DISPERSANT

摘要

A novel ashless polymeric dispersant is claimed which is suitable for use in an automotive lubricant composition. The ashless polymeric dispersant has a number average molecular weight of between 200 and 15,000 and derived from the reaction of a polar head group, which comprises a polar moiety having more than one amine, alcohol, acid or halogen functionality with two or more polar tail groups where each polar tail group comprises a polymeric backbone of 2 to 30 monomeric repeat units, each repeat unit comprising a hydrocarbon chain functionalised by the presence of at least one electronegative element or moiety. The dispersant has good dispersancy properties, when used as a sole dispersant or in combination with other dispersants. It provides enhanced seal resistance and has good oxidative stability in automotive applications as compared to current commercial products. Furthermore the low temperature viscosity of an automotive lubricant composition containing the dispersant is superior to that of a composition with current commercial dispersants.