Patent US4545920A successfully refreshed from Google Patents.
US4545920A
Expired / Lapsed
US
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Boiler water treating compositions
Assignee: ChampionX LLC
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Filing: 1984-02-03
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Granted: 1985-10-08
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Expires: 2004-02-03
Abstract
Abstract A blend of polymers is disclosed which, when used as described, prevents and removes scale on heat transfer surfaces in contact with boiler waters.
Inventors
- 👤 Walter F. Lorenc
- 👤 John A. Kelly
- 👤 Frederick S. Mandel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 16:47
CPC Classifications
C; C02; C02F; C02F5/00; C02F5/08; C02F5/10; C02F5/12
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
124 words
A polymeric composition useful in treating boiler waters to prevent scale and to remove existing scale from heat transfer surfaces in contact with such boiler waters which comprises a combination of: A. a water-soluble anionic vinyl polymer containing at least 70% by weight of a carboxylate functionality, a molecular weight within the range of 500-30,000, and a chelation value of at least 200; and B. a second water-soluble anionic polymeric dispersant copolymer from the group consisting essentially of vinyl sulphonate-acrylic acid copolymers, and vinyl sulphonate-methacrylic acid copolymers, and having a molecular weight range of 750 to about 50,000, wherein the content of vinyl sulfonate is between 5-25 mole percent; with the ratio of A to B being within the range of 10:1 to 30:1.
Claim 2
Dependent Claim
124 words
A polymeric composition useful in treating boiler waters to prevent scale and to remove existing scale from heat transfer surfaces in contact with such boiler waters which comprises a combination of: A. a water-soluble anionic vinyl polymer containing at least 70% by weight of a carboxylate functionality, a molecular weight within the range of 500-30,000, and a chelation value of at least 200; and B. a second water-soluble anionic polymeric dispersant copolymer from the group consisting essentially of vinyl sulphonate-acrylic acid copolymers, and vinyl sulphonate-methacrylic acid copolymers, and having a molecular weight range of 750 to about 50,000, wherein the content of vinyl sulfonate is between 5-25 mole percent; with the ratio of A to B being within the range of 10:1 to 30:1.
Claim 3
Dependent Claim
20 words
The polymeric composition of claim 1 where the water-soluble dispersant polymer of B is a vinyl sulphonate acrylic acid copolymer.
Claim 4
Dependent Claim
18 words
The polymer composition of claim 1 where the water-soluble anionic polymer of A is an acrylic acid-acrylamide copolymer.
Claim 5
Dependent Claim
22 words
The polymer composition of claim 3 where the weight ratio of acrylic acid to acrylamide is in the range 3:1 to 4:1.
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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) | 1988-10-07 | 1989-04-08 | 1989-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-10-07 | 1993-04-08 | 1993-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-10-07 | 1997-04-08 | 1997-10-08 | $7700.00 | Window Closed / Lapsed |