US4617129A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Scale inhibition
Assignee: FMC Corp
•
Filing: 1985-07-03
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Granted: 1986-10-14
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Expires: 2005-07-03
Abstract
Abstract Method of inhibiting the precipitation of calcium carbonate from an aqueous system, comprises adding to the aqueous system a scale precipitation inhibiting amount of bis(phosphonomethylene) aminomethylene carboxylic acid. Typical aqueous systems usefully treated by the new method are water- or oil well systems, cooling water systems, steam generating systems, sea-water evaporators, hydrostatic cookers, gas-scrubbing systems, closed circuit heating systems, reverse-osmosis systems and aqueous-based refrigeration systems.
Inventors
- 👤 Michael J. Lees
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 03:45
CPC Classifications
C; C02; C02F; C02F5/00; C02F5/08; C02F5/10; C02F5/14; C23; C23F; C23F14/00; C23F14/02; Y; Y10; Y10S; Y10S166/00; Y10S166/902; Y10S507/00; Y10S507/927
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
37 words
A method of inhibiting the precipitation of calcium carbonate from an aqeuous system, comprising adding to the aqueous system an effective precipitation inhibiting amount of bis(phosphonomethylene) aminomethylene carboxylic acid to inhibit said precipitation of said calcium carbonate.
Claim 2
Independent Claim
37 words
A method of inhibiting the precipitation of calcium carbonate from an aqeuous system, comprising adding to the aqueous system an effective precipitation inhibiting amount of bis(phosphonomethylene) aminomethylene carboxylic acid to inhibit said precipitation of said calcium carbonate.
Claim 3
Dependent Claim
29 words
Method according to claim 1 wherein the amount of bis(phosphonomethylene) aminomethylene carboxylic acid added to the aqueous system is from 1 to 200 ppm, based on the aqueous system.
Claim 4
Dependent Claim
29 words
Method according to claim 2 wherein the amount of bis(phosphonomethylene) aminomethylene carboxylic acid added to the aqueous system is from 1 to 30 ppm, based on the aqueous system.
References Cited (Backward Citations)
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GB1438079A
Cited
US4079006A
Cited
US3932303A
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US4033896A
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US4501667A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-10-13 | 1990-04-14 | 1990-10-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-10-13 | 1994-04-14 | 1994-10-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-10-13 | 1998-04-14 | 1998-10-14 | $7700.00 | Window Closed / Lapsed |