Patent US4076932A successfully refreshed from Google Patents.
US4076932A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing regenerated cellulosic articles
Assignee: Rayonier Inc
•
Filing: 1976-02-27
•
Granted: 1978-02-28
•
Expires: 1996-02-27
Abstract
Abstract Regenerated cellulosic articles are produced by nitrosating and dissolving cellulose in a dialkylacylamide solvent, such as dimethylformamide, and regenerating the dissolved cellulose by passing into a coagulant bath. The coagulant comprises water or a 1 to 4 carbon atom aliphatic monohydric alcohol and a soluble reactive base, the latter in an amount ranging from 6% to 25% by weight of the regenerant. The process produces regenerated cellulose products of improved resistance to alkaline solubility.
Inventors
- 👤 Richard Benjamin Hammer
- 👤 Albin Frank Turbak
- 👤 Norman A. Portnoy
- 👤 Arthur C. West
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 15:10
CPC Classifications
C; C08; C08B; C08B5/00; C08B16/00
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
124 words
In a process for producing a regenerated cellulosic article comprising nitrosating cellulose with a nitrosating agent selected from the group consisting of an oxide of nitrogen and nitrosyl chloride and dissolving the cellulose in a dialkylacylamide solvent and then regenerating the dissolved cellulose by contacting the dissolved cellulose with a regenerant, said process introducing substantial quantities of nitric acid into the regenerant, the improvement in which the regenerant comprises a liquid selected from the group consisting of water and a 1 - 4 carbon atom aliphatic monohydric alcohol, and a reactive base which is soluble in the regenerant in an amount ranging from 6% to 25% by weight of the regenerant, said improvement producing a regenerated cellulosic article of improved resistance to alkaline solubility.
Claim 2
Dependent Claim
124 words
In a process for producing a regenerated cellulosic article comprising nitrosating cellulose with a nitrosating agent selected from the group consisting of an oxide of nitrogen and nitrosyl chloride and dissolving the cellulose in a dialkylacylamide solvent and then regenerating the dissolved cellulose by contacting the dissolved cellulose with a regenerant, said process introducing substantial quantities of nitric acid into the regenerant, the improvement in which the regenerant comprises a liquid selected from the group consisting of water and a 1 - 4 carbon atom aliphatic monohydric alcohol, and a reactive base which is soluble in the regenerant in an amount ranging from 6% to 25% by weight of the regenerant, said improvement producing a regenerated cellulosic article of improved resistance to alkaline solubility.
Claim 3
Dependent Claim
18 words
The process of claim 1 in which the regenerant is a 1 - 4 carbon aliphatic monohydric alcohol.
Claim 4
Dependent Claim
11 words
The process of claim 2 in which the regenerant is methanol.
Claim 5
Dependent Claim
11 words
The process of claim 1 in which the regenerant is water.
Claim 6
Dependent Claim
29 words
The process of claim 1 in which the base is selected from the group consisting of alkali and alkaline earth metal hydroxides and the alkoxides of said alcohol regenerants.
Claim 7
Dependent Claim
12 words
The process of claim 5 in which the base is sodium hydroxide.
Claim 8
Dependent Claim
36 words
The process of claim 1 in which the nitrosation and dissolution of the cellulosic material occurs at a temperature of no more than 20° C and regeneration occurs before significant oxidation of the cellulose takes place.
Claim 9
Dependent Claim
16 words
The process of claim 1 in which the nitrosating agent is N 2 O 4 .
Claim 10
Dependent Claim
11 words
The process of claim 1 in which the solvent is dimethylformamide.
References Cited (Backward Citations)
CA786225A
Cited
CA876148A
Cited
US2472591A
Cited
US3087775A
Cited
US3236669A
Cited
CA899559A
Cited
US3702843A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-02-27 | 1981-08-29 | 1982-02-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-02-27 | 1985-08-29 | 1986-02-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-02-27 | 1989-08-29 | 1990-02-28 | $7700.00 | Window Closed / Lapsed |