The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 19, 1981
Filed:
Mar. 29, 1979
Alberto Baldini, Garlasco, IT;
Roberto Leoni, Milan, IT;
Angelo Calloni, Buscato, IT;
Gianfranco Angelini, Buscate, IT;
Abstract
A process for the dissolution of cellulose in organic solvents such as dihylformamide, dimethylacetamide, and N-methylpyrrolidone is described which comprises contacting the cellulose with an excess of paraformaldehyde and with the solvent at elevated temperatures, preferably higher than 115.degree. C. The amount of paraformaldehyde used preferably corresponds to at least 13 CH.sub.2 O units per anhydroglucosidic unit of the cellulose. The solution obtained can be rendered stable at room temperature by heating it under stirring to lower the paraformaldehyde content, preferably to not less than 8 CH.sub.2 O units per anhydroglucosidic unit. Formed bodies of regenerated cellulose can be obtained from said solutions by coagulating them in an aqueous bath, which may be alkaline or may be a mixture of water and the solvent of the solution, or even by evaporating the solvent.