Patent US3800845A successfully refreshed from Google Patents.
US3800845A
Expired / Lapsed
US
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Solvent removal from poly(arylene sulfide) reaction slurry
Assignee: Phillips Petroleum Co
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Filing: 1971-12-14
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Granted: 1974-04-02
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Expires: 1991-12-14
Abstract
Abstract A method is provided for the removal of polar organic diluent from a reaction slurry of poly(arylene sulfide) solid polymer particles, organic polar diluent, by-product alkali metal halide, and other impurities by the isothermal evaporation of the reaction slurry reducing the pressure on the slurry from reaction pressure sufficiently to evaporate essentially all of the water and approximately one third of the diluent and then removing the concentrated reaction slurry to another vessel flashing the mixture adiabatically to atmospheric pressure to remove essentially all the diluent from the polymer.
Inventors
- 👤 J Scoggin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 21:20
CPC Classifications
C; C08; C08G; C08G75/00; C08G75/02; C08G75/0204; C08G75/0277; C08G75/0281; C08G75/0209; C08G75/0213; C08G75/025; C08G75/0254
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
17 words
The process of claim 1 wherein the pressure reduction in the isothermal evaporation is approximately 200 psig.
Claim 2
Dependent Claim
14 words
The process of claim 1 wherein the adiabatic expansion is carried to atmospheric pressure.
Claim 3
Dependent Claim
13 words
The process of claim 1 wherein the polar organic diluent is n-methyl pyrrolidone.
Claim 4
Dependent Claim
29 words
The process of claim 1 wherein the poly(arylene sulfide)-alkali halide-impurity mixture remaining after the adiabatic flash contains less than 0.15 pounds polar organic diluent per pound of said mixture.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-04-01 | 1977-10-01 | 1978-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-01 | 1981-10-01 | 1982-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-01 | 1985-10-01 | 1986-04-02 | $7700.00 | Window Closed / Lapsed |