| abstract |
The prodn. of cycle-free, organo-functional modified polysiloxanes of formula R<1>xR3-xSiO(R2SiO)n(R<1>yR2-ySiO)mSiR<1>zR3-z (I) comprises the reaction of: (a) poly organo siloxanes contg. at least one Si-bonded H atom; with (b) hydrocarbons and/or organic polymers contg. 1-500C; in presence of (c) a conventional hydrosilylation catalyst.The novel feature is that poly organo-siloxanes (a) are obtd. by reacting two or more (poly)organosiloxanes of formula R<2>aSiO(4-a)/2 (II) in the presence of an exclusively equilibration-promoting and cyclisation-suppressing catalysts, with (II) free of condensible gps. but contg. at least one R<2>3SiO0.5- (M) gp. and at least one -R<2>3SiO- (D) gp. (See also DE4444173).In the formulae, R = 1-6C hydrocarbyl, -R2SiO-, -R<1>yR2-ySiO- and/or -R<1>xR3-xSiO-; R<1> = as for R or hydrocarbon and/or organic polymer with 1-500C; n = 1-5000; m = 1-1000; x, y and z = 0 or 1, with at least one of them being 1; and R<2> = H or 1-30C hydrocarbon, provided that only one H atom is bonded per Si and that at least one of (II) has an Si-bonded H atom; and a = above 1. |