| abstract |
A component of a polymerisation catalyst is prepared by reacting an organo-magnesium halide with a solid, inorganic oxide, then reacting the product with a Lewis Base compound, particularly as ester and finally with titanium tetrachloride. After reacting the organo-magnesium halide with the inorganic oxide it may be treated with a halogenating agent before it is reacted with the Lewis Base compound. The product obtained is combined with an organo=aluminium compound preferably together with a Lewis Base and used to polymerise an olefine monomer particularly propylene or mixtures of ethylene and a I-olefine containing at least 4 carbon atoms. The catalyst system has a high activity, is stereospecific and has a lower proportion of halogen than some other catalyst systems. |