Method of hydrolyzing organochlorosilanes

Claim 1

In the method of hydrolyzing organochlorosilane of the formula R.sub.(a) H.sub.(b) SiX.sub.(4-a-b), in a hydrolysis reactor, where R is selected from C.sub.(1-13) monovalent hydrocarbon radicals and substituted monovalent hydrocarbon radicals and X is a halogen radical, utilizing a substantially stoichiometric equivalent of organohalosilane and water required for such organohalosilane hydrolysis, resulting in organopolysiloxane hydrolyzate having greater than about 5% by weight, based on the weight of organopolysiloxane hydrolyzate, of halogen radicals in the form of dissolved HX or terminal--SiX groups as a result of the recycling of aqueous HX to the hydrolysis reactor, whereby a loss of halide values results upon the neutralization of the organopolysiloxane hydrolyzate with base, to reduce its acidity, the improvement which comprises, utilizing as the source of water for the organochlorosilane hydrolysis, an aqueous hydrochloric acid solution having at least 35% by weight of hydrogen chloride which is utilized in an amount sufficient to provide a ratio of moles of water to moles of organochlorosilane having a value of from about 10 to about 30, whereby a substantial reduction in the weight percent of chemically combined halogen radicals, based on the weight of organopolysiloxane hydrolyzate is effected and improved yields of organocyclopolysiloxane is achieved.