Hydrogenated polydiolefins as viscosity index improvers - for lubricating oil, giving improved shear stability

摘要

Hydrogenated polydiolefins are added to mineral oils in an amt. of 0.5-6 wt. %. Although they are of the same compsn. as known V.I. improvers from completely hydrogenated ethylene/butene-1 copolymers, they give improved shear stability. Pref. polybutadiene contg. 30-95 (40-65) double bonds with 1,2-consign. is used and hydrogenated catalytically in homogeneous or heterogeneous phase until it contains =3 pref. 1% olefinic double bonds, based on those originally present.