AUTOMOTIVE GEARBOX LUBRICATING OIL COMPOSITION Russian patent published in 2022 - IPC C10M111/04 C10M169/04 C10M101/02 C10M171/00 C10N20/02 C10N30/02 C10N30/06 C10N40/04 

FIELD: lubricants.

SUBSTANCE: present invention discloses a lubricating oil composition for an automobile gearbox, containing: as low-viscosity base oils: (i) from 45 to 95 wt. % synthetic low-viscosity Fischer — Tropsch base oil with kinematic viscosity at 100 °C from 1 mm²/s to 2 mm²/s and from 0 to 25 wt. % polyalphaolefin base oil with kinematic viscosity at 100 °C from 1 mm²/s to 2 mm²/s, and (ii) from 0 to 35 wt. % synthetic base oil Fischer — Tropsch with kinematic viscosity at 100 °C more than 2 mm²/s and not more than 5 mm²/s; and (iii) from 11 to 30 wt. % olefin polymer or copolymer as a high-viscosity base oil with kinematic viscosity at 100 °C from 100 to 800 mm²/s. Lubricating oil composition for automatic transmission is characterized by the fact that kinematic viscosity at 100 °C ranges from 3.8 to 5.5 mm²/s, viscosity index is not less than 190, flash point is not less than 140 °C and degree of reduction of kinematic viscosity at 100 °C after shear stability test at 60 °C for 20 hours is maintained at the level of not more than 3 %.

EFFECT: obtaining a lubricating oil which is suitable for use in a wide temperature range and which can improve fuel economy, as well as lubricating oil for an automatic transmission, which has high viscosity index at low viscosity, which has excellent viscosity characteristics at low temperatures, which has good shear stability and which is also characterized by weak evaporation at high temperatures and has a high flash point.

4 cl, 4 tbl, 8 ex