US3865672A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the removal of volatiles from polymer solutions
Assignee: BASF SE
•
Filing: 1972-07-26
•
Granted: 1975-02-11
•
Expires: 1992-07-26
Abstract
Abstract Process for the removal of volatiles, in a single stage by vacuum evaporation, from polymer solutions obtained in the continuous solution polymerization of monomer mixtures containing acrylonitrile or methacrylonitrile. The evaporation is effected in a devolatilizing zone in which the temperature of the polymer solution rises in its direction of flow. This process causes no damage to the polymers on account of decomposition products of the heat-sensitive nitrile monomers.
Inventors
- 👤 Lothar Metzinger
- 👤 Alfred Gottschalk
- 👤 Klaus Schoettle
- 👤 Josef Schwaab
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:10
CPC Classifications
C; C08; C08F; C08F6/00; C08F6/06; C08F6/10
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
62 words
A CONTINOUS SINGLE-STAGE PROCESS FOR REMOVING VOLATILES FROM A POLYMER SOLUTION OBTAINED BY SOLUTION POLYMERIZATION OF A MONOMER MIXTURE CONTAINING FROM 10 TO 80 PERCENT BY WEIGHT OF ACRYLONTRILE OR METHACRYLONTRILE, SAID SOLUTION HAVING A SOLIDS CONTENT OF FROM 30 TO 90 PERCENT BY WEIGHT, WHICH COMPRISES CONTINUOUSLY CONDUCTING SAID SOLUTION COUNTERCURRENT TEMPERATURE OF FROM 100* TO 180*C IN INDIRECT COUNTERCURRENT HEAT
Claim 2
Dependent Claim
62 words
A CONTINOUS SINGLE-STAGE PROCESS FOR REMOVING VOLATILES FROM A POLYMER SOLUTION OBTAINED BY SOLUTION POLYMERIZATION OF A MONOMER MIXTURE CONTAINING FROM 10 TO 80 PERCENT BY WEIGHT OF ACRYLONTRILE OR METHACRYLONTRILE, SAID SOLUTION HAVING A SOLIDS CONTENT OF FROM 30 TO 90 PERCENT BY WEIGHT, WHICH COMPRISES CONTINUOUSLY CONDUCTING SAID SOLUTION COUNTERCURRENT TEMPERATURE OF FROM 100* TO 180*C IN INDIRECT COUNTERCURRENT HEAT
Claim 3
Dependent Claim
26 words
A process as set forth in claim 1, wherein said polymer is a copolymer of styrene and from 15 to 40 percent by weight of acrylonitrile.
Claim 4
Dependent Claim
63 words
A process as set forth in claim 1, wherein said heating medium is a condensable vapor, and an inert gas is admixed with the condensable vapor at one or more points between the inlet and outlet for the heating medium to effect a progressive reduction of the medium vapor concentration flowing countercurrently to the said solution to thereby help maintain said temperature gradient.
Claim 5
Dependent Claim
56 words
A process as set forth in claim 1, wherein said heating medium is a condensable vapor, and an inert gas is admixed with the condensable vapor at the inlet for the heating medium to effect a progressive reduction of the medium vapor concentration flowing countercurrently to the said solution to thereby help maintain said temperature gradient.
Claim 6
Dependent Claim
26 words
A process as set forth in claim 1, wherein said polymer is a copolymer of acrylonitrile or methacrylonitrile and styrene, alpha-methylstyrene, an acrylate, or a methacrylate.
Claim 7
Dependent Claim
16 words
A process as set forth in claim 5, wherein said solution contains an alkylaromatic hydrocarbon solvent.
References Cited (Backward Citations)
US2266941A
Cited
US2731081A
Cited
US2914120A
Cited
US2941985A
Cited
US3147174A
Cited
US3201365A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-10 | 1978-08-12 | 1979-02-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-10 | 1982-08-12 | 1983-02-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-10 | 1986-08-12 | 1987-02-11 | $7700.00 | Window Closed / Lapsed |