Patent US2558054A successfully refreshed from Google Patents.
US2558054A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Purification of cellulosic materials
Assignee: Celanese Corp
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Filing: 1949-03-16
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Granted: 1951-06-26
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Expires: 1969-03-16
Abstract
No abstract record available.
Inventors
- 👤 Mervin E Martin
- 👤 Daniel L Sherk
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 21:29
CPC Classifications
D; D21; D21C; D21C9/00; D21C9/08; D21C9/083
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
179 words
IN A PROCESS FOR PURIFYING CELLULOSIC MATERIALS, THE STEPS WHICH COMPRISES TREATING SAID CELLULOSIC MATERIALS FOR BETWEEN ABOUT 15 AND 30 MINUTES AT A TEMPERATURE OF BETWEEN ABOUT 120 AND 135* C. WITH A SUFFICIENT QUANTITY OF SODIUM HYDROXIDE HAVING A CONCENTRATION OF BETWEEN ABOUT 0.25 AND 1.25% BY WEIGHT TO FORM A MIXTURE HAVING A CONSISTENCY OF BETWEEN ABOUT 1 AND 12% BY WEIGHT, TREATING SAID CELLULOSIC MATERIALS IN THE FORM OF AN AQUEOUS MIXTURE HAVING A CONSISTENCY OF BETWEEN ABOUT 2.0 AND 3.5% BY WEIGHT WITH CHLORINE IN AN AMOUNT OF FROM ABOUT 50 TO 70% OF THE CHLORINE DEMAND OF THE CELLULOSIC MATERIAL FOR BETWEEN ABOUT 30 AND 60 MINUTES AT A TEMPERATURE BETWEEN ABOUT 10 AND 30* C., AND TREATING SAID CELLULOSIC MATERIALS FOR UP TO ABOUT 30 MINUTES AT A TEMPERATURE BETWEEN ABOUT 160 AND 185* C. WITH A SUFFICIENT QUANTITY OF AN AQUEOUS SOLUTION OF SODIUM HYDROXIDE HAVING A CONCENTRATION OF BETWEEN ABOUT 0.1 AND 5.0% BY WEIGHT TO FORM A MIXTURE HAVING A CONSISTENCY OF BETWEEN ABOUT 1 AND 12% BY WEIGHT.
Claim 2
Dependent Claim
179 words
IN A PROCESS FOR PURIFYING CELLULOSIC MATERIALS, THE STEPS WHICH COMPRISES TREATING SAID CELLULOSIC MATERIALS FOR BETWEEN ABOUT 15 AND 30 MINUTES AT A TEMPERATURE OF BETWEEN ABOUT 120 AND 135* C. WITH A SUFFICIENT QUANTITY OF SODIUM HYDROXIDE HAVING A CONCENTRATION OF BETWEEN ABOUT 0.25 AND 1.25% BY WEIGHT TO FORM A MIXTURE HAVING A CONSISTENCY OF BETWEEN ABOUT 1 AND 12% BY WEIGHT, TREATING SAID CELLULOSIC MATERIALS IN THE FORM OF AN AQUEOUS MIXTURE HAVING A CONSISTENCY OF BETWEEN ABOUT 2.0 AND 3.5% BY WEIGHT WITH CHLORINE IN AN AMOUNT OF FROM ABOUT 50 TO 70% OF THE CHLORINE DEMAND OF THE CELLULOSIC MATERIAL FOR BETWEEN ABOUT 30 AND 60 MINUTES AT A TEMPERATURE BETWEEN ABOUT 10 AND 30* C., AND TREATING SAID CELLULOSIC MATERIALS FOR UP TO ABOUT 30 MINUTES AT A TEMPERATURE BETWEEN ABOUT 160 AND 185* C. WITH A SUFFICIENT QUANTITY OF AN AQUEOUS SOLUTION OF SODIUM HYDROXIDE HAVING A CONCENTRATION OF BETWEEN ABOUT 0.1 AND 5.0% BY WEIGHT TO FORM A MIXTURE HAVING A CONSISTENCY OF BETWEEN ABOUT 1 AND 12% BY WEIGHT.
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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) | 1954-06-25 | 1954-12-25 | 1955-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-06-25 | 1958-12-25 | 1959-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-06-25 | 1962-12-25 | 1963-06-26 | $7700.00 | Window Closed / Lapsed |