US3758449A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Drilling fluid stabilizer
Assignee: Dow Produktions und Vertriebs GmbH and Co OHG
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Filing: 1971-06-29
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Granted: 1973-09-11
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Expires: 1991-06-29
Abstract
Abstract A DRILLING FLUID STABILIZER COMPRISING A HYDROLYSIS PRODUCT OF POLYACRYONITRILE WITH AN AMOUNT OF HYDROLYSED AND NONHYDROLYSED NITRILE GROUPS, THE HYDROLYSED NITRILE GROUPS CONSISTING OF CARBOXYLIC ACID AMIDE GROUPS AND AMMONIUM CARBOXYLATE GROUPS.
Inventors
- 👤 L Hoppe
- 👤 D Dobbertin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:53
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/02; C09K8/03; C09K8/035; C08; C08F; C08F8/00; C08F8/12
Claims Analysis
Total Claims: 0
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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) | 1976-09-10 | 1977-03-12 | 1977-09-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-10 | 1981-03-12 | 1981-09-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-10 | 1985-03-12 | 1985-09-11 | $7700.00 | Window Closed / Lapsed |