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Abstract

The present invention is a method for the preparation of branched organopolysiloxane in which polysiloxane with the formula SiO.sub.2 constitutes the branching center or branch origin and the terminal on only one side of diorganopolysiloxane is bonded to the branch origin wherein this bonding is exactly to the branch origin. Specifically, the method for preparation of branched polyorganosiloxane comprises the reaction of an alkali metal compound with a silanol-containing polysiloxane described by formula {SiO.sub.4/2 }.sub.x {R.sup.1.sub.2 (OH)SiO.sub.1/2 }.sub.y {R.sup.1.sub.3 SiO.sub.1/2 }.sub.z {RO.sub.1/2 }.sub.u, wherein each R.sup.1 is independently selected from a group consisting of C1-8 alkyls, haloalkyls, alkenyls, and aryls; R is selected from a group consisting of hydrogen atom and C1-8 alkyls; 2.ltoreq.x.ltoreq.500; 2.ltoreq.y+z+u.ltoreq.150; 2.ltoreq.y; 0.ltoreq.z; 0.3 .ltoreq.(y+z+u)/x.ltoreq.3; and 0.ltoreq.u/(x+y+z).ltoreq.0.1); by subsequent reaction with cyclic organopolysiloxane described by formula {SiR.sup.2 R.sup.3 O}.sub.m, where R.sup.2 and R.sup.3 are defined as for R.sup.1 and 3.ltoreq.m.ltoreq.8; and finally by endcapping with triorganomonohalosilane or protic acid.

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First Claim