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Patent US4125708A successfully refreshed from Google Patents.
US4125708A
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US
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Chitosan modified with anionic agent and glutaraldehyde
Assignee: United States Department of Agriculture
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Filing: 1977-02-15
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Granted: 1978-11-14
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Expires: 1997-02-15
Abstract
Abstract Superoxy-anion-forming metals, such as chromium, manganese, and the like, are removed from materials containing the same by contacting the material with an anionically-modified, nitrogen-containing polymer, such as sulfite-modified, sulfate-modified, or chloride-modified chitosan.
Inventors
- 👤 Merle S. Masri
- 👤 Virginia G. Randall
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 15:11
CPC Classifications
B; B01; B01J; B01J20/00; B01J20/22; B01J20/24; C; C02; C02F; C02F1/00; C02F1/28; C02F1/286; C08; C08B; C08B37/00; C08B37/0006; C08B37/0024; C08B37/0027; C08B37/003; C08L; C08L5/00; C08L5/08
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
55 words
An insolubilized composition for removing superoxyanion-forming metals from materials containing the same, consisting of chitosan modified at all the titratable basic groups thereof with an anionic modifying agent selected from the group consisting of sulfite, sulfate, chloride, borate, and hexafluoride and further modified with glutaraldehyde in an amount of 0.1-0.3 parts per part of chitosan.
Claim 2
Dependent Claim
55 words
An insolubilized composition for removing superoxyanion-forming metals from materials containing the same, consisting of chitosan modified at all the titratable basic groups thereof with an anionic modifying agent selected from the group consisting of sulfite, sulfate, chloride, borate, and hexafluoride and further modified with glutaraldehyde in an amount of 0.1-0.3 parts per part of chitosan.
References Cited (Backward Citations)
US2040879A
Cited
US2072771A
Cited
US2689244A
Cited
US2670329A
Cited
US2832766A
Cited
US2783148A
Cited
US2755275A
Cited
US2831851A
Cited
US2910408A
Cited
US3155575A
Cited
US3796634A
Cited
US3823129A
Cited
US3761585A
Cited
US4056432A
Cited
US3985696A
Cited
US4066735A
Cited
US4029727A
Cited
US4063016A
Cited
US4059457A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-11-13 | 1982-05-15 | 1982-11-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-11-13 | 1986-05-15 | 1986-11-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-11-13 | 1990-05-15 | 1990-11-14 | $7700.00 | Window Closed / Lapsed |