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US4756881A
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Composition of corrosion inhibitors for cooling water systems using chemically modified acrylamide or methacrylamide polymers
Assignee: Ecolab USA Inc
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Filing: 1986-05-09
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Granted: 1988-07-12
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Expires: 2006-05-09
Abstract
Abstract A composition and method for inhibiting corrosion in industrial cooling waters which contain hardness and have a pH of at least 8, which composition comprises a water-soluble organic phosphonate capable of inhibiting corrosion in an aqueous alkaliine environment and a hydrocarbon polymer containing an N-substituted acrylamide polymer with an amide structure as follows: <IMAGE> where R2 is hydrogen or methyl, R1 is a hydrogen or an alkyl and R is alkylene or phenylene, and X is sulfonate, (poly)hydroxyl, and combinations thereof.
Inventors
- 👤 John E. Hoots
- 👤 Donald A. Johnson
- 👤 Dodd W. Fong
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 12:53
CPC Classifications
C; C23; C23F; C23F11/00; C23F11/08; C23F11/10
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
136 words
A method for inhibiting corrosion in industrial cooling water which contain hardness and have a pH of at least 8 which comprises dosing the cooling water with from 10-50 ppm of a composition comprising: I. A water-soluble organic phosphonate capable of inhibiting corrosion in an aqueous alkaline environment, and II. An effective amount of a hydrocarbon polymer selected from the group consisting of: N-substituted amide polymers containing an amide structure as follows: ##STR8## where R 2 is hydrogen or methyl, where R 1 is a hydrogen or an alkyl and R is alkylene and X is selected from the group consisting of sulfonate, (poly)hydroxyl alkyl with the weight ratio of polymer:phosphonate being within the range of 0.2:1 to 2:1, and where X is sulfonate then R--X-- is selected from the group consisting of sulfomethyl, or 2-sulfoethyl.
Claim 2
Independent Claim
136 words
A method for inhibiting corrosion in industrial cooling water which contain hardness and have a pH of at least 8 which comprises dosing the cooling water with from 10-50 ppm of a composition comprising: I. A water-soluble organic phosphonate capable of inhibiting corrosion in an aqueous alkaline environment, and II. An effective amount of a hydrocarbon polymer selected from the group consisting of: N-substituted amide polymers containing an amide structure as follows: ##STR8## where R 2 is hydrogen or methyl, where R 1 is a hydrogen or an alkyl and R is alkylene and X is selected from the group consisting of sulfonate, (poly)hydroxyl alkyl with the weight ratio of polymer:phosphonate being within the range of 0.2:1 to 2:1, and where X is sulfonate then R--X-- is selected from the group consisting of sulfomethyl, or 2-sulfoethyl.
Claim 3
Dependent Claim
9 words
The method of claim 1 wherein x is sulfomethyl.
Claim 4
Dependent Claim
48 words
The method of claim 1, wherein the polymer is an acrylic acid/acrylamide/sulfomethylacrylamide having a mole ratio of acrylic acid to acrylamide to sulfomethylacrylamide with the range of 13-95 to 0-73 to 5-41 respectively; and wherein the polymer has a weight average molecular weight within the range of 7,000-82,000.
Claim 5
Dependent Claim
44 words
The method of claim 3, wherein the polymer has a mole ratio of acrylic acid to acrylamide to sulfomethylacrylamide within the range of 40-90 to 0-50 to 10-40 respectively; and wherein the polymer has a weight average molecular weight within the range of 10,000-40,000.
Claim 6
Dependent Claim
9 words
The method of claim 1, where X is (2-sulfoethyl).
Claim 7
Dependent Claim
47 words
The method of claim 1 wherein the polymer is an acrylic/acid/acrylamide/2-sulfoethylacrylamide having a mole ratio of acrylic acid to acrylamide to 2-sulfoethylacrylamide within the range of 19-95 to 0-54 to 5-58 respectively; and wherein the polymer has a weight average molecular weight within the range of 6,000-56,000.
Claim 8
Dependent Claim
44 words
The method of claim 6 wherein the polymer has a mole ratio of acrylic acid to acrylamide to 2-sulfoethylacrylamide within the range of 40-90 to 0-50 to 10-40 respectively; and wherein the polymer has a weight average molecular weight within the range of 10,000-40,000.
Claim 9
Dependent Claim
25 words
The method of claim 1, wherein the phosphonate dosage includes a ratio of 2-phosphonobutane-1,2,4-tricarboxylic acid to 1-hydroxyethane-1,1-diphosphonic acid within the range of 0.5:1 to 4:1.
Claim 10
Dependent Claim
22 words
The method of claim 8 wherein said aqueous system is dosed within the range of 8 to 30 ppm with said composition.
References Cited (Backward Citations)
US3332904A
Cited
US3692673A
Cited
US3898037A
Cited
US3880765A
Cited
US4288327A
Cited
US4288327B1
Cited
US4159922A
Cited
US4306991A
Cited
US4324684A
Cited
US4303568A
Cited
US4406811A
Cited
GB2082600A
Cited
US4373056A
Cited
US4384979A
Cited
US4443340A
Cited
US4547540A
Cited
US4581145A
Cited
US4576722A
Cited
US4659482A
Cited
US4600524A
Cited
US4640793A
Cited
US4575425A
Cited
US4650591A
Cited
US4604431A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-07-12 | 1992-01-11 | 1992-07-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-07-12 | 1996-01-11 | 1996-07-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-07-12 | 2000-01-11 | 2000-07-12 | $7700.00 | Window Closed / Lapsed |