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:
Oct. 23, 2012
Filed:
Jul. 21, 2009
Gerhardus Meier, Frankfurt am Main, DE;
Shahram Mihan, Bad Soden, DE;
Massimo Covezzi, Ferrara, IT;
Basell Polyolefine GmbH, Wesseling, DE;
Abstract
A method for transitioning from a first to a second catalyst system for the olefin polymerization reaction in one reactor, wherein the first catalyst system is incompatible with the second catalyst system, is described. The method comprises the steps of a) discontinuing a first olefin polymerization reaction performed in the presence of the first catalyst system; and b) performing a second olefin polymerization reaction in the presence of the second catalyst system comprising catalyst components (A) and (B) producing, respectively, a first and a second polyolefin fraction, wherein the Mof the first polyolefin fraction is less than the Mof the second polyolefin fraction and the initial activity of catalyst component (A) exceeds the initial activity of catalyst component (B). Thanks to this method, there is no need to empty the reactor after the first olefin polymerization reaction, and the transitioning time needed to attain the desired quality of the polyolefin obtained in the second olefin polymerization reaction is sufficiently short to permit a quick and reliable change of production.