US4048065A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control of corrosion and scale in circulating water systems by means of partial esters of polyfunctional organic acids
Assignee: Wyeth Holdings LLC
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Filing: 1975-07-17
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Granted: 1977-09-13
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Expires: 1995-07-17
Abstract
Abstract For inhibiting corrosion and scale on ferrous metal parts in a circulating water system there is added to the water in such system from 10 to 500 ppm of a partial ester of a polyfunctional acid having a free carboxylate, phosphonate or sulfonate group and another carboxyl group which is esterified with a polyoxyalkylated derivative of an alkyl, alkaryl, or alkenyl alcohol having a terminal hydrocarbon group of 8-20 carbon atoms. In some preferred embodiments there is added with the partial ester from 10 to 500 ppm of a dispersible enhancing agent which may also include a surface active agent for dispersing the agent in water. Preferred partial esters include partial esters of citric, malic, tartaric, maleic, adipic and phthalic acids partially esterified with an alkyl polyoxyethylene alcohol having 2 to 4 ethoxy groups.
Inventors
- 👤 Tzeng Jiueq Suen
- 👤 Arthur James Begala, Jr.
- 👤 Martin Grayson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 04:53
CPC Classifications
C; C23; C23F; C23F11/00; C23F11/08; C23F11/10; C23F11/12; C23F11/128; C02; C02F; C02F5/00; C02F5/08; C02F5/10; C23F11/167; C23F11/1676
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
75 words
A process for inhibiting corrosion and scale on ferrous metal surfaces in a circulating water system comprising the addition to circulating water in said system of from 10 - 500 parts per million parts water of additive selected from compounds having the formula: ##STR19## wherein: R is H or --(CH 2 ) x-2 CH 3 x = 10 to 18 y = 0 or X n = 0 or 1 m = 0 or 1
Claim 2
Dependent Claim
75 words
A process for inhibiting corrosion and scale on ferrous metal surfaces in a circulating water system comprising the addition to circulating water in said system of from 10 - 500 parts per million parts water of additive selected from compounds having the formula: ##STR19## wherein: R is H or --(CH 2 ) x-2 CH 3 x = 10 to 18 y = 0 or X n = 0 or 1 m = 0 or 1
Claim 3
Dependent Claim
60 words
A process for inhibiting corrosion and scale on ferrous metal surfaces in a circulating water system comprising, the addition to circulating water in said system of from 10 to 500 parts per million parts water of additive selected from compounds of the formula: ##STR20## wherein: R = alkyl of C 6 - C 14 , and m = 1 -3
Claim 4
Dependent Claim
60 words
A process for inhibiting corrosion and scale on ferrous metal surfaces in a circulating water system comprising, the addition to circulating water in said system of from 10 to 500 parts per million parts water of additive selected from compounds of the formula: ##STR20## wherein: R = alkyl of C 6 - C 14 , and m = 1 -3
Claim 5
Dependent Claim
197 words
A process for inhibiting corrosion and scale on ferrous metal surfaces in a circulating water system comprising the addition to circulating water in said system an effective amount of additive selected from partial ester compounds having the formula: ##STR21## R is a hydrocarbon radical having 8 to 20 carbon atoms selected from alkyl, alkenyl, cycloalkyl and arylalkyl; m is a value from 1 to 5; Z is hydrogen or methyl; Y is selected from alkylene or arylene having 2 to 8 carbon atoms, ##STR22## where n is from 2 to 6, ##STR23## where n is from zero to 3, ##STR24## wherein R' is alkyl or alkenyl of 1 - 12 carbon atoms, ##STR25## where y is ≦ x, where x ≦ 300, and ##STR26## wherein x is ≧ 0, x = y ≧ z, where x + y ≦ 300 and R' is phenyl or a hydrocarbon radical of from 10 to 18 carbon atoms, and wherein m and Z are as defined before, and M is selected from hydrogen, ammonium, alkylammonium, polyalkylammonium, alkali metal, or alkali earth metal; and X is selected from COOM, PO(OM) 2 and SO 3 M wherein M is as defined before.
Claim 6
Dependent Claim
197 words
A process for inhibiting corrosion and scale on ferrous metal surfaces in a circulating water system comprising the addition to circulating water in said system an effective amount of additive selected from partial ester compounds having the formula: ##STR21## R is a hydrocarbon radical having 8 to 20 carbon atoms selected from alkyl, alkenyl, cycloalkyl and arylalkyl; m is a value from 1 to 5; Z is hydrogen or methyl; Y is selected from alkylene or arylene having 2 to 8 carbon atoms, ##STR22## where n is from 2 to 6, ##STR23## where n is from zero to 3, ##STR24## wherein R' is alkyl or alkenyl of 1 - 12 carbon atoms, ##STR25## where y is ≦ x, where x ≦ 300, and ##STR26## wherein x is ≧ 0, x = y ≧ z, where x + y ≦ 300 and R' is phenyl or a hydrocarbon radical of from 10 to 18 carbon atoms, and wherein m and Z are as defined before, and M is selected from hydrogen, ammonium, alkylammonium, polyalkylammonium, alkali metal, or alkali earth metal; and X is selected from COOM, PO(OM) 2 and SO 3 M wherein M is as defined before.
Claim 7
Dependent Claim
24 words
The process of claim 3 wherein the partial ester compound is added at a concentration of from 10 -500 parts per million parts water.
Claim 8
Dependent Claim
30 words
The process of claim 4 further comprising the addition of from 10-500 parts per million parts water of a selected dispersible hydrocarbon or vegetable oil dispersed in said circulating water.
Claim 9
Dependent Claim
15 words
The process defined by claim 3 wherein X is COOM as defined in the formula.
Claim 10
Dependent Claim
16 words
The process defined by claim 6 wherein Z is hydrogen and m is 2 to 4.
Claim 11
Dependent Claim
13 words
The process of claim 7 wherein R is alkyl having 10-14 carbon atoms.
Claim 12
Dependent Claim
9 words
The process of claim 8 wherein m is 3.
References Cited (Backward Citations)
US2950310A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-09-12 | 1981-03-14 | 1981-09-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-09-12 | 1985-03-14 | 1985-09-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-09-12 | 1989-03-14 | 1989-09-13 | $7700.00 | Window Closed / Lapsed |