Patent US4944885A successfully refreshed from Google Patents.
US4944885A
Expired / Lapsed
US
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Water treatment polymers and methods of use thereof
Assignee: Veolia WTS USA Inc
•
Filing: 1989-10-05
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Granted: 1990-07-31
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Expires: 2009-10-05
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 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
2026-10-30 18:10
CPC Classifications
C; C23; C23F; C23F11/00; C23F11/08; C02; C02F; C02F5/00; C02F5/08; C02F5/10; C02F5/105; C02F5/12; C02F5/125; C23F14/00; C23F14/02
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
143 words
A method of controlling the deposition of calcium phosphate on the structural parts of a system exposed to an aqueous medium containing said calcium and phosphate ions under deposit forming conditions, said method comprising adding to said aqueous medium at least about 10 ppm of a water soluble polymer comprising repeat unit moieties (a) and (b) wherein said repeat unit (a) comprises the structure ##STR10## and wherein said repeat unit (b) comprises the structure ##STR11## 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; and Z is H or hydrogen atoms or a water soluble cation or cations which together counterbalance the valence of SO 3 ; and the molar ratio x:y of said polymer being between about 8:1 to 1:5.
Claim 2
Independent Claim
143 words
A method of controlling the deposition of calcium phosphate on the structural parts of a system exposed to an aqueous medium containing said calcium and phosphate ions under deposit forming conditions, said method comprising adding to said aqueous medium at least about 10 ppm of a water soluble polymer comprising repeat unit moieties (a) and (b) wherein said repeat unit (a) comprises the structure ##STR10## and wherein said repeat unit (b) comprises the structure ##STR11## 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; and Z is H or hydrogen atoms or a water soluble cation or cations which together counterbalance the valence of SO 3 ; and the molar ratio x:y of said polymer being between about 8:1 to 1:5.
Claim 3
Dependent Claim
24 words
A method as recited in claim 1, wherein the number average molecular weight of said water soluble polymer is between about 1,500 to 500,000.
Claim 4
Dependent Claim
24 words
A method as recited in claim 1, wherein the number average molecular weight of said water soluble polymer is between about 1,500 to 20,000.
Claim 5
Dependent Claim
45 words
A method as recited in claim 3, wherein R 1 in both said repeat units (a) and (b) is hydrogen, R 2 is OH, Z is a member or members selected from the group consisting of H, Na, NH 4 + , Ca and K.
Claim 6
Dependent Claim
51 words
A method as recited in claim 3, wherein R 1 in said repeat unit (b) is methyl, R 1 in said repeat unit (a) is H, R 2 is OH, Z is a member or members selected from the group consisting of H, Na, NH 4 + , Ca and K.
Claim 7
Dependent Claim
36 words
A method as recited in claim 4 or 5, wherein said water soluble polymer is added to said aqueous medium in an amount of 10-500 parts polymer based upon 1 million parts of said aqueous medium.
Claim 8
Dependent Claim
15 words
A method as recited in claim 6, wherein said system is a steam generating system.
Claim 9
Dependent Claim
15 words
A method as recited in claim 6, wherein said system is a cooling water system.
Claim 10
Dependent Claim
15 words
A method as recited in claim 6, wherein said system is a gas scrubbing 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) | 1993-07-30 | 1994-01-29 | 1994-07-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-07-30 | 1998-01-29 | 1998-07-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-07-30 | 2002-01-29 | 2002-07-31 | $7700.00 | Window Closed / Lapsed |