US4303568A
Expired / Lapsed
US
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Corrosion inhibition treatments and method
Assignee: Veolia WTS USA Inc
•
Filing: 1979-12-10
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Granted: 1981-12-01
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Expires: 1999-12-10
Abstract
Abstract The invention deals with a method and composition(s) for use in inhibiting corrosion of metallic parts in contact with aqueous systems. It has been discovered that protective oxide films can be formed on the metallic surface if such is allowed to contact an aqueous system containing a sufficient amount for the purpose of a polymer composed primarily of acrylic moieties and hydroxylated lower alkyl acrylate moieties and a water-soluble orthophosphate. Optionally but desirably, polyphosphates, organo-phosphonates, and copper corrosion inhibitors may be included.
Inventors
- 👤 Roger C. May
- 👤 Gary E. Geiger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:24
CPC Classifications
C; C23; C23F; C23F11/00; C23F11/08; C02; C02F; C02F5/00; C02F5/08; C02F5/10; C02F5/105; C02F5/12; C02F5/125; C02F5/14
Claims Analysis
Total Claims: 50
Claim 1
Independent Claim
243 words
A method of inhibiting the corrosion of ferrous metal parts in contact with an aqueous solution with little or no attendant deposition of scale on said ferrous parts, which corrosion inhibition is obtained by providing for the formation of a protective passive oxide film on the metal surface in contact with said aqueous medium, which method comprises (i) assuring that the pH of said aqueous medium is 5.5 or above; (ii) assuring that the aqueous medium contains a calcium or other appropriate ion concentration selected from the group consisting of zinc, nickel and chromium and mixtures thereof; and (iii) adding to said aqueous medium (a) a water-soluble polymer comprising moieties derived from an acrylic acid or water-soluble salt thereof and moieties of an hydroxylated lower alkyl acrylate, wherein the moieties of the polymer having the following formulas: ##STR14## wherein R is hydrogen or a lower alkyl of from 1 to 3 carbon atoms; R 1 is OH, OM or NH 2 where M is a water-soluble cation; R 2 is a lower alkyl of from about 2 to 6 carbon atoms and the mole ratio of x:y is 34:1 to 1:4; and (b) a water-soluble orthophosphate compound; said polymer being such that together with the orthophosphate compound is effective to promote the metal oxide film with no attendant deposition, and the amount of (a) and (b) being added being sufficient to provide a substantially scale-free protective passive oxide film on the metallic surface.
Claim 2
Independent Claim
243 words
A method of inhibiting the corrosion of ferrous metal parts in contact with an aqueous solution with little or no attendant deposition of scale on said ferrous parts, which corrosion inhibition is obtained by providing for the formation of a protective passive oxide film on the metal surface in contact with said aqueous medium, which method comprises (i) assuring that the pH of said aqueous medium is 5.5 or above; (ii) assuring that the aqueous medium contains a calcium or other appropriate ion concentration selected from the group consisting of zinc, nickel and chromium and mixtures thereof; and (iii) adding to said aqueous medium (a) a water-soluble polymer comprising moieties derived from an acrylic acid or water-soluble salt thereof and moieties of an hydroxylated lower alkyl acrylate, wherein the moieties of the polymer having the following formulas: ##STR14## wherein R is hydrogen or a lower alkyl of from 1 to 3 carbon atoms; R 1 is OH, OM or NH 2 where M is a water-soluble cation; R 2 is a lower alkyl of from about 2 to 6 carbon atoms and the mole ratio of x:y is 34:1 to 1:4; and (b) a water-soluble orthophosphate compound; said polymer being such that together with the orthophosphate compound is effective to promote the metal oxide film with no attendant deposition, and the amount of (a) and (b) being added being sufficient to provide a substantially scale-free protective passive oxide film on the metallic surface.
Claim 3
Dependent Claim
27 words
The method of claim 1, wherein the weight ratio of said polymer to said orthophosphate expressed as PO 4 --- is from about 1:6 to about 2:1.
Claim 4
Dependent Claim
54 words
A method according to claim 1, wherein the orthophosphate (expressed as PO 4 --- ) is added to said aqueous medium in an amount of about 6 to 30 parts per million parts of water and said polymer is added in an amount of from 3 to 25 parts per million parts of water.
Claim 5
Dependent Claim
54 words
A method according to claim 2, wherein the orthophosphate (expressed as PO 4 --- ) is added to said aqueous medium in an amount of about 6 to 30 parts per million parts of water and said polymer is added in an amount of from 3 to 25 parts per million parts of water.
Claim 6
Dependent Claim
35 words
A method according to claim 4, wherein the pH is maintained or adjusted within the range of 6.5 to 9.5 and said calcium ion concentration is 15 parts per million parts of water or above.
Claim 7
Dependent Claim
24 words
A method according to claim 1, wherein additionally is added to said aqueous medium a water-soluble organo phosphonic acid compound or its water-soluble salts.
Claim 8
Dependent Claim
61 words
A method according to claim 6, wherein the weight ratio of compounds and polymer added are as follows: said polymer to said orthophosphate compound expressed as PO 4 --- is from about 1:6 to about 2:1; and said orthophosphate expressed as PO 4 --- to said organo phosphonic acid compound expressed as PO 4 --- is from about 2:1 to 8:1.
Claim 9
Dependent Claim
66 words
A method according to claim 7, wherein the compounds and polymer are added to said aqueous medium as follows: orthophosphate compound expressed as PO 4 --- : 6 to 30 parts per million parts of water; organo phosphonic acid compound expressed as PO 4 --- : 1 to 6 parts per million parts of water; and polymer: 3 to 25 parts per million parts of water.
Claim 10
Dependent Claim
37 words
A method according to claim 7, wherein the pH of the aqueous medium is adjusted or maintained at about 6.5 to 9.5 and the calcium ion concentration is 15 parts per million parts of water or above.
Claim 11
Dependent Claim
17 words
A method according to claim 1, wherein the aqueous medium is contained in a cooling water system.
Claim 12
Dependent Claim
17 words
A method according to claim 9, wherein the aqueous medium is contained in a cooling water system.
Claim 13
Dependent Claim
21 words
A method according to claim 7, wherein R is hydrogen and R 2 is a lower alkyl of 3 carbon atoms.
Claim 14
Independent Claim
250 words
A method of inhibiting the corrosion of ferrous metal parts in contact with an aqueous solution with little or no attendant deposition of scale on said ferrous parts, which corrosion inhibition is obtained by providing for the formation of a protective passive oxide film on the metal surface in contact with said aqueous medium, which method comprises (i) assuring that the pH of said aqueous medium is 5.5 or above; (ii) assuring that the aqueous medium contains a calcium or other appropriate ion concentration selected from the group consisting of zinc, nickel and chromium and mixtures thereof; and (iii) adding to said aqueous medium (a) a water-soluble polymer comprising moieties derived from an acrylic acid or water-soluble salt thereof and moieties of an hydroxylated lower alkyl acrylate, wherein the moieties of the polymer have the following formulas: ##STR15## wherein R is hydrogen or a lower alkyl of from 1 to 3 carbon atoms; R 1 is OH, OM or NH 2 where M is a water-soluble cation; R 2 is a lower alkyl of from about 2 to 6 carbon atoms and the mole ratio of x:y is 34:1 to 1:4; and (b) a water-soluble orthophosphate compound; and (c) a water-soluble polyphosphate compound; said polymer being such that together with the orthophosphate compound is effective to promote the metal oxide film with no attendant deposition, and the amount of (a), (b) and (c) being added being sufficient to provide a substantially scale-free protective passive oxide film on the metallic surface.
Claim 15
Independent Claim
250 words
A method of inhibiting the corrosion of ferrous metal parts in contact with an aqueous solution with little or no attendant deposition of scale on said ferrous parts, which corrosion inhibition is obtained by providing for the formation of a protective passive oxide film on the metal surface in contact with said aqueous medium, which method comprises (i) assuring that the pH of said aqueous medium is 5.5 or above; (ii) assuring that the aqueous medium contains a calcium or other appropriate ion concentration selected from the group consisting of zinc, nickel and chromium and mixtures thereof; and (iii) adding to said aqueous medium (a) a water-soluble polymer comprising moieties derived from an acrylic acid or water-soluble salt thereof and moieties of an hydroxylated lower alkyl acrylate, wherein the moieties of the polymer have the following formulas: ##STR15## wherein R is hydrogen or a lower alkyl of from 1 to 3 carbon atoms; R 1 is OH, OM or NH 2 where M is a water-soluble cation; R 2 is a lower alkyl of from about 2 to 6 carbon atoms and the mole ratio of x:y is 34:1 to 1:4; and (b) a water-soluble orthophosphate compound; and (c) a water-soluble polyphosphate compound; said polymer being such that together with the orthophosphate compound is effective to promote the metal oxide film with no attendant deposition, and the amount of (a), (b) and (c) being added being sufficient to provide a substantially scale-free protective passive oxide film on the metallic surface.
Claim 16
Dependent Claim
48 words
A method according to claim 13, wherein the weight ratio of said compounds and polymer are: polymer to orthophosphate expressed as PO 4 --- of about 1:6 to 2:1; and orthophosphate expressed as PO 4 --- to polyphosphate expressed as PO 4 --- of about 2.5:1 to 1:1.
Claim 17
Dependent Claim
65 words
A method according to claim 14, wherein the compounds and the polymer are added to the aqueous medium in the following amounts: orthophosphate expressed as PO 4 --- : 6 to 30 parts per million parts of water; polymer: 3 to 25 parts per million parts of water; and polyphosphate expressed as PO 4 --- : 3 to 10 parts per million parts of water.
Claim 18
Dependent Claim
42 words
A method according to claim 15, wherein the pH of the aqueous medium is adjusted or maintained within the range of 6.5 to 9.5 and said calcium ion concentration in the water is 15 parts per million parts of water or above.
Claim 19
Dependent Claim
42 words
A method according to claim 16, wherein a copper corrosion inhibitor selected from the group consisting of benzotriazole compounds and benzothiazole compounds is added to said aqueous medium in an amount of from 0.5 to 5 parts per million parts of water.
Claim 20
Dependent Claim
20 words
A method according to claim 16, wherein R is hydrogen R 2 is a lower alkyl of 3 carbon atoms.
Claim 21
Dependent Claim
42 words
A method according to claim 18, wherein a copper corrosion inhibitor selected from the group consisting of benzotriazole compounds and benzothiazole compounds is added to said aqueous medium in an amount of from 0.5 to 5 parts per million parts of water.
Claim 22
Dependent Claim
17 words
A method according to claim 16, wherein the aqueous medium is contained in a cooling water system.
Claim 23
Dependent Claim
17 words
A method according to claim 18, wherein the aqueous medium is contained in a cooling water system.
Claim 24
Dependent Claim
78 words
A method according to claim 13, wherein additionally a water-soluble organo phosphonic acid compound is added to the aqueous medium and the weight ratio of the compounds and polymer are as follows: polymer to orthophosphate expressed as PO 4 --- : about 1:6 to about 2:1; orthophosphate to polyphosphate both expressed as PO 4 --- : about 2.5:1 to about 1:1; orthophosphate to said organo phosphonate both expressed as PO 4 --- : about 2:1 to about 8:1.
Claim 25
Dependent Claim
88 words
A method according to claim 22, wherein the compounds and polymer are added to the aqueous medium in the following amounts: orthophosphate compound expressed as PO 4 --- : about 6 to 30 parts per million parts of water; polyphosphate compound expressed as PO 4 --- : about 3 to 10 parts per million parts of water; phosphonic acid compound expressed as PO 4 --- : about 1 to 6 parts per million parts of water; and polymer: about 3 to 25 parts per million parts of water.
Claim 26
Dependent Claim
39 words
A method according to claim 23, wherein the pH of the aqueous medium is adjusted or maintained within the range of 6.5 to 9.5 and the calcium ion concentration is 15 parts per million parts of water or above.
Claim 27
Dependent Claim
31 words
A method according to claim 24, wherein a copper corrosion inhibitor is added to said aqueous medium in the amount of about 0.5 to 5 parts per million parts of water.
Claim 28
Dependent Claim
17 words
A method according to claim 24, wherein said aqueous medium is contained in a cooling water system.
Claim 29
Dependent Claim
17 words
A method according to claim 25, wherein said aqueous medium is contained in a cooling water system.
Claim 30
Dependent Claim
42 words
A method according to claim 13, wherein the hydroxy alkyl acrylate is hydroxy propyl acrylate and the ratios of the acrylic acid moieties to said hydroxy propyl acrylate moieties is about 3:1 and the polymer has a molecular weight of about 6,000.
Claim 31
Dependent Claim
19 words
A method according to claim 28, wherein the aqueous medium is the cooling water of a cooling water system.
Claim 32
Dependent Claim
28 words
A method according to claim 29, wherein a copper corrosion inhibitor is added and said inhibitor is selected from the group consisting of tolyltriazole, benzotriazole, and benzothiazole compounds.
Claim 33
Dependent Claim
56 words
A method according to claim 28, wherein the hydroxy alkyl acrylate is hydroxy propyl acrylate and the ratios of the acrylic acid moieties to said hydroxy propyl acrylate moieties is about 3:1 and the polymer has a molecular weight of about 6,000, and said organo phosphonic acid compound is hydroxyethylidene diphosphonic acid or its water-soluble salt.
Claim 34
Dependent Claim
155 words
A composition for providing a protective passive oxide film on the surface of a ferrous metallic part in contact with an aqueous solution with little or no attendant deposition of scale on said part, which comprises (i) a water-soluble polymer consisting essentially of moieties derived from an acrylic acid or water-soluble salt thereof and moieties of an hydroxylated lower alkyl acrylate, wherein the moieties of the polymer have the following formulas: ##STR16## wherein R is hydrogen or a lower alkyl of from 1 to 3 carbon atoms; R 1 is OH, OM or NH 2 where M is a water-soluble cation; R 2 is a lower alkyl of from about 2 to 6 carbon atoms and the mole ratio of x:y is 34:1 to 1:4; and (ii) a water-soluble orthophosphate compound, the ratio on a weight basis of the polymer to the orthophosphate expressed as PO 4 --- being from about 1:8 to about 4:1.
Claim 35
Dependent Claim
155 words
A composition for providing a protective passive oxide film on the surface of a ferrous metallic part in contact with an aqueous solution with little or no attendant deposition of scale on said part, which comprises (i) a water-soluble polymer consisting essentially of moieties derived from an acrylic acid or water-soluble salt thereof and moieties of an hydroxylated lower alkyl acrylate, wherein the moieties of the polymer have the following formulas: ##STR16## wherein R is hydrogen or a lower alkyl of from 1 to 3 carbon atoms; R 1 is OH, OM or NH 2 where M is a water-soluble cation; R 2 is a lower alkyl of from about 2 to 6 carbon atoms and the mole ratio of x:y is 34:1 to 1:4; and (ii) a water-soluble orthophosphate compound, the ratio on a weight basis of the polymer to the orthophosphate expressed as PO 4 --- being from about 1:8 to about 4:1.
Claim 36
Dependent Claim
41 words
A composition according to claim 32, wherein the hydroxy alkyl acrylate is hydroxy propyl acrylate and the ratios of the acrylic acid moieties to said hydroxy propyl moieties is about 3:1 and the polymer has a molecular weight of about 6,000.
Claim 37
Dependent Claim
43 words
A composition according to claim 32, which additionally contains a compound selected from the group consisting of an organo phosphonic acid compound or derivatives thereof and a copper corrosion inhibitor selected from the group of benzothiazole compounds and benzotriazole compounds, or mixtures thereof.
Claim 38
Dependent Claim
42 words
A composition according to claim 34, wherein the organo phosphonic acid derivative and said compound is present in said composition on a weight ratio of orthophosphate to organo phosphonic derivative both expressed as PO 4 --- of about 1:2 to about 13:1.
Claim 39
Dependent Claim
20 words
A composition according to claim 35, which contains a mixture of copper corrosion inhibitors and said organo phosphonic acid derivative.
Claim 40
Dependent Claim
13 words
A composition according to claim 36, wherein the copper corrosion inhibitor is tolyltriazole.
Claim 41
Dependent Claim
29 words
A composition according to claim 35, wherein the hydroxy alkyl acrylate is an hydroxy propyl acrylate, and the phosphonic acid derivative is hydroxyethylidene diphosphonic acid or its water-soluble salt.
Claim 42
Dependent Claim
177 words
A composition for providing a protective passive oxide film on the surface of a metallic part in contact with an aqueous solution with little or no attendant deposition of scale on said part, which comprises (i) a water-soluble polymer consisting essentially of moieties derived from an acrylic acid or water-soluble salt thereof and moieties of an hydroxylated lower alkyl acrylate, wherein the moieties of the polymer have the following formulas: ##STR17## wherein R is hydrogen or a lower alkyl of from 1 to 3 carbon atoms; R 1 is OH, OM or NH 2 where M is a water-soluble cation; R 2 is a lower alkyl of from about 2 to 6 carbon atoms and the mole ratio of x:y is 34:1 to 1:4; (ii) a water-soluble orthophosphate compound, the ratio on a weight basis of the polymer to the orthophosphate expressed as PO 4 --- being from about 1:8 to about 4:1, and (iii) a water-soluble polyphosphate compound, the ratio of orthophosphate to polyphosphate both expressed as PO 4 --- being about 15:1 to about 1:3.
Claim 43
Dependent Claim
177 words
A composition for providing a protective passive oxide film on the surface of a metallic part in contact with an aqueous solution with little or no attendant deposition of scale on said part, which comprises (i) a water-soluble polymer consisting essentially of moieties derived from an acrylic acid or water-soluble salt thereof and moieties of an hydroxylated lower alkyl acrylate, wherein the moieties of the polymer have the following formulas: ##STR17## wherein R is hydrogen or a lower alkyl of from 1 to 3 carbon atoms; R 1 is OH, OM or NH 2 where M is a water-soluble cation; R 2 is a lower alkyl of from about 2 to 6 carbon atoms and the mole ratio of x:y is 34:1 to 1:4; (ii) a water-soluble orthophosphate compound, the ratio on a weight basis of the polymer to the orthophosphate expressed as PO 4 --- being from about 1:8 to about 4:1, and (iii) a water-soluble polyphosphate compound, the ratio of orthophosphate to polyphosphate both expressed as PO 4 --- being about 15:1 to about 1:3.
Claim 44
Dependent Claim
15 words
A composition according to claim 39, wherein the hydroxy alkyl acrylate is hydroxy propyl acrylate.
Claim 45
Dependent Claim
33 words
A composition according to claim 40, wherein the ratios of the acrylic acid moieties to said hydroxy propyl acrylate moieties is about 3:1 and the polymer has a molecular weight of about 6,000.
Claim 46
Dependent Claim
44 words
A composition according to claim 39, which additionally contains a compound selected from the group consisting of an organo phosphonic acid compound or derivatives thereof and a copper corrosion inhibitor selected from the group consisting of benzothiazole compounds and benzotriazole compounds, or mixtures thereof.
Claim 47
Dependent Claim
45 words
A composition according to claim 42, wherein the compound is an organo phosphonic acid derivative and said compound is present in said composition on a weight ratio of orthophosphate to organo phosphonic derivative both expressed as PO 4 --- of about 1:2 to about 13:1.
Claim 48
Dependent Claim
19 words
A composition according to claim 43, which contains a mixture of said copper inhibitor and said organo phosphonic acid.
Claim 49
Dependent Claim
24 words
A composition according to claim 44, which contains a copper corrosion inhibitor selected from the group consisting of tolyltriazole, benzotriazole compounds, and benzothiazole compounds.
Claim 50
Dependent Claim
29 words
A composition according to claim 43, wherein the hydroxy alkyl acrylate is an hydroxy propyl acrylate, and the phosphonic acid derivative is hydroxyethylidene diphosphonic acid or its water-soluble salt.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1984-11-30 | 1985-06-01 | 1985-12-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-11-30 | 1989-06-01 | 1989-12-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-11-30 | 1993-06-01 | 1993-12-01 | $7700.00 | Window Closed / Lapsed |