POLYMER APPLICABLE AS VISCOSITY INDEX IMPROVER Russian patent published in 2016 - IPC C08F220/10 C08F220/18 C10M145/14 

FIELD: chemistry.

SUBSTANCE: what is described is a polymer applicable as a viscosity index improver, containing structural units produced of one or more ethylene-unsaturated esters of formula (I) where R is hydrogen or methyl; R¹ means a linear, branched or cyclic alkyl residue with 1-6 carbon atoms; R² and R³ independently represent hydrogen or a group of formula -COOR′, where R′ means hydrogen or an alkyl group with 1-6 carbon atoms; structural units of one or more ethylene-unsaturated esters of formula (II) where R is hydrogen or methyl, R⁴ means 2-alkyl-branched alkyl residue with 12-18 carbon atoms; R⁵ and R⁶ are independently hydrogen or a group of formula -COOR″, where R″ means hydrogen or an alkyl group with 12-18 carbon atoms, and structural units of one or more ethylene-unsaturated esters of formula (III) where R is hydrogen or methyl, R⁷ means a linear alkyl residue with 12-24 carbon atoms, R⁸ and R⁹ are independently hydrogen or a group of formula -COOR″, where R″ means hydrogen or an alkyl group with 12-24 carbon atoms; the polymer is characterised by the fact that it contains at least 10 wt % of the structural units produced from one or more compounds of formula (I) calculated using the total weight of the polymer, at least 10 wt % of the structural units produced from one or more ethylene-unsaturated esters of formula (II) calculated using the total weight of the polymer, and at least 10 wt % of the structural units produced from one or more ethylene-unsaturated esters of formula (III) calculated using the total weight of the polymer; a mass ratio of the structural units produced from one or more ethylene-unsaturated esters of formula (II) and the structural units produced from one or more ethylene-unsaturated esters of formula (III) ranges from 4:1 to 1:1. There are also described a lubricant composition containing the above polymer, and using the above composition for an automatic gearbox.

EFFECT: producing the polymer providing the high efficacy as a viscosity index improver with maintaining high shear stability.

22 cl, 2 tbl, 10 ex