Sulphur-containing additives to lubricants with antiwear and extreme-pressure effect and the processes for their preparation and compositions containing the said additives

摘要

This invention relates to additives to lubricants with antiwear and extreme-pressure effect consisting of asymmetric dihydrocarbyl polysulphides containing a hydrocarbyl polysulphide group R-Sx- in a vicinal position of a secondary or tertiary alcohol, and to lubricating compositions containing these additives. The additives are prepared by reaction of a basic salt of a hydrocarbyl (poly)sulphide either with a compound containing at least one epoxy group or with an alpha-hydroxylated organic thiosulphate.