Method for the separation of hexamethylcyclotrisiloxane

摘要

A method for separating hexamethylcyclotrisiloxane that does not require the use of a distillation set up adapted for use with solids and that collects the hexamethylcyclotrisiloxane in the form of an easy-to-handle solution. The method comprising inducing the ascent in the gaseous state of a hexamethylcyclotrisiloxane-containing mixture of polydimethylcyclosiloxanes in a distillation column provided with a sidestream element in the middle region of the column so as to induce the ascent of gaseous hexamethylcyclotrisiloxane to at least the level of the sidestream element, supplying into said distillation column solvent having a boiling point below that of hexamethylcyclotrisiloxane and capable of dissolving hexamethylcyclotrisiloxane, so as to form a liquid mixture of hexamethylcyclotrisiloxane and said solvent in the vicinity of the sidestream element, and withdrawing the said liquid mixture from the sidestream element.