Patent US3687907A successfully refreshed from Google Patents.
US3687907A
Expired / Lapsed
US
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Recovery of solvent in arylene sulfide polymer production
Assignee: Phillips Petroleum Co
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Filing: 1970-11-09
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Granted: 1972-08-29
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Expires: 1990-11-09
Abstract
Abstract A polar organic solvent selected from amides, lactams, and sulfones is extracted from an aqueous solution containing alkali metal halide. In the production of arylene sulfide polymers by the reaction of a polyhalo-substituted aromatic compound with an alkali metal sulfide in a polar organic solvent, solids are removed from an aqueous mixture of the reaction effluent and polar organic solvent is recovered from the aqueous solution by extraction with a solvent. In a preferred embodiment N-methyl-2pyrrolidone is recovered from the aqueous solution by extraction with a solvent such as dichloromethane, chloroform, and 1,1,2,2tetrachloroethane.
Inventors
- 👤 Willie W Crouch
- 👤 Charles W Moberly
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 02:33
CPC Classifications
C; C08; C08G; C08G75/00; C08G75/02; C08G75/0204; C08G75/0277; C08G75/0281; C07; C07D; C07D207/00; C07D207/02; C07D207/18; C07D207/22; C07D207/24; C07D207/26; C07D207/263; C07D207/267
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
20 words
The method of claim 1 wherein the method of separating the polar organic solvent and the extractant is by distillation.
Claim 2
Dependent Claim
64 words
The method of claim 1 wherein extracting the N-methyl-2-pyrrolidone from an aqueous solution which comprises an amount of water sufficient to provide 0.01 to 100 parts by weight water per part by weight polar organic diluent is accomplished at a ratio of 1:1 to 20:1 weight ratio of extractant to aqueous solution within a temperature range of about 0* C to about 200* C.
Claim 3
Dependent Claim
26 words
The method of claim 1 wherein the method of separating the solid and liquid components of the aqueous reaction mixture is chosen from filtration and centrifugation.
Claim 4
Dependent Claim
19 words
The method of claim 1 wherein the extractant is selected from the group consisting of dichloromethane, chloroform, and 1,1,2,2-tetrachloroethane.
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) | 1975-08-29 | 1976-02-28 | 1976-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-29 | 1980-02-28 | 1980-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-29 | 1984-02-28 | 1984-08-29 | $7700.00 | Window Closed / Lapsed |