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Title
Verfahren zur Herstellung von Cellulosecarbamatformkoerpern
Date Issued
2004
Author(s)
Loth, F.
Schaaf, E.
Weigel, P.
Fink, H.
Gensrich, H.J.
Patent No
2002-10223174
Abstract
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.
Language
de
Patenprio
DE 2002-10223174 A: 20020524