Patent US4801388A successfully refreshed from Google Patents.
US4801388A
Expired / Lapsed
US
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Modified acrylamide polymers used as scale inhibitors
Assignee: Ecolab USA Inc
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Filing: 1986-11-25
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Granted: 1989-01-31
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Expires: 2006-11-25
Abstract
Abstract Water supplies are treated to inhibit the formation of scale deposits of alkaline earth phosphates, phosphonates, sulphates and carbonates using various hydrocarbon polymers which contain an amido functionality and which have been prepared by post-polymerization derivatization.
Inventors
- 👤 Dodd W. Fong
- 👤 John E. Hoots
- 👤 Donald A. Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 22:20
CPC Classifications
C; C02; C02F; C02F5/00; C02F5/08; C02F5/10; C02F5/12; C02F5/14
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
95 words
A method of controlling scale deposits by adding to waters having a tendency to form scale, a scale-inhibitorily effective amount of a hydrocarbon polymer wherein said hydrocarbon polymer is a copolymer of from about 25 to about 95 mole % (meth)acrylic acid and from about 5 to about 75 mole % sulfoalkyl(meth)acrylamide having a molecular weight of about 5,000 to 80,000 and wherein said sulfoalkyl(meth)acrylamide includes a moiety having the general structural formula: ##STR3## wherein R 1 is hydrogen or an alkyl and R is a hydrocarbon group containing from one to three carbon atoms.
Claim 2
Independent Claim
95 words
A method of controlling scale deposits by adding to waters having a tendency to form scale, a scale-inhibitorily effective amount of a hydrocarbon polymer wherein said hydrocarbon polymer is a copolymer of from about 25 to about 95 mole % (meth)acrylic acid and from about 5 to about 75 mole % sulfoalkyl(meth)acrylamide having a molecular weight of about 5,000 to 80,000 and wherein said sulfoalkyl(meth)acrylamide includes a moiety having the general structural formula: ##STR3## wherein R 1 is hydrogen or an alkyl and R is a hydrocarbon group containing from one to three carbon atoms.
Claim 3
Independent Claim
104 words
A method of controlling scale deposits by adding to waters having a tendency to form scale, a scale-inhibitorily effective amount of a hydrocarbon polymer wherein said hydrocarbon polymer is a terpolymer of from about 10 to about 90 mole % (meth)acrylic acid, from about 5 to about 85 mole % (meth)acrylamide, and from about 5 to 85 mole % sulfoalkyl(meth)acrylamide having a molecular weight of about 5,000 to 80,000 and wherein said sulfoalkyl(meth)acrylamide includes a moiety having the general structural formula: ##STR4## wherein R 1 is a hydrogen or an alkyl and R is a hydrocarbon group containing from one to three carbon atoms.
Claim 4
Independent Claim
104 words
A method of controlling scale deposits by adding to waters having a tendency to form scale, a scale-inhibitorily effective amount of a hydrocarbon polymer wherein said hydrocarbon polymer is a terpolymer of from about 10 to about 90 mole % (meth)acrylic acid, from about 5 to about 85 mole % (meth)acrylamide, and from about 5 to 85 mole % sulfoalkyl(meth)acrylamide having a molecular weight of about 5,000 to 80,000 and wherein said sulfoalkyl(meth)acrylamide includes a moiety having the general structural formula: ##STR4## wherein R 1 is a hydrogen or an alkyl and R is a hydrocarbon group containing from one to three carbon atoms.
Claim 5
Independent Claim
110 words
A method of controlling scale deposits by adding to waters having a tendency to form scale, a scale-inhitorily effective amount of a hydrocarbon polymer wherein said hydrocarbon polymer is a terpolymer of from about 20 to about 80 mole % (meth)acrylic acid, from about 5 to about 60 mole % (meth)acrylamide, and from about 5 to about 70 mole % N-substituted(meth)acrylamide having a molecular weight of about 5,000 to about 100,000 and wherein said N-substituted(meth)acrylamide includes a moiety having the structural formula: ##STR5## wherein X is SO 3 - and R 1 is a hydrogen or an alkyl and R is a hydrocarbon group containing one to three carbon atoms.
Claim 6
Independent Claim
110 words
A method of controlling scale deposits by adding to waters having a tendency to form scale, a scale-inhitorily effective amount of a hydrocarbon polymer wherein said hydrocarbon polymer is a terpolymer of from about 20 to about 80 mole % (meth)acrylic acid, from about 5 to about 60 mole % (meth)acrylamide, and from about 5 to about 70 mole % N-substituted(meth)acrylamide having a molecular weight of about 5,000 to about 100,000 and wherein said N-substituted(meth)acrylamide includes a moiety having the structural formula: ##STR5## wherein X is SO 3 - and R 1 is a hydrogen or an alkyl and R is a hydrocarbon group containing one to three carbon atoms.
Claim 7
Dependent Claim
54 words
The method according to claim 3 wherein said hydrocarbon polymer is a terpolymer of from about 20 to about 80 mole % (meth)acrylic acid, from about 5 to about 60 mole % (meth)acrylamide, and from about 5 to about 55 mole % sulfomethyl(meth)acrylamide having a molecular weight of from about 7,000 to about 90,000.
Claim 8
Independent Claim
26 words
The method according to either of claims 1, 2, or 3 wherein the scale is at least one of calcium phosphate, iron phosphate, and magnesium phosphate.
Claim 9
Dependent Claim
12 words
The method according to claim 2 wherein the scale is calcium carbonate.
Claim 10
Dependent Claim
12 words
The method according to claim 2 wherein the scale is calcium phosphonate.
Claim 11
Dependent Claim
12 words
The method according to claim 2 wherein the scale is barium sulfate.
Claim 12
Independent Claim
23 words
The method according to either of claims 1, 2, or 3 wherein the effective amount is from about 1 to about 200 ppm.
References Cited (Backward Citations)
US3285886A
Cited
US3709816A
Cited
US3709815A
Cited
US3928196A
Cited
US4401587A
Cited
US4446028A
Cited
JPS60187491A
Cited
JPS60187489A
Cited
US4536292A
Cited
US4584105A
Cited
US4604431A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-01-31 | 1992-08-01 | 1993-01-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-01-31 | 1996-08-01 | 1997-01-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-01-31 | 2000-08-01 | 2001-01-31 | $7700.00 | Window Closed / Lapsed |