ETHYLENE/ALPHA-OLEFIN COPOLYMER

摘要

A copolymer of ethylene and an alpha-olefin having an ethylene content of from 30 to 90 mole%, a number average molecular weight of from 300 to 30,000 and a molecular weight distribution defined by a Q value (the ratio of the weight average molecular weight to the number average molecular weight) of not more than 3 and a Z value (the ratio of the maximum value of the molecular weight to the minimum value of the molecular weight when the molecular weight is measured by gel permeation chromatography) of from 15 to 200. The said copolymer can be produced by a process comprising copolymerizing ethylene with an alpha-olerin in the liquid phase in the presence of a polymerization catalyst composed of a combination of a soluble vanadium compound and an organoaluminum compound in the copresence of hydrogen, characterized in that (a) the copolymerization is carried out in a continuous manner, (b) the concentration of the vanadium compound in the polymerization system is maintained at 0 3 to 30 millimoles/liter, and (c) the vanadium compound is supplied to the polymerization system as a solution in a polymerization medium in a concentration which is 1 to 5 times the concentration of the vanadium compound in the liquid phase. This compound is useful as a synthetic lubricant oil, a fuel oil additive and a lubricant oil additive.