US2511096A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of cellulose
Assignee: Celanese Corp
•
Filing: 1944-10-11
•
Granted: 1950-06-13
•
Expires: 1964-10-11
Abstract
No abstract record available.
Inventors
- 👤 Bate Stanley Charles
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 20:19
CPC Classifications
D; D21; D21C; D21C3/00; D21C3/04; D21C3/045
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
90 words
IN A PROCESS FOR PRODUCING CELLULOSE FROM DECIDUOUS WOOD BY DIGESTING THE MATERIALS BETWEEN 70 AND 110*C. FOR AT MOST 6 HOURS WITH 5-20 TIMES THEIR WEIGHT OF A MIXTURE OF NITRIC ACID AND AQUEOUS ACETIC ACID AND SUBSEQUENTLY WASHING THE MATERIALS WITH ALKALI TO DISSOLVE THEREFROM LIGNIN-OXIDATION PRODUCTS, THE IMPROVEMENT WHICH CONSISTS IN EMPLOYING THE NITRIC ACID IN AMOUTN 8-12% OF THE AIR-DRY WEIGHT OF THE MATERIALS AND THE AQUEOUS ACETIC ACID IN A CONCENTRATION OF 50-90%, AND PASSING OXYEN THROUGH THE SLURRY OF MIXED ACIDS AND CELLULOSIC MATERIAL.
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Cited
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Cited
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Cited
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Cited
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Cited
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Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1953-06-12 | 1953-12-12 | 1954-06-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-06-12 | 1957-12-12 | 1958-06-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-06-12 | 1961-12-12 | 1962-06-13 | $7700.00 | Window Closed / Lapsed |