Patent US4460477A successfully refreshed from Google Patents.
US4460477A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Use of a carboxylic functional polyampholyte to inhibit the precipitation and deposit of scale in aqueous systems
Assignee: ECC SPECIALTY CHEMICALS Inc
•
Filing: 1982-08-25
•
Granted: 1984-07-17
•
Expires: 2002-08-25
Abstract
Abstract The instant invention is directed to a method of inhibiting the precipitation and deposition of scale in an aqueous system comprising adding an effective amount, preferably at least 0.1 ppm, of a carboxylic functional polyampholyte, or the salt thereof, to said aqueous system.
Inventors
- 👤 Christine A. Costello
- 👤 Gary F. Matz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:52
CPC Classifications
C; C23; C23F; C23F11/00; C23F11/08; C23F11/10; C23F11/173; C02; C02F; C02F5/00; C02F5/08; C02F5/10; C02F5/12; C02F5/14; C08; C08F; C08F220/00; C08F220/02; C08F220/04; C08F220/52; C08F220/54; C09; C09K; C09K8/00; C09K8/02; C09K8/04; C09K8/14; C09K8/60
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
245 words
A method of inhibiting the precipitation and deposition of calcium phosphate in an aqueous system comprising adding to the aqueous system at least 0.1 ppm, of a carboxylic functional polyampholyte, or the salt thereof, having an intrinsic viscosity of 0.05 to 4.3 dl/g measured in 1.0M sodium chloride, prepared from: (i) 22.5 to 90%, by weight, of at least one carboxylic functional monomer of the formula: ##STR5## wherein R, which may be the same or different, is hydrogen or an alkyl group of from 1 to 3 carbon atoms, R 1 is a straight or branched chain of from 0 to 3 carbon atoms, and X is hydrogen or an alkali or alkaline earth metal; (ii) 2.5 to 20%, by weight, of at least one cationic-containing monomer selected from the group consisting of: ##STR6## wherein R 3 is hydrogen, or an alkyl group of from 1 to 3 carbon atoms, R 4 is a hydrogen or an alkyl group of from 1 to 3 carbon atoms, R 5 is a straight or branched chain of from 1 to 12 carbon atoms, and X is an anion; and (iii) 5 to 67.5%, by weight, of at least one non-ionic monomer of the formula: ##STR7## wherein R 6 is hydrogen, a phenyl or an alkyl group of from 1 to 3 carbon atoms, R 2 , which may be the same or different, is a hydrogen, or an alkyl group of from 1 to 3 carbon atoms.
Claim 2
Independent Claim
245 words
A method of inhibiting the precipitation and deposition of calcium phosphate in an aqueous system comprising adding to the aqueous system at least 0.1 ppm, of a carboxylic functional polyampholyte, or the salt thereof, having an intrinsic viscosity of 0.05 to 4.3 dl/g measured in 1.0M sodium chloride, prepared from: (i) 22.5 to 90%, by weight, of at least one carboxylic functional monomer of the formula: ##STR5## wherein R, which may be the same or different, is hydrogen or an alkyl group of from 1 to 3 carbon atoms, R 1 is a straight or branched chain of from 0 to 3 carbon atoms, and X is hydrogen or an alkali or alkaline earth metal; (ii) 2.5 to 20%, by weight, of at least one cationic-containing monomer selected from the group consisting of: ##STR6## wherein R 3 is hydrogen, or an alkyl group of from 1 to 3 carbon atoms, R 4 is a hydrogen or an alkyl group of from 1 to 3 carbon atoms, R 5 is a straight or branched chain of from 1 to 12 carbon atoms, and X is an anion; and (iii) 5 to 67.5%, by weight, of at least one non-ionic monomer of the formula: ##STR7## wherein R 6 is hydrogen, a phenyl or an alkyl group of from 1 to 3 carbon atoms, R 2 , which may be the same or different, is a hydrogen, or an alkyl group of from 1 to 3 carbon atoms.
Claim 3
Dependent Claim
43 words
The method of claim 1, wherein said polyampholyte is prepared from: (i) 22.5 to 70%, by weight, of said carboxylic functional monomer; (ii) 2.5 to 17.5%, by weight, of said cationic-containing monomer; and (iii) 5 to 67.5%, by weight, of said non-ionic monomer.
Claim 4
Dependent Claim
58 words
The method of claim 1, wherein said carboxylic functional monomer is acrylic acid; said non-ionic, monomer is selected from the group consisting of acrylamide, methacrylamide N,N-dimethyl acrylamide and hydroxypropyl acrylate; and said cationic-containing monomer is selected from the group consisting of diethyldiallyl ammonium chloride, dimethyldiallyl ammonium chloride, methacryloyloxy ethyl trimethyl ammonium, methylsulfate and methacrylamido propyl trimethyl ammonium chloride.
Claim 5
Dependent Claim
13 words
The method of claim 1, wherein said carboxylic functional polyampholyte is a terpolymer.
Claim 6
Dependent Claim
14 words
The method of claim 1, wherein said aqueous system is a cooling water system.
Claim 7
Dependent Claim
14 words
The method of claim 1, wherein said aqueous system is a boiler water system.
Claim 8
Dependent Claim
30 words
The method of claim 1, wherein said aqueous system is a desalination system and said polyampholyte has an intrinsic viscosity above 0.05 but below 2.8 dl/g in 1.0M sodium chloride.
Claim 9
Dependent Claim
14 words
The method of claim 1, wherein said aqueous system is a gas scrubber system.
References Cited (Backward Citations)
US3085916A
Cited
US3752761A
Cited
US4029577A
Cited
US4209398A
Cited
US4164521A
Cited
GB2026517A
Cited
US4271058A
Cited
US4357207A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-07-17 | 1988-01-16 | 1988-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-07-17 | 1992-01-16 | 1992-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-07-17 | 1996-01-16 | 1996-07-17 | $7700.00 | Window Closed / Lapsed |