Patent US4801387A successfully refreshed from Google Patents.
US4801387A
Expired / Lapsed
US
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Water treatment polymers and methods of use thereof
Assignee: Veolia WTS USA Inc
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Filing: 1987-04-13
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Granted: 1989-01-31
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Expires: 2007-04-13
Abstract
Abstract A water soluble polymer composition is disclosed. The polymer has repeat units characterized by the structural formula: ##STR1## wherein R 1 is H or lower alkyl (C 1 -C 3 ); R 2 is OH, OM, or NH 2 ; M is a water soluble cation; R 3 is a hydroxy substituted alkyl or alkylene radical having from 1 to about 6 carbon atoms or a non-substituted alkyl or alkylene radical having from 1 to 6 carbon atoms; X is an anionic radical; Z is H or hydrogens or a water soluble cation or cations which together counterbalance the valence of X, and a is 0 or 1. The copolymer is effective in inhibiting the precipitation of certain scale forming salts, and also acts to inhibit corrosion of metal parts in contact with water systems.
Inventors
- 👤 Fu Chen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 13:56
CPC Classifications
C; C02; C02F; C02F5/00; C02F5/08; C02F5/10; C02F5/12; C02F5/105; C02F5/125; C23; C23F; C23F11/00; C23F11/08
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
155 words
A method for simultaneously inhibiting corrosion and scale formation including calcium carbonate in a cooling water system, comprising (a) maintaining the pH of said cooling water system within the pH range of about 7.5 to about 9.0; (b) maintaining the cooling water system in a state of supersaturation with respect to calcium carbonate; (c) adding from about 0.5-50 ppm of a water soluble acylic acid/allyhydroxylsulfonate ether copolymer or water soluble salt form thereof to said cooling water system, based upon one million parts of water in said system; said copolymer having the formula ##STR15## wherein M is a water soluble cation and the molar ratio x:y being from about 10:1 to 1:5; (d) adding to said cooling water system from about 0.2-50 ppm of water soluble phosphonate compound to cooling water; and (e) adding to said cooling water system from about 0.1-15 ppm of a zinc compound adapted to liberate Zn 2+ ions in water.
Claim 2
Independent Claim
155 words
A method for simultaneously inhibiting corrosion and scale formation including calcium carbonate in a cooling water system, comprising (a) maintaining the pH of said cooling water system within the pH range of about 7.5 to about 9.0; (b) maintaining the cooling water system in a state of supersaturation with respect to calcium carbonate; (c) adding from about 0.5-50 ppm of a water soluble acylic acid/allyhydroxylsulfonate ether copolymer or water soluble salt form thereof to said cooling water system, based upon one million parts of water in said system; said copolymer having the formula ##STR15## wherein M is a water soluble cation and the molar ratio x:y being from about 10:1 to 1:5; (d) adding to said cooling water system from about 0.2-50 ppm of water soluble phosphonate compound to cooling water; and (e) adding to said cooling water system from about 0.1-15 ppm of a zinc compound adapted to liberate Zn 2+ ions in water.
Claim 3
Dependent Claim
50 words
A method as recited in claim 1 further comprising maintaining the M-alkalinity of said cooling water system within the range of from 150 ppm -400 ppm (as CaCO 3 ) and maintaining the Langeliere Saturation Index of said cooling water system within the range of from about 1.0 to 2.5.
Claim 4
Dependent Claim
19 words
A method as recited in claim 1 wherein said copolymer has a molar ratio x:y of from about 3:1-6:1.
Claim 5
Dependent Claim
14 words
A method as recited in claim 1 wherein said phosphate comprises hydroxyethylidene diphosphonic acid.
Claim 6
Dependent Claim
30 words
A method as recited in claim 1 further comprising adding from about 1-50 ppm (as Cr 2 O 4 ) of a water soluble chromate compound containing hexavalent chromium ions.
Claim 7
Dependent Claim
23 words
A method and recited in claim 1 further comprising adding from about 0.2-30 ppm of an azole compound to said cooling water 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) | 1992-01-31 | 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 |