| abstract |
Gel-free dispersant additives for lubricating and fuel oil compositions comprise at least one adduct of (A) α-olefin homopolymer or interpolymer of 700 to 10,000 M^¨B7n, free radically grafted with an average of from 0.5 to 5 carboxylic acid producing moieties per polymer chain, and (B) at least one non-aromatic nucleophilic post-treating reactant selected from: (i) amines containing only a single reactive amino group per molecule, (ii) alcohols containing only a single hydroxy group per molecule, (iii) polyamines containing at least two reactive amino groups per molecule, (iv) polyols containing at least two reactive hydroxy groups per molecule, (v) aminoalcohols containing at least one reactive amino group and at least one reactive hydroxy group per molecule, and (vi) mixtures of (i) to (v); provided that when said post-treating reactant includes one or more of (iii), (iv) or (v), the reaction between ( A) and (B) is conducted in the presence of sufficient chain-stopping or end-capping co-reactant (C) to ensure that the grafted and post-reacted product mixture is gel-free. |