To provide an environmentally friendly viscosity index improving composition useful for passenger car motor oil (PCMO), gear oil, automatic transmission fluid (ATF), hydraulic fluid, chamber lubricant, sliding surface lubricant for machine operation, diesel lubricant and tractor fluid.
The environmentally friendly viscosity index improving composition comprises (A) at least one vegetable or synthetic triglyceride oil of formula (1) (wherein, R1, R2 and R3 are aliphatic hydrocarbyl groups having at least 60% monounsaturated character and containing from about 6 to about 24 carbon atoms), and (B) at least one mixed ester of a carboxy-containing interpolymer. In addition to constituents (A) and (B), the composition may also contain (C) a synthetic ester base oil and/or (D) an antioxidant.
SEEBAUER JOSEPH G
MAMAJEK CONRAD A
Takaaki Yasumura
Natsuki Morishita