GB899148A - Improvements in or relating to the production of organosilicon polymers - Google Patents

Abstract

An organosilicon polymer of the formula <FORM:0899148/IV (a)/1> p is made by reacting R2SiX2 with water and H2SO4 in the proportions represented by the overall equation:-(n+2m+2)R2SiX2+ --> (n+m+1)H2O+m(H2SO4) polymer of the above formula, wherein each R is a substituted or unsubstituted hydrocarbon radical, each X is a halogen atom or an alkoxy radical, and n and m are numbers which may be fractional when the formula represents an average formula of a mixture of polymers. The process may be carried out in one stage or in several stages with equilibration of the resulting intermediate products, e.g. (a) in a first step (n+m+1) moles of R2SiX2 are reacted with (n+m+1) moles of water; (b) in a second step m moles of R2SiX2 are reacted with m moles of H2SO4; (c) in a third step the reaction products of (a) and (b) are reacted with 1 mole of R2SiX2 and equilibrated by heating to 150 DEG C. Thus the starting materials may include one or more compounds which may be obtained by the reaction of the silane with water and/or sulphuric acid, such as pure cyclic or chain polysiloxanes and their silyl sulphates, e.g. <FORM:0899148/IV (a)/2> which may also be obtained by reacting diakyl siloxanes with chlorosulphonic acid. In examples dimethyl-dichlorosilane is reacted with sulphuric acid and water in the above proportions to yield viscous oils.