METHOD FOR THE PREPARATION OF CELLULOSE ETHERS WITH A HIGH SOLIDS PROCESS, PRODUCT OBTAINED AND USES OF THE PRODUCT

摘要

The present invention provides a method for production of cellulose ethers in a high solids process substantially without use of organic solvents as reaction and/or washing medium. In the method of the invention the first alkalization step is carried out by using high solids content cellulose pulp and solid sodium hydroxide. This is followed by an etherification step where the solids content is preferably further increased and the use of solid etherification reactant is preferred. As no organic solvents are used as reaction media the invented method enables production of cellulose ethers directly from never dried pulp with significant savings in energy and investment costs. The method is especially suitable for the production of carboxymethyl cellulose sodium salt (CMC) with low degree of substitution (DS<0.3). The use of the resulting none or low water soluble carboxymethylated cellulosic fibres is suitable for example for producing microfibrillated cellulose.