| 摘要 |
A copolymer additive is a base copolymer obtainable by reacting, under free radical polymerisation conditions, (i) a set of first monomers comprising a mixture of alkylacrylates having C1-7, C8-16, and C17-30 alkyl groups with (ii) a second monomer comprising an olefinic carboxylic acylating agent. The second monomer is preferably maleic anhydride. The gravimetric ratio of the mixture of alkylacrylate monomers is typically 5:95:0.05 to 35:55:10. The base polymer optionally may be further reacted with an amine compound to provide a multi-functional polyalkylacrylate copolymer. The amine may be chosen from an aromatic amine and an aliphatic amine. The amine compound is selected from N-phenyl phenylene diamine and 4,4-diamino diphenylene amine. In another aspect, a multi-functional polymer viscosity modifier comprising the copolymer additive has a molecular weight of 50,000-1,000,000. Processes for forming the copolymer additive and a lubricating oil composition containing the copolymer additive are also disclosed. |
