US4589985A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polyelectrolyte and surfactant compositions for controlling alkaline earth metal scales
Assignee: ECC SPECIALTY CHEMICALS Inc
•
Filing: 1984-12-03
•
Granted: 1986-05-20
•
Expires: 2004-12-03
Abstract
Abstract The instant invention is directed to a method of inhibiting the precipitation and deposition of alkaline earth metal scales in an aqueous system, comprising adding to said system an effective amount of (a) an anionic polyelectrolyte; and (b) an anionic surfactant, wherein said polyelectrolyte/surfactant ratio ranges from 1000:1 to 1:10, by weight.
Inventors
- 👤 Monica A. Yorke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 17:17
CPC Classifications
C; C02; C02F; C02F5/00; C02F5/08; C02F5/10; C02F5/12; C02F5/14
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
133 words
A method of inhibiting the precipitation and deposition of alkaline earth metal scales including calcium carbonate in an aqueous system having a pH of at least 8, comprising adding to said system 0.1 to 100 ppm of (a) a water-soluble anionic polyelectrolyte selected from the group of copolymers containing from about 95 mole percent to about 25 mole percent acrylic acid or methacrylic acid and containing from about 5 mole percent to about 75 percent 2-acrylamido-2-methylpropyl sulfonic acid or 2-methacrylamido-2-methylpropyl sulfonic acid, and salts of these polymers; and (b) an anionic surfactant selected from octylphenoxy polyethoxy ethyl phosphate, and sodium or potassium salts thereof, wherein the anionic polyelectrolyte/anionic surfactant ratio ranges from 50:1 to 1:5, by weight, and wherein the molecular weight of said anionic polyelectrolyte ranges from about 1000 to about 20,000.
Claim 2
Independent Claim
133 words
A method of inhibiting the precipitation and deposition of alkaline earth metal scales including calcium carbonate in an aqueous system having a pH of at least 8, comprising adding to said system 0.1 to 100 ppm of (a) a water-soluble anionic polyelectrolyte selected from the group of copolymers containing from about 95 mole percent to about 25 mole percent acrylic acid or methacrylic acid and containing from about 5 mole percent to about 75 percent 2-acrylamido-2-methylpropyl sulfonic acid or 2-methacrylamido-2-methylpropyl sulfonic acid, and salts of these polymers; and (b) an anionic surfactant selected from octylphenoxy polyethoxy ethyl phosphate, and sodium or potassium salts thereof, wherein the anionic polyelectrolyte/anionic surfactant ratio ranges from 50:1 to 1:5, by weight, and wherein the molecular weight of said anionic polyelectrolyte ranges from about 1000 to about 20,000.
Claim 3
Dependent Claim
22 words
The method of claim 1, wherein said anionic polyelectrolyte is a copolymer of acrylic acid and 2-acrylamido-2-methylpropyl sulfonic acid and salts thereof.
References Cited (Backward Citations)
SU279628A1
Cited
US3578589A
Cited
US3692673A
Cited
US3709815A
Cited
US3806367A
Cited
US3898037A
Cited
US3981779A
Cited
US3928196A
Cited
US4062796A
Cited
US3951793A
Cited
US4029577A
Cited
US4146473A
Cited
US4118318A
Cited
US4168230A
Cited
US4153549A
Cited
JPS5594690A
Cited
US4326980A
Cited
US4324664A
Cited
US4427568A
Cited
JPS5892499A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-05-19 | 1989-11-18 | 1990-05-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-05-19 | 1993-11-18 | 1994-05-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-05-19 | 1997-11-18 | 1998-05-20 | $7700.00 | Window Closed / Lapsed |