| 摘要 |
A dispersant prepared by (i) reacting polyamine with acyclic hydrocarbyl substituted succinic acylating agent in which the substituent contains an average of at least 70 carbon atoms, and (ii) reacting the product so formed with an aliphatic vicinal dicarboxylic acylating agent having 4 to 6 carbon atoms in the molecule (excluding, in the case of esters, the carbon atoms of the esterifying alcohol). In step (i) the acylating agent is reacted with the polyamine in a mole ratio of from 1.05 to 2.85 moles of acylating agent per mole of polyamine, and in step (ii) the vicinal dicarboxylic acylating agent is employed in an amount sufficient to provide a total mole ratio of at least 3.05 moles of acylating agents per mole of polyamine. Lubricant compositions and additive concentrates capable of passing the ASTM Sequence VE Engine Test for "SG" performance and the Volkswagen Seal Test can be formed using dispersants made in this manner. |
