US4664884A
Expired / Lapsed
US
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Corrosion inhibitor
Assignee: Drew Chemical Corp
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Filing: 1985-06-14
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Granted: 1987-05-12
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Expires: 2005-06-14
Abstract
Abstract A corrosion inhibitor for ferrous and non-ferrous aqueous systems comprising (a) a water soluble phosphonic acid or salt thereof, preferably an amino methylene phosphonic acid; (b) a phosphonocarboxylic acid, preferably a phosphonoalkane carboxylic acid; and (c) a triazole, preferably benzotriazole or tolyltriazole.
Inventors
- 👤 Michael A. Mullins
- 👤 Peter A. Thomas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 12:50
CPC Classifications
C; C23; C23F; C23F11/00; C23F11/08; C23F11/10
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
54 words
A composition for use in inhibiting the corrosion of metallic surfaces including mild steel in an alkaline cooling water system in which the active components consists essentially of (a) 0.3-30% by wt. of nitrilotrimethylene phosphonic acid or a salt thereof; (b) 0.4-40% by wt. of 2-phosphonobutane-tricarboxylic acid-1,2,4; and (c) 0.4-40% by wt. of tolyltriazole.
Claim 2
Dependent Claim
54 words
A composition for use in inhibiting the corrosion of metallic surfaces including mild steel in an alkaline cooling water system in which the active components consists essentially of (a) 0.3-30% by wt. of nitrilotrimethylene phosphonic acid or a salt thereof; (b) 0.4-40% by wt. of 2-phosphonobutane-tricarboxylic acid-1,2,4; and (c) 0.4-40% by wt. of tolyltriazole.
Claim 3
Dependent Claim
35 words
A method of inhibiting the corrosion of metallic surfaces including mild steel in an alkaline cooling water system which comprises incorporating in the cooling water an effective amount of a composition according to claim 1.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-05-11 | 1990-11-10 | 1991-05-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-05-11 | 1994-11-10 | 1995-05-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-05-11 | 1998-11-10 | 1999-05-12 | $7700.00 | Window Closed / Lapsed |