Method of preparing trialkyl organo-oxysilanes

Abstract

A method for the continuous or batch preparation of trialkyl organo-oxysilanes by reaction of organic hydroxy compounds with trialkyl halogen silanes in the absence of acid-binding substances is disclosed. The organic hydroxy compound is added directly to the trialkoxy halogen silane in an amount which corresponds to no more than the stoichiometrically necessary amount. The trialkyl halogen silane, or the resultant mixture is always at the boiling temperature or above the boiling temperature in the gaseous state. The reaction mixture is subjected, no later than toward the end of the reaction, to a column distillation in which the column temperature is held such that the reaction is carried to the end within the column. In continuous operation, the trialkyl halogen silane is introduced in gaseous form into the bottom of a column and either kept under reflux or introduced into a reactor into which corresponding stoichiometric amounts of organic hydroxy compound are simultaneously introduced. In the column, either a raw product or freshly introduced organic hydroxy compound in liquid form flows against the gaseous trialkyl halogen silane, and the desired trailkyl organo-oxysilane collects at ebullition on the floor of the column and is continuously removed.