Alkaline earth metal hydrocarbyl salicylate concentrates, their preparation and use

摘要

An additive concentrate having a TBN greater than 300 suitable for incorporation into a finished lubricating oil comprises: (I) a lubricating oil soluble overbased alkaline earth metal hydrocarbyl salicylate modified by reaction to incorporate (a) an aldehyde, and (b) from 2 to 40% by weight, based on the weight of the concentrate, of either (i) at least one carboxylic acid having the formula: <IMAGE> (I) wherein R3 is a C10 to C24 alkyl or alkenyl group and R4 is either hydrogen, a C1 to C4 alkyl group or a CH2COOH group, or an anhydride or ester thereof, or (ii) a di- or poly-carboxylic acid containing from 36 to 100 carbon atoms or an acid anhydride, acid chloride or ester thereof, and (II) a lubricating oil.