Patent US3810877A successfully refreshed from Google Patents.
US3810877A
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US
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Polyacid halide modified copolymers of vinylpyridines and acrylamide or methacrylamide
Assignee: Phillips Petroleum Co
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Filing: 1972-02-18
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Granted: 1974-05-14
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Expires: 1992-02-18
Abstract
Abstract SEWAGE AND WATER ARE CHEMICALLY CONDITIONED WITH POLYACID HALIDE MODIFIED COPOLYMERS OF VINYLPYRIDINE WITH ACRYLAMIDE OR METHACRYLAMIDE. COAGULATION, FLOCCULATION, AND FILTRATION IN SEWAGE AND WATER TREATMENT PROCESSES ARE SIGNIFICANTLY IMPROVED BY THE USE OF THE AFORESAID MODIFIED COPOLYMERS.
Inventors
- 👤 R Doss
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:47
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/52; C02F1/54; C08; C08F; C08F8/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-05-13 | 1977-11-12 | 1978-05-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-13 | 1981-11-12 | 1982-05-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-13 | 1985-11-12 | 1986-05-14 | $7700.00 | Window Closed / Lapsed |