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US3687906A
Expired / Lapsed
US
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Anhydride polymer amination process
Assignee: Dow Chemical Co
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Filing: 1971-05-24
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Granted: 1972-08-29
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Expires: 1991-05-24
Abstract
Abstract The preparation of water soluble polymers by amination of an anhydride containing polymer such as styrene-maleic anhydride may be effected with better control and moderation of the reaction exotherm by mixing said anhydride polymer in certain proportions with a similar, previously ammoniated polymer having an excess of aminating agent absorbed thereon. The process is readily adaptable to a continuous process by merely recycling a portion of the final product to reabsorb excess aminating agent.
Inventors
- 👤 Alden W Hanson
- 👤 Syamalarao Evani
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 11:55
CPC Classifications
C; C08; C08F; C08F8/00
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
11 words
The process of claim 1 wherein said anhydride is maleic anhydride.
Claim 2
Dependent Claim
17 words
The process of claim 2 wherein said anhydride polymer is a copolymer of styrene and maleic anhydride.
Claim 3
Dependent Claim
14 words
The process of claim 1 wherein said aminating agent is liquid or gaseous ammonia.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-29 | 1976-02-28 | 1976-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-29 | 1980-02-28 | 1980-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-29 | 1984-02-28 | 1984-08-29 | $7700.00 | Window Closed / Lapsed |