Copolymer of ethylene and alpha-olefin, and method for preparing same

摘要

A liquid random copolymer of ethylene and alpha-olefin prepared by using specific metallocene catalyst and ionic compound and a method for preparing the same are disclosed. The liquid random copolymer has high viscosity index and shear stability so that it is useful as synthetic lubricants. The liquid random copolymer of ethylene and alpha-olefin (1) comprises 60 to 40 mol % of ethylene units and 40 to 60 mol % of alpha-olefin unit having 3 to 20 carbon atoms, (2) has number average molecular weight (Mn) of 500 to 10,000 and a molecular weight distribution (Mw/Mn, Mw is the weight average molecular weight) of 3 or less measured by Gel Permeation Chromatography (GPC) (3) has Kinematic Viscosity at 100° C. of 30 to 5,000, (4) has pour point of 30 to −45° C., and (5) has Bromine Number of 0.1 or less.

主权项

1. A method for preparing a liquid random copolymer of ethylene and alpha-olefin, comprising a step of:
carrying out solution polymerization of ethylene and alpha-olefin having 3 to 20 carbon atoms, under a catalyst system containing:
(A) a bridged metallocene compound represented by following Formula 1, and(B) at least one compound selected from a group consisting of (i) an organoaluminum oxy-compound and (ii) a compound which reacts with the bridged metallocene compound to form ion pair, wherein, R1 and R4 are hydrogen atom; R2, R3, R5, R8, R9 and R12 are independently hydrogen atom, hydrocarbon group or silicon-containing hydrocarbon group, and adjacent groups can be connected to form a ring structure at least one of R2 and R3 is hydrocarbon group having 4 or more carbon atoms; R6 and R11 are the same as each other and are hydrogen atom, hydrocarbon group or silicon-containing hydrocarbon group R7 and R10 are the same as each other and are hydrogen atom, hydrocarbon group or silicon-containing hydrocarbon group; R6 and R7 can be connected to hydrocarbon having 2 to 3 carbon atoms to form a ring structure R11 and R10 can be connected to hydrocarbon having 2 to 3 carbon atoms to form a ring structure; R6, R7, R10 and R11 are not hydrogen atom at the same time; Y is carbon atom or silicon atom; R13 and R14 are independently aryl group; M is Ti, Zr or Hf; Q is independently halogen, hydrocarbon group, anionic ligands or a neutral ligand which can be coordinated to a lone pair of electrons; j is an integer of 1-4; and wherein the liquid random copolymer (1) comprises 40 to 60 mol % of ethylene units and 60 to 40 mol % of alpha-olefin units having 3 to 20 carbon atoms; (2) has a number average molecular weight (Mn) of 500 to 10,000 and a molecular weight distribution (Mw/Mn wherein Mw is weight average molecular weight) of 3 or less measured by gel permeation chromatography (GPC); (3) has a kinematic viscosity at 100° C. of 30 to 5,000; (4) has a pour point of 30 to −45° C., and (5) has a bromine number of 0.1 or less.