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:
Nov. 24, 1992
Filed:
Jan. 02, 1990
Jean-Claude A Bailly, Martigues, FR;
John G Speakman, Bo'ness, GB;
BP Chemicals Limited, London, GB;
Abstract
The present invention relates to a process for the polymerization of ethylene or copolymerization of ethylene and at least one other alpha-olefin, in the gas phase in a fluidized bed reactor, in the presence of a catalyst comprising chromium compounds associated with a granular support comprising a refractory oxide and activated by thermal treatment, which process is characterized in that the catalyst is used in the form of active particles of prepolymer, obtained by bringing the said catalyst in contact with ethylene, alone, or in a mixture with at least one higher alpha-olefin, in such a way that the prepolymer contains from 4.times.10.sup.-5 to 3 milligram atoms of chromium in the catalyst per gram.