| 摘要 |
<p>A catalyst composition suitable for promoting the polymerization of 1-olefins comprises a porous, crystalline zeolite having a silica to alumina ratio of at least 12 and a Constraint Index of 1 to 12 and a catalytically active chromium or titanium compound selected from:- a) a pi-bonded organochromium [II] compound, b) chromium ion exchanged with the zeolite, and c) an organometallic compound of the formula:- <CHEM> wherein M is a metal selected from titanium or chromium; R1 and R2 are each selected from H and methyl; R3 is H, alkyl, cyclohexyl, alkylcyclohexyl, cyclohexylalkyl, phenyl, alklphenyl, benzyl or dimethylbenzyl; and x is 3 or 4. l</p> |
