PURPOSE: To obtain the titled compound, useful as an extreme pressure additive for lubricating oils, and having reduced corrosiveness of copper plates, by treating a dialkyl polysulfide obtained by reacting an alkyl mercaptan with sulfur with a specific sulfur compound.
CONSTITUTION: A 3W18C alkyl mercaptan is reacted with sulfur to give a dialkyl polysulfide, which is then treated with one of sodium sulfide or a phosphine compound, e.g. triphenylphosphine, to afford a dialkyl trisulfide. The reaction is carried out by using 0.7W1.5g atoms sulfur based on one mole alkyl mercaptan, sulfur in the presence of an alkaline earth metallic oxide catalyst, e.g. magnesium oxide, and mixing the resultant dialkyl polysulfide with the above-mentioned slufur compound at 30W80°C for 1W5hr. The resultant triphenylphosphine sulfide formed by the reaction of the higher polysulfide with the above-mentioned phosphine compound reduces the corrosiveness of copper plates.
NAKAZAWA HIROSHI
MORIYAMA HITOSHI
TAKANAMI KINJI
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