Patent US1917394A successfully refreshed from Google Patents.
US4126549A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Treatment of water
Assignee: FMC Technologies Ltd
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Filing: 1977-06-30
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Granted: 1978-11-21
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Expires: 1997-06-30
Abstract
Abstract A process for the prevention of scale and the inhibition of corrosion which comprises adding to water a hydrolyzed terpolymer of maleic anhydride with vinyl acetate and ethyl acrylate, the molar ratio of maleic anhydride to the other monomers being from 2.5:1 to 5:1, the ratio of vinyl acetate to ethyl acrylate being 1:1 to 2:1, and the molecular weight of the terpolymer being below 1000.
Inventors
- 👤 Thomas I. Jones
- 👤 Geoffrey Graham
- 👤 Michael A. Finan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:55
CPC Classifications
C; C23; C23F; C23F11/00; C23F11/08; C23F11/10; C23F11/173; C02; C02F; C02F5/00; C02F5/08; C02F5/10; C08; C08F; C08F22/00; C08F22/04; C08F222/00; C08F222/04; C08F222/06; C08F8/00; C08F8/12; C08F8/44; Y; Y10; Y10S; Y10S507/00; Y10S507/927
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
148 words
A process for the prevention of the deposition of scale from water caused by scale forming materials in the water and the inhibition of corrosion which comprises adding to water 0.1 to 100 parts per million by weight of a hydrolyzed terpolymer of maleic anhydride with two ethylenically unsaturated monomers selected from the group consisting of acrylic acid, methacrylic acid, crotonic acid, itaconic acid, aconitic acid, ethyl acrylate, methyl methacrylate, other esters of said acids, acrylonitrile, acrylamide, vinyl acetate, styrene, α-methylstyrene, methyl vinyl ketone, acrolein, ethylene and propylene, the molar ratio of maleic anhydride to the sum of the moles of the other two monomers being from 2.5:1 to 5:1, the molar ratio of the two monomers to each other being from 1:1 to 2:1, and the molecular weight of the terpolymer, measured by vapor phase osmometry in methyl ethyl ketone solution, being in the range below 1000.
Claim 2
Dependent Claim
148 words
A process for the prevention of the deposition of scale from water caused by scale forming materials in the water and the inhibition of corrosion which comprises adding to water 0.1 to 100 parts per million by weight of a hydrolyzed terpolymer of maleic anhydride with two ethylenically unsaturated monomers selected from the group consisting of acrylic acid, methacrylic acid, crotonic acid, itaconic acid, aconitic acid, ethyl acrylate, methyl methacrylate, other esters of said acids, acrylonitrile, acrylamide, vinyl acetate, styrene, α-methylstyrene, methyl vinyl ketone, acrolein, ethylene and propylene, the molar ratio of maleic anhydride to the sum of the moles of the other two monomers being from 2.5:1 to 5:1, the molar ratio of the two monomers to each other being from 1:1 to 2:1, and the molecular weight of the terpolymer, measured by vapor phase osmometry in methyl ethyl ketone solution, being in the range below 1000.
Claim 3
Dependent Claim
76 words
A process according to claim 1 wherein the hydrolyzed terpolymer is a terpolymer of maleic anhydride either with (a) vinyl acetate and another ethylenically unsaturated monomer selected from the group consisting of ethyl acrylate, acrylamide, methyl vinyl ketone, acrylonitrile and crotonic acid, wherein the molar ratio of vinyl acetate to the other monomer is 1:1 to 2:1, or with (b) a 1:1 molar ratio of methyl methacrylate and ethyl acrylate; or of methyl acrylate and acrolein.
Claim 4
Dependent Claim
22 words
A process according to claim 1 wherein the hydrolyzed terpolymer is a terpolymer of maleic anhydride with vinyl acetate and ethyl acrylate.
Claim 5
Dependent Claim
26 words
A process according to claim 1 wherein the amount of hydrolyzed terpolymer added to the water is from 2 to 100 parts per million by weight.
Claim 6
Dependent Claim
19 words
A process according to claim 1 in which a reactive solvent is used in the preparation of the terpolymer.
Claim 7
Dependent Claim
33 words
A process according to claim 5 in which the reactive solvent used in the preparation of the terpolymer is carbon tetrabromide, carbon tetrachloride, toluene, xylene, methyl ethyl ketone, acetone, acetic acid or ethylbenzene.
Claim 8
Dependent Claim
15 words
A process according to claim 1 in which the terpolymer is finally hydrolyzed with water.
Claim 9
Dependent Claim
14 words
A process according to claim 1 in which the terpolymer is hydrolyzed with alkali.
Claim 10
Dependent Claim
16 words
A process according to claim 1 in which the terpolymer is hydrolyzed with a mineral acid.
References Cited (Backward Citations)
US2723956A
Cited
GB772775A
Cited
US3558570A
Cited
US3617577A
Cited
US3810834A
Cited
US3684779A
Cited
US3715307A
Cited
US3755264A
Cited
GB1414918A
Cited
US4065607A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-11-20 | 1982-05-22 | 1982-11-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-11-20 | 1986-05-22 | 1986-11-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-11-20 | 1990-05-22 | 1990-11-21 | $7700.00 | Window Closed / Lapsed |