Patent US4352770A successfully refreshed from Google Patents.
US4352770A
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Process for forming shaped cellulosic product
Assignee: ITT Inc
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Filing: 1981-05-01
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Granted: 1982-10-05
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Expires: 2001-05-01
Abstract
Abstract Cellulose is activated by penetration of the cellulose with a polar medium and mixed at a temperature at which no significant degradation occurs with an amide selected from the group consisting of dimethylacetamide, 1-methyl-2-pyrrolidinone and mixtures thereof and from 3 to 15% by weight of lithium chloride. The cellulose is then dissolved in the amide and lithium chloride in the substantial absence of any polar medium other than the amide. Shaped cellulosic products may be formed by reconstituting the cellulose in fiber, sheet or other form.
Inventors
- 👤 Albin F. Turbak
- 👤 Adel El-Kafrawy
- 👤 Fred W. Snyder, Jr.
- 👤 Andrew B. Auerbach
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:42
CPC Classifications
D; D01; D01F; D01F2/00; D01F2/02; C; C08; C08B; C08B1/00; C08B1/003
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
54 words
A process of forming a shaped cellulosic product comprising dissolving activated cellulose without significant depolymerization thereof in an amide selected from the group consisting of dimethylacetamide, 1-methyl-2-pyrrolidinone and mixtures thereof and from 3 to 15% by weight of the solution of lithium chloride, and reconstituting the cellulose to form a shaped cellulosic product therefrom.
Claim 2
Dependent Claim
54 words
A process of forming a shaped cellulosic product comprising dissolving activated cellulose without significant depolymerization thereof in an amide selected from the group consisting of dimethylacetamide, 1-methyl-2-pyrrolidinone and mixtures thereof and from 3 to 15% by weight of the solution of lithium chloride, and reconstituting the cellulose to form a shaped cellulosic product therefrom.
Claim 3
Dependent Claim
19 words
The process of claim 1 in which the cellulose is reconstituted by contacting said cellulosic solution with a non-solvent.
Claim 4
Dependent Claim
23 words
The process of claim 1 in which the shaped cellulosic product is a fiber and is formed by wet spinning into a coagulant.
Claim 5
Dependent Claim
21 words
The process of claim 1 in which the shaped cellulosic product is a fiber and is formed by dry jet-wet spinning.
Claim 6
Dependent Claim
20 words
The process of claim 1 in which the shaped cellulosic product is a fiber and is formed by dry spinning.
Claim 7
Dependent Claim
26 words
The process of claim 2 in which the non-solvent is selected from the group consisting of water, a lower monohydric alcohol, acetonitrile, tetrahydrofuran and mixtures thereof.
Claim 8
Dependent Claim
36 words
The process of claim 1 in which the cellulose is activated by penetration with a polar medium which swells the cellulose, which polar medium, other than the amide, is removed prior to dissolution of the cellulose.
References Cited (Backward Citations)
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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) | 1985-10-04 | 1986-04-05 | 1986-10-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-10-04 | 1990-04-05 | 1990-10-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-10-04 | 1994-04-05 | 1994-10-05 | $7700.00 | Window Closed / Lapsed |