US3684779A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Maleic/acrylic/alkenyl phosphonate terpolymers
Assignee: JOHN N RAPKO
•
Filing: 1971-04-07
•
Granted: 1972-08-15
•
Expires: 1991-04-07
Abstract
Abstract Maleic/acrylic/alkenyl phosphonate terpolymers are useful as sequestrants and for inhibition of deposition of metal ion precipitates from aqueous solutions.
Inventors
- 👤 John N Rapko
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 12:54
CPC Classifications
C; C08; C08F; C08F22/00; C02; C02F; C02F5/00; C02F5/08; C02F5/10; C02F5/14; C08F20/00; C08F20/62; C08F30/00; C08F30/02
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
19 words
The terpolymer of claim 1 wherein said maleic monomer is maleic anhydride and said acrylic monomer is acrylic acid.
Claim 2
Dependent Claim
14 words
The terpolymer of claim 2 wherein said alkenyl phosphonate monomer is diethyl vinyl phosphonate.
Claim 3
Dependent Claim
14 words
The terpolymer of claim 2 wherein said alkenyl phosphonate monomer is diethyl allyl phosphonate.
Claim 4
Dependent Claim
12 words
The terpolymer of claim 2 in the form of the sodium salt.
References Cited (Backward Citations)
US2636027A
Cited
US3227696A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-15 | 1976-02-14 | 1976-08-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-15 | 1980-02-14 | 1980-08-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-15 | 1984-02-14 | 1984-08-15 | $7700.00 | Window Closed / Lapsed |