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US4283507A
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US
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Hydrolysis of acrylamide polymers
Assignee: ChampionX LLC
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Filing: 1980-02-25
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Granted: 1981-08-11
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Expires: 2000-02-25
Abstract
Abstract This invention relates to a method for the hydrolysis of acrylamide polymers utilizing less than stoichiometric amounts of a hydrolysis agent selected from the group consisting of alkali metal hydroxides and alkali metal sulfites. The process is conducted with a water-in-oil emulsion (latex) of the acrylamide polymer at an elevated temperature and pressure.
Inventors
- 👤 Kenneth G. Phillips
- 👤 Mary E. Bingham
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 09:37
CPC Classifications
C; C08; C08F; C08F8/00; C08F8/12
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
85 words
A method of enhancing hydrolysis of an acrylamide polymer contained in a latex, employing either sodium hydroxide or sodium sulfite as a hydrolyzing agent for imparting anionic character to the polymer, comprising: (a) incorporating a mixture of the latex and hydrolyzing agent in a reaction vessel having a vapor space above the mixture; and (b) reacting the mixture at about 125° C. while maintaining a pressure in the vapor space sufficient to suppress boiling, for a time sufficient to convert amide groups to anionic character.
Claim 2
Independent Claim
85 words
A method of enhancing hydrolysis of an acrylamide polymer contained in a latex, employing either sodium hydroxide or sodium sulfite as a hydrolyzing agent for imparting anionic character to the polymer, comprising: (a) incorporating a mixture of the latex and hydrolyzing agent in a reaction vessel having a vapor space above the mixture; and (b) reacting the mixture at about 125° C. while maintaining a pressure in the vapor space sufficient to suppress boiling, for a time sufficient to convert amide groups to anionic character.
Claim 3
Dependent Claim
44 words
A method according to claim 1 wherein the aqueous phase of the latex is about 65-85 percent by weight and in which about 25 to 50 mole percent of the polyacrylamide is hydrolyzed respectively by 5 to 20 mole percent of the hydrolyzing agent.
Claim 4
Dependent Claim
34 words
A method according to claim 2 in which the hydrolyzing agent is caustic and in which an alkali stable emulsifying agent is added to the reaction mixture to maintain the integrity of the latex.
References Cited (Backward Citations)
US2812317A
Cited
US2861059A
Cited
GB772734A
Cited
US3029228A
Cited
US3442879A
Cited
DE2729754A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-08-10 | 1985-02-09 | 1985-08-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-08-10 | 1989-02-09 | 1989-08-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-08-10 | 1993-02-09 | 1993-08-11 | $7700.00 | Window Closed / Lapsed |