Patent US3639645A successfully refreshed from Google Patents.
US3639645A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Scale inhibiting composition and method using phosphonic acid and di- or hydroxy-carboxylic acid
Assignee: Solvay Solutions UK Ltd
•
Filing: 1969-02-28
•
Granted: 1972-02-01
•
Expires: 1989-02-28
Abstract
Abstract SYNERGISTIC THRESHOLD COMPOSITION COMPRISING AN ALKYLENE POLYAMINO METHYLENE PHOSPHONIC ACID SUCH AS EDTMP AND A DI- OR HYDROXY-CARBOXYLIC ACID.
Inventors
- 👤 Glyn Miller
- 👤 Graham Michael Smart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 20:42
CPC Classifications
C; C23; C23F; C23F11/00; C23F11/08; C23F11/10; C02; C02F; C02F5/00; C02F5/08; C02F5/10; C02F5/14
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-31 | 1975-08-02 | 1976-02-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-31 | 1979-08-02 | 1980-02-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-31 | 1983-08-02 | 1984-02-01 | $7700.00 | Window Closed / Lapsed |