Abstract: An additive, adapted to improve the viscosity index of a mineral or synthetic lubricating oil, is prepared from polymeric material of very high viscosity boiling above 175.degree.C, and obtained through polymerization of normal alpha-olefines having the general formula R--CH = CH.sub.2, wherein R is an alkyl radical containing from 2 to 16 carbon atoms, in the presence of a TiCl.sub.4 /polyiminoalane catalyst, in a substantially inert atmosphere which may contain hydrogen up to a manometer pressure of 1 kg/cm.sup.2, by distilling said polymeric material so that the fraction boiling at a temperature below 350.degree.C at atmospheric pressure is removed therefrom, and catalytically hydrogenating the balance thereof to produce the desired end product.

Abstract: Synthetic lubricating oil having a high viscosity index, very low pour point, low viscosity at 0.degree.F, high thermal stability, high resistance to depolymerization, high flash point and very low carbon residue, is prepared by subjecting polymeric material of very high viscosity boiling above 175.degree.C, and obtained through polymerization of normal alpha-olefines having the general formula R-CH = CH.sub.2, wherein R is an alkyl radical containing from 2 to 16 carbon atoms, in the presence of a TiCl.sub.4 /polyiminoalane catalyst, in a substantially inert atmosphere which may contain hydrogen up to a manometer pressure of 1 kg/cm.sup.2, to thermal cracking at atmospheric pressure and in the temperature range of 300.degree.C to 420.degree.C at a contact time in the range of 5 minutes to 4 hours, and then distilling product so obtained under vacuum to a temperature which corresponds to a distillation temperature of 400.degree.

Abstract: A liquid polymer having a very high viscosity of between 250 cSt and 15,000 cSt at 210.degree.F, is prepared by polymerizing one, or a mixture of more than one, n-alpha olefine represented by the formula R - CH = CH.sub.2, in which R is an alkyl radical containing from 6 to 8 carbon atoms, in the presence of a catalyst system formed at a temperature in the range of 0.degree.-150.degree.C by a catalyst consisting of TiCl.sub.4 and a polyiminoalane having the formula: ##EQU1## IN WHICH N IS A WHOLE NUMBER NOT GREATER THAN 50 AND R is an isopropyl radical, and in an atmosphere consisting essentially of an inert gas. The liquid polymer of very high viscosity so formed is useful as a lubricant.