SHEAR STABLE MULTIVISCOSITY GRADE LUBRICATING OILS ALPHAOLEFIN POLYMERS OF CONTROLLED MOLECULAR SIZE AND DISTRIBUTION AND METHOD OF PREPARATION

摘要

1359067 Olefin polymers GULF RESEARCH & DEVELOPMENT CO 8 June 1972 [14 June 1971 (2) 18 April 1972 (2)] 26719/72 Heading C3P [Also in Division C5] Alpha-olefin polymers produced from a C 5 -C 12 α-olefin or mixture of C 3 -C 12 α-olefins with at least 20 mol. per cent of C 5 -C 12 α- olefins and having a weight average molecular weight Mw of 50,000 (M/84) to 1,000,000 (M/84), a number average molecular weight Mn of 4,000 (M/84) to 1,000,000 (M/84) where M is the molecular weight of the α-olefin or average molecular weight of the mixture of α-olefins, and a distribution factor Mw/Mn of 1 to 12, the upper limit of said distribution factor being 12 when Mw is 50,000 (M/84) and 2 when Mw is 1,000,000 (M/84) with the upper limit of the distribution factor proportionately decreasing from 12 to 2 as Mw increases from 50,000 (M/84) to 1,000,000 (M/84), may be prepared by reacting the monomers at 38 to 121‹ C. in the presence of hydrogen at a partial pressure of 0À007 to 10À5 kg/cmSP2/SP and a Ziegler-Natta catalyst useful for the polymerization of propylene at an olefin to catalyst weight ratio of 300 to 6000. The olefin may be 1-pentene, 1-hexane, 4-methyl-1-pentene or 1-decene, optionally in admixture with propylene, 1- butene, isobutylene or 1-octane. Preferred catalysts are titanium and vanadium halides mixed with aluminium alkyls and alkyl halides. The process may be effected batchwise or continuously, optionally in the presence of modifiers such as zinc chloride or diethyl zinc. The products may be used to improve the viscosity characteristics of lubricating oils. Examples describe the preparation of (1 to 3 and 5 to 28) polyhexenes and (4) polydecene in the presence of aluminium activated titanium trichloride and triethyl aluminium.