Patent US2761931A successfully refreshed from Google Patents.
Patent US3752760A successfully refreshed from Google Patents.
US3752760A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Silt removal
Assignee: Calgon Corp
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Filing: 1972-03-09
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Granted: 1973-08-14
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Expires: 1992-03-09
Abstract
Abstract POLYMERS OF CERTAIN N-(ALKYL) AMINO ACRYLAMIDES ARE USEFUL TO REMOVE AND PREVENT SILT ACCUMULATIONS IN WATER SYSTEMS, SUCH AS COOLING SYSTEMS AND THE LIKE. THE PREFERRED MONOMER IS (3-ACRYLAMIDO-3-METHYL) BUTYL TRIMETHYL AMMONIUM CHLORIDE; THIS MONOMER MAY BE HOMOPOLYMERIZED OR PRESENT TO THE EXTENT OF AT LEAST 1 PERCENT IN A WATER-SOLUBLE POLYMER OF AT LEAST 100,000 MOLECULAR WEIGHT.
Inventors
- 👤 A Sharpe
- 👤 J Boothe
- 👤 R Gordon
- 👤 J Walker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 08:09
CPC Classifications
C; C02; C02F; C02F5/00; C02F5/08; C02F5/10; C02F5/12
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) | 1976-08-13 | 1977-02-12 | 1977-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-13 | 1981-02-12 | 1981-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-13 | 1985-02-12 | 1985-08-14 | $7700.00 | Window Closed / Lapsed |