Conversion of alpha-olefin dimer to liquid lubricant basestock

Abstract

A process is disclosed for the preparation of low viscosity lubricant range hydrocarbons having high viscosity index which comprises: contacting olefinic dimer, or mixtures thereof, with a Group 6 metal oxide disproportionation catalyst on a solid support under disproportionation reaction conditions. The dimer comprises the product of the oligomerization of C.sub.6 -C.sub.20 alpha-olefins in contact with reduced chromium oxide catalyst on silica support. The disproportionation catalyst preparation includes treatment by oxidation at a temperature of 200.degree. C. to 900.degree. C. in the presence of an oxidizing gas and then treatment with a reducing agent at a temperature and a time sufficient to reduce said catalyst. The disproportionation reaction effluent is separated and lubricant range hydrocarbons recovered. The preferred disproportionation catalyst for the process is reduced tungsten oxide on silica support. It has been found that the instant invention produces a novel lubricant composition which comprises the mono-olefinic bimolecular adduct of C.sub.12 -C.sub.40 mono-olefin hydrocarbons. The adduct contains between 2n-2 and 2n-(n/2+3) carbon atoms, where n is the number of carbon atoms in said C.sub.12 -C.sub.40 mono-olefins hydrocarbons. A preferred mono-olefin hydrocarbon is the dimer of 1-decene.

Dependencies are inferred from the claim text.