GB1479792A - Production of a catalytic composition suitable for the polymerization of alpha-olefins and its use - Google Patents

Abstract

1479792 Polymerizing olefins SNAMPROGETTI SpA 27 March 1975 [28 March 1974 (2)] 13093/75 Heading C3P Olefins may be polymerized in the presence of a catalyst comprising (A) an aluminium compound AlR 3 or AlR x Y 3-x where R is hydrocarbyl, Y is H or halogen and x is 1 or 2, and (B) the combination or association of titanium trichloride and another transition metal chloride finely dispersed on a material having a surface area of at least 50 m.<SP>2</SP>/g. which has been prepared by impregnating the high surface area material with a solution of a compound of the transition metal in a low or zero valence state and with titanium tetrachloride, causing or allowing the transition metal compound and titanium tetrachloride to react to produce titanium trichloride and a chloride of the other transition metal, evaporating the solvent, removing excess titanium tetrachloride and treating with the aluminium compound. The support may be a rare earth, magnesium, calcium, titanium or zinc oxide, silica, or silica-alumina. The transition metal may be vanadium, manganese, cobalt or iron complexed with allyl, carbonyl, nitrosyl or carbonic groups or with olefin or cyclopentadiene molecules. Many examples are given describing the polymerization of ethylene in the presence of hydrogen and catalysts formed by impregnating Nd 2 O 3 , La 2 O 3 , Ce 2 O 3 , silica-alumina, silica and magnesium oxide with Mn 2 (CO) 10 , cyclopentadienyl vanadium tetracarbonyl, iron pentacarbonyl or CO 2 (CO) 8 and with titanium tetraehloride, and treating the product with triisobutyl aluminium or diethyl aluminium chloride. In Example 19 the silica/alumina support is pretreated with isobutyl magnesium chloride.