POLY(METH)ACRYLATE COPOLYMERS WITH BRANCHED C ALKYL CHAINS AND USE THEREOF IN LUBRICATING OIL COMPOSITIONS Russian patent published in 2020 - IPC C10M145/14 

FIELD: chemistry; lubricants.

SUBSTANCE: present invention relates to lubricating oil compositions containing poly(meth)acrylate copolymers containing an alkyl(meth)acrylate comonomer with branched C₁₇ alkyl group as a component, improving viscosity index. Disclosed is a poly(meth)acrylate copolymer obtained by polymerising a mixture containing: C₁₇ alkyl(meth)acrylate, where C₁₇ alkyl chain is branched with average degree of branching from 2.0 to 4.0, wherein average degree of branching is determined by means of ¹H-NMR spectroscopy, methyl methacrylate and/or methyl acrylate, and alkyl methacrylate and/or alkyl acrylate with linear or branched C₂-C₁₈ alkyl chain, wherein comonomer (C) is linear or branched, having branched degree of 1.0, and a method of improving stability under shear conditions of lubricating oil.

EFFECT: technical result is obtaining poly(meth)acrylate copolymers, capable of providing lubricating oil compositions with favorable properties of modifying rheological properties at low and high temperatures, including high viscosity index and excellent stability under shear conditions.

12 cl, 4 tbl, 6 ex