US3928196A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Inhibition of scale deposition
Assignee: Calgon Corp
•
Filing: 1973-12-05
•
Granted: 1975-12-23
•
Expires: 1993-12-05
Abstract
Abstract Method of inhibiting scale formation in aqueous systems in which copolymers of 2-acrylamido-2-methylpropyl sulfonic acid and acrylic acid are used.
Inventors
- 👤 Leonard John Persinski
- 👤 Paul Hotchkiss Ralston
- 👤 Jr Robert Cornelius Gordon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 07:39
CPC Classifications
C; C02; C02F; C02F5/00; C02F5/08; C02F5/10; C02F5/12
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
66 words
A METHOD OF INHIBITING THE PRECIPITATION OF SCALE FORMING SALTS IN AN AQUEOUS SYSTEM COMPRISING ADDING FROM 1 TO 100 PPM OF A COPOLYMER HAVING A MOLECULAR WEIGHT IN THE RANGE OF FROM ABOUT 1,000 TO ABOUT 10,000 WHEREIN SAID COPOLYMER CONTAINS FROM ABOUT 5 TO ABOUT 75 MOLE % OF 2-ACRYLAMIDO-2METHYLPROPYL SULFONIC ACID AND FROM ABOUT 95 TO ABOUT 25 MOLE % OF ACRYLIC ACID.
Claim 2
Independent Claim
66 words
A METHOD OF INHIBITING THE PRECIPITATION OF SCALE FORMING SALTS IN AN AQUEOUS SYSTEM COMPRISING ADDING FROM 1 TO 100 PPM OF A COPOLYMER HAVING A MOLECULAR WEIGHT IN THE RANGE OF FROM ABOUT 1,000 TO ABOUT 10,000 WHEREIN SAID COPOLYMER CONTAINS FROM ABOUT 5 TO ABOUT 75 MOLE % OF 2-ACRYLAMIDO-2METHYLPROPYL SULFONIC ACID AND FROM ABOUT 95 TO ABOUT 25 MOLE % OF ACRYLIC ACID.
Claim 3
Dependent Claim
27 words
A method as in claim 1 wherein the copolymer is a copolymer of about 25 mole % 2-acrylamido-2-methylpropyl sulfonic acid and about 75 mole % acrylic acid.
References Cited (Backward Citations)
US3709815A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-22 | 1979-06-23 | 1979-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-22 | 1983-06-23 | 1983-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-22 | 1987-06-23 | 1987-12-23 | $7700.00 | Window Closed / Lapsed |