US3787319A
Expired / Lapsed
US
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Amine/phosphate composition useful as corrosion and scale inhibitor
Assignee: Marathon Oil Co
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Filing: 1971-10-18
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Granted: 1974-01-22
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Expires: 1991-10-18
Abstract
Abstract A composition useful as a corrosion and scale inhibitor is obtained by reacting an N-secondary alkyl alkylene diamine (e.g., contains an average of eight-20 carbon atoms in the alkyl group and two-four carbons atoms in the alkylene group) and a phosphate ester, obtained for example by reacting about equal molar amounts of polyphosphoric acid and a condensation product of an aliphatic primary alcohol (preferably contains three-six carbon atoms) and at least 1 mole (preferably 1-10 moles) of an alkylene oxide (preferably ethylene oxide). Final reaction product can have a pH of 5 9.
Inventors
- 👤 A Larsen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:30
CPC Classifications
C; C02; C02F; C02F5/00; C02F5/08; C02F5/10; C02F5/14; C23; C23F; C23F11/00; C23F11/08; C23F11/10; Y; Y10; Y10S; Y10S166/00; Y10S166/902; Y10S507/00; Y10S507/939
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
32 words
an N-secondary alkyl alkylene diamine wherein the alkyl group contains an average of about seven to about 31 carbon atoms and the alkylene group contains about two to about four carbon atoms.
Claim 2
Dependent Claim
16 words
The method of claim 1 wherein the alcohol contains about three to about six carbon atoms.
Claim 3
Dependent Claim
32 words
an N-secondary alkyl alkylene diamine wherein the alkyl group contains an average of about seven to about 31 carbon atoms and the alkylene group contains about two to about four carbon atoms.
Claim 4
Dependent Claim
14 words
The method of claim 1 wherein the alkylene grouping of the diamine is trimethylene.
Claim 5
Independent Claim
70 words
A method of inhibiting corrosion of carbon steel wherein the carbon steel is corroded in the presence of a corrosive fluid present in oil and gas wells, the process comprising incorporating in the fluid sufficient amounts to inhibit the corrosion of the carbon steel of a phosphorous containing compound obtained by neutralizing to a pH of about 5 to about 9 at a temperature of less than about 100* F
Claim 6
Dependent Claim
23 words
The process of claim 4 wherein about 2 to about 500 ppm. of the phosphorous containing compound is incorporated into the corrosive fluid.
Claim 7
Dependent Claim
23 words
The process of claim 4 wherein the alkyl group of the diamine contains an average of about 10 to about 20 carbon atoms.
Claim 8
Dependent Claim
16 words
The process of claim 4 wherein the alcohol contains about three to about six carbon atoms.
Claim 9
Dependent Claim
20 words
The process of claim 4 wherein the phosphate ester is neutralized to a pH of about 6.5 to about 7.5.
Claim 10
Dependent Claim
21 words
The process of claim 4 wherein about 1 to about 10 moles of the alkylene oxide is condensed with the alcohol.
Claim 11
Dependent Claim
12 words
The process of claim 9 wherein the alkylene oxide is ethylene oxide.
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) | 1977-01-21 | 1977-07-23 | 1978-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-21 | 1981-07-23 | 1982-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-21 | 1985-07-23 | 1986-01-22 | $7700.00 | Window Closed / Lapsed |