US2735858A
Expired / Lapsed
US
⏱️ 0.0 years remaining
bergman
Assignee: —
•
Filing: —
•
Granted: 1956-02-21
•
Expires: 1973-02-21
Abstract
No abstract record available.
Inventors
No inventors recorded.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 09:37
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/02; C09K8/03; C09K8/035
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
46 words
A METHOD FOR PRODUCING A DRILLING MUD ADDITIVE WHICH COMPRISES LEACHING, WITH WATER, THE TANNINS FROM TANNIN CONTAINING VEGETABLE MATTER; ADDING SODIUM METAALUMINATE TO THE RESULTING NON-ALKALINE AQUEOUS EXTRACT, THUS PRECIPITATING ALUMINUM TANNATE; AND SEPARATING, AS A DRILLING MUD ADDITIVE, ALUMINUM TANNATE FROM THE AQUEOUS PHASE.
References Cited (Backward Citations)
US517626A
Cited
GB190718773A
Cited
US1516641A
Cited
DE479229C
Cited
US1999766A
Cited
US2109858A
Cited
US2557657A
Cited
US2636857A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1959-02-20 | 1959-08-22 | 1960-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-02-20 | 1963-08-22 | 1964-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-02-20 | 1967-08-22 | 1968-02-21 | $7700.00 | Window Closed / Lapsed |