Patent US3960501A successfully refreshed from Google Patents.
Patent US2760028A successfully refreshed from Google Patents.
Patent US2505818A successfully refreshed from Google Patents.
US2505818A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Solubilizing tanning bark extracts with waste sulfite liquors
Assignee: United States Department of Agriculture
•
Filing: 1946-07-23
•
Granted: 1950-05-02
•
Expires: 1966-07-23
Abstract
No abstract record available.
Inventors
- 👤 Kenneth T Williams
- 👤 Earl F Potter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:25
CPC Classifications
C; C08; C08H; C08H6/00
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
113 words
A METHOD OF SOLUBILIZING THE INSOLUBLE MATERIAL CONTAINED IN AN AQUEOUS EXTRACT OF WESTERN HEMLOCK BARK, COMPRISING MIXING THE AQUEOUS EXTRACT WITH A SULFITE LIQUOR PRODUCED DURING THE COOKING OF WOOD IN THE MANUFACTURE OF WOOD PULP AND MODIFIED SOLELY BY HAVING HAD ITS PH RAISED TO APPROXIMATELY 5 AND ITS ALKALINE EARTH METAL IONS SUBSTANTIALLY REPLACED BY SODIUM IONS, SAID EXTRACT AND SAID LIQUOR BEING MIXED IN SUCH PROPORTIONS THAT ABOUT THREE-FOURTHS OF THE TOTAL DISSOLVED MATERIAL PRESENT IN THE MIXTURE IS DERIVED FROM THE EXTRACT AND THE REMAINDER OF TOTAL DISSOLVED MATERIAL IS DERIVED FROM THE LIQUOR, AND HEATING THIS MIXTURE AT A TEMPERATURE OF ABOUT 180*F. FOR ABOUT THREE HOURS.
References Cited (Backward Citations)
US909343A
Cited
US1063428A
Cited
US940394A
Cited
US1147245A
Cited
US1327105A
Cited
US1563010A
Cited
US2244410A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1953-05-01 | 1953-10-31 | 1954-05-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-05-01 | 1957-10-31 | 1958-05-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-05-01 | 1961-10-31 | 1962-05-02 | $7700.00 | Window Closed / Lapsed |