US4089796A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Treatment of water or aqueous systems
Assignee: FMC Corp
•
Filing: 1976-06-14
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Granted: 1978-05-16
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Expires: 1996-06-14
Abstract
Abstract Compositions for inhibiting corrosion and scale formation in aqueous systems which consist essentially of from 20 to 97.5% by weight of total composition of (a) a combination of zinc and hydrolyzed polymaleic anhydride and (b) 2.5 to 80% by weight of total composition of a corrosion inhibitor, particularly benzotriazole.
Inventors
- 👤 Arthur Harris
- 👤 John Burrows
- 👤 Thomas Ivor Jones
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 18:15
CPC Classifications
C; C02; C02F; C02F5/00; C02F5/08; C02F5/10; C02F5/105; C23; C23F; C23F11/00; C23F11/08
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
112 words
A composition for inhibiting the corrosion and scale forming tendencies of water or an aqueous system consisting essentially of (a) from 20 to 97.5% by weight of the total composition of an additive combination which consists of from 2.5 to 80% by weight of zinc (calculated as Zn ++ ) and from 97.5 to 20% by weight of hydrolysed polymaleic anhydride, having an average molecular weight of from 300 to 5,000, or of a water soluble salt of such a hydrolysed polymaleic anhydride, and (b) from 2.5 to 80% by weight of the total composition of at least one corrosion inhibitor selected from the group consisting of a benzotriazole and a bis-benzotriazole.
Claim 2
Dependent Claim
112 words
A composition for inhibiting the corrosion and scale forming tendencies of water or an aqueous system consisting essentially of (a) from 20 to 97.5% by weight of the total composition of an additive combination which consists of from 2.5 to 80% by weight of zinc (calculated as Zn ++ ) and from 97.5 to 20% by weight of hydrolysed polymaleic anhydride, having an average molecular weight of from 300 to 5,000, or of a water soluble salt of such a hydrolysed polymaleic anhydride, and (b) from 2.5 to 80% by weight of the total composition of at least one corrosion inhibitor selected from the group consisting of a benzotriazole and a bis-benzotriazole.
Claim 3
Dependent Claim
12 words
A composition according to claim 1, wherein corrosion inhibitor (b) is benzotriazole.
Claim 4
Dependent Claim
37 words
A composition according to claim 1, wherein additive combination (a) consists of from 10 to 60% by weight of zinc and from 90 to 40% by weight of hydrolysed polymaleic anhydride or a water soluble salt thereof.
Claim 5
Dependent Claim
30 words
A composition according to claim 1, consisting essentially of from 75 to 95% by weight of additive combination (a) and from 5 to 25% by weight of corrosion inhibitor (b).
Claim 6
Dependent Claim
24 words
A composition according to claim 1, wherein the hydrolysed polymaleic anhydride or the water soluble salt thereof has a molecular weight not exceeding 2,000.
Claim 7
Dependent Claim
26 words
A composition according to claim 1, wherein the amount of (a) plus (b) is from 0.1 to 500 ppm. calculated on the water or aqueous system.
Claim 8
Dependent Claim
26 words
A composition according to claim 1, wherein the amount of (a) plus (b) is from 1 to 200 ppm. calculated on the water or aqueous system.
References Cited (Backward Citations)
US3794603A
Cited
US3963636A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-05-15 | 1981-11-14 | 1982-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-05-15 | 1985-11-14 | 1986-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-05-15 | 1989-11-14 | 1990-05-16 | $7700.00 | Window Closed / Lapsed |