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:
Mar. 19, 2002
Filed:
Mar. 10, 2000
Olivier Lhost, Howré, BE;
Nicole Dewaele, Brussels, BE;
Martine Frederickx, Ophain Bois-Seigneur Isaac, BE;
Joel Kaisin, Ligny, BE;
Solvay Polyolefins Europe - Belgium, Brussels, BE;
Abstract
The invention relates to a process for the production of ethylene polymers by the polymerization of ethylene or the copolymerization of ethylene with one or more C to C olefins in contact with a chromium-based catalyst deposited on a support essentially consisting of silica. According to the invention, the chromium catalyst is subjected in succession to a heat treatment in nitrogen and then to a heat treatment in air under defined temperature conditions before bringing it into contact with ethylene and, optionally, one or more olefins under polymerizing conditions. The process of the invention makes it possible to manufacture ethylene polymers having an improved compromise between processability, stiffness and resistance to slow crack growth.