| 摘要 |
Process for polymerizing ethylene or mixtures of ethylene with up to 40 weight % of other 1-olefin(s) by contacting the monomer with a catalyst (A) in the presence of a catalyst modifier (B), catalyst (A) being prepared by supporting chromium trioxide, or a chromium compound calcinable thereto, on a refractory oxide support material and heat activating, catalyst modifier (B) comprising (1) a trihydrocarbyl aluminum compound and (2) an alpha , omega -aliphatic diene containing a chain of at least 6 carbon atoms. The refractory oxide is preferably silica, alumina, zirconia, thoria or silica-alumina. The trihydrocarbyl aluminum compound is suitably an alkyl, aryl or alkaryl aluminum. The alpha , omega -diene is peferably 1,5-hexadiene or 1,7-octadiene. The polymerization is preferably carried out under particle form process conditions in a fluid medium. |
