US4052160A
Expired / Lapsed
US
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Corrosion inhibitors
Assignee: FMC Corp
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Filing: 1976-07-20
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Granted: 1977-10-04
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Expires: 1996-07-20
Abstract
Abstract A method of treating an aqueous system to inhibit the corrosion of metals in contact therewith and/or inhibit the deposition of scale therefrom comprising adding to the aqueous system a minor proportion of a compound of the formula: ##STR1## wherein n is 0 or 1 and when n is O, R 3 and R 4 are the same or different and each is hydrogen, an alkyl group having from 1 to 4 carbon atoms, a benzyl, allyl, --CH 2 PO 3 H 2 -- or --CHCOOH.CH 2 COOH group or a group of formula ##STR2## wherein R 5 is hydrogen, a methyl, --CH 2 COOH or --CH 2 CH 2 COOH group and Z is a group --COOH or --PO 3 H 2 , with the proviso that when Z is a PO 3 H 2 group then R 5 is hydrogen or methyl, and when n is 1, R 1 and R 2 are the same or different and each is hydrogen, or a methyl or phenyl residue and R 3 is hydrogen and R 4 is hydrogen, an alkyl group having from 1 to 4 carbon atoms or a --CH 2 CH 2 COOH group, or R 3 and R 4 together may form a methylene group ═CH 2 .
Inventors
- 👤 Barry Cook
- 👤 John Grey Dingwall
- 👤 Brian Martin Thomas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 06:53
CPC Classifications
C; C23; C23F; C23F11/00; C23F11/08; C23F11/10; C23F11/167; C23F11/1676; C02; C02F; C02F5/00; C02F5/08; C02F5/10; C02F5/14; C07; C07F; C07F9/00; C07F9/02; C07F9/28; C07F9/38; C07F9/3804; C07F9/3808; C07F9/3839; C07F9/3869
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
99 words
A method of treating an aqueous system to inhibit the corrosion of metals in contact therewith and to inhibit the deposition of scale therefrom which comprises adding to the aqueous system a minor proportion of a compound of the formula ##STR18## wherein n is 0 or 1, and when n is 0, R 3 and R 4 are each hydrogen; or when n is 1, R 1 , R 2 , R 3 and R 4 are each hydrogen; or when n is 1, R 1 , R 2 and R 3 are hydrogen, and R 4 is methyl.
Claim 2
Independent Claim
99 words
A method of treating an aqueous system to inhibit the corrosion of metals in contact therewith and to inhibit the deposition of scale therefrom which comprises adding to the aqueous system a minor proportion of a compound of the formula ##STR18## wherein n is 0 or 1, and when n is 0, R 3 and R 4 are each hydrogen; or when n is 1, R 1 , R 2 , R 3 and R 4 are each hydrogen; or when n is 1, R 1 , R 2 and R 3 are hydrogen, and R 4 is methyl.
Claim 3
Dependent Claim
29 words
A method as claimed in claim 1 wherein the water-soluble salt of the compound of formula I is an alkali metal salt, an ammonium salt or an amine salt.
Claim 4
Dependent Claim
30 words
A method as claimed in claim 1 wherein the water-soluble partial ester of the compound of formula I is derived from an alcohol having from 1 to 4 carbon atoms.
Claim 5
Dependent Claim
20 words
A method as claimed in claim 1 wherein n is 0 and R 3 and R 4 are each hydrogen.
Claim 6
Dependent Claim
21 words
A method as claimed in claim 1 wherein the compound of formula I is used in conjunction with other corrosion inhibitors.
Claim 7
Dependent Claim
34 words
A method as claimed in claim 5 wherein the other corrosion inhibitors are zinc, phosphates, polyphosphates, nitrites, sodium chromate, nitrates, benzotriazole, bis-benzotriazole or copper-deactivating benzotriazole derivatives, N-acyl sarcosines, triethanolamines, fatty amines or polycarboxylic acids.
Claim 8
Dependent Claim
26 words
A method as claimed in claim 6 wherein the other corrosion inhibitors are zinc ions, nitrite ions, phosphate or polyphosphate ions or benzotriazoles or derivatives thereof.
Claim 9
Dependent Claim
38 words
A method as claimed in claim 7 wherein the corrosion inhibitor of formula I is such that n is 0 and R 3 and R 4 are each hydrogen and the other corrosion inhibitors are zinc and benzotriazole.
Claim 10
Dependent Claim
44 words
A method as claimed in claim 7, wherein the corrosion inhibitor of formula I is such that n is 1 and R 1 , R 2 , R 3 and R 4 are each hydrogen and the other corrosion inhibitors are zinc and benzotriazole.
Claim 11
Dependent Claim
43 words
A method as claimed in claim 7 wherein the corrosion inhibitor of formula I is such that n is 1, R 1 , R 2 and R 3 hydrogen and R 4 is methyl and the other corrosion inhibitors are zinc and benzotriazole.
Claim 12
Dependent Claim
24 words
A method as claimed in claim 1 wherein the total amount of corrosion inhibitor is within the range of from 1 to 200 ppm.
Claim 13
Dependent Claim
24 words
A method as claimed in claim 11 wherein the total amount of corrosion inhibitor is within the range of from 1 to 100 ppm.
Claim 14
Dependent Claim
33 words
A method as claimed in claim 5 wherein the corrosion inhibitor mixture contains 20 to 97.5% of the compound of formula I and 2.5 to 80% of the other corrosion inhibitor or inhibitors.
Claim 15
Dependent Claim
34 words
A method as claimed in claim 13 wherein the corrosion inhibitor mixture contains 40 to 90% of the compound of formula I and from 10 to 60% of the other corrosion inhibitor or inhibitors.
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) | 1980-10-03 | 1981-04-04 | 1981-10-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-03 | 1985-04-04 | 1985-10-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-03 | 1989-04-04 | 1989-10-04 | $7700.00 | Window Closed / Lapsed |