US4869828A
Expired / Lapsed
US
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Stabilization of iron in aqueous systems
Assignee: ChampionX LLC
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Filing: 1988-02-26
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Granted: 1989-09-26
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Expires: 2008-02-26
Abstract
Abstract The present invention is directed to a process for stabilizing iron hydr(oxide) in aqueous systems which comprises adding to an aqueous system in which the water contains or will contain soluble iron a polymer which contains pendant N-substituted amide functionality, including amide substituted with sulfoalkyl wherein the alkyl is of 1 to 3 carbon atoms, sulfophenyl, or such groups substituted further with (poly)hydroxy.
Inventors
- 👤 John E. Hoots
- 👤 Kenneth P. Fivizzani
- 👤 Roy I. Kaplan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 23:06
CPC Classifications
C; C02; C02F; C02F5/00; C02F5/08; C02F5/10; C02F5/12
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
182 words
A process for stabilizing iron hydr(oxide) formed in situ in an aqueous system from soluble iron contained therein, upon an increase of oxidizing conditions comprising an increase in pH to a pH of greater than 8.0, to at least reduce iron hydr(oxide) deposits, comprising: treating said aqueous system with from 1.0 to 50 ppm of a water soluble polymer having a molecular weight of from 5,000 to 100,000 which contains from 5 to 85 mole percent pendant N-substituted amide functionality units having the chemical formula of ##STR3## wherein R' is hydrogen or methyl, R 1 is hydrogen, R is alkylene having 1 to 3 carbon atoms or phenylene, X is sulfonate, and said alkylene may be further substituted with hydroxy, wherein said water soluble polymer is further comprised of from 15 to 95 mole percent of acrylic acid units or a mixture of acrylic acid and (meth)acrylamide units and wherein said polymer is substantially derived from acrylic acid and acrylamide monomers, subjected to post-polymerization, wherein at least 5 mole percent of its acrylamide amide functionality is converted to said N-substituted amide functionality.
Claim 2
Dependent Claim
182 words
A process for stabilizing iron hydr(oxide) formed in situ in an aqueous system from soluble iron contained therein, upon an increase of oxidizing conditions comprising an increase in pH to a pH of greater than 8.0, to at least reduce iron hydr(oxide) deposits, comprising: treating said aqueous system with from 1.0 to 50 ppm of a water soluble polymer having a molecular weight of from 5,000 to 100,000 which contains from 5 to 85 mole percent pendant N-substituted amide functionality units having the chemical formula of ##STR3## wherein R' is hydrogen or methyl, R 1 is hydrogen, R is alkylene having 1 to 3 carbon atoms or phenylene, X is sulfonate, and said alkylene may be further substituted with hydroxy, wherein said water soluble polymer is further comprised of from 15 to 95 mole percent of acrylic acid units or a mixture of acrylic acid and (meth)acrylamide units and wherein said polymer is substantially derived from acrylic acid and acrylamide monomers, subjected to post-polymerization, wherein at least 5 mole percent of its acrylamide amide functionality is converted to said N-substituted amide functionality.
Claim 3
Dependent Claim
43 words
The process of claim 1 wherein said polymer has a mole ratio of from 5 to 85 moles of said N-substituted amide functionality-containing units, from about 10 to 90 moles of acrylic acid units, and from 5 to 85 moles of acrylamide units.
Claim 4
Dependent Claim
54 words
The process of claim 1 wherein said polymer is substantially a copolymer having a mole ratio of units of from about 5 to about 50 moles of said N-substituted amide-containing units to about 50 to about 95 moles of acrylic acid units and has a molecular weight of from about 5,000 to about 85,000.
Claim 5
Dependent Claim
64 words
The process of claim 1 wherein said polymer is substantially a terpolymer having a mole ratio of units of from about 5 to about 70 moles of said N-substituted amide functionality-containing units, from about 20 to about 85 moles of acrylic acid units, and from about 5 to about 60 moles of (meth)acrylamide units, and has a molecular weight of from 5,000 to 85,000.
Claim 6
Dependent Claim
55 words
The process of claim 4 wherein said polymer has a mole ratio of units of about from 5 to 50 moles of said N-substituted amide functionality-containing units, from 40 to 85 moles of acrylic acid units, and from 10 to 50 moles of acrylamide units, and has a molecular weight of from 5,000 to 50,000.
Claim 7
Dependent Claim
17 words
The process of claim 1 or 3 wherein said polymer is a copolymer of acrylic acid/sulfomethyl (meth)acrylamide.
Claim 8
Dependent Claim
17 words
The process of claim 1 or 3 wherein said polymer is a copolymer of acrylic acid/sulfoethyl (meth)acrylamide.
Claim 9
Dependent Claim
18 words
The process of claim 1, 2, or 4 wherein said polymer is a terpolymer of acrylic acid/(meth)acrylamide/sulfomethyl (meth)acrylamide.
Claim 10
Dependent Claim
17 words
The process of claim 1, 2, or 4 wherein said polymer is a terpolymer of acrylic acid/(meth)acrylamide/sulfoethyl(meth)acrylamide.
Claim 11
Dependent Claim
18 words
The process of claim 1, 2, or 4 wherein said polymer is a terpolymer of acrylic acid/(meth)acrylamide/2-hydroxy-3-sulfopropyl (meth)acrylamide.
Claim 12
Dependent Claim
18 words
The process of claim 1, 2, or 4 wherein said polymer is a terpolymer of acrylic acid/(meth)acrylamide/sulfophenyl (meth)acrylamide.
Claim 13
Dependent Claim
31 words
The process of claim 1 wherein said polymer is a terpolymer of acrylic acid/(meth)acrylamide/sulfomethyl (meth)acrylamide in mole ratio respectively of 40-85/10-50/5-40, and having a molecular weight of from 10,000 to 40,000.
Claim 14
Dependent Claim
31 words
The process of claim 1 wherein said polymer is a terpolymer of acrylic acid/(meth)acrylamide/sulfoethyl (meth)acrylamide in mole ratio respectively of 40-85/10-50/5-40, and having a molecular weight of from 10,000 to 40,000.
Claim 15
Dependent Claim
36 words
The process of claim 1 wherein said aqueous system is treated with said polymer in the amount of from 0.5 to ppm of said polymer for every 1 ppm of soluble iron in said aqueous system.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-09-25 | 1993-03-27 | 1993-09-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-09-25 | 1997-03-27 | 1997-09-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-09-25 | 2001-03-27 | 2001-09-26 | $7700.00 | Window Closed / Lapsed |