Patent ID: 6303729
Filing Date: 2001-10-16
Classification: C08G

Abstract:
A process for preparing a partially added cyclic organohydrogensiloxane, comprising the steps of:mixing (A) a cyclic organohydrogensiloxane having at least two Si--H bonds in a molecule with (B) a cyclic or acyclic organic unsaturated compound having an aliphatic unsaturated double bond in a molecule such that the moles of S--H bonds in component (A) may be excessive relative to the moles of aliphatic unsaturated double bonds in component (B),effecting addition reaction between components (A) and (B) in the presence of a platinum catalyst to form a partially added cyclic organohydrogensiloxane,adding a silylating agent to the reaction mixture, andisolating the partially added cyclic organohydrogen-siloxane from the reaction mixture by distillation.