US4530955A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Water treatment composition comprising a hydrolyzed maleic anhydride copolymer and a zinc compound
Assignee: FMC Corp
•
Filing: 1984-03-28
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Granted: 1985-07-23
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Expires: 2004-03-28
Abstract
Abstract A composition for inhibiting the corrosion and scale forming tendencies of water or an aqueous system comprises 2.5 to 80% by weight of zinc (calculated as Zn++) and from 97.5 to 20% by weight of a hydrolyzed copolymer of maleic anhydride with a mono-ethylenically unsaturated monomer or a mixture of monomers, the molar ratio of maleic anhydride to the total of other monomers being from 1:1 to 100:1, the molecular weight of the copolymer being up to 1000.
Inventors
- 👤 David Wilson
- 👤 John A. Reverter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 00:05
CPC Classifications
C; C23; C23F; C23F11/00; C23F11/08; C02; C02F; C02F5/00; C02F5/08; C02F5/10; C02F5/105
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
74 words
A composition for treating water or an aqueous system which comprises 2.5 to 80% by weight of zinc (calculated as Zn++) and from 97.5 to 20% by weight of a hydrolysed copolymer of maleic anhydride with a monoethylenically unsaturated monomer or a mixture of monomers, the molar ratio of maleic anhydride to the total of other monomers being from 1:1 to 100:1, the number average molecular weight of the copolymer being up to 1000.
Claim 2
Dependent Claim
74 words
A composition for treating water or an aqueous system which comprises 2.5 to 80% by weight of zinc (calculated as Zn++) and from 97.5 to 20% by weight of a hydrolysed copolymer of maleic anhydride with a monoethylenically unsaturated monomer or a mixture of monomers, the molar ratio of maleic anhydride to the total of other monomers being from 1:1 to 100:1, the number average molecular weight of the copolymer being up to 1000.
Claim 3
Dependent Claim
28 words
A composition as claimed in claim 1 which comprises from 10 to 60% by weight of zinc and from 90 to 40% by weight of the hydrolysed copolymer.
Claim 4
Dependent Claim
27 words
A composition as claimed in claim 1 in which the molar ratio of maleic anhydride to the total of the other monomers is from 2.5:1 to 100:1.
Claim 5
Dependent Claim
26 words
A composition as claimed in claim 3 in which the ratio of maleic anhydride to the total of the other monomers is from 2.5:1 to 7:1.
Claim 6
Dependent Claim
18 words
A composition as claimed in claim 1 in which the copolymer is formed from maleic anhydride and styrene.
Claim 7
Dependent Claim
21 words
A composition as claimed in claim 1 in which the copolymer is formed from maleic anhydride, ethyl acrylate and vinyl acetate.
Claim 8
Dependent Claim
20 words
A composition as claimed in claim 1 in which the copolymer has a molecular weight of from 300 to 1000.
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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) | 1988-07-22 | 1989-01-21 | 1989-07-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-07-22 | 1993-01-21 | 1993-07-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-07-22 | 1997-01-21 | 1997-07-23 | $7700.00 | Window Closed / Lapsed |