Method for the preparation of olefin polysulfides, the products obtained and their utilization as lubricant additives

A method for the preparation of an olefin polysulfide, comprising the following steps:

• (1) reacting at least one compound chosen from sulfur monochloride or dichloride with at least one mono-olefin containing 2 to 5 carbon atoms, in a proportion of 1.5 to 2.5 moles of mono-olefin per mole of sulfur monochloride and/or dichloride, thereby forming an addition compound or adduct;
• (2) contacting said addition compound or adduct with at least one hydrocarbyl halide chosen from C.sub.1 to C.sub.12 alkyl, C.sub.5 to C.sub.12 cycloalkyl C.sub.6 to C.sub.12 arylalkyl chlorides, bromides and iodides, the proportion of said hydrocarbyl halide corresponding to 1-70% in gram-atoms of halogen with respect to the number of gram-atoms of halogen in the aggregate formed by said adduct and said hydrocarbyl halide, and with at least one sulfur compound selected from the sulfides, hydrosulfides and polysulfides of alkali metals, ammonium or alkaline-earth metals used in a proportion of about 0.4 to 0.8 mole per gram-atom of halogen contained in the aggregate formed by said adduct and said hydrocarbyl halide, and a proportion of elemental sulfur of 0 to 7 gram-atoms per mole of said sulfur compound, in an aqueous medium;
• and
• (3) heating the resultant mixture, separating it into an aqueous phase and an organic phase and recovering resultant olefin polysulfide from the organic phase.