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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: 1974-03-29
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Granted: 1976-08-10
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Expires: 1994-03-29
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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 oil which may also include a surface active agent for dispersing the oil 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 2026-11-08 05:33
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; C23F11/12; C23F11/128; C23F11/16; C23F11/163

Claims Analysis

Total Claims: 11
Claim 1
Independent Claim 150 words
A process of 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 having the formula ##EQU1## wherein: 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, ##EQU2## wherein W is hydrogen or hydroxy, ##EQU3## wherein m and Z are as defined before, and M is a member selected from the group consisting of hydrogen, ammonium, alkylammonium, polyalkylammonium, alkali metal, and alkaline earth metal; and X is a member selected from the group consisting of COOM, PO(OM) 2 and SO 3 M wherein M is as defined before.
Claim 2
Dependent Claim 150 words
A process of 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 having the formula ##EQU1## wherein: 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, ##EQU2## wherein W is hydrogen or hydroxy, ##EQU3## wherein m and Z are as defined before, and M is a member selected from the group consisting of hydrogen, ammonium, alkylammonium, polyalkylammonium, alkali metal, and alkaline earth metal; and X is a member selected from the group consisting of COOM, PO(OM) 2 and SO 3 M wherein M is as defined before.
Claim 3
Dependent Claim 15 words
A process defined by claim 1 wherein X is COOM as defined in the formula.
Claim 4
Dependent Claim 16 words
A process defined by claim 2 wherein Z is hydrogen and m is 2 to 4.
Claim 5
Dependent Claim 16 words
A process defined by claim 3 wherein R is alkyl having 10 to 14 carbon atoms.
Claim 6
Dependent Claim 10 words
A process defined by claim 4 wherein m is 3.
Claim 7
Dependent Claim 10 words
A process defined by claim 5 wherein Y is ##STR4##
Claim 8
Dependent Claim 15 words
A process defined by claim 5 wherein Y is -- CH = CH -- .
Claim 9
Dependent Claim 12 words
A process defined by claim 5 wherein Y is selected from ##STR5##
Claim 10
Dependent Claim 35 words
A process defined by claim 1 further comprising the addition of from 10 to 500 parts per million water of a dispersible oil selected from hydrocarbon oils and vegetable oils dispersed in said circulating water.
Claim 11
Dependent Claim 31 words
A process defined by claim 9 wherein said oil is a light oil petroluem fraction dispersed by means of a nonionic ethylene oxide adduct type of surfactant additive in said water.

References Cited (Backward Citations)

US2950310A Cited
US3360544A Cited
US3293176A Cited
US3453345A Cited
US3607762A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1979-08-10 1980-02-09 1980-08-10 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1983-08-10 1984-02-09 1984-08-10 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1987-08-10 1988-02-09 1988-08-10 $7700.00 Window Closed / Lapsed

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