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:
Sep. 24, 2002
Filed:
Nov. 07, 2000
Ole Jan Myhre, Pregarten, AT;
Auli Nummila-Pakarinen, Porvoo, FI;
Jarmo Lindroos, Stathelle, NO;
Päivi Waldvogel, Porvoo, FI;
Thomas Garoff, Helsinki, FI;
Borealis Technology Oy, Porvoo, FI;
Abstract
The present invention concerns a process for producing homogeneous polyethylene materials and processes for making high density, medium density and low density films therefrom. The process involves producing a polyethylene composition in a multistage reaction sequence of successive polymerization stages in the presence of an ethylene-polymerizing catalyst system. According to the invention, the process is carried out using an unsupported catalyst having magnesium and titanium as active constituents, in at least one loop polymerization stage and at least one gas phase polymerization stage and, operated with different amounts of hydrogen and comonomers to produce a high molecular weight portion in one of the polymerization stages and a low molecular weight portion in another so as to provide a polyethylene composition with the low molecular weight part having a MFR of 250 g/10 min or more. With this process it is possible to obtain homogeneous bimodal polyethylene material.