Process for the preparation of dispersant viscosity index improvers.

摘要

The invention provides a process for the preparation of a dispersant viscosity index improver aminated polymer comprising the steps of: (a) producing a functionalised polymer by grafting an alpha-beta unsaturated carboxylic moiety selected from the group consisting of acids, anhydrides and esters, to a base polymer selected from the group consisting of i) selectively hydrogenated block copolymers comprising one or more blocks comprising predominantly conjugated diolefin monomer units, and one or more blocks comprising predominantly monoalkenyl arene monomer units, and ii) hydrogenated polymers comprising conjugated diolefin monomer units, where the functionalisation is performed in a device capable of imparting high mechanical energy and is performed in the presence of from 3.0% to 15% by weight based on the amount of base polymer of an diluent oil; (b) reacting the functionalised polymer with an amine to form an aminated polymer; and (c) recovering the aminated polymer; and lubricating oils containing the aminated polymers prepared by the process.