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. 16, 1998
Filed:
Aug. 12, 1997
Harri Hokkanen, Helsinki, FI;
Hilkka Knuuttila, Porvoo, FI;
Eeva-Liisa Lakomaa, Espoo, FI;
Pekka Sormunen, Charlottenlund, DK;
Borealis A/S, Lyngby, DK;
Abstract
Provided are heterogeneous catalysts for homo- and copolymerization of olefins as well as a method for preparing these catalysts, which comprise at least one metallocene compound of a Group 4A, 5A or 6A (Hubbard) transition metal on a solid inorganic support. The mtehod comprises the steps of vaporizing the metallocene compound, treating the support material with the vaporized metallocene compound at a temperature which is sufficiently high to keep the metallocene compound in the vaporous state, contacting the support material with an amount of the vaporized metallocene compound which is sufficient to allow for a reaction between the metallocene compound and at least a substantial part of the available surface sites capable of reacting therewith, removing the rest of the metallocene compound not bound to the support, and optionally treating the product thus obtained with an activating agent. The catalysts are active even if very low amounts of activator agents, such as alumoxane, are used. Furthermore, the polymerization performance of the catalysts can be regulated during the preparation of the catalysts. Thus, by using different support pretreatment temperatures, or by using two or more different metallocenes, and by altering the order in which they are added on the support, it is possible to control and regulate the activity of the catalysts and the polymer properties, such as molecular weight and molecular weight distribution.