| 摘要 |
PURPOSE:To prepare a propylene copolymer containing small amount of a component soluble in cold xylene, and having excellent slippery, anti-blocking property and low-temperature heat-sealability, by the block copolymerization of propylene and other alpha-olefin using a specific catalyst system. CONSTITUTION:Propylene is copolymerized with a 4-18C alpha-olefin (pref. butene), (and a small amount of ethylene), by the bulk polymerization at about 40-80 deg.C in the liquid phase of the monomers, in the presence of a catalyst system comprising (A) a titanium compound obtained by treating (a) a beta-type TiCl3 obtained by reducing TiCl4with an organo-aluminum compound with (b) a complexing agent, an organo-aluminum compound, TiCl 4, etc. and (B) an organo-aluminum compound. The resulting copolymer pref. contains about 3-30 wt% of alpha-olefin unit and about 0-5 wt% of ethylene unit. |
