US4650591A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Acrylic acid/2-acrylamido-2-methylpropylsulfonic acid/2-acrylamido-2-methylpropyl phosphonic acid polymers as scale and corrosion inhibitors
Assignee: ECC SPECIALTY CHEMICALS Inc
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Filing: 1985-08-29
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Granted: 1987-03-17
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Expires: 2005-08-29
Abstract
Abstract The present invention is directed to a method of inhibiting corrosion and the precipitation of scale-forming salts in an aqueous system, comprising adding to the system at least 0.1 mg/l of a polymer having an intrinsic viscosity of 0.05 to 4.5 dl/g, in 1.0 M NaCl, prepared from: (A) 35 to 65%, by weight, of acrylic acid or methacrylic acid; (B) 15 to 45%, by weight, of 2-acrylamido-2-methylpropylsulfonic acid or 2-methacrylamido-2-methylpropylsulfonic acid; and (C) 15 to 25%, by weight, of 2-acrylamido-2-methylpropyl phosphonic acid or 2-methacrylamido-2-methylpropylphosphonic acid.
Inventors
- 👤 Jerry E. Boothe
- 👤 Raymond J. Schaper
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 23:39
CPC Classifications
C; C23; C23F; C23F11/00; C23F11/08; C23F11/10; C23F11/173; C02; C02F; C02F5/00; C02F5/08; C02F5/10; C02F5/14
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
79 words
A method of inhibiting corrosion and the precipitation of scale-forming salts in an aqueous system, comprising adding to the system at least 0.1 mg/l of a polymer having an intrinsic viscosity of 0.05 to 4.5 dl/g, in 1.0M NaCl, prepared from: (A) 35 to 65%, by weight, of acrylic acid or methacrylic acid; (B) 15 to 45%, by weight, of 2-acrylamido-2-methylpropylsulfonic acid or 2-methacrylamido-2-methylpropylsulfonic acid; and (C) 15 to 25%, by weight, of 2-acrylamido-2-methylpropyl phosphonic acid or 2-methacrylamido-2-methylpropylphosphonic acid.
Claim 2
Independent Claim
79 words
A method of inhibiting corrosion and the precipitation of scale-forming salts in an aqueous system, comprising adding to the system at least 0.1 mg/l of a polymer having an intrinsic viscosity of 0.05 to 4.5 dl/g, in 1.0M NaCl, prepared from: (A) 35 to 65%, by weight, of acrylic acid or methacrylic acid; (B) 15 to 45%, by weight, of 2-acrylamido-2-methylpropylsulfonic acid or 2-methacrylamido-2-methylpropylsulfonic acid; and (C) 15 to 25%, by weight, of 2-acrylamido-2-methylpropyl phosphonic acid or 2-methacrylamido-2-methylpropylphosphonic acid.
Claim 3
Dependent Claim
18 words
The method of claim 1, wherein 1 to 100 mg/l of said polymer is added to the system.
Claim 4
Dependent Claim
15 words
The method of claim 1, wherein said scale-forming salts are calcium carbonate and calcium phosphate.
Claim 5
Dependent Claim
19 words
The method of claim 1, wherein said polymer is prepared from acrylic acid, 2-acrylamido-2-methylpropylsulfonic acid and 2-acrylamido-2-methylpropyl phosphonic acid.
Claim 6
Dependent Claim
34 words
The method of claim 1, wherein said polymer is prepared from 40 to 60%, by weight, acrylic acid; 20 to 40%, by weight, 2-acrylamido-2-methylpropylsulfonic acid; and 15 to 25%, by weight, 2-acrylamido-2-methylpropyl phosphonic acid.
Claim 7
Dependent Claim
20 words
The method of claim 1, wherein said polymer has an intrinsic viscosity of 0.05 to 2.5 dl/g, in 1.0M NaCl.
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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) | 1990-03-16 | 1990-09-15 | 1991-03-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-03-16 | 1994-09-15 | 1995-03-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-03-16 | 1998-09-15 | 1999-03-17 | $7700.00 | Window Closed / Lapsed |