US2542492A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of viscose
Assignee: Akzo Nobel UK PLC
•
Filing: 1949-04-28
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Granted: 1951-02-20
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Expires: 1969-04-28
Abstract
No abstract record available.
Inventors
- 👤 Entwistle Donald
- 👤 Weigham William Reginald
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:31
CPC Classifications
C; C08; C08B; C08B1/00; C08B1/08; D; D01; D01F; D01F2/00; D01F2/06; D01F2/08
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
122 words
A PROCESS FOR THE PRODUCTION OF VISCOSE WHICH COMPRISES, IN COMBINATION, THE STEPS OF FORMING A SLURRY OF CELLULOSE FIBERS IN AQUEOUS CASTIC SODA SOLUTION CONTAINING FROM 17 TO 25 PER CENT OF CAUSTIC SODA AND COBALT ACETATE IN A PROPORTION NOT EXCEEDING 40 PARTS BY WEIGHT OF COBALT PER MILLION PARTS BY WEIGHT OF SOLUTION, MINATAINING THE TEMPERATURE OF THE SLURRY WITHIN THE RANGE OF 35* TO 45* CENTIGRADE, PASSING A STREAM OF AIR THROUGH THE SLURRY UNTIL THE FLUIDITY OF THE CELLULOSE IS REDUCED TO THE VALUE DESIRED TO VSCOSE PRODUCTION, PRESSING, CONVERTING THE PRESSED ALKALI CELLULOSE WITHOUT FURTHER RIPENING TO CELLULOSE XANTHATE BY REACTION WITH CARBON DISULPHIDE AND DISSOLVING THE CELLULOSE XANTHATE IN AQUEOUS CAUSTIC SODA TO FORM VISCOSE.
References Cited (Backward Citations)
US1860432A
Cited
GB342779A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-02-19 | 1954-08-21 | 1955-02-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-02-19 | 1958-08-21 | 1959-02-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-02-19 | 1962-08-21 | 1963-02-20 | $7700.00 | Window Closed / Lapsed |