US4056675A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing regenerated cellulosic fibers
Assignee: Rayonier Inc
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Filing: 1976-02-27
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Granted: 1977-11-01
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Expires: 1996-02-27
Abstract
Abstract Regenerated cellulosic fibers of improved resistance to alkaline treatment are produced by nitrosating and dissolving from 5 to 14% by weight of a cellulosic material in a dialkylacylamide solvent while said solution is maintained at a temperature no greater than 20 DEG C to form a cellulose nitrite ester, and regenerating the cellulose by contacting the cellulose ester with a regenerant. Regeneration of the cellulose occurs before significant oxidation of the cellulose takes place.
Inventors
- 👤 Albin Frank Turbak
- 👤 Richard Benjamin Hammer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 03:47
CPC Classifications
C; C08; C08B; C08B16/00
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
138 words
A process for producing a regenerated cellulosic fiber of improved alkaline resistance comprising nitrosating cellulose with a nitrosating agent selected from the group consisting of an oxide of nitrogen and nitrosyl chloride and dissolving from 5 to 14% by weight of the cellulose in a dialkylacylamide solvent to form a solution of cellulose nitrite ester while said solution is maintained at a temperature no greater than 20° C. and regenerating said cellulose by contacting the cellulose ester solution with a regenerant therefor containing a protonic group, the time at temperature of said cellulose ester solution from completion of dissolution to regeneration ranging from a maximum of 2 hours at a temperature not exceeding 20° C. to a maximum of 60 hours at a temperature below 0° C., said regeneration occurring before significant oxidation of said cellulose takes place.
Claim 2
Dependent Claim
138 words
A process for producing a regenerated cellulosic fiber of improved alkaline resistance comprising nitrosating cellulose with a nitrosating agent selected from the group consisting of an oxide of nitrogen and nitrosyl chloride and dissolving from 5 to 14% by weight of the cellulose in a dialkylacylamide solvent to form a solution of cellulose nitrite ester while said solution is maintained at a temperature no greater than 20° C. and regenerating said cellulose by contacting the cellulose ester solution with a regenerant therefor containing a protonic group, the time at temperature of said cellulose ester solution from completion of dissolution to regeneration ranging from a maximum of 2 hours at a temperature not exceeding 20° C. to a maximum of 60 hours at a temperature below 0° C., said regeneration occurring before significant oxidation of said cellulose takes place.
Claim 3
Dependent Claim
38 words
The process of claim 1 in which the cellulose nitrite ester solution is regenerated in a maximum of 2 hours after completion of dissolution and the temperature of the solution prior to regeneration does not exceed 20° C.
Claim 4
Dependent Claim
36 words
The process of claim 1 in which the cellulose nitrite ester solution is regenerated within 60 hours after dissolution and the temperature of the solution from completion of dissolution to regeneration does not exceed 0° C.
Claim 5
Dependent Claim
23 words
The process of claim 1 in which the solution is maintained at a temperature no greater than 10° C during nitrosation and dissolution.
Claim 6
Dependent Claim
11 words
The process of claim 1, in which the solvent is dimethylformamide.
Claim 7
Dependent Claim
16 words
The process of claim 1 in which the nitrosating agent is N 2 O 4 .
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) | 1980-10-31 | 1981-05-02 | 1981-11-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-31 | 1985-05-02 | 1985-11-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-31 | 1989-05-02 | 1989-11-01 | $7700.00 | Window Closed / Lapsed |