Process for preparing cyclic polysiloxanes from linear polysiloxanes

Abstract

Cyclic polysiloxanes are produced by continuously passing a feed comprising linear polysiloxanes through a reactor containing a solid acidic catalyst at a pressure greater than one atmosphere under an inert atmosphere to produce a mixture comprising volatile cyclic polysiloxanes, nonvolatile reaction products, and unreacted linear polysiloxanes. The volatile products can then be recovered, and the nonvolatile reaction products and unreacted linear polysiloxanes can be added to the linear polysiloxane feed to form a recycle stream that is passed back through the reactor. Recycling increases the yield of the desired cyclic species.

Dependencies are inferred from the claim text.