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:
Aug. 18, 2009
Filed:
Jun. 19, 2003
Jari Äärilä, Porvoo, FI;
Irene Helland, Porsgrunn, NO;
Ole Jan Myhre, Porsgrunn, NO;
Jorunn Nilsen, Porsgrunn, NO;
Markku Vahteri, Porvoo, FI;
Jari Äärilä, Porvoo, FI;
Irene Helland, Porsgrunn, NO;
Ole Jan Myhre, Porsgrunn, NO;
Jorunn Nilsen, Porsgrunn, NO;
Markku Vahteri, Porvoo, FI;
Borealis Technology Oy, Porvoo, FI;
Abstract
A process for producing bimodal linear low-density polyethylene polymer compositions, useful for making films. The polymer compositions have a melt flow rate MFRof 0.4 to 1.0 g/10 min and a density of 918 to 925 kn/m. The process to produce the polymer compositions involves copolymerizing ethylene with an alpha-olefin comonomer in a loop reactor to produce a low molecular weight polymer having a melt flow rate MFRof 50 to 500 g/10 min and a density of 945 to 953 kg/m. The polymerization is continued in a gas phase reactor to produce a high molecular weight polymer, such that the final polymer composition has the desired properties. The final composition contains from 41 to 48% by weight of the low molecular weight polymer and from 59 to 52% by weight of the high molecular weight polymer. The resulting films have an excellent visual appearance and good mechanical properties. The compositions can easily be converted to films. The process can be operated a long time without a shutdown.