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Verfahren zur Herstellung von Cellulosecarbamat

Production of cellulose carbamate, for producing fibers, film, beads, sponge, sponge cloth and other moldings, involves mixing activated cellulose or pulp, urea and high-boiling organic solvent by mechanical shear; drying and heating.
 
: Loth, F.; Schaaf, E.; Weigel, P.; Fink, H.; Gensrich, H.J.

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Frontpage ()

DE 2002-10223171 A: 20020524
DE 2002-10223171 A: 20020524
WO 2003-EP5370 A: 20030522
DE 10223171 A1: 20031211
C08B0003
C08B0015
Deutsch
Patent, Elektronische Publikation
Fraunhofer IAP ()

Abstract
Die Erfindung betrifft ein Verfahren zur Herstellung homogener Mischungen von Cellulose und Harnstoff und deren Umsetzung zu Cellulosecarbamat. Die erfindungsgemaess hergestellten Cellulosecarbamate sind in waessriger Alkalilauge loeslich und koennen zur Herstellung von Fasern, Folien, Perlen, Schwaemmen und anderen Formkoerpern auf Cellulosebasis verarbeitet werden.

 

WO2003099873 A UPAB: 20040115 NOVELTY - Production of cellulose carbamate (I) comprises (a) producing a mixture of activated cellulose or pulp, urea and a high-boiling organic solvent for urea in a mixing aggregate, using mechanical shear; (b) drying the mixture; and (c) conversion to (I) by reaction at 120-220 deg. C. USE - The process is used for producing fibers, films, beads, sponge and sponge cloths (all claimed) and other moldings based on cellulose. ADVANTAGE - Cellulose carbamates provide an alternative to the viscose process for producing regenerated cellulose fibers. However, activation with excess concentrated aqueous sodium hydroxide solution necessitates washing, whilst mixing with solid urea does not give uniform distribution and mixing with aqueous urea solution increases the energy consumption for drying. The present process avoids these drawbacks. It improves activation and homogeneous mixing of activated cellulose with urea before and during reaction and gives a product of more uniform quality.

: http://publica.fraunhofer.de/dokumente/N-44222.html