Process for the preparation of organosilicon compounds

1. Process for the preparation of an organosilicon compound of the formula (I)

R 1 R 2 R 3 SiR 4 ) 2 S x   (I)

in which the meanings are as follows

R 1 , R 2 , R 3 are: identical to or different from one another and are branched or straight-chain alkyl groups, branched or straight-chain alkoxy groups or aryl radicals, at least one of the groups R 1 ,

R 2 , R 3 being an alkoxy group,

R 4 is: a branched or straight-chain, saturated or unsaturated, aliphatic, aromatic or mixed aliphatic/aromatic divalent C 1 -C 30 hydrocarbon group,

x is a number >1,

comprising reacting, without a phase-transfer catalyst, haloalkoxysilanes of the general formula (II)

R 1 R 2 R 3 SiR 4 X  (II)

in which

R 1 , R 2 , R 3 , R 4 have the above meaning from formula (I) and

X is a halogen atom,

with a dry polysulphide of the formula (III)

M 2 S z   (III)

and/or dry sulphide of the general formula IV

M 2 S  (IV)

in which

M represents an alkali metal cation, an ammonium cation or half an alkaline earth metal

or zinc cation and

z represents a number from 2 to 8,

and optionally sulphur,

in an organic solvent,

to form a suspension, removing the organic solvent from the suspension, obtaining a mixture containing the organosilicon compound of the formula (I) and the solid MX and mixing said mixture with water, containing at least one buffer in an amount of from 0.1 to 80% by weight in the water to form a plurality of phases.

2. The process according to claim 1 further comprising separating the phases.