Patent ID: 7259257

Claim:
A process for producing particulate water-soluble cellulose derivatives, comprising: a) forming a feed composition comprising a cellulose derivative, and 50 wt. % to 80 wt. % of water, based on the total weight of the feed composition, wherein the cellulose derivative is at least one of swelled and dissolved in the feed composition; b) contacting, in a high rotational speed gas jet impact mill, the feed composition with a superheated gas mixture selected from (i) a superheated gaseous mixture of steam and an inert gas, and (ii) a superheated gas mixture of steam and air, thereby converting the cellulose derivative of the feed composition into a solid state form of finely particulate particles, wherein the superheated gas mixture has a steam content of 40 wt. % to 99 wt. %, based on the total weight of the superheated gas mixture; c) separating the particulate cellulose derivative from the superheated gas mixture; and d) optionally drying the particulate cellulose derivative.