Patent ID: 6037434
Filing Date: 2000-03-14
Classification: C08G

Abstract:
A method for producing a polydiorganosiloxane partially end-blocked with substituted silethylene groups comprising the steps of:A) mixing a hydroxyl end-blocked polydiorganosiloxane with a silicon-containing compound having at least two silicon-bonded hydrogen atoms and a --Si(R').sub.3 end-blocked siloxane in the presence of an acidic polymerization catalyst to form a mixture;B) conducting a reaction with the mixture of step A so to produce a reaction product comprising polydiorganosiloxane having at least one silicon-bonded hydrogen atom and at least one --Si(R').sub.3 group; andC) adding a substituted alkenylsilane in the presence of a hydrosilylation catalyst to the reaction product obtained from step B to form a polydiorganosiloxane partially end-blocked with substituted silethylene groups;wherein each R' is independently selected from the group consisting of a monovalent hydrocarbon having 1 to 6 carbon atoms and a monovalent halohydrocarbon having 1 to 6 carbon atoms.