Patent ID: 7915440

Claim:
A method for preparing a polyorganosiloxane which is solid at 25° C. and has R 1 3 SiO 0.5 units wherein R 1 is a hydrocarbon group having 1 to 10 carbon atoms and SiO 2 units, said method comprising the steps of: [1] subjecting at least one selected from an organosilane and an organodisiloxane, and at least one selected from a tetralkoxysilane and a partial condensate of hydrolysates of the tetralkoxysilane to hydrolysis reaction and condensation reaction in the presence of an acidic catalyst; [2] adding an isoparaffinic solvent having 7 to 10 carbon atoms in an amount of from 25 to 250 parts by weight per 100 parts by weight of a theoretical yield of the polyorganosilixane, provided that the step [2] may be performed before, during, or after the step [1]; [3] adding a basic substance to the reaction mixture to make the reaction mixture basic, followed by subjecting the reaction mixture to a condensation reaction while heating; [4] adding an aqueous solution of an organic acid to neutralize the reaction mixture; and subsequently [5] separating a liquid aliphatic hydrocarbon phase and an aqueous phase and then removing said aqueous phase.