LUBRICATING OIL COMPOSITION FOR AUTOMATIC GEARBOX Russian patent published in 2020 - IPC C10M169/04 

FIELD: chemistry.

SUBSTANCE: invention relates to a lubricating oil composition for automatic transmissions, containing low viscosity base oil from 55 to 85 wt % synthetic Fischer—Tropsch oil with kinematic viscosity making at 100 °C from 2 to 4 mm²/s; high-viscosity basic oil is from 1 to 10 wt % ethylene-α-olefin copolymer with kinematic viscosity of, at 100 °C from 150 to 1000 mm²/s; and from 9 wt % up to 11 wt % polymethacrylate with weight-average molecular weight of 15000 to 30000; and wherein viscosity index of composition is not less than 190, Brookfield viscosity at low temperature (−40 °C) is not more than 6000 MPa·s, kinematic viscosity at 100 °C ranges from 6 to 7 mm²/s, and rate of reduction of kinematic viscosity after KRL-test for shear resistance (60 °C, 20 hours) is maintained within not more than 3 %.

EFFECT: technical result is excellent viscosity characteristics at low temperatures and good shear resistance.

3 cl, 12 ex, 3 tbl