US4759851A
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: 1988-07-26
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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 formulae: ##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 5 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
2026-11-02 09:13
CPC Classifications
C; C23; C23F; C23F11/00; C23F11/08; C02; C02F; C02F5/00; C02F5/08; C02F5/10; C02F5/105; C02F5/12; C02F5/125
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
152 words
A method of controlling the deposition of calcium phosphonate on the structural parts of a system exposed to an aqueous medium containing said calcium phosphonate under deposit forming conditions, said method comprising adding to said aqueous medium an effective amount for the purpose of a water soluble polymer comprising repeat unit moieties (a) and (b) wherein said repeat unit (a) comprises the structure ##STR14## and wherein said repeat unit (b) comprises the structure ##STR15## wherein each R 1 is independently H or lower alkyl (C 1 -C 3 ), R 2 is OH or OM, M is a water soluble cation, R 3 is 2-hydroxypropylidene, X is SO 3 , Z is H or a water soluble cation, p is 1, the molar ratio x:y of said polymer being between about 4:1 to about 1:5 wherein the number average molecular weight of said water soluble polymer is between about 1,500 to 10,000.
Claim 2
Independent Claim
152 words
A method of controlling the deposition of calcium phosphonate on the structural parts of a system exposed to an aqueous medium containing said calcium phosphonate under deposit forming conditions, said method comprising adding to said aqueous medium an effective amount for the purpose of a water soluble polymer comprising repeat unit moieties (a) and (b) wherein said repeat unit (a) comprises the structure ##STR14## and wherein said repeat unit (b) comprises the structure ##STR15## wherein each R 1 is independently H or lower alkyl (C 1 -C 3 ), R 2 is OH or OM, M is a water soluble cation, R 3 is 2-hydroxypropylidene, X is SO 3 , Z is H or a water soluble cation, p is 1, the molar ratio x:y of said polymer being between about 4:1 to about 1:5 wherein the number average molecular weight of said water soluble polymer is between about 1,500 to 10,000.
Claim 3
Dependent Claim
24 words
A method as recited in claim 1 wherein R 1 in both said repeat units (a) and (b) is hydrogen, R 2 is OH.
Claim 4
Dependent Claim
34 words
A method as recited in claim 1, wherein said water soluble polymer is added to said aqueous medium in an amount of 0.1-500 parts polymer based upon 1 million parts of said aqueous medium.
Claim 5
Dependent Claim
15 words
A method as recited in claim 1 wherein said system is a steam generating system.
Claim 6
Dependent Claim
15 words
A method as recited in claim 1, wherein said system is a cooling water system.
Claim 7
Dependent Claim
15 words
A method as recited in claim 1, wherein said system is a gas scrubbing system.
Claim 8
Dependent Claim
81 words
A method as defined in claim 1 further comprising adding to said system an effective amount for the purpose of a topping agent selected from the group consisting of inorganic phosphoric acids and water soluble salts thereof, phosphonic acids and water soluble salts thereof, organic phosphoric acid esters and water soluble salts thereof, polyvalent metal salts capable of being dissociated to polyvalent metal ions in water, chromate compounds adapted to provide chromate radicals in water solutions, azole compounds, and molybdate compounds.
Claim 9
Dependent Claim
42 words
A method as defined in claim 7, wherein said inorganic phosphoric acid is a member selected from the group consisting of orthophosphoric acid, primary phosphoric acid, secondary phosphoric acid, pyrophosphoric acid, tripolyphosphoric acid, trimetaphosphoric acid, tetrametaphosphoric acid and water soluble salts thereof.
Claim 10
Dependent Claim
34 words
A method as defined in claim 7, wherein said phosphonic acid is a member selected from the group consisting of ethylenediamine tetramethylene phosphonic acid, methylene diphosphonic acid, hydroxyethylidene diphosphonic acid and 2-phosphonobutane 1,2,4-tricarboxylic acid.
Claim 11
Dependent Claim
30 words
A method as defined in claim 7, wherein said polyvalent metal salt is a member selected from the group consisting of zinc chloride, nickel chloride, zinc sulfate and nickel sulfate.
Claim 12
Dependent Claim
42 words
A method as defined in claim 7, wherein said chromate compound comprises a member selected from the group consisting of sodium chromate dihydrate, sodium chromate anhydrous, sodium chromate tetrahydrate, sodium chromate hexahydrate, sodium chromate decahydrate, potassium chromate, ammonium dichromate, and chromic acid.
Claim 13
Dependent Claim
26 words
A method as defined in claim 7, wherein said azole compound comprises a member selected from the group consisting of 1,2,3-tolyltriazole, benzotriazole, thiazole, mercaptobenzothiazole, and benzothiazole.
Claim 14
Dependent Claim
31 words
A method as defined in claim 7, wherein said topping agent is added to said system in an amount of 1 to about 500 parts per million parts of said 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) | 1991-07-26 | 1992-01-25 | 1992-07-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-07-26 | 1996-01-25 | 1996-07-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-07-26 | 2000-01-25 | 2000-07-26 | $7700.00 | Window Closed / Lapsed |