Verfahren zur Herstellung endstaendig carbofunktioneller Organosiloxane

An organopolysiloxane consisting of units of the general formula and of at least 2 terminal units of the formula O 1/2 -Si(CH3)2-CH2-X-A-Y-H, in which n is 1 or 2, each R is a hydrocarbon radical with or without substituents, the group X-A-Y is or X is -CH2- or Y, and Y is an oxygen or sulphur atom or an NH or N-alkyl group, is made by subjecting a mixture of (a) a compound of the formula and (b) a silane of the formula RnSiZ4- n, wherein Z is halogen or a lower alkoxy radical, or a mixture of such silanes or siloxanes derived therefrom, to a hydrolytic reaction (in the presence of an alkaline or acidic catalyst) with sufficient water for the stoichiometrically calculated molar ratio of H2O : Y + Z in the reaction-mixture to amount to at least 1 : 2. In a typical Example (1), HCl was slowly added to an ethanol solution of 2,2-dimethyl-2-sila-1,4-dioxan and the mixture was allowed to stand for 1 day, after which volatiles were removed by distillation and the residue was filtered to yield, as a colourless oil, a dodecasiloxane containing terminal -CH2.O.CH2. CH2OH radicals. Uses.-As surface active agents: for making siloxaneoxyalkylene copolymers and Si-containing polyesters and polyurethanes, and for modifying other organic resins.