US3992318A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Corrosion inhibitor
Assignee: Drew Chemical Corp
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Filing: 1973-10-09
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Granted: 1976-11-16
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Expires: 1993-10-09
Abstract
Abstract A corrosion inhibitor which is comprised of a polyphosphate; a phosphonic acid or salt thereof; and a polymer of acrylic or methacrylic acid. The corrosion inhibitor is employed in aqueous systems and is capable of operating at a wide variety of conditions, including high temperature, high pH and in the presence of contaminants such as hydrogen sulfide and hydrocarbons. A typical composition is comprised of sodium hexametaphosphate, sodium salt of amino tri(methylene-phosphonic acid) and polyacrylic acid.
Inventors
- 👤 Raymond H. Gaupp
- 👤 John A. Nygren, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:24
CPC Classifications
C; C23; C23F; C23F11/00; C23F11/08
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
75 words
A corrosion inhibiting composition comprising: a. at least one water soluble phosphonic acid or salt thereof, selected from the group consisting of ethane-1-hydroxy-1, 1-diphosphonic acid, and amino tri(methylene phosphonic acid); b. at least one water soluble phosphate selected from the group consisting of sodium hexametaphosphate and tetrapotassium pyrophosphate; c. at least one water soluble acrylic acid polymer, said components (a), (b) and (c) being present in an amount effective to inhibit corrosion in aqueous systems.
Claim 2
Dependent Claim
75 words
A corrosion inhibiting composition comprising: a. at least one water soluble phosphonic acid or salt thereof, selected from the group consisting of ethane-1-hydroxy-1, 1-diphosphonic acid, and amino tri(methylene phosphonic acid); b. at least one water soluble phosphate selected from the group consisting of sodium hexametaphosphate and tetrapotassium pyrophosphate; c. at least one water soluble acrylic acid polymer, said components (a), (b) and (c) being present in an amount effective to inhibit corrosion in aqueous systems.
Claim 3
Dependent Claim
71 words
A process for inhibiting corrosion in aqueous systems comprising: dissolving in the aqueous system a corrosion inhibiting amount of (a) at least one phosphonic acid or salt thereof, selected from the group consisting of ethane-1-hydroxy-1, 1-diphosphonic acid and amino tri(methylene phosphonic acid); (b) at least one water soluble phosphate selected from the group consisting of sodium hexametaphosphate and tetrapotassium pyrophosphate; and (c) at least one water soluble polymer of acrylic acid.
Claim 4
Dependent Claim
71 words
A process for inhibiting corrosion in aqueous systems comprising: dissolving in the aqueous system a corrosion inhibiting amount of (a) at least one phosphonic acid or salt thereof, selected from the group consisting of ethane-1-hydroxy-1, 1-diphosphonic acid and amino tri(methylene phosphonic acid); (b) at least one water soluble phosphate selected from the group consisting of sodium hexametaphosphate and tetrapotassium pyrophosphate; and (c) at least one water soluble polymer of acrylic acid.
Claim 5
Dependent Claim
47 words
The composition of claim 1 wherein the weight ratio of component (a) to component (b) both calculated as PO 4 is from 0.1:1 to about 10:1 and the weight ratio of component (c) to component (b) calculated as PO 4 is from about 0.01:1 to about 10:1.
Claim 6
Dependent Claim
14 words
The composition of claim 3 wherein component (c) is a homopolymer of acrylic acid.
Claim 7
Dependent Claim
11 words
The composition of claim 4 wherein component (b) is sodium hexametaphosphate.
Claim 8
Dependent Claim
68 words
The process of claim 2 wherein said component (b) is dissolved in the aqueous system in an amount from about 1 ppm to about 50 ppm and the weight ratio of component (a) to component (b) both calculated as PO 4 is from 0.1:1 to about 10:1 and the weight ratio of component (c) to component (b), calculated as PO 4 is from about 0.01 to about 10:1.
Claim 9
Dependent Claim
14 words
The process of claim 6 wherein component (c) is a homopolymer of acrylic acid.
Claim 10
Dependent Claim
11 words
The process of claim 7 wherein component (b) is sodium hexametaphosphate.
Claim 11
Dependent Claim
13 words
The composition of claim 5 wherein component (a) is amino tri(methylene phosphonic acid).
Claim 12
Dependent Claim
13 words
The process of claim 8 wherein component (a) is amino tri(methylene phosphonic acid).
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) | 1979-11-16 | 1980-05-17 | 1980-11-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-11-16 | 1984-05-17 | 1984-11-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-11-16 | 1988-05-17 | 1988-11-16 | $7700.00 | Window Closed / Lapsed |