Neste Oy

Borealis Holding A/s

Marjaana Lommi

Sirpa Ala-Huikku

Eero I Iiskola

Ulf Palmqvist

A procatalyst composition which is suitable for the homo- and copolymerization of alpha olefins together with an organometallic cocatalyst compound and which is prepared by treating an inorganic carrier with a component system containing a complex of a magnesium halide and a tetraalkyl titanate, and a chlorinating compound which does not contain a transition metal compound. In order to raise the Mg:Ti ratio, the component system additionally contains an organomagnesium compound.

Procatalyst composition for homo- and copolymerization of alpha olefins,

The present invention relates to a procatalyst composition for the polymerization of alpha-olefines, which has been prepared in steps, in which is arranged a carrier agent based on at least one inorganic oxide, having few or no hydroxyl groups on its surface, and the carier agent is reacted with the magnesium compound and one or more transition metal compounds of the groups IVB and VB of the periodic table. It has been observed that such a catalyst is most-advantageous when a) this carrier agent is impregnated with a mixture of the Mg compound and one or more compounds of a transition metal of the groups IVb or Vb of the periodic table, which dissolves the Mg compound, and b) by chlorinating with a compound that does not contain titanium so that 1) the carrier is first treated with a mixture in the form of a solution of the Mg compound and the transition metal compound and the product thus obtained is chlorinated, or 2) the carrier is first chlorinated and subsequently treated with the above mixture in the form of a solution, or 3) the Mg compound and the transition metal compound are impregnated into the carrier without any separate dissolving and the product thus obtained is chlorinated.

Procatalyst composition for the polymerization of alpha-olefines,

A problem in the conventional olefin polymerization catalyst systems, the procatalysts of which are based on a solid carrier and a titanium compound and an electron donor on its surface, is that unsufficiently high activities are achieved by the morphology of the carrier. Moreover, the active age of such a catalyst in the polymerization is too short. These problems have now been solved by the olefin polymerization catalyst system according to the invention, the procatalyst of which comprises a solid carrier and a layer on its surface consisting of a titanium compound, a magnesium compound and an electron donor. The advantages of the invention become more emphasized when using monocyclopentadienyl titaniumtrichloride as the titanium compound.

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Kulloo, Finland

Marjaana Lommi