| 摘要 |
<p>A catalyst composition for the polymerization of olefins, particularly the copolymerization of ethylene with at least one C3C7 alpha olefin, comprises a porous crystalline siliceous material containing in catalytically active form 0.03 to 3 weight percent chromium, 1.5 to 9 weight percent titanium and up to 2.5 weight percent fluorine.</p> |
