Patent ID: 6187827
Filing Date: 2001-02-13
Classification: C07F,C08J,Y02W

Abstract:
A process for the recovery of methyl polysiloxane in the form of methyl cyclosiloxane of the general formula, (R.sub.2 SiO)x wherein R is selected from alkyl, alkenyl, aryl or alkaryl groups and ""x"" is an integer selected from 3-6, comprising:a) liquifying silicone feedstock in a solvent selected from alcohol or siloxane in the presence of a catalyst at a temperature of between 110-180.degree. C. to obtain a liquefied mass consisting of a mixture of methyl polysiloxane, solvent and filler;b) adding a metal hydroxide to the liquified mass so as to convert the silica fillers to their corresponding silicates, removing the said silicates thus obtained and recovering the liquid; andc) cyclyzing the methyl polysiloxane in the liquid medium thus obtained in the presence of a cracking catalyst in the temperature range of 115-160.degree. C. so as to crack the liquid methyl polysiloxane to a mixture of volatile methyl cyclosiloxane.