摘要 |
Process for obtaining monoorganoxysilane polysulfides comprises a 3-stage preparaton by (a) reaction of a monohalogenosilylalkylprecursor with an allyl derivative ; (b) reaction of the product from (a) with an alcohol ; and finally, reaction of the alkoxylated compound from (b) with an alkali metal sulfide. Preparation of bis(monoorganoxysilylpropyl) polysulfides of formula: asterisk asterisk FORMULA - - in which R<1> = 1 - 15C alkyl or 2 - 8C alkoxyalkyl; R2, r<3>(identical or different) = 1 - 6C alkyl or phenyl; x = 1.5/!0.1 - 5/!0.1. -by the following stages, shown by the equations : a) -Hal represents halogen(Cl, Br or I), A is a replaceable group chosen from Hal, a group para-R<0>C6H4-O-or R60-SO2-O-(R<0> is 1 - 4C alkyl) ; -the reaction taking place at -10 to 200 deg C between a mole of (V) and a stoichiometric or non-stoichiometric amount of (VI) in homogeneous or heterogeneous conditions and in the presence of an activator comprising either a catalytic activator, a transition metal from Co, Ru, Rh, Pd Ir or Pt, and optionally a promoter or a photochemical activator.The derivative (VII) may be isolated. b) The product or reaction mixture from (a) is reacted with an alcohol(VIII) at -20 to 200 deg C using at least one mole of alcohol per mole of reactant in the presence of a base and/or organic solvent, and, optionally, separating the derivative(IX) formed ; c) The product or reaction mixture form (b) is reacted with metallic polysulfide(X) in the anhydrous state at 20 - 120 deg C using 0.5/!25% mole of (X) per mole of (IX) in the presence of a polar or non-polar inert solvent. The bis(monoorganoxysilylpropyl) polysulfide formed is separated. |