CATALYST FOR POLMERIZING AN OLEFIN AND PROCESS FOR POLYMERIZING AN OLEFIN BY USING SUCH CATALYST

摘要

An olefin is polymerized or copolymerized in the presence of an olefin-polymerizing catalyst prepared from (A) a transition-metal compound or (A') a transition-metal compound loaded on a fine-particle carrier, said transition metal being selected from group IVB in the periodic table; (B) an aluminoxane; and (C) an organoaluminum compound represented by the general formula ¢I! or ¢II!: R1mAl(OR2)3-m ¢I! R3nAl(OSiR43)3-n ¢II! wherein R1, R2, and R3 are independently selected from hydrocarbon radicals, R4 is selected from the group consisiting of hydrocarbon, alkoxy, and aryloxy radicals, and m and n are independently a positive number of more than 0 and less than 3. This catalyst has a significantly high polymerization activity, and the thus produced olefin polymer or copolymer has a narrow molecular-weight distribution as well as a narrow composition distribution, a high bulk density, and excellent powder properties.