Polyorganosiloxanes with functional sulfur

Sulfur-functional polyorganosiloxanes containing side-chain groups which can bond with silicic acid (preferably alkoxy or haloalkoxy) and side-chain groups which can bond with elastomers, preferably mercapto, thiocyanato, disulfide or polysulfide groups. Sulfur-functional polyorganosiloxanes of formula (I), R -R = H, 1-4C alkyl, alkoxy, haloalkyl or haloalkoxy, phenyl, aryl or aralkyl; W = a group which can bond to silicic acid, preferably 1-4C alkoxy or haloalkoxy; Y = alkyl, haloalkyl, phenyl, aryl or aralkyl; Z = a 0-6C alkylidene group; A = a group which can form bonds with at least one elastomer in a rubber mixture, i.e. mercapto or thiocyanato if q = 1, or disulfide or polysulfide (Sx) if q = 2; x = 2-10; (k+m+n+p) = 3 or more; k = n = 0 (optionally). Independent claims are also included for (a) a process for the production of (I) by reacting compounds of formula (IV) with compounds of formula MSH, MSCN or M2Sx, or with M2S and sulfur, in an alcohol W-H at 20-150 degrees C under normal pressure, optionally with a catalyst, using compounds in which X = halogen; M = a metal ion; (b) rubber mixtures containing (I); (c) a process for the production of rubber mixtures by using (I) and other filler(s) in addition to rubber; (d) molded products obtained from these rubber mixtures.