Polythylene composition

• Main Authors: A. HARLIN, V. KILPELAEINEN, A. SAHILA
• Format: Patent
• Language: English
• Published: 11.07.2001
• Edition: 7
• Subjects: CHEMISTRY; COMPOSITIONS BASED THEREON; COMPOSITIONS OF MACROMOLECULAR COMPOUNDS; MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVINGCARBON-TO-CARBON UNSATURATED BONDS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP

PCT No. PCT/FI95/00669 Sec. 371 Date Jun. 16, 1997 Sec. 102(e) Date Jun. 16, 1997 PCT Filed Dec. 8, 1995 PCT Pub. No. WO96/18677 PCT Pub. Date Jun. 20, 1996The invention relates to polyethylene compositions containing 85-99.5 weight % of component A, which is a linear (co)polymer of ethylene having a bimodal weight distribution, and 0.5-15 weight % of component B having a unimodal molecular weight distribution. Component A is 40-60% by weight of a low molecular weight component (A1) having a weight average molecular weight between 5,000 and 50,000 g/mol, and a molecular weight distribution Mw/Mn between 2.5 and 9 and 60-40% by weight of a high molecular weight component (A2) having a weight average molecular weight between 300,000 and 900,000 g/mol, and a molecular weight distribution M/w/Mn between 4.5 and 12. Component B is a linear ethylene polymer having a molecular weight between 150,000-600,O00 g/mol and an average molecular weight which is higher than the average molecular weight of component (A1) but lower than the average molecular weight of component (A2) and a density controlled within the range of 910-960 kg/m3. Component B is produced separately from component A by using Ziegler-Natta or metallocene catalysts.