GB940143A - Liquid polymers from alpha-olefins - Google Patents

Abstract

940,143. Liquid alpha - olefin polymers. ATLANTIC REFINING CO. April 20, 1961 [May 5, 1960], No. 14268/61. Heading C3P. Liquid hydrogenated polymers, suitable for use as lubricating oils, having a high oxidation inhibitor susceptability, a viscosity index of at least 135, or pour point not higher than about -25‹F., and a molecular weight of from about 400 to 700, are made by polymerizing an alphaolefin of the formula R-CH=CH 2 where R is a straight-chain alkyl radical containing from 6 to 10 carbon atoms in the presence of a catalyst consisting essentially of titanium tetrachloride and aluminium triisobutyl or an aluminium dialkyl hydride wherein the Ti to Al atomic ratio ranges from 2:1 to 7:1, recovering the liquid polymer, and hydrogenating it to produce a saturated oil. The polymerization is preferably effected in an inert hydrocarbon diluent. The alpha-olefin may be octene-1, nonene-1, decene-1, undecene-1, or dodecene-1. The aluminium hydride may be aluminium diethyl, dipropyl, or diisobutyl hydride. At the end of the polymerization reaction the catalyst is destroyed by conventional techniques e.g. water, methyl alcohol, or a dilute aqueous acid solution. The hydrogenation is generally effected at a pressure of 2,000 to 3,000 p.s.i. and at a temperature between 350 and 450‹F. using a Ni-on-kieselguhr or a platinum dioxide catalyst. The hydrocarbon diluent may be a pentane, hexane, heptane, octane, nonane, or decane, cyclohexane, methylcyclohexane, or dimethylcyclohexane, or benzene, toluene, or a xylene. Prior to hydrogenation unreacted monomer, and dimers are removed by distillation.