US4317744A
Expired / Lapsed
US
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Corrosion inhibitor
Assignee: Ashland Inc
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Filing: 1979-04-25
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Granted: 1982-03-02
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Expires: 1999-04-25
Abstract
Abstract Corrosion inhibitor comprised of corrosion inhibiting amounts of a water soluble phosphonic acid or salt thereof; polymer of acrylic, methacrylic, maleic acid or its anhydride; and tolyltriazole. The corrosion inhibitor is particularly employed for inhibiting corrosion of ferrous containing metal; e.g., mild steel employed in cooling water systems.
Inventors
- 👤 Elliott J. Levi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:05
CPC Classifications
C; C23; C23F; C23F11/00; C23F11/08; C23F11/10
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
104 words
A corrosion inhibiting composition, consisting essentially of: (a) at least one water soluble phosphonic acid or water soluble salt thereof; (b) at least one member selected from the group consisting of water soluble acrylic acid polymers, water soluble methacrylic acid polymers and water soluble polymers of maleic acid or its anhydride; and (c) tolyltriazole, said components (a), (b) and (c), being present in an amount effective to inhibit corrosion in aqueous systems, and wherein the composition includes from 65 to 80% of (a), from 5% to 20% of (b) and from 15% to 25% of (c), based on the three components, all by weight.
Claim 2
Dependent Claim
104 words
A corrosion inhibiting composition, consisting essentially of: (a) at least one water soluble phosphonic acid or water soluble salt thereof; (b) at least one member selected from the group consisting of water soluble acrylic acid polymers, water soluble methacrylic acid polymers and water soluble polymers of maleic acid or its anhydride; and (c) tolyltriazole, said components (a), (b) and (c), being present in an amount effective to inhibit corrosion in aqueous systems, and wherein the composition includes from 65 to 80% of (a), from 5% to 20% of (b) and from 15% to 25% of (c), based on the three components, all by weight.
Claim 3
Dependent Claim
17 words
The composition of claim 1 wherein component (a) is an amino methylene phosphonic acid or salt thereof.
Claim 4
Dependent Claim
17 words
The composition of claim 2 wherein the polymer is a homopolymer of maleic acid or its anhydride.
Claim 5
Dependent Claim
41 words
The composition of Composition of claim 1 wherein component (a) is selected from the group consisting of ethane-1-hydroxy-1, 1-diphosphonic acid, amino tri (methylene)phosphonic acid, ethylene diamine tetra (methylene phosphonic acid), hexamethylene diamine tetra (methylene phosphonic acid) and water soluble salts thereof.
Claim 6
Dependent Claim
16 words
The composition of claim 4 wherein (b) is a homopolymer of maleic acid or its anhydride.
Claim 7
Dependent Claim
17 words
The composition of claim 5 wherein component (b) is ethane-1-hydroxy-1, 1-diphosphonic acid or water soluble salt thereof.
Claim 8
Dependent Claim
75 words
A process for inhibiting corrosion in an aqueous system, comprising: dissolving in the aqueous system a corrosion inhibiting amount of corrosion inhibiting components consisting essentially of: (a) at least one water soluble phosphonic acid or water soluble salt thereof; (b) at least one member selected from the group consisting of water soluble polymers of acrylic acid, water soluble polymers of methacrylic acid and water soluble polymers of maleic acid or its anhydride; and (c) tolyltriazole.
Claim 9
Dependent Claim
75 words
A process for inhibiting corrosion in an aqueous system, comprising: dissolving in the aqueous system a corrosion inhibiting amount of corrosion inhibiting components consisting essentially of: (a) at least one water soluble phosphonic acid or water soluble salt thereof; (b) at least one member selected from the group consisting of water soluble polymers of acrylic acid, water soluble polymers of methacrylic acid and water soluble polymers of maleic acid or its anhydride; and (c) tolyltriazole.
Claim 10
Dependent Claim
19 words
The process of claim 7 wherein the corrosion inhibiting is in an aqueous system in contact with ferrous surfaces.
Claim 11
Dependent Claim
17 words
The process of claim 8 wherein component (a) is an amino methylene phosphonic acid or salt thereof.
Claim 12
Dependent Claim
17 words
The process of claim 9 wherein the polymer is a homopolymer of maleic acid or its anhydride.
Claim 13
Dependent Claim
37 words
The process of claim 7 wherein (a) is present in an amount of from 65% to 80%, (b) from 5% to 20% and (c) from 15% to 25%, based on the three components and all by weight.
Claim 14
Dependent Claim
22 words
The process of claim 11 wherein components (a), (b) and (c) are employed in a total concentration of at least 1 ppm.
Claim 15
Dependent Claim
40 words
The process of claim 12 wherein component (a) is selected from the group consisting of ethane-1-hydroxy-1, 1-diphosphonic acid, amino tri (methylene) phosphonic acid, ethylene diamine tetra (methylene phosphonic acid), hexamethylene diamine tetra (methylene phosphonic acid) and water soluble salts thereof.
Claim 16
Dependent Claim
16 words
The process of claim 13 wherein (b) is a homopolymer of maleic acid or its anhydride.
Claim 17
Dependent Claim
17 words
The process of claim 14 wherein component (b) is ethane-1-hydroxy-1, 1-diphosphonic acid or water soluble salt thereof.
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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) | 1985-03-01 | 1985-08-31 | 1986-03-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-03-01 | 1989-08-31 | 1990-03-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-03-01 | 1993-08-31 | 1994-03-02 | $7700.00 | Window Closed / Lapsed |