| abstract |
This invention relates to a process for preparing an additive comprising the steps of: (1) reacting a polymer derived from of an olefin containing 2 to 8 carbon atoms with an acylating agent to form an acylated polymer; and (2) reacting the acylated polymer of step (1) in a medium substantially free of to free of sulphur with: (a) ammonia or an amine to form a succinimide product; or (b) water to form a hydrolysed product, wherein the mole ratio of the acylating agent to polymer in step (1) is from 0.3:1 to 1.6:1. The invention further relates to compositions containing the additive and its use. |