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Verfahren zur Herstellung von Cellulosecarbamatformkoerpern

Production of cellulose carbamate, for molding e.g. to fibers, film, beads, sponge or sponge cloth, involves mixing activated cellulose with urea, drying and reaction, then conversion to solution and molding.
: Loth, F.; Schaaf, E.; Weigel, P.; Fink, H.; Gensrich, H.J.

Frontpage ()

DE 2002-10223174 A: 20020524
DE 2002-10223174 A: 20020524
WO 2003-EP4879 A: 20030509
EP 2003-725182 AW: 20030509
DE 10223174 A1: 20031211
EP 1509548 A1: 20050302
Patent, Elektronische Publikation
Fraunhofer IAP ()

Die Erfindung betrifft ein Verfahren zur direkten Herstellung von Fasern, Folien, Perlen, Schwaemmen und anderen Formkoerpern aus Cellulosecarbamat, das durch Umsetzung von Cellulose mit Harnstoff bei erhoehter Temperatur und direkter Aufloesung des Reaktionsproduktes in Natronlauge ohne zusaetzliche Wasch- und Reinigungsoperation erhalten wurde.


WO2003099871 A UPAB: 20040115 NOVELTY - Production of cellulose carbamate moldings involves (a) producing a mixture of activated cellulose or pulp and urea in a mixing aggregate with shear treatment; (b) drying the mixture; (c) reaction at 120-180 deg. C; (d) dissolving the untreated reaction product in dilute aqueous alkali hydroxide solution; (e) filtering and/or deaerating the alkaline solution; and (f) molding to moldings. USE - The process is used for producing fibers, films, beads, sponges and sponge cloths (all claimed). ADVANTAGE - Cellulose carbamates provide an alternative to the viscose process for producing regenerated cellulose fibers. However, existing methods of production use several costly process stages in different technical aggregates and the products require costly purification, e.g. by washing and/or distillation. The present process is technically simple and economically attractive. The activation, washing, reaction dissolution and spinning stages are improved and working up is simplified.