US3442803A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thickened friction reducer for waterbased oil well treating fluids
Assignee: Calgon Corp
•
Filing: 1966-01-19
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Granted: 1969-05-06
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Expires: 1986-01-19
Abstract
No abstract record available.
Inventors
- 👤 Merwin Frederick Hoover
- 👤 John J Padden
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:58
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/60; C09K8/62; Y; Y10; Y10S; Y10S507/00; Y10S507/903; Y10S507/922; Y10T; Y10T137/00; Y10T137/0318; Y10T137/0391
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-05-05 | 1972-11-04 | 1973-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-05-05 | 1976-11-04 | 1977-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-05-05 | 1980-11-04 | 1981-05-06 | $7700.00 | Window Closed / Lapsed |