| 摘要 |
PURPOSE:To provide the title copolymer compsn. with excellent rigidity and impact resistance of a molded item thereof and improve hardly whitening properties by compounding a block copolymer obtd by copolymerizing ethylene with propylene at two specified stages with a specified amt. of a high-density polyethylene. CONSTITUTION:Ethylene and propylene are copolymerized by two stage copolymn. wherein in the first-stage copolymn., 80-90wt.% ethylene/propylene copolymer with an ethylene content of 1-2wt.% is produced based on the whole amt. of polymn. and then, in the second-stage copolymn, 20-10wt.% ethylene/ propylene copolymer with an ethylene content of 75-85wt.% is produced based on the whole amt. of polymn. Then, an ethylene/propylene copolymer compsn. is prepd. by compounding the obtd. ethylene/propylene block copolymer with 5-15wt.% high-density polyethylene with a density of 0.945g/cm<2> or higher. |
