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:
Sep. 21, 2004
Filed:
Nov. 27, 2000
Arild Follestad, Stathelle, NO;
Klaus-Joachim Jens, Langesund, NO;
Richard Blom, Oslo, NO;
Ivar Martin Dahl, Oslo, NO;
Borealis Technology Oy, Porvoo, FI;
Abstract
A catalyst system for the polymerization of ethylene, comprising a particulate inorganic oxide supporting a chromium oxide being in a reduced oxidation state and a metallocene compound having the formula Cp ZrR′R″, wherein each Cp, being equal or different, is an unsubstituted or substituted cyclopentadienyl compound, and R′ and R′, independent of each other, are selected from the group comprising alkyls having 1 to 6 carbon atoms, unsubstituted or substituted benzyl, and phenoxy substituted with alkyls having 1 to 6 carbon atoms; or R′ or R″ may be a halide. The catalyst system is prepared by a method comprising the steps of calcining the support, joining onto the surface of the support a chronium-organic compound, subjecting the obtained catalyst precursor to oxidizing conditions to obtain the chromium in an oxidized state, reducing the oxidized chromium to obtain a main part thereof in a bivalent oxidation state, and contacting the reduced catalyst with the metallocene compound.