US3905946A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Extraction of polylactams
Assignee: BASF SE
•
Filing: 1973-08-28
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Granted: 1975-09-16
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Expires: 1993-08-28
Abstract
Abstract Continuous extraction of polylactam granules for the removal of monomers and/or oligomers therefrom by means of hot water flowing countercurrently in an extraction zone, which extraction zone is divided into subzones by at least one heating zone and the water is accelerated, at certain time intervals, cocurrently and countercurrently to the flow of granules.
Inventors
- 👤 Werner Nieswandt
- 👤 Werner Hoerauf
- 👤 Ernst Guenther
- 👤 Ernst Kissel
- 👤 Eckart Neumann
- 👤 Guenter Valentin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 16:57
CPC Classifications
C; C08; C08G; C08G69/00; C08G69/46
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
200 words
A PROCESS FOR THE EXTRACTION OF MONOMER-CONTAINING AND/OR OLIGOMER-CONTAINING POLYLACTAM GRANULES WHICH COMPRISES CONTINUOUSLY EXTRACTING POLYLACTAM GRANULES WITH A COUNTERCURRENT OF WATER AT TEMPERATURES ABOVE 80*C, UNDER THE FOLLOWING CONDITIONS: A. THE WATER FLOWS UPWARDLY THROUGH A SUBSTANTIALLY VERTICAL EXTRACTION ZONE AT A MEAN OF FROM 0.5 TO 20 CM/MIN AND THE POLYLACTAM GRANULES PASS DOWNWARDLY THROUGH SAID EXTRACTION ZONE AT A RATE OF FROM 0.2 TO 5 CM/MIN AND B. THE TEMPERATURE AT THE UPPER END OF THE EXTRACTION ZONE IS HIGHER THAN AT ITS LOWER END, C. THE EXTRACTION ZONE IS DIVIDED INTO SUBZONES Y AT LEAST ONE HEATING ZONE SO THAT THE DENSITY OF THE WATER CONTAINING EXTRACTABLES IN AN UPPER SUBZONE IS LOWER THAN THAT OF THE WATER CONTAINED IN THE SUBZONE IMMEDIATELY BELOW BY AT LEAST 0.0002, D. THE UPPERMOST HEATING ZONE DIVIDES THE ENTIRE EXTRACTION ZONE INTO LENGTHS BEARING A RATIO TO EACH OTHER OF FROM 50:50 TO 85:15, THE SHORTER SECTION BEING AT THE UPPER END OF THE EXTRACTION ZONE, AND E. THE WATER, WHICH SHOWS AN OVERALL ASCENT THROUGH THE EXTRACTION ZONE, IS ACCELERATED AT INTERVALS OF FROM 0.5 TO 180 MINUTES ALTERNATELY COCURRENTLY AND COUNTERUCRRENTLY TO THE FLOW OF POLYLACTAM GRANULES.
Claim 2
Dependent Claim
200 words
A PROCESS FOR THE EXTRACTION OF MONOMER-CONTAINING AND/OR OLIGOMER-CONTAINING POLYLACTAM GRANULES WHICH COMPRISES CONTINUOUSLY EXTRACTING POLYLACTAM GRANULES WITH A COUNTERCURRENT OF WATER AT TEMPERATURES ABOVE 80*C, UNDER THE FOLLOWING CONDITIONS: A. THE WATER FLOWS UPWARDLY THROUGH A SUBSTANTIALLY VERTICAL EXTRACTION ZONE AT A MEAN OF FROM 0.5 TO 20 CM/MIN AND THE POLYLACTAM GRANULES PASS DOWNWARDLY THROUGH SAID EXTRACTION ZONE AT A RATE OF FROM 0.2 TO 5 CM/MIN AND B. THE TEMPERATURE AT THE UPPER END OF THE EXTRACTION ZONE IS HIGHER THAN AT ITS LOWER END, C. THE EXTRACTION ZONE IS DIVIDED INTO SUBZONES Y AT LEAST ONE HEATING ZONE SO THAT THE DENSITY OF THE WATER CONTAINING EXTRACTABLES IN AN UPPER SUBZONE IS LOWER THAN THAT OF THE WATER CONTAINED IN THE SUBZONE IMMEDIATELY BELOW BY AT LEAST 0.0002, D. THE UPPERMOST HEATING ZONE DIVIDES THE ENTIRE EXTRACTION ZONE INTO LENGTHS BEARING A RATIO TO EACH OTHER OF FROM 50:50 TO 85:15, THE SHORTER SECTION BEING AT THE UPPER END OF THE EXTRACTION ZONE, AND E. THE WATER, WHICH SHOWS AN OVERALL ASCENT THROUGH THE EXTRACTION ZONE, IS ACCELERATED AT INTERVALS OF FROM 0.5 TO 180 MINUTES ALTERNATELY COCURRENTLY AND COUNTERUCRRENTLY TO THE FLOW OF POLYLACTAM GRANULES.
Claim 3
Dependent Claim
12 words
A process as claimed in claim 1, wherein polycaprolactam granules are extracted.
Claim 4
Dependent Claim
21 words
A process as claimed in claim 1, wherein the extraction zone is divided into subzones by at least two heating zones.
Claim 5
Dependent Claim
41 words
A process as claimed in claim 1, wherein the density of the water containing extractables in a subzone lying above a heating zone is lower than that of the water contained in the subzone Immediately below by from 0.0005 to 0.0004.
Claim 6
Dependent Claim
20 words
A process as claimed in claim 1, wherein the water is accelerated at intervals of from 1 to 20 minutes.
Claim 7
Dependent Claim
34 words
A process as claimed in claim 1, wherein the water showing an overall ascent is accelerated at intervals to a speed which is from 10 to 60 times as great as its mean speed.
Claim 8
Dependent Claim
30 words
A process as claimed in claim 1, wherein said heating zone or the total of said heating zones constitute 1/7 to 1/20 of the length to the vertical extraction zone.
Claim 9
Dependent Claim
24 words
A process as claimed in claim 7 wherein said heating zone or zones respectively constitute a tubular heat exchanger with tubes of constricted cross-section.
Claim 10
Dependent Claim
40 words
A process as claimed in claim 1 wherein the temperature of the water in the upper subzone is 95*-99*C., and the temperature of the water in the next lower subzone is 5*-9*C. below the water temperature in said upper zone.
Claim 11
Dependent Claim
79 words
A process as claimed in claim 1, wherein the extraction zone is divided into subzones by at least two heating zones, the temperature of the water in the upper subzone is 95*-99*C., and the temperature of the water in the next lower subzone is 5*-9*C. below the water temperature in said upper zone, and the temperature of the water in the next lower subzone or successive, lower subzones is 2*-4*C. below the water temperature of the subzone immediately thereabove.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-15 | 1979-03-17 | 1979-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-15 | 1983-03-17 | 1983-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-15 | 1987-03-17 | 1987-09-16 | $7700.00 | Window Closed / Lapsed |