Patent US1247389A successfully refreshed from Google Patents.
US4289723A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of regenerated cellulose formed bodies from solutions of cellulose derivatives in organic solvents
Assignee: SNIA Viscosa SpA
•
Filing: 1979-07-25
•
Granted: 1981-09-15
•
Expires: 1999-07-25
Abstract
Abstract A process for the preparation of regenerated cellulose formed bodies from solutions of cellulose derivatives in organic solvents is disclosed. The cellulose derivatives is firstly precipitated in a coagulating bath constituted of a cellulose non-solvent, non-regenerating organic liquid, then the coagulated body is drawn in subsequent baths and the cellulose is regenerated. The drawing and the regeneration occur, at least in part, concurrently.
Inventors
- 👤 Roberto Leoni
- 👤 Alberto Baldini
- 👤 Gianfranco Angelini
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 21:09
CPC Classifications
D; D01; D01F; D01F2/00
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
131 words
A process for the preparation of regenerated cellulose formed bodies from organic solutions of methylol cellulose derivatives having 0.8 or more formaldehyde units per anhydroglucosidic unit, which comprises first precipitating said cellulose derivative in a coagulating bath consisted of the organic solvent for said cellulose derivatives and a cellulose derivative non-solvent, non-regenerating organic liquid selected from the group consisting of alcohols, ethers, esters, aldehydes, ketones, chlorinated organic liquids and nitriles, and subsequently drawing the cellulose derivative body (in a subsequent hot water bath to an extent) between 10% and the maximum value which said cellulose body can withstand without breaking, and regenerating the cellulose in (said hot water bath) one or more aqueous baths consisting essentially of hot water, wherein the drawing and the regeneration occur, at least in part, concurrently.
Claim 2
Dependent Claim
131 words
A process for the preparation of regenerated cellulose formed bodies from organic solutions of methylol cellulose derivatives having 0.8 or more formaldehyde units per anhydroglucosidic unit, which comprises first precipitating said cellulose derivative in a coagulating bath consisted of the organic solvent for said cellulose derivatives and a cellulose derivative non-solvent, non-regenerating organic liquid selected from the group consisting of alcohols, ethers, esters, aldehydes, ketones, chlorinated organic liquids and nitriles, and subsequently drawing the cellulose derivative body (in a subsequent hot water bath to an extent) between 10% and the maximum value which said cellulose body can withstand without breaking, and regenerating the cellulose in (said hot water bath) one or more aqueous baths consisting essentially of hot water, wherein the drawing and the regeneration occur, at least in part, concurrently.
Claim 3
Dependent Claim
18 words
Process according to claim 1, wherein the drawing occurs, at least to a substantial degree, before the regeneration.
Claim 4
Dependent Claim
44 words
Process according to claim 1, wherein the cellulose derivative non-solvent non-regenerating organic liquid is selected from the group consisting of tetrahydrofurane, dioxane, monoethyl ether of ethylene glycol, monomethyl ether of ethylene glycol, dimethyl ether or dimethylether of ethylene glycol, trichloromethane, acetonitrile and ethyl acetate.
Claim 5
Dependent Claim
14 words
Process according to claim 1, wherein the cellulose non-solvent non-regenerating organic liquid is methanol.
Claim 6
Dependent Claim
23 words
Process according to claim 1, wherein the coagulating bath contains between 0.5 and 30% of the organic solvent of the cellulose derivative solution.
Claim 7
Dependent Claim
26 words
Process according to claim 1, wherein the organic solvent of the cellulose derivative solution is selected from the class consisting of dimethylsulphoxide, dimethylformamide, dimethylacetamide and N-methylpyrrolidone.
Claim 8
Dependent Claim
27 words
Process according to claim 1, wherein the regeneration occurs in successive stages, by passage of the formed body through a series of aqueous baths at increasing temperatures.
Claim 9
Dependent Claim
17 words
Process according to claim 7, wherein the temperature of the baths varies between 40° and 95° C.
References Cited (Backward Citations)
US4022631A
Cited
US4129640A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-09-14 | 1985-03-16 | 1985-09-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-09-14 | 1989-03-16 | 1989-09-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-09-14 | 1993-03-16 | 1993-09-15 | $7700.00 | Window Closed / Lapsed |