LUBRICATING COMPOSITION WITH IMPROVED VISCOSITY CHARACTERISTICS AT LOW OPERATING TEMPERATURE Russian patent published in 2021 - IPC C10M145/14 C10M107/28 C10M169/04 C10M143/10 C08F290/00 C08F299/00 C10N30/02 

FIELD: lubricants.

SUBSTANCE: present invention relates to lubricating compositions intended for industrial applications that have improved viscosity characteristics at low operating temperature. The lubricating composition contains: (A) 20 to 90 wt % synthetic base oil and (B) 10 to 80 wt % comb polymer containing the following monomers: (a) 20 to 35 wt % esters (meth)acrylic acid with hydroxylated hydrogenated polybutadiene, (b) 0.2 to 15 wt % styrene, (c) 0.2 to 20 wt % alkyl methacrylates containing 12 to 15 carbon atoms in the alkyl chain, (d) 50 to 70 wt % alkyl (meth) acrylates containing from 1 to 4 carbon atoms in the alkyl chain, and (e) 0.1 to 0.2 wt % methyl methacrylate, based on the total weight of the comb polymer. The application also describes the use of a comb polymer to produce a lubricating composition with an unexpectedly low R value of 1 to 8, where the R value is defined as the ratio of the kinematic viscosity at -20ºC to the kinematic viscosity at +20ºC, where the viscosities are determined in accordance with the ASTM D445 standard.

EFFECT: proposed lubricating compositions have improved viscosity characteristics at low operating temperature.

14 cl, 3 tbl