAXIMUM PRESSURE OF 15 ATMOSPHERES SETS IN AND A PRECONDENSATE IS FORMED HAVING A SOLUTION VISCOSITY OF FROM ABOUT 1.30 TO ABOUT 1.50 MEASURED IN 1% SOLUTION 90% FORMIC ACID AT 25*C. AND THEREAFTER RELEASING THE PRESSURE BUILT UP IN THE CLOSED VESSEL TO A PRESSURE SLIGHTLY ABOVE ATMOSPHERIC PRESSURE WHILE HEATING THE PRECONDENSATE TO A TEMPERATURE OF FROM ABOUT 20 TO ABOUT 60*C. BELOW THE MELTING TEMPERATURE OF THE END CONDENSATION PRODUCT AND CONTINUING THE HEATING OF SAID REACTION MIXTURE FOR FROM ABOUT 1 TO ABOUT 5 HOURS WHILE PASSING NITROGEN THROUGH SAID REACTION MIXTURE.
References Cited (Backward Citations)
US3232909A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1971-04-23 | 1971-10-23 | 1972-04-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-04-23 | 1975-10-23 | 1976-04-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-04-23 | 1979-10-23 | 1980-04-23 | $7700.00 | Window Closed / Lapsed |