Process for the production of bis (silyorganyl) polysulphanes

A process for the production of a bis(silylorganyl)polysulphane of the formula

• (R.sup.1 R.sup.2 R.sup.3 SiR.sup.4).sub.2 S.sub.x (I)
• in which
• R.sup.1, R.sup.2 R.sup.3 are identical or different from each other, and are branched and unbranched alkyl and/or alkoxy groups having a chain length of 1-8 C atoms, wherein at least one alkoxy group is present, aryl residues, in particular phenyl, toluyl, benzyl;
• R.sup.4 is a divalent alkylidene residue having a chain length of 1-8 C atoms, or
• --(CH.sub.2).sub.n --C.sub.6 H.sub.4 --(CH.sub.2).sub.n --n=1 to 4);
• x means a number >1, comprising reacting a haloalkylalkoxysilane or haloalkoxysilane of the formula
• R.sup.1 R.sup.2 R.sup.3 SiR.sup.4 X (II)
• in which
• R.sup.1, R.sup.2, R.sup.3 R.sup.4 each have the same meaning as in formula (I) above and
• X designates a halogen atom with a polysulphide of the formula
• M.sub.2 S.sub.x (III),
• wherein
• M is an alkali metal cation, half an alkaline earth metal or zinc cation and
• x denotes a number from 2 to 8, where in a first stage a dehydrated polysulphide according to the formula (III) is obtained by reacting a sulphide containing water of crystallization of the formula
• M.sub.2 S.sub.x-z (IV)
• in which M and x have the same meanings as above, z designates a number from 1 to 7 and (x-z) is .gtoreq.1,
• with sulphur in the absence of an organic solvent under a vacuum at a temperature of 60.degree. to 300.degree. C.