The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 21, 1994
Filed:
Sep. 18, 1991
Neste Oy, Espoo, FI;
Abstract
The invention relates to a method for the preparation of a supported procatalyst intended for the polymerization of olefins, in which particles are formed from magnesium halide and alcohol, the particles are reacted with an organometallic compound of any of the metals of the groups I to III, the thus obtained particulate product is activated by means of a titanium(IV) compound, and optionally a prepolymerization is carried out for the activated particles. A problem with this kind of a method is, how to form particles from magnesium dihalide and alcohol having an advantageous structure for the polymerization of ethylene and particularly ethylene with a narrow molecular weight distribution. The problem has in the present invention been solved so that the particles are formed by spray-crystallizing a mixture of magnesium dihalide and alcohol to complex particles of magnesium dihalide and alcohol and that titanium(IV) alcoxyhalide has been used as the titanium compound. The catalytic properties of the particles thus obtained are improved, especially after the prepolymerization carried out by means of ethylene, which leads in the polymerization to a still more active, very hydrogen and comonomer sensible procatalyst having a better molecular weight selectivity. The invention also relates to the specific use of the procatalyst prepared by such a method for the polymerization of alpha-olefins. By a procatalyst is meant in this context the catalyst component of the Ziegler-Natta-catalyst which is based on the transition metal and which before the polymerization is combined with the organometallic compound of aluminium or some other metal acting as a cocatalyst.