US4076501A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Corrosion inhibition of water systems with phosphonic acids
Assignee: FMC Corp
•
Filing: 1976-01-28
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Granted: 1978-02-28
•
Expires: 1996-01-28
Abstract
Abstract Process for inhibiting corrosion by corrosive water systems on metals which comprises adding to the water systems a phosphonic acid having the general formula: ##STR1## wherein R 1 is a straight chain alkyl group having 1-5 carbon atoms, an alkenyl group having 3-5 carbon atoms in which the double bond is not adjacent to the nitrogen atom, a tolyl group, a benzyl group or a cyclohexyl group.
Inventors
- 👤 Arthur Harris
- 👤 John Burrows
- 👤 James Roger Hargreaves
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 21:20
CPC Classifications
C; C23; C23F; C23F11/00; C23F11/08; C23F11/10; C23F11/167; C23F11/1676
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
80 words
A process for inhibiting the attack of a corrosive water system on metals with which it comes into contact which comprises incorporating in the system a phosphonic acid of the general formula: ##STR8## in which R 1 is a straight-chain alkyl group containing from 1 to 5 carbon atoms, an alkenyl group containing from 3 to 5 carbon atoms in which the double bond is not adjacent to the nitrogen, a tolyl group, a benzyl group or a cyclohexyl group.
Claim 2
Dependent Claim
80 words
A process for inhibiting the attack of a corrosive water system on metals with which it comes into contact which comprises incorporating in the system a phosphonic acid of the general formula: ##STR8## in which R 1 is a straight-chain alkyl group containing from 1 to 5 carbon atoms, an alkenyl group containing from 3 to 5 carbon atoms in which the double bond is not adjacent to the nitrogen, a tolyl group, a benzyl group or a cyclohexyl group.
Claim 3
Dependent Claim
34 words
A process as claimed in claim 1 for inhibiting the attack of a corrosive water system on metals wherein R 1 is a methyl, n-propyl, allyl, cyclohexyl, ethyl, n-butyl, n-pentyl, p-tolyl or benzyl group.
Claim 4
Dependent Claim
38 words
A process for inhibiting the attack of a corrosive water system on metals as claimed in claim 2 in which the amount of phosphonic acid in the corrosive water system is from 5 to 50 parts per million.
Claim 5
Dependent Claim
31 words
A process for inhibiting the attack of a corrosive water system on metals as claimed in claim 2 in which the phosphonic acid has the formula CH.sub.3 --N (CH.sub.2 PO.sub.3 H.sub.2).sub.2.
Claim 6
Dependent Claim
32 words
A process for inhibiting the attack of a corrosive water system on metals as claimed in claim 2 in which the phosphonic acid has the formula n--C.sub.3 H.sub.8 --N (CH.sub.2 PO.sub.3 H.sub.2).sub.2.
Claim 7
Dependent Claim
34 words
A process for inhibiting the attack of a corrosive water system on metals as claimed in claim 2 in which the phosphonic acid has the formula CH.sub.2 ═ CH --CH.sub.2 --N (CH.sub.2 PO.sub.3 H.sub.2).sub.2.
Claim 8
Dependent Claim
27 words
A process for inhibiting the attack of a corrosive water system on metals as claimed in claim 2 in which the phosphonic acid has the formula ##STR9##
References Cited (Backward Citations)
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US3803047A
Cited
GB1201334A
Cited
US3483133A
Cited
US3809694A
Cited
US3668138A
Cited
US3901651A
Cited
US3718603A
Cited
US3837803A
Cited
US3974090A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-02-27 | 1981-08-29 | 1982-02-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-02-27 | 1985-08-29 | 1986-02-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-02-27 | 1989-08-29 | 1990-02-28 | $7700.00 | Window Closed / Lapsed |