Process for the preparation of regenerated cellulose formed bodies from solutions of cellulose derivatives in organic solvents
AssigneeSnia Viscosa Societa' Nazionale Industria Applicazioni Viscosa S.p.A.
InventorsRoberto Leoni, Alberto Baldini, Gianfranco Angelini
Life of this patent
Estimating the term…
Abstract
A process for the preparation of regenerated cellulose formed bodies from lutions 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.
Claims8
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.
Dependencies are inferred from the claim text.