| 摘要 |
Olefin polysulphide compositions which have a high sulphur content and a very low chlorine content, which are obtained by a process in which: 1 - sulphur mono- and/or dichloride is reacted with at least one C2-C5 aliphatic monoolefin to form an addition product or "adduct"; 2 - hydrogen sulphide is reacted with an alkali metal hydroxide or ammonium hydroxide in solution in at least one substantially anhydrous C1-C4 aliphatic monoalcohol, with optional addition of elemental sulphur; 3 - the said "adduct", together with at least one monohalogenated hydrocarbon compound, is placed in contact with the alcoholic solution obtained at the end of stage 2; 4 - the mixture resulting from stage 3 is heated, the monoalcohol is removed, while water is added; and 5 - after separation and removal of the aqueous phase the organic phase, consisting at least predominantly of the required olefin polysulphide composition, is recovered. These compositions, exhibiting a sulphur content which may go up to approximately 65 % on a mass basis and a chlorine content which is generally lower than approximate 0.1 % on a mass basis, are employed especially as additives for improving the extreme-pressure properties of lubricants. Single plate to be published. <IMAGE>
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