Patent US3837803A successfully refreshed from Google Patents.
US3837803A
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US
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Orthophosphate corrosion inhibitors and their use
Assignee: Veolia WTS USA Inc
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Filing: 1972-07-11
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Granted: 1974-09-24
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Expires: 1992-07-11
Abstract
Abstract The present disclosure is directed to the inhibition of the corrosion of metallic parts in contact with aqueous systems. This effect is accomplished by the addition to the system of a corrosion inhibiting concentration of a water-soluble organophosphonic acid compound having a carbon to phosphorus bond in combination with a water-soluble orthophosphate. The aqueous system should contain solubilized calcium salts and should possess a basic pH. Under certain conditions it is desirable to utilize water-soluble metal cations as a adjunct to the treatment.
Inventors
- 👤 D Carter
- 👤 C Bishof
- 👤 F Vogt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:14
CPC Classifications
C; C23; C23F; C23F11/00; C23F11/08
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
79 words
A method according to claim 1 wherein the solubilized calcium salts are present in a concentration to provide 50 parts or less of calcium ion per million parts of said aqueous system and a water-soluble salt of a metal selected from the group consisting of zinc, nickel, cobalt, chromium, and cadmium is added to said system in an amount to provide from about 0.1 to about 50 parts of said metal ion per million parts of said aqueous system.
Claim 2
Dependent Claim
52 words
A method according to claim 1 wherein the solubilized calcium salt concentration is present in an amount sufficient to provide a calcium ion concentration of above 80 parts per million parts of said system and said pH is adjusted so as to insure a pH of from about 7.1 to about 7.5.
Claim 3
Dependent Claim
58 words
A method according to claim 1 wherein the aqueous system before addition of said phosphate compound contains dissolved orthophosphate compound and the amounts of said compounds (i) and (ii) added are adjusted so as to reflect the concentration of the dissolved phosphate compound to insure that the weight ratio of (i) to (ii) is within the specified range.
Claim 4
Dependent Claim
19 words
A method according to claim 1 wherein said phosphonic acid compound has a formula selected from the group of:
Claim 5
Dependent Claim
35 words
A method according to claim 5 wherein the pH of the aqueous system is from about 7.1 to about 9.5 and contains at least 4 parts of calcium ion per million parts of aqueous system.
Claim 6
Dependent Claim
80 words
A method according to claim 5 wherein the solubilized calcium salts are not present in a concentration to provide 50 ppm or less of calcium ion per million parts of said aqueous system and a water-soluble salt of a metal selected from the group consisting of zinc, nickel, cobalt, chromium, and cadmium is added to said system in an amount to provide from about 0.1 to about 50 parts of said metal ion per million parts of said aqueous system.
Claim 7
Dependent Claim
53 words
A method according to claim 5 wherein the solubilized calcium salt concentration is present in an amount sufficient to provide a calcium ion concentration of about 80 parts per million parts of said system and said pH is adjusted so as to insure that the pH is from about 7.1 to about 7.5.
Claim 8
Dependent Claim
58 words
A method according to claim 5 wherein the aqueous system before addition of said phosphate compounds contains dissolved orthophosphate compound and the amounts of said compounds (i) and (ii) added are adjusted so as to reflect the concentration of the dissolved phosphate compound to insure that the weight ratio of (i) to (ii) is within the specified range.
Claim 9
Dependent Claim
37 words
A method according to claim 5 wherein the pH of the aqueous system is from about 7.5 to about 8.5 and the ratio of phosphonic acid compound to phosphate compound is from about 1:10 to about 20:1.
Claim 10
Dependent Claim
17 words
A method according to claim 10 wherein said phosphonic acid compound is that as represented by (1).
Claim 11
Dependent Claim
28 words
A method according to claim 11 wherein said compound is selected from the group consisting of methylphosphonic acid, ethylphosphonic acid, benzene phosphonic acid and the water-soluble salts thereof.
Claim 12
Dependent Claim
16 words
A method according to claim 10 wherein said phosphonic acid compound is that represented by (2).
Claim 13
Dependent Claim
19 words
A method according to claim 13 wherein the compound is 1-hydroxyethylidene 1,1-diphosphonic acid or the water-soluble metal salts thereof.
Claim 14
Dependent Claim
18 words
A method according to claim 11 wherein said pHosphonic acid compound is that as represented by formula (3).
Claim 15
Dependent Claim
34 words
A method according to claim 15 wherein the compound is selected from the group consisting of nitrilotri(methylene phosphonic acid), dodecylaminodimethylenephosphonic acid, ethylene diamine tetra(methylphosphonic acid), hexamethylene diamine tetra(methylphosphonic acid) and the water-soluble salts thereof.
Claim 16
Dependent Claim
85 words
A method according to claim 1 wherein the pH of said system is from about 7.5 to 8.5, said system contains at least 4 parts of calcium ion per million parts of said aqueous system and said phosponate and phosphate are added as a mixture in an amount of from about 2 to about 250 parts per million parts of said aqueous system and said orthophosphate compound is selected from the group consisting of phosphoric acid, sodium orthophosphates, potassium orthophosphates, lithium orthophosphates and ammonium orthophosphates.
Claim 17
Dependent Claim
85 words
A method according to claim 5 wherein the pH of said system is from about 7.5 to 8.5, said system contains at least 4 parts of calcium ion per million parts of said aqueous system and said phosphonate and phosphate are added as a mixture in an amount of from about 2 to about 250 parts per million parts of said aqueous system and said orthophosphate compound is selected from the group consisting of phosphoric acid, sodium orthophosphates, potassium orthophosphates, lithium orthophosphates and ammonium orthophosphates.
Claim 18
Dependent Claim
15 words
A method according to claim 17 wherein the aqueous system is a cooling water system.
Claim 19
Dependent Claim
15 words
A method according to claim 18 wherein the aqueous system is a cooling water system.
Claim 20
Dependent Claim
66 words
A composition for controlling the corrosion of metallic parts in contact with an aqueous media comprising, (i) a single water-soluble organo-phosphonic acid compound having a carbon to phosphorus bond, or water-soluble salt thereof, and (ii) a water-soluble orthophosphate compound; said compounds being present in the composition to provide a weight ratio of said phosphonic acid compound to said phosphate of from about 1:4 to about 4:1.
Claim 21
Dependent Claim
35 words
A composition according to claim 21 which contains from about 0.2 to about 10 percent weight of a water-soluble salt of a metal selected from the group consisting of zinc, nickel, cobalt, chromium and cadmium.
Claim 22
Dependent Claim
11 words
A composition according to claim 22 wherein the metal is zinc.
Claim 23
Dependent Claim
20 words
A composition according to claim 21 wherein the phosphonic acid compound has a formula selected from the group consisting of:
Claim 24
Dependent Claim
27 words
A composition according to claim 24 wherein said orthophosphate is selected from the group consisting of phosphoric acid, sodium orthophosphates, potassium orthophosphates, lithium orthophosphates and ammonium orthophosphatEs.
Claim 25
Dependent Claim
42 words
A composition according to claim 25 wherein said phosphonic acid compound is selected from the group consisting of methylphosphonic acid, ethyl phosphonic acid, benzene phosphonic acid, 1-hydroxy-ethylidene-1,1-diphosphonic acid, nitrilotri (methylenephosphonic acid), dodecylamino-dimethylenephosphonic acid, ethylene diamine tetra(methylphosphonic acid) and the water-soluble salts thereof.
Claim 26
Dependent Claim
39 words
A composition according to claim 26 which contains from about 0.2 to about 10 percent weight of a water-soluble salt of a metal selected from the group consisting of zinc, nickel, cobalt, cerium, chromium manganese, cadmium, lead and tin.
Claim 27
Dependent Claim
11 words
A composition according to claim 27 where the metal is zinc.
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) | 1977-09-23 | 1978-03-25 | 1978-09-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-23 | 1982-03-25 | 1982-09-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-23 | 1986-03-25 | 1986-09-24 | $7700.00 | Window Closed / Lapsed |