Patent ID: 6255258
Filing Date: 2001-07-03
Classification: C10M,C10N

Abstract:
An oil-soluble, post-treated dispersant obtained by reacting:(A) the reaction product of a polyamine of formula (I):H.sub.2 N--(CHR.sup.1).sub.x --CH.sub.2 --(A--CH.sub.2 --(CHR.sup.1).sub.2).sub.y --NH.sub.2 (I)wherein A is NH or O; each R.sup.1 is H or methyl; x is 1-6; and y is 1-10 when A is NH, or 1 to 200 when A is O; and a long-chain hydrocarbyl-substituted dicarboxylic acid, anhydride or ester thereof, which is a reaction product of a polyolefin and a C.sub.4 -C.sub.10 dicarboxylic acid, anhydride or ester; with(B) a polyanhydride;characterised in that the post-treated dispersant provides a reduced viscosity increase in a sooted oil relative to a corresponding, non-post-treated dispersant.