Multi-stage process for producing multimodal linear low density polyethylene polymers

US8461280B2 · kind B2 · utility

Assignee

• Borealis Technology Oy · FI

Inventors

• Virginie Eriksson · Stenungsund, SE
• Marjo Vaananen · Helsinki, FI
• Markku Vahteri · Porvoo, FI
• Thomas Garoff · Helsinki, FI
• Petri Rekonen · Helsinki, FI
• Jari Hatonen · Porvoo, FI
• Siw Bodil Fredriksen · Skien, NO
• Katrin Nord-Varhaug · Porsgrunn, NO
• Marit Seim · Langesund, NO
• Jorunn Nilsen · Porsgrunn, NO
• Irene Helland · Porsgrunn, NO

Key dates

• Filing date: Dec 5, 2008
• Grant date: Jun 11, 2013
• Expiry date: Feb 16, 2029

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08L2205/02
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

A multimodal linear low density polyethylene polymer having a final density of 900 to 940 kg/m3, and containing at least one α-olefin comonomer in addition to ethylene comprising: (A) 30 to 60 wt % of a lower molecular weight component being an ethylene homopolymer or a copolymer of ethylene and at least one α-olefin; and (B) 70 to 40 wt % of a higher molecular weight component being a copolymer of ethylene and at least one α-olefin, said α-olefin being the same or different from any α-olefin used in component (A) but with the proviso that both components (A) and (B) are not polymers of ethylene and butane alone; wherein the multimodal LLDPE has a dart drop of at least 700 g; and wherein components (A) and (B) are obtainable using a Ziegler-Natta catalyst.