Reibungsmodifizierende Zusammensetzungen und ihre Verwendung

A new friction modifier system is described. It has the capability of establishing and maintaining a substantially constant static breakaway coefficient of friction between a pair of friction surfaces that are periodically frictionally engaged with each other. Also this system is capable of maintaining a substantially constant ratio between (i) the low speed dynamic coefficient of friction of such friction surfaces, and (ii) the (midpoint) dynamic coefficient of friction of such friction surfaces. The additive composition yielding these results comprises at least the following components: a) a hydroxyalkyl aliphatic imidazoline in which the hydroxyalkyl group contains from 2 to about 4 carbon atoms, and in which the aliphatic group is an acyclic hydrocarbyl group containing from about 10 to about 25 carbon atoms; and b) a di(hydroxyalkyl) aliphatic tertiary amine in which the hydroxyalkyl groups, being the same or different, each contain from 2 to about 4 carbon atoms, and in which the aliphatic group is an acyclic hydrocarbyl group containing from about 10 to about 25 carbon atoms.