HYDRAULIC OIL Russian patent published in 2000 - IPC

FIELD: hydraulic drive and hydrocontrol of building, road, lumbering, hoisting and transport, and other machines operating in air at working temperatures from minus 55 C to minus 65 C. SUBSTANCE: oil comprises, wt %: polymethyl siloxane, 0.001-0.005; ionol (2,6-di- tertbutyl-4-methylphenol), 0.2-0.3; zinc dialkyl dithiophospate, 1.0-1.6; triple ethylene-propylene- dicyclopentadiene copolymer with molecular weight of 30,000-70,000, 0.2-1.0; polyisobutylene with molecular weight of 6000-20,000, 1.0-5.0; and transformer oil-base distillate, up to 100. Transformer oil-base distillate has kinematic viscosity of least 3.6-4.3 cSt at 50 C, 290-360 cSt, at minus 40 C, evaporates within 275-340 C, solidification temperature is minus 53 C, flash temperature is 135 C. EFFECT: improved low-temperature properties (solidification temperature is minus 53 C), improved compatibility with rubber seals in shock absorbers. 7 ex, 2 tbl