US3666809A
Expired / Lapsed
US
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Method for the production of acrylamide crystals
Assignee: Mitsubishi Chemical Corp
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Filing: 1970-09-25
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Granted: 1972-05-30
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Expires: 1990-09-25
Abstract
Abstract A method for the production of acrylamide crystals, characterized in preparing acrylamide crystals from an aqueous acrylamide solution, which contains at least one kind of surfactant selected from the group consisting of a cellulose glycolic acid salt and polyoxyethylene alkyl amine- and polyoxyethylene alkyl amide-type surfactants. The resulting acrylamide crystals are of higher purity, having less susceptibility to being concreted.
Inventors
- 👤 Kenzo Okuno
- 👤 Takaharu Itagaki
- 👤 Yoshimasa Isogai
- 👤 Kazuo Yoshida
- 👤 Konosuke Fujiki
- 👤 Katumi Odagawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 14:12
CPC Classifications
B; B01; B01D; B01D9/00; B01D9/0004; B01D9/0036; B01D9/005
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
50 words
A method as claimed in claim 1, further characterized in that the aqueous acrylamide solution contains, in combination, a cellulose glycolic acid salt and at least one member selected from the group consisting of polyoxyethylene sorbitan alkyl ester, polyoxyethylene alkyl ester, polyoxyethylene alkyl ether, polypropyleneglycol polyethyleneglycol ether, and polypropyleneglycol surfactants.
Claim 2
Independent Claim
31 words
A method for the production of acrylamide crystals, characterized in crystallizing acrylamide out of an aqueous medium containing a polyoxyethylene alkyl amine surfactant with a concentration from 5 to 1,000 ppm.
Claim 3
Independent Claim
37 words
A method for the production of acrylamide crystals, characterized in crystallizing acrylamide out of an aqueous medium containing a cellulose glycolic acid salt and polyoxyethylene alkyl ether surfactant with a concentration from 5 to 1,000 ppm, respectively.
Claim 4
Independent Claim
38 words
A method for the production of acrylamide crystals, characterized in crystallizing acrylamide out of an aqueous medium containing a cellulose glycolic acid salt and polyoxyethylene sorbitan alkyl ester surfactant with a concentration from 5 to 1,000 ppm, respectively.
Claim 5
Dependent Claim
20 words
A method as claimed in claim 1, in which the concentration of the surfactant is in the range 5-1,000 ppm.
Claim 6
Dependent Claim
34 words
A method as claimed in claim 2 in which the respective concentrations of two or more surfactants, including cellulose glycolic acid salt contained in the aqueous acrylamide solution are in the range 5-1,000 ppm.
References Cited (Backward Citations)
US2186976A
Cited
US3499879A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-30 | 1975-11-29 | 1976-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-30 | 1979-11-29 | 1980-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-30 | 1983-11-29 | 1984-05-30 | $7700.00 | Window Closed / Lapsed |