CONTINUOUSLY VARIABLE TRANSMISSION LIQUID FREE FROM ZINC

摘要

PROBLEM TO BE SOLVED: To obtain a zinc-free lubricant oil that has an ability to give a high steel-steel friction factor and is useful for variable speed transmission by adding a large amount of lubricant and a specific enhancing additive. SOLUTION: This objective lubricant composition is prepared by using (A) a large amount of lubricant and (B) the performance-enhancing mixture comprising (i) a polyisobutenenyl succinimide ash-free dispersant with the number average molecular weight of polyisobutenyl group of 700-1,200; (ii) an organic phosphite of formula I (R is a hydrocarbyl, H; R1 is a hydrocarbyl; R or R1 may includes thioether); (iii) a calcium perbasic phenate washing agent in an concentration enough to keep the calcium <= about 5,000 ppm in the fluid; (iv) a friction improving agent that including a succinimide of formula II (R7 is a 6-30 alkyl; z is 1-10) and an ethoxylated amine and (v) a primary amine amide of a long-chain carboxylic acid.