Patent ID: 6180811
Filing Date: 2001-01-30
Classification: C07F,C08G

Abstract:
A continuous process for reducing the amount of low molecular weight cyclic organosiloxane in a recirculating process stream comprising,(A) washing a process stream in a wash step to reduce chloride content of the process stream,(B) distilling the process stream into a low-boiling fraction comprising low molecular weight cyclic organosiloxanes described by formula (R.sub.2 SiO).sub.n and an inert solvent and a high-boiling fraction comprising linear organosiloxanes and high molecular weight cyclic organosiloxanes described by formula(R.sub.2 SiO).sub.m,(C) reequilibrating the low-boiling fraction in the presence of a reequilibration catalyst to form a reequilibration mixture comprising high molecular weight cyclic organosiloxanes and the inert solvent, and(D) recycling the reequilibration mixture to the wash step, where each R is independently selected from the group consisting of saturated monovalent hydrocarbon radicals comprising one to about 12 carbon atoms and an aryl radical, n is less than 5, and m is 4 to 14.