US3897333A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flocculating agents
Assignee: Ciba Specialty Chemicals Water Treatments Ltd
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Filing: 1974-03-28
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Granted: 1975-07-29
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Expires: 1994-03-28
Abstract
Abstract New high molecular weight, water soluble polymers containing a substantial proportion of recurring quaternised aminomethyl acrylamide or methacrylamide groups are of value as flocculants, especially for suspensions of organic matter of a proteinaceous or cellulosic nature.
Inventors
- 👤 John R Field
- 👤 Graham Smalley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 17:28
CPC Classifications
C; C12; C12H; C12H1/00; C12H1/02; C12H1/04; C12H1/0416; C12H1/0424; C02; C02F; C02F1/00; C02F1/52; C02F1/54; C08; C08F; C08F8/00
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
60 words
A METHOD IN WHICH AN ORGANIC SUSPENSION SELECTED FROM RAW SEWAGE SLUDGES AND SLUDGES OBTAINED BY BIOLOGICAL DEGRADATION IS FLOCCULATED BY ADDING TO THE SUSPENSION AN AQUEOUS SOLUTION OF A POLYMER HAVING AN INTRINSIC VISCOSITY OF AT LEAST 0.5 WHEN MEASURED IN 3 MOLAR SODIUM CHLORIDE AND COMPOSED OF RECURRING UNITS OF WHICH SUBSTANTIALLY 60% OR MORE HAVE THE FORMULA:
Claim 2
Independent Claim
60 words
A METHOD IN WHICH AN ORGANIC SUSPENSION SELECTED FROM RAW SEWAGE SLUDGES AND SLUDGES OBTAINED BY BIOLOGICAL DEGRADATION IS FLOCCULATED BY ADDING TO THE SUSPENSION AN AQUEOUS SOLUTION OF A POLYMER HAVING AN INTRINSIC VISCOSITY OF AT LEAST 0.5 WHEN MEASURED IN 3 MOLAR SODIUM CHLORIDE AND COMPOSED OF RECURRING UNITS OF WHICH SUBSTANTIALLY 60% OR MORE HAVE THE FORMULA:
Claim 3
Dependent Claim
17 words
A method according to claim 1 in which the suspension is a sludge obtained by biological degradation.
Claim 4
Dependent Claim
23 words
A method according to claim 1 in which the suspension is a sludge obtained by biological degradation and is a digested sewage sludge.
Claim 5
Dependent Claim
21 words
A method according to claim 1 wherein the polymer is composed of substantially 80 percent or more of the recurring units.
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) | 1978-07-28 | 1979-01-27 | 1979-07-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-28 | 1983-01-27 | 1983-07-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-28 | 1987-01-27 | 1987-07-29 | $7700.00 | Window Closed / Lapsed |