| 摘要 |
PURPOSE:To provide the subject composition having a high crystallization rate and extremely good modulability, giving molded products having good mechanical strengths and optical characteristics and efficiently prepared in a catalyst residue-reduced state by comprising a specific butene-1 (co)polymer and polyethylene. CONSTITUTION:A polyolefin composition comprises (A) 0.002-5wt.% of polyethylene produced by the preliminary polymerization of ethylene and (B) 99.998-95wt.% of butene-1 homopolymer or a butene-1 copolymer containing <=25% of any other olefin monomer units prepared by polymerizing the monomer or monomers in the presence of a solid catalyst component containing Mg, a halogen, Ti and an electron-donating compound as essential components and having an intrinsic viscosity of 1.0-5.5dl/g (measured in a decalin solution at a temperature of 135 deg.C). The polyolefin composition is prepared by preliminarily polymerizing the ethylene in the presence of the solid catalyst component and an organic aluminum compound (in a preliminary polymerization amount of 0.2-100g/mmol-Ti) and subsequently polymerizing the butene-1 (mixture) in the ethylene prepolymer at 50-100 deg.C. |
