PROCESS FOR PRODUCING CELLULOSE DERIVATIVES OF HIGH BULK DENSITY, GOOD FLOWABILITY AND/OR DISPERSIBILITY IN COLD WATER AS WELL AS LOW SOLUTION COLOR

摘要

A particulate cellulose derivative is obtained in a process of grinding and drying a moist cellulose derivative which comprises the steps of A) providing a cellulose derivative having a moisture content of from 60 to 95 percent, based on the total weight of the moist cellulose derivative; B) grinding and partially drying the moist cellulose derivative in a gas-swept impact mill; C) contacting the ground and partially dried cellulose derivative with an additional amount of a drying gas outside the gas-swept impact mill; and D) subjecting the cellulose derivative to partial depolymerization after having contacted the cellulose derivative with a drying gas in step C). The obtained particulate cellulose derivative has a high untapped bulk density, a good flowability and a low color intensity.

主权项

1. A process for producing a particulate cellulose derivative comprising the steps of
A) providing a cellulose derivative having a moisture content of from 25 to 95 percent, based on the total weight of the moist cellulose derivative, B) grinding and partially drying the moist cellulose derivative in a gas-swept impact mill wherein the gas fed into the impact mill has a temperature of 100° C. or less; C) contacting the ground and partially dried cellulose derivative with an additional amount of a drying gas outside the gas-swept impact mill, wherein the additional amount of drying gas outside the gas-swept impact mill has a higher temperature than the gas fed into the impact mill; and D) subjecting the cellulose derivative to partial depolymerization after having contacted the cellulose derivative with a drying gas in step C).