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. 08, 2004
Filed:
Dec. 18, 2002
Steven P. Diefenbach, Baton Rouge, LA (US);
Albemarle Corporation, Richmond, VA (US);
Abstract
Described are solid olefin polymerization catalysts that have, inter alia, very high productivities (at least 18,000 grams of polyethylene per gram of catalyst in one hour) as shown by a standard test procedure for measuring this property or characteristic. Such particulate catalysts can be prepared by prepolymerizing vinylolefin with a Group 4 metallocene-aluminoxane solution, using proportions of vinylolefin (most preferably, ethylene) in the range of about 150 to about 1500, and preferably in the range of about 175 to about 1000, moles per mole of Group 4 metallocene used in forming the solution. The atom ratio of aluminum to Group 4 metal in the solution is in the range of about 150:1 to about 1500:1, and preferably in the range of about 175:1 to about 1000:1. In addition, the Group 4 metallocene ingredient used in forming these highly productive catalysts has in its molecular structure at least one polymerizable olefinic substituent. These particulate catalysts do not contain, and thus are not produced in the presence of, a preformed support such as an inorganic compound (silica or etc.) or a preformed particulate polymeric support.