US3701712A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for treating cellulosic materials with alkali and oxygen in the presence of complex magnesium salts
Assignee: Mo och Domsjo AB
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Filing: 1971-02-26
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Granted: 1972-10-31
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Expires: 1991-02-26
Abstract
Abstract A PROCESS IS PROVIDED FOR TREATING CELLULOSIC METERIALS WITH ALKALI IN THE PRESENCE OF OXYGEN, AND PRTICULARLY AIR, AND IN THE PRESENCE OF COMPLEX MAGNESIUM SALTS OF AMINOPOLYCARBOXYLIC ACIDS OF ALKALI METAL SALTS THEREOF. THE INVENTION IS OF PARTICULAR APPLICATION TO THE REDUCTION OF LIGNIN CONTENT IN CELLULOSE PULPS AND THE DIGESTION OF WOOD CELLULOSE WITHOUT CAUSING DELETERIOUS DEGRADATION OF THE CELLULOSE, THE COMPLEX MAGNESIUM SALTS REDICING OR ENTIRELY PREVENTING ATTACK OF OXYGEN ON HEMICELLULOSE AND CELLULOSE CARBOHYDRATES, WITHOUT APPRECIABLY DIMINISHING THE OXIDATION OF THE LIGNIN AND ITS DISSOLUTION IN THE COURSE OF THE PROCESS.
Inventors
- 👤 Hans Olof Samuelson
- 👤 Sture Erik Olof Noreus
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 03:31
CPC Classifications
C; C08; C08B; C08B1/00; C08B1/08; D; D21; D21C; D21C9/00; D21C9/10; D21C9/1026; D21C9/1036
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) | 1975-10-31 | 1976-05-01 | 1976-10-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-31 | 1980-05-01 | 1980-10-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-31 | 1984-05-01 | 1984-10-31 | $7700.00 | Window Closed / Lapsed |