Preparation of alkoxy- and/or halosilane (poly)sulfides and coupling agents comprised thereof

A process for the preparation of at least one alkoxy-and/or halosilane (poly)sulfide, comprising reacting, via an ionic addition mechanism, at least one sulfur-containing reactant (Rs) with at least one alkoxy-and/or halosilane of formula (I):

• in which:
• the R1 symbols, which may be identical or different, are each:
• a linear, branched or cyclic alkyl radical having from 1 to 20 carbon atoms,
• an aryl radical having from 6 to 18 carbon atoms,
• an —OR2 alkoxy radical, wherein R2 is a linear, branched or cyclic alkyl radical having from 1 to 20 carbon atoms or an aryl radical having from 6 to 18 carbon atoms,
• an arylalkyl radical or an alkylaryl radical (C6-C18 aryl, C1-C20 alkyl),
• a hydroxyl radical,
• or a halogen,
• with the proviso that at least one of these R1 radicals is —OR2, —OH or a halogen and such R1 radicals, when they are neither hydroxyl nor halogens, optionally bear at least one halogenated substituent;
• the Y symbol has the formula (II):
• in which:
• the R3 and R4 symbols, which may be identical or different, are each hydrogen or a monovalent hydrocarbon radical selected from the group consisting of a linear, branched or cyclic alkyl radical having from 1 to 20 carbon atoms and a linear, branched or cyclic alkoxyalkyl radical having from 1 to 20 carbon atoms;
• the R5 symbol is CH2 or CR6R7, wherein R6 and R7, which may be identical or different, are each hydrogen or a monovalent hydrocarbon radical selected from the group consisting of a linear, branched or cyclic alkyl radical having from 1 to 20 carbon atoms and a linear, branched or cyclic alkoxyalkyl radical having from 1 to 20 carbon atoms;
• and
• the n symbol is an integer greater than or equal to 1.