| 摘要 |
PURPOSE:To obtain a low-crystallinity ethylene copolymer of a narrow MW distribution and a narrow composition distribution by increasing the polymerization activity, by copolymerizing ethylene with an alpha-olefin in the presence of a catalyst comprising a specified transition metal compound and an aluminoxane. CONSTITUTION:Ethylene is copolymerized with an alpha-olefin at -50-200 deg.C in the presence of a catalyst comprising an aluminoxane and a compound of a transition metal selected from among zirconium, hafnium and vanadium. By said polymerization, a low-crystallinity ethylene copolymer of an ethylene component content of 20-85wt%, a MW distribution (formula I) <=2.5 and a crystallinity <=30% is obtained. Said transition metal compound is preferably in a form of a compound having hydrocarbyl groups or a compound having hydrocarbyl groups and halogenatoms. Examples of said aluminoxanes include organoaluminum compounds of formulas II and III (wherein R is a hydrocarbyl group and m is an integer >=2). |
