US3156520A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dyestuffs and alkali metal salts of wood sugar acids and lignin sulfonates
Assignee: Primerica Inc
•
Filing: 1963-04-01
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Granted: 1964-11-10
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Expires: 1983-04-01
Abstract
No abstract record available.
Inventors
- 👤 Leroy A Blaisdell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:17
CPC Classifications
C; C09; C09B; C09B67/00; C09B67/0071; Y; Y10; Y10S; Y10S8/00; Y10S8/908
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
97 words
A DYESTUFF PASTE OF IMPROVED STABILITY AND REDISPERSIBILITY COMPRISING A WATER-DISPERSED SOLID DYESTUFF AND A MODIFYING ADDITIVE OBTAINED BY ADDING AN EXCESS OF LIME TO SPENT SULFITE LIQUOR, FILTERING TO REMOVE SOLIDS COMPRISING CALCIUM LIGNOSULFONATE, TREATING THE FILTRATE WITH CARBON DIOXIDE TO PRECIPITATE FREE LIME AS CALCIUM CARBONATE, ADDING SUFFICIENT ALKALI METAL CARBONATE TO CONVERT THE CALCIUM SALTS OF THE WOOD SUGAR ACIDS AND LIGNOSULFONIC ACIDS TO ALKALI METAL SALTS, FILTERING TO REMOVE CALCIUM CARBONATE AND CONCENTRATING THE FILTRATE TO OBTAIN THE ALKALI METAL SALTS OF WOOD SUGAR ACIDS AND LIGNOSULFONIC ACIDS SUBSTANTIALLY FREE OF LIME-PRECIPITABLE LIGNOSULFONATES.
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US2067926A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1967-11-10 | 1968-05-11 | 1968-11-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1971-11-10 | 1972-05-11 | 1972-11-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1975-11-10 | 1976-05-11 | 1976-11-10 | $7700.00 | Window Closed / Lapsed |