US3714136A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for recovering acrylamide polymers from gels
Assignee: Wyeth Holdings LLC
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Filing: 1971-10-21
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Granted: 1973-01-30
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Expires: 1991-10-21
Abstract
Abstract A method for the production of free-flowing, dry polymers of acrylamide having molecular weights of over about 6 million wherein fragments of said polymers are cut into particles of about 7-100 mesh and dried while suspended in a gas stream, is disclosed.
Inventors
- 👤 D Gershberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 08:10
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/12; C08J2333/00; C08J2333/24; C08J2333/26
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
98 words
A method which comprises cutting acrylamide polymer gel fragments of at least 1/8 inch diameter, having a molecular weight of at least about 6 million, containing from about 20 percent to about 70 percent water and having been produced by solution polymerization into particles of from about 7 to about 100 mesh at a temperature of not over about 75* C and drying said particles while suspended in a gas stream at a temperature ranging from about room temperature to about 100* C. for from about 5 to about 60 minutes and recovering the resultant substantially dry product.
Claim 2
Independent Claim
98 words
A method which comprises cutting acrylamide polymer gel fragments of at least 1/8 inch diameter, having a molecular weight of at least about 6 million, containing from about 20 percent to about 70 percent water and having been produced by solution polymerization into particles of from about 7 to about 100 mesh at a temperature of not over about 75* C and drying said particles while suspended in a gas stream at a temperature ranging from about room temperature to about 100* C. for from about 5 to about 60 minutes and recovering the resultant substantially dry product.
Claim 3
Dependent Claim
11 words
A method according to claim 1 wherein the polymer is polyacrylamide.
Claim 4
Dependent Claim
16 words
A method according to claim 1 wherein said molecular weight is at least about 12 million.
Claim 5
Dependent Claim
15 words
A method according to claim 1 wherein said cutting temperature is not over about 50*C.
Claim 6
Dependent Claim
17 words
A method according to claim 1 wherein said fragments are dusted with sodium sulfate prior to cutting.
Claim 7
Dependent Claim
14 words
A method according to claim 1 wherein said fragments are frozen prior to cutting.
Claim 8
Dependent Claim
17 words
A method according to claim 1 wherein said polymer is a copolymer of acrylamide and acrylic acid.
Claim 9
Dependent Claim
11 words
A method according to claim 5 wherein said polymer is polyacrylamide.
Claim 10
Dependent Claim
11 words
A method according to claim 6 wherein said polymer is polyacrylamide.
References Cited (Backward Citations)
US3255142A
Cited
GB974023A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-01-30 | 1976-07-31 | 1977-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-30 | 1980-07-31 | 1981-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-30 | 1984-07-31 | 1985-01-30 | $7700.00 | Window Closed / Lapsed |