METHOD FOR PRODUCING DIALKYL POLYSULFIDE, DIALKYL POLYSULFIDE, EXTREME-PRESSURE ADDITIVE AND LUBRICATING FLUID COMPOSITION

摘要

For the purpose of efficiently producing a dialkyl polysulfide which is able to be favorably used as an extreme-pressure additive which does not easily corrode the metal surface, and an extreme-pressure additive and lubricating fluid composition including the dialkyl polysulfide, provided is a method for producing dialkyl polysulfide including a first step of reacting an olefin compound (a) represented by General Formula (1): R 1 R 2 C=CHR 3 (where R 1 and R 2 each are an alkyl group, R 3 is a hydrogen atom or an alkyl group, and the total number of carbon atoms of R 1 , R 2 and R 3 is 2 to 20) with sulfur in the presence of a hydrogen sulfide to thereby obtain crude dialkyl polysulfide (A), and a second step of reacting the crude dialkyl polysulfide (A) and a sulfide of an alkali metal in a solvent including an alcohol to thereby reduce the number of sulfur atoms in the crude dialkyl polysulfide (A).