Reinforcing additive

Abstract

Sulfur containing organosilicon compounds having the formula: Z -- Alk -- S.sub.n --Alk -- Z in which Z is: ##STR1## where R.sub.1 is alkyl of 1 to 4 carbon atoms cyclohexyl or phenyl and R.sub.2 is alkoxy of 1 to 8 carbon atoms, cycloalkoxy of 5 to 8 carbon atoms or alkylmercapto of 1 to 8 carbon atoms, alk of a divalent aliphatic hydrocarbon or unsaturated aliphatic hydrocarbon or a cyclic hydrocarbon containing 1 to 18 carbon atoms and n is a whole number from 2 to 6 are used as reinforcing additives in rubber mixtures containing a silica or silicate filler, and in a given case carbon black; the organosilane is coated on the surface of the silica or silicate filler particles.

Dependencies are inferred from the claim text.