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US3933427A
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US
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Process for preventing corrosion and the formation of scale in water circulating system
Assignee: Bayer AG
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Filing: 1973-05-21
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Granted: 1976-01-20
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Expires: 1993-05-21
Abstract
Abstract Preventing corrosion and scale formation in water re-circulating systems by adding to each cubic meter of the water being re-circulated from about 5 to 100 grams of a compound selected from the group consisting of those of the formula ##EQU1## and the water-soluble salts thereof R being hydrogen, alkyl, alkenyl or alkinyl having up to 4 carbon atoms; phenyl; cycloalkyl having 3 to 6 carbon atoms; benzyl; phenethyl or ##EQU2## wherein R' is hydrogen, alkyl having 1 to 4 carbon atoms or carboxyl, R" is hydrogen or methyl and R'" is carboxyl.
Inventors
- 👤 Gerhard Bohnsack
- 👤 Hans Geffers
- 👤 Herbert Kallfass
- 👤 Walter Radt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:21
CPC Classifications
C; C02; C02F; C02F5/00; C02F5/08; C02F5/10; C02F5/14; C02F5/145; C23; C23F; C23F11/00; C23F11/08; C23F11/10; C23F11/167; C23F11/1676
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
99 words
A process for preventing corrosion and the formation of scale in a water re-circulating system which comprises adding to each cubic meter of the water being re-circulated from about 5 to 100 grams of a compound selected from the group consisting of those of the formula ##EQU6## and the water-soluble salts thereof, R being hydrogen, alkyl, alkenyl or alkinyl having up to 4 carbon atoms; phenyl; cycloalkyl having 3 to 6 carbon atoms; benzyl; phenethyl or ##EQU7## wherein R' is hydrogen, alkyl having 1 to 4 carbon atoms or carboxyl, R" is hydrogen or methyl and R'" is carboxyl.
Claim 2
Dependent Claim
99 words
A process for preventing corrosion and the formation of scale in a water re-circulating system which comprises adding to each cubic meter of the water being re-circulated from about 5 to 100 grams of a compound selected from the group consisting of those of the formula ##EQU6## and the water-soluble salts thereof, R being hydrogen, alkyl, alkenyl or alkinyl having up to 4 carbon atoms; phenyl; cycloalkyl having 3 to 6 carbon atoms; benzyl; phenethyl or ##EQU7## wherein R' is hydrogen, alkyl having 1 to 4 carbon atoms or carboxyl, R" is hydrogen or methyl and R'" is carboxyl.
Claim 3
Dependent Claim
22 words
The process of claim 1 wherein the compound of said formula is 2-phosphono-butane-tricarboxylic acid-(1,2,4) or a water soluble base addition salt thereof.
Claim 4
Dependent Claim
18 words
The process of claim 1 wherein an additional corrosion inhibitor is added to said water to be re-circulated.
Claim 5
Dependent Claim
17 words
The process of claim 3 wherein said additional corrosion inhibitor introduces phosphate or zinc ions into solution.
Claim 6
Dependent Claim
19 words
The process of claim 1 wherein the salt added to said water is the zinc salt of 2-phosphono-butane-tricarboxylic acid-(1,2,4).
Claim 7
Dependent Claim
16 words
The process of claim 1 wherein said water re-circulating system is a cooling water circulating system.
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) | 1979-01-19 | 1979-07-21 | 1980-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-01-19 | 1983-07-21 | 1984-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-01-19 | 1987-07-21 | 1988-01-20 | $7700.00 | Window Closed / Lapsed |