Patent US2997365A successfully refreshed from Google Patents.
US2997365A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of regenerated cellulose filaments
Assignee: Akzo Nobel UK PLC
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Filing: 1959-07-30
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Granted: 1961-08-22
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Expires: 1979-07-30
Abstract
No abstract record available.
Inventors
- 👤 Smith John Oliver
- 👤 Tyler David Nicholson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 17:18
CPC Classifications
D; D01; D01F; D01F2/00; D01F2/06; D01F2/08
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
168 words
A PROCESS FOR THE PRODUCTION OF VISCOSE RAYON FILAMENTS COMPRISING EXTRUDING VISCOSE HAVING A CELLULOSE CONTENT BETWEEN 4 AND 6 PERCENT AND A CAUSTIC SODA CONTENT APPROXIMATELY HALF THAT OF THE CELLULOSE, THE CELLULOSE HAVING AN AVERAGE DEGREE OF POLYMERIZATION OF AT LEAST 300 AND THE VISCOSE HAVING A SALT FIGURE OF AT LEAST 10 AND A BALL FALL VISCOSITY BETWEEN ABOUT 50 AND ABOUT 200 SECONDS AT 18* C., INTO A COAGULATING BATH CONTAINING FROM 2.0 PERCENT TO 3.5 PERCENT OF SULPHURIC ACID, LESS THAN 15 PERCENT SODIUM SULPHATE, AND NOT MORE THAN 0.02 PERCENT OF ZINC SULPHATE AS AN IMPURITY, TO FORM FILAMENTS, MAINTAINING THE BATH TEMPERATURE BETWEEN 20* C. AND 30* C., REMOVING THE FILAMENTS FROM THE BATH WHILE THEY ARE STILL CAPABLE OF BEING STRETCHED IN AIR AT LEAST 80% OF THEIR ORIGINAL LENGTH, STRETCHING THE FILAMENTS IN AIR IMMEDIATELY AFTER THEY HAVE BEEN REMOVED FROM THE BATH BY AT LEAST 80% AND COMPLETING THE REGENERATION OF THE FILAMENTS AFTER THEY HAVE BEEN STRETCHED.
Claim 2
Dependent Claim
168 words
A PROCESS FOR THE PRODUCTION OF VISCOSE RAYON FILAMENTS COMPRISING EXTRUDING VISCOSE HAVING A CELLULOSE CONTENT BETWEEN 4 AND 6 PERCENT AND A CAUSTIC SODA CONTENT APPROXIMATELY HALF THAT OF THE CELLULOSE, THE CELLULOSE HAVING AN AVERAGE DEGREE OF POLYMERIZATION OF AT LEAST 300 AND THE VISCOSE HAVING A SALT FIGURE OF AT LEAST 10 AND A BALL FALL VISCOSITY BETWEEN ABOUT 50 AND ABOUT 200 SECONDS AT 18* C., INTO A COAGULATING BATH CONTAINING FROM 2.0 PERCENT TO 3.5 PERCENT OF SULPHURIC ACID, LESS THAN 15 PERCENT SODIUM SULPHATE, AND NOT MORE THAN 0.02 PERCENT OF ZINC SULPHATE AS AN IMPURITY, TO FORM FILAMENTS, MAINTAINING THE BATH TEMPERATURE BETWEEN 20* C. AND 30* C., REMOVING THE FILAMENTS FROM THE BATH WHILE THEY ARE STILL CAPABLE OF BEING STRETCHED IN AIR AT LEAST 80% OF THEIR ORIGINAL LENGTH, STRETCHING THE FILAMENTS IN AIR IMMEDIATELY AFTER THEY HAVE BEEN REMOVED FROM THE BATH BY AT LEAST 80% AND COMPLETING THE REGENERATION OF THE FILAMENTS AFTER THEY HAVE BEEN STRETCHED.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-08-21 | 1965-02-20 | 1965-08-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-08-21 | 1969-02-20 | 1969-08-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-08-21 | 1973-02-20 | 1973-08-22 | $7700.00 | Window Closed / Lapsed |