Patent ID: 6242595
Filing Date: 2001-06-05
Classification: C08B

Abstract:
A process for the recovery of cellulose carbamate from a reaction mixture after its production by conversion of cellulose with excess urea in an inert organic liquid reaction carrier, the process consisting of:adding water to the reaction mixture after the conversion is complete;keeping the resulting mixture at about 70 to 100.degree. C. for 5 to 120 min without distilling off said organic reaction carrier, thereby dissolving unconverted urea and reaction by-products in said added water, and then filtering the mixture to separate the liquid phase;washing the cellulose carbamate remaining on the filter with water of 30 to 90.degree. C.;optionally pre-drying and/or drying the washed cellulose carbamate with a hot inert gas, and condensing the condensable components of the inert gas that was used to pre-dry and/or dry the cellulose carbamate; andrecovering the cellulose carbamate.