US4481316A
Expired / Lapsed
US
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Method for inhibiting the degradation of an aqueous solution of an acrylamide polymer in a petroleum recovery process
Assignee: Mitsubishi Chemical Corp
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Filing: 1982-12-22
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Granted: 1984-11-06
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Expires: 2002-12-22
Abstract
Abstract 2-Mercaptobenzoimidazole or its water-soluble salt is added to a water-soluble acrylamide polymer containing a predominant amount of acrylamide in the molecule to inhibit degradation, especially at high temperatures, in a petroleum recovery process.
Inventors
- 👤 Shoichi Kanda
- 👤 Gengiro Kawamura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:11
CPC Classifications
C; C08; C08K; C08K5/00; C08K5/36; C08K5/37
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
110 words
A method for inhibiting the degradation of an aqueous solution of an acrylamide polymer in a petroleum recovery process which comprises incorporating a stabilizing effective amount of 2-mercaptobenzoimidazole or a water-soluble salt thereof having the general formula ##STR2## wherein R 1 , R 2 , R 3 and R 4 each represents a hydrogen atom or a lower alkyl group, and X represents a hydrogen atom, an alkali metal atom or an ammonium group, into an acrylamide polymer which is an acrylamide copolymer containing at least 50 mol % acrylamide and having the remaining amount of vinylmonomer selected from the group consisting of acrylic or methacrylic acid or salts thereof.
Claim 2
Independent Claim
110 words
A method for inhibiting the degradation of an aqueous solution of an acrylamide polymer in a petroleum recovery process which comprises incorporating a stabilizing effective amount of 2-mercaptobenzoimidazole or a water-soluble salt thereof having the general formula ##STR2## wherein R 1 , R 2 , R 3 and R 4 each represents a hydrogen atom or a lower alkyl group, and X represents a hydrogen atom, an alkali metal atom or an ammonium group, into an acrylamide polymer which is an acrylamide copolymer containing at least 50 mol % acrylamide and having the remaining amount of vinylmonomer selected from the group consisting of acrylic or methacrylic acid or salts thereof.
Claim 3
Dependent Claim
33 words
The method of claim 1, wherein the 2-mercaptobenzoimidazole or the water-soluble salt thereof is added in an amount of from about 0.1 to 20% by weight based on the weight of acrylamide polymer.
Claim 4
Dependent Claim
14 words
The method of claim 1, wherein said acrylamide polymer is in an aqueous solution.
Claim 5
Dependent Claim
18 words
The method of claim 1, wherein said 2-mercaptobenzoimidazole is employed as the sodium, potassium or ammonium salt thereof.
References Cited (Backward Citations)
US2778825A
Cited
US2864803A
Cited
US3255146A
Cited
US3235523A
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US3979358A
Cited
US3969329A
Cited
US4080493A
Cited
US4204928A
Cited
US4306045A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-11-06 | 1988-05-07 | 1988-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-11-06 | 1992-05-07 | 1992-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-11-06 | 1996-05-07 | 1996-11-06 | $7700.00 | Window Closed / Lapsed |