Patent US3624154A successfully refreshed from Google Patents.
US3624154A
Expired / Lapsed
US
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Concentration of aqueous acrylamide
Assignee: Dow Chemical Co
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Filing: 1970-03-26
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Granted: 1971-11-30
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Expires: 1990-03-26
Abstract
Abstract Aqueous solutions containing up to about 25 percent by weight of acrylamide are concentrated to a maximum concentration of about 30 percent by cooling the less concentrated solutions to produce a mush of ice crystals and separating the ice from the mother liquor. Adiabatic cooling under reduced pressure is preferred.
Inventors
- 👤 Lanny A Robbins
- 👤 Edward R Winkler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 08:18
CPC Classifications
C; C07; C07C; C07C233/00; C07C233/01; C07C233/02; C07C233/09
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
18 words
The process of claim 1 wherein the solution is cooled to about -1* C. to about -9* C.
Claim 2
Dependent Claim
20 words
The process of claim 2 wherein the fluid mush of ice crystals contains 10-40 percent by weight of said crystals.
Claim 3
Dependent Claim
22 words
The process of claim 1 wherein the solution is cooled by adiabatic vaporization of water from the acrylamide solution under reduced pressure.
Claim 4
Dependent Claim
23 words
The process of claim 1 wherein adhering mother liquor is washed from the separated ice crystals with water or a water-immiscible organic solvent.
Claim 5
Dependent Claim
23 words
The process of claim 5 wherein the separated ice crystals are washed with water and the water wash is recycled to the process.
Claim 6
Dependent Claim
34 words
The process of claim 6 wherein there is continuous addition of aqueous feed with continuous removal of ice and mother liquor and continuous recycle of a portion of the mother liquor to the process.
Claim 7
Dependent Claim
25 words
The process of claim 7 wherein the rate of removal of mother liquor is adjusted to maintain the acrylamide concentration therein at a predetermined value.
References Cited (Backward Citations)
US3489512A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-29 | 1975-05-31 | 1975-11-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-29 | 1979-05-31 | 1979-11-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-29 | 1983-05-31 | 1983-11-30 | $7700.00 | Window Closed / Lapsed |