Patent ID: 9657252
Date: 2017-05-23
CPC Classifications: C10M,C10N

Claim:
1. A lubricant additive for reducing a boundary friction coefficient of a lubricant composition, comprising a synergistic mixture comprising: a) a zinc dihydrocarbyl dithiophosphate antiwear compound derived from at least one secondary alcohol in an amount sufficient to provide the lubricant composition with from about 200 to about 835 ppm by weight phosphorus based on a total weight of the lubricant composition, wherein each hydrocarbyl group contains from 2 to 8 carbon atoms, wherein component (a) comprises a mixture of (i) a zinc dihydrocarbyl dithiophosphate antiwear compound derived from primary alcohols and (ii) a zinc dihydrocarbyl dithiophosphate antiwear compound derived from secondary alcohols, wherein a weight ratio of (i) to (ii) based on ppm by weight phosphorus provided by (i) and (ii) to the lubricant composition ranges from 0:1 to about 3:1, and b) a polyol derived from a diol and a mono-ol having a diol to mono-ol molar ratio ranging from about 0.3:1 to about 2.0:1, wherein the diol contains from 6 to 36 carbon atoms and the mono-ol contains from 12 to 16 carbon atoms, wherein the polyol in combination with component (a) provide a synergistic reduction in the boundary friction coefficient of the lubricant composition, wherein the polyol is present in an amount ranging from about 0.2 to about 1.0 wt. % based on the total weight of the lubricant composition.