Patent ID: 7504467

Claim:
A process for preparing organopolysiloxanes which bear triorganosiloxy groups, of the formula where R is a monovalent, SiC-bonded, optionally substituted hydrocarbon radical which is free of aliphatic carbon-carbon double bonds and has from 1 to 18 carbon atoms, R 1 is R or R 3 , and R 2 is R or R 3 , where R 3 is a monovalent, SiC-bonded hydrocarbon radical having a terminal aliphatic carbon-carbon double bond and from 2 to 8 carbon atoms per radical, a is an integer from 80 to 1000, b is an integer from 0 to 100, c is an integer from 1 to 100, d is an integer from 0 to 100, by (a) in a first step, reacting organopolysiloxane(s) (A) which have SiH groups and are of the formula where e is the sum of b+c and is an integer from 1 to 200, R 4 is R or a hydrogen atom, and R, a, b, c and d are each as defined above, in the presence of at least one catalyst (B) selected from the group consisting of the metals of transition group VIII of the Periodic Table and compounds thereof, and in the presence of at least one cocatalyst K selected from the group consisting of organic acids and low molecular weight organosilicon hydrides, with water (C), to provide intermediate(s) which have Si—OH groups and are of the formula where R 5 is R or an HO group, and R, a, b, c and d are each as defined above, and, (b) in a second step, reacting the intermediates which have SiOH groups with at least one silane (D) which has a group reactive with SiOH groups.