| 摘要 |
Alumina-supported halogen-containing transition metal compounds prepared in such manner that (a) the transition metal compound is chemically bound to and supported by an activated alumina having a high surface area and an internal pore volume greater than 0.8 cc/g., (b) the concentration of the transition metal compound chemically bound to the support is greater than 10 grams of transition metal per kilogram of activated alumina, and (c) the atom ratio of halogen to transition metal on the support is higher than that of the halogen-containing transition metal compound which is used and preferably greater than 3:1, have been found to be unusually effective cocatalysts for the polymerization of ethylene and other alpha -olefins. These supported cocatalysts, which may be used to produce polyethylene as well as interpolymers of ethylene with other alpha -olefins and with diolefins, are prepared by heating an alumina hydrate (such as boehmite) to a temperature in the range from about 500 DEG C. to 900 DEG C. for a period of time sufficient to form an activated alumina having an internal pore volume greater than 0.8 cc/g., and then reacting the resultant activated alumina under substantially anhydrous conditions with a halogen-containing compound of a transition metal of Groups IV-A, V-A or VI-A of the Periodic Table. When ethylene is polymerized or copolymerized in the presence of a catalytic amount of the reaction product of an organometallic compound of a metal of Groups I-B, II-A, II-B, III-B or IV-B of the Periodic Table, and one of these supported cocatalysts, it is possible to produce normally solid, high molecular weight polyethylene or interpolymers of ethylene and other alpha -olefins at exceptionally high yields of polymer per gram of catalyst. |
