Overbased colloidal products containing an organic sulphurised compound and their use as detergent additives with anti-wear and extreme-pressure activity in lubricating oils.

摘要

Sulphur-containing colloidal products, their preparation and their use as additives in lubricating oils. These products are defined as resulting from the reaction with an overbasic detergent additive, optionally modified by reaction with a boron derivative, of a sulphur-containing carboxylic acid "of small size", corresponding to the general formula X-R<1>-Sx-R<3>-Sy-R<2>-COOH in which each of R<1> and R<2> denotes a divalent hydrocarbon radical, R<3> denotes a single bond or a divalent hydrocarbon radical, X denotes a hydrogen atom or a carboxylic group, and each of x and y is a number from 1 to 4 when R<3> is a hydrocarbon radical and the sum x plus y is a number from 1 to 4 when R<3> denotes a single bond. Apart from their detergent properties, these products exhibit high antiwear and extreme pressure properties as well as an improved heat stability and a satisfactory corrosiveness towards copper. They are particularly suited to a use especially in engine oils, gear oils, hydraulic fluids and oils for metal working.